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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/fs/btrfs/extent-tree.c

10108 строки
270 KiB
C
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/*
* Copyright (C) 2007 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/sched.h>
#include <linux/pagemap.h>
#include <linux/writeback.h>
#include <linux/blkdev.h>
#include <linux/sort.h>
#include <linux/rcupdate.h>
#include <linux/kthread.h>
#include <linux/slab.h>
#include <linux/ratelimit.h>
#include <linux/percpu_counter.h>
#include "hash.h"
#include "tree-log.h"
#include "disk-io.h"
#include "print-tree.h"
#include "volumes.h"
#include "raid56.h"
#include "locking.h"
#include "free-space-cache.h"
#include "math.h"
#include "sysfs.h"
#include "qgroup.h"
#undef SCRAMBLE_DELAYED_REFS
/*
* control flags for do_chunk_alloc's force field
* CHUNK_ALLOC_NO_FORCE means to only allocate a chunk
* if we really need one.
*
* CHUNK_ALLOC_LIMITED means to only try and allocate one
* if we have very few chunks already allocated. This is
* used as part of the clustering code to help make sure
* we have a good pool of storage to cluster in, without
* filling the FS with empty chunks
*
* CHUNK_ALLOC_FORCE means it must try to allocate one
*
*/
enum {
CHUNK_ALLOC_NO_FORCE = 0,
CHUNK_ALLOC_LIMITED = 1,
CHUNK_ALLOC_FORCE = 2,
};
/*
* Control how reservations are dealt with.
*
* RESERVE_FREE - freeing a reservation.
* RESERVE_ALLOC - allocating space and we need to update bytes_may_use for
* ENOSPC accounting
* RESERVE_ALLOC_NO_ACCOUNT - allocating space and we should not update
* bytes_may_use as the ENOSPC accounting is done elsewhere
*/
enum {
RESERVE_FREE = 0,
RESERVE_ALLOC = 1,
RESERVE_ALLOC_NO_ACCOUNT = 2,
};
static int update_block_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytenr,
u64 num_bytes, int alloc);
static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, u64 parent,
u64 root_objectid, u64 owner_objectid,
u64 owner_offset, int refs_to_drop,
struct btrfs_delayed_extent_op *extra_op,
int no_quota);
static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
struct extent_buffer *leaf,
struct btrfs_extent_item *ei);
static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 parent, u64 root_objectid,
u64 flags, u64 owner, u64 offset,
struct btrfs_key *ins, int ref_mod);
static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 parent, u64 root_objectid,
u64 flags, struct btrfs_disk_key *key,
int level, struct btrfs_key *ins,
int no_quota);
static int do_chunk_alloc(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root, u64 flags,
int force);
static int find_next_key(struct btrfs_path *path, int level,
struct btrfs_key *key);
static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
int dump_block_groups);
static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
u64 num_bytes, int reserve,
int delalloc);
static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
u64 num_bytes);
int btrfs_pin_extent(struct btrfs_root *root,
u64 bytenr, u64 num_bytes, int reserved);
static noinline int
block_group_cache_done(struct btrfs_block_group_cache *cache)
{
smp_mb();
return cache->cached == BTRFS_CACHE_FINISHED ||
cache->cached == BTRFS_CACHE_ERROR;
}
static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
{
return (cache->flags & bits) == bits;
}
static void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
{
atomic_inc(&cache->count);
}
void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
{
if (atomic_dec_and_test(&cache->count)) {
WARN_ON(cache->pinned > 0);
WARN_ON(cache->reserved > 0);
kfree(cache->free_space_ctl);
kfree(cache);
}
}
/*
* this adds the block group to the fs_info rb tree for the block group
* cache
*/
static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
struct btrfs_block_group_cache *block_group)
{
struct rb_node **p;
struct rb_node *parent = NULL;
struct btrfs_block_group_cache *cache;
spin_lock(&info->block_group_cache_lock);
p = &info->block_group_cache_tree.rb_node;
while (*p) {
parent = *p;
cache = rb_entry(parent, struct btrfs_block_group_cache,
cache_node);
if (block_group->key.objectid < cache->key.objectid) {
p = &(*p)->rb_left;
} else if (block_group->key.objectid > cache->key.objectid) {
p = &(*p)->rb_right;
} else {
spin_unlock(&info->block_group_cache_lock);
return -EEXIST;
}
}
rb_link_node(&block_group->cache_node, parent, p);
rb_insert_color(&block_group->cache_node,
&info->block_group_cache_tree);
if (info->first_logical_byte > block_group->key.objectid)
info->first_logical_byte = block_group->key.objectid;
spin_unlock(&info->block_group_cache_lock);
return 0;
}
/*
* This will return the block group at or after bytenr if contains is 0, else
* it will return the block group that contains the bytenr
*/
static struct btrfs_block_group_cache *
block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
int contains)
{
struct btrfs_block_group_cache *cache, *ret = NULL;
struct rb_node *n;
u64 end, start;
spin_lock(&info->block_group_cache_lock);
n = info->block_group_cache_tree.rb_node;
while (n) {
cache = rb_entry(n, struct btrfs_block_group_cache,
cache_node);
end = cache->key.objectid + cache->key.offset - 1;
start = cache->key.objectid;
if (bytenr < start) {
if (!contains && (!ret || start < ret->key.objectid))
ret = cache;
n = n->rb_left;
} else if (bytenr > start) {
if (contains && bytenr <= end) {
ret = cache;
break;
}
n = n->rb_right;
} else {
ret = cache;
break;
}
}
if (ret) {
btrfs_get_block_group(ret);
if (bytenr == 0 && info->first_logical_byte > ret->key.objectid)
info->first_logical_byte = ret->key.objectid;
}
spin_unlock(&info->block_group_cache_lock);
return ret;
}
static int add_excluded_extent(struct btrfs_root *root,
u64 start, u64 num_bytes)
{
u64 end = start + num_bytes - 1;
set_extent_bits(&root->fs_info->freed_extents[0],
start, end, EXTENT_UPTODATE, GFP_NOFS);
set_extent_bits(&root->fs_info->freed_extents[1],
start, end, EXTENT_UPTODATE, GFP_NOFS);
return 0;
}
static void free_excluded_extents(struct btrfs_root *root,
struct btrfs_block_group_cache *cache)
{
u64 start, end;
start = cache->key.objectid;
end = start + cache->key.offset - 1;
clear_extent_bits(&root->fs_info->freed_extents[0],
start, end, EXTENT_UPTODATE, GFP_NOFS);
clear_extent_bits(&root->fs_info->freed_extents[1],
start, end, EXTENT_UPTODATE, GFP_NOFS);
}
static int exclude_super_stripes(struct btrfs_root *root,
struct btrfs_block_group_cache *cache)
{
u64 bytenr;
u64 *logical;
int stripe_len;
int i, nr, ret;
if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
cache->bytes_super += stripe_len;
ret = add_excluded_extent(root, cache->key.objectid,
stripe_len);
if (ret)
return ret;
}
for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
bytenr = btrfs_sb_offset(i);
ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
cache->key.objectid, bytenr,
0, &logical, &nr, &stripe_len);
if (ret)
return ret;
while (nr--) {
u64 start, len;
if (logical[nr] > cache->key.objectid +
cache->key.offset)
continue;
if (logical[nr] + stripe_len <= cache->key.objectid)
continue;
start = logical[nr];
if (start < cache->key.objectid) {
start = cache->key.objectid;
len = (logical[nr] + stripe_len) - start;
} else {
len = min_t(u64, stripe_len,
cache->key.objectid +
cache->key.offset - start);
}
cache->bytes_super += len;
ret = add_excluded_extent(root, start, len);
if (ret) {
kfree(logical);
return ret;
}
}
kfree(logical);
}
return 0;
}
static struct btrfs_caching_control *
get_caching_control(struct btrfs_block_group_cache *cache)
{
struct btrfs_caching_control *ctl;
spin_lock(&cache->lock);
if (!cache->caching_ctl) {
spin_unlock(&cache->lock);
return NULL;
}
ctl = cache->caching_ctl;
atomic_inc(&ctl->count);
spin_unlock(&cache->lock);
return ctl;
}
static void put_caching_control(struct btrfs_caching_control *ctl)
{
if (atomic_dec_and_test(&ctl->count))
kfree(ctl);
}
/*
* this is only called by cache_block_group, since we could have freed extents
* we need to check the pinned_extents for any extents that can't be used yet
* since their free space will be released as soon as the transaction commits.
*/
static u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
struct btrfs_fs_info *info, u64 start, u64 end)
{
u64 extent_start, extent_end, size, total_added = 0;
int ret;
while (start < end) {
ret = find_first_extent_bit(info->pinned_extents, start,
&extent_start, &extent_end,
EXTENT_DIRTY | EXTENT_UPTODATE,
NULL);
if (ret)
break;
if (extent_start <= start) {
start = extent_end + 1;
} else if (extent_start > start && extent_start < end) {
size = extent_start - start;
total_added += size;
ret = btrfs_add_free_space(block_group, start,
size);
BUG_ON(ret); /* -ENOMEM or logic error */
start = extent_end + 1;
} else {
break;
}
}
if (start < end) {
size = end - start;
total_added += size;
ret = btrfs_add_free_space(block_group, start, size);
BUG_ON(ret); /* -ENOMEM or logic error */
}
return total_added;
}
static noinline void caching_thread(struct btrfs_work *work)
{
struct btrfs_block_group_cache *block_group;
struct btrfs_fs_info *fs_info;
struct btrfs_caching_control *caching_ctl;
struct btrfs_root *extent_root;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_key key;
u64 total_found = 0;
u64 last = 0;
u32 nritems;
int ret = -ENOMEM;
caching_ctl = container_of(work, struct btrfs_caching_control, work);
block_group = caching_ctl->block_group;
fs_info = block_group->fs_info;
extent_root = fs_info->extent_root;
path = btrfs_alloc_path();
if (!path)
goto out;
last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
/*
* We don't want to deadlock with somebody trying to allocate a new
* extent for the extent root while also trying to search the extent
* root to add free space. So we skip locking and search the commit
* root, since its read-only
*/
path->skip_locking = 1;
path->search_commit_root = 1;
path->reada = 1;
key.objectid = last;
key.offset = 0;
key.type = BTRFS_EXTENT_ITEM_KEY;
again:
mutex_lock(&caching_ctl->mutex);
/* need to make sure the commit_root doesn't disappear */
down_read(&fs_info->commit_root_sem);
next:
ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
if (ret < 0)
goto err;
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
while (1) {
if (btrfs_fs_closing(fs_info) > 1) {
last = (u64)-1;
break;
}
if (path->slots[0] < nritems) {
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
} else {
ret = find_next_key(path, 0, &key);
if (ret)
break;
if (need_resched() ||
rwsem_is_contended(&fs_info->commit_root_sem)) {
caching_ctl->progress = last;
btrfs_release_path(path);
up_read(&fs_info->commit_root_sem);
mutex_unlock(&caching_ctl->mutex);
cond_resched();
goto again;
}
ret = btrfs_next_leaf(extent_root, path);
if (ret < 0)
goto err;
if (ret)
break;
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
continue;
}
if (key.objectid < last) {
key.objectid = last;
key.offset = 0;
key.type = BTRFS_EXTENT_ITEM_KEY;
caching_ctl->progress = last;
btrfs_release_path(path);
goto next;
}
if (key.objectid < block_group->key.objectid) {
path->slots[0]++;
continue;
}
if (key.objectid >= block_group->key.objectid +
block_group->key.offset)
break;
if (key.type == BTRFS_EXTENT_ITEM_KEY ||
key.type == BTRFS_METADATA_ITEM_KEY) {
total_found += add_new_free_space(block_group,
fs_info, last,
key.objectid);
if (key.type == BTRFS_METADATA_ITEM_KEY)
last = key.objectid +
fs_info->tree_root->nodesize;
else
last = key.objectid + key.offset;
if (total_found > (1024 * 1024 * 2)) {
total_found = 0;
wake_up(&caching_ctl->wait);
}
}
path->slots[0]++;
}
ret = 0;
total_found += add_new_free_space(block_group, fs_info, last,
block_group->key.objectid +
block_group->key.offset);
caching_ctl->progress = (u64)-1;
spin_lock(&block_group->lock);
block_group->caching_ctl = NULL;
block_group->cached = BTRFS_CACHE_FINISHED;
spin_unlock(&block_group->lock);
err:
btrfs_free_path(path);
up_read(&fs_info->commit_root_sem);
free_excluded_extents(extent_root, block_group);
mutex_unlock(&caching_ctl->mutex);
out:
if (ret) {
spin_lock(&block_group->lock);
block_group->caching_ctl = NULL;
block_group->cached = BTRFS_CACHE_ERROR;
spin_unlock(&block_group->lock);
}
wake_up(&caching_ctl->wait);
put_caching_control(caching_ctl);
btrfs_put_block_group(block_group);
}
static int cache_block_group(struct btrfs_block_group_cache *cache,
int load_cache_only)
{
DEFINE_WAIT(wait);
struct btrfs_fs_info *fs_info = cache->fs_info;
struct btrfs_caching_control *caching_ctl;
int ret = 0;
caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
if (!caching_ctl)
return -ENOMEM;
INIT_LIST_HEAD(&caching_ctl->list);
mutex_init(&caching_ctl->mutex);
init_waitqueue_head(&caching_ctl->wait);
caching_ctl->block_group = cache;
caching_ctl->progress = cache->key.objectid;
atomic_set(&caching_ctl->count, 1);
btrfs_init_work(&caching_ctl->work, btrfs_cache_helper,
caching_thread, NULL, NULL);
spin_lock(&cache->lock);
/*
* This should be a rare occasion, but this could happen I think in the
* case where one thread starts to load the space cache info, and then
* some other thread starts a transaction commit which tries to do an
* allocation while the other thread is still loading the space cache
* info. The previous loop should have kept us from choosing this block
* group, but if we've moved to the state where we will wait on caching
* block groups we need to first check if we're doing a fast load here,
* so we can wait for it to finish, otherwise we could end up allocating
* from a block group who's cache gets evicted for one reason or
* another.
*/
while (cache->cached == BTRFS_CACHE_FAST) {
struct btrfs_caching_control *ctl;
ctl = cache->caching_ctl;
atomic_inc(&ctl->count);
prepare_to_wait(&ctl->wait, &wait, TASK_UNINTERRUPTIBLE);
spin_unlock(&cache->lock);
schedule();
finish_wait(&ctl->wait, &wait);
put_caching_control(ctl);
spin_lock(&cache->lock);
}
if (cache->cached != BTRFS_CACHE_NO) {
spin_unlock(&cache->lock);
kfree(caching_ctl);
return 0;
}
WARN_ON(cache->caching_ctl);
cache->caching_ctl = caching_ctl;
cache->cached = BTRFS_CACHE_FAST;
spin_unlock(&cache->lock);
if (fs_info->mount_opt & BTRFS_MOUNT_SPACE_CACHE) {
mutex_lock(&caching_ctl->mutex);
ret = load_free_space_cache(fs_info, cache);
spin_lock(&cache->lock);
if (ret == 1) {
cache->caching_ctl = NULL;
cache->cached = BTRFS_CACHE_FINISHED;
cache->last_byte_to_unpin = (u64)-1;
caching_ctl->progress = (u64)-1;
} else {
if (load_cache_only) {
cache->caching_ctl = NULL;
cache->cached = BTRFS_CACHE_NO;
} else {
cache->cached = BTRFS_CACHE_STARTED;
cache->has_caching_ctl = 1;
}
}
spin_unlock(&cache->lock);
mutex_unlock(&caching_ctl->mutex);
wake_up(&caching_ctl->wait);
if (ret == 1) {
put_caching_control(caching_ctl);
free_excluded_extents(fs_info->extent_root, cache);
return 0;
}
} else {
/*
* We are not going to do the fast caching, set cached to the
* appropriate value and wakeup any waiters.
*/
spin_lock(&cache->lock);
if (load_cache_only) {
cache->caching_ctl = NULL;
cache->cached = BTRFS_CACHE_NO;
} else {
cache->cached = BTRFS_CACHE_STARTED;
cache->has_caching_ctl = 1;
}
spin_unlock(&cache->lock);
wake_up(&caching_ctl->wait);
}
if (load_cache_only) {
put_caching_control(caching_ctl);
return 0;
}
down_write(&fs_info->commit_root_sem);
atomic_inc(&caching_ctl->count);
list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups);
up_write(&fs_info->commit_root_sem);
btrfs_get_block_group(cache);
btrfs_queue_work(fs_info->caching_workers, &caching_ctl->work);
return ret;
}
/*
* return the block group that starts at or after bytenr
*/
static struct btrfs_block_group_cache *
btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr)
{
struct btrfs_block_group_cache *cache;
cache = block_group_cache_tree_search(info, bytenr, 0);
return cache;
}
/*
* return the block group that contains the given bytenr
*/
struct btrfs_block_group_cache *btrfs_lookup_block_group(
struct btrfs_fs_info *info,
u64 bytenr)
{
struct btrfs_block_group_cache *cache;
cache = block_group_cache_tree_search(info, bytenr, 1);
return cache;
}
static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
u64 flags)
{
struct list_head *head = &info->space_info;
struct btrfs_space_info *found;
flags &= BTRFS_BLOCK_GROUP_TYPE_MASK;
rcu_read_lock();
list_for_each_entry_rcu(found, head, list) {
if (found->flags & flags) {
rcu_read_unlock();
return found;
}
}
rcu_read_unlock();
return NULL;
}
/*
* after adding space to the filesystem, we need to clear the full flags
* on all the space infos.
*/
void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
{
struct list_head *head = &info->space_info;
struct btrfs_space_info *found;
rcu_read_lock();
list_for_each_entry_rcu(found, head, list)
found->full = 0;
rcu_read_unlock();
}
/* simple helper to search for an existing data extent at a given offset */
int btrfs_lookup_data_extent(struct btrfs_root *root, u64 start, u64 len)
{
int ret;
struct btrfs_key key;
struct btrfs_path *path;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = start;
key.offset = len;
key.type = BTRFS_EXTENT_ITEM_KEY;
ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
0, 0);
btrfs_free_path(path);
return ret;
}
/*
* helper function to lookup reference count and flags of a tree block.
*
* the head node for delayed ref is used to store the sum of all the
* reference count modifications queued up in the rbtree. the head
* node may also store the extent flags to set. This way you can check
* to see what the reference count and extent flags would be if all of
* the delayed refs are not processed.
*/
int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytenr,
u64 offset, int metadata, u64 *refs, u64 *flags)
{
struct btrfs_delayed_ref_head *head;
struct btrfs_delayed_ref_root *delayed_refs;
struct btrfs_path *path;
struct btrfs_extent_item *ei;
struct extent_buffer *leaf;
struct btrfs_key key;
u32 item_size;
u64 num_refs;
u64 extent_flags;
int ret;
/*
* If we don't have skinny metadata, don't bother doing anything
* different
*/
if (metadata && !btrfs_fs_incompat(root->fs_info, SKINNY_METADATA)) {
offset = root->nodesize;
metadata = 0;
}
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
if (!trans) {
path->skip_locking = 1;
path->search_commit_root = 1;
}
search_again:
key.objectid = bytenr;
key.offset = offset;
if (metadata)
key.type = BTRFS_METADATA_ITEM_KEY;
else
key.type = BTRFS_EXTENT_ITEM_KEY;
ret = btrfs_search_slot(trans, root->fs_info->extent_root,
&key, path, 0, 0);
if (ret < 0)
goto out_free;
if (ret > 0 && metadata && key.type == BTRFS_METADATA_ITEM_KEY) {
if (path->slots[0]) {
path->slots[0]--;
btrfs_item_key_to_cpu(path->nodes[0], &key,
path->slots[0]);
if (key.objectid == bytenr &&
key.type == BTRFS_EXTENT_ITEM_KEY &&
key.offset == root->nodesize)
ret = 0;
}
}
if (ret == 0) {
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
if (item_size >= sizeof(*ei)) {
ei = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_item);
num_refs = btrfs_extent_refs(leaf, ei);
extent_flags = btrfs_extent_flags(leaf, ei);
} else {
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
struct btrfs_extent_item_v0 *ei0;
BUG_ON(item_size != sizeof(*ei0));
ei0 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_item_v0);
num_refs = btrfs_extent_refs_v0(leaf, ei0);
/* FIXME: this isn't correct for data */
extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
#else
BUG();
#endif
}
BUG_ON(num_refs == 0);
} else {
num_refs = 0;
extent_flags = 0;
ret = 0;
}
if (!trans)
goto out;
delayed_refs = &trans->transaction->delayed_refs;
spin_lock(&delayed_refs->lock);
head = btrfs_find_delayed_ref_head(trans, bytenr);
if (head) {
if (!mutex_trylock(&head->mutex)) {
atomic_inc(&head->node.refs);
spin_unlock(&delayed_refs->lock);
btrfs_release_path(path);
/*
* Mutex was contended, block until it's released and try
* again
*/
mutex_lock(&head->mutex);
mutex_unlock(&head->mutex);
btrfs_put_delayed_ref(&head->node);
goto search_again;
}
spin_lock(&head->lock);
if (head->extent_op && head->extent_op->update_flags)
extent_flags |= head->extent_op->flags_to_set;
else
BUG_ON(num_refs == 0);
num_refs += head->node.ref_mod;
spin_unlock(&head->lock);
mutex_unlock(&head->mutex);
}
spin_unlock(&delayed_refs->lock);
out:
WARN_ON(num_refs == 0);
if (refs)
*refs = num_refs;
if (flags)
*flags = extent_flags;
out_free:
btrfs_free_path(path);
return ret;
}
/*
* Back reference rules. Back refs have three main goals:
*
* 1) differentiate between all holders of references to an extent so that
* when a reference is dropped we can make sure it was a valid reference
* before freeing the extent.
*
* 2) Provide enough information to quickly find the holders of an extent
* if we notice a given block is corrupted or bad.
*
* 3) Make it easy to migrate blocks for FS shrinking or storage pool
* maintenance. This is actually the same as #2, but with a slightly
* different use case.
*
* There are two kinds of back refs. The implicit back refs is optimized
* for pointers in non-shared tree blocks. For a given pointer in a block,
* back refs of this kind provide information about the block's owner tree
* and the pointer's key. These information allow us to find the block by
* b-tree searching. The full back refs is for pointers in tree blocks not
* referenced by their owner trees. The location of tree block is recorded
* in the back refs. Actually the full back refs is generic, and can be
* used in all cases the implicit back refs is used. The major shortcoming
* of the full back refs is its overhead. Every time a tree block gets
* COWed, we have to update back refs entry for all pointers in it.
*
* For a newly allocated tree block, we use implicit back refs for
* pointers in it. This means most tree related operations only involve
* implicit back refs. For a tree block created in old transaction, the
* only way to drop a reference to it is COW it. So we can detect the
* event that tree block loses its owner tree's reference and do the
* back refs conversion.
*
* When a tree block is COW'd through a tree, there are four cases:
*
* The reference count of the block is one and the tree is the block's
* owner tree. Nothing to do in this case.
*
* The reference count of the block is one and the tree is not the
* block's owner tree. In this case, full back refs is used for pointers
* in the block. Remove these full back refs, add implicit back refs for
* every pointers in the new block.
*
* The reference count of the block is greater than one and the tree is
* the block's owner tree. In this case, implicit back refs is used for
* pointers in the block. Add full back refs for every pointers in the
* block, increase lower level extents' reference counts. The original
* implicit back refs are entailed to the new block.
*
* The reference count of the block is greater than one and the tree is
* not the block's owner tree. Add implicit back refs for every pointer in
* the new block, increase lower level extents' reference count.
*
* Back Reference Key composing:
*
* The key objectid corresponds to the first byte in the extent,
* The key type is used to differentiate between types of back refs.
* There are different meanings of the key offset for different types
* of back refs.
*
* File extents can be referenced by:
*
* - multiple snapshots, subvolumes, or different generations in one subvol
* - different files inside a single subvolume
* - different offsets inside a file (bookend extents in file.c)
*
* The extent ref structure for the implicit back refs has fields for:
*
* - Objectid of the subvolume root
* - objectid of the file holding the reference
* - original offset in the file
* - how many bookend extents
*
* The key offset for the implicit back refs is hash of the first
* three fields.
*
* The extent ref structure for the full back refs has field for:
*
* - number of pointers in the tree leaf
*
* The key offset for the implicit back refs is the first byte of
* the tree leaf
*
* When a file extent is allocated, The implicit back refs is used.
* the fields are filled in:
*
* (root_key.objectid, inode objectid, offset in file, 1)
*
* When a file extent is removed file truncation, we find the
* corresponding implicit back refs and check the following fields:
*
* (btrfs_header_owner(leaf), inode objectid, offset in file)
*
* Btree extents can be referenced by:
*
* - Different subvolumes
*
* Both the implicit back refs and the full back refs for tree blocks
* only consist of key. The key offset for the implicit back refs is
* objectid of block's owner tree. The key offset for the full back refs
* is the first byte of parent block.
*
* When implicit back refs is used, information about the lowest key and
* level of the tree block are required. These information are stored in
* tree block info structure.
*/
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 owner, u32 extra_size)
{
struct btrfs_extent_item *item;
struct btrfs_extent_item_v0 *ei0;
struct btrfs_extent_ref_v0 *ref0;
struct btrfs_tree_block_info *bi;
struct extent_buffer *leaf;
struct btrfs_key key;
struct btrfs_key found_key;
u32 new_size = sizeof(*item);
u64 refs;
int ret;
leaf = path->nodes[0];
BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
ei0 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_item_v0);
refs = btrfs_extent_refs_v0(leaf, ei0);
if (owner == (u64)-1) {
while (1) {
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
return ret;
BUG_ON(ret > 0); /* Corruption */
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &found_key,
path->slots[0]);
BUG_ON(key.objectid != found_key.objectid);
if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
path->slots[0]++;
continue;
}
ref0 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref_v0);
owner = btrfs_ref_objectid_v0(leaf, ref0);
break;
}
}
btrfs_release_path(path);
if (owner < BTRFS_FIRST_FREE_OBJECTID)
new_size += sizeof(*bi);
new_size -= sizeof(*ei0);
ret = btrfs_search_slot(trans, root, &key, path,
new_size + extra_size, 1);
if (ret < 0)
return ret;
BUG_ON(ret); /* Corruption */
btrfs_extend_item(root, path, new_size);
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
btrfs_set_extent_refs(leaf, item, refs);
/* FIXME: get real generation */
btrfs_set_extent_generation(leaf, item, 0);
if (owner < BTRFS_FIRST_FREE_OBJECTID) {
btrfs_set_extent_flags(leaf, item,
BTRFS_EXTENT_FLAG_TREE_BLOCK |
BTRFS_BLOCK_FLAG_FULL_BACKREF);
bi = (struct btrfs_tree_block_info *)(item + 1);
/* FIXME: get first key of the block */
memset_extent_buffer(leaf, 0, (unsigned long)bi, sizeof(*bi));
btrfs_set_tree_block_level(leaf, bi, (int)owner);
} else {
btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);
}
btrfs_mark_buffer_dirty(leaf);
return 0;
}
#endif
static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
{
u32 high_crc = ~(u32)0;
u32 low_crc = ~(u32)0;
__le64 lenum;
lenum = cpu_to_le64(root_objectid);
high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum));
lenum = cpu_to_le64(owner);
low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
lenum = cpu_to_le64(offset);
low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
return ((u64)high_crc << 31) ^ (u64)low_crc;
}
static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
struct btrfs_extent_data_ref *ref)
{
return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
btrfs_extent_data_ref_objectid(leaf, ref),
btrfs_extent_data_ref_offset(leaf, ref));
}
static int match_extent_data_ref(struct extent_buffer *leaf,
struct btrfs_extent_data_ref *ref,
u64 root_objectid, u64 owner, u64 offset)
{
if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
btrfs_extent_data_ref_offset(leaf, ref) != offset)
return 0;
return 1;
}
static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, u64 parent,
u64 root_objectid,
u64 owner, u64 offset)
{
struct btrfs_key key;
struct btrfs_extent_data_ref *ref;
struct extent_buffer *leaf;
u32 nritems;
int ret;
int recow;
int err = -ENOENT;
key.objectid = bytenr;
if (parent) {
key.type = BTRFS_SHARED_DATA_REF_KEY;
key.offset = parent;
} else {
key.type = BTRFS_EXTENT_DATA_REF_KEY;
key.offset = hash_extent_data_ref(root_objectid,
owner, offset);
}
again:
recow = 0;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0) {
err = ret;
goto fail;
}
if (parent) {
if (!ret)
return 0;
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
key.type = BTRFS_EXTENT_REF_V0_KEY;
btrfs_release_path(path);
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0) {
err = ret;
goto fail;
}
if (!ret)
return 0;
#endif
goto fail;
}
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
while (1) {
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
err = ret;
if (ret)
goto fail;
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
recow = 1;
}
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid != bytenr ||
key.type != BTRFS_EXTENT_DATA_REF_KEY)
goto fail;
ref = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_data_ref);
if (match_extent_data_ref(leaf, ref, root_objectid,
owner, offset)) {
if (recow) {
btrfs_release_path(path);
goto again;
}
err = 0;
break;
}
path->slots[0]++;
}
fail:
return err;
}
static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, u64 parent,
u64 root_objectid, u64 owner,
u64 offset, int refs_to_add)
{
struct btrfs_key key;
struct extent_buffer *leaf;
u32 size;
u32 num_refs;
int ret;
key.objectid = bytenr;
if (parent) {
key.type = BTRFS_SHARED_DATA_REF_KEY;
key.offset = parent;
size = sizeof(struct btrfs_shared_data_ref);
} else {
key.type = BTRFS_EXTENT_DATA_REF_KEY;
key.offset = hash_extent_data_ref(root_objectid,
owner, offset);
size = sizeof(struct btrfs_extent_data_ref);
}
ret = btrfs_insert_empty_item(trans, root, path, &key, size);
if (ret && ret != -EEXIST)
goto fail;
leaf = path->nodes[0];
if (parent) {
struct btrfs_shared_data_ref *ref;
ref = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_shared_data_ref);
if (ret == 0) {
btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
} else {
num_refs = btrfs_shared_data_ref_count(leaf, ref);
num_refs += refs_to_add;
btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
}
} else {
struct btrfs_extent_data_ref *ref;
while (ret == -EEXIST) {
ref = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_data_ref);
if (match_extent_data_ref(leaf, ref, root_objectid,
owner, offset))
break;
btrfs_release_path(path);
key.offset++;
ret = btrfs_insert_empty_item(trans, root, path, &key,
size);
if (ret && ret != -EEXIST)
goto fail;
leaf = path->nodes[0];
}
ref = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_data_ref);
if (ret == 0) {
btrfs_set_extent_data_ref_root(leaf, ref,
root_objectid);
btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
btrfs_set_extent_data_ref_offset(leaf, ref, offset);
btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
} else {
num_refs = btrfs_extent_data_ref_count(leaf, ref);
num_refs += refs_to_add;
btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
}
}
btrfs_mark_buffer_dirty(leaf);
ret = 0;
fail:
btrfs_release_path(path);
return ret;
}
static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
int refs_to_drop, int *last_ref)
{
struct btrfs_key key;
struct btrfs_extent_data_ref *ref1 = NULL;
struct btrfs_shared_data_ref *ref2 = NULL;
struct extent_buffer *leaf;
u32 num_refs = 0;
int ret = 0;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
ref1 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_data_ref);
num_refs = btrfs_extent_data_ref_count(leaf, ref1);
} else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
ref2 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_shared_data_ref);
num_refs = btrfs_shared_data_ref_count(leaf, ref2);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
} else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
struct btrfs_extent_ref_v0 *ref0;
ref0 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref_v0);
num_refs = btrfs_ref_count_v0(leaf, ref0);
#endif
} else {
BUG();
}
BUG_ON(num_refs < refs_to_drop);
num_refs -= refs_to_drop;
if (num_refs == 0) {
ret = btrfs_del_item(trans, root, path);
*last_ref = 1;
} else {
if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
else {
struct btrfs_extent_ref_v0 *ref0;
ref0 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref_v0);
btrfs_set_ref_count_v0(leaf, ref0, num_refs);
}
#endif
btrfs_mark_buffer_dirty(leaf);
}
return ret;
}
static noinline u32 extent_data_ref_count(struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_extent_inline_ref *iref)
{
struct btrfs_key key;
struct extent_buffer *leaf;
struct btrfs_extent_data_ref *ref1;
struct btrfs_shared_data_ref *ref2;
u32 num_refs = 0;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (iref) {
if (btrfs_extent_inline_ref_type(leaf, iref) ==
BTRFS_EXTENT_DATA_REF_KEY) {
ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
num_refs = btrfs_extent_data_ref_count(leaf, ref1);
} else {
ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
num_refs = btrfs_shared_data_ref_count(leaf, ref2);
}
} else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
ref1 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_data_ref);
num_refs = btrfs_extent_data_ref_count(leaf, ref1);
} else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
ref2 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_shared_data_ref);
num_refs = btrfs_shared_data_ref_count(leaf, ref2);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
} else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
struct btrfs_extent_ref_v0 *ref0;
ref0 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref_v0);
num_refs = btrfs_ref_count_v0(leaf, ref0);
#endif
} else {
WARN_ON(1);
}
return num_refs;
}
static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, u64 parent,
u64 root_objectid)
{
struct btrfs_key key;
int ret;
key.objectid = bytenr;
if (parent) {
key.type = BTRFS_SHARED_BLOCK_REF_KEY;
key.offset = parent;
} else {
key.type = BTRFS_TREE_BLOCK_REF_KEY;
key.offset = root_objectid;
}
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret > 0)
ret = -ENOENT;
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (ret == -ENOENT && parent) {
btrfs_release_path(path);
key.type = BTRFS_EXTENT_REF_V0_KEY;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret > 0)
ret = -ENOENT;
}
#endif
return ret;
}
static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, u64 parent,
u64 root_objectid)
{
struct btrfs_key key;
int ret;
key.objectid = bytenr;
if (parent) {
key.type = BTRFS_SHARED_BLOCK_REF_KEY;
key.offset = parent;
} else {
key.type = BTRFS_TREE_BLOCK_REF_KEY;
key.offset = root_objectid;
}
ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
btrfs_release_path(path);
return ret;
}
static inline int extent_ref_type(u64 parent, u64 owner)
{
int type;
if (owner < BTRFS_FIRST_FREE_OBJECTID) {
if (parent > 0)
type = BTRFS_SHARED_BLOCK_REF_KEY;
else
type = BTRFS_TREE_BLOCK_REF_KEY;
} else {
if (parent > 0)
type = BTRFS_SHARED_DATA_REF_KEY;
else
type = BTRFS_EXTENT_DATA_REF_KEY;
}
return type;
}
static int find_next_key(struct btrfs_path *path, int level,
struct btrfs_key *key)
{
for (; level < BTRFS_MAX_LEVEL; level++) {
if (!path->nodes[level])
break;
if (path->slots[level] + 1 >=
btrfs_header_nritems(path->nodes[level]))
continue;
if (level == 0)
btrfs_item_key_to_cpu(path->nodes[level], key,
path->slots[level] + 1);
else
btrfs_node_key_to_cpu(path->nodes[level], key,
path->slots[level] + 1);
return 0;
}
return 1;
}
/*
* look for inline back ref. if back ref is found, *ref_ret is set
* to the address of inline back ref, and 0 is returned.
*
* if back ref isn't found, *ref_ret is set to the address where it
* should be inserted, and -ENOENT is returned.
*
* if insert is true and there are too many inline back refs, the path
* points to the extent item, and -EAGAIN is returned.
*
* NOTE: inline back refs are ordered in the same way that back ref
* items in the tree are ordered.
*/
static noinline_for_stack
int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_extent_inline_ref **ref_ret,
u64 bytenr, u64 num_bytes,
u64 parent, u64 root_objectid,
u64 owner, u64 offset, int insert)
{
struct btrfs_key key;
struct extent_buffer *leaf;
struct btrfs_extent_item *ei;
struct btrfs_extent_inline_ref *iref;
u64 flags;
u64 item_size;
unsigned long ptr;
unsigned long end;
int extra_size;
int type;
int want;
int ret;
int err = 0;
bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
SKINNY_METADATA);
key.objectid = bytenr;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = num_bytes;
want = extent_ref_type(parent, owner);
if (insert) {
extra_size = btrfs_extent_inline_ref_size(want);
path->keep_locks = 1;
} else
extra_size = -1;
/*
* Owner is our parent level, so we can just add one to get the level
* for the block we are interested in.
*/
if (skinny_metadata && owner < BTRFS_FIRST_FREE_OBJECTID) {
key.type = BTRFS_METADATA_ITEM_KEY;
key.offset = owner;
}
again:
ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
if (ret < 0) {
err = ret;
goto out;
}
/*
* We may be a newly converted file system which still has the old fat
* extent entries for metadata, so try and see if we have one of those.
*/
if (ret > 0 && skinny_metadata) {
skinny_metadata = false;
if (path->slots[0]) {
path->slots[0]--;
btrfs_item_key_to_cpu(path->nodes[0], &key,
path->slots[0]);
if (key.objectid == bytenr &&
key.type == BTRFS_EXTENT_ITEM_KEY &&
key.offset == num_bytes)
ret = 0;
}
if (ret) {
key.objectid = bytenr;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = num_bytes;
btrfs_release_path(path);
goto again;
}
}
if (ret && !insert) {
err = -ENOENT;
goto out;
} else if (WARN_ON(ret)) {
err = -EIO;
goto out;
}
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (item_size < sizeof(*ei)) {
if (!insert) {
err = -ENOENT;
goto out;
}
ret = convert_extent_item_v0(trans, root, path, owner,
extra_size);
if (ret < 0) {
err = ret;
goto out;
}
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
}
#endif
BUG_ON(item_size < sizeof(*ei));
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
flags = btrfs_extent_flags(leaf, ei);
ptr = (unsigned long)(ei + 1);
end = (unsigned long)ei + item_size;
if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK && !skinny_metadata) {
ptr += sizeof(struct btrfs_tree_block_info);
BUG_ON(ptr > end);
}
err = -ENOENT;
while (1) {
if (ptr >= end) {
WARN_ON(ptr > end);
break;
}
iref = (struct btrfs_extent_inline_ref *)ptr;
type = btrfs_extent_inline_ref_type(leaf, iref);
if (want < type)
break;
if (want > type) {
ptr += btrfs_extent_inline_ref_size(type);
continue;
}
if (type == BTRFS_EXTENT_DATA_REF_KEY) {
struct btrfs_extent_data_ref *dref;
dref = (struct btrfs_extent_data_ref *)(&iref->offset);
if (match_extent_data_ref(leaf, dref, root_objectid,
owner, offset)) {
err = 0;
break;
}
if (hash_extent_data_ref_item(leaf, dref) <
hash_extent_data_ref(root_objectid, owner, offset))
break;
} else {
u64 ref_offset;
ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
if (parent > 0) {
if (parent == ref_offset) {
err = 0;
break;
}
if (ref_offset < parent)
break;
} else {
if (root_objectid == ref_offset) {
err = 0;
break;
}
if (ref_offset < root_objectid)
break;
}
}
ptr += btrfs_extent_inline_ref_size(type);
}
if (err == -ENOENT && insert) {
if (item_size + extra_size >=
BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
err = -EAGAIN;
goto out;
}
/*
* To add new inline back ref, we have to make sure
* there is no corresponding back ref item.
* For simplicity, we just do not add new inline back
* ref if there is any kind of item for this block
*/
if (find_next_key(path, 0, &key) == 0 &&
key.objectid == bytenr &&
key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
err = -EAGAIN;
goto out;
}
}
*ref_ret = (struct btrfs_extent_inline_ref *)ptr;
out:
if (insert) {
path->keep_locks = 0;
btrfs_unlock_up_safe(path, 1);
}
return err;
}
/*
* helper to add new inline back ref
*/
static noinline_for_stack
void setup_inline_extent_backref(struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_extent_inline_ref *iref,
u64 parent, u64 root_objectid,
u64 owner, u64 offset, int refs_to_add,
struct btrfs_delayed_extent_op *extent_op)
{
struct extent_buffer *leaf;
struct btrfs_extent_item *ei;
unsigned long ptr;
unsigned long end;
unsigned long item_offset;
u64 refs;
int size;
int type;
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
item_offset = (unsigned long)iref - (unsigned long)ei;
type = extent_ref_type(parent, owner);
size = btrfs_extent_inline_ref_size(type);
btrfs_extend_item(root, path, size);
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
refs = btrfs_extent_refs(leaf, ei);
refs += refs_to_add;
btrfs_set_extent_refs(leaf, ei, refs);
if (extent_op)
__run_delayed_extent_op(extent_op, leaf, ei);
ptr = (unsigned long)ei + item_offset;
end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]);
if (ptr < end - size)
memmove_extent_buffer(leaf, ptr + size, ptr,
end - size - ptr);
iref = (struct btrfs_extent_inline_ref *)ptr;
btrfs_set_extent_inline_ref_type(leaf, iref, type);
if (type == BTRFS_EXTENT_DATA_REF_KEY) {
struct btrfs_extent_data_ref *dref;
dref = (struct btrfs_extent_data_ref *)(&iref->offset);
btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
btrfs_set_extent_data_ref_offset(leaf, dref, offset);
btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
} else if (type == BTRFS_SHARED_DATA_REF_KEY) {
struct btrfs_shared_data_ref *sref;
sref = (struct btrfs_shared_data_ref *)(iref + 1);
btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
} else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
} else {
btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
}
btrfs_mark_buffer_dirty(leaf);
}
static int lookup_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_extent_inline_ref **ref_ret,
u64 bytenr, u64 num_bytes, u64 parent,
u64 root_objectid, u64 owner, u64 offset)
{
int ret;
ret = lookup_inline_extent_backref(trans, root, path, ref_ret,
bytenr, num_bytes, parent,
root_objectid, owner, offset, 0);
if (ret != -ENOENT)
return ret;
btrfs_release_path(path);
*ref_ret = NULL;
if (owner < BTRFS_FIRST_FREE_OBJECTID) {
ret = lookup_tree_block_ref(trans, root, path, bytenr, parent,
root_objectid);
} else {
ret = lookup_extent_data_ref(trans, root, path, bytenr, parent,
root_objectid, owner, offset);
}
return ret;
}
/*
* helper to update/remove inline back ref
*/
static noinline_for_stack
void update_inline_extent_backref(struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_extent_inline_ref *iref,
int refs_to_mod,
struct btrfs_delayed_extent_op *extent_op,
int *last_ref)
{
struct extent_buffer *leaf;
struct btrfs_extent_item *ei;
struct btrfs_extent_data_ref *dref = NULL;
struct btrfs_shared_data_ref *sref = NULL;
unsigned long ptr;
unsigned long end;
u32 item_size;
int size;
int type;
u64 refs;
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
refs = btrfs_extent_refs(leaf, ei);
WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
refs += refs_to_mod;
btrfs_set_extent_refs(leaf, ei, refs);
if (extent_op)
__run_delayed_extent_op(extent_op, leaf, ei);
type = btrfs_extent_inline_ref_type(leaf, iref);
if (type == BTRFS_EXTENT_DATA_REF_KEY) {
dref = (struct btrfs_extent_data_ref *)(&iref->offset);
refs = btrfs_extent_data_ref_count(leaf, dref);
} else if (type == BTRFS_SHARED_DATA_REF_KEY) {
sref = (struct btrfs_shared_data_ref *)(iref + 1);
refs = btrfs_shared_data_ref_count(leaf, sref);
} else {
refs = 1;
BUG_ON(refs_to_mod != -1);
}
BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
refs += refs_to_mod;
if (refs > 0) {
if (type == BTRFS_EXTENT_DATA_REF_KEY)
btrfs_set_extent_data_ref_count(leaf, dref, refs);
else
btrfs_set_shared_data_ref_count(leaf, sref, refs);
} else {
*last_ref = 1;
size = btrfs_extent_inline_ref_size(type);
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
ptr = (unsigned long)iref;
end = (unsigned long)ei + item_size;
if (ptr + size < end)
memmove_extent_buffer(leaf, ptr, ptr + size,
end - ptr - size);
item_size -= size;
btrfs_truncate_item(root, path, item_size, 1);
}
btrfs_mark_buffer_dirty(leaf);
}
static noinline_for_stack
int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, u64 num_bytes, u64 parent,
u64 root_objectid, u64 owner,
u64 offset, int refs_to_add,
struct btrfs_delayed_extent_op *extent_op)
{
struct btrfs_extent_inline_ref *iref;
int ret;
ret = lookup_inline_extent_backref(trans, root, path, &iref,
bytenr, num_bytes, parent,
root_objectid, owner, offset, 1);
if (ret == 0) {
BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
update_inline_extent_backref(root, path, iref,
refs_to_add, extent_op, NULL);
} else if (ret == -ENOENT) {
setup_inline_extent_backref(root, path, iref, parent,
root_objectid, owner, offset,
refs_to_add, extent_op);
ret = 0;
}
return ret;
}
static int insert_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, u64 parent, u64 root_objectid,
u64 owner, u64 offset, int refs_to_add)
{
int ret;
if (owner < BTRFS_FIRST_FREE_OBJECTID) {
BUG_ON(refs_to_add != 1);
ret = insert_tree_block_ref(trans, root, path, bytenr,
parent, root_objectid);
} else {
ret = insert_extent_data_ref(trans, root, path, bytenr,
parent, root_objectid,
owner, offset, refs_to_add);
}
return ret;
}
static int remove_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_extent_inline_ref *iref,
int refs_to_drop, int is_data, int *last_ref)
{
int ret = 0;
BUG_ON(!is_data && refs_to_drop != 1);
if (iref) {
update_inline_extent_backref(root, path, iref,
-refs_to_drop, NULL, last_ref);
} else if (is_data) {
ret = remove_extent_data_ref(trans, root, path, refs_to_drop,
last_ref);
} else {
*last_ref = 1;
ret = btrfs_del_item(trans, root, path);
}
return ret;
}
static int btrfs_issue_discard(struct block_device *bdev,
u64 start, u64 len)
{
return blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_NOFS, 0);
}
int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
u64 num_bytes, u64 *actual_bytes)
{
int ret;
u64 discarded_bytes = 0;
struct btrfs_bio *bbio = NULL;
/* Tell the block device(s) that the sectors can be discarded */
ret = btrfs_map_block(root->fs_info, REQ_DISCARD,
bytenr, &num_bytes, &bbio, 0);
/* Error condition is -ENOMEM */
if (!ret) {
struct btrfs_bio_stripe *stripe = bbio->stripes;
int i;
for (i = 0; i < bbio->num_stripes; i++, stripe++) {
if (!stripe->dev->can_discard)
continue;
ret = btrfs_issue_discard(stripe->dev->bdev,
stripe->physical,
stripe->length);
if (!ret)
discarded_bytes += stripe->length;
else if (ret != -EOPNOTSUPP)
break; /* Logic errors or -ENOMEM, or -EIO but I don't know how that could happen JDM */
/*
* Just in case we get back EOPNOTSUPP for some reason,
* just ignore the return value so we don't screw up
* people calling discard_extent.
*/
ret = 0;
}
btrfs_put_bbio(bbio);
}
if (actual_bytes)
*actual_bytes = discarded_bytes;
if (ret == -EOPNOTSUPP)
ret = 0;
return ret;
}
/* Can return -ENOMEM */
int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, u64 parent,
u64 root_objectid, u64 owner, u64 offset,
int no_quota)
{
int ret;
struct btrfs_fs_info *fs_info = root->fs_info;
BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID &&
root_objectid == BTRFS_TREE_LOG_OBJECTID);
if (owner < BTRFS_FIRST_FREE_OBJECTID) {
ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
num_bytes,
parent, root_objectid, (int)owner,
BTRFS_ADD_DELAYED_REF, NULL, no_quota);
} else {
ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr,
num_bytes,
parent, root_objectid, owner, offset,
BTRFS_ADD_DELAYED_REF, NULL, no_quota);
}
return ret;
}
static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes,
u64 parent, u64 root_objectid,
u64 owner, u64 offset, int refs_to_add,
int no_quota,
struct btrfs_delayed_extent_op *extent_op)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_extent_item *item;
struct btrfs_key key;
u64 refs;
int ret;
enum btrfs_qgroup_operation_type type = BTRFS_QGROUP_OPER_ADD_EXCL;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
if (!is_fstree(root_objectid) || !root->fs_info->quota_enabled)
no_quota = 1;
path->reada = 1;
path->leave_spinning = 1;
/* this will setup the path even if it fails to insert the back ref */
ret = insert_inline_extent_backref(trans, fs_info->extent_root, path,
bytenr, num_bytes, parent,
root_objectid, owner, offset,
refs_to_add, extent_op);
if ((ret < 0 && ret != -EAGAIN) || (!ret && no_quota))
goto out;
/*
* Ok we were able to insert an inline extent and it appears to be a new
* reference, deal with the qgroup accounting.
*/
if (!ret && !no_quota) {
ASSERT(root->fs_info->quota_enabled);
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_item);
if (btrfs_extent_refs(leaf, item) > (u64)refs_to_add)
type = BTRFS_QGROUP_OPER_ADD_SHARED;
btrfs_release_path(path);
ret = btrfs_qgroup_record_ref(trans, fs_info, root_objectid,
bytenr, num_bytes, type, 0);
goto out;
}
/*
* Ok we had -EAGAIN which means we didn't have space to insert and
* inline extent ref, so just update the reference count and add a
* normal backref.
*/
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
refs = btrfs_extent_refs(leaf, item);
if (refs)
type = BTRFS_QGROUP_OPER_ADD_SHARED;
btrfs_set_extent_refs(leaf, item, refs + refs_to_add);
if (extent_op)
__run_delayed_extent_op(extent_op, leaf, item);
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
if (!no_quota) {
ret = btrfs_qgroup_record_ref(trans, fs_info, root_objectid,
bytenr, num_bytes, type, 0);
if (ret)
goto out;
}
path->reada = 1;
path->leave_spinning = 1;
/* now insert the actual backref */
ret = insert_extent_backref(trans, root->fs_info->extent_root,
path, bytenr, parent, root_objectid,
owner, offset, refs_to_add);
if (ret)
btrfs_abort_transaction(trans, root, ret);
out:
btrfs_free_path(path);
return ret;
}
static int run_delayed_data_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_delayed_ref_node *node,
struct btrfs_delayed_extent_op *extent_op,
int insert_reserved)
{
int ret = 0;
struct btrfs_delayed_data_ref *ref;
struct btrfs_key ins;
u64 parent = 0;
u64 ref_root = 0;
u64 flags = 0;
ins.objectid = node->bytenr;
ins.offset = node->num_bytes;
ins.type = BTRFS_EXTENT_ITEM_KEY;
ref = btrfs_delayed_node_to_data_ref(node);
trace_run_delayed_data_ref(node, ref, node->action);
if (node->type == BTRFS_SHARED_DATA_REF_KEY)
parent = ref->parent;
ref_root = ref->root;
if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
if (extent_op)
flags |= extent_op->flags_to_set;
ret = alloc_reserved_file_extent(trans, root,
parent, ref_root, flags,
ref->objectid, ref->offset,
&ins, node->ref_mod);
} else if (node->action == BTRFS_ADD_DELAYED_REF) {
ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
node->num_bytes, parent,
ref_root, ref->objectid,
ref->offset, node->ref_mod,
node->no_quota, extent_op);
} else if (node->action == BTRFS_DROP_DELAYED_REF) {
ret = __btrfs_free_extent(trans, root, node->bytenr,
node->num_bytes, parent,
ref_root, ref->objectid,
ref->offset, node->ref_mod,
extent_op, node->no_quota);
} else {
BUG();
}
return ret;
}
static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
struct extent_buffer *leaf,
struct btrfs_extent_item *ei)
{
u64 flags = btrfs_extent_flags(leaf, ei);
if (extent_op->update_flags) {
flags |= extent_op->flags_to_set;
btrfs_set_extent_flags(leaf, ei, flags);
}
if (extent_op->update_key) {
struct btrfs_tree_block_info *bi;
BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK));
bi = (struct btrfs_tree_block_info *)(ei + 1);
btrfs_set_tree_block_key(leaf, bi, &extent_op->key);
}
}
static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_delayed_ref_node *node,
struct btrfs_delayed_extent_op *extent_op)
{
struct btrfs_key key;
struct btrfs_path *path;
struct btrfs_extent_item *ei;
struct extent_buffer *leaf;
u32 item_size;
int ret;
int err = 0;
int metadata = !extent_op->is_data;
if (trans->aborted)
return 0;
if (metadata && !btrfs_fs_incompat(root->fs_info, SKINNY_METADATA))
metadata = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = node->bytenr;
if (metadata) {
key.type = BTRFS_METADATA_ITEM_KEY;
key.offset = extent_op->level;
} else {
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = node->num_bytes;
}
again:
path->reada = 1;
path->leave_spinning = 1;
ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key,
path, 0, 1);
if (ret < 0) {
err = ret;
goto out;
}
if (ret > 0) {
if (metadata) {
if (path->slots[0] > 0) {
path->slots[0]--;
btrfs_item_key_to_cpu(path->nodes[0], &key,
path->slots[0]);
if (key.objectid == node->bytenr &&
key.type == BTRFS_EXTENT_ITEM_KEY &&
key.offset == node->num_bytes)
ret = 0;
}
if (ret > 0) {
btrfs_release_path(path);
metadata = 0;
key.objectid = node->bytenr;
key.offset = node->num_bytes;
key.type = BTRFS_EXTENT_ITEM_KEY;
goto again;
}
} else {
err = -EIO;
goto out;
}
}
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (item_size < sizeof(*ei)) {
ret = convert_extent_item_v0(trans, root->fs_info->extent_root,
path, (u64)-1, 0);
if (ret < 0) {
err = ret;
goto out;
}
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
}
#endif
BUG_ON(item_size < sizeof(*ei));
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
__run_delayed_extent_op(extent_op, leaf, ei);
btrfs_mark_buffer_dirty(leaf);
out:
btrfs_free_path(path);
return err;
}
static int run_delayed_tree_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_delayed_ref_node *node,
struct btrfs_delayed_extent_op *extent_op,
int insert_reserved)
{
int ret = 0;
struct btrfs_delayed_tree_ref *ref;
struct btrfs_key ins;
u64 parent = 0;
u64 ref_root = 0;
bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
SKINNY_METADATA);
ref = btrfs_delayed_node_to_tree_ref(node);
trace_run_delayed_tree_ref(node, ref, node->action);
if (node->type == BTRFS_SHARED_BLOCK_REF_KEY)
parent = ref->parent;
ref_root = ref->root;
ins.objectid = node->bytenr;
if (skinny_metadata) {
ins.offset = ref->level;
ins.type = BTRFS_METADATA_ITEM_KEY;
} else {
ins.offset = node->num_bytes;
ins.type = BTRFS_EXTENT_ITEM_KEY;
}
BUG_ON(node->ref_mod != 1);
if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
BUG_ON(!extent_op || !extent_op->update_flags);
ret = alloc_reserved_tree_block(trans, root,
parent, ref_root,
extent_op->flags_to_set,
&extent_op->key,
ref->level, &ins,
node->no_quota);
} else if (node->action == BTRFS_ADD_DELAYED_REF) {
ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
node->num_bytes, parent, ref_root,
ref->level, 0, 1, node->no_quota,
extent_op);
} else if (node->action == BTRFS_DROP_DELAYED_REF) {
ret = __btrfs_free_extent(trans, root, node->bytenr,
node->num_bytes, parent, ref_root,
ref->level, 0, 1, extent_op,
node->no_quota);
} else {
BUG();
}
return ret;
}
/* helper function to actually process a single delayed ref entry */
static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_delayed_ref_node *node,
struct btrfs_delayed_extent_op *extent_op,
int insert_reserved)
{
int ret = 0;
if (trans->aborted) {
if (insert_reserved)
btrfs_pin_extent(root, node->bytenr,
node->num_bytes, 1);
return 0;
}
if (btrfs_delayed_ref_is_head(node)) {
struct btrfs_delayed_ref_head *head;
/*
* we've hit the end of the chain and we were supposed
* to insert this extent into the tree. But, it got
* deleted before we ever needed to insert it, so all
* we have to do is clean up the accounting
*/
BUG_ON(extent_op);
head = btrfs_delayed_node_to_head(node);
trace_run_delayed_ref_head(node, head, node->action);
if (insert_reserved) {
btrfs_pin_extent(root, node->bytenr,
node->num_bytes, 1);
if (head->is_data) {
ret = btrfs_del_csums(trans, root,
node->bytenr,
node->num_bytes);
}
}
return ret;
}
if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
node->type == BTRFS_SHARED_BLOCK_REF_KEY)
ret = run_delayed_tree_ref(trans, root, node, extent_op,
insert_reserved);
else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
node->type == BTRFS_SHARED_DATA_REF_KEY)
ret = run_delayed_data_ref(trans, root, node, extent_op,
insert_reserved);
else
BUG();
return ret;
}
static noinline struct btrfs_delayed_ref_node *
select_delayed_ref(struct btrfs_delayed_ref_head *head)
{
struct rb_node *node;
struct btrfs_delayed_ref_node *ref, *last = NULL;;
/*
* select delayed ref of type BTRFS_ADD_DELAYED_REF first.
* this prevents ref count from going down to zero when
* there still are pending delayed ref.
*/
node = rb_first(&head->ref_root);
while (node) {
ref = rb_entry(node, struct btrfs_delayed_ref_node,
rb_node);
if (ref->action == BTRFS_ADD_DELAYED_REF)
return ref;
else if (last == NULL)
last = ref;
node = rb_next(node);
}
return last;
}
/*
* Returns 0 on success or if called with an already aborted transaction.
* Returns -ENOMEM or -EIO on failure and will abort the transaction.
*/
static noinline int __btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
unsigned long nr)
{
struct btrfs_delayed_ref_root *delayed_refs;
struct btrfs_delayed_ref_node *ref;
struct btrfs_delayed_ref_head *locked_ref = NULL;
struct btrfs_delayed_extent_op *extent_op;
struct btrfs_fs_info *fs_info = root->fs_info;
ktime_t start = ktime_get();
int ret;
unsigned long count = 0;
unsigned long actual_count = 0;
int must_insert_reserved = 0;
delayed_refs = &trans->transaction->delayed_refs;
while (1) {
if (!locked_ref) {
if (count >= nr)
break;
spin_lock(&delayed_refs->lock);
locked_ref = btrfs_select_ref_head(trans);
if (!locked_ref) {
spin_unlock(&delayed_refs->lock);
break;
}
/* grab the lock that says we are going to process
* all the refs for this head */
ret = btrfs_delayed_ref_lock(trans, locked_ref);
spin_unlock(&delayed_refs->lock);
/*
* we may have dropped the spin lock to get the head
* mutex lock, and that might have given someone else
* time to free the head. If that's true, it has been
* removed from our list and we can move on.
*/
if (ret == -EAGAIN) {
locked_ref = NULL;
count++;
continue;
}
}
/*
* We need to try and merge add/drops of the same ref since we
* can run into issues with relocate dropping the implicit ref
* and then it being added back again before the drop can
* finish. If we merged anything we need to re-loop so we can
* get a good ref.
*/
spin_lock(&locked_ref->lock);
btrfs_merge_delayed_refs(trans, fs_info, delayed_refs,
locked_ref);
/*
* locked_ref is the head node, so we have to go one
* node back for any delayed ref updates
*/
ref = select_delayed_ref(locked_ref);
if (ref && ref->seq &&
btrfs_check_delayed_seq(fs_info, delayed_refs, ref->seq)) {
spin_unlock(&locked_ref->lock);
btrfs_delayed_ref_unlock(locked_ref);
spin_lock(&delayed_refs->lock);
locked_ref->processing = 0;
delayed_refs->num_heads_ready++;
spin_unlock(&delayed_refs->lock);
locked_ref = NULL;
cond_resched();
count++;
continue;
}
/*
* record the must insert reserved flag before we
* drop the spin lock.
*/
must_insert_reserved = locked_ref->must_insert_reserved;
locked_ref->must_insert_reserved = 0;
extent_op = locked_ref->extent_op;
locked_ref->extent_op = NULL;
if (!ref) {
/* All delayed refs have been processed, Go ahead
* and send the head node to run_one_delayed_ref,
* so that any accounting fixes can happen
*/
ref = &locked_ref->node;
if (extent_op && must_insert_reserved) {
btrfs_free_delayed_extent_op(extent_op);
extent_op = NULL;
}
if (extent_op) {
spin_unlock(&locked_ref->lock);
ret = run_delayed_extent_op(trans, root,
ref, extent_op);
btrfs_free_delayed_extent_op(extent_op);
if (ret) {
/*
* Need to reset must_insert_reserved if
* there was an error so the abort stuff
* can cleanup the reserved space
* properly.
*/
if (must_insert_reserved)
locked_ref->must_insert_reserved = 1;
locked_ref->processing = 0;
btrfs_debug(fs_info, "run_delayed_extent_op returned %d", ret);
btrfs_delayed_ref_unlock(locked_ref);
return ret;
}
continue;
}
/*
* Need to drop our head ref lock and re-aqcuire the
* delayed ref lock and then re-check to make sure
* nobody got added.
*/
spin_unlock(&locked_ref->lock);
spin_lock(&delayed_refs->lock);
spin_lock(&locked_ref->lock);
if (rb_first(&locked_ref->ref_root) ||
locked_ref->extent_op) {
spin_unlock(&locked_ref->lock);
spin_unlock(&delayed_refs->lock);
continue;
}
ref->in_tree = 0;
delayed_refs->num_heads--;
rb_erase(&locked_ref->href_node,
&delayed_refs->href_root);
spin_unlock(&delayed_refs->lock);
} else {
actual_count++;
ref->in_tree = 0;
rb_erase(&ref->rb_node, &locked_ref->ref_root);
}
atomic_dec(&delayed_refs->num_entries);
if (!btrfs_delayed_ref_is_head(ref)) {
/*
* when we play the delayed ref, also correct the
* ref_mod on head
*/
switch (ref->action) {
case BTRFS_ADD_DELAYED_REF:
case BTRFS_ADD_DELAYED_EXTENT:
locked_ref->node.ref_mod -= ref->ref_mod;
break;
case BTRFS_DROP_DELAYED_REF:
locked_ref->node.ref_mod += ref->ref_mod;
break;
default:
WARN_ON(1);
}
}
spin_unlock(&locked_ref->lock);
ret = run_one_delayed_ref(trans, root, ref, extent_op,
must_insert_reserved);
btrfs_free_delayed_extent_op(extent_op);
if (ret) {
locked_ref->processing = 0;
btrfs_delayed_ref_unlock(locked_ref);
btrfs_put_delayed_ref(ref);
btrfs_debug(fs_info, "run_one_delayed_ref returned %d", ret);
return ret;
}
/*
* If this node is a head, that means all the refs in this head
* have been dealt with, and we will pick the next head to deal
* with, so we must unlock the head and drop it from the cluster
* list before we release it.
*/
if (btrfs_delayed_ref_is_head(ref)) {
if (locked_ref->is_data &&
locked_ref->total_ref_mod < 0) {
spin_lock(&delayed_refs->lock);
delayed_refs->pending_csums -= ref->num_bytes;
spin_unlock(&delayed_refs->lock);
}
btrfs_delayed_ref_unlock(locked_ref);
locked_ref = NULL;
}
btrfs_put_delayed_ref(ref);
count++;
cond_resched();
}
/*
* We don't want to include ref heads since we can have empty ref heads
* and those will drastically skew our runtime down since we just do
* accounting, no actual extent tree updates.
*/
if (actual_count > 0) {
u64 runtime = ktime_to_ns(ktime_sub(ktime_get(), start));
u64 avg;
/*
* We weigh the current average higher than our current runtime
* to avoid large swings in the average.
*/
spin_lock(&delayed_refs->lock);
avg = fs_info->avg_delayed_ref_runtime * 3 + runtime;
fs_info->avg_delayed_ref_runtime = avg >> 2; /* div by 4 */
spin_unlock(&delayed_refs->lock);
}
return 0;
}
#ifdef SCRAMBLE_DELAYED_REFS
/*
* Normally delayed refs get processed in ascending bytenr order. This
* correlates in most cases to the order added. To expose dependencies on this
* order, we start to process the tree in the middle instead of the beginning
*/
static u64 find_middle(struct rb_root *root)
{
struct rb_node *n = root->rb_node;
struct btrfs_delayed_ref_node *entry;
int alt = 1;
u64 middle;
u64 first = 0, last = 0;
n = rb_first(root);
if (n) {
entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
first = entry->bytenr;
}
n = rb_last(root);
if (n) {
entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
last = entry->bytenr;
}
n = root->rb_node;
while (n) {
entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
WARN_ON(!entry->in_tree);
middle = entry->bytenr;
if (alt)
n = n->rb_left;
else
n = n->rb_right;
alt = 1 - alt;
}
return middle;
}
#endif
static inline u64 heads_to_leaves(struct btrfs_root *root, u64 heads)
{
u64 num_bytes;
num_bytes = heads * (sizeof(struct btrfs_extent_item) +
sizeof(struct btrfs_extent_inline_ref));
if (!btrfs_fs_incompat(root->fs_info, SKINNY_METADATA))
num_bytes += heads * sizeof(struct btrfs_tree_block_info);
/*
* We don't ever fill up leaves all the way so multiply by 2 just to be
* closer to what we're really going to want to ouse.
*/
return div_u64(num_bytes, BTRFS_LEAF_DATA_SIZE(root));
}
/*
* Takes the number of bytes to be csumm'ed and figures out how many leaves it
* would require to store the csums for that many bytes.
*/
u64 btrfs_csum_bytes_to_leaves(struct btrfs_root *root, u64 csum_bytes)
{
u64 csum_size;
u64 num_csums_per_leaf;
u64 num_csums;
csum_size = BTRFS_LEAF_DATA_SIZE(root) - sizeof(struct btrfs_item);
num_csums_per_leaf = div64_u64(csum_size,
(u64)btrfs_super_csum_size(root->fs_info->super_copy));
num_csums = div64_u64(csum_bytes, root->sectorsize);
num_csums += num_csums_per_leaf - 1;
num_csums = div64_u64(num_csums, num_csums_per_leaf);
return num_csums;
}
int btrfs_check_space_for_delayed_refs(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_block_rsv *global_rsv;
u64 num_heads = trans->transaction->delayed_refs.num_heads_ready;
u64 csum_bytes = trans->transaction->delayed_refs.pending_csums;
u64 num_dirty_bgs = trans->transaction->num_dirty_bgs;
u64 num_bytes, num_dirty_bgs_bytes;
int ret = 0;
num_bytes = btrfs_calc_trans_metadata_size(root, 1);
num_heads = heads_to_leaves(root, num_heads);
if (num_heads > 1)
num_bytes += (num_heads - 1) * root->nodesize;
num_bytes <<= 1;
num_bytes += btrfs_csum_bytes_to_leaves(root, csum_bytes) * root->nodesize;
num_dirty_bgs_bytes = btrfs_calc_trans_metadata_size(root,
num_dirty_bgs);
global_rsv = &root->fs_info->global_block_rsv;
/*
* If we can't allocate any more chunks lets make sure we have _lots_ of
* wiggle room since running delayed refs can create more delayed refs.
*/
if (global_rsv->space_info->full) {
num_dirty_bgs_bytes <<= 1;
num_bytes <<= 1;
}
spin_lock(&global_rsv->lock);
if (global_rsv->reserved <= num_bytes + num_dirty_bgs_bytes)
ret = 1;
spin_unlock(&global_rsv->lock);
return ret;
}
int btrfs_should_throttle_delayed_refs(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
u64 num_entries =
atomic_read(&trans->transaction->delayed_refs.num_entries);
u64 avg_runtime;
u64 val;
smp_mb();
avg_runtime = fs_info->avg_delayed_ref_runtime;
val = num_entries * avg_runtime;
if (num_entries * avg_runtime >= NSEC_PER_SEC)
return 1;
if (val >= NSEC_PER_SEC / 2)
return 2;
return btrfs_check_space_for_delayed_refs(trans, root);
}
struct async_delayed_refs {
struct btrfs_root *root;
int count;
int error;
int sync;
struct completion wait;
struct btrfs_work work;
};
static void delayed_ref_async_start(struct btrfs_work *work)
{
struct async_delayed_refs *async;
struct btrfs_trans_handle *trans;
int ret;
async = container_of(work, struct async_delayed_refs, work);
trans = btrfs_join_transaction(async->root);
if (IS_ERR(trans)) {
async->error = PTR_ERR(trans);
goto done;
}
/*
* trans->sync means that when we call end_transaciton, we won't
* wait on delayed refs
*/
trans->sync = true;
ret = btrfs_run_delayed_refs(trans, async->root, async->count);
if (ret)
async->error = ret;
ret = btrfs_end_transaction(trans, async->root);
if (ret && !async->error)
async->error = ret;
done:
if (async->sync)
complete(&async->wait);
else
kfree(async);
}
int btrfs_async_run_delayed_refs(struct btrfs_root *root,
unsigned long count, int wait)
{
struct async_delayed_refs *async;
int ret;
async = kmalloc(sizeof(*async), GFP_NOFS);
if (!async)
return -ENOMEM;
async->root = root->fs_info->tree_root;
async->count = count;
async->error = 0;
if (wait)
async->sync = 1;
else
async->sync = 0;
init_completion(&async->wait);
btrfs_init_work(&async->work, btrfs_extent_refs_helper,
delayed_ref_async_start, NULL, NULL);
btrfs_queue_work(root->fs_info->extent_workers, &async->work);
if (wait) {
wait_for_completion(&async->wait);
ret = async->error;
kfree(async);
return ret;
}
return 0;
}
/*
* this starts processing the delayed reference count updates and
* extent insertions we have queued up so far. count can be
* 0, which means to process everything in the tree at the start
* of the run (but not newly added entries), or it can be some target
* number you'd like to process.
*
* Returns 0 on success or if called with an aborted transaction
* Returns <0 on error and aborts the transaction
*/
int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
struct btrfs_root *root, unsigned long count)
{
struct rb_node *node;
struct btrfs_delayed_ref_root *delayed_refs;
struct btrfs_delayed_ref_head *head;
int ret;
int run_all = count == (unsigned long)-1;
/* We'll clean this up in btrfs_cleanup_transaction */
if (trans->aborted)
return 0;
if (root == root->fs_info->extent_root)
root = root->fs_info->tree_root;
delayed_refs = &trans->transaction->delayed_refs;
if (count == 0)
count = atomic_read(&delayed_refs->num_entries) * 2;
again:
#ifdef SCRAMBLE_DELAYED_REFS
delayed_refs->run_delayed_start = find_middle(&delayed_refs->root);
#endif
ret = __btrfs_run_delayed_refs(trans, root, count);
if (ret < 0) {
btrfs_abort_transaction(trans, root, ret);
return ret;
}
if (run_all) {
if (!list_empty(&trans->new_bgs))
btrfs_create_pending_block_groups(trans, root);
spin_lock(&delayed_refs->lock);
node = rb_first(&delayed_refs->href_root);
if (!node) {
spin_unlock(&delayed_refs->lock);
goto out;
}
count = (unsigned long)-1;
while (node) {
head = rb_entry(node, struct btrfs_delayed_ref_head,
href_node);
if (btrfs_delayed_ref_is_head(&head->node)) {
struct btrfs_delayed_ref_node *ref;
ref = &head->node;
atomic_inc(&ref->refs);
spin_unlock(&delayed_refs->lock);
/*
* Mutex was contended, block until it's
* released and try again
*/
mutex_lock(&head->mutex);
mutex_unlock(&head->mutex);
btrfs_put_delayed_ref(ref);
cond_resched();
goto again;
} else {
WARN_ON(1);
}
node = rb_next(node);
}
spin_unlock(&delayed_refs->lock);
cond_resched();
goto again;
}
out:
ret = btrfs_delayed_qgroup_accounting(trans, root->fs_info);
if (ret)
return ret;
assert_qgroups_uptodate(trans);
return 0;
}
int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, u64 flags,
int level, int is_data)
{
struct btrfs_delayed_extent_op *extent_op;
int ret;
extent_op = btrfs_alloc_delayed_extent_op();
if (!extent_op)
return -ENOMEM;
extent_op->flags_to_set = flags;
extent_op->update_flags = 1;
extent_op->update_key = 0;
extent_op->is_data = is_data ? 1 : 0;
extent_op->level = level;
ret = btrfs_add_delayed_extent_op(root->fs_info, trans, bytenr,
num_bytes, extent_op);
if (ret)
btrfs_free_delayed_extent_op(extent_op);
return ret;
}
static noinline int check_delayed_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 objectid, u64 offset, u64 bytenr)
{
struct btrfs_delayed_ref_head *head;
struct btrfs_delayed_ref_node *ref;
struct btrfs_delayed_data_ref *data_ref;
struct btrfs_delayed_ref_root *delayed_refs;
struct rb_node *node;
int ret = 0;
delayed_refs = &trans->transaction->delayed_refs;
spin_lock(&delayed_refs->lock);
head = btrfs_find_delayed_ref_head(trans, bytenr);
if (!head) {
spin_unlock(&delayed_refs->lock);
return 0;
}
if (!mutex_trylock(&head->mutex)) {
atomic_inc(&head->node.refs);
spin_unlock(&delayed_refs->lock);
btrfs_release_path(path);
/*
* Mutex was contended, block until it's released and let
* caller try again
*/
mutex_lock(&head->mutex);
mutex_unlock(&head->mutex);
btrfs_put_delayed_ref(&head->node);
return -EAGAIN;
}
spin_unlock(&delayed_refs->lock);
spin_lock(&head->lock);
node = rb_first(&head->ref_root);
while (node) {
ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
node = rb_next(node);
/* If it's a shared ref we know a cross reference exists */
if (ref->type != BTRFS_EXTENT_DATA_REF_KEY) {
ret = 1;
break;
}
data_ref = btrfs_delayed_node_to_data_ref(ref);
/*
* If our ref doesn't match the one we're currently looking at
* then we have a cross reference.
*/
if (data_ref->root != root->root_key.objectid ||
data_ref->objectid != objectid ||
data_ref->offset != offset) {
ret = 1;
break;
}
}
spin_unlock(&head->lock);
mutex_unlock(&head->mutex);
return ret;
}
static noinline int check_committed_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 objectid, u64 offset, u64 bytenr)
{
struct btrfs_root *extent_root = root->fs_info->extent_root;
struct extent_buffer *leaf;
struct btrfs_extent_data_ref *ref;
struct btrfs_extent_inline_ref *iref;
struct btrfs_extent_item *ei;
struct btrfs_key key;
u32 item_size;
int ret;
key.objectid = bytenr;
key.offset = (u64)-1;
key.type = BTRFS_EXTENT_ITEM_KEY;
ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
if (ret < 0)
goto out;
BUG_ON(ret == 0); /* Corruption */
ret = -ENOENT;
if (path->slots[0] == 0)
goto out;
path->slots[0]--;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY)
goto out;
ret = 1;
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (item_size < sizeof(*ei)) {
WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
goto out;
}
#endif
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
if (item_size != sizeof(*ei) +
btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY))
goto out;
if (btrfs_extent_generation(leaf, ei) <=
btrfs_root_last_snapshot(&root->root_item))
goto out;
iref = (struct btrfs_extent_inline_ref *)(ei + 1);
if (btrfs_extent_inline_ref_type(leaf, iref) !=
BTRFS_EXTENT_DATA_REF_KEY)
goto out;
ref = (struct btrfs_extent_data_ref *)(&iref->offset);
if (btrfs_extent_refs(leaf, ei) !=
btrfs_extent_data_ref_count(leaf, ref) ||
btrfs_extent_data_ref_root(leaf, ref) !=
root->root_key.objectid ||
btrfs_extent_data_ref_objectid(leaf, ref) != objectid ||
btrfs_extent_data_ref_offset(leaf, ref) != offset)
goto out;
ret = 0;
out:
return ret;
}
int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 objectid, u64 offset, u64 bytenr)
{
struct btrfs_path *path;
int ret;
int ret2;
path = btrfs_alloc_path();
if (!path)
return -ENOENT;
do {
ret = check_committed_ref(trans, root, path, objectid,
offset, bytenr);
if (ret && ret != -ENOENT)
goto out;
ret2 = check_delayed_ref(trans, root, path, objectid,
offset, bytenr);
} while (ret2 == -EAGAIN);
if (ret2 && ret2 != -ENOENT) {
ret = ret2;
goto out;
}
if (ret != -ENOENT || ret2 != -ENOENT)
ret = 0;
out:
btrfs_free_path(path);
if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
WARN_ON(ret > 0);
return ret;
}
static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *buf,
int full_backref, int inc)
{
u64 bytenr;
u64 num_bytes;
u64 parent;
u64 ref_root;
u32 nritems;
struct btrfs_key key;
struct btrfs_file_extent_item *fi;
int i;
int level;
int ret = 0;
int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
u64, u64, u64, u64, u64, u64, int);
if (btrfs_test_is_dummy_root(root))
return 0;
ref_root = btrfs_header_owner(buf);
nritems = btrfs_header_nritems(buf);
level = btrfs_header_level(buf);
if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state) && level == 0)
return 0;
if (inc)
process_func = btrfs_inc_extent_ref;
else
process_func = btrfs_free_extent;
if (full_backref)
parent = buf->start;
else
parent = 0;
for (i = 0; i < nritems; i++) {
if (level == 0) {
btrfs_item_key_to_cpu(buf, &key, i);
if (key.type != BTRFS_EXTENT_DATA_KEY)
continue;
fi = btrfs_item_ptr(buf, i,
struct btrfs_file_extent_item);
if (btrfs_file_extent_type(buf, fi) ==
BTRFS_FILE_EXTENT_INLINE)
continue;
bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
if (bytenr == 0)
continue;
num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
key.offset -= btrfs_file_extent_offset(buf, fi);
ret = process_func(trans, root, bytenr, num_bytes,
parent, ref_root, key.objectid,
key.offset, 1);
if (ret)
goto fail;
} else {
bytenr = btrfs_node_blockptr(buf, i);
num_bytes = root->nodesize;
ret = process_func(trans, root, bytenr, num_bytes,
parent, ref_root, level - 1, 0,
1);
if (ret)
goto fail;
}
}
return 0;
fail:
return ret;
}
int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct extent_buffer *buf, int full_backref)
{
return __btrfs_mod_ref(trans, root, buf, full_backref, 1);
}
int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct extent_buffer *buf, int full_backref)
{
return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
}
static int write_one_cache_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_block_group_cache *cache)
{
int ret;
struct btrfs_root *extent_root = root->fs_info->extent_root;
unsigned long bi;
struct extent_buffer *leaf;
ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
if (ret) {
if (ret > 0)
ret = -ENOENT;
goto fail;
}
leaf = path->nodes[0];
bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
fail:
if (ret)
btrfs_abort_transaction(trans, root, ret);
return ret;
}
static struct btrfs_block_group_cache *
next_block_group(struct btrfs_root *root,
struct btrfs_block_group_cache *cache)
{
struct rb_node *node;
spin_lock(&root->fs_info->block_group_cache_lock);
/* If our block group was removed, we need a full search. */
if (RB_EMPTY_NODE(&cache->cache_node)) {
const u64 next_bytenr = cache->key.objectid + cache->key.offset;
spin_unlock(&root->fs_info->block_group_cache_lock);
btrfs_put_block_group(cache);
cache = btrfs_lookup_first_block_group(root->fs_info,
next_bytenr);
return cache;
}
node = rb_next(&cache->cache_node);
btrfs_put_block_group(cache);
if (node) {
cache = rb_entry(node, struct btrfs_block_group_cache,
cache_node);
btrfs_get_block_group(cache);
} else
cache = NULL;
spin_unlock(&root->fs_info->block_group_cache_lock);
return cache;
}
static int cache_save_setup(struct btrfs_block_group_cache *block_group,
struct btrfs_trans_handle *trans,
struct btrfs_path *path)
{
struct btrfs_root *root = block_group->fs_info->tree_root;
struct inode *inode = NULL;
u64 alloc_hint = 0;
int dcs = BTRFS_DC_ERROR;
u64 num_pages = 0;
int retries = 0;
int ret = 0;
/*
* If this block group is smaller than 100 megs don't bother caching the
* block group.
*/
if (block_group->key.offset < (100 * 1024 * 1024)) {
spin_lock(&block_group->lock);
block_group->disk_cache_state = BTRFS_DC_WRITTEN;
spin_unlock(&block_group->lock);
return 0;
}
if (trans->aborted)
return 0;
again:
inode = lookup_free_space_inode(root, block_group, path);
if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {
ret = PTR_ERR(inode);
btrfs_release_path(path);
goto out;
}
if (IS_ERR(inode)) {
BUG_ON(retries);
retries++;
if (block_group->ro)
goto out_free;
ret = create_free_space_inode(root, trans, block_group, path);
if (ret)
goto out_free;
goto again;
}
/* We've already setup this transaction, go ahead and exit */
if (block_group->cache_generation == trans->transid &&
i_size_read(inode)) {
dcs = BTRFS_DC_SETUP;
goto out_put;
}
/*
* We want to set the generation to 0, that way if anything goes wrong
* from here on out we know not to trust this cache when we load up next
* time.
*/
BTRFS_I(inode)->generation = 0;
ret = btrfs_update_inode(trans, root, inode);
if (ret) {
/*
* So theoretically we could recover from this, simply set the
* super cache generation to 0 so we know to invalidate the
* cache, but then we'd have to keep track of the block groups
* that fail this way so we know we _have_ to reset this cache
* before the next commit or risk reading stale cache. So to
* limit our exposure to horrible edge cases lets just abort the
* transaction, this only happens in really bad situations
* anyway.
*/
btrfs_abort_transaction(trans, root, ret);
goto out_put;
}
WARN_ON(ret);
if (i_size_read(inode) > 0) {
ret = btrfs_check_trunc_cache_free_space(root,
&root->fs_info->global_block_rsv);
if (ret)
goto out_put;
ret = btrfs_truncate_free_space_cache(root, trans, NULL, inode);
if (ret)
goto out_put;
}
spin_lock(&block_group->lock);
if (block_group->cached != BTRFS_CACHE_FINISHED ||
!btrfs_test_opt(root, SPACE_CACHE) ||
block_group->delalloc_bytes) {
/*
* don't bother trying to write stuff out _if_
* a) we're not cached,
* b) we're with nospace_cache mount option.
*/
dcs = BTRFS_DC_WRITTEN;
spin_unlock(&block_group->lock);
goto out_put;
}
spin_unlock(&block_group->lock);
/*
* Try to preallocate enough space based on how big the block group is.
* Keep in mind this has to include any pinned space which could end up
* taking up quite a bit since it's not folded into the other space
* cache.
*/
num_pages = div_u64(block_group->key.offset, 256 * 1024 * 1024);
if (!num_pages)
num_pages = 1;
num_pages *= 16;
num_pages *= PAGE_CACHE_SIZE;
ret = btrfs_check_data_free_space(inode, num_pages, num_pages);
if (ret)
goto out_put;
ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages,
num_pages, num_pages,
&alloc_hint);
if (!ret)
dcs = BTRFS_DC_SETUP;
btrfs_free_reserved_data_space(inode, num_pages);
out_put:
iput(inode);
out_free:
btrfs_release_path(path);
out:
spin_lock(&block_group->lock);
if (!ret && dcs == BTRFS_DC_SETUP)
block_group->cache_generation = trans->transid;
block_group->disk_cache_state = dcs;
spin_unlock(&block_group->lock);
return ret;
}
int btrfs_setup_space_cache(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_block_group_cache *cache, *tmp;
struct btrfs_transaction *cur_trans = trans->transaction;
struct btrfs_path *path;
if (list_empty(&cur_trans->dirty_bgs) ||
!btrfs_test_opt(root, SPACE_CACHE))
return 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/* Could add new block groups, use _safe just in case */
list_for_each_entry_safe(cache, tmp, &cur_trans->dirty_bgs,
dirty_list) {
if (cache->disk_cache_state == BTRFS_DC_CLEAR)
cache_save_setup(cache, trans, path);
}
btrfs_free_path(path);
return 0;
}
/*
* transaction commit does final block group cache writeback during a
* critical section where nothing is allowed to change the FS. This is
* required in order for the cache to actually match the block group,
* but can introduce a lot of latency into the commit.
*
* So, btrfs_start_dirty_block_groups is here to kick off block group
* cache IO. There's a chance we'll have to redo some of it if the
* block group changes again during the commit, but it greatly reduces
* the commit latency by getting rid of the easy block groups while
* we're still allowing others to join the commit.
*/
int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_block_group_cache *cache;
struct btrfs_transaction *cur_trans = trans->transaction;
int ret = 0;
int should_put;
struct btrfs_path *path = NULL;
LIST_HEAD(dirty);
struct list_head *io = &cur_trans->io_bgs;
int num_started = 0;
int loops = 0;
spin_lock(&cur_trans->dirty_bgs_lock);
if (!list_empty(&cur_trans->dirty_bgs)) {
list_splice_init(&cur_trans->dirty_bgs, &dirty);
}
spin_unlock(&cur_trans->dirty_bgs_lock);
again:
if (list_empty(&dirty)) {
btrfs_free_path(path);
return 0;
}
/*
* make sure all the block groups on our dirty list actually
* exist
*/
btrfs_create_pending_block_groups(trans, root);
if (!path) {
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
}
while (!list_empty(&dirty)) {
cache = list_first_entry(&dirty,
struct btrfs_block_group_cache,
dirty_list);
/*
* cache_write_mutex is here only to save us from balance
* deleting this block group while we are writing out the
* cache
*/
mutex_lock(&trans->transaction->cache_write_mutex);
/*
* this can happen if something re-dirties a block
* group that is already under IO. Just wait for it to
* finish and then do it all again
*/
if (!list_empty(&cache->io_list)) {
list_del_init(&cache->io_list);
btrfs_wait_cache_io(root, trans, cache,
&cache->io_ctl, path,
cache->key.objectid);
btrfs_put_block_group(cache);
}
/*
* btrfs_wait_cache_io uses the cache->dirty_list to decide
* if it should update the cache_state. Don't delete
* until after we wait.
*
* Since we're not running in the commit critical section
* we need the dirty_bgs_lock to protect from update_block_group
*/
spin_lock(&cur_trans->dirty_bgs_lock);
list_del_init(&cache->dirty_list);
spin_unlock(&cur_trans->dirty_bgs_lock);
should_put = 1;
cache_save_setup(cache, trans, path);
if (cache->disk_cache_state == BTRFS_DC_SETUP) {
cache->io_ctl.inode = NULL;
ret = btrfs_write_out_cache(root, trans, cache, path);
if (ret == 0 && cache->io_ctl.inode) {
num_started++;
should_put = 0;
/*
* the cache_write_mutex is protecting
* the io_list
*/
list_add_tail(&cache->io_list, io);
} else {
/*
* if we failed to write the cache, the
* generation will be bad and life goes on
*/
ret = 0;
}
}
if (!ret)
ret = write_one_cache_group(trans, root, path, cache);
mutex_unlock(&trans->transaction->cache_write_mutex);
/* if its not on the io list, we need to put the block group */
if (should_put)
btrfs_put_block_group(cache);
if (ret)
break;
}
/*
* go through delayed refs for all the stuff we've just kicked off
* and then loop back (just once)
*/
ret = btrfs_run_delayed_refs(trans, root, 0);
if (!ret && loops == 0) {
loops++;
spin_lock(&cur_trans->dirty_bgs_lock);
list_splice_init(&cur_trans->dirty_bgs, &dirty);
spin_unlock(&cur_trans->dirty_bgs_lock);
goto again;
}
btrfs_free_path(path);
return ret;
}
int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_block_group_cache *cache;
struct btrfs_transaction *cur_trans = trans->transaction;
int ret = 0;
int should_put;
struct btrfs_path *path;
struct list_head *io = &cur_trans->io_bgs;
int num_started = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/*
* We don't need the lock here since we are protected by the transaction
* commit. We want to do the cache_save_setup first and then run the
* delayed refs to make sure we have the best chance at doing this all
* in one shot.
*/
while (!list_empty(&cur_trans->dirty_bgs)) {
cache = list_first_entry(&cur_trans->dirty_bgs,
struct btrfs_block_group_cache,
dirty_list);
/*
* this can happen if cache_save_setup re-dirties a block
* group that is already under IO. Just wait for it to
* finish and then do it all again
*/
if (!list_empty(&cache->io_list)) {
list_del_init(&cache->io_list);
btrfs_wait_cache_io(root, trans, cache,
&cache->io_ctl, path,
cache->key.objectid);
btrfs_put_block_group(cache);
}
/*
* don't remove from the dirty list until after we've waited
* on any pending IO
*/
list_del_init(&cache->dirty_list);
should_put = 1;
cache_save_setup(cache, trans, path);
if (!ret)
ret = btrfs_run_delayed_refs(trans, root, (unsigned long) -1);
if (!ret && cache->disk_cache_state == BTRFS_DC_SETUP) {
cache->io_ctl.inode = NULL;
ret = btrfs_write_out_cache(root, trans, cache, path);
if (ret == 0 && cache->io_ctl.inode) {
num_started++;
should_put = 0;
list_add_tail(&cache->io_list, io);
} else {
/*
* if we failed to write the cache, the
* generation will be bad and life goes on
*/
ret = 0;
}
}
if (!ret)
ret = write_one_cache_group(trans, root, path, cache);
/* if its not on the io list, we need to put the block group */
if (should_put)
btrfs_put_block_group(cache);
}
while (!list_empty(io)) {
cache = list_first_entry(io, struct btrfs_block_group_cache,
io_list);
list_del_init(&cache->io_list);
btrfs_wait_cache_io(root, trans, cache,
&cache->io_ctl, path, cache->key.objectid);
btrfs_put_block_group(cache);
}
btrfs_free_path(path);
return ret;
}
int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr)
{
struct btrfs_block_group_cache *block_group;
int readonly = 0;
block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
if (!block_group || block_group->ro)
readonly = 1;
if (block_group)
btrfs_put_block_group(block_group);
return readonly;
}
static const char *alloc_name(u64 flags)
{
switch (flags) {
case BTRFS_BLOCK_GROUP_METADATA|BTRFS_BLOCK_GROUP_DATA:
return "mixed";
case BTRFS_BLOCK_GROUP_METADATA:
return "metadata";
case BTRFS_BLOCK_GROUP_DATA:
return "data";
case BTRFS_BLOCK_GROUP_SYSTEM:
return "system";
default:
WARN_ON(1);
return "invalid-combination";
};
}
static int update_space_info(struct btrfs_fs_info *info, u64 flags,
u64 total_bytes, u64 bytes_used,
struct btrfs_space_info **space_info)
{
struct btrfs_space_info *found;
int i;
int factor;
int ret;
if (flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10))
factor = 2;
else
factor = 1;
found = __find_space_info(info, flags);
if (found) {
spin_lock(&found->lock);
found->total_bytes += total_bytes;
found->disk_total += total_bytes * factor;
found->bytes_used += bytes_used;
found->disk_used += bytes_used * factor;
found->full = 0;
spin_unlock(&found->lock);
*space_info = found;
return 0;
}
found = kzalloc(sizeof(*found), GFP_NOFS);
if (!found)
return -ENOMEM;
ret = percpu_counter_init(&found->total_bytes_pinned, 0, GFP_KERNEL);
if (ret) {
kfree(found);
return ret;
}
for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
INIT_LIST_HEAD(&found->block_groups[i]);
init_rwsem(&found->groups_sem);
spin_lock_init(&found->lock);
found->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
found->total_bytes = total_bytes;
found->disk_total = total_bytes * factor;
found->bytes_used = bytes_used;
found->disk_used = bytes_used * factor;
found->bytes_pinned = 0;
found->bytes_reserved = 0;
found->bytes_readonly = 0;
found->bytes_may_use = 0;
found->full = 0;
found->force_alloc = CHUNK_ALLOC_NO_FORCE;
found->chunk_alloc = 0;
found->flush = 0;
init_waitqueue_head(&found->wait);
INIT_LIST_HEAD(&found->ro_bgs);
ret = kobject_init_and_add(&found->kobj, &space_info_ktype,
info->space_info_kobj, "%s",
alloc_name(found->flags));
if (ret) {
kfree(found);
return ret;
}
*space_info = found;
list_add_rcu(&found->list, &info->space_info);
if (flags & BTRFS_BLOCK_GROUP_DATA)
info->data_sinfo = found;
return ret;
}
static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
{
u64 extra_flags = chunk_to_extended(flags) &
BTRFS_EXTENDED_PROFILE_MASK;
write_seqlock(&fs_info->profiles_lock);
if (flags & BTRFS_BLOCK_GROUP_DATA)
fs_info->avail_data_alloc_bits |= extra_flags;
if (flags & BTRFS_BLOCK_GROUP_METADATA)
fs_info->avail_metadata_alloc_bits |= extra_flags;
if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
fs_info->avail_system_alloc_bits |= extra_flags;
write_sequnlock(&fs_info->profiles_lock);
}
/*
* returns target flags in extended format or 0 if restripe for this
* chunk_type is not in progress
*
* should be called with either volume_mutex or balance_lock held
*/
static u64 get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags)
{
struct btrfs_balance_control *bctl = fs_info->balance_ctl;
u64 target = 0;
if (!bctl)
return 0;
if (flags & BTRFS_BLOCK_GROUP_DATA &&
bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) {
target = BTRFS_BLOCK_GROUP_DATA | bctl->data.target;
} else if (flags & BTRFS_BLOCK_GROUP_SYSTEM &&
bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
target = BTRFS_BLOCK_GROUP_SYSTEM | bctl->sys.target;
} else if (flags & BTRFS_BLOCK_GROUP_METADATA &&
bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) {
target = BTRFS_BLOCK_GROUP_METADATA | bctl->meta.target;
}
return target;
}
/*
* @flags: available profiles in extended format (see ctree.h)
*
* Returns reduced profile in chunk format. If profile changing is in
* progress (either running or paused) picks the target profile (if it's
* already available), otherwise falls back to plain reducing.
*/
static u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
{
u64 num_devices = root->fs_info->fs_devices->rw_devices;
u64 target;
u64 tmp;
/*
* see if restripe for this chunk_type is in progress, if so
* try to reduce to the target profile
*/
spin_lock(&root->fs_info->balance_lock);
target = get_restripe_target(root->fs_info, flags);
if (target) {
/* pick target profile only if it's already available */
if ((flags & target) & BTRFS_EXTENDED_PROFILE_MASK) {
spin_unlock(&root->fs_info->balance_lock);
return extended_to_chunk(target);
}
}
spin_unlock(&root->fs_info->balance_lock);
/* First, mask out the RAID levels which aren't possible */
if (num_devices == 1)
flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID5);
if (num_devices < 3)
flags &= ~BTRFS_BLOCK_GROUP_RAID6;
if (num_devices < 4)
flags &= ~BTRFS_BLOCK_GROUP_RAID10;
tmp = flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID5 |
BTRFS_BLOCK_GROUP_RAID6 | BTRFS_BLOCK_GROUP_RAID10);
flags &= ~tmp;
if (tmp & BTRFS_BLOCK_GROUP_RAID6)
tmp = BTRFS_BLOCK_GROUP_RAID6;
else if (tmp & BTRFS_BLOCK_GROUP_RAID5)
tmp = BTRFS_BLOCK_GROUP_RAID5;
else if (tmp & BTRFS_BLOCK_GROUP_RAID10)
tmp = BTRFS_BLOCK_GROUP_RAID10;
else if (tmp & BTRFS_BLOCK_GROUP_RAID1)
tmp = BTRFS_BLOCK_GROUP_RAID1;
else if (tmp & BTRFS_BLOCK_GROUP_RAID0)
tmp = BTRFS_BLOCK_GROUP_RAID0;
return extended_to_chunk(flags | tmp);
}
static u64 get_alloc_profile(struct btrfs_root *root, u64 orig_flags)
{
unsigned seq;
u64 flags;
do {
flags = orig_flags;
seq = read_seqbegin(&root->fs_info->profiles_lock);
if (flags & BTRFS_BLOCK_GROUP_DATA)
flags |= root->fs_info->avail_data_alloc_bits;
else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
flags |= root->fs_info->avail_system_alloc_bits;
else if (flags & BTRFS_BLOCK_GROUP_METADATA)
flags |= root->fs_info->avail_metadata_alloc_bits;
} while (read_seqretry(&root->fs_info->profiles_lock, seq));
return btrfs_reduce_alloc_profile(root, flags);
}
u64 btrfs_get_alloc_profile(struct btrfs_root *root, int data)
{
u64 flags;
u64 ret;
if (data)
flags = BTRFS_BLOCK_GROUP_DATA;
else if (root == root->fs_info->chunk_root)
flags = BTRFS_BLOCK_GROUP_SYSTEM;
else
flags = BTRFS_BLOCK_GROUP_METADATA;
ret = get_alloc_profile(root, flags);
return ret;
}
/*
* This will check the space that the inode allocates from to make sure we have
* enough space for bytes.
*/
int btrfs_check_data_free_space(struct inode *inode, u64 bytes, u64 write_bytes)
{
struct btrfs_space_info *data_sinfo;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_fs_info *fs_info = root->fs_info;
u64 used;
int ret = 0;
int need_commit = 2;
int have_pinned_space;
/* make sure bytes are sectorsize aligned */
bytes = ALIGN(bytes, root->sectorsize);
if (btrfs_is_free_space_inode(inode)) {
need_commit = 0;
ASSERT(current->journal_info);
}
data_sinfo = fs_info->data_sinfo;
if (!data_sinfo)
goto alloc;
again:
/* make sure we have enough space to handle the data first */
spin_lock(&data_sinfo->lock);
used = data_sinfo->bytes_used + data_sinfo->bytes_reserved +
data_sinfo->bytes_pinned + data_sinfo->bytes_readonly +
data_sinfo->bytes_may_use;
if (used + bytes > data_sinfo->total_bytes) {
struct btrfs_trans_handle *trans;
/*
* if we don't have enough free bytes in this space then we need
* to alloc a new chunk.
*/
if (!data_sinfo->full) {
u64 alloc_target;
data_sinfo->force_alloc = CHUNK_ALLOC_FORCE;
spin_unlock(&data_sinfo->lock);
alloc:
alloc_target = btrfs_get_alloc_profile(root, 1);
/*
* It is ugly that we don't call nolock join
* transaction for the free space inode case here.
* But it is safe because we only do the data space
* reservation for the free space cache in the
* transaction context, the common join transaction
* just increase the counter of the current transaction
* handler, doesn't try to acquire the trans_lock of
* the fs.
*/
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = do_chunk_alloc(trans, root->fs_info->extent_root,
alloc_target,
CHUNK_ALLOC_NO_FORCE);
btrfs_end_transaction(trans, root);
if (ret < 0) {
if (ret != -ENOSPC)
return ret;
else {
have_pinned_space = 1;
goto commit_trans;
}
}
if (!data_sinfo)
data_sinfo = fs_info->data_sinfo;
goto again;
}
/*
* If we don't have enough pinned space to deal with this
* allocation, and no removed chunk in current transaction,
* don't bother committing the transaction.
*/
have_pinned_space = percpu_counter_compare(
&data_sinfo->total_bytes_pinned,
used + bytes - data_sinfo->total_bytes);
spin_unlock(&data_sinfo->lock);
/* commit the current transaction and try again */
commit_trans:
if (need_commit &&
!atomic_read(&root->fs_info->open_ioctl_trans)) {
need_commit--;
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
return PTR_ERR(trans);
if (have_pinned_space >= 0 ||
trans->transaction->have_free_bgs ||
need_commit > 0) {
ret = btrfs_commit_transaction(trans, root);
if (ret)
return ret;
/*
* make sure that all running delayed iput are
* done
*/
down_write(&root->fs_info->delayed_iput_sem);
up_write(&root->fs_info->delayed_iput_sem);
goto again;
} else {
btrfs_end_transaction(trans, root);
}
}
trace_btrfs_space_reservation(root->fs_info,
"space_info:enospc",
data_sinfo->flags, bytes, 1);
return -ENOSPC;
}
ret = btrfs_qgroup_reserve(root, write_bytes);
if (ret)
goto out;
data_sinfo->bytes_may_use += bytes;
trace_btrfs_space_reservation(root->fs_info, "space_info",
data_sinfo->flags, bytes, 1);
out:
spin_unlock(&data_sinfo->lock);
return ret;
}
/*
* Called if we need to clear a data reservation for this inode.
*/
void btrfs_free_reserved_data_space(struct inode *inode, u64 bytes)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_space_info *data_sinfo;
/* make sure bytes are sectorsize aligned */
bytes = ALIGN(bytes, root->sectorsize);
data_sinfo = root->fs_info->data_sinfo;
spin_lock(&data_sinfo->lock);
WARN_ON(data_sinfo->bytes_may_use < bytes);
data_sinfo->bytes_may_use -= bytes;
trace_btrfs_space_reservation(root->fs_info, "space_info",
data_sinfo->flags, bytes, 0);
spin_unlock(&data_sinfo->lock);
}
static void force_metadata_allocation(struct btrfs_fs_info *info)
{
struct list_head *head = &info->space_info;
struct btrfs_space_info *found;
rcu_read_lock();
list_for_each_entry_rcu(found, head, list) {
if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
found->force_alloc = CHUNK_ALLOC_FORCE;
}
rcu_read_unlock();
}
static inline u64 calc_global_rsv_need_space(struct btrfs_block_rsv *global)
{
return (global->size << 1);
}
static int should_alloc_chunk(struct btrfs_root *root,
struct btrfs_space_info *sinfo, int force)
{
struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly;
u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved;
u64 thresh;
if (force == CHUNK_ALLOC_FORCE)
return 1;
/*
* We need to take into account the global rsv because for all intents
* and purposes it's used space. Don't worry about locking the
* global_rsv, it doesn't change except when the transaction commits.
*/
if (sinfo->flags & BTRFS_BLOCK_GROUP_METADATA)
num_allocated += calc_global_rsv_need_space(global_rsv);
/*
* in limited mode, we want to have some free space up to
* about 1% of the FS size.
*/
if (force == CHUNK_ALLOC_LIMITED) {
thresh = btrfs_super_total_bytes(root->fs_info->super_copy);
thresh = max_t(u64, 64 * 1024 * 1024,
div_factor_fine(thresh, 1));
if (num_bytes - num_allocated < thresh)
return 1;
}
if (num_allocated + 2 * 1024 * 1024 < div_factor(num_bytes, 8))
return 0;
return 1;
}
static u64 get_system_chunk_thresh(struct btrfs_root *root, u64 type)
{
u64 num_dev;
if (type & (BTRFS_BLOCK_GROUP_RAID10 |
BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID5 |
BTRFS_BLOCK_GROUP_RAID6))
num_dev = root->fs_info->fs_devices->rw_devices;
else if (type & BTRFS_BLOCK_GROUP_RAID1)
num_dev = 2;
else
num_dev = 1; /* DUP or single */
/* metadata for updaing devices and chunk tree */
return btrfs_calc_trans_metadata_size(root, num_dev + 1);
}
static void check_system_chunk(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 type)
{
struct btrfs_space_info *info;
u64 left;
u64 thresh;
info = __find_space_info(root->fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
spin_lock(&info->lock);
left = info->total_bytes - info->bytes_used - info->bytes_pinned -
info->bytes_reserved - info->bytes_readonly;
spin_unlock(&info->lock);
thresh = get_system_chunk_thresh(root, type);
if (left < thresh && btrfs_test_opt(root, ENOSPC_DEBUG)) {
btrfs_info(root->fs_info, "left=%llu, need=%llu, flags=%llu",
left, thresh, type);
dump_space_info(info, 0, 0);
}
if (left < thresh) {
u64 flags;
flags = btrfs_get_alloc_profile(root->fs_info->chunk_root, 0);
btrfs_alloc_chunk(trans, root, flags);
}
}
static int do_chunk_alloc(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root, u64 flags, int force)
{
struct btrfs_space_info *space_info;
struct btrfs_fs_info *fs_info = extent_root->fs_info;
int wait_for_alloc = 0;
int ret = 0;
/* Don't re-enter if we're already allocating a chunk */
if (trans->allocating_chunk)
return -ENOSPC;
space_info = __find_space_info(extent_root->fs_info, flags);
if (!space_info) {
ret = update_space_info(extent_root->fs_info, flags,
0, 0, &space_info);
BUG_ON(ret); /* -ENOMEM */
}
BUG_ON(!space_info); /* Logic error */
again:
spin_lock(&space_info->lock);
if (force < space_info->force_alloc)
force = space_info->force_alloc;
if (space_info->full) {
if (should_alloc_chunk(extent_root, space_info, force))
ret = -ENOSPC;
else
ret = 0;
spin_unlock(&space_info->lock);
return ret;
}
if (!should_alloc_chunk(extent_root, space_info, force)) {
spin_unlock(&space_info->lock);
return 0;
} else if (space_info->chunk_alloc) {
wait_for_alloc = 1;
} else {
space_info->chunk_alloc = 1;
}
spin_unlock(&space_info->lock);
mutex_lock(&fs_info->chunk_mutex);
/*
* The chunk_mutex is held throughout the entirety of a chunk
* allocation, so once we've acquired the chunk_mutex we know that the
* other guy is done and we need to recheck and see if we should
* allocate.
*/
if (wait_for_alloc) {
mutex_unlock(&fs_info->chunk_mutex);
wait_for_alloc = 0;
goto again;
}
trans->allocating_chunk = true;
/*
* If we have mixed data/metadata chunks we want to make sure we keep
* allocating mixed chunks instead of individual chunks.
*/
if (btrfs_mixed_space_info(space_info))
flags |= (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA);
/*
* if we're doing a data chunk, go ahead and make sure that
* we keep a reasonable number of metadata chunks allocated in the
* FS as well.
*/
if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) {
fs_info->data_chunk_allocations++;
if (!(fs_info->data_chunk_allocations %
fs_info->metadata_ratio))
force_metadata_allocation(fs_info);
}
/*
* Check if we have enough space in SYSTEM chunk because we may need
* to update devices.
*/
check_system_chunk(trans, extent_root, flags);
ret = btrfs_alloc_chunk(trans, extent_root, flags);
trans->allocating_chunk = false;
spin_lock(&space_info->lock);
if (ret < 0 && ret != -ENOSPC)
goto out;
if (ret)
space_info->full = 1;
else
ret = 1;
space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
out:
space_info->chunk_alloc = 0;
spin_unlock(&space_info->lock);
mutex_unlock(&fs_info->chunk_mutex);
return ret;
}
static int can_overcommit(struct btrfs_root *root,
struct btrfs_space_info *space_info, u64 bytes,
enum btrfs_reserve_flush_enum flush)
{
struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
u64 profile = btrfs_get_alloc_profile(root, 0);
u64 space_size;
u64 avail;
u64 used;
used = space_info->bytes_used + space_info->bytes_reserved +
space_info->bytes_pinned + space_info->bytes_readonly;
/*
* We only want to allow over committing if we have lots of actual space
* free, but if we don't have enough space to handle the global reserve
* space then we could end up having a real enospc problem when trying
* to allocate a chunk or some other such important allocation.
*/
spin_lock(&global_rsv->lock);
space_size = calc_global_rsv_need_space(global_rsv);
spin_unlock(&global_rsv->lock);
if (used + space_size >= space_info->total_bytes)
return 0;
used += space_info->bytes_may_use;
spin_lock(&root->fs_info->free_chunk_lock);
avail = root->fs_info->free_chunk_space;
spin_unlock(&root->fs_info->free_chunk_lock);
/*
* If we have dup, raid1 or raid10 then only half of the free
* space is actually useable. For raid56, the space info used
* doesn't include the parity drive, so we don't have to
* change the math
*/
if (profile & (BTRFS_BLOCK_GROUP_DUP |
BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10))
avail >>= 1;
/*
* If we aren't flushing all things, let us overcommit up to
* 1/2th of the space. If we can flush, don't let us overcommit
* too much, let it overcommit up to 1/8 of the space.
*/
if (flush == BTRFS_RESERVE_FLUSH_ALL)
avail >>= 3;
else
avail >>= 1;
if (used + bytes < space_info->total_bytes + avail)
return 1;
return 0;
}
static void btrfs_writeback_inodes_sb_nr(struct btrfs_root *root,
unsigned long nr_pages, int nr_items)
{
struct super_block *sb = root->fs_info->sb;
if (down_read_trylock(&sb->s_umount)) {
writeback_inodes_sb_nr(sb, nr_pages, WB_REASON_FS_FREE_SPACE);
up_read(&sb->s_umount);
} else {
/*
* We needn't worry the filesystem going from r/w to r/o though
* we don't acquire ->s_umount mutex, because the filesystem
* should guarantee the delalloc inodes list be empty after
* the filesystem is readonly(all dirty pages are written to
* the disk).
*/
btrfs_start_delalloc_roots(root->fs_info, 0, nr_items);
if (!current->journal_info)
btrfs_wait_ordered_roots(root->fs_info, nr_items);
}
}
static inline int calc_reclaim_items_nr(struct btrfs_root *root, u64 to_reclaim)
{
u64 bytes;
int nr;
bytes = btrfs_calc_trans_metadata_size(root, 1);
nr = (int)div64_u64(to_reclaim, bytes);
if (!nr)
nr = 1;
return nr;
}
#define EXTENT_SIZE_PER_ITEM (256 * 1024)
/*
* shrink metadata reservation for delalloc
*/
static void shrink_delalloc(struct btrfs_root *root, u64 to_reclaim, u64 orig,
bool wait_ordered)
{
struct btrfs_block_rsv *block_rsv;
struct btrfs_space_info *space_info;
struct btrfs_trans_handle *trans;
u64 delalloc_bytes;
u64 max_reclaim;
long time_left;
unsigned long nr_pages;
int loops;
int items;
enum btrfs_reserve_flush_enum flush;
/* Calc the number of the pages we need flush for space reservation */
items = calc_reclaim_items_nr(root, to_reclaim);
to_reclaim = items * EXTENT_SIZE_PER_ITEM;
trans = (struct btrfs_trans_handle *)current->journal_info;
block_rsv = &root->fs_info->delalloc_block_rsv;
space_info = block_rsv->space_info;
delalloc_bytes = percpu_counter_sum_positive(
&root->fs_info->delalloc_bytes);
if (delalloc_bytes == 0) {
if (trans)
return;
if (wait_ordered)
btrfs_wait_ordered_roots(root->fs_info, items);
return;
}
loops = 0;
while (delalloc_bytes && loops < 3) {
max_reclaim = min(delalloc_bytes, to_reclaim);
nr_pages = max_reclaim >> PAGE_CACHE_SHIFT;
btrfs_writeback_inodes_sb_nr(root, nr_pages, items);
/*
* We need to wait for the async pages to actually start before
* we do anything.
*/
max_reclaim = atomic_read(&root->fs_info->async_delalloc_pages);
if (!max_reclaim)
goto skip_async;
if (max_reclaim <= nr_pages)
max_reclaim = 0;
else
max_reclaim -= nr_pages;
wait_event(root->fs_info->async_submit_wait,
atomic_read(&root->fs_info->async_delalloc_pages) <=
(int)max_reclaim);
skip_async:
if (!trans)
flush = BTRFS_RESERVE_FLUSH_ALL;
else
flush = BTRFS_RESERVE_NO_FLUSH;
spin_lock(&space_info->lock);
if (can_overcommit(root, space_info, orig, flush)) {
spin_unlock(&space_info->lock);
break;
}
spin_unlock(&space_info->lock);
loops++;
if (wait_ordered && !trans) {
btrfs_wait_ordered_roots(root->fs_info, items);
} else {
time_left = schedule_timeout_killable(1);
if (time_left)
break;
}
delalloc_bytes = percpu_counter_sum_positive(
&root->fs_info->delalloc_bytes);
}
}
/**
* maybe_commit_transaction - possibly commit the transaction if its ok to
* @root - the root we're allocating for
* @bytes - the number of bytes we want to reserve
* @force - force the commit
*
* This will check to make sure that committing the transaction will actually
* get us somewhere and then commit the transaction if it does. Otherwise it
* will return -ENOSPC.
*/
static int may_commit_transaction(struct btrfs_root *root,
struct btrfs_space_info *space_info,
u64 bytes, int force)
{
struct btrfs_block_rsv *delayed_rsv = &root->fs_info->delayed_block_rsv;
struct btrfs_trans_handle *trans;
trans = (struct btrfs_trans_handle *)current->journal_info;
if (trans)
return -EAGAIN;
if (force)
goto commit;
/* See if there is enough pinned space to make this reservation */
if (percpu_counter_compare(&space_info->total_bytes_pinned,
bytes) >= 0)
goto commit;
/*
* See if there is some space in the delayed insertion reservation for
* this reservation.
*/
if (space_info != delayed_rsv->space_info)
return -ENOSPC;
spin_lock(&delayed_rsv->lock);
if (percpu_counter_compare(&space_info->total_bytes_pinned,
bytes - delayed_rsv->size) >= 0) {
spin_unlock(&delayed_rsv->lock);
return -ENOSPC;
}
spin_unlock(&delayed_rsv->lock);
commit:
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
return -ENOSPC;
return btrfs_commit_transaction(trans, root);
}
enum flush_state {
FLUSH_DELAYED_ITEMS_NR = 1,
FLUSH_DELAYED_ITEMS = 2,
FLUSH_DELALLOC = 3,
FLUSH_DELALLOC_WAIT = 4,
ALLOC_CHUNK = 5,
COMMIT_TRANS = 6,
};
static int flush_space(struct btrfs_root *root,
struct btrfs_space_info *space_info, u64 num_bytes,
u64 orig_bytes, int state)
{
struct btrfs_trans_handle *trans;
int nr;
int ret = 0;
switch (state) {
case FLUSH_DELAYED_ITEMS_NR:
case FLUSH_DELAYED_ITEMS:
if (state == FLUSH_DELAYED_ITEMS_NR)
nr = calc_reclaim_items_nr(root, num_bytes) * 2;
else
nr = -1;
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
break;
}
ret = btrfs_run_delayed_items_nr(trans, root, nr);
btrfs_end_transaction(trans, root);
break;
case FLUSH_DELALLOC:
case FLUSH_DELALLOC_WAIT:
shrink_delalloc(root, num_bytes * 2, orig_bytes,
state == FLUSH_DELALLOC_WAIT);
break;
case ALLOC_CHUNK:
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
break;
}
ret = do_chunk_alloc(trans, root->fs_info->extent_root,
btrfs_get_alloc_profile(root, 0),
CHUNK_ALLOC_NO_FORCE);
btrfs_end_transaction(trans, root);
if (ret == -ENOSPC)
ret = 0;
break;
case COMMIT_TRANS:
ret = may_commit_transaction(root, space_info, orig_bytes, 0);
break;
default:
ret = -ENOSPC;
break;
}
return ret;
}
static inline u64
btrfs_calc_reclaim_metadata_size(struct btrfs_root *root,
struct btrfs_space_info *space_info)
{
u64 used;
u64 expected;
u64 to_reclaim;
to_reclaim = min_t(u64, num_online_cpus() * 1024 * 1024,
16 * 1024 * 1024);
spin_lock(&space_info->lock);
if (can_overcommit(root, space_info, to_reclaim,
BTRFS_RESERVE_FLUSH_ALL)) {
to_reclaim = 0;
goto out;
}
used = space_info->bytes_used + space_info->bytes_reserved +
space_info->bytes_pinned + space_info->bytes_readonly +
space_info->bytes_may_use;
if (can_overcommit(root, space_info, 1024 * 1024,
BTRFS_RESERVE_FLUSH_ALL))
expected = div_factor_fine(space_info->total_bytes, 95);
else
expected = div_factor_fine(space_info->total_bytes, 90);
if (used > expected)
to_reclaim = used - expected;
else
to_reclaim = 0;
to_reclaim = min(to_reclaim, space_info->bytes_may_use +
space_info->bytes_reserved);
out:
spin_unlock(&space_info->lock);
return to_reclaim;
}
static inline int need_do_async_reclaim(struct btrfs_space_info *space_info,
struct btrfs_fs_info *fs_info, u64 used)
{
u64 thresh = div_factor_fine(space_info->total_bytes, 98);
/* If we're just plain full then async reclaim just slows us down. */
if (space_info->bytes_used >= thresh)
return 0;
return (used >= thresh && !btrfs_fs_closing(fs_info) &&
!test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state));
}
static int btrfs_need_do_async_reclaim(struct btrfs_space_info *space_info,
struct btrfs_fs_info *fs_info,
int flush_state)
{
u64 used;
spin_lock(&space_info->lock);
/*
* We run out of space and have not got any free space via flush_space,
* so don't bother doing async reclaim.
*/
if (flush_state > COMMIT_TRANS && space_info->full) {
spin_unlock(&space_info->lock);
return 0;
}
used = space_info->bytes_used + space_info->bytes_reserved +
space_info->bytes_pinned + space_info->bytes_readonly +
space_info->bytes_may_use;
if (need_do_async_reclaim(space_info, fs_info, used)) {
spin_unlock(&space_info->lock);
return 1;
}
spin_unlock(&space_info->lock);
return 0;
}
static void btrfs_async_reclaim_metadata_space(struct work_struct *work)
{
struct btrfs_fs_info *fs_info;
struct btrfs_space_info *space_info;
u64 to_reclaim;
int flush_state;
fs_info = container_of(work, struct btrfs_fs_info, async_reclaim_work);
space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info->fs_root,
space_info);
if (!to_reclaim)
return;
flush_state = FLUSH_DELAYED_ITEMS_NR;
do {
flush_space(fs_info->fs_root, space_info, to_reclaim,
to_reclaim, flush_state);
flush_state++;
if (!btrfs_need_do_async_reclaim(space_info, fs_info,
flush_state))
return;
} while (flush_state < COMMIT_TRANS);
}
void btrfs_init_async_reclaim_work(struct work_struct *work)
{
INIT_WORK(work, btrfs_async_reclaim_metadata_space);
}
/**
* reserve_metadata_bytes - try to reserve bytes from the block_rsv's space
* @root - the root we're allocating for
* @block_rsv - the block_rsv we're allocating for
* @orig_bytes - the number of bytes we want
* @flush - whether or not we can flush to make our reservation
*
* This will reserve orgi_bytes number of bytes from the space info associated
* with the block_rsv. If there is not enough space it will make an attempt to
* flush out space to make room. It will do this by flushing delalloc if
* possible or committing the transaction. If flush is 0 then no attempts to
* regain reservations will be made and this will fail if there is not enough
* space already.
*/
static int reserve_metadata_bytes(struct btrfs_root *root,
struct btrfs_block_rsv *block_rsv,
u64 orig_bytes,
enum btrfs_reserve_flush_enum flush)
{
struct btrfs_space_info *space_info = block_rsv->space_info;
u64 used;
u64 num_bytes = orig_bytes;
int flush_state = FLUSH_DELAYED_ITEMS_NR;
int ret = 0;
bool flushing = false;
again:
ret = 0;
spin_lock(&space_info->lock);
/*
* We only want to wait if somebody other than us is flushing and we
* are actually allowed to flush all things.
*/
while (flush == BTRFS_RESERVE_FLUSH_ALL && !flushing &&
space_info->flush) {
spin_unlock(&space_info->lock);
/*
* If we have a trans handle we can't wait because the flusher
* may have to commit the transaction, which would mean we would
* deadlock since we are waiting for the flusher to finish, but
* hold the current transaction open.
*/
if (current->journal_info)
return -EAGAIN;
ret = wait_event_killable(space_info->wait, !space_info->flush);
/* Must have been killed, return */
if (ret)
return -EINTR;
spin_lock(&space_info->lock);
}
ret = -ENOSPC;
used = space_info->bytes_used + space_info->bytes_reserved +
space_info->bytes_pinned + space_info->bytes_readonly +
space_info->bytes_may_use;
/*
* The idea here is that we've not already over-reserved the block group
* then we can go ahead and save our reservation first and then start
* flushing if we need to. Otherwise if we've already overcommitted
* lets start flushing stuff first and then come back and try to make
* our reservation.
*/
if (used <= space_info->total_bytes) {
if (used + orig_bytes <= space_info->total_bytes) {
space_info->bytes_may_use += orig_bytes;
trace_btrfs_space_reservation(root->fs_info,
"space_info", space_info->flags, orig_bytes, 1);
ret = 0;
} else {
/*
* Ok set num_bytes to orig_bytes since we aren't
* overocmmitted, this way we only try and reclaim what
* we need.
*/
num_bytes = orig_bytes;
}
} else {
/*
* Ok we're over committed, set num_bytes to the overcommitted
* amount plus the amount of bytes that we need for this
* reservation.
*/
num_bytes = used - space_info->total_bytes +
(orig_bytes * 2);
}
if (ret && can_overcommit(root, space_info, orig_bytes, flush)) {
space_info->bytes_may_use += orig_bytes;
trace_btrfs_space_reservation(root->fs_info, "space_info",
space_info->flags, orig_bytes,
1);
ret = 0;
}
/*
* Couldn't make our reservation, save our place so while we're trying
* to reclaim space we can actually use it instead of somebody else
* stealing it from us.
*
* We make the other tasks wait for the flush only when we can flush
* all things.
*/
if (ret && flush != BTRFS_RESERVE_NO_FLUSH) {
flushing = true;
space_info->flush = 1;
} else if (!ret && space_info->flags & BTRFS_BLOCK_GROUP_METADATA) {
used += orig_bytes;
/*
* We will do the space reservation dance during log replay,
* which means we won't have fs_info->fs_root set, so don't do
* the async reclaim as we will panic.
*/
if (!root->fs_info->log_root_recovering &&
need_do_async_reclaim(space_info, root->fs_info, used) &&
!work_busy(&root->fs_info->async_reclaim_work))
queue_work(system_unbound_wq,
&root->fs_info->async_reclaim_work);
}
spin_unlock(&space_info->lock);
if (!ret || flush == BTRFS_RESERVE_NO_FLUSH)
goto out;
ret = flush_space(root, space_info, num_bytes, orig_bytes,
flush_state);
flush_state++;
/*
* If we are FLUSH_LIMIT, we can not flush delalloc, or the deadlock
* would happen. So skip delalloc flush.
*/
if (flush == BTRFS_RESERVE_FLUSH_LIMIT &&
(flush_state == FLUSH_DELALLOC ||
flush_state == FLUSH_DELALLOC_WAIT))
flush_state = ALLOC_CHUNK;
if (!ret)
goto again;
else if (flush == BTRFS_RESERVE_FLUSH_LIMIT &&
flush_state < COMMIT_TRANS)
goto again;
else if (flush == BTRFS_RESERVE_FLUSH_ALL &&
flush_state <= COMMIT_TRANS)
goto again;
out:
if (ret == -ENOSPC &&
unlikely(root->orphan_cleanup_state == ORPHAN_CLEANUP_STARTED)) {
struct btrfs_block_rsv *global_rsv =
&root->fs_info->global_block_rsv;
if (block_rsv != global_rsv &&
!block_rsv_use_bytes(global_rsv, orig_bytes))
ret = 0;
}
if (ret == -ENOSPC)
trace_btrfs_space_reservation(root->fs_info,
"space_info:enospc",
space_info->flags, orig_bytes, 1);
if (flushing) {
spin_lock(&space_info->lock);
space_info->flush = 0;
wake_up_all(&space_info->wait);
spin_unlock(&space_info->lock);
}
return ret;
}
static struct btrfs_block_rsv *get_block_rsv(
const struct btrfs_trans_handle *trans,
const struct btrfs_root *root)
{
struct btrfs_block_rsv *block_rsv = NULL;
if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
block_rsv = trans->block_rsv;
if (root == root->fs_info->csum_root && trans->adding_csums)
block_rsv = trans->block_rsv;
if (root == root->fs_info->uuid_root)
block_rsv = trans->block_rsv;
if (!block_rsv)
block_rsv = root->block_rsv;
if (!block_rsv)
block_rsv = &root->fs_info->empty_block_rsv;
return block_rsv;
}
static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
u64 num_bytes)
{
int ret = -ENOSPC;
spin_lock(&block_rsv->lock);
if (block_rsv->reserved >= num_bytes) {
block_rsv->reserved -= num_bytes;
if (block_rsv->reserved < block_rsv->size)
block_rsv->full = 0;
ret = 0;
}
spin_unlock(&block_rsv->lock);
return ret;
}
static void block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
u64 num_bytes, int update_size)
{
spin_lock(&block_rsv->lock);
block_rsv->reserved += num_bytes;
if (update_size)
block_rsv->size += num_bytes;
else if (block_rsv->reserved >= block_rsv->size)
block_rsv->full = 1;
spin_unlock(&block_rsv->lock);
}
int btrfs_cond_migrate_bytes(struct btrfs_fs_info *fs_info,
struct btrfs_block_rsv *dest, u64 num_bytes,
int min_factor)
{
struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
u64 min_bytes;
if (global_rsv->space_info != dest->space_info)
return -ENOSPC;
spin_lock(&global_rsv->lock);
min_bytes = div_factor(global_rsv->size, min_factor);
if (global_rsv->reserved < min_bytes + num_bytes) {
spin_unlock(&global_rsv->lock);
return -ENOSPC;
}
global_rsv->reserved -= num_bytes;
if (global_rsv->reserved < global_rsv->size)
global_rsv->full = 0;
spin_unlock(&global_rsv->lock);
block_rsv_add_bytes(dest, num_bytes, 1);
return 0;
}
static void block_rsv_release_bytes(struct btrfs_fs_info *fs_info,
struct btrfs_block_rsv *block_rsv,
struct btrfs_block_rsv *dest, u64 num_bytes)
{
struct btrfs_space_info *space_info = block_rsv->space_info;
spin_lock(&block_rsv->lock);
if (num_bytes == (u64)-1)
num_bytes = block_rsv->size;
block_rsv->size -= num_bytes;
if (block_rsv->reserved >= block_rsv->size) {
num_bytes = block_rsv->reserved - block_rsv->size;
block_rsv->reserved = block_rsv->size;
block_rsv->full = 1;
} else {
num_bytes = 0;
}
spin_unlock(&block_rsv->lock);
if (num_bytes > 0) {
if (dest) {
spin_lock(&dest->lock);
if (!dest->full) {
u64 bytes_to_add;
bytes_to_add = dest->size - dest->reserved;
bytes_to_add = min(num_bytes, bytes_to_add);
dest->reserved += bytes_to_add;
if (dest->reserved >= dest->size)
dest->full = 1;
num_bytes -= bytes_to_add;
}
spin_unlock(&dest->lock);
}
if (num_bytes) {
spin_lock(&space_info->lock);
space_info->bytes_may_use -= num_bytes;
trace_btrfs_space_reservation(fs_info, "space_info",
space_info->flags, num_bytes, 0);
spin_unlock(&space_info->lock);
}
}
}
static int block_rsv_migrate_bytes(struct btrfs_block_rsv *src,
struct btrfs_block_rsv *dst, u64 num_bytes)
{
int ret;
ret = block_rsv_use_bytes(src, num_bytes);
if (ret)
return ret;
block_rsv_add_bytes(dst, num_bytes, 1);
return 0;
}
void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, unsigned short type)
{
memset(rsv, 0, sizeof(*rsv));
spin_lock_init(&rsv->lock);
rsv->type = type;
}
struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root,
unsigned short type)
{
struct btrfs_block_rsv *block_rsv;
struct btrfs_fs_info *fs_info = root->fs_info;
block_rsv = kmalloc(sizeof(*block_rsv), GFP_NOFS);
if (!block_rsv)
return NULL;
btrfs_init_block_rsv(block_rsv, type);
block_rsv->space_info = __find_space_info(fs_info,
BTRFS_BLOCK_GROUP_METADATA);
return block_rsv;
}
void btrfs_free_block_rsv(struct btrfs_root *root,
struct btrfs_block_rsv *rsv)
{
if (!rsv)
return;
btrfs_block_rsv_release(root, rsv, (u64)-1);
kfree(rsv);
}
void __btrfs_free_block_rsv(struct btrfs_block_rsv *rsv)
{
kfree(rsv);
}
int btrfs_block_rsv_add(struct btrfs_root *root,
struct btrfs_block_rsv *block_rsv, u64 num_bytes,
enum btrfs_reserve_flush_enum flush)
{
int ret;
if (num_bytes == 0)
return 0;
ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
if (!ret) {
block_rsv_add_bytes(block_rsv, num_bytes, 1);
return 0;
}
return ret;
}
int btrfs_block_rsv_check(struct btrfs_root *root,
struct btrfs_block_rsv *block_rsv, int min_factor)
{
u64 num_bytes = 0;
int ret = -ENOSPC;
if (!block_rsv)
return 0;
spin_lock(&block_rsv->lock);
num_bytes = div_factor(block_rsv->size, min_factor);
if (block_rsv->reserved >= num_bytes)
ret = 0;
spin_unlock(&block_rsv->lock);
return ret;
}
int btrfs_block_rsv_refill(struct btrfs_root *root,
struct btrfs_block_rsv *block_rsv, u64 min_reserved,
enum btrfs_reserve_flush_enum flush)
{
u64 num_bytes = 0;
int ret = -ENOSPC;
if (!block_rsv)
return 0;
spin_lock(&block_rsv->lock);
num_bytes = min_reserved;
if (block_rsv->reserved >= num_bytes)
ret = 0;
else
num_bytes -= block_rsv->reserved;
spin_unlock(&block_rsv->lock);
if (!ret)
return 0;
ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
if (!ret) {
block_rsv_add_bytes(block_rsv, num_bytes, 0);
return 0;
}
return ret;
}
int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src_rsv,
struct btrfs_block_rsv *dst_rsv,
u64 num_bytes)
{
return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
}
void btrfs_block_rsv_release(struct btrfs_root *root,
struct btrfs_block_rsv *block_rsv,
u64 num_bytes)
{
struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
if (global_rsv == block_rsv ||
block_rsv->space_info != global_rsv->space_info)
global_rsv = NULL;
block_rsv_release_bytes(root->fs_info, block_rsv, global_rsv,
num_bytes);
}
/*
* helper to calculate size of global block reservation.
* the desired value is sum of space used by extent tree,
* checksum tree and root tree
*/
static u64 calc_global_metadata_size(struct btrfs_fs_info *fs_info)
{
struct btrfs_space_info *sinfo;
u64 num_bytes;
u64 meta_used;
u64 data_used;
int csum_size = btrfs_super_csum_size(fs_info->super_copy);
sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_DATA);
spin_lock(&sinfo->lock);
data_used = sinfo->bytes_used;
spin_unlock(&sinfo->lock);
sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
spin_lock(&sinfo->lock);
if (sinfo->flags & BTRFS_BLOCK_GROUP_DATA)
data_used = 0;
meta_used = sinfo->bytes_used;
spin_unlock(&sinfo->lock);
num_bytes = (data_used >> fs_info->sb->s_blocksize_bits) *
csum_size * 2;
num_bytes += div_u64(data_used + meta_used, 50);
if (num_bytes * 3 > meta_used)
num_bytes = div_u64(meta_used, 3);
return ALIGN(num_bytes, fs_info->extent_root->nodesize << 10);
}
static void update_global_block_rsv(struct btrfs_fs_info *fs_info)
{
struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
struct btrfs_space_info *sinfo = block_rsv->space_info;
u64 num_bytes;
num_bytes = calc_global_metadata_size(fs_info);
spin_lock(&sinfo->lock);
spin_lock(&block_rsv->lock);
block_rsv->size = min_t(u64, num_bytes, 512 * 1024 * 1024);
num_bytes = sinfo->bytes_used + sinfo->bytes_pinned +
sinfo->bytes_reserved + sinfo->bytes_readonly +
sinfo->bytes_may_use;
if (sinfo->total_bytes > num_bytes) {
num_bytes = sinfo->total_bytes - num_bytes;
block_rsv->reserved += num_bytes;
sinfo->bytes_may_use += num_bytes;
trace_btrfs_space_reservation(fs_info, "space_info",
sinfo->flags, num_bytes, 1);
}
if (block_rsv->reserved >= block_rsv->size) {
num_bytes = block_rsv->reserved - block_rsv->size;
sinfo->bytes_may_use -= num_bytes;
trace_btrfs_space_reservation(fs_info, "space_info",
sinfo->flags, num_bytes, 0);
block_rsv->reserved = block_rsv->size;
block_rsv->full = 1;
}
spin_unlock(&block_rsv->lock);
spin_unlock(&sinfo->lock);
}
static void init_global_block_rsv(struct btrfs_fs_info *fs_info)
{
struct btrfs_space_info *space_info;
space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
fs_info->chunk_block_rsv.space_info = space_info;
space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
fs_info->global_block_rsv.space_info = space_info;
fs_info->delalloc_block_rsv.space_info = space_info;
fs_info->trans_block_rsv.space_info = space_info;
fs_info->empty_block_rsv.space_info = space_info;
fs_info->delayed_block_rsv.space_info = space_info;
fs_info->extent_root->block_rsv = &fs_info->global_block_rsv;
fs_info->csum_root->block_rsv = &fs_info->global_block_rsv;
fs_info->dev_root->block_rsv = &fs_info->global_block_rsv;
fs_info->tree_root->block_rsv = &fs_info->global_block_rsv;
if (fs_info->quota_root)
fs_info->quota_root->block_rsv = &fs_info->global_block_rsv;
fs_info->chunk_root->block_rsv = &fs_info->chunk_block_rsv;
update_global_block_rsv(fs_info);
}
static void release_global_block_rsv(struct btrfs_fs_info *fs_info)
{
block_rsv_release_bytes(fs_info, &fs_info->global_block_rsv, NULL,
(u64)-1);
WARN_ON(fs_info->delalloc_block_rsv.size > 0);
WARN_ON(fs_info->delalloc_block_rsv.reserved > 0);
WARN_ON(fs_info->trans_block_rsv.size > 0);
WARN_ON(fs_info->trans_block_rsv.reserved > 0);
WARN_ON(fs_info->chunk_block_rsv.size > 0);
WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
WARN_ON(fs_info->delayed_block_rsv.size > 0);
WARN_ON(fs_info->delayed_block_rsv.reserved > 0);
}
void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
if (!trans->block_rsv)
return;
if (!trans->bytes_reserved)
return;
trace_btrfs_space_reservation(root->fs_info, "transaction",
trans->transid, trans->bytes_reserved, 0);
btrfs_block_rsv_release(root, trans->block_rsv, trans->bytes_reserved);
trans->bytes_reserved = 0;
}
/* Can only return 0 or -ENOSPC */
int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans,
struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_block_rsv *src_rsv = get_block_rsv(trans, root);
struct btrfs_block_rsv *dst_rsv = root->orphan_block_rsv;
/*
* We need to hold space in order to delete our orphan item once we've
* added it, so this takes the reservation so we can release it later
* when we are truly done with the orphan item.
*/
u64 num_bytes = btrfs_calc_trans_metadata_size(root, 1);
trace_btrfs_space_reservation(root->fs_info, "orphan",
btrfs_ino(inode), num_bytes, 1);
return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
}
void btrfs_orphan_release_metadata(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 num_bytes = btrfs_calc_trans_metadata_size(root, 1);
trace_btrfs_space_reservation(root->fs_info, "orphan",
btrfs_ino(inode), num_bytes, 0);
btrfs_block_rsv_release(root, root->orphan_block_rsv, num_bytes);
}
/*
* btrfs_subvolume_reserve_metadata() - reserve space for subvolume operation
* root: the root of the parent directory
* rsv: block reservation
* items: the number of items that we need do reservation
* qgroup_reserved: used to return the reserved size in qgroup
*
* This function is used to reserve the space for snapshot/subvolume
* creation and deletion. Those operations are different with the
* common file/directory operations, they change two fs/file trees
* and root tree, the number of items that the qgroup reserves is
* different with the free space reservation. So we can not use
* the space reseravtion mechanism in start_transaction().
*/
int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
struct btrfs_block_rsv *rsv,
int items,
u64 *qgroup_reserved,
bool use_global_rsv)
{
u64 num_bytes;
int ret;
struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
if (root->fs_info->quota_enabled) {
/* One for parent inode, two for dir entries */
num_bytes = 3 * root->nodesize;
ret = btrfs_qgroup_reserve(root, num_bytes);
if (ret)
return ret;
} else {
num_bytes = 0;
}
*qgroup_reserved = num_bytes;
num_bytes = btrfs_calc_trans_metadata_size(root, items);
rsv->space_info = __find_space_info(root->fs_info,
BTRFS_BLOCK_GROUP_METADATA);
ret = btrfs_block_rsv_add(root, rsv, num_bytes,
BTRFS_RESERVE_FLUSH_ALL);
if (ret == -ENOSPC && use_global_rsv)
ret = btrfs_block_rsv_migrate(global_rsv, rsv, num_bytes);
if (ret) {
if (*qgroup_reserved)
btrfs_qgroup_free(root, *qgroup_reserved);
}
return ret;
}
void btrfs_subvolume_release_metadata(struct btrfs_root *root,
struct btrfs_block_rsv *rsv,
u64 qgroup_reserved)
{
btrfs_block_rsv_release(root, rsv, (u64)-1);
}
/**
* drop_outstanding_extent - drop an outstanding extent
* @inode: the inode we're dropping the extent for
* @num_bytes: the number of bytes we're relaseing.
*
* This is called when we are freeing up an outstanding extent, either called
* after an error or after an extent is written. This will return the number of
* reserved extents that need to be freed. This must be called with
* BTRFS_I(inode)->lock held.
*/
static unsigned drop_outstanding_extent(struct inode *inode, u64 num_bytes)
{
unsigned drop_inode_space = 0;
unsigned dropped_extents = 0;
unsigned num_extents = 0;
num_extents = (unsigned)div64_u64(num_bytes +
BTRFS_MAX_EXTENT_SIZE - 1,
BTRFS_MAX_EXTENT_SIZE);
ASSERT(num_extents);
ASSERT(BTRFS_I(inode)->outstanding_extents >= num_extents);
BTRFS_I(inode)->outstanding_extents -= num_extents;
if (BTRFS_I(inode)->outstanding_extents == 0 &&
test_and_clear_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
&BTRFS_I(inode)->runtime_flags))
drop_inode_space = 1;
/*
* If we have more or the same amount of outsanding extents than we have
* reserved then we need to leave the reserved extents count alone.
*/
if (BTRFS_I(inode)->outstanding_extents >=
BTRFS_I(inode)->reserved_extents)
return drop_inode_space;
dropped_extents = BTRFS_I(inode)->reserved_extents -
BTRFS_I(inode)->outstanding_extents;
BTRFS_I(inode)->reserved_extents -= dropped_extents;
return dropped_extents + drop_inode_space;
}
/**
* calc_csum_metadata_size - return the amount of metada space that must be
* reserved/free'd for the given bytes.
* @inode: the inode we're manipulating
* @num_bytes: the number of bytes in question
* @reserve: 1 if we are reserving space, 0 if we are freeing space
*
* This adjusts the number of csum_bytes in the inode and then returns the
* correct amount of metadata that must either be reserved or freed. We
* calculate how many checksums we can fit into one leaf and then divide the
* number of bytes that will need to be checksumed by this value to figure out
* how many checksums will be required. If we are adding bytes then the number
* may go up and we will return the number of additional bytes that must be
* reserved. If it is going down we will return the number of bytes that must
* be freed.
*
* This must be called with BTRFS_I(inode)->lock held.
*/
static u64 calc_csum_metadata_size(struct inode *inode, u64 num_bytes,
int reserve)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 old_csums, num_csums;
if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM &&
BTRFS_I(inode)->csum_bytes == 0)
return 0;
old_csums = btrfs_csum_bytes_to_leaves(root, BTRFS_I(inode)->csum_bytes);
if (reserve)
BTRFS_I(inode)->csum_bytes += num_bytes;
else
BTRFS_I(inode)->csum_bytes -= num_bytes;
num_csums = btrfs_csum_bytes_to_leaves(root, BTRFS_I(inode)->csum_bytes);
/* No change, no need to reserve more */
if (old_csums == num_csums)
return 0;
if (reserve)
return btrfs_calc_trans_metadata_size(root,
num_csums - old_csums);
return btrfs_calc_trans_metadata_size(root, old_csums - num_csums);
}
int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_block_rsv *block_rsv = &root->fs_info->delalloc_block_rsv;
u64 to_reserve = 0;
u64 csum_bytes;
unsigned nr_extents = 0;
int extra_reserve = 0;
enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_FLUSH_ALL;
int ret = 0;
bool delalloc_lock = true;
u64 to_free = 0;
unsigned dropped;
/* If we are a free space inode we need to not flush since we will be in
* the middle of a transaction commit. We also don't need the delalloc
* mutex since we won't race with anybody. We need this mostly to make
* lockdep shut its filthy mouth.
*/
if (btrfs_is_free_space_inode(inode)) {
flush = BTRFS_RESERVE_NO_FLUSH;
delalloc_lock = false;
}
if (flush != BTRFS_RESERVE_NO_FLUSH &&
btrfs_transaction_in_commit(root->fs_info))
schedule_timeout(1);
if (delalloc_lock)
mutex_lock(&BTRFS_I(inode)->delalloc_mutex);
num_bytes = ALIGN(num_bytes, root->sectorsize);
spin_lock(&BTRFS_I(inode)->lock);
nr_extents = (unsigned)div64_u64(num_bytes +
BTRFS_MAX_EXTENT_SIZE - 1,
BTRFS_MAX_EXTENT_SIZE);
BTRFS_I(inode)->outstanding_extents += nr_extents;
nr_extents = 0;
if (BTRFS_I(inode)->outstanding_extents >
BTRFS_I(inode)->reserved_extents)
nr_extents = BTRFS_I(inode)->outstanding_extents -
BTRFS_I(inode)->reserved_extents;
/*
* Add an item to reserve for updating the inode when we complete the
* delalloc io.
*/
if (!test_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
&BTRFS_I(inode)->runtime_flags)) {
nr_extents++;
extra_reserve = 1;
}
to_reserve = btrfs_calc_trans_metadata_size(root, nr_extents);
to_reserve += calc_csum_metadata_size(inode, num_bytes, 1);
csum_bytes = BTRFS_I(inode)->csum_bytes;
spin_unlock(&BTRFS_I(inode)->lock);
if (root->fs_info->quota_enabled) {
ret = btrfs_qgroup_reserve(root, nr_extents * root->nodesize);
if (ret)
goto out_fail;
}
ret = reserve_metadata_bytes(root, block_rsv, to_reserve, flush);
if (unlikely(ret)) {
if (root->fs_info->quota_enabled)
btrfs_qgroup_free(root, nr_extents * root->nodesize);
goto out_fail;
}
spin_lock(&BTRFS_I(inode)->lock);
if (extra_reserve) {
set_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
&BTRFS_I(inode)->runtime_flags);
nr_extents--;
}
BTRFS_I(inode)->reserved_extents += nr_extents;
spin_unlock(&BTRFS_I(inode)->lock);
if (delalloc_lock)
mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);
if (to_reserve)
trace_btrfs_space_reservation(root->fs_info, "delalloc",
btrfs_ino(inode), to_reserve, 1);
block_rsv_add_bytes(block_rsv, to_reserve, 1);
return 0;
out_fail:
spin_lock(&BTRFS_I(inode)->lock);
dropped = drop_outstanding_extent(inode, num_bytes);
/*
* If the inodes csum_bytes is the same as the original
* csum_bytes then we know we haven't raced with any free()ers
* so we can just reduce our inodes csum bytes and carry on.
*/
if (BTRFS_I(inode)->csum_bytes == csum_bytes) {
calc_csum_metadata_size(inode, num_bytes, 0);
} else {
u64 orig_csum_bytes = BTRFS_I(inode)->csum_bytes;
u64 bytes;
/*
* This is tricky, but first we need to figure out how much we
* free'd from any free-ers that occured during this
* reservation, so we reset ->csum_bytes to the csum_bytes
* before we dropped our lock, and then call the free for the
* number of bytes that were freed while we were trying our
* reservation.
*/
bytes = csum_bytes - BTRFS_I(inode)->csum_bytes;
BTRFS_I(inode)->csum_bytes = csum_bytes;
to_free = calc_csum_metadata_size(inode, bytes, 0);
/*
* Now we need to see how much we would have freed had we not
* been making this reservation and our ->csum_bytes were not
* artificially inflated.
*/
BTRFS_I(inode)->csum_bytes = csum_bytes - num_bytes;
bytes = csum_bytes - orig_csum_bytes;
bytes = calc_csum_metadata_size(inode, bytes, 0);
/*
* Now reset ->csum_bytes to what it should be. If bytes is
* more than to_free then we would have free'd more space had we
* not had an artificially high ->csum_bytes, so we need to free
* the remainder. If bytes is the same or less then we don't
* need to do anything, the other free-ers did the correct
* thing.
*/
BTRFS_I(inode)->csum_bytes = orig_csum_bytes - num_bytes;
if (bytes > to_free)
to_free = bytes - to_free;
else
to_free = 0;
}
spin_unlock(&BTRFS_I(inode)->lock);
if (dropped)
to_free += btrfs_calc_trans_metadata_size(root, dropped);
if (to_free) {
btrfs_block_rsv_release(root, block_rsv, to_free);
trace_btrfs_space_reservation(root->fs_info, "delalloc",
btrfs_ino(inode), to_free, 0);
}
if (delalloc_lock)
mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);
return ret;
}
/**
* btrfs_delalloc_release_metadata - release a metadata reservation for an inode
* @inode: the inode to release the reservation for
* @num_bytes: the number of bytes we're releasing
*
* This will release the metadata reservation for an inode. This can be called
* once we complete IO for a given set of bytes to release their metadata
* reservations.
*/
void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 to_free = 0;
unsigned dropped;
num_bytes = ALIGN(num_bytes, root->sectorsize);
spin_lock(&BTRFS_I(inode)->lock);
dropped = drop_outstanding_extent(inode, num_bytes);
if (num_bytes)
to_free = calc_csum_metadata_size(inode, num_bytes, 0);
spin_unlock(&BTRFS_I(inode)->lock);
if (dropped > 0)
to_free += btrfs_calc_trans_metadata_size(root, dropped);
if (btrfs_test_is_dummy_root(root))
return;
trace_btrfs_space_reservation(root->fs_info, "delalloc",
btrfs_ino(inode), to_free, 0);
btrfs_block_rsv_release(root, &root->fs_info->delalloc_block_rsv,
to_free);
}
/**
* btrfs_delalloc_reserve_space - reserve data and metadata space for delalloc
* @inode: inode we're writing to
* @num_bytes: the number of bytes we want to allocate
*
* This will do the following things
*
* o reserve space in the data space info for num_bytes
* o reserve space in the metadata space info based on number of outstanding
* extents and how much csums will be needed
* o add to the inodes ->delalloc_bytes
* o add it to the fs_info's delalloc inodes list.
*
* This will return 0 for success and -ENOSPC if there is no space left.
*/
int btrfs_delalloc_reserve_space(struct inode *inode, u64 num_bytes)
{
int ret;
ret = btrfs_check_data_free_space(inode, num_bytes, num_bytes);
if (ret)
return ret;
ret = btrfs_delalloc_reserve_metadata(inode, num_bytes);
if (ret) {
btrfs_free_reserved_data_space(inode, num_bytes);
return ret;
}
return 0;
}
/**
* btrfs_delalloc_release_space - release data and metadata space for delalloc
* @inode: inode we're releasing space for
* @num_bytes: the number of bytes we want to free up
*
* This must be matched with a call to btrfs_delalloc_reserve_space. This is
* called in the case that we don't need the metadata AND data reservations
* anymore. So if there is an error or we insert an inline extent.
*
* This function will release the metadata space that was not used and will
* decrement ->delalloc_bytes and remove it from the fs_info delalloc_inodes
* list if there are no delalloc bytes left.
*/
void btrfs_delalloc_release_space(struct inode *inode, u64 num_bytes)
{
btrfs_delalloc_release_metadata(inode, num_bytes);
btrfs_free_reserved_data_space(inode, num_bytes);
}
static int update_block_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytenr,
u64 num_bytes, int alloc)
{
struct btrfs_block_group_cache *cache = NULL;
struct btrfs_fs_info *info = root->fs_info;
u64 total = num_bytes;
u64 old_val;
u64 byte_in_group;
int factor;
/* block accounting for super block */
spin_lock(&info->delalloc_root_lock);
old_val = btrfs_super_bytes_used(info->super_copy);
if (alloc)
old_val += num_bytes;
else
old_val -= num_bytes;
btrfs_set_super_bytes_used(info->super_copy, old_val);
spin_unlock(&info->delalloc_root_lock);
while (total) {
cache = btrfs_lookup_block_group(info, bytenr);
if (!cache)
return -ENOENT;
if (cache->flags & (BTRFS_BLOCK_GROUP_DUP |
BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10))
factor = 2;
else
factor = 1;
/*
* If this block group has free space cache written out, we
* need to make sure to load it if we are removing space. This
* is because we need the unpinning stage to actually add the
* space back to the block group, otherwise we will leak space.
*/
if (!alloc && cache->cached == BTRFS_CACHE_NO)
cache_block_group(cache, 1);
byte_in_group = bytenr - cache->key.objectid;
WARN_ON(byte_in_group > cache->key.offset);
spin_lock(&cache->space_info->lock);
spin_lock(&cache->lock);
if (btrfs_test_opt(root, SPACE_CACHE) &&
cache->disk_cache_state < BTRFS_DC_CLEAR)
cache->disk_cache_state = BTRFS_DC_CLEAR;
old_val = btrfs_block_group_used(&cache->item);
num_bytes = min(total, cache->key.offset - byte_in_group);
if (alloc) {
old_val += num_bytes;
btrfs_set_block_group_used(&cache->item, old_val);
cache->reserved -= num_bytes;
cache->space_info->bytes_reserved -= num_bytes;
cache->space_info->bytes_used += num_bytes;
cache->space_info->disk_used += num_bytes * factor;
spin_unlock(&cache->lock);
spin_unlock(&cache->space_info->lock);
} else {
old_val -= num_bytes;
btrfs_set_block_group_used(&cache->item, old_val);
cache->pinned += num_bytes;
cache->space_info->bytes_pinned += num_bytes;
cache->space_info->bytes_used -= num_bytes;
cache->space_info->disk_used -= num_bytes * factor;
spin_unlock(&cache->lock);
spin_unlock(&cache->space_info->lock);
set_extent_dirty(info->pinned_extents,
bytenr, bytenr + num_bytes - 1,
GFP_NOFS | __GFP_NOFAIL);
/*
* No longer have used bytes in this block group, queue
* it for deletion.
*/
if (old_val == 0) {
spin_lock(&info->unused_bgs_lock);
if (list_empty(&cache->bg_list)) {
btrfs_get_block_group(cache);
list_add_tail(&cache->bg_list,
&info->unused_bgs);
}
spin_unlock(&info->unused_bgs_lock);
}
}
spin_lock(&trans->transaction->dirty_bgs_lock);
if (list_empty(&cache->dirty_list)) {
list_add_tail(&cache->dirty_list,
&trans->transaction->dirty_bgs);
trans->transaction->num_dirty_bgs++;
btrfs_get_block_group(cache);
}
spin_unlock(&trans->transaction->dirty_bgs_lock);
btrfs_put_block_group(cache);
total -= num_bytes;
bytenr += num_bytes;
}
return 0;
}
static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
{
struct btrfs_block_group_cache *cache;
u64 bytenr;
spin_lock(&root->fs_info->block_group_cache_lock);
bytenr = root->fs_info->first_logical_byte;
spin_unlock(&root->fs_info->block_group_cache_lock);
if (bytenr < (u64)-1)
return bytenr;
cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
if (!cache)
return 0;
bytenr = cache->key.objectid;
btrfs_put_block_group(cache);
return bytenr;
}
static int pin_down_extent(struct btrfs_root *root,
struct btrfs_block_group_cache *cache,
u64 bytenr, u64 num_bytes, int reserved)
{
spin_lock(&cache->space_info->lock);
spin_lock(&cache->lock);
cache->pinned += num_bytes;
cache->space_info->bytes_pinned += num_bytes;
if (reserved) {
cache->reserved -= num_bytes;
cache->space_info->bytes_reserved -= num_bytes;
}
spin_unlock(&cache->lock);
spin_unlock(&cache->space_info->lock);
set_extent_dirty(root->fs_info->pinned_extents, bytenr,
bytenr + num_bytes - 1, GFP_NOFS | __GFP_NOFAIL);
if (reserved)
trace_btrfs_reserved_extent_free(root, bytenr, num_bytes);
return 0;
}
/*
* this function must be called within transaction
*/
int btrfs_pin_extent(struct btrfs_root *root,
u64 bytenr, u64 num_bytes, int reserved)
{
struct btrfs_block_group_cache *cache;
cache = btrfs_lookup_block_group(root->fs_info, bytenr);
BUG_ON(!cache); /* Logic error */
pin_down_extent(root, cache, bytenr, num_bytes, reserved);
btrfs_put_block_group(cache);
return 0;
}
/*
* this function must be called within transaction
*/
int btrfs_pin_extent_for_log_replay(struct btrfs_root *root,
u64 bytenr, u64 num_bytes)
{
struct btrfs_block_group_cache *cache;
int ret;
cache = btrfs_lookup_block_group(root->fs_info, bytenr);
if (!cache)
return -EINVAL;
/*
* pull in the free space cache (if any) so that our pin
* removes the free space from the cache. We have load_only set
* to one because the slow code to read in the free extents does check
* the pinned extents.
*/
cache_block_group(cache, 1);
pin_down_extent(root, cache, bytenr, num_bytes, 0);
/* remove us from the free space cache (if we're there at all) */
ret = btrfs_remove_free_space(cache, bytenr, num_bytes);
btrfs_put_block_group(cache);
return ret;
}
static int __exclude_logged_extent(struct btrfs_root *root, u64 start, u64 num_bytes)
{
int ret;
struct btrfs_block_group_cache *block_group;
struct btrfs_caching_control *caching_ctl;
block_group = btrfs_lookup_block_group(root->fs_info, start);
if (!block_group)
return -EINVAL;
cache_block_group(block_group, 0);
caching_ctl = get_caching_control(block_group);
if (!caching_ctl) {
/* Logic error */
BUG_ON(!block_group_cache_done(block_group));
ret = btrfs_remove_free_space(block_group, start, num_bytes);
} else {
mutex_lock(&caching_ctl->mutex);
if (start >= caching_ctl->progress) {
ret = add_excluded_extent(root, start, num_bytes);
} else if (start + num_bytes <= caching_ctl->progress) {
ret = btrfs_remove_free_space(block_group,
start, num_bytes);
} else {
num_bytes = caching_ctl->progress - start;
ret = btrfs_remove_free_space(block_group,
start, num_bytes);
if (ret)
goto out_lock;
num_bytes = (start + num_bytes) -
caching_ctl->progress;
start = caching_ctl->progress;
ret = add_excluded_extent(root, start, num_bytes);
}
out_lock:
mutex_unlock(&caching_ctl->mutex);
put_caching_control(caching_ctl);
}
btrfs_put_block_group(block_group);
return ret;
}
int btrfs_exclude_logged_extents(struct btrfs_root *log,
struct extent_buffer *eb)
{
struct btrfs_file_extent_item *item;
struct btrfs_key key;
int found_type;
int i;
if (!btrfs_fs_incompat(log->fs_info, MIXED_GROUPS))
return 0;
for (i = 0; i < btrfs_header_nritems(eb); i++) {
btrfs_item_key_to_cpu(eb, &key, i);
if (key.type != BTRFS_EXTENT_DATA_KEY)
continue;
item = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
found_type = btrfs_file_extent_type(eb, item);
if (found_type == BTRFS_FILE_EXTENT_INLINE)
continue;
if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
continue;
key.objectid = btrfs_file_extent_disk_bytenr(eb, item);
key.offset = btrfs_file_extent_disk_num_bytes(eb, item);
__exclude_logged_extent(log, key.objectid, key.offset);
}
return 0;
}
/**
* btrfs_update_reserved_bytes - update the block_group and space info counters
* @cache: The cache we are manipulating
* @num_bytes: The number of bytes in question
* @reserve: One of the reservation enums
* @delalloc: The blocks are allocated for the delalloc write
*
* This is called by the allocator when it reserves space, or by somebody who is
* freeing space that was never actually used on disk. For example if you
* reserve some space for a new leaf in transaction A and before transaction A
* commits you free that leaf, you call this with reserve set to 0 in order to
* clear the reservation.
*
* Metadata reservations should be called with RESERVE_ALLOC so we do the proper
* ENOSPC accounting. For data we handle the reservation through clearing the
* delalloc bits in the io_tree. We have to do this since we could end up
* allocating less disk space for the amount of data we have reserved in the
* case of compression.
*
* If this is a reservation and the block group has become read only we cannot
* make the reservation and return -EAGAIN, otherwise this function always
* succeeds.
*/
static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
u64 num_bytes, int reserve, int delalloc)
{
struct btrfs_space_info *space_info = cache->space_info;
int ret = 0;
spin_lock(&space_info->lock);
spin_lock(&cache->lock);
if (reserve != RESERVE_FREE) {
if (cache->ro) {
ret = -EAGAIN;
} else {
cache->reserved += num_bytes;
space_info->bytes_reserved += num_bytes;
if (reserve == RESERVE_ALLOC) {
trace_btrfs_space_reservation(cache->fs_info,
"space_info", space_info->flags,
num_bytes, 0);
space_info->bytes_may_use -= num_bytes;
}
if (delalloc)
cache->delalloc_bytes += num_bytes;
}
} else {
if (cache->ro)
space_info->bytes_readonly += num_bytes;
cache->reserved -= num_bytes;
space_info->bytes_reserved -= num_bytes;
if (delalloc)
cache->delalloc_bytes -= num_bytes;
}
spin_unlock(&cache->lock);
spin_unlock(&space_info->lock);
return ret;
}
void btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_caching_control *next;
struct btrfs_caching_control *caching_ctl;
struct btrfs_block_group_cache *cache;
down_write(&fs_info->commit_root_sem);
list_for_each_entry_safe(caching_ctl, next,
&fs_info->caching_block_groups, list) {
cache = caching_ctl->block_group;
if (block_group_cache_done(cache)) {
cache->last_byte_to_unpin = (u64)-1;
list_del_init(&caching_ctl->list);
put_caching_control(caching_ctl);
} else {
cache->last_byte_to_unpin = caching_ctl->progress;
}
}
if (fs_info->pinned_extents == &fs_info->freed_extents[0])
fs_info->pinned_extents = &fs_info->freed_extents[1];
else
fs_info->pinned_extents = &fs_info->freed_extents[0];
up_write(&fs_info->commit_root_sem);
update_global_block_rsv(fs_info);
}
static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end,
const bool return_free_space)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_block_group_cache *cache = NULL;
struct btrfs_space_info *space_info;
struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
u64 len;
bool readonly;
while (start <= end) {
readonly = false;
if (!cache ||
start >= cache->key.objectid + cache->key.offset) {
if (cache)
btrfs_put_block_group(cache);
cache = btrfs_lookup_block_group(fs_info, start);
BUG_ON(!cache); /* Logic error */
}
len = cache->key.objectid + cache->key.offset - start;
len = min(len, end + 1 - start);
if (start < cache->last_byte_to_unpin) {
len = min(len, cache->last_byte_to_unpin - start);
if (return_free_space)
btrfs_add_free_space(cache, start, len);
}
start += len;
space_info = cache->space_info;
spin_lock(&space_info->lock);
spin_lock(&cache->lock);
cache->pinned -= len;
space_info->bytes_pinned -= len;
percpu_counter_add(&space_info->total_bytes_pinned, -len);
if (cache->ro) {
space_info->bytes_readonly += len;
readonly = true;
}
spin_unlock(&cache->lock);
if (!readonly && global_rsv->space_info == space_info) {
spin_lock(&global_rsv->lock);
if (!global_rsv->full) {
len = min(len, global_rsv->size -
global_rsv->reserved);
global_rsv->reserved += len;
space_info->bytes_may_use += len;
if (global_rsv->reserved >= global_rsv->size)
global_rsv->full = 1;
}
spin_unlock(&global_rsv->lock);
}
spin_unlock(&space_info->lock);
}
if (cache)
btrfs_put_block_group(cache);
return 0;
}
int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct extent_io_tree *unpin;
u64 start;
u64 end;
int ret;
if (trans->aborted)
return 0;
if (fs_info->pinned_extents == &fs_info->freed_extents[0])
unpin = &fs_info->freed_extents[1];
else
unpin = &fs_info->freed_extents[0];
while (1) {
mutex_lock(&fs_info->unused_bg_unpin_mutex);
ret = find_first_extent_bit(unpin, 0, &start, &end,
EXTENT_DIRTY, NULL);
if (ret) {
mutex_unlock(&fs_info->unused_bg_unpin_mutex);
break;
}
if (btrfs_test_opt(root, DISCARD))
ret = btrfs_discard_extent(root, start,
end + 1 - start, NULL);
clear_extent_dirty(unpin, start, end, GFP_NOFS);
unpin_extent_range(root, start, end, true);
mutex_unlock(&fs_info->unused_bg_unpin_mutex);
cond_resched();
}
return 0;
}
static void add_pinned_bytes(struct btrfs_fs_info *fs_info, u64 num_bytes,
u64 owner, u64 root_objectid)
{
struct btrfs_space_info *space_info;
u64 flags;
if (owner < BTRFS_FIRST_FREE_OBJECTID) {
if (root_objectid == BTRFS_CHUNK_TREE_OBJECTID)
flags = BTRFS_BLOCK_GROUP_SYSTEM;
else
flags = BTRFS_BLOCK_GROUP_METADATA;
} else {
flags = BTRFS_BLOCK_GROUP_DATA;
}
space_info = __find_space_info(fs_info, flags);
BUG_ON(!space_info); /* Logic bug */
percpu_counter_add(&space_info->total_bytes_pinned, num_bytes);
}
static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, u64 parent,
u64 root_objectid, u64 owner_objectid,
u64 owner_offset, int refs_to_drop,
struct btrfs_delayed_extent_op *extent_op,
int no_quota)
{
struct btrfs_key key;
struct btrfs_path *path;
struct btrfs_fs_info *info = root->fs_info;
struct btrfs_root *extent_root = info->extent_root;
struct extent_buffer *leaf;
struct btrfs_extent_item *ei;
struct btrfs_extent_inline_ref *iref;
int ret;
int is_data;
int extent_slot = 0;
int found_extent = 0;
int num_to_del = 1;
u32 item_size;
u64 refs;
int last_ref = 0;
enum btrfs_qgroup_operation_type type = BTRFS_QGROUP_OPER_SUB_EXCL;
bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
SKINNY_METADATA);
if (!info->quota_enabled || !is_fstree(root_objectid))
no_quota = 1;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = 1;
path->leave_spinning = 1;
is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
BUG_ON(!is_data && refs_to_drop != 1);
if (is_data)
skinny_metadata = 0;
ret = lookup_extent_backref(trans, extent_root, path, &iref,
bytenr, num_bytes, parent,
root_objectid, owner_objectid,
owner_offset);
if (ret == 0) {
extent_slot = path->slots[0];
while (extent_slot >= 0) {
btrfs_item_key_to_cpu(path->nodes[0], &key,
extent_slot);
if (key.objectid != bytenr)
break;
if (key.type == BTRFS_EXTENT_ITEM_KEY &&
key.offset == num_bytes) {
found_extent = 1;
break;
}
if (key.type == BTRFS_METADATA_ITEM_KEY &&
key.offset == owner_objectid) {
found_extent = 1;
break;
}
if (path->slots[0] - extent_slot > 5)
break;
extent_slot--;
}
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
if (found_extent && item_size < sizeof(*ei))
found_extent = 0;
#endif
if (!found_extent) {
BUG_ON(iref);
ret = remove_extent_backref(trans, extent_root, path,
NULL, refs_to_drop,
is_data, &last_ref);
if (ret) {
btrfs_abort_transaction(trans, extent_root, ret);
goto out;
}
btrfs_release_path(path);
path->leave_spinning = 1;
key.objectid = bytenr;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = num_bytes;
if (!is_data && skinny_metadata) {
key.type = BTRFS_METADATA_ITEM_KEY;
key.offset = owner_objectid;
}
ret = btrfs_search_slot(trans, extent_root,
&key, path, -1, 1);
if (ret > 0 && skinny_metadata && path->slots[0]) {
/*
* Couldn't find our skinny metadata item,
* see if we have ye olde extent item.
*/
path->slots[0]--;
btrfs_item_key_to_cpu(path->nodes[0], &key,
path->slots[0]);
if (key.objectid == bytenr &&
key.type == BTRFS_EXTENT_ITEM_KEY &&
key.offset == num_bytes)
ret = 0;
}
if (ret > 0 && skinny_metadata) {
skinny_metadata = false;
key.objectid = bytenr;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = num_bytes;
btrfs_release_path(path);
ret = btrfs_search_slot(trans, extent_root,
&key, path, -1, 1);
}
if (ret) {
btrfs_err(info, "umm, got %d back from search, was looking for %llu",
ret, bytenr);
if (ret > 0)
btrfs_print_leaf(extent_root,
path->nodes[0]);
}
if (ret < 0) {
btrfs_abort_transaction(trans, extent_root, ret);
goto out;
}
extent_slot = path->slots[0];
}
} else if (WARN_ON(ret == -ENOENT)) {
btrfs_print_leaf(extent_root, path->nodes[0]);
btrfs_err(info,
"unable to find ref byte nr %llu parent %llu root %llu owner %llu offset %llu",
bytenr, parent, root_objectid, owner_objectid,
owner_offset);
btrfs_abort_transaction(trans, extent_root, ret);
goto out;
} else {
btrfs_abort_transaction(trans, extent_root, ret);
goto out;
}
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, extent_slot);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (item_size < sizeof(*ei)) {
BUG_ON(found_extent || extent_slot != path->slots[0]);
ret = convert_extent_item_v0(trans, extent_root, path,
owner_objectid, 0);
if (ret < 0) {
btrfs_abort_transaction(trans, extent_root, ret);
goto out;
}
btrfs_release_path(path);
path->leave_spinning = 1;
key.objectid = bytenr;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = num_bytes;
ret = btrfs_search_slot(trans, extent_root, &key, path,
-1, 1);
if (ret) {
btrfs_err(info, "umm, got %d back from search, was looking for %llu",
ret, bytenr);
btrfs_print_leaf(extent_root, path->nodes[0]);
}
if (ret < 0) {
btrfs_abort_transaction(trans, extent_root, ret);
goto out;
}
extent_slot = path->slots[0];
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, extent_slot);
}
#endif
BUG_ON(item_size < sizeof(*ei));
ei = btrfs_item_ptr(leaf, extent_slot,
struct btrfs_extent_item);
if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID &&
key.type == BTRFS_EXTENT_ITEM_KEY) {
struct btrfs_tree_block_info *bi;
BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
bi = (struct btrfs_tree_block_info *)(ei + 1);
WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
}
refs = btrfs_extent_refs(leaf, ei);
if (refs < refs_to_drop) {
btrfs_err(info, "trying to drop %d refs but we only have %Lu "
"for bytenr %Lu", refs_to_drop, refs, bytenr);
ret = -EINVAL;
btrfs_abort_transaction(trans, extent_root, ret);
goto out;
}
refs -= refs_to_drop;
if (refs > 0) {
type = BTRFS_QGROUP_OPER_SUB_SHARED;
if (extent_op)
__run_delayed_extent_op(extent_op, leaf, ei);
/*
* In the case of inline back ref, reference count will
* be updated by remove_extent_backref
*/
if (iref) {
BUG_ON(!found_extent);
} else {
btrfs_set_extent_refs(leaf, ei, refs);
btrfs_mark_buffer_dirty(leaf);
}
if (found_extent) {
ret = remove_extent_backref(trans, extent_root, path,
iref, refs_to_drop,
is_data, &last_ref);
if (ret) {
btrfs_abort_transaction(trans, extent_root, ret);
goto out;
}
}
add_pinned_bytes(root->fs_info, -num_bytes, owner_objectid,
root_objectid);
} else {
if (found_extent) {
BUG_ON(is_data && refs_to_drop !=
extent_data_ref_count(root, path, iref));
if (iref) {
BUG_ON(path->slots[0] != extent_slot);
} else {
BUG_ON(path->slots[0] != extent_slot + 1);
path->slots[0] = extent_slot;
num_to_del = 2;
}
}
last_ref = 1;
ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
num_to_del);
if (ret) {
btrfs_abort_transaction(trans, extent_root, ret);
goto out;
}
btrfs_release_path(path);
if (is_data) {
ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
if (ret) {
btrfs_abort_transaction(trans, extent_root, ret);
goto out;
}
}
ret = update_block_group(trans, root, bytenr, num_bytes, 0);
if (ret) {
btrfs_abort_transaction(trans, extent_root, ret);
goto out;
}
}
btrfs_release_path(path);
/* Deal with the quota accounting */
if (!ret && last_ref && !no_quota) {
int mod_seq = 0;
if (owner_objectid >= BTRFS_FIRST_FREE_OBJECTID &&
type == BTRFS_QGROUP_OPER_SUB_SHARED)
mod_seq = 1;
ret = btrfs_qgroup_record_ref(trans, info, root_objectid,
bytenr, num_bytes, type,
mod_seq);
}
out:
btrfs_free_path(path);
return ret;
}
/*
* when we free an block, it is possible (and likely) that we free the last
* delayed ref for that extent as well. This searches the delayed ref tree for
* a given extent, and if there are no other delayed refs to be processed, it
* removes it from the tree.
*/
static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytenr)
{
struct btrfs_delayed_ref_head *head;
struct btrfs_delayed_ref_root *delayed_refs;
int ret = 0;
delayed_refs = &trans->transaction->delayed_refs;
spin_lock(&delayed_refs->lock);
head = btrfs_find_delayed_ref_head(trans, bytenr);
if (!head)
goto out_delayed_unlock;
spin_lock(&head->lock);
if (rb_first(&head->ref_root))
goto out;
if (head->extent_op) {
if (!head->must_insert_reserved)
goto out;
btrfs_free_delayed_extent_op(head->extent_op);
head->extent_op = NULL;
}
/*
* waiting for the lock here would deadlock. If someone else has it
* locked they are already in the process of dropping it anyway
*/
if (!mutex_trylock(&head->mutex))
goto out;
/*
* at this point we have a head with no other entries. Go
* ahead and process it.
*/
head->node.in_tree = 0;
rb_erase(&head->href_node, &delayed_refs->href_root);
atomic_dec(&delayed_refs->num_entries);
/*
* we don't take a ref on the node because we're removing it from the
* tree, so we just steal the ref the tree was holding.
*/
delayed_refs->num_heads--;
if (head->processing == 0)
delayed_refs->num_heads_ready--;
head->processing = 0;
spin_unlock(&head->lock);
spin_unlock(&delayed_refs->lock);
BUG_ON(head->extent_op);
if (head->must_insert_reserved)
ret = 1;
mutex_unlock(&head->mutex);
btrfs_put_delayed_ref(&head->node);
return ret;
out:
spin_unlock(&head->lock);
out_delayed_unlock:
spin_unlock(&delayed_refs->lock);
return 0;
}
void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *buf,
u64 parent, int last_ref)
{
int pin = 1;
int ret;
if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
ret = btrfs_add_delayed_tree_ref(root->fs_info, trans,
buf->start, buf->len,
parent, root->root_key.objectid,
btrfs_header_level(buf),
BTRFS_DROP_DELAYED_REF, NULL, 0);
BUG_ON(ret); /* -ENOMEM */
}
if (!last_ref)
return;
if (btrfs_header_generation(buf) == trans->transid) {
struct btrfs_block_group_cache *cache;
if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
ret = check_ref_cleanup(trans, root, buf->start);
if (!ret)
goto out;
}
cache = btrfs_lookup_block_group(root->fs_info, buf->start);
if (btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
pin_down_extent(root, cache, buf->start, buf->len, 1);
btrfs_put_block_group(cache);
goto out;
}
WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags));
btrfs_add_free_space(cache, buf->start, buf->len);
btrfs_update_reserved_bytes(cache, buf->len, RESERVE_FREE, 0);
btrfs_put_block_group(cache);
trace_btrfs_reserved_extent_free(root, buf->start, buf->len);
pin = 0;
}
out:
if (pin)
add_pinned_bytes(root->fs_info, buf->len,
btrfs_header_level(buf),
root->root_key.objectid);
/*
* Deleting the buffer, clear the corrupt flag since it doesn't matter
* anymore.
*/
clear_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags);
}
/* Can return -ENOMEM */
int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root,
u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid,
u64 owner, u64 offset, int no_quota)
{
int ret;
struct btrfs_fs_info *fs_info = root->fs_info;
if (btrfs_test_is_dummy_root(root))
return 0;
add_pinned_bytes(root->fs_info, num_bytes, owner, root_objectid);
/*
* tree log blocks never actually go into the extent allocation
* tree, just update pinning info and exit early.
*/
if (root_objectid == BTRFS_TREE_LOG_OBJECTID) {
WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID);
/* unlocks the pinned mutex */
btrfs_pin_extent(root, bytenr, num_bytes, 1);
ret = 0;
} else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
num_bytes,
parent, root_objectid, (int)owner,
BTRFS_DROP_DELAYED_REF, NULL, no_quota);
} else {
ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr,
num_bytes,
parent, root_objectid, owner,
offset, BTRFS_DROP_DELAYED_REF,
NULL, no_quota);
}
return ret;
}
/*
* when we wait for progress in the block group caching, its because
* our allocation attempt failed at least once. So, we must sleep
* and let some progress happen before we try again.
*
* This function will sleep at least once waiting for new free space to
* show up, and then it will check the block group free space numbers
* for our min num_bytes. Another option is to have it go ahead
* and look in the rbtree for a free extent of a given size, but this
* is a good start.
*
* Callers of this must check if cache->cached == BTRFS_CACHE_ERROR before using
* any of the information in this block group.
*/
static noinline void
wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
u64 num_bytes)
{
struct btrfs_caching_control *caching_ctl;
caching_ctl = get_caching_control(cache);
if (!caching_ctl)
return;
wait_event(caching_ctl->wait, block_group_cache_done(cache) ||
(cache->free_space_ctl->free_space >= num_bytes));
put_caching_control(caching_ctl);
}
static noinline int
wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
{
struct btrfs_caching_control *caching_ctl;
int ret = 0;
caching_ctl = get_caching_control(cache);
if (!caching_ctl)
return (cache->cached == BTRFS_CACHE_ERROR) ? -EIO : 0;
wait_event(caching_ctl->wait, block_group_cache_done(cache));
if (cache->cached == BTRFS_CACHE_ERROR)
ret = -EIO;
put_caching_control(caching_ctl);
return ret;
}
int __get_raid_index(u64 flags)
{
if (flags & BTRFS_BLOCK_GROUP_RAID10)
return BTRFS_RAID_RAID10;
else if (flags & BTRFS_BLOCK_GROUP_RAID1)
return BTRFS_RAID_RAID1;
else if (flags & BTRFS_BLOCK_GROUP_DUP)
return BTRFS_RAID_DUP;
else if (flags & BTRFS_BLOCK_GROUP_RAID0)
return BTRFS_RAID_RAID0;
else if (flags & BTRFS_BLOCK_GROUP_RAID5)
return BTRFS_RAID_RAID5;
else if (flags & BTRFS_BLOCK_GROUP_RAID6)
return BTRFS_RAID_RAID6;
return BTRFS_RAID_SINGLE; /* BTRFS_BLOCK_GROUP_SINGLE */
}
int get_block_group_index(struct btrfs_block_group_cache *cache)
{
return __get_raid_index(cache->flags);
}
static const char *btrfs_raid_type_names[BTRFS_NR_RAID_TYPES] = {
[BTRFS_RAID_RAID10] = "raid10",
[BTRFS_RAID_RAID1] = "raid1",
[BTRFS_RAID_DUP] = "dup",
[BTRFS_RAID_RAID0] = "raid0",
[BTRFS_RAID_SINGLE] = "single",
[BTRFS_RAID_RAID5] = "raid5",
[BTRFS_RAID_RAID6] = "raid6",
};
static const char *get_raid_name(enum btrfs_raid_types type)
{
if (type >= BTRFS_NR_RAID_TYPES)
return NULL;
return btrfs_raid_type_names[type];
}
enum btrfs_loop_type {
LOOP_CACHING_NOWAIT = 0,
LOOP_CACHING_WAIT = 1,
LOOP_ALLOC_CHUNK = 2,
LOOP_NO_EMPTY_SIZE = 3,
};
static inline void
btrfs_lock_block_group(struct btrfs_block_group_cache *cache,
int delalloc)
{
if (delalloc)
down_read(&cache->data_rwsem);
}
static inline void
btrfs_grab_block_group(struct btrfs_block_group_cache *cache,
int delalloc)
{
btrfs_get_block_group(cache);
if (delalloc)
down_read(&cache->data_rwsem);
}
static struct btrfs_block_group_cache *
btrfs_lock_cluster(struct btrfs_block_group_cache *block_group,
struct btrfs_free_cluster *cluster,
int delalloc)
{
struct btrfs_block_group_cache *used_bg;
bool locked = false;
again:
spin_lock(&cluster->refill_lock);
if (locked) {
if (used_bg == cluster->block_group)
return used_bg;
up_read(&used_bg->data_rwsem);
btrfs_put_block_group(used_bg);
}
used_bg = cluster->block_group;
if (!used_bg)
return NULL;
if (used_bg == block_group)
return used_bg;
btrfs_get_block_group(used_bg);
if (!delalloc)
return used_bg;
if (down_read_trylock(&used_bg->data_rwsem))
return used_bg;
spin_unlock(&cluster->refill_lock);
down_read(&used_bg->data_rwsem);
locked = true;
goto again;
}
static inline void
btrfs_release_block_group(struct btrfs_block_group_cache *cache,
int delalloc)
{
if (delalloc)
up_read(&cache->data_rwsem);
btrfs_put_block_group(cache);
}
/*
* walks the btree of allocated extents and find a hole of a given size.
* The key ins is changed to record the hole:
* ins->objectid == start position
* ins->flags = BTRFS_EXTENT_ITEM_KEY
* ins->offset == the size of the hole.
* Any available blocks before search_start are skipped.
*
* If there is no suitable free space, we will record the max size of
* the free space extent currently.
*/
static noinline int find_free_extent(struct btrfs_root *orig_root,
u64 num_bytes, u64 empty_size,
u64 hint_byte, struct btrfs_key *ins,
u64 flags, int delalloc)
{
int ret = 0;
struct btrfs_root *root = orig_root->fs_info->extent_root;
struct btrfs_free_cluster *last_ptr = NULL;
struct btrfs_block_group_cache *block_group = NULL;
u64 search_start = 0;
u64 max_extent_size = 0;
int empty_cluster = 2 * 1024 * 1024;
struct btrfs_space_info *space_info;
int loop = 0;
int index = __get_raid_index(flags);
int alloc_type = (flags & BTRFS_BLOCK_GROUP_DATA) ?
RESERVE_ALLOC_NO_ACCOUNT : RESERVE_ALLOC;
bool failed_cluster_refill = false;
bool failed_alloc = false;
bool use_cluster = true;
bool have_caching_bg = false;
WARN_ON(num_bytes < root->sectorsize);
ins->type = BTRFS_EXTENT_ITEM_KEY;
ins->objectid = 0;
ins->offset = 0;
trace_find_free_extent(orig_root, num_bytes, empty_size, flags);
space_info = __find_space_info(root->fs_info, flags);
if (!space_info) {
btrfs_err(root->fs_info, "No space info for %llu", flags);
return -ENOSPC;
}
/*
* If the space info is for both data and metadata it means we have a
* small filesystem and we can't use the clustering stuff.
*/
if (btrfs_mixed_space_info(space_info))
use_cluster = false;
if (flags & BTRFS_BLOCK_GROUP_METADATA && use_cluster) {
last_ptr = &root->fs_info->meta_alloc_cluster;
if (!btrfs_test_opt(root, SSD))
empty_cluster = 64 * 1024;
}
if ((flags & BTRFS_BLOCK_GROUP_DATA) && use_cluster &&
btrfs_test_opt(root, SSD)) {
last_ptr = &root->fs_info->data_alloc_cluster;
}
if (last_ptr) {
spin_lock(&last_ptr->lock);
if (last_ptr->block_group)
hint_byte = last_ptr->window_start;
spin_unlock(&last_ptr->lock);
}
search_start = max(search_start, first_logical_byte(root, 0));
search_start = max(search_start, hint_byte);
if (!last_ptr)
empty_cluster = 0;
if (search_start == hint_byte) {
block_group = btrfs_lookup_block_group(root->fs_info,
search_start);
/*
* we don't want to use the block group if it doesn't match our
* allocation bits, or if its not cached.
*
* However if we are re-searching with an ideal block group
* picked out then we don't care that the block group is cached.
*/
if (block_group && block_group_bits(block_group, flags) &&
block_group->cached != BTRFS_CACHE_NO) {
down_read(&space_info->groups_sem);
if (list_empty(&block_group->list) ||
block_group->ro) {
/*
* someone is removing this block group,
* we can't jump into the have_block_group
* target because our list pointers are not
* valid
*/
btrfs_put_block_group(block_group);
up_read(&space_info->groups_sem);
} else {
index = get_block_group_index(block_group);
btrfs_lock_block_group(block_group, delalloc);
goto have_block_group;
}
} else if (block_group) {
btrfs_put_block_group(block_group);
}
}
search:
have_caching_bg = false;
down_read(&space_info->groups_sem);
list_for_each_entry(block_group, &space_info->block_groups[index],
list) {
u64 offset;
int cached;
btrfs_grab_block_group(block_group, delalloc);
search_start = block_group->key.objectid;
/*
* this can happen if we end up cycling through all the
* raid types, but we want to make sure we only allocate
* for the proper type.
*/
if (!block_group_bits(block_group, flags)) {
u64 extra = BTRFS_BLOCK_GROUP_DUP |
BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID5 |
BTRFS_BLOCK_GROUP_RAID6 |
BTRFS_BLOCK_GROUP_RAID10;
/*
* if they asked for extra copies and this block group
* doesn't provide them, bail. This does allow us to
* fill raid0 from raid1.
*/
if ((flags & extra) && !(block_group->flags & extra))
goto loop;
}
have_block_group:
cached = block_group_cache_done(block_group);
if (unlikely(!cached)) {
ret = cache_block_group(block_group, 0);
BUG_ON(ret < 0);
ret = 0;
}
if (unlikely(block_group->cached == BTRFS_CACHE_ERROR))
goto loop;
if (unlikely(block_group->ro))
goto loop;
/*
* Ok we want to try and use the cluster allocator, so
* lets look there
*/
if (last_ptr) {
struct btrfs_block_group_cache *used_block_group;
unsigned long aligned_cluster;
/*
* the refill lock keeps out other
* people trying to start a new cluster
*/
used_block_group = btrfs_lock_cluster(block_group,
last_ptr,
delalloc);
if (!used_block_group)
goto refill_cluster;
if (used_block_group != block_group &&
(used_block_group->ro ||
!block_group_bits(used_block_group, flags)))
goto release_cluster;
offset = btrfs_alloc_from_cluster(used_block_group,
last_ptr,
num_bytes,
used_block_group->key.objectid,
&max_extent_size);
if (offset) {
/* we have a block, we're done */
spin_unlock(&last_ptr->refill_lock);
trace_btrfs_reserve_extent_cluster(root,
used_block_group,
search_start, num_bytes);
if (used_block_group != block_group) {
btrfs_release_block_group(block_group,
delalloc);
block_group = used_block_group;
}
goto checks;
}
WARN_ON(last_ptr->block_group != used_block_group);
release_cluster:
/* If we are on LOOP_NO_EMPTY_SIZE, we can't
* set up a new clusters, so lets just skip it
* and let the allocator find whatever block
* it can find. If we reach this point, we
* will have tried the cluster allocator
* plenty of times and not have found
* anything, so we are likely way too
* fragmented for the clustering stuff to find
* anything.
*
* However, if the cluster is taken from the
* current block group, release the cluster
* first, so that we stand a better chance of
* succeeding in the unclustered
* allocation. */
if (loop >= LOOP_NO_EMPTY_SIZE &&
used_block_group != block_group) {
spin_unlock(&last_ptr->refill_lock);
btrfs_release_block_group(used_block_group,
delalloc);
goto unclustered_alloc;
}
/*
* this cluster didn't work out, free it and
* start over
*/
btrfs_return_cluster_to_free_space(NULL, last_ptr);
if (used_block_group != block_group)
btrfs_release_block_group(used_block_group,
delalloc);
refill_cluster:
if (loop >= LOOP_NO_EMPTY_SIZE) {
spin_unlock(&last_ptr->refill_lock);
goto unclustered_alloc;
}
aligned_cluster = max_t(unsigned long,
empty_cluster + empty_size,
block_group->full_stripe_len);
/* allocate a cluster in this block group */
ret = btrfs_find_space_cluster(root, block_group,
last_ptr, search_start,
num_bytes,
aligned_cluster);
if (ret == 0) {
/*
* now pull our allocation out of this
* cluster
*/
offset = btrfs_alloc_from_cluster(block_group,
last_ptr,
num_bytes,
search_start,
&max_extent_size);
if (offset) {
/* we found one, proceed */
spin_unlock(&last_ptr->refill_lock);
trace_btrfs_reserve_extent_cluster(root,
block_group, search_start,
num_bytes);
goto checks;
}
} else if (!cached && loop > LOOP_CACHING_NOWAIT
&& !failed_cluster_refill) {
spin_unlock(&last_ptr->refill_lock);
failed_cluster_refill = true;
wait_block_group_cache_progress(block_group,
num_bytes + empty_cluster + empty_size);
goto have_block_group;
}
/*
* at this point we either didn't find a cluster
* or we weren't able to allocate a block from our
* cluster. Free the cluster we've been trying
* to use, and go to the next block group
*/
btrfs_return_cluster_to_free_space(NULL, last_ptr);
spin_unlock(&last_ptr->refill_lock);
goto loop;
}
unclustered_alloc:
spin_lock(&block_group->free_space_ctl->tree_lock);
if (cached &&
block_group->free_space_ctl->free_space <
num_bytes + empty_cluster + empty_size) {
if (block_group->free_space_ctl->free_space >
max_extent_size)
max_extent_size =
block_group->free_space_ctl->free_space;
spin_unlock(&block_group->free_space_ctl->tree_lock);
goto loop;
}
spin_unlock(&block_group->free_space_ctl->tree_lock);
offset = btrfs_find_space_for_alloc(block_group, search_start,
num_bytes, empty_size,
&max_extent_size);
/*
* If we didn't find a chunk, and we haven't failed on this
* block group before, and this block group is in the middle of
* caching and we are ok with waiting, then go ahead and wait
* for progress to be made, and set failed_alloc to true.
*
* If failed_alloc is true then we've already waited on this
* block group once and should move on to the next block group.
*/
if (!offset && !failed_alloc && !cached &&
loop > LOOP_CACHING_NOWAIT) {
wait_block_group_cache_progress(block_group,
num_bytes + empty_size);
failed_alloc = true;
goto have_block_group;
} else if (!offset) {
if (!cached)
have_caching_bg = true;
goto loop;
}
checks:
search_start = ALIGN(offset, root->stripesize);
/* move on to the next group */
if (search_start + num_bytes >
block_group->key.objectid + block_group->key.offset) {
btrfs_add_free_space(block_group, offset, num_bytes);
goto loop;
}
if (offset < search_start)
btrfs_add_free_space(block_group, offset,
search_start - offset);
BUG_ON(offset > search_start);
ret = btrfs_update_reserved_bytes(block_group, num_bytes,
alloc_type, delalloc);
if (ret == -EAGAIN) {
btrfs_add_free_space(block_group, offset, num_bytes);
goto loop;
}
/* we are all good, lets return */
ins->objectid = search_start;
ins->offset = num_bytes;
trace_btrfs_reserve_extent(orig_root, block_group,
search_start, num_bytes);
btrfs_release_block_group(block_group, delalloc);
break;
loop:
failed_cluster_refill = false;
failed_alloc = false;
BUG_ON(index != get_block_group_index(block_group));
btrfs_release_block_group(block_group, delalloc);
}
up_read(&space_info->groups_sem);
if (!ins->objectid && loop >= LOOP_CACHING_WAIT && have_caching_bg)
goto search;
if (!ins->objectid && ++index < BTRFS_NR_RAID_TYPES)
goto search;
/*
* LOOP_CACHING_NOWAIT, search partially cached block groups, kicking
* caching kthreads as we move along
* LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
* LOOP_ALLOC_CHUNK, force a chunk allocation and try again
* LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
* again
*/
if (!ins->objectid && loop < LOOP_NO_EMPTY_SIZE) {
index = 0;
loop++;
if (loop == LOOP_ALLOC_CHUNK) {
struct btrfs_trans_handle *trans;
int exist = 0;
trans = current->journal_info;
if (trans)
exist = 1;
else
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out;
}
ret = do_chunk_alloc(trans, root, flags,
CHUNK_ALLOC_FORCE);
/*
* Do not bail out on ENOSPC since we
* can do more things.
*/
if (ret < 0 && ret != -ENOSPC)
btrfs_abort_transaction(trans,
root, ret);
else
ret = 0;
if (!exist)
btrfs_end_transaction(trans, root);
if (ret)
goto out;
}
if (loop == LOOP_NO_EMPTY_SIZE) {
empty_size = 0;
empty_cluster = 0;
}
goto search;
} else if (!ins->objectid) {
ret = -ENOSPC;
} else if (ins->objectid) {
ret = 0;
}
out:
if (ret == -ENOSPC)
ins->offset = max_extent_size;
return ret;
}
static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
int dump_block_groups)
{
struct btrfs_block_group_cache *cache;
int index = 0;
spin_lock(&info->lock);
printk(KERN_INFO "BTRFS: space_info %llu has %llu free, is %sfull\n",
info->flags,
info->total_bytes - info->bytes_used - info->bytes_pinned -
info->bytes_reserved - info->bytes_readonly,
(info->full) ? "" : "not ");
printk(KERN_INFO "BTRFS: space_info total=%llu, used=%llu, pinned=%llu, "
"reserved=%llu, may_use=%llu, readonly=%llu\n",
info->total_bytes, info->bytes_used, info->bytes_pinned,
info->bytes_reserved, info->bytes_may_use,
info->bytes_readonly);
spin_unlock(&info->lock);
if (!dump_block_groups)
return;
down_read(&info->groups_sem);
again:
list_for_each_entry(cache, &info->block_groups[index], list) {
spin_lock(&cache->lock);
printk(KERN_INFO "BTRFS: "
"block group %llu has %llu bytes, "
"%llu used %llu pinned %llu reserved %s\n",
cache->key.objectid, cache->key.offset,
btrfs_block_group_used(&cache->item), cache->pinned,
cache->reserved, cache->ro ? "[readonly]" : "");
btrfs_dump_free_space(cache, bytes);
spin_unlock(&cache->lock);
}
if (++index < BTRFS_NR_RAID_TYPES)
goto again;
up_read(&info->groups_sem);
}
int btrfs_reserve_extent(struct btrfs_root *root,
u64 num_bytes, u64 min_alloc_size,
u64 empty_size, u64 hint_byte,
struct btrfs_key *ins, int is_data, int delalloc)
{
bool final_tried = false;
u64 flags;
int ret;
flags = btrfs_get_alloc_profile(root, is_data);
again:
WARN_ON(num_bytes < root->sectorsize);
ret = find_free_extent(root, num_bytes, empty_size, hint_byte, ins,
flags, delalloc);
if (ret == -ENOSPC) {
if (!final_tried && ins->offset) {
num_bytes = min(num_bytes >> 1, ins->offset);
num_bytes = round_down(num_bytes, root->sectorsize);
num_bytes = max(num_bytes, min_alloc_size);
if (num_bytes == min_alloc_size)
final_tried = true;
goto again;
} else if (btrfs_test_opt(root, ENOSPC_DEBUG)) {
struct btrfs_space_info *sinfo;
sinfo = __find_space_info(root->fs_info, flags);
btrfs_err(root->fs_info, "allocation failed flags %llu, wanted %llu",
flags, num_bytes);
if (sinfo)
dump_space_info(sinfo, num_bytes, 1);
}
}
return ret;
}
static int __btrfs_free_reserved_extent(struct btrfs_root *root,
u64 start, u64 len,
int pin, int delalloc)
{
struct btrfs_block_group_cache *cache;
int ret = 0;
cache = btrfs_lookup_block_group(root->fs_info, start);
if (!cache) {
btrfs_err(root->fs_info, "Unable to find block group for %llu",
start);
return -ENOSPC;
}
if (pin)
pin_down_extent(root, cache, start, len, 1);
else {
if (btrfs_test_opt(root, DISCARD))
ret = btrfs_discard_extent(root, start, len, NULL);
btrfs_add_free_space(cache, start, len);
btrfs_update_reserved_bytes(cache, len, RESERVE_FREE, delalloc);
}
btrfs_put_block_group(cache);
trace_btrfs_reserved_extent_free(root, start, len);
return ret;
}
int btrfs_free_reserved_extent(struct btrfs_root *root,
u64 start, u64 len, int delalloc)
{
return __btrfs_free_reserved_extent(root, start, len, 0, delalloc);
}
int btrfs_free_and_pin_reserved_extent(struct btrfs_root *root,
u64 start, u64 len)
{
return __btrfs_free_reserved_extent(root, start, len, 1, 0);
}
static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 parent, u64 root_objectid,
u64 flags, u64 owner, u64 offset,
struct btrfs_key *ins, int ref_mod)
{
int ret;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_extent_item *extent_item;
struct btrfs_extent_inline_ref *iref;
struct btrfs_path *path;
struct extent_buffer *leaf;
int type;
u32 size;
if (parent > 0)
type = BTRFS_SHARED_DATA_REF_KEY;
else
type = BTRFS_EXTENT_DATA_REF_KEY;
size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->leave_spinning = 1;
ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
ins, size);
if (ret) {
btrfs_free_path(path);
return ret;
}
leaf = path->nodes[0];
extent_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_item);
btrfs_set_extent_refs(leaf, extent_item, ref_mod);
btrfs_set_extent_generation(leaf, extent_item, trans->transid);
btrfs_set_extent_flags(leaf, extent_item,
flags | BTRFS_EXTENT_FLAG_DATA);
iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
btrfs_set_extent_inline_ref_type(leaf, iref, type);
if (parent > 0) {
struct btrfs_shared_data_ref *ref;
ref = (struct btrfs_shared_data_ref *)(iref + 1);
btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
btrfs_set_shared_data_ref_count(leaf, ref, ref_mod);
} else {
struct btrfs_extent_data_ref *ref;
ref = (struct btrfs_extent_data_ref *)(&iref->offset);
btrfs_set_extent_data_ref_root(leaf, ref, root_objectid);
btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
btrfs_set_extent_data_ref_offset(leaf, ref, offset);
btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
}
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_free_path(path);
/* Always set parent to 0 here since its exclusive anyway. */
ret = btrfs_qgroup_record_ref(trans, fs_info, root_objectid,
ins->objectid, ins->offset,
BTRFS_QGROUP_OPER_ADD_EXCL, 0);
if (ret)
return ret;
ret = update_block_group(trans, root, ins->objectid, ins->offset, 1);
if (ret) { /* -ENOENT, logic error */
btrfs_err(fs_info, "update block group failed for %llu %llu",
ins->objectid, ins->offset);
BUG();
}
trace_btrfs_reserved_extent_alloc(root, ins->objectid, ins->offset);
return ret;
}
static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 parent, u64 root_objectid,
u64 flags, struct btrfs_disk_key *key,
int level, struct btrfs_key *ins,
int no_quota)
{
int ret;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_extent_item *extent_item;
struct btrfs_tree_block_info *block_info;
struct btrfs_extent_inline_ref *iref;
struct btrfs_path *path;
struct extent_buffer *leaf;
u32 size = sizeof(*extent_item) + sizeof(*iref);
u64 num_bytes = ins->offset;
bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
SKINNY_METADATA);
if (!skinny_metadata)
size += sizeof(*block_info);
path = btrfs_alloc_path();
if (!path) {
btrfs_free_and_pin_reserved_extent(root, ins->objectid,
root->nodesize);
return -ENOMEM;
}
path->leave_spinning = 1;
ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
ins, size);
if (ret) {
btrfs_free_path(path);
btrfs_free_and_pin_reserved_extent(root, ins->objectid,
root->nodesize);
return ret;
}
leaf = path->nodes[0];
extent_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_item);
btrfs_set_extent_refs(leaf, extent_item, 1);
btrfs_set_extent_generation(leaf, extent_item, trans->transid);
btrfs_set_extent_flags(leaf, extent_item,
flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
if (skinny_metadata) {
iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
num_bytes = root->nodesize;
} else {
block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
btrfs_set_tree_block_key(leaf, block_info, key);
btrfs_set_tree_block_level(leaf, block_info, level);
iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
}
if (parent > 0) {
BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
btrfs_set_extent_inline_ref_type(leaf, iref,
BTRFS_SHARED_BLOCK_REF_KEY);
btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
} else {
btrfs_set_extent_inline_ref_type(leaf, iref,
BTRFS_TREE_BLOCK_REF_KEY);
btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
}
btrfs_mark_buffer_dirty(leaf);
btrfs_free_path(path);
if (!no_quota) {
ret = btrfs_qgroup_record_ref(trans, fs_info, root_objectid,
ins->objectid, num_bytes,
BTRFS_QGROUP_OPER_ADD_EXCL, 0);
if (ret)
return ret;
}
ret = update_block_group(trans, root, ins->objectid, root->nodesize,
1);
if (ret) { /* -ENOENT, logic error */
btrfs_err(fs_info, "update block group failed for %llu %llu",
ins->objectid, ins->offset);
BUG();
}
trace_btrfs_reserved_extent_alloc(root, ins->objectid, root->nodesize);
return ret;
}
int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 root_objectid, u64 owner,
u64 offset, struct btrfs_key *ins)
{
int ret;
BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
ret = btrfs_add_delayed_data_ref(root->fs_info, trans, ins->objectid,
ins->offset, 0,
root_objectid, owner, offset,
BTRFS_ADD_DELAYED_EXTENT, NULL, 0);
return ret;
}
/*
* this is used by the tree logging recovery code. It records that
* an extent has been allocated and makes sure to clear the free
* space cache bits as well
*/
int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 root_objectid, u64 owner, u64 offset,
struct btrfs_key *ins)
{
int ret;
struct btrfs_block_group_cache *block_group;
/*
* Mixed block groups will exclude before processing the log so we only
* need to do the exlude dance if this fs isn't mixed.
*/
if (!btrfs_fs_incompat(root->fs_info, MIXED_GROUPS)) {
ret = __exclude_logged_extent(root, ins->objectid, ins->offset);
if (ret)
return ret;
}
block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
if (!block_group)
return -EINVAL;
ret = btrfs_update_reserved_bytes(block_group, ins->offset,
RESERVE_ALLOC_NO_ACCOUNT, 0);
BUG_ON(ret); /* logic error */
ret = alloc_reserved_file_extent(trans, root, 0, root_objectid,
0, owner, offset, ins, 1);
btrfs_put_block_group(block_group);
return ret;
}
static struct extent_buffer *
btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root,
u64 bytenr, int level)
{
struct extent_buffer *buf;
buf = btrfs_find_create_tree_block(root, bytenr);
if (!buf)
return ERR_PTR(-ENOMEM);
btrfs_set_header_generation(buf, trans->transid);
btrfs_set_buffer_lockdep_class(root->root_key.objectid, buf, level);
btrfs_tree_lock(buf);
clean_tree_block(trans, root->fs_info, buf);
clear_bit(EXTENT_BUFFER_STALE, &buf->bflags);
btrfs_set_lock_blocking(buf);
btrfs_set_buffer_uptodate(buf);
if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
buf->log_index = root->log_transid % 2;
/*
* we allow two log transactions at a time, use different
* EXENT bit to differentiate dirty pages.
*/
if (buf->log_index == 0)
set_extent_dirty(&root->dirty_log_pages, buf->start,
buf->start + buf->len - 1, GFP_NOFS);
else
set_extent_new(&root->dirty_log_pages, buf->start,
buf->start + buf->len - 1, GFP_NOFS);
} else {
buf->log_index = -1;
set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
buf->start + buf->len - 1, GFP_NOFS);
}
trans->blocks_used++;
/* this returns a buffer locked for blocking */
return buf;
}
static struct btrfs_block_rsv *
use_block_rsv(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u32 blocksize)
{
struct btrfs_block_rsv *block_rsv;
struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
int ret;
bool global_updated = false;
block_rsv = get_block_rsv(trans, root);
if (unlikely(block_rsv->size == 0))
goto try_reserve;
again:
ret = block_rsv_use_bytes(block_rsv, blocksize);
if (!ret)
return block_rsv;
if (block_rsv->failfast)
return ERR_PTR(ret);
if (block_rsv->type == BTRFS_BLOCK_RSV_GLOBAL && !global_updated) {
global_updated = true;
update_global_block_rsv(root->fs_info);
goto again;
}
if (btrfs_test_opt(root, ENOSPC_DEBUG)) {
static DEFINE_RATELIMIT_STATE(_rs,
DEFAULT_RATELIMIT_INTERVAL * 10,
/*DEFAULT_RATELIMIT_BURST*/ 1);
if (__ratelimit(&_rs))
WARN(1, KERN_DEBUG
"BTRFS: block rsv returned %d\n", ret);
}
try_reserve:
ret = reserve_metadata_bytes(root, block_rsv, blocksize,
BTRFS_RESERVE_NO_FLUSH);
if (!ret)
return block_rsv;
/*
* If we couldn't reserve metadata bytes try and use some from
* the global reserve if its space type is the same as the global
* reservation.
*/
if (block_rsv->type != BTRFS_BLOCK_RSV_GLOBAL &&
block_rsv->space_info == global_rsv->space_info) {
ret = block_rsv_use_bytes(global_rsv, blocksize);
if (!ret)
return global_rsv;
}
return ERR_PTR(ret);
}
static void unuse_block_rsv(struct btrfs_fs_info *fs_info,
struct btrfs_block_rsv *block_rsv, u32 blocksize)
{
block_rsv_add_bytes(block_rsv, blocksize, 0);
block_rsv_release_bytes(fs_info, block_rsv, NULL, 0);
}
/*
* finds a free extent and does all the dirty work required for allocation
* returns the key for the extent through ins, and a tree buffer for
* the first block of the extent through buf.
*
* returns the tree buffer or NULL.
*/
struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 parent, u64 root_objectid,
struct btrfs_disk_key *key, int level,
u64 hint, u64 empty_size)
{
struct btrfs_key ins;
struct btrfs_block_rsv *block_rsv;
struct extent_buffer *buf;
u64 flags = 0;
int ret;
u32 blocksize = root->nodesize;
bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
SKINNY_METADATA);
if (btrfs_test_is_dummy_root(root)) {
buf = btrfs_init_new_buffer(trans, root, root->alloc_bytenr,
level);
if (!IS_ERR(buf))
root->alloc_bytenr += blocksize;
return buf;
}
block_rsv = use_block_rsv(trans, root, blocksize);
if (IS_ERR(block_rsv))
return ERR_CAST(block_rsv);
ret = btrfs_reserve_extent(root, blocksize, blocksize,
empty_size, hint, &ins, 0, 0);
if (ret) {
unuse_block_rsv(root->fs_info, block_rsv, blocksize);
return ERR_PTR(ret);
}
buf = btrfs_init_new_buffer(trans, root, ins.objectid, level);
BUG_ON(IS_ERR(buf)); /* -ENOMEM */
if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
if (parent == 0)
parent = ins.objectid;
flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
} else
BUG_ON(parent > 0);
if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
struct btrfs_delayed_extent_op *extent_op;
extent_op = btrfs_alloc_delayed_extent_op();
BUG_ON(!extent_op); /* -ENOMEM */
if (key)
memcpy(&extent_op->key, key, sizeof(extent_op->key));
else
memset(&extent_op->key, 0, sizeof(extent_op->key));
extent_op->flags_to_set = flags;
if (skinny_metadata)
extent_op->update_key = 0;
else
extent_op->update_key = 1;
extent_op->update_flags = 1;
extent_op->is_data = 0;
extent_op->level = level;
ret = btrfs_add_delayed_tree_ref(root->fs_info, trans,
ins.objectid,
ins.offset, parent, root_objectid,
level, BTRFS_ADD_DELAYED_EXTENT,
extent_op, 0);
BUG_ON(ret); /* -ENOMEM */
}
return buf;
}
struct walk_control {
u64 refs[BTRFS_MAX_LEVEL];
u64 flags[BTRFS_MAX_LEVEL];
struct btrfs_key update_progress;
int stage;
int level;
int shared_level;
int update_ref;
int keep_locks;
int reada_slot;
int reada_count;
int for_reloc;
};
#define DROP_REFERENCE 1
#define UPDATE_BACKREF 2
static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct walk_control *wc,
struct btrfs_path *path)
{
u64 bytenr;
u64 generation;
u64 refs;
u64 flags;
u32 nritems;
u32 blocksize;
struct btrfs_key key;
struct extent_buffer *eb;
int ret;
int slot;
int nread = 0;
if (path->slots[wc->level] < wc->reada_slot) {
wc->reada_count = wc->reada_count * 2 / 3;
wc->reada_count = max(wc->reada_count, 2);
} else {
wc->reada_count = wc->reada_count * 3 / 2;
wc->reada_count = min_t(int, wc->reada_count,
BTRFS_NODEPTRS_PER_BLOCK(root));
}
eb = path->nodes[wc->level];
nritems = btrfs_header_nritems(eb);
blocksize = root->nodesize;
for (slot = path->slots[wc->level]; slot < nritems; slot++) {
if (nread >= wc->reada_count)
break;
cond_resched();
bytenr = btrfs_node_blockptr(eb, slot);
generation = btrfs_node_ptr_generation(eb, slot);
if (slot == path->slots[wc->level])
goto reada;
if (wc->stage == UPDATE_BACKREF &&
generation <= root->root_key.offset)
continue;
/* We don't lock the tree block, it's OK to be racy here */
ret = btrfs_lookup_extent_info(trans, root, bytenr,
wc->level - 1, 1, &refs,
&flags);
/* We don't care about errors in readahead. */
if (ret < 0)
continue;
BUG_ON(refs == 0);
if (wc->stage == DROP_REFERENCE) {
if (refs == 1)
goto reada;
if (wc->level == 1 &&
(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
continue;
if (!wc->update_ref ||
generation <= root->root_key.offset)
continue;
btrfs_node_key_to_cpu(eb, &key, slot);
ret = btrfs_comp_cpu_keys(&key,
&wc->update_progress);
if (ret < 0)
continue;
} else {
if (wc->level == 1 &&
(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
continue;
}
reada:
readahead_tree_block(root, bytenr);
nread++;
}
wc->reada_slot = slot;
}
static int account_leaf_items(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *eb)
{
int nr = btrfs_header_nritems(eb);
int i, extent_type, ret;
struct btrfs_key key;
struct btrfs_file_extent_item *fi;
u64 bytenr, num_bytes;
for (i = 0; i < nr; i++) {
btrfs_item_key_to_cpu(eb, &key, i);
if (key.type != BTRFS_EXTENT_DATA_KEY)
continue;
fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
/* filter out non qgroup-accountable extents */
extent_type = btrfs_file_extent_type(eb, fi);
if (extent_type == BTRFS_FILE_EXTENT_INLINE)
continue;
bytenr = btrfs_file_extent_disk_bytenr(eb, fi);
if (!bytenr)
continue;
num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi);
ret = btrfs_qgroup_record_ref(trans, root->fs_info,
root->objectid,
bytenr, num_bytes,
BTRFS_QGROUP_OPER_SUB_SUBTREE, 0);
if (ret)
return ret;
}
return 0;
}
/*
* Walk up the tree from the bottom, freeing leaves and any interior
* nodes which have had all slots visited. If a node (leaf or
* interior) is freed, the node above it will have it's slot
* incremented. The root node will never be freed.
*
* At the end of this function, we should have a path which has all
* slots incremented to the next position for a search. If we need to
* read a new node it will be NULL and the node above it will have the
* correct slot selected for a later read.
*
* If we increment the root nodes slot counter past the number of
* elements, 1 is returned to signal completion of the search.
*/
static int adjust_slots_upwards(struct btrfs_root *root,
struct btrfs_path *path, int root_level)
{
int level = 0;
int nr, slot;
struct extent_buffer *eb;
if (root_level == 0)
return 1;
while (level <= root_level) {
eb = path->nodes[level];
nr = btrfs_header_nritems(eb);
path->slots[level]++;
slot = path->slots[level];
if (slot >= nr || level == 0) {
/*
* Don't free the root - we will detect this
* condition after our loop and return a
* positive value for caller to stop walking the tree.
*/
if (level != root_level) {
btrfs_tree_unlock_rw(eb, path->locks[level]);
path->locks[level] = 0;
free_extent_buffer(eb);
path->nodes[level] = NULL;
path->slots[level] = 0;
}
} else {
/*
* We have a valid slot to walk back down
* from. Stop here so caller can process these
* new nodes.
*/
break;
}
level++;
}
eb = path->nodes[root_level];
if (path->slots[root_level] >= btrfs_header_nritems(eb))
return 1;
return 0;
}
/*
* root_eb is the subtree root and is locked before this function is called.
*/
static int account_shared_subtree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *root_eb,
u64 root_gen,
int root_level)
{
int ret = 0;
int level;
struct extent_buffer *eb = root_eb;
struct btrfs_path *path = NULL;
BUG_ON(root_level < 0 || root_level > BTRFS_MAX_LEVEL);
BUG_ON(root_eb == NULL);
if (!root->fs_info->quota_enabled)
return 0;
if (!extent_buffer_uptodate(root_eb)) {
ret = btrfs_read_buffer(root_eb, root_gen);
if (ret)
goto out;
}
if (root_level == 0) {
ret = account_leaf_items(trans, root, root_eb);
goto out;
}
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/*
* Walk down the tree. Missing extent blocks are filled in as
* we go. Metadata is accounted every time we read a new
* extent block.
*
* When we reach a leaf, we account for file extent items in it,
* walk back up the tree (adjusting slot pointers as we go)
* and restart the search process.
*/
extent_buffer_get(root_eb); /* For path */
path->nodes[root_level] = root_eb;
path->slots[root_level] = 0;
path->locks[root_level] = 0; /* so release_path doesn't try to unlock */
walk_down:
level = root_level;
while (level >= 0) {
if (path->nodes[level] == NULL) {
int parent_slot;
u64 child_gen;
u64 child_bytenr;
/* We need to get child blockptr/gen from
* parent before we can read it. */
eb = path->nodes[level + 1];
parent_slot = path->slots[level + 1];
child_bytenr = btrfs_node_blockptr(eb, parent_slot);
child_gen = btrfs_node_ptr_generation(eb, parent_slot);
eb = read_tree_block(root, child_bytenr, child_gen);
if (!eb || !extent_buffer_uptodate(eb)) {
ret = -EIO;
goto out;
}
path->nodes[level] = eb;
path->slots[level] = 0;
btrfs_tree_read_lock(eb);
btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
path->locks[level] = BTRFS_READ_LOCK_BLOCKING;
ret = btrfs_qgroup_record_ref(trans, root->fs_info,
root->objectid,
child_bytenr,
root->nodesize,
BTRFS_QGROUP_OPER_SUB_SUBTREE,
0);
if (ret)
goto out;
}
if (level == 0) {
ret = account_leaf_items(trans, root, path->nodes[level]);
if (ret)
goto out;
/* Nonzero return here means we completed our search */
ret = adjust_slots_upwards(root, path, root_level);
if (ret)
break;
/* Restart search with new slots */
goto walk_down;
}
level--;
}
ret = 0;
out:
btrfs_free_path(path);
return ret;
}
/*
* helper to process tree block while walking down the tree.
*
* when wc->stage == UPDATE_BACKREF, this function updates
* back refs for pointers in the block.
*
* NOTE: return value 1 means we should stop walking down.
*/
static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct walk_control *wc, int lookup_info)
{
int level = wc->level;
struct extent_buffer *eb = path->nodes[level];
u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF;
int ret;
if (wc->stage == UPDATE_BACKREF &&
btrfs_header_owner(eb) != root->root_key.objectid)
return 1;
/*
* when reference count of tree block is 1, it won't increase
* again. once full backref flag is set, we never clear it.
*/
if (lookup_info &&
((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
(wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) {
BUG_ON(!path->locks[level]);
ret = btrfs_lookup_extent_info(trans, root,
eb->start, level, 1,
&wc->refs[level],
&wc->flags[level]);
BUG_ON(ret == -ENOMEM);
if (ret)
return ret;
BUG_ON(wc->refs[level] == 0);
}
if (wc->stage == DROP_REFERENCE) {
if (wc->refs[level] > 1)
return 1;
if (path->locks[level] && !wc->keep_locks) {
btrfs_tree_unlock_rw(eb, path->locks[level]);
path->locks[level] = 0;
}
return 0;
}
/* wc->stage == UPDATE_BACKREF */
if (!(wc->flags[level] & flag)) {
BUG_ON(!path->locks[level]);
ret = btrfs_inc_ref(trans, root, eb, 1);
BUG_ON(ret); /* -ENOMEM */
ret = btrfs_dec_ref(trans, root, eb, 0);
BUG_ON(ret); /* -ENOMEM */
ret = btrfs_set_disk_extent_flags(trans, root, eb->start,
eb->len, flag,
btrfs_header_level(eb), 0);
BUG_ON(ret); /* -ENOMEM */
wc->flags[level] |= flag;
}
/*
* the block is shared by multiple trees, so it's not good to
* keep the tree lock
*/
if (path->locks[level] && level > 0) {
btrfs_tree_unlock_rw(eb, path->locks[level]);
path->locks[level] = 0;
}
return 0;
}
/*
* helper to process tree block pointer.
*
* when wc->stage == DROP_REFERENCE, this function checks
* reference count of the block pointed to. if the block
* is shared and we need update back refs for the subtree
* rooted at the block, this function changes wc->stage to
* UPDATE_BACKREF. if the block is shared and there is no
* need to update back, this function drops the reference
* to the block.
*
* NOTE: return value 1 means we should stop walking down.
*/
static noinline int do_walk_down(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct walk_control *wc, int *lookup_info)
{
u64 bytenr;
u64 generation;
u64 parent;
u32 blocksize;
struct btrfs_key key;
struct extent_buffer *next;
int level = wc->level;
int reada = 0;
int ret = 0;
bool need_account = false;
generation = btrfs_node_ptr_generation(path->nodes[level],
path->slots[level]);
/*
* if the lower level block was created before the snapshot
* was created, we know there is no need to update back refs
* for the subtree
*/
if (wc->stage == UPDATE_BACKREF &&
generation <= root->root_key.offset) {
*lookup_info = 1;
return 1;
}
bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
blocksize = root->nodesize;
next = btrfs_find_tree_block(root->fs_info, bytenr);
if (!next) {
next = btrfs_find_create_tree_block(root, bytenr);
if (!next)
return -ENOMEM;
btrfs_set_buffer_lockdep_class(root->root_key.objectid, next,
level - 1);
reada = 1;
}
btrfs_tree_lock(next);
btrfs_set_lock_blocking(next);
ret = btrfs_lookup_extent_info(trans, root, bytenr, level - 1, 1,
&wc->refs[level - 1],
&wc->flags[level - 1]);
if (ret < 0) {
btrfs_tree_unlock(next);
return ret;
}
if (unlikely(wc->refs[level - 1] == 0)) {
btrfs_err(root->fs_info, "Missing references.");
BUG();
}
*lookup_info = 0;
if (wc->stage == DROP_REFERENCE) {
if (wc->refs[level - 1] > 1) {
need_account = true;
if (level == 1 &&
(wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
goto skip;
if (!wc->update_ref ||
generation <= root->root_key.offset)
goto skip;
btrfs_node_key_to_cpu(path->nodes[level], &key,
path->slots[level]);
ret = btrfs_comp_cpu_keys(&key, &wc->update_progress);
if (ret < 0)
goto skip;
wc->stage = UPDATE_BACKREF;
wc->shared_level = level - 1;
}
} else {
if (level == 1 &&
(wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
goto skip;
}
if (!btrfs_buffer_uptodate(next, generation, 0)) {
btrfs_tree_unlock(next);
free_extent_buffer(next);
next = NULL;
*lookup_info = 1;
}
if (!next) {
if (reada && level == 1)
reada_walk_down(trans, root, wc, path);
next = read_tree_block(root, bytenr, generation);
if (!next || !extent_buffer_uptodate(next)) {
free_extent_buffer(next);
return -EIO;
}
btrfs_tree_lock(next);
btrfs_set_lock_blocking(next);
}
level--;
BUG_ON(level != btrfs_header_level(next));
path->nodes[level] = next;
path->slots[level] = 0;
path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
wc->level = level;
if (wc->level == 1)
wc->reada_slot = 0;
return 0;
skip:
wc->refs[level - 1] = 0;
wc->flags[level - 1] = 0;
if (wc->stage == DROP_REFERENCE) {
if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
parent = path->nodes[level]->start;
} else {
BUG_ON(root->root_key.objectid !=
btrfs_header_owner(path->nodes[level]));
parent = 0;
}
if (need_account) {
ret = account_shared_subtree(trans, root, next,
generation, level - 1);
if (ret) {
printk_ratelimited(KERN_ERR "BTRFS: %s Error "
"%d accounting shared subtree. Quota "
"is out of sync, rescan required.\n",
root->fs_info->sb->s_id, ret);
}
}
ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
root->root_key.objectid, level - 1, 0, 0);
BUG_ON(ret); /* -ENOMEM */
}
btrfs_tree_unlock(next);
free_extent_buffer(next);
*lookup_info = 1;
return 1;
}
/*
* helper to process tree block while walking up the tree.
*
* when wc->stage == DROP_REFERENCE, this function drops
* reference count on the block.
*
* when wc->stage == UPDATE_BACKREF, this function changes
* wc->stage back to DROP_REFERENCE if we changed wc->stage
* to UPDATE_BACKREF previously while processing the block.
*
* NOTE: return value 1 means we should stop walking up.
*/
static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct walk_control *wc)
{
int ret;
int level = wc->level;
struct extent_buffer *eb = path->nodes[level];
u64 parent = 0;
if (wc->stage == UPDATE_BACKREF) {
BUG_ON(wc->shared_level < level);
if (level < wc->shared_level)
goto out;
ret = find_next_key(path, level + 1, &wc->update_progress);
if (ret > 0)
wc->update_ref = 0;
wc->stage = DROP_REFERENCE;
wc->shared_level = -1;
path->slots[level] = 0;
/*
* check reference count again if the block isn't locked.
* we should start walking down the tree again if reference
* count is one.
*/
if (!path->locks[level]) {
BUG_ON(level == 0);
btrfs_tree_lock(eb);
btrfs_set_lock_blocking(eb);
path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
ret = btrfs_lookup_extent_info(trans, root,
eb->start, level, 1,
&wc->refs[level],
&wc->flags[level]);
if (ret < 0) {
btrfs_tree_unlock_rw(eb, path->locks[level]);
path->locks[level] = 0;
return ret;
}
BUG_ON(wc->refs[level] == 0);
if (wc->refs[level] == 1) {
btrfs_tree_unlock_rw(eb, path->locks[level]);
path->locks[level] = 0;
return 1;
}
}
}
/* wc->stage == DROP_REFERENCE */
BUG_ON(wc->refs[level] > 1 && !path->locks[level]);
if (wc->refs[level] == 1) {
if (level == 0) {
if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
ret = btrfs_dec_ref(trans, root, eb, 1);
else
ret = btrfs_dec_ref(trans, root, eb, 0);
BUG_ON(ret); /* -ENOMEM */
ret = account_leaf_items(trans, root, eb);
if (ret) {
printk_ratelimited(KERN_ERR "BTRFS: %s Error "
"%d accounting leaf items. Quota "
"is out of sync, rescan required.\n",
root->fs_info->sb->s_id, ret);
}
}
/* make block locked assertion in clean_tree_block happy */
if (!path->locks[level] &&
btrfs_header_generation(eb) == trans->transid) {
btrfs_tree_lock(eb);
btrfs_set_lock_blocking(eb);
path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
}
clean_tree_block(trans, root->fs_info, eb);
}
if (eb == root->node) {
if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
parent = eb->start;
else
BUG_ON(root->root_key.objectid !=
btrfs_header_owner(eb));
} else {
if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
parent = path->nodes[level + 1]->start;
else
BUG_ON(root->root_key.objectid !=
btrfs_header_owner(path->nodes[level + 1]));
}
btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1);
out:
wc->refs[level] = 0;
wc->flags[level] = 0;
return 0;
}
static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct walk_control *wc)
{
int level = wc->level;
int lookup_info = 1;
int ret;
while (level >= 0) {
ret = walk_down_proc(trans, root, path, wc, lookup_info);
if (ret > 0)
break;
if (level == 0)
break;
if (path->slots[level] >=
btrfs_header_nritems(path->nodes[level]))
break;
ret = do_walk_down(trans, root, path, wc, &lookup_info);
if (ret > 0) {
path->slots[level]++;
continue;
} else if (ret < 0)
return ret;
level = wc->level;
}
return 0;
}
static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct walk_control *wc, int max_level)
{
int level = wc->level;
int ret;
path->slots[level] = btrfs_header_nritems(path->nodes[level]);
while (level < max_level && path->nodes[level]) {
wc->level = level;
if (path->slots[level] + 1 <
btrfs_header_nritems(path->nodes[level])) {
path->slots[level]++;
return 0;
} else {
ret = walk_up_proc(trans, root, path, wc);
if (ret > 0)
return 0;
if (path->locks[level]) {
btrfs_tree_unlock_rw(path->nodes[level],
path->locks[level]);
path->locks[level] = 0;
}
free_extent_buffer(path->nodes[level]);
path->nodes[level] = NULL;
level++;
}
}
return 1;
}
/*
* drop a subvolume tree.
*
* this function traverses the tree freeing any blocks that only
* referenced by the tree.
*
* when a shared tree block is found. this function decreases its
* reference count by one. if update_ref is true, this function
* also make sure backrefs for the shared block and all lower level
* blocks are properly updated.
*
* If called with for_reloc == 0, may exit early with -EAGAIN
*/
int btrfs_drop_snapshot(struct btrfs_root *root,
struct btrfs_block_rsv *block_rsv, int update_ref,
int for_reloc)
{
struct btrfs_path *path;
struct btrfs_trans_handle *trans;
struct btrfs_root *tree_root = root->fs_info->tree_root;
struct btrfs_root_item *root_item = &root->root_item;
struct walk_control *wc;
struct btrfs_key key;
int err = 0;
int ret;
int level;
bool root_dropped = false;
btrfs_debug(root->fs_info, "Drop subvolume %llu", root->objectid);
path = btrfs_alloc_path();
if (!path) {
err = -ENOMEM;
goto out;
}
wc = kzalloc(sizeof(*wc), GFP_NOFS);
if (!wc) {
btrfs_free_path(path);
err = -ENOMEM;
goto out;
}
trans = btrfs_start_transaction(tree_root, 0);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
goto out_free;
}
if (block_rsv)
trans->block_rsv = block_rsv;
if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
level = btrfs_header_level(root->node);
path->nodes[level] = btrfs_lock_root_node(root);
btrfs_set_lock_blocking(path->nodes[level]);
path->slots[level] = 0;
path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
memset(&wc->update_progress, 0,
sizeof(wc->update_progress));
} else {
btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
memcpy(&wc->update_progress, &key,
sizeof(wc->update_progress));
level = root_item->drop_level;
BUG_ON(level == 0);
path->lowest_level = level;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
path->lowest_level = 0;
if (ret < 0) {
err = ret;
goto out_end_trans;
}
WARN_ON(ret > 0);
/*
* unlock our path, this is safe because only this
* function is allowed to delete this snapshot
*/
btrfs_unlock_up_safe(path, 0);
level = btrfs_header_level(root->node);
while (1) {
btrfs_tree_lock(path->nodes[level]);
btrfs_set_lock_blocking(path->nodes[level]);
path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
ret = btrfs_lookup_extent_info(trans, root,
path->nodes[level]->start,
level, 1, &wc->refs[level],
&wc->flags[level]);
if (ret < 0) {
err = ret;
goto out_end_trans;
}
BUG_ON(wc->refs[level] == 0);
if (level == root_item->drop_level)
break;
btrfs_tree_unlock(path->nodes[level]);
path->locks[level] = 0;
WARN_ON(wc->refs[level] != 1);
level--;
}
}
wc->level = level;
wc->shared_level = -1;
wc->stage = DROP_REFERENCE;
wc->update_ref = update_ref;
wc->keep_locks = 0;
wc->for_reloc = for_reloc;
wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
while (1) {
ret = walk_down_tree(trans, root, path, wc);
if (ret < 0) {
err = ret;
break;
}
ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL);
if (ret < 0) {
err = ret;
break;
}
if (ret > 0) {
BUG_ON(wc->stage != DROP_REFERENCE);
break;
}
if (wc->stage == DROP_REFERENCE) {
level = wc->level;
btrfs_node_key(path->nodes[level],
&root_item->drop_progress,
path->slots[level]);
root_item->drop_level = level;
}
BUG_ON(wc->level == 0);
if (btrfs_should_end_transaction(trans, tree_root) ||
(!for_reloc && btrfs_need_cleaner_sleep(root))) {
ret = btrfs_update_root(trans, tree_root,
&root->root_key,
root_item);
if (ret) {
btrfs_abort_transaction(trans, tree_root, ret);
err = ret;
goto out_end_trans;
}
/*
* Qgroup update accounting is run from
* delayed ref handling. This usually works
* out because delayed refs are normally the
* only way qgroup updates are added. However,
* we may have added updates during our tree
* walk so run qgroups here to make sure we
* don't lose any updates.
*/
ret = btrfs_delayed_qgroup_accounting(trans,
root->fs_info);
if (ret)
printk_ratelimited(KERN_ERR "BTRFS: Failure %d "
"running qgroup updates "
"during snapshot delete. "
"Quota is out of sync, "
"rescan required.\n", ret);
btrfs_end_transaction_throttle(trans, tree_root);
if (!for_reloc && btrfs_need_cleaner_sleep(root)) {
pr_debug("BTRFS: drop snapshot early exit\n");
err = -EAGAIN;
goto out_free;
}
trans = btrfs_start_transaction(tree_root, 0);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
goto out_free;
}
if (block_rsv)
trans->block_rsv = block_rsv;
}
}
btrfs_release_path(path);
if (err)
goto out_end_trans;
ret = btrfs_del_root(trans, tree_root, &root->root_key);
if (ret) {
btrfs_abort_transaction(trans, tree_root, ret);
goto out_end_trans;
}
if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
ret = btrfs_find_root(tree_root, &root->root_key, path,
NULL, NULL);
if (ret < 0) {
btrfs_abort_transaction(trans, tree_root, ret);
err = ret;
goto out_end_trans;
} else if (ret > 0) {
/* if we fail to delete the orphan item this time
* around, it'll get picked up the next time.
*
* The most common failure here is just -ENOENT.
*/
btrfs_del_orphan_item(trans, tree_root,
root->root_key.objectid);
}
}
if (test_bit(BTRFS_ROOT_IN_RADIX, &root->state)) {
btrfs_drop_and_free_fs_root(tree_root->fs_info, root);
} else {
free_extent_buffer(root->node);
free_extent_buffer(root->commit_root);
btrfs_put_fs_root(root);
}
root_dropped = true;
out_end_trans:
ret = btrfs_delayed_qgroup_accounting(trans, tree_root->fs_info);
if (ret)
printk_ratelimited(KERN_ERR "BTRFS: Failure %d "
"running qgroup updates "
"during snapshot delete. "
"Quota is out of sync, "
"rescan required.\n", ret);
btrfs_end_transaction_throttle(trans, tree_root);
out_free:
kfree(wc);
btrfs_free_path(path);
out:
/*
* So if we need to stop dropping the snapshot for whatever reason we
* need to make sure to add it back to the dead root list so that we
* keep trying to do the work later. This also cleans up roots if we
* don't have it in the radix (like when we recover after a power fail
* or unmount) so we don't leak memory.
*/
if (!for_reloc && root_dropped == false)
btrfs_add_dead_root(root);
if (err && err != -EAGAIN)
btrfs_std_error(root->fs_info, err);
return err;
}
/*
* drop subtree rooted at tree block 'node'.
*
* NOTE: this function will unlock and release tree block 'node'
* only used by relocation code
*/
int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *node,
struct extent_buffer *parent)
{
struct btrfs_path *path;
struct walk_control *wc;
int level;
int parent_level;
int ret = 0;
int wret;
BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
wc = kzalloc(sizeof(*wc), GFP_NOFS);
if (!wc) {
btrfs_free_path(path);
return -ENOMEM;
}
btrfs_assert_tree_locked(parent);
parent_level = btrfs_header_level(parent);
extent_buffer_get(parent);
path->nodes[parent_level] = parent;
path->slots[parent_level] = btrfs_header_nritems(parent);
btrfs_assert_tree_locked(node);
level = btrfs_header_level(node);
path->nodes[level] = node;
path->slots[level] = 0;
path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
wc->refs[parent_level] = 1;
wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
wc->level = level;
wc->shared_level = -1;
wc->stage = DROP_REFERENCE;
wc->update_ref = 0;
wc->keep_locks = 1;
wc->for_reloc = 1;
wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
while (1) {
wret = walk_down_tree(trans, root, path, wc);
if (wret < 0) {
ret = wret;
break;
}
wret = walk_up_tree(trans, root, path, wc, parent_level);
if (wret < 0)
ret = wret;
if (wret != 0)
break;
}
kfree(wc);
btrfs_free_path(path);
return ret;
}
static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
{
u64 num_devices;
u64 stripped;
/*
* if restripe for this chunk_type is on pick target profile and
* return, otherwise do the usual balance
*/
stripped = get_restripe_target(root->fs_info, flags);
if (stripped)
return extended_to_chunk(stripped);
num_devices = root->fs_info->fs_devices->rw_devices;
stripped = BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 |
BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
if (num_devices == 1) {
stripped |= BTRFS_BLOCK_GROUP_DUP;
stripped = flags & ~stripped;
/* turn raid0 into single device chunks */
if (flags & BTRFS_BLOCK_GROUP_RAID0)
return stripped;
/* turn mirroring into duplication */
if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10))
return stripped | BTRFS_BLOCK_GROUP_DUP;
} else {
/* they already had raid on here, just return */
if (flags & stripped)
return flags;
stripped |= BTRFS_BLOCK_GROUP_DUP;
stripped = flags & ~stripped;
/* switch duplicated blocks with raid1 */
if (flags & BTRFS_BLOCK_GROUP_DUP)
return stripped | BTRFS_BLOCK_GROUP_RAID1;
/* this is drive concat, leave it alone */
}
return flags;
}
static int set_block_group_ro(struct btrfs_block_group_cache *cache, int force)
{
struct btrfs_space_info *sinfo = cache->space_info;
u64 num_bytes;
u64 min_allocable_bytes;
int ret = -ENOSPC;
/*
* We need some metadata space and system metadata space for
* allocating chunks in some corner cases until we force to set
* it to be readonly.
*/
if ((sinfo->flags &
(BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA)) &&
!force)
min_allocable_bytes = 1 * 1024 * 1024;
else
min_allocable_bytes = 0;
spin_lock(&sinfo->lock);
spin_lock(&cache->lock);
if (cache->ro) {
ret = 0;
goto out;
}
num_bytes = cache->key.offset - cache->reserved - cache->pinned -
cache->bytes_super - btrfs_block_group_used(&cache->item);
if (sinfo->bytes_used + sinfo->bytes_reserved + sinfo->bytes_pinned +
sinfo->bytes_may_use + sinfo->bytes_readonly + num_bytes +
min_allocable_bytes <= sinfo->total_bytes) {
sinfo->bytes_readonly += num_bytes;
cache->ro = 1;
list_add_tail(&cache->ro_list, &sinfo->ro_bgs);
ret = 0;
}
out:
spin_unlock(&cache->lock);
spin_unlock(&sinfo->lock);
return ret;
}
int btrfs_set_block_group_ro(struct btrfs_root *root,
struct btrfs_block_group_cache *cache)
{
struct btrfs_trans_handle *trans;
u64 alloc_flags;
int ret;
BUG_ON(cache->ro);
again:
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
return PTR_ERR(trans);
/*
* we're not allowed to set block groups readonly after the dirty
* block groups cache has started writing. If it already started,
* back off and let this transaction commit
*/
mutex_lock(&root->fs_info->ro_block_group_mutex);
if (trans->transaction->dirty_bg_run) {
u64 transid = trans->transid;
mutex_unlock(&root->fs_info->ro_block_group_mutex);
btrfs_end_transaction(trans, root);
ret = btrfs_wait_for_commit(root, transid);
if (ret)
return ret;
goto again;
}
ret = set_block_group_ro(cache, 0);
if (!ret)
goto out;
alloc_flags = get_alloc_profile(root, cache->space_info->flags);
ret = do_chunk_alloc(trans, root, alloc_flags,
CHUNK_ALLOC_FORCE);
if (ret < 0)
goto out;
ret = set_block_group_ro(cache, 0);
out:
if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
alloc_flags = update_block_group_flags(root, cache->flags);
check_system_chunk(trans, root, alloc_flags);
}
mutex_unlock(&root->fs_info->ro_block_group_mutex);
btrfs_end_transaction(trans, root);
return ret;
}
int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 type)
{
u64 alloc_flags = get_alloc_profile(root, type);
return do_chunk_alloc(trans, root, alloc_flags,
CHUNK_ALLOC_FORCE);
}
/*
* helper to account the unused space of all the readonly block group in the
* space_info. takes mirrors into account.
*/
u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo)
{
struct btrfs_block_group_cache *block_group;
u64 free_bytes = 0;
int factor;
/* It's df, we don't care if it's racey */
if (list_empty(&sinfo->ro_bgs))
return 0;
spin_lock(&sinfo->lock);
list_for_each_entry(block_group, &sinfo->ro_bgs, ro_list) {
spin_lock(&block_group->lock);
if (!block_group->ro) {
spin_unlock(&block_group->lock);
continue;
}
if (block_group->flags & (BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10 |
BTRFS_BLOCK_GROUP_DUP))
factor = 2;
else
factor = 1;
free_bytes += (block_group->key.offset -
btrfs_block_group_used(&block_group->item)) *
factor;
spin_unlock(&block_group->lock);
}
spin_unlock(&sinfo->lock);
return free_bytes;
}
void btrfs_set_block_group_rw(struct btrfs_root *root,
struct btrfs_block_group_cache *cache)
{
struct btrfs_space_info *sinfo = cache->space_info;
u64 num_bytes;
BUG_ON(!cache->ro);
spin_lock(&sinfo->lock);
spin_lock(&cache->lock);
num_bytes = cache->key.offset - cache->reserved - cache->pinned -
cache->bytes_super - btrfs_block_group_used(&cache->item);
sinfo->bytes_readonly -= num_bytes;
cache->ro = 0;
list_del_init(&cache->ro_list);
spin_unlock(&cache->lock);
spin_unlock(&sinfo->lock);
}
/*
* checks to see if its even possible to relocate this block group.
*
* @return - -1 if it's not a good idea to relocate this block group, 0 if its
* ok to go ahead and try.
*/
int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
{
struct btrfs_block_group_cache *block_group;
struct btrfs_space_info *space_info;
struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
struct btrfs_device *device;
struct btrfs_trans_handle *trans;
u64 min_free;
u64 dev_min = 1;
u64 dev_nr = 0;
u64 target;
int index;
int full = 0;
int ret = 0;
block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
/* odd, couldn't find the block group, leave it alone */
if (!block_group)
return -1;
min_free = btrfs_block_group_used(&block_group->item);
/* no bytes used, we're good */
if (!min_free)
goto out;
space_info = block_group->space_info;
spin_lock(&space_info->lock);
full = space_info->full;
/*
* if this is the last block group we have in this space, we can't
* relocate it unless we're able to allocate a new chunk below.
*
* Otherwise, we need to make sure we have room in the space to handle
* all of the extents from this block group. If we can, we're good
*/
if ((space_info->total_bytes != block_group->key.offset) &&
(space_info->bytes_used + space_info->bytes_reserved +
space_info->bytes_pinned + space_info->bytes_readonly +
min_free < space_info->total_bytes)) {
spin_unlock(&space_info->lock);
goto out;
}
spin_unlock(&space_info->lock);
/*
* ok we don't have enough space, but maybe we have free space on our
* devices to allocate new chunks for relocation, so loop through our
* alloc devices and guess if we have enough space. if this block
* group is going to be restriped, run checks against the target
* profile instead of the current one.
*/
ret = -1;
/*
* index:
* 0: raid10
* 1: raid1
* 2: dup
* 3: raid0
* 4: single
*/
target = get_restripe_target(root->fs_info, block_group->flags);
if (target) {
index = __get_raid_index(extended_to_chunk(target));
} else {
/*
* this is just a balance, so if we were marked as full
* we know there is no space for a new chunk
*/
if (full)
goto out;
index = get_block_group_index(block_group);
}
if (index == BTRFS_RAID_RAID10) {
dev_min = 4;
/* Divide by 2 */
min_free >>= 1;
} else if (index == BTRFS_RAID_RAID1) {
dev_min = 2;
} else if (index == BTRFS_RAID_DUP) {
/* Multiply by 2 */
min_free <<= 1;
} else if (index == BTRFS_RAID_RAID0) {
dev_min = fs_devices->rw_devices;
min_free = div64_u64(min_free, dev_min);
}
/* We need to do this so that we can look at pending chunks */
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out;
}
mutex_lock(&root->fs_info->chunk_mutex);
list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
u64 dev_offset;
/*
* check to make sure we can actually find a chunk with enough
* space to fit our block group in.
*/
if (device->total_bytes > device->bytes_used + min_free &&
!device->is_tgtdev_for_dev_replace) {
ret = find_free_dev_extent(trans, device, min_free,
&dev_offset, NULL);
if (!ret)
dev_nr++;
if (dev_nr >= dev_min)
break;
ret = -1;
}
}
mutex_unlock(&root->fs_info->chunk_mutex);
btrfs_end_transaction(trans, root);
out:
btrfs_put_block_group(block_group);
return ret;
}
static int find_first_block_group(struct btrfs_root *root,
struct btrfs_path *path, struct btrfs_key *key)
{
int ret = 0;
struct btrfs_key found_key;
struct extent_buffer *leaf;
int slot;
ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
if (ret < 0)
goto out;
while (1) {
slot = path->slots[0];
leaf = path->nodes[0];
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret == 0)
continue;
if (ret < 0)
goto out;
break;
}
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.objectid >= key->objectid &&
found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
ret = 0;
goto out;
}
path->slots[0]++;
}
out:
return ret;
}
void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
{
struct btrfs_block_group_cache *block_group;
u64 last = 0;
while (1) {
struct inode *inode;
block_group = btrfs_lookup_first_block_group(info, last);
while (block_group) {
spin_lock(&block_group->lock);
if (block_group->iref)
break;
spin_unlock(&block_group->lock);
block_group = next_block_group(info->tree_root,
block_group);
}
if (!block_group) {
if (last == 0)
break;
last = 0;
continue;
}
inode = block_group->inode;
block_group->iref = 0;
block_group->inode = NULL;
spin_unlock(&block_group->lock);
iput(inode);
last = block_group->key.objectid + block_group->key.offset;
btrfs_put_block_group(block_group);
}
}
int btrfs_free_block_groups(struct btrfs_fs_info *info)
{
struct btrfs_block_group_cache *block_group;
struct btrfs_space_info *space_info;
struct btrfs_caching_control *caching_ctl;
struct rb_node *n;
down_write(&info->commit_root_sem);
while (!list_empty(&info->caching_block_groups)) {
caching_ctl = list_entry(info->caching_block_groups.next,
struct btrfs_caching_control, list);
list_del(&caching_ctl->list);
put_caching_control(caching_ctl);
}
up_write(&info->commit_root_sem);
spin_lock(&info->unused_bgs_lock);
while (!list_empty(&info->unused_bgs)) {
block_group = list_first_entry(&info->unused_bgs,
struct btrfs_block_group_cache,
bg_list);
list_del_init(&block_group->bg_list);
btrfs_put_block_group(block_group);
}
spin_unlock(&info->unused_bgs_lock);
spin_lock(&info->block_group_cache_lock);
while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
block_group = rb_entry(n, struct btrfs_block_group_cache,
cache_node);
rb_erase(&block_group->cache_node,
&info->block_group_cache_tree);
RB_CLEAR_NODE(&block_group->cache_node);
spin_unlock(&info->block_group_cache_lock);
down_write(&block_group->space_info->groups_sem);
list_del(&block_group->list);
up_write(&block_group->space_info->groups_sem);
if (block_group->cached == BTRFS_CACHE_STARTED)
wait_block_group_cache_done(block_group);
/*
* We haven't cached this block group, which means we could
* possibly have excluded extents on this block group.
*/
if (block_group->cached == BTRFS_CACHE_NO ||
block_group->cached == BTRFS_CACHE_ERROR)
free_excluded_extents(info->extent_root, block_group);
btrfs_remove_free_space_cache(block_group);
btrfs_put_block_group(block_group);
spin_lock(&info->block_group_cache_lock);
}
spin_unlock(&info->block_group_cache_lock);
/* now that all the block groups are freed, go through and
* free all the space_info structs. This is only called during
* the final stages of unmount, and so we know nobody is
* using them. We call synchronize_rcu() once before we start,
* just to be on the safe side.
*/
synchronize_rcu();
release_global_block_rsv(info);
while (!list_empty(&info->space_info)) {
int i;
space_info = list_entry(info->space_info.next,
struct btrfs_space_info,
list);
if (btrfs_test_opt(info->tree_root, ENOSPC_DEBUG)) {
if (WARN_ON(space_info->bytes_pinned > 0 ||
space_info->bytes_reserved > 0 ||
space_info->bytes_may_use > 0)) {
dump_space_info(space_info, 0, 0);
}
}
list_del(&space_info->list);
for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
struct kobject *kobj;
kobj = space_info->block_group_kobjs[i];
space_info->block_group_kobjs[i] = NULL;
if (kobj) {
kobject_del(kobj);
kobject_put(kobj);
}
}
kobject_del(&space_info->kobj);
kobject_put(&space_info->kobj);
}
return 0;
}
static void __link_block_group(struct btrfs_space_info *space_info,
struct btrfs_block_group_cache *cache)
{
int index = get_block_group_index(cache);
bool first = false;
down_write(&space_info->groups_sem);
if (list_empty(&space_info->block_groups[index]))
first = true;
list_add_tail(&cache->list, &space_info->block_groups[index]);
up_write(&space_info->groups_sem);
if (first) {
struct raid_kobject *rkobj;
int ret;
rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
if (!rkobj)
goto out_err;
rkobj->raid_type = index;
kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
ret = kobject_add(&rkobj->kobj, &space_info->kobj,
"%s", get_raid_name(index));
if (ret) {
kobject_put(&rkobj->kobj);
goto out_err;
}
space_info->block_group_kobjs[index] = &rkobj->kobj;
}
return;
out_err:
pr_warn("BTRFS: failed to add kobject for block cache. ignoring.\n");
}
static struct btrfs_block_group_cache *
btrfs_create_block_group_cache(struct btrfs_root *root, u64 start, u64 size)
{
struct btrfs_block_group_cache *cache;
cache = kzalloc(sizeof(*cache), GFP_NOFS);
if (!cache)
return NULL;
cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),
GFP_NOFS);
if (!cache->free_space_ctl) {
kfree(cache);
return NULL;
}
cache->key.objectid = start;
cache->key.offset = size;
cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
cache->sectorsize = root->sectorsize;
cache->fs_info = root->fs_info;
cache->full_stripe_len = btrfs_full_stripe_len(root,
&root->fs_info->mapping_tree,
start);
atomic_set(&cache->count, 1);
spin_lock_init(&cache->lock);
init_rwsem(&cache->data_rwsem);
INIT_LIST_HEAD(&cache->list);
INIT_LIST_HEAD(&cache->cluster_list);
INIT_LIST_HEAD(&cache->bg_list);
INIT_LIST_HEAD(&cache->ro_list);
INIT_LIST_HEAD(&cache->dirty_list);
INIT_LIST_HEAD(&cache->io_list);
btrfs_init_free_space_ctl(cache);
atomic_set(&cache->trimming, 0);
return cache;
}
int btrfs_read_block_groups(struct btrfs_root *root)
{
struct btrfs_path *path;
int ret;
struct btrfs_block_group_cache *cache;
struct btrfs_fs_info *info = root->fs_info;
struct btrfs_space_info *space_info;
struct btrfs_key key;
struct btrfs_key found_key;
struct extent_buffer *leaf;
int need_clear = 0;
u64 cache_gen;
root = info->extent_root;
key.objectid = 0;
key.offset = 0;
key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = 1;
cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
if (btrfs_test_opt(root, SPACE_CACHE) &&
btrfs_super_generation(root->fs_info->super_copy) != cache_gen)
need_clear = 1;
if (btrfs_test_opt(root, CLEAR_CACHE))
need_clear = 1;
while (1) {
ret = find_first_block_group(root, path, &key);
if (ret > 0)
break;
if (ret != 0)
goto error;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
cache = btrfs_create_block_group_cache(root, found_key.objectid,
found_key.offset);
if (!cache) {
ret = -ENOMEM;
goto error;
}
if (need_clear) {
/*
* When we mount with old space cache, we need to
* set BTRFS_DC_CLEAR and set dirty flag.
*
* a) Setting 'BTRFS_DC_CLEAR' makes sure that we
* truncate the old free space cache inode and
* setup a new one.
* b) Setting 'dirty flag' makes sure that we flush
* the new space cache info onto disk.
*/
if (btrfs_test_opt(root, SPACE_CACHE))
cache->disk_cache_state = BTRFS_DC_CLEAR;
}
read_extent_buffer(leaf, &cache->item,
btrfs_item_ptr_offset(leaf, path->slots[0]),
sizeof(cache->item));
cache->flags = btrfs_block_group_flags(&cache->item);
key.objectid = found_key.objectid + found_key.offset;
btrfs_release_path(path);
/*
* We need to exclude the super stripes now so that the space
* info has super bytes accounted for, otherwise we'll think
* we have more space than we actually do.
*/
ret = exclude_super_stripes(root, cache);
if (ret) {
/*
* We may have excluded something, so call this just in
* case.
*/
free_excluded_extents(root, cache);
btrfs_put_block_group(cache);
goto error;
}
/*
* check for two cases, either we are full, and therefore
* don't need to bother with the caching work since we won't
* find any space, or we are empty, and we can just add all
* the space in and be done with it. This saves us _alot_ of
* time, particularly in the full case.
*/
if (found_key.offset == btrfs_block_group_used(&cache->item)) {
cache->last_byte_to_unpin = (u64)-1;
cache->cached = BTRFS_CACHE_FINISHED;
free_excluded_extents(root, cache);
} else if (btrfs_block_group_used(&cache->item) == 0) {
cache->last_byte_to_unpin = (u64)-1;
cache->cached = BTRFS_CACHE_FINISHED;
add_new_free_space(cache, root->fs_info,
found_key.objectid,
found_key.objectid +
found_key.offset);
free_excluded_extents(root, cache);
}
ret = btrfs_add_block_group_cache(root->fs_info, cache);
if (ret) {
btrfs_remove_free_space_cache(cache);
btrfs_put_block_group(cache);
goto error;
}
ret = update_space_info(info, cache->flags, found_key.offset,
btrfs_block_group_used(&cache->item),
&space_info);
if (ret) {
btrfs_remove_free_space_cache(cache);
spin_lock(&info->block_group_cache_lock);
rb_erase(&cache->cache_node,
&info->block_group_cache_tree);
RB_CLEAR_NODE(&cache->cache_node);
spin_unlock(&info->block_group_cache_lock);
btrfs_put_block_group(cache);
goto error;
}
cache->space_info = space_info;
spin_lock(&cache->space_info->lock);
cache->space_info->bytes_readonly += cache->bytes_super;
spin_unlock(&cache->space_info->lock);
__link_block_group(space_info, cache);
set_avail_alloc_bits(root->fs_info, cache->flags);
if (btrfs_chunk_readonly(root, cache->key.objectid)) {
set_block_group_ro(cache, 1);
} else if (btrfs_block_group_used(&cache->item) == 0) {
spin_lock(&info->unused_bgs_lock);
/* Should always be true but just in case. */
if (list_empty(&cache->bg_list)) {
btrfs_get_block_group(cache);
list_add_tail(&cache->bg_list,
&info->unused_bgs);
}
spin_unlock(&info->unused_bgs_lock);
}
}
list_for_each_entry_rcu(space_info, &root->fs_info->space_info, list) {
if (!(get_alloc_profile(root, space_info->flags) &
(BTRFS_BLOCK_GROUP_RAID10 |
BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID5 |
BTRFS_BLOCK_GROUP_RAID6 |
BTRFS_BLOCK_GROUP_DUP)))
continue;
/*
* avoid allocating from un-mirrored block group if there are
* mirrored block groups.
*/
list_for_each_entry(cache,
&space_info->block_groups[BTRFS_RAID_RAID0],
list)
set_block_group_ro(cache, 1);
list_for_each_entry(cache,
&space_info->block_groups[BTRFS_RAID_SINGLE],
list)
set_block_group_ro(cache, 1);
}
init_global_block_rsv(info);
ret = 0;
error:
btrfs_free_path(path);
return ret;
}
void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_block_group_cache *block_group, *tmp;
struct btrfs_root *extent_root = root->fs_info->extent_root;
struct btrfs_block_group_item item;
struct btrfs_key key;
int ret = 0;
list_for_each_entry_safe(block_group, tmp, &trans->new_bgs, bg_list) {
if (ret)
goto next;
spin_lock(&block_group->lock);
memcpy(&item, &block_group->item, sizeof(item));
memcpy(&key, &block_group->key, sizeof(key));
spin_unlock(&block_group->lock);
ret = btrfs_insert_item(trans, extent_root, &key, &item,
sizeof(item));
if (ret)
btrfs_abort_transaction(trans, extent_root, ret);
ret = btrfs_finish_chunk_alloc(trans, extent_root,
key.objectid, key.offset);
if (ret)
btrfs_abort_transaction(trans, extent_root, ret);
next:
list_del_init(&block_group->bg_list);
}
}
int btrfs_make_block_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytes_used,
u64 type, u64 chunk_objectid, u64 chunk_offset,
u64 size)
{
int ret;
struct btrfs_root *extent_root;
struct btrfs_block_group_cache *cache;
extent_root = root->fs_info->extent_root;
btrfs_set_log_full_commit(root->fs_info, trans);
cache = btrfs_create_block_group_cache(root, chunk_offset, size);
if (!cache)
return -ENOMEM;
btrfs_set_block_group_used(&cache->item, bytes_used);
btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
btrfs_set_block_group_flags(&cache->item, type);
cache->flags = type;
cache->last_byte_to_unpin = (u64)-1;
cache->cached = BTRFS_CACHE_FINISHED;
ret = exclude_super_stripes(root, cache);
if (ret) {
/*
* We may have excluded something, so call this just in
* case.
*/
free_excluded_extents(root, cache);
btrfs_put_block_group(cache);
return ret;
}
add_new_free_space(cache, root->fs_info, chunk_offset,
chunk_offset + size);
free_excluded_extents(root, cache);
ret = btrfs_add_block_group_cache(root->fs_info, cache);
if (ret) {
btrfs_remove_free_space_cache(cache);
btrfs_put_block_group(cache);
return ret;
}
ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
&cache->space_info);
if (ret) {
btrfs_remove_free_space_cache(cache);
spin_lock(&root->fs_info->block_group_cache_lock);
rb_erase(&cache->cache_node,
&root->fs_info->block_group_cache_tree);
RB_CLEAR_NODE(&cache->cache_node);
spin_unlock(&root->fs_info->block_group_cache_lock);
btrfs_put_block_group(cache);
return ret;
}
update_global_block_rsv(root->fs_info);
spin_lock(&cache->space_info->lock);
cache->space_info->bytes_readonly += cache->bytes_super;
spin_unlock(&cache->space_info->lock);
__link_block_group(cache->space_info, cache);
list_add_tail(&cache->bg_list, &trans->new_bgs);
set_avail_alloc_bits(extent_root->fs_info, type);
return 0;
}
static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
{
u64 extra_flags = chunk_to_extended(flags) &
BTRFS_EXTENDED_PROFILE_MASK;
write_seqlock(&fs_info->profiles_lock);
if (flags & BTRFS_BLOCK_GROUP_DATA)
fs_info->avail_data_alloc_bits &= ~extra_flags;
if (flags & BTRFS_BLOCK_GROUP_METADATA)
fs_info->avail_metadata_alloc_bits &= ~extra_flags;
if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
fs_info->avail_system_alloc_bits &= ~extra_flags;
write_sequnlock(&fs_info->profiles_lock);
}
int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 group_start,
struct extent_map *em)
{
struct btrfs_path *path;
struct btrfs_block_group_cache *block_group;
struct btrfs_free_cluster *cluster;
struct btrfs_root *tree_root = root->fs_info->tree_root;
struct btrfs_key key;
struct inode *inode;
struct kobject *kobj = NULL;
int ret;
int index;
int factor;
struct btrfs_caching_control *caching_ctl = NULL;
bool remove_em;
root = root->fs_info->extent_root;
block_group = btrfs_lookup_block_group(root->fs_info, group_start);
BUG_ON(!block_group);
BUG_ON(!block_group->ro);
/*
* Free the reserved super bytes from this block group before
* remove it.
*/
free_excluded_extents(root, block_group);
memcpy(&key, &block_group->key, sizeof(key));
index = get_block_group_index(block_group);
if (block_group->flags & (BTRFS_BLOCK_GROUP_DUP |
BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10))
factor = 2;
else
factor = 1;
/* make sure this block group isn't part of an allocation cluster */
cluster = &root->fs_info->data_alloc_cluster;
spin_lock(&cluster->refill_lock);
btrfs_return_cluster_to_free_space(block_group, cluster);
spin_unlock(&cluster->refill_lock);
/*
* make sure this block group isn't part of a metadata
* allocation cluster
*/
cluster = &root->fs_info->meta_alloc_cluster;
spin_lock(&cluster->refill_lock);
btrfs_return_cluster_to_free_space(block_group, cluster);
spin_unlock(&cluster->refill_lock);
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
/*
* get the inode first so any iput calls done for the io_list
* aren't the final iput (no unlinks allowed now)
*/
inode = lookup_free_space_inode(tree_root, block_group, path);
mutex_lock(&trans->transaction->cache_write_mutex);
/*
* make sure our free spache cache IO is done before remove the
* free space inode
*/
spin_lock(&trans->transaction->dirty_bgs_lock);
if (!list_empty(&block_group->io_list)) {
list_del_init(&block_group->io_list);
WARN_ON(!IS_ERR(inode) && inode != block_group->io_ctl.inode);
spin_unlock(&trans->transaction->dirty_bgs_lock);
btrfs_wait_cache_io(root, trans, block_group,
&block_group->io_ctl, path,
block_group->key.objectid);
btrfs_put_block_group(block_group);
spin_lock(&trans->transaction->dirty_bgs_lock);
}
if (!list_empty(&block_group->dirty_list)) {
list_del_init(&block_group->dirty_list);
btrfs_put_block_group(block_group);
}
spin_unlock(&trans->transaction->dirty_bgs_lock);
mutex_unlock(&trans->transaction->cache_write_mutex);
if (!IS_ERR(inode)) {
ret = btrfs_orphan_add(trans, inode);
if (ret) {
btrfs_add_delayed_iput(inode);
goto out;
}
clear_nlink(inode);
/* One for the block groups ref */
spin_lock(&block_group->lock);
if (block_group->iref) {
block_group->iref = 0;
block_group->inode = NULL;
spin_unlock(&block_group->lock);
iput(inode);
} else {
spin_unlock(&block_group->lock);
}
/* One for our lookup ref */
btrfs_add_delayed_iput(inode);
}
key.objectid = BTRFS_FREE_SPACE_OBJECTID;
key.offset = block_group->key.objectid;
key.type = 0;
ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
if (ret < 0)
goto out;
if (ret > 0)
btrfs_release_path(path);
if (ret == 0) {
ret = btrfs_del_item(trans, tree_root, path);
if (ret)
goto out;
btrfs_release_path(path);
}
spin_lock(&root->fs_info->block_group_cache_lock);
rb_erase(&block_group->cache_node,
&root->fs_info->block_group_cache_tree);
RB_CLEAR_NODE(&block_group->cache_node);
if (root->fs_info->first_logical_byte == block_group->key.objectid)
root->fs_info->first_logical_byte = (u64)-1;
spin_unlock(&root->fs_info->block_group_cache_lock);
down_write(&block_group->space_info->groups_sem);
/*
* we must use list_del_init so people can check to see if they
* are still on the list after taking the semaphore
*/
list_del_init(&block_group->list);
if (list_empty(&block_group->space_info->block_groups[index])) {
kobj = block_group->space_info->block_group_kobjs[index];
block_group->space_info->block_group_kobjs[index] = NULL;
clear_avail_alloc_bits(root->fs_info, block_group->flags);
}
up_write(&block_group->space_info->groups_sem);
if (kobj) {
kobject_del(kobj);
kobject_put(kobj);
}
if (block_group->has_caching_ctl)
caching_ctl = get_caching_control(block_group);
if (block_group->cached == BTRFS_CACHE_STARTED)
wait_block_group_cache_done(block_group);
if (block_group->has_caching_ctl) {
down_write(&root->fs_info->commit_root_sem);
if (!caching_ctl) {
struct btrfs_caching_control *ctl;
list_for_each_entry(ctl,
&root->fs_info->caching_block_groups, list)
if (ctl->block_group == block_group) {
caching_ctl = ctl;
atomic_inc(&caching_ctl->count);
break;
}
}
if (caching_ctl)
list_del_init(&caching_ctl->list);
up_write(&root->fs_info->commit_root_sem);
if (caching_ctl) {
/* Once for the caching bgs list and once for us. */
put_caching_control(caching_ctl);
put_caching_control(caching_ctl);
}
}
spin_lock(&trans->transaction->dirty_bgs_lock);
if (!list_empty(&block_group->dirty_list)) {
WARN_ON(1);
}
if (!list_empty(&block_group->io_list)) {
WARN_ON(1);
}
spin_unlock(&trans->transaction->dirty_bgs_lock);
btrfs_remove_free_space_cache(block_group);
spin_lock(&block_group->space_info->lock);
list_del_init(&block_group->ro_list);
if (btrfs_test_opt(root, ENOSPC_DEBUG)) {
WARN_ON(block_group->space_info->total_bytes
< block_group->key.offset);
WARN_ON(block_group->space_info->bytes_readonly
< block_group->key.offset);
WARN_ON(block_group->space_info->disk_total
< block_group->key.offset * factor);
}
block_group->space_info->total_bytes -= block_group->key.offset;
block_group->space_info->bytes_readonly -= block_group->key.offset;
block_group->space_info->disk_total -= block_group->key.offset * factor;
spin_unlock(&block_group->space_info->lock);
memcpy(&key, &block_group->key, sizeof(key));
lock_chunks(root);
if (!list_empty(&em->list)) {
/* We're in the transaction->pending_chunks list. */
free_extent_map(em);
}
spin_lock(&block_group->lock);
block_group->removed = 1;
/*
* At this point trimming can't start on this block group, because we
* removed the block group from the tree fs_info->block_group_cache_tree
* so no one can't find it anymore and even if someone already got this
* block group before we removed it from the rbtree, they have already
* incremented block_group->trimming - if they didn't, they won't find
* any free space entries because we already removed them all when we
* called btrfs_remove_free_space_cache().
*
* And we must not remove the extent map from the fs_info->mapping_tree
* to prevent the same logical address range and physical device space
* ranges from being reused for a new block group. This is because our
* fs trim operation (btrfs_trim_fs() / btrfs_ioctl_fitrim()) is
* completely transactionless, so while it is trimming a range the
* currently running transaction might finish and a new one start,
* allowing for new block groups to be created that can reuse the same
* physical device locations unless we take this special care.
*/
remove_em = (atomic_read(&block_group->trimming) == 0);
/*
* Make sure a trimmer task always sees the em in the pinned_chunks list
* if it sees block_group->removed == 1 (needs to lock block_group->lock
* before checking block_group->removed).
*/
if (!remove_em) {
/*
* Our em might be in trans->transaction->pending_chunks which
* is protected by fs_info->chunk_mutex ([lock|unlock]_chunks),
* and so is the fs_info->pinned_chunks list.
*
* So at this point we must be holding the chunk_mutex to avoid
* any races with chunk allocation (more specifically at
* volumes.c:contains_pending_extent()), to ensure it always
* sees the em, either in the pending_chunks list or in the
* pinned_chunks list.
*/
list_move_tail(&em->list, &root->fs_info->pinned_chunks);
}
spin_unlock(&block_group->lock);
if (remove_em) {
struct extent_map_tree *em_tree;
em_tree = &root->fs_info->mapping_tree.map_tree;
write_lock(&em_tree->lock);
/*
* The em might be in the pending_chunks list, so make sure the
* chunk mutex is locked, since remove_extent_mapping() will
* delete us from that list.
*/
remove_extent_mapping(em_tree, em);
write_unlock(&em_tree->lock);
/* once for the tree */
free_extent_map(em);
}
unlock_chunks(root);
btrfs_put_block_group(block_group);
btrfs_put_block_group(block_group);
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret > 0)
ret = -EIO;
if (ret < 0)
goto out;
ret = btrfs_del_item(trans, root, path);
out:
btrfs_free_path(path);
return ret;
}
/*
* Process the unused_bgs list and remove any that don't have any allocated
* space inside of them.
*/
void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
{
struct btrfs_block_group_cache *block_group;
struct btrfs_space_info *space_info;
struct btrfs_root *root = fs_info->extent_root;
struct btrfs_trans_handle *trans;
int ret = 0;
if (!fs_info->open)
return;
spin_lock(&fs_info->unused_bgs_lock);
while (!list_empty(&fs_info->unused_bgs)) {
u64 start, end;
block_group = list_first_entry(&fs_info->unused_bgs,
struct btrfs_block_group_cache,
bg_list);
space_info = block_group->space_info;
list_del_init(&block_group->bg_list);
if (ret || btrfs_mixed_space_info(space_info)) {
btrfs_put_block_group(block_group);
continue;
}
spin_unlock(&fs_info->unused_bgs_lock);
/* Don't want to race with allocators so take the groups_sem */
down_write(&space_info->groups_sem);
spin_lock(&block_group->lock);
if (block_group->reserved ||
btrfs_block_group_used(&block_group->item) ||
block_group->ro) {
/*
* We want to bail if we made new allocations or have
* outstanding allocations in this block group. We do
* the ro check in case balance is currently acting on
* this block group.
*/
spin_unlock(&block_group->lock);
up_write(&space_info->groups_sem);
goto next;
}
spin_unlock(&block_group->lock);
/* We don't want to force the issue, only flip if it's ok. */
ret = set_block_group_ro(block_group, 0);
up_write(&space_info->groups_sem);
if (ret < 0) {
ret = 0;
goto next;
}
/*
* Want to do this before we do anything else so we can recover
* properly if we fail to join the transaction.
*/
/* 1 for btrfs_orphan_reserve_metadata() */
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
btrfs_set_block_group_rw(root, block_group);
ret = PTR_ERR(trans);
goto next;
}
/*
* We could have pending pinned extents for this block group,
* just delete them, we don't care about them anymore.
*/
start = block_group->key.objectid;
end = start + block_group->key.offset - 1;
/*
* Hold the unused_bg_unpin_mutex lock to avoid racing with
* btrfs_finish_extent_commit(). If we are at transaction N,
* another task might be running finish_extent_commit() for the
* previous transaction N - 1, and have seen a range belonging
* to the block group in freed_extents[] before we were able to
* clear the whole block group range from freed_extents[]. This
* means that task can lookup for the block group after we
* unpinned it from freed_extents[] and removed it, leading to
* a BUG_ON() at btrfs_unpin_extent_range().
*/
mutex_lock(&fs_info->unused_bg_unpin_mutex);
ret = clear_extent_bits(&fs_info->freed_extents[0], start, end,
EXTENT_DIRTY, GFP_NOFS);
if (ret) {
mutex_unlock(&fs_info->unused_bg_unpin_mutex);
btrfs_set_block_group_rw(root, block_group);
goto end_trans;
}
ret = clear_extent_bits(&fs_info->freed_extents[1], start, end,
EXTENT_DIRTY, GFP_NOFS);
if (ret) {
mutex_unlock(&fs_info->unused_bg_unpin_mutex);
btrfs_set_block_group_rw(root, block_group);
goto end_trans;
}
mutex_unlock(&fs_info->unused_bg_unpin_mutex);
/* Reset pinned so btrfs_put_block_group doesn't complain */
spin_lock(&space_info->lock);
spin_lock(&block_group->lock);
space_info->bytes_pinned -= block_group->pinned;
space_info->bytes_readonly += block_group->pinned;
percpu_counter_add(&space_info->total_bytes_pinned,
-block_group->pinned);
block_group->pinned = 0;
spin_unlock(&block_group->lock);
spin_unlock(&space_info->lock);
/*
* Btrfs_remove_chunk will abort the transaction if things go
* horribly wrong.
*/
ret = btrfs_remove_chunk(trans, root,
block_group->key.objectid);
end_trans:
btrfs_end_transaction(trans, root);
next:
btrfs_put_block_group(block_group);
spin_lock(&fs_info->unused_bgs_lock);
}
spin_unlock(&fs_info->unused_bgs_lock);
}
int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
{
struct btrfs_space_info *space_info;
struct btrfs_super_block *disk_super;
u64 features;
u64 flags;
int mixed = 0;
int ret;
disk_super = fs_info->super_copy;
if (!btrfs_super_root(disk_super))
return 1;
features = btrfs_super_incompat_flags(disk_super);
if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
mixed = 1;
flags = BTRFS_BLOCK_GROUP_SYSTEM;
ret = update_space_info(fs_info, flags, 0, 0, &space_info);
if (ret)
goto out;
if (mixed) {
flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA;
ret = update_space_info(fs_info, flags, 0, 0, &space_info);
} else {
flags = BTRFS_BLOCK_GROUP_METADATA;
ret = update_space_info(fs_info, flags, 0, 0, &space_info);
if (ret)
goto out;
flags = BTRFS_BLOCK_GROUP_DATA;
ret = update_space_info(fs_info, flags, 0, 0, &space_info);
}
out:
return ret;
}
int btrfs_error_unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
{
return unpin_extent_range(root, start, end, false);
}
int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_block_group_cache *cache = NULL;
u64 group_trimmed;
u64 start;
u64 end;
u64 trimmed = 0;
u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
int ret = 0;
/*
* try to trim all FS space, our block group may start from non-zero.
*/
if (range->len == total_bytes)
cache = btrfs_lookup_first_block_group(fs_info, range->start);
else
cache = btrfs_lookup_block_group(fs_info, range->start);
while (cache) {
if (cache->key.objectid >= (range->start + range->len)) {
btrfs_put_block_group(cache);
break;
}
start = max(range->start, cache->key.objectid);
end = min(range->start + range->len,
cache->key.objectid + cache->key.offset);
if (end - start >= range->minlen) {
if (!block_group_cache_done(cache)) {
ret = cache_block_group(cache, 0);
if (ret) {
btrfs_put_block_group(cache);
break;
}
ret = wait_block_group_cache_done(cache);
if (ret) {
btrfs_put_block_group(cache);
break;
}
}
ret = btrfs_trim_block_group(cache,
&group_trimmed,
start,
end,
range->minlen);
trimmed += group_trimmed;
if (ret) {
btrfs_put_block_group(cache);
break;
}
}
cache = next_block_group(fs_info->tree_root, cache);
}
range->len = trimmed;
return ret;
}
/*
* btrfs_{start,end}_write_no_snapshoting() are similar to
* mnt_{want,drop}_write(), they are used to prevent some tasks from writing
* data into the page cache through nocow before the subvolume is snapshoted,
* but flush the data into disk after the snapshot creation, or to prevent
* operations while snapshoting is ongoing and that cause the snapshot to be
* inconsistent (writes followed by expanding truncates for example).
*/
void btrfs_end_write_no_snapshoting(struct btrfs_root *root)
{
percpu_counter_dec(&root->subv_writers->counter);
/*
* Make sure counter is updated before we wake up
* waiters.
*/
smp_mb();
if (waitqueue_active(&root->subv_writers->wait))
wake_up(&root->subv_writers->wait);
}
int btrfs_start_write_no_snapshoting(struct btrfs_root *root)
{
if (atomic_read(&root->will_be_snapshoted))
return 0;
percpu_counter_inc(&root->subv_writers->counter);
/*
* Make sure counter is updated before we check for snapshot creation.
*/
smp_mb();
if (atomic_read(&root->will_be_snapshoted)) {
btrfs_end_write_no_snapshoting(root);
return 0;
}
return 1;
}
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