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WSL2-Linux-Kernel/fs/ext4/fast_commit.c

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// SPDX-License-Identifier: GPL-2.0
/*
* fs/ext4/fast_commit.c
*
* Written by Harshad Shirwadkar <harshadshirwadkar@gmail.com>
*
* Ext4 fast commits routines.
*/
#include "ext4.h"
#include "ext4_jbd2.h"
#include "ext4_extents.h"
#include "mballoc.h"
/*
* Ext4 Fast Commits
* -----------------
*
* Ext4 fast commits implement fine grained journalling for Ext4.
*
* Fast commits are organized as a log of tag-length-value (TLV) structs. (See
* struct ext4_fc_tl). Each TLV contains some delta that is replayed TLV by
* TLV during the recovery phase. For the scenarios for which we currently
* don't have replay code, fast commit falls back to full commits.
* Fast commits record delta in one of the following three categories.
*
* (A) Directory entry updates:
*
* - EXT4_FC_TAG_UNLINK - records directory entry unlink
* - EXT4_FC_TAG_LINK - records directory entry link
* - EXT4_FC_TAG_CREAT - records inode and directory entry creation
*
* (B) File specific data range updates:
*
* - EXT4_FC_TAG_ADD_RANGE - records addition of new blocks to an inode
* - EXT4_FC_TAG_DEL_RANGE - records deletion of blocks from an inode
*
* (C) Inode metadata (mtime / ctime etc):
*
* - EXT4_FC_TAG_INODE - record the inode that should be replayed
* during recovery. Note that iblocks field is
* not replayed and instead derived during
* replay.
* Commit Operation
* ----------------
* With fast commits, we maintain all the directory entry operations in the
* order in which they are issued in an in-memory queue. This queue is flushed
* to disk during the commit operation. We also maintain a list of inodes
* that need to be committed during a fast commit in another in memory queue of
* inodes. During the commit operation, we commit in the following order:
*
* [1] Lock inodes for any further data updates by setting COMMITTING state
* [2] Submit data buffers of all the inodes
* [3] Wait for [2] to complete
* [4] Commit all the directory entry updates in the fast commit space
* [5] Commit all the changed inode structures
* [6] Write tail tag (this tag ensures the atomicity, please read the following
* section for more details).
* [7] Wait for [4], [5] and [6] to complete.
*
* All the inode updates must call ext4_fc_start_update() before starting an
* update. If such an ongoing update is present, fast commit waits for it to
* complete. The completion of such an update is marked by
* ext4_fc_stop_update().
*
* Fast Commit Ineligibility
* -------------------------
*
* Not all operations are supported by fast commits today (e.g extended
* attributes). Fast commit ineligibility is marked by calling
* ext4_fc_mark_ineligible(): This makes next fast commit operation to fall back
* to full commit.
*
* Atomicity of commits
* --------------------
* In order to guarantee atomicity during the commit operation, fast commit
* uses "EXT4_FC_TAG_TAIL" tag that marks a fast commit as complete. Tail
* tag contains CRC of the contents and TID of the transaction after which
* this fast commit should be applied. Recovery code replays fast commit
* logs only if there's at least 1 valid tail present. For every fast commit
* operation, there is 1 tail. This means, we may end up with multiple tails
* in the fast commit space. Here's an example:
*
* - Create a new file A and remove existing file B
* - fsync()
* - Append contents to file A
* - Truncate file A
* - fsync()
*
* The fast commit space at the end of above operations would look like this:
* [HEAD] [CREAT A] [UNLINK B] [TAIL] [ADD_RANGE A] [DEL_RANGE A] [TAIL]
* |<--- Fast Commit 1 --->|<--- Fast Commit 2 ---->|
*
* Replay code should thus check for all the valid tails in the FC area.
*
* Fast Commit Replay Idempotence
* ------------------------------
*
* Fast commits tags are idempotent in nature provided the recovery code follows
* certain rules. The guiding principle that the commit path follows while
* committing is that it stores the result of a particular operation instead of
* storing the procedure.
*
* Let's consider this rename operation: 'mv /a /b'. Let's assume dirent '/a'
* was associated with inode 10. During fast commit, instead of storing this
* operation as a procedure "rename a to b", we store the resulting file system
* state as a "series" of outcomes:
*
* - Link dirent b to inode 10
* - Unlink dirent a
* - Inode <10> with valid refcount
*
* Now when recovery code runs, it needs "enforce" this state on the file
* system. This is what guarantees idempotence of fast commit replay.
*
* Let's take an example of a procedure that is not idempotent and see how fast
* commits make it idempotent. Consider following sequence of operations:
*
* rm A; mv B A; read A
* (x) (y) (z)
*
* (x), (y) and (z) are the points at which we can crash. If we store this
* sequence of operations as is then the replay is not idempotent. Let's say
* while in replay, we crash at (z). During the second replay, file A (which was
* actually created as a result of "mv B A" operation) would get deleted. Thus,
* file named A would be absent when we try to read A. So, this sequence of
* operations is not idempotent. However, as mentioned above, instead of storing
* the procedure fast commits store the outcome of each procedure. Thus the fast
* commit log for above procedure would be as follows:
*
* (Let's assume dirent A was linked to inode 10 and dirent B was linked to
* inode 11 before the replay)
*
* [Unlink A] [Link A to inode 11] [Unlink B] [Inode 11]
* (w) (x) (y) (z)
*
* If we crash at (z), we will have file A linked to inode 11. During the second
* replay, we will remove file A (inode 11). But we will create it back and make
* it point to inode 11. We won't find B, so we'll just skip that step. At this
* point, the refcount for inode 11 is not reliable, but that gets fixed by the
* replay of last inode 11 tag. Crashes at points (w), (x) and (y) get handled
* similarly. Thus, by converting a non-idempotent procedure into a series of
* idempotent outcomes, fast commits ensured idempotence during the replay.
*
* TODOs
* -----
*
* 0) Fast commit replay path hardening: Fast commit replay code should use
* journal handles to make sure all the updates it does during the replay
* path are atomic. With that if we crash during fast commit replay, after
* trying to do recovery again, we will find a file system where fast commit
* area is invalid (because new full commit would be found). In order to deal
* with that, fast commit replay code should ensure that the "FC_REPLAY"
* superblock state is persisted before starting the replay, so that after
* the crash, fast commit recovery code can look at that flag and perform
* fast commit recovery even if that area is invalidated by later full
* commits.
*
* 1) Make fast commit atomic updates more fine grained. Today, a fast commit
* eligible update must be protected within ext4_fc_start_update() and
* ext4_fc_stop_update(). These routines are called at much higher
* routines. This can be made more fine grained by combining with
* ext4_journal_start().
*
* 2) Same above for ext4_fc_start_ineligible() and ext4_fc_stop_ineligible()
*
* 3) Handle more ineligible cases.
*/
#include <trace/events/ext4.h>
static struct kmem_cache *ext4_fc_dentry_cachep;
static void ext4_end_buffer_io_sync(struct buffer_head *bh, int uptodate)
{
BUFFER_TRACE(bh, "");
if (uptodate) {
ext4_debug("%s: Block %lld up-to-date",
__func__, bh->b_blocknr);
set_buffer_uptodate(bh);
} else {
ext4_debug("%s: Block %lld not up-to-date",
__func__, bh->b_blocknr);
clear_buffer_uptodate(bh);
}
unlock_buffer(bh);
}
static inline void ext4_fc_reset_inode(struct inode *inode)
{
struct ext4_inode_info *ei = EXT4_I(inode);
ei->i_fc_lblk_start = 0;
ei->i_fc_lblk_len = 0;
}
void ext4_fc_init_inode(struct inode *inode)
{
struct ext4_inode_info *ei = EXT4_I(inode);
ext4_fc_reset_inode(inode);
ext4_clear_inode_state(inode, EXT4_STATE_FC_COMMITTING);
INIT_LIST_HEAD(&ei->i_fc_list);
init_waitqueue_head(&ei->i_fc_wait);
atomic_set(&ei->i_fc_updates, 0);
}
/* This function must be called with sbi->s_fc_lock held. */
static void ext4_fc_wait_committing_inode(struct inode *inode)
__releases(&EXT4_SB(inode->i_sb)->s_fc_lock)
{
wait_queue_head_t *wq;
struct ext4_inode_info *ei = EXT4_I(inode);
#if (BITS_PER_LONG < 64)
DEFINE_WAIT_BIT(wait, &ei->i_state_flags,
EXT4_STATE_FC_COMMITTING);
wq = bit_waitqueue(&ei->i_state_flags,
EXT4_STATE_FC_COMMITTING);
#else
DEFINE_WAIT_BIT(wait, &ei->i_flags,
EXT4_STATE_FC_COMMITTING);
wq = bit_waitqueue(&ei->i_flags,
EXT4_STATE_FC_COMMITTING);
#endif
lockdep_assert_held(&EXT4_SB(inode->i_sb)->s_fc_lock);
prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
spin_unlock(&EXT4_SB(inode->i_sb)->s_fc_lock);
schedule();
finish_wait(wq, &wait.wq_entry);
}
/*
* Inform Ext4's fast about start of an inode update
*
* This function is called by the high level call VFS callbacks before
* performing any inode update. This function blocks if there's an ongoing
* fast commit on the inode in question.
*/
void ext4_fc_start_update(struct inode *inode)
{
struct ext4_inode_info *ei = EXT4_I(inode);
if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT) ||
(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY))
return;
restart:
spin_lock(&EXT4_SB(inode->i_sb)->s_fc_lock);
if (list_empty(&ei->i_fc_list))
goto out;
if (ext4_test_inode_state(inode, EXT4_STATE_FC_COMMITTING)) {
ext4_fc_wait_committing_inode(inode);
goto restart;
}
out:
atomic_inc(&ei->i_fc_updates);
spin_unlock(&EXT4_SB(inode->i_sb)->s_fc_lock);
}
/*
* Stop inode update and wake up waiting fast commits if any.
*/
void ext4_fc_stop_update(struct inode *inode)
{
struct ext4_inode_info *ei = EXT4_I(inode);
if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT) ||
(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY))
return;
if (atomic_dec_and_test(&ei->i_fc_updates))
wake_up_all(&ei->i_fc_wait);
}
/*
* Remove inode from fast commit list. If the inode is being committed
* we wait until inode commit is done.
*/
void ext4_fc_del(struct inode *inode)
{
struct ext4_inode_info *ei = EXT4_I(inode);
if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT) ||
(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY))
return;
restart:
spin_lock(&EXT4_SB(inode->i_sb)->s_fc_lock);
if (list_empty(&ei->i_fc_list)) {
spin_unlock(&EXT4_SB(inode->i_sb)->s_fc_lock);
return;
}
if (ext4_test_inode_state(inode, EXT4_STATE_FC_COMMITTING)) {
ext4_fc_wait_committing_inode(inode);
goto restart;
}
list_del_init(&ei->i_fc_list);
spin_unlock(&EXT4_SB(inode->i_sb)->s_fc_lock);
}
/*
* Mark file system as fast commit ineligible, and record latest
* ineligible transaction tid. This means until the recorded
* transaction, commit operation would result in a full jbd2 commit.
*/
void ext4_fc_mark_ineligible(struct super_block *sb, int reason, handle_t *handle)
{
struct ext4_sb_info *sbi = EXT4_SB(sb);
tid_t tid;
if (!test_opt2(sb, JOURNAL_FAST_COMMIT) ||
(EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY))
return;
ext4_set_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
if (handle && !IS_ERR(handle))
tid = handle->h_transaction->t_tid;
else {
read_lock(&sbi->s_journal->j_state_lock);
tid = sbi->s_journal->j_running_transaction ?
sbi->s_journal->j_running_transaction->t_tid : 0;
read_unlock(&sbi->s_journal->j_state_lock);
}
spin_lock(&sbi->s_fc_lock);
if (sbi->s_fc_ineligible_tid < tid)
sbi->s_fc_ineligible_tid = tid;
spin_unlock(&sbi->s_fc_lock);
WARN_ON(reason >= EXT4_FC_REASON_MAX);
sbi->s_fc_stats.fc_ineligible_reason_count[reason]++;
}
/*
* Generic fast commit tracking function. If this is the first time this we are
* called after a full commit, we initialize fast commit fields and then call
* __fc_track_fn() with update = 0. If we have already been called after a full
* commit, we pass update = 1. Based on that, the track function can determine
* if it needs to track a field for the first time or if it needs to just
* update the previously tracked value.
*
* If enqueue is set, this function enqueues the inode in fast commit list.
*/
static int ext4_fc_track_template(
handle_t *handle, struct inode *inode,
int (*__fc_track_fn)(struct inode *, void *, bool),
void *args, int enqueue)
{
bool update = false;
struct ext4_inode_info *ei = EXT4_I(inode);
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
tid_t tid = 0;
int ret;
tid = handle->h_transaction->t_tid;
mutex_lock(&ei->i_fc_lock);
if (tid == ei->i_sync_tid) {
update = true;
} else {
ext4_fc_reset_inode(inode);
ei->i_sync_tid = tid;
}
ret = __fc_track_fn(inode, args, update);
mutex_unlock(&ei->i_fc_lock);
if (!enqueue)
return ret;
spin_lock(&sbi->s_fc_lock);
if (list_empty(&EXT4_I(inode)->i_fc_list))
list_add_tail(&EXT4_I(inode)->i_fc_list,
(sbi->s_journal->j_flags & JBD2_FULL_COMMIT_ONGOING ||
sbi->s_journal->j_flags & JBD2_FAST_COMMIT_ONGOING) ?
&sbi->s_fc_q[FC_Q_STAGING] :
&sbi->s_fc_q[FC_Q_MAIN]);
spin_unlock(&sbi->s_fc_lock);
return ret;
}
struct __track_dentry_update_args {
struct dentry *dentry;
int op;
};
/* __track_fn for directory entry updates. Called with ei->i_fc_lock. */
static int __track_dentry_update(struct inode *inode, void *arg, bool update)
{
struct ext4_fc_dentry_update *node;
struct ext4_inode_info *ei = EXT4_I(inode);
struct __track_dentry_update_args *dentry_update =
(struct __track_dentry_update_args *)arg;
struct dentry *dentry = dentry_update->dentry;
struct inode *dir = dentry->d_parent->d_inode;
struct super_block *sb = inode->i_sb;
struct ext4_sb_info *sbi = EXT4_SB(sb);
mutex_unlock(&ei->i_fc_lock);
if (IS_ENCRYPTED(dir)) {
ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_ENCRYPTED_FILENAME,
NULL);
mutex_lock(&ei->i_fc_lock);
return -EOPNOTSUPP;
}
node = kmem_cache_alloc(ext4_fc_dentry_cachep, GFP_NOFS);
if (!node) {
ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_NOMEM, NULL);
mutex_lock(&ei->i_fc_lock);
return -ENOMEM;
}
node->fcd_op = dentry_update->op;
node->fcd_parent = dir->i_ino;
node->fcd_ino = inode->i_ino;
if (dentry->d_name.len > DNAME_INLINE_LEN) {
node->fcd_name.name = kmalloc(dentry->d_name.len, GFP_NOFS);
if (!node->fcd_name.name) {
kmem_cache_free(ext4_fc_dentry_cachep, node);
ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_NOMEM, NULL);
mutex_lock(&ei->i_fc_lock);
return -ENOMEM;
}
memcpy((u8 *)node->fcd_name.name, dentry->d_name.name,
dentry->d_name.len);
} else {
memcpy(node->fcd_iname, dentry->d_name.name,
dentry->d_name.len);
node->fcd_name.name = node->fcd_iname;
}
node->fcd_name.len = dentry->d_name.len;
spin_lock(&sbi->s_fc_lock);
if (sbi->s_journal->j_flags & JBD2_FULL_COMMIT_ONGOING ||
sbi->s_journal->j_flags & JBD2_FAST_COMMIT_ONGOING)
list_add_tail(&node->fcd_list,
&sbi->s_fc_dentry_q[FC_Q_STAGING]);
else
list_add_tail(&node->fcd_list, &sbi->s_fc_dentry_q[FC_Q_MAIN]);
spin_unlock(&sbi->s_fc_lock);
mutex_lock(&ei->i_fc_lock);
return 0;
}
void __ext4_fc_track_unlink(handle_t *handle,
struct inode *inode, struct dentry *dentry)
{
struct __track_dentry_update_args args;
int ret;
args.dentry = dentry;
args.op = EXT4_FC_TAG_UNLINK;
ret = ext4_fc_track_template(handle, inode, __track_dentry_update,
(void *)&args, 0);
trace_ext4_fc_track_unlink(inode, dentry, ret);
}
void ext4_fc_track_unlink(handle_t *handle, struct dentry *dentry)
{
struct inode *inode = d_inode(dentry);
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT) ||
(sbi->s_mount_state & EXT4_FC_REPLAY))
return;
if (ext4_test_mount_flag(inode->i_sb, EXT4_MF_FC_INELIGIBLE))
return;
__ext4_fc_track_unlink(handle, inode, dentry);
}
void __ext4_fc_track_link(handle_t *handle,
struct inode *inode, struct dentry *dentry)
{
struct __track_dentry_update_args args;
int ret;
args.dentry = dentry;
args.op = EXT4_FC_TAG_LINK;
ret = ext4_fc_track_template(handle, inode, __track_dentry_update,
(void *)&args, 0);
trace_ext4_fc_track_link(inode, dentry, ret);
}
void ext4_fc_track_link(handle_t *handle, struct dentry *dentry)
{
struct inode *inode = d_inode(dentry);
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT) ||
(sbi->s_mount_state & EXT4_FC_REPLAY))
return;
if (ext4_test_mount_flag(inode->i_sb, EXT4_MF_FC_INELIGIBLE))
return;
__ext4_fc_track_link(handle, inode, dentry);
}
void __ext4_fc_track_create(handle_t *handle, struct inode *inode,
struct dentry *dentry)
{
struct __track_dentry_update_args args;
int ret;
args.dentry = dentry;
args.op = EXT4_FC_TAG_CREAT;
ret = ext4_fc_track_template(handle, inode, __track_dentry_update,
(void *)&args, 0);
trace_ext4_fc_track_create(inode, dentry, ret);
}
void ext4_fc_track_create(handle_t *handle, struct dentry *dentry)
{
struct inode *inode = d_inode(dentry);
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT) ||
(sbi->s_mount_state & EXT4_FC_REPLAY))
return;
if (ext4_test_mount_flag(inode->i_sb, EXT4_MF_FC_INELIGIBLE))
return;
__ext4_fc_track_create(handle, inode, dentry);
}
/* __track_fn for inode tracking */
static int __track_inode(struct inode *inode, void *arg, bool update)
{
if (update)
return -EEXIST;
EXT4_I(inode)->i_fc_lblk_len = 0;
return 0;
}
void ext4_fc_track_inode(handle_t *handle, struct inode *inode)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
int ret;
if (S_ISDIR(inode->i_mode))
return;
if (ext4_should_journal_data(inode)) {
ext4_fc_mark_ineligible(inode->i_sb,
EXT4_FC_REASON_INODE_JOURNAL_DATA, handle);
return;
}
if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT) ||
(sbi->s_mount_state & EXT4_FC_REPLAY))
return;
if (ext4_test_mount_flag(inode->i_sb, EXT4_MF_FC_INELIGIBLE))
return;
ret = ext4_fc_track_template(handle, inode, __track_inode, NULL, 1);
trace_ext4_fc_track_inode(inode, ret);
}
struct __track_range_args {
ext4_lblk_t start, end;
};
/* __track_fn for tracking data updates */
static int __track_range(struct inode *inode, void *arg, bool update)
{
struct ext4_inode_info *ei = EXT4_I(inode);
ext4_lblk_t oldstart;
struct __track_range_args *__arg =
(struct __track_range_args *)arg;
if (inode->i_ino < EXT4_FIRST_INO(inode->i_sb)) {
ext4_debug("Special inode %ld being modified\n", inode->i_ino);
return -ECANCELED;
}
oldstart = ei->i_fc_lblk_start;
if (update && ei->i_fc_lblk_len > 0) {
ei->i_fc_lblk_start = min(ei->i_fc_lblk_start, __arg->start);
ei->i_fc_lblk_len =
max(oldstart + ei->i_fc_lblk_len - 1, __arg->end) -
ei->i_fc_lblk_start + 1;
} else {
ei->i_fc_lblk_start = __arg->start;
ei->i_fc_lblk_len = __arg->end - __arg->start + 1;
}
return 0;
}
void ext4_fc_track_range(handle_t *handle, struct inode *inode, ext4_lblk_t start,
ext4_lblk_t end)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
struct __track_range_args args;
int ret;
if (S_ISDIR(inode->i_mode))
return;
if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT) ||
(sbi->s_mount_state & EXT4_FC_REPLAY))
return;
if (ext4_test_mount_flag(inode->i_sb, EXT4_MF_FC_INELIGIBLE))
return;
if (ext4_has_inline_data(inode)) {
ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR,
handle);
return;
}
args.start = start;
args.end = end;
ret = ext4_fc_track_template(handle, inode, __track_range, &args, 1);
trace_ext4_fc_track_range(inode, start, end, ret);
}
static void ext4_fc_submit_bh(struct super_block *sb, bool is_tail)
{
int write_flags = REQ_SYNC;
struct buffer_head *bh = EXT4_SB(sb)->s_fc_bh;
/* Add REQ_FUA | REQ_PREFLUSH only its tail */
if (test_opt(sb, BARRIER) && is_tail)
write_flags |= REQ_FUA | REQ_PREFLUSH;
lock_buffer(bh);
set_buffer_dirty(bh);
set_buffer_uptodate(bh);
bh->b_end_io = ext4_end_buffer_io_sync;
submit_bh(REQ_OP_WRITE, write_flags, bh);
EXT4_SB(sb)->s_fc_bh = NULL;
}
/* Ext4 commit path routines */
/* memcpy to fc reserved space and update CRC */
static void *ext4_fc_memcpy(struct super_block *sb, void *dst, const void *src,
int len, u32 *crc)
{
if (crc)
*crc = ext4_chksum(EXT4_SB(sb), *crc, src, len);
return memcpy(dst, src, len);
}
/* memzero and update CRC */
static void *ext4_fc_memzero(struct super_block *sb, void *dst, int len,
u32 *crc)
{
void *ret;
ret = memset(dst, 0, len);
if (crc)
*crc = ext4_chksum(EXT4_SB(sb), *crc, dst, len);
return ret;
}
/*
* Allocate len bytes on a fast commit buffer.
*
* During the commit time this function is used to manage fast commit
* block space. We don't split a fast commit log onto different
* blocks. So this function makes sure that if there's not enough space
* on the current block, the remaining space in the current block is
* marked as unused by adding EXT4_FC_TAG_PAD tag. In that case,
* new block is from jbd2 and CRC is updated to reflect the padding
* we added.
*/
static u8 *ext4_fc_reserve_space(struct super_block *sb, int len, u32 *crc)
{
struct ext4_fc_tl tl;
struct ext4_sb_info *sbi = EXT4_SB(sb);
struct buffer_head *bh;
int bsize = sbi->s_journal->j_blocksize;
int ret, off = sbi->s_fc_bytes % bsize;
int remaining;
u8 *dst;
/*
* If 'len' is too long to fit in any block alongside a PAD tlv, then we
* cannot fulfill the request.
*/
if (len > bsize - EXT4_FC_TAG_BASE_LEN)
return NULL;
if (!sbi->s_fc_bh) {
ret = jbd2_fc_get_buf(EXT4_SB(sb)->s_journal, &bh);
if (ret)
return NULL;
sbi->s_fc_bh = bh;
}
dst = sbi->s_fc_bh->b_data + off;
/*
* Allocate the bytes in the current block if we can do so while still
* leaving enough space for a PAD tlv.
*/
remaining = bsize - EXT4_FC_TAG_BASE_LEN - off;
if (len <= remaining) {
sbi->s_fc_bytes += len;
return dst;
}
/*
* Else, terminate the current block with a PAD tlv, then allocate a new
* block and allocate the bytes at the start of that new block.
*/
tl.fc_tag = cpu_to_le16(EXT4_FC_TAG_PAD);
tl.fc_len = cpu_to_le16(remaining);
ext4_fc_memcpy(sb, dst, &tl, EXT4_FC_TAG_BASE_LEN, crc);
ext4_fc_memzero(sb, dst + EXT4_FC_TAG_BASE_LEN, remaining, crc);
ext4_fc_submit_bh(sb, false);
ret = jbd2_fc_get_buf(EXT4_SB(sb)->s_journal, &bh);
if (ret)
return NULL;
sbi->s_fc_bh = bh;
sbi->s_fc_bytes += bsize - off + len;
return sbi->s_fc_bh->b_data;
}
/*
* Complete a fast commit by writing tail tag.
*
* Writing tail tag marks the end of a fast commit. In order to guarantee
* atomicity, after writing tail tag, even if there's space remaining
* in the block, next commit shouldn't use it. That's why tail tag
* has the length as that of the remaining space on the block.
*/
static int ext4_fc_write_tail(struct super_block *sb, u32 crc)
{
struct ext4_sb_info *sbi = EXT4_SB(sb);
struct ext4_fc_tl tl;
struct ext4_fc_tail tail;
int off, bsize = sbi->s_journal->j_blocksize;
u8 *dst;
/*
* ext4_fc_reserve_space takes care of allocating an extra block if
* there's no enough space on this block for accommodating this tail.
*/
dst = ext4_fc_reserve_space(sb, EXT4_FC_TAG_BASE_LEN + sizeof(tail), &crc);
if (!dst)
return -ENOSPC;
off = sbi->s_fc_bytes % bsize;
tl.fc_tag = cpu_to_le16(EXT4_FC_TAG_TAIL);
tl.fc_len = cpu_to_le16(bsize - off + sizeof(struct ext4_fc_tail));
sbi->s_fc_bytes = round_up(sbi->s_fc_bytes, bsize);
ext4_fc_memcpy(sb, dst, &tl, EXT4_FC_TAG_BASE_LEN, &crc);
dst += EXT4_FC_TAG_BASE_LEN;
tail.fc_tid = cpu_to_le32(sbi->s_journal->j_running_transaction->t_tid);
ext4_fc_memcpy(sb, dst, &tail.fc_tid, sizeof(tail.fc_tid), &crc);
dst += sizeof(tail.fc_tid);
tail.fc_crc = cpu_to_le32(crc);
ext4_fc_memcpy(sb, dst, &tail.fc_crc, sizeof(tail.fc_crc), NULL);
dst += sizeof(tail.fc_crc);
memset(dst, 0, bsize - off); /* Don't leak uninitialized memory. */
ext4_fc_submit_bh(sb, true);
return 0;
}
/*
* Adds tag, length, value and updates CRC. Returns true if tlv was added.
* Returns false if there's not enough space.
*/
static bool ext4_fc_add_tlv(struct super_block *sb, u16 tag, u16 len, u8 *val,
u32 *crc)
{
struct ext4_fc_tl tl;
u8 *dst;
dst = ext4_fc_reserve_space(sb, EXT4_FC_TAG_BASE_LEN + len, crc);
if (!dst)
return false;
tl.fc_tag = cpu_to_le16(tag);
tl.fc_len = cpu_to_le16(len);
ext4_fc_memcpy(sb, dst, &tl, EXT4_FC_TAG_BASE_LEN, crc);
ext4_fc_memcpy(sb, dst + EXT4_FC_TAG_BASE_LEN, val, len, crc);
return true;
}
/* Same as above, but adds dentry tlv. */
static bool ext4_fc_add_dentry_tlv(struct super_block *sb, u32 *crc,
struct ext4_fc_dentry_update *fc_dentry)
{
struct ext4_fc_dentry_info fcd;
struct ext4_fc_tl tl;
int dlen = fc_dentry->fcd_name.len;
u8 *dst = ext4_fc_reserve_space(sb,
EXT4_FC_TAG_BASE_LEN + sizeof(fcd) + dlen, crc);
if (!dst)
return false;
fcd.fc_parent_ino = cpu_to_le32(fc_dentry->fcd_parent);
fcd.fc_ino = cpu_to_le32(fc_dentry->fcd_ino);
tl.fc_tag = cpu_to_le16(fc_dentry->fcd_op);
tl.fc_len = cpu_to_le16(sizeof(fcd) + dlen);
ext4_fc_memcpy(sb, dst, &tl, EXT4_FC_TAG_BASE_LEN, crc);
dst += EXT4_FC_TAG_BASE_LEN;
ext4_fc_memcpy(sb, dst, &fcd, sizeof(fcd), crc);
dst += sizeof(fcd);
ext4_fc_memcpy(sb, dst, fc_dentry->fcd_name.name, dlen, crc);
dst += dlen;
return true;
}
/*
* Writes inode in the fast commit space under TLV with tag @tag.
* Returns 0 on success, error on failure.
*/
static int ext4_fc_write_inode(struct inode *inode, u32 *crc)
{
struct ext4_inode_info *ei = EXT4_I(inode);
int inode_len = EXT4_GOOD_OLD_INODE_SIZE;
int ret;
struct ext4_iloc iloc;
struct ext4_fc_inode fc_inode;
struct ext4_fc_tl tl;
u8 *dst;
ret = ext4_get_inode_loc(inode, &iloc);
if (ret)
return ret;
if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE)
inode_len += ei->i_extra_isize;
fc_inode.fc_ino = cpu_to_le32(inode->i_ino);
tl.fc_tag = cpu_to_le16(EXT4_FC_TAG_INODE);
tl.fc_len = cpu_to_le16(inode_len + sizeof(fc_inode.fc_ino));
ret = -ECANCELED;
dst = ext4_fc_reserve_space(inode->i_sb,
EXT4_FC_TAG_BASE_LEN + inode_len + sizeof(fc_inode.fc_ino), crc);
if (!dst)
goto err;
if (!ext4_fc_memcpy(inode->i_sb, dst, &tl, EXT4_FC_TAG_BASE_LEN, crc))
goto err;
dst += EXT4_FC_TAG_BASE_LEN;
if (!ext4_fc_memcpy(inode->i_sb, dst, &fc_inode, sizeof(fc_inode), crc))
goto err;
dst += sizeof(fc_inode);
if (!ext4_fc_memcpy(inode->i_sb, dst, (u8 *)ext4_raw_inode(&iloc),
inode_len, crc))
goto err;
ret = 0;
err:
brelse(iloc.bh);
return ret;
}
/*
* Writes updated data ranges for the inode in question. Updates CRC.
* Returns 0 on success, error otherwise.
*/
static int ext4_fc_write_inode_data(struct inode *inode, u32 *crc)
{
ext4_lblk_t old_blk_size, cur_lblk_off, new_blk_size;
struct ext4_inode_info *ei = EXT4_I(inode);
struct ext4_map_blocks map;
struct ext4_fc_add_range fc_ext;
struct ext4_fc_del_range lrange;
struct ext4_extent *ex;
int ret;
mutex_lock(&ei->i_fc_lock);
if (ei->i_fc_lblk_len == 0) {
mutex_unlock(&ei->i_fc_lock);
return 0;
}
old_blk_size = ei->i_fc_lblk_start;
new_blk_size = ei->i_fc_lblk_start + ei->i_fc_lblk_len - 1;
ei->i_fc_lblk_len = 0;
mutex_unlock(&ei->i_fc_lock);
cur_lblk_off = old_blk_size;
ext4_debug("will try writing %d to %d for inode %ld\n",
cur_lblk_off, new_blk_size, inode->i_ino);
while (cur_lblk_off <= new_blk_size) {
map.m_lblk = cur_lblk_off;
map.m_len = new_blk_size - cur_lblk_off + 1;
ret = ext4_map_blocks(NULL, inode, &map, 0);
if (ret < 0)
return -ECANCELED;
if (map.m_len == 0) {
cur_lblk_off++;
continue;
}
if (ret == 0) {
lrange.fc_ino = cpu_to_le32(inode->i_ino);
lrange.fc_lblk = cpu_to_le32(map.m_lblk);
lrange.fc_len = cpu_to_le32(map.m_len);
if (!ext4_fc_add_tlv(inode->i_sb, EXT4_FC_TAG_DEL_RANGE,
sizeof(lrange), (u8 *)&lrange, crc))
return -ENOSPC;
} else {
unsigned int max = (map.m_flags & EXT4_MAP_UNWRITTEN) ?
EXT_UNWRITTEN_MAX_LEN : EXT_INIT_MAX_LEN;
/* Limit the number of blocks in one extent */
map.m_len = min(max, map.m_len);
fc_ext.fc_ino = cpu_to_le32(inode->i_ino);
ex = (struct ext4_extent *)&fc_ext.fc_ex;
ex->ee_block = cpu_to_le32(map.m_lblk);
ex->ee_len = cpu_to_le16(map.m_len);
ext4_ext_store_pblock(ex, map.m_pblk);
if (map.m_flags & EXT4_MAP_UNWRITTEN)
ext4_ext_mark_unwritten(ex);
else
ext4_ext_mark_initialized(ex);
if (!ext4_fc_add_tlv(inode->i_sb, EXT4_FC_TAG_ADD_RANGE,
sizeof(fc_ext), (u8 *)&fc_ext, crc))
return -ENOSPC;
}
cur_lblk_off += map.m_len;
}
return 0;
}
/* Submit data for all the fast commit inodes */
static int ext4_fc_submit_inode_data_all(journal_t *journal)
{
struct super_block *sb = (struct super_block *)(journal->j_private);
struct ext4_sb_info *sbi = EXT4_SB(sb);
struct ext4_inode_info *ei;
int ret = 0;
spin_lock(&sbi->s_fc_lock);
list_for_each_entry(ei, &sbi->s_fc_q[FC_Q_MAIN], i_fc_list) {
ext4_set_inode_state(&ei->vfs_inode, EXT4_STATE_FC_COMMITTING);
while (atomic_read(&ei->i_fc_updates)) {
DEFINE_WAIT(wait);
prepare_to_wait(&ei->i_fc_wait, &wait,
TASK_UNINTERRUPTIBLE);
if (atomic_read(&ei->i_fc_updates)) {
spin_unlock(&sbi->s_fc_lock);
schedule();
spin_lock(&sbi->s_fc_lock);
}
finish_wait(&ei->i_fc_wait, &wait);
}
spin_unlock(&sbi->s_fc_lock);
ret = jbd2_submit_inode_data(ei->jinode);
if (ret)
return ret;
spin_lock(&sbi->s_fc_lock);
}
spin_unlock(&sbi->s_fc_lock);
return ret;
}
/* Wait for completion of data for all the fast commit inodes */
static int ext4_fc_wait_inode_data_all(journal_t *journal)
{
struct super_block *sb = (struct super_block *)(journal->j_private);
struct ext4_sb_info *sbi = EXT4_SB(sb);
struct ext4_inode_info *pos, *n;
int ret = 0;
spin_lock(&sbi->s_fc_lock);
list_for_each_entry_safe(pos, n, &sbi->s_fc_q[FC_Q_MAIN], i_fc_list) {
if (!ext4_test_inode_state(&pos->vfs_inode,
EXT4_STATE_FC_COMMITTING))
continue;
spin_unlock(&sbi->s_fc_lock);
ret = jbd2_wait_inode_data(journal, pos->jinode);
if (ret)
return ret;
spin_lock(&sbi->s_fc_lock);
}
spin_unlock(&sbi->s_fc_lock);
return 0;
}
/* Commit all the directory entry updates */
static int ext4_fc_commit_dentry_updates(journal_t *journal, u32 *crc)
__acquires(&sbi->s_fc_lock)
__releases(&sbi->s_fc_lock)
{
struct super_block *sb = (struct super_block *)(journal->j_private);
struct ext4_sb_info *sbi = EXT4_SB(sb);
struct ext4_fc_dentry_update *fc_dentry, *fc_dentry_n;
struct inode *inode;
struct ext4_inode_info *ei, *ei_n;
int ret;
if (list_empty(&sbi->s_fc_dentry_q[FC_Q_MAIN]))
return 0;
list_for_each_entry_safe(fc_dentry, fc_dentry_n,
&sbi->s_fc_dentry_q[FC_Q_MAIN], fcd_list) {
if (fc_dentry->fcd_op != EXT4_FC_TAG_CREAT) {
spin_unlock(&sbi->s_fc_lock);
if (!ext4_fc_add_dentry_tlv(sb, crc, fc_dentry)) {
ret = -ENOSPC;
goto lock_and_exit;
}
spin_lock(&sbi->s_fc_lock);
continue;
}
inode = NULL;
list_for_each_entry_safe(ei, ei_n, &sbi->s_fc_q[FC_Q_MAIN],
i_fc_list) {
if (ei->vfs_inode.i_ino == fc_dentry->fcd_ino) {
inode = &ei->vfs_inode;
break;
}
}
/*
* If we don't find inode in our list, then it was deleted,
* in which case, we don't need to record it's create tag.
*/
if (!inode)
continue;
spin_unlock(&sbi->s_fc_lock);
/*
* We first write the inode and then the create dirent. This
* allows the recovery code to create an unnamed inode first
* and then link it to a directory entry. This allows us
* to use namei.c routines almost as is and simplifies
* the recovery code.
*/
ret = ext4_fc_write_inode(inode, crc);
if (ret)
goto lock_and_exit;
ret = ext4_fc_write_inode_data(inode, crc);
if (ret)
goto lock_and_exit;
if (!ext4_fc_add_dentry_tlv(sb, crc, fc_dentry)) {
ret = -ENOSPC;
goto lock_and_exit;
}
spin_lock(&sbi->s_fc_lock);
}
return 0;
lock_and_exit:
spin_lock(&sbi->s_fc_lock);
return ret;
}
static int ext4_fc_perform_commit(journal_t *journal)
{
struct super_block *sb = (struct super_block *)(journal->j_private);
struct ext4_sb_info *sbi = EXT4_SB(sb);
struct ext4_inode_info *iter;
struct ext4_fc_head head;
struct inode *inode;
struct blk_plug plug;
int ret = 0;
u32 crc = 0;
ret = ext4_fc_submit_inode_data_all(journal);
if (ret)
return ret;
ret = ext4_fc_wait_inode_data_all(journal);
if (ret)
return ret;
/*
* If file system device is different from journal device, issue a cache
* flush before we start writing fast commit blocks.
*/
if (journal->j_fs_dev != journal->j_dev)
blkdev_issue_flush(journal->j_fs_dev);
blk_start_plug(&plug);
if (sbi->s_fc_bytes == 0) {
/*
* Add a head tag only if this is the first fast commit
* in this TID.
*/
head.fc_features = cpu_to_le32(EXT4_FC_SUPPORTED_FEATURES);
head.fc_tid = cpu_to_le32(
sbi->s_journal->j_running_transaction->t_tid);
if (!ext4_fc_add_tlv(sb, EXT4_FC_TAG_HEAD, sizeof(head),
(u8 *)&head, &crc)) {
ret = -ENOSPC;
goto out;
}
}
spin_lock(&sbi->s_fc_lock);
ret = ext4_fc_commit_dentry_updates(journal, &crc);
if (ret) {
spin_unlock(&sbi->s_fc_lock);
goto out;
}
list_for_each_entry(iter, &sbi->s_fc_q[FC_Q_MAIN], i_fc_list) {
inode = &iter->vfs_inode;
if (!ext4_test_inode_state(inode, EXT4_STATE_FC_COMMITTING))
continue;
spin_unlock(&sbi->s_fc_lock);
ret = ext4_fc_write_inode_data(inode, &crc);
if (ret)
goto out;
ret = ext4_fc_write_inode(inode, &crc);
if (ret)
goto out;
spin_lock(&sbi->s_fc_lock);
}
spin_unlock(&sbi->s_fc_lock);
ret = ext4_fc_write_tail(sb, crc);
out:
blk_finish_plug(&plug);
return ret;
}
static void ext4_fc_update_stats(struct super_block *sb, int status,
u64 commit_time, int nblks)
{
struct ext4_fc_stats *stats = &EXT4_SB(sb)->s_fc_stats;
ext4_debug("Fast commit ended with status = %d", status);
if (status == EXT4_FC_STATUS_OK) {
stats->fc_num_commits++;
stats->fc_numblks += nblks;
if (likely(stats->s_fc_avg_commit_time))
stats->s_fc_avg_commit_time =
(commit_time +
stats->s_fc_avg_commit_time * 3) / 4;
else
stats->s_fc_avg_commit_time = commit_time;
} else if (status == EXT4_FC_STATUS_FAILED ||
status == EXT4_FC_STATUS_INELIGIBLE) {
if (status == EXT4_FC_STATUS_FAILED)
stats->fc_failed_commits++;
stats->fc_ineligible_commits++;
} else {
stats->fc_skipped_commits++;
}
trace_ext4_fc_commit_stop(sb, nblks, status);
}
/*
* The main commit entry point. Performs a fast commit for transaction
* commit_tid if needed. If it's not possible to perform a fast commit
* due to various reasons, we fall back to full commit. Returns 0
* on success, error otherwise.
*/
int ext4_fc_commit(journal_t *journal, tid_t commit_tid)
{
struct super_block *sb = (struct super_block *)(journal->j_private);
struct ext4_sb_info *sbi = EXT4_SB(sb);
int nblks = 0, ret, bsize = journal->j_blocksize;
int subtid = atomic_read(&sbi->s_fc_subtid);
int status = EXT4_FC_STATUS_OK, fc_bufs_before = 0;
ktime_t start_time, commit_time;
trace_ext4_fc_commit_start(sb);
start_time = ktime_get();
if (!test_opt2(sb, JOURNAL_FAST_COMMIT))
return jbd2_complete_transaction(journal, commit_tid);
restart_fc:
ret = jbd2_fc_begin_commit(journal, commit_tid);
if (ret == -EALREADY) {
/* There was an ongoing commit, check if we need to restart */
if (atomic_read(&sbi->s_fc_subtid) <= subtid &&
commit_tid > journal->j_commit_sequence)
goto restart_fc;
ext4_fc_update_stats(sb, EXT4_FC_STATUS_SKIPPED, 0, 0);
return 0;
} else if (ret) {
/*
* Commit couldn't start. Just update stats and perform a
* full commit.
*/
ext4_fc_update_stats(sb, EXT4_FC_STATUS_FAILED, 0, 0);
return jbd2_complete_transaction(journal, commit_tid);
}
/*
* After establishing journal barrier via jbd2_fc_begin_commit(), check
* if we are fast commit ineligible.
*/
if (ext4_test_mount_flag(sb, EXT4_MF_FC_INELIGIBLE)) {
status = EXT4_FC_STATUS_INELIGIBLE;
goto fallback;
}
fc_bufs_before = (sbi->s_fc_bytes + bsize - 1) / bsize;
ret = ext4_fc_perform_commit(journal);
if (ret < 0) {
status = EXT4_FC_STATUS_FAILED;
goto fallback;
}
nblks = (sbi->s_fc_bytes + bsize - 1) / bsize - fc_bufs_before;
ret = jbd2_fc_wait_bufs(journal, nblks);
if (ret < 0) {
status = EXT4_FC_STATUS_FAILED;
goto fallback;
}
atomic_inc(&sbi->s_fc_subtid);
ret = jbd2_fc_end_commit(journal);
/*
* weight the commit time higher than the average time so we
* don't react too strongly to vast changes in the commit time
*/
commit_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
ext4_fc_update_stats(sb, status, commit_time, nblks);
return ret;
fallback:
ret = jbd2_fc_end_commit_fallback(journal);
ext4_fc_update_stats(sb, status, 0, 0);
return ret;
}
/*
* Fast commit cleanup routine. This is called after every fast commit and
* full commit. full is true if we are called after a full commit.
*/
static void ext4_fc_cleanup(journal_t *journal, int full, tid_t tid)
{
struct super_block *sb = journal->j_private;
struct ext4_sb_info *sbi = EXT4_SB(sb);
struct ext4_inode_info *iter, *iter_n;
struct ext4_fc_dentry_update *fc_dentry;
if (full && sbi->s_fc_bh)
sbi->s_fc_bh = NULL;
jbd2_fc_release_bufs(journal);
spin_lock(&sbi->s_fc_lock);
list_for_each_entry_safe(iter, iter_n, &sbi->s_fc_q[FC_Q_MAIN],
i_fc_list) {
list_del_init(&iter->i_fc_list);
ext4_clear_inode_state(&iter->vfs_inode,
EXT4_STATE_FC_COMMITTING);
if (iter->i_sync_tid <= tid)
ext4_fc_reset_inode(&iter->vfs_inode);
/* Make sure EXT4_STATE_FC_COMMITTING bit is clear */
smp_mb();
#if (BITS_PER_LONG < 64)
wake_up_bit(&iter->i_state_flags, EXT4_STATE_FC_COMMITTING);
#else
wake_up_bit(&iter->i_flags, EXT4_STATE_FC_COMMITTING);
#endif
}
while (!list_empty(&sbi->s_fc_dentry_q[FC_Q_MAIN])) {
fc_dentry = list_first_entry(&sbi->s_fc_dentry_q[FC_Q_MAIN],
struct ext4_fc_dentry_update,
fcd_list);
list_del_init(&fc_dentry->fcd_list);
spin_unlock(&sbi->s_fc_lock);
if (fc_dentry->fcd_name.name &&
fc_dentry->fcd_name.len > DNAME_INLINE_LEN)
kfree(fc_dentry->fcd_name.name);
kmem_cache_free(ext4_fc_dentry_cachep, fc_dentry);
spin_lock(&sbi->s_fc_lock);
}
list_splice_init(&sbi->s_fc_dentry_q[FC_Q_STAGING],
&sbi->s_fc_dentry_q[FC_Q_MAIN]);
list_splice_init(&sbi->s_fc_q[FC_Q_STAGING],
&sbi->s_fc_q[FC_Q_MAIN]);
if (tid >= sbi->s_fc_ineligible_tid) {
sbi->s_fc_ineligible_tid = 0;
ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
}
if (full)
sbi->s_fc_bytes = 0;
spin_unlock(&sbi->s_fc_lock);
trace_ext4_fc_stats(sb);
}
/* Ext4 Replay Path Routines */
/* Helper struct for dentry replay routines */
struct dentry_info_args {
int parent_ino, dname_len, ino, inode_len;
char *dname;
};
/* Same as struct ext4_fc_tl, but uses native endianness fields */
struct ext4_fc_tl_mem {
u16 fc_tag;
u16 fc_len;
};
static inline void tl_to_darg(struct dentry_info_args *darg,
struct ext4_fc_tl_mem *tl, u8 *val)
{
struct ext4_fc_dentry_info fcd;
memcpy(&fcd, val, sizeof(fcd));
darg->parent_ino = le32_to_cpu(fcd.fc_parent_ino);
darg->ino = le32_to_cpu(fcd.fc_ino);
darg->dname = val + offsetof(struct ext4_fc_dentry_info, fc_dname);
darg->dname_len = tl->fc_len - sizeof(struct ext4_fc_dentry_info);
}
static inline void ext4_fc_get_tl(struct ext4_fc_tl_mem *tl, u8 *val)
{
struct ext4_fc_tl tl_disk;
memcpy(&tl_disk, val, EXT4_FC_TAG_BASE_LEN);
tl->fc_len = le16_to_cpu(tl_disk.fc_len);
tl->fc_tag = le16_to_cpu(tl_disk.fc_tag);
}
/* Unlink replay function */
static int ext4_fc_replay_unlink(struct super_block *sb,
struct ext4_fc_tl_mem *tl, u8 *val)
{
struct inode *inode, *old_parent;
struct qstr entry;
struct dentry_info_args darg;
int ret = 0;
tl_to_darg(&darg, tl, val);
trace_ext4_fc_replay(sb, EXT4_FC_TAG_UNLINK, darg.ino,
darg.parent_ino, darg.dname_len);
entry.name = darg.dname;
entry.len = darg.dname_len;
inode = ext4_iget(sb, darg.ino, EXT4_IGET_NORMAL);
if (IS_ERR(inode)) {
ext4_debug("Inode %d not found", darg.ino);
return 0;
}
old_parent = ext4_iget(sb, darg.parent_ino,
EXT4_IGET_NORMAL);
if (IS_ERR(old_parent)) {
ext4_debug("Dir with inode %d not found", darg.parent_ino);
iput(inode);
return 0;
}
ret = __ext4_unlink(old_parent, &entry, inode, NULL);
/* -ENOENT ok coz it might not exist anymore. */
if (ret == -ENOENT)
ret = 0;
iput(old_parent);
iput(inode);
return ret;
}
static int ext4_fc_replay_link_internal(struct super_block *sb,
struct dentry_info_args *darg,
struct inode *inode)
{
struct inode *dir = NULL;
struct dentry *dentry_dir = NULL, *dentry_inode = NULL;
struct qstr qstr_dname = QSTR_INIT(darg->dname, darg->dname_len);
int ret = 0;
dir = ext4_iget(sb, darg->parent_ino, EXT4_IGET_NORMAL);
if (IS_ERR(dir)) {
ext4_debug("Dir with inode %d not found.", darg->parent_ino);
dir = NULL;
goto out;
}
dentry_dir = d_obtain_alias(dir);
if (IS_ERR(dentry_dir)) {
ext4_debug("Failed to obtain dentry");
dentry_dir = NULL;
goto out;
}
dentry_inode = d_alloc(dentry_dir, &qstr_dname);
if (!dentry_inode) {
ext4_debug("Inode dentry not created.");
ret = -ENOMEM;
goto out;
}
ret = __ext4_link(dir, inode, dentry_inode);
/*
* It's possible that link already existed since data blocks
* for the dir in question got persisted before we crashed OR
* we replayed this tag and crashed before the entire replay
* could complete.
*/
if (ret && ret != -EEXIST) {
ext4_debug("Failed to link\n");
goto out;
}
ret = 0;
out:
if (dentry_dir) {
d_drop(dentry_dir);
dput(dentry_dir);
} else if (dir) {
iput(dir);
}
if (dentry_inode) {
d_drop(dentry_inode);
dput(dentry_inode);
}
return ret;
}
/* Link replay function */
static int ext4_fc_replay_link(struct super_block *sb,
struct ext4_fc_tl_mem *tl, u8 *val)
{
struct inode *inode;
struct dentry_info_args darg;
int ret = 0;
tl_to_darg(&darg, tl, val);
trace_ext4_fc_replay(sb, EXT4_FC_TAG_LINK, darg.ino,
darg.parent_ino, darg.dname_len);
inode = ext4_iget(sb, darg.ino, EXT4_IGET_NORMAL);
if (IS_ERR(inode)) {
ext4_debug("Inode not found.");
return 0;
}
ret = ext4_fc_replay_link_internal(sb, &darg, inode);
iput(inode);
return ret;
}
/*
* Record all the modified inodes during replay. We use this later to setup
* block bitmaps correctly.
*/
static int ext4_fc_record_modified_inode(struct super_block *sb, int ino)
{
struct ext4_fc_replay_state *state;
int i;
state = &EXT4_SB(sb)->s_fc_replay_state;
for (i = 0; i < state->fc_modified_inodes_used; i++)
if (state->fc_modified_inodes[i] == ino)
return 0;
if (state->fc_modified_inodes_used == state->fc_modified_inodes_size) {
int *fc_modified_inodes;
fc_modified_inodes = krealloc(state->fc_modified_inodes,
sizeof(int) * (state->fc_modified_inodes_size +
EXT4_FC_REPLAY_REALLOC_INCREMENT),
GFP_KERNEL);
if (!fc_modified_inodes)
return -ENOMEM;
state->fc_modified_inodes = fc_modified_inodes;
state->fc_modified_inodes_size +=
EXT4_FC_REPLAY_REALLOC_INCREMENT;
}
state->fc_modified_inodes[state->fc_modified_inodes_used++] = ino;
return 0;
}
/*
* Inode replay function
*/
static int ext4_fc_replay_inode(struct super_block *sb,
struct ext4_fc_tl_mem *tl, u8 *val)
{
struct ext4_fc_inode fc_inode;
struct ext4_inode *raw_inode;
struct ext4_inode *raw_fc_inode;
struct inode *inode = NULL;
struct ext4_iloc iloc;
int inode_len, ino, ret, tag = tl->fc_tag;
struct ext4_extent_header *eh;
memcpy(&fc_inode, val, sizeof(fc_inode));
ino = le32_to_cpu(fc_inode.fc_ino);
trace_ext4_fc_replay(sb, tag, ino, 0, 0);
inode = ext4_iget(sb, ino, EXT4_IGET_NORMAL);
if (!IS_ERR(inode)) {
ext4_ext_clear_bb(inode);
iput(inode);
}
inode = NULL;
ret = ext4_fc_record_modified_inode(sb, ino);
if (ret)
goto out;
raw_fc_inode = (struct ext4_inode *)
(val + offsetof(struct ext4_fc_inode, fc_raw_inode));
ret = ext4_get_fc_inode_loc(sb, ino, &iloc);
if (ret)
goto out;
inode_len = tl->fc_len - sizeof(struct ext4_fc_inode);
raw_inode = ext4_raw_inode(&iloc);
memcpy(raw_inode, raw_fc_inode, offsetof(struct ext4_inode, i_block));
memcpy(&raw_inode->i_generation, &raw_fc_inode->i_generation,
inode_len - offsetof(struct ext4_inode, i_generation));
if (le32_to_cpu(raw_inode->i_flags) & EXT4_EXTENTS_FL) {
eh = (struct ext4_extent_header *)(&raw_inode->i_block[0]);
if (eh->eh_magic != EXT4_EXT_MAGIC) {
memset(eh, 0, sizeof(*eh));
eh->eh_magic = EXT4_EXT_MAGIC;
eh->eh_max = cpu_to_le16(
(sizeof(raw_inode->i_block) -
sizeof(struct ext4_extent_header))
/ sizeof(struct ext4_extent));
}
} else if (le32_to_cpu(raw_inode->i_flags) & EXT4_INLINE_DATA_FL) {
memcpy(raw_inode->i_block, raw_fc_inode->i_block,
sizeof(raw_inode->i_block));
}
/* Immediately update the inode on disk. */
ret = ext4_handle_dirty_metadata(NULL, NULL, iloc.bh);
if (ret)
goto out;
ret = sync_dirty_buffer(iloc.bh);
if (ret)
goto out;
ret = ext4_mark_inode_used(sb, ino);
if (ret)
goto out;
/* Given that we just wrote the inode on disk, this SHOULD succeed. */
inode = ext4_iget(sb, ino, EXT4_IGET_NORMAL);
if (IS_ERR(inode)) {
ext4_debug("Inode not found.");
return -EFSCORRUPTED;
}
/*
* Our allocator could have made different decisions than before
* crashing. This should be fixed but until then, we calculate
* the number of blocks the inode.
*/
ext4_ext_replay_set_iblocks(inode);
inode->i_generation = le32_to_cpu(ext4_raw_inode(&iloc)->i_generation);
ext4_reset_inode_seed(inode);
ext4_inode_csum_set(inode, ext4_raw_inode(&iloc), EXT4_I(inode));
ret = ext4_handle_dirty_metadata(NULL, NULL, iloc.bh);
sync_dirty_buffer(iloc.bh);
brelse(iloc.bh);
out:
iput(inode);
if (!ret)
blkdev_issue_flush(sb->s_bdev);
return 0;
}
/*
* Dentry create replay function.
*
* EXT4_FC_TAG_CREAT is preceded by EXT4_FC_TAG_INODE_FULL. Which means, the
* inode for which we are trying to create a dentry here, should already have
* been replayed before we start here.
*/
static int ext4_fc_replay_create(struct super_block *sb,
struct ext4_fc_tl_mem *tl, u8 *val)
{
int ret = 0;
struct inode *inode = NULL;
struct inode *dir = NULL;
struct dentry_info_args darg;
tl_to_darg(&darg, tl, val);
trace_ext4_fc_replay(sb, EXT4_FC_TAG_CREAT, darg.ino,
darg.parent_ino, darg.dname_len);
/* This takes care of update group descriptor and other metadata */
ret = ext4_mark_inode_used(sb, darg.ino);
if (ret)
goto out;
inode = ext4_iget(sb, darg.ino, EXT4_IGET_NORMAL);
if (IS_ERR(inode)) {
ext4_debug("inode %d not found.", darg.ino);
inode = NULL;
ret = -EINVAL;
goto out;
}
if (S_ISDIR(inode->i_mode)) {
/*
* If we are creating a directory, we need to make sure that the
* dot and dot dot dirents are setup properly.
*/
dir = ext4_iget(sb, darg.parent_ino, EXT4_IGET_NORMAL);
if (IS_ERR(dir)) {
ext4_debug("Dir %d not found.", darg.ino);
goto out;
}
ret = ext4_init_new_dir(NULL, dir, inode);
iput(dir);
if (ret) {
ret = 0;
goto out;
}
}
ret = ext4_fc_replay_link_internal(sb, &darg, inode);
if (ret)
goto out;
set_nlink(inode, 1);
ext4_mark_inode_dirty(NULL, inode);
out:
if (inode)
iput(inode);
return ret;
}
/*
* Record physical disk regions which are in use as per fast commit area,
* and used by inodes during replay phase. Our simple replay phase
* allocator excludes these regions from allocation.
*/
int ext4_fc_record_regions(struct super_block *sb, int ino,
ext4_lblk_t lblk, ext4_fsblk_t pblk, int len, int replay)
{
struct ext4_fc_replay_state *state;
struct ext4_fc_alloc_region *region;
state = &EXT4_SB(sb)->s_fc_replay_state;
/*
* during replay phase, the fc_regions_valid may not same as
* fc_regions_used, update it when do new additions.
*/
if (replay && state->fc_regions_used != state->fc_regions_valid)
state->fc_regions_used = state->fc_regions_valid;
if (state->fc_regions_used == state->fc_regions_size) {
struct ext4_fc_alloc_region *fc_regions;
fc_regions = krealloc(state->fc_regions,
sizeof(struct ext4_fc_alloc_region) *
(state->fc_regions_size +
EXT4_FC_REPLAY_REALLOC_INCREMENT),
GFP_KERNEL);
if (!fc_regions)
return -ENOMEM;
state->fc_regions_size +=
EXT4_FC_REPLAY_REALLOC_INCREMENT;
state->fc_regions = fc_regions;
}
region = &state->fc_regions[state->fc_regions_used++];
region->ino = ino;
region->lblk = lblk;
region->pblk = pblk;
region->len = len;
if (replay)
state->fc_regions_valid++;
return 0;
}
/* Replay add range tag */
static int ext4_fc_replay_add_range(struct super_block *sb,
struct ext4_fc_tl_mem *tl, u8 *val)
{
struct ext4_fc_add_range fc_add_ex;
struct ext4_extent newex, *ex;
struct inode *inode;
ext4_lblk_t start, cur;
int remaining, len;
ext4_fsblk_t start_pblk;
struct ext4_map_blocks map;
struct ext4_ext_path *path = NULL;
int ret;
memcpy(&fc_add_ex, val, sizeof(fc_add_ex));
ex = (struct ext4_extent *)&fc_add_ex.fc_ex;
trace_ext4_fc_replay(sb, EXT4_FC_TAG_ADD_RANGE,
le32_to_cpu(fc_add_ex.fc_ino), le32_to_cpu(ex->ee_block),
ext4_ext_get_actual_len(ex));
inode = ext4_iget(sb, le32_to_cpu(fc_add_ex.fc_ino), EXT4_IGET_NORMAL);
if (IS_ERR(inode)) {
ext4_debug("Inode not found.");
return 0;
}
ret = ext4_fc_record_modified_inode(sb, inode->i_ino);
if (ret)
goto out;
start = le32_to_cpu(ex->ee_block);
start_pblk = ext4_ext_pblock(ex);
len = ext4_ext_get_actual_len(ex);
cur = start;
remaining = len;
ext4_debug("ADD_RANGE, lblk %d, pblk %lld, len %d, unwritten %d, inode %ld\n",
start, start_pblk, len, ext4_ext_is_unwritten(ex),
inode->i_ino);
while (remaining > 0) {
map.m_lblk = cur;
map.m_len = remaining;
map.m_pblk = 0;
ret = ext4_map_blocks(NULL, inode, &map, 0);
if (ret < 0)
goto out;
if (ret == 0) {
/* Range is not mapped */
path = ext4_find_extent(inode, cur, NULL, 0);
if (IS_ERR(path))
goto out;
memset(&newex, 0, sizeof(newex));
newex.ee_block = cpu_to_le32(cur);
ext4_ext_store_pblock(
&newex, start_pblk + cur - start);
newex.ee_len = cpu_to_le16(map.m_len);
if (ext4_ext_is_unwritten(ex))
ext4_ext_mark_unwritten(&newex);
down_write(&EXT4_I(inode)->i_data_sem);
ret = ext4_ext_insert_extent(
NULL, inode, &path, &newex, 0);
up_write((&EXT4_I(inode)->i_data_sem));
ext4_ext_drop_refs(path);
kfree(path);
if (ret)
goto out;
goto next;
}
if (start_pblk + cur - start != map.m_pblk) {
/*
* Logical to physical mapping changed. This can happen
* if this range was removed and then reallocated to
* map to new physical blocks during a fast commit.
*/
ret = ext4_ext_replay_update_ex(inode, cur, map.m_len,
ext4_ext_is_unwritten(ex),
start_pblk + cur - start);
if (ret)
goto out;
/*
* Mark the old blocks as free since they aren't used
* anymore. We maintain an array of all the modified
* inodes. In case these blocks are still used at either
* a different logical range in the same inode or in
* some different inode, we will mark them as allocated
* at the end of the FC replay using our array of
* modified inodes.
*/
ext4_mb_mark_bb(inode->i_sb, map.m_pblk, map.m_len, 0);
goto next;
}
/* Range is mapped and needs a state change */
ext4_debug("Converting from %ld to %d %lld",
map.m_flags & EXT4_MAP_UNWRITTEN,
ext4_ext_is_unwritten(ex), map.m_pblk);
ret = ext4_ext_replay_update_ex(inode, cur, map.m_len,
ext4_ext_is_unwritten(ex), map.m_pblk);
if (ret)
goto out;
/*
* We may have split the extent tree while toggling the state.
* Try to shrink the extent tree now.
*/
ext4_ext_replay_shrink_inode(inode, start + len);
next:
cur += map.m_len;
remaining -= map.m_len;
}
ext4_ext_replay_shrink_inode(inode, i_size_read(inode) >>
sb->s_blocksize_bits);
out:
iput(inode);
return 0;
}
/* Replay DEL_RANGE tag */
static int
ext4_fc_replay_del_range(struct super_block *sb,
struct ext4_fc_tl_mem *tl, u8 *val)
{
struct inode *inode;
struct ext4_fc_del_range lrange;
struct ext4_map_blocks map;
ext4_lblk_t cur, remaining;
int ret;
memcpy(&lrange, val, sizeof(lrange));
cur = le32_to_cpu(lrange.fc_lblk);
remaining = le32_to_cpu(lrange.fc_len);
trace_ext4_fc_replay(sb, EXT4_FC_TAG_DEL_RANGE,
le32_to_cpu(lrange.fc_ino), cur, remaining);
inode = ext4_iget(sb, le32_to_cpu(lrange.fc_ino), EXT4_IGET_NORMAL);
if (IS_ERR(inode)) {
ext4_debug("Inode %d not found", le32_to_cpu(lrange.fc_ino));
return 0;
}
ret = ext4_fc_record_modified_inode(sb, inode->i_ino);
if (ret)
goto out;
ext4_debug("DEL_RANGE, inode %ld, lblk %d, len %d\n",
inode->i_ino, le32_to_cpu(lrange.fc_lblk),
le32_to_cpu(lrange.fc_len));
while (remaining > 0) {
map.m_lblk = cur;
map.m_len = remaining;
ret = ext4_map_blocks(NULL, inode, &map, 0);
if (ret < 0)
goto out;
if (ret > 0) {
remaining -= ret;
cur += ret;
ext4_mb_mark_bb(inode->i_sb, map.m_pblk, map.m_len, 0);
} else {
remaining -= map.m_len;
cur += map.m_len;
}
}
down_write(&EXT4_I(inode)->i_data_sem);
ret = ext4_ext_remove_space(inode, le32_to_cpu(lrange.fc_lblk),
le32_to_cpu(lrange.fc_lblk) +
le32_to_cpu(lrange.fc_len) - 1);
up_write(&EXT4_I(inode)->i_data_sem);
if (ret)
goto out;
ext4_ext_replay_shrink_inode(inode,
i_size_read(inode) >> sb->s_blocksize_bits);
ext4_mark_inode_dirty(NULL, inode);
out:
iput(inode);
return 0;
}
static void ext4_fc_set_bitmaps_and_counters(struct super_block *sb)
{
struct ext4_fc_replay_state *state;
struct inode *inode;
struct ext4_ext_path *path = NULL;
struct ext4_map_blocks map;
int i, ret, j;
ext4_lblk_t cur, end;
state = &EXT4_SB(sb)->s_fc_replay_state;
for (i = 0; i < state->fc_modified_inodes_used; i++) {
inode = ext4_iget(sb, state->fc_modified_inodes[i],
EXT4_IGET_NORMAL);
if (IS_ERR(inode)) {
ext4_debug("Inode %d not found.",
state->fc_modified_inodes[i]);
continue;
}
cur = 0;
end = EXT_MAX_BLOCKS;
while (cur < end) {
map.m_lblk = cur;
map.m_len = end - cur;
ret = ext4_map_blocks(NULL, inode, &map, 0);
if (ret < 0)
break;
if (ret > 0) {
path = ext4_find_extent(inode, map.m_lblk, NULL, 0);
if (!IS_ERR(path)) {
for (j = 0; j < path->p_depth; j++)
ext4_mb_mark_bb(inode->i_sb,
path[j].p_block, 1, 1);
ext4_ext_drop_refs(path);
kfree(path);
}
cur += ret;
ext4_mb_mark_bb(inode->i_sb, map.m_pblk,
map.m_len, 1);
} else {
cur = cur + (map.m_len ? map.m_len : 1);
}
}
iput(inode);
}
}
/*
* Check if block is in excluded regions for block allocation. The simple
* allocator that runs during replay phase is calls this function to see
* if it is okay to use a block.
*/
bool ext4_fc_replay_check_excluded(struct super_block *sb, ext4_fsblk_t blk)
{
int i;
struct ext4_fc_replay_state *state;
state = &EXT4_SB(sb)->s_fc_replay_state;
for (i = 0; i < state->fc_regions_valid; i++) {
if (state->fc_regions[i].ino == 0 ||
state->fc_regions[i].len == 0)
continue;
if (blk >= state->fc_regions[i].pblk &&
blk < state->fc_regions[i].pblk + state->fc_regions[i].len)
return true;
}
return false;
}
/* Cleanup function called after replay */
void ext4_fc_replay_cleanup(struct super_block *sb)
{
struct ext4_sb_info *sbi = EXT4_SB(sb);
sbi->s_mount_state &= ~EXT4_FC_REPLAY;
kfree(sbi->s_fc_replay_state.fc_regions);
kfree(sbi->s_fc_replay_state.fc_modified_inodes);
}
static bool ext4_fc_value_len_isvalid(struct ext4_sb_info *sbi,
int tag, int len)
{
switch (tag) {
case EXT4_FC_TAG_ADD_RANGE:
return len == sizeof(struct ext4_fc_add_range);
case EXT4_FC_TAG_DEL_RANGE:
return len == sizeof(struct ext4_fc_del_range);
case EXT4_FC_TAG_CREAT:
case EXT4_FC_TAG_LINK:
case EXT4_FC_TAG_UNLINK:
len -= sizeof(struct ext4_fc_dentry_info);
return len >= 1 && len <= EXT4_NAME_LEN;
case EXT4_FC_TAG_INODE:
len -= sizeof(struct ext4_fc_inode);
return len >= EXT4_GOOD_OLD_INODE_SIZE &&
len <= sbi->s_inode_size;
case EXT4_FC_TAG_PAD:
return true; /* padding can have any length */
case EXT4_FC_TAG_TAIL:
return len >= sizeof(struct ext4_fc_tail);
case EXT4_FC_TAG_HEAD:
return len == sizeof(struct ext4_fc_head);
}
return false;
}
/*
* Recovery Scan phase handler
*
* This function is called during the scan phase and is responsible
* for doing following things:
* - Make sure the fast commit area has valid tags for replay
* - Count number of tags that need to be replayed by the replay handler
* - Verify CRC
* - Create a list of excluded blocks for allocation during replay phase
*
* This function returns JBD2_FC_REPLAY_CONTINUE to indicate that SCAN is
* incomplete and JBD2 should send more blocks. It returns JBD2_FC_REPLAY_STOP
* to indicate that scan has finished and JBD2 can now start replay phase.
* It returns a negative error to indicate that there was an error. At the end
* of a successful scan phase, sbi->s_fc_replay_state.fc_replay_num_tags is set
* to indicate the number of tags that need to replayed during the replay phase.
*/
static int ext4_fc_replay_scan(journal_t *journal,
struct buffer_head *bh, int off,
tid_t expected_tid)
{
struct super_block *sb = journal->j_private;
struct ext4_sb_info *sbi = EXT4_SB(sb);
struct ext4_fc_replay_state *state;
int ret = JBD2_FC_REPLAY_CONTINUE;
struct ext4_fc_add_range ext;
struct ext4_fc_tl_mem tl;
struct ext4_fc_tail tail;
__u8 *start, *end, *cur, *val;
struct ext4_fc_head head;
struct ext4_extent *ex;
state = &sbi->s_fc_replay_state;
start = (u8 *)bh->b_data;
end = start + journal->j_blocksize;
if (state->fc_replay_expected_off == 0) {
state->fc_cur_tag = 0;
state->fc_replay_num_tags = 0;
state->fc_crc = 0;
state->fc_regions = NULL;
state->fc_regions_valid = state->fc_regions_used =
state->fc_regions_size = 0;
/* Check if we can stop early */
if (le16_to_cpu(((struct ext4_fc_tl *)start)->fc_tag)
!= EXT4_FC_TAG_HEAD)
return 0;
}
if (off != state->fc_replay_expected_off) {
ret = -EFSCORRUPTED;
goto out_err;
}
state->fc_replay_expected_off++;
for (cur = start; cur <= end - EXT4_FC_TAG_BASE_LEN;
cur = cur + EXT4_FC_TAG_BASE_LEN + tl.fc_len) {
ext4_fc_get_tl(&tl, cur);
val = cur + EXT4_FC_TAG_BASE_LEN;
if (tl.fc_len > end - val ||
!ext4_fc_value_len_isvalid(sbi, tl.fc_tag, tl.fc_len)) {
ret = state->fc_replay_num_tags ?
JBD2_FC_REPLAY_STOP : -ECANCELED;
goto out_err;
}
ext4_debug("Scan phase, tag:%s, blk %lld\n",
tag2str(tl.fc_tag), bh->b_blocknr);
switch (tl.fc_tag) {
case EXT4_FC_TAG_ADD_RANGE:
memcpy(&ext, val, sizeof(ext));
ex = (struct ext4_extent *)&ext.fc_ex;
ret = ext4_fc_record_regions(sb,
le32_to_cpu(ext.fc_ino),
le32_to_cpu(ex->ee_block), ext4_ext_pblock(ex),
ext4_ext_get_actual_len(ex), 0);
if (ret < 0)
break;
ret = JBD2_FC_REPLAY_CONTINUE;
fallthrough;
case EXT4_FC_TAG_DEL_RANGE:
case EXT4_FC_TAG_LINK:
case EXT4_FC_TAG_UNLINK:
case EXT4_FC_TAG_CREAT:
case EXT4_FC_TAG_INODE:
case EXT4_FC_TAG_PAD:
state->fc_cur_tag++;
state->fc_crc = ext4_chksum(sbi, state->fc_crc, cur,
EXT4_FC_TAG_BASE_LEN + tl.fc_len);
break;
case EXT4_FC_TAG_TAIL:
state->fc_cur_tag++;
memcpy(&tail, val, sizeof(tail));
state->fc_crc = ext4_chksum(sbi, state->fc_crc, cur,
EXT4_FC_TAG_BASE_LEN +
offsetof(struct ext4_fc_tail,
fc_crc));
if (le32_to_cpu(tail.fc_tid) == expected_tid &&
le32_to_cpu(tail.fc_crc) == state->fc_crc) {
state->fc_replay_num_tags = state->fc_cur_tag;
state->fc_regions_valid =
state->fc_regions_used;
} else {
ret = state->fc_replay_num_tags ?
JBD2_FC_REPLAY_STOP : -EFSBADCRC;
}
state->fc_crc = 0;
break;
case EXT4_FC_TAG_HEAD:
memcpy(&head, val, sizeof(head));
if (le32_to_cpu(head.fc_features) &
~EXT4_FC_SUPPORTED_FEATURES) {
ret = -EOPNOTSUPP;
break;
}
if (le32_to_cpu(head.fc_tid) != expected_tid) {
ret = JBD2_FC_REPLAY_STOP;
break;
}
state->fc_cur_tag++;
state->fc_crc = ext4_chksum(sbi, state->fc_crc, cur,
EXT4_FC_TAG_BASE_LEN + tl.fc_len);
break;
default:
ret = state->fc_replay_num_tags ?
JBD2_FC_REPLAY_STOP : -ECANCELED;
}
if (ret < 0 || ret == JBD2_FC_REPLAY_STOP)
break;
}
out_err:
trace_ext4_fc_replay_scan(sb, ret, off);
return ret;
}
/*
* Main recovery path entry point.
* The meaning of return codes is similar as above.
*/
static int ext4_fc_replay(journal_t *journal, struct buffer_head *bh,
enum passtype pass, int off, tid_t expected_tid)
{
struct super_block *sb = journal->j_private;
struct ext4_sb_info *sbi = EXT4_SB(sb);
struct ext4_fc_tl_mem tl;
__u8 *start, *end, *cur, *val;
int ret = JBD2_FC_REPLAY_CONTINUE;
struct ext4_fc_replay_state *state = &sbi->s_fc_replay_state;
struct ext4_fc_tail tail;
if (pass == PASS_SCAN) {
state->fc_current_pass = PASS_SCAN;
return ext4_fc_replay_scan(journal, bh, off, expected_tid);
}
if (state->fc_current_pass != pass) {
state->fc_current_pass = pass;
sbi->s_mount_state |= EXT4_FC_REPLAY;
}
if (!sbi->s_fc_replay_state.fc_replay_num_tags) {
ext4_debug("Replay stops\n");
ext4_fc_set_bitmaps_and_counters(sb);
return 0;
}
#ifdef CONFIG_EXT4_DEBUG
if (sbi->s_fc_debug_max_replay && off >= sbi->s_fc_debug_max_replay) {
pr_warn("Dropping fc block %d because max_replay set\n", off);
return JBD2_FC_REPLAY_STOP;
}
#endif
start = (u8 *)bh->b_data;
end = start + journal->j_blocksize;
for (cur = start; cur <= end - EXT4_FC_TAG_BASE_LEN;
cur = cur + EXT4_FC_TAG_BASE_LEN + tl.fc_len) {
ext4_fc_get_tl(&tl, cur);
val = cur + EXT4_FC_TAG_BASE_LEN;
if (state->fc_replay_num_tags == 0) {
ret = JBD2_FC_REPLAY_STOP;
ext4_fc_set_bitmaps_and_counters(sb);
break;
}
ext4_debug("Replay phase, tag:%s\n", tag2str(tl.fc_tag));
state->fc_replay_num_tags--;
switch (tl.fc_tag) {
case EXT4_FC_TAG_LINK:
ret = ext4_fc_replay_link(sb, &tl, val);
break;
case EXT4_FC_TAG_UNLINK:
ret = ext4_fc_replay_unlink(sb, &tl, val);
break;
case EXT4_FC_TAG_ADD_RANGE:
ret = ext4_fc_replay_add_range(sb, &tl, val);
break;
case EXT4_FC_TAG_CREAT:
ret = ext4_fc_replay_create(sb, &tl, val);
break;
case EXT4_FC_TAG_DEL_RANGE:
ret = ext4_fc_replay_del_range(sb, &tl, val);
break;
case EXT4_FC_TAG_INODE:
ret = ext4_fc_replay_inode(sb, &tl, val);
break;
case EXT4_FC_TAG_PAD:
trace_ext4_fc_replay(sb, EXT4_FC_TAG_PAD, 0,
tl.fc_len, 0);
break;
case EXT4_FC_TAG_TAIL:
trace_ext4_fc_replay(sb, EXT4_FC_TAG_TAIL,
0, tl.fc_len, 0);
memcpy(&tail, val, sizeof(tail));
WARN_ON(le32_to_cpu(tail.fc_tid) != expected_tid);
break;
case EXT4_FC_TAG_HEAD:
break;
default:
trace_ext4_fc_replay(sb, tl.fc_tag, 0, tl.fc_len, 0);
ret = -ECANCELED;
break;
}
if (ret < 0)
break;
ret = JBD2_FC_REPLAY_CONTINUE;
}
return ret;
}
void ext4_fc_init(struct super_block *sb, journal_t *journal)
{
/*
* We set replay callback even if fast commit disabled because we may
* could still have fast commit blocks that need to be replayed even if
* fast commit has now been turned off.
*/
journal->j_fc_replay_callback = ext4_fc_replay;
if (!test_opt2(sb, JOURNAL_FAST_COMMIT))
return;
journal->j_fc_cleanup_callback = ext4_fc_cleanup;
}
static const char * const fc_ineligible_reasons[] = {
[EXT4_FC_REASON_XATTR] = "Extended attributes changed",
[EXT4_FC_REASON_CROSS_RENAME] = "Cross rename",
[EXT4_FC_REASON_JOURNAL_FLAG_CHANGE] = "Journal flag changed",
[EXT4_FC_REASON_NOMEM] = "Insufficient memory",
[EXT4_FC_REASON_SWAP_BOOT] = "Swap boot",
[EXT4_FC_REASON_RESIZE] = "Resize",
[EXT4_FC_REASON_RENAME_DIR] = "Dir renamed",
[EXT4_FC_REASON_FALLOC_RANGE] = "Falloc range op",
[EXT4_FC_REASON_INODE_JOURNAL_DATA] = "Data journalling",
[EXT4_FC_REASON_ENCRYPTED_FILENAME] = "Encrypted filename",
};
int ext4_fc_info_show(struct seq_file *seq, void *v)
{
struct ext4_sb_info *sbi = EXT4_SB((struct super_block *)seq->private);
struct ext4_fc_stats *stats = &sbi->s_fc_stats;
int i;
if (v != SEQ_START_TOKEN)
return 0;
seq_printf(seq,
"fc stats:\n%ld commits\n%ld ineligible\n%ld numblks\n%lluus avg_commit_time\n",
stats->fc_num_commits, stats->fc_ineligible_commits,
stats->fc_numblks,
div_u64(stats->s_fc_avg_commit_time, 1000));
seq_puts(seq, "Ineligible reasons:\n");
for (i = 0; i < EXT4_FC_REASON_MAX; i++)
seq_printf(seq, "\"%s\":\t%d\n", fc_ineligible_reasons[i],
stats->fc_ineligible_reason_count[i]);
return 0;
}
int __init ext4_fc_init_dentry_cache(void)
{
ext4_fc_dentry_cachep = KMEM_CACHE(ext4_fc_dentry_update,
SLAB_RECLAIM_ACCOUNT);
if (ext4_fc_dentry_cachep == NULL)
return -ENOMEM;
return 0;
}
void ext4_fc_destroy_dentry_cache(void)
{
kmem_cache_destroy(ext4_fc_dentry_cachep);
}
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