5136 строки
128 KiB
C
5136 строки
128 KiB
C
#include <linux/bitops.h>
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#include <linux/slab.h>
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#include <linux/bio.h>
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#include <linux/mm.h>
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#include <linux/pagemap.h>
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#include <linux/page-flags.h>
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#include <linux/spinlock.h>
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#include <linux/blkdev.h>
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#include <linux/swap.h>
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#include <linux/writeback.h>
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#include <linux/pagevec.h>
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#include <linux/prefetch.h>
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#include <linux/cleancache.h>
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#include "extent_io.h"
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#include "extent_map.h"
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#include "compat.h"
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#include "ctree.h"
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#include "btrfs_inode.h"
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#include "volumes.h"
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#include "check-integrity.h"
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#include "locking.h"
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#include "rcu-string.h"
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static struct kmem_cache *extent_state_cache;
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static struct kmem_cache *extent_buffer_cache;
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static struct bio_set *btrfs_bioset;
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#ifdef CONFIG_BTRFS_DEBUG
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static LIST_HEAD(buffers);
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static LIST_HEAD(states);
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static DEFINE_SPINLOCK(leak_lock);
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static inline
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void btrfs_leak_debug_add(struct list_head *new, struct list_head *head)
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{
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unsigned long flags;
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spin_lock_irqsave(&leak_lock, flags);
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list_add(new, head);
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spin_unlock_irqrestore(&leak_lock, flags);
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}
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static inline
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void btrfs_leak_debug_del(struct list_head *entry)
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{
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unsigned long flags;
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spin_lock_irqsave(&leak_lock, flags);
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list_del(entry);
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spin_unlock_irqrestore(&leak_lock, flags);
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}
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static inline
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void btrfs_leak_debug_check(void)
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{
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struct extent_state *state;
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struct extent_buffer *eb;
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while (!list_empty(&states)) {
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state = list_entry(states.next, struct extent_state, leak_list);
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printk(KERN_ERR "btrfs state leak: start %llu end %llu "
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"state %lu in tree %p refs %d\n",
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(unsigned long long)state->start,
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(unsigned long long)state->end,
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state->state, state->tree, atomic_read(&state->refs));
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list_del(&state->leak_list);
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kmem_cache_free(extent_state_cache, state);
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}
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while (!list_empty(&buffers)) {
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eb = list_entry(buffers.next, struct extent_buffer, leak_list);
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printk(KERN_ERR "btrfs buffer leak start %llu len %lu "
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"refs %d\n", (unsigned long long)eb->start,
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eb->len, atomic_read(&eb->refs));
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list_del(&eb->leak_list);
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kmem_cache_free(extent_buffer_cache, eb);
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}
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}
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#define btrfs_debug_check_extent_io_range(inode, start, end) \
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__btrfs_debug_check_extent_io_range(__func__, (inode), (start), (end))
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static inline void __btrfs_debug_check_extent_io_range(const char *caller,
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struct inode *inode, u64 start, u64 end)
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{
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u64 isize = i_size_read(inode);
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if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) {
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printk_ratelimited(KERN_DEBUG
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"btrfs: %s: ino %llu isize %llu odd range [%llu,%llu]\n",
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caller,
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(unsigned long long)btrfs_ino(inode),
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(unsigned long long)isize,
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(unsigned long long)start,
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(unsigned long long)end);
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}
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}
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#else
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#define btrfs_leak_debug_add(new, head) do {} while (0)
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#define btrfs_leak_debug_del(entry) do {} while (0)
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#define btrfs_leak_debug_check() do {} while (0)
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#define btrfs_debug_check_extent_io_range(c, s, e) do {} while (0)
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#endif
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#define BUFFER_LRU_MAX 64
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struct tree_entry {
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u64 start;
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u64 end;
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struct rb_node rb_node;
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};
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struct extent_page_data {
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struct bio *bio;
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struct extent_io_tree *tree;
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get_extent_t *get_extent;
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unsigned long bio_flags;
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/* tells writepage not to lock the state bits for this range
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* it still does the unlocking
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*/
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unsigned int extent_locked:1;
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/* tells the submit_bio code to use a WRITE_SYNC */
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unsigned int sync_io:1;
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};
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static noinline void flush_write_bio(void *data);
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static inline struct btrfs_fs_info *
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tree_fs_info(struct extent_io_tree *tree)
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{
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return btrfs_sb(tree->mapping->host->i_sb);
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}
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int __init extent_io_init(void)
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{
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extent_state_cache = kmem_cache_create("btrfs_extent_state",
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sizeof(struct extent_state), 0,
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SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
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if (!extent_state_cache)
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return -ENOMEM;
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extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer",
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sizeof(struct extent_buffer), 0,
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SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
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if (!extent_buffer_cache)
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goto free_state_cache;
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btrfs_bioset = bioset_create(BIO_POOL_SIZE,
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offsetof(struct btrfs_io_bio, bio));
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if (!btrfs_bioset)
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goto free_buffer_cache;
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return 0;
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free_buffer_cache:
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kmem_cache_destroy(extent_buffer_cache);
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extent_buffer_cache = NULL;
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free_state_cache:
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kmem_cache_destroy(extent_state_cache);
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extent_state_cache = NULL;
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return -ENOMEM;
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}
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void extent_io_exit(void)
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{
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btrfs_leak_debug_check();
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/*
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* Make sure all delayed rcu free are flushed before we
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* destroy caches.
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*/
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rcu_barrier();
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if (extent_state_cache)
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kmem_cache_destroy(extent_state_cache);
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if (extent_buffer_cache)
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kmem_cache_destroy(extent_buffer_cache);
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if (btrfs_bioset)
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bioset_free(btrfs_bioset);
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}
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void extent_io_tree_init(struct extent_io_tree *tree,
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struct address_space *mapping)
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{
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tree->state = RB_ROOT;
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INIT_RADIX_TREE(&tree->buffer, GFP_ATOMIC);
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tree->ops = NULL;
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tree->dirty_bytes = 0;
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spin_lock_init(&tree->lock);
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spin_lock_init(&tree->buffer_lock);
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tree->mapping = mapping;
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}
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static struct extent_state *alloc_extent_state(gfp_t mask)
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{
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struct extent_state *state;
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state = kmem_cache_alloc(extent_state_cache, mask);
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if (!state)
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return state;
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state->state = 0;
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state->private = 0;
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state->tree = NULL;
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btrfs_leak_debug_add(&state->leak_list, &states);
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atomic_set(&state->refs, 1);
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init_waitqueue_head(&state->wq);
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trace_alloc_extent_state(state, mask, _RET_IP_);
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return state;
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}
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void free_extent_state(struct extent_state *state)
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{
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if (!state)
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return;
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if (atomic_dec_and_test(&state->refs)) {
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WARN_ON(state->tree);
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btrfs_leak_debug_del(&state->leak_list);
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trace_free_extent_state(state, _RET_IP_);
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kmem_cache_free(extent_state_cache, state);
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}
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}
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static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
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struct rb_node *node)
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{
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struct rb_node **p = &root->rb_node;
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struct rb_node *parent = NULL;
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struct tree_entry *entry;
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while (*p) {
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parent = *p;
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entry = rb_entry(parent, struct tree_entry, rb_node);
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if (offset < entry->start)
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p = &(*p)->rb_left;
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else if (offset > entry->end)
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p = &(*p)->rb_right;
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else
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return parent;
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}
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rb_link_node(node, parent, p);
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rb_insert_color(node, root);
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return NULL;
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}
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static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
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struct rb_node **prev_ret,
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struct rb_node **next_ret)
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{
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struct rb_root *root = &tree->state;
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struct rb_node *n = root->rb_node;
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struct rb_node *prev = NULL;
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struct rb_node *orig_prev = NULL;
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struct tree_entry *entry;
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struct tree_entry *prev_entry = NULL;
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while (n) {
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entry = rb_entry(n, struct tree_entry, rb_node);
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prev = n;
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prev_entry = entry;
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if (offset < entry->start)
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n = n->rb_left;
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else if (offset > entry->end)
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n = n->rb_right;
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else
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return n;
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}
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if (prev_ret) {
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orig_prev = prev;
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while (prev && offset > prev_entry->end) {
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prev = rb_next(prev);
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prev_entry = rb_entry(prev, struct tree_entry, rb_node);
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}
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*prev_ret = prev;
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prev = orig_prev;
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}
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if (next_ret) {
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prev_entry = rb_entry(prev, struct tree_entry, rb_node);
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while (prev && offset < prev_entry->start) {
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prev = rb_prev(prev);
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prev_entry = rb_entry(prev, struct tree_entry, rb_node);
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}
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*next_ret = prev;
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}
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return NULL;
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}
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static inline struct rb_node *tree_search(struct extent_io_tree *tree,
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u64 offset)
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{
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struct rb_node *prev = NULL;
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struct rb_node *ret;
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ret = __etree_search(tree, offset, &prev, NULL);
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if (!ret)
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return prev;
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return ret;
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}
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static void merge_cb(struct extent_io_tree *tree, struct extent_state *new,
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struct extent_state *other)
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{
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if (tree->ops && tree->ops->merge_extent_hook)
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tree->ops->merge_extent_hook(tree->mapping->host, new,
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other);
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}
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/*
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* utility function to look for merge candidates inside a given range.
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* Any extents with matching state are merged together into a single
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* extent in the tree. Extents with EXTENT_IO in their state field
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* are not merged because the end_io handlers need to be able to do
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* operations on them without sleeping (or doing allocations/splits).
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*
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* This should be called with the tree lock held.
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*/
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static void merge_state(struct extent_io_tree *tree,
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struct extent_state *state)
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{
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struct extent_state *other;
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struct rb_node *other_node;
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if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
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return;
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other_node = rb_prev(&state->rb_node);
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if (other_node) {
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other = rb_entry(other_node, struct extent_state, rb_node);
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if (other->end == state->start - 1 &&
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other->state == state->state) {
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merge_cb(tree, state, other);
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state->start = other->start;
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other->tree = NULL;
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rb_erase(&other->rb_node, &tree->state);
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free_extent_state(other);
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}
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}
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other_node = rb_next(&state->rb_node);
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if (other_node) {
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other = rb_entry(other_node, struct extent_state, rb_node);
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if (other->start == state->end + 1 &&
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other->state == state->state) {
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merge_cb(tree, state, other);
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state->end = other->end;
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other->tree = NULL;
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rb_erase(&other->rb_node, &tree->state);
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free_extent_state(other);
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}
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}
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}
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static void set_state_cb(struct extent_io_tree *tree,
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struct extent_state *state, unsigned long *bits)
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{
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if (tree->ops && tree->ops->set_bit_hook)
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tree->ops->set_bit_hook(tree->mapping->host, state, bits);
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}
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static void clear_state_cb(struct extent_io_tree *tree,
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struct extent_state *state, unsigned long *bits)
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{
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if (tree->ops && tree->ops->clear_bit_hook)
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tree->ops->clear_bit_hook(tree->mapping->host, state, bits);
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}
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static void set_state_bits(struct extent_io_tree *tree,
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struct extent_state *state, unsigned long *bits);
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/*
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* insert an extent_state struct into the tree. 'bits' are set on the
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* struct before it is inserted.
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*
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* This may return -EEXIST if the extent is already there, in which case the
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* state struct is freed.
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*
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* The tree lock is not taken internally. This is a utility function and
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* probably isn't what you want to call (see set/clear_extent_bit).
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*/
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static int insert_state(struct extent_io_tree *tree,
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struct extent_state *state, u64 start, u64 end,
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unsigned long *bits)
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{
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struct rb_node *node;
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if (end < start)
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WARN(1, KERN_ERR "btrfs end < start %llu %llu\n",
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(unsigned long long)end,
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(unsigned long long)start);
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state->start = start;
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state->end = end;
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set_state_bits(tree, state, bits);
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node = tree_insert(&tree->state, end, &state->rb_node);
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if (node) {
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struct extent_state *found;
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found = rb_entry(node, struct extent_state, rb_node);
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printk(KERN_ERR "btrfs found node %llu %llu on insert of "
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"%llu %llu\n", (unsigned long long)found->start,
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(unsigned long long)found->end,
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(unsigned long long)start, (unsigned long long)end);
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return -EEXIST;
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}
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state->tree = tree;
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merge_state(tree, state);
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return 0;
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}
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static void split_cb(struct extent_io_tree *tree, struct extent_state *orig,
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u64 split)
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{
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if (tree->ops && tree->ops->split_extent_hook)
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tree->ops->split_extent_hook(tree->mapping->host, orig, split);
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}
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/*
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* split a given extent state struct in two, inserting the preallocated
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* struct 'prealloc' as the newly created second half. 'split' indicates an
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* offset inside 'orig' where it should be split.
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*
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* Before calling,
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* the tree has 'orig' at [orig->start, orig->end]. After calling, there
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* are two extent state structs in the tree:
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* prealloc: [orig->start, split - 1]
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* orig: [ split, orig->end ]
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*
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* The tree locks are not taken by this function. They need to be held
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* by the caller.
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*/
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static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
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struct extent_state *prealloc, u64 split)
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{
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struct rb_node *node;
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split_cb(tree, orig, split);
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prealloc->start = orig->start;
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prealloc->end = split - 1;
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prealloc->state = orig->state;
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orig->start = split;
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node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node);
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if (node) {
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free_extent_state(prealloc);
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return -EEXIST;
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}
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prealloc->tree = tree;
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return 0;
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}
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static struct extent_state *next_state(struct extent_state *state)
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{
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struct rb_node *next = rb_next(&state->rb_node);
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if (next)
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return rb_entry(next, struct extent_state, rb_node);
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else
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return NULL;
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}
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/*
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* utility function to clear some bits in an extent state struct.
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* it will optionally wake up any one waiting on this state (wake == 1).
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*
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* If no bits are set on the state struct after clearing things, the
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* struct is freed and removed from the tree
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*/
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static struct extent_state *clear_state_bit(struct extent_io_tree *tree,
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struct extent_state *state,
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unsigned long *bits, int wake)
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{
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struct extent_state *next;
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unsigned long bits_to_clear = *bits & ~EXTENT_CTLBITS;
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if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
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u64 range = state->end - state->start + 1;
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WARN_ON(range > tree->dirty_bytes);
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tree->dirty_bytes -= range;
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}
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clear_state_cb(tree, state, bits);
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state->state &= ~bits_to_clear;
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if (wake)
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wake_up(&state->wq);
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if (state->state == 0) {
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next = next_state(state);
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if (state->tree) {
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rb_erase(&state->rb_node, &tree->state);
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state->tree = NULL;
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free_extent_state(state);
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} else {
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WARN_ON(1);
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}
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} else {
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merge_state(tree, state);
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next = next_state(state);
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}
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return next;
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}
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static struct extent_state *
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alloc_extent_state_atomic(struct extent_state *prealloc)
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{
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if (!prealloc)
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prealloc = alloc_extent_state(GFP_ATOMIC);
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return prealloc;
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}
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static void extent_io_tree_panic(struct extent_io_tree *tree, int err)
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{
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btrfs_panic(tree_fs_info(tree), err, "Locking error: "
|
|
"Extent tree was modified by another "
|
|
"thread while locked.");
|
|
}
|
|
|
|
/*
|
|
* clear some bits on a range in the tree. This may require splitting
|
|
* or inserting elements in the tree, so the gfp mask is used to
|
|
* indicate which allocations or sleeping are allowed.
|
|
*
|
|
* pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
|
|
* the given range from the tree regardless of state (ie for truncate).
|
|
*
|
|
* the range [start, end] is inclusive.
|
|
*
|
|
* This takes the tree lock, and returns 0 on success and < 0 on error.
|
|
*/
|
|
int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
|
|
unsigned long bits, int wake, int delete,
|
|
struct extent_state **cached_state,
|
|
gfp_t mask)
|
|
{
|
|
struct extent_state *state;
|
|
struct extent_state *cached;
|
|
struct extent_state *prealloc = NULL;
|
|
struct rb_node *node;
|
|
u64 last_end;
|
|
int err;
|
|
int clear = 0;
|
|
|
|
btrfs_debug_check_extent_io_range(tree->mapping->host, start, end);
|
|
|
|
if (bits & EXTENT_DELALLOC)
|
|
bits |= EXTENT_NORESERVE;
|
|
|
|
if (delete)
|
|
bits |= ~EXTENT_CTLBITS;
|
|
bits |= EXTENT_FIRST_DELALLOC;
|
|
|
|
if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
|
|
clear = 1;
|
|
again:
|
|
if (!prealloc && (mask & __GFP_WAIT)) {
|
|
prealloc = alloc_extent_state(mask);
|
|
if (!prealloc)
|
|
return -ENOMEM;
|
|
}
|
|
|
|
spin_lock(&tree->lock);
|
|
if (cached_state) {
|
|
cached = *cached_state;
|
|
|
|
if (clear) {
|
|
*cached_state = NULL;
|
|
cached_state = NULL;
|
|
}
|
|
|
|
if (cached && cached->tree && cached->start <= start &&
|
|
cached->end > start) {
|
|
if (clear)
|
|
atomic_dec(&cached->refs);
|
|
state = cached;
|
|
goto hit_next;
|
|
}
|
|
if (clear)
|
|
free_extent_state(cached);
|
|
}
|
|
/*
|
|
* this search will find the extents that end after
|
|
* our range starts
|
|
*/
|
|
node = tree_search(tree, start);
|
|
if (!node)
|
|
goto out;
|
|
state = rb_entry(node, struct extent_state, rb_node);
|
|
hit_next:
|
|
if (state->start > end)
|
|
goto out;
|
|
WARN_ON(state->end < start);
|
|
last_end = state->end;
|
|
|
|
/* the state doesn't have the wanted bits, go ahead */
|
|
if (!(state->state & bits)) {
|
|
state = next_state(state);
|
|
goto next;
|
|
}
|
|
|
|
/*
|
|
* | ---- desired range ---- |
|
|
* | state | or
|
|
* | ------------- state -------------- |
|
|
*
|
|
* We need to split the extent we found, and may flip
|
|
* bits on second half.
|
|
*
|
|
* If the extent we found extends past our range, we
|
|
* just split and search again. It'll get split again
|
|
* the next time though.
|
|
*
|
|
* If the extent we found is inside our range, we clear
|
|
* the desired bit on it.
|
|
*/
|
|
|
|
if (state->start < start) {
|
|
prealloc = alloc_extent_state_atomic(prealloc);
|
|
BUG_ON(!prealloc);
|
|
err = split_state(tree, state, prealloc, start);
|
|
if (err)
|
|
extent_io_tree_panic(tree, err);
|
|
|
|
prealloc = NULL;
|
|
if (err)
|
|
goto out;
|
|
if (state->end <= end) {
|
|
state = clear_state_bit(tree, state, &bits, wake);
|
|
goto next;
|
|
}
|
|
goto search_again;
|
|
}
|
|
/*
|
|
* | ---- desired range ---- |
|
|
* | state |
|
|
* We need to split the extent, and clear the bit
|
|
* on the first half
|
|
*/
|
|
if (state->start <= end && state->end > end) {
|
|
prealloc = alloc_extent_state_atomic(prealloc);
|
|
BUG_ON(!prealloc);
|
|
err = split_state(tree, state, prealloc, end + 1);
|
|
if (err)
|
|
extent_io_tree_panic(tree, err);
|
|
|
|
if (wake)
|
|
wake_up(&state->wq);
|
|
|
|
clear_state_bit(tree, prealloc, &bits, wake);
|
|
|
|
prealloc = NULL;
|
|
goto out;
|
|
}
|
|
|
|
state = clear_state_bit(tree, state, &bits, wake);
|
|
next:
|
|
if (last_end == (u64)-1)
|
|
goto out;
|
|
start = last_end + 1;
|
|
if (start <= end && state && !need_resched())
|
|
goto hit_next;
|
|
goto search_again;
|
|
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
if (prealloc)
|
|
free_extent_state(prealloc);
|
|
|
|
return 0;
|
|
|
|
search_again:
|
|
if (start > end)
|
|
goto out;
|
|
spin_unlock(&tree->lock);
|
|
if (mask & __GFP_WAIT)
|
|
cond_resched();
|
|
goto again;
|
|
}
|
|
|
|
static void wait_on_state(struct extent_io_tree *tree,
|
|
struct extent_state *state)
|
|
__releases(tree->lock)
|
|
__acquires(tree->lock)
|
|
{
|
|
DEFINE_WAIT(wait);
|
|
prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
|
|
spin_unlock(&tree->lock);
|
|
schedule();
|
|
spin_lock(&tree->lock);
|
|
finish_wait(&state->wq, &wait);
|
|
}
|
|
|
|
/*
|
|
* waits for one or more bits to clear on a range in the state tree.
|
|
* The range [start, end] is inclusive.
|
|
* The tree lock is taken by this function
|
|
*/
|
|
static void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
|
|
unsigned long bits)
|
|
{
|
|
struct extent_state *state;
|
|
struct rb_node *node;
|
|
|
|
btrfs_debug_check_extent_io_range(tree->mapping->host, start, end);
|
|
|
|
spin_lock(&tree->lock);
|
|
again:
|
|
while (1) {
|
|
/*
|
|
* this search will find all the extents that end after
|
|
* our range starts
|
|
*/
|
|
node = tree_search(tree, start);
|
|
if (!node)
|
|
break;
|
|
|
|
state = rb_entry(node, struct extent_state, rb_node);
|
|
|
|
if (state->start > end)
|
|
goto out;
|
|
|
|
if (state->state & bits) {
|
|
start = state->start;
|
|
atomic_inc(&state->refs);
|
|
wait_on_state(tree, state);
|
|
free_extent_state(state);
|
|
goto again;
|
|
}
|
|
start = state->end + 1;
|
|
|
|
if (start > end)
|
|
break;
|
|
|
|
cond_resched_lock(&tree->lock);
|
|
}
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
}
|
|
|
|
static void set_state_bits(struct extent_io_tree *tree,
|
|
struct extent_state *state,
|
|
unsigned long *bits)
|
|
{
|
|
unsigned long bits_to_set = *bits & ~EXTENT_CTLBITS;
|
|
|
|
set_state_cb(tree, state, bits);
|
|
if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
|
|
u64 range = state->end - state->start + 1;
|
|
tree->dirty_bytes += range;
|
|
}
|
|
state->state |= bits_to_set;
|
|
}
|
|
|
|
static void cache_state(struct extent_state *state,
|
|
struct extent_state **cached_ptr)
|
|
{
|
|
if (cached_ptr && !(*cached_ptr)) {
|
|
if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY)) {
|
|
*cached_ptr = state;
|
|
atomic_inc(&state->refs);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void uncache_state(struct extent_state **cached_ptr)
|
|
{
|
|
if (cached_ptr && (*cached_ptr)) {
|
|
struct extent_state *state = *cached_ptr;
|
|
*cached_ptr = NULL;
|
|
free_extent_state(state);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* set some bits on a range in the tree. This may require allocations or
|
|
* sleeping, so the gfp mask is used to indicate what is allowed.
|
|
*
|
|
* If any of the exclusive bits are set, this will fail with -EEXIST if some
|
|
* part of the range already has the desired bits set. The start of the
|
|
* existing range is returned in failed_start in this case.
|
|
*
|
|
* [start, end] is inclusive This takes the tree lock.
|
|
*/
|
|
|
|
static int __must_check
|
|
__set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
|
|
unsigned long bits, unsigned long exclusive_bits,
|
|
u64 *failed_start, struct extent_state **cached_state,
|
|
gfp_t mask)
|
|
{
|
|
struct extent_state *state;
|
|
struct extent_state *prealloc = NULL;
|
|
struct rb_node *node;
|
|
int err = 0;
|
|
u64 last_start;
|
|
u64 last_end;
|
|
|
|
btrfs_debug_check_extent_io_range(tree->mapping->host, start, end);
|
|
|
|
bits |= EXTENT_FIRST_DELALLOC;
|
|
again:
|
|
if (!prealloc && (mask & __GFP_WAIT)) {
|
|
prealloc = alloc_extent_state(mask);
|
|
BUG_ON(!prealloc);
|
|
}
|
|
|
|
spin_lock(&tree->lock);
|
|
if (cached_state && *cached_state) {
|
|
state = *cached_state;
|
|
if (state->start <= start && state->end > start &&
|
|
state->tree) {
|
|
node = &state->rb_node;
|
|
goto hit_next;
|
|
}
|
|
}
|
|
/*
|
|
* this search will find all the extents that end after
|
|
* our range starts.
|
|
*/
|
|
node = tree_search(tree, start);
|
|
if (!node) {
|
|
prealloc = alloc_extent_state_atomic(prealloc);
|
|
BUG_ON(!prealloc);
|
|
err = insert_state(tree, prealloc, start, end, &bits);
|
|
if (err)
|
|
extent_io_tree_panic(tree, err);
|
|
|
|
prealloc = NULL;
|
|
goto out;
|
|
}
|
|
state = rb_entry(node, struct extent_state, rb_node);
|
|
hit_next:
|
|
last_start = state->start;
|
|
last_end = state->end;
|
|
|
|
/*
|
|
* | ---- desired range ---- |
|
|
* | state |
|
|
*
|
|
* Just lock what we found and keep going
|
|
*/
|
|
if (state->start == start && state->end <= end) {
|
|
if (state->state & exclusive_bits) {
|
|
*failed_start = state->start;
|
|
err = -EEXIST;
|
|
goto out;
|
|
}
|
|
|
|
set_state_bits(tree, state, &bits);
|
|
cache_state(state, cached_state);
|
|
merge_state(tree, state);
|
|
if (last_end == (u64)-1)
|
|
goto out;
|
|
start = last_end + 1;
|
|
state = next_state(state);
|
|
if (start < end && state && state->start == start &&
|
|
!need_resched())
|
|
goto hit_next;
|
|
goto search_again;
|
|
}
|
|
|
|
/*
|
|
* | ---- desired range ---- |
|
|
* | state |
|
|
* or
|
|
* | ------------- state -------------- |
|
|
*
|
|
* We need to split the extent we found, and may flip bits on
|
|
* second half.
|
|
*
|
|
* If the extent we found extends past our
|
|
* range, we just split and search again. It'll get split
|
|
* again the next time though.
|
|
*
|
|
* If the extent we found is inside our range, we set the
|
|
* desired bit on it.
|
|
*/
|
|
if (state->start < start) {
|
|
if (state->state & exclusive_bits) {
|
|
*failed_start = start;
|
|
err = -EEXIST;
|
|
goto out;
|
|
}
|
|
|
|
prealloc = alloc_extent_state_atomic(prealloc);
|
|
BUG_ON(!prealloc);
|
|
err = split_state(tree, state, prealloc, start);
|
|
if (err)
|
|
extent_io_tree_panic(tree, err);
|
|
|
|
prealloc = NULL;
|
|
if (err)
|
|
goto out;
|
|
if (state->end <= end) {
|
|
set_state_bits(tree, state, &bits);
|
|
cache_state(state, cached_state);
|
|
merge_state(tree, state);
|
|
if (last_end == (u64)-1)
|
|
goto out;
|
|
start = last_end + 1;
|
|
state = next_state(state);
|
|
if (start < end && state && state->start == start &&
|
|
!need_resched())
|
|
goto hit_next;
|
|
}
|
|
goto search_again;
|
|
}
|
|
/*
|
|
* | ---- desired range ---- |
|
|
* | state | or | state |
|
|
*
|
|
* There's a hole, we need to insert something in it and
|
|
* ignore the extent we found.
|
|
*/
|
|
if (state->start > start) {
|
|
u64 this_end;
|
|
if (end < last_start)
|
|
this_end = end;
|
|
else
|
|
this_end = last_start - 1;
|
|
|
|
prealloc = alloc_extent_state_atomic(prealloc);
|
|
BUG_ON(!prealloc);
|
|
|
|
/*
|
|
* Avoid to free 'prealloc' if it can be merged with
|
|
* the later extent.
|
|
*/
|
|
err = insert_state(tree, prealloc, start, this_end,
|
|
&bits);
|
|
if (err)
|
|
extent_io_tree_panic(tree, err);
|
|
|
|
cache_state(prealloc, cached_state);
|
|
prealloc = NULL;
|
|
start = this_end + 1;
|
|
goto search_again;
|
|
}
|
|
/*
|
|
* | ---- desired range ---- |
|
|
* | state |
|
|
* We need to split the extent, and set the bit
|
|
* on the first half
|
|
*/
|
|
if (state->start <= end && state->end > end) {
|
|
if (state->state & exclusive_bits) {
|
|
*failed_start = start;
|
|
err = -EEXIST;
|
|
goto out;
|
|
}
|
|
|
|
prealloc = alloc_extent_state_atomic(prealloc);
|
|
BUG_ON(!prealloc);
|
|
err = split_state(tree, state, prealloc, end + 1);
|
|
if (err)
|
|
extent_io_tree_panic(tree, err);
|
|
|
|
set_state_bits(tree, prealloc, &bits);
|
|
cache_state(prealloc, cached_state);
|
|
merge_state(tree, prealloc);
|
|
prealloc = NULL;
|
|
goto out;
|
|
}
|
|
|
|
goto search_again;
|
|
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
if (prealloc)
|
|
free_extent_state(prealloc);
|
|
|
|
return err;
|
|
|
|
search_again:
|
|
if (start > end)
|
|
goto out;
|
|
spin_unlock(&tree->lock);
|
|
if (mask & __GFP_WAIT)
|
|
cond_resched();
|
|
goto again;
|
|
}
|
|
|
|
int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
|
|
unsigned long bits, u64 * failed_start,
|
|
struct extent_state **cached_state, gfp_t mask)
|
|
{
|
|
return __set_extent_bit(tree, start, end, bits, 0, failed_start,
|
|
cached_state, mask);
|
|
}
|
|
|
|
|
|
/**
|
|
* convert_extent_bit - convert all bits in a given range from one bit to
|
|
* another
|
|
* @tree: the io tree to search
|
|
* @start: the start offset in bytes
|
|
* @end: the end offset in bytes (inclusive)
|
|
* @bits: the bits to set in this range
|
|
* @clear_bits: the bits to clear in this range
|
|
* @cached_state: state that we're going to cache
|
|
* @mask: the allocation mask
|
|
*
|
|
* This will go through and set bits for the given range. If any states exist
|
|
* already in this range they are set with the given bit and cleared of the
|
|
* clear_bits. This is only meant to be used by things that are mergeable, ie
|
|
* converting from say DELALLOC to DIRTY. This is not meant to be used with
|
|
* boundary bits like LOCK.
|
|
*/
|
|
int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
|
|
unsigned long bits, unsigned long clear_bits,
|
|
struct extent_state **cached_state, gfp_t mask)
|
|
{
|
|
struct extent_state *state;
|
|
struct extent_state *prealloc = NULL;
|
|
struct rb_node *node;
|
|
int err = 0;
|
|
u64 last_start;
|
|
u64 last_end;
|
|
|
|
btrfs_debug_check_extent_io_range(tree->mapping->host, start, end);
|
|
|
|
again:
|
|
if (!prealloc && (mask & __GFP_WAIT)) {
|
|
prealloc = alloc_extent_state(mask);
|
|
if (!prealloc)
|
|
return -ENOMEM;
|
|
}
|
|
|
|
spin_lock(&tree->lock);
|
|
if (cached_state && *cached_state) {
|
|
state = *cached_state;
|
|
if (state->start <= start && state->end > start &&
|
|
state->tree) {
|
|
node = &state->rb_node;
|
|
goto hit_next;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* this search will find all the extents that end after
|
|
* our range starts.
|
|
*/
|
|
node = tree_search(tree, start);
|
|
if (!node) {
|
|
prealloc = alloc_extent_state_atomic(prealloc);
|
|
if (!prealloc) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
err = insert_state(tree, prealloc, start, end, &bits);
|
|
prealloc = NULL;
|
|
if (err)
|
|
extent_io_tree_panic(tree, err);
|
|
goto out;
|
|
}
|
|
state = rb_entry(node, struct extent_state, rb_node);
|
|
hit_next:
|
|
last_start = state->start;
|
|
last_end = state->end;
|
|
|
|
/*
|
|
* | ---- desired range ---- |
|
|
* | state |
|
|
*
|
|
* Just lock what we found and keep going
|
|
*/
|
|
if (state->start == start && state->end <= end) {
|
|
set_state_bits(tree, state, &bits);
|
|
cache_state(state, cached_state);
|
|
state = clear_state_bit(tree, state, &clear_bits, 0);
|
|
if (last_end == (u64)-1)
|
|
goto out;
|
|
start = last_end + 1;
|
|
if (start < end && state && state->start == start &&
|
|
!need_resched())
|
|
goto hit_next;
|
|
goto search_again;
|
|
}
|
|
|
|
/*
|
|
* | ---- desired range ---- |
|
|
* | state |
|
|
* or
|
|
* | ------------- state -------------- |
|
|
*
|
|
* We need to split the extent we found, and may flip bits on
|
|
* second half.
|
|
*
|
|
* If the extent we found extends past our
|
|
* range, we just split and search again. It'll get split
|
|
* again the next time though.
|
|
*
|
|
* If the extent we found is inside our range, we set the
|
|
* desired bit on it.
|
|
*/
|
|
if (state->start < start) {
|
|
prealloc = alloc_extent_state_atomic(prealloc);
|
|
if (!prealloc) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
err = split_state(tree, state, prealloc, start);
|
|
if (err)
|
|
extent_io_tree_panic(tree, err);
|
|
prealloc = NULL;
|
|
if (err)
|
|
goto out;
|
|
if (state->end <= end) {
|
|
set_state_bits(tree, state, &bits);
|
|
cache_state(state, cached_state);
|
|
state = clear_state_bit(tree, state, &clear_bits, 0);
|
|
if (last_end == (u64)-1)
|
|
goto out;
|
|
start = last_end + 1;
|
|
if (start < end && state && state->start == start &&
|
|
!need_resched())
|
|
goto hit_next;
|
|
}
|
|
goto search_again;
|
|
}
|
|
/*
|
|
* | ---- desired range ---- |
|
|
* | state | or | state |
|
|
*
|
|
* There's a hole, we need to insert something in it and
|
|
* ignore the extent we found.
|
|
*/
|
|
if (state->start > start) {
|
|
u64 this_end;
|
|
if (end < last_start)
|
|
this_end = end;
|
|
else
|
|
this_end = last_start - 1;
|
|
|
|
prealloc = alloc_extent_state_atomic(prealloc);
|
|
if (!prealloc) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Avoid to free 'prealloc' if it can be merged with
|
|
* the later extent.
|
|
*/
|
|
err = insert_state(tree, prealloc, start, this_end,
|
|
&bits);
|
|
if (err)
|
|
extent_io_tree_panic(tree, err);
|
|
cache_state(prealloc, cached_state);
|
|
prealloc = NULL;
|
|
start = this_end + 1;
|
|
goto search_again;
|
|
}
|
|
/*
|
|
* | ---- desired range ---- |
|
|
* | state |
|
|
* We need to split the extent, and set the bit
|
|
* on the first half
|
|
*/
|
|
if (state->start <= end && state->end > end) {
|
|
prealloc = alloc_extent_state_atomic(prealloc);
|
|
if (!prealloc) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
err = split_state(tree, state, prealloc, end + 1);
|
|
if (err)
|
|
extent_io_tree_panic(tree, err);
|
|
|
|
set_state_bits(tree, prealloc, &bits);
|
|
cache_state(prealloc, cached_state);
|
|
clear_state_bit(tree, prealloc, &clear_bits, 0);
|
|
prealloc = NULL;
|
|
goto out;
|
|
}
|
|
|
|
goto search_again;
|
|
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
if (prealloc)
|
|
free_extent_state(prealloc);
|
|
|
|
return err;
|
|
|
|
search_again:
|
|
if (start > end)
|
|
goto out;
|
|
spin_unlock(&tree->lock);
|
|
if (mask & __GFP_WAIT)
|
|
cond_resched();
|
|
goto again;
|
|
}
|
|
|
|
/* wrappers around set/clear extent bit */
|
|
int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
|
|
gfp_t mask)
|
|
{
|
|
return set_extent_bit(tree, start, end, EXTENT_DIRTY, NULL,
|
|
NULL, mask);
|
|
}
|
|
|
|
int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
|
|
unsigned long bits, gfp_t mask)
|
|
{
|
|
return set_extent_bit(tree, start, end, bits, NULL,
|
|
NULL, mask);
|
|
}
|
|
|
|
int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
|
|
unsigned long bits, gfp_t mask)
|
|
{
|
|
return clear_extent_bit(tree, start, end, bits, 0, 0, NULL, mask);
|
|
}
|
|
|
|
int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
|
|
struct extent_state **cached_state, gfp_t mask)
|
|
{
|
|
return set_extent_bit(tree, start, end,
|
|
EXTENT_DELALLOC | EXTENT_UPTODATE,
|
|
NULL, cached_state, mask);
|
|
}
|
|
|
|
int set_extent_defrag(struct extent_io_tree *tree, u64 start, u64 end,
|
|
struct extent_state **cached_state, gfp_t mask)
|
|
{
|
|
return set_extent_bit(tree, start, end,
|
|
EXTENT_DELALLOC | EXTENT_UPTODATE | EXTENT_DEFRAG,
|
|
NULL, cached_state, mask);
|
|
}
|
|
|
|
int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
|
|
gfp_t mask)
|
|
{
|
|
return clear_extent_bit(tree, start, end,
|
|
EXTENT_DIRTY | EXTENT_DELALLOC |
|
|
EXTENT_DO_ACCOUNTING, 0, 0, NULL, mask);
|
|
}
|
|
|
|
int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
|
|
gfp_t mask)
|
|
{
|
|
return set_extent_bit(tree, start, end, EXTENT_NEW, NULL,
|
|
NULL, mask);
|
|
}
|
|
|
|
int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
|
|
struct extent_state **cached_state, gfp_t mask)
|
|
{
|
|
return set_extent_bit(tree, start, end, EXTENT_UPTODATE, NULL,
|
|
cached_state, mask);
|
|
}
|
|
|
|
int clear_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
|
|
struct extent_state **cached_state, gfp_t mask)
|
|
{
|
|
return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0,
|
|
cached_state, mask);
|
|
}
|
|
|
|
/*
|
|
* either insert or lock state struct between start and end use mask to tell
|
|
* us if waiting is desired.
|
|
*/
|
|
int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
|
|
unsigned long bits, struct extent_state **cached_state)
|
|
{
|
|
int err;
|
|
u64 failed_start;
|
|
while (1) {
|
|
err = __set_extent_bit(tree, start, end, EXTENT_LOCKED | bits,
|
|
EXTENT_LOCKED, &failed_start,
|
|
cached_state, GFP_NOFS);
|
|
if (err == -EEXIST) {
|
|
wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
|
|
start = failed_start;
|
|
} else
|
|
break;
|
|
WARN_ON(start > end);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
int lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
|
|
{
|
|
return lock_extent_bits(tree, start, end, 0, NULL);
|
|
}
|
|
|
|
int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
|
|
{
|
|
int err;
|
|
u64 failed_start;
|
|
|
|
err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
|
|
&failed_start, NULL, GFP_NOFS);
|
|
if (err == -EEXIST) {
|
|
if (failed_start > start)
|
|
clear_extent_bit(tree, start, failed_start - 1,
|
|
EXTENT_LOCKED, 1, 0, NULL, GFP_NOFS);
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
int unlock_extent_cached(struct extent_io_tree *tree, u64 start, u64 end,
|
|
struct extent_state **cached, gfp_t mask)
|
|
{
|
|
return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, cached,
|
|
mask);
|
|
}
|
|
|
|
int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end)
|
|
{
|
|
return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, NULL,
|
|
GFP_NOFS);
|
|
}
|
|
|
|
int extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end)
|
|
{
|
|
unsigned long index = start >> PAGE_CACHE_SHIFT;
|
|
unsigned long end_index = end >> PAGE_CACHE_SHIFT;
|
|
struct page *page;
|
|
|
|
while (index <= end_index) {
|
|
page = find_get_page(inode->i_mapping, index);
|
|
BUG_ON(!page); /* Pages should be in the extent_io_tree */
|
|
clear_page_dirty_for_io(page);
|
|
page_cache_release(page);
|
|
index++;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end)
|
|
{
|
|
unsigned long index = start >> PAGE_CACHE_SHIFT;
|
|
unsigned long end_index = end >> PAGE_CACHE_SHIFT;
|
|
struct page *page;
|
|
|
|
while (index <= end_index) {
|
|
page = find_get_page(inode->i_mapping, index);
|
|
BUG_ON(!page); /* Pages should be in the extent_io_tree */
|
|
account_page_redirty(page);
|
|
__set_page_dirty_nobuffers(page);
|
|
page_cache_release(page);
|
|
index++;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* helper function to set both pages and extents in the tree writeback
|
|
*/
|
|
static int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
|
|
{
|
|
unsigned long index = start >> PAGE_CACHE_SHIFT;
|
|
unsigned long end_index = end >> PAGE_CACHE_SHIFT;
|
|
struct page *page;
|
|
|
|
while (index <= end_index) {
|
|
page = find_get_page(tree->mapping, index);
|
|
BUG_ON(!page); /* Pages should be in the extent_io_tree */
|
|
set_page_writeback(page);
|
|
page_cache_release(page);
|
|
index++;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* find the first state struct with 'bits' set after 'start', and
|
|
* return it. tree->lock must be held. NULL will returned if
|
|
* nothing was found after 'start'
|
|
*/
|
|
static struct extent_state *
|
|
find_first_extent_bit_state(struct extent_io_tree *tree,
|
|
u64 start, unsigned long bits)
|
|
{
|
|
struct rb_node *node;
|
|
struct extent_state *state;
|
|
|
|
/*
|
|
* this search will find all the extents that end after
|
|
* our range starts.
|
|
*/
|
|
node = tree_search(tree, start);
|
|
if (!node)
|
|
goto out;
|
|
|
|
while (1) {
|
|
state = rb_entry(node, struct extent_state, rb_node);
|
|
if (state->end >= start && (state->state & bits))
|
|
return state;
|
|
|
|
node = rb_next(node);
|
|
if (!node)
|
|
break;
|
|
}
|
|
out:
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* find the first offset in the io tree with 'bits' set. zero is
|
|
* returned if we find something, and *start_ret and *end_ret are
|
|
* set to reflect the state struct that was found.
|
|
*
|
|
* If nothing was found, 1 is returned. If found something, return 0.
|
|
*/
|
|
int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
|
|
u64 *start_ret, u64 *end_ret, unsigned long bits,
|
|
struct extent_state **cached_state)
|
|
{
|
|
struct extent_state *state;
|
|
struct rb_node *n;
|
|
int ret = 1;
|
|
|
|
spin_lock(&tree->lock);
|
|
if (cached_state && *cached_state) {
|
|
state = *cached_state;
|
|
if (state->end == start - 1 && state->tree) {
|
|
n = rb_next(&state->rb_node);
|
|
while (n) {
|
|
state = rb_entry(n, struct extent_state,
|
|
rb_node);
|
|
if (state->state & bits)
|
|
goto got_it;
|
|
n = rb_next(n);
|
|
}
|
|
free_extent_state(*cached_state);
|
|
*cached_state = NULL;
|
|
goto out;
|
|
}
|
|
free_extent_state(*cached_state);
|
|
*cached_state = NULL;
|
|
}
|
|
|
|
state = find_first_extent_bit_state(tree, start, bits);
|
|
got_it:
|
|
if (state) {
|
|
cache_state(state, cached_state);
|
|
*start_ret = state->start;
|
|
*end_ret = state->end;
|
|
ret = 0;
|
|
}
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* find a contiguous range of bytes in the file marked as delalloc, not
|
|
* more than 'max_bytes'. start and end are used to return the range,
|
|
*
|
|
* 1 is returned if we find something, 0 if nothing was in the tree
|
|
*/
|
|
static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
|
|
u64 *start, u64 *end, u64 max_bytes,
|
|
struct extent_state **cached_state)
|
|
{
|
|
struct rb_node *node;
|
|
struct extent_state *state;
|
|
u64 cur_start = *start;
|
|
u64 found = 0;
|
|
u64 total_bytes = 0;
|
|
|
|
spin_lock(&tree->lock);
|
|
|
|
/*
|
|
* this search will find all the extents that end after
|
|
* our range starts.
|
|
*/
|
|
node = tree_search(tree, cur_start);
|
|
if (!node) {
|
|
if (!found)
|
|
*end = (u64)-1;
|
|
goto out;
|
|
}
|
|
|
|
while (1) {
|
|
state = rb_entry(node, struct extent_state, rb_node);
|
|
if (found && (state->start != cur_start ||
|
|
(state->state & EXTENT_BOUNDARY))) {
|
|
goto out;
|
|
}
|
|
if (!(state->state & EXTENT_DELALLOC)) {
|
|
if (!found)
|
|
*end = state->end;
|
|
goto out;
|
|
}
|
|
if (!found) {
|
|
*start = state->start;
|
|
*cached_state = state;
|
|
atomic_inc(&state->refs);
|
|
}
|
|
found++;
|
|
*end = state->end;
|
|
cur_start = state->end + 1;
|
|
node = rb_next(node);
|
|
if (!node)
|
|
break;
|
|
total_bytes += state->end - state->start + 1;
|
|
if (total_bytes >= max_bytes)
|
|
break;
|
|
}
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
return found;
|
|
}
|
|
|
|
static noinline void __unlock_for_delalloc(struct inode *inode,
|
|
struct page *locked_page,
|
|
u64 start, u64 end)
|
|
{
|
|
int ret;
|
|
struct page *pages[16];
|
|
unsigned long index = start >> PAGE_CACHE_SHIFT;
|
|
unsigned long end_index = end >> PAGE_CACHE_SHIFT;
|
|
unsigned long nr_pages = end_index - index + 1;
|
|
int i;
|
|
|
|
if (index == locked_page->index && end_index == index)
|
|
return;
|
|
|
|
while (nr_pages > 0) {
|
|
ret = find_get_pages_contig(inode->i_mapping, index,
|
|
min_t(unsigned long, nr_pages,
|
|
ARRAY_SIZE(pages)), pages);
|
|
for (i = 0; i < ret; i++) {
|
|
if (pages[i] != locked_page)
|
|
unlock_page(pages[i]);
|
|
page_cache_release(pages[i]);
|
|
}
|
|
nr_pages -= ret;
|
|
index += ret;
|
|
cond_resched();
|
|
}
|
|
}
|
|
|
|
static noinline int lock_delalloc_pages(struct inode *inode,
|
|
struct page *locked_page,
|
|
u64 delalloc_start,
|
|
u64 delalloc_end)
|
|
{
|
|
unsigned long index = delalloc_start >> PAGE_CACHE_SHIFT;
|
|
unsigned long start_index = index;
|
|
unsigned long end_index = delalloc_end >> PAGE_CACHE_SHIFT;
|
|
unsigned long pages_locked = 0;
|
|
struct page *pages[16];
|
|
unsigned long nrpages;
|
|
int ret;
|
|
int i;
|
|
|
|
/* the caller is responsible for locking the start index */
|
|
if (index == locked_page->index && index == end_index)
|
|
return 0;
|
|
|
|
/* skip the page at the start index */
|
|
nrpages = end_index - index + 1;
|
|
while (nrpages > 0) {
|
|
ret = find_get_pages_contig(inode->i_mapping, index,
|
|
min_t(unsigned long,
|
|
nrpages, ARRAY_SIZE(pages)), pages);
|
|
if (ret == 0) {
|
|
ret = -EAGAIN;
|
|
goto done;
|
|
}
|
|
/* now we have an array of pages, lock them all */
|
|
for (i = 0; i < ret; i++) {
|
|
/*
|
|
* the caller is taking responsibility for
|
|
* locked_page
|
|
*/
|
|
if (pages[i] != locked_page) {
|
|
lock_page(pages[i]);
|
|
if (!PageDirty(pages[i]) ||
|
|
pages[i]->mapping != inode->i_mapping) {
|
|
ret = -EAGAIN;
|
|
unlock_page(pages[i]);
|
|
page_cache_release(pages[i]);
|
|
goto done;
|
|
}
|
|
}
|
|
page_cache_release(pages[i]);
|
|
pages_locked++;
|
|
}
|
|
nrpages -= ret;
|
|
index += ret;
|
|
cond_resched();
|
|
}
|
|
ret = 0;
|
|
done:
|
|
if (ret && pages_locked) {
|
|
__unlock_for_delalloc(inode, locked_page,
|
|
delalloc_start,
|
|
((u64)(start_index + pages_locked - 1)) <<
|
|
PAGE_CACHE_SHIFT);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* find a contiguous range of bytes in the file marked as delalloc, not
|
|
* more than 'max_bytes'. start and end are used to return the range,
|
|
*
|
|
* 1 is returned if we find something, 0 if nothing was in the tree
|
|
*/
|
|
static noinline u64 find_lock_delalloc_range(struct inode *inode,
|
|
struct extent_io_tree *tree,
|
|
struct page *locked_page,
|
|
u64 *start, u64 *end,
|
|
u64 max_bytes)
|
|
{
|
|
u64 delalloc_start;
|
|
u64 delalloc_end;
|
|
u64 found;
|
|
struct extent_state *cached_state = NULL;
|
|
int ret;
|
|
int loops = 0;
|
|
|
|
again:
|
|
/* step one, find a bunch of delalloc bytes starting at start */
|
|
delalloc_start = *start;
|
|
delalloc_end = 0;
|
|
found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
|
|
max_bytes, &cached_state);
|
|
if (!found || delalloc_end <= *start) {
|
|
*start = delalloc_start;
|
|
*end = delalloc_end;
|
|
free_extent_state(cached_state);
|
|
return found;
|
|
}
|
|
|
|
/*
|
|
* start comes from the offset of locked_page. We have to lock
|
|
* pages in order, so we can't process delalloc bytes before
|
|
* locked_page
|
|
*/
|
|
if (delalloc_start < *start)
|
|
delalloc_start = *start;
|
|
|
|
/*
|
|
* make sure to limit the number of pages we try to lock down
|
|
* if we're looping.
|
|
*/
|
|
if (delalloc_end + 1 - delalloc_start > max_bytes && loops)
|
|
delalloc_end = delalloc_start + PAGE_CACHE_SIZE - 1;
|
|
|
|
/* step two, lock all the pages after the page that has start */
|
|
ret = lock_delalloc_pages(inode, locked_page,
|
|
delalloc_start, delalloc_end);
|
|
if (ret == -EAGAIN) {
|
|
/* some of the pages are gone, lets avoid looping by
|
|
* shortening the size of the delalloc range we're searching
|
|
*/
|
|
free_extent_state(cached_state);
|
|
if (!loops) {
|
|
unsigned long offset = (*start) & (PAGE_CACHE_SIZE - 1);
|
|
max_bytes = PAGE_CACHE_SIZE - offset;
|
|
loops = 1;
|
|
goto again;
|
|
} else {
|
|
found = 0;
|
|
goto out_failed;
|
|
}
|
|
}
|
|
BUG_ON(ret); /* Only valid values are 0 and -EAGAIN */
|
|
|
|
/* step three, lock the state bits for the whole range */
|
|
lock_extent_bits(tree, delalloc_start, delalloc_end, 0, &cached_state);
|
|
|
|
/* then test to make sure it is all still delalloc */
|
|
ret = test_range_bit(tree, delalloc_start, delalloc_end,
|
|
EXTENT_DELALLOC, 1, cached_state);
|
|
if (!ret) {
|
|
unlock_extent_cached(tree, delalloc_start, delalloc_end,
|
|
&cached_state, GFP_NOFS);
|
|
__unlock_for_delalloc(inode, locked_page,
|
|
delalloc_start, delalloc_end);
|
|
cond_resched();
|
|
goto again;
|
|
}
|
|
free_extent_state(cached_state);
|
|
*start = delalloc_start;
|
|
*end = delalloc_end;
|
|
out_failed:
|
|
return found;
|
|
}
|
|
|
|
int extent_clear_unlock_delalloc(struct inode *inode,
|
|
struct extent_io_tree *tree,
|
|
u64 start, u64 end, struct page *locked_page,
|
|
unsigned long op)
|
|
{
|
|
int ret;
|
|
struct page *pages[16];
|
|
unsigned long index = start >> PAGE_CACHE_SHIFT;
|
|
unsigned long end_index = end >> PAGE_CACHE_SHIFT;
|
|
unsigned long nr_pages = end_index - index + 1;
|
|
int i;
|
|
unsigned long clear_bits = 0;
|
|
|
|
if (op & EXTENT_CLEAR_UNLOCK)
|
|
clear_bits |= EXTENT_LOCKED;
|
|
if (op & EXTENT_CLEAR_DIRTY)
|
|
clear_bits |= EXTENT_DIRTY;
|
|
|
|
if (op & EXTENT_CLEAR_DELALLOC)
|
|
clear_bits |= EXTENT_DELALLOC;
|
|
|
|
clear_extent_bit(tree, start, end, clear_bits, 1, 0, NULL, GFP_NOFS);
|
|
if (!(op & (EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
|
|
EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK |
|
|
EXTENT_SET_PRIVATE2)))
|
|
return 0;
|
|
|
|
while (nr_pages > 0) {
|
|
ret = find_get_pages_contig(inode->i_mapping, index,
|
|
min_t(unsigned long,
|
|
nr_pages, ARRAY_SIZE(pages)), pages);
|
|
for (i = 0; i < ret; i++) {
|
|
|
|
if (op & EXTENT_SET_PRIVATE2)
|
|
SetPagePrivate2(pages[i]);
|
|
|
|
if (pages[i] == locked_page) {
|
|
page_cache_release(pages[i]);
|
|
continue;
|
|
}
|
|
if (op & EXTENT_CLEAR_DIRTY)
|
|
clear_page_dirty_for_io(pages[i]);
|
|
if (op & EXTENT_SET_WRITEBACK)
|
|
set_page_writeback(pages[i]);
|
|
if (op & EXTENT_END_WRITEBACK)
|
|
end_page_writeback(pages[i]);
|
|
if (op & EXTENT_CLEAR_UNLOCK_PAGE)
|
|
unlock_page(pages[i]);
|
|
page_cache_release(pages[i]);
|
|
}
|
|
nr_pages -= ret;
|
|
index += ret;
|
|
cond_resched();
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* count the number of bytes in the tree that have a given bit(s)
|
|
* set. This can be fairly slow, except for EXTENT_DIRTY which is
|
|
* cached. The total number found is returned.
|
|
*/
|
|
u64 count_range_bits(struct extent_io_tree *tree,
|
|
u64 *start, u64 search_end, u64 max_bytes,
|
|
unsigned long bits, int contig)
|
|
{
|
|
struct rb_node *node;
|
|
struct extent_state *state;
|
|
u64 cur_start = *start;
|
|
u64 total_bytes = 0;
|
|
u64 last = 0;
|
|
int found = 0;
|
|
|
|
if (search_end <= cur_start) {
|
|
WARN_ON(1);
|
|
return 0;
|
|
}
|
|
|
|
spin_lock(&tree->lock);
|
|
if (cur_start == 0 && bits == EXTENT_DIRTY) {
|
|
total_bytes = tree->dirty_bytes;
|
|
goto out;
|
|
}
|
|
/*
|
|
* this search will find all the extents that end after
|
|
* our range starts.
|
|
*/
|
|
node = tree_search(tree, cur_start);
|
|
if (!node)
|
|
goto out;
|
|
|
|
while (1) {
|
|
state = rb_entry(node, struct extent_state, rb_node);
|
|
if (state->start > search_end)
|
|
break;
|
|
if (contig && found && state->start > last + 1)
|
|
break;
|
|
if (state->end >= cur_start && (state->state & bits) == bits) {
|
|
total_bytes += min(search_end, state->end) + 1 -
|
|
max(cur_start, state->start);
|
|
if (total_bytes >= max_bytes)
|
|
break;
|
|
if (!found) {
|
|
*start = max(cur_start, state->start);
|
|
found = 1;
|
|
}
|
|
last = state->end;
|
|
} else if (contig && found) {
|
|
break;
|
|
}
|
|
node = rb_next(node);
|
|
if (!node)
|
|
break;
|
|
}
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
return total_bytes;
|
|
}
|
|
|
|
/*
|
|
* set the private field for a given byte offset in the tree. If there isn't
|
|
* an extent_state there already, this does nothing.
|
|
*/
|
|
int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
|
|
{
|
|
struct rb_node *node;
|
|
struct extent_state *state;
|
|
int ret = 0;
|
|
|
|
spin_lock(&tree->lock);
|
|
/*
|
|
* this search will find all the extents that end after
|
|
* our range starts.
|
|
*/
|
|
node = tree_search(tree, start);
|
|
if (!node) {
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
state = rb_entry(node, struct extent_state, rb_node);
|
|
if (state->start != start) {
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
state->private = private;
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
return ret;
|
|
}
|
|
|
|
void extent_cache_csums_dio(struct extent_io_tree *tree, u64 start, u32 csums[],
|
|
int count)
|
|
{
|
|
struct rb_node *node;
|
|
struct extent_state *state;
|
|
|
|
spin_lock(&tree->lock);
|
|
/*
|
|
* this search will find all the extents that end after
|
|
* our range starts.
|
|
*/
|
|
node = tree_search(tree, start);
|
|
BUG_ON(!node);
|
|
|
|
state = rb_entry(node, struct extent_state, rb_node);
|
|
BUG_ON(state->start != start);
|
|
|
|
while (count) {
|
|
state->private = *csums++;
|
|
count--;
|
|
state = next_state(state);
|
|
}
|
|
spin_unlock(&tree->lock);
|
|
}
|
|
|
|
static inline u64 __btrfs_get_bio_offset(struct bio *bio, int bio_index)
|
|
{
|
|
struct bio_vec *bvec = bio->bi_io_vec + bio_index;
|
|
|
|
return page_offset(bvec->bv_page) + bvec->bv_offset;
|
|
}
|
|
|
|
void extent_cache_csums(struct extent_io_tree *tree, struct bio *bio, int bio_index,
|
|
u32 csums[], int count)
|
|
{
|
|
struct rb_node *node;
|
|
struct extent_state *state = NULL;
|
|
u64 start;
|
|
|
|
spin_lock(&tree->lock);
|
|
do {
|
|
start = __btrfs_get_bio_offset(bio, bio_index);
|
|
if (state == NULL || state->start != start) {
|
|
node = tree_search(tree, start);
|
|
BUG_ON(!node);
|
|
|
|
state = rb_entry(node, struct extent_state, rb_node);
|
|
BUG_ON(state->start != start);
|
|
}
|
|
state->private = *csums++;
|
|
count--;
|
|
bio_index++;
|
|
|
|
state = next_state(state);
|
|
} while (count);
|
|
spin_unlock(&tree->lock);
|
|
}
|
|
|
|
int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
|
|
{
|
|
struct rb_node *node;
|
|
struct extent_state *state;
|
|
int ret = 0;
|
|
|
|
spin_lock(&tree->lock);
|
|
/*
|
|
* this search will find all the extents that end after
|
|
* our range starts.
|
|
*/
|
|
node = tree_search(tree, start);
|
|
if (!node) {
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
state = rb_entry(node, struct extent_state, rb_node);
|
|
if (state->start != start) {
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
*private = state->private;
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* searches a range in the state tree for a given mask.
|
|
* If 'filled' == 1, this returns 1 only if every extent in the tree
|
|
* has the bits set. Otherwise, 1 is returned if any bit in the
|
|
* range is found set.
|
|
*/
|
|
int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
|
|
unsigned long bits, int filled, struct extent_state *cached)
|
|
{
|
|
struct extent_state *state = NULL;
|
|
struct rb_node *node;
|
|
int bitset = 0;
|
|
|
|
spin_lock(&tree->lock);
|
|
if (cached && cached->tree && cached->start <= start &&
|
|
cached->end > start)
|
|
node = &cached->rb_node;
|
|
else
|
|
node = tree_search(tree, start);
|
|
while (node && start <= end) {
|
|
state = rb_entry(node, struct extent_state, rb_node);
|
|
|
|
if (filled && state->start > start) {
|
|
bitset = 0;
|
|
break;
|
|
}
|
|
|
|
if (state->start > end)
|
|
break;
|
|
|
|
if (state->state & bits) {
|
|
bitset = 1;
|
|
if (!filled)
|
|
break;
|
|
} else if (filled) {
|
|
bitset = 0;
|
|
break;
|
|
}
|
|
|
|
if (state->end == (u64)-1)
|
|
break;
|
|
|
|
start = state->end + 1;
|
|
if (start > end)
|
|
break;
|
|
node = rb_next(node);
|
|
if (!node) {
|
|
if (filled)
|
|
bitset = 0;
|
|
break;
|
|
}
|
|
}
|
|
spin_unlock(&tree->lock);
|
|
return bitset;
|
|
}
|
|
|
|
/*
|
|
* helper function to set a given page up to date if all the
|
|
* extents in the tree for that page are up to date
|
|
*/
|
|
static void check_page_uptodate(struct extent_io_tree *tree, struct page *page)
|
|
{
|
|
u64 start = page_offset(page);
|
|
u64 end = start + PAGE_CACHE_SIZE - 1;
|
|
if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
|
|
SetPageUptodate(page);
|
|
}
|
|
|
|
/*
|
|
* When IO fails, either with EIO or csum verification fails, we
|
|
* try other mirrors that might have a good copy of the data. This
|
|
* io_failure_record is used to record state as we go through all the
|
|
* mirrors. If another mirror has good data, the page is set up to date
|
|
* and things continue. If a good mirror can't be found, the original
|
|
* bio end_io callback is called to indicate things have failed.
|
|
*/
|
|
struct io_failure_record {
|
|
struct page *page;
|
|
u64 start;
|
|
u64 len;
|
|
u64 logical;
|
|
unsigned long bio_flags;
|
|
int this_mirror;
|
|
int failed_mirror;
|
|
int in_validation;
|
|
};
|
|
|
|
static int free_io_failure(struct inode *inode, struct io_failure_record *rec,
|
|
int did_repair)
|
|
{
|
|
int ret;
|
|
int err = 0;
|
|
struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
|
|
|
|
set_state_private(failure_tree, rec->start, 0);
|
|
ret = clear_extent_bits(failure_tree, rec->start,
|
|
rec->start + rec->len - 1,
|
|
EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
|
|
if (ret)
|
|
err = ret;
|
|
|
|
ret = clear_extent_bits(&BTRFS_I(inode)->io_tree, rec->start,
|
|
rec->start + rec->len - 1,
|
|
EXTENT_DAMAGED, GFP_NOFS);
|
|
if (ret && !err)
|
|
err = ret;
|
|
|
|
kfree(rec);
|
|
return err;
|
|
}
|
|
|
|
static void repair_io_failure_callback(struct bio *bio, int err)
|
|
{
|
|
complete(bio->bi_private);
|
|
}
|
|
|
|
/*
|
|
* this bypasses the standard btrfs submit functions deliberately, as
|
|
* the standard behavior is to write all copies in a raid setup. here we only
|
|
* want to write the one bad copy. so we do the mapping for ourselves and issue
|
|
* submit_bio directly.
|
|
* to avoid any synchronization issues, wait for the data after writing, which
|
|
* actually prevents the read that triggered the error from finishing.
|
|
* currently, there can be no more than two copies of every data bit. thus,
|
|
* exactly one rewrite is required.
|
|
*/
|
|
int repair_io_failure(struct btrfs_fs_info *fs_info, u64 start,
|
|
u64 length, u64 logical, struct page *page,
|
|
int mirror_num)
|
|
{
|
|
struct bio *bio;
|
|
struct btrfs_device *dev;
|
|
DECLARE_COMPLETION_ONSTACK(compl);
|
|
u64 map_length = 0;
|
|
u64 sector;
|
|
struct btrfs_bio *bbio = NULL;
|
|
struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
|
|
int ret;
|
|
|
|
BUG_ON(!mirror_num);
|
|
|
|
/* we can't repair anything in raid56 yet */
|
|
if (btrfs_is_parity_mirror(map_tree, logical, length, mirror_num))
|
|
return 0;
|
|
|
|
bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
|
|
if (!bio)
|
|
return -EIO;
|
|
bio->bi_private = &compl;
|
|
bio->bi_end_io = repair_io_failure_callback;
|
|
bio->bi_size = 0;
|
|
map_length = length;
|
|
|
|
ret = btrfs_map_block(fs_info, WRITE, logical,
|
|
&map_length, &bbio, mirror_num);
|
|
if (ret) {
|
|
bio_put(bio);
|
|
return -EIO;
|
|
}
|
|
BUG_ON(mirror_num != bbio->mirror_num);
|
|
sector = bbio->stripes[mirror_num-1].physical >> 9;
|
|
bio->bi_sector = sector;
|
|
dev = bbio->stripes[mirror_num-1].dev;
|
|
kfree(bbio);
|
|
if (!dev || !dev->bdev || !dev->writeable) {
|
|
bio_put(bio);
|
|
return -EIO;
|
|
}
|
|
bio->bi_bdev = dev->bdev;
|
|
bio_add_page(bio, page, length, start - page_offset(page));
|
|
btrfsic_submit_bio(WRITE_SYNC, bio);
|
|
wait_for_completion(&compl);
|
|
|
|
if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
|
|
/* try to remap that extent elsewhere? */
|
|
bio_put(bio);
|
|
btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
|
|
return -EIO;
|
|
}
|
|
|
|
printk_ratelimited_in_rcu(KERN_INFO "btrfs read error corrected: ino %lu off %llu "
|
|
"(dev %s sector %llu)\n", page->mapping->host->i_ino,
|
|
start, rcu_str_deref(dev->name), sector);
|
|
|
|
bio_put(bio);
|
|
return 0;
|
|
}
|
|
|
|
int repair_eb_io_failure(struct btrfs_root *root, struct extent_buffer *eb,
|
|
int mirror_num)
|
|
{
|
|
u64 start = eb->start;
|
|
unsigned long i, num_pages = num_extent_pages(eb->start, eb->len);
|
|
int ret = 0;
|
|
|
|
for (i = 0; i < num_pages; i++) {
|
|
struct page *p = extent_buffer_page(eb, i);
|
|
ret = repair_io_failure(root->fs_info, start, PAGE_CACHE_SIZE,
|
|
start, p, mirror_num);
|
|
if (ret)
|
|
break;
|
|
start += PAGE_CACHE_SIZE;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* each time an IO finishes, we do a fast check in the IO failure tree
|
|
* to see if we need to process or clean up an io_failure_record
|
|
*/
|
|
static int clean_io_failure(u64 start, struct page *page)
|
|
{
|
|
u64 private;
|
|
u64 private_failure;
|
|
struct io_failure_record *failrec;
|
|
struct btrfs_fs_info *fs_info;
|
|
struct extent_state *state;
|
|
int num_copies;
|
|
int did_repair = 0;
|
|
int ret;
|
|
struct inode *inode = page->mapping->host;
|
|
|
|
private = 0;
|
|
ret = count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
|
|
(u64)-1, 1, EXTENT_DIRTY, 0);
|
|
if (!ret)
|
|
return 0;
|
|
|
|
ret = get_state_private(&BTRFS_I(inode)->io_failure_tree, start,
|
|
&private_failure);
|
|
if (ret)
|
|
return 0;
|
|
|
|
failrec = (struct io_failure_record *)(unsigned long) private_failure;
|
|
BUG_ON(!failrec->this_mirror);
|
|
|
|
if (failrec->in_validation) {
|
|
/* there was no real error, just free the record */
|
|
pr_debug("clean_io_failure: freeing dummy error at %llu\n",
|
|
failrec->start);
|
|
did_repair = 1;
|
|
goto out;
|
|
}
|
|
|
|
spin_lock(&BTRFS_I(inode)->io_tree.lock);
|
|
state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
|
|
failrec->start,
|
|
EXTENT_LOCKED);
|
|
spin_unlock(&BTRFS_I(inode)->io_tree.lock);
|
|
|
|
if (state && state->start == failrec->start) {
|
|
fs_info = BTRFS_I(inode)->root->fs_info;
|
|
num_copies = btrfs_num_copies(fs_info, failrec->logical,
|
|
failrec->len);
|
|
if (num_copies > 1) {
|
|
ret = repair_io_failure(fs_info, start, failrec->len,
|
|
failrec->logical, page,
|
|
failrec->failed_mirror);
|
|
did_repair = !ret;
|
|
}
|
|
ret = 0;
|
|
}
|
|
|
|
out:
|
|
if (!ret)
|
|
ret = free_io_failure(inode, failrec, did_repair);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* this is a generic handler for readpage errors (default
|
|
* readpage_io_failed_hook). if other copies exist, read those and write back
|
|
* good data to the failed position. does not investigate in remapping the
|
|
* failed extent elsewhere, hoping the device will be smart enough to do this as
|
|
* needed
|
|
*/
|
|
|
|
static int bio_readpage_error(struct bio *failed_bio, struct page *page,
|
|
u64 start, u64 end, int failed_mirror,
|
|
struct extent_state *state)
|
|
{
|
|
struct io_failure_record *failrec = NULL;
|
|
u64 private;
|
|
struct extent_map *em;
|
|
struct inode *inode = page->mapping->host;
|
|
struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
|
|
struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
|
|
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
|
|
struct bio *bio;
|
|
int num_copies;
|
|
int ret;
|
|
int read_mode;
|
|
u64 logical;
|
|
|
|
BUG_ON(failed_bio->bi_rw & REQ_WRITE);
|
|
|
|
ret = get_state_private(failure_tree, start, &private);
|
|
if (ret) {
|
|
failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
|
|
if (!failrec)
|
|
return -ENOMEM;
|
|
failrec->start = start;
|
|
failrec->len = end - start + 1;
|
|
failrec->this_mirror = 0;
|
|
failrec->bio_flags = 0;
|
|
failrec->in_validation = 0;
|
|
|
|
read_lock(&em_tree->lock);
|
|
em = lookup_extent_mapping(em_tree, start, failrec->len);
|
|
if (!em) {
|
|
read_unlock(&em_tree->lock);
|
|
kfree(failrec);
|
|
return -EIO;
|
|
}
|
|
|
|
if (em->start > start || em->start + em->len < start) {
|
|
free_extent_map(em);
|
|
em = NULL;
|
|
}
|
|
read_unlock(&em_tree->lock);
|
|
|
|
if (!em) {
|
|
kfree(failrec);
|
|
return -EIO;
|
|
}
|
|
logical = start - em->start;
|
|
logical = em->block_start + logical;
|
|
if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
|
|
logical = em->block_start;
|
|
failrec->bio_flags = EXTENT_BIO_COMPRESSED;
|
|
extent_set_compress_type(&failrec->bio_flags,
|
|
em->compress_type);
|
|
}
|
|
pr_debug("bio_readpage_error: (new) logical=%llu, start=%llu, "
|
|
"len=%llu\n", logical, start, failrec->len);
|
|
failrec->logical = logical;
|
|
free_extent_map(em);
|
|
|
|
/* set the bits in the private failure tree */
|
|
ret = set_extent_bits(failure_tree, start, end,
|
|
EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
|
|
if (ret >= 0)
|
|
ret = set_state_private(failure_tree, start,
|
|
(u64)(unsigned long)failrec);
|
|
/* set the bits in the inode's tree */
|
|
if (ret >= 0)
|
|
ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED,
|
|
GFP_NOFS);
|
|
if (ret < 0) {
|
|
kfree(failrec);
|
|
return ret;
|
|
}
|
|
} else {
|
|
failrec = (struct io_failure_record *)(unsigned long)private;
|
|
pr_debug("bio_readpage_error: (found) logical=%llu, "
|
|
"start=%llu, len=%llu, validation=%d\n",
|
|
failrec->logical, failrec->start, failrec->len,
|
|
failrec->in_validation);
|
|
/*
|
|
* when data can be on disk more than twice, add to failrec here
|
|
* (e.g. with a list for failed_mirror) to make
|
|
* clean_io_failure() clean all those errors at once.
|
|
*/
|
|
}
|
|
num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info,
|
|
failrec->logical, failrec->len);
|
|
if (num_copies == 1) {
|
|
/*
|
|
* we only have a single copy of the data, so don't bother with
|
|
* all the retry and error correction code that follows. no
|
|
* matter what the error is, it is very likely to persist.
|
|
*/
|
|
pr_debug("bio_readpage_error: cannot repair, num_copies == 1. "
|
|
"state=%p, num_copies=%d, next_mirror %d, "
|
|
"failed_mirror %d\n", state, num_copies,
|
|
failrec->this_mirror, failed_mirror);
|
|
free_io_failure(inode, failrec, 0);
|
|
return -EIO;
|
|
}
|
|
|
|
if (!state) {
|
|
spin_lock(&tree->lock);
|
|
state = find_first_extent_bit_state(tree, failrec->start,
|
|
EXTENT_LOCKED);
|
|
if (state && state->start != failrec->start)
|
|
state = NULL;
|
|
spin_unlock(&tree->lock);
|
|
}
|
|
|
|
/*
|
|
* there are two premises:
|
|
* a) deliver good data to the caller
|
|
* b) correct the bad sectors on disk
|
|
*/
|
|
if (failed_bio->bi_vcnt > 1) {
|
|
/*
|
|
* to fulfill b), we need to know the exact failing sectors, as
|
|
* we don't want to rewrite any more than the failed ones. thus,
|
|
* we need separate read requests for the failed bio
|
|
*
|
|
* if the following BUG_ON triggers, our validation request got
|
|
* merged. we need separate requests for our algorithm to work.
|
|
*/
|
|
BUG_ON(failrec->in_validation);
|
|
failrec->in_validation = 1;
|
|
failrec->this_mirror = failed_mirror;
|
|
read_mode = READ_SYNC | REQ_FAILFAST_DEV;
|
|
} else {
|
|
/*
|
|
* we're ready to fulfill a) and b) alongside. get a good copy
|
|
* of the failed sector and if we succeed, we have setup
|
|
* everything for repair_io_failure to do the rest for us.
|
|
*/
|
|
if (failrec->in_validation) {
|
|
BUG_ON(failrec->this_mirror != failed_mirror);
|
|
failrec->in_validation = 0;
|
|
failrec->this_mirror = 0;
|
|
}
|
|
failrec->failed_mirror = failed_mirror;
|
|
failrec->this_mirror++;
|
|
if (failrec->this_mirror == failed_mirror)
|
|
failrec->this_mirror++;
|
|
read_mode = READ_SYNC;
|
|
}
|
|
|
|
if (!state || failrec->this_mirror > num_copies) {
|
|
pr_debug("bio_readpage_error: (fail) state=%p, num_copies=%d, "
|
|
"next_mirror %d, failed_mirror %d\n", state,
|
|
num_copies, failrec->this_mirror, failed_mirror);
|
|
free_io_failure(inode, failrec, 0);
|
|
return -EIO;
|
|
}
|
|
|
|
bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
|
|
if (!bio) {
|
|
free_io_failure(inode, failrec, 0);
|
|
return -EIO;
|
|
}
|
|
bio->bi_private = state;
|
|
bio->bi_end_io = failed_bio->bi_end_io;
|
|
bio->bi_sector = failrec->logical >> 9;
|
|
bio->bi_bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
|
|
bio->bi_size = 0;
|
|
|
|
bio_add_page(bio, page, failrec->len, start - page_offset(page));
|
|
|
|
pr_debug("bio_readpage_error: submitting new read[%#x] to "
|
|
"this_mirror=%d, num_copies=%d, in_validation=%d\n", read_mode,
|
|
failrec->this_mirror, num_copies, failrec->in_validation);
|
|
|
|
ret = tree->ops->submit_bio_hook(inode, read_mode, bio,
|
|
failrec->this_mirror,
|
|
failrec->bio_flags, 0);
|
|
return ret;
|
|
}
|
|
|
|
/* lots and lots of room for performance fixes in the end_bio funcs */
|
|
|
|
int end_extent_writepage(struct page *page, int err, u64 start, u64 end)
|
|
{
|
|
int uptodate = (err == 0);
|
|
struct extent_io_tree *tree;
|
|
int ret;
|
|
|
|
tree = &BTRFS_I(page->mapping->host)->io_tree;
|
|
|
|
if (tree->ops && tree->ops->writepage_end_io_hook) {
|
|
ret = tree->ops->writepage_end_io_hook(page, start,
|
|
end, NULL, uptodate);
|
|
if (ret)
|
|
uptodate = 0;
|
|
}
|
|
|
|
if (!uptodate) {
|
|
ClearPageUptodate(page);
|
|
SetPageError(page);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* after a writepage IO is done, we need to:
|
|
* clear the uptodate bits on error
|
|
* clear the writeback bits in the extent tree for this IO
|
|
* end_page_writeback if the page has no more pending IO
|
|
*
|
|
* Scheduling is not allowed, so the extent state tree is expected
|
|
* to have one and only one object corresponding to this IO.
|
|
*/
|
|
static void end_bio_extent_writepage(struct bio *bio, int err)
|
|
{
|
|
struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
|
|
struct extent_io_tree *tree;
|
|
u64 start;
|
|
u64 end;
|
|
|
|
do {
|
|
struct page *page = bvec->bv_page;
|
|
tree = &BTRFS_I(page->mapping->host)->io_tree;
|
|
|
|
/* We always issue full-page reads, but if some block
|
|
* in a page fails to read, blk_update_request() will
|
|
* advance bv_offset and adjust bv_len to compensate.
|
|
* Print a warning for nonzero offsets, and an error
|
|
* if they don't add up to a full page. */
|
|
if (bvec->bv_offset || bvec->bv_len != PAGE_CACHE_SIZE)
|
|
printk("%s page write in btrfs with offset %u and length %u\n",
|
|
bvec->bv_offset + bvec->bv_len != PAGE_CACHE_SIZE
|
|
? KERN_ERR "partial" : KERN_INFO "incomplete",
|
|
bvec->bv_offset, bvec->bv_len);
|
|
|
|
start = page_offset(page);
|
|
end = start + bvec->bv_offset + bvec->bv_len - 1;
|
|
|
|
if (--bvec >= bio->bi_io_vec)
|
|
prefetchw(&bvec->bv_page->flags);
|
|
|
|
if (end_extent_writepage(page, err, start, end))
|
|
continue;
|
|
|
|
end_page_writeback(page);
|
|
} while (bvec >= bio->bi_io_vec);
|
|
|
|
bio_put(bio);
|
|
}
|
|
|
|
/*
|
|
* after a readpage IO is done, we need to:
|
|
* clear the uptodate bits on error
|
|
* set the uptodate bits if things worked
|
|
* set the page up to date if all extents in the tree are uptodate
|
|
* clear the lock bit in the extent tree
|
|
* unlock the page if there are no other extents locked for it
|
|
*
|
|
* Scheduling is not allowed, so the extent state tree is expected
|
|
* to have one and only one object corresponding to this IO.
|
|
*/
|
|
static void end_bio_extent_readpage(struct bio *bio, int err)
|
|
{
|
|
int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
|
|
struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
|
|
struct bio_vec *bvec = bio->bi_io_vec;
|
|
struct extent_io_tree *tree;
|
|
u64 start;
|
|
u64 end;
|
|
int mirror;
|
|
int ret;
|
|
|
|
if (err)
|
|
uptodate = 0;
|
|
|
|
do {
|
|
struct page *page = bvec->bv_page;
|
|
struct extent_state *cached = NULL;
|
|
struct extent_state *state;
|
|
struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
|
|
struct inode *inode = page->mapping->host;
|
|
|
|
pr_debug("end_bio_extent_readpage: bi_sector=%llu, err=%d, "
|
|
"mirror=%lu\n", (u64)bio->bi_sector, err,
|
|
io_bio->mirror_num);
|
|
tree = &BTRFS_I(inode)->io_tree;
|
|
|
|
/* We always issue full-page reads, but if some block
|
|
* in a page fails to read, blk_update_request() will
|
|
* advance bv_offset and adjust bv_len to compensate.
|
|
* Print a warning for nonzero offsets, and an error
|
|
* if they don't add up to a full page. */
|
|
if (bvec->bv_offset || bvec->bv_len != PAGE_CACHE_SIZE)
|
|
printk("%s page read in btrfs with offset %u and length %u\n",
|
|
bvec->bv_offset + bvec->bv_len != PAGE_CACHE_SIZE
|
|
? KERN_ERR "partial" : KERN_INFO "incomplete",
|
|
bvec->bv_offset, bvec->bv_len);
|
|
|
|
start = page_offset(page);
|
|
end = start + bvec->bv_offset + bvec->bv_len - 1;
|
|
|
|
if (++bvec <= bvec_end)
|
|
prefetchw(&bvec->bv_page->flags);
|
|
|
|
spin_lock(&tree->lock);
|
|
state = find_first_extent_bit_state(tree, start, EXTENT_LOCKED);
|
|
if (state && state->start == start) {
|
|
/*
|
|
* take a reference on the state, unlock will drop
|
|
* the ref
|
|
*/
|
|
cache_state(state, &cached);
|
|
}
|
|
spin_unlock(&tree->lock);
|
|
|
|
mirror = io_bio->mirror_num;
|
|
if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
|
|
ret = tree->ops->readpage_end_io_hook(page, start, end,
|
|
state, mirror);
|
|
if (ret)
|
|
uptodate = 0;
|
|
else
|
|
clean_io_failure(start, page);
|
|
}
|
|
|
|
if (!uptodate && tree->ops && tree->ops->readpage_io_failed_hook) {
|
|
ret = tree->ops->readpage_io_failed_hook(page, mirror);
|
|
if (!ret && !err &&
|
|
test_bit(BIO_UPTODATE, &bio->bi_flags))
|
|
uptodate = 1;
|
|
} else if (!uptodate) {
|
|
/*
|
|
* The generic bio_readpage_error handles errors the
|
|
* following way: If possible, new read requests are
|
|
* created and submitted and will end up in
|
|
* end_bio_extent_readpage as well (if we're lucky, not
|
|
* in the !uptodate case). In that case it returns 0 and
|
|
* we just go on with the next page in our bio. If it
|
|
* can't handle the error it will return -EIO and we
|
|
* remain responsible for that page.
|
|
*/
|
|
ret = bio_readpage_error(bio, page, start, end, mirror, NULL);
|
|
if (ret == 0) {
|
|
uptodate =
|
|
test_bit(BIO_UPTODATE, &bio->bi_flags);
|
|
if (err)
|
|
uptodate = 0;
|
|
uncache_state(&cached);
|
|
continue;
|
|
}
|
|
}
|
|
|
|
if (uptodate && tree->track_uptodate) {
|
|
set_extent_uptodate(tree, start, end, &cached,
|
|
GFP_ATOMIC);
|
|
}
|
|
unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
|
|
|
|
if (uptodate) {
|
|
loff_t i_size = i_size_read(inode);
|
|
pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
|
|
unsigned offset;
|
|
|
|
/* Zero out the end if this page straddles i_size */
|
|
offset = i_size & (PAGE_CACHE_SIZE-1);
|
|
if (page->index == end_index && offset)
|
|
zero_user_segment(page, offset, PAGE_CACHE_SIZE);
|
|
SetPageUptodate(page);
|
|
} else {
|
|
ClearPageUptodate(page);
|
|
SetPageError(page);
|
|
}
|
|
unlock_page(page);
|
|
} while (bvec <= bvec_end);
|
|
|
|
bio_put(bio);
|
|
}
|
|
|
|
/*
|
|
* this allocates from the btrfs_bioset. We're returning a bio right now
|
|
* but you can call btrfs_io_bio for the appropriate container_of magic
|
|
*/
|
|
struct bio *
|
|
btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
|
|
gfp_t gfp_flags)
|
|
{
|
|
struct bio *bio;
|
|
|
|
bio = bio_alloc_bioset(gfp_flags, nr_vecs, btrfs_bioset);
|
|
|
|
if (bio == NULL && (current->flags & PF_MEMALLOC)) {
|
|
while (!bio && (nr_vecs /= 2)) {
|
|
bio = bio_alloc_bioset(gfp_flags,
|
|
nr_vecs, btrfs_bioset);
|
|
}
|
|
}
|
|
|
|
if (bio) {
|
|
bio->bi_size = 0;
|
|
bio->bi_bdev = bdev;
|
|
bio->bi_sector = first_sector;
|
|
}
|
|
return bio;
|
|
}
|
|
|
|
struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask)
|
|
{
|
|
return bio_clone_bioset(bio, gfp_mask, btrfs_bioset);
|
|
}
|
|
|
|
|
|
/* this also allocates from the btrfs_bioset */
|
|
struct bio *btrfs_io_bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
|
|
{
|
|
return bio_alloc_bioset(gfp_mask, nr_iovecs, btrfs_bioset);
|
|
}
|
|
|
|
|
|
static int __must_check submit_one_bio(int rw, struct bio *bio,
|
|
int mirror_num, unsigned long bio_flags)
|
|
{
|
|
int ret = 0;
|
|
struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
|
|
struct page *page = bvec->bv_page;
|
|
struct extent_io_tree *tree = bio->bi_private;
|
|
u64 start;
|
|
|
|
start = page_offset(page) + bvec->bv_offset;
|
|
|
|
bio->bi_private = NULL;
|
|
|
|
bio_get(bio);
|
|
|
|
if (tree->ops && tree->ops->submit_bio_hook)
|
|
ret = tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
|
|
mirror_num, bio_flags, start);
|
|
else
|
|
btrfsic_submit_bio(rw, bio);
|
|
|
|
if (bio_flagged(bio, BIO_EOPNOTSUPP))
|
|
ret = -EOPNOTSUPP;
|
|
bio_put(bio);
|
|
return ret;
|
|
}
|
|
|
|
static int merge_bio(int rw, struct extent_io_tree *tree, struct page *page,
|
|
unsigned long offset, size_t size, struct bio *bio,
|
|
unsigned long bio_flags)
|
|
{
|
|
int ret = 0;
|
|
if (tree->ops && tree->ops->merge_bio_hook)
|
|
ret = tree->ops->merge_bio_hook(rw, page, offset, size, bio,
|
|
bio_flags);
|
|
BUG_ON(ret < 0);
|
|
return ret;
|
|
|
|
}
|
|
|
|
static int submit_extent_page(int rw, struct extent_io_tree *tree,
|
|
struct page *page, sector_t sector,
|
|
size_t size, unsigned long offset,
|
|
struct block_device *bdev,
|
|
struct bio **bio_ret,
|
|
unsigned long max_pages,
|
|
bio_end_io_t end_io_func,
|
|
int mirror_num,
|
|
unsigned long prev_bio_flags,
|
|
unsigned long bio_flags)
|
|
{
|
|
int ret = 0;
|
|
struct bio *bio;
|
|
int nr;
|
|
int contig = 0;
|
|
int this_compressed = bio_flags & EXTENT_BIO_COMPRESSED;
|
|
int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
|
|
size_t page_size = min_t(size_t, size, PAGE_CACHE_SIZE);
|
|
|
|
if (bio_ret && *bio_ret) {
|
|
bio = *bio_ret;
|
|
if (old_compressed)
|
|
contig = bio->bi_sector == sector;
|
|
else
|
|
contig = bio_end_sector(bio) == sector;
|
|
|
|
if (prev_bio_flags != bio_flags || !contig ||
|
|
merge_bio(rw, tree, page, offset, page_size, bio, bio_flags) ||
|
|
bio_add_page(bio, page, page_size, offset) < page_size) {
|
|
ret = submit_one_bio(rw, bio, mirror_num,
|
|
prev_bio_flags);
|
|
if (ret < 0)
|
|
return ret;
|
|
bio = NULL;
|
|
} else {
|
|
return 0;
|
|
}
|
|
}
|
|
if (this_compressed)
|
|
nr = BIO_MAX_PAGES;
|
|
else
|
|
nr = bio_get_nr_vecs(bdev);
|
|
|
|
bio = btrfs_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
|
|
if (!bio)
|
|
return -ENOMEM;
|
|
|
|
bio_add_page(bio, page, page_size, offset);
|
|
bio->bi_end_io = end_io_func;
|
|
bio->bi_private = tree;
|
|
|
|
if (bio_ret)
|
|
*bio_ret = bio;
|
|
else
|
|
ret = submit_one_bio(rw, bio, mirror_num, bio_flags);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void attach_extent_buffer_page(struct extent_buffer *eb,
|
|
struct page *page)
|
|
{
|
|
if (!PagePrivate(page)) {
|
|
SetPagePrivate(page);
|
|
page_cache_get(page);
|
|
set_page_private(page, (unsigned long)eb);
|
|
} else {
|
|
WARN_ON(page->private != (unsigned long)eb);
|
|
}
|
|
}
|
|
|
|
void set_page_extent_mapped(struct page *page)
|
|
{
|
|
if (!PagePrivate(page)) {
|
|
SetPagePrivate(page);
|
|
page_cache_get(page);
|
|
set_page_private(page, EXTENT_PAGE_PRIVATE);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* basic readpage implementation. Locked extent state structs are inserted
|
|
* into the tree that are removed when the IO is done (by the end_io
|
|
* handlers)
|
|
* XXX JDM: This needs looking at to ensure proper page locking
|
|
*/
|
|
static int __extent_read_full_page(struct extent_io_tree *tree,
|
|
struct page *page,
|
|
get_extent_t *get_extent,
|
|
struct bio **bio, int mirror_num,
|
|
unsigned long *bio_flags, int rw)
|
|
{
|
|
struct inode *inode = page->mapping->host;
|
|
u64 start = page_offset(page);
|
|
u64 page_end = start + PAGE_CACHE_SIZE - 1;
|
|
u64 end;
|
|
u64 cur = start;
|
|
u64 extent_offset;
|
|
u64 last_byte = i_size_read(inode);
|
|
u64 block_start;
|
|
u64 cur_end;
|
|
sector_t sector;
|
|
struct extent_map *em;
|
|
struct block_device *bdev;
|
|
struct btrfs_ordered_extent *ordered;
|
|
int ret;
|
|
int nr = 0;
|
|
size_t pg_offset = 0;
|
|
size_t iosize;
|
|
size_t disk_io_size;
|
|
size_t blocksize = inode->i_sb->s_blocksize;
|
|
unsigned long this_bio_flag = 0;
|
|
|
|
set_page_extent_mapped(page);
|
|
|
|
if (!PageUptodate(page)) {
|
|
if (cleancache_get_page(page) == 0) {
|
|
BUG_ON(blocksize != PAGE_SIZE);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
end = page_end;
|
|
while (1) {
|
|
lock_extent(tree, start, end);
|
|
ordered = btrfs_lookup_ordered_extent(inode, start);
|
|
if (!ordered)
|
|
break;
|
|
unlock_extent(tree, start, end);
|
|
btrfs_start_ordered_extent(inode, ordered, 1);
|
|
btrfs_put_ordered_extent(ordered);
|
|
}
|
|
|
|
if (page->index == last_byte >> PAGE_CACHE_SHIFT) {
|
|
char *userpage;
|
|
size_t zero_offset = last_byte & (PAGE_CACHE_SIZE - 1);
|
|
|
|
if (zero_offset) {
|
|
iosize = PAGE_CACHE_SIZE - zero_offset;
|
|
userpage = kmap_atomic(page);
|
|
memset(userpage + zero_offset, 0, iosize);
|
|
flush_dcache_page(page);
|
|
kunmap_atomic(userpage);
|
|
}
|
|
}
|
|
while (cur <= end) {
|
|
unsigned long pnr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
|
|
|
|
if (cur >= last_byte) {
|
|
char *userpage;
|
|
struct extent_state *cached = NULL;
|
|
|
|
iosize = PAGE_CACHE_SIZE - pg_offset;
|
|
userpage = kmap_atomic(page);
|
|
memset(userpage + pg_offset, 0, iosize);
|
|
flush_dcache_page(page);
|
|
kunmap_atomic(userpage);
|
|
set_extent_uptodate(tree, cur, cur + iosize - 1,
|
|
&cached, GFP_NOFS);
|
|
unlock_extent_cached(tree, cur, cur + iosize - 1,
|
|
&cached, GFP_NOFS);
|
|
break;
|
|
}
|
|
em = get_extent(inode, page, pg_offset, cur,
|
|
end - cur + 1, 0);
|
|
if (IS_ERR_OR_NULL(em)) {
|
|
SetPageError(page);
|
|
unlock_extent(tree, cur, end);
|
|
break;
|
|
}
|
|
extent_offset = cur - em->start;
|
|
BUG_ON(extent_map_end(em) <= cur);
|
|
BUG_ON(end < cur);
|
|
|
|
if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
|
|
this_bio_flag = EXTENT_BIO_COMPRESSED;
|
|
extent_set_compress_type(&this_bio_flag,
|
|
em->compress_type);
|
|
}
|
|
|
|
iosize = min(extent_map_end(em) - cur, end - cur + 1);
|
|
cur_end = min(extent_map_end(em) - 1, end);
|
|
iosize = ALIGN(iosize, blocksize);
|
|
if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
|
|
disk_io_size = em->block_len;
|
|
sector = em->block_start >> 9;
|
|
} else {
|
|
sector = (em->block_start + extent_offset) >> 9;
|
|
disk_io_size = iosize;
|
|
}
|
|
bdev = em->bdev;
|
|
block_start = em->block_start;
|
|
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
|
|
block_start = EXTENT_MAP_HOLE;
|
|
free_extent_map(em);
|
|
em = NULL;
|
|
|
|
/* we've found a hole, just zero and go on */
|
|
if (block_start == EXTENT_MAP_HOLE) {
|
|
char *userpage;
|
|
struct extent_state *cached = NULL;
|
|
|
|
userpage = kmap_atomic(page);
|
|
memset(userpage + pg_offset, 0, iosize);
|
|
flush_dcache_page(page);
|
|
kunmap_atomic(userpage);
|
|
|
|
set_extent_uptodate(tree, cur, cur + iosize - 1,
|
|
&cached, GFP_NOFS);
|
|
unlock_extent_cached(tree, cur, cur + iosize - 1,
|
|
&cached, GFP_NOFS);
|
|
cur = cur + iosize;
|
|
pg_offset += iosize;
|
|
continue;
|
|
}
|
|
/* the get_extent function already copied into the page */
|
|
if (test_range_bit(tree, cur, cur_end,
|
|
EXTENT_UPTODATE, 1, NULL)) {
|
|
check_page_uptodate(tree, page);
|
|
unlock_extent(tree, cur, cur + iosize - 1);
|
|
cur = cur + iosize;
|
|
pg_offset += iosize;
|
|
continue;
|
|
}
|
|
/* we have an inline extent but it didn't get marked up
|
|
* to date. Error out
|
|
*/
|
|
if (block_start == EXTENT_MAP_INLINE) {
|
|
SetPageError(page);
|
|
unlock_extent(tree, cur, cur + iosize - 1);
|
|
cur = cur + iosize;
|
|
pg_offset += iosize;
|
|
continue;
|
|
}
|
|
|
|
pnr -= page->index;
|
|
ret = submit_extent_page(rw, tree, page,
|
|
sector, disk_io_size, pg_offset,
|
|
bdev, bio, pnr,
|
|
end_bio_extent_readpage, mirror_num,
|
|
*bio_flags,
|
|
this_bio_flag);
|
|
if (!ret) {
|
|
nr++;
|
|
*bio_flags = this_bio_flag;
|
|
} else {
|
|
SetPageError(page);
|
|
unlock_extent(tree, cur, cur + iosize - 1);
|
|
}
|
|
cur = cur + iosize;
|
|
pg_offset += iosize;
|
|
}
|
|
out:
|
|
if (!nr) {
|
|
if (!PageError(page))
|
|
SetPageUptodate(page);
|
|
unlock_page(page);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
|
|
get_extent_t *get_extent, int mirror_num)
|
|
{
|
|
struct bio *bio = NULL;
|
|
unsigned long bio_flags = 0;
|
|
int ret;
|
|
|
|
ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num,
|
|
&bio_flags, READ);
|
|
if (bio)
|
|
ret = submit_one_bio(READ, bio, mirror_num, bio_flags);
|
|
return ret;
|
|
}
|
|
|
|
static noinline void update_nr_written(struct page *page,
|
|
struct writeback_control *wbc,
|
|
unsigned long nr_written)
|
|
{
|
|
wbc->nr_to_write -= nr_written;
|
|
if (wbc->range_cyclic || (wbc->nr_to_write > 0 &&
|
|
wbc->range_start == 0 && wbc->range_end == LLONG_MAX))
|
|
page->mapping->writeback_index = page->index + nr_written;
|
|
}
|
|
|
|
/*
|
|
* the writepage semantics are similar to regular writepage. extent
|
|
* records are inserted to lock ranges in the tree, and as dirty areas
|
|
* are found, they are marked writeback. Then the lock bits are removed
|
|
* and the end_io handler clears the writeback ranges
|
|
*/
|
|
static int __extent_writepage(struct page *page, struct writeback_control *wbc,
|
|
void *data)
|
|
{
|
|
struct inode *inode = page->mapping->host;
|
|
struct extent_page_data *epd = data;
|
|
struct extent_io_tree *tree = epd->tree;
|
|
u64 start = page_offset(page);
|
|
u64 delalloc_start;
|
|
u64 page_end = start + PAGE_CACHE_SIZE - 1;
|
|
u64 end;
|
|
u64 cur = start;
|
|
u64 extent_offset;
|
|
u64 last_byte = i_size_read(inode);
|
|
u64 block_start;
|
|
u64 iosize;
|
|
sector_t sector;
|
|
struct extent_state *cached_state = NULL;
|
|
struct extent_map *em;
|
|
struct block_device *bdev;
|
|
int ret;
|
|
int nr = 0;
|
|
size_t pg_offset = 0;
|
|
size_t blocksize;
|
|
loff_t i_size = i_size_read(inode);
|
|
unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
|
|
u64 nr_delalloc;
|
|
u64 delalloc_end;
|
|
int page_started;
|
|
int compressed;
|
|
int write_flags;
|
|
unsigned long nr_written = 0;
|
|
bool fill_delalloc = true;
|
|
|
|
if (wbc->sync_mode == WB_SYNC_ALL)
|
|
write_flags = WRITE_SYNC;
|
|
else
|
|
write_flags = WRITE;
|
|
|
|
trace___extent_writepage(page, inode, wbc);
|
|
|
|
WARN_ON(!PageLocked(page));
|
|
|
|
ClearPageError(page);
|
|
|
|
pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
|
|
if (page->index > end_index ||
|
|
(page->index == end_index && !pg_offset)) {
|
|
page->mapping->a_ops->invalidatepage(page, 0, PAGE_CACHE_SIZE);
|
|
unlock_page(page);
|
|
return 0;
|
|
}
|
|
|
|
if (page->index == end_index) {
|
|
char *userpage;
|
|
|
|
userpage = kmap_atomic(page);
|
|
memset(userpage + pg_offset, 0,
|
|
PAGE_CACHE_SIZE - pg_offset);
|
|
kunmap_atomic(userpage);
|
|
flush_dcache_page(page);
|
|
}
|
|
pg_offset = 0;
|
|
|
|
set_page_extent_mapped(page);
|
|
|
|
if (!tree->ops || !tree->ops->fill_delalloc)
|
|
fill_delalloc = false;
|
|
|
|
delalloc_start = start;
|
|
delalloc_end = 0;
|
|
page_started = 0;
|
|
if (!epd->extent_locked && fill_delalloc) {
|
|
u64 delalloc_to_write = 0;
|
|
/*
|
|
* make sure the wbc mapping index is at least updated
|
|
* to this page.
|
|
*/
|
|
update_nr_written(page, wbc, 0);
|
|
|
|
while (delalloc_end < page_end) {
|
|
nr_delalloc = find_lock_delalloc_range(inode, tree,
|
|
page,
|
|
&delalloc_start,
|
|
&delalloc_end,
|
|
128 * 1024 * 1024);
|
|
if (nr_delalloc == 0) {
|
|
delalloc_start = delalloc_end + 1;
|
|
continue;
|
|
}
|
|
ret = tree->ops->fill_delalloc(inode, page,
|
|
delalloc_start,
|
|
delalloc_end,
|
|
&page_started,
|
|
&nr_written);
|
|
/* File system has been set read-only */
|
|
if (ret) {
|
|
SetPageError(page);
|
|
goto done;
|
|
}
|
|
/*
|
|
* delalloc_end is already one less than the total
|
|
* length, so we don't subtract one from
|
|
* PAGE_CACHE_SIZE
|
|
*/
|
|
delalloc_to_write += (delalloc_end - delalloc_start +
|
|
PAGE_CACHE_SIZE) >>
|
|
PAGE_CACHE_SHIFT;
|
|
delalloc_start = delalloc_end + 1;
|
|
}
|
|
if (wbc->nr_to_write < delalloc_to_write) {
|
|
int thresh = 8192;
|
|
|
|
if (delalloc_to_write < thresh * 2)
|
|
thresh = delalloc_to_write;
|
|
wbc->nr_to_write = min_t(u64, delalloc_to_write,
|
|
thresh);
|
|
}
|
|
|
|
/* did the fill delalloc function already unlock and start
|
|
* the IO?
|
|
*/
|
|
if (page_started) {
|
|
ret = 0;
|
|
/*
|
|
* we've unlocked the page, so we can't update
|
|
* the mapping's writeback index, just update
|
|
* nr_to_write.
|
|
*/
|
|
wbc->nr_to_write -= nr_written;
|
|
goto done_unlocked;
|
|
}
|
|
}
|
|
if (tree->ops && tree->ops->writepage_start_hook) {
|
|
ret = tree->ops->writepage_start_hook(page, start,
|
|
page_end);
|
|
if (ret) {
|
|
/* Fixup worker will requeue */
|
|
if (ret == -EBUSY)
|
|
wbc->pages_skipped++;
|
|
else
|
|
redirty_page_for_writepage(wbc, page);
|
|
update_nr_written(page, wbc, nr_written);
|
|
unlock_page(page);
|
|
ret = 0;
|
|
goto done_unlocked;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* we don't want to touch the inode after unlocking the page,
|
|
* so we update the mapping writeback index now
|
|
*/
|
|
update_nr_written(page, wbc, nr_written + 1);
|
|
|
|
end = page_end;
|
|
if (last_byte <= start) {
|
|
if (tree->ops && tree->ops->writepage_end_io_hook)
|
|
tree->ops->writepage_end_io_hook(page, start,
|
|
page_end, NULL, 1);
|
|
goto done;
|
|
}
|
|
|
|
blocksize = inode->i_sb->s_blocksize;
|
|
|
|
while (cur <= end) {
|
|
if (cur >= last_byte) {
|
|
if (tree->ops && tree->ops->writepage_end_io_hook)
|
|
tree->ops->writepage_end_io_hook(page, cur,
|
|
page_end, NULL, 1);
|
|
break;
|
|
}
|
|
em = epd->get_extent(inode, page, pg_offset, cur,
|
|
end - cur + 1, 1);
|
|
if (IS_ERR_OR_NULL(em)) {
|
|
SetPageError(page);
|
|
break;
|
|
}
|
|
|
|
extent_offset = cur - em->start;
|
|
BUG_ON(extent_map_end(em) <= cur);
|
|
BUG_ON(end < cur);
|
|
iosize = min(extent_map_end(em) - cur, end - cur + 1);
|
|
iosize = ALIGN(iosize, blocksize);
|
|
sector = (em->block_start + extent_offset) >> 9;
|
|
bdev = em->bdev;
|
|
block_start = em->block_start;
|
|
compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
|
|
free_extent_map(em);
|
|
em = NULL;
|
|
|
|
/*
|
|
* compressed and inline extents are written through other
|
|
* paths in the FS
|
|
*/
|
|
if (compressed || block_start == EXTENT_MAP_HOLE ||
|
|
block_start == EXTENT_MAP_INLINE) {
|
|
/*
|
|
* end_io notification does not happen here for
|
|
* compressed extents
|
|
*/
|
|
if (!compressed && tree->ops &&
|
|
tree->ops->writepage_end_io_hook)
|
|
tree->ops->writepage_end_io_hook(page, cur,
|
|
cur + iosize - 1,
|
|
NULL, 1);
|
|
else if (compressed) {
|
|
/* we don't want to end_page_writeback on
|
|
* a compressed extent. this happens
|
|
* elsewhere
|
|
*/
|
|
nr++;
|
|
}
|
|
|
|
cur += iosize;
|
|
pg_offset += iosize;
|
|
continue;
|
|
}
|
|
/* leave this out until we have a page_mkwrite call */
|
|
if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
|
|
EXTENT_DIRTY, 0, NULL)) {
|
|
cur = cur + iosize;
|
|
pg_offset += iosize;
|
|
continue;
|
|
}
|
|
|
|
if (tree->ops && tree->ops->writepage_io_hook) {
|
|
ret = tree->ops->writepage_io_hook(page, cur,
|
|
cur + iosize - 1);
|
|
} else {
|
|
ret = 0;
|
|
}
|
|
if (ret) {
|
|
SetPageError(page);
|
|
} else {
|
|
unsigned long max_nr = end_index + 1;
|
|
|
|
set_range_writeback(tree, cur, cur + iosize - 1);
|
|
if (!PageWriteback(page)) {
|
|
printk(KERN_ERR "btrfs warning page %lu not "
|
|
"writeback, cur %llu end %llu\n",
|
|
page->index, (unsigned long long)cur,
|
|
(unsigned long long)end);
|
|
}
|
|
|
|
ret = submit_extent_page(write_flags, tree, page,
|
|
sector, iosize, pg_offset,
|
|
bdev, &epd->bio, max_nr,
|
|
end_bio_extent_writepage,
|
|
0, 0, 0);
|
|
if (ret)
|
|
SetPageError(page);
|
|
}
|
|
cur = cur + iosize;
|
|
pg_offset += iosize;
|
|
nr++;
|
|
}
|
|
done:
|
|
if (nr == 0) {
|
|
/* make sure the mapping tag for page dirty gets cleared */
|
|
set_page_writeback(page);
|
|
end_page_writeback(page);
|
|
}
|
|
unlock_page(page);
|
|
|
|
done_unlocked:
|
|
|
|
/* drop our reference on any cached states */
|
|
free_extent_state(cached_state);
|
|
return 0;
|
|
}
|
|
|
|
static int eb_wait(void *word)
|
|
{
|
|
io_schedule();
|
|
return 0;
|
|
}
|
|
|
|
void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
|
|
{
|
|
wait_on_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK, eb_wait,
|
|
TASK_UNINTERRUPTIBLE);
|
|
}
|
|
|
|
static int lock_extent_buffer_for_io(struct extent_buffer *eb,
|
|
struct btrfs_fs_info *fs_info,
|
|
struct extent_page_data *epd)
|
|
{
|
|
unsigned long i, num_pages;
|
|
int flush = 0;
|
|
int ret = 0;
|
|
|
|
if (!btrfs_try_tree_write_lock(eb)) {
|
|
flush = 1;
|
|
flush_write_bio(epd);
|
|
btrfs_tree_lock(eb);
|
|
}
|
|
|
|
if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) {
|
|
btrfs_tree_unlock(eb);
|
|
if (!epd->sync_io)
|
|
return 0;
|
|
if (!flush) {
|
|
flush_write_bio(epd);
|
|
flush = 1;
|
|
}
|
|
while (1) {
|
|
wait_on_extent_buffer_writeback(eb);
|
|
btrfs_tree_lock(eb);
|
|
if (!test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags))
|
|
break;
|
|
btrfs_tree_unlock(eb);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We need to do this to prevent races in people who check if the eb is
|
|
* under IO since we can end up having no IO bits set for a short period
|
|
* of time.
|
|
*/
|
|
spin_lock(&eb->refs_lock);
|
|
if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
|
|
set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
|
|
spin_unlock(&eb->refs_lock);
|
|
btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
|
|
__percpu_counter_add(&fs_info->dirty_metadata_bytes,
|
|
-eb->len,
|
|
fs_info->dirty_metadata_batch);
|
|
ret = 1;
|
|
} else {
|
|
spin_unlock(&eb->refs_lock);
|
|
}
|
|
|
|
btrfs_tree_unlock(eb);
|
|
|
|
if (!ret)
|
|
return ret;
|
|
|
|
num_pages = num_extent_pages(eb->start, eb->len);
|
|
for (i = 0; i < num_pages; i++) {
|
|
struct page *p = extent_buffer_page(eb, i);
|
|
|
|
if (!trylock_page(p)) {
|
|
if (!flush) {
|
|
flush_write_bio(epd);
|
|
flush = 1;
|
|
}
|
|
lock_page(p);
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void end_extent_buffer_writeback(struct extent_buffer *eb)
|
|
{
|
|
clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
|
|
smp_mb__after_clear_bit();
|
|
wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
|
|
}
|
|
|
|
static void end_bio_extent_buffer_writepage(struct bio *bio, int err)
|
|
{
|
|
int uptodate = err == 0;
|
|
struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
|
|
struct extent_buffer *eb;
|
|
int done;
|
|
|
|
do {
|
|
struct page *page = bvec->bv_page;
|
|
|
|
bvec--;
|
|
eb = (struct extent_buffer *)page->private;
|
|
BUG_ON(!eb);
|
|
done = atomic_dec_and_test(&eb->io_pages);
|
|
|
|
if (!uptodate || test_bit(EXTENT_BUFFER_IOERR, &eb->bflags)) {
|
|
set_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
|
|
ClearPageUptodate(page);
|
|
SetPageError(page);
|
|
}
|
|
|
|
end_page_writeback(page);
|
|
|
|
if (!done)
|
|
continue;
|
|
|
|
end_extent_buffer_writeback(eb);
|
|
} while (bvec >= bio->bi_io_vec);
|
|
|
|
bio_put(bio);
|
|
|
|
}
|
|
|
|
static int write_one_eb(struct extent_buffer *eb,
|
|
struct btrfs_fs_info *fs_info,
|
|
struct writeback_control *wbc,
|
|
struct extent_page_data *epd)
|
|
{
|
|
struct block_device *bdev = fs_info->fs_devices->latest_bdev;
|
|
u64 offset = eb->start;
|
|
unsigned long i, num_pages;
|
|
unsigned long bio_flags = 0;
|
|
int rw = (epd->sync_io ? WRITE_SYNC : WRITE) | REQ_META;
|
|
int ret = 0;
|
|
|
|
clear_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
|
|
num_pages = num_extent_pages(eb->start, eb->len);
|
|
atomic_set(&eb->io_pages, num_pages);
|
|
if (btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID)
|
|
bio_flags = EXTENT_BIO_TREE_LOG;
|
|
|
|
for (i = 0; i < num_pages; i++) {
|
|
struct page *p = extent_buffer_page(eb, i);
|
|
|
|
clear_page_dirty_for_io(p);
|
|
set_page_writeback(p);
|
|
ret = submit_extent_page(rw, eb->tree, p, offset >> 9,
|
|
PAGE_CACHE_SIZE, 0, bdev, &epd->bio,
|
|
-1, end_bio_extent_buffer_writepage,
|
|
0, epd->bio_flags, bio_flags);
|
|
epd->bio_flags = bio_flags;
|
|
if (ret) {
|
|
set_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
|
|
SetPageError(p);
|
|
if (atomic_sub_and_test(num_pages - i, &eb->io_pages))
|
|
end_extent_buffer_writeback(eb);
|
|
ret = -EIO;
|
|
break;
|
|
}
|
|
offset += PAGE_CACHE_SIZE;
|
|
update_nr_written(p, wbc, 1);
|
|
unlock_page(p);
|
|
}
|
|
|
|
if (unlikely(ret)) {
|
|
for (; i < num_pages; i++) {
|
|
struct page *p = extent_buffer_page(eb, i);
|
|
unlock_page(p);
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
int btree_write_cache_pages(struct address_space *mapping,
|
|
struct writeback_control *wbc)
|
|
{
|
|
struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
|
|
struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info;
|
|
struct extent_buffer *eb, *prev_eb = NULL;
|
|
struct extent_page_data epd = {
|
|
.bio = NULL,
|
|
.tree = tree,
|
|
.extent_locked = 0,
|
|
.sync_io = wbc->sync_mode == WB_SYNC_ALL,
|
|
.bio_flags = 0,
|
|
};
|
|
int ret = 0;
|
|
int done = 0;
|
|
int nr_to_write_done = 0;
|
|
struct pagevec pvec;
|
|
int nr_pages;
|
|
pgoff_t index;
|
|
pgoff_t end; /* Inclusive */
|
|
int scanned = 0;
|
|
int tag;
|
|
|
|
pagevec_init(&pvec, 0);
|
|
if (wbc->range_cyclic) {
|
|
index = mapping->writeback_index; /* Start from prev offset */
|
|
end = -1;
|
|
} else {
|
|
index = wbc->range_start >> PAGE_CACHE_SHIFT;
|
|
end = wbc->range_end >> PAGE_CACHE_SHIFT;
|
|
scanned = 1;
|
|
}
|
|
if (wbc->sync_mode == WB_SYNC_ALL)
|
|
tag = PAGECACHE_TAG_TOWRITE;
|
|
else
|
|
tag = PAGECACHE_TAG_DIRTY;
|
|
retry:
|
|
if (wbc->sync_mode == WB_SYNC_ALL)
|
|
tag_pages_for_writeback(mapping, index, end);
|
|
while (!done && !nr_to_write_done && (index <= end) &&
|
|
(nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
|
|
min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
|
|
unsigned i;
|
|
|
|
scanned = 1;
|
|
for (i = 0; i < nr_pages; i++) {
|
|
struct page *page = pvec.pages[i];
|
|
|
|
if (!PagePrivate(page))
|
|
continue;
|
|
|
|
if (!wbc->range_cyclic && page->index > end) {
|
|
done = 1;
|
|
break;
|
|
}
|
|
|
|
spin_lock(&mapping->private_lock);
|
|
if (!PagePrivate(page)) {
|
|
spin_unlock(&mapping->private_lock);
|
|
continue;
|
|
}
|
|
|
|
eb = (struct extent_buffer *)page->private;
|
|
|
|
/*
|
|
* Shouldn't happen and normally this would be a BUG_ON
|
|
* but no sense in crashing the users box for something
|
|
* we can survive anyway.
|
|
*/
|
|
if (!eb) {
|
|
spin_unlock(&mapping->private_lock);
|
|
WARN_ON(1);
|
|
continue;
|
|
}
|
|
|
|
if (eb == prev_eb) {
|
|
spin_unlock(&mapping->private_lock);
|
|
continue;
|
|
}
|
|
|
|
ret = atomic_inc_not_zero(&eb->refs);
|
|
spin_unlock(&mapping->private_lock);
|
|
if (!ret)
|
|
continue;
|
|
|
|
prev_eb = eb;
|
|
ret = lock_extent_buffer_for_io(eb, fs_info, &epd);
|
|
if (!ret) {
|
|
free_extent_buffer(eb);
|
|
continue;
|
|
}
|
|
|
|
ret = write_one_eb(eb, fs_info, wbc, &epd);
|
|
if (ret) {
|
|
done = 1;
|
|
free_extent_buffer(eb);
|
|
break;
|
|
}
|
|
free_extent_buffer(eb);
|
|
|
|
/*
|
|
* the filesystem may choose to bump up nr_to_write.
|
|
* We have to make sure to honor the new nr_to_write
|
|
* at any time
|
|
*/
|
|
nr_to_write_done = wbc->nr_to_write <= 0;
|
|
}
|
|
pagevec_release(&pvec);
|
|
cond_resched();
|
|
}
|
|
if (!scanned && !done) {
|
|
/*
|
|
* We hit the last page and there is more work to be done: wrap
|
|
* back to the start of the file
|
|
*/
|
|
scanned = 1;
|
|
index = 0;
|
|
goto retry;
|
|
}
|
|
flush_write_bio(&epd);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
|
|
* @mapping: address space structure to write
|
|
* @wbc: subtract the number of written pages from *@wbc->nr_to_write
|
|
* @writepage: function called for each page
|
|
* @data: data passed to writepage function
|
|
*
|
|
* If a page is already under I/O, write_cache_pages() skips it, even
|
|
* if it's dirty. This is desirable behaviour for memory-cleaning writeback,
|
|
* but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
|
|
* and msync() need to guarantee that all the data which was dirty at the time
|
|
* the call was made get new I/O started against them. If wbc->sync_mode is
|
|
* WB_SYNC_ALL then we were called for data integrity and we must wait for
|
|
* existing IO to complete.
|
|
*/
|
|
static int extent_write_cache_pages(struct extent_io_tree *tree,
|
|
struct address_space *mapping,
|
|
struct writeback_control *wbc,
|
|
writepage_t writepage, void *data,
|
|
void (*flush_fn)(void *))
|
|
{
|
|
struct inode *inode = mapping->host;
|
|
int ret = 0;
|
|
int done = 0;
|
|
int nr_to_write_done = 0;
|
|
struct pagevec pvec;
|
|
int nr_pages;
|
|
pgoff_t index;
|
|
pgoff_t end; /* Inclusive */
|
|
int scanned = 0;
|
|
int tag;
|
|
|
|
/*
|
|
* We have to hold onto the inode so that ordered extents can do their
|
|
* work when the IO finishes. The alternative to this is failing to add
|
|
* an ordered extent if the igrab() fails there and that is a huge pain
|
|
* to deal with, so instead just hold onto the inode throughout the
|
|
* writepages operation. If it fails here we are freeing up the inode
|
|
* anyway and we'd rather not waste our time writing out stuff that is
|
|
* going to be truncated anyway.
|
|
*/
|
|
if (!igrab(inode))
|
|
return 0;
|
|
|
|
pagevec_init(&pvec, 0);
|
|
if (wbc->range_cyclic) {
|
|
index = mapping->writeback_index; /* Start from prev offset */
|
|
end = -1;
|
|
} else {
|
|
index = wbc->range_start >> PAGE_CACHE_SHIFT;
|
|
end = wbc->range_end >> PAGE_CACHE_SHIFT;
|
|
scanned = 1;
|
|
}
|
|
if (wbc->sync_mode == WB_SYNC_ALL)
|
|
tag = PAGECACHE_TAG_TOWRITE;
|
|
else
|
|
tag = PAGECACHE_TAG_DIRTY;
|
|
retry:
|
|
if (wbc->sync_mode == WB_SYNC_ALL)
|
|
tag_pages_for_writeback(mapping, index, end);
|
|
while (!done && !nr_to_write_done && (index <= end) &&
|
|
(nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
|
|
min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
|
|
unsigned i;
|
|
|
|
scanned = 1;
|
|
for (i = 0; i < nr_pages; i++) {
|
|
struct page *page = pvec.pages[i];
|
|
|
|
/*
|
|
* At this point we hold neither mapping->tree_lock nor
|
|
* lock on the page itself: the page may be truncated or
|
|
* invalidated (changing page->mapping to NULL), or even
|
|
* swizzled back from swapper_space to tmpfs file
|
|
* mapping
|
|
*/
|
|
if (!trylock_page(page)) {
|
|
flush_fn(data);
|
|
lock_page(page);
|
|
}
|
|
|
|
if (unlikely(page->mapping != mapping)) {
|
|
unlock_page(page);
|
|
continue;
|
|
}
|
|
|
|
if (!wbc->range_cyclic && page->index > end) {
|
|
done = 1;
|
|
unlock_page(page);
|
|
continue;
|
|
}
|
|
|
|
if (wbc->sync_mode != WB_SYNC_NONE) {
|
|
if (PageWriteback(page))
|
|
flush_fn(data);
|
|
wait_on_page_writeback(page);
|
|
}
|
|
|
|
if (PageWriteback(page) ||
|
|
!clear_page_dirty_for_io(page)) {
|
|
unlock_page(page);
|
|
continue;
|
|
}
|
|
|
|
ret = (*writepage)(page, wbc, data);
|
|
|
|
if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
|
|
unlock_page(page);
|
|
ret = 0;
|
|
}
|
|
if (ret)
|
|
done = 1;
|
|
|
|
/*
|
|
* the filesystem may choose to bump up nr_to_write.
|
|
* We have to make sure to honor the new nr_to_write
|
|
* at any time
|
|
*/
|
|
nr_to_write_done = wbc->nr_to_write <= 0;
|
|
}
|
|
pagevec_release(&pvec);
|
|
cond_resched();
|
|
}
|
|
if (!scanned && !done) {
|
|
/*
|
|
* We hit the last page and there is more work to be done: wrap
|
|
* back to the start of the file
|
|
*/
|
|
scanned = 1;
|
|
index = 0;
|
|
goto retry;
|
|
}
|
|
btrfs_add_delayed_iput(inode);
|
|
return ret;
|
|
}
|
|
|
|
static void flush_epd_write_bio(struct extent_page_data *epd)
|
|
{
|
|
if (epd->bio) {
|
|
int rw = WRITE;
|
|
int ret;
|
|
|
|
if (epd->sync_io)
|
|
rw = WRITE_SYNC;
|
|
|
|
ret = submit_one_bio(rw, epd->bio, 0, epd->bio_flags);
|
|
BUG_ON(ret < 0); /* -ENOMEM */
|
|
epd->bio = NULL;
|
|
}
|
|
}
|
|
|
|
static noinline void flush_write_bio(void *data)
|
|
{
|
|
struct extent_page_data *epd = data;
|
|
flush_epd_write_bio(epd);
|
|
}
|
|
|
|
int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
|
|
get_extent_t *get_extent,
|
|
struct writeback_control *wbc)
|
|
{
|
|
int ret;
|
|
struct extent_page_data epd = {
|
|
.bio = NULL,
|
|
.tree = tree,
|
|
.get_extent = get_extent,
|
|
.extent_locked = 0,
|
|
.sync_io = wbc->sync_mode == WB_SYNC_ALL,
|
|
.bio_flags = 0,
|
|
};
|
|
|
|
ret = __extent_writepage(page, wbc, &epd);
|
|
|
|
flush_epd_write_bio(&epd);
|
|
return ret;
|
|
}
|
|
|
|
int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
|
|
u64 start, u64 end, get_extent_t *get_extent,
|
|
int mode)
|
|
{
|
|
int ret = 0;
|
|
struct address_space *mapping = inode->i_mapping;
|
|
struct page *page;
|
|
unsigned long nr_pages = (end - start + PAGE_CACHE_SIZE) >>
|
|
PAGE_CACHE_SHIFT;
|
|
|
|
struct extent_page_data epd = {
|
|
.bio = NULL,
|
|
.tree = tree,
|
|
.get_extent = get_extent,
|
|
.extent_locked = 1,
|
|
.sync_io = mode == WB_SYNC_ALL,
|
|
.bio_flags = 0,
|
|
};
|
|
struct writeback_control wbc_writepages = {
|
|
.sync_mode = mode,
|
|
.nr_to_write = nr_pages * 2,
|
|
.range_start = start,
|
|
.range_end = end + 1,
|
|
};
|
|
|
|
while (start <= end) {
|
|
page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
|
|
if (clear_page_dirty_for_io(page))
|
|
ret = __extent_writepage(page, &wbc_writepages, &epd);
|
|
else {
|
|
if (tree->ops && tree->ops->writepage_end_io_hook)
|
|
tree->ops->writepage_end_io_hook(page, start,
|
|
start + PAGE_CACHE_SIZE - 1,
|
|
NULL, 1);
|
|
unlock_page(page);
|
|
}
|
|
page_cache_release(page);
|
|
start += PAGE_CACHE_SIZE;
|
|
}
|
|
|
|
flush_epd_write_bio(&epd);
|
|
return ret;
|
|
}
|
|
|
|
int extent_writepages(struct extent_io_tree *tree,
|
|
struct address_space *mapping,
|
|
get_extent_t *get_extent,
|
|
struct writeback_control *wbc)
|
|
{
|
|
int ret = 0;
|
|
struct extent_page_data epd = {
|
|
.bio = NULL,
|
|
.tree = tree,
|
|
.get_extent = get_extent,
|
|
.extent_locked = 0,
|
|
.sync_io = wbc->sync_mode == WB_SYNC_ALL,
|
|
.bio_flags = 0,
|
|
};
|
|
|
|
ret = extent_write_cache_pages(tree, mapping, wbc,
|
|
__extent_writepage, &epd,
|
|
flush_write_bio);
|
|
flush_epd_write_bio(&epd);
|
|
return ret;
|
|
}
|
|
|
|
int extent_readpages(struct extent_io_tree *tree,
|
|
struct address_space *mapping,
|
|
struct list_head *pages, unsigned nr_pages,
|
|
get_extent_t get_extent)
|
|
{
|
|
struct bio *bio = NULL;
|
|
unsigned page_idx;
|
|
unsigned long bio_flags = 0;
|
|
struct page *pagepool[16];
|
|
struct page *page;
|
|
int i = 0;
|
|
int nr = 0;
|
|
|
|
for (page_idx = 0; page_idx < nr_pages; page_idx++) {
|
|
page = list_entry(pages->prev, struct page, lru);
|
|
|
|
prefetchw(&page->flags);
|
|
list_del(&page->lru);
|
|
if (add_to_page_cache_lru(page, mapping,
|
|
page->index, GFP_NOFS)) {
|
|
page_cache_release(page);
|
|
continue;
|
|
}
|
|
|
|
pagepool[nr++] = page;
|
|
if (nr < ARRAY_SIZE(pagepool))
|
|
continue;
|
|
for (i = 0; i < nr; i++) {
|
|
__extent_read_full_page(tree, pagepool[i], get_extent,
|
|
&bio, 0, &bio_flags, READ);
|
|
page_cache_release(pagepool[i]);
|
|
}
|
|
nr = 0;
|
|
}
|
|
for (i = 0; i < nr; i++) {
|
|
__extent_read_full_page(tree, pagepool[i], get_extent,
|
|
&bio, 0, &bio_flags, READ);
|
|
page_cache_release(pagepool[i]);
|
|
}
|
|
|
|
BUG_ON(!list_empty(pages));
|
|
if (bio)
|
|
return submit_one_bio(READ, bio, 0, bio_flags);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* basic invalidatepage code, this waits on any locked or writeback
|
|
* ranges corresponding to the page, and then deletes any extent state
|
|
* records from the tree
|
|
*/
|
|
int extent_invalidatepage(struct extent_io_tree *tree,
|
|
struct page *page, unsigned long offset)
|
|
{
|
|
struct extent_state *cached_state = NULL;
|
|
u64 start = page_offset(page);
|
|
u64 end = start + PAGE_CACHE_SIZE - 1;
|
|
size_t blocksize = page->mapping->host->i_sb->s_blocksize;
|
|
|
|
start += ALIGN(offset, blocksize);
|
|
if (start > end)
|
|
return 0;
|
|
|
|
lock_extent_bits(tree, start, end, 0, &cached_state);
|
|
wait_on_page_writeback(page);
|
|
clear_extent_bit(tree, start, end,
|
|
EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
|
|
EXTENT_DO_ACCOUNTING,
|
|
1, 1, &cached_state, GFP_NOFS);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* a helper for releasepage, this tests for areas of the page that
|
|
* are locked or under IO and drops the related state bits if it is safe
|
|
* to drop the page.
|
|
*/
|
|
static int try_release_extent_state(struct extent_map_tree *map,
|
|
struct extent_io_tree *tree,
|
|
struct page *page, gfp_t mask)
|
|
{
|
|
u64 start = page_offset(page);
|
|
u64 end = start + PAGE_CACHE_SIZE - 1;
|
|
int ret = 1;
|
|
|
|
if (test_range_bit(tree, start, end,
|
|
EXTENT_IOBITS, 0, NULL))
|
|
ret = 0;
|
|
else {
|
|
if ((mask & GFP_NOFS) == GFP_NOFS)
|
|
mask = GFP_NOFS;
|
|
/*
|
|
* at this point we can safely clear everything except the
|
|
* locked bit and the nodatasum bit
|
|
*/
|
|
ret = clear_extent_bit(tree, start, end,
|
|
~(EXTENT_LOCKED | EXTENT_NODATASUM),
|
|
0, 0, NULL, mask);
|
|
|
|
/* if clear_extent_bit failed for enomem reasons,
|
|
* we can't allow the release to continue.
|
|
*/
|
|
if (ret < 0)
|
|
ret = 0;
|
|
else
|
|
ret = 1;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* a helper for releasepage. As long as there are no locked extents
|
|
* in the range corresponding to the page, both state records and extent
|
|
* map records are removed
|
|
*/
|
|
int try_release_extent_mapping(struct extent_map_tree *map,
|
|
struct extent_io_tree *tree, struct page *page,
|
|
gfp_t mask)
|
|
{
|
|
struct extent_map *em;
|
|
u64 start = page_offset(page);
|
|
u64 end = start + PAGE_CACHE_SIZE - 1;
|
|
|
|
if ((mask & __GFP_WAIT) &&
|
|
page->mapping->host->i_size > 16 * 1024 * 1024) {
|
|
u64 len;
|
|
while (start <= end) {
|
|
len = end - start + 1;
|
|
write_lock(&map->lock);
|
|
em = lookup_extent_mapping(map, start, len);
|
|
if (!em) {
|
|
write_unlock(&map->lock);
|
|
break;
|
|
}
|
|
if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
|
|
em->start != start) {
|
|
write_unlock(&map->lock);
|
|
free_extent_map(em);
|
|
break;
|
|
}
|
|
if (!test_range_bit(tree, em->start,
|
|
extent_map_end(em) - 1,
|
|
EXTENT_LOCKED | EXTENT_WRITEBACK,
|
|
0, NULL)) {
|
|
remove_extent_mapping(map, em);
|
|
/* once for the rb tree */
|
|
free_extent_map(em);
|
|
}
|
|
start = extent_map_end(em);
|
|
write_unlock(&map->lock);
|
|
|
|
/* once for us */
|
|
free_extent_map(em);
|
|
}
|
|
}
|
|
return try_release_extent_state(map, tree, page, mask);
|
|
}
|
|
|
|
/*
|
|
* helper function for fiemap, which doesn't want to see any holes.
|
|
* This maps until we find something past 'last'
|
|
*/
|
|
static struct extent_map *get_extent_skip_holes(struct inode *inode,
|
|
u64 offset,
|
|
u64 last,
|
|
get_extent_t *get_extent)
|
|
{
|
|
u64 sectorsize = BTRFS_I(inode)->root->sectorsize;
|
|
struct extent_map *em;
|
|
u64 len;
|
|
|
|
if (offset >= last)
|
|
return NULL;
|
|
|
|
while(1) {
|
|
len = last - offset;
|
|
if (len == 0)
|
|
break;
|
|
len = ALIGN(len, sectorsize);
|
|
em = get_extent(inode, NULL, 0, offset, len, 0);
|
|
if (IS_ERR_OR_NULL(em))
|
|
return em;
|
|
|
|
/* if this isn't a hole return it */
|
|
if (!test_bit(EXTENT_FLAG_VACANCY, &em->flags) &&
|
|
em->block_start != EXTENT_MAP_HOLE) {
|
|
return em;
|
|
}
|
|
|
|
/* this is a hole, advance to the next extent */
|
|
offset = extent_map_end(em);
|
|
free_extent_map(em);
|
|
if (offset >= last)
|
|
break;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
|
|
__u64 start, __u64 len, get_extent_t *get_extent)
|
|
{
|
|
int ret = 0;
|
|
u64 off = start;
|
|
u64 max = start + len;
|
|
u32 flags = 0;
|
|
u32 found_type;
|
|
u64 last;
|
|
u64 last_for_get_extent = 0;
|
|
u64 disko = 0;
|
|
u64 isize = i_size_read(inode);
|
|
struct btrfs_key found_key;
|
|
struct extent_map *em = NULL;
|
|
struct extent_state *cached_state = NULL;
|
|
struct btrfs_path *path;
|
|
struct btrfs_file_extent_item *item;
|
|
int end = 0;
|
|
u64 em_start = 0;
|
|
u64 em_len = 0;
|
|
u64 em_end = 0;
|
|
unsigned long emflags;
|
|
|
|
if (len == 0)
|
|
return -EINVAL;
|
|
|
|
path = btrfs_alloc_path();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
path->leave_spinning = 1;
|
|
|
|
start = ALIGN(start, BTRFS_I(inode)->root->sectorsize);
|
|
len = ALIGN(len, BTRFS_I(inode)->root->sectorsize);
|
|
|
|
/*
|
|
* lookup the last file extent. We're not using i_size here
|
|
* because there might be preallocation past i_size
|
|
*/
|
|
ret = btrfs_lookup_file_extent(NULL, BTRFS_I(inode)->root,
|
|
path, btrfs_ino(inode), -1, 0);
|
|
if (ret < 0) {
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
WARN_ON(!ret);
|
|
path->slots[0]--;
|
|
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
|
|
struct btrfs_file_extent_item);
|
|
btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
|
|
found_type = btrfs_key_type(&found_key);
|
|
|
|
/* No extents, but there might be delalloc bits */
|
|
if (found_key.objectid != btrfs_ino(inode) ||
|
|
found_type != BTRFS_EXTENT_DATA_KEY) {
|
|
/* have to trust i_size as the end */
|
|
last = (u64)-1;
|
|
last_for_get_extent = isize;
|
|
} else {
|
|
/*
|
|
* remember the start of the last extent. There are a
|
|
* bunch of different factors that go into the length of the
|
|
* extent, so its much less complex to remember where it started
|
|
*/
|
|
last = found_key.offset;
|
|
last_for_get_extent = last + 1;
|
|
}
|
|
btrfs_free_path(path);
|
|
|
|
/*
|
|
* we might have some extents allocated but more delalloc past those
|
|
* extents. so, we trust isize unless the start of the last extent is
|
|
* beyond isize
|
|
*/
|
|
if (last < isize) {
|
|
last = (u64)-1;
|
|
last_for_get_extent = isize;
|
|
}
|
|
|
|
lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len - 1, 0,
|
|
&cached_state);
|
|
|
|
em = get_extent_skip_holes(inode, start, last_for_get_extent,
|
|
get_extent);
|
|
if (!em)
|
|
goto out;
|
|
if (IS_ERR(em)) {
|
|
ret = PTR_ERR(em);
|
|
goto out;
|
|
}
|
|
|
|
while (!end) {
|
|
u64 offset_in_extent = 0;
|
|
|
|
/* break if the extent we found is outside the range */
|
|
if (em->start >= max || extent_map_end(em) < off)
|
|
break;
|
|
|
|
/*
|
|
* get_extent may return an extent that starts before our
|
|
* requested range. We have to make sure the ranges
|
|
* we return to fiemap always move forward and don't
|
|
* overlap, so adjust the offsets here
|
|
*/
|
|
em_start = max(em->start, off);
|
|
|
|
/*
|
|
* record the offset from the start of the extent
|
|
* for adjusting the disk offset below. Only do this if the
|
|
* extent isn't compressed since our in ram offset may be past
|
|
* what we have actually allocated on disk.
|
|
*/
|
|
if (!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
|
|
offset_in_extent = em_start - em->start;
|
|
em_end = extent_map_end(em);
|
|
em_len = em_end - em_start;
|
|
emflags = em->flags;
|
|
disko = 0;
|
|
flags = 0;
|
|
|
|
/*
|
|
* bump off for our next call to get_extent
|
|
*/
|
|
off = extent_map_end(em);
|
|
if (off >= max)
|
|
end = 1;
|
|
|
|
if (em->block_start == EXTENT_MAP_LAST_BYTE) {
|
|
end = 1;
|
|
flags |= FIEMAP_EXTENT_LAST;
|
|
} else if (em->block_start == EXTENT_MAP_INLINE) {
|
|
flags |= (FIEMAP_EXTENT_DATA_INLINE |
|
|
FIEMAP_EXTENT_NOT_ALIGNED);
|
|
} else if (em->block_start == EXTENT_MAP_DELALLOC) {
|
|
flags |= (FIEMAP_EXTENT_DELALLOC |
|
|
FIEMAP_EXTENT_UNKNOWN);
|
|
} else {
|
|
disko = em->block_start + offset_in_extent;
|
|
}
|
|
if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
|
|
flags |= FIEMAP_EXTENT_ENCODED;
|
|
|
|
free_extent_map(em);
|
|
em = NULL;
|
|
if ((em_start >= last) || em_len == (u64)-1 ||
|
|
(last == (u64)-1 && isize <= em_end)) {
|
|
flags |= FIEMAP_EXTENT_LAST;
|
|
end = 1;
|
|
}
|
|
|
|
/* now scan forward to see if this is really the last extent. */
|
|
em = get_extent_skip_holes(inode, off, last_for_get_extent,
|
|
get_extent);
|
|
if (IS_ERR(em)) {
|
|
ret = PTR_ERR(em);
|
|
goto out;
|
|
}
|
|
if (!em) {
|
|
flags |= FIEMAP_EXTENT_LAST;
|
|
end = 1;
|
|
}
|
|
ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
|
|
em_len, flags);
|
|
if (ret)
|
|
goto out_free;
|
|
}
|
|
out_free:
|
|
free_extent_map(em);
|
|
out:
|
|
unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len - 1,
|
|
&cached_state, GFP_NOFS);
|
|
return ret;
|
|
}
|
|
|
|
static void __free_extent_buffer(struct extent_buffer *eb)
|
|
{
|
|
btrfs_leak_debug_del(&eb->leak_list);
|
|
kmem_cache_free(extent_buffer_cache, eb);
|
|
}
|
|
|
|
static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
|
|
u64 start,
|
|
unsigned long len,
|
|
gfp_t mask)
|
|
{
|
|
struct extent_buffer *eb = NULL;
|
|
|
|
eb = kmem_cache_zalloc(extent_buffer_cache, mask);
|
|
if (eb == NULL)
|
|
return NULL;
|
|
eb->start = start;
|
|
eb->len = len;
|
|
eb->tree = tree;
|
|
eb->bflags = 0;
|
|
rwlock_init(&eb->lock);
|
|
atomic_set(&eb->write_locks, 0);
|
|
atomic_set(&eb->read_locks, 0);
|
|
atomic_set(&eb->blocking_readers, 0);
|
|
atomic_set(&eb->blocking_writers, 0);
|
|
atomic_set(&eb->spinning_readers, 0);
|
|
atomic_set(&eb->spinning_writers, 0);
|
|
eb->lock_nested = 0;
|
|
init_waitqueue_head(&eb->write_lock_wq);
|
|
init_waitqueue_head(&eb->read_lock_wq);
|
|
|
|
btrfs_leak_debug_add(&eb->leak_list, &buffers);
|
|
|
|
spin_lock_init(&eb->refs_lock);
|
|
atomic_set(&eb->refs, 1);
|
|
atomic_set(&eb->io_pages, 0);
|
|
|
|
/*
|
|
* Sanity checks, currently the maximum is 64k covered by 16x 4k pages
|
|
*/
|
|
BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
|
|
> MAX_INLINE_EXTENT_BUFFER_SIZE);
|
|
BUG_ON(len > MAX_INLINE_EXTENT_BUFFER_SIZE);
|
|
|
|
return eb;
|
|
}
|
|
|
|
struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
|
|
{
|
|
unsigned long i;
|
|
struct page *p;
|
|
struct extent_buffer *new;
|
|
unsigned long num_pages = num_extent_pages(src->start, src->len);
|
|
|
|
new = __alloc_extent_buffer(NULL, src->start, src->len, GFP_ATOMIC);
|
|
if (new == NULL)
|
|
return NULL;
|
|
|
|
for (i = 0; i < num_pages; i++) {
|
|
p = alloc_page(GFP_ATOMIC);
|
|
BUG_ON(!p);
|
|
attach_extent_buffer_page(new, p);
|
|
WARN_ON(PageDirty(p));
|
|
SetPageUptodate(p);
|
|
new->pages[i] = p;
|
|
}
|
|
|
|
copy_extent_buffer(new, src, 0, 0, src->len);
|
|
set_bit(EXTENT_BUFFER_UPTODATE, &new->bflags);
|
|
set_bit(EXTENT_BUFFER_DUMMY, &new->bflags);
|
|
|
|
return new;
|
|
}
|
|
|
|
struct extent_buffer *alloc_dummy_extent_buffer(u64 start, unsigned long len)
|
|
{
|
|
struct extent_buffer *eb;
|
|
unsigned long num_pages = num_extent_pages(0, len);
|
|
unsigned long i;
|
|
|
|
eb = __alloc_extent_buffer(NULL, start, len, GFP_ATOMIC);
|
|
if (!eb)
|
|
return NULL;
|
|
|
|
for (i = 0; i < num_pages; i++) {
|
|
eb->pages[i] = alloc_page(GFP_ATOMIC);
|
|
if (!eb->pages[i])
|
|
goto err;
|
|
}
|
|
set_extent_buffer_uptodate(eb);
|
|
btrfs_set_header_nritems(eb, 0);
|
|
set_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
|
|
|
|
return eb;
|
|
err:
|
|
for (; i > 0; i--)
|
|
__free_page(eb->pages[i - 1]);
|
|
__free_extent_buffer(eb);
|
|
return NULL;
|
|
}
|
|
|
|
static int extent_buffer_under_io(struct extent_buffer *eb)
|
|
{
|
|
return (atomic_read(&eb->io_pages) ||
|
|
test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) ||
|
|
test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
|
|
}
|
|
|
|
/*
|
|
* Helper for releasing extent buffer page.
|
|
*/
|
|
static void btrfs_release_extent_buffer_page(struct extent_buffer *eb,
|
|
unsigned long start_idx)
|
|
{
|
|
unsigned long index;
|
|
unsigned long num_pages;
|
|
struct page *page;
|
|
int mapped = !test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
|
|
|
|
BUG_ON(extent_buffer_under_io(eb));
|
|
|
|
num_pages = num_extent_pages(eb->start, eb->len);
|
|
index = start_idx + num_pages;
|
|
if (start_idx >= index)
|
|
return;
|
|
|
|
do {
|
|
index--;
|
|
page = extent_buffer_page(eb, index);
|
|
if (page && mapped) {
|
|
spin_lock(&page->mapping->private_lock);
|
|
/*
|
|
* We do this since we'll remove the pages after we've
|
|
* removed the eb from the radix tree, so we could race
|
|
* and have this page now attached to the new eb. So
|
|
* only clear page_private if it's still connected to
|
|
* this eb.
|
|
*/
|
|
if (PagePrivate(page) &&
|
|
page->private == (unsigned long)eb) {
|
|
BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
|
|
BUG_ON(PageDirty(page));
|
|
BUG_ON(PageWriteback(page));
|
|
/*
|
|
* We need to make sure we haven't be attached
|
|
* to a new eb.
|
|
*/
|
|
ClearPagePrivate(page);
|
|
set_page_private(page, 0);
|
|
/* One for the page private */
|
|
page_cache_release(page);
|
|
}
|
|
spin_unlock(&page->mapping->private_lock);
|
|
|
|
}
|
|
if (page) {
|
|
/* One for when we alloced the page */
|
|
page_cache_release(page);
|
|
}
|
|
} while (index != start_idx);
|
|
}
|
|
|
|
/*
|
|
* Helper for releasing the extent buffer.
|
|
*/
|
|
static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
|
|
{
|
|
btrfs_release_extent_buffer_page(eb, 0);
|
|
__free_extent_buffer(eb);
|
|
}
|
|
|
|
static void check_buffer_tree_ref(struct extent_buffer *eb)
|
|
{
|
|
int refs;
|
|
/* the ref bit is tricky. We have to make sure it is set
|
|
* if we have the buffer dirty. Otherwise the
|
|
* code to free a buffer can end up dropping a dirty
|
|
* page
|
|
*
|
|
* Once the ref bit is set, it won't go away while the
|
|
* buffer is dirty or in writeback, and it also won't
|
|
* go away while we have the reference count on the
|
|
* eb bumped.
|
|
*
|
|
* We can't just set the ref bit without bumping the
|
|
* ref on the eb because free_extent_buffer might
|
|
* see the ref bit and try to clear it. If this happens
|
|
* free_extent_buffer might end up dropping our original
|
|
* ref by mistake and freeing the page before we are able
|
|
* to add one more ref.
|
|
*
|
|
* So bump the ref count first, then set the bit. If someone
|
|
* beat us to it, drop the ref we added.
|
|
*/
|
|
refs = atomic_read(&eb->refs);
|
|
if (refs >= 2 && test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
|
|
return;
|
|
|
|
spin_lock(&eb->refs_lock);
|
|
if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
|
|
atomic_inc(&eb->refs);
|
|
spin_unlock(&eb->refs_lock);
|
|
}
|
|
|
|
static void mark_extent_buffer_accessed(struct extent_buffer *eb)
|
|
{
|
|
unsigned long num_pages, i;
|
|
|
|
check_buffer_tree_ref(eb);
|
|
|
|
num_pages = num_extent_pages(eb->start, eb->len);
|
|
for (i = 0; i < num_pages; i++) {
|
|
struct page *p = extent_buffer_page(eb, i);
|
|
mark_page_accessed(p);
|
|
}
|
|
}
|
|
|
|
struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
|
|
u64 start, unsigned long len)
|
|
{
|
|
unsigned long num_pages = num_extent_pages(start, len);
|
|
unsigned long i;
|
|
unsigned long index = start >> PAGE_CACHE_SHIFT;
|
|
struct extent_buffer *eb;
|
|
struct extent_buffer *exists = NULL;
|
|
struct page *p;
|
|
struct address_space *mapping = tree->mapping;
|
|
int uptodate = 1;
|
|
int ret;
|
|
|
|
rcu_read_lock();
|
|
eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
|
|
if (eb && atomic_inc_not_zero(&eb->refs)) {
|
|
rcu_read_unlock();
|
|
mark_extent_buffer_accessed(eb);
|
|
return eb;
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
eb = __alloc_extent_buffer(tree, start, len, GFP_NOFS);
|
|
if (!eb)
|
|
return NULL;
|
|
|
|
for (i = 0; i < num_pages; i++, index++) {
|
|
p = find_or_create_page(mapping, index, GFP_NOFS);
|
|
if (!p)
|
|
goto free_eb;
|
|
|
|
spin_lock(&mapping->private_lock);
|
|
if (PagePrivate(p)) {
|
|
/*
|
|
* We could have already allocated an eb for this page
|
|
* and attached one so lets see if we can get a ref on
|
|
* the existing eb, and if we can we know it's good and
|
|
* we can just return that one, else we know we can just
|
|
* overwrite page->private.
|
|
*/
|
|
exists = (struct extent_buffer *)p->private;
|
|
if (atomic_inc_not_zero(&exists->refs)) {
|
|
spin_unlock(&mapping->private_lock);
|
|
unlock_page(p);
|
|
page_cache_release(p);
|
|
mark_extent_buffer_accessed(exists);
|
|
goto free_eb;
|
|
}
|
|
|
|
/*
|
|
* Do this so attach doesn't complain and we need to
|
|
* drop the ref the old guy had.
|
|
*/
|
|
ClearPagePrivate(p);
|
|
WARN_ON(PageDirty(p));
|
|
page_cache_release(p);
|
|
}
|
|
attach_extent_buffer_page(eb, p);
|
|
spin_unlock(&mapping->private_lock);
|
|
WARN_ON(PageDirty(p));
|
|
mark_page_accessed(p);
|
|
eb->pages[i] = p;
|
|
if (!PageUptodate(p))
|
|
uptodate = 0;
|
|
|
|
/*
|
|
* see below about how we avoid a nasty race with release page
|
|
* and why we unlock later
|
|
*/
|
|
}
|
|
if (uptodate)
|
|
set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
|
|
again:
|
|
ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
|
|
if (ret)
|
|
goto free_eb;
|
|
|
|
spin_lock(&tree->buffer_lock);
|
|
ret = radix_tree_insert(&tree->buffer, start >> PAGE_CACHE_SHIFT, eb);
|
|
if (ret == -EEXIST) {
|
|
exists = radix_tree_lookup(&tree->buffer,
|
|
start >> PAGE_CACHE_SHIFT);
|
|
if (!atomic_inc_not_zero(&exists->refs)) {
|
|
spin_unlock(&tree->buffer_lock);
|
|
radix_tree_preload_end();
|
|
exists = NULL;
|
|
goto again;
|
|
}
|
|
spin_unlock(&tree->buffer_lock);
|
|
radix_tree_preload_end();
|
|
mark_extent_buffer_accessed(exists);
|
|
goto free_eb;
|
|
}
|
|
/* add one reference for the tree */
|
|
check_buffer_tree_ref(eb);
|
|
spin_unlock(&tree->buffer_lock);
|
|
radix_tree_preload_end();
|
|
|
|
/*
|
|
* there is a race where release page may have
|
|
* tried to find this extent buffer in the radix
|
|
* but failed. It will tell the VM it is safe to
|
|
* reclaim the, and it will clear the page private bit.
|
|
* We must make sure to set the page private bit properly
|
|
* after the extent buffer is in the radix tree so
|
|
* it doesn't get lost
|
|
*/
|
|
SetPageChecked(eb->pages[0]);
|
|
for (i = 1; i < num_pages; i++) {
|
|
p = extent_buffer_page(eb, i);
|
|
ClearPageChecked(p);
|
|
unlock_page(p);
|
|
}
|
|
unlock_page(eb->pages[0]);
|
|
return eb;
|
|
|
|
free_eb:
|
|
for (i = 0; i < num_pages; i++) {
|
|
if (eb->pages[i])
|
|
unlock_page(eb->pages[i]);
|
|
}
|
|
|
|
WARN_ON(!atomic_dec_and_test(&eb->refs));
|
|
btrfs_release_extent_buffer(eb);
|
|
return exists;
|
|
}
|
|
|
|
struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
|
|
u64 start, unsigned long len)
|
|
{
|
|
struct extent_buffer *eb;
|
|
|
|
rcu_read_lock();
|
|
eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
|
|
if (eb && atomic_inc_not_zero(&eb->refs)) {
|
|
rcu_read_unlock();
|
|
mark_extent_buffer_accessed(eb);
|
|
return eb;
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
|
|
{
|
|
struct extent_buffer *eb =
|
|
container_of(head, struct extent_buffer, rcu_head);
|
|
|
|
__free_extent_buffer(eb);
|
|
}
|
|
|
|
/* Expects to have eb->eb_lock already held */
|
|
static int release_extent_buffer(struct extent_buffer *eb)
|
|
{
|
|
WARN_ON(atomic_read(&eb->refs) == 0);
|
|
if (atomic_dec_and_test(&eb->refs)) {
|
|
if (test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags)) {
|
|
spin_unlock(&eb->refs_lock);
|
|
} else {
|
|
struct extent_io_tree *tree = eb->tree;
|
|
|
|
spin_unlock(&eb->refs_lock);
|
|
|
|
spin_lock(&tree->buffer_lock);
|
|
radix_tree_delete(&tree->buffer,
|
|
eb->start >> PAGE_CACHE_SHIFT);
|
|
spin_unlock(&tree->buffer_lock);
|
|
}
|
|
|
|
/* Should be safe to release our pages at this point */
|
|
btrfs_release_extent_buffer_page(eb, 0);
|
|
call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
|
|
return 1;
|
|
}
|
|
spin_unlock(&eb->refs_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
void free_extent_buffer(struct extent_buffer *eb)
|
|
{
|
|
int refs;
|
|
int old;
|
|
if (!eb)
|
|
return;
|
|
|
|
while (1) {
|
|
refs = atomic_read(&eb->refs);
|
|
if (refs <= 3)
|
|
break;
|
|
old = atomic_cmpxchg(&eb->refs, refs, refs - 1);
|
|
if (old == refs)
|
|
return;
|
|
}
|
|
|
|
spin_lock(&eb->refs_lock);
|
|
if (atomic_read(&eb->refs) == 2 &&
|
|
test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))
|
|
atomic_dec(&eb->refs);
|
|
|
|
if (atomic_read(&eb->refs) == 2 &&
|
|
test_bit(EXTENT_BUFFER_STALE, &eb->bflags) &&
|
|
!extent_buffer_under_io(eb) &&
|
|
test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
|
|
atomic_dec(&eb->refs);
|
|
|
|
/*
|
|
* I know this is terrible, but it's temporary until we stop tracking
|
|
* the uptodate bits and such for the extent buffers.
|
|
*/
|
|
release_extent_buffer(eb);
|
|
}
|
|
|
|
void free_extent_buffer_stale(struct extent_buffer *eb)
|
|
{
|
|
if (!eb)
|
|
return;
|
|
|
|
spin_lock(&eb->refs_lock);
|
|
set_bit(EXTENT_BUFFER_STALE, &eb->bflags);
|
|
|
|
if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb) &&
|
|
test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
|
|
atomic_dec(&eb->refs);
|
|
release_extent_buffer(eb);
|
|
}
|
|
|
|
void clear_extent_buffer_dirty(struct extent_buffer *eb)
|
|
{
|
|
unsigned long i;
|
|
unsigned long num_pages;
|
|
struct page *page;
|
|
|
|
num_pages = num_extent_pages(eb->start, eb->len);
|
|
|
|
for (i = 0; i < num_pages; i++) {
|
|
page = extent_buffer_page(eb, i);
|
|
if (!PageDirty(page))
|
|
continue;
|
|
|
|
lock_page(page);
|
|
WARN_ON(!PagePrivate(page));
|
|
|
|
clear_page_dirty_for_io(page);
|
|
spin_lock_irq(&page->mapping->tree_lock);
|
|
if (!PageDirty(page)) {
|
|
radix_tree_tag_clear(&page->mapping->page_tree,
|
|
page_index(page),
|
|
PAGECACHE_TAG_DIRTY);
|
|
}
|
|
spin_unlock_irq(&page->mapping->tree_lock);
|
|
ClearPageError(page);
|
|
unlock_page(page);
|
|
}
|
|
WARN_ON(atomic_read(&eb->refs) == 0);
|
|
}
|
|
|
|
int set_extent_buffer_dirty(struct extent_buffer *eb)
|
|
{
|
|
unsigned long i;
|
|
unsigned long num_pages;
|
|
int was_dirty = 0;
|
|
|
|
check_buffer_tree_ref(eb);
|
|
|
|
was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
|
|
|
|
num_pages = num_extent_pages(eb->start, eb->len);
|
|
WARN_ON(atomic_read(&eb->refs) == 0);
|
|
WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags));
|
|
|
|
for (i = 0; i < num_pages; i++)
|
|
set_page_dirty(extent_buffer_page(eb, i));
|
|
return was_dirty;
|
|
}
|
|
|
|
int clear_extent_buffer_uptodate(struct extent_buffer *eb)
|
|
{
|
|
unsigned long i;
|
|
struct page *page;
|
|
unsigned long num_pages;
|
|
|
|
clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
|
|
num_pages = num_extent_pages(eb->start, eb->len);
|
|
for (i = 0; i < num_pages; i++) {
|
|
page = extent_buffer_page(eb, i);
|
|
if (page)
|
|
ClearPageUptodate(page);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int set_extent_buffer_uptodate(struct extent_buffer *eb)
|
|
{
|
|
unsigned long i;
|
|
struct page *page;
|
|
unsigned long num_pages;
|
|
|
|
set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
|
|
num_pages = num_extent_pages(eb->start, eb->len);
|
|
for (i = 0; i < num_pages; i++) {
|
|
page = extent_buffer_page(eb, i);
|
|
SetPageUptodate(page);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int extent_buffer_uptodate(struct extent_buffer *eb)
|
|
{
|
|
return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
|
|
}
|
|
|
|
int read_extent_buffer_pages(struct extent_io_tree *tree,
|
|
struct extent_buffer *eb, u64 start, int wait,
|
|
get_extent_t *get_extent, int mirror_num)
|
|
{
|
|
unsigned long i;
|
|
unsigned long start_i;
|
|
struct page *page;
|
|
int err;
|
|
int ret = 0;
|
|
int locked_pages = 0;
|
|
int all_uptodate = 1;
|
|
unsigned long num_pages;
|
|
unsigned long num_reads = 0;
|
|
struct bio *bio = NULL;
|
|
unsigned long bio_flags = 0;
|
|
|
|
if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
|
|
return 0;
|
|
|
|
if (start) {
|
|
WARN_ON(start < eb->start);
|
|
start_i = (start >> PAGE_CACHE_SHIFT) -
|
|
(eb->start >> PAGE_CACHE_SHIFT);
|
|
} else {
|
|
start_i = 0;
|
|
}
|
|
|
|
num_pages = num_extent_pages(eb->start, eb->len);
|
|
for (i = start_i; i < num_pages; i++) {
|
|
page = extent_buffer_page(eb, i);
|
|
if (wait == WAIT_NONE) {
|
|
if (!trylock_page(page))
|
|
goto unlock_exit;
|
|
} else {
|
|
lock_page(page);
|
|
}
|
|
locked_pages++;
|
|
if (!PageUptodate(page)) {
|
|
num_reads++;
|
|
all_uptodate = 0;
|
|
}
|
|
}
|
|
if (all_uptodate) {
|
|
if (start_i == 0)
|
|
set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
|
|
goto unlock_exit;
|
|
}
|
|
|
|
clear_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
|
|
eb->read_mirror = 0;
|
|
atomic_set(&eb->io_pages, num_reads);
|
|
for (i = start_i; i < num_pages; i++) {
|
|
page = extent_buffer_page(eb, i);
|
|
if (!PageUptodate(page)) {
|
|
ClearPageError(page);
|
|
err = __extent_read_full_page(tree, page,
|
|
get_extent, &bio,
|
|
mirror_num, &bio_flags,
|
|
READ | REQ_META);
|
|
if (err)
|
|
ret = err;
|
|
} else {
|
|
unlock_page(page);
|
|
}
|
|
}
|
|
|
|
if (bio) {
|
|
err = submit_one_bio(READ | REQ_META, bio, mirror_num,
|
|
bio_flags);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
if (ret || wait != WAIT_COMPLETE)
|
|
return ret;
|
|
|
|
for (i = start_i; i < num_pages; i++) {
|
|
page = extent_buffer_page(eb, i);
|
|
wait_on_page_locked(page);
|
|
if (!PageUptodate(page))
|
|
ret = -EIO;
|
|
}
|
|
|
|
return ret;
|
|
|
|
unlock_exit:
|
|
i = start_i;
|
|
while (locked_pages > 0) {
|
|
page = extent_buffer_page(eb, i);
|
|
i++;
|
|
unlock_page(page);
|
|
locked_pages--;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
void read_extent_buffer(struct extent_buffer *eb, void *dstv,
|
|
unsigned long start,
|
|
unsigned long len)
|
|
{
|
|
size_t cur;
|
|
size_t offset;
|
|
struct page *page;
|
|
char *kaddr;
|
|
char *dst = (char *)dstv;
|
|
size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
|
|
unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
|
|
|
|
WARN_ON(start > eb->len);
|
|
WARN_ON(start + len > eb->start + eb->len);
|
|
|
|
offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
|
|
|
|
while (len > 0) {
|
|
page = extent_buffer_page(eb, i);
|
|
|
|
cur = min(len, (PAGE_CACHE_SIZE - offset));
|
|
kaddr = page_address(page);
|
|
memcpy(dst, kaddr + offset, cur);
|
|
|
|
dst += cur;
|
|
len -= cur;
|
|
offset = 0;
|
|
i++;
|
|
}
|
|
}
|
|
|
|
int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
|
|
unsigned long min_len, char **map,
|
|
unsigned long *map_start,
|
|
unsigned long *map_len)
|
|
{
|
|
size_t offset = start & (PAGE_CACHE_SIZE - 1);
|
|
char *kaddr;
|
|
struct page *p;
|
|
size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
|
|
unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
|
|
unsigned long end_i = (start_offset + start + min_len - 1) >>
|
|
PAGE_CACHE_SHIFT;
|
|
|
|
if (i != end_i)
|
|
return -EINVAL;
|
|
|
|
if (i == 0) {
|
|
offset = start_offset;
|
|
*map_start = 0;
|
|
} else {
|
|
offset = 0;
|
|
*map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset;
|
|
}
|
|
|
|
if (start + min_len > eb->len) {
|
|
WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, "
|
|
"wanted %lu %lu\n", (unsigned long long)eb->start,
|
|
eb->len, start, min_len);
|
|
return -EINVAL;
|
|
}
|
|
|
|
p = extent_buffer_page(eb, i);
|
|
kaddr = page_address(p);
|
|
*map = kaddr + offset;
|
|
*map_len = PAGE_CACHE_SIZE - offset;
|
|
return 0;
|
|
}
|
|
|
|
int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
|
|
unsigned long start,
|
|
unsigned long len)
|
|
{
|
|
size_t cur;
|
|
size_t offset;
|
|
struct page *page;
|
|
char *kaddr;
|
|
char *ptr = (char *)ptrv;
|
|
size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
|
|
unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
|
|
int ret = 0;
|
|
|
|
WARN_ON(start > eb->len);
|
|
WARN_ON(start + len > eb->start + eb->len);
|
|
|
|
offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
|
|
|
|
while (len > 0) {
|
|
page = extent_buffer_page(eb, i);
|
|
|
|
cur = min(len, (PAGE_CACHE_SIZE - offset));
|
|
|
|
kaddr = page_address(page);
|
|
ret = memcmp(ptr, kaddr + offset, cur);
|
|
if (ret)
|
|
break;
|
|
|
|
ptr += cur;
|
|
len -= cur;
|
|
offset = 0;
|
|
i++;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
|
|
unsigned long start, unsigned long len)
|
|
{
|
|
size_t cur;
|
|
size_t offset;
|
|
struct page *page;
|
|
char *kaddr;
|
|
char *src = (char *)srcv;
|
|
size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
|
|
unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
|
|
|
|
WARN_ON(start > eb->len);
|
|
WARN_ON(start + len > eb->start + eb->len);
|
|
|
|
offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
|
|
|
|
while (len > 0) {
|
|
page = extent_buffer_page(eb, i);
|
|
WARN_ON(!PageUptodate(page));
|
|
|
|
cur = min(len, PAGE_CACHE_SIZE - offset);
|
|
kaddr = page_address(page);
|
|
memcpy(kaddr + offset, src, cur);
|
|
|
|
src += cur;
|
|
len -= cur;
|
|
offset = 0;
|
|
i++;
|
|
}
|
|
}
|
|
|
|
void memset_extent_buffer(struct extent_buffer *eb, char c,
|
|
unsigned long start, unsigned long len)
|
|
{
|
|
size_t cur;
|
|
size_t offset;
|
|
struct page *page;
|
|
char *kaddr;
|
|
size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
|
|
unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
|
|
|
|
WARN_ON(start > eb->len);
|
|
WARN_ON(start + len > eb->start + eb->len);
|
|
|
|
offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
|
|
|
|
while (len > 0) {
|
|
page = extent_buffer_page(eb, i);
|
|
WARN_ON(!PageUptodate(page));
|
|
|
|
cur = min(len, PAGE_CACHE_SIZE - offset);
|
|
kaddr = page_address(page);
|
|
memset(kaddr + offset, c, cur);
|
|
|
|
len -= cur;
|
|
offset = 0;
|
|
i++;
|
|
}
|
|
}
|
|
|
|
void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
|
|
unsigned long dst_offset, unsigned long src_offset,
|
|
unsigned long len)
|
|
{
|
|
u64 dst_len = dst->len;
|
|
size_t cur;
|
|
size_t offset;
|
|
struct page *page;
|
|
char *kaddr;
|
|
size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
|
|
unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
|
|
|
|
WARN_ON(src->len != dst_len);
|
|
|
|
offset = (start_offset + dst_offset) &
|
|
((unsigned long)PAGE_CACHE_SIZE - 1);
|
|
|
|
while (len > 0) {
|
|
page = extent_buffer_page(dst, i);
|
|
WARN_ON(!PageUptodate(page));
|
|
|
|
cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));
|
|
|
|
kaddr = page_address(page);
|
|
read_extent_buffer(src, kaddr + offset, src_offset, cur);
|
|
|
|
src_offset += cur;
|
|
len -= cur;
|
|
offset = 0;
|
|
i++;
|
|
}
|
|
}
|
|
|
|
static void move_pages(struct page *dst_page, struct page *src_page,
|
|
unsigned long dst_off, unsigned long src_off,
|
|
unsigned long len)
|
|
{
|
|
char *dst_kaddr = page_address(dst_page);
|
|
if (dst_page == src_page) {
|
|
memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);
|
|
} else {
|
|
char *src_kaddr = page_address(src_page);
|
|
char *p = dst_kaddr + dst_off + len;
|
|
char *s = src_kaddr + src_off + len;
|
|
|
|
while (len--)
|
|
*--p = *--s;
|
|
}
|
|
}
|
|
|
|
static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
|
|
{
|
|
unsigned long distance = (src > dst) ? src - dst : dst - src;
|
|
return distance < len;
|
|
}
|
|
|
|
static void copy_pages(struct page *dst_page, struct page *src_page,
|
|
unsigned long dst_off, unsigned long src_off,
|
|
unsigned long len)
|
|
{
|
|
char *dst_kaddr = page_address(dst_page);
|
|
char *src_kaddr;
|
|
int must_memmove = 0;
|
|
|
|
if (dst_page != src_page) {
|
|
src_kaddr = page_address(src_page);
|
|
} else {
|
|
src_kaddr = dst_kaddr;
|
|
if (areas_overlap(src_off, dst_off, len))
|
|
must_memmove = 1;
|
|
}
|
|
|
|
if (must_memmove)
|
|
memmove(dst_kaddr + dst_off, src_kaddr + src_off, len);
|
|
else
|
|
memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
|
|
}
|
|
|
|
void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
|
|
unsigned long src_offset, unsigned long len)
|
|
{
|
|
size_t cur;
|
|
size_t dst_off_in_page;
|
|
size_t src_off_in_page;
|
|
size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
|
|
unsigned long dst_i;
|
|
unsigned long src_i;
|
|
|
|
if (src_offset + len > dst->len) {
|
|
printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
|
|
"len %lu dst len %lu\n", src_offset, len, dst->len);
|
|
BUG_ON(1);
|
|
}
|
|
if (dst_offset + len > dst->len) {
|
|
printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
|
|
"len %lu dst len %lu\n", dst_offset, len, dst->len);
|
|
BUG_ON(1);
|
|
}
|
|
|
|
while (len > 0) {
|
|
dst_off_in_page = (start_offset + dst_offset) &
|
|
((unsigned long)PAGE_CACHE_SIZE - 1);
|
|
src_off_in_page = (start_offset + src_offset) &
|
|
((unsigned long)PAGE_CACHE_SIZE - 1);
|
|
|
|
dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
|
|
src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;
|
|
|
|
cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -
|
|
src_off_in_page));
|
|
cur = min_t(unsigned long, cur,
|
|
(unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page));
|
|
|
|
copy_pages(extent_buffer_page(dst, dst_i),
|
|
extent_buffer_page(dst, src_i),
|
|
dst_off_in_page, src_off_in_page, cur);
|
|
|
|
src_offset += cur;
|
|
dst_offset += cur;
|
|
len -= cur;
|
|
}
|
|
}
|
|
|
|
void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
|
|
unsigned long src_offset, unsigned long len)
|
|
{
|
|
size_t cur;
|
|
size_t dst_off_in_page;
|
|
size_t src_off_in_page;
|
|
unsigned long dst_end = dst_offset + len - 1;
|
|
unsigned long src_end = src_offset + len - 1;
|
|
size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
|
|
unsigned long dst_i;
|
|
unsigned long src_i;
|
|
|
|
if (src_offset + len > dst->len) {
|
|
printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
|
|
"len %lu len %lu\n", src_offset, len, dst->len);
|
|
BUG_ON(1);
|
|
}
|
|
if (dst_offset + len > dst->len) {
|
|
printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
|
|
"len %lu len %lu\n", dst_offset, len, dst->len);
|
|
BUG_ON(1);
|
|
}
|
|
if (dst_offset < src_offset) {
|
|
memcpy_extent_buffer(dst, dst_offset, src_offset, len);
|
|
return;
|
|
}
|
|
while (len > 0) {
|
|
dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT;
|
|
src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;
|
|
|
|
dst_off_in_page = (start_offset + dst_end) &
|
|
((unsigned long)PAGE_CACHE_SIZE - 1);
|
|
src_off_in_page = (start_offset + src_end) &
|
|
((unsigned long)PAGE_CACHE_SIZE - 1);
|
|
|
|
cur = min_t(unsigned long, len, src_off_in_page + 1);
|
|
cur = min(cur, dst_off_in_page + 1);
|
|
move_pages(extent_buffer_page(dst, dst_i),
|
|
extent_buffer_page(dst, src_i),
|
|
dst_off_in_page - cur + 1,
|
|
src_off_in_page - cur + 1, cur);
|
|
|
|
dst_end -= cur;
|
|
src_end -= cur;
|
|
len -= cur;
|
|
}
|
|
}
|
|
|
|
int try_release_extent_buffer(struct page *page)
|
|
{
|
|
struct extent_buffer *eb;
|
|
|
|
/*
|
|
* We need to make sure noboody is attaching this page to an eb right
|
|
* now.
|
|
*/
|
|
spin_lock(&page->mapping->private_lock);
|
|
if (!PagePrivate(page)) {
|
|
spin_unlock(&page->mapping->private_lock);
|
|
return 1;
|
|
}
|
|
|
|
eb = (struct extent_buffer *)page->private;
|
|
BUG_ON(!eb);
|
|
|
|
/*
|
|
* This is a little awful but should be ok, we need to make sure that
|
|
* the eb doesn't disappear out from under us while we're looking at
|
|
* this page.
|
|
*/
|
|
spin_lock(&eb->refs_lock);
|
|
if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) {
|
|
spin_unlock(&eb->refs_lock);
|
|
spin_unlock(&page->mapping->private_lock);
|
|
return 0;
|
|
}
|
|
spin_unlock(&page->mapping->private_lock);
|
|
|
|
/*
|
|
* If tree ref isn't set then we know the ref on this eb is a real ref,
|
|
* so just return, this page will likely be freed soon anyway.
|
|
*/
|
|
if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) {
|
|
spin_unlock(&eb->refs_lock);
|
|
return 0;
|
|
}
|
|
|
|
return release_extent_buffer(eb);
|
|
}
|