![Jens Axboe](/assets/img/avatar_default.png)
a_ops->readpages() is only ever used for read-ahead. Ensure that we pass this information down to the block layer. Link: http://lkml.kernel.org/r/20180621010725.17813-4-axboe@kernel.dk Signed-off-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Chris Mason <clm@fb.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
5903 lines
149 KiB
C
5903 lines
149 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#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 "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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#include "backref.h"
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#include "disk-io.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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static inline bool extent_state_in_tree(const struct extent_state *state)
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{
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return !RB_EMPTY_NODE(&state->rb_node);
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}
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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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pr_err("BTRFS: state leak: start %llu end %llu state %u in tree %d refs %d\n",
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state->start, state->end, state->state,
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extent_state_in_tree(state),
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refcount_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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pr_err("BTRFS: buffer leak start %llu len %lu refs %d bflags %lu\n",
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eb->start, eb->len, atomic_read(&eb->refs), eb->bflags);
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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(tree, start, end) \
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__btrfs_debug_check_extent_io_range(__func__, (tree), (start), (end))
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static inline void __btrfs_debug_check_extent_io_range(const char *caller,
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struct extent_io_tree *tree, u64 start, u64 end)
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{
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if (tree->ops && tree->ops->check_extent_io_range)
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tree->ops->check_extent_io_range(tree->private_data, caller,
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start, end);
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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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/* 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 REQ_SYNC */
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unsigned int sync_io:1;
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};
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static int add_extent_changeset(struct extent_state *state, unsigned bits,
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struct extent_changeset *changeset,
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int set)
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{
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int ret;
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if (!changeset)
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return 0;
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if (set && (state->state & bits) == bits)
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return 0;
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if (!set && (state->state & bits) == 0)
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return 0;
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changeset->bytes_changed += state->end - state->start + 1;
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ret = ulist_add(&changeset->range_changed, state->start, state->end,
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GFP_ATOMIC);
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return ret;
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}
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static void flush_write_bio(struct extent_page_data *epd);
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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_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_MEM_SPREAD, NULL);
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if (!extent_buffer_cache)
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goto free_state_cache;
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if (bioset_init(&btrfs_bioset, BIO_POOL_SIZE,
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offsetof(struct btrfs_io_bio, bio),
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BIOSET_NEED_BVECS))
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goto free_buffer_cache;
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if (bioset_integrity_create(&btrfs_bioset, BIO_POOL_SIZE))
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goto free_bioset;
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return 0;
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free_bioset:
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bioset_exit(&btrfs_bioset);
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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 __cold 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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kmem_cache_destroy(extent_state_cache);
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kmem_cache_destroy(extent_buffer_cache);
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bioset_exit(&btrfs_bioset);
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}
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void extent_io_tree_init(struct extent_io_tree *tree,
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void *private_data)
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{
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tree->state = RB_ROOT;
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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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tree->private_data = private_data;
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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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/*
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* The given mask might be not appropriate for the slab allocator,
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* drop the unsupported bits
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*/
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mask &= ~(__GFP_DMA32|__GFP_HIGHMEM);
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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->failrec = NULL;
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RB_CLEAR_NODE(&state->rb_node);
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btrfs_leak_debug_add(&state->leak_list, &states);
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refcount_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 (refcount_dec_and_test(&state->refs)) {
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WARN_ON(extent_state_in_tree(state));
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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,
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struct rb_node *search_start,
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u64 offset,
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struct rb_node *node,
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struct rb_node ***p_in,
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struct rb_node **parent_in)
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{
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struct rb_node **p;
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struct rb_node *parent = NULL;
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struct tree_entry *entry;
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if (p_in && parent_in) {
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p = *p_in;
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parent = *parent_in;
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goto do_insert;
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}
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p = search_start ? &search_start : &root->rb_node;
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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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do_insert:
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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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struct rb_node ***p_ret,
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struct rb_node **parent_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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prev = *n;
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entry = rb_entry(prev, struct tree_entry, rb_node);
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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 (p_ret)
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*p_ret = n;
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if (parent_ret)
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*parent_ret = prev;
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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 *
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tree_search_for_insert(struct extent_io_tree *tree,
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u64 offset,
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struct rb_node ***p_ret,
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struct rb_node **parent_ret)
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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, p_ret, parent_ret);
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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 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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return tree_search_for_insert(tree, offset, NULL, NULL);
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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->private_data, new, 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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rb_erase(&other->rb_node, &tree->state);
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RB_CLEAR_NODE(&other->rb_node);
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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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rb_erase(&other->rb_node, &tree->state);
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RB_CLEAR_NODE(&other->rb_node);
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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 *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->private_data, 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 *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->private_data, 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 *bits,
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struct extent_changeset *changeset);
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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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struct rb_node ***p,
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struct rb_node **parent,
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unsigned *bits, struct extent_changeset *changeset)
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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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end, 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, changeset);
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node = tree_insert(&tree->state, NULL, end, &state->rb_node, p, parent);
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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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pr_err("BTRFS: found node %llu %llu on insert of %llu %llu\n",
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found->start, found->end, start, end);
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return -EEXIST;
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}
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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->private_data, 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, &orig->rb_node, prealloc->end,
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&prealloc->rb_node, NULL, NULL);
|
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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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return 0;
|
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}
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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)
|
|
return rb_entry(next, struct extent_state, rb_node);
|
|
else
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* utility function to clear some bits in an extent state struct.
|
|
* it will optionally wake up any one waiting on this state (wake == 1).
|
|
*
|
|
* If no bits are set on the state struct after clearing things, the
|
|
* struct is freed and removed from the tree
|
|
*/
|
|
static struct extent_state *clear_state_bit(struct extent_io_tree *tree,
|
|
struct extent_state *state,
|
|
unsigned *bits, int wake,
|
|
struct extent_changeset *changeset)
|
|
{
|
|
struct extent_state *next;
|
|
unsigned bits_to_clear = *bits & ~EXTENT_CTLBITS;
|
|
int ret;
|
|
|
|
if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
|
|
u64 range = state->end - state->start + 1;
|
|
WARN_ON(range > tree->dirty_bytes);
|
|
tree->dirty_bytes -= range;
|
|
}
|
|
clear_state_cb(tree, state, bits);
|
|
ret = add_extent_changeset(state, bits_to_clear, changeset, 0);
|
|
BUG_ON(ret < 0);
|
|
state->state &= ~bits_to_clear;
|
|
if (wake)
|
|
wake_up(&state->wq);
|
|
if (state->state == 0) {
|
|
next = next_state(state);
|
|
if (extent_state_in_tree(state)) {
|
|
rb_erase(&state->rb_node, &tree->state);
|
|
RB_CLEAR_NODE(&state->rb_node);
|
|
free_extent_state(state);
|
|
} else {
|
|
WARN_ON(1);
|
|
}
|
|
} else {
|
|
merge_state(tree, state);
|
|
next = next_state(state);
|
|
}
|
|
return next;
|
|
}
|
|
|
|
static struct extent_state *
|
|
alloc_extent_state_atomic(struct extent_state *prealloc)
|
|
{
|
|
if (!prealloc)
|
|
prealloc = alloc_extent_state(GFP_ATOMIC);
|
|
|
|
return prealloc;
|
|
}
|
|
|
|
static void extent_io_tree_panic(struct extent_io_tree *tree, int err)
|
|
{
|
|
struct inode *inode = tree->private_data;
|
|
|
|
btrfs_panic(btrfs_sb(inode->i_sb), 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 bits, int wake, int delete,
|
|
struct extent_state **cached_state,
|
|
gfp_t mask, struct extent_changeset *changeset)
|
|
{
|
|
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, 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 && gfpflags_allow_blocking(mask)) {
|
|
/*
|
|
* Don't care for allocation failure here because we might end
|
|
* up not needing the pre-allocated extent state at all, which
|
|
* is the case if we only have in the tree extent states that
|
|
* cover our input range and don't cover too any other range.
|
|
* If we end up needing a new extent state we allocate it later.
|
|
*/
|
|
prealloc = alloc_extent_state(mask);
|
|
}
|
|
|
|
spin_lock(&tree->lock);
|
|
if (cached_state) {
|
|
cached = *cached_state;
|
|
|
|
if (clear) {
|
|
*cached_state = NULL;
|
|
cached_state = NULL;
|
|
}
|
|
|
|
if (cached && extent_state_in_tree(cached) &&
|
|
cached->start <= start && cached->end > start) {
|
|
if (clear)
|
|
refcount_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,
|
|
changeset);
|
|
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, changeset);
|
|
|
|
prealloc = NULL;
|
|
goto out;
|
|
}
|
|
|
|
state = clear_state_bit(tree, state, &bits, wake, changeset);
|
|
next:
|
|
if (last_end == (u64)-1)
|
|
goto out;
|
|
start = last_end + 1;
|
|
if (start <= end && state && !need_resched())
|
|
goto hit_next;
|
|
|
|
search_again:
|
|
if (start > end)
|
|
goto out;
|
|
spin_unlock(&tree->lock);
|
|
if (gfpflags_allow_blocking(mask))
|
|
cond_resched();
|
|
goto again;
|
|
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
if (prealloc)
|
|
free_extent_state(prealloc);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
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, 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);
|
|
process_node:
|
|
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;
|
|
refcount_inc(&state->refs);
|
|
wait_on_state(tree, state);
|
|
free_extent_state(state);
|
|
goto again;
|
|
}
|
|
start = state->end + 1;
|
|
|
|
if (start > end)
|
|
break;
|
|
|
|
if (!cond_resched_lock(&tree->lock)) {
|
|
node = rb_next(node);
|
|
goto process_node;
|
|
}
|
|
}
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
}
|
|
|
|
static void set_state_bits(struct extent_io_tree *tree,
|
|
struct extent_state *state,
|
|
unsigned *bits, struct extent_changeset *changeset)
|
|
{
|
|
unsigned bits_to_set = *bits & ~EXTENT_CTLBITS;
|
|
int ret;
|
|
|
|
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;
|
|
}
|
|
ret = add_extent_changeset(state, bits_to_set, changeset, 1);
|
|
BUG_ON(ret < 0);
|
|
state->state |= bits_to_set;
|
|
}
|
|
|
|
static void cache_state_if_flags(struct extent_state *state,
|
|
struct extent_state **cached_ptr,
|
|
unsigned flags)
|
|
{
|
|
if (cached_ptr && !(*cached_ptr)) {
|
|
if (!flags || (state->state & flags)) {
|
|
*cached_ptr = state;
|
|
refcount_inc(&state->refs);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void cache_state(struct extent_state *state,
|
|
struct extent_state **cached_ptr)
|
|
{
|
|
return cache_state_if_flags(state, cached_ptr,
|
|
EXTENT_IOBITS | EXTENT_BOUNDARY);
|
|
}
|
|
|
|
/*
|
|
* 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 bits, unsigned exclusive_bits,
|
|
u64 *failed_start, struct extent_state **cached_state,
|
|
gfp_t mask, struct extent_changeset *changeset)
|
|
{
|
|
struct extent_state *state;
|
|
struct extent_state *prealloc = NULL;
|
|
struct rb_node *node;
|
|
struct rb_node **p;
|
|
struct rb_node *parent;
|
|
int err = 0;
|
|
u64 last_start;
|
|
u64 last_end;
|
|
|
|
btrfs_debug_check_extent_io_range(tree, start, end);
|
|
|
|
bits |= EXTENT_FIRST_DELALLOC;
|
|
again:
|
|
if (!prealloc && gfpflags_allow_blocking(mask)) {
|
|
/*
|
|
* Don't care for allocation failure here because we might end
|
|
* up not needing the pre-allocated extent state at all, which
|
|
* is the case if we only have in the tree extent states that
|
|
* cover our input range and don't cover too any other range.
|
|
* If we end up needing a new extent state we allocate it later.
|
|
*/
|
|
prealloc = alloc_extent_state(mask);
|
|
}
|
|
|
|
spin_lock(&tree->lock);
|
|
if (cached_state && *cached_state) {
|
|
state = *cached_state;
|
|
if (state->start <= start && state->end > start &&
|
|
extent_state_in_tree(state)) {
|
|
node = &state->rb_node;
|
|
goto hit_next;
|
|
}
|
|
}
|
|
/*
|
|
* this search will find all the extents that end after
|
|
* our range starts.
|
|
*/
|
|
node = tree_search_for_insert(tree, start, &p, &parent);
|
|
if (!node) {
|
|
prealloc = alloc_extent_state_atomic(prealloc);
|
|
BUG_ON(!prealloc);
|
|
err = insert_state(tree, prealloc, start, end,
|
|
&p, &parent, &bits, changeset);
|
|
if (err)
|
|
extent_io_tree_panic(tree, err);
|
|
|
|
cache_state(prealloc, cached_state);
|
|
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, changeset);
|
|
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, changeset);
|
|
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,
|
|
NULL, NULL, &bits, changeset);
|
|
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, changeset);
|
|
cache_state(prealloc, cached_state);
|
|
merge_state(tree, prealloc);
|
|
prealloc = NULL;
|
|
goto out;
|
|
}
|
|
|
|
search_again:
|
|
if (start > end)
|
|
goto out;
|
|
spin_unlock(&tree->lock);
|
|
if (gfpflags_allow_blocking(mask))
|
|
cond_resched();
|
|
goto again;
|
|
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
if (prealloc)
|
|
free_extent_state(prealloc);
|
|
|
|
return err;
|
|
|
|
}
|
|
|
|
int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
|
|
unsigned 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, NULL);
|
|
}
|
|
|
|
|
|
/**
|
|
* 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
|
|
*
|
|
* 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.
|
|
*
|
|
* All allocations are done with GFP_NOFS.
|
|
*/
|
|
int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
|
|
unsigned bits, unsigned clear_bits,
|
|
struct extent_state **cached_state)
|
|
{
|
|
struct extent_state *state;
|
|
struct extent_state *prealloc = NULL;
|
|
struct rb_node *node;
|
|
struct rb_node **p;
|
|
struct rb_node *parent;
|
|
int err = 0;
|
|
u64 last_start;
|
|
u64 last_end;
|
|
bool first_iteration = true;
|
|
|
|
btrfs_debug_check_extent_io_range(tree, start, end);
|
|
|
|
again:
|
|
if (!prealloc) {
|
|
/*
|
|
* Best effort, don't worry if extent state allocation fails
|
|
* here for the first iteration. We might have a cached state
|
|
* that matches exactly the target range, in which case no
|
|
* extent state allocations are needed. We'll only know this
|
|
* after locking the tree.
|
|
*/
|
|
prealloc = alloc_extent_state(GFP_NOFS);
|
|
if (!prealloc && !first_iteration)
|
|
return -ENOMEM;
|
|
}
|
|
|
|
spin_lock(&tree->lock);
|
|
if (cached_state && *cached_state) {
|
|
state = *cached_state;
|
|
if (state->start <= start && state->end > start &&
|
|
extent_state_in_tree(state)) {
|
|
node = &state->rb_node;
|
|
goto hit_next;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* this search will find all the extents that end after
|
|
* our range starts.
|
|
*/
|
|
node = tree_search_for_insert(tree, start, &p, &parent);
|
|
if (!node) {
|
|
prealloc = alloc_extent_state_atomic(prealloc);
|
|
if (!prealloc) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
err = insert_state(tree, prealloc, start, end,
|
|
&p, &parent, &bits, NULL);
|
|
if (err)
|
|
extent_io_tree_panic(tree, err);
|
|
cache_state(prealloc, cached_state);
|
|
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) {
|
|
set_state_bits(tree, state, &bits, NULL);
|
|
cache_state(state, cached_state);
|
|
state = clear_state_bit(tree, state, &clear_bits, 0, NULL);
|
|
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, NULL);
|
|
cache_state(state, cached_state);
|
|
state = clear_state_bit(tree, state, &clear_bits, 0,
|
|
NULL);
|
|
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,
|
|
NULL, NULL, &bits, NULL);
|
|
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, NULL);
|
|
cache_state(prealloc, cached_state);
|
|
clear_state_bit(tree, prealloc, &clear_bits, 0, NULL);
|
|
prealloc = NULL;
|
|
goto out;
|
|
}
|
|
|
|
search_again:
|
|
if (start > end)
|
|
goto out;
|
|
spin_unlock(&tree->lock);
|
|
cond_resched();
|
|
first_iteration = false;
|
|
goto again;
|
|
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
if (prealloc)
|
|
free_extent_state(prealloc);
|
|
|
|
return err;
|
|
}
|
|
|
|
/* wrappers around set/clear extent bit */
|
|
int set_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
|
|
unsigned bits, struct extent_changeset *changeset)
|
|
{
|
|
/*
|
|
* We don't support EXTENT_LOCKED yet, as current changeset will
|
|
* record any bits changed, so for EXTENT_LOCKED case, it will
|
|
* either fail with -EEXIST or changeset will record the whole
|
|
* range.
|
|
*/
|
|
BUG_ON(bits & EXTENT_LOCKED);
|
|
|
|
return __set_extent_bit(tree, start, end, bits, 0, NULL, NULL, GFP_NOFS,
|
|
changeset);
|
|
}
|
|
|
|
int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
|
|
unsigned bits, int wake, int delete,
|
|
struct extent_state **cached)
|
|
{
|
|
return __clear_extent_bit(tree, start, end, bits, wake, delete,
|
|
cached, GFP_NOFS, NULL);
|
|
}
|
|
|
|
int clear_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
|
|
unsigned bits, struct extent_changeset *changeset)
|
|
{
|
|
/*
|
|
* Don't support EXTENT_LOCKED case, same reason as
|
|
* set_record_extent_bits().
|
|
*/
|
|
BUG_ON(bits & EXTENT_LOCKED);
|
|
|
|
return __clear_extent_bit(tree, start, end, bits, 0, 0, NULL, GFP_NOFS,
|
|
changeset);
|
|
}
|
|
|
|
/*
|
|
* 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,
|
|
struct extent_state **cached_state)
|
|
{
|
|
int err;
|
|
u64 failed_start;
|
|
|
|
while (1) {
|
|
err = __set_extent_bit(tree, start, end, EXTENT_LOCKED,
|
|
EXTENT_LOCKED, &failed_start,
|
|
cached_state, GFP_NOFS, NULL);
|
|
if (err == -EEXIST) {
|
|
wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
|
|
start = failed_start;
|
|
} else
|
|
break;
|
|
WARN_ON(start > end);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
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, NULL);
|
|
if (err == -EEXIST) {
|
|
if (failed_start > start)
|
|
clear_extent_bit(tree, start, failed_start - 1,
|
|
EXTENT_LOCKED, 1, 0, NULL);
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end)
|
|
{
|
|
unsigned long index = start >> PAGE_SHIFT;
|
|
unsigned long end_index = end >> PAGE_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);
|
|
put_page(page);
|
|
index++;
|
|
}
|
|
}
|
|
|
|
void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end)
|
|
{
|
|
unsigned long index = start >> PAGE_SHIFT;
|
|
unsigned long end_index = end >> PAGE_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 */
|
|
__set_page_dirty_nobuffers(page);
|
|
account_page_redirty(page);
|
|
put_page(page);
|
|
index++;
|
|
}
|
|
}
|
|
|
|
/* 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 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 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 && extent_state_in_tree(state)) {
|
|
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_if_flags(state, cached_state, 0);
|
|
*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;
|
|
refcount_inc(&state->refs);
|
|
}
|
|
found++;
|
|
*end = state->end;
|
|
cur_start = state->end + 1;
|
|
node = rb_next(node);
|
|
total_bytes += state->end - state->start + 1;
|
|
if (total_bytes >= max_bytes)
|
|
break;
|
|
if (!node)
|
|
break;
|
|
}
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
return found;
|
|
}
|
|
|
|
static int __process_pages_contig(struct address_space *mapping,
|
|
struct page *locked_page,
|
|
pgoff_t start_index, pgoff_t end_index,
|
|
unsigned long page_ops, pgoff_t *index_ret);
|
|
|
|
static noinline void __unlock_for_delalloc(struct inode *inode,
|
|
struct page *locked_page,
|
|
u64 start, u64 end)
|
|
{
|
|
unsigned long index = start >> PAGE_SHIFT;
|
|
unsigned long end_index = end >> PAGE_SHIFT;
|
|
|
|
ASSERT(locked_page);
|
|
if (index == locked_page->index && end_index == index)
|
|
return;
|
|
|
|
__process_pages_contig(inode->i_mapping, locked_page, index, end_index,
|
|
PAGE_UNLOCK, NULL);
|
|
}
|
|
|
|
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_SHIFT;
|
|
unsigned long index_ret = index;
|
|
unsigned long end_index = delalloc_end >> PAGE_SHIFT;
|
|
int ret;
|
|
|
|
ASSERT(locked_page);
|
|
if (index == locked_page->index && index == end_index)
|
|
return 0;
|
|
|
|
ret = __process_pages_contig(inode->i_mapping, locked_page, index,
|
|
end_index, PAGE_LOCK, &index_ret);
|
|
if (ret == -EAGAIN)
|
|
__unlock_for_delalloc(inode, locked_page, delalloc_start,
|
|
(u64)index_ret << PAGE_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 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 0;
|
|
}
|
|
|
|
/*
|
|
* 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 (delalloc_end + 1 - delalloc_start > max_bytes)
|
|
delalloc_end = delalloc_start + max_bytes - 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);
|
|
cached_state = NULL;
|
|
if (!loops) {
|
|
max_bytes = PAGE_SIZE;
|
|
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, &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);
|
|
__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;
|
|
}
|
|
|
|
static int __process_pages_contig(struct address_space *mapping,
|
|
struct page *locked_page,
|
|
pgoff_t start_index, pgoff_t end_index,
|
|
unsigned long page_ops, pgoff_t *index_ret)
|
|
{
|
|
unsigned long nr_pages = end_index - start_index + 1;
|
|
unsigned long pages_locked = 0;
|
|
pgoff_t index = start_index;
|
|
struct page *pages[16];
|
|
unsigned ret;
|
|
int err = 0;
|
|
int i;
|
|
|
|
if (page_ops & PAGE_LOCK) {
|
|
ASSERT(page_ops == PAGE_LOCK);
|
|
ASSERT(index_ret && *index_ret == start_index);
|
|
}
|
|
|
|
if ((page_ops & PAGE_SET_ERROR) && nr_pages > 0)
|
|
mapping_set_error(mapping, -EIO);
|
|
|
|
while (nr_pages > 0) {
|
|
ret = find_get_pages_contig(mapping, index,
|
|
min_t(unsigned long,
|
|
nr_pages, ARRAY_SIZE(pages)), pages);
|
|
if (ret == 0) {
|
|
/*
|
|
* Only if we're going to lock these pages,
|
|
* can we find nothing at @index.
|
|
*/
|
|
ASSERT(page_ops & PAGE_LOCK);
|
|
err = -EAGAIN;
|
|
goto out;
|
|
}
|
|
|
|
for (i = 0; i < ret; i++) {
|
|
if (page_ops & PAGE_SET_PRIVATE2)
|
|
SetPagePrivate2(pages[i]);
|
|
|
|
if (pages[i] == locked_page) {
|
|
put_page(pages[i]);
|
|
pages_locked++;
|
|
continue;
|
|
}
|
|
if (page_ops & PAGE_CLEAR_DIRTY)
|
|
clear_page_dirty_for_io(pages[i]);
|
|
if (page_ops & PAGE_SET_WRITEBACK)
|
|
set_page_writeback(pages[i]);
|
|
if (page_ops & PAGE_SET_ERROR)
|
|
SetPageError(pages[i]);
|
|
if (page_ops & PAGE_END_WRITEBACK)
|
|
end_page_writeback(pages[i]);
|
|
if (page_ops & PAGE_UNLOCK)
|
|
unlock_page(pages[i]);
|
|
if (page_ops & PAGE_LOCK) {
|
|
lock_page(pages[i]);
|
|
if (!PageDirty(pages[i]) ||
|
|
pages[i]->mapping != mapping) {
|
|
unlock_page(pages[i]);
|
|
put_page(pages[i]);
|
|
err = -EAGAIN;
|
|
goto out;
|
|
}
|
|
}
|
|
put_page(pages[i]);
|
|
pages_locked++;
|
|
}
|
|
nr_pages -= ret;
|
|
index += ret;
|
|
cond_resched();
|
|
}
|
|
out:
|
|
if (err && index_ret)
|
|
*index_ret = start_index + pages_locked - 1;
|
|
return err;
|
|
}
|
|
|
|
void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
|
|
u64 delalloc_end, struct page *locked_page,
|
|
unsigned clear_bits,
|
|
unsigned long page_ops)
|
|
{
|
|
clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, clear_bits, 1, 0,
|
|
NULL);
|
|
|
|
__process_pages_contig(inode->i_mapping, locked_page,
|
|
start >> PAGE_SHIFT, end >> PAGE_SHIFT,
|
|
page_ops, NULL);
|
|
}
|
|
|
|
/*
|
|
* 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 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 (WARN_ON(search_end <= cur_start))
|
|
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.
|
|
*/
|
|
static noinline int set_state_failrec(struct extent_io_tree *tree, u64 start,
|
|
struct io_failure_record *failrec)
|
|
{
|
|
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->failrec = failrec;
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
return ret;
|
|
}
|
|
|
|
static noinline int get_state_failrec(struct extent_io_tree *tree, u64 start,
|
|
struct io_failure_record **failrec)
|
|
{
|
|
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;
|
|
}
|
|
*failrec = state->failrec;
|
|
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 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 && extent_state_in_tree(cached) && 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_SIZE - 1;
|
|
if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
|
|
SetPageUptodate(page);
|
|
}
|
|
|
|
int free_io_failure(struct extent_io_tree *failure_tree,
|
|
struct extent_io_tree *io_tree,
|
|
struct io_failure_record *rec)
|
|
{
|
|
int ret;
|
|
int err = 0;
|
|
|
|
set_state_failrec(failure_tree, rec->start, NULL);
|
|
ret = clear_extent_bits(failure_tree, rec->start,
|
|
rec->start + rec->len - 1,
|
|
EXTENT_LOCKED | EXTENT_DIRTY);
|
|
if (ret)
|
|
err = ret;
|
|
|
|
ret = clear_extent_bits(io_tree, rec->start,
|
|
rec->start + rec->len - 1,
|
|
EXTENT_DAMAGED);
|
|
if (ret && !err)
|
|
err = ret;
|
|
|
|
kfree(rec);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* 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 ino, u64 start,
|
|
u64 length, u64 logical, struct page *page,
|
|
unsigned int pg_offset, int mirror_num)
|
|
{
|
|
struct bio *bio;
|
|
struct btrfs_device *dev;
|
|
u64 map_length = 0;
|
|
u64 sector;
|
|
struct btrfs_bio *bbio = NULL;
|
|
int ret;
|
|
|
|
ASSERT(!(fs_info->sb->s_flags & SB_RDONLY));
|
|
BUG_ON(!mirror_num);
|
|
|
|
bio = btrfs_io_bio_alloc(1);
|
|
bio->bi_iter.bi_size = 0;
|
|
map_length = length;
|
|
|
|
/*
|
|
* Avoid races with device replace and make sure our bbio has devices
|
|
* associated to its stripes that don't go away while we are doing the
|
|
* read repair operation.
|
|
*/
|
|
btrfs_bio_counter_inc_blocked(fs_info);
|
|
if (btrfs_is_parity_mirror(fs_info, logical, length)) {
|
|
/*
|
|
* Note that we don't use BTRFS_MAP_WRITE because it's supposed
|
|
* to update all raid stripes, but here we just want to correct
|
|
* bad stripe, thus BTRFS_MAP_READ is abused to only get the bad
|
|
* stripe's dev and sector.
|
|
*/
|
|
ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, logical,
|
|
&map_length, &bbio, 0);
|
|
if (ret) {
|
|
btrfs_bio_counter_dec(fs_info);
|
|
bio_put(bio);
|
|
return -EIO;
|
|
}
|
|
ASSERT(bbio->mirror_num == 1);
|
|
} else {
|
|
ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, logical,
|
|
&map_length, &bbio, mirror_num);
|
|
if (ret) {
|
|
btrfs_bio_counter_dec(fs_info);
|
|
bio_put(bio);
|
|
return -EIO;
|
|
}
|
|
BUG_ON(mirror_num != bbio->mirror_num);
|
|
}
|
|
|
|
sector = bbio->stripes[bbio->mirror_num - 1].physical >> 9;
|
|
bio->bi_iter.bi_sector = sector;
|
|
dev = bbio->stripes[bbio->mirror_num - 1].dev;
|
|
btrfs_put_bbio(bbio);
|
|
if (!dev || !dev->bdev ||
|
|
!test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) {
|
|
btrfs_bio_counter_dec(fs_info);
|
|
bio_put(bio);
|
|
return -EIO;
|
|
}
|
|
bio_set_dev(bio, dev->bdev);
|
|
bio->bi_opf = REQ_OP_WRITE | REQ_SYNC;
|
|
bio_add_page(bio, page, length, pg_offset);
|
|
|
|
if (btrfsic_submit_bio_wait(bio)) {
|
|
/* try to remap that extent elsewhere? */
|
|
btrfs_bio_counter_dec(fs_info);
|
|
bio_put(bio);
|
|
btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
|
|
return -EIO;
|
|
}
|
|
|
|
btrfs_info_rl_in_rcu(fs_info,
|
|
"read error corrected: ino %llu off %llu (dev %s sector %llu)",
|
|
ino, start,
|
|
rcu_str_deref(dev->name), sector);
|
|
btrfs_bio_counter_dec(fs_info);
|
|
bio_put(bio);
|
|
return 0;
|
|
}
|
|
|
|
int repair_eb_io_failure(struct btrfs_fs_info *fs_info,
|
|
struct extent_buffer *eb, int mirror_num)
|
|
{
|
|
u64 start = eb->start;
|
|
int i, num_pages = num_extent_pages(eb);
|
|
int ret = 0;
|
|
|
|
if (sb_rdonly(fs_info->sb))
|
|
return -EROFS;
|
|
|
|
for (i = 0; i < num_pages; i++) {
|
|
struct page *p = eb->pages[i];
|
|
|
|
ret = repair_io_failure(fs_info, 0, start, PAGE_SIZE, start, p,
|
|
start - page_offset(p), mirror_num);
|
|
if (ret)
|
|
break;
|
|
start += PAGE_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
|
|
*/
|
|
int clean_io_failure(struct btrfs_fs_info *fs_info,
|
|
struct extent_io_tree *failure_tree,
|
|
struct extent_io_tree *io_tree, u64 start,
|
|
struct page *page, u64 ino, unsigned int pg_offset)
|
|
{
|
|
u64 private;
|
|
struct io_failure_record *failrec;
|
|
struct extent_state *state;
|
|
int num_copies;
|
|
int ret;
|
|
|
|
private = 0;
|
|
ret = count_range_bits(failure_tree, &private, (u64)-1, 1,
|
|
EXTENT_DIRTY, 0);
|
|
if (!ret)
|
|
return 0;
|
|
|
|
ret = get_state_failrec(failure_tree, start, &failrec);
|
|
if (ret)
|
|
return 0;
|
|
|
|
BUG_ON(!failrec->this_mirror);
|
|
|
|
if (failrec->in_validation) {
|
|
/* there was no real error, just free the record */
|
|
btrfs_debug(fs_info,
|
|
"clean_io_failure: freeing dummy error at %llu",
|
|
failrec->start);
|
|
goto out;
|
|
}
|
|
if (sb_rdonly(fs_info->sb))
|
|
goto out;
|
|
|
|
spin_lock(&io_tree->lock);
|
|
state = find_first_extent_bit_state(io_tree,
|
|
failrec->start,
|
|
EXTENT_LOCKED);
|
|
spin_unlock(&io_tree->lock);
|
|
|
|
if (state && state->start <= failrec->start &&
|
|
state->end >= failrec->start + failrec->len - 1) {
|
|
num_copies = btrfs_num_copies(fs_info, failrec->logical,
|
|
failrec->len);
|
|
if (num_copies > 1) {
|
|
repair_io_failure(fs_info, ino, start, failrec->len,
|
|
failrec->logical, page, pg_offset,
|
|
failrec->failed_mirror);
|
|
}
|
|
}
|
|
|
|
out:
|
|
free_io_failure(failure_tree, io_tree, failrec);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Can be called when
|
|
* - hold extent lock
|
|
* - under ordered extent
|
|
* - the inode is freeing
|
|
*/
|
|
void btrfs_free_io_failure_record(struct btrfs_inode *inode, u64 start, u64 end)
|
|
{
|
|
struct extent_io_tree *failure_tree = &inode->io_failure_tree;
|
|
struct io_failure_record *failrec;
|
|
struct extent_state *state, *next;
|
|
|
|
if (RB_EMPTY_ROOT(&failure_tree->state))
|
|
return;
|
|
|
|
spin_lock(&failure_tree->lock);
|
|
state = find_first_extent_bit_state(failure_tree, start, EXTENT_DIRTY);
|
|
while (state) {
|
|
if (state->start > end)
|
|
break;
|
|
|
|
ASSERT(state->end <= end);
|
|
|
|
next = next_state(state);
|
|
|
|
failrec = state->failrec;
|
|
free_extent_state(state);
|
|
kfree(failrec);
|
|
|
|
state = next;
|
|
}
|
|
spin_unlock(&failure_tree->lock);
|
|
}
|
|
|
|
int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
|
|
struct io_failure_record **failrec_ret)
|
|
{
|
|
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
|
|
struct io_failure_record *failrec;
|
|
struct extent_map *em;
|
|
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;
|
|
int ret;
|
|
u64 logical;
|
|
|
|
ret = get_state_failrec(failure_tree, start, &failrec);
|
|
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);
|
|
}
|
|
|
|
btrfs_debug(fs_info,
|
|
"Get IO Failure Record: (new) logical=%llu, start=%llu, len=%llu",
|
|
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);
|
|
if (ret >= 0)
|
|
ret = set_state_failrec(failure_tree, start, failrec);
|
|
/* set the bits in the inode's tree */
|
|
if (ret >= 0)
|
|
ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED);
|
|
if (ret < 0) {
|
|
kfree(failrec);
|
|
return ret;
|
|
}
|
|
} else {
|
|
btrfs_debug(fs_info,
|
|
"Get IO Failure Record: (found) logical=%llu, start=%llu, len=%llu, validation=%d",
|
|
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.
|
|
*/
|
|
}
|
|
|
|
*failrec_ret = failrec;
|
|
|
|
return 0;
|
|
}
|
|
|
|
bool btrfs_check_repairable(struct inode *inode, unsigned failed_bio_pages,
|
|
struct io_failure_record *failrec, int failed_mirror)
|
|
{
|
|
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
|
|
int num_copies;
|
|
|
|
num_copies = btrfs_num_copies(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.
|
|
*/
|
|
btrfs_debug(fs_info,
|
|
"Check Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
|
|
num_copies, failrec->this_mirror, failed_mirror);
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* there are two premises:
|
|
* a) deliver good data to the caller
|
|
* b) correct the bad sectors on disk
|
|
*/
|
|
if (failed_bio_pages > 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;
|
|
} 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++;
|
|
}
|
|
|
|
if (failrec->this_mirror > num_copies) {
|
|
btrfs_debug(fs_info,
|
|
"Check Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
|
|
num_copies, failrec->this_mirror, failed_mirror);
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
|
|
struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio,
|
|
struct io_failure_record *failrec,
|
|
struct page *page, int pg_offset, int icsum,
|
|
bio_end_io_t *endio_func, void *data)
|
|
{
|
|
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
|
|
struct bio *bio;
|
|
struct btrfs_io_bio *btrfs_failed_bio;
|
|
struct btrfs_io_bio *btrfs_bio;
|
|
|
|
bio = btrfs_io_bio_alloc(1);
|
|
bio->bi_end_io = endio_func;
|
|
bio->bi_iter.bi_sector = failrec->logical >> 9;
|
|
bio_set_dev(bio, fs_info->fs_devices->latest_bdev);
|
|
bio->bi_iter.bi_size = 0;
|
|
bio->bi_private = data;
|
|
|
|
btrfs_failed_bio = btrfs_io_bio(failed_bio);
|
|
if (btrfs_failed_bio->csum) {
|
|
u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
|
|
|
|
btrfs_bio = btrfs_io_bio(bio);
|
|
btrfs_bio->csum = btrfs_bio->csum_inline;
|
|
icsum *= csum_size;
|
|
memcpy(btrfs_bio->csum, btrfs_failed_bio->csum + icsum,
|
|
csum_size);
|
|
}
|
|
|
|
bio_add_page(bio, page, failrec->len, pg_offset);
|
|
|
|
return bio;
|
|
}
|
|
|
|
/*
|
|
* 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, u64 phy_offset,
|
|
struct page *page, u64 start, u64 end,
|
|
int failed_mirror)
|
|
{
|
|
struct io_failure_record *failrec;
|
|
struct inode *inode = page->mapping->host;
|
|
struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
|
|
struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
|
|
struct bio *bio;
|
|
int read_mode = 0;
|
|
blk_status_t status;
|
|
int ret;
|
|
unsigned failed_bio_pages = bio_pages_all(failed_bio);
|
|
|
|
BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
|
|
|
|
ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (!btrfs_check_repairable(inode, failed_bio_pages, failrec,
|
|
failed_mirror)) {
|
|
free_io_failure(failure_tree, tree, failrec);
|
|
return -EIO;
|
|
}
|
|
|
|
if (failed_bio_pages > 1)
|
|
read_mode |= REQ_FAILFAST_DEV;
|
|
|
|
phy_offset >>= inode->i_sb->s_blocksize_bits;
|
|
bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
|
|
start - page_offset(page),
|
|
(int)phy_offset, failed_bio->bi_end_io,
|
|
NULL);
|
|
bio->bi_opf = REQ_OP_READ | read_mode;
|
|
|
|
btrfs_debug(btrfs_sb(inode->i_sb),
|
|
"Repair Read Error: submitting new read[%#x] to this_mirror=%d, in_validation=%d",
|
|
read_mode, failrec->this_mirror, failrec->in_validation);
|
|
|
|
status = tree->ops->submit_bio_hook(tree->private_data, bio, failrec->this_mirror,
|
|
failrec->bio_flags, 0);
|
|
if (status) {
|
|
free_io_failure(failure_tree, tree, failrec);
|
|
bio_put(bio);
|
|
ret = blk_status_to_errno(status);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* lots and lots of room for performance fixes in the end_bio funcs */
|
|
|
|
void end_extent_writepage(struct page *page, int err, u64 start, u64 end)
|
|
{
|
|
int uptodate = (err == 0);
|
|
struct extent_io_tree *tree;
|
|
int ret = 0;
|
|
|
|
tree = &BTRFS_I(page->mapping->host)->io_tree;
|
|
|
|
if (tree->ops && tree->ops->writepage_end_io_hook)
|
|
tree->ops->writepage_end_io_hook(page, start, end, NULL,
|
|
uptodate);
|
|
|
|
if (!uptodate) {
|
|
ClearPageUptodate(page);
|
|
SetPageError(page);
|
|
ret = err < 0 ? err : -EIO;
|
|
mapping_set_error(page->mapping, ret);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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 error = blk_status_to_errno(bio->bi_status);
|
|
struct bio_vec *bvec;
|
|
u64 start;
|
|
u64 end;
|
|
int i;
|
|
|
|
ASSERT(!bio_flagged(bio, BIO_CLONED));
|
|
bio_for_each_segment_all(bvec, bio, i) {
|
|
struct page *page = bvec->bv_page;
|
|
struct inode *inode = page->mapping->host;
|
|
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
|
|
|
|
/* 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_SIZE) {
|
|
if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
|
|
btrfs_err(fs_info,
|
|
"partial page write in btrfs with offset %u and length %u",
|
|
bvec->bv_offset, bvec->bv_len);
|
|
else
|
|
btrfs_info(fs_info,
|
|
"incomplete page write in btrfs with offset %u and length %u",
|
|
bvec->bv_offset, bvec->bv_len);
|
|
}
|
|
|
|
start = page_offset(page);
|
|
end = start + bvec->bv_offset + bvec->bv_len - 1;
|
|
|
|
end_extent_writepage(page, error, start, end);
|
|
end_page_writeback(page);
|
|
}
|
|
|
|
bio_put(bio);
|
|
}
|
|
|
|
static void
|
|
endio_readpage_release_extent(struct extent_io_tree *tree, u64 start, u64 len,
|
|
int uptodate)
|
|
{
|
|
struct extent_state *cached = NULL;
|
|
u64 end = start + len - 1;
|
|
|
|
if (uptodate && tree->track_uptodate)
|
|
set_extent_uptodate(tree, start, end, &cached, GFP_ATOMIC);
|
|
unlock_extent_cached_atomic(tree, start, end, &cached);
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
struct bio_vec *bvec;
|
|
int uptodate = !bio->bi_status;
|
|
struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
|
|
struct extent_io_tree *tree, *failure_tree;
|
|
u64 offset = 0;
|
|
u64 start;
|
|
u64 end;
|
|
u64 len;
|
|
u64 extent_start = 0;
|
|
u64 extent_len = 0;
|
|
int mirror;
|
|
int ret;
|
|
int i;
|
|
|
|
ASSERT(!bio_flagged(bio, BIO_CLONED));
|
|
bio_for_each_segment_all(bvec, bio, i) {
|
|
struct page *page = bvec->bv_page;
|
|
struct inode *inode = page->mapping->host;
|
|
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
|
|
|
|
btrfs_debug(fs_info,
|
|
"end_bio_extent_readpage: bi_sector=%llu, err=%d, mirror=%u",
|
|
(u64)bio->bi_iter.bi_sector, bio->bi_status,
|
|
io_bio->mirror_num);
|
|
tree = &BTRFS_I(inode)->io_tree;
|
|
failure_tree = &BTRFS_I(inode)->io_failure_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_SIZE) {
|
|
if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
|
|
btrfs_err(fs_info,
|
|
"partial page read in btrfs with offset %u and length %u",
|
|
bvec->bv_offset, bvec->bv_len);
|
|
else
|
|
btrfs_info(fs_info,
|
|
"incomplete page read in btrfs with offset %u and length %u",
|
|
bvec->bv_offset, bvec->bv_len);
|
|
}
|
|
|
|
start = page_offset(page);
|
|
end = start + bvec->bv_offset + bvec->bv_len - 1;
|
|
len = bvec->bv_len;
|
|
|
|
mirror = io_bio->mirror_num;
|
|
if (likely(uptodate && tree->ops)) {
|
|
ret = tree->ops->readpage_end_io_hook(io_bio, offset,
|
|
page, start, end,
|
|
mirror);
|
|
if (ret)
|
|
uptodate = 0;
|
|
else
|
|
clean_io_failure(BTRFS_I(inode)->root->fs_info,
|
|
failure_tree, tree, start,
|
|
page,
|
|
btrfs_ino(BTRFS_I(inode)), 0);
|
|
}
|
|
|
|
if (likely(uptodate))
|
|
goto readpage_ok;
|
|
|
|
if (tree->ops) {
|
|
ret = tree->ops->readpage_io_failed_hook(page, mirror);
|
|
if (ret == -EAGAIN) {
|
|
/*
|
|
* Data inode's readpage_io_failed_hook() always
|
|
* returns -EAGAIN.
|
|
*
|
|
* 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, offset, page,
|
|
start, end, mirror);
|
|
if (ret == 0) {
|
|
uptodate = !bio->bi_status;
|
|
offset += len;
|
|
continue;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* metadata's readpage_io_failed_hook() always returns
|
|
* -EIO and fixes nothing. -EIO is also returned if
|
|
* data inode error could not be fixed.
|
|
*/
|
|
ASSERT(ret == -EIO);
|
|
}
|
|
readpage_ok:
|
|
if (likely(uptodate)) {
|
|
loff_t i_size = i_size_read(inode);
|
|
pgoff_t end_index = i_size >> PAGE_SHIFT;
|
|
unsigned off;
|
|
|
|
/* Zero out the end if this page straddles i_size */
|
|
off = i_size & (PAGE_SIZE-1);
|
|
if (page->index == end_index && off)
|
|
zero_user_segment(page, off, PAGE_SIZE);
|
|
SetPageUptodate(page);
|
|
} else {
|
|
ClearPageUptodate(page);
|
|
SetPageError(page);
|
|
}
|
|
unlock_page(page);
|
|
offset += len;
|
|
|
|
if (unlikely(!uptodate)) {
|
|
if (extent_len) {
|
|
endio_readpage_release_extent(tree,
|
|
extent_start,
|
|
extent_len, 1);
|
|
extent_start = 0;
|
|
extent_len = 0;
|
|
}
|
|
endio_readpage_release_extent(tree, start,
|
|
end - start + 1, 0);
|
|
} else if (!extent_len) {
|
|
extent_start = start;
|
|
extent_len = end + 1 - start;
|
|
} else if (extent_start + extent_len == start) {
|
|
extent_len += end + 1 - start;
|
|
} else {
|
|
endio_readpage_release_extent(tree, extent_start,
|
|
extent_len, uptodate);
|
|
extent_start = start;
|
|
extent_len = end + 1 - start;
|
|
}
|
|
}
|
|
|
|
if (extent_len)
|
|
endio_readpage_release_extent(tree, extent_start, extent_len,
|
|
uptodate);
|
|
if (io_bio->end_io)
|
|
io_bio->end_io(io_bio, blk_status_to_errno(bio->bi_status));
|
|
bio_put(bio);
|
|
}
|
|
|
|
/*
|
|
* Initialize the members up to but not including 'bio'. Use after allocating a
|
|
* new bio by bio_alloc_bioset as it does not initialize the bytes outside of
|
|
* 'bio' because use of __GFP_ZERO is not supported.
|
|
*/
|
|
static inline void btrfs_io_bio_init(struct btrfs_io_bio *btrfs_bio)
|
|
{
|
|
memset(btrfs_bio, 0, offsetof(struct btrfs_io_bio, bio));
|
|
}
|
|
|
|
/*
|
|
* The following helpers allocate a bio. As it's backed by a bioset, it'll
|
|
* never fail. 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_byte)
|
|
{
|
|
struct bio *bio;
|
|
|
|
bio = bio_alloc_bioset(GFP_NOFS, BIO_MAX_PAGES, &btrfs_bioset);
|
|
bio_set_dev(bio, bdev);
|
|
bio->bi_iter.bi_sector = first_byte >> 9;
|
|
btrfs_io_bio_init(btrfs_io_bio(bio));
|
|
return bio;
|
|
}
|
|
|
|
struct bio *btrfs_bio_clone(struct bio *bio)
|
|
{
|
|
struct btrfs_io_bio *btrfs_bio;
|
|
struct bio *new;
|
|
|
|
/* Bio allocation backed by a bioset does not fail */
|
|
new = bio_clone_fast(bio, GFP_NOFS, &btrfs_bioset);
|
|
btrfs_bio = btrfs_io_bio(new);
|
|
btrfs_io_bio_init(btrfs_bio);
|
|
btrfs_bio->iter = bio->bi_iter;
|
|
return new;
|
|
}
|
|
|
|
struct bio *btrfs_io_bio_alloc(unsigned int nr_iovecs)
|
|
{
|
|
struct bio *bio;
|
|
|
|
/* Bio allocation backed by a bioset does not fail */
|
|
bio = bio_alloc_bioset(GFP_NOFS, nr_iovecs, &btrfs_bioset);
|
|
btrfs_io_bio_init(btrfs_io_bio(bio));
|
|
return bio;
|
|
}
|
|
|
|
struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size)
|
|
{
|
|
struct bio *bio;
|
|
struct btrfs_io_bio *btrfs_bio;
|
|
|
|
/* this will never fail when it's backed by a bioset */
|
|
bio = bio_clone_fast(orig, GFP_NOFS, &btrfs_bioset);
|
|
ASSERT(bio);
|
|
|
|
btrfs_bio = btrfs_io_bio(bio);
|
|
btrfs_io_bio_init(btrfs_bio);
|
|
|
|
bio_trim(bio, offset >> 9, size >> 9);
|
|
btrfs_bio->iter = bio->bi_iter;
|
|
return bio;
|
|
}
|
|
|
|
static int __must_check submit_one_bio(struct bio *bio, int mirror_num,
|
|
unsigned long bio_flags)
|
|
{
|
|
blk_status_t ret = 0;
|
|
struct bio_vec *bvec = bio_last_bvec_all(bio);
|
|
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;
|
|
|
|
if (tree->ops)
|
|
ret = tree->ops->submit_bio_hook(tree->private_data, bio,
|
|
mirror_num, bio_flags, start);
|
|
else
|
|
btrfsic_submit_bio(bio);
|
|
|
|
return blk_status_to_errno(ret);
|
|
}
|
|
|
|
/*
|
|
* @opf: bio REQ_OP_* and REQ_* flags as one value
|
|
* @tree: tree so we can call our merge_bio hook
|
|
* @wbc: optional writeback control for io accounting
|
|
* @page: page to add to the bio
|
|
* @pg_offset: offset of the new bio or to check whether we are adding
|
|
* a contiguous page to the previous one
|
|
* @size: portion of page that we want to write
|
|
* @offset: starting offset in the page
|
|
* @bdev: attach newly created bios to this bdev
|
|
* @bio_ret: must be valid pointer, newly allocated bio will be stored there
|
|
* @end_io_func: end_io callback for new bio
|
|
* @mirror_num: desired mirror to read/write
|
|
* @prev_bio_flags: flags of previous bio to see if we can merge the current one
|
|
* @bio_flags: flags of the current bio to see if we can merge them
|
|
*/
|
|
static int submit_extent_page(unsigned int opf, struct extent_io_tree *tree,
|
|
struct writeback_control *wbc,
|
|
struct page *page, u64 offset,
|
|
size_t size, unsigned long pg_offset,
|
|
struct block_device *bdev,
|
|
struct bio **bio_ret,
|
|
bio_end_io_t end_io_func,
|
|
int mirror_num,
|
|
unsigned long prev_bio_flags,
|
|
unsigned long bio_flags,
|
|
bool force_bio_submit)
|
|
{
|
|
int ret = 0;
|
|
struct bio *bio;
|
|
size_t page_size = min_t(size_t, size, PAGE_SIZE);
|
|
sector_t sector = offset >> 9;
|
|
|
|
ASSERT(bio_ret);
|
|
|
|
if (*bio_ret) {
|
|
bool contig;
|
|
bool can_merge = true;
|
|
|
|
bio = *bio_ret;
|
|
if (prev_bio_flags & EXTENT_BIO_COMPRESSED)
|
|
contig = bio->bi_iter.bi_sector == sector;
|
|
else
|
|
contig = bio_end_sector(bio) == sector;
|
|
|
|
if (tree->ops && btrfs_merge_bio_hook(page, offset, page_size,
|
|
bio, bio_flags))
|
|
can_merge = false;
|
|
|
|
if (prev_bio_flags != bio_flags || !contig || !can_merge ||
|
|
force_bio_submit ||
|
|
bio_add_page(bio, page, page_size, pg_offset) < page_size) {
|
|
ret = submit_one_bio(bio, mirror_num, prev_bio_flags);
|
|
if (ret < 0) {
|
|
*bio_ret = NULL;
|
|
return ret;
|
|
}
|
|
bio = NULL;
|
|
} else {
|
|
if (wbc)
|
|
wbc_account_io(wbc, page, page_size);
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
bio = btrfs_bio_alloc(bdev, offset);
|
|
bio_add_page(bio, page, page_size, pg_offset);
|
|
bio->bi_end_io = end_io_func;
|
|
bio->bi_private = tree;
|
|
bio->bi_write_hint = page->mapping->host->i_write_hint;
|
|
bio->bi_opf = opf;
|
|
if (wbc) {
|
|
wbc_init_bio(wbc, bio);
|
|
wbc_account_io(wbc, page, page_size);
|
|
}
|
|
|
|
*bio_ret = bio;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void attach_extent_buffer_page(struct extent_buffer *eb,
|
|
struct page *page)
|
|
{
|
|
if (!PagePrivate(page)) {
|
|
SetPagePrivate(page);
|
|
get_page(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);
|
|
get_page(page);
|
|
set_page_private(page, EXTENT_PAGE_PRIVATE);
|
|
}
|
|
}
|
|
|
|
static struct extent_map *
|
|
__get_extent_map(struct inode *inode, struct page *page, size_t pg_offset,
|
|
u64 start, u64 len, get_extent_t *get_extent,
|
|
struct extent_map **em_cached)
|
|
{
|
|
struct extent_map *em;
|
|
|
|
if (em_cached && *em_cached) {
|
|
em = *em_cached;
|
|
if (extent_map_in_tree(em) && start >= em->start &&
|
|
start < extent_map_end(em)) {
|
|
refcount_inc(&em->refs);
|
|
return em;
|
|
}
|
|
|
|
free_extent_map(em);
|
|
*em_cached = NULL;
|
|
}
|
|
|
|
em = get_extent(BTRFS_I(inode), page, pg_offset, start, len, 0);
|
|
if (em_cached && !IS_ERR_OR_NULL(em)) {
|
|
BUG_ON(*em_cached);
|
|
refcount_inc(&em->refs);
|
|
*em_cached = em;
|
|
}
|
|
return em;
|
|
}
|
|
/*
|
|
* 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
|
|
* return 0 on success, otherwise return error
|
|
*/
|
|
static int __do_readpage(struct extent_io_tree *tree,
|
|
struct page *page,
|
|
get_extent_t *get_extent,
|
|
struct extent_map **em_cached,
|
|
struct bio **bio, int mirror_num,
|
|
unsigned long *bio_flags, unsigned int read_flags,
|
|
u64 *prev_em_start)
|
|
{
|
|
struct inode *inode = page->mapping->host;
|
|
u64 start = page_offset(page);
|
|
const u64 end = start + PAGE_SIZE - 1;
|
|
u64 cur = start;
|
|
u64 extent_offset;
|
|
u64 last_byte = i_size_read(inode);
|
|
u64 block_start;
|
|
u64 cur_end;
|
|
struct extent_map *em;
|
|
struct block_device *bdev;
|
|
int ret = 0;
|
|
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);
|
|
unlock_extent(tree, start, end);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
if (page->index == last_byte >> PAGE_SHIFT) {
|
|
char *userpage;
|
|
size_t zero_offset = last_byte & (PAGE_SIZE - 1);
|
|
|
|
if (zero_offset) {
|
|
iosize = PAGE_SIZE - zero_offset;
|
|
userpage = kmap_atomic(page);
|
|
memset(userpage + zero_offset, 0, iosize);
|
|
flush_dcache_page(page);
|
|
kunmap_atomic(userpage);
|
|
}
|
|
}
|
|
while (cur <= end) {
|
|
bool force_bio_submit = false;
|
|
u64 offset;
|
|
|
|
if (cur >= last_byte) {
|
|
char *userpage;
|
|
struct extent_state *cached = NULL;
|
|
|
|
iosize = PAGE_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);
|
|
break;
|
|
}
|
|
em = __get_extent_map(inode, page, pg_offset, cur,
|
|
end - cur + 1, get_extent, em_cached);
|
|
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;
|
|
offset = em->block_start;
|
|
} else {
|
|
offset = em->block_start + extent_offset;
|
|
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;
|
|
|
|
/*
|
|
* If we have a file range that points to a compressed extent
|
|
* and it's followed by a consecutive file range that points to
|
|
* to the same compressed extent (possibly with a different
|
|
* offset and/or length, so it either points to the whole extent
|
|
* or only part of it), we must make sure we do not submit a
|
|
* single bio to populate the pages for the 2 ranges because
|
|
* this makes the compressed extent read zero out the pages
|
|
* belonging to the 2nd range. Imagine the following scenario:
|
|
*
|
|
* File layout
|
|
* [0 - 8K] [8K - 24K]
|
|
* | |
|
|
* | |
|
|
* points to extent X, points to extent X,
|
|
* offset 4K, length of 8K offset 0, length 16K
|
|
*
|
|
* [extent X, compressed length = 4K uncompressed length = 16K]
|
|
*
|
|
* If the bio to read the compressed extent covers both ranges,
|
|
* it will decompress extent X into the pages belonging to the
|
|
* first range and then it will stop, zeroing out the remaining
|
|
* pages that belong to the other range that points to extent X.
|
|
* So here we make sure we submit 2 bios, one for the first
|
|
* range and another one for the third range. Both will target
|
|
* the same physical extent from disk, but we can't currently
|
|
* make the compressed bio endio callback populate the pages
|
|
* for both ranges because each compressed bio is tightly
|
|
* coupled with a single extent map, and each range can have
|
|
* an extent map with a different offset value relative to the
|
|
* uncompressed data of our extent and different lengths. This
|
|
* is a corner case so we prioritize correctness over
|
|
* non-optimal behavior (submitting 2 bios for the same extent).
|
|
*/
|
|
if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) &&
|
|
prev_em_start && *prev_em_start != (u64)-1 &&
|
|
*prev_em_start != em->orig_start)
|
|
force_bio_submit = true;
|
|
|
|
if (prev_em_start)
|
|
*prev_em_start = em->orig_start;
|
|
|
|
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);
|
|
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;
|
|
}
|
|
|
|
ret = submit_extent_page(REQ_OP_READ | read_flags, tree, NULL,
|
|
page, offset, disk_io_size,
|
|
pg_offset, bdev, bio,
|
|
end_bio_extent_readpage, mirror_num,
|
|
*bio_flags,
|
|
this_bio_flag,
|
|
force_bio_submit);
|
|
if (!ret) {
|
|
nr++;
|
|
*bio_flags = this_bio_flag;
|
|
} else {
|
|
SetPageError(page);
|
|
unlock_extent(tree, cur, cur + iosize - 1);
|
|
goto out;
|
|
}
|
|
cur = cur + iosize;
|
|
pg_offset += iosize;
|
|
}
|
|
out:
|
|
if (!nr) {
|
|
if (!PageError(page))
|
|
SetPageUptodate(page);
|
|
unlock_page(page);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static inline void __do_contiguous_readpages(struct extent_io_tree *tree,
|
|
struct page *pages[], int nr_pages,
|
|
u64 start, u64 end,
|
|
struct extent_map **em_cached,
|
|
struct bio **bio,
|
|
unsigned long *bio_flags,
|
|
u64 *prev_em_start)
|
|
{
|
|
struct inode *inode;
|
|
struct btrfs_ordered_extent *ordered;
|
|
int index;
|
|
|
|
inode = pages[0]->mapping->host;
|
|
while (1) {
|
|
lock_extent(tree, start, end);
|
|
ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
|
|
end - start + 1);
|
|
if (!ordered)
|
|
break;
|
|
unlock_extent(tree, start, end);
|
|
btrfs_start_ordered_extent(inode, ordered, 1);
|
|
btrfs_put_ordered_extent(ordered);
|
|
}
|
|
|
|
for (index = 0; index < nr_pages; index++) {
|
|
__do_readpage(tree, pages[index], btrfs_get_extent, em_cached,
|
|
bio, 0, bio_flags, REQ_RAHEAD, prev_em_start);
|
|
put_page(pages[index]);
|
|
}
|
|
}
|
|
|
|
static void __extent_readpages(struct extent_io_tree *tree,
|
|
struct page *pages[],
|
|
int nr_pages,
|
|
struct extent_map **em_cached,
|
|
struct bio **bio, unsigned long *bio_flags,
|
|
u64 *prev_em_start)
|
|
{
|
|
u64 start = 0;
|
|
u64 end = 0;
|
|
u64 page_start;
|
|
int index;
|
|
int first_index = 0;
|
|
|
|
for (index = 0; index < nr_pages; index++) {
|
|
page_start = page_offset(pages[index]);
|
|
if (!end) {
|
|
start = page_start;
|
|
end = start + PAGE_SIZE - 1;
|
|
first_index = index;
|
|
} else if (end + 1 == page_start) {
|
|
end += PAGE_SIZE;
|
|
} else {
|
|
__do_contiguous_readpages(tree, &pages[first_index],
|
|
index - first_index, start,
|
|
end, em_cached,
|
|
bio, bio_flags,
|
|
prev_em_start);
|
|
start = page_start;
|
|
end = start + PAGE_SIZE - 1;
|
|
first_index = index;
|
|
}
|
|
}
|
|
|
|
if (end)
|
|
__do_contiguous_readpages(tree, &pages[first_index],
|
|
index - first_index, start,
|
|
end, em_cached, bio,
|
|
bio_flags, prev_em_start);
|
|
}
|
|
|
|
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,
|
|
unsigned int read_flags)
|
|
{
|
|
struct inode *inode = page->mapping->host;
|
|
struct btrfs_ordered_extent *ordered;
|
|
u64 start = page_offset(page);
|
|
u64 end = start + PAGE_SIZE - 1;
|
|
int ret;
|
|
|
|
while (1) {
|
|
lock_extent(tree, start, end);
|
|
ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
|
|
PAGE_SIZE);
|
|
if (!ordered)
|
|
break;
|
|
unlock_extent(tree, start, end);
|
|
btrfs_start_ordered_extent(inode, ordered, 1);
|
|
btrfs_put_ordered_extent(ordered);
|
|
}
|
|
|
|
ret = __do_readpage(tree, page, get_extent, NULL, bio, mirror_num,
|
|
bio_flags, read_flags, NULL);
|
|
return ret;
|
|
}
|
|
|
|
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, 0);
|
|
if (bio)
|
|
ret = submit_one_bio(bio, mirror_num, bio_flags);
|
|
return ret;
|
|
}
|
|
|
|
static void update_nr_written(struct writeback_control *wbc,
|
|
unsigned long nr_written)
|
|
{
|
|
wbc->nr_to_write -= nr_written;
|
|
}
|
|
|
|
/*
|
|
* helper for __extent_writepage, doing all of the delayed allocation setup.
|
|
*
|
|
* This returns 1 if our fill_delalloc function did all the work required
|
|
* to write the page (copy into inline extent). In this case the IO has
|
|
* been started and the page is already unlocked.
|
|
*
|
|
* This returns 0 if all went well (page still locked)
|
|
* This returns < 0 if there were errors (page still locked)
|
|
*/
|
|
static noinline_for_stack int writepage_delalloc(struct inode *inode,
|
|
struct page *page, struct writeback_control *wbc,
|
|
struct extent_page_data *epd,
|
|
u64 delalloc_start,
|
|
unsigned long *nr_written)
|
|
{
|
|
struct extent_io_tree *tree = epd->tree;
|
|
u64 page_end = delalloc_start + PAGE_SIZE - 1;
|
|
u64 nr_delalloc;
|
|
u64 delalloc_to_write = 0;
|
|
u64 delalloc_end = 0;
|
|
int ret;
|
|
int page_started = 0;
|
|
|
|
if (epd->extent_locked || !tree->ops || !tree->ops->fill_delalloc)
|
|
return 0;
|
|
|
|
while (delalloc_end < page_end) {
|
|
nr_delalloc = find_lock_delalloc_range(inode, tree,
|
|
page,
|
|
&delalloc_start,
|
|
&delalloc_end,
|
|
BTRFS_MAX_EXTENT_SIZE);
|
|
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, wbc);
|
|
/* File system has been set read-only */
|
|
if (ret) {
|
|
SetPageError(page);
|
|
/* fill_delalloc should be return < 0 for error
|
|
* but just in case, we use > 0 here meaning the
|
|
* IO is started, so we don't want to return > 0
|
|
* unless things are going well.
|
|
*/
|
|
ret = ret < 0 ? ret : -EIO;
|
|
goto done;
|
|
}
|
|
/*
|
|
* delalloc_end is already one less than the total length, so
|
|
* we don't subtract one from PAGE_SIZE
|
|
*/
|
|
delalloc_to_write += (delalloc_end - delalloc_start +
|
|
PAGE_SIZE) >> PAGE_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) {
|
|
/*
|
|
* 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;
|
|
return 1;
|
|
}
|
|
|
|
ret = 0;
|
|
|
|
done:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* helper for __extent_writepage. This calls the writepage start hooks,
|
|
* and does the loop to map the page into extents and bios.
|
|
*
|
|
* We return 1 if the IO is started and the page is unlocked,
|
|
* 0 if all went well (page still locked)
|
|
* < 0 if there were errors (page still locked)
|
|
*/
|
|
static noinline_for_stack int __extent_writepage_io(struct inode *inode,
|
|
struct page *page,
|
|
struct writeback_control *wbc,
|
|
struct extent_page_data *epd,
|
|
loff_t i_size,
|
|
unsigned long nr_written,
|
|
unsigned int write_flags, int *nr_ret)
|
|
{
|
|
struct extent_io_tree *tree = epd->tree;
|
|
u64 start = page_offset(page);
|
|
u64 page_end = start + PAGE_SIZE - 1;
|
|
u64 end;
|
|
u64 cur = start;
|
|
u64 extent_offset;
|
|
u64 block_start;
|
|
u64 iosize;
|
|
struct extent_map *em;
|
|
struct block_device *bdev;
|
|
size_t pg_offset = 0;
|
|
size_t blocksize;
|
|
int ret = 0;
|
|
int nr = 0;
|
|
bool compressed;
|
|
|
|
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(wbc, nr_written);
|
|
unlock_page(page);
|
|
return 1;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* we don't want to touch the inode after unlocking the page,
|
|
* so we update the mapping writeback index now
|
|
*/
|
|
update_nr_written(wbc, nr_written + 1);
|
|
|
|
end = page_end;
|
|
if (i_size <= 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) {
|
|
u64 em_end;
|
|
u64 offset;
|
|
|
|
if (cur >= i_size) {
|
|
if (tree->ops && tree->ops->writepage_end_io_hook)
|
|
tree->ops->writepage_end_io_hook(page, cur,
|
|
page_end, NULL, 1);
|
|
break;
|
|
}
|
|
em = btrfs_get_extent(BTRFS_I(inode), page, pg_offset, cur,
|
|
end - cur + 1, 1);
|
|
if (IS_ERR_OR_NULL(em)) {
|
|
SetPageError(page);
|
|
ret = PTR_ERR_OR_ZERO(em);
|
|
break;
|
|
}
|
|
|
|
extent_offset = cur - em->start;
|
|
em_end = extent_map_end(em);
|
|
BUG_ON(em_end <= cur);
|
|
BUG_ON(end < cur);
|
|
iosize = min(em_end - cur, end - cur + 1);
|
|
iosize = ALIGN(iosize, blocksize);
|
|
offset = em->block_start + extent_offset;
|
|
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;
|
|
}
|
|
|
|
btrfs_set_range_writeback(tree, cur, cur + iosize - 1);
|
|
if (!PageWriteback(page)) {
|
|
btrfs_err(BTRFS_I(inode)->root->fs_info,
|
|
"page %lu not writeback, cur %llu end %llu",
|
|
page->index, cur, end);
|
|
}
|
|
|
|
ret = submit_extent_page(REQ_OP_WRITE | write_flags, tree, wbc,
|
|
page, offset, iosize, pg_offset,
|
|
bdev, &epd->bio,
|
|
end_bio_extent_writepage,
|
|
0, 0, 0, false);
|
|
if (ret) {
|
|
SetPageError(page);
|
|
if (PageWriteback(page))
|
|
end_page_writeback(page);
|
|
}
|
|
|
|
cur = cur + iosize;
|
|
pg_offset += iosize;
|
|
nr++;
|
|
}
|
|
done:
|
|
*nr_ret = nr;
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* 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,
|
|
struct extent_page_data *epd)
|
|
{
|
|
struct inode *inode = page->mapping->host;
|
|
u64 start = page_offset(page);
|
|
u64 page_end = start + PAGE_SIZE - 1;
|
|
int ret;
|
|
int nr = 0;
|
|
size_t pg_offset = 0;
|
|
loff_t i_size = i_size_read(inode);
|
|
unsigned long end_index = i_size >> PAGE_SHIFT;
|
|
unsigned int write_flags = 0;
|
|
unsigned long nr_written = 0;
|
|
|
|
write_flags = wbc_to_write_flags(wbc);
|
|
|
|
trace___extent_writepage(page, inode, wbc);
|
|
|
|
WARN_ON(!PageLocked(page));
|
|
|
|
ClearPageError(page);
|
|
|
|
pg_offset = i_size & (PAGE_SIZE - 1);
|
|
if (page->index > end_index ||
|
|
(page->index == end_index && !pg_offset)) {
|
|
page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
|
|
unlock_page(page);
|
|
return 0;
|
|
}
|
|
|
|
if (page->index == end_index) {
|
|
char *userpage;
|
|
|
|
userpage = kmap_atomic(page);
|
|
memset(userpage + pg_offset, 0,
|
|
PAGE_SIZE - pg_offset);
|
|
kunmap_atomic(userpage);
|
|
flush_dcache_page(page);
|
|
}
|
|
|
|
pg_offset = 0;
|
|
|
|
set_page_extent_mapped(page);
|
|
|
|
ret = writepage_delalloc(inode, page, wbc, epd, start, &nr_written);
|
|
if (ret == 1)
|
|
goto done_unlocked;
|
|
if (ret)
|
|
goto done;
|
|
|
|
ret = __extent_writepage_io(inode, page, wbc, epd,
|
|
i_size, nr_written, write_flags, &nr);
|
|
if (ret == 1)
|
|
goto done_unlocked;
|
|
|
|
done:
|
|
if (nr == 0) {
|
|
/* make sure the mapping tag for page dirty gets cleared */
|
|
set_page_writeback(page);
|
|
end_page_writeback(page);
|
|
}
|
|
if (PageError(page)) {
|
|
ret = ret < 0 ? ret : -EIO;
|
|
end_extent_writepage(page, ret, start, page_end);
|
|
}
|
|
unlock_page(page);
|
|
return ret;
|
|
|
|
done_unlocked:
|
|
return 0;
|
|
}
|
|
|
|
void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
|
|
{
|
|
wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK,
|
|
TASK_UNINTERRUPTIBLE);
|
|
}
|
|
|
|
static noinline_for_stack int
|
|
lock_extent_buffer_for_io(struct extent_buffer *eb,
|
|
struct btrfs_fs_info *fs_info,
|
|
struct extent_page_data *epd)
|
|
{
|
|
int 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_batch(&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);
|
|
for (i = 0; i < num_pages; i++) {
|
|
struct page *p = eb->pages[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_atomic();
|
|
wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
|
|
}
|
|
|
|
static void set_btree_ioerr(struct page *page)
|
|
{
|
|
struct extent_buffer *eb = (struct extent_buffer *)page->private;
|
|
|
|
SetPageError(page);
|
|
if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags))
|
|
return;
|
|
|
|
/*
|
|
* If writeback for a btree extent that doesn't belong to a log tree
|
|
* failed, increment the counter transaction->eb_write_errors.
|
|
* We do this because while the transaction is running and before it's
|
|
* committing (when we call filemap_fdata[write|wait]_range against
|
|
* the btree inode), we might have
|
|
* btree_inode->i_mapping->a_ops->writepages() called by the VM - if it
|
|
* returns an error or an error happens during writeback, when we're
|
|
* committing the transaction we wouldn't know about it, since the pages
|
|
* can be no longer dirty nor marked anymore for writeback (if a
|
|
* subsequent modification to the extent buffer didn't happen before the
|
|
* transaction commit), which makes filemap_fdata[write|wait]_range not
|
|
* able to find the pages tagged with SetPageError at transaction
|
|
* commit time. So if this happens we must abort the transaction,
|
|
* otherwise we commit a super block with btree roots that point to
|
|
* btree nodes/leafs whose content on disk is invalid - either garbage
|
|
* or the content of some node/leaf from a past generation that got
|
|
* cowed or deleted and is no longer valid.
|
|
*
|
|
* Note: setting AS_EIO/AS_ENOSPC in the btree inode's i_mapping would
|
|
* not be enough - we need to distinguish between log tree extents vs
|
|
* non-log tree extents, and the next filemap_fdatawait_range() call
|
|
* will catch and clear such errors in the mapping - and that call might
|
|
* be from a log sync and not from a transaction commit. Also, checking
|
|
* for the eb flag EXTENT_BUFFER_WRITE_ERR at transaction commit time is
|
|
* not done and would not be reliable - the eb might have been released
|
|
* from memory and reading it back again means that flag would not be
|
|
* set (since it's a runtime flag, not persisted on disk).
|
|
*
|
|
* Using the flags below in the btree inode also makes us achieve the
|
|
* goal of AS_EIO/AS_ENOSPC when writepages() returns success, started
|
|
* writeback for all dirty pages and before filemap_fdatawait_range()
|
|
* is called, the writeback for all dirty pages had already finished
|
|
* with errors - because we were not using AS_EIO/AS_ENOSPC,
|
|
* filemap_fdatawait_range() would return success, as it could not know
|
|
* that writeback errors happened (the pages were no longer tagged for
|
|
* writeback).
|
|
*/
|
|
switch (eb->log_index) {
|
|
case -1:
|
|
set_bit(BTRFS_FS_BTREE_ERR, &eb->fs_info->flags);
|
|
break;
|
|
case 0:
|
|
set_bit(BTRFS_FS_LOG1_ERR, &eb->fs_info->flags);
|
|
break;
|
|
case 1:
|
|
set_bit(BTRFS_FS_LOG2_ERR, &eb->fs_info->flags);
|
|
break;
|
|
default:
|
|
BUG(); /* unexpected, logic error */
|
|
}
|
|
}
|
|
|
|
static void end_bio_extent_buffer_writepage(struct bio *bio)
|
|
{
|
|
struct bio_vec *bvec;
|
|
struct extent_buffer *eb;
|
|
int i, done;
|
|
|
|
ASSERT(!bio_flagged(bio, BIO_CLONED));
|
|
bio_for_each_segment_all(bvec, bio, i) {
|
|
struct page *page = bvec->bv_page;
|
|
|
|
eb = (struct extent_buffer *)page->private;
|
|
BUG_ON(!eb);
|
|
done = atomic_dec_and_test(&eb->io_pages);
|
|
|
|
if (bio->bi_status ||
|
|
test_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) {
|
|
ClearPageUptodate(page);
|
|
set_btree_ioerr(page);
|
|
}
|
|
|
|
end_page_writeback(page);
|
|
|
|
if (!done)
|
|
continue;
|
|
|
|
end_extent_buffer_writeback(eb);
|
|
}
|
|
|
|
bio_put(bio);
|
|
}
|
|
|
|
static noinline_for_stack 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;
|
|
struct extent_io_tree *tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
|
|
u64 offset = eb->start;
|
|
u32 nritems;
|
|
int i, num_pages;
|
|
unsigned long start, end;
|
|
unsigned int write_flags = wbc_to_write_flags(wbc) | REQ_META;
|
|
int ret = 0;
|
|
|
|
clear_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags);
|
|
num_pages = num_extent_pages(eb);
|
|
atomic_set(&eb->io_pages, num_pages);
|
|
|
|
/* set btree blocks beyond nritems with 0 to avoid stale content. */
|
|
nritems = btrfs_header_nritems(eb);
|
|
if (btrfs_header_level(eb) > 0) {
|
|
end = btrfs_node_key_ptr_offset(nritems);
|
|
|
|
memzero_extent_buffer(eb, end, eb->len - end);
|
|
} else {
|
|
/*
|
|
* leaf:
|
|
* header 0 1 2 .. N ... data_N .. data_2 data_1 data_0
|
|
*/
|
|
start = btrfs_item_nr_offset(nritems);
|
|
end = BTRFS_LEAF_DATA_OFFSET + leaf_data_end(fs_info, eb);
|
|
memzero_extent_buffer(eb, start, end - start);
|
|
}
|
|
|
|
for (i = 0; i < num_pages; i++) {
|
|
struct page *p = eb->pages[i];
|
|
|
|
clear_page_dirty_for_io(p);
|
|
set_page_writeback(p);
|
|
ret = submit_extent_page(REQ_OP_WRITE | write_flags, tree, wbc,
|
|
p, offset, PAGE_SIZE, 0, bdev,
|
|
&epd->bio,
|
|
end_bio_extent_buffer_writepage,
|
|
0, 0, 0, false);
|
|
if (ret) {
|
|
set_btree_ioerr(p);
|
|
if (PageWriteback(p))
|
|
end_page_writeback(p);
|
|
if (atomic_sub_and_test(num_pages - i, &eb->io_pages))
|
|
end_extent_buffer_writeback(eb);
|
|
ret = -EIO;
|
|
break;
|
|
}
|
|
offset += PAGE_SIZE;
|
|
update_nr_written(wbc, 1);
|
|
unlock_page(p);
|
|
}
|
|
|
|
if (unlikely(ret)) {
|
|
for (; i < num_pages; i++) {
|
|
struct page *p = eb->pages[i];
|
|
clear_page_dirty_for_io(p);
|
|
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,
|
|
};
|
|
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);
|
|
if (wbc->range_cyclic) {
|
|
index = mapping->writeback_index; /* Start from prev offset */
|
|
end = -1;
|
|
} else {
|
|
index = wbc->range_start >> PAGE_SHIFT;
|
|
end = wbc->range_end >> PAGE_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_range_tag(&pvec, mapping, &index, end,
|
|
tag))) {
|
|
unsigned i;
|
|
|
|
scanned = 1;
|
|
for (i = 0; i < nr_pages; i++) {
|
|
struct page *page = pvec.pages[i];
|
|
|
|
if (!PagePrivate(page))
|
|
continue;
|
|
|
|
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 (WARN_ON(!eb)) {
|
|
spin_unlock(&mapping->private_lock);
|
|
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
|
|
* @data: data passed to __extent_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 address_space *mapping,
|
|
struct writeback_control *wbc,
|
|
struct extent_page_data *epd)
|
|
{
|
|
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 */
|
|
pgoff_t done_index;
|
|
int range_whole = 0;
|
|
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);
|
|
if (wbc->range_cyclic) {
|
|
index = mapping->writeback_index; /* Start from prev offset */
|
|
end = -1;
|
|
} else {
|
|
index = wbc->range_start >> PAGE_SHIFT;
|
|
end = wbc->range_end >> PAGE_SHIFT;
|
|
if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
|
|
range_whole = 1;
|
|
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);
|
|
done_index = index;
|
|
while (!done && !nr_to_write_done && (index <= end) &&
|
|
(nr_pages = pagevec_lookup_range_tag(&pvec, mapping,
|
|
&index, end, tag))) {
|
|
unsigned i;
|
|
|
|
scanned = 1;
|
|
for (i = 0; i < nr_pages; i++) {
|
|
struct page *page = pvec.pages[i];
|
|
|
|
done_index = page->index;
|
|
/*
|
|
* At this point we hold neither the i_pages lock nor
|
|
* the page lock: 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_write_bio(epd);
|
|
lock_page(page);
|
|
}
|
|
|
|
if (unlikely(page->mapping != mapping)) {
|
|
unlock_page(page);
|
|
continue;
|
|
}
|
|
|
|
if (wbc->sync_mode != WB_SYNC_NONE) {
|
|
if (PageWriteback(page))
|
|
flush_write_bio(epd);
|
|
wait_on_page_writeback(page);
|
|
}
|
|
|
|
if (PageWriteback(page) ||
|
|
!clear_page_dirty_for_io(page)) {
|
|
unlock_page(page);
|
|
continue;
|
|
}
|
|
|
|
ret = __extent_writepage(page, wbc, epd);
|
|
|
|
if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
|
|
unlock_page(page);
|
|
ret = 0;
|
|
}
|
|
if (ret < 0) {
|
|
/*
|
|
* done_index is set past this page,
|
|
* so media errors will not choke
|
|
* background writeout for the entire
|
|
* file. This has consequences for
|
|
* range_cyclic semantics (ie. it may
|
|
* not be suitable for data integrity
|
|
* writeout).
|
|
*/
|
|
done_index = page->index + 1;
|
|
done = 1;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
if (wbc->range_cyclic || (wbc->nr_to_write > 0 && range_whole))
|
|
mapping->writeback_index = done_index;
|
|
|
|
btrfs_add_delayed_iput(inode);
|
|
return ret;
|
|
}
|
|
|
|
static void flush_write_bio(struct extent_page_data *epd)
|
|
{
|
|
if (epd->bio) {
|
|
int ret;
|
|
|
|
ret = submit_one_bio(epd->bio, 0, 0);
|
|
BUG_ON(ret < 0); /* -ENOMEM */
|
|
epd->bio = NULL;
|
|
}
|
|
}
|
|
|
|
int extent_write_full_page(struct page *page, struct writeback_control *wbc)
|
|
{
|
|
int ret;
|
|
struct extent_page_data epd = {
|
|
.bio = NULL,
|
|
.tree = &BTRFS_I(page->mapping->host)->io_tree,
|
|
.extent_locked = 0,
|
|
.sync_io = wbc->sync_mode == WB_SYNC_ALL,
|
|
};
|
|
|
|
ret = __extent_writepage(page, wbc, &epd);
|
|
|
|
flush_write_bio(&epd);
|
|
return ret;
|
|
}
|
|
|
|
int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
|
|
int mode)
|
|
{
|
|
int ret = 0;
|
|
struct address_space *mapping = inode->i_mapping;
|
|
struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
|
|
struct page *page;
|
|
unsigned long nr_pages = (end - start + PAGE_SIZE) >>
|
|
PAGE_SHIFT;
|
|
|
|
struct extent_page_data epd = {
|
|
.bio = NULL,
|
|
.tree = tree,
|
|
.extent_locked = 1,
|
|
.sync_io = mode == WB_SYNC_ALL,
|
|
};
|
|
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_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_SIZE - 1,
|
|
NULL, 1);
|
|
unlock_page(page);
|
|
}
|
|
put_page(page);
|
|
start += PAGE_SIZE;
|
|
}
|
|
|
|
flush_write_bio(&epd);
|
|
return ret;
|
|
}
|
|
|
|
int extent_writepages(struct address_space *mapping,
|
|
struct writeback_control *wbc)
|
|
{
|
|
int ret = 0;
|
|
struct extent_page_data epd = {
|
|
.bio = NULL,
|
|
.tree = &BTRFS_I(mapping->host)->io_tree,
|
|
.extent_locked = 0,
|
|
.sync_io = wbc->sync_mode == WB_SYNC_ALL,
|
|
};
|
|
|
|
ret = extent_write_cache_pages(mapping, wbc, &epd);
|
|
flush_write_bio(&epd);
|
|
return ret;
|
|
}
|
|
|
|
int extent_readpages(struct address_space *mapping, struct list_head *pages,
|
|
unsigned nr_pages)
|
|
{
|
|
struct bio *bio = NULL;
|
|
unsigned page_idx;
|
|
unsigned long bio_flags = 0;
|
|
struct page *pagepool[16];
|
|
struct page *page;
|
|
struct extent_map *em_cached = NULL;
|
|
struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
|
|
int nr = 0;
|
|
u64 prev_em_start = (u64)-1;
|
|
|
|
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,
|
|
readahead_gfp_mask(mapping))) {
|
|
put_page(page);
|
|
continue;
|
|
}
|
|
|
|
pagepool[nr++] = page;
|
|
if (nr < ARRAY_SIZE(pagepool))
|
|
continue;
|
|
__extent_readpages(tree, pagepool, nr, &em_cached, &bio,
|
|
&bio_flags, &prev_em_start);
|
|
nr = 0;
|
|
}
|
|
if (nr)
|
|
__extent_readpages(tree, pagepool, nr, &em_cached, &bio,
|
|
&bio_flags, &prev_em_start);
|
|
|
|
if (em_cached)
|
|
free_extent_map(em_cached);
|
|
|
|
BUG_ON(!list_empty(pages));
|
|
if (bio)
|
|
return submit_one_bio(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_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, &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);
|
|
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_io_tree *tree,
|
|
struct page *page, gfp_t mask)
|
|
{
|
|
u64 start = page_offset(page);
|
|
u64 end = start + PAGE_SIZE - 1;
|
|
int ret = 1;
|
|
|
|
if (test_range_bit(tree, start, end,
|
|
EXTENT_IOBITS, 0, NULL))
|
|
ret = 0;
|
|
else {
|
|
/*
|
|
* 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, NULL);
|
|
|
|
/* 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 page *page, gfp_t mask)
|
|
{
|
|
struct extent_map *em;
|
|
u64 start = page_offset(page);
|
|
u64 end = start + PAGE_SIZE - 1;
|
|
struct btrfs_inode *btrfs_inode = BTRFS_I(page->mapping->host);
|
|
struct extent_io_tree *tree = &btrfs_inode->io_tree;
|
|
struct extent_map_tree *map = &btrfs_inode->extent_tree;
|
|
|
|
if (gfpflags_allow_blocking(mask) &&
|
|
page->mapping->host->i_size > SZ_16M) {
|
|
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)) {
|
|
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
|
|
&btrfs_inode->runtime_flags);
|
|
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(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)
|
|
{
|
|
u64 sectorsize = btrfs_inode_sectorsize(inode);
|
|
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 = btrfs_get_extent_fiemap(BTRFS_I(inode), NULL, 0, offset,
|
|
len, 0);
|
|
if (IS_ERR_OR_NULL(em))
|
|
return em;
|
|
|
|
/* if this isn't a hole return it */
|
|
if (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;
|
|
}
|
|
|
|
/*
|
|
* To cache previous fiemap extent
|
|
*
|
|
* Will be used for merging fiemap extent
|
|
*/
|
|
struct fiemap_cache {
|
|
u64 offset;
|
|
u64 phys;
|
|
u64 len;
|
|
u32 flags;
|
|
bool cached;
|
|
};
|
|
|
|
/*
|
|
* Helper to submit fiemap extent.
|
|
*
|
|
* Will try to merge current fiemap extent specified by @offset, @phys,
|
|
* @len and @flags with cached one.
|
|
* And only when we fails to merge, cached one will be submitted as
|
|
* fiemap extent.
|
|
*
|
|
* Return value is the same as fiemap_fill_next_extent().
|
|
*/
|
|
static int emit_fiemap_extent(struct fiemap_extent_info *fieinfo,
|
|
struct fiemap_cache *cache,
|
|
u64 offset, u64 phys, u64 len, u32 flags)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (!cache->cached)
|
|
goto assign;
|
|
|
|
/*
|
|
* Sanity check, extent_fiemap() should have ensured that new
|
|
* fiemap extent won't overlap with cahced one.
|
|
* Not recoverable.
|
|
*
|
|
* NOTE: Physical address can overlap, due to compression
|
|
*/
|
|
if (cache->offset + cache->len > offset) {
|
|
WARN_ON(1);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/*
|
|
* Only merges fiemap extents if
|
|
* 1) Their logical addresses are continuous
|
|
*
|
|
* 2) Their physical addresses are continuous
|
|
* So truly compressed (physical size smaller than logical size)
|
|
* extents won't get merged with each other
|
|
*
|
|
* 3) Share same flags except FIEMAP_EXTENT_LAST
|
|
* So regular extent won't get merged with prealloc extent
|
|
*/
|
|
if (cache->offset + cache->len == offset &&
|
|
cache->phys + cache->len == phys &&
|
|
(cache->flags & ~FIEMAP_EXTENT_LAST) ==
|
|
(flags & ~FIEMAP_EXTENT_LAST)) {
|
|
cache->len += len;
|
|
cache->flags |= flags;
|
|
goto try_submit_last;
|
|
}
|
|
|
|
/* Not mergeable, need to submit cached one */
|
|
ret = fiemap_fill_next_extent(fieinfo, cache->offset, cache->phys,
|
|
cache->len, cache->flags);
|
|
cache->cached = false;
|
|
if (ret)
|
|
return ret;
|
|
assign:
|
|
cache->cached = true;
|
|
cache->offset = offset;
|
|
cache->phys = phys;
|
|
cache->len = len;
|
|
cache->flags = flags;
|
|
try_submit_last:
|
|
if (cache->flags & FIEMAP_EXTENT_LAST) {
|
|
ret = fiemap_fill_next_extent(fieinfo, cache->offset,
|
|
cache->phys, cache->len, cache->flags);
|
|
cache->cached = false;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Emit last fiemap cache
|
|
*
|
|
* The last fiemap cache may still be cached in the following case:
|
|
* 0 4k 8k
|
|
* |<- Fiemap range ->|
|
|
* |<------------ First extent ----------->|
|
|
*
|
|
* In this case, the first extent range will be cached but not emitted.
|
|
* So we must emit it before ending extent_fiemap().
|
|
*/
|
|
static int emit_last_fiemap_cache(struct btrfs_fs_info *fs_info,
|
|
struct fiemap_extent_info *fieinfo,
|
|
struct fiemap_cache *cache)
|
|
{
|
|
int ret;
|
|
|
|
if (!cache->cached)
|
|
return 0;
|
|
|
|
ret = fiemap_fill_next_extent(fieinfo, cache->offset, cache->phys,
|
|
cache->len, cache->flags);
|
|
cache->cached = false;
|
|
if (ret > 0)
|
|
ret = 0;
|
|
return ret;
|
|
}
|
|
|
|
int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
|
|
__u64 start, __u64 len)
|
|
{
|
|
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_root *root = BTRFS_I(inode)->root;
|
|
struct fiemap_cache cache = { 0 };
|
|
int end = 0;
|
|
u64 em_start = 0;
|
|
u64 em_len = 0;
|
|
u64 em_end = 0;
|
|
|
|
if (len == 0)
|
|
return -EINVAL;
|
|
|
|
path = btrfs_alloc_path();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
path->leave_spinning = 1;
|
|
|
|
start = round_down(start, btrfs_inode_sectorsize(inode));
|
|
len = round_up(max, btrfs_inode_sectorsize(inode)) - start;
|
|
|
|
/*
|
|
* 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, root, path,
|
|
btrfs_ino(BTRFS_I(inode)), -1, 0);
|
|
if (ret < 0) {
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
} else {
|
|
WARN_ON(!ret);
|
|
if (ret == 1)
|
|
ret = 0;
|
|
}
|
|
|
|
path->slots[0]--;
|
|
btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
|
|
found_type = found_key.type;
|
|
|
|
/* No extents, but there might be delalloc bits */
|
|
if (found_key.objectid != btrfs_ino(BTRFS_I(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_release_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,
|
|
&cached_state);
|
|
|
|
em = get_extent_skip_holes(inode, start, last_for_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;
|
|
flags = 0;
|
|
if (em->block_start < EXTENT_MAP_LAST_BYTE)
|
|
disko = em->block_start + offset_in_extent;
|
|
else
|
|
disko = 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 if (fieinfo->fi_extents_max) {
|
|
u64 bytenr = em->block_start -
|
|
(em->start - em->orig_start);
|
|
|
|
/*
|
|
* As btrfs supports shared space, this information
|
|
* can be exported to userspace tools via
|
|
* flag FIEMAP_EXTENT_SHARED. If fi_extents_max == 0
|
|
* then we're just getting a count and we can skip the
|
|
* lookup stuff.
|
|
*/
|
|
ret = btrfs_check_shared(root,
|
|
btrfs_ino(BTRFS_I(inode)),
|
|
bytenr);
|
|
if (ret < 0)
|
|
goto out_free;
|
|
if (ret)
|
|
flags |= FIEMAP_EXTENT_SHARED;
|
|
ret = 0;
|
|
}
|
|
if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
|
|
flags |= FIEMAP_EXTENT_ENCODED;
|
|
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
|
|
flags |= FIEMAP_EXTENT_UNWRITTEN;
|
|
|
|
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);
|
|
if (IS_ERR(em)) {
|
|
ret = PTR_ERR(em);
|
|
goto out;
|
|
}
|
|
if (!em) {
|
|
flags |= FIEMAP_EXTENT_LAST;
|
|
end = 1;
|
|
}
|
|
ret = emit_fiemap_extent(fieinfo, &cache, em_start, disko,
|
|
em_len, flags);
|
|
if (ret) {
|
|
if (ret == 1)
|
|
ret = 0;
|
|
goto out_free;
|
|
}
|
|
}
|
|
out_free:
|
|
if (!ret)
|
|
ret = emit_last_fiemap_cache(root->fs_info, fieinfo, &cache);
|
|
free_extent_map(em);
|
|
out:
|
|
btrfs_free_path(path);
|
|
unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len - 1,
|
|
&cached_state);
|
|
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);
|
|
}
|
|
|
|
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));
|
|
}
|
|
|
|
/*
|
|
* Release all pages attached to the extent buffer.
|
|
*/
|
|
static void btrfs_release_extent_buffer_pages(struct extent_buffer *eb)
|
|
{
|
|
int i;
|
|
int num_pages;
|
|
int mapped = !test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags);
|
|
|
|
BUG_ON(extent_buffer_under_io(eb));
|
|
|
|
num_pages = num_extent_pages(eb);
|
|
for (i = 0; i < num_pages; i++) {
|
|
struct page *page = eb->pages[i];
|
|
|
|
if (!page)
|
|
continue;
|
|
if (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 */
|
|
put_page(page);
|
|
}
|
|
|
|
if (mapped)
|
|
spin_unlock(&page->mapping->private_lock);
|
|
|
|
/* One for when we allocated the page */
|
|
put_page(page);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Helper for releasing the extent buffer.
|
|
*/
|
|
static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
|
|
{
|
|
btrfs_release_extent_buffer_pages(eb);
|
|
__free_extent_buffer(eb);
|
|
}
|
|
|
|
static struct extent_buffer *
|
|
__alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
|
|
unsigned long len)
|
|
{
|
|
struct extent_buffer *eb = NULL;
|
|
|
|
eb = kmem_cache_zalloc(extent_buffer_cache, GFP_NOFS|__GFP_NOFAIL);
|
|
eb->start = start;
|
|
eb->len = len;
|
|
eb->fs_info = fs_info;
|
|
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)
|
|
{
|
|
int i;
|
|
struct page *p;
|
|
struct extent_buffer *new;
|
|
int num_pages = num_extent_pages(src);
|
|
|
|
new = __alloc_extent_buffer(src->fs_info, src->start, src->len);
|
|
if (new == NULL)
|
|
return NULL;
|
|
|
|
for (i = 0; i < num_pages; i++) {
|
|
p = alloc_page(GFP_NOFS);
|
|
if (!p) {
|
|
btrfs_release_extent_buffer(new);
|
|
return NULL;
|
|
}
|
|
attach_extent_buffer_page(new, p);
|
|
WARN_ON(PageDirty(p));
|
|
SetPageUptodate(p);
|
|
new->pages[i] = p;
|
|
copy_page(page_address(p), page_address(src->pages[i]));
|
|
}
|
|
|
|
set_bit(EXTENT_BUFFER_UPTODATE, &new->bflags);
|
|
set_bit(EXTENT_BUFFER_UNMAPPED, &new->bflags);
|
|
|
|
return new;
|
|
}
|
|
|
|
struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
|
|
u64 start, unsigned long len)
|
|
{
|
|
struct extent_buffer *eb;
|
|
int num_pages;
|
|
int i;
|
|
|
|
eb = __alloc_extent_buffer(fs_info, start, len);
|
|
if (!eb)
|
|
return NULL;
|
|
|
|
num_pages = num_extent_pages(eb);
|
|
for (i = 0; i < num_pages; i++) {
|
|
eb->pages[i] = alloc_page(GFP_NOFS);
|
|
if (!eb->pages[i])
|
|
goto err;
|
|
}
|
|
set_extent_buffer_uptodate(eb);
|
|
btrfs_set_header_nritems(eb, 0);
|
|
set_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags);
|
|
|
|
return eb;
|
|
err:
|
|
for (; i > 0; i--)
|
|
__free_page(eb->pages[i - 1]);
|
|
__free_extent_buffer(eb);
|
|
return NULL;
|
|
}
|
|
|
|
struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
|
|
u64 start)
|
|
{
|
|
return __alloc_dummy_extent_buffer(fs_info, start, fs_info->nodesize);
|
|
}
|
|
|
|
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,
|
|
struct page *accessed)
|
|
{
|
|
int num_pages, i;
|
|
|
|
check_buffer_tree_ref(eb);
|
|
|
|
num_pages = num_extent_pages(eb);
|
|
for (i = 0; i < num_pages; i++) {
|
|
struct page *p = eb->pages[i];
|
|
|
|
if (p != accessed)
|
|
mark_page_accessed(p);
|
|
}
|
|
}
|
|
|
|
struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
|
|
u64 start)
|
|
{
|
|
struct extent_buffer *eb;
|
|
|
|
rcu_read_lock();
|
|
eb = radix_tree_lookup(&fs_info->buffer_radix,
|
|
start >> PAGE_SHIFT);
|
|
if (eb && atomic_inc_not_zero(&eb->refs)) {
|
|
rcu_read_unlock();
|
|
/*
|
|
* Lock our eb's refs_lock to avoid races with
|
|
* free_extent_buffer. When we get our eb it might be flagged
|
|
* with EXTENT_BUFFER_STALE and another task running
|
|
* free_extent_buffer might have seen that flag set,
|
|
* eb->refs == 2, that the buffer isn't under IO (dirty and
|
|
* writeback flags not set) and it's still in the tree (flag
|
|
* EXTENT_BUFFER_TREE_REF set), therefore being in the process
|
|
* of decrementing the extent buffer's reference count twice.
|
|
* So here we could race and increment the eb's reference count,
|
|
* clear its stale flag, mark it as dirty and drop our reference
|
|
* before the other task finishes executing free_extent_buffer,
|
|
* which would later result in an attempt to free an extent
|
|
* buffer that is dirty.
|
|
*/
|
|
if (test_bit(EXTENT_BUFFER_STALE, &eb->bflags)) {
|
|
spin_lock(&eb->refs_lock);
|
|
spin_unlock(&eb->refs_lock);
|
|
}
|
|
mark_extent_buffer_accessed(eb, NULL);
|
|
return eb;
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
return NULL;
|
|
}
|
|
|
|
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
|
|
struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
|
|
u64 start)
|
|
{
|
|
struct extent_buffer *eb, *exists = NULL;
|
|
int ret;
|
|
|
|
eb = find_extent_buffer(fs_info, start);
|
|
if (eb)
|
|
return eb;
|
|
eb = alloc_dummy_extent_buffer(fs_info, start);
|
|
if (!eb)
|
|
return NULL;
|
|
eb->fs_info = fs_info;
|
|
again:
|
|
ret = radix_tree_preload(GFP_NOFS);
|
|
if (ret)
|
|
goto free_eb;
|
|
spin_lock(&fs_info->buffer_lock);
|
|
ret = radix_tree_insert(&fs_info->buffer_radix,
|
|
start >> PAGE_SHIFT, eb);
|
|
spin_unlock(&fs_info->buffer_lock);
|
|
radix_tree_preload_end();
|
|
if (ret == -EEXIST) {
|
|
exists = find_extent_buffer(fs_info, start);
|
|
if (exists)
|
|
goto free_eb;
|
|
else
|
|
goto again;
|
|
}
|
|
check_buffer_tree_ref(eb);
|
|
set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
|
|
|
|
/*
|
|
* We will free dummy extent buffer's if they come into
|
|
* free_extent_buffer with a ref count of 2, but if we are using this we
|
|
* want the buffers to stay in memory until we're done with them, so
|
|
* bump the ref count again.
|
|
*/
|
|
atomic_inc(&eb->refs);
|
|
return eb;
|
|
free_eb:
|
|
btrfs_release_extent_buffer(eb);
|
|
return exists;
|
|
}
|
|
#endif
|
|
|
|
struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
|
|
u64 start)
|
|
{
|
|
unsigned long len = fs_info->nodesize;
|
|
int num_pages;
|
|
int i;
|
|
unsigned long index = start >> PAGE_SHIFT;
|
|
struct extent_buffer *eb;
|
|
struct extent_buffer *exists = NULL;
|
|
struct page *p;
|
|
struct address_space *mapping = fs_info->btree_inode->i_mapping;
|
|
int uptodate = 1;
|
|
int ret;
|
|
|
|
if (!IS_ALIGNED(start, fs_info->sectorsize)) {
|
|
btrfs_err(fs_info, "bad tree block start %llu", start);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
eb = find_extent_buffer(fs_info, start);
|
|
if (eb)
|
|
return eb;
|
|
|
|
eb = __alloc_extent_buffer(fs_info, start, len);
|
|
if (!eb)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
num_pages = num_extent_pages(eb);
|
|
for (i = 0; i < num_pages; i++, index++) {
|
|
p = find_or_create_page(mapping, index, GFP_NOFS|__GFP_NOFAIL);
|
|
if (!p) {
|
|
exists = ERR_PTR(-ENOMEM);
|
|
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);
|
|
put_page(p);
|
|
mark_extent_buffer_accessed(exists, p);
|
|
goto free_eb;
|
|
}
|
|
exists = NULL;
|
|
|
|
/*
|
|
* Do this so attach doesn't complain and we need to
|
|
* drop the ref the old guy had.
|
|
*/
|
|
ClearPagePrivate(p);
|
|
WARN_ON(PageDirty(p));
|
|
put_page(p);
|
|
}
|
|
attach_extent_buffer_page(eb, p);
|
|
spin_unlock(&mapping->private_lock);
|
|
WARN_ON(PageDirty(p));
|
|
eb->pages[i] = p;
|
|
if (!PageUptodate(p))
|
|
uptodate = 0;
|
|
|
|
/*
|
|
* We can't unlock the pages just yet since the extent buffer
|
|
* hasn't been properly inserted in the radix tree, this
|
|
* opens a race with btree_releasepage which can free a page
|
|
* while we are still filling in all pages for the buffer and
|
|
* we could crash.
|
|
*/
|
|
}
|
|
if (uptodate)
|
|
set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
|
|
again:
|
|
ret = radix_tree_preload(GFP_NOFS);
|
|
if (ret) {
|
|
exists = ERR_PTR(ret);
|
|
goto free_eb;
|
|
}
|
|
|
|
spin_lock(&fs_info->buffer_lock);
|
|
ret = radix_tree_insert(&fs_info->buffer_radix,
|
|
start >> PAGE_SHIFT, eb);
|
|
spin_unlock(&fs_info->buffer_lock);
|
|
radix_tree_preload_end();
|
|
if (ret == -EEXIST) {
|
|
exists = find_extent_buffer(fs_info, start);
|
|
if (exists)
|
|
goto free_eb;
|
|
else
|
|
goto again;
|
|
}
|
|
/* add one reference for the tree */
|
|
check_buffer_tree_ref(eb);
|
|
set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
|
|
|
|
/*
|
|
* Now it's safe to unlock the pages because any calls to
|
|
* btree_releasepage will correctly detect that a page belongs to a
|
|
* live buffer and won't free them prematurely.
|
|
*/
|
|
for (i = 0; i < num_pages; i++)
|
|
unlock_page(eb->pages[i]);
|
|
return eb;
|
|
|
|
free_eb:
|
|
WARN_ON(!atomic_dec_and_test(&eb->refs));
|
|
for (i = 0; i < num_pages; i++) {
|
|
if (eb->pages[i])
|
|
unlock_page(eb->pages[i]);
|
|
}
|
|
|
|
btrfs_release_extent_buffer(eb);
|
|
return exists;
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
static int release_extent_buffer(struct extent_buffer *eb)
|
|
{
|
|
lockdep_assert_held(&eb->refs_lock);
|
|
|
|
WARN_ON(atomic_read(&eb->refs) == 0);
|
|
if (atomic_dec_and_test(&eb->refs)) {
|
|
if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags)) {
|
|
struct btrfs_fs_info *fs_info = eb->fs_info;
|
|
|
|
spin_unlock(&eb->refs_lock);
|
|
|
|
spin_lock(&fs_info->buffer_lock);
|
|
radix_tree_delete(&fs_info->buffer_radix,
|
|
eb->start >> PAGE_SHIFT);
|
|
spin_unlock(&fs_info->buffer_lock);
|
|
} else {
|
|
spin_unlock(&eb->refs_lock);
|
|
}
|
|
|
|
/* Should be safe to release our pages at this point */
|
|
btrfs_release_extent_buffer_pages(eb);
|
|
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
|
|
if (unlikely(test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags))) {
|
|
__free_extent_buffer(eb);
|
|
return 1;
|
|
}
|
|
#endif
|
|
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_UNMAPPED, &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)
|
|
{
|
|
int i;
|
|
int num_pages;
|
|
struct page *page;
|
|
|
|
num_pages = num_extent_pages(eb);
|
|
|
|
for (i = 0; i < num_pages; i++) {
|
|
page = eb->pages[i];
|
|
if (!PageDirty(page))
|
|
continue;
|
|
|
|
lock_page(page);
|
|
WARN_ON(!PagePrivate(page));
|
|
|
|
clear_page_dirty_for_io(page);
|
|
xa_lock_irq(&page->mapping->i_pages);
|
|
if (!PageDirty(page)) {
|
|
radix_tree_tag_clear(&page->mapping->i_pages,
|
|
page_index(page),
|
|
PAGECACHE_TAG_DIRTY);
|
|
}
|
|
xa_unlock_irq(&page->mapping->i_pages);
|
|
ClearPageError(page);
|
|
unlock_page(page);
|
|
}
|
|
WARN_ON(atomic_read(&eb->refs) == 0);
|
|
}
|
|
|
|
int set_extent_buffer_dirty(struct extent_buffer *eb)
|
|
{
|
|
int i;
|
|
int 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);
|
|
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(eb->pages[i]);
|
|
return was_dirty;
|
|
}
|
|
|
|
void clear_extent_buffer_uptodate(struct extent_buffer *eb)
|
|
{
|
|
int i;
|
|
struct page *page;
|
|
int num_pages;
|
|
|
|
clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
|
|
num_pages = num_extent_pages(eb);
|
|
for (i = 0; i < num_pages; i++) {
|
|
page = eb->pages[i];
|
|
if (page)
|
|
ClearPageUptodate(page);
|
|
}
|
|
}
|
|
|
|
void set_extent_buffer_uptodate(struct extent_buffer *eb)
|
|
{
|
|
int i;
|
|
struct page *page;
|
|
int num_pages;
|
|
|
|
set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
|
|
num_pages = num_extent_pages(eb);
|
|
for (i = 0; i < num_pages; i++) {
|
|
page = eb->pages[i];
|
|
SetPageUptodate(page);
|
|
}
|
|
}
|
|
|
|
int read_extent_buffer_pages(struct extent_io_tree *tree,
|
|
struct extent_buffer *eb, int wait, int mirror_num)
|
|
{
|
|
int i;
|
|
struct page *page;
|
|
int err;
|
|
int ret = 0;
|
|
int locked_pages = 0;
|
|
int all_uptodate = 1;
|
|
int 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;
|
|
|
|
num_pages = num_extent_pages(eb);
|
|
for (i = 0; i < num_pages; i++) {
|
|
page = eb->pages[i];
|
|
if (wait == WAIT_NONE) {
|
|
if (!trylock_page(page))
|
|
goto unlock_exit;
|
|
} else {
|
|
lock_page(page);
|
|
}
|
|
locked_pages++;
|
|
}
|
|
/*
|
|
* We need to firstly lock all pages to make sure that
|
|
* the uptodate bit of our pages won't be affected by
|
|
* clear_extent_buffer_uptodate().
|
|
*/
|
|
for (i = 0; i < num_pages; i++) {
|
|
page = eb->pages[i];
|
|
if (!PageUptodate(page)) {
|
|
num_reads++;
|
|
all_uptodate = 0;
|
|
}
|
|
}
|
|
|
|
if (all_uptodate) {
|
|
set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
|
|
goto unlock_exit;
|
|
}
|
|
|
|
clear_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
|
|
eb->read_mirror = 0;
|
|
atomic_set(&eb->io_pages, num_reads);
|
|
for (i = 0; i < num_pages; i++) {
|
|
page = eb->pages[i];
|
|
|
|
if (!PageUptodate(page)) {
|
|
if (ret) {
|
|
atomic_dec(&eb->io_pages);
|
|
unlock_page(page);
|
|
continue;
|
|
}
|
|
|
|
ClearPageError(page);
|
|
err = __extent_read_full_page(tree, page,
|
|
btree_get_extent, &bio,
|
|
mirror_num, &bio_flags,
|
|
REQ_META);
|
|
if (err) {
|
|
ret = err;
|
|
/*
|
|
* We use &bio in above __extent_read_full_page,
|
|
* so we ensure that if it returns error, the
|
|
* current page fails to add itself to bio and
|
|
* it's been unlocked.
|
|
*
|
|
* We must dec io_pages by ourselves.
|
|
*/
|
|
atomic_dec(&eb->io_pages);
|
|
}
|
|
} else {
|
|
unlock_page(page);
|
|
}
|
|
}
|
|
|
|
if (bio) {
|
|
err = submit_one_bio(bio, mirror_num, bio_flags);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
if (ret || wait != WAIT_COMPLETE)
|
|
return ret;
|
|
|
|
for (i = 0; i < num_pages; i++) {
|
|
page = eb->pages[i];
|
|
wait_on_page_locked(page);
|
|
if (!PageUptodate(page))
|
|
ret = -EIO;
|
|
}
|
|
|
|
return ret;
|
|
|
|
unlock_exit:
|
|
while (locked_pages > 0) {
|
|
locked_pages--;
|
|
page = eb->pages[locked_pages];
|
|
unlock_page(page);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
void read_extent_buffer(const 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_SIZE - 1);
|
|
unsigned long i = (start_offset + start) >> PAGE_SHIFT;
|
|
|
|
if (start + len > eb->len) {
|
|
WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, wanted %lu %lu\n",
|
|
eb->start, eb->len, start, len);
|
|
memset(dst, 0, len);
|
|
return;
|
|
}
|
|
|
|
offset = (start_offset + start) & (PAGE_SIZE - 1);
|
|
|
|
while (len > 0) {
|
|
page = eb->pages[i];
|
|
|
|
cur = min(len, (PAGE_SIZE - offset));
|
|
kaddr = page_address(page);
|
|
memcpy(dst, kaddr + offset, cur);
|
|
|
|
dst += cur;
|
|
len -= cur;
|
|
offset = 0;
|
|
i++;
|
|
}
|
|
}
|
|
|
|
int read_extent_buffer_to_user(const struct extent_buffer *eb,
|
|
void __user *dstv,
|
|
unsigned long start, unsigned long len)
|
|
{
|
|
size_t cur;
|
|
size_t offset;
|
|
struct page *page;
|
|
char *kaddr;
|
|
char __user *dst = (char __user *)dstv;
|
|
size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
|
|
unsigned long i = (start_offset + start) >> PAGE_SHIFT;
|
|
int ret = 0;
|
|
|
|
WARN_ON(start > eb->len);
|
|
WARN_ON(start + len > eb->start + eb->len);
|
|
|
|
offset = (start_offset + start) & (PAGE_SIZE - 1);
|
|
|
|
while (len > 0) {
|
|
page = eb->pages[i];
|
|
|
|
cur = min(len, (PAGE_SIZE - offset));
|
|
kaddr = page_address(page);
|
|
if (copy_to_user(dst, kaddr + offset, cur)) {
|
|
ret = -EFAULT;
|
|
break;
|
|
}
|
|
|
|
dst += cur;
|
|
len -= cur;
|
|
offset = 0;
|
|
i++;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* return 0 if the item is found within a page.
|
|
* return 1 if the item spans two pages.
|
|
* return -EINVAL otherwise.
|
|
*/
|
|
int map_private_extent_buffer(const 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_SIZE - 1);
|
|
char *kaddr;
|
|
struct page *p;
|
|
size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
|
|
unsigned long i = (start_offset + start) >> PAGE_SHIFT;
|
|
unsigned long end_i = (start_offset + start + min_len - 1) >>
|
|
PAGE_SHIFT;
|
|
|
|
if (start + min_len > eb->len) {
|
|
WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, wanted %lu %lu\n",
|
|
eb->start, eb->len, start, min_len);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (i != end_i)
|
|
return 1;
|
|
|
|
if (i == 0) {
|
|
offset = start_offset;
|
|
*map_start = 0;
|
|
} else {
|
|
offset = 0;
|
|
*map_start = ((u64)i << PAGE_SHIFT) - start_offset;
|
|
}
|
|
|
|
p = eb->pages[i];
|
|
kaddr = page_address(p);
|
|
*map = kaddr + offset;
|
|
*map_len = PAGE_SIZE - offset;
|
|
return 0;
|
|
}
|
|
|
|
int memcmp_extent_buffer(const 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_SIZE - 1);
|
|
unsigned long i = (start_offset + start) >> PAGE_SHIFT;
|
|
int ret = 0;
|
|
|
|
WARN_ON(start > eb->len);
|
|
WARN_ON(start + len > eb->start + eb->len);
|
|
|
|
offset = (start_offset + start) & (PAGE_SIZE - 1);
|
|
|
|
while (len > 0) {
|
|
page = eb->pages[i];
|
|
|
|
cur = min(len, (PAGE_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_chunk_tree_uuid(struct extent_buffer *eb,
|
|
const void *srcv)
|
|
{
|
|
char *kaddr;
|
|
|
|
WARN_ON(!PageUptodate(eb->pages[0]));
|
|
kaddr = page_address(eb->pages[0]);
|
|
memcpy(kaddr + offsetof(struct btrfs_header, chunk_tree_uuid), srcv,
|
|
BTRFS_FSID_SIZE);
|
|
}
|
|
|
|
void write_extent_buffer_fsid(struct extent_buffer *eb, const void *srcv)
|
|
{
|
|
char *kaddr;
|
|
|
|
WARN_ON(!PageUptodate(eb->pages[0]));
|
|
kaddr = page_address(eb->pages[0]);
|
|
memcpy(kaddr + offsetof(struct btrfs_header, fsid), srcv,
|
|
BTRFS_FSID_SIZE);
|
|
}
|
|
|
|
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_SIZE - 1);
|
|
unsigned long i = (start_offset + start) >> PAGE_SHIFT;
|
|
|
|
WARN_ON(start > eb->len);
|
|
WARN_ON(start + len > eb->start + eb->len);
|
|
|
|
offset = (start_offset + start) & (PAGE_SIZE - 1);
|
|
|
|
while (len > 0) {
|
|
page = eb->pages[i];
|
|
WARN_ON(!PageUptodate(page));
|
|
|
|
cur = min(len, PAGE_SIZE - offset);
|
|
kaddr = page_address(page);
|
|
memcpy(kaddr + offset, src, cur);
|
|
|
|
src += cur;
|
|
len -= cur;
|
|
offset = 0;
|
|
i++;
|
|
}
|
|
}
|
|
|
|
void memzero_extent_buffer(struct extent_buffer *eb, 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_SIZE - 1);
|
|
unsigned long i = (start_offset + start) >> PAGE_SHIFT;
|
|
|
|
WARN_ON(start > eb->len);
|
|
WARN_ON(start + len > eb->start + eb->len);
|
|
|
|
offset = (start_offset + start) & (PAGE_SIZE - 1);
|
|
|
|
while (len > 0) {
|
|
page = eb->pages[i];
|
|
WARN_ON(!PageUptodate(page));
|
|
|
|
cur = min(len, PAGE_SIZE - offset);
|
|
kaddr = page_address(page);
|
|
memset(kaddr + offset, 0, cur);
|
|
|
|
len -= cur;
|
|
offset = 0;
|
|
i++;
|
|
}
|
|
}
|
|
|
|
void copy_extent_buffer_full(struct extent_buffer *dst,
|
|
struct extent_buffer *src)
|
|
{
|
|
int i;
|
|
int num_pages;
|
|
|
|
ASSERT(dst->len == src->len);
|
|
|
|
num_pages = num_extent_pages(dst);
|
|
for (i = 0; i < num_pages; i++)
|
|
copy_page(page_address(dst->pages[i]),
|
|
page_address(src->pages[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_SIZE - 1);
|
|
unsigned long i = (start_offset + dst_offset) >> PAGE_SHIFT;
|
|
|
|
WARN_ON(src->len != dst_len);
|
|
|
|
offset = (start_offset + dst_offset) &
|
|
(PAGE_SIZE - 1);
|
|
|
|
while (len > 0) {
|
|
page = dst->pages[i];
|
|
WARN_ON(!PageUptodate(page));
|
|
|
|
cur = min(len, (unsigned long)(PAGE_SIZE - offset));
|
|
|
|
kaddr = page_address(page);
|
|
read_extent_buffer(src, kaddr + offset, src_offset, cur);
|
|
|
|
src_offset += cur;
|
|
len -= cur;
|
|
offset = 0;
|
|
i++;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* eb_bitmap_offset() - calculate the page and offset of the byte containing the
|
|
* given bit number
|
|
* @eb: the extent buffer
|
|
* @start: offset of the bitmap item in the extent buffer
|
|
* @nr: bit number
|
|
* @page_index: return index of the page in the extent buffer that contains the
|
|
* given bit number
|
|
* @page_offset: return offset into the page given by page_index
|
|
*
|
|
* This helper hides the ugliness of finding the byte in an extent buffer which
|
|
* contains a given bit.
|
|
*/
|
|
static inline void eb_bitmap_offset(struct extent_buffer *eb,
|
|
unsigned long start, unsigned long nr,
|
|
unsigned long *page_index,
|
|
size_t *page_offset)
|
|
{
|
|
size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
|
|
size_t byte_offset = BIT_BYTE(nr);
|
|
size_t offset;
|
|
|
|
/*
|
|
* The byte we want is the offset of the extent buffer + the offset of
|
|
* the bitmap item in the extent buffer + the offset of the byte in the
|
|
* bitmap item.
|
|
*/
|
|
offset = start_offset + start + byte_offset;
|
|
|
|
*page_index = offset >> PAGE_SHIFT;
|
|
*page_offset = offset & (PAGE_SIZE - 1);
|
|
}
|
|
|
|
/**
|
|
* extent_buffer_test_bit - determine whether a bit in a bitmap item is set
|
|
* @eb: the extent buffer
|
|
* @start: offset of the bitmap item in the extent buffer
|
|
* @nr: bit number to test
|
|
*/
|
|
int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
|
|
unsigned long nr)
|
|
{
|
|
u8 *kaddr;
|
|
struct page *page;
|
|
unsigned long i;
|
|
size_t offset;
|
|
|
|
eb_bitmap_offset(eb, start, nr, &i, &offset);
|
|
page = eb->pages[i];
|
|
WARN_ON(!PageUptodate(page));
|
|
kaddr = page_address(page);
|
|
return 1U & (kaddr[offset] >> (nr & (BITS_PER_BYTE - 1)));
|
|
}
|
|
|
|
/**
|
|
* extent_buffer_bitmap_set - set an area of a bitmap
|
|
* @eb: the extent buffer
|
|
* @start: offset of the bitmap item in the extent buffer
|
|
* @pos: bit number of the first bit
|
|
* @len: number of bits to set
|
|
*/
|
|
void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
|
|
unsigned long pos, unsigned long len)
|
|
{
|
|
u8 *kaddr;
|
|
struct page *page;
|
|
unsigned long i;
|
|
size_t offset;
|
|
const unsigned int size = pos + len;
|
|
int bits_to_set = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
|
|
u8 mask_to_set = BITMAP_FIRST_BYTE_MASK(pos);
|
|
|
|
eb_bitmap_offset(eb, start, pos, &i, &offset);
|
|
page = eb->pages[i];
|
|
WARN_ON(!PageUptodate(page));
|
|
kaddr = page_address(page);
|
|
|
|
while (len >= bits_to_set) {
|
|
kaddr[offset] |= mask_to_set;
|
|
len -= bits_to_set;
|
|
bits_to_set = BITS_PER_BYTE;
|
|
mask_to_set = ~0;
|
|
if (++offset >= PAGE_SIZE && len > 0) {
|
|
offset = 0;
|
|
page = eb->pages[++i];
|
|
WARN_ON(!PageUptodate(page));
|
|
kaddr = page_address(page);
|
|
}
|
|
}
|
|
if (len) {
|
|
mask_to_set &= BITMAP_LAST_BYTE_MASK(size);
|
|
kaddr[offset] |= mask_to_set;
|
|
}
|
|
}
|
|
|
|
|
|
/**
|
|
* extent_buffer_bitmap_clear - clear an area of a bitmap
|
|
* @eb: the extent buffer
|
|
* @start: offset of the bitmap item in the extent buffer
|
|
* @pos: bit number of the first bit
|
|
* @len: number of bits to clear
|
|
*/
|
|
void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
|
|
unsigned long pos, unsigned long len)
|
|
{
|
|
u8 *kaddr;
|
|
struct page *page;
|
|
unsigned long i;
|
|
size_t offset;
|
|
const unsigned int size = pos + len;
|
|
int bits_to_clear = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
|
|
u8 mask_to_clear = BITMAP_FIRST_BYTE_MASK(pos);
|
|
|
|
eb_bitmap_offset(eb, start, pos, &i, &offset);
|
|
page = eb->pages[i];
|
|
WARN_ON(!PageUptodate(page));
|
|
kaddr = page_address(page);
|
|
|
|
while (len >= bits_to_clear) {
|
|
kaddr[offset] &= ~mask_to_clear;
|
|
len -= bits_to_clear;
|
|
bits_to_clear = BITS_PER_BYTE;
|
|
mask_to_clear = ~0;
|
|
if (++offset >= PAGE_SIZE && len > 0) {
|
|
offset = 0;
|
|
page = eb->pages[++i];
|
|
WARN_ON(!PageUptodate(page));
|
|
kaddr = page_address(page);
|
|
}
|
|
}
|
|
if (len) {
|
|
mask_to_clear &= BITMAP_LAST_BYTE_MASK(size);
|
|
kaddr[offset] &= ~mask_to_clear;
|
|
}
|
|
}
|
|
|
|
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)
|
|
{
|
|
struct btrfs_fs_info *fs_info = dst->fs_info;
|
|
size_t cur;
|
|
size_t dst_off_in_page;
|
|
size_t src_off_in_page;
|
|
size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
|
|
unsigned long dst_i;
|
|
unsigned long src_i;
|
|
|
|
if (src_offset + len > dst->len) {
|
|
btrfs_err(fs_info,
|
|
"memmove bogus src_offset %lu move len %lu dst len %lu",
|
|
src_offset, len, dst->len);
|
|
BUG_ON(1);
|
|
}
|
|
if (dst_offset + len > dst->len) {
|
|
btrfs_err(fs_info,
|
|
"memmove bogus dst_offset %lu move len %lu dst len %lu",
|
|
dst_offset, len, dst->len);
|
|
BUG_ON(1);
|
|
}
|
|
|
|
while (len > 0) {
|
|
dst_off_in_page = (start_offset + dst_offset) &
|
|
(PAGE_SIZE - 1);
|
|
src_off_in_page = (start_offset + src_offset) &
|
|
(PAGE_SIZE - 1);
|
|
|
|
dst_i = (start_offset + dst_offset) >> PAGE_SHIFT;
|
|
src_i = (start_offset + src_offset) >> PAGE_SHIFT;
|
|
|
|
cur = min(len, (unsigned long)(PAGE_SIZE -
|
|
src_off_in_page));
|
|
cur = min_t(unsigned long, cur,
|
|
(unsigned long)(PAGE_SIZE - dst_off_in_page));
|
|
|
|
copy_pages(dst->pages[dst_i], dst->pages[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)
|
|
{
|
|
struct btrfs_fs_info *fs_info = dst->fs_info;
|
|
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_SIZE - 1);
|
|
unsigned long dst_i;
|
|
unsigned long src_i;
|
|
|
|
if (src_offset + len > dst->len) {
|
|
btrfs_err(fs_info,
|
|
"memmove bogus src_offset %lu move len %lu len %lu",
|
|
src_offset, len, dst->len);
|
|
BUG_ON(1);
|
|
}
|
|
if (dst_offset + len > dst->len) {
|
|
btrfs_err(fs_info,
|
|
"memmove bogus dst_offset %lu move len %lu len %lu",
|
|
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_SHIFT;
|
|
src_i = (start_offset + src_end) >> PAGE_SHIFT;
|
|
|
|
dst_off_in_page = (start_offset + dst_end) &
|
|
(PAGE_SIZE - 1);
|
|
src_off_in_page = (start_offset + src_end) &
|
|
(PAGE_SIZE - 1);
|
|
|
|
cur = min_t(unsigned long, len, src_off_in_page + 1);
|
|
cur = min(cur, dst_off_in_page + 1);
|
|
copy_pages(dst->pages[dst_i], dst->pages[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 nobody 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);
|
|
}
|