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7247 lines
189 KiB
7247 lines
189 KiB
// 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 "misc.h" |
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#include "extent_io.h" |
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#include "extent-io-tree.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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#include "subpage.h" |
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#include "zoned.h" |
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#include "block-group.h" |
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|
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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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|
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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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|
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#ifdef CONFIG_BTRFS_DEBUG |
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static LIST_HEAD(states); |
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static DEFINE_SPINLOCK(leak_lock); |
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|
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static inline void btrfs_leak_debug_add(spinlock_t *lock, |
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struct list_head *new, |
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struct list_head *head) |
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{ |
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unsigned long flags; |
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|
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spin_lock_irqsave(lock, flags); |
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list_add(new, head); |
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spin_unlock_irqrestore(lock, flags); |
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} |
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|
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static inline void btrfs_leak_debug_del(spinlock_t *lock, |
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struct list_head *entry) |
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{ |
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unsigned long flags; |
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|
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spin_lock_irqsave(lock, flags); |
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list_del(entry); |
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spin_unlock_irqrestore(lock, flags); |
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} |
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|
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void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info) |
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{ |
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struct extent_buffer *eb; |
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unsigned long flags; |
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|
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/* |
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* If we didn't get into open_ctree our allocated_ebs will not be |
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* initialized, so just skip this. |
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*/ |
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if (!fs_info->allocated_ebs.next) |
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return; |
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|
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spin_lock_irqsave(&fs_info->eb_leak_lock, flags); |
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while (!list_empty(&fs_info->allocated_ebs)) { |
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eb = list_first_entry(&fs_info->allocated_ebs, |
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struct extent_buffer, leak_list); |
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pr_err( |
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"BTRFS: buffer leak start %llu len %lu refs %d bflags %lu owner %llu\n", |
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eb->start, eb->len, atomic_read(&eb->refs), eb->bflags, |
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btrfs_header_owner(eb)); |
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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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spin_unlock_irqrestore(&fs_info->eb_leak_lock, flags); |
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} |
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|
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static inline void btrfs_extent_state_leak_debug_check(void) |
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{ |
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struct extent_state *state; |
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|
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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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} |
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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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struct inode *inode = tree->private_data; |
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u64 isize; |
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|
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if (!inode || !is_data_inode(inode)) |
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return; |
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|
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isize = i_size_read(inode); |
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if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) { |
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btrfs_debug_rl(BTRFS_I(inode)->root->fs_info, |
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"%s: ino %llu isize %llu odd range [%llu,%llu]", |
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caller, btrfs_ino(BTRFS_I(inode)), isize, start, end); |
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} |
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} |
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#else |
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#define btrfs_leak_debug_add(lock, new, head) do {} while (0) |
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#define btrfs_leak_debug_del(lock, entry) do {} while (0) |
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#define btrfs_extent_state_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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|
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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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|
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struct extent_page_data { |
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struct btrfs_bio_ctrl bio_ctrl; |
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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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|
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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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|
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static int add_extent_changeset(struct extent_state *state, u32 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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|
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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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|
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int __must_check submit_one_bio(struct bio *bio, int mirror_num, |
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unsigned long bio_flags) |
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{ |
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blk_status_t ret = 0; |
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struct extent_io_tree *tree = bio->bi_private; |
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|
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bio->bi_private = NULL; |
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|
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if (is_data_inode(tree->private_data)) |
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ret = btrfs_submit_data_bio(tree->private_data, bio, mirror_num, |
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bio_flags); |
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else |
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ret = btrfs_submit_metadata_bio(tree->private_data, bio, |
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mirror_num, bio_flags); |
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|
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return blk_status_to_errno(ret); |
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} |
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|
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/* Cleanup unsubmitted bios */ |
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static void end_write_bio(struct extent_page_data *epd, int ret) |
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{ |
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struct bio *bio = epd->bio_ctrl.bio; |
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|
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if (bio) { |
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bio->bi_status = errno_to_blk_status(ret); |
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bio_endio(bio); |
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epd->bio_ctrl.bio = NULL; |
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} |
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} |
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|
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/* |
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* Submit bio from extent page data via submit_one_bio |
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* |
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* Return 0 if everything is OK. |
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* Return <0 for error. |
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*/ |
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static int __must_check flush_write_bio(struct extent_page_data *epd) |
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{ |
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int ret = 0; |
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struct bio *bio = epd->bio_ctrl.bio; |
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|
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if (bio) { |
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ret = submit_one_bio(bio, 0, 0); |
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/* |
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* Clean up of epd->bio is handled by its endio function. |
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* And endio is either triggered by successful bio execution |
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* or the error handler of submit bio hook. |
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* So at this point, no matter what happened, we don't need |
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* to clean up epd->bio. |
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*/ |
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epd->bio_ctrl.bio = NULL; |
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} |
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return ret; |
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} |
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|
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int __init extent_state_cache_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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return 0; |
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} |
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|
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int __init extent_io_init(void) |
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{ |
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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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return -ENOMEM; |
|
|
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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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|
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if (bioset_integrity_create(&btrfs_bioset, BIO_POOL_SIZE)) |
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goto free_bioset; |
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|
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return 0; |
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|
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free_bioset: |
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bioset_exit(&btrfs_bioset); |
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|
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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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return -ENOMEM; |
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} |
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|
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void __cold extent_state_cache_exit(void) |
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{ |
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btrfs_extent_state_leak_debug_check(); |
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kmem_cache_destroy(extent_state_cache); |
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} |
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|
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void __cold extent_io_exit(void) |
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{ |
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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_buffer_cache); |
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bioset_exit(&btrfs_bioset); |
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} |
|
|
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/* |
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* For the file_extent_tree, we want to hold the inode lock when we lookup and |
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* update the disk_i_size, but lockdep will complain because our io_tree we hold |
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* the tree lock and get the inode lock when setting delalloc. These two things |
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* are unrelated, so make a class for the file_extent_tree so we don't get the |
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* two locking patterns mixed up. |
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*/ |
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static struct lock_class_key file_extent_tree_class; |
|
|
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void extent_io_tree_init(struct btrfs_fs_info *fs_info, |
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struct extent_io_tree *tree, unsigned int owner, |
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void *private_data) |
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{ |
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tree->fs_info = fs_info; |
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tree->state = RB_ROOT; |
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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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tree->owner = owner; |
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if (owner == IO_TREE_INODE_FILE_EXTENT) |
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lockdep_set_class(&tree->lock, &file_extent_tree_class); |
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} |
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|
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void extent_io_tree_release(struct extent_io_tree *tree) |
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{ |
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spin_lock(&tree->lock); |
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/* |
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* Do a single barrier for the waitqueue_active check here, the state |
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* of the waitqueue should not change once extent_io_tree_release is |
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* called. |
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*/ |
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smp_mb(); |
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while (!RB_EMPTY_ROOT(&tree->state)) { |
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struct rb_node *node; |
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struct extent_state *state; |
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|
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node = rb_first(&tree->state); |
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state = rb_entry(node, struct extent_state, rb_node); |
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rb_erase(&state->rb_node, &tree->state); |
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RB_CLEAR_NODE(&state->rb_node); |
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/* |
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* btree io trees aren't supposed to have tasks waiting for |
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* changes in the flags of extent states ever. |
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*/ |
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ASSERT(!waitqueue_active(&state->wq)); |
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free_extent_state(state); |
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|
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cond_resched_lock(&tree->lock); |
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} |
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spin_unlock(&tree->lock); |
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} |
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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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/* |
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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(&leak_lock, &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)) { |
|
WARN_ON(extent_state_in_tree(state)); |
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btrfs_leak_debug_del(&leak_lock, &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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|
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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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|
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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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} |
|
|
|
do_insert: |
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rb_link_node(node, parent, p); |
|
rb_insert_color(node, root); |
|
return NULL; |
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} |
|
|
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/** |
|
* Search @tree for an entry that contains @offset. Such entry would have |
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* entry->start <= offset && entry->end >= offset. |
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* |
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* @tree: the tree to search |
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* @offset: offset that should fall within an entry in @tree |
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* @next_ret: pointer to the first entry whose range ends after @offset |
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* @prev_ret: pointer to the first entry whose range begins before @offset |
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* @p_ret: pointer where new node should be anchored (used when inserting an |
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* entry in the tree) |
|
* @parent_ret: points to entry which would have been the parent of the entry, |
|
* containing @offset |
|
* |
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* This function returns a pointer to the entry that contains @offset byte |
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* address. If no such entry exists, then NULL is returned and the other |
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* pointer arguments to the function are filled, otherwise the found entry is |
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* returned and other pointers are left untouched. |
|
*/ |
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static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset, |
|
struct rb_node **next_ret, |
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struct rb_node **prev_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); |
|
prev_entry = entry; |
|
|
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if (offset < entry->start) |
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n = &(*n)->rb_left; |
|
else if (offset > entry->end) |
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n = &(*n)->rb_right; |
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else |
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return *n; |
|
} |
|
|
|
if (p_ret) |
|
*p_ret = n; |
|
if (parent_ret) |
|
*parent_ret = prev; |
|
|
|
if (next_ret) { |
|
orig_prev = prev; |
|
while (prev && offset > prev_entry->end) { |
|
prev = rb_next(prev); |
|
prev_entry = rb_entry(prev, struct tree_entry, rb_node); |
|
} |
|
*next_ret = prev; |
|
prev = orig_prev; |
|
} |
|
|
|
if (prev_ret) { |
|
prev_entry = rb_entry(prev, struct tree_entry, rb_node); |
|
while (prev && offset < prev_entry->start) { |
|
prev = rb_prev(prev); |
|
prev_entry = rb_entry(prev, struct tree_entry, rb_node); |
|
} |
|
*prev_ret = prev; |
|
} |
|
return NULL; |
|
} |
|
|
|
static inline struct rb_node * |
|
tree_search_for_insert(struct extent_io_tree *tree, |
|
u64 offset, |
|
struct rb_node ***p_ret, |
|
struct rb_node **parent_ret) |
|
{ |
|
struct rb_node *next= NULL; |
|
struct rb_node *ret; |
|
|
|
ret = __etree_search(tree, offset, &next, NULL, p_ret, parent_ret); |
|
if (!ret) |
|
return next; |
|
return ret; |
|
} |
|
|
|
static inline struct rb_node *tree_search(struct extent_io_tree *tree, |
|
u64 offset) |
|
{ |
|
return tree_search_for_insert(tree, offset, NULL, NULL); |
|
} |
|
|
|
/* |
|
* utility function to look for merge candidates inside a given range. |
|
* Any extents with matching state are merged together into a single |
|
* extent in the tree. Extents with EXTENT_IO in their state field |
|
* are not merged because the end_io handlers need to be able to do |
|
* operations on them without sleeping (or doing allocations/splits). |
|
* |
|
* This should be called with the tree lock held. |
|
*/ |
|
static void merge_state(struct extent_io_tree *tree, |
|
struct extent_state *state) |
|
{ |
|
struct extent_state *other; |
|
struct rb_node *other_node; |
|
|
|
if (state->state & (EXTENT_LOCKED | EXTENT_BOUNDARY)) |
|
return; |
|
|
|
other_node = rb_prev(&state->rb_node); |
|
if (other_node) { |
|
other = rb_entry(other_node, struct extent_state, rb_node); |
|
if (other->end == state->start - 1 && |
|
other->state == state->state) { |
|
if (tree->private_data && |
|
is_data_inode(tree->private_data)) |
|
btrfs_merge_delalloc_extent(tree->private_data, |
|
state, other); |
|
state->start = other->start; |
|
rb_erase(&other->rb_node, &tree->state); |
|
RB_CLEAR_NODE(&other->rb_node); |
|
free_extent_state(other); |
|
} |
|
} |
|
other_node = rb_next(&state->rb_node); |
|
if (other_node) { |
|
other = rb_entry(other_node, struct extent_state, rb_node); |
|
if (other->start == state->end + 1 && |
|
other->state == state->state) { |
|
if (tree->private_data && |
|
is_data_inode(tree->private_data)) |
|
btrfs_merge_delalloc_extent(tree->private_data, |
|
state, other); |
|
state->end = other->end; |
|
rb_erase(&other->rb_node, &tree->state); |
|
RB_CLEAR_NODE(&other->rb_node); |
|
free_extent_state(other); |
|
} |
|
} |
|
} |
|
|
|
static void set_state_bits(struct extent_io_tree *tree, |
|
struct extent_state *state, u32 *bits, |
|
struct extent_changeset *changeset); |
|
|
|
/* |
|
* insert an extent_state struct into the tree. 'bits' are set on the |
|
* struct before it is inserted. |
|
* |
|
* This may return -EEXIST if the extent is already there, in which case the |
|
* state struct is freed. |
|
* |
|
* The tree lock is not taken internally. This is a utility function and |
|
* probably isn't what you want to call (see set/clear_extent_bit). |
|
*/ |
|
static int insert_state(struct extent_io_tree *tree, |
|
struct extent_state *state, u64 start, u64 end, |
|
struct rb_node ***p, |
|
struct rb_node **parent, |
|
u32 *bits, struct extent_changeset *changeset) |
|
{ |
|
struct rb_node *node; |
|
|
|
if (end < start) { |
|
btrfs_err(tree->fs_info, |
|
"insert state: end < start %llu %llu", end, start); |
|
WARN_ON(1); |
|
} |
|
state->start = start; |
|
state->end = end; |
|
|
|
set_state_bits(tree, state, bits, changeset); |
|
|
|
node = tree_insert(&tree->state, NULL, end, &state->rb_node, p, parent); |
|
if (node) { |
|
struct extent_state *found; |
|
found = rb_entry(node, struct extent_state, rb_node); |
|
btrfs_err(tree->fs_info, |
|
"found node %llu %llu on insert of %llu %llu", |
|
found->start, found->end, start, end); |
|
return -EEXIST; |
|
} |
|
merge_state(tree, state); |
|
return 0; |
|
} |
|
|
|
/* |
|
* split a given extent state struct in two, inserting the preallocated |
|
* struct 'prealloc' as the newly created second half. 'split' indicates an |
|
* offset inside 'orig' where it should be split. |
|
* |
|
* Before calling, |
|
* the tree has 'orig' at [orig->start, orig->end]. After calling, there |
|
* are two extent state structs in the tree: |
|
* prealloc: [orig->start, split - 1] |
|
* orig: [ split, orig->end ] |
|
* |
|
* The tree locks are not taken by this function. They need to be held |
|
* by the caller. |
|
*/ |
|
static int split_state(struct extent_io_tree *tree, struct extent_state *orig, |
|
struct extent_state *prealloc, u64 split) |
|
{ |
|
struct rb_node *node; |
|
|
|
if (tree->private_data && is_data_inode(tree->private_data)) |
|
btrfs_split_delalloc_extent(tree->private_data, orig, split); |
|
|
|
prealloc->start = orig->start; |
|
prealloc->end = split - 1; |
|
prealloc->state = orig->state; |
|
orig->start = split; |
|
|
|
node = tree_insert(&tree->state, &orig->rb_node, prealloc->end, |
|
&prealloc->rb_node, NULL, NULL); |
|
if (node) { |
|
free_extent_state(prealloc); |
|
return -EEXIST; |
|
} |
|
return 0; |
|
} |
|
|
|
static struct extent_state *next_state(struct extent_state *state) |
|
{ |
|
struct rb_node *next = rb_next(&state->rb_node); |
|
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 anyone 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, |
|
u32 *bits, int wake, |
|
struct extent_changeset *changeset) |
|
{ |
|
struct extent_state *next; |
|
u32 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; |
|
} |
|
|
|
if (tree->private_data && is_data_inode(tree->private_data)) |
|
btrfs_clear_delalloc_extent(tree->private_data, 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) |
|
{ |
|
btrfs_panic(tree->fs_info, 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, |
|
u32 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); |
|
trace_btrfs_clear_extent_bit(tree, start, end - start + 1, bits); |
|
|
|
if (bits & EXTENT_DELALLOC) |
|
bits |= EXTENT_NORESERVE; |
|
|
|
if (delete) |
|
bits |= ~EXTENT_CTLBITS; |
|
|
|
if (bits & (EXTENT_LOCKED | 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, |
|
u32 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, |
|
u32 *bits, struct extent_changeset *changeset) |
|
{ |
|
u32 bits_to_set = *bits & ~EXTENT_CTLBITS; |
|
int ret; |
|
|
|
if (tree->private_data && is_data_inode(tree->private_data)) |
|
btrfs_set_delalloc_extent(tree->private_data, 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_LOCKED | 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. |
|
*/ |
|
int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, u32 bits, |
|
u32 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); |
|
trace_btrfs_set_extent_bit(tree, start, end - start + 1, bits); |
|
|
|
if (exclusive_bits) |
|
ASSERT(failed_start); |
|
else |
|
ASSERT(failed_start == NULL); |
|
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; |
|
} |
|
|
|
/* |
|
* If this extent already has all the bits we want set, then |
|
* skip it, not necessary to split it or do anything with it. |
|
*/ |
|
if ((state->state & bits) == bits) { |
|
start = state->end + 1; |
|
cache_state(state, cached_state); |
|
goto search_again; |
|
} |
|
|
|
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; |
|
|
|
} |
|
|
|
/** |
|
* 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, |
|
u32 bits, u32 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); |
|
trace_btrfs_convert_extent_bit(tree, start, end - start + 1, bits, |
|
clear_bits); |
|
|
|
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, |
|
u32 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 set_extent_bits_nowait(struct extent_io_tree *tree, u64 start, u64 end, |
|
u32 bits) |
|
{ |
|
return set_extent_bit(tree, start, end, bits, 0, NULL, NULL, |
|
GFP_NOWAIT, NULL); |
|
} |
|
|
|
int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, |
|
u32 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, |
|
u32 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, u32 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 one or more @bits set. |
|
* |
|
* Note: If there are multiple bits set in @bits, any of them will match. |
|
* |
|
* Return 0 if we find something, and update @start_ret and @end_ret. |
|
* Return 1 if we found nothing. |
|
*/ |
|
int find_first_extent_bit(struct extent_io_tree *tree, u64 start, |
|
u64 *start_ret, u64 *end_ret, u32 bits, |
|
struct extent_state **cached_state) |
|
{ |
|
struct extent_state *state; |
|
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)) { |
|
while ((state = next_state(state)) != NULL) { |
|
if (state->state & bits) |
|
goto got_it; |
|
} |
|
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 area of bits |
|
* |
|
* @tree: io tree to check |
|
* @start: offset to start the search from |
|
* @start_ret: the first offset we found with the bits set |
|
* @end_ret: the final contiguous range of the bits that were set |
|
* @bits: bits to look for |
|
* |
|
* set_extent_bit and clear_extent_bit can temporarily split contiguous ranges |
|
* to set bits appropriately, and then merge them again. During this time it |
|
* will drop the tree->lock, so use this helper if you want to find the actual |
|
* contiguous area for given bits. We will search to the first bit we find, and |
|
* then walk down the tree until we find a non-contiguous area. The area |
|
* returned will be the full contiguous area with the bits set. |
|
*/ |
|
int find_contiguous_extent_bit(struct extent_io_tree *tree, u64 start, |
|
u64 *start_ret, u64 *end_ret, u32 bits) |
|
{ |
|
struct extent_state *state; |
|
int ret = 1; |
|
|
|
spin_lock(&tree->lock); |
|
state = find_first_extent_bit_state(tree, start, bits); |
|
if (state) { |
|
*start_ret = state->start; |
|
*end_ret = state->end; |
|
while ((state = next_state(state)) != NULL) { |
|
if (state->start > (*end_ret + 1)) |
|
break; |
|
*end_ret = state->end; |
|
} |
|
ret = 0; |
|
} |
|
spin_unlock(&tree->lock); |
|
return ret; |
|
} |
|
|
|
/** |
|
* Find the first range that has @bits not set. This range could start before |
|
* @start. |
|
* |
|
* @tree: the tree to search |
|
* @start: offset at/after which the found extent should start |
|
* @start_ret: records the beginning of the range |
|
* @end_ret: records the end of the range (inclusive) |
|
* @bits: the set of bits which must be unset |
|
* |
|
* Since unallocated range is also considered one which doesn't have the bits |
|
* set it's possible that @end_ret contains -1, this happens in case the range |
|
* spans (last_range_end, end of device]. In this case it's up to the caller to |
|
* trim @end_ret to the appropriate size. |
|
*/ |
|
void find_first_clear_extent_bit(struct extent_io_tree *tree, u64 start, |
|
u64 *start_ret, u64 *end_ret, u32 bits) |
|
{ |
|
struct extent_state *state; |
|
struct rb_node *node, *prev = NULL, *next; |
|
|
|
spin_lock(&tree->lock); |
|
|
|
/* Find first extent with bits cleared */ |
|
while (1) { |
|
node = __etree_search(tree, start, &next, &prev, NULL, NULL); |
|
if (!node && !next && !prev) { |
|
/* |
|
* Tree is completely empty, send full range and let |
|
* caller deal with it |
|
*/ |
|
*start_ret = 0; |
|
*end_ret = -1; |
|
goto out; |
|
} else if (!node && !next) { |
|
/* |
|
* We are past the last allocated chunk, set start at |
|
* the end of the last extent. |
|
*/ |
|
state = rb_entry(prev, struct extent_state, rb_node); |
|
*start_ret = state->end + 1; |
|
*end_ret = -1; |
|
goto out; |
|
} else if (!node) { |
|
node = next; |
|
} |
|
/* |
|
* At this point 'node' either contains 'start' or start is |
|
* before 'node' |
|
*/ |
|
state = rb_entry(node, struct extent_state, rb_node); |
|
|
|
if (in_range(start, state->start, state->end - state->start + 1)) { |
|
if (state->state & bits) { |
|
/* |
|
* |--range with bits sets--| |
|
* | |
|
* start |
|
*/ |
|
start = state->end + 1; |
|
} else { |
|
/* |
|
* 'start' falls within a range that doesn't |
|
* have the bits set, so take its start as |
|
* the beginning of the desired range |
|
* |
|
* |--range with bits cleared----| |
|
* | |
|
* start |
|
*/ |
|
*start_ret = state->start; |
|
break; |
|
} |
|
} else { |
|
/* |
|
* |---prev range---|---hole/unset---|---node range---| |
|
* | |
|
* start |
|
* |
|
* or |
|
* |
|
* |---hole/unset--||--first node--| |
|
* 0 | |
|
* start |
|
*/ |
|
if (prev) { |
|
state = rb_entry(prev, struct extent_state, |
|
rb_node); |
|
*start_ret = state->end + 1; |
|
} else { |
|
*start_ret = 0; |
|
} |
|
break; |
|
} |
|
} |
|
|
|
/* |
|
* Find the longest stretch from start until an entry which has the |
|
* bits set |
|
*/ |
|
while (1) { |
|
state = rb_entry(node, struct extent_state, rb_node); |
|
if (state->end >= start && !(state->state & bits)) { |
|
*end_ret = state->end; |
|
} else { |
|
*end_ret = state->start - 1; |
|
break; |
|
} |
|
|
|
node = rb_next(node); |
|
if (!node) |
|
break; |
|
} |
|
out: |
|
spin_unlock(&tree->lock); |
|
} |
|
|
|
/* |
|
* 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, |
|
* |
|
* true is returned if we find something, false if nothing was in the tree |
|
*/ |
|
bool btrfs_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; |
|
bool found = false; |
|
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) { |
|
*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 = true; |
|
*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; |
|
} |
|
|
|
/* |
|
* Process one page for __process_pages_contig(). |
|
* |
|
* Return >0 if we hit @page == @locked_page. |
|
* Return 0 if we updated the page status. |
|
* Return -EGAIN if the we need to try again. |
|
* (For PAGE_LOCK case but got dirty page or page not belong to mapping) |
|
*/ |
|
static int process_one_page(struct btrfs_fs_info *fs_info, |
|
struct address_space *mapping, |
|
struct page *page, struct page *locked_page, |
|
unsigned long page_ops, u64 start, u64 end) |
|
{ |
|
u32 len; |
|
|
|
ASSERT(end + 1 - start != 0 && end + 1 - start < U32_MAX); |
|
len = end + 1 - start; |
|
|
|
if (page_ops & PAGE_SET_ORDERED) |
|
btrfs_page_clamp_set_ordered(fs_info, page, start, len); |
|
if (page_ops & PAGE_SET_ERROR) |
|
btrfs_page_clamp_set_error(fs_info, page, start, len); |
|
if (page_ops & PAGE_START_WRITEBACK) { |
|
btrfs_page_clamp_clear_dirty(fs_info, page, start, len); |
|
btrfs_page_clamp_set_writeback(fs_info, page, start, len); |
|
} |
|
if (page_ops & PAGE_END_WRITEBACK) |
|
btrfs_page_clamp_clear_writeback(fs_info, page, start, len); |
|
|
|
if (page == locked_page) |
|
return 1; |
|
|
|
if (page_ops & PAGE_LOCK) { |
|
int ret; |
|
|
|
ret = btrfs_page_start_writer_lock(fs_info, page, start, len); |
|
if (ret) |
|
return ret; |
|
if (!PageDirty(page) || page->mapping != mapping) { |
|
btrfs_page_end_writer_lock(fs_info, page, start, len); |
|
return -EAGAIN; |
|
} |
|
} |
|
if (page_ops & PAGE_UNLOCK) |
|
btrfs_page_end_writer_lock(fs_info, page, start, len); |
|
return 0; |
|
} |
|
|
|
static int __process_pages_contig(struct address_space *mapping, |
|
struct page *locked_page, |
|
u64 start, u64 end, unsigned long page_ops, |
|
u64 *processed_end) |
|
{ |
|
struct btrfs_fs_info *fs_info = btrfs_sb(mapping->host->i_sb); |
|
pgoff_t start_index = start >> PAGE_SHIFT; |
|
pgoff_t end_index = end >> PAGE_SHIFT; |
|
pgoff_t index = start_index; |
|
unsigned long nr_pages = end_index - start_index + 1; |
|
unsigned long pages_processed = 0; |
|
struct page *pages[16]; |
|
int err = 0; |
|
int i; |
|
|
|
if (page_ops & PAGE_LOCK) { |
|
ASSERT(page_ops == PAGE_LOCK); |
|
ASSERT(processed_end && *processed_end == start); |
|
} |
|
|
|
if ((page_ops & PAGE_SET_ERROR) && nr_pages > 0) |
|
mapping_set_error(mapping, -EIO); |
|
|
|
while (nr_pages > 0) { |
|
int found_pages; |
|
|
|
found_pages = find_get_pages_contig(mapping, index, |
|
min_t(unsigned long, |
|
nr_pages, ARRAY_SIZE(pages)), pages); |
|
if (found_pages == 0) { |
|
/* |
|
* Only if we're going to lock these pages, we can find |
|
* nothing at @index. |
|
*/ |
|
ASSERT(page_ops & PAGE_LOCK); |
|
err = -EAGAIN; |
|
goto out; |
|
} |
|
|
|
for (i = 0; i < found_pages; i++) { |
|
int process_ret; |
|
|
|
process_ret = process_one_page(fs_info, mapping, |
|
pages[i], locked_page, page_ops, |
|
start, end); |
|
if (process_ret < 0) { |
|
for (; i < found_pages; i++) |
|
put_page(pages[i]); |
|
err = -EAGAIN; |
|
goto out; |
|
} |
|
put_page(pages[i]); |
|
pages_processed++; |
|
} |
|
nr_pages -= found_pages; |
|
index += found_pages; |
|
cond_resched(); |
|
} |
|
out: |
|
if (err && processed_end) { |
|
/* |
|
* Update @processed_end. I know this is awful since it has |
|
* two different return value patterns (inclusive vs exclusive). |
|
* |
|
* But the exclusive pattern is necessary if @start is 0, or we |
|
* underflow and check against processed_end won't work as |
|
* expected. |
|
*/ |
|
if (pages_processed) |
|
*processed_end = min(end, |
|
((u64)(start_index + pages_processed) << PAGE_SHIFT) - 1); |
|
else |
|
*processed_end = start; |
|
} |
|
return err; |
|
} |
|
|
|
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, start, end, |
|
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 end_index = delalloc_end >> PAGE_SHIFT; |
|
u64 processed_end = delalloc_start; |
|
int ret; |
|
|
|
ASSERT(locked_page); |
|
if (index == locked_page->index && index == end_index) |
|
return 0; |
|
|
|
ret = __process_pages_contig(inode->i_mapping, locked_page, delalloc_start, |
|
delalloc_end, PAGE_LOCK, &processed_end); |
|
if (ret == -EAGAIN && processed_end > delalloc_start) |
|
__unlock_for_delalloc(inode, locked_page, delalloc_start, |
|
processed_end); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Find and lock a contiguous range of bytes in the file marked as delalloc, no |
|
* more than @max_bytes. @Start and @end are used to return the range, |
|
* |
|
* Return: true if we find something |
|
* false if nothing was in the tree |
|
*/ |
|
EXPORT_FOR_TESTS |
|
noinline_for_stack bool find_lock_delalloc_range(struct inode *inode, |
|
struct page *locked_page, u64 *start, |
|
u64 *end) |
|
{ |
|
struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree; |
|
u64 max_bytes = BTRFS_MAX_EXTENT_SIZE; |
|
u64 delalloc_start; |
|
u64 delalloc_end; |
|
bool 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 = btrfs_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 false; |
|
} |
|
|
|
/* |
|
* 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); |
|
ASSERT(!ret || ret == -EAGAIN); |
|
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 = false; |
|
goto out_failed; |
|
} |
|
} |
|
|
|
/* 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; |
|
} |
|
|
|
void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end, |
|
struct page *locked_page, |
|
u32 clear_bits, unsigned long page_ops) |
|
{ |
|
clear_extent_bit(&inode->io_tree, start, end, clear_bits, 1, 0, NULL); |
|
|
|
__process_pages_contig(inode->vfs_inode.i_mapping, locked_page, |
|
start, end, 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, |
|
u32 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. |
|
*/ |
|
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; |
|
} |
|
|
|
struct io_failure_record *get_state_failrec(struct extent_io_tree *tree, u64 start) |
|
{ |
|
struct rb_node *node; |
|
struct extent_state *state; |
|
struct io_failure_record *failrec; |
|
|
|
spin_lock(&tree->lock); |
|
/* |
|
* this search will find all the extents that end after |
|
* our range starts. |
|
*/ |
|
node = tree_search(tree, start); |
|
if (!node) { |
|
failrec = ERR_PTR(-ENOENT); |
|
goto out; |
|
} |
|
state = rb_entry(node, struct extent_state, rb_node); |
|
if (state->start != start) { |
|
failrec = ERR_PTR(-ENOENT); |
|
goto out; |
|
} |
|
|
|
failrec = state->failrec; |
|
out: |
|
spin_unlock(&tree->lock); |
|
return failrec; |
|
} |
|
|
|
/* |
|
* 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, |
|
u32 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); |
|
|
|
if (btrfs_is_zoned(fs_info)) |
|
return btrfs_repair_one_zone(fs_info, logical); |
|
|
|
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 btrfs_repair_eb_io_failure(const struct extent_buffer *eb, int mirror_num) |
|
{ |
|
struct btrfs_fs_info *fs_info = eb->fs_info; |
|
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; |
|
|
|
failrec = get_state_failrec(failure_tree, start); |
|
if (IS_ERR(failrec)) |
|
return 0; |
|
|
|
BUG_ON(!failrec->this_mirror); |
|
|
|
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); |
|
} |
|
|
|
static struct io_failure_record *btrfs_get_io_failure_record(struct inode *inode, |
|
u64 start) |
|
{ |
|
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; |
|
const u32 sectorsize = fs_info->sectorsize; |
|
int ret; |
|
u64 logical; |
|
|
|
failrec = get_state_failrec(failure_tree, start); |
|
if (!IS_ERR(failrec)) { |
|
btrfs_debug(fs_info, |
|
"Get IO Failure Record: (found) logical=%llu, start=%llu, len=%llu", |
|
failrec->logical, failrec->start, failrec->len); |
|
/* |
|
* 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. |
|
*/ |
|
|
|
return failrec; |
|
} |
|
|
|
failrec = kzalloc(sizeof(*failrec), GFP_NOFS); |
|
if (!failrec) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
failrec->start = start; |
|
failrec->len = sectorsize; |
|
failrec->this_mirror = 0; |
|
failrec->bio_flags = 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 ERR_PTR(-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 ERR_PTR(-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, start + sectorsize - 1, |
|
EXTENT_LOCKED | EXTENT_DIRTY); |
|
if (ret >= 0) { |
|
ret = set_state_failrec(failure_tree, start, failrec); |
|
/* Set the bits in the inode's tree */ |
|
ret = set_extent_bits(tree, start, start + sectorsize - 1, |
|
EXTENT_DAMAGED); |
|
} else if (ret < 0) { |
|
kfree(failrec); |
|
return ERR_PTR(ret); |
|
} |
|
|
|
return failrec; |
|
} |
|
|
|
static bool btrfs_check_repairable(struct inode *inode, |
|
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; |
|
} |
|
|
|
/* The failure record should only contain one sector */ |
|
ASSERT(failrec->len == fs_info->sectorsize); |
|
|
|
/* |
|
* There are two premises: |
|
* a) deliver good data to the caller |
|
* b) correct the bad sectors on disk |
|
* |
|
* Since we're only doing repair for one sector, we only need to 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. |
|
*/ |
|
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; |
|
} |
|
|
|
int btrfs_repair_one_sector(struct inode *inode, |
|
struct bio *failed_bio, u32 bio_offset, |
|
struct page *page, unsigned int pgoff, |
|
u64 start, int failed_mirror, |
|
submit_bio_hook_t *submit_bio_hook) |
|
{ |
|
struct io_failure_record *failrec; |
|
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); |
|
struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree; |
|
struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree; |
|
struct btrfs_io_bio *failed_io_bio = btrfs_io_bio(failed_bio); |
|
const int icsum = bio_offset >> fs_info->sectorsize_bits; |
|
struct bio *repair_bio; |
|
struct btrfs_io_bio *repair_io_bio; |
|
blk_status_t status; |
|
|
|
btrfs_debug(fs_info, |
|
"repair read error: read error at %llu", start); |
|
|
|
BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE); |
|
|
|
failrec = btrfs_get_io_failure_record(inode, start); |
|
if (IS_ERR(failrec)) |
|
return PTR_ERR(failrec); |
|
|
|
|
|
if (!btrfs_check_repairable(inode, failrec, failed_mirror)) { |
|
free_io_failure(failure_tree, tree, failrec); |
|
return -EIO; |
|
} |
|
|
|
repair_bio = btrfs_io_bio_alloc(1); |
|
repair_io_bio = btrfs_io_bio(repair_bio); |
|
repair_bio->bi_opf = REQ_OP_READ; |
|
repair_bio->bi_end_io = failed_bio->bi_end_io; |
|
repair_bio->bi_iter.bi_sector = failrec->logical >> 9; |
|
repair_bio->bi_private = failed_bio->bi_private; |
|
|
|
if (failed_io_bio->csum) { |
|
const u32 csum_size = fs_info->csum_size; |
|
|
|
repair_io_bio->csum = repair_io_bio->csum_inline; |
|
memcpy(repair_io_bio->csum, |
|
failed_io_bio->csum + csum_size * icsum, csum_size); |
|
} |
|
|
|
bio_add_page(repair_bio, page, failrec->len, pgoff); |
|
repair_io_bio->logical = failrec->start; |
|
repair_io_bio->iter = repair_bio->bi_iter; |
|
|
|
btrfs_debug(btrfs_sb(inode->i_sb), |
|
"repair read error: submitting new read to mirror %d", |
|
failrec->this_mirror); |
|
|
|
status = submit_bio_hook(inode, repair_bio, failrec->this_mirror, |
|
failrec->bio_flags); |
|
if (status) { |
|
free_io_failure(failure_tree, tree, failrec); |
|
bio_put(repair_bio); |
|
} |
|
return blk_status_to_errno(status); |
|
} |
|
|
|
static void end_page_read(struct page *page, bool uptodate, u64 start, u32 len) |
|
{ |
|
struct btrfs_fs_info *fs_info = btrfs_sb(page->mapping->host->i_sb); |
|
|
|
ASSERT(page_offset(page) <= start && |
|
start + len <= page_offset(page) + PAGE_SIZE); |
|
|
|
if (uptodate) { |
|
btrfs_page_set_uptodate(fs_info, page, start, len); |
|
} else { |
|
btrfs_page_clear_uptodate(fs_info, page, start, len); |
|
btrfs_page_set_error(fs_info, page, start, len); |
|
} |
|
|
|
if (fs_info->sectorsize == PAGE_SIZE) |
|
unlock_page(page); |
|
else |
|
btrfs_subpage_end_reader(fs_info, page, start, len); |
|
} |
|
|
|
static blk_status_t submit_read_repair(struct inode *inode, |
|
struct bio *failed_bio, u32 bio_offset, |
|
struct page *page, unsigned int pgoff, |
|
u64 start, u64 end, int failed_mirror, |
|
unsigned int error_bitmap, |
|
submit_bio_hook_t *submit_bio_hook) |
|
{ |
|
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); |
|
const u32 sectorsize = fs_info->sectorsize; |
|
const int nr_bits = (end + 1 - start) >> fs_info->sectorsize_bits; |
|
int error = 0; |
|
int i; |
|
|
|
BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE); |
|
|
|
/* We're here because we had some read errors or csum mismatch */ |
|
ASSERT(error_bitmap); |
|
|
|
/* |
|
* We only get called on buffered IO, thus page must be mapped and bio |
|
* must not be cloned. |
|
*/ |
|
ASSERT(page->mapping && !bio_flagged(failed_bio, BIO_CLONED)); |
|
|
|
/* Iterate through all the sectors in the range */ |
|
for (i = 0; i < nr_bits; i++) { |
|
const unsigned int offset = i * sectorsize; |
|
struct extent_state *cached = NULL; |
|
bool uptodate = false; |
|
int ret; |
|
|
|
if (!(error_bitmap & (1U << i))) { |
|
/* |
|
* This sector has no error, just end the page read |
|
* and unlock the range. |
|
*/ |
|
uptodate = true; |
|
goto next; |
|
} |
|
|
|
ret = btrfs_repair_one_sector(inode, failed_bio, |
|
bio_offset + offset, |
|
page, pgoff + offset, start + offset, |
|
failed_mirror, submit_bio_hook); |
|
if (!ret) { |
|
/* |
|
* We have submitted the read repair, the page release |
|
* will be handled by the endio function of the |
|
* submitted repair bio. |
|
* Thus we don't need to do any thing here. |
|
*/ |
|
continue; |
|
} |
|
/* |
|
* Repair failed, just record the error but still continue. |
|
* Or the remaining sectors will not be properly unlocked. |
|
*/ |
|
if (!error) |
|
error = ret; |
|
next: |
|
end_page_read(page, uptodate, start + offset, sectorsize); |
|
if (uptodate) |
|
set_extent_uptodate(&BTRFS_I(inode)->io_tree, |
|
start + offset, |
|
start + offset + sectorsize - 1, |
|
&cached, GFP_ATOMIC); |
|
unlock_extent_cached_atomic(&BTRFS_I(inode)->io_tree, |
|
start + offset, |
|
start + offset + sectorsize - 1, |
|
&cached); |
|
} |
|
return errno_to_blk_status(error); |
|
} |
|
|
|
/* 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) |
|
{ |
|
struct btrfs_inode *inode; |
|
int uptodate = (err == 0); |
|
int ret = 0; |
|
|
|
ASSERT(page && page->mapping); |
|
inode = BTRFS_I(page->mapping->host); |
|
btrfs_writepage_endio_finish_ordered(inode, page, start, end, 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; |
|
struct bvec_iter_all iter_all; |
|
bool first_bvec = true; |
|
|
|
ASSERT(!bio_flagged(bio, BIO_CLONED)); |
|
bio_for_each_segment_all(bvec, bio, iter_all) { |
|
struct page *page = bvec->bv_page; |
|
struct inode *inode = page->mapping->host; |
|
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); |
|
const u32 sectorsize = fs_info->sectorsize; |
|
|
|
/* Our read/write should always be sector aligned. */ |
|
if (!IS_ALIGNED(bvec->bv_offset, sectorsize)) |
|
btrfs_err(fs_info, |
|
"partial page write in btrfs with offset %u and length %u", |
|
bvec->bv_offset, bvec->bv_len); |
|
else if (!IS_ALIGNED(bvec->bv_len, sectorsize)) |
|
btrfs_info(fs_info, |
|
"incomplete page write with offset %u and length %u", |
|
bvec->bv_offset, bvec->bv_len); |
|
|
|
start = page_offset(page) + bvec->bv_offset; |
|
end = start + bvec->bv_len - 1; |
|
|
|
if (first_bvec) { |
|
btrfs_record_physical_zoned(inode, start, bio); |
|
first_bvec = false; |
|
} |
|
|
|
end_extent_writepage(page, error, start, end); |
|
|
|
btrfs_page_clear_writeback(fs_info, page, start, bvec->bv_len); |
|
} |
|
|
|
bio_put(bio); |
|
} |
|
|
|
/* |
|
* Record previously processed extent range |
|
* |
|
* For endio_readpage_release_extent() to handle a full extent range, reducing |
|
* the extent io operations. |
|
*/ |
|
struct processed_extent { |
|
struct btrfs_inode *inode; |
|
/* Start of the range in @inode */ |
|
u64 start; |
|
/* End of the range in @inode */ |
|
u64 end; |
|
bool uptodate; |
|
}; |
|
|
|
/* |
|
* Try to release processed extent range |
|
* |
|
* May not release the extent range right now if the current range is |
|
* contiguous to processed extent. |
|
* |
|
* Will release processed extent when any of @inode, @uptodate, the range is |
|
* no longer contiguous to the processed range. |
|
* |
|
* Passing @inode == NULL will force processed extent to be released. |
|
*/ |
|
static void endio_readpage_release_extent(struct processed_extent *processed, |
|
struct btrfs_inode *inode, u64 start, u64 end, |
|
bool uptodate) |
|
{ |
|
struct extent_state *cached = NULL; |
|
struct extent_io_tree *tree; |
|
|
|
/* The first extent, initialize @processed */ |
|
if (!processed->inode) |
|
goto update; |
|
|
|
/* |
|
* Contiguous to processed extent, just uptodate the end. |
|
* |
|
* Several things to notice: |
|
* |
|
* - bio can be merged as long as on-disk bytenr is contiguous |
|
* This means we can have page belonging to other inodes, thus need to |
|
* check if the inode still matches. |
|
* - bvec can contain range beyond current page for multi-page bvec |
|
* Thus we need to do processed->end + 1 >= start check |
|
*/ |
|
if (processed->inode == inode && processed->uptodate == uptodate && |
|
processed->end + 1 >= start && end >= processed->end) { |
|
processed->end = end; |
|
return; |
|
} |
|
|
|
tree = &processed->inode->io_tree; |
|
/* |
|
* Now we don't have range contiguous to the processed range, release |
|
* the processed range now. |
|
*/ |
|
if (processed->uptodate && tree->track_uptodate) |
|
set_extent_uptodate(tree, processed->start, processed->end, |
|
&cached, GFP_ATOMIC); |
|
unlock_extent_cached_atomic(tree, processed->start, processed->end, |
|
&cached); |
|
|
|
update: |
|
/* Update processed to current range */ |
|
processed->inode = inode; |
|
processed->start = start; |
|
processed->end = end; |
|
processed->uptodate = uptodate; |
|
} |
|
|
|
static void begin_page_read(struct btrfs_fs_info *fs_info, struct page *page) |
|
{ |
|
ASSERT(PageLocked(page)); |
|
if (fs_info->sectorsize == PAGE_SIZE) |
|
return; |
|
|
|
ASSERT(PagePrivate(page)); |
|
btrfs_subpage_start_reader(fs_info, page, page_offset(page), PAGE_SIZE); |
|
} |
|
|
|
/* |
|
* Find extent buffer for a givne bytenr. |
|
* |
|
* This is for end_bio_extent_readpage(), thus we can't do any unsafe locking |
|
* in endio context. |
|
*/ |
|
static struct extent_buffer *find_extent_buffer_readpage( |
|
struct btrfs_fs_info *fs_info, struct page *page, u64 bytenr) |
|
{ |
|
struct extent_buffer *eb; |
|
|
|
/* |
|
* For regular sectorsize, we can use page->private to grab extent |
|
* buffer |
|
*/ |
|
if (fs_info->sectorsize == PAGE_SIZE) { |
|
ASSERT(PagePrivate(page) && page->private); |
|
return (struct extent_buffer *)page->private; |
|
} |
|
|
|
/* For subpage case, we need to lookup buffer radix tree */ |
|
rcu_read_lock(); |
|
eb = radix_tree_lookup(&fs_info->buffer_radix, |
|
bytenr >> fs_info->sectorsize_bits); |
|
rcu_read_unlock(); |
|
ASSERT(eb); |
|
return eb; |
|
} |
|
|
|
/* |
|
* 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; |
|
struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); |
|
struct extent_io_tree *tree, *failure_tree; |
|
struct processed_extent processed = { 0 }; |
|
/* |
|
* The offset to the beginning of a bio, since one bio can never be |
|
* larger than UINT_MAX, u32 here is enough. |
|
*/ |
|
u32 bio_offset = 0; |
|
int mirror; |
|
int ret; |
|
struct bvec_iter_all iter_all; |
|
|
|
ASSERT(!bio_flagged(bio, BIO_CLONED)); |
|
bio_for_each_segment_all(bvec, bio, iter_all) { |
|
bool uptodate = !bio->bi_status; |
|
struct page *page = bvec->bv_page; |
|
struct inode *inode = page->mapping->host; |
|
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); |
|
const u32 sectorsize = fs_info->sectorsize; |
|
unsigned int error_bitmap = (unsigned int)-1; |
|
u64 start; |
|
u64 end; |
|
u32 len; |
|
|
|
btrfs_debug(fs_info, |
|
"end_bio_extent_readpage: bi_sector=%llu, err=%d, mirror=%u", |
|
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-sector 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 unaligned offsets, and an error if they don't add up to |
|
* a full sector. |
|
*/ |
|
if (!IS_ALIGNED(bvec->bv_offset, sectorsize)) |
|
btrfs_err(fs_info, |
|
"partial page read in btrfs with offset %u and length %u", |
|
bvec->bv_offset, bvec->bv_len); |
|
else if (!IS_ALIGNED(bvec->bv_offset + bvec->bv_len, |
|
sectorsize)) |
|
btrfs_info(fs_info, |
|
"incomplete page read with offset %u and length %u", |
|
bvec->bv_offset, bvec->bv_len); |
|
|
|
start = page_offset(page) + bvec->bv_offset; |
|
end = start + bvec->bv_len - 1; |
|
len = bvec->bv_len; |
|
|
|
mirror = io_bio->mirror_num; |
|
if (likely(uptodate)) { |
|
if (is_data_inode(inode)) { |
|
error_bitmap = btrfs_verify_data_csum(io_bio, |
|
bio_offset, page, start, end); |
|
ret = error_bitmap; |
|
} else { |
|
ret = btrfs_validate_metadata_buffer(io_bio, |
|
page, start, end, mirror); |
|
} |
|
if (ret) |
|
uptodate = false; |
|
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 (is_data_inode(inode)) { |
|
/* |
|
* btrfs_submit_read_repair() will handle all the good |
|
* and bad sectors, we just continue to the next bvec. |
|
*/ |
|
submit_read_repair(inode, bio, bio_offset, page, |
|
start - page_offset(page), start, |
|
end, mirror, error_bitmap, |
|
btrfs_submit_data_bio); |
|
|
|
ASSERT(bio_offset + len > bio_offset); |
|
bio_offset += len; |
|
continue; |
|
} else { |
|
struct extent_buffer *eb; |
|
|
|
eb = find_extent_buffer_readpage(fs_info, page, start); |
|
set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags); |
|
eb->read_mirror = mirror; |
|
atomic_dec(&eb->io_pages); |
|
if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD, |
|
&eb->bflags)) |
|
btree_readahead_hook(eb, -EIO); |
|
} |
|
readpage_ok: |
|
if (likely(uptodate)) { |
|
loff_t i_size = i_size_read(inode); |
|
pgoff_t end_index = i_size >> PAGE_SHIFT; |
|
|
|
/* |
|
* Zero out the remaining part if this range straddles |
|
* i_size. |
|
* |
|
* Here we should only zero the range inside the bvec, |
|
* not touch anything else. |
|
* |
|
* NOTE: i_size is exclusive while end is inclusive. |
|
*/ |
|
if (page->index == end_index && i_size <= end) { |
|
u32 zero_start = max(offset_in_page(i_size), |
|
offset_in_page(start)); |
|
|
|
zero_user_segment(page, zero_start, |
|
offset_in_page(end) + 1); |
|
} |
|
} |
|
ASSERT(bio_offset + len > bio_offset); |
|
bio_offset += len; |
|
|
|
/* Update page status and unlock */ |
|
end_page_read(page, uptodate, start, len); |
|
endio_readpage_release_extent(&processed, BTRFS_I(inode), |
|
start, end, uptodate); |
|
} |
|
/* Release the last extent */ |
|
endio_readpage_release_extent(&processed, NULL, 0, 0, false); |
|
btrfs_io_bio_free_csum(io_bio); |
|
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(u64 first_byte) |
|
{ |
|
struct bio *bio; |
|
|
|
bio = bio_alloc_bioset(GFP_NOFS, BIO_MAX_VECS, &btrfs_bioset); |
|
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; |
|
} |
|
|
|
/** |
|
* Attempt to add a page to bio |
|
* |
|
* @bio: destination bio |
|
* @page: page to add to the bio |
|
* @disk_bytenr: offset of the new bio or to check whether we are adding |
|
* a contiguous page to the previous one |
|
* @pg_offset: starting offset in the page |
|
* @size: portion of page that we want to 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 |
|
* @return: true if page was added, false otherwise |
|
* |
|
* Attempt to add a page to bio considering stripe alignment etc. |
|
* |
|
* Return true if successfully page added. Otherwise, return false. |
|
*/ |
|
static bool btrfs_bio_add_page(struct btrfs_bio_ctrl *bio_ctrl, |
|
struct page *page, |
|
u64 disk_bytenr, unsigned int size, |
|
unsigned int pg_offset, |
|
unsigned long bio_flags) |
|
{ |
|
struct bio *bio = bio_ctrl->bio; |
|
u32 bio_size = bio->bi_iter.bi_size; |
|
const sector_t sector = disk_bytenr >> SECTOR_SHIFT; |
|
bool contig; |
|
int ret; |
|
|
|
ASSERT(bio); |
|
/* The limit should be calculated when bio_ctrl->bio is allocated */ |
|
ASSERT(bio_ctrl->len_to_oe_boundary && bio_ctrl->len_to_stripe_boundary); |
|
if (bio_ctrl->bio_flags != bio_flags) |
|
return false; |
|
|
|
if (bio_ctrl->bio_flags & EXTENT_BIO_COMPRESSED) |
|
contig = bio->bi_iter.bi_sector == sector; |
|
else |
|
contig = bio_end_sector(bio) == sector; |
|
if (!contig) |
|
return false; |
|
|
|
if (bio_size + size > bio_ctrl->len_to_oe_boundary || |
|
bio_size + size > bio_ctrl->len_to_stripe_boundary) |
|
return false; |
|
|
|
if (bio_op(bio) == REQ_OP_ZONE_APPEND) |
|
ret = bio_add_zone_append_page(bio, page, size, pg_offset); |
|
else |
|
ret = bio_add_page(bio, page, size, pg_offset); |
|
|
|
return ret == size; |
|
} |
|
|
|
static int calc_bio_boundaries(struct btrfs_bio_ctrl *bio_ctrl, |
|
struct btrfs_inode *inode) |
|
{ |
|
struct btrfs_fs_info *fs_info = inode->root->fs_info; |
|
struct btrfs_io_geometry geom; |
|
struct btrfs_ordered_extent *ordered; |
|
struct extent_map *em; |
|
u64 logical = (bio_ctrl->bio->bi_iter.bi_sector << SECTOR_SHIFT); |
|
int ret; |
|
|
|
/* |
|
* Pages for compressed extent are never submitted to disk directly, |
|
* thus it has no real boundary, just set them to U32_MAX. |
|
* |
|
* The split happens for real compressed bio, which happens in |
|
* btrfs_submit_compressed_read/write(). |
|
*/ |
|
if (bio_ctrl->bio_flags & EXTENT_BIO_COMPRESSED) { |
|
bio_ctrl->len_to_oe_boundary = U32_MAX; |
|
bio_ctrl->len_to_stripe_boundary = U32_MAX; |
|
return 0; |
|
} |
|
em = btrfs_get_chunk_map(fs_info, logical, fs_info->sectorsize); |
|
if (IS_ERR(em)) |
|
return PTR_ERR(em); |
|
ret = btrfs_get_io_geometry(fs_info, em, btrfs_op(bio_ctrl->bio), |
|
logical, &geom); |
|
free_extent_map(em); |
|
if (ret < 0) { |
|
return ret; |
|
} |
|
if (geom.len > U32_MAX) |
|
bio_ctrl->len_to_stripe_boundary = U32_MAX; |
|
else |
|
bio_ctrl->len_to_stripe_boundary = (u32)geom.len; |
|
|
|
if (!btrfs_is_zoned(fs_info) || |
|
bio_op(bio_ctrl->bio) != REQ_OP_ZONE_APPEND) { |
|
bio_ctrl->len_to_oe_boundary = U32_MAX; |
|
return 0; |
|
} |
|
|
|
ASSERT(fs_info->max_zone_append_size > 0); |
|
/* Ordered extent not yet created, so we're good */ |
|
ordered = btrfs_lookup_ordered_extent(inode, logical); |
|
if (!ordered) { |
|
bio_ctrl->len_to_oe_boundary = U32_MAX; |
|
return 0; |
|
} |
|
|
|
bio_ctrl->len_to_oe_boundary = min_t(u32, U32_MAX, |
|
ordered->disk_bytenr + ordered->disk_num_bytes - logical); |
|
btrfs_put_ordered_extent(ordered); |
|
return 0; |
|
} |
|
|
|
/* |
|
* @opf: bio REQ_OP_* and REQ_* flags as one value |
|
* @wbc: optional writeback control for io accounting |
|
* @page: page to add to the bio |
|
* @disk_bytenr: logical bytenr where the write will be |
|
* @size: portion of page that we want to write to |
|
* @pg_offset: offset of the new bio or to check whether we are adding |
|
* a contiguous page to the previous one |
|
* @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 writeback_control *wbc, |
|
struct btrfs_bio_ctrl *bio_ctrl, |
|
struct page *page, u64 disk_bytenr, |
|
size_t size, unsigned long pg_offset, |
|
bio_end_io_t end_io_func, |
|
int mirror_num, |
|
unsigned long bio_flags, |
|
bool force_bio_submit) |
|
{ |
|
int ret = 0; |
|
struct bio *bio; |
|
size_t io_size = min_t(size_t, size, PAGE_SIZE); |
|
struct btrfs_inode *inode = BTRFS_I(page->mapping->host); |
|
struct extent_io_tree *tree = &inode->io_tree; |
|
struct btrfs_fs_info *fs_info = inode->root->fs_info; |
|
|
|
ASSERT(bio_ctrl); |
|
|
|
ASSERT(pg_offset < PAGE_SIZE && size <= PAGE_SIZE && |
|
pg_offset + size <= PAGE_SIZE); |
|
if (bio_ctrl->bio) { |
|
bio = bio_ctrl->bio; |
|
if (force_bio_submit || |
|
!btrfs_bio_add_page(bio_ctrl, page, disk_bytenr, io_size, |
|
pg_offset, bio_flags)) { |
|
ret = submit_one_bio(bio, mirror_num, bio_ctrl->bio_flags); |
|
bio_ctrl->bio = NULL; |
|
if (ret < 0) |
|
return ret; |
|
} else { |
|
if (wbc) |
|
wbc_account_cgroup_owner(wbc, page, io_size); |
|
return 0; |
|
} |
|
} |
|
|
|
bio = btrfs_bio_alloc(disk_bytenr); |
|
bio_add_page(bio, page, io_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) { |
|
struct block_device *bdev; |
|
|
|
bdev = fs_info->fs_devices->latest_bdev; |
|
bio_set_dev(bio, bdev); |
|
wbc_init_bio(wbc, bio); |
|
wbc_account_cgroup_owner(wbc, page, io_size); |
|
} |
|
if (btrfs_is_zoned(fs_info) && bio_op(bio) == REQ_OP_ZONE_APPEND) { |
|
struct btrfs_device *device; |
|
|
|
device = btrfs_zoned_get_device(fs_info, disk_bytenr, io_size); |
|
if (IS_ERR(device)) |
|
return PTR_ERR(device); |
|
|
|
btrfs_io_bio(bio)->device = device; |
|
} |
|
|
|
bio_ctrl->bio = bio; |
|
bio_ctrl->bio_flags = bio_flags; |
|
ret = calc_bio_boundaries(bio_ctrl, inode); |
|
|
|
return ret; |
|
} |
|
|
|
static int attach_extent_buffer_page(struct extent_buffer *eb, |
|
struct page *page, |
|
struct btrfs_subpage *prealloc) |
|
{ |
|
struct btrfs_fs_info *fs_info = eb->fs_info; |
|
int ret = 0; |
|
|
|
/* |
|
* If the page is mapped to btree inode, we should hold the private |
|
* lock to prevent race. |
|
* For cloned or dummy extent buffers, their pages are not mapped and |
|
* will not race with any other ebs. |
|
*/ |
|
if (page->mapping) |
|
lockdep_assert_held(&page->mapping->private_lock); |
|
|
|
if (fs_info->sectorsize == PAGE_SIZE) { |
|
if (!PagePrivate(page)) |
|
attach_page_private(page, eb); |
|
else |
|
WARN_ON(page->private != (unsigned long)eb); |
|
return 0; |
|
} |
|
|
|
/* Already mapped, just free prealloc */ |
|
if (PagePrivate(page)) { |
|
btrfs_free_subpage(prealloc); |
|
return 0; |
|
} |
|
|
|
if (prealloc) |
|
/* Has preallocated memory for subpage */ |
|
attach_page_private(page, prealloc); |
|
else |
|
/* Do new allocation to attach subpage */ |
|
ret = btrfs_attach_subpage(fs_info, page, |
|
BTRFS_SUBPAGE_METADATA); |
|
return ret; |
|
} |
|
|
|
int set_page_extent_mapped(struct page *page) |
|
{ |
|
struct btrfs_fs_info *fs_info; |
|
|
|
ASSERT(page->mapping); |
|
|
|
if (PagePrivate(page)) |
|
return 0; |
|
|
|
fs_info = btrfs_sb(page->mapping->host->i_sb); |
|
|
|
if (fs_info->sectorsize < PAGE_SIZE) |
|
return btrfs_attach_subpage(fs_info, page, BTRFS_SUBPAGE_DATA); |
|
|
|
attach_page_private(page, (void *)EXTENT_PAGE_PRIVATE); |
|
return 0; |
|
} |
|
|
|
void clear_page_extent_mapped(struct page *page) |
|
{ |
|
struct btrfs_fs_info *fs_info; |
|
|
|
ASSERT(page->mapping); |
|
|
|
if (!PagePrivate(page)) |
|
return; |
|
|
|
fs_info = btrfs_sb(page->mapping->host->i_sb); |
|
if (fs_info->sectorsize < PAGE_SIZE) |
|
return btrfs_detach_subpage(fs_info, page); |
|
|
|
detach_page_private(page); |
|
} |
|
|
|
static struct extent_map * |
|
__get_extent_map(struct inode *inode, struct page *page, size_t pg_offset, |
|
u64 start, u64 len, 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 = btrfs_get_extent(BTRFS_I(inode), page, pg_offset, start, len); |
|
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 |
|
*/ |
|
int btrfs_do_readpage(struct page *page, struct extent_map **em_cached, |
|
struct btrfs_bio_ctrl *bio_ctrl, |
|
unsigned int read_flags, u64 *prev_em_start) |
|
{ |
|
struct inode *inode = page->mapping->host; |
|
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); |
|
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; |
|
int ret = 0; |
|
int nr = 0; |
|
size_t pg_offset = 0; |
|
size_t iosize; |
|
size_t blocksize = inode->i_sb->s_blocksize; |
|
unsigned long this_bio_flag = 0; |
|
struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree; |
|
|
|
ret = set_page_extent_mapped(page); |
|
if (ret < 0) { |
|
unlock_extent(tree, start, end); |
|
btrfs_page_set_error(fs_info, page, start, PAGE_SIZE); |
|
unlock_page(page); |
|
goto out; |
|
} |
|
|
|
if (!PageUptodate(page)) { |
|
if (cleancache_get_page(page) == 0) { |
|
BUG_ON(blocksize != PAGE_SIZE); |
|
unlock_extent(tree, start, end); |
|
unlock_page(page); |
|
goto out; |
|
} |
|
} |
|
|
|
if (page->index == last_byte >> PAGE_SHIFT) { |
|
size_t zero_offset = offset_in_page(last_byte); |
|
|
|
if (zero_offset) { |
|
iosize = PAGE_SIZE - zero_offset; |
|
memzero_page(page, zero_offset, iosize); |
|
flush_dcache_page(page); |
|
} |
|
} |
|
begin_page_read(fs_info, page); |
|
while (cur <= end) { |
|
bool force_bio_submit = false; |
|
u64 disk_bytenr; |
|
|
|
if (cur >= last_byte) { |
|
struct extent_state *cached = NULL; |
|
|
|
iosize = PAGE_SIZE - pg_offset; |
|
memzero_page(page, pg_offset, iosize); |
|
flush_dcache_page(page); |
|
set_extent_uptodate(tree, cur, cur + iosize - 1, |
|
&cached, GFP_NOFS); |
|
unlock_extent_cached(tree, cur, |
|
cur + iosize - 1, &cached); |
|
end_page_read(page, true, cur, iosize); |
|
break; |
|
} |
|
em = __get_extent_map(inode, page, pg_offset, cur, |
|
end - cur + 1, em_cached); |
|
if (IS_ERR_OR_NULL(em)) { |
|
unlock_extent(tree, cur, end); |
|
end_page_read(page, false, cur, end + 1 - cur); |
|
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_bytenr = em->block_start; |
|
else |
|
disk_bytenr = em->block_start + extent_offset; |
|
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 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->start) |
|
force_bio_submit = true; |
|
|
|
if (prev_em_start) |
|
*prev_em_start = em->start; |
|
|
|
free_extent_map(em); |
|
em = NULL; |
|
|
|
/* we've found a hole, just zero and go on */ |
|
if (block_start == EXTENT_MAP_HOLE) { |
|
struct extent_state *cached = NULL; |
|
|
|
memzero_page(page, pg_offset, iosize); |
|
flush_dcache_page(page); |
|
|
|
set_extent_uptodate(tree, cur, cur + iosize - 1, |
|
&cached, GFP_NOFS); |
|
unlock_extent_cached(tree, cur, |
|
cur + iosize - 1, &cached); |
|
end_page_read(page, true, cur, iosize); |
|
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); |
|
end_page_read(page, true, cur, iosize); |
|
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) { |
|
unlock_extent(tree, cur, cur + iosize - 1); |
|
end_page_read(page, false, cur, iosize); |
|
cur = cur + iosize; |
|
pg_offset += iosize; |
|
continue; |
|
} |
|
|
|
ret = submit_extent_page(REQ_OP_READ | read_flags, NULL, |
|
bio_ctrl, page, disk_bytenr, iosize, |
|
pg_offset, |
|
end_bio_extent_readpage, 0, |
|
this_bio_flag, |
|
force_bio_submit); |
|
if (!ret) { |
|
nr++; |
|
} else { |
|
unlock_extent(tree, cur, cur + iosize - 1); |
|
end_page_read(page, false, cur, iosize); |
|
goto out; |
|
} |
|
cur = cur + iosize; |
|
pg_offset += iosize; |
|
} |
|
out: |
|
return ret; |
|
} |
|
|
|
static inline void contiguous_readpages(struct page *pages[], int nr_pages, |
|
u64 start, u64 end, |
|
struct extent_map **em_cached, |
|
struct btrfs_bio_ctrl *bio_ctrl, |
|
u64 *prev_em_start) |
|
{ |
|
struct btrfs_inode *inode = BTRFS_I(pages[0]->mapping->host); |
|
int index; |
|
|
|
btrfs_lock_and_flush_ordered_range(inode, start, end, NULL); |
|
|
|
for (index = 0; index < nr_pages; index++) { |
|
btrfs_do_readpage(pages[index], em_cached, bio_ctrl, |
|
REQ_RAHEAD, prev_em_start); |
|
put_page(pages[index]); |
|
} |
|
} |
|
|
|
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 btrfs_run_delalloc_range 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 btrfs_inode *inode, |
|
struct page *page, struct writeback_control *wbc, |
|
u64 delalloc_start, unsigned long *nr_written) |
|
{ |
|
u64 page_end = delalloc_start + PAGE_SIZE - 1; |
|
bool found; |
|
u64 delalloc_to_write = 0; |
|
u64 delalloc_end = 0; |
|
int ret; |
|
int page_started = 0; |
|
|
|
|
|
while (delalloc_end < page_end) { |
|
found = find_lock_delalloc_range(&inode->vfs_inode, page, |
|
&delalloc_start, |
|
&delalloc_end); |
|
if (!found) { |
|
delalloc_start = delalloc_end + 1; |
|
continue; |
|
} |
|
ret = btrfs_run_delalloc_range(inode, page, delalloc_start, |
|
delalloc_end, &page_started, nr_written, wbc); |
|
if (ret) { |
|
SetPageError(page); |
|
/* |
|
* btrfs_run_delalloc_range should 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. |
|
*/ |
|
return ret < 0 ? ret : -EIO; |
|
} |
|
/* |
|
* 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; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* Find the first byte we need to write. |
|
* |
|
* For subpage, one page can contain several sectors, and |
|
* __extent_writepage_io() will just grab all extent maps in the page |
|
* range and try to submit all non-inline/non-compressed extents. |
|
* |
|
* This is a big problem for subpage, we shouldn't re-submit already written |
|
* data at all. |
|
* This function will lookup subpage dirty bit to find which range we really |
|
* need to submit. |
|
* |
|
* Return the next dirty range in [@start, @end). |
|
* If no dirty range is found, @start will be page_offset(page) + PAGE_SIZE. |
|
*/ |
|
static void find_next_dirty_byte(struct btrfs_fs_info *fs_info, |
|
struct page *page, u64 *start, u64 *end) |
|
{ |
|
struct btrfs_subpage *subpage = (struct btrfs_subpage *)page->private; |
|
u64 orig_start = *start; |
|
/* Declare as unsigned long so we can use bitmap ops */ |
|
unsigned long dirty_bitmap; |
|
unsigned long flags; |
|
int nbits = (orig_start - page_offset(page)) >> fs_info->sectorsize_bits; |
|
int range_start_bit = nbits; |
|
int range_end_bit; |
|
|
|
/* |
|
* For regular sector size == page size case, since one page only |
|
* contains one sector, we return the page offset directly. |
|
*/ |
|
if (fs_info->sectorsize == PAGE_SIZE) { |
|
*start = page_offset(page); |
|
*end = page_offset(page) + PAGE_SIZE; |
|
return; |
|
} |
|
|
|
/* We should have the page locked, but just in case */ |
|
spin_lock_irqsave(&subpage->lock, flags); |
|
dirty_bitmap = subpage->dirty_bitmap; |
|
spin_unlock_irqrestore(&subpage->lock, flags); |
|
|
|
bitmap_next_set_region(&dirty_bitmap, &range_start_bit, &range_end_bit, |
|
BTRFS_SUBPAGE_BITMAP_SIZE); |
|
*start = page_offset(page) + range_start_bit * fs_info->sectorsize; |
|
*end = page_offset(page) + range_end_bit * fs_info->sectorsize; |
|
} |
|
|
|
/* |
|
* 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 btrfs_inode *inode, |
|
struct page *page, |
|
struct writeback_control *wbc, |
|
struct extent_page_data *epd, |
|
loff_t i_size, |
|
unsigned long nr_written, |
|
int *nr_ret) |
|
{ |
|
struct btrfs_fs_info *fs_info = inode->root->fs_info; |
|
u64 start = page_offset(page); |
|
u64 end = start + PAGE_SIZE - 1; |
|
u64 cur = start; |
|
u64 extent_offset; |
|
u64 block_start; |
|
struct extent_map *em; |
|
int ret = 0; |
|
int nr = 0; |
|
u32 opf = REQ_OP_WRITE; |
|
const unsigned int write_flags = wbc_to_write_flags(wbc); |
|
bool compressed; |
|
|
|
ret = btrfs_writepage_cow_fixup(page, start, end); |
|
if (ret) { |
|
/* Fixup worker will requeue */ |
|
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); |
|
|
|
while (cur <= end) { |
|
u64 disk_bytenr; |
|
u64 em_end; |
|
u64 dirty_range_start = cur; |
|
u64 dirty_range_end; |
|
u32 iosize; |
|
|
|
if (cur >= i_size) { |
|
btrfs_writepage_endio_finish_ordered(inode, page, cur, |
|
end, 1); |
|
break; |
|
} |
|
|
|
find_next_dirty_byte(fs_info, page, &dirty_range_start, |
|
&dirty_range_end); |
|
if (cur < dirty_range_start) { |
|
cur = dirty_range_start; |
|
continue; |
|
} |
|
|
|
em = btrfs_get_extent(inode, NULL, 0, cur, end - cur + 1); |
|
if (IS_ERR_OR_NULL(em)) { |
|
btrfs_page_set_error(fs_info, page, cur, end - cur + 1); |
|
ret = PTR_ERR_OR_ZERO(em); |
|
break; |
|
} |
|
|
|
extent_offset = cur - em->start; |
|
em_end = extent_map_end(em); |
|
ASSERT(cur <= em_end); |
|
ASSERT(cur < end); |
|
ASSERT(IS_ALIGNED(em->start, fs_info->sectorsize)); |
|
ASSERT(IS_ALIGNED(em->len, fs_info->sectorsize)); |
|
block_start = em->block_start; |
|
compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags); |
|
disk_bytenr = em->block_start + extent_offset; |
|
|
|
/* |
|
* Note that em_end from extent_map_end() and dirty_range_end from |
|
* find_next_dirty_byte() are all exclusive |
|
*/ |
|
iosize = min(min(em_end, end + 1), dirty_range_end) - cur; |
|
|
|
if (btrfs_use_zone_append(inode, em->block_start)) |
|
opf = REQ_OP_ZONE_APPEND; |
|
|
|
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) { |
|
if (compressed) |
|
nr++; |
|
else |
|
btrfs_writepage_endio_finish_ordered(inode, |
|
page, cur, cur + iosize - 1, 1); |
|
cur += iosize; |
|
continue; |
|
} |
|
|
|
btrfs_set_range_writeback(inode, cur, cur + iosize - 1); |
|
if (!PageWriteback(page)) { |
|
btrfs_err(inode->root->fs_info, |
|
"page %lu not writeback, cur %llu end %llu", |
|
page->index, cur, end); |
|
} |
|
|
|
/* |
|
* Although the PageDirty bit is cleared before entering this |
|
* function, subpage dirty bit is not cleared. |
|
* So clear subpage dirty bit here so next time we won't submit |
|
* page for range already written to disk. |
|
*/ |
|
btrfs_page_clear_dirty(fs_info, page, cur, iosize); |
|
|
|
ret = submit_extent_page(opf | write_flags, wbc, |
|
&epd->bio_ctrl, page, |
|
disk_bytenr, iosize, |
|
cur - page_offset(page), |
|
end_bio_extent_writepage, |
|
0, 0, false); |
|
if (ret) { |
|
btrfs_page_set_error(fs_info, page, cur, iosize); |
|
if (PageWriteback(page)) |
|
btrfs_page_clear_writeback(fs_info, page, cur, |
|
iosize); |
|
} |
|
|
|
cur += iosize; |
|
nr++; |
|
} |
|
*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 |
|
* |
|
* Return 0 if everything goes well. |
|
* Return <0 for error. |
|
*/ |
|
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; |
|
loff_t i_size = i_size_read(inode); |
|
unsigned long end_index = i_size >> PAGE_SHIFT; |
|
unsigned long nr_written = 0; |
|
|
|
trace___extent_writepage(page, inode, wbc); |
|
|
|
WARN_ON(!PageLocked(page)); |
|
|
|
ClearPageError(page); |
|
|
|
pg_offset = offset_in_page(i_size); |
|
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) { |
|
memzero_page(page, pg_offset, PAGE_SIZE - pg_offset); |
|
flush_dcache_page(page); |
|
} |
|
|
|
ret = set_page_extent_mapped(page); |
|
if (ret < 0) { |
|
SetPageError(page); |
|
goto done; |
|
} |
|
|
|
if (!epd->extent_locked) { |
|
ret = writepage_delalloc(BTRFS_I(inode), page, wbc, start, |
|
&nr_written); |
|
if (ret == 1) |
|
return 0; |
|
if (ret) |
|
goto done; |
|
} |
|
|
|
ret = __extent_writepage_io(BTRFS_I(inode), page, wbc, epd, i_size, |
|
nr_written, &nr); |
|
if (ret == 1) |
|
return 0; |
|
|
|
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); |
|
ASSERT(ret <= 0); |
|
return ret; |
|
} |
|
|
|
void wait_on_extent_buffer_writeback(struct extent_buffer *eb) |
|
{ |
|
wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK, |
|
TASK_UNINTERRUPTIBLE); |
|
} |
|
|
|
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); |
|
} |
|
|
|
/* |
|
* Lock extent buffer status and pages for writeback. |
|
* |
|
* May try to flush write bio if we can't get the lock. |
|
* |
|
* Return 0 if the extent buffer doesn't need to be submitted. |
|
* (E.g. the extent buffer is not dirty) |
|
* Return >0 is the extent buffer is submitted to bio. |
|
* Return <0 if something went wrong, no page is locked. |
|
*/ |
|
static noinline_for_stack int lock_extent_buffer_for_io(struct extent_buffer *eb, |
|
struct extent_page_data *epd) |
|
{ |
|
struct btrfs_fs_info *fs_info = eb->fs_info; |
|
int i, num_pages, failed_page_nr; |
|
int flush = 0; |
|
int ret = 0; |
|
|
|
if (!btrfs_try_tree_write_lock(eb)) { |
|
ret = flush_write_bio(epd); |
|
if (ret < 0) |
|
return ret; |
|
flush = 1; |
|
btrfs_tree_lock(eb); |
|
} |
|
|
|
if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) { |
|
btrfs_tree_unlock(eb); |
|
if (!epd->sync_io) |
|
return 0; |
|
if (!flush) { |
|
ret = flush_write_bio(epd); |
|
if (ret < 0) |
|
return ret; |
|
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); |
|
|
|
/* |
|
* Either we don't need to submit any tree block, or we're submitting |
|
* subpage eb. |
|
* Subpage metadata doesn't use page locking at all, so we can skip |
|
* the page locking. |
|
*/ |
|
if (!ret || fs_info->sectorsize < PAGE_SIZE) |
|
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) { |
|
int err; |
|
|
|
err = flush_write_bio(epd); |
|
if (err < 0) { |
|
ret = err; |
|
failed_page_nr = i; |
|
goto err_unlock; |
|
} |
|
flush = 1; |
|
} |
|
lock_page(p); |
|
} |
|
} |
|
|
|
return ret; |
|
err_unlock: |
|
/* Unlock already locked pages */ |
|
for (i = 0; i < failed_page_nr; i++) |
|
unlock_page(eb->pages[i]); |
|
/* |
|
* Clear EXTENT_BUFFER_WRITEBACK and wake up anyone waiting on it. |
|
* Also set back EXTENT_BUFFER_DIRTY so future attempts to this eb can |
|
* be made and undo everything done before. |
|
*/ |
|
btrfs_tree_lock(eb); |
|
spin_lock(&eb->refs_lock); |
|
set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags); |
|
end_extent_buffer_writeback(eb); |
|
spin_unlock(&eb->refs_lock); |
|
percpu_counter_add_batch(&fs_info->dirty_metadata_bytes, eb->len, |
|
fs_info->dirty_metadata_batch); |
|
btrfs_clear_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN); |
|
btrfs_tree_unlock(eb); |
|
return ret; |
|
} |
|
|
|
static void set_btree_ioerr(struct page *page, struct extent_buffer *eb) |
|
{ |
|
struct btrfs_fs_info *fs_info = eb->fs_info; |
|
|
|
btrfs_page_set_error(fs_info, page, eb->start, eb->len); |
|
if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) |
|
return; |
|
|
|
/* |
|
* If we error out, we should add back the dirty_metadata_bytes |
|
* to make it consistent. |
|
*/ |
|
percpu_counter_add_batch(&fs_info->dirty_metadata_bytes, |
|
eb->len, fs_info->dirty_metadata_batch); |
|
|
|
/* |
|
* 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, &fs_info->flags); |
|
break; |
|
case 0: |
|
set_bit(BTRFS_FS_LOG1_ERR, &fs_info->flags); |
|
break; |
|
case 1: |
|
set_bit(BTRFS_FS_LOG2_ERR, &fs_info->flags); |
|
break; |
|
default: |
|
BUG(); /* unexpected, logic error */ |
|
} |
|
} |
|
|
|
/* |
|
* The endio specific version which won't touch any unsafe spinlock in endio |
|
* context. |
|
*/ |
|
static struct extent_buffer *find_extent_buffer_nolock( |
|
struct btrfs_fs_info *fs_info, u64 start) |
|
{ |
|
struct extent_buffer *eb; |
|
|
|
rcu_read_lock(); |
|
eb = radix_tree_lookup(&fs_info->buffer_radix, |
|
start >> fs_info->sectorsize_bits); |
|
if (eb && atomic_inc_not_zero(&eb->refs)) { |
|
rcu_read_unlock(); |
|
return eb; |
|
} |
|
rcu_read_unlock(); |
|
return NULL; |
|
} |
|
|
|
/* |
|
* The endio function for subpage extent buffer write. |
|
* |
|
* Unlike end_bio_extent_buffer_writepage(), we only call end_page_writeback() |
|
* after all extent buffers in the page has finished their writeback. |
|
*/ |
|
static void end_bio_subpage_eb_writepage(struct bio *bio) |
|
{ |
|
struct btrfs_fs_info *fs_info; |
|
struct bio_vec *bvec; |
|
struct bvec_iter_all iter_all; |
|
|
|
fs_info = btrfs_sb(bio_first_page_all(bio)->mapping->host->i_sb); |
|
ASSERT(fs_info->sectorsize < PAGE_SIZE); |
|
|
|
ASSERT(!bio_flagged(bio, BIO_CLONED)); |
|
bio_for_each_segment_all(bvec, bio, iter_all) { |
|
struct page *page = bvec->bv_page; |
|
u64 bvec_start = page_offset(page) + bvec->bv_offset; |
|
u64 bvec_end = bvec_start + bvec->bv_len - 1; |
|
u64 cur_bytenr = bvec_start; |
|
|
|
ASSERT(IS_ALIGNED(bvec->bv_len, fs_info->nodesize)); |
|
|
|
/* Iterate through all extent buffers in the range */ |
|
while (cur_bytenr <= bvec_end) { |
|
struct extent_buffer *eb; |
|
int done; |
|
|
|
/* |
|
* Here we can't use find_extent_buffer(), as it may |
|
* try to lock eb->refs_lock, which is not safe in endio |
|
* context. |
|
*/ |
|
eb = find_extent_buffer_nolock(fs_info, cur_bytenr); |
|
ASSERT(eb); |
|
|
|
cur_bytenr = eb->start + eb->len; |
|
|
|
ASSERT(test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)); |
|
done = atomic_dec_and_test(&eb->io_pages); |
|
ASSERT(done); |
|
|
|
if (bio->bi_status || |
|
test_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) { |
|
ClearPageUptodate(page); |
|
set_btree_ioerr(page, eb); |
|
} |
|
|
|
btrfs_subpage_clear_writeback(fs_info, page, eb->start, |
|
eb->len); |
|
end_extent_buffer_writeback(eb); |
|
/* |
|
* free_extent_buffer() will grab spinlock which is not |
|
* safe in endio context. Thus here we manually dec |
|
* the ref. |
|
*/ |
|
atomic_dec(&eb->refs); |
|
} |
|
} |
|
bio_put(bio); |
|
} |
|
|
|
static void end_bio_extent_buffer_writepage(struct bio *bio) |
|
{ |
|
struct bio_vec *bvec; |
|
struct extent_buffer *eb; |
|
int done; |
|
struct bvec_iter_all iter_all; |
|
|
|
ASSERT(!bio_flagged(bio, BIO_CLONED)); |
|
bio_for_each_segment_all(bvec, bio, iter_all) { |
|
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, eb); |
|
} |
|
|
|
end_page_writeback(page); |
|
|
|
if (!done) |
|
continue; |
|
|
|
end_extent_buffer_writeback(eb); |
|
} |
|
|
|
bio_put(bio); |
|
} |
|
|
|
static void prepare_eb_write(struct extent_buffer *eb) |
|
{ |
|
u32 nritems; |
|
unsigned long start; |
|
unsigned long end; |
|
|
|
clear_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags); |
|
atomic_set(&eb->io_pages, num_extent_pages(eb)); |
|
|
|
/* 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(eb); |
|
memzero_extent_buffer(eb, start, end - start); |
|
} |
|
} |
|
|
|
/* |
|
* Unlike the work in write_one_eb(), we rely completely on extent locking. |
|
* Page locking is only utilized at minimum to keep the VMM code happy. |
|
*/ |
|
static int write_one_subpage_eb(struct extent_buffer *eb, |
|
struct writeback_control *wbc, |
|
struct extent_page_data *epd) |
|
{ |
|
struct btrfs_fs_info *fs_info = eb->fs_info; |
|
struct page *page = eb->pages[0]; |
|
unsigned int write_flags = wbc_to_write_flags(wbc) | REQ_META; |
|
bool no_dirty_ebs = false; |
|
int ret; |
|
|
|
prepare_eb_write(eb); |
|
|
|
/* clear_page_dirty_for_io() in subpage helper needs page locked */ |
|
lock_page(page); |
|
btrfs_subpage_set_writeback(fs_info, page, eb->start, eb->len); |
|
|
|
/* Check if this is the last dirty bit to update nr_written */ |
|
no_dirty_ebs = btrfs_subpage_clear_and_test_dirty(fs_info, page, |
|
eb->start, eb->len); |
|
if (no_dirty_ebs) |
|
clear_page_dirty_for_io(page); |
|
|
|
ret = submit_extent_page(REQ_OP_WRITE | write_flags, wbc, |
|
&epd->bio_ctrl, page, eb->start, eb->len, |
|
eb->start - page_offset(page), |
|
end_bio_subpage_eb_writepage, 0, 0, false); |
|
if (ret) { |
|
btrfs_subpage_clear_writeback(fs_info, page, eb->start, eb->len); |
|
set_btree_ioerr(page, eb); |
|
unlock_page(page); |
|
|
|
if (atomic_dec_and_test(&eb->io_pages)) |
|
end_extent_buffer_writeback(eb); |
|
return -EIO; |
|
} |
|
unlock_page(page); |
|
/* |
|
* Submission finished without problem, if no range of the page is |
|
* dirty anymore, we have submitted a page. Update nr_written in wbc. |
|
*/ |
|
if (no_dirty_ebs) |
|
update_nr_written(wbc, 1); |
|
return ret; |
|
} |
|
|
|
static noinline_for_stack int write_one_eb(struct extent_buffer *eb, |
|
struct writeback_control *wbc, |
|
struct extent_page_data *epd) |
|
{ |
|
u64 disk_bytenr = eb->start; |
|
int i, num_pages; |
|
unsigned int write_flags = wbc_to_write_flags(wbc) | REQ_META; |
|
int ret = 0; |
|
|
|
prepare_eb_write(eb); |
|
|
|
num_pages = num_extent_pages(eb); |
|
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, wbc, |
|
&epd->bio_ctrl, p, disk_bytenr, |
|
PAGE_SIZE, 0, |
|
end_bio_extent_buffer_writepage, |
|
0, 0, false); |
|
if (ret) { |
|
set_btree_ioerr(p, eb); |
|
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; |
|
} |
|
disk_bytenr += 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; |
|
} |
|
|
|
/* |
|
* Submit one subpage btree page. |
|
* |
|
* The main difference to submit_eb_page() is: |
|
* - Page locking |
|
* For subpage, we don't rely on page locking at all. |
|
* |
|
* - Flush write bio |
|
* We only flush bio if we may be unable to fit current extent buffers into |
|
* current bio. |
|
* |
|
* Return >=0 for the number of submitted extent buffers. |
|
* Return <0 for fatal error. |
|
*/ |
|
static int submit_eb_subpage(struct page *page, |
|
struct writeback_control *wbc, |
|
struct extent_page_data *epd) |
|
{ |
|
struct btrfs_fs_info *fs_info = btrfs_sb(page->mapping->host->i_sb); |
|
int submitted = 0; |
|
u64 page_start = page_offset(page); |
|
int bit_start = 0; |
|
const int nbits = BTRFS_SUBPAGE_BITMAP_SIZE; |
|
int sectors_per_node = fs_info->nodesize >> fs_info->sectorsize_bits; |
|
int ret; |
|
|
|
/* Lock and write each dirty extent buffers in the range */ |
|
while (bit_start < nbits) { |
|
struct btrfs_subpage *subpage = (struct btrfs_subpage *)page->private; |
|
struct extent_buffer *eb; |
|
unsigned long flags; |
|
u64 start; |
|
|
|
/* |
|
* Take private lock to ensure the subpage won't be detached |
|
* in the meantime. |
|
*/ |
|
spin_lock(&page->mapping->private_lock); |
|
if (!PagePrivate(page)) { |
|
spin_unlock(&page->mapping->private_lock); |
|
break; |
|
} |
|
spin_lock_irqsave(&subpage->lock, flags); |
|
if (!((1 << bit_start) & subpage->dirty_bitmap)) { |
|
spin_unlock_irqrestore(&subpage->lock, flags); |
|
spin_unlock(&page->mapping->private_lock); |
|
bit_start++; |
|
continue; |
|
} |
|
|
|
start = page_start + bit_start * fs_info->sectorsize; |
|
bit_start += sectors_per_node; |
|
|
|
/* |
|
* Here we just want to grab the eb without touching extra |
|
* spin locks, so call find_extent_buffer_nolock(). |
|
*/ |
|
eb = find_extent_buffer_nolock(fs_info, start); |
|
spin_unlock_irqrestore(&subpage->lock, flags); |
|
spin_unlock(&page->mapping->private_lock); |
|
|
|
/* |
|
* The eb has already reached 0 refs thus find_extent_buffer() |
|
* doesn't return it. We don't need to write back such eb |
|
* anyway. |
|
*/ |
|
if (!eb) |
|
continue; |
|
|
|
ret = lock_extent_buffer_for_io(eb, epd); |
|
if (ret == 0) { |
|
free_extent_buffer(eb); |
|
continue; |
|
} |
|
if (ret < 0) { |
|
free_extent_buffer(eb); |
|
goto cleanup; |
|
} |
|
ret = write_one_subpage_eb(eb, wbc, epd); |
|
free_extent_buffer(eb); |
|
if (ret < 0) |
|
goto cleanup; |
|
submitted++; |
|
} |
|
return submitted; |
|
|
|
cleanup: |
|
/* We hit error, end bio for the submitted extent buffers */ |
|
end_write_bio(epd, ret); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Submit all page(s) of one extent buffer. |
|
* |
|
* @page: the page of one extent buffer |
|
* @eb_context: to determine if we need to submit this page, if current page |
|
* belongs to this eb, we don't need to submit |
|
* |
|
* The caller should pass each page in their bytenr order, and here we use |
|
* @eb_context to determine if we have submitted pages of one extent buffer. |
|
* |
|
* If we have, we just skip until we hit a new page that doesn't belong to |
|
* current @eb_context. |
|
* |
|
* If not, we submit all the page(s) of the extent buffer. |
|
* |
|
* Return >0 if we have submitted the extent buffer successfully. |
|
* Return 0 if we don't need to submit the page, as it's already submitted by |
|
* previous call. |
|
* Return <0 for fatal error. |
|
*/ |
|
static int submit_eb_page(struct page *page, struct writeback_control *wbc, |
|
struct extent_page_data *epd, |
|
struct extent_buffer **eb_context) |
|
{ |
|
struct address_space *mapping = page->mapping; |
|
struct btrfs_block_group *cache = NULL; |
|
struct extent_buffer *eb; |
|
int ret; |
|
|
|
if (!PagePrivate(page)) |
|
return 0; |
|
|
|
if (btrfs_sb(page->mapping->host->i_sb)->sectorsize < PAGE_SIZE) |
|
return submit_eb_subpage(page, wbc, epd); |
|
|
|
spin_lock(&mapping->private_lock); |
|
if (!PagePrivate(page)) { |
|
spin_unlock(&mapping->private_lock); |
|
return 0; |
|
} |
|
|
|
eb = (struct extent_buffer *)page->private; |
|
|
|
/* |
|
* Shouldn't happen and normally this would be a BUG_ON but no point |
|
* crashing the machine for something we can survive anyway. |
|
*/ |
|
if (WARN_ON(!eb)) { |
|
spin_unlock(&mapping->private_lock); |
|
return 0; |
|
} |
|
|
|
if (eb == *eb_context) { |
|
spin_unlock(&mapping->private_lock); |
|
return 0; |
|
} |
|
ret = atomic_inc_not_zero(&eb->refs); |
|
spin_unlock(&mapping->private_lock); |
|
if (!ret) |
|
return 0; |
|
|
|
if (!btrfs_check_meta_write_pointer(eb->fs_info, eb, &cache)) { |
|
/* |
|
* If for_sync, this hole will be filled with |
|
* trasnsaction commit. |
|
*/ |
|
if (wbc->sync_mode == WB_SYNC_ALL && !wbc->for_sync) |
|
ret = -EAGAIN; |
|
else |
|
ret = 0; |
|
free_extent_buffer(eb); |
|
return ret; |
|
} |
|
|
|
*eb_context = eb; |
|
|
|
ret = lock_extent_buffer_for_io(eb, epd); |
|
if (ret <= 0) { |
|
btrfs_revert_meta_write_pointer(cache, eb); |
|
if (cache) |
|
btrfs_put_block_group(cache); |
|
free_extent_buffer(eb); |
|
return ret; |
|
} |
|
if (cache) |
|
btrfs_put_block_group(cache); |
|
ret = write_one_eb(eb, wbc, epd); |
|
free_extent_buffer(eb); |
|
if (ret < 0) |
|
return ret; |
|
return 1; |
|
} |
|
|
|
int btree_write_cache_pages(struct address_space *mapping, |
|
struct writeback_control *wbc) |
|
{ |
|
struct extent_buffer *eb_context = NULL; |
|
struct extent_page_data epd = { |
|
.bio_ctrl = { 0 }, |
|
.extent_locked = 0, |
|
.sync_io = wbc->sync_mode == WB_SYNC_ALL, |
|
}; |
|
struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info; |
|
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; |
|
xa_mark_t tag; |
|
|
|
pagevec_init(&pvec); |
|
if (wbc->range_cyclic) { |
|
index = mapping->writeback_index; /* Start from prev offset */ |
|
end = -1; |
|
/* |
|
* Start from the beginning does not need to cycle over the |
|
* range, mark it as scanned. |
|
*/ |
|
scanned = (index == 0); |
|
} 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; |
|
btrfs_zoned_meta_io_lock(fs_info); |
|
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; |
|
|
|
for (i = 0; i < nr_pages; i++) { |
|
struct page *page = pvec.pages[i]; |
|
|
|
ret = submit_eb_page(page, wbc, &epd, &eb_context); |
|
if (ret == 0) |
|
continue; |
|
if (ret < 0) { |
|
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 (ret < 0) { |
|
end_write_bio(&epd, ret); |
|
goto out; |
|
} |
|
/* |
|
* If something went wrong, don't allow any metadata write bio to be |
|
* submitted. |
|
* |
|
* This would prevent use-after-free if we had dirty pages not |
|
* cleaned up, which can still happen by fuzzed images. |
|
* |
|
* - Bad extent tree |
|
* Allowing existing tree block to be allocated for other trees. |
|
* |
|
* - Log tree operations |
|
* Exiting tree blocks get allocated to log tree, bumps its |
|
* generation, then get cleaned in tree re-balance. |
|
* Such tree block will not be written back, since it's clean, |
|
* thus no WRITTEN flag set. |
|
* And after log writes back, this tree block is not traced by |
|
* any dirty extent_io_tree. |
|
* |
|
* - Offending tree block gets re-dirtied from its original owner |
|
* Since it has bumped generation, no WRITTEN flag, it can be |
|
* reused without COWing. This tree block will not be traced |
|
* by btrfs_transaction::dirty_pages. |
|
* |
|
* Now such dirty tree block will not be cleaned by any dirty |
|
* extent io tree. Thus we don't want to submit such wild eb |
|
* if the fs already has error. |
|
*/ |
|
if (!test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) { |
|
ret = flush_write_bio(&epd); |
|
} else { |
|
ret = -EROFS; |
|
end_write_bio(&epd, ret); |
|
} |
|
out: |
|
btrfs_zoned_meta_io_unlock(fs_info); |
|
return ret; |
|
} |
|
|
|
/** |
|
* 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 |
|
* @epd: holds context for the write, namely the bio |
|
* |
|
* 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; |
|
xa_mark_t 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; |
|
/* |
|
* Start from the beginning does not need to cycle over the |
|
* range, mark it as scanned. |
|
*/ |
|
scanned = (index == 0); |
|
} 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; |
|
} |
|
|
|
/* |
|
* We do the tagged writepage as long as the snapshot flush bit is set |
|
* and we are the first one who do the filemap_flush() on this inode. |
|
* |
|
* The nr_to_write == LONG_MAX is needed to make sure other flushers do |
|
* not race in and drop the bit. |
|
*/ |
|
if (range_whole && wbc->nr_to_write == LONG_MAX && |
|
test_and_clear_bit(BTRFS_INODE_SNAPSHOT_FLUSH, |
|
&BTRFS_I(inode)->runtime_flags)) |
|
wbc->tagged_writepages = 1; |
|
|
|
if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) |
|
tag = PAGECACHE_TAG_TOWRITE; |
|
else |
|
tag = PAGECACHE_TAG_DIRTY; |
|
retry: |
|
if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) |
|
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; |
|
|
|
for (i = 0; i < nr_pages; i++) { |
|
struct page *page = pvec.pages[i]; |
|
|
|
done_index = page->index + 1; |
|
/* |
|
* 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)) { |
|
ret = flush_write_bio(epd); |
|
BUG_ON(ret < 0); |
|
lock_page(page); |
|
} |
|
|
|
if (unlikely(page->mapping != mapping)) { |
|
unlock_page(page); |
|
continue; |
|
} |
|
|
|
if (wbc->sync_mode != WB_SYNC_NONE) { |
|
if (PageWriteback(page)) { |
|
ret = flush_write_bio(epd); |
|
BUG_ON(ret < 0); |
|
} |
|
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 (ret < 0) { |
|
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; |
|
|
|
/* |
|
* If we're looping we could run into a page that is locked by a |
|
* writer and that writer could be waiting on writeback for a |
|
* page in our current bio, and thus deadlock, so flush the |
|
* write bio here. |
|
*/ |
|
ret = flush_write_bio(epd); |
|
if (!ret) |
|
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; |
|
} |
|
|
|
int extent_write_full_page(struct page *page, struct writeback_control *wbc) |
|
{ |
|
int ret; |
|
struct extent_page_data epd = { |
|
.bio_ctrl = { 0 }, |
|
.extent_locked = 0, |
|
.sync_io = wbc->sync_mode == WB_SYNC_ALL, |
|
}; |
|
|
|
ret = __extent_writepage(page, wbc, &epd); |
|
ASSERT(ret <= 0); |
|
if (ret < 0) { |
|
end_write_bio(&epd, ret); |
|
return ret; |
|
} |
|
|
|
ret = flush_write_bio(&epd); |
|
ASSERT(ret <= 0); |
|
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 page *page; |
|
unsigned long nr_pages = (end - start + PAGE_SIZE) >> |
|
PAGE_SHIFT; |
|
|
|
struct extent_page_data epd = { |
|
.bio_ctrl = { 0 }, |
|
.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, |
|
/* We're called from an async helper function */ |
|
.punt_to_cgroup = 1, |
|
.no_cgroup_owner = 1, |
|
}; |
|
|
|
wbc_attach_fdatawrite_inode(&wbc_writepages, inode); |
|
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 { |
|
btrfs_writepage_endio_finish_ordered(BTRFS_I(inode), |
|
page, start, start + PAGE_SIZE - 1, 1); |
|
unlock_page(page); |
|
} |
|
put_page(page); |
|
start += PAGE_SIZE; |
|
} |
|
|
|
ASSERT(ret <= 0); |
|
if (ret == 0) |
|
ret = flush_write_bio(&epd); |
|
else |
|
end_write_bio(&epd, ret); |
|
|
|
wbc_detach_inode(&wbc_writepages); |
|
return ret; |
|
} |
|
|
|
int extent_writepages(struct address_space *mapping, |
|
struct writeback_control *wbc) |
|
{ |
|
int ret = 0; |
|
struct extent_page_data epd = { |
|
.bio_ctrl = { 0 }, |
|
.extent_locked = 0, |
|
.sync_io = wbc->sync_mode == WB_SYNC_ALL, |
|
}; |
|
|
|
ret = extent_write_cache_pages(mapping, wbc, &epd); |
|
ASSERT(ret <= 0); |
|
if (ret < 0) { |
|
end_write_bio(&epd, ret); |
|
return ret; |
|
} |
|
ret = flush_write_bio(&epd); |
|
return ret; |
|
} |
|
|
|
void extent_readahead(struct readahead_control *rac) |
|
{ |
|
struct btrfs_bio_ctrl bio_ctrl = { 0 }; |
|
struct page *pagepool[16]; |
|
struct extent_map *em_cached = NULL; |
|
u64 prev_em_start = (u64)-1; |
|
int nr; |
|
|
|
while ((nr = readahead_page_batch(rac, pagepool))) { |
|
u64 contig_start = readahead_pos(rac); |
|
u64 contig_end = contig_start + readahead_batch_length(rac) - 1; |
|
|
|
contiguous_readpages(pagepool, nr, contig_start, contig_end, |
|
&em_cached, &bio_ctrl, &prev_em_start); |
|
} |
|
|
|
if (em_cached) |
|
free_extent_map(em_cached); |
|
|
|
if (bio_ctrl.bio) { |
|
if (submit_one_bio(bio_ctrl.bio, 0, bio_ctrl.bio_flags)) |
|
return; |
|
} |
|
} |
|
|
|
/* |
|
* 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; |
|
|
|
/* This function is only called for the btree inode */ |
|
ASSERT(tree->owner == IO_TREE_BTREE_INODE_IO); |
|
|
|
start += ALIGN(offset, blocksize); |
|
if (start > end) |
|
return 0; |
|
|
|
lock_extent_bits(tree, start, end, &cached_state); |
|
wait_on_page_writeback(page); |
|
|
|
/* |
|
* Currently for btree io tree, only EXTENT_LOCKED is utilized, |
|
* so here we only need to unlock the extent range to free any |
|
* existing extent state. |
|
*/ |
|
unlock_extent_cached(tree, start, end, &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_LOCKED, 0, NULL)) { |
|
ret = 0; |
|
} else { |
|
/* |
|
* At this point we can safely clear everything except the |
|
* locked bit, the nodatasum bit and the delalloc new bit. |
|
* The delalloc new bit will be cleared by ordered extent |
|
* completion. |
|
*/ |
|
ret = __clear_extent_bit(tree, start, end, |
|
~(EXTENT_LOCKED | EXTENT_NODATASUM | EXTENT_DELALLOC_NEW), |
|
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) { |
|
struct btrfs_fs_info *fs_info; |
|
u64 cur_gen; |
|
|
|
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, 0, NULL)) |
|
goto next; |
|
/* |
|
* If it's not in the list of modified extents, used |
|
* by a fast fsync, we can remove it. If it's being |
|
* logged we can safely remove it since fsync took an |
|
* extra reference on the em. |
|
*/ |
|
if (list_empty(&em->list) || |
|
test_bit(EXTENT_FLAG_LOGGING, &em->flags)) |
|
goto remove_em; |
|
/* |
|
* If it's in the list of modified extents, remove it |
|
* only if its generation is older then the current one, |
|
* in which case we don't need it for a fast fsync. |
|
* Otherwise don't remove it, we could be racing with an |
|
* ongoing fast fsync that could miss the new extent. |
|
*/ |
|
fs_info = btrfs_inode->root->fs_info; |
|
spin_lock(&fs_info->trans_lock); |
|
cur_gen = fs_info->generation; |
|
spin_unlock(&fs_info->trans_lock); |
|
if (em->generation >= cur_gen) |
|
goto next; |
|
remove_em: |
|
/* |
|
* We only remove extent maps that are not in the list of |
|
* modified extents or that are in the list but with a |
|
* generation lower then the current generation, so there |
|
* is no need to set the full fsync flag on the inode (it |
|
* hurts the fsync performance for workloads with a data |
|
* size that exceeds or is close to the system's memory). |
|
*/ |
|
remove_extent_mapping(map, em); |
|
/* once for the rb tree */ |
|
free_extent_map(em); |
|
next: |
|
start = extent_map_end(em); |
|
write_unlock(&map->lock); |
|
|
|
/* once for us */ |
|
free_extent_map(em); |
|
|
|
cond_resched(); /* Allow large-extent preemption. */ |
|
} |
|
} |
|
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 btrfs_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(inode, offset, len); |
|
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 cached 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 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 btrfs_inode *inode, struct fiemap_extent_info *fieinfo, |
|
u64 start, u64 len) |
|
{ |
|
int ret = 0; |
|
u64 off; |
|
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->vfs_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 = inode->root; |
|
struct fiemap_cache cache = { 0 }; |
|
struct ulist *roots; |
|
struct ulist *tmp_ulist; |
|
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; |
|
|
|
roots = ulist_alloc(GFP_KERNEL); |
|
tmp_ulist = ulist_alloc(GFP_KERNEL); |
|
if (!roots || !tmp_ulist) { |
|
ret = -ENOMEM; |
|
goto out_free_ulist; |
|
} |
|
|
|
/* |
|
* We can't initialize that to 'start' as this could miss extents due |
|
* to extent item merging |
|
*/ |
|
off = 0; |
|
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(inode), -1, |
|
0); |
|
if (ret < 0) { |
|
goto out_free_ulist; |
|
} 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(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(&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(inode), |
|
bytenr, roots, tmp_ulist); |
|
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(fieinfo, &cache); |
|
free_extent_map(em); |
|
out: |
|
unlock_extent_cached(&inode->io_tree, start, start + len - 1, |
|
&cached_state); |
|
|
|
out_free_ulist: |
|
btrfs_free_path(path); |
|
ulist_free(roots); |
|
ulist_free(tmp_ulist); |
|
return ret; |
|
} |
|
|
|
static void __free_extent_buffer(struct extent_buffer *eb) |
|
{ |
|
kmem_cache_free(extent_buffer_cache, eb); |
|
} |
|
|
|
int extent_buffer_under_io(const struct extent_buffer *eb) |
|
{ |
|
return (atomic_read(&eb->io_pages) || |
|
test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) || |
|
test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)); |
|
} |
|
|
|
static bool page_range_has_eb(struct btrfs_fs_info *fs_info, struct page *page) |
|
{ |
|
struct btrfs_subpage *subpage; |
|
|
|
lockdep_assert_held(&page->mapping->private_lock); |
|
|
|
if (PagePrivate(page)) { |
|
subpage = (struct btrfs_subpage *)page->private; |
|
if (atomic_read(&subpage->eb_refs)) |
|
return true; |
|
/* |
|
* Even there is no eb refs here, we may still have |
|
* end_page_read() call relying on page::private. |
|
*/ |
|
if (atomic_read(&subpage->readers)) |
|
return true; |
|
} |
|
return false; |
|
} |
|
|
|
static void detach_extent_buffer_page(struct extent_buffer *eb, struct page *page) |
|
{ |
|
struct btrfs_fs_info *fs_info = eb->fs_info; |
|
const bool mapped = !test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags); |
|
|
|
/* |
|
* For mapped eb, we're going to change the page private, which should |
|
* be done under the private_lock. |
|
*/ |
|
if (mapped) |
|
spin_lock(&page->mapping->private_lock); |
|
|
|
if (!PagePrivate(page)) { |
|
if (mapped) |
|
spin_unlock(&page->mapping->private_lock); |
|
return; |
|
} |
|
|
|
if (fs_info->sectorsize == PAGE_SIZE) { |
|
/* |
|
* 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. |
|
*/ |
|
detach_page_private(page); |
|
} |
|
if (mapped) |
|
spin_unlock(&page->mapping->private_lock); |
|
return; |
|
} |
|
|
|
/* |
|
* For subpage, we can have dummy eb with page private. In this case, |
|
* we can directly detach the private as such page is only attached to |
|
* one dummy eb, no sharing. |
|
*/ |
|
if (!mapped) { |
|
btrfs_detach_subpage(fs_info, page); |
|
return; |
|
} |
|
|
|
btrfs_page_dec_eb_refs(fs_info, page); |
|
|
|
/* |
|
* We can only detach the page private if there are no other ebs in the |
|
* page range and no unfinished IO. |
|
*/ |
|
if (!page_range_has_eb(fs_info, page)) |
|
btrfs_detach_subpage(fs_info, page); |
|
|
|
spin_unlock(&page->mapping->private_lock); |
|
} |
|
|
|
/* Release all pages attached to the extent buffer */ |
|
static void btrfs_release_extent_buffer_pages(struct extent_buffer *eb) |
|
{ |
|
int i; |
|
int num_pages; |
|
|
|
ASSERT(!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; |
|
|
|
detach_extent_buffer_page(eb, page); |
|
|
|
/* 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); |
|
btrfs_leak_debug_del(&eb->fs_info->eb_leak_lock, &eb->leak_list); |
|
__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; |
|
init_rwsem(&eb->lock); |
|
|
|
btrfs_leak_debug_add(&fs_info->eb_leak_lock, &eb->leak_list, |
|
&fs_info->allocated_ebs); |
|
INIT_LIST_HEAD(&eb->release_list); |
|
|
|
spin_lock_init(&eb->refs_lock); |
|
atomic_set(&eb->refs, 1); |
|
atomic_set(&eb->io_pages, 0); |
|
|
|
ASSERT(len <= BTRFS_MAX_METADATA_BLOCKSIZE); |
|
|
|
return eb; |
|
} |
|
|
|
struct extent_buffer *btrfs_clone_extent_buffer(const 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; |
|
|
|
/* |
|
* Set UNMAPPED before calling btrfs_release_extent_buffer(), as |
|
* btrfs_release_extent_buffer() have different behavior for |
|
* UNMAPPED subpage extent buffer. |
|
*/ |
|
set_bit(EXTENT_BUFFER_UNMAPPED, &new->bflags); |
|
|
|
for (i = 0; i < num_pages; i++) { |
|
int ret; |
|
|
|
p = alloc_page(GFP_NOFS); |
|
if (!p) { |
|
btrfs_release_extent_buffer(new); |
|
return NULL; |
|
} |
|
ret = attach_extent_buffer_page(new, p, NULL); |
|
if (ret < 0) { |
|
put_page(p); |
|
btrfs_release_extent_buffer(new); |
|
return NULL; |
|
} |
|
WARN_ON(PageDirty(p)); |
|
new->pages[i] = p; |
|
copy_page(page_address(p), page_address(src->pages[i])); |
|
} |
|
set_extent_buffer_uptodate(new); |
|
|
|
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++) { |
|
int ret; |
|
|
|
eb->pages[i] = alloc_page(GFP_NOFS); |
|
if (!eb->pages[i]) |
|
goto err; |
|
ret = attach_extent_buffer_page(eb, eb->pages[i], NULL); |
|
if (ret < 0) |
|
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--) { |
|
detach_extent_buffer_page(eb, eb->pages[i - 1]); |
|
__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 TREE_REF bit is first set when the extent_buffer is added |
|
* to the radix tree. It is also reset, if unset, when a new reference |
|
* is created by find_extent_buffer. |
|
* |
|
* It is only cleared in two cases: freeing the last non-tree |
|
* reference to the extent_buffer when its STALE bit is set or |
|
* calling releasepage when the tree reference is the only reference. |
|
* |
|
* In both cases, care is taken to ensure that the extent_buffer's |
|
* pages are not under io. However, releasepage can be concurrently |
|
* called with creating new references, which is prone to race |
|
* conditions between the calls to check_buffer_tree_ref in those |
|
* codepaths and clearing TREE_REF in try_release_extent_buffer. |
|
* |
|
* The actual lifetime of the extent_buffer in the radix tree is |
|
* adequately protected by the refcount, but the TREE_REF bit and |
|
* its corresponding reference are not. To protect against this |
|
* class of races, we call check_buffer_tree_ref from the codepaths |
|
* which trigger io after they set eb->io_pages. Note that once io is |
|
* initiated, TREE_REF can no longer be cleared, so that is the |
|
* moment at which any such race is best fixed. |
|
*/ |
|
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; |
|
|
|
eb = find_extent_buffer_nolock(fs_info, start); |
|
if (!eb) |
|
return NULL; |
|
/* |
|
* 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; |
|
} |
|
|
|
#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 ERR_PTR(-ENOMEM); |
|
eb->fs_info = fs_info; |
|
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 >> fs_info->sectorsize_bits, 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); |
|
|
|
return eb; |
|
free_eb: |
|
btrfs_release_extent_buffer(eb); |
|
return exists; |
|
} |
|
#endif |
|
|
|
static struct extent_buffer *grab_extent_buffer( |
|
struct btrfs_fs_info *fs_info, struct page *page) |
|
{ |
|
struct extent_buffer *exists; |
|
|
|
/* |
|
* For subpage case, we completely rely on radix tree to ensure we |
|
* don't try to insert two ebs for the same bytenr. So here we always |
|
* return NULL and just continue. |
|
*/ |
|
if (fs_info->sectorsize < PAGE_SIZE) |
|
return NULL; |
|
|
|
/* Page not yet attached to an extent buffer */ |
|
if (!PagePrivate(page)) |
|
return NULL; |
|
|
|
/* |
|
* 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 *)page->private; |
|
if (atomic_inc_not_zero(&exists->refs)) |
|
return exists; |
|
|
|
WARN_ON(PageDirty(page)); |
|
detach_page_private(page); |
|
return NULL; |
|
} |
|
|
|
struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, |
|
u64 start, u64 owner_root, int level) |
|
{ |
|
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); |
|
} |
|
|
|
#if BITS_PER_LONG == 32 |
|
if (start >= MAX_LFS_FILESIZE) { |
|
btrfs_err_rl(fs_info, |
|
"extent buffer %llu is beyond 32bit page cache limit", start); |
|
btrfs_err_32bit_limit(fs_info); |
|
return ERR_PTR(-EOVERFLOW); |
|
} |
|
if (start >= BTRFS_32BIT_EARLY_WARN_THRESHOLD) |
|
btrfs_warn_32bit_limit(fs_info); |
|
#endif |
|
|
|
if (fs_info->sectorsize < PAGE_SIZE && |
|
offset_in_page(start) + len > PAGE_SIZE) { |
|
btrfs_err(fs_info, |
|
"tree block crosses page boundary, start %llu nodesize %lu", |
|
start, len); |
|
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); |
|
btrfs_set_buffer_lockdep_class(owner_root, eb, level); |
|
|
|
num_pages = num_extent_pages(eb); |
|
for (i = 0; i < num_pages; i++, index++) { |
|
struct btrfs_subpage *prealloc = NULL; |
|
|
|
p = find_or_create_page(mapping, index, GFP_NOFS|__GFP_NOFAIL); |
|
if (!p) { |
|
exists = ERR_PTR(-ENOMEM); |
|
goto free_eb; |
|
} |
|
|
|
/* |
|
* Preallocate page->private for subpage case, so that we won't |
|
* allocate memory with private_lock hold. The memory will be |
|
* freed by attach_extent_buffer_page() or freed manually if |
|
* we exit earlier. |
|
* |
|
* Although we have ensured one subpage eb can only have one |
|
* page, but it may change in the future for 16K page size |
|
* support, so we still preallocate the memory in the loop. |
|
*/ |
|
ret = btrfs_alloc_subpage(fs_info, &prealloc, |
|
BTRFS_SUBPAGE_METADATA); |
|
if (ret < 0) { |
|
unlock_page(p); |
|
put_page(p); |
|
exists = ERR_PTR(ret); |
|
goto free_eb; |
|
} |
|
|
|
spin_lock(&mapping->private_lock); |
|
exists = grab_extent_buffer(fs_info, p); |
|
if (exists) { |
|
spin_unlock(&mapping->private_lock); |
|
unlock_page(p); |
|
put_page(p); |
|
mark_extent_buffer_accessed(exists, p); |
|
btrfs_free_subpage(prealloc); |
|
goto free_eb; |
|
} |
|
/* Should not fail, as we have preallocated the memory */ |
|
ret = attach_extent_buffer_page(eb, p, prealloc); |
|
ASSERT(!ret); |
|
/* |
|
* To inform we have extra eb under allocation, so that |
|
* detach_extent_buffer_page() won't release the page private |
|
* when the eb hasn't yet been inserted into radix tree. |
|
* |
|
* The ref will be decreased when the eb released the page, in |
|
* detach_extent_buffer_page(). |
|
* Thus needs no special handling in error path. |
|
*/ |
|
btrfs_page_inc_eb_refs(fs_info, p); |
|
spin_unlock(&mapping->private_lock); |
|
|
|
WARN_ON(btrfs_page_test_dirty(fs_info, p, eb->start, eb->len)); |
|
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 >> fs_info->sectorsize_bits, 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) |
|
__releases(&eb->refs_lock) |
|
{ |
|
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 >> fs_info->sectorsize_bits); |
|
spin_unlock(&fs_info->buffer_lock); |
|
} else { |
|
spin_unlock(&eb->refs_lock); |
|
} |
|
|
|
btrfs_leak_debug_del(&eb->fs_info->eb_leak_lock, &eb->leak_list); |
|
/* 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 ((!test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags) && refs <= 3) |
|
|| (test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags) && |
|
refs == 1)) |
|
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_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); |
|
} |
|
|
|
static void btree_clear_page_dirty(struct page *page) |
|
{ |
|
ASSERT(PageDirty(page)); |
|
ASSERT(PageLocked(page)); |
|
clear_page_dirty_for_io(page); |
|
xa_lock_irq(&page->mapping->i_pages); |
|
if (!PageDirty(page)) |
|
__xa_clear_mark(&page->mapping->i_pages, |
|
page_index(page), PAGECACHE_TAG_DIRTY); |
|
xa_unlock_irq(&page->mapping->i_pages); |
|
} |
|
|
|
static void clear_subpage_extent_buffer_dirty(const struct extent_buffer *eb) |
|
{ |
|
struct btrfs_fs_info *fs_info = eb->fs_info; |
|
struct page *page = eb->pages[0]; |
|
bool last; |
|
|
|
/* btree_clear_page_dirty() needs page locked */ |
|
lock_page(page); |
|
last = btrfs_subpage_clear_and_test_dirty(fs_info, page, eb->start, |
|
eb->len); |
|
if (last) |
|
btree_clear_page_dirty(page); |
|
unlock_page(page); |
|
WARN_ON(atomic_read(&eb->refs) == 0); |
|
} |
|
|
|
void clear_extent_buffer_dirty(const struct extent_buffer *eb) |
|
{ |
|
int i; |
|
int num_pages; |
|
struct page *page; |
|
|
|
if (eb->fs_info->sectorsize < PAGE_SIZE) |
|
return clear_subpage_extent_buffer_dirty(eb); |
|
|
|
num_pages = num_extent_pages(eb); |
|
|
|
for (i = 0; i < num_pages; i++) { |
|
page = eb->pages[i]; |
|
if (!PageDirty(page)) |
|
continue; |
|
lock_page(page); |
|
btree_clear_page_dirty(page); |
|
ClearPageError(page); |
|
unlock_page(page); |
|
} |
|
WARN_ON(atomic_read(&eb->refs) == 0); |
|
} |
|
|
|
bool set_extent_buffer_dirty(struct extent_buffer *eb) |
|
{ |
|
int i; |
|
int num_pages; |
|
bool was_dirty; |
|
|
|
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)); |
|
|
|
if (!was_dirty) { |
|
bool subpage = eb->fs_info->sectorsize < PAGE_SIZE; |
|
|
|
/* |
|
* For subpage case, we can have other extent buffers in the |
|
* same page, and in clear_subpage_extent_buffer_dirty() we |
|
* have to clear page dirty without subpage lock held. |
|
* This can cause race where our page gets dirty cleared after |
|
* we just set it. |
|
* |
|
* Thankfully, clear_subpage_extent_buffer_dirty() has locked |
|
* its page for other reasons, we can use page lock to prevent |
|
* the above race. |
|
*/ |
|
if (subpage) |
|
lock_page(eb->pages[0]); |
|
for (i = 0; i < num_pages; i++) |
|
btrfs_page_set_dirty(eb->fs_info, eb->pages[i], |
|
eb->start, eb->len); |
|
if (subpage) |
|
unlock_page(eb->pages[0]); |
|
} |
|
#ifdef CONFIG_BTRFS_DEBUG |
|
for (i = 0; i < num_pages; i++) |
|
ASSERT(PageDirty(eb->pages[i])); |
|
#endif |
|
|
|
return was_dirty; |
|
} |
|
|
|
void clear_extent_buffer_uptodate(struct extent_buffer *eb) |
|
{ |
|
struct btrfs_fs_info *fs_info = eb->fs_info; |
|
struct page *page; |
|
int num_pages; |
|
int i; |
|
|
|
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) |
|
btrfs_page_clear_uptodate(fs_info, page, |
|
eb->start, eb->len); |
|
} |
|
} |
|
|
|
void set_extent_buffer_uptodate(struct extent_buffer *eb) |
|
{ |
|
struct btrfs_fs_info *fs_info = eb->fs_info; |
|
struct page *page; |
|
int num_pages; |
|
int i; |
|
|
|
set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); |
|
num_pages = num_extent_pages(eb); |
|
for (i = 0; i < num_pages; i++) { |
|
page = eb->pages[i]; |
|
btrfs_page_set_uptodate(fs_info, page, eb->start, eb->len); |
|
} |
|
} |
|
|
|
static int read_extent_buffer_subpage(struct extent_buffer *eb, int wait, |
|
int mirror_num) |
|
{ |
|
struct btrfs_fs_info *fs_info = eb->fs_info; |
|
struct extent_io_tree *io_tree; |
|
struct page *page = eb->pages[0]; |
|
struct btrfs_bio_ctrl bio_ctrl = { 0 }; |
|
int ret = 0; |
|
|
|
ASSERT(!test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags)); |
|
ASSERT(PagePrivate(page)); |
|
io_tree = &BTRFS_I(fs_info->btree_inode)->io_tree; |
|
|
|
if (wait == WAIT_NONE) { |
|
if (!try_lock_extent(io_tree, eb->start, eb->start + eb->len - 1)) |
|
return -EAGAIN; |
|
} else { |
|
ret = lock_extent(io_tree, eb->start, eb->start + eb->len - 1); |
|
if (ret < 0) |
|
return ret; |
|
} |
|
|
|
ret = 0; |
|
if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags) || |
|
PageUptodate(page) || |
|
btrfs_subpage_test_uptodate(fs_info, page, eb->start, eb->len)) { |
|
set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); |
|
unlock_extent(io_tree, eb->start, eb->start + eb->len - 1); |
|
return ret; |
|
} |
|
|
|
clear_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags); |
|
eb->read_mirror = 0; |
|
atomic_set(&eb->io_pages, 1); |
|
check_buffer_tree_ref(eb); |
|
btrfs_subpage_clear_error(fs_info, page, eb->start, eb->len); |
|
|
|
btrfs_subpage_start_reader(fs_info, page, eb->start, eb->len); |
|
ret = submit_extent_page(REQ_OP_READ | REQ_META, NULL, &bio_ctrl, |
|
page, eb->start, eb->len, |
|
eb->start - page_offset(page), |
|
end_bio_extent_readpage, mirror_num, 0, |
|
true); |
|
if (ret) { |
|
/* |
|
* In the endio function, if we hit something wrong we will |
|
* increase the io_pages, so here we need to decrease it for |
|
* error path. |
|
*/ |
|
atomic_dec(&eb->io_pages); |
|
} |
|
if (bio_ctrl.bio) { |
|
int tmp; |
|
|
|
tmp = submit_one_bio(bio_ctrl.bio, mirror_num, 0); |
|
bio_ctrl.bio = NULL; |
|
if (tmp < 0) |
|
return tmp; |
|
} |
|
if (ret || wait != WAIT_COMPLETE) |
|
return ret; |
|
|
|
wait_extent_bit(io_tree, eb->start, eb->start + eb->len - 1, EXTENT_LOCKED); |
|
if (!test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags)) |
|
ret = -EIO; |
|
return ret; |
|
} |
|
|
|
int read_extent_buffer_pages(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 btrfs_bio_ctrl bio_ctrl = { 0 }; |
|
|
|
if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags)) |
|
return 0; |
|
|
|
if (eb->fs_info->sectorsize < PAGE_SIZE) |
|
return read_extent_buffer_subpage(eb, wait, mirror_num); |
|
|
|
num_pages = num_extent_pages(eb); |
|
for (i = 0; i < num_pages; i++) { |
|
page = eb->pages[i]; |
|
if (wait == WAIT_NONE) { |
|
/* |
|
* WAIT_NONE is only utilized by readahead. If we can't |
|
* acquire the lock atomically it means either the eb |
|
* is being read out or under modification. |
|
* Either way the eb will be or has been cached, |
|
* readahead can exit safely. |
|
*/ |
|
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); |
|
/* |
|
* It is possible for releasepage to clear the TREE_REF bit before we |
|
* set io_pages. See check_buffer_tree_ref for a more detailed comment. |
|
*/ |
|
check_buffer_tree_ref(eb); |
|
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 = submit_extent_page(REQ_OP_READ | REQ_META, NULL, |
|
&bio_ctrl, page, page_offset(page), |
|
PAGE_SIZE, 0, end_bio_extent_readpage, |
|
mirror_num, 0, false); |
|
if (err) { |
|
/* |
|
* We failed to submit the bio so it's the |
|
* caller's responsibility to perform cleanup |
|
* i.e unlock page/set error bit. |
|
*/ |
|
ret = err; |
|
SetPageError(page); |
|
unlock_page(page); |
|
atomic_dec(&eb->io_pages); |
|
} |
|
} else { |
|
unlock_page(page); |
|
} |
|
} |
|
|
|
if (bio_ctrl.bio) { |
|
err = submit_one_bio(bio_ctrl.bio, mirror_num, bio_ctrl.bio_flags); |
|
bio_ctrl.bio = NULL; |
|
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; |
|
} |
|
|
|
static bool report_eb_range(const struct extent_buffer *eb, unsigned long start, |
|
unsigned long len) |
|
{ |
|
btrfs_warn(eb->fs_info, |
|
"access to eb bytenr %llu len %lu out of range start %lu len %lu", |
|
eb->start, eb->len, start, len); |
|
WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG)); |
|
|
|
return true; |
|
} |
|
|
|
/* |
|
* Check if the [start, start + len) range is valid before reading/writing |
|
* the eb. |
|
* NOTE: @start and @len are offset inside the eb, not logical address. |
|
* |
|
* Caller should not touch the dst/src memory if this function returns error. |
|
*/ |
|
static inline int check_eb_range(const struct extent_buffer *eb, |
|
unsigned long start, unsigned long len) |
|
{ |
|
unsigned long offset; |
|
|
|
/* start, start + len should not go beyond eb->len nor overflow */ |
|
if (unlikely(check_add_overflow(start, len, &offset) || offset > eb->len)) |
|
return report_eb_range(eb, start, len); |
|
|
|
return false; |
|
} |
|
|
|
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; |
|
unsigned long i = get_eb_page_index(start); |
|
|
|
if (check_eb_range(eb, start, len)) |
|
return; |
|
|
|
offset = get_eb_offset_in_page(eb, start); |
|
|
|
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_nofault(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; |
|
unsigned long i = get_eb_page_index(start); |
|
int ret = 0; |
|
|
|
WARN_ON(start > eb->len); |
|
WARN_ON(start + len > eb->start + eb->len); |
|
|
|
offset = get_eb_offset_in_page(eb, start); |
|
|
|
while (len > 0) { |
|
page = eb->pages[i]; |
|
|
|
cur = min(len, (PAGE_SIZE - offset)); |
|
kaddr = page_address(page); |
|
if (copy_to_user_nofault(dst, kaddr + offset, cur)) { |
|
ret = -EFAULT; |
|
break; |
|
} |
|
|
|
dst += cur; |
|
len -= cur; |
|
offset = 0; |
|
i++; |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
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; |
|
unsigned long i = get_eb_page_index(start); |
|
int ret = 0; |
|
|
|
if (check_eb_range(eb, start, len)) |
|
return -EINVAL; |
|
|
|
offset = get_eb_offset_in_page(eb, start); |
|
|
|
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; |
|
} |
|
|
|
/* |
|
* Check that the extent buffer is uptodate. |
|
* |
|
* For regular sector size == PAGE_SIZE case, check if @page is uptodate. |
|
* For subpage case, check if the range covered by the eb has EXTENT_UPTODATE. |
|
*/ |
|
static void assert_eb_page_uptodate(const struct extent_buffer *eb, |
|
struct page *page) |
|
{ |
|
struct btrfs_fs_info *fs_info = eb->fs_info; |
|
|
|
if (fs_info->sectorsize < PAGE_SIZE) { |
|
bool uptodate; |
|
|
|
uptodate = btrfs_subpage_test_uptodate(fs_info, page, |
|
eb->start, eb->len); |
|
WARN_ON(!uptodate); |
|
} else { |
|
WARN_ON(!PageUptodate(page)); |
|
} |
|
} |
|
|
|
void write_extent_buffer_chunk_tree_uuid(const struct extent_buffer *eb, |
|
const void *srcv) |
|
{ |
|
char *kaddr; |
|
|
|
assert_eb_page_uptodate(eb, eb->pages[0]); |
|
kaddr = page_address(eb->pages[0]) + |
|
get_eb_offset_in_page(eb, offsetof(struct btrfs_header, |
|
chunk_tree_uuid)); |
|
memcpy(kaddr, srcv, BTRFS_FSID_SIZE); |
|
} |
|
|
|
void write_extent_buffer_fsid(const struct extent_buffer *eb, const void *srcv) |
|
{ |
|
char *kaddr; |
|
|
|
assert_eb_page_uptodate(eb, eb->pages[0]); |
|
kaddr = page_address(eb->pages[0]) + |
|
get_eb_offset_in_page(eb, offsetof(struct btrfs_header, fsid)); |
|
memcpy(kaddr, srcv, BTRFS_FSID_SIZE); |
|
} |
|
|
|
void write_extent_buffer(const 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; |
|
unsigned long i = get_eb_page_index(start); |
|
|
|
WARN_ON(test_bit(EXTENT_BUFFER_NO_CHECK, &eb->bflags)); |
|
|
|
if (check_eb_range(eb, start, len)) |
|
return; |
|
|
|
offset = get_eb_offset_in_page(eb, start); |
|
|
|
while (len > 0) { |
|
page = eb->pages[i]; |
|
assert_eb_page_uptodate(eb, 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(const struct extent_buffer *eb, unsigned long start, |
|
unsigned long len) |
|
{ |
|
size_t cur; |
|
size_t offset; |
|
struct page *page; |
|
char *kaddr; |
|
unsigned long i = get_eb_page_index(start); |
|
|
|
if (check_eb_range(eb, start, len)) |
|
return; |
|
|
|
offset = get_eb_offset_in_page(eb, start); |
|
|
|
while (len > 0) { |
|
page = eb->pages[i]; |
|
assert_eb_page_uptodate(eb, 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(const struct extent_buffer *dst, |
|
const struct extent_buffer *src) |
|
{ |
|
int i; |
|
int num_pages; |
|
|
|
ASSERT(dst->len == src->len); |
|
|
|
if (dst->fs_info->sectorsize == PAGE_SIZE) { |
|
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])); |
|
} else { |
|
size_t src_offset = get_eb_offset_in_page(src, 0); |
|
size_t dst_offset = get_eb_offset_in_page(dst, 0); |
|
|
|
ASSERT(src->fs_info->sectorsize < PAGE_SIZE); |
|
memcpy(page_address(dst->pages[0]) + dst_offset, |
|
page_address(src->pages[0]) + src_offset, |
|
src->len); |
|
} |
|
} |
|
|
|
void copy_extent_buffer(const struct extent_buffer *dst, |
|
const 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; |
|
unsigned long i = get_eb_page_index(dst_offset); |
|
|
|
if (check_eb_range(dst, dst_offset, len) || |
|
check_eb_range(src, src_offset, len)) |
|
return; |
|
|
|
WARN_ON(src->len != dst_len); |
|
|
|
offset = get_eb_offset_in_page(dst, dst_offset); |
|
|
|
while (len > 0) { |
|
page = dst->pages[i]; |
|
assert_eb_page_uptodate(dst, 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(const struct extent_buffer *eb, |
|
unsigned long start, unsigned long nr, |
|
unsigned long *page_index, |
|
size_t *page_offset) |
|
{ |
|
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_in_page(eb->start) + byte_offset; |
|
|
|
*page_index = offset >> PAGE_SHIFT; |
|
*page_offset = offset_in_page(offset); |
|
} |
|
|
|
/** |
|
* 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(const 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]; |
|
assert_eb_page_uptodate(eb, 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(const 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]; |
|
assert_eb_page_uptodate(eb, 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]; |
|
assert_eb_page_uptodate(eb, 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(const 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]; |
|
assert_eb_page_uptodate(eb, 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]; |
|
assert_eb_page_uptodate(eb, 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(const struct extent_buffer *dst, |
|
unsigned long dst_offset, unsigned long src_offset, |
|
unsigned long len) |
|
{ |
|
size_t cur; |
|
size_t dst_off_in_page; |
|
size_t src_off_in_page; |
|
unsigned long dst_i; |
|
unsigned long src_i; |
|
|
|
if (check_eb_range(dst, dst_offset, len) || |
|
check_eb_range(dst, src_offset, len)) |
|
return; |
|
|
|
while (len > 0) { |
|
dst_off_in_page = get_eb_offset_in_page(dst, dst_offset); |
|
src_off_in_page = get_eb_offset_in_page(dst, src_offset); |
|
|
|
dst_i = get_eb_page_index(dst_offset); |
|
src_i = get_eb_page_index(src_offset); |
|
|
|
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(const struct extent_buffer *dst, |
|
unsigned long dst_offset, unsigned long src_offset, |
|
unsigned long len) |
|
{ |
|
size_t cur; |
|
size_t dst_off_in_page; |
|
size_t src_off_in_page; |
|
unsigned long dst_end = dst_offset + len - 1; |
|
unsigned long src_end = src_offset + len - 1; |
|
unsigned long dst_i; |
|
unsigned long src_i; |
|
|
|
if (check_eb_range(dst, dst_offset, len) || |
|
check_eb_range(dst, src_offset, len)) |
|
return; |
|
if (dst_offset < src_offset) { |
|
memcpy_extent_buffer(dst, dst_offset, src_offset, len); |
|
return; |
|
} |
|
while (len > 0) { |
|
dst_i = get_eb_page_index(dst_end); |
|
src_i = get_eb_page_index(src_end); |
|
|
|
dst_off_in_page = get_eb_offset_in_page(dst, dst_end); |
|
src_off_in_page = get_eb_offset_in_page(dst, src_end); |
|
|
|
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; |
|
} |
|
} |
|
|
|
static struct extent_buffer *get_next_extent_buffer( |
|
struct btrfs_fs_info *fs_info, struct page *page, u64 bytenr) |
|
{ |
|
struct extent_buffer *gang[BTRFS_SUBPAGE_BITMAP_SIZE]; |
|
struct extent_buffer *found = NULL; |
|
u64 page_start = page_offset(page); |
|
int ret; |
|
int i; |
|
|
|
ASSERT(in_range(bytenr, page_start, PAGE_SIZE)); |
|
ASSERT(PAGE_SIZE / fs_info->nodesize <= BTRFS_SUBPAGE_BITMAP_SIZE); |
|
lockdep_assert_held(&fs_info->buffer_lock); |
|
|
|
ret = radix_tree_gang_lookup(&fs_info->buffer_radix, (void **)gang, |
|
bytenr >> fs_info->sectorsize_bits, |
|
PAGE_SIZE / fs_info->nodesize); |
|
for (i = 0; i < ret; i++) { |
|
/* Already beyond page end */ |
|
if (gang[i]->start >= page_start + PAGE_SIZE) |
|
break; |
|
/* Found one */ |
|
if (gang[i]->start >= bytenr) { |
|
found = gang[i]; |
|
break; |
|
} |
|
} |
|
return found; |
|
} |
|
|
|
static int try_release_subpage_extent_buffer(struct page *page) |
|
{ |
|
struct btrfs_fs_info *fs_info = btrfs_sb(page->mapping->host->i_sb); |
|
u64 cur = page_offset(page); |
|
const u64 end = page_offset(page) + PAGE_SIZE; |
|
int ret; |
|
|
|
while (cur < end) { |
|
struct extent_buffer *eb = NULL; |
|
|
|
/* |
|
* Unlike try_release_extent_buffer() which uses page->private |
|
* to grab buffer, for subpage case we rely on radix tree, thus |
|
* we need to ensure radix tree consistency. |
|
* |
|
* We also want an atomic snapshot of the radix tree, thus go |
|
* with spinlock rather than RCU. |
|
*/ |
|
spin_lock(&fs_info->buffer_lock); |
|
eb = get_next_extent_buffer(fs_info, page, cur); |
|
if (!eb) { |
|
/* No more eb in the page range after or at cur */ |
|
spin_unlock(&fs_info->buffer_lock); |
|
break; |
|
} |
|
cur = eb->start + eb->len; |
|
|
|
/* |
|
* The same as try_release_extent_buffer(), to ensure the eb |
|
* won't disappear out from under us. |
|
*/ |
|
spin_lock(&eb->refs_lock); |
|
if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) { |
|
spin_unlock(&eb->refs_lock); |
|
spin_unlock(&fs_info->buffer_lock); |
|
break; |
|
} |
|
spin_unlock(&fs_info->buffer_lock); |
|
|
|
/* |
|
* If tree ref isn't set then we know the ref on this eb is a |
|
* real ref, so just return, this eb will likely be freed soon |
|
* anyway. |
|
*/ |
|
if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) { |
|
spin_unlock(&eb->refs_lock); |
|
break; |
|
} |
|
|
|
/* |
|
* Here we don't care about the return value, we will always |
|
* check the page private at the end. And |
|
* release_extent_buffer() will release the refs_lock. |
|
*/ |
|
release_extent_buffer(eb); |
|
} |
|
/* |
|
* Finally to check if we have cleared page private, as if we have |
|
* released all ebs in the page, the page private should be cleared now. |
|
*/ |
|
spin_lock(&page->mapping->private_lock); |
|
if (!PagePrivate(page)) |
|
ret = 1; |
|
else |
|
ret = 0; |
|
spin_unlock(&page->mapping->private_lock); |
|
return ret; |
|
|
|
} |
|
|
|
int try_release_extent_buffer(struct page *page) |
|
{ |
|
struct extent_buffer *eb; |
|
|
|
if (btrfs_sb(page->mapping->host->i_sb)->sectorsize < PAGE_SIZE) |
|
return try_release_subpage_extent_buffer(page); |
|
|
|
/* |
|
* We need to make sure nobody is changing page->private, as we rely on |
|
* page->private as the pointer to extent buffer. |
|
*/ |
|
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); |
|
} |
|
|
|
/* |
|
* btrfs_readahead_tree_block - attempt to readahead a child block |
|
* @fs_info: the fs_info |
|
* @bytenr: bytenr to read |
|
* @owner_root: objectid of the root that owns this eb |
|
* @gen: generation for the uptodate check, can be 0 |
|
* @level: level for the eb |
|
* |
|
* Attempt to readahead a tree block at @bytenr. If @gen is 0 then we do a |
|
* normal uptodate check of the eb, without checking the generation. If we have |
|
* to read the block we will not block on anything. |
|
*/ |
|
void btrfs_readahead_tree_block(struct btrfs_fs_info *fs_info, |
|
u64 bytenr, u64 owner_root, u64 gen, int level) |
|
{ |
|
struct extent_buffer *eb; |
|
int ret; |
|
|
|
eb = btrfs_find_create_tree_block(fs_info, bytenr, owner_root, level); |
|
if (IS_ERR(eb)) |
|
return; |
|
|
|
if (btrfs_buffer_uptodate(eb, gen, 1)) { |
|
free_extent_buffer(eb); |
|
return; |
|
} |
|
|
|
ret = read_extent_buffer_pages(eb, WAIT_NONE, 0); |
|
if (ret < 0) |
|
free_extent_buffer_stale(eb); |
|
else |
|
free_extent_buffer(eb); |
|
} |
|
|
|
/* |
|
* btrfs_readahead_node_child - readahead a node's child block |
|
* @node: parent node we're reading from |
|
* @slot: slot in the parent node for the child we want to read |
|
* |
|
* A helper for btrfs_readahead_tree_block, we simply read the bytenr pointed at |
|
* the slot in the node provided. |
|
*/ |
|
void btrfs_readahead_node_child(struct extent_buffer *node, int slot) |
|
{ |
|
btrfs_readahead_tree_block(node->fs_info, |
|
btrfs_node_blockptr(node, slot), |
|
btrfs_header_owner(node), |
|
btrfs_node_ptr_generation(node, slot), |
|
btrfs_header_level(node) - 1); |
|
}
|
|
|