| // SPDX-License-Identifier: GPL-2.0 |
| |
| #include <linux/bitops.h> |
| #include <linux/slab.h> |
| #include <linux/bio.h> |
| #include <linux/mm.h> |
| #include <linux/pagemap.h> |
| #include <linux/page-flags.h> |
| #include <linux/spinlock.h> |
| #include <linux/blkdev.h> |
| #include <linux/swap.h> |
| #include <linux/writeback.h> |
| #include <linux/pagevec.h> |
| #include <linux/prefetch.h> |
| #include <linux/cleancache.h> |
| #include <linux/fsverity.h> |
| #include "misc.h" |
| #include "extent_io.h" |
| #include "extent-io-tree.h" |
| #include "extent_map.h" |
| #include "ctree.h" |
| #include "btrfs_inode.h" |
| #include "volumes.h" |
| #include "check-integrity.h" |
| #include "locking.h" |
| #include "rcu-string.h" |
| #include "backref.h" |
| #include "disk-io.h" |
| #include "subpage.h" |
| #include "zoned.h" |
| #include "block-group.h" |
| |
| static struct kmem_cache *extent_state_cache; |
| static struct kmem_cache *extent_buffer_cache; |
| static struct bio_set btrfs_bioset; |
| |
| static inline bool extent_state_in_tree(const struct extent_state *state) |
| { |
| return !RB_EMPTY_NODE(&state->rb_node); |
| } |
| |
| #ifdef CONFIG_BTRFS_DEBUG |
| static LIST_HEAD(states); |
| static DEFINE_SPINLOCK(leak_lock); |
| |
| static inline void btrfs_leak_debug_add(spinlock_t *lock, |
| struct list_head *new, |
| struct list_head *head) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(lock, flags); |
| list_add(new, head); |
| spin_unlock_irqrestore(lock, flags); |
| } |
| |
| static inline void btrfs_leak_debug_del(spinlock_t *lock, |
| struct list_head *entry) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(lock, flags); |
| list_del(entry); |
| spin_unlock_irqrestore(lock, flags); |
| } |
| |
| void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info) |
| { |
| struct extent_buffer *eb; |
| unsigned long flags; |
| |
| /* |
| * If we didn't get into open_ctree our allocated_ebs will not be |
| * initialized, so just skip this. |
| */ |
| if (!fs_info->allocated_ebs.next) |
| return; |
| |
| spin_lock_irqsave(&fs_info->eb_leak_lock, flags); |
| while (!list_empty(&fs_info->allocated_ebs)) { |
| eb = list_first_entry(&fs_info->allocated_ebs, |
| struct extent_buffer, leak_list); |
| pr_err( |
| "BTRFS: buffer leak start %llu len %lu refs %d bflags %lu owner %llu\n", |
| eb->start, eb->len, atomic_read(&eb->refs), eb->bflags, |
| btrfs_header_owner(eb)); |
| list_del(&eb->leak_list); |
| kmem_cache_free(extent_buffer_cache, eb); |
| } |
| spin_unlock_irqrestore(&fs_info->eb_leak_lock, flags); |
| } |
| |
| static inline void btrfs_extent_state_leak_debug_check(void) |
| { |
| struct extent_state *state; |
| |
| while (!list_empty(&states)) { |
| state = list_entry(states.next, struct extent_state, leak_list); |
| pr_err("BTRFS: state leak: start %llu end %llu state %u in tree %d refs %d\n", |
| state->start, state->end, state->state, |
| extent_state_in_tree(state), |
| refcount_read(&state->refs)); |
| list_del(&state->leak_list); |
| kmem_cache_free(extent_state_cache, state); |
| } |
| } |
| |
| #define btrfs_debug_check_extent_io_range(tree, start, end) \ |
| __btrfs_debug_check_extent_io_range(__func__, (tree), (start), (end)) |
| static inline void __btrfs_debug_check_extent_io_range(const char *caller, |
| struct extent_io_tree *tree, u64 start, u64 end) |
| { |
| struct inode *inode = tree->private_data; |
| u64 isize; |
| |
| if (!inode || !is_data_inode(inode)) |
| return; |
| |
| isize = i_size_read(inode); |
| if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) { |
| btrfs_debug_rl(BTRFS_I(inode)->root->fs_info, |
| "%s: ino %llu isize %llu odd range [%llu,%llu]", |
| caller, btrfs_ino(BTRFS_I(inode)), isize, start, end); |
| } |
| } |
| #else |
| #define btrfs_leak_debug_add(lock, new, head) do {} while (0) |
| #define btrfs_leak_debug_del(lock, entry) do {} while (0) |
| #define btrfs_extent_state_leak_debug_check() do {} while (0) |
| #define btrfs_debug_check_extent_io_range(c, s, e) do {} while (0) |
| #endif |
| |
| struct tree_entry { |
| u64 start; |
| u64 end; |
| struct rb_node rb_node; |
| }; |
| |
| struct extent_page_data { |
| struct btrfs_bio_ctrl bio_ctrl; |
| /* tells writepage not to lock the state bits for this range |
| * it still does the unlocking |
| */ |
| unsigned int extent_locked:1; |
| |
| /* tells the submit_bio code to use REQ_SYNC */ |
| unsigned int sync_io:1; |
| }; |
| |
| static int add_extent_changeset(struct extent_state *state, u32 bits, |
| struct extent_changeset *changeset, |
| int set) |
| { |
| int ret; |
| |
| if (!changeset) |
| return 0; |
| if (set && (state->state & bits) == bits) |
| return 0; |
| if (!set && (state->state & bits) == 0) |
| return 0; |
| changeset->bytes_changed += state->end - state->start + 1; |
| ret = ulist_add(&changeset->range_changed, state->start, state->end, |
| GFP_ATOMIC); |
| return ret; |
| } |
| |
| int __must_check submit_one_bio(struct bio *bio, int mirror_num, |
| unsigned long bio_flags) |
| { |
| blk_status_t ret = 0; |
| struct extent_io_tree *tree = bio->bi_private; |
| |
| bio->bi_private = NULL; |
| |
| /* Caller should ensure the bio has at least some range added */ |
| ASSERT(bio->bi_iter.bi_size); |
| if (is_data_inode(tree->private_data)) |
| ret = btrfs_submit_data_bio(tree->private_data, bio, mirror_num, |
| bio_flags); |
| else |
| ret = btrfs_submit_metadata_bio(tree->private_data, bio, |
| mirror_num, bio_flags); |
| |
| return blk_status_to_errno(ret); |
| } |
| |
| /* Cleanup unsubmitted bios */ |
| static void end_write_bio(struct extent_page_data *epd, int ret) |
| { |
| struct bio *bio = epd->bio_ctrl.bio; |
| |
| if (bio) { |
| bio->bi_status = errno_to_blk_status(ret); |
| bio_endio(bio); |
| epd->bio_ctrl.bio = NULL; |
| } |
| } |
| |
| /* |
| * Submit bio from extent page data via submit_one_bio |
| * |
| * Return 0 if everything is OK. |
| * Return <0 for error. |
| */ |
| static int __must_check flush_write_bio(struct extent_page_data *epd) |
| { |
| int ret = 0; |
| struct bio *bio = epd->bio_ctrl.bio; |
| |
| if (bio) { |
| ret = submit_one_bio(bio, 0, 0); |
| /* |
| * Clean up of epd->bio is handled by its endio function. |
| * And endio is either triggered by successful bio execution |
| * or the error handler of submit bio hook. |
| * So at this point, no matter what happened, we don't need |
| * to clean up epd->bio. |
| */ |
| epd->bio_ctrl.bio = NULL; |
| } |
| return ret; |
| } |
| |
| int __init extent_state_cache_init(void) |
| { |
| extent_state_cache = kmem_cache_create("btrfs_extent_state", |
| sizeof(struct extent_state), 0, |
| SLAB_MEM_SPREAD, NULL); |
| if (!extent_state_cache) |
| return -ENOMEM; |
| return 0; |
| } |
| |
| int __init extent_io_init(void) |
| { |
| extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer", |
| sizeof(struct extent_buffer), 0, |
| SLAB_MEM_SPREAD, NULL); |
| if (!extent_buffer_cache) |
| return -ENOMEM; |
| |
| if (bioset_init(&btrfs_bioset, BIO_POOL_SIZE, |
| offsetof(struct btrfs_bio, bio), |
| BIOSET_NEED_BVECS)) |
| goto free_buffer_cache; |
| |
| if (bioset_integrity_create(&btrfs_bioset, BIO_POOL_SIZE)) |
| goto free_bioset; |
| |
| return 0; |
| |
| free_bioset: |
| bioset_exit(&btrfs_bioset); |
| |
| free_buffer_cache: |
| kmem_cache_destroy(extent_buffer_cache); |
| extent_buffer_cache = NULL; |
| return -ENOMEM; |
| } |
| |
| void __cold extent_state_cache_exit(void) |
| { |
| btrfs_extent_state_leak_debug_check(); |
| kmem_cache_destroy(extent_state_cache); |
| } |
| |
| void __cold extent_io_exit(void) |
| { |
| /* |
| * Make sure all delayed rcu free are flushed before we |
| * destroy caches. |
| */ |
| rcu_barrier(); |
| kmem_cache_destroy(extent_buffer_cache); |
| bioset_exit(&btrfs_bioset); |
| } |
| |
| /* |
| * For the file_extent_tree, we want to hold the inode lock when we lookup and |
| * update the disk_i_size, but lockdep will complain because our io_tree we hold |
| * the tree lock and get the inode lock when setting delalloc. These two things |
| * are unrelated, so make a class for the file_extent_tree so we don't get the |
| * two locking patterns mixed up. |
| */ |
| static struct lock_class_key file_extent_tree_class; |
| |
| void extent_io_tree_init(struct btrfs_fs_info *fs_info, |
| struct extent_io_tree *tree, unsigned int owner, |
| void *private_data) |
| { |
| tree->fs_info = fs_info; |
| tree->state = RB_ROOT; |
| tree->dirty_bytes = 0; |
| spin_lock_init(&tree->lock); |
| tree->private_data = private_data; |
| tree->owner = owner; |
| if (owner == IO_TREE_INODE_FILE_EXTENT) |
| lockdep_set_class(&tree->lock, &file_extent_tree_class); |
| } |
| |
| void extent_io_tree_release(struct extent_io_tree *tree) |
| { |
| spin_lock(&tree->lock); |
| /* |
| * Do a single barrier for the waitqueue_active check here, the state |
| * of the waitqueue should not change once extent_io_tree_release is |
| * called. |
| */ |
| smp_mb(); |
| while (!RB_EMPTY_ROOT(&tree->state)) { |
| struct rb_node *node; |
| struct extent_state *state; |
| |
| node = rb_first(&tree->state); |
| state = rb_entry(node, struct extent_state, rb_node); |
| rb_erase(&state->rb_node, &tree->state); |
| RB_CLEAR_NODE(&state->rb_node); |
| /* |
| * btree io trees aren't supposed to have tasks waiting for |
| * changes in the flags of extent states ever. |
| */ |
| ASSERT(!waitqueue_active(&state->wq)); |
| free_extent_state(state); |
| |
| cond_resched_lock(&tree->lock); |
| } |
| spin_unlock(&tree->lock); |
| } |
| |
| static struct extent_state *alloc_extent_state(gfp_t mask) |
| { |
| struct extent_state *state; |
| |
| /* |
| * The given mask might be not appropriate for the slab allocator, |
| * drop the unsupported bits |
| */ |
| mask &= ~(__GFP_DMA32|__GFP_HIGHMEM); |
| state = kmem_cache_alloc(extent_state_cache, mask); |
| if (!state) |
| return state; |
| state->state = 0; |
| state->failrec = NULL; |
| RB_CLEAR_NODE(&state->rb_node); |
| btrfs_leak_debug_add(&leak_lock, &state->leak_list, &states); |
| refcount_set(&state->refs, 1); |
| init_waitqueue_head(&state->wq); |
| trace_alloc_extent_state(state, mask, _RET_IP_); |
| return state; |
| } |
| |
| void free_extent_state(struct extent_state *state) |
| { |
| if (!state) |
| return; |
| if (refcount_dec_and_test(&state->refs)) { |
| WARN_ON(extent_state_in_tree(state)); |
| btrfs_leak_debug_del(&leak_lock, &state->leak_list); |
| trace_free_extent_state(state, _RET_IP_); |
| kmem_cache_free(extent_state_cache, state); |
| } |
| } |
| |
| static struct rb_node *tree_insert(struct rb_root *root, |
| struct rb_node *search_start, |
| u64 offset, |
| struct rb_node *node, |
| struct rb_node ***p_in, |
| struct rb_node **parent_in) |
| { |
| struct rb_node **p; |
| struct rb_node *parent = NULL; |
| struct tree_entry *entry; |
| |
| if (p_in && parent_in) { |
| p = *p_in; |
| parent = *parent_in; |
| goto do_insert; |
| } |
| |
| p = search_start ? &search_start : &root->rb_node; |
| while (*p) { |
| parent = *p; |
| entry = rb_entry(parent, struct tree_entry, rb_node); |
| |
| if (offset < entry->start) |
| p = &(*p)->rb_left; |
| else if (offset > entry->end) |
| p = &(*p)->rb_right; |
| else |
| return parent; |
| } |
| |
| do_insert: |
| rb_link_node(node, parent, p); |
| rb_insert_color(node, root); |
| return NULL; |
| } |
| |
| /** |
| * Search @tree for an entry that contains @offset. Such entry would have |
| * entry->start <= offset && entry->end >= offset. |
| * |
| * @tree: the tree to search |
| * @offset: offset that should fall within an entry in @tree |
| * @next_ret: pointer to the first entry whose range ends after @offset |
| * @prev_ret: pointer to the first entry whose range begins before @offset |
| * @p_ret: pointer where new node should be anchored (used when inserting an |
| * entry in the tree) |
| * @parent_ret: points to entry which would have been the parent of the entry, |
| * containing @offset |
| * |
| * This function returns a pointer to the entry that contains @offset byte |
| * address. If no such entry exists, then NULL is returned and the other |
| * pointer arguments to the function are filled, otherwise the found entry is |
| * returned and other pointers are left untouched. |
| */ |
| static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset, |
| struct rb_node **next_ret, |
| struct rb_node **prev_ret, |
| struct rb_node ***p_ret, |
| struct rb_node **parent_ret) |
| { |
| struct rb_root *root = &tree->state; |
| struct rb_node **n = &root->rb_node; |
| struct rb_node *prev = NULL; |
| struct rb_node *orig_prev = NULL; |
| struct tree_entry *entry; |
| struct tree_entry *prev_entry = NULL; |
| |
| while (*n) { |
| prev = *n; |
| entry = rb_entry(prev, struct tree_entry, rb_node); |
| prev_entry = entry; |
| |
| if (offset < entry->start) |
| n = &(*n)->rb_left; |
| else if (offset > entry->end) |
| n = &(*n)->rb_right; |
| else |
| 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: The original start bytenr to search. |
| * Will store the extent range start bytenr. |
| * @end: The original end bytenr of the search range |
| * Will store the extent range end bytenr. |
| * |
| * Return true if we find a delalloc range which starts inside the original |
| * range, and @start/@end will store the delalloc range start/end. |
| * |
| * Return false if we can't find any delalloc range which starts inside the |
| * original range, and @start/@end will be the non-delalloc range start/end. |
| */ |
| 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; |
| const u64 orig_start = *start; |
| const u64 orig_end = *end; |
| 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; |
| |
| /* Caller should pass a valid @end to indicate the search range end */ |
| ASSERT(orig_end > orig_start); |
| |
| /* The range should at least cover part of the page */ |
| ASSERT(!(orig_start >= page_offset(locked_page) + PAGE_SIZE || |
| orig_end <= page_offset(locked_page))); |
| 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 || delalloc_start > orig_end) { |
| *start = delalloc_start; |
| |
| /* @delalloc_end can be -1, never go beyond @orig_end */ |
| *end = min(delalloc_end, orig_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; |
| } |
| |
| 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. |
| */ |
| static 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_io_context *bioc = NULL; |
| int ret; |
| |
| ASSERT(!(fs_info->sb->s_flags & SB_RDONLY)); |
| BUG_ON(!mirror_num); |
| |
| if (btrfs_repair_one_zone(fs_info, logical)) |
| return 0; |
| |
| bio = btrfs_bio_alloc(1); |
| bio->bi_iter.bi_size = 0; |
| map_length = length; |
| |
| /* |
| * Avoid races with device replace and make sure our bioc 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, &bioc, 0); |
| if (ret) { |
| btrfs_bio_counter_dec(fs_info); |
| bio_put(bio); |
| return -EIO; |
| } |
| ASSERT(bioc->mirror_num == 1); |
| } else { |
| ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, logical, |
| &map_length, &bioc, mirror_num); |
| if (ret) { |
| btrfs_bio_counter_dec(fs_info); |
| bio_put(bio); |
| return -EIO; |
| } |
| BUG_ON(mirror_num != bioc->mirror_num); |
| } |
| |
| sector = bioc->stripes[bioc->mirror_num - 1].physical >> 9; |
| bio->bi_iter.bi_sector = sector; |
| dev = bioc->stripes[bioc->mirror_num - 1].dev; |
| btrfs_put_bioc(bioc); |
| 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_bio *failed_bbio = btrfs_bio(failed_bio); |
| const int icsum = bio_offset >> fs_info->sectorsize_bits; |
| struct bio *repair_bio; |
| struct btrfs_bio *repair_bbio; |
| 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_bio_alloc(1); |
| repair_bbio = btrfs_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_bbio->csum) { |
| const u32 csum_size = fs_info->csum_size; |
| |
| repair_bbio->csum = repair_bbio->csum_inline; |
| memcpy(repair_bbio->csum, |
| failed_bbio->csum + csum_size * icsum, csum_size); |
| } |
| |
| bio_add_page(repair_bio, page, failrec->len, pgoff); |
| repair_bbio->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) { |
| if (fsverity_active(page->mapping->host) && |
| !PageError(page) && |
| !PageUptodate(page) && |
| start < i_size_read(page->mapping->host) && |
| !fsverity_verify_page(page)) { |
| btrfs_page_set_error(fs_info, page, start, len); |
| } else { |
| 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; |
| const bool 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) { |
| const struct btrfs_fs_info *fs_info = inode->root->fs_info; |
| u32 len; |
| |
| ASSERT(end + 1 - start <= U32_MAX); |
| len = end + 1 - start; |
| |
| btrfs_page_clear_uptodate(fs_info, page, start, len); |
| btrfs_page_set_error(fs_info, page, start, len); |
| 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_bio *bbio = btrfs_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, |
| bbio->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 = bbio->mirror_num; |
| if (likely(uptodate)) { |
| if (is_data_inode(inode)) { |
| error_bitmap = btrfs_verify_data_csum(bbio, |
| bio_offset, page, start, end); |
| ret = error_bitmap; |
| } else { |
| ret = btrfs_validate_metadata_buffer(bbio, |
| 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); |
| } |
| 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, PageUptodate(page)); |
| } |
| /* Release the last extent */ |
| endio_readpage_release_extent(&processed, NULL, 0, 0, false); |
| btrfs_bio_free_csum(bbio); |
| 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_bio_init(struct btrfs_bio *bbio) |
| { |
| memset(bbio, 0, offsetof(struct btrfs_bio, bio)); |
| } |
| |
| /* |
| * Allocate a btrfs_io_bio, with @nr_iovecs as maximum number of iovecs. |
| * |
| * The bio allocation is backed by bioset and does not fail. |
| */ |
| struct bio *btrfs_bio_alloc(unsigned int nr_iovecs) |
| { |
| struct bio *bio; |
| |
| ASSERT(0 < nr_iovecs && nr_iovecs <= BIO_MAX_VECS); |
| bio = bio_alloc_bioset(GFP_NOFS, nr_iovecs, &btrfs_bioset); |
| btrfs_bio_init(btrfs_bio(bio)); |
| return bio; |
| } |
| |
| struct bio *btrfs_bio_clone(struct bio *bio) |
| { |
| struct btrfs_bio *bbio; |
| struct bio *new; |
| |
| /* Bio allocation backed by a bioset does not fail */ |
| new = bio_clone_fast(bio, GFP_NOFS, &btrfs_bioset); |
| bbio = btrfs_bio(new); |
| btrfs_bio_init(bbio); |
| bbio->iter = bio->bi_iter; |
| return new; |
| } |
| |
| struct bio *btrfs_bio_clone_partial(struct bio *orig, u64 offset, u64 size) |
| { |
| struct bio *bio; |
| struct btrfs_bio *bbio; |
| |
| ASSERT(offset <= UINT_MAX && size <= UINT_MAX); |
| |
| /* this will never fail when it's backed by a bioset */ |
| bio = bio_clone_fast(orig, GFP_NOFS, &btrfs_bioset); |
| ASSERT(bio); |
| |
| bbio = btrfs_bio(bio); |
| btrfs_bio_init(bbio); |
| |
| bio_trim(bio, offset >> 9, size >> 9); |
| bbio->iter = bio->bi_iter; |
| return bio; |
| } |
| |
| /** |
| * Attempt to add a page to bio |
| * |
| * @bio_ctrl: record both the bio, and its bio_flags |
| * @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 |
| * @size: portion of page that we want to write |
| * @pg_offset: starting offset in the page |
| * @bio_flags: flags of the current bio to see if we can merge them |
| * |
| * Attempt to add a page to bio considering stripe alignment etc. |
| * |
| * Return >= 0 for the number of bytes added to the bio. |
| * Can return 0 if the current bio is already at stripe/zone boundary. |
| * Return <0 for error. |
| */ |
| static int 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; |
| u32 real_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 0; |
| |
| 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 0; |
| |
| real_size = min(bio_ctrl->len_to_oe_boundary, |
| bio_ctrl->len_to_stripe_boundary) - bio_size; |
| real_size = min(real_size, size); |
| |
| /* |
| * If real_size is 0, never call bio_add_*_page(), as even size is 0, |
| * bio will still execute its endio function on the page! |
| */ |
| if (real_size == 0) |
| return 0; |
| |
| if (bio_op(bio) == REQ_OP_ZONE_APPEND) |
| ret = bio_add_zone_append_page(bio, page, real_size, pg_offset); |
| else |
| ret = bio_add_page(bio, page, real_size, pg_offset); |
| |
| return ret; |
| } |
| |
| static int calc_bio_boundaries(struct btrfs_bio_ctrl *bio_ctrl, |
| struct btrfs_inode *inode, u64 file_offset) |
| { |
| 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 (bio_op(bio_ctrl->bio) != REQ_OP_ZONE_APPEND) { |
| bio_ctrl->len_to_oe_boundary = U32_MAX; |
| return 0; |
| } |
| |
| /* Ordered extent not yet created, so we're good */ |
| ordered = btrfs_lookup_ordered_extent(inode, file_offset); |
| 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; |
| } |
| |
| static int alloc_new_bio(struct btrfs_inode *inode, |
| struct btrfs_bio_ctrl *bio_ctrl, |
| struct writeback_control *wbc, |
| unsigned int opf, |
| bio_end_io_t end_io_func, |
| u64 disk_bytenr, u32 offset, u64 file_offset, |
| unsigned long bio_flags) |
| { |
| struct btrfs_fs_info *fs_info = inode->root->fs_info; |
| struct bio *bio; |
| int ret; |
| |
| bio = btrfs_bio_alloc(BIO_MAX_VECS); |
| /* |
| * For compressed page range, its disk_bytenr is always @disk_bytenr |
| * passed in, no matter if we have added any range into previous bio. |
| */ |
| if (bio_flags & EXTENT_BIO_COMPRESSED) |
| bio->bi_iter.bi_sector = disk_bytenr >> SECTOR_SHIFT; |
| else |
| bio->bi_iter.bi_sector = (disk_bytenr + offset) >> SECTOR_SHIFT; |
| bio_ctrl->bio = bio; |
| bio_ctrl->bio_flags = bio_flags; |
| bio->bi_end_io = end_io_func; |
| bio->bi_private = &inode->io_tree; |
| bio->bi_write_hint = inode->vfs_inode.i_write_hint; |
| bio->bi_opf = opf; |
| ret = calc_bio_boundaries(bio_ctrl, inode, file_offset); |
| if (ret < 0) |
| goto error; |
| if (wbc) { |
| struct block_device *bdev; |
| |
| bdev = fs_info->fs_devices->latest_dev->bdev; |
| bio_set_dev(bio, bdev); |
| wbc_init_bio(wbc, bio); |
| } |
| if (bio_op(bio) == REQ_OP_ZONE_APPEND) { |
| struct btrfs_device *device; |
| |
| device = btrfs_zoned_get_device(fs_info, disk_bytenr, |
| fs_info->sectorsize); |
| if (IS_ERR(device)) { |
| ret = PTR_ERR(device); |
| goto error; |
| } |
| |
| btrfs_bio(bio)->device = device; |
| } |
| return 0; |
| error: |
| bio_ctrl->bio = NULL; |
| bio->bi_status = errno_to_blk_status(ret); |
| bio_endio(bio); |
| return ret; |
| } |
| |
| /* |
| * @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 btrfs_inode *inode = BTRFS_I(page->mapping->host); |
| unsigned int cur = pg_offset; |
| |
| ASSERT(bio_ctrl); |
| |
| ASSERT(pg_offset < PAGE_SIZE && size <= PAGE_SIZE && |
| pg_offset + size <= PAGE_SIZE); |
| if (force_bio_submit && bio_ctrl->bio) { |
| ret = submit_one_bio(bio_ctrl->bio, mirror_num, bio_ctrl->bio_flags); |
| bio_ctrl->bio = NULL; |
| if (ret < 0) |
| return ret; |
| } |
| |
| while (cur < pg_offset + size) { |
| u32 offset = cur - pg_offset; |
| int added; |
| |
| /* Allocate new bio if needed */ |
| if (!bio_ctrl->bio) { |
| ret = alloc_new_bio(inode, bio_ctrl, wbc, opf, |
| end_io_func, disk_bytenr, offset, |
| page_offset(page) + cur, |
| bio_flags); |
| if (ret < 0) |
| return ret; |
| } |
| /* |
| * We must go through btrfs_bio_add_page() to ensure each |
| * page range won't cross various boundaries. |
| */ |
| if (bio_flags & EXTENT_BIO_COMPRESSED) |
| added = btrfs_bio_add_page(bio_ctrl, page, disk_bytenr, |
| size - offset, pg_offset + offset, |
| bio_flags); |
| else |
| added = btrfs_bio_add_page(bio_ctrl, page, |
| disk_bytenr + offset, size - offset, |
| pg_offset + offset, bio_flags); |
| |
| /* Metadata page range should never be split */ |
| if (!is_data_inode(&inode->vfs_inode)) |
| ASSERT(added == 0 || added == size - offset); |
| |
| /* At least we added some page, update the account */ |
| if (wbc && added) |
| wbc_account_cgroup_owner(wbc, page, added); |
| |
| /* We have reached boundary, submit right now */ |
| if (added < size - offset) { |
| /* The bio should contain some page(s) */ |
| ASSERT(bio_ctrl->bio->bi_iter.bi_size); |
| ret = submit_one_bio(bio_ctrl->bio, mirror_num, |
| bio_ctrl->bio_flags); |
| bio_ctrl->bio = NULL; |
| if (ret < 0) |
| return ret; |
| } |
| cur += added; |
| } |
| return 0; |
| } |
| |
| 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; |
| 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) { |
| unsigned long this_bio_flag = 0; |
| bool force_bio_submit = false; |
| u64 disk_bytenr; |
| |
| ASSERT(IS_ALIGNED(cur, fs_info->sectorsize)); |
| 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)) { |
| 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) |
| { |
| const u64 page_end = page_offset(page) + PAGE_SIZE - 1; |
| u64 delalloc_start = page_offset(page); |
| u64 delalloc_to_write = 0; |
| /* How many pages are started by btrfs_run_delalloc_range() */ |
| unsigned long nr_written = 0; |
| int ret; |
| int page_started = 0; |
| |
| while (delalloc_start < page_end) { |
| u64 delalloc_end = page_end; |
| bool found; |
| |
| 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) { |
| btrfs_page_set_error(inode->root->fs_info, page, |
| page_offset(page), PAGE_SIZE); |
| return ret; |
| } |
| /* |
| * 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 btrfs_run_dealloc_range() 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; |
| struct btrfs_subpage_info *spi = fs_info->subpage_info; |
| u64 orig_start = *start; |
| /* Declare as unsigned long so we can use bitmap ops */ |
| unsigned long flags; |
| int range_start_bit; |
| 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; |
| } |
| |
| range_start_bit = spi->dirty_offset + |
| (offset_in_page(orig_start) >> fs_info->sectorsize_bits); |
| |
| /* We should have the page locked, but just in case */ |
| spin_lock_irqsave(&subpage->lock, flags); |
| bitmap_next_set_region(subpage->bitmaps, &range_start_bit, &range_end_bit, |
| spi->dirty_offset + spi->bitmap_nr_bits); |
| spin_unlock_irqrestore(&subpage->lock, flags); |
| |
| range_start_bit -= spi->dirty_offset; |
| range_end_bit -= spi->dirty_offset; |
| |
| *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, |
| int *nr_ret) |
| { |
| struct btrfs_fs_info *fs_info = inode->root->fs_info; |
| u64 cur = page_offset(page); |
| u64 end = cur + PAGE_SIZE - 1; |
| 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); |
| if (ret) { |
| /* Fixup worker will requeue */ |
| redirty_page_for_writepage(wbc, page); |
| 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, 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, true); |
| /* |
| * This range is beyond i_size, thus we don't need to |
| * bother writing back. |
| * But we still need to clear the dirty subpage bit, or |
| * the next time the page gets dirtied, we will try to |
| * writeback the sectors with subpage dirty bits, |
| * causing writeback without ordered extent. |
| */ |
| btrfs_page_clear_dirty(fs_info, page, cur, end + 1 - cur); |
| 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, true); |
| btrfs_page_clear_dirty(fs_info, page, cur, iosize); |
| 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++; |
| } |
| /* |
| * If we finish without problem, we should not only clear page dirty, |
| * but also empty subpage dirty bits |
| */ |
| if (!ret) |
| btrfs_page_assert_not_dirty(fs_info, page); |
| *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; |
| struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); |
| const u64 page_start = page_offset(page); |
| const u64 page_end = page_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; |
| |
| trace___extent_writepage(page, inode, wbc); |
| |
| WARN_ON(!PageLocked(page)); |
| |
| btrfs_page_clear_error(btrfs_sb(inode->i_sb), page, |
| page_offset(page), PAGE_SIZE); |
| |
| 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); |
| if (ret == 1) |
| return 0; |
| if (ret) |
| goto done; |
| } |
| |
| ret = __extent_writepage_io(BTRFS_I(inode), page, wbc, epd, i_size, |
| &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); |
| } |
| /* |
| * Here we used to have a check for PageError() and then set @ret and |
| * call end_extent_writepage(). |
| * |
| * But in fact setting @ret here will cause different error paths |
| * between subpage and regular sectorsize. |
| * |
| * For regular page size, we never submit current page, but only add |
| * current page to current bio. |
| * The bio submission can only happen in next page. |
| * Thus if we hit the PageError() branch, @ret is already set to |
| * non-zero value and will not get updated for regular sectorsize. |
| * |
| * But for subpage case, it's possible we submit part of current page, |
| * thus can get PageError() set by submitted bio of the same page, |
| * while our @ret is still 0. |
| * |
| * So here we unify the behavior and don't set @ret. |
| * Error can still be properly passed to higher layer as page will |
| * be set error, here we just don't handle the IO failure. |
| * |
| * NOTE: This is just a hotfix for subpage. |
| * The root fix will be properly ending ordered extent when we hit |
| * an error during writeback. |
| * |
| * But that needs a bigger refactoring, as we not only need to grab the |
| * submitted OE, but also need to know exactly at which bytenr we hit |
| * the error. |
| * Currently the full page based __extent_writepage_io() is not |
| * capable of that. |
| */ |
| if (PageError(page)) |
| end_extent_writepage(page, ret, page_start, page_end); |
| if (epd->extent_locked) { |
| /* |
| * If epd->extent_locked, it's from extent_write_locked_range(), |
| * the page can either be locked by lock_page() or |
| * process_one_page(). |
| * Let btrfs_page_unlock_writer() handle both cases. |
| */ |
| ASSERT(wbc); |
| btrfs_page_unlock_writer(fs_info, page, wbc->range_start, |
| wbc->range_end + 1 - wbc->range_start); |
| } else { |
| 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) |
| { |
| if (test_bit(EXTENT_BUFFER_ZONE_FINISH, &eb->bflags)) |
| btrfs_zone_finish_endio(eb->fs_info, eb->start, eb->len); |
| |
| 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; |
| |
| /* |
| * A read may stumble upon this buffer later, make sure that it gets an |
| * error and knows there was an error. |
| */ |
| clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); |
| |
| /* |
| * We need to set the mapping with the io error as well because a write |
| * error will flip the file system readonly, and then syncfs() will |
| * return a 0 because we are readonly if we don't modify the err seq for |
| * the superblock. |
| */ |
| mapping_set_error(page->mapping, -EIO); |
| |
| /* |
| * 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; |
| 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 < fs_info->subpage_info->bitmap_nr_bits) { |
| 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 (!test_bit(bit_start + fs_info->subpage_info->dirty_offset, |
| subpage->bitmaps)) { |
| 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) { |
| /* Impiles write in zoned mode */ |
| btrfs_put_block_group(cache); |
| /* Mark the last eb in a block group */ |
| if (cache->seq_zone && eb->start + eb->len == cache->zone_capacity) |
| set_bit(EXTENT_BUFFER_ZONE_FINISH, &eb->bflags); |
| } |
| 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 (!BTRFS_FS_ERROR(fs_info)) { |
| 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; |
| } |
| |
| /* |
| * Submit the pages in the range to bio for call sites which delalloc range has |
| * already been ran (aka, ordered extent inserted) and all pages are still |
| * locked. |
| */ |
| int extent_write_locked_range(struct inode *inode, u64 start, u64 end) |
| { |
| bool found_error = false; |
| int first_error = 0; |
| int ret = 0; |
| struct address_space *mapping = inode->i_mapping; |
| struct page *page; |
| u64 cur = start; |
| unsigned long nr_pages; |
| const u32 sectorsize = btrfs_sb(inode->i_sb)->sectorsize; |
| struct extent_page_data epd = { |
| .bio_ctrl = { 0 }, |
| .extent_locked = 1, |
| .sync_io = 1, |
| }; |
| struct writeback_control wbc_writepages = { |
| .sync_mode = WB_SYNC_ALL, |
| .range_start = start, |
| .range_end = end + 1, |
| /* We're called from an async helper function */ |
| .punt_to_cgroup = 1, |
| .no_cgroup_owner = 1, |
| }; |
| |
| ASSERT(IS_ALIGNED(start, sectorsize) && IS_ALIGNED(end + 1, sectorsize)); |
| nr_pages = (round_up(end, PAGE_SIZE) - round_down(start, PAGE_SIZE)) >> |
| PAGE_SHIFT; |
| wbc_writepages.nr_to_write = nr_pages * 2; |
| |
| wbc_attach_fdatawrite_inode(&wbc_writepages, inode); |
| while (cur <= end) { |
| u64 cur_end = min(round_down(cur, PAGE_SIZE) + PAGE_SIZE - 1, end); |
| |
| page = find_get_page(mapping, cur >> PAGE_SHIFT); |
| /* |
| * All pages in the range are locked since |
| * btrfs_run_delalloc_range(), thus there is no way to clear |
| * the page dirty flag. |
| */ |
| ASSERT(PageLocked(page)); |
| ASSERT(PageDirty(page)); |
| clear_page_dirty_for_io(page); |
| ret = __extent_writepage(page, &wbc_writepages, &epd); |
| ASSERT(ret <= 0); |
| if (ret < 0) { |
| found_error = true; |
| first_error = ret; |
| } |
| put_page(page); |
| cur = cur_end + 1; |
| } |
| |
| if (!found_error) |
| ret = flush_write_bio(&epd); |
| else |
| end_write_bio(&epd, ret); |
| |
| wbc_detach_inode(&wbc_writepages); |
| if (found_error) |
| return first_error; |
| return ret; |
| } |
| |
| int extent_writepages(struct address_space *mapping, |
| struct writeback_control *wbc) |
| { |
| struct inode *inode = mapping->host; |
| int ret = 0; |
| struct extent_page_data epd = { |
| .bio_ctrl = { 0 }, |
| .extent_locked = 0, |
| .sync_io = wbc->sync_mode == WB_SYNC_ALL, |
| }; |
| |
| /* |
| * Allow only a single thread to do the reloc work in zoned mode to |
| * protect the write pointer updates. |
| */ |
| btrfs_zoned_data_reloc_lock(BTRFS_I(inode)); |
| ret = extent_write_cache_pages(mapping, wbc, &epd); |
| btrfs_zoned_data_reloc_unlock(BTRFS_I(inode)); |
| 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. |
| */ |
| if (fs_info->sectorsize < PAGE_SIZE) { |
| prealloc = btrfs_alloc_subpage(fs_info, BTRFS_SUBPAGE_METADATA); |
| if (IS_ERR(prealloc)) { |
| ret = PTR_ERR(prealloc); |
| 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; |
| |
| /* |
| * We could have had EXTENT_BUFFER_UPTODATE cleared by the write |
| * operation, which could potentially still be in flight. In this case |
| * we simply want to return an error. |
| */ |
| if (unlikely(test_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags))) |
| return -EIO; |
| |
| 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; |
| } |
| } |
| |
| #define GANG_LOOKUP_SIZE 16 |
| static struct extent_buffer *get_next_extent_buffer( |
| struct btrfs_fs_info *fs_info, struct page *page, u64 bytenr) |
| { |
| struct extent_buffer *gang[GANG_LOOKUP_SIZE]; |
| struct extent_buffer *found = NULL; |
| u64 page_start = page_offset(page); |
| u64 cur = page_start; |
| |
| ASSERT(in_range(bytenr, page_start, PAGE_SIZE)); |
| lockdep_assert_held(&fs_info->buffer_lock); |
| |
| while (cur < page_start + PAGE_SIZE) { |
| int ret; |
| int i; |
| |
| ret = radix_tree_gang_lookup(&fs_info->buffer_radix, |
| (void **)gang, cur >> fs_info->sectorsize_bits, |
| min_t(unsigned int, GANG_LOOKUP_SIZE, |
| PAGE_SIZE / fs_info->nodesize)); |
| if (ret == 0) |
| goto out; |
| for (i = 0; i < ret; i++) { |
| /* Already beyond page end */ |
| if (gang[i]->start >= page_start + PAGE_SIZE) |
| goto out; |
| /* Found one */ |
| if (gang[i]->start >= bytenr) { |
| found = gang[i]; |
| goto out; |
| } |
| } |
| cur = gang[ret - 1]->start + gang[ret - 1]->len; |
| } |
| out: |
| 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); |
| } |