| // 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 "extent_io.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" |
| |
| 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(buffers); |
| static LIST_HEAD(states); |
| |
| static DEFINE_SPINLOCK(leak_lock); |
| |
| static inline |
| void btrfs_leak_debug_add(struct list_head *new, struct list_head *head) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&leak_lock, flags); |
| list_add(new, head); |
| spin_unlock_irqrestore(&leak_lock, flags); |
| } |
| |
| static inline |
| void btrfs_leak_debug_del(struct list_head *entry) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&leak_lock, flags); |
| list_del(entry); |
| spin_unlock_irqrestore(&leak_lock, flags); |
| } |
| |
| static inline |
| void btrfs_leak_debug_check(void) |
| { |
| struct extent_state *state; |
| struct extent_buffer *eb; |
| |
| 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); |
| } |
| |
| while (!list_empty(&buffers)) { |
| eb = list_entry(buffers.next, struct extent_buffer, leak_list); |
| pr_err("BTRFS: buffer leak start %llu len %lu refs %d bflags %lu\n", |
| eb->start, eb->len, atomic_read(&eb->refs), eb->bflags); |
| list_del(&eb->leak_list); |
| kmem_cache_free(extent_buffer_cache, eb); |
| } |
| } |
| |
| #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(new, head) do {} while (0) |
| #define btrfs_leak_debug_del(entry) do {} while (0) |
| #define btrfs_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 bio *bio; |
| struct extent_io_tree *tree; |
| /* 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, unsigned 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; |
| } |
| |
| static 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; |
| |
| if (tree->ops) |
| ret = tree->ops->submit_bio_hook(tree->private_data, bio, |
| mirror_num, bio_flags); |
| else |
| btrfsic_submit_bio(bio); |
| |
| return blk_status_to_errno(ret); |
| } |
| |
| /* Cleanup unsubmitted bios */ |
| static void end_write_bio(struct extent_page_data *epd, int ret) |
| { |
| if (epd->bio) { |
| epd->bio->bi_status = errno_to_blk_status(ret); |
| bio_endio(epd->bio); |
| epd->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; |
| |
| if (epd->bio) { |
| ret = submit_one_bio(epd->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 = NULL; |
| } |
| return ret; |
| } |
| |
| int __init extent_io_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; |
| |
| extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer", |
| sizeof(struct extent_buffer), 0, |
| SLAB_MEM_SPREAD, NULL); |
| if (!extent_buffer_cache) |
| goto free_state_cache; |
| |
| if (bioset_init(&btrfs_bioset, BIO_POOL_SIZE, |
| offsetof(struct btrfs_io_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; |
| |
| free_state_cache: |
| kmem_cache_destroy(extent_state_cache); |
| extent_state_cache = NULL; |
| return -ENOMEM; |
| } |
| |
| void __cold extent_io_exit(void) |
| { |
| btrfs_leak_debug_check(); |
| |
| /* |
| * Make sure all delayed rcu free are flushed before we |
| * destroy caches. |
| */ |
| rcu_barrier(); |
| kmem_cache_destroy(extent_state_cache); |
| kmem_cache_destroy(extent_buffer_cache); |
| bioset_exit(&btrfs_bioset); |
| } |
| |
| 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->ops = NULL; |
| tree->dirty_bytes = 0; |
| spin_lock_init(&tree->lock); |
| tree->private_data = private_data; |
| tree->owner = owner; |
| } |
| |
| 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(&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(&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; |
| } |
| |
| /** |
| * __etree_search - searche @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 - 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, unsigned *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, |
| unsigned *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, |
| unsigned *bits, int wake, |
| struct extent_changeset *changeset) |
| { |
| struct extent_state *next; |
| unsigned bits_to_clear = *bits & ~EXTENT_CTLBITS; |
| int ret; |
| |
| if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) { |
| u64 range = state->end - state->start + 1; |
| WARN_ON(range > tree->dirty_bytes); |
| tree->dirty_bytes -= range; |
| } |
| |
| 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, |
| unsigned bits, int wake, int delete, |
| struct extent_state **cached_state, |
| gfp_t mask, struct extent_changeset *changeset) |
| { |
| struct extent_state *state; |
| struct extent_state *cached; |
| struct extent_state *prealloc = NULL; |
| struct rb_node *node; |
| u64 last_end; |
| int err; |
| int clear = 0; |
| |
| btrfs_debug_check_extent_io_range(tree, start, end); |
| 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, |
| unsigned long bits) |
| { |
| struct extent_state *state; |
| struct rb_node *node; |
| |
| btrfs_debug_check_extent_io_range(tree, start, end); |
| |
| spin_lock(&tree->lock); |
| again: |
| while (1) { |
| /* |
| * this search will find all the extents that end after |
| * our range starts |
| */ |
| node = tree_search(tree, start); |
| process_node: |
| if (!node) |
| break; |
| |
| state = rb_entry(node, struct extent_state, rb_node); |
| |
| if (state->start > end) |
| goto out; |
| |
| if (state->state & bits) { |
| start = state->start; |
| refcount_inc(&state->refs); |
| wait_on_state(tree, state); |
| free_extent_state(state); |
| goto again; |
| } |
| start = state->end + 1; |
| |
| if (start > end) |
| break; |
| |
| if (!cond_resched_lock(&tree->lock)) { |
| node = rb_next(node); |
| goto process_node; |
| } |
| } |
| out: |
| spin_unlock(&tree->lock); |
| } |
| |
| static void set_state_bits(struct extent_io_tree *tree, |
| struct extent_state *state, |
| unsigned *bits, struct extent_changeset *changeset) |
| { |
| unsigned bits_to_set = *bits & ~EXTENT_CTLBITS; |
| int ret; |
| |
| 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. |
| */ |
| |
| static int __must_check |
| __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, |
| unsigned bits, unsigned exclusive_bits, |
| u64 *failed_start, struct extent_state **cached_state, |
| gfp_t mask, struct extent_changeset *changeset) |
| { |
| struct extent_state *state; |
| struct extent_state *prealloc = NULL; |
| struct rb_node *node; |
| struct rb_node **p; |
| struct rb_node *parent; |
| int err = 0; |
| u64 last_start; |
| u64 last_end; |
| |
| btrfs_debug_check_extent_io_range(tree, start, end); |
| trace_btrfs_set_extent_bit(tree, start, end - start + 1, bits); |
| |
| again: |
| if (!prealloc && gfpflags_allow_blocking(mask)) { |
| /* |
| * Don't care for allocation failure here because we might end |
| * up not needing the pre-allocated extent state at all, which |
| * is the case if we only have in the tree extent states that |
| * cover our input range and don't cover too any other range. |
| * If we end up needing a new extent state we allocate it later. |
| */ |
| prealloc = alloc_extent_state(mask); |
| } |
| |
| spin_lock(&tree->lock); |
| if (cached_state && *cached_state) { |
| state = *cached_state; |
| if (state->start <= start && state->end > start && |
| extent_state_in_tree(state)) { |
| node = &state->rb_node; |
| goto hit_next; |
| } |
| } |
| /* |
| * this search will find all the extents that end after |
| * our range starts. |
| */ |
| node = tree_search_for_insert(tree, start, &p, &parent); |
| if (!node) { |
| prealloc = alloc_extent_state_atomic(prealloc); |
| BUG_ON(!prealloc); |
| err = insert_state(tree, prealloc, start, end, |
| &p, &parent, &bits, changeset); |
| if (err) |
| extent_io_tree_panic(tree, err); |
| |
| cache_state(prealloc, cached_state); |
| prealloc = NULL; |
| goto out; |
| } |
| state = rb_entry(node, struct extent_state, rb_node); |
| hit_next: |
| last_start = state->start; |
| last_end = state->end; |
| |
| /* |
| * | ---- desired range ---- | |
| * | state | |
| * |
| * Just lock what we found and keep going |
| */ |
| if (state->start == start && state->end <= end) { |
| if (state->state & exclusive_bits) { |
| *failed_start = state->start; |
| err = -EEXIST; |
| goto out; |
| } |
| |
| set_state_bits(tree, state, &bits, changeset); |
| cache_state(state, cached_state); |
| merge_state(tree, state); |
| if (last_end == (u64)-1) |
| goto out; |
| start = last_end + 1; |
| state = next_state(state); |
| if (start < end && state && state->start == start && |
| !need_resched()) |
| goto hit_next; |
| goto search_again; |
| } |
| |
| /* |
| * | ---- desired range ---- | |
| * | state | |
| * or |
| * | ------------- state -------------- | |
| * |
| * We need to split the extent we found, and may flip bits on |
| * second half. |
| * |
| * If the extent we found extends past our |
| * range, we just split and search again. It'll get split |
| * again the next time though. |
| * |
| * If the extent we found is inside our range, we set the |
| * desired bit on it. |
| */ |
| if (state->start < start) { |
| if (state->state & exclusive_bits) { |
| *failed_start = start; |
| err = -EEXIST; |
| goto out; |
| } |
| |
| prealloc = alloc_extent_state_atomic(prealloc); |
| BUG_ON(!prealloc); |
| err = split_state(tree, state, prealloc, start); |
| if (err) |
| extent_io_tree_panic(tree, err); |
| |
| prealloc = NULL; |
| if (err) |
| goto out; |
| if (state->end <= end) { |
| set_state_bits(tree, state, &bits, changeset); |
| cache_state(state, cached_state); |
| merge_state(tree, state); |
| if (last_end == (u64)-1) |
| goto out; |
| start = last_end + 1; |
| state = next_state(state); |
| if (start < end && state && state->start == start && |
| !need_resched()) |
| goto hit_next; |
| } |
| goto search_again; |
| } |
| /* |
| * | ---- desired range ---- | |
| * | state | or | state | |
| * |
| * There's a hole, we need to insert something in it and |
| * ignore the extent we found. |
| */ |
| if (state->start > start) { |
| u64 this_end; |
| if (end < last_start) |
| this_end = end; |
| else |
| this_end = last_start - 1; |
| |
| prealloc = alloc_extent_state_atomic(prealloc); |
| BUG_ON(!prealloc); |
| |
| /* |
| * Avoid to free 'prealloc' if it can be merged with |
| * the later extent. |
| */ |
| err = insert_state(tree, prealloc, start, this_end, |
| NULL, NULL, &bits, changeset); |
| if (err) |
| extent_io_tree_panic(tree, err); |
| |
| cache_state(prealloc, cached_state); |
| prealloc = NULL; |
| start = this_end + 1; |
| goto search_again; |
| } |
| /* |
| * | ---- desired range ---- | |
| * | state | |
| * We need to split the extent, and set the bit |
| * on the first half |
| */ |
| if (state->start <= end && state->end > end) { |
| if (state->state & exclusive_bits) { |
| *failed_start = start; |
| err = -EEXIST; |
| goto out; |
| } |
| |
| prealloc = alloc_extent_state_atomic(prealloc); |
| BUG_ON(!prealloc); |
| err = split_state(tree, state, prealloc, end + 1); |
| if (err) |
| extent_io_tree_panic(tree, err); |
| |
| set_state_bits(tree, prealloc, &bits, changeset); |
| cache_state(prealloc, cached_state); |
| merge_state(tree, prealloc); |
| prealloc = NULL; |
| goto out; |
| } |
| |
| search_again: |
| if (start > end) |
| goto out; |
| spin_unlock(&tree->lock); |
| if (gfpflags_allow_blocking(mask)) |
| cond_resched(); |
| goto again; |
| |
| out: |
| spin_unlock(&tree->lock); |
| if (prealloc) |
| free_extent_state(prealloc); |
| |
| return err; |
| |
| } |
| |
| int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, |
| unsigned bits, u64 * failed_start, |
| struct extent_state **cached_state, gfp_t mask) |
| { |
| return __set_extent_bit(tree, start, end, bits, 0, failed_start, |
| cached_state, mask, NULL); |
| } |
| |
| |
| /** |
| * convert_extent_bit - convert all bits in a given range from one bit to |
| * another |
| * @tree: the io tree to search |
| * @start: the start offset in bytes |
| * @end: the end offset in bytes (inclusive) |
| * @bits: the bits to set in this range |
| * @clear_bits: the bits to clear in this range |
| * @cached_state: state that we're going to cache |
| * |
| * This will go through and set bits for the given range. If any states exist |
| * already in this range they are set with the given bit and cleared of the |
| * clear_bits. This is only meant to be used by things that are mergeable, ie |
| * converting from say DELALLOC to DIRTY. This is not meant to be used with |
| * boundary bits like LOCK. |
| * |
| * All allocations are done with GFP_NOFS. |
| */ |
| int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, |
| unsigned bits, unsigned clear_bits, |
| struct extent_state **cached_state) |
| { |
| struct extent_state *state; |
| struct extent_state *prealloc = NULL; |
| struct rb_node *node; |
| struct rb_node **p; |
| struct rb_node *parent; |
| int err = 0; |
| u64 last_start; |
| u64 last_end; |
| bool first_iteration = true; |
| |
| btrfs_debug_check_extent_io_range(tree, start, end); |
| 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, |
| unsigned bits, struct extent_changeset *changeset) |
| { |
| /* |
| * We don't support EXTENT_LOCKED yet, as current changeset will |
| * record any bits changed, so for EXTENT_LOCKED case, it will |
| * either fail with -EEXIST or changeset will record the whole |
| * range. |
| */ |
| BUG_ON(bits & EXTENT_LOCKED); |
| |
| return __set_extent_bit(tree, start, end, bits, 0, NULL, NULL, GFP_NOFS, |
| changeset); |
| } |
| |
| int set_extent_bits_nowait(struct extent_io_tree *tree, u64 start, u64 end, |
| unsigned 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, |
| unsigned bits, int wake, int delete, |
| struct extent_state **cached) |
| { |
| return __clear_extent_bit(tree, start, end, bits, wake, delete, |
| cached, GFP_NOFS, NULL); |
| } |
| |
| int clear_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, |
| unsigned bits, struct extent_changeset *changeset) |
| { |
| /* |
| * Don't support EXTENT_LOCKED case, same reason as |
| * set_record_extent_bits(). |
| */ |
| BUG_ON(bits & EXTENT_LOCKED); |
| |
| return __clear_extent_bit(tree, start, end, bits, 0, 0, NULL, GFP_NOFS, |
| changeset); |
| } |
| |
| /* |
| * either insert or lock state struct between start and end use mask to tell |
| * us if waiting is desired. |
| */ |
| int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, |
| struct extent_state **cached_state) |
| { |
| int err; |
| u64 failed_start; |
| |
| while (1) { |
| err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, |
| EXTENT_LOCKED, &failed_start, |
| cached_state, GFP_NOFS, NULL); |
| if (err == -EEXIST) { |
| wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED); |
| start = failed_start; |
| } else |
| break; |
| WARN_ON(start > end); |
| } |
| return err; |
| } |
| |
| int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end) |
| { |
| int err; |
| u64 failed_start; |
| |
| err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED, |
| &failed_start, NULL, GFP_NOFS, NULL); |
| if (err == -EEXIST) { |
| if (failed_start > start) |
| clear_extent_bit(tree, start, failed_start - 1, |
| EXTENT_LOCKED, 1, 0, NULL); |
| return 0; |
| } |
| return 1; |
| } |
| |
| void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end) |
| { |
| unsigned long index = start >> PAGE_SHIFT; |
| unsigned long end_index = end >> PAGE_SHIFT; |
| struct page *page; |
| |
| while (index <= end_index) { |
| page = find_get_page(inode->i_mapping, index); |
| BUG_ON(!page); /* Pages should be in the extent_io_tree */ |
| clear_page_dirty_for_io(page); |
| put_page(page); |
| index++; |
| } |
| } |
| |
| void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end) |
| { |
| unsigned long index = start >> PAGE_SHIFT; |
| unsigned long end_index = end >> PAGE_SHIFT; |
| struct page *page; |
| |
| while (index <= end_index) { |
| page = find_get_page(inode->i_mapping, index); |
| BUG_ON(!page); /* Pages should be in the extent_io_tree */ |
| __set_page_dirty_nobuffers(page); |
| account_page_redirty(page); |
| put_page(page); |
| index++; |
| } |
| } |
| |
| /* find the first state struct with 'bits' set after 'start', and |
| * return it. tree->lock must be held. NULL will returned if |
| * nothing was found after 'start' |
| */ |
| static struct extent_state * |
| find_first_extent_bit_state(struct extent_io_tree *tree, |
| u64 start, unsigned bits) |
| { |
| struct rb_node *node; |
| struct extent_state *state; |
| |
| /* |
| * this search will find all the extents that end after |
| * our range starts. |
| */ |
| node = tree_search(tree, start); |
| if (!node) |
| goto out; |
| |
| while (1) { |
| state = rb_entry(node, struct extent_state, rb_node); |
| if (state->end >= start && (state->state & bits)) |
| return state; |
| |
| node = rb_next(node); |
| if (!node) |
| break; |
| } |
| out: |
| return NULL; |
| } |
| |
| /* |
| * find the first offset in the io tree with 'bits' set. zero is |
| * returned if we find something, and *start_ret and *end_ret are |
| * set to reflect the state struct that was found. |
| * |
| * If nothing was found, 1 is returned. If found something, return 0. |
| */ |
| int find_first_extent_bit(struct extent_io_tree *tree, u64 start, |
| u64 *start_ret, u64 *end_ret, unsigned bits, |
| struct extent_state **cached_state) |
| { |
| struct extent_state *state; |
| 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_first_clear_extent_bit - find the first range that has @bits not set. |
| * This range could start before @start. |
| * |
| * @tree - the tree to search |
| * @start - the 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, unsigned 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 |
| */ |
| static noinline bool 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; |
| } |
| |
| static int __process_pages_contig(struct address_space *mapping, |
| struct page *locked_page, |
| pgoff_t start_index, pgoff_t end_index, |
| unsigned long page_ops, pgoff_t *index_ret); |
| |
| static noinline void __unlock_for_delalloc(struct inode *inode, |
| struct page *locked_page, |
| u64 start, u64 end) |
| { |
| unsigned long index = start >> PAGE_SHIFT; |
| unsigned long end_index = end >> PAGE_SHIFT; |
| |
| ASSERT(locked_page); |
| if (index == locked_page->index && end_index == index) |
| return; |
| |
| __process_pages_contig(inode->i_mapping, locked_page, index, end_index, |
| PAGE_UNLOCK, NULL); |
| } |
| |
| static noinline int lock_delalloc_pages(struct inode *inode, |
| struct page *locked_page, |
| u64 delalloc_start, |
| u64 delalloc_end) |
| { |
| unsigned long index = delalloc_start >> PAGE_SHIFT; |
| unsigned long index_ret = index; |
| unsigned long end_index = delalloc_end >> PAGE_SHIFT; |
| int ret; |
| |
| ASSERT(locked_page); |
| if (index == locked_page->index && index == end_index) |
| return 0; |
| |
| ret = __process_pages_contig(inode->i_mapping, locked_page, index, |
| end_index, PAGE_LOCK, &index_ret); |
| if (ret == -EAGAIN) |
| __unlock_for_delalloc(inode, locked_page, delalloc_start, |
| (u64)index_ret << PAGE_SHIFT); |
| return ret; |
| } |
| |
| /* |
| * Find and lock a contiguous range of bytes in the file marked as delalloc, no |
| * more than @max_bytes. @Start and @end are used to return the range, |
| * |
| * Return: true if we find something |
| * false if nothing was in the tree |
| */ |
| EXPORT_FOR_TESTS |
| noinline_for_stack bool find_lock_delalloc_range(struct inode *inode, |
| struct page *locked_page, u64 *start, |
| u64 *end) |
| { |
| struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree; |
| u64 max_bytes = BTRFS_MAX_EXTENT_SIZE; |
| u64 delalloc_start; |
| u64 delalloc_end; |
| bool found; |
| struct extent_state *cached_state = NULL; |
| int ret; |
| int loops = 0; |
| |
| again: |
| /* step one, find a bunch of delalloc bytes starting at start */ |
| delalloc_start = *start; |
| delalloc_end = 0; |
| found = find_delalloc_range(tree, &delalloc_start, &delalloc_end, |
| max_bytes, &cached_state); |
| if (!found || delalloc_end <= *start) { |
| *start = delalloc_start; |
| *end = delalloc_end; |
| free_extent_state(cached_state); |
| return false; |
| } |
| |
| /* |
| * start comes from the offset of locked_page. We have to lock |
| * pages in order, so we can't process delalloc bytes before |
| * locked_page |
| */ |
| if (delalloc_start < *start) |
| delalloc_start = *start; |
| |
| /* |
| * make sure to limit the number of pages we try to lock down |
| */ |
| if (delalloc_end + 1 - delalloc_start > max_bytes) |
| delalloc_end = delalloc_start + max_bytes - 1; |
| |
| /* step two, lock all the pages after the page that has start */ |
| ret = lock_delalloc_pages(inode, locked_page, |
| delalloc_start, delalloc_end); |
| ASSERT(!ret || ret == -EAGAIN); |
| if (ret == -EAGAIN) { |
| /* some of the pages are gone, lets avoid looping by |
| * shortening the size of the delalloc range we're searching |
| */ |
| free_extent_state(cached_state); |
| cached_state = NULL; |
| if (!loops) { |
| max_bytes = PAGE_SIZE; |
| loops = 1; |
| goto again; |
| } else { |
| found = false; |
| goto out_failed; |
| } |
| } |
| |
| /* step three, lock the state bits for the whole range */ |
| lock_extent_bits(tree, delalloc_start, delalloc_end, &cached_state); |
| |
| /* then test to make sure it is all still delalloc */ |
| ret = test_range_bit(tree, delalloc_start, delalloc_end, |
| EXTENT_DELALLOC, 1, cached_state); |
| if (!ret) { |
| unlock_extent_cached(tree, delalloc_start, delalloc_end, |
| &cached_state); |
| __unlock_for_delalloc(inode, locked_page, |
| delalloc_start, delalloc_end); |
| cond_resched(); |
| goto again; |
| } |
| free_extent_state(cached_state); |
| *start = delalloc_start; |
| *end = delalloc_end; |
| out_failed: |
| return found; |
| } |
| |
| static int __process_pages_contig(struct address_space *mapping, |
| struct page *locked_page, |
| pgoff_t start_index, pgoff_t end_index, |
| unsigned long page_ops, pgoff_t *index_ret) |
| { |
| unsigned long nr_pages = end_index - start_index + 1; |
| unsigned long pages_locked = 0; |
| pgoff_t index = start_index; |
| struct page *pages[16]; |
| unsigned ret; |
| int err = 0; |
| int i; |
| |
| if (page_ops & PAGE_LOCK) { |
| ASSERT(page_ops == PAGE_LOCK); |
| ASSERT(index_ret && *index_ret == start_index); |
| } |
| |
| if ((page_ops & PAGE_SET_ERROR) && nr_pages > 0) |
| mapping_set_error(mapping, -EIO); |
| |
| while (nr_pages > 0) { |
| ret = find_get_pages_contig(mapping, index, |
| min_t(unsigned long, |
| nr_pages, ARRAY_SIZE(pages)), pages); |
| if (ret == 0) { |
| /* |
| * Only if we're going to lock these pages, |
| * can we find nothing at @index. |
| */ |
| ASSERT(page_ops & PAGE_LOCK); |
| err = -EAGAIN; |
| goto out; |
| } |
| |
| for (i = 0; i < ret; i++) { |
| if (page_ops & PAGE_SET_PRIVATE2) |
| SetPagePrivate2(pages[i]); |
| |
| if (locked_page && pages[i] == locked_page) { |
| put_page(pages[i]); |
| pages_locked++; |
| continue; |
| } |
| if (page_ops & PAGE_CLEAR_DIRTY) |
| clear_page_dirty_for_io(pages[i]); |
| if (page_ops & PAGE_SET_WRITEBACK) |
| set_page_writeback(pages[i]); |
| if (page_ops & PAGE_SET_ERROR) |
| SetPageError(pages[i]); |
| if (page_ops & PAGE_END_WRITEBACK) |
| end_page_writeback(pages[i]); |
| if (page_ops & PAGE_UNLOCK) |
| unlock_page(pages[i]); |
| if (page_ops & PAGE_LOCK) { |
| lock_page(pages[i]); |
| if (!PageDirty(pages[i]) || |
| pages[i]->mapping != mapping) { |
| unlock_page(pages[i]); |
| for (; i < ret; i++) |
| put_page(pages[i]); |
| err = -EAGAIN; |
| goto out; |
| } |
| } |
| put_page(pages[i]); |
| pages_locked++; |
| } |
| nr_pages -= ret; |
| index += ret; |
| cond_resched(); |
| } |
| out: |
| if (err && index_ret) |
| *index_ret = start_index + pages_locked - 1; |
| return err; |
| } |
| |
| void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end, |
| struct page *locked_page, |
| unsigned clear_bits, |
| unsigned long page_ops) |
| { |
| clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, clear_bits, 1, 0, |
| NULL); |
| |
| __process_pages_contig(inode->i_mapping, locked_page, |
| start >> PAGE_SHIFT, end >> PAGE_SHIFT, |
| page_ops, NULL); |
| } |
| |
| /* |
| * count the number of bytes in the tree that have a given bit(s) |
| * set. This can be fairly slow, except for EXTENT_DIRTY which is |
| * cached. The total number found is returned. |
| */ |
| u64 count_range_bits(struct extent_io_tree *tree, |
| u64 *start, u64 search_end, u64 max_bytes, |
| unsigned bits, int contig) |
| { |
| struct rb_node *node; |
| struct extent_state *state; |
| u64 cur_start = *start; |
| u64 total_bytes = 0; |
| u64 last = 0; |
| int found = 0; |
| |
| if (WARN_ON(search_end <= cur_start)) |
| return 0; |
| |
| spin_lock(&tree->lock); |
| if (cur_start == 0 && bits == EXTENT_DIRTY) { |
| total_bytes = tree->dirty_bytes; |
| goto out; |
| } |
| /* |
| * this search will find all the extents that end after |
| * our range starts. |
| */ |
| node = tree_search(tree, cur_start); |
| if (!node) |
| goto out; |
| |
| while (1) { |
| state = rb_entry(node, struct extent_state, rb_node); |
| if (state->start > search_end) |
| break; |
| if (contig && found && state->start > last + 1) |
| break; |
| if (state->end >= cur_start && (state->state & bits) == bits) { |
| total_bytes += min(search_end, state->end) + 1 - |
| max(cur_start, state->start); |
| if (total_bytes >= max_bytes) |
| break; |
| if (!found) { |
| *start = max(cur_start, state->start); |
| found = 1; |
| } |
| last = state->end; |
| } else if (contig && found) { |
| break; |
| } |
| node = rb_next(node); |
| if (!node) |
| break; |
| } |
| out: |
| spin_unlock(&tree->lock); |
| return total_bytes; |
| } |
| |
| /* |
| * set the private field for a given byte offset in the tree. If there isn't |
| * an extent_state there already, this does nothing. |
| */ |
| static noinline int set_state_failrec(struct extent_io_tree *tree, u64 start, |
| struct io_failure_record *failrec) |
| { |
| struct rb_node *node; |
| struct extent_state *state; |
| int ret = 0; |
| |
| spin_lock(&tree->lock); |
| /* |
| * this search will find all the extents that end after |
| * our range starts. |
| */ |
| node = tree_search(tree, start); |
| if (!node) { |
| ret = -ENOENT; |
| goto out; |
| } |
| state = rb_entry(node, struct extent_state, rb_node); |
| if (state->start != start) { |
| ret = -ENOENT; |
| goto out; |
| } |
| state->failrec = failrec; |
| out: |
| spin_unlock(&tree->lock); |
| return ret; |
| } |
| |
| static noinline int get_state_failrec(struct extent_io_tree *tree, u64 start, |
| struct io_failure_record **failrec) |
| { |
| struct rb_node *node; |
| struct extent_state *state; |
| int ret = 0; |
| |
| spin_lock(&tree->lock); |
| /* |
| * this search will find all the extents that end after |
| * our range starts. |
| */ |
| node = tree_search(tree, start); |
| if (!node) { |
| ret = -ENOENT; |
| goto out; |
| } |
| state = rb_entry(node, struct extent_state, rb_node); |
| if (state->start != start) { |
| ret = -ENOENT; |
| goto out; |
| } |
| *failrec = state->failrec; |
| out: |
| spin_unlock(&tree->lock); |
| return ret; |
| } |
| |
| /* |
| * searches a range in the state tree for a given mask. |
| * If 'filled' == 1, this returns 1 only if every extent in the tree |
| * has the bits set. Otherwise, 1 is returned if any bit in the |
| * range is found set. |
| */ |
| int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end, |
| unsigned bits, int filled, struct extent_state *cached) |
| { |
| struct extent_state *state = NULL; |
| struct rb_node *node; |
| int bitset = 0; |
| |
| spin_lock(&tree->lock); |
| if (cached && extent_state_in_tree(cached) && cached->start <= start && |
| cached->end > start) |
| node = &cached->rb_node; |
| else |
| node = tree_search(tree, start); |
| while (node && start <= end) { |
| state = rb_entry(node, struct extent_state, rb_node); |
| |
| if (filled && state->start > start) { |
| bitset = 0; |
| break; |
| } |
| |
| if (state->start > end) |
| break; |
| |
| if (state->state & bits) { |
| bitset = 1; |
| if (!filled) |
| break; |
| } else if (filled) { |
| bitset = 0; |
| break; |
| } |
| |
| if (state->end == (u64)-1) |
| break; |
| |
| start = state->end + 1; |
| if (start > end) |
| break; |
| node = rb_next(node); |
| if (!node) { |
| if (filled) |
| bitset = 0; |
| break; |
| } |
| } |
| spin_unlock(&tree->lock); |
| return bitset; |
| } |
| |
| /* |
| * helper function to set a given page up to date if all the |
| * extents in the tree for that page are up to date |
| */ |
| static void check_page_uptodate(struct extent_io_tree *tree, struct page *page) |
| { |
| u64 start = page_offset(page); |
| u64 end = start + PAGE_SIZE - 1; |
| if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL)) |
| SetPageUptodate(page); |
| } |
| |
| int free_io_failure(struct extent_io_tree *failure_tree, |
| struct extent_io_tree *io_tree, |
| struct io_failure_record *rec) |
| { |
| int ret; |
| int err = 0; |
| |
| set_state_failrec(failure_tree, rec->start, NULL); |
| ret = clear_extent_bits(failure_tree, rec->start, |
| rec->start + rec->len - 1, |
| EXTENT_LOCKED | EXTENT_DIRTY); |
| if (ret) |
| err = ret; |
| |
| ret = clear_extent_bits(io_tree, rec->start, |
| rec->start + rec->len - 1, |
| EXTENT_DAMAGED); |
| if (ret && !err) |
| err = ret; |
| |
| kfree(rec); |
| return err; |
| } |
| |
| /* |
| * this bypasses the standard btrfs submit functions deliberately, as |
| * the standard behavior is to write all copies in a raid setup. here we only |
| * want to write the one bad copy. so we do the mapping for ourselves and issue |
| * submit_bio directly. |
| * to avoid any synchronization issues, wait for the data after writing, which |
| * actually prevents the read that triggered the error from finishing. |
| * currently, there can be no more than two copies of every data bit. thus, |
| * exactly one rewrite is required. |
| */ |
| int repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start, |
| u64 length, u64 logical, struct page *page, |
| unsigned int pg_offset, int mirror_num) |
| { |
| struct bio *bio; |
| struct btrfs_device *dev; |
| u64 map_length = 0; |
| u64 sector; |
| struct btrfs_bio *bbio = NULL; |
| int ret; |
| |
| ASSERT(!(fs_info->sb->s_flags & SB_RDONLY)); |
| BUG_ON(!mirror_num); |
| |
| bio = btrfs_io_bio_alloc(1); |
| bio->bi_iter.bi_size = 0; |
| map_length = length; |
| |
| /* |
| * Avoid races with device replace and make sure our bbio has devices |
| * associated to its stripes that don't go away while we are doing the |
| * read repair operation. |
| */ |
| btrfs_bio_counter_inc_blocked(fs_info); |
| if (btrfs_is_parity_mirror(fs_info, logical, length)) { |
| /* |
| * Note that we don't use BTRFS_MAP_WRITE because it's supposed |
| * to update all raid stripes, but here we just want to correct |
| * bad stripe, thus BTRFS_MAP_READ is abused to only get the bad |
| * stripe's dev and sector. |
| */ |
| ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, logical, |
| &map_length, &bbio, 0); |
| if (ret) { |
| btrfs_bio_counter_dec(fs_info); |
| bio_put(bio); |
| return -EIO; |
| } |
| ASSERT(bbio->mirror_num == 1); |
| } else { |
| ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, logical, |
| &map_length, &bbio, mirror_num); |
| if (ret) { |
| btrfs_bio_counter_dec(fs_info); |
| bio_put(bio); |
| return -EIO; |
| } |
| BUG_ON(mirror_num != bbio->mirror_num); |
| } |
| |
| sector = bbio->stripes[bbio->mirror_num - 1].physical >> 9; |
| bio->bi_iter.bi_sector = sector; |
| dev = bbio->stripes[bbio->mirror_num - 1].dev; |
| btrfs_put_bbio(bbio); |
| if (!dev || !dev->bdev || |
| !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) { |
| btrfs_bio_counter_dec(fs_info); |
| bio_put(bio); |
| return -EIO; |
| } |
| bio_set_dev(bio, dev->bdev); |
| bio->bi_opf = REQ_OP_WRITE | REQ_SYNC; |
| bio_add_page(bio, page, length, pg_offset); |
| |
| if (btrfsic_submit_bio_wait(bio)) { |
| /* try to remap that extent elsewhere? */ |
| btrfs_bio_counter_dec(fs_info); |
| bio_put(bio); |
| btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS); |
| return -EIO; |
| } |
| |
| btrfs_info_rl_in_rcu(fs_info, |
| "read error corrected: ino %llu off %llu (dev %s sector %llu)", |
| ino, start, |
| rcu_str_deref(dev->name), sector); |
| btrfs_bio_counter_dec(fs_info); |
| bio_put(bio); |
| return 0; |
| } |
| |
| int btrfs_repair_eb_io_failure(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; |
| |
| ret = get_state_failrec(failure_tree, start, &failrec); |
| if (ret) |
| return 0; |
| |
| BUG_ON(!failrec->this_mirror); |
| |
| if (failrec->in_validation) { |
| /* there was no real error, just free the record */ |
| btrfs_debug(fs_info, |
| "clean_io_failure: freeing dummy error at %llu", |
| failrec->start); |
| goto out; |
| } |
| if (sb_rdonly(fs_info->sb)) |
| goto out; |
| |
| spin_lock(&io_tree->lock); |
| state = find_first_extent_bit_state(io_tree, |
| failrec->start, |
| EXTENT_LOCKED); |
| spin_unlock(&io_tree->lock); |
| |
| if (state && state->start <= failrec->start && |
| state->end >= failrec->start + failrec->len - 1) { |
| num_copies = btrfs_num_copies(fs_info, failrec->logical, |
| failrec->len); |
| if (num_copies > 1) { |
| repair_io_failure(fs_info, ino, start, failrec->len, |
| failrec->logical, page, pg_offset, |
| failrec->failed_mirror); |
| } |
| } |
| |
| out: |
| free_io_failure(failure_tree, io_tree, failrec); |
| |
| return 0; |
| } |
| |
| /* |
| * Can be called when |
| * - hold extent lock |
| * - under ordered extent |
| * - the inode is freeing |
| */ |
| void btrfs_free_io_failure_record(struct btrfs_inode *inode, u64 start, u64 end) |
| { |
| struct extent_io_tree *failure_tree = &inode->io_failure_tree; |
| struct io_failure_record *failrec; |
| struct extent_state *state, *next; |
| |
| if (RB_EMPTY_ROOT(&failure_tree->state)) |
| return; |
| |
| spin_lock(&failure_tree->lock); |
| state = find_first_extent_bit_state(failure_tree, start, EXTENT_DIRTY); |
| while (state) { |
| if (state->start > end) |
| break; |
| |
| ASSERT(state->end <= end); |
| |
| next = next_state(state); |
| |
| failrec = state->failrec; |
| free_extent_state(state); |
| kfree(failrec); |
| |
| state = next; |
| } |
| spin_unlock(&failure_tree->lock); |
| } |
| |
| int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end, |
| struct io_failure_record **failrec_ret) |
| { |
| struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); |
| struct io_failure_record *failrec; |
| struct extent_map *em; |
| struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree; |
| struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree; |
| struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; |
| int ret; |
| u64 logical; |
| |
| ret = get_state_failrec(failure_tree, start, &failrec); |
| if (ret) { |
| failrec = kzalloc(sizeof(*failrec), GFP_NOFS); |
| if (!failrec) |
| return -ENOMEM; |
| |
| failrec->start = start; |
| failrec->len = end - start + 1; |
| failrec->this_mirror = 0; |
| failrec->bio_flags = 0; |
| failrec->in_validation = 0; |
| |
| read_lock(&em_tree->lock); |
| em = lookup_extent_mapping(em_tree, start, failrec->len); |
| if (!em) { |
| read_unlock(&em_tree->lock); |
| kfree(failrec); |
| return -EIO; |
| } |
| |
| if (em->start > start || em->start + em->len <= start) { |
| free_extent_map(em); |
| em = NULL; |
| } |
| read_unlock(&em_tree->lock); |
| if (!em) { |
| kfree(failrec); |
| return -EIO; |
| } |
| |
| logical = start - em->start; |
| logical = em->block_start + logical; |
| if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { |
| logical = em->block_start; |
| failrec->bio_flags = EXTENT_BIO_COMPRESSED; |
| extent_set_compress_type(&failrec->bio_flags, |
| em->compress_type); |
| } |
| |
| btrfs_debug(fs_info, |
| "Get IO Failure Record: (new) logical=%llu, start=%llu, len=%llu", |
| logical, start, failrec->len); |
| |
| failrec->logical = logical; |
| free_extent_map(em); |
| |
| /* set the bits in the private failure tree */ |
| ret = set_extent_bits(failure_tree, start, end, |
| EXTENT_LOCKED | EXTENT_DIRTY); |
| if (ret >= 0) |
| ret = set_state_failrec(failure_tree, start, failrec); |
| /* set the bits in the inode's tree */ |
| if (ret >= 0) |
| ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED); |
| if (ret < 0) { |
| kfree(failrec); |
| return ret; |
| } |
| } else { |
| btrfs_debug(fs_info, |
| "Get IO Failure Record: (found) logical=%llu, start=%llu, len=%llu, validation=%d", |
| failrec->logical, failrec->start, failrec->len, |
| failrec->in_validation); |
| /* |
| * when data can be on disk more than twice, add to failrec here |
| * (e.g. with a list for failed_mirror) to make |
| * clean_io_failure() clean all those errors at once. |
| */ |
| } |
| |
| *failrec_ret = failrec; |
| |
| return 0; |
| } |
| |
| bool btrfs_check_repairable(struct inode *inode, unsigned failed_bio_pages, |
| struct io_failure_record *failrec, int failed_mirror) |
| { |
| struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); |
| int num_copies; |
| |
| num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len); |
| if (num_copies == 1) { |
| /* |
| * we only have a single copy of the data, so don't bother with |
| * all the retry and error correction code that follows. no |
| * matter what the error is, it is very likely to persist. |
| */ |
| btrfs_debug(fs_info, |
| "Check Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d", |
| num_copies, failrec->this_mirror, failed_mirror); |
| return false; |
| } |
| |
| /* |
| * there are two premises: |
| * a) deliver good data to the caller |
| * b) correct the bad sectors on disk |
| */ |
| if (failed_bio_pages > 1) { |
| /* |
| * to fulfill b), we need to know the exact failing sectors, as |
| * we don't want to rewrite any more than the failed ones. thus, |
| * we need separate read requests for the failed bio |
| * |
| * if the following BUG_ON triggers, our validation request got |
| * merged. we need separate requests for our algorithm to work. |
| */ |
| BUG_ON(failrec->in_validation); |
| failrec->in_validation = 1; |
| failrec->this_mirror = failed_mirror; |
| } else { |
| /* |
| * we're ready to fulfill a) and b) alongside. get a good copy |
| * of the failed sector and if we succeed, we have setup |
| * everything for repair_io_failure to do the rest for us. |
| */ |
| if (failrec->in_validation) { |
| BUG_ON(failrec->this_mirror != failed_mirror); |
| failrec->in_validation = 0; |
| failrec->this_mirror = 0; |
| } |
| failrec->failed_mirror = failed_mirror; |
| failrec->this_mirror++; |
| if (failrec->this_mirror == failed_mirror) |
| failrec->this_mirror++; |
| } |
| |
| if (failrec->this_mirror > num_copies) { |
| btrfs_debug(fs_info, |
| "Check Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d", |
| num_copies, failrec->this_mirror, failed_mirror); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| |
| struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio, |
| struct io_failure_record *failrec, |
| struct page *page, int pg_offset, int icsum, |
| bio_end_io_t *endio_func, void *data) |
| { |
| struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); |
| struct bio *bio; |
| struct btrfs_io_bio *btrfs_failed_bio; |
| struct btrfs_io_bio *btrfs_bio; |
| |
| bio = btrfs_io_bio_alloc(1); |
| bio->bi_end_io = endio_func; |
| bio->bi_iter.bi_sector = failrec->logical >> 9; |
| bio_set_dev(bio, fs_info->fs_devices->latest_bdev); |
| bio->bi_iter.bi_size = 0; |
| bio->bi_private = data; |
| |
| btrfs_failed_bio = btrfs_io_bio(failed_bio); |
| if (btrfs_failed_bio->csum) { |
| u16 csum_size = btrfs_super_csum_size(fs_info->super_copy); |
| |
| btrfs_bio = btrfs_io_bio(bio); |
| btrfs_bio->csum = btrfs_bio->csum_inline; |
| icsum *= csum_size; |
| memcpy(btrfs_bio->csum, btrfs_failed_bio->csum + icsum, |
| csum_size); |
| } |
| |
| bio_add_page(bio, page, failrec->len, pg_offset); |
| |
| return bio; |
| } |
| |
| /* |
| * This is a generic handler for readpage errors. If other copies exist, read |
| * those and write back good data to the failed position. Does not investigate |
| * in remapping the failed extent elsewhere, hoping the device will be smart |
| * enough to do this as needed |
| */ |
| static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset, |
| struct page *page, u64 start, u64 end, |
| int failed_mirror) |
| { |
| struct io_failure_record *failrec; |
| struct inode *inode = page->mapping->host; |
| struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree; |
| struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree; |
| struct bio *bio; |
| int read_mode = 0; |
| blk_status_t status; |
| int ret; |
| unsigned failed_bio_pages = failed_bio->bi_iter.bi_size >> PAGE_SHIFT; |
| |
| BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE); |
| |
| ret = btrfs_get_io_failure_record(inode, start, end, &failrec); |
| if (ret) |
| return ret; |
| |
| if (!btrfs_check_repairable(inode, failed_bio_pages, failrec, |
| failed_mirror)) { |
| free_io_failure(failure_tree, tree, failrec); |
| return -EIO; |
| } |
| |
| if (failed_bio_pages > 1) |
| read_mode |= REQ_FAILFAST_DEV; |
| |
| phy_offset >>= inode->i_sb->s_blocksize_bits; |
| bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page, |
| start - page_offset(page), |
| (int)phy_offset, failed_bio->bi_end_io, |
| NULL); |
| bio->bi_opf = REQ_OP_READ | read_mode; |
| |
| btrfs_debug(btrfs_sb(inode->i_sb), |
| "Repair Read Error: submitting new read[%#x] to this_mirror=%d, in_validation=%d", |
| read_mode, failrec->this_mirror, failrec->in_validation); |
| |
| status = tree->ops->submit_bio_hook(tree->private_data, bio, failrec->this_mirror, |
| failrec->bio_flags); |
| if (status) { |
| free_io_failure(failure_tree, tree, failrec); |
| bio_put(bio); |
| ret = blk_status_to_errno(status); |
| } |
| |
| return ret; |
| } |
| |
| /* lots and lots of room for performance fixes in the end_bio funcs */ |
| |
| void end_extent_writepage(struct page *page, int err, u64 start, u64 end) |
| { |
| int uptodate = (err == 0); |
| int ret = 0; |
| |
| btrfs_writepage_endio_finish_ordered(page, start, end, uptodate); |
| |
| if (!uptodate) { |
| ClearPageUptodate(page); |
| SetPageError(page); |
| ret = err < 0 ? err : -EIO; |
| mapping_set_error(page->mapping, ret); |
| } |
| } |
| |
| /* |
| * after a writepage IO is done, we need to: |
| * clear the uptodate bits on error |
| * clear the writeback bits in the extent tree for this IO |
| * end_page_writeback if the page has no more pending IO |
| * |
| * Scheduling is not allowed, so the extent state tree is expected |
| * to have one and only one object corresponding to this IO. |
| */ |
| static void end_bio_extent_writepage(struct bio *bio) |
| { |
| int error = blk_status_to_errno(bio->bi_status); |
| struct bio_vec *bvec; |
| u64 start; |
| u64 end; |
| struct bvec_iter_all iter_all; |
| |
| 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); |
| |
| /* We always issue full-page reads, but if some block |
| * in a page fails to read, blk_update_request() will |
| * advance bv_offset and adjust bv_len to compensate. |
| * Print a warning for nonzero offsets, and an error |
| * if they don't add up to a full page. */ |
| if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) { |
| if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE) |
| btrfs_err(fs_info, |
| "partial page write in btrfs with offset %u and length %u", |
| bvec->bv_offset, bvec->bv_len); |
| else |
| btrfs_info(fs_info, |
| "incomplete page write in btrfs with offset %u and length %u", |
| bvec->bv_offset, bvec->bv_len); |
| } |
| |
| start = page_offset(page); |
| end = start + bvec->bv_offset + bvec->bv_len - 1; |
| |
| end_extent_writepage(page, error, start, end); |
| end_page_writeback(page); |
| } |
| |
| bio_put(bio); |
| } |
| |
| static void |
| endio_readpage_release_extent(struct extent_io_tree *tree, u64 start, u64 len, |
| int uptodate) |
| { |
| struct extent_state *cached = NULL; |
| u64 end = start + len - 1; |
| |
| if (uptodate && tree->track_uptodate) |
| set_extent_uptodate(tree, start, end, &cached, GFP_ATOMIC); |
| unlock_extent_cached_atomic(tree, start, end, &cached); |
| } |
| |
| /* |
| * after a readpage IO is done, we need to: |
| * clear the uptodate bits on error |
| * set the uptodate bits if things worked |
| * set the page up to date if all extents in the tree are uptodate |
| * clear the lock bit in the extent tree |
| * unlock the page if there are no other extents locked for it |
| * |
| * Scheduling is not allowed, so the extent state tree is expected |
| * to have one and only one object corresponding to this IO. |
| */ |
| static void end_bio_extent_readpage(struct bio *bio) |
| { |
| struct bio_vec *bvec; |
| int uptodate = !bio->bi_status; |
| struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); |
| struct extent_io_tree *tree, *failure_tree; |
| u64 offset = 0; |
| u64 start; |
| u64 end; |
| u64 len; |
| u64 extent_start = 0; |
| u64 extent_len = 0; |
| int mirror; |
| int ret; |
| 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; |
| struct inode *inode = page->mapping->host; |
| struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); |
| bool data_inode = btrfs_ino(BTRFS_I(inode)) |
| != BTRFS_BTREE_INODE_OBJECTID; |
| |
| btrfs_debug(fs_info, |
| "end_bio_extent_readpage: bi_sector=%llu, err=%d, mirror=%u", |
| (u64)bio->bi_iter.bi_sector, bio->bi_status, |
| io_bio->mirror_num); |
| tree = &BTRFS_I(inode)->io_tree; |
| failure_tree = &BTRFS_I(inode)->io_failure_tree; |
| |
| /* We always issue full-page reads, but if some block |
| * in a page fails to read, blk_update_request() will |
| * advance bv_offset and adjust bv_len to compensate. |
| * Print a warning for nonzero offsets, and an error |
| * if they don't add up to a full page. */ |
| if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) { |
| if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE) |
| btrfs_err(fs_info, |
| "partial page read in btrfs with offset %u and length %u", |
| bvec->bv_offset, bvec->bv_len); |
| else |
| btrfs_info(fs_info, |
| "incomplete page read in btrfs with offset %u and length %u", |
| bvec->bv_offset, bvec->bv_len); |
| } |
| |
| start = page_offset(page); |
| end = start + bvec->bv_offset + bvec->bv_len - 1; |
| len = bvec->bv_len; |
| |
| mirror = io_bio->mirror_num; |
| if (likely(uptodate)) { |
| ret = tree->ops->readpage_end_io_hook(io_bio, offset, |
| page, start, end, |
| mirror); |
| if (ret) |
| uptodate = 0; |
| else |
| clean_io_failure(BTRFS_I(inode)->root->fs_info, |
| failure_tree, tree, start, |
| page, |
| btrfs_ino(BTRFS_I(inode)), 0); |
| } |
| |
| if (likely(uptodate)) |
| goto readpage_ok; |
| |
| if (data_inode) { |
| |
| /* |
| * The generic bio_readpage_error handles errors the |
| * following way: If possible, new read requests are |
| * created and submitted and will end up in |
| * end_bio_extent_readpage as well (if we're lucky, |
| * not in the !uptodate case). In that case it returns |
| * 0 and we just go on with the next page in our bio. |
| * If it can't handle the error it will return -EIO and |
| * we remain responsible for that page. |
| */ |
| ret = bio_readpage_error(bio, offset, page, start, end, |
| mirror); |
| if (ret == 0) { |
| uptodate = !bio->bi_status; |
| offset += len; |
| continue; |
| } |
| } else { |
| struct extent_buffer *eb; |
| |
| eb = (struct extent_buffer *)page->private; |
| set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags); |
| eb->read_mirror = mirror; |
| atomic_dec(&eb->io_pages); |
| if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD, |
| &eb->bflags)) |
| btree_readahead_hook(eb, -EIO); |
| } |
| readpage_ok: |
| if (likely(uptodate)) { |
| loff_t i_size = i_size_read(inode); |
| pgoff_t end_index = i_size >> PAGE_SHIFT; |
| unsigned off; |
| |
| /* Zero out the end if this page straddles i_size */ |
| off = offset_in_page(i_size); |
| if (page->index == end_index && off) |
| zero_user_segment(page, off, PAGE_SIZE); |
| SetPageUptodate(page); |
| } else { |
| ClearPageUptodate(page); |
| SetPageError(page); |
| } |
| unlock_page(page); |
| offset += len; |
| |
| if (unlikely(!uptodate)) { |
| if (extent_len) { |
| endio_readpage_release_extent(tree, |
| extent_start, |
| extent_len, 1); |
| extent_start = 0; |
| extent_len = 0; |
| } |
| endio_readpage_release_extent(tree, start, |
| end - start + 1, 0); |
| } else if (!extent_len) { |
| extent_start = start; |
| extent_len = end + 1 - start; |
| } else if (extent_start + extent_len == start) { |
| extent_len += end + 1 - start; |
| } else { |
| endio_readpage_release_extent(tree, extent_start, |
| extent_len, uptodate); |
| extent_start = start; |
| extent_len = end + 1 - start; |
| } |
| } |
| |
| if (extent_len) |
| endio_readpage_release_extent(tree, extent_start, extent_len, |
| uptodate); |
| btrfs_io_bio_free_csum(io_bio); |
| bio_put(bio); |
| } |
| |
| /* |
| * Initialize the members up to but not including 'bio'. Use after allocating a |
| * new bio by bio_alloc_bioset as it does not initialize the bytes outside of |
| * 'bio' because use of __GFP_ZERO is not supported. |
| */ |
| static inline void btrfs_io_bio_init(struct btrfs_io_bio *btrfs_bio) |
| { |
| memset(btrfs_bio, 0, offsetof(struct btrfs_io_bio, bio)); |
| } |
| |
| /* |
| * The following helpers allocate a bio. As it's backed by a bioset, it'll |
| * never fail. We're returning a bio right now but you can call btrfs_io_bio |
| * for the appropriate container_of magic |
| */ |
| struct bio *btrfs_bio_alloc(u64 first_byte) |
| { |
| struct bio *bio; |
| |
| bio = bio_alloc_bioset(GFP_NOFS, BIO_MAX_PAGES, &btrfs_bioset); |
| bio->bi_iter.bi_sector = first_byte >> 9; |
| btrfs_io_bio_init(btrfs_io_bio(bio)); |
| return bio; |
| } |
| |
| struct bio *btrfs_bio_clone(struct bio *bio) |
| { |
| struct btrfs_io_bio *btrfs_bio; |
| struct bio *new; |
| |
| /* Bio allocation backed by a bioset does not fail */ |
| new = bio_clone_fast(bio, GFP_NOFS, &btrfs_bioset); |
| btrfs_bio = btrfs_io_bio(new); |
| btrfs_io_bio_init(btrfs_bio); |
| btrfs_bio->iter = bio->bi_iter; |
| return new; |
| } |
| |
| struct bio *btrfs_io_bio_alloc(unsigned int nr_iovecs) |
| { |
| struct bio *bio; |
| |
| /* Bio allocation backed by a bioset does not fail */ |
| bio = bio_alloc_bioset(GFP_NOFS, nr_iovecs, &btrfs_bioset); |
| btrfs_io_bio_init(btrfs_io_bio(bio)); |
| return bio; |
| } |
| |
| struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size) |
| { |
| struct bio *bio; |
| struct btrfs_io_bio *btrfs_bio; |
| |
| /* this will never fail when it's backed by a bioset */ |
| bio = bio_clone_fast(orig, GFP_NOFS, &btrfs_bioset); |
| ASSERT(bio); |
| |
| btrfs_bio = btrfs_io_bio(bio); |
| btrfs_io_bio_init(btrfs_bio); |
| |
| bio_trim(bio, offset >> 9, size >> 9); |
| btrfs_bio->iter = bio->bi_iter; |
| return bio; |
| } |
| |
| /* |
| * @opf: bio REQ_OP_* and REQ_* flags as one value |
| * @tree: tree so we can call our merge_bio hook |
| * @wbc: optional writeback control for io accounting |
| * @page: page to add to the bio |
| * @pg_offset: offset of the new bio or to check whether we are adding |
| * a contiguous page to the previous one |
| * @size: portion of page that we want to write |
| * @offset: starting offset in the page |
| * @bdev: attach newly created bios to this bdev |
| * @bio_ret: must be valid pointer, newly allocated bio will be stored there |
| * @end_io_func: end_io callback for new bio |
| * @mirror_num: desired mirror to read/write |
| * @prev_bio_flags: flags of previous bio to see if we can merge the current one |
| * @bio_flags: flags of the current bio to see if we can merge them |
| */ |
| static int submit_extent_page(unsigned int opf, struct extent_io_tree *tree, |
| struct writeback_control *wbc, |
| struct page *page, u64 offset, |
| size_t size, unsigned long pg_offset, |
| struct block_device *bdev, |
| struct bio **bio_ret, |
| bio_end_io_t end_io_func, |
| int mirror_num, |
| unsigned long prev_bio_flags, |
| unsigned long bio_flags, |
| bool force_bio_submit) |
| { |
| int ret = 0; |
| struct bio *bio; |
| size_t page_size = min_t(size_t, size, PAGE_SIZE); |
| sector_t sector = offset >> 9; |
| |
| ASSERT(bio_ret); |
| |
| if (*bio_ret) { |
| bool contig; |
| bool can_merge = true; |
| |
| bio = *bio_ret; |
| if (prev_bio_flags & EXTENT_BIO_COMPRESSED) |
| contig = bio->bi_iter.bi_sector == sector; |
| else |
| contig = bio_end_sector(bio) == sector; |
| |
| ASSERT(tree->ops); |
| if (btrfs_bio_fits_in_stripe(page, page_size, bio, bio_flags)) |
| can_merge = false; |
| |
| if (prev_bio_flags != bio_flags || !contig || !can_merge || |
| force_bio_submit || |
| bio_add_page(bio, page, page_size, pg_offset) < page_size) { |
| ret = submit_one_bio(bio, mirror_num, prev_bio_flags); |
| if (ret < 0) { |
| *bio_ret = NULL; |
| return ret; |
| } |
| bio = NULL; |
| } else { |
| if (wbc) |
| wbc_account_cgroup_owner(wbc, page, page_size); |
| return 0; |
| } |
| } |
| |
| bio = btrfs_bio_alloc(offset); |
| bio_set_dev(bio, bdev); |
| bio_add_page(bio, page, page_size, pg_offset); |
| bio->bi_end_io = end_io_func; |
| bio->bi_private = tree; |
| bio->bi_write_hint = page->mapping->host->i_write_hint; |
| bio->bi_opf = opf; |
| if (wbc) { |
| wbc_init_bio(wbc, bio); |
| wbc_account_cgroup_owner(wbc, page, page_size); |
| } |
| |
| *bio_ret = bio; |
| |
| return ret; |
| } |
| |
| static void attach_extent_buffer_page(struct extent_buffer *eb, |
| struct page *page) |
| { |
| if (!PagePrivate(page)) { |
| SetPagePrivate(page); |
| get_page(page); |
| set_page_private(page, (unsigned long)eb); |
| } else { |
| WARN_ON(page->private != (unsigned long)eb); |
| } |
| } |
| |
| void set_page_extent_mapped(struct page *page) |
| { |
| if (!PagePrivate(page)) { |
| SetPagePrivate(page); |
| get_page(page); |
| set_page_private(page, EXTENT_PAGE_PRIVATE); |
| } |
| } |
| |
| static struct extent_map * |
| __get_extent_map(struct inode *inode, struct page *page, size_t pg_offset, |
| u64 start, u64 len, get_extent_t *get_extent, |
| struct extent_map **em_cached) |
| { |
| struct extent_map *em; |
| |
| if (em_cached && *em_cached) { |
| em = *em_cached; |
| if (extent_map_in_tree(em) && start >= em->start && |
| start < extent_map_end(em)) { |
| refcount_inc(&em->refs); |
| return em; |
| } |
| |
| free_extent_map(em); |
| *em_cached = NULL; |
| } |
| |
| em = get_extent(BTRFS_I(inode), page, pg_offset, start, len, 0); |
| if (em_cached && !IS_ERR_OR_NULL(em)) { |
| BUG_ON(*em_cached); |
| refcount_inc(&em->refs); |
| *em_cached = em; |
| } |
| return em; |
| } |
| /* |
| * basic readpage implementation. Locked extent state structs are inserted |
| * into the tree that are removed when the IO is done (by the end_io |
| * handlers) |
| * XXX JDM: This needs looking at to ensure proper page locking |
| * return 0 on success, otherwise return error |
| */ |
| static int __do_readpage(struct extent_io_tree *tree, |
| struct page *page, |
| get_extent_t *get_extent, |
| struct extent_map **em_cached, |
| struct bio **bio, int mirror_num, |
| unsigned long *bio_flags, unsigned int read_flags, |
| u64 *prev_em_start) |
| { |
| struct inode *inode = page->mapping->host; |
| u64 start = page_offset(page); |
| const u64 end = start + PAGE_SIZE - 1; |
| u64 cur = start; |
| u64 extent_offset; |
| u64 last_byte = i_size_read(inode); |
| u64 block_start; |
| u64 cur_end; |
| struct extent_map *em; |
| struct block_device *bdev; |
| int ret = 0; |
| int nr = 0; |
| size_t pg_offset = 0; |
| size_t iosize; |
| size_t disk_io_size; |
| size_t blocksize = inode->i_sb->s_blocksize; |
| unsigned long this_bio_flag = 0; |
| |
| set_page_extent_mapped(page); |
| |
| if (!PageUptodate(page)) { |
| if (cleancache_get_page(page) == 0) { |
| BUG_ON(blocksize != PAGE_SIZE); |
| unlock_extent(tree, start, end); |
| goto out; |
| } |
| } |
| |
| if (page->index == last_byte >> PAGE_SHIFT) { |
| char *userpage; |
| size_t zero_offset = offset_in_page(last_byte); |
| |
| if (zero_offset) { |
| iosize = PAGE_SIZE - zero_offset; |
| userpage = kmap_atomic(page); |
| memset(userpage + zero_offset, 0, iosize); |
| flush_dcache_page(page); |
| kunmap_atomic(userpage); |
| } |
| } |
| while (cur <= end) { |
| bool force_bio_submit = false; |
| u64 offset; |
| |
| if (cur >= last_byte) { |
| char *userpage; |
| struct extent_state *cached = NULL; |
| |
| iosize = PAGE_SIZE - pg_offset; |
| userpage = kmap_atomic(page); |
| memset(userpage + pg_offset, 0, iosize); |
| flush_dcache_page(page); |
| kunmap_atomic(userpage); |
| set_extent_uptodate(tree, cur, cur + iosize - 1, |
| &cached, GFP_NOFS); |
| unlock_extent_cached(tree, cur, |
| cur + iosize - 1, &cached); |
| break; |
| } |
| em = __get_extent_map(inode, page, pg_offset, cur, |
| end - cur + 1, get_extent, em_cached); |
| if (IS_ERR_OR_NULL(em)) { |
| SetPageError(page); |
| unlock_extent(tree, cur, end); |
| break; |
| } |
| extent_offset = cur - em->start; |
| BUG_ON(extent_map_end(em) <= cur); |
| BUG_ON(end < cur); |
| |
| if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { |
| this_bio_flag |= EXTENT_BIO_COMPRESSED; |
| extent_set_compress_type(&this_bio_flag, |
| em->compress_type); |
| } |
| |
| iosize = min(extent_map_end(em) - cur, end - cur + 1); |
| cur_end = min(extent_map_end(em) - 1, end); |
| iosize = ALIGN(iosize, blocksize); |
| if (this_bio_flag & EXTENT_BIO_COMPRESSED) { |
| disk_io_size = em->block_len; |
| offset = em->block_start; |
| } else { |
| offset = em->block_start + extent_offset; |
| disk_io_size = iosize; |
| } |
| bdev = em->bdev; |
| block_start = em->block_start; |
| if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) |
| block_start = EXTENT_MAP_HOLE; |
| |
| /* |
| * If we have a file range that points to a compressed extent |
| * and it's followed by a consecutive file range that points |
| * to 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) { |
| char *userpage; |
| struct extent_state *cached = NULL; |
| |
| userpage = kmap_atomic(page); |
| memset(userpage + pg_offset, 0, iosize); |
| flush_dcache_page(page); |
| kunmap_atomic(userpage); |
| |
| set_extent_uptodate(tree, cur, cur + iosize - 1, |
| &cached, GFP_NOFS); |
| unlock_extent_cached(tree, cur, |
| cur + iosize - 1, &cached); |
| cur = cur + iosize; |
| pg_offset += iosize; |
| continue; |
| } |
| /* the get_extent function already copied into the page */ |
| if (test_range_bit(tree, cur, cur_end, |
| EXTENT_UPTODATE, 1, NULL)) { |
| check_page_uptodate(tree, page); |
| unlock_extent(tree, cur, cur + iosize - 1); |
| cur = cur + iosize; |
| pg_offset += iosize; |
| continue; |
| } |
| /* we have an inline extent but it didn't get marked up |
| * to date. Error out |
| */ |
| if (block_start == EXTENT_MAP_INLINE) { |
| SetPageError(page); |
| unlock_extent(tree, cur, cur + iosize - 1); |
| cur = cur + iosize; |
| pg_offset += iosize; |
| continue; |
| } |
| |
| ret = submit_extent_page(REQ_OP_READ | read_flags, tree, NULL, |
| page, offset, disk_io_size, |
| pg_offset, bdev, bio, |
| end_bio_extent_readpage, mirror_num, |
| *bio_flags, |
| this_bio_flag, |
| force_bio_submit); |
| if (!ret) { |
| nr++; |
| *bio_flags = this_bio_flag; |
| } else { |
| SetPageError(page); |
| unlock_extent(tree, cur, cur + iosize - 1); |
| goto out; |
| } |
| cur = cur + iosize; |
| pg_offset += iosize; |
| } |
| out: |
| if (!nr) { |
| if (!PageError(page)) |
| SetPageUptodate(page); |
| unlock_page(page); |
| } |
| return ret; |
| } |
| |
| static inline void contiguous_readpages(struct extent_io_tree *tree, |
| struct page *pages[], int nr_pages, |
| u64 start, u64 end, |
| struct extent_map **em_cached, |
| struct bio **bio, |
| unsigned long *bio_flags, |
| u64 *prev_em_start) |
| { |
| struct btrfs_inode *inode = BTRFS_I(pages[0]->mapping->host); |
| int index; |
| |
| btrfs_lock_and_flush_ordered_range(tree, inode, start, end, NULL); |
| |
| for (index = 0; index < nr_pages; index++) { |
| __do_readpage(tree, pages[index], btrfs_get_extent, em_cached, |
| bio, 0, bio_flags, REQ_RAHEAD, prev_em_start); |
| put_page(pages[index]); |
| } |
| } |
| |
| static int __extent_read_full_page(struct extent_io_tree *tree, |
| struct page *page, |
| get_extent_t *get_extent, |
| struct bio **bio, int mirror_num, |
| unsigned long *bio_flags, |
| unsigned int read_flags) |
| { |
| struct btrfs_inode *inode = BTRFS_I(page->mapping->host); |
| u64 start = page_offset(page); |
| u64 end = start + PAGE_SIZE - 1; |
| int ret; |
| |
| btrfs_lock_and_flush_ordered_range(tree, inode, start, end, NULL); |
| |
| ret = __do_readpage(tree, page, get_extent, NULL, bio, mirror_num, |
| bio_flags, read_flags, NULL); |
| return ret; |
| } |
| |
| int extent_read_full_page(struct extent_io_tree *tree, struct page *page, |
| get_extent_t *get_extent, int mirror_num) |
| { |
| struct bio *bio = NULL; |
| unsigned long bio_flags = 0; |
| int ret; |
| |
| ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num, |
| &bio_flags, 0); |
| if (bio) |
| ret = submit_one_bio(bio, mirror_num, bio_flags); |
| return ret; |
| } |
| |
| static void update_nr_written(struct writeback_control *wbc, |
| unsigned long nr_written) |
| { |
| wbc->nr_to_write -= nr_written; |
| } |
| |
| /* |
| * helper for __extent_writepage, doing all of the delayed allocation setup. |
| * |
| * This returns 1 if 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 inode *inode, |
| struct page *page, struct writeback_control *wbc, |
| u64 delalloc_start, unsigned long *nr_written) |
| { |
| u64 page_end = delalloc_start + PAGE_SIZE - 1; |
| bool found; |
| u64 delalloc_to_write = 0; |
| u64 delalloc_end = 0; |
| int ret; |
| int page_started = 0; |
| |
| |
| while (delalloc_end < page_end) { |
| found = find_lock_delalloc_range(inode, page, |
| &delalloc_start, |
| &delalloc_end); |
| if (!found) { |
| delalloc_start = delalloc_end + 1; |
| continue; |
| } |
| ret = btrfs_run_delalloc_range(inode, page, delalloc_start, |
| delalloc_end, &page_started, nr_written, wbc); |
| if (ret) { |
| SetPageError(page); |
| /* |
| * btrfs_run_delalloc_range should return < 0 for error |
| * but just in case, we use > 0 here meaning the IO is |
| * started, so we don't want to return > 0 unless |
| * things are going well. |
| */ |
| ret = ret < 0 ? ret : -EIO; |
| goto done; |
| } |
| /* |
| * delalloc_end is already one less than the total length, so |
| * we don't subtract one from PAGE_SIZE |
| */ |
| delalloc_to_write += (delalloc_end - delalloc_start + |
| PAGE_SIZE) >> PAGE_SHIFT; |
| delalloc_start = delalloc_end + 1; |
| } |
| if (wbc->nr_to_write < delalloc_to_write) { |
| int thresh = 8192; |
| |
| if (delalloc_to_write < thresh * 2) |
| thresh = delalloc_to_write; |
| wbc->nr_to_write = min_t(u64, delalloc_to_write, |
| thresh); |
| } |
| |
| /* did the fill delalloc function already unlock and start |
| * the IO? |
| */ |
| if (page_started) { |
| /* |
| * we've unlocked the page, so we can't update |
| * the mapping's writeback index, just update |
| * nr_to_write. |
| */ |
| wbc->nr_to_write -= *nr_written; |
| return 1; |
| } |
| |
| ret = 0; |
| |
| done: |
| return ret; |
| } |
| |
| /* |
| * helper for __extent_writepage. This calls the writepage start hooks, |
| * and does the loop to map the page into extents and bios. |
| * |
| * We return 1 if the IO is started and the page is unlocked, |
| * 0 if all went well (page still locked) |
| * < 0 if there were errors (page still locked) |
| */ |
| static noinline_for_stack int __extent_writepage_io(struct inode *inode, |
| struct page *page, |
| struct writeback_control *wbc, |
| struct extent_page_data *epd, |
| loff_t i_size, |
| unsigned long nr_written, |
| unsigned int write_flags, int *nr_ret) |
| { |
| struct extent_io_tree *tree = epd->tree; |
| u64 start = page_offset(page); |
| u64 page_end = start + PAGE_SIZE - 1; |
| u64 end; |
| u64 cur = start; |
| u64 extent_offset; |
| u64 block_start; |
| u64 iosize; |
| struct extent_map *em; |
| struct block_device *bdev; |
| size_t pg_offset = 0; |
| size_t blocksize; |
| int ret = 0; |
| int nr = 0; |
| bool compressed; |
| |
| ret = btrfs_writepage_cow_fixup(page, start, page_end); |
| if (ret) { |
| /* Fixup worker will requeue */ |
| if (ret == -EBUSY) |
| wbc->pages_skipped++; |
| else |
| redirty_page_for_writepage(wbc, page); |
| |
| update_nr_written(wbc, nr_written); |
| unlock_page(page); |
| return 1; |
| } |
| |
| /* |
| * we don't want to touch the inode after unlocking the page, |
| * so we update the mapping writeback index now |
| */ |
| update_nr_written(wbc, nr_written + 1); |
| |
| end = page_end; |
| if (i_size <= start) { |
| btrfs_writepage_endio_finish_ordered(page, start, page_end, 1); |
| goto done; |
| } |
| |
| blocksize = inode->i_sb->s_blocksize; |
| |
| while (cur <= end) { |
| u64 em_end; |
| u64 offset; |
| |
| if (cur >= i_size) { |
| btrfs_writepage_endio_finish_ordered(page, cur, |
| page_end, 1); |
| break; |
| } |
| em = btrfs_get_extent(BTRFS_I(inode), page, pg_offset, cur, |
| end - cur + 1, 1); |
| if (IS_ERR_OR_NULL(em)) { |
| SetPageError(page); |
| ret = PTR_ERR_OR_ZERO(em); |
| break; |
| } |
| |
| extent_offset = cur - em->start; |
| em_end = extent_map_end(em); |
| BUG_ON(em_end <= cur); |
| BUG_ON(end < cur); |
| iosize = min(em_end - cur, end - cur + 1); |
| iosize = ALIGN(iosize, blocksize); |
| offset = em->block_start + extent_offset; |
| bdev = em->bdev; |
| block_start = em->block_start; |
| compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags); |
| free_extent_map(em); |
| em = NULL; |
| |
| /* |
| * compressed and inline extents are written through other |
| * paths in the FS |
| */ |
| if (compressed || block_start == EXTENT_MAP_HOLE || |
| block_start == EXTENT_MAP_INLINE) { |
| /* |
| * end_io notification does not happen here for |
| * compressed extents |
| */ |
| if (!compressed) |
| btrfs_writepage_endio_finish_ordered(page, cur, |
| cur + iosize - 1, |
| 1); |
| else if (compressed) { |
| /* we don't want to end_page_writeback on |
| * a compressed extent. this happens |
| * elsewhere |
| */ |
| nr++; |
| } |
| |
| cur += iosize; |
| pg_offset += iosize; |
| continue; |
| } |
| |
| btrfs_set_range_writeback(tree, cur, cur + iosize - 1); |
| if (!PageWriteback(page)) { |
| btrfs_err(BTRFS_I(inode)->root->fs_info, |
| "page %lu not writeback, cur %llu end %llu", |
| page->index, cur, end); |
| } |
| |
| ret = submit_extent_page(REQ_OP_WRITE | write_flags, tree, wbc, |
| page, offset, iosize, pg_offset, |
| bdev, &epd->bio, |
| end_bio_extent_writepage, |
| 0, 0, 0, false); |
| if (ret) { |
| SetPageError(page); |
| if (PageWriteback(page)) |
| end_page_writeback(page); |
| } |
| |
| cur = cur + iosize; |
| pg_offset += iosize; |
| nr++; |
| } |
| done: |
| *nr_ret = nr; |
| return ret; |
| } |
| |
| /* |
| * the writepage semantics are similar to regular writepage. extent |
| * records are inserted to lock ranges in the tree, and as dirty areas |
| * are found, they are marked writeback. Then the lock bits are removed |
| * and the end_io handler clears the writeback ranges |
| * |
| * Return 0 if everything goes well. |
| * Return <0 for error. |
| */ |
| static int __extent_writepage(struct page *page, struct writeback_control *wbc, |
| struct extent_page_data *epd) |
| { |
| struct inode *inode = page->mapping->host; |
| u64 start = page_offset(page); |
| u64 page_end = start + PAGE_SIZE - 1; |
| int ret; |
| int nr = 0; |
| size_t pg_offset = 0; |
| loff_t i_size = i_size_read(inode); |
| unsigned long end_index = i_size >> PAGE_SHIFT; |
| unsigned int write_flags = 0; |
| unsigned long nr_written = 0; |
| |
| write_flags = wbc_to_write_flags(wbc); |
| |
| trace___extent_writepage(page, inode, wbc); |
| |
| WARN_ON(!PageLocked(page)); |
| |
| ClearPageError(page); |
| |
| pg_offset = 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) { |
| char *userpage; |
| |
| userpage = kmap_atomic(page); |
| memset(userpage + pg_offset, 0, |
| PAGE_SIZE - pg_offset); |
| kunmap_atomic(userpage); |
| flush_dcache_page(page); |
| } |
| |
| pg_offset = 0; |
| |
| set_page_extent_mapped(page); |
| |
| if (!epd->extent_locked) { |
| ret = writepage_delalloc(inode, page, wbc, start, &nr_written); |
| if (ret == 1) |
| goto done_unlocked; |
| if (ret) |
| goto done; |
| } |
| |
| ret = __extent_writepage_io(inode, page, wbc, epd, |
| i_size, nr_written, write_flags, &nr); |
| if (ret == 1) |
| goto done_unlocked; |
| |
| done: |
| if (nr == 0) { |
| /* make sure the mapping tag for page dirty gets cleared */ |
| set_page_writeback(page); |
| end_page_writeback(page); |
| } |
| if (PageError(page)) { |
| ret = ret < 0 ? ret : -EIO; |
| end_extent_writepage(page, ret, start, page_end); |
| } |
| unlock_page(page); |
| ASSERT(ret <= 0); |
| return ret; |
| |
| done_unlocked: |
| return 0; |
| } |
| |
| void wait_on_extent_buffer_writeback(struct extent_buffer *eb) |
| { |
| wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK, |
| TASK_UNINTERRUPTIBLE); |
| } |
| |
| static void end_extent_buffer_writeback(struct extent_buffer *eb) |
| { |
| clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags); |
| smp_mb__after_atomic(); |
| wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK); |
| } |
| |
| /* |
| * Lock eb pages and flush the bio if we can't the locks |
| * |
| * Return 0 if nothing went wrong |
| * Return >0 is same as 0, except bio is not submitted |
| * 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); |
| |
| if (!ret) |
| return ret; |
| |
| num_pages = num_extent_pages(eb); |
| for (i = 0; i < num_pages; i++) { |
| struct page *p = eb->pages[i]; |
| |
| if (!trylock_page(p)) { |
| if (!flush) { |
| 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 extent_buffer *)page->private; |
| struct btrfs_fs_info *fs_info; |
| |
| SetPageError(page); |
| 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); |
| |
| /* |
| * If we error out, we should add back the dirty_metadata_bytes |
| * to make it consistent. |
| */ |
| fs_info = eb->fs_info; |
| 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, &eb->fs_info->flags); |
| break; |
| case 0: |
| set_bit(BTRFS_FS_LOG1_ERR, &eb->fs_info->flags); |
| break; |
| case 1: |
| set_bit(BTRFS_FS_LOG2_ERR, &eb->fs_info->flags); |
| break; |
| default: |
| BUG(); /* unexpected, logic error */ |
| } |
| } |
| |
| static void end_bio_extent_buffer_writepage(struct bio *bio) |
| { |
| struct bio_vec *bvec; |
| struct extent_buffer *eb; |
| int 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); |
| } |
| |
| end_page_writeback(page); |
| |
| if (!done) |
| continue; |
| |
| end_extent_buffer_writeback(eb); |
| } |
| |
| bio_put(bio); |
| } |
| |
| static noinline_for_stack int write_one_eb(struct extent_buffer *eb, |
| struct writeback_control *wbc, |
| struct extent_page_data *epd) |
| { |
| struct btrfs_fs_info *fs_info = eb->fs_info; |
| struct block_device *bdev = fs_info->fs_devices->latest_bdev; |
| struct extent_io_tree *tree = &BTRFS_I(fs_info->btree_inode)->io_tree; |
| u64 offset = eb->start; |
| u32 nritems; |
| int i, num_pages; |
| unsigned long start, end; |
| unsigned int write_flags = wbc_to_write_flags(wbc) | REQ_META; |
| int ret = 0; |
| |
| clear_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags); |
| num_pages = num_extent_pages(eb); |
| atomic_set(&eb->io_pages, num_pages); |
| |
| /* set btree blocks beyond nritems with 0 to avoid stale content. */ |
| nritems = btrfs_header_nritems(eb); |
| if (btrfs_header_level(eb) > 0) { |
| end = btrfs_node_key_ptr_offset(nritems); |
| |
| memzero_extent_buffer(eb, end, eb->len - end); |
| } else { |
| /* |
| * leaf: |
| * header 0 1 2 .. N ... data_N .. data_2 data_1 data_0 |
| */ |
| start = btrfs_item_nr_offset(nritems); |
| end = BTRFS_LEAF_DATA_OFFSET + leaf_data_end(eb); |
| memzero_extent_buffer(eb, start, end - start); |
| } |
| |
| for (i = 0; i < num_pages; i++) { |
| struct page *p = eb->pages[i]; |
| |
| clear_page_dirty_for_io(p); |
| set_page_writeback(p); |
| ret = submit_extent_page(REQ_OP_WRITE | write_flags, tree, wbc, |
| p, offset, PAGE_SIZE, 0, bdev, |
| &epd->bio, |
| end_bio_extent_buffer_writepage, |
| 0, 0, 0, false); |
| if (ret) { |
| set_btree_ioerr(p); |
| if (PageWriteback(p)) |
| end_page_writeback(p); |
| if (atomic_sub_and_test(num_pages - i, &eb->io_pages)) |
| end_extent_buffer_writeback(eb); |
| ret = -EIO; |
| break; |
| } |
| offset += PAGE_SIZE; |
| update_nr_written(wbc, 1); |
| unlock_page(p); |
| } |
| |
| if (unlikely(ret)) { |
| for (; i < num_pages; i++) { |
| struct page *p = eb->pages[i]; |
| clear_page_dirty_for_io(p); |
| unlock_page(p); |
| } |
| } |
| |
| return ret; |
| } |
| |
| int btree_write_cache_pages(struct address_space *mapping, |
| struct writeback_control *wbc) |
| { |
| struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree; |
| struct extent_buffer *eb, *prev_eb = NULL; |
| struct extent_page_data epd = { |
| .bio = NULL, |
| .tree = tree, |
| .extent_locked = 0, |
| .sync_io = wbc->sync_mode == WB_SYNC_ALL, |
| }; |
| 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; |
| 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]; |
| |
| if (!PagePrivate(page)) |
| continue; |
| |
| spin_lock(&mapping->private_lock); |
| if (!PagePrivate(page)) { |
| spin_unlock(&mapping->private_lock); |
| continue; |
| } |
| |
| eb = (struct extent_buffer *)page->private; |
| |
| /* |
| * Shouldn't happen and normally this would be a BUG_ON |
| * but no sense in crashing the users box for something |
| * we can survive anyway. |
| */ |
| if (WARN_ON(!eb)) { |
| spin_unlock(&mapping->private_lock); |
| continue; |
| } |
| |
| if (eb == prev_eb) { |
| spin_unlock(&mapping->private_lock); |
| continue; |
| } |
| |
| ret = atomic_inc_not_zero(&eb->refs); |
| spin_unlock(&mapping->private_lock); |
| if (!ret) |
| continue; |
| |
| prev_eb = eb; |
| ret = lock_extent_buffer_for_io(eb, &epd); |
| if (!ret) { |
| free_extent_buffer(eb); |
| continue; |
| } else if (ret < 0) { |
| done = 1; |
| free_extent_buffer(eb); |
| break; |
| } |
| |
| ret = write_one_eb(eb, wbc, &epd); |
| if (ret) { |
| done = 1; |
| free_extent_buffer(eb); |
| break; |
| } |
| free_extent_buffer(eb); |
| |
| /* |
| * The filesystem may choose to bump up nr_to_write. |
| * We have to make sure to honor the new nr_to_write |
| * at any time. |
| */ |
| nr_to_write_done = (wbc->sync_mode == WB_SYNC_NONE && |
| 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; |
| } |
| ASSERT(ret <= 0); |
| if (ret < 0) { |
| end_write_bio(&epd, ret); |
| return ret; |
| } |
| /* |
| * If something went wrong, don't allow any metadata write bio to be |
| * submitted. |
| * |
| * This would prevent use-after-free if we had dirty pages not |
| * cleaned up, which can still happen by fuzzed images. |
| * |
| * - Bad extent tree |
| * Allowing existing tree block to be allocated for other trees. |
| * |
| * - Log tree operations |
| * Exiting tree blocks get allocated to log tree, bumps its |
| * generation, then get cleaned in tree re-balance. |
| * Such tree block will not be written back, since it's clean, |
| * thus no WRITTEN flag set. |
| * And after log writes back, this tree block is not traced by |
| * any dirty extent_io_tree. |
| * |
| * - Offending tree block gets re-dirtied from its original owner |
| * Since it has bumped generation, no WRITTEN flag, it can be |
| * reused without COWing. This tree block will not be traced |
| * by btrfs_transaction::dirty_pages. |
| * |
| * Now such dirty tree block will not be cleaned by any dirty |
| * extent io tree. Thus we don't want to submit such wild eb |
| * if the fs already has error. |
| */ |
| if (!test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) { |
| ret = flush_write_bio(&epd); |
| } else { |
| ret = -EROFS; |
| end_write_bio(&epd, ret); |
| } |
| return ret; |
| } |
| |
| /** |
| * write_cache_pages - walk the list of dirty pages of the given address space and write all of them. |
| * @mapping: address space structure to write |
| * @wbc: subtract the number of written pages from *@wbc->nr_to_write |
| * @data: data passed to __extent_writepage function |
| * |
| * If a page is already under I/O, write_cache_pages() skips it, even |
| * if it's dirty. This is desirable behaviour for memory-cleaning writeback, |
| * but it is INCORRECT for data-integrity system calls such as fsync(). fsync() |
| * and msync() need to guarantee that all the data which was dirty at the time |
| * the call was made get new I/O started against them. If wbc->sync_mode is |
| * WB_SYNC_ALL then we were called for data integrity and we must wait for |
| * existing IO to complete. |
| */ |
| static int extent_write_cache_pages(struct address_space *mapping, |
| struct writeback_control *wbc, |
| struct extent_page_data *epd) |
| { |
| struct inode *inode = mapping->host; |
| int ret = 0; |
| int done = 0; |
| int nr_to_write_done = 0; |
| struct pagevec pvec; |
| int nr_pages; |
| pgoff_t index; |
| pgoff_t end; /* Inclusive */ |
| pgoff_t done_index; |
| int range_whole = 0; |
| int scanned = 0; |
| 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 = NULL, |
| .tree = &BTRFS_I(page->mapping->host)->io_tree, |
| .extent_locked = 0, |
| .sync_io = wbc->sync_mode == WB_SYNC_ALL, |
| }; |
| |
| ret = __extent_writepage(page, wbc, &epd); |
| ASSERT(ret <= 0); |
| if (ret < 0) { |
| end_write_bio(&epd, ret); |
| return ret; |
| } |
| |
| ret = flush_write_bio(&epd); |
| ASSERT(ret <= 0); |
| return ret; |
| } |
| |
| int extent_write_locked_range(struct inode *inode, u64 start, u64 end, |
| int mode) |
| { |
| int ret = 0; |
| struct address_space *mapping = inode->i_mapping; |
| struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree; |
| struct page *page; |
| unsigned long nr_pages = (end - start + PAGE_SIZE) >> |
| PAGE_SHIFT; |
| |
| struct extent_page_data epd = { |
| .bio = NULL, |
| .tree = tree, |
| .extent_locked = 1, |
| .sync_io = mode == WB_SYNC_ALL, |
| }; |
| struct writeback_control wbc_writepages = { |
| .sync_mode = mode, |
| .nr_to_write = nr_pages * 2, |
| .range_start = start, |
| .range_end = end + 1, |
| }; |
| |
| while (start <= end) { |
| page = find_get_page(mapping, start >> PAGE_SHIFT); |
| if (clear_page_dirty_for_io(page)) |
| ret = __extent_writepage(page, &wbc_writepages, &epd); |
| else { |
| btrfs_writepage_endio_finish_ordered(page, start, |
| start + PAGE_SIZE - 1, 1); |
| unlock_page(page); |
| } |
| put_page(page); |
| start += PAGE_SIZE; |
| } |
| |
| ASSERT(ret <= 0); |
| if (ret < 0) { |
| end_write_bio(&epd, ret); |
| return ret; |
| } |
| ret = flush_write_bio(&epd); |
| return ret; |
| } |
| |
| int extent_writepages(struct address_space *mapping, |
| struct writeback_control *wbc) |
| { |
| int ret = 0; |
| struct extent_page_data epd = { |
| .bio = NULL, |
| .tree = &BTRFS_I(mapping->host)->io_tree, |
| .extent_locked = 0, |
| .sync_io = wbc->sync_mode == WB_SYNC_ALL, |
| }; |
| |
| ret = extent_write_cache_pages(mapping, wbc, &epd); |
| ASSERT(ret <= 0); |
| if (ret < 0) { |
| end_write_bio(&epd, ret); |
| return ret; |
| } |
| ret = flush_write_bio(&epd); |
| return ret; |
| } |
| |
| int extent_readpages(struct address_space *mapping, struct list_head *pages, |
| unsigned nr_pages) |
| { |
| struct bio *bio = NULL; |
| unsigned long bio_flags = 0; |
| struct page *pagepool[16]; |
| struct extent_map *em_cached = NULL; |
| struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree; |
| int nr = 0; |
| u64 prev_em_start = (u64)-1; |
| |
| while (!list_empty(pages)) { |
| u64 contig_end = 0; |
| |
| for (nr = 0; nr < ARRAY_SIZE(pagepool) && !list_empty(pages);) { |
| struct page *page = lru_to_page(pages); |
| |
| prefetchw(&page->flags); |
| list_del(&page->lru); |
| if (add_to_page_cache_lru(page, mapping, page->index, |
| readahead_gfp_mask(mapping))) { |
| put_page(page); |
| break; |
| } |
| |
| pagepool[nr++] = page; |
| contig_end = page_offset(page) + PAGE_SIZE - 1; |
| } |
| |
| if (nr) { |
| u64 contig_start = page_offset(pagepool[0]); |
| |
| ASSERT(contig_start + nr * PAGE_SIZE - 1 == contig_end); |
| |
| contiguous_readpages(tree, pagepool, nr, contig_start, |
| contig_end, &em_cached, &bio, &bio_flags, |
| &prev_em_start); |
| } |
| } |
| |
| if (em_cached) |
| free_extent_map(em_cached); |
| |
| if (bio) |
| return submit_one_bio(bio, 0, bio_flags); |
| return 0; |
| } |
| |
| /* |
| * basic invalidatepage code, this waits on any locked or writeback |
| * ranges corresponding to the page, and then deletes any extent state |
| * records from the tree |
| */ |
| int extent_invalidatepage(struct extent_io_tree *tree, |
| struct page *page, unsigned long offset) |
| { |
| struct extent_state *cached_state = NULL; |
| u64 start = page_offset(page); |
| u64 end = start + PAGE_SIZE - 1; |
| size_t blocksize = page->mapping->host->i_sb->s_blocksize; |
| |
| start += ALIGN(offset, blocksize); |
| if (start > end) |
| return 0; |
| |
| lock_extent_bits(tree, start, end, &cached_state); |
| wait_on_page_writeback(page); |
| clear_extent_bit(tree, start, end, EXTENT_LOCKED | EXTENT_DELALLOC | |
| EXTENT_DO_ACCOUNTING, 1, 1, &cached_state); |
| return 0; |
| } |
| |
| /* |
| * a helper for releasepage, this tests for areas of the page that |
| * are locked or under IO and drops the related state bits if it is safe |
| * to drop the page. |
| */ |
| static int try_release_extent_state(struct extent_io_tree *tree, |
| struct page *page, gfp_t mask) |
| { |
| u64 start = page_offset(page); |
| u64 end = start + PAGE_SIZE - 1; |
| int ret = 1; |
| |
| if (test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL)) { |
| ret = 0; |
| } else { |
| /* |
| * at this point we can safely clear everything except the |
| * locked bit and the nodatasum bit |
| */ |
| ret = __clear_extent_bit(tree, start, end, |
| ~(EXTENT_LOCKED | EXTENT_NODATASUM), |
| 0, 0, NULL, mask, NULL); |
| |
| /* if clear_extent_bit failed for enomem reasons, |
| * we can't allow the release to continue. |
| */ |
| if (ret < 0) |
| ret = 0; |
| else |
| ret = 1; |
| } |
| return ret; |
| } |
| |
| /* |
| * a helper for releasepage. As long as there are no locked extents |
| * in the range corresponding to the page, both state records and extent |
| * map records are removed |
| */ |
| int try_release_extent_mapping(struct page *page, gfp_t mask) |
| { |
| struct extent_map *em; |
| u64 start = page_offset(page); |
| u64 end = start + PAGE_SIZE - 1; |
| struct btrfs_inode *btrfs_inode = BTRFS_I(page->mapping->host); |
| struct extent_io_tree *tree = &btrfs_inode->io_tree; |
| struct extent_map_tree *map = &btrfs_inode->extent_tree; |
| |
| if (gfpflags_allow_blocking(mask) && |
| page->mapping->host->i_size > SZ_16M) { |
| u64 len; |
| while (start <= end) { |
| len = end - start + 1; |
| write_lock(&map->lock); |
| em = lookup_extent_mapping(map, start, len); |
| if (!em) { |
| write_unlock(&map->lock); |
| break; |
| } |
| if (test_bit(EXTENT_FLAG_PINNED, &em->flags) || |
| em->start != start) { |
| write_unlock(&map->lock); |
| free_extent_map(em); |
| break; |
| } |
| if (test_range_bit(tree, em->start, |
| extent_map_end(em) - 1, |
| EXTENT_LOCKED, 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)) { |
| set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, |
| &btrfs_inode->runtime_flags); |
| remove_extent_mapping(map, em); |
| /* once for the rb tree */ |
| free_extent_map(em); |
| } |
| 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 inode *inode, |
| u64 offset, u64 last) |
| { |
| u64 sectorsize = btrfs_inode_sectorsize(inode); |
| struct extent_map *em; |
| u64 len; |
| |
| if (offset >= last) |
| return NULL; |
| |
| while (1) { |
| len = last - offset; |
| if (len == 0) |
| break; |
| len = ALIGN(len, sectorsize); |
| em = btrfs_get_extent_fiemap(BTRFS_I(inode), 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 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); |
| struct btrfs_key found_key; |
| struct extent_map *em = NULL; |
| struct extent_state *cached_state = NULL; |
| struct btrfs_path *path; |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| struct fiemap_cache cache = { 0 }; |
| 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; |
| path->leave_spinning = 1; |
| |
| 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(BTRFS_I(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(BTRFS_I(inode)) || |
| found_type != BTRFS_EXTENT_DATA_KEY) { |
| /* have to trust i_size as the end */ |
| last = (u64)-1; |
| last_for_get_extent = isize; |
| } else { |
| /* |
| * remember the start of the last extent. There are a |
| * bunch of different factors that go into the length of the |
| * extent, so its much less complex to remember where it started |
| */ |
| last = found_key.offset; |
| last_for_get_extent = last + 1; |
| } |
| btrfs_release_path(path); |
| |
| /* |
| * we might have some extents allocated but more delalloc past those |
| * extents. so, we trust isize unless the start of the last extent is |
| * beyond isize |
| */ |
| if (last < isize) { |
| last = (u64)-1; |
| last_for_get_extent = isize; |
| } |
| |
| lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len - 1, |
| &cached_state); |
| |
| em = get_extent_skip_holes(inode, start, last_for_get_extent); |
| if (!em) |
| goto out; |
| if (IS_ERR(em)) { |
| ret = PTR_ERR(em); |
| goto out; |
| } |
| |
| while (!end) { |
| u64 offset_in_extent = 0; |
| |
| /* break if the extent we found is outside the range */ |
| if (em->start >= max || extent_map_end(em) < off) |
| break; |
| |
| /* |
| * get_extent may return an extent that starts before our |
| * requested range. We have to make sure the ranges |
| * we return to fiemap always move forward and don't |
| * overlap, so adjust the offsets here |
| */ |
| em_start = max(em->start, off); |
| |
| /* |
| * record the offset from the start of the extent |
| * for adjusting the disk offset below. Only do this if the |
| * extent isn't compressed since our in ram offset may be past |
| * what we have actually allocated on disk. |
| */ |
| if (!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) |
| offset_in_extent = em_start - em->start; |
| em_end = extent_map_end(em); |
| em_len = em_end - em_start; |
| flags = 0; |
| if (em->block_start < EXTENT_MAP_LAST_BYTE) |
| disko = em->block_start + offset_in_extent; |
| else |
| disko = 0; |
| |
| /* |
| * bump off for our next call to get_extent |
| */ |
| off = extent_map_end(em); |
| if (off >= max) |
| end = 1; |
| |
| if (em->block_start == EXTENT_MAP_LAST_BYTE) { |
| end = 1; |
| flags |= FIEMAP_EXTENT_LAST; |
| } else if (em->block_start == EXTENT_MAP_INLINE) { |
| flags |= (FIEMAP_EXTENT_DATA_INLINE | |
| FIEMAP_EXTENT_NOT_ALIGNED); |
| } else if (em->block_start == EXTENT_MAP_DELALLOC) { |
| flags |= (FIEMAP_EXTENT_DELALLOC | |
| FIEMAP_EXTENT_UNKNOWN); |
| } else if (fieinfo->fi_extents_max) { |
| u64 bytenr = em->block_start - |
| (em->start - em->orig_start); |
| |
| /* |
| * As btrfs supports shared space, this information |
| * can be exported to userspace tools via |
| * flag FIEMAP_EXTENT_SHARED. If fi_extents_max == 0 |
| * then we're just getting a count and we can skip the |
| * lookup stuff. |
| */ |
| ret = btrfs_check_shared(root, |
| btrfs_ino(BTRFS_I(inode)), |
| bytenr, 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(&BTRFS_I(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) |
| { |
| btrfs_leak_debug_del(&eb->leak_list); |
| kmem_cache_free(extent_buffer_cache, eb); |
| } |
| |
| int extent_buffer_under_io(struct extent_buffer *eb) |
| { |
| return (atomic_read(&eb->io_pages) || |
| test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) || |
| test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)); |
| } |
| |
| /* |
| * Release all pages attached to the extent buffer. |
| */ |
| static void btrfs_release_extent_buffer_pages(struct extent_buffer *eb) |
| { |
| int i; |
| int num_pages; |
| int mapped = !test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags); |
| |
| BUG_ON(extent_buffer_under_io(eb)); |
| |
| num_pages = num_extent_pages(eb); |
| for (i = 0; i < num_pages; i++) { |
| struct page *page = eb->pages[i]; |
| |
| if (!page) |
| continue; |
| if (mapped) |
| spin_lock(&page->mapping->private_lock); |
| /* |
| * We do this since we'll remove the pages after we've |
| * removed the eb from the radix tree, so we could race |
| * and have this page now attached to the new eb. So |
| * only clear page_private if it's still connected to |
| * this eb. |
| */ |
| if (PagePrivate(page) && |
| page->private == (unsigned long)eb) { |
| BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)); |
| BUG_ON(PageDirty(page)); |
| BUG_ON(PageWriteback(page)); |
| /* |
| * We need to make sure we haven't be attached |
| * to a new eb. |
| */ |
| ClearPagePrivate(page); |
| set_page_private(page, 0); |
| /* One for the page private */ |
| put_page(page); |
| } |
| |
| if (mapped) |
| spin_unlock(&page->mapping->private_lock); |
| |
| /* One for when we allocated the page */ |
| put_page(page); |
| } |
| } |
| |
| /* |
| * Helper for releasing the extent buffer. |
| */ |
| static inline void btrfs_release_extent_buffer(struct extent_buffer *eb) |
| { |
| btrfs_release_extent_buffer_pages(eb); |
| __free_extent_buffer(eb); |
| } |
| |
| static struct extent_buffer * |
| __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start, |
| unsigned long len) |
| { |
| struct extent_buffer *eb = NULL; |
| |
| eb = kmem_cache_zalloc(extent_buffer_cache, GFP_NOFS|__GFP_NOFAIL); |
| eb->start = start; |
| eb->len = len; |
| eb->fs_info = fs_info; |
| eb->bflags = 0; |
| rwlock_init(&eb->lock); |
| atomic_set(&eb->blocking_readers, 0); |
| eb->blocking_writers = 0; |
| eb->lock_nested = false; |
| init_waitqueue_head(&eb->write_lock_wq); |
| init_waitqueue_head(&eb->read_lock_wq); |
| |
| btrfs_leak_debug_add(&eb->leak_list, &buffers); |
| |
| spin_lock_init(&eb->refs_lock); |
| atomic_set(&eb->refs, 1); |
| atomic_set(&eb->io_pages, 0); |
| |
| /* |
| * Sanity checks, currently the maximum is 64k covered by 16x 4k pages |
| */ |
| BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE |
| > MAX_INLINE_EXTENT_BUFFER_SIZE); |
| BUG_ON(len > MAX_INLINE_EXTENT_BUFFER_SIZE); |
| |
| #ifdef CONFIG_BTRFS_DEBUG |
| eb->spinning_writers = 0; |
| atomic_set(&eb->spinning_readers, 0); |
| atomic_set(&eb->read_locks, 0); |
| eb->write_locks = 0; |
| #endif |
| |
| return eb; |
| } |
| |
| struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src) |
| { |
| int i; |
| struct page *p; |
| struct extent_buffer *new; |
| int num_pages = num_extent_pages(src); |
| |
| new = __alloc_extent_buffer(src->fs_info, src->start, src->len); |
| if (new == NULL) |
| return NULL; |
| |
| for (i = 0; i < num_pages; i++) { |
| p = alloc_page(GFP_NOFS); |
| if (!p) { |
| btrfs_release_extent_buffer(new); |
| return NULL; |
| } |
| attach_extent_buffer_page(new, p); |
| WARN_ON(PageDirty(p)); |
| SetPageUptodate(p); |
| new->pages[i] = p; |
| copy_page(page_address(p), page_address(src->pages[i])); |
| } |
| |
| set_bit(EXTENT_BUFFER_UPTODATE, &new->bflags); |
| set_bit(EXTENT_BUFFER_UNMAPPED, &new->bflags); |
| |
| return new; |
| } |
| |
| struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, |
| u64 start, unsigned long len) |
| { |
| struct extent_buffer *eb; |
| int num_pages; |
| int i; |
| |
| eb = __alloc_extent_buffer(fs_info, start, len); |
| if (!eb) |
| return NULL; |
| |
| num_pages = num_extent_pages(eb); |
| for (i = 0; i < num_pages; i++) { |
| eb->pages[i] = alloc_page(GFP_NOFS); |
| if (!eb->pages[i]) |
| goto err; |
| } |
| set_extent_buffer_uptodate(eb); |
| btrfs_set_header_nritems(eb, 0); |
| set_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags); |
| |
| return eb; |
| err: |
| for (; i > 0; i--) |
| __free_page(eb->pages[i - 1]); |
| __free_extent_buffer(eb); |
| return NULL; |
| } |
| |
| struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, |
| u64 start) |
| { |
| return __alloc_dummy_extent_buffer(fs_info, start, fs_info->nodesize); |
| } |
| |
| static void check_buffer_tree_ref(struct extent_buffer *eb) |
| { |
| int refs; |
| /* |
| * The 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; |
| |
| rcu_read_lock(); |
| eb = radix_tree_lookup(&fs_info->buffer_radix, |
| start >> PAGE_SHIFT); |
| if (eb && atomic_inc_not_zero(&eb->refs)) { |
| rcu_read_unlock(); |
| /* |
| * Lock our eb's refs_lock to avoid races with |
| * free_extent_buffer. When we get our eb it might be flagged |
| * with EXTENT_BUFFER_STALE and another task running |
| * free_extent_buffer might have seen that flag set, |
| * eb->refs == 2, that the buffer isn't under IO (dirty and |
| * writeback flags not set) and it's still in the tree (flag |
| * EXTENT_BUFFER_TREE_REF set), therefore being in the process |
| * of decrementing the extent buffer's reference count twice. |
| * So here we could race and increment the eb's reference count, |
| * clear its stale flag, mark it as dirty and drop our reference |
| * before the other task finishes executing free_extent_buffer, |
| * which would later result in an attempt to free an extent |
| * buffer that is dirty. |
| */ |
| if (test_bit(EXTENT_BUFFER_STALE, &eb->bflags)) { |
| spin_lock(&eb->refs_lock); |
| spin_unlock(&eb->refs_lock); |
| } |
| mark_extent_buffer_accessed(eb, NULL); |
| return eb; |
| } |
| rcu_read_unlock(); |
| |
| return NULL; |
| } |
| |
| #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS |
| struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info, |
| u64 start) |
| { |
| struct extent_buffer *eb, *exists = NULL; |
| int ret; |
| |
| eb = find_extent_buffer(fs_info, start); |
| if (eb) |
| return eb; |
| eb = alloc_dummy_extent_buffer(fs_info, start); |
| if (!eb) |
| return 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 >> PAGE_SHIFT, eb); |
| spin_unlock(&fs_info->buffer_lock); |
| radix_tree_preload_end(); |
| if (ret == -EEXIST) { |
| exists = find_extent_buffer(fs_info, start); |
| if (exists) |
| goto free_eb; |
| else |
| goto again; |
| } |
| check_buffer_tree_ref(eb); |
| set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags); |
| |
| return eb; |
| free_eb: |
| btrfs_release_extent_buffer(eb); |
| return exists; |
| } |
| #endif |
| |
| struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, |
| u64 start) |
| { |
| unsigned long len = fs_info->nodesize; |
| int num_pages; |
| int i; |
| unsigned long index = start >> PAGE_SHIFT; |
| struct extent_buffer *eb; |
| struct extent_buffer *exists = NULL; |
| struct page *p; |
| struct address_space *mapping = fs_info->btree_inode->i_mapping; |
| int uptodate = 1; |
| int ret; |
| |
| if (!IS_ALIGNED(start, fs_info->sectorsize)) { |
| btrfs_err(fs_info, "bad tree block start %llu", start); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| eb = find_extent_buffer(fs_info, start); |
| if (eb) |
| return eb; |
| |
| eb = __alloc_extent_buffer(fs_info, start, len); |
| if (!eb) |
| return ERR_PTR(-ENOMEM); |
| |
| num_pages = num_extent_pages(eb); |
| for (i = 0; i < num_pages; i++, index++) { |
| p = find_or_create_page(mapping, index, GFP_NOFS|__GFP_NOFAIL); |
| if (!p) { |
| exists = ERR_PTR(-ENOMEM); |
| goto free_eb; |
| } |
| |
| spin_lock(&mapping->private_lock); |
| if (PagePrivate(p)) { |
| /* |
| * We could have already allocated an eb for this page |
| * and attached one so lets see if we can get a ref on |
| * the existing eb, and if we can we know it's good and |
| * we can just return that one, else we know we can just |
| * overwrite page->private. |
| */ |
| exists = (struct extent_buffer *)p->private; |
| if (atomic_inc_not_zero(&exists->refs)) { |
| spin_unlock(&mapping->private_lock); |
| unlock_page(p); |
| put_page(p); |
| mark_extent_buffer_accessed(exists, p); |
| goto free_eb; |
| } |
| exists = NULL; |
| |
| /* |
| * Do this so attach doesn't complain and we need to |
| * drop the ref the old guy had. |
| */ |
| ClearPagePrivate(p); |
| WARN_ON(PageDirty(p)); |
| put_page(p); |
| } |
| attach_extent_buffer_page(eb, p); |
| spin_unlock(&mapping->private_lock); |
| WARN_ON(PageDirty(p)); |
| eb->pages[i] = p; |
| if (!PageUptodate(p)) |
| uptodate = 0; |
| |
| /* |
| * We can't unlock the pages just yet since the extent buffer |
| * hasn't been properly inserted in the radix tree, this |
| * opens a race with btree_releasepage which can free a page |
| * while we are still filling in all pages for the buffer and |
| * we could crash. |
| */ |
| } |
| if (uptodate) |
| set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); |
| again: |
| ret = radix_tree_preload(GFP_NOFS); |
| if (ret) { |
| exists = ERR_PTR(ret); |
| goto free_eb; |
| } |
| |
| spin_lock(&fs_info->buffer_lock); |
| ret = radix_tree_insert(&fs_info->buffer_radix, |
| start >> PAGE_SHIFT, eb); |
| spin_unlock(&fs_info->buffer_lock); |
| radix_tree_preload_end(); |
| if (ret == -EEXIST) { |
| exists = find_extent_buffer(fs_info, start); |
| if (exists) |
| goto free_eb; |
| else |
| goto again; |
| } |
| /* add one reference for the tree */ |
| check_buffer_tree_ref(eb); |
| set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags); |
| |
| /* |
| * Now it's safe to unlock the pages because any calls to |
| * btree_releasepage will correctly detect that a page belongs to a |
| * live buffer and won't free them prematurely. |
| */ |
| for (i = 0; i < num_pages; i++) |
| unlock_page(eb->pages[i]); |
| return eb; |
| |
| free_eb: |
| WARN_ON(!atomic_dec_and_test(&eb->refs)); |
| for (i = 0; i < num_pages; i++) { |
| if (eb->pages[i]) |
| unlock_page(eb->pages[i]); |
| } |
| |
| btrfs_release_extent_buffer(eb); |
| return exists; |
| } |
| |
| static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head) |
| { |
| struct extent_buffer *eb = |
| container_of(head, struct extent_buffer, rcu_head); |
| |
| __free_extent_buffer(eb); |
| } |
| |
| static int release_extent_buffer(struct extent_buffer *eb) |
| { |
| lockdep_assert_held(&eb->refs_lock); |
| |
| WARN_ON(atomic_read(&eb->refs) == 0); |
| if (atomic_dec_and_test(&eb->refs)) { |
| if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags)) { |
| struct btrfs_fs_info *fs_info = eb->fs_info; |
| |
| spin_unlock(&eb->refs_lock); |
| |
| spin_lock(&fs_info->buffer_lock); |
| radix_tree_delete(&fs_info->buffer_radix, |
| eb->start >> PAGE_SHIFT); |
| spin_unlock(&fs_info->buffer_lock); |
| } else { |
| spin_unlock(&eb->refs_lock); |
| } |
| |
| /* Should be safe to release our pages at this point */ |
| btrfs_release_extent_buffer_pages(eb); |
| #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS |
| if (unlikely(test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags))) { |
| __free_extent_buffer(eb); |
| return 1; |
| } |
| #endif |
| call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu); |
| return 1; |
| } |
| spin_unlock(&eb->refs_lock); |
| |
| return 0; |
| } |
| |
| void free_extent_buffer(struct extent_buffer *eb) |
| { |
| int refs; |
| int old; |
| if (!eb) |
| return; |
| |
| while (1) { |
| refs = atomic_read(&eb->refs); |
| if ((!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); |
| } |
| |
| void clear_extent_buffer_dirty(struct extent_buffer *eb) |
| { |
| int i; |
| int num_pages; |
| struct page *page; |
| |
| num_pages = num_extent_pages(eb); |
| |
| for (i = 0; i < num_pages; i++) { |
| page = eb->pages[i]; |
| if (!PageDirty(page)) |
| continue; |
| |
| lock_page(page); |
| WARN_ON(!PagePrivate(page)); |
| |
| clear_page_dirty_for_io(page); |
| xa_lock_irq(&page->mapping->i_pages); |
| if (!PageDirty(page)) |
| __xa_clear_mark(&page->mapping->i_pages, |
| page_index(page), PAGECACHE_TAG_DIRTY); |
| xa_unlock_irq(&page->mapping->i_pages); |
| ClearPageError(page); |
| unlock_page(page); |
| } |
| WARN_ON(atomic_read(&eb->refs) == 0); |
| } |
| |
| 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) |
| for (i = 0; i < num_pages; i++) |
| set_page_dirty(eb->pages[i]); |
| |
| #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) |
| { |
| int i; |
| struct page *page; |
| int num_pages; |
| |
| clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); |
| num_pages = num_extent_pages(eb); |
| for (i = 0; i < num_pages; i++) { |
| page = eb->pages[i]; |
| if (page) |
| ClearPageUptodate(page); |
| } |
| } |
| |
| void set_extent_buffer_uptodate(struct extent_buffer *eb) |
| { |
| int i; |
| struct page *page; |
| int num_pages; |
| |
| set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); |
| num_pages = num_extent_pages(eb); |
| for (i = 0; i < num_pages; i++) { |
| page = eb->pages[i]; |
| SetPageUptodate(page); |
| } |
| } |
| |
| int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num) |
| { |
| int i; |
| struct page *page; |
| int err; |
| int ret = 0; |
| int locked_pages = 0; |
| int all_uptodate = 1; |
| int num_pages; |
| unsigned long num_reads = 0; |
| struct bio *bio = NULL; |
| unsigned long bio_flags = 0; |
| struct extent_io_tree *tree = &BTRFS_I(eb->fs_info->btree_inode)->io_tree; |
| |
| if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags)) |
| return 0; |
| |
| num_pages = num_extent_pages(eb); |
| for (i = 0; i < num_pages; i++) { |
| page = eb->pages[i]; |
| if (wait == WAIT_NONE) { |
| if (!trylock_page(page)) |
| goto unlock_exit; |
| } else { |
| lock_page(page); |
| } |
| locked_pages++; |
| } |
| /* |
| * We need to firstly lock all pages to make sure that |
| * the uptodate bit of our pages won't be affected by |
| * clear_extent_buffer_uptodate(). |
| */ |
| for (i = 0; i < num_pages; i++) { |
| page = eb->pages[i]; |
| if (!PageUptodate(page)) { |
| num_reads++; |
| all_uptodate = 0; |
| } |
| } |
| |
| if (all_uptodate) { |
| set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); |
| goto unlock_exit; |
| } |
| |
| clear_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags); |
| eb->read_mirror = 0; |
| atomic_set(&eb->io_pages, num_reads); |
| /* |
| * 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 = __extent_read_full_page(tree, page, |
| btree_get_extent, &bio, |
| mirror_num, &bio_flags, |
| REQ_META); |
| if (err) { |
| ret = err; |
| /* |
| * We use &bio in above __extent_read_full_page, |
| * so we ensure that if it returns error, the |
| * current page fails to add itself to bio and |
| * it's been unlocked. |
| * |
| * We must dec io_pages by ourselves. |
| */ |
| atomic_dec(&eb->io_pages); |
| } |
| } else { |
| unlock_page(page); |
| } |
| } |
| |
| if (bio) { |
| err = submit_one_bio(bio, mirror_num, bio_flags); |
| if (err) |
| return err; |
| } |
| |
| if (ret || wait != WAIT_COMPLETE) |
| return ret; |
| |
| for (i = 0; i < num_pages; i++) { |
| page = eb->pages[i]; |
| wait_on_page_locked(page); |
| if (!PageUptodate(page)) |
| ret = -EIO; |
| } |
| |
| return ret; |
| |
| unlock_exit: |
| while (locked_pages > 0) { |
| locked_pages--; |
| page = eb->pages[locked_pages]; |
| unlock_page(page); |
| } |
| return ret; |
| } |
| |
| void read_extent_buffer(const struct extent_buffer *eb, void *dstv, |
| unsigned long start, unsigned long len) |
| { |
| size_t cur; |
| size_t offset; |
| struct page *page; |
| char *kaddr; |
| char *dst = (char *)dstv; |
| size_t start_offset = offset_in_page(eb->start); |
| unsigned long i = (start_offset + start) >> PAGE_SHIFT; |
| |
| if (start + len > eb->len) { |
| WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, wanted %lu %lu\n", |
| eb->start, eb->len, start, len); |
| memset(dst, 0, len); |
| return; |
| } |
| |
| offset = offset_in_page(start_offset + 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; |
| size_t start_offset = offset_in_page(eb->start); |
| unsigned long i = (start_offset + start) >> PAGE_SHIFT; |
| int ret = 0; |
| |
| WARN_ON(start > eb->len); |
| WARN_ON(start + len > eb->start + eb->len); |
| |
| offset = offset_in_page(start_offset + start); |
| |
| while (len > 0) { |
| page = eb->pages[i]; |
| |
| cur = min(len, (PAGE_SIZE - offset)); |
| kaddr = page_address(page); |
| if (probe_user_write(dst, kaddr + offset, cur)) { |
| ret = -EFAULT; |
| break; |
| } |
| |
| dst += cur; |
| len -= cur; |
| offset = 0; |
| i++; |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * return 0 if the item is found within a page. |
| * return 1 if the item spans two pages. |
| * return -EINVAL otherwise. |
| */ |
| int map_private_extent_buffer(const struct extent_buffer *eb, |
| unsigned long start, unsigned long min_len, |
| char **map, unsigned long *map_start, |
| unsigned long *map_len) |
| { |
| size_t offset; |
| char *kaddr; |
| struct page *p; |
| size_t start_offset = offset_in_page(eb->start); |
| unsigned long i = (start_offset + start) >> PAGE_SHIFT; |
| unsigned long end_i = (start_offset + start + min_len - 1) >> |
| PAGE_SHIFT; |
| |
| if (start + min_len > eb->len) { |
| WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, wanted %lu %lu\n", |
| eb->start, eb->len, start, min_len); |
| return -EINVAL; |
| } |
| |
| if (i != end_i) |
| return 1; |
| |
| if (i == 0) { |
| offset = start_offset; |
| *map_start = 0; |
| } else { |
| offset = 0; |
| *map_start = ((u64)i << PAGE_SHIFT) - start_offset; |
| } |
| |
| p = eb->pages[i]; |
| kaddr = page_address(p); |
| *map = kaddr + offset; |
| *map_len = PAGE_SIZE - offset; |
| return 0; |
| } |
| |
| int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv, |
| unsigned long start, unsigned long len) |
| { |
| size_t cur; |
| size_t offset; |
| struct page *page; |
| char *kaddr; |
| char *ptr = (char *)ptrv; |
| size_t start_offset = offset_in_page(eb->start); |
| unsigned long i = (start_offset + start) >> PAGE_SHIFT; |
| int ret = 0; |
| |
| WARN_ON(start > eb->len); |
| WARN_ON(start + len > eb->start + eb->len); |
| |
| offset = offset_in_page(start_offset + 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; |
| } |
| |
| void write_extent_buffer_chunk_tree_uuid(struct extent_buffer *eb, |
| const void *srcv) |
| { |
| char *kaddr; |
| |
| WARN_ON(!PageUptodate(eb->pages[0])); |
| kaddr = page_address(eb->pages[0]); |
| memcpy(kaddr + offsetof(struct btrfs_header, chunk_tree_uuid), srcv, |
| BTRFS_FSID_SIZE); |
| } |
| |
| void write_extent_buffer_fsid(struct extent_buffer *eb, const void *srcv) |
| { |
| char *kaddr; |
| |
| WARN_ON(!PageUptodate(eb->pages[0])); |
| kaddr = page_address(eb->pages[0]); |
| memcpy(kaddr + offsetof(struct btrfs_header, fsid), srcv, |
| BTRFS_FSID_SIZE); |
| } |
| |
| void write_extent_buffer(struct extent_buffer *eb, const void *srcv, |
| unsigned long start, unsigned long len) |
| { |
| size_t cur; |
| size_t offset; |
| struct page *page; |
| char *kaddr; |
| char *src = (char *)srcv; |
| size_t start_offset = offset_in_page(eb->start); |
| unsigned long i = (start_offset + start) >> PAGE_SHIFT; |
| |
| WARN_ON(start > eb->len); |
| WARN_ON(start + len > eb->start + eb->len); |
| |
| offset = offset_in_page(start_offset + start); |
| |
| while (len > 0) { |
| page = eb->pages[i]; |
| WARN_ON(!PageUptodate(page)); |
| |
| cur = min(len, PAGE_SIZE - offset); |
| kaddr = page_address(page); |
| memcpy(kaddr + offset, src, cur); |
| |
| src += cur; |
| len -= cur; |
| offset = 0; |
| i++; |
| } |
| } |
| |
| void memzero_extent_buffer(struct extent_buffer *eb, unsigned long start, |
| unsigned long len) |
| { |
| size_t cur; |
| size_t offset; |
| struct page *page; |
| char *kaddr; |
| size_t start_offset = offset_in_page(eb->start); |
| unsigned long i = (start_offset + start) >> PAGE_SHIFT; |
| |
| WARN_ON(start > eb->len); |
| WARN_ON(start + len > eb->start + eb->len); |
| |
| offset = offset_in_page(start_offset + start); |
| |
| while (len > 0) { |
| page = eb->pages[i]; |
| WARN_ON(!PageUptodate(page)); |
| |
| cur = min(len, PAGE_SIZE - offset); |
| kaddr = page_address(page); |
| memset(kaddr + offset, 0, cur); |
| |
| len -= cur; |
| offset = 0; |
| i++; |
| } |
| } |
| |
| void copy_extent_buffer_full(struct extent_buffer *dst, |
| struct extent_buffer *src) |
| { |
| int i; |
| int num_pages; |
| |
| ASSERT(dst->len == src->len); |
| |
| num_pages = num_extent_pages(dst); |
| for (i = 0; i < num_pages; i++) |
| copy_page(page_address(dst->pages[i]), |
| page_address(src->pages[i])); |
| } |
| |
| void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src, |
| unsigned long dst_offset, unsigned long src_offset, |
| unsigned long len) |
| { |
| u64 dst_len = dst->len; |
| size_t cur; |
| size_t offset; |
| struct page *page; |
| char *kaddr; |
| size_t start_offset = offset_in_page(dst->start); |
| unsigned long i = (start_offset + dst_offset) >> PAGE_SHIFT; |
| |
| WARN_ON(src->len != dst_len); |
| |
| offset = offset_in_page(start_offset + dst_offset); |
| |
| while (len > 0) { |
| page = dst->pages[i]; |
| WARN_ON(!PageUptodate(page)); |
| |
| cur = min(len, (unsigned long)(PAGE_SIZE - offset)); |
| |
| kaddr = page_address(page); |
| read_extent_buffer(src, kaddr + offset, src_offset, cur); |
| |
| src_offset += cur; |
| len -= cur; |
| offset = 0; |
| i++; |
| } |
| } |
| |
| /* |
| * eb_bitmap_offset() - calculate the page and offset of the byte containing the |
| * given bit number |
| * @eb: the extent buffer |
| * @start: offset of the bitmap item in the extent buffer |
| * @nr: bit number |
| * @page_index: return index of the page in the extent buffer that contains the |
| * given bit number |
| * @page_offset: return offset into the page given by page_index |
| * |
| * This helper hides the ugliness of finding the byte in an extent buffer which |
| * contains a given bit. |
| */ |
| static inline void eb_bitmap_offset(struct extent_buffer *eb, |
| unsigned long start, unsigned long nr, |
| unsigned long *page_index, |
| size_t *page_offset) |
| { |
| size_t start_offset = offset_in_page(eb->start); |
| size_t byte_offset = BIT_BYTE(nr); |
| size_t offset; |
| |
| /* |
| * The byte we want is the offset of the extent buffer + the offset of |
| * the bitmap item in the extent buffer + the offset of the byte in the |
| * bitmap item. |
| */ |
| offset = start_offset + start + byte_offset; |
| |
| *page_index = offset >> PAGE_SHIFT; |
| *page_offset = offset_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(struct extent_buffer *eb, unsigned long start, |
| unsigned long nr) |
| { |
| u8 *kaddr; |
| struct page *page; |
| unsigned long i; |
| size_t offset; |
| |
| eb_bitmap_offset(eb, start, nr, &i, &offset); |
| page = eb->pages[i]; |
| WARN_ON(!PageUptodate(page)); |
| kaddr = page_address(page); |
| return 1U & (kaddr[offset] >> (nr & (BITS_PER_BYTE - 1))); |
| } |
| |
| /** |
| * extent_buffer_bitmap_set - set an area of a bitmap |
| * @eb: the extent buffer |
| * @start: offset of the bitmap item in the extent buffer |
| * @pos: bit number of the first bit |
| * @len: number of bits to set |
| */ |
| void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start, |
| unsigned long pos, unsigned long len) |
| { |
| u8 *kaddr; |
| struct page *page; |
| unsigned long i; |
| size_t offset; |
| const unsigned int size = pos + len; |
| int bits_to_set = BITS_PER_BYTE - (pos % BITS_PER_BYTE); |
| u8 mask_to_set = BITMAP_FIRST_BYTE_MASK(pos); |
| |
| eb_bitmap_offset(eb, start, pos, &i, &offset); |
| page = eb->pages[i]; |
| WARN_ON(!PageUptodate(page)); |
| kaddr = page_address(page); |
| |
| while (len >= bits_to_set) { |
| kaddr[offset] |= mask_to_set; |
| len -= bits_to_set; |
| bits_to_set = BITS_PER_BYTE; |
| mask_to_set = ~0; |
| if (++offset >= PAGE_SIZE && len > 0) { |
| offset = 0; |
| page = eb->pages[++i]; |
| WARN_ON(!PageUptodate(page)); |
| kaddr = page_address(page); |
| } |
| } |
| if (len) { |
| mask_to_set &= BITMAP_LAST_BYTE_MASK(size); |
| kaddr[offset] |= mask_to_set; |
| } |
| } |
| |
| |
| /** |
| * extent_buffer_bitmap_clear - clear an area of a bitmap |
| * @eb: the extent buffer |
| * @start: offset of the bitmap item in the extent buffer |
| * @pos: bit number of the first bit |
| * @len: number of bits to clear |
| */ |
| void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start, |
| unsigned long pos, unsigned long len) |
| { |
| u8 *kaddr; |
| struct page *page; |
| unsigned long i; |
| size_t offset; |
| const unsigned int size = pos + len; |
| int bits_to_clear = BITS_PER_BYTE - (pos % BITS_PER_BYTE); |
| u8 mask_to_clear = BITMAP_FIRST_BYTE_MASK(pos); |
| |
| eb_bitmap_offset(eb, start, pos, &i, &offset); |
| page = eb->pages[i]; |
| WARN_ON(!PageUptodate(page)); |
| kaddr = page_address(page); |
| |
| while (len >= bits_to_clear) { |
| kaddr[offset] &= ~mask_to_clear; |
| len -= bits_to_clear; |
| bits_to_clear = BITS_PER_BYTE; |
| mask_to_clear = ~0; |
| if (++offset >= PAGE_SIZE && len > 0) { |
| offset = 0; |
| page = eb->pages[++i]; |
| WARN_ON(!PageUptodate(page)); |
| kaddr = page_address(page); |
| } |
| } |
| if (len) { |
| mask_to_clear &= BITMAP_LAST_BYTE_MASK(size); |
| kaddr[offset] &= ~mask_to_clear; |
| } |
| } |
| |
| static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len) |
| { |
| unsigned long distance = (src > dst) ? src - dst : dst - src; |
| return distance < len; |
| } |
| |
| static void copy_pages(struct page *dst_page, struct page *src_page, |
| unsigned long dst_off, unsigned long src_off, |
| unsigned long len) |
| { |
| char *dst_kaddr = page_address(dst_page); |
| char *src_kaddr; |
| int must_memmove = 0; |
| |
| if (dst_page != src_page) { |
| src_kaddr = page_address(src_page); |
| } else { |
| src_kaddr = dst_kaddr; |
| if (areas_overlap(src_off, dst_off, len)) |
| must_memmove = 1; |
| } |
| |
| if (must_memmove) |
| memmove(dst_kaddr + dst_off, src_kaddr + src_off, len); |
| else |
| memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len); |
| } |
| |
| void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, |
| unsigned long src_offset, unsigned long len) |
| { |
| struct btrfs_fs_info *fs_info = dst->fs_info; |
| size_t cur; |
| size_t dst_off_in_page; |
| size_t src_off_in_page; |
| size_t start_offset = offset_in_page(dst->start); |
| unsigned long dst_i; |
| unsigned long src_i; |
| |
| if (src_offset + len > dst->len) { |
| btrfs_err(fs_info, |
| "memmove bogus src_offset %lu move len %lu dst len %lu", |
| src_offset, len, dst->len); |
| BUG(); |
| } |
| if (dst_offset + len > dst->len) { |
| btrfs_err(fs_info, |
| "memmove bogus dst_offset %lu move len %lu dst len %lu", |
| dst_offset, len, dst->len); |
| BUG(); |
| } |
| |
| while (len > 0) { |
| dst_off_in_page = offset_in_page(start_offset + dst_offset); |
| src_off_in_page = offset_in_page(start_offset + src_offset); |
| |
| dst_i = (start_offset + dst_offset) >> PAGE_SHIFT; |
| src_i = (start_offset + src_offset) >> PAGE_SHIFT; |
| |
| cur = min(len, (unsigned long)(PAGE_SIZE - |
| src_off_in_page)); |
| cur = min_t(unsigned long, cur, |
| (unsigned long)(PAGE_SIZE - dst_off_in_page)); |
| |
| copy_pages(dst->pages[dst_i], dst->pages[src_i], |
| dst_off_in_page, src_off_in_page, cur); |
| |
| src_offset += cur; |
| dst_offset += cur; |
| len -= cur; |
| } |
| } |
| |
| void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, |
| unsigned long src_offset, unsigned long len) |
| { |
| struct btrfs_fs_info *fs_info = dst->fs_info; |
| size_t cur; |
| size_t dst_off_in_page; |
| size_t src_off_in_page; |
| unsigned long dst_end = dst_offset + len - 1; |
| unsigned long src_end = src_offset + len - 1; |
| size_t start_offset = offset_in_page(dst->start); |
| unsigned long dst_i; |
| unsigned long src_i; |
| |
| if (src_offset + len > dst->len) { |
| btrfs_err(fs_info, |
| "memmove bogus src_offset %lu move len %lu len %lu", |
| src_offset, len, dst->len); |
| BUG(); |
| } |
| if (dst_offset + len > dst->len) { |
| btrfs_err(fs_info, |
| "memmove bogus dst_offset %lu move len %lu len %lu", |
| dst_offset, len, dst->len); |
| BUG(); |
| } |
| if (dst_offset < src_offset) { |
| memcpy_extent_buffer(dst, dst_offset, src_offset, len); |
| return; |
| } |
| while (len > 0) { |
| dst_i = (start_offset + dst_end) >> PAGE_SHIFT; |
| src_i = (start_offset + src_end) >> PAGE_SHIFT; |
| |
| dst_off_in_page = offset_in_page(start_offset + dst_end); |
| src_off_in_page = offset_in_page(start_offset + 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; |
| } |
| } |
| |
| int try_release_extent_buffer(struct page *page) |
| { |
| struct extent_buffer *eb; |
| |
| /* |
| * We need to make sure nobody is attaching this page to an eb right |
| * now. |
| */ |
| spin_lock(&page->mapping->private_lock); |
| if (!PagePrivate(page)) { |
| spin_unlock(&page->mapping->private_lock); |
| return 1; |
| } |
| |
| eb = (struct extent_buffer *)page->private; |
| BUG_ON(!eb); |
| |
| /* |
| * This is a little awful but should be ok, we need to make sure that |
| * the eb doesn't disappear out from under us while we're looking at |
| * this page. |
| */ |
| spin_lock(&eb->refs_lock); |
| if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) { |
| spin_unlock(&eb->refs_lock); |
| spin_unlock(&page->mapping->private_lock); |
| return 0; |
| } |
| spin_unlock(&page->mapping->private_lock); |
| |
| /* |
| * If tree ref isn't set then we know the ref on this eb is a real ref, |
| * so just return, this page will likely be freed soon anyway. |
| */ |
| if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) { |
| spin_unlock(&eb->refs_lock); |
| return 0; |
| } |
| |
| return release_extent_buffer(eb); |
| } |