| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Chris Mason | 10668 | 40.99% | 79 | 15.64% |
| Josef Bacik | 3796 | 14.58% | 49 | 9.70% |
| Jan Schmidt | 1498 | 5.76% | 4 | 0.79% |
| Miao Xie | 1471 | 5.65% | 18 | 3.56% |
| Liu Bo | 1069 | 4.11% | 39 | 7.72% |
| Nikolay Borisov | 1066 | 4.10% | 44 | 8.71% |
| Qu Wenruo | 1062 | 4.08% | 17 | 3.37% |
| David Sterba | 1061 | 4.08% | 85 | 16.83% |
| Filipe David Borba Manana | 851 | 3.27% | 24 | 4.75% |
| Omar Sandoval | 616 | 2.37% | 7 | 1.39% |
| Jeff Mahoney | 410 | 1.58% | 16 | 3.17% |
| Yehuda Sadeh Weinraub | 294 | 1.13% | 1 | 0.20% |
| Josef Whiter | 228 | 0.88% | 9 | 1.78% |
| Gerhard Heift | 174 | 0.67% | 1 | 0.20% |
| Xiao Guangrong | 173 | 0.66% | 5 | 0.99% |
| Zheng Yan | 156 | 0.60% | 6 | 1.19% |
| Eric Sandeen | 146 | 0.56% | 3 | 0.59% |
| Li Zefan | 100 | 0.38% | 3 | 0.59% |
| Kirill A. Shutemov | 95 | 0.37% | 3 | 0.59% |
| Chandra Seetharaman | 78 | 0.30% | 1 | 0.20% |
| Alexandre Oliva | 74 | 0.28% | 1 | 0.20% |
| Johannes Thumshirn | 73 | 0.28% | 2 | 0.40% |
| Christoph Hellwig | 67 | 0.26% | 9 | 1.78% |
| Kent Overstreet | 63 | 0.24% | 6 | 1.19% |
| Sergei Trofimovich | 56 | 0.22% | 1 | 0.20% |
| David Woodhouse | 55 | 0.21% | 2 | 0.40% |
| Frank Holton | 53 | 0.20% | 1 | 0.20% |
| Arne Jansen | 44 | 0.17% | 2 | 0.40% |
| Ethan Lien | 38 | 0.15% | 1 | 0.20% |
| Ilya Dryomov | 32 | 0.12% | 1 | 0.20% |
| Mel Gorman | 30 | 0.12% | 2 | 0.40% |
| Dennis Zhou | 28 | 0.11% | 1 | 0.20% |
| Ming Lei | 25 | 0.10% | 2 | 0.40% |
| Heiko Carstens | 25 | 0.10% | 1 | 0.20% |
| Michael Christie | 23 | 0.09% | 2 | 0.40% |
| Stefan Behrens | 22 | 0.08% | 4 | 0.79% |
| Takafumi Kubota | 21 | 0.08% | 1 | 0.20% |
| Mark Fasheh | 20 | 0.08% | 1 | 0.20% |
| Michal Hocko | 18 | 0.07% | 3 | 0.59% |
| Darrick J. Wong | 18 | 0.07% | 1 | 0.20% |
| Linus Torvalds | 16 | 0.06% | 3 | 0.59% |
| Sven Wegener | 16 | 0.06% | 1 | 0.20% |
| Lu Fengqi | 16 | 0.06% | 1 | 0.20% |
| Dan Carpenter | 14 | 0.05% | 1 | 0.20% |
| Goldwyn Rodrigues | 13 | 0.05% | 1 | 0.20% |
| Jens Axboe | 13 | 0.05% | 2 | 0.40% |
| Yan Zheng | 12 | 0.05% | 1 | 0.20% |
| Chengyu Song | 12 | 0.05% | 1 | 0.20% |
| Forrest Liu | 11 | 0.04% | 1 | 0.20% |
| Matthew Wilcox | 9 | 0.03% | 3 | 0.59% |
| Dan Magenheimer | 9 | 0.03% | 1 | 0.20% |
| Elena Reshetova | 8 | 0.03% | 2 | 0.40% |
| Arnd Bergmann | 8 | 0.03% | 1 | 0.20% |
| Naohiro Aota | 7 | 0.03% | 1 | 0.20% |
| Anand Jain | 7 | 0.03% | 1 | 0.20% |
| Colin Ian King | 7 | 0.03% | 2 | 0.40% |
| Dulshani Gunawardhana | 6 | 0.02% | 1 | 0.20% |
| David Howells | 6 | 0.02% | 1 | 0.20% |
| Tsutomu Itoh | 6 | 0.02% | 3 | 0.59% |
| Robbie Ko | 5 | 0.02% | 1 | 0.20% |
| Tejun Heo | 4 | 0.02% | 2 | 0.40% |
| Jan Kara | 4 | 0.02% | 1 | 0.20% |
| Neil Brown | 3 | 0.01% | 2 | 0.40% |
| Andi Kleen | 3 | 0.01% | 1 | 0.20% |
| Andrea Gelmini | 2 | 0.01% | 1 | 0.20% |
| Nicholas D Steeves | 2 | 0.01% | 1 | 0.20% |
| Konstantin Khlebnikov | 2 | 0.01% | 1 | 0.20% |
| Shaun Tancheff | 1 | 0.00% | 1 | 0.20% |
| Julia Lawall | 1 | 0.00% | 1 | 0.20% |
| Nicholas Piggin | 1 | 0.00% | 1 | 0.20% |
| Eric Paris | 1 | 0.00% | 1 | 0.20% |
| Wang Sheng-Hui | 1 | 0.00% | 1 | 0.20% |
| Byongho Lee | 1 | 0.00% | 1 | 0.20% |
| Greg Kroah-Hartman | 1 | 0.00% | 1 | 0.20% |
| Zhao Lei | 1 | 0.00% | 1 | 0.20% |
| Zach Brown | 1 | 0.00% | 1 | 0.20% |
| Total | 26027 | 505 |
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// 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-io-tree.h" #include "extent_map.h" #include "ctree.h" #include "btrfs_inode.h" #include "volumes.h" #include "check-integrity.h" #include "locking.h" #include "rcu-string.h" #include "backref.h" #include "disk-io.h" 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_extent_buffer_leak_debug_check(void) { struct extent_buffer *eb; 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); } } static inline void btrfs_extent_state_leak_debug_check(void) { struct extent_state *state; while (!list_empty(&states)) { state = list_entry(states.next, struct extent_state, leak_list); pr_err("BTRFS: state leak: start %llu end %llu state %u in tree %d refs %d\n", state->start, state->end, state->state, extent_state_in_tree(state), refcount_read(&state->refs)); list_del(&state->leak_list); kmem_cache_free(extent_state_cache, state); } } #define btrfs_debug_check_extent_io_range(tree, start, end) \ __btrfs_debug_check_extent_io_range(__func__, (tree), (start), (end)) static inline void __btrfs_debug_check_extent_io_range(const char *caller, struct extent_io_tree *tree, u64 start, u64 end) { struct inode *inode = tree->private_data; u64 isize; if (!inode || !is_data_inode(inode)) return; isize = i_size_read(inode); if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) { btrfs_debug_rl(BTRFS_I(inode)->root->fs_info, "%s: ino %llu isize %llu odd range [%llu,%llu]", caller, btrfs_ino(BTRFS_I(inode)), isize, start, end); } } #else #define btrfs_leak_debug_add(new, head) do {} while (0) #define btrfs_leak_debug_del(entry) do {} while (0) #define btrfs_extent_buffer_leak_debug_check() do {} while (0) #define btrfs_extent_state_leak_debug_check() do {} while (0) #define btrfs_debug_check_extent_io_range(c, s, e) do {} while (0) #endif struct tree_entry { u64 start; u64 end; struct rb_node rb_node; }; struct extent_page_data { struct 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_state_cache_init(void) { extent_state_cache = kmem_cache_create("btrfs_extent_state", sizeof(struct extent_state), 0, SLAB_MEM_SPREAD, NULL); if (!extent_state_cache) return -ENOMEM; return 0; } int __init extent_io_init(void) { extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer", sizeof(struct extent_buffer), 0, SLAB_MEM_SPREAD, NULL); if (!extent_buffer_cache) return -ENOMEM; if (bioset_init(&btrfs_bioset, BIO_POOL_SIZE, offsetof(struct btrfs_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; return -ENOMEM; } void __cold extent_state_cache_exit(void) { btrfs_extent_state_leak_debug_check(); kmem_cache_destroy(extent_state_cache); } void __cold extent_io_exit(void) { btrfs_extent_buffer_leak_debug_check(); /* * Make sure all delayed rcu free are flushed before we * destroy caches. */ rcu_barrier(); 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) { struct inode *inode = tree->private_data; btrfs_panic(btrfs_sb(inode->i_sb), err, "locking error: extent tree was modified by another thread while locked"); } /* * clear some bits on a range in the tree. This may require splitting * or inserting elements in the tree, so the gfp mask is used to * indicate which allocations or sleeping are allowed. * * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove * the given range from the tree regardless of state (ie for truncate). * * the range [start, end] is inclusive. * * This takes the tree lock, and returns 0 on success and < 0 on error. */ int __clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, unsigned bits, int wake, int delete, struct extent_state **cached_state, gfp_t mask, struct extent_changeset *changeset) { struct extent_state *state; struct extent_state *cached; struct extent_state *prealloc = NULL; struct rb_node *node; u64 last_end; int err; int clear = 0; btrfs_debug_check_extent_io_range(tree, start, end); 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 */ bool btrfs_find_delalloc_range(struct extent_io_tree *tree, u64 *start, u64 *end, u64 max_bytes, struct extent_state **cached_state) { struct rb_node *node; struct extent_state *state; u64 cur_start = *start; bool found = false; u64 total_bytes = 0; spin_lock(&tree->lock); /* * this search will find all the extents that end after * our range starts. */ node = tree_search(tree, cur_start); if (!node) { *end = (u64)-1; goto out; } while (1) { state = rb_entry(node, struct extent_state, rb_node); if (found && (state->start != cur_start || (state->state & EXTENT_BOUNDARY))) { goto out; } if (!(state->state & EXTENT_DELALLOC)) { if (!found) *end = state->end; goto out; } if (!found) { *start = state->start; *cached_state = state; refcount_inc(&state->refs); } found = true; *end = state->end; cur_start = state->end + 1; node = rb_next(node); total_bytes += state->end - state->start + 1; if (total_bytes >= max_bytes) break; if (!node) break; } out: spin_unlock(&tree->lock); return found; } 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 = btrfs_find_delalloc_range(tree, &delalloc_start, &delalloc_end, max_bytes, &cached_state); if (!found || delalloc_end <= *start) { *start = delalloc_start; *end = delalloc_end; free_extent_state(cached_state); return false; } /* * start comes from the offset of locked_page. We have to lock * pages in order, so we can't process delalloc bytes before * locked_page */ if (delalloc_start < *start) delalloc_start = *start; /* * make sure to limit the number of pages we try to lock down */ if (delalloc_end + 1 - delalloc_start > max_bytes) delalloc_end = delalloc_start + max_bytes - 1; /* step two, lock all the pages after the page that has start */ ret = lock_delalloc_pages(inode, locked_page, delalloc_start, delalloc_end); ASSERT(!ret || ret == -EAGAIN); if (ret == -EAGAIN) { /* some of the pages are gone, lets avoid looping by * shortening the size of the delalloc range we're searching */ free_extent_state(cached_state); cached_state = NULL; if (!loops) { max_bytes = PAGE_SIZE; loops = 1; goto again; } else { found = false; goto out_failed; } } /* step three, lock the state bits for the whole range */ lock_extent_bits(tree, delalloc_start, delalloc_end, &cached_state); /* then test to make sure it is all still delalloc */ ret = test_range_bit(tree, delalloc_start, delalloc_end, EXTENT_DELALLOC, 1, cached_state); if (!ret) { unlock_extent_cached(tree, delalloc_start, delalloc_end, &cached_state); __unlock_for_delalloc(inode, locked_page, delalloc_start, delalloc_end); cond_resched(); goto again; } free_extent_state(cached_state); *start = delalloc_start; *end = delalloc_end; out_failed: return found; } 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]); 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. */ 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; } 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->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 * @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 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_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) { struct block_device *bdev; bdev = BTRFS_I(page->mapping->host)->root->fs_info->fs_devices->latest_bdev; bio_set_dev(bio, bdev); 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); 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; 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; } block_start = em->block_start; if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) block_start = EXTENT_MAP_HOLE; /* * If we have a file range that points to a compressed extent * and it's followed by a consecutive file range that points to * to the same compressed extent (possibly with a different * offset and/or length, so it either points to the whole extent * or only part of it), we must make sure we do not submit a * single bio to populate the pages for the 2 ranges because * this makes the compressed extent read zero out the pages * belonging to the 2nd range. Imagine the following scenario: * * File layout * [0 - 8K] [8K - 24K] * | | * | | * points to extent X, points to extent X, * offset 4K, length of 8K offset 0, length 16K * * [extent X, compressed length = 4K uncompressed length = 16K] * * If the bio to read the compressed extent covers both ranges, * it will decompress extent X into the pages belonging to the * first range and then it will stop, zeroing out the remaining * pages that belong to the other range that points to extent X. * So here we make sure we submit 2 bios, one for the first * range and another one for the third range. Both will target * the same physical extent from disk, but we can't currently * make the compressed bio endio callback populate the pages * for both ranges because each compressed bio is tightly * coupled with a single extent map, and each range can have * an extent map with a different offset value relative to the * uncompressed data of our extent and different lengths. This * is a corner case so we prioritize correctness over * non-optimal behavior (submitting 2 bios for the same extent). */ if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) && prev_em_start && *prev_em_start != (u64)-1 && *prev_em_start != em->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, 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, 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; size_t pg_offset = 0; size_t blocksize; int ret = 0; int nr = 0; const unsigned int write_flags = wbc_to_write_flags(wbc); bool compressed; ret = btrfs_writepage_cow_fixup(page, start, page_end); if (ret) { /* Fixup worker will requeue */ redirty_page_for_writepage(wbc, page); update_nr_written(wbc, nr_written); unlock_page(page); return 1; } /* * we don't want to touch the inode after unlocking the page, * so we update the mapping writeback index now */ update_nr_written(wbc, nr_written + 1); end = page_end; 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), NULL, 0, cur, end - cur + 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; 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) { if (compressed) nr++; else btrfs_writepage_endio_finish_ordered(page, cur, cur + iosize - 1, 1); 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, &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++; } *nr_ret = nr; return ret; } /* * the writepage semantics are similar to regular writepage. extent * records are inserted to lock ranges in the tree, and as dirty areas * are found, they are marked writeback. Then the lock bits are removed * and the end_io handler clears the writeback ranges * * Return 0 if everything goes well. * Return <0 for error. */ static int __extent_writepage(struct page *page, struct writeback_control *wbc, struct extent_page_data *epd) { struct inode *inode = page->mapping->host; u64 start = page_offset(page); u64 page_end = start + PAGE_SIZE - 1; int ret; int nr = 0; size_t pg_offset; loff_t i_size = i_size_read(inode); unsigned long end_index = i_size >> PAGE_SHIFT; unsigned long nr_written = 0; trace___extent_writepage(page, inode, wbc); WARN_ON(!PageLocked(page)); ClearPageError(page); pg_offset = offset_in_page(i_size); if (page->index > end_index || (page->index == end_index && !pg_offset)) { page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE); unlock_page(page); return 0; } if (page->index == end_index) { char *userpage; userpage = kmap_atomic(page); memset(userpage + pg_offset, 0, PAGE_SIZE - pg_offset); kunmap_atomic(userpage); flush_dcache_page(page); } set_page_extent_mapped(page); if (!epd->extent_locked) { ret = writepage_delalloc(inode, page, wbc, start, &nr_written); if (ret == 1) return 0; if (ret) goto done; } ret = __extent_writepage_io(inode, page, wbc, epd, i_size, nr_written, &nr); if (ret == 1) return 0; done: if (nr == 0) { /* make sure the mapping tag for page dirty gets cleared */ set_page_writeback(page); end_page_writeback(page); } if (PageError(page)) { ret = ret < 0 ? ret : -EIO; end_extent_writepage(page, ret, start, page_end); } unlock_page(page); ASSERT(ret <= 0); return ret; } void wait_on_extent_buffer_writeback(struct extent_buffer *eb) { wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK, TASK_UNINTERRUPTIBLE); } static void end_extent_buffer_writeback(struct extent_buffer *eb) { clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags); smp_mb__after_atomic(); wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK); } /* * Lock 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; /* * 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 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, &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, }; 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->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; } ret = flush_write_bio(&epd); return ret; } /** * write_cache_pages - walk the list of dirty pages of the given address space and write all of them. * @mapping: address space structure to write * @wbc: subtract the number of written pages from *@wbc->nr_to_write * @data: data passed to __extent_writepage function * * If a page is already under I/O, write_cache_pages() skips it, even * if it's dirty. This is desirable behaviour for memory-cleaning writeback, * but it is INCORRECT for data-integrity system calls such as fsync(). fsync() * and msync() need to guarantee that all the data which was dirty at the time * the call was made get new I/O started against them. If wbc->sync_mode is * WB_SYNC_ALL then we were called for data integrity and we must wait for * existing IO to complete. */ static int extent_write_cache_pages(struct address_space *mapping, struct writeback_control *wbc, struct extent_page_data *epd) { struct inode *inode = mapping->host; int ret = 0; int done = 0; int nr_to_write_done = 0; struct pagevec pvec; int nr_pages; pgoff_t index; pgoff_t end; /* Inclusive */ pgoff_t done_index; int range_whole = 0; int scanned = 0; 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, /* We're called from an async helper function */ .punt_to_cgroup = 1, .no_cgroup_owner = 1, }; wbc_attach_fdatawrite_inode(&wbc_writepages, inode); while (start <= end) { page = find_get_page(mapping, start >> PAGE_SHIFT); if (clear_page_dirty_for_io(page)) ret = __extent_writepage(page, &wbc_writepages, &epd); else { btrfs_writepage_endio_finish_ordered(page, start, start + PAGE_SIZE - 1, 1); unlock_page(page); } put_page(page); start += PAGE_SIZE; } ASSERT(ret <= 0); if (ret == 0) ret = flush_write_bio(&epd); else end_write_bio(&epd, ret); wbc_detach_inode(&wbc_writepages); return ret; } int extent_writepages(struct address_space *mapping, struct writeback_control *wbc) { int ret = 0; struct extent_page_data epd = { .bio = 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)) { set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &btrfs_inode->runtime_flags); remove_extent_mapping(map, em); /* once for the rb tree */ free_extent_map(em); } start = extent_map_end(em); write_unlock(&map->lock); /* once for us */ free_extent_map(em); } } return try_release_extent_state(tree, page, mask); } /* * helper function for fiemap, which doesn't want to see any holes. * This maps until we find something past 'last' */ static struct extent_map *get_extent_skip_holes(struct inode *inode, u64 offset, u64 last) { u64 sectorsize = btrfs_inode_sectorsize(inode); struct extent_map *em; u64 len; if (offset >= last) return NULL; while (1) { len = last - offset; if (len == 0) break; len = ALIGN(len, sectorsize); em = btrfs_get_extent_fiemap(BTRFS_I(inode), 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 = start; u64 max = start + len; u32 flags = 0; u32 found_type; u64 last; u64 last_for_get_extent = 0; u64 disko = 0; u64 isize = i_size_read(inode); struct btrfs_key found_key; struct extent_map *em = NULL; struct extent_state *cached_state = NULL; struct btrfs_path *path; struct btrfs_root *root = BTRFS_I(inode)->root; struct fiemap_cache cache = { 0 }; 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; } 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 ref bit is tricky. We have to make sure it is set * if we have the buffer dirty. Otherwise the * code to free a buffer can end up dropping a dirty * page * * Once the ref bit is set, it won't go away while the * buffer is dirty or in writeback, and it also won't * go away while we have the reference count on the * eb bumped. * * We can't just set the ref bit without bumping the * ref on the eb because free_extent_buffer might * see the ref bit and try to clear it. If this happens * free_extent_buffer might end up dropping our original * ref by mistake and freeing the page before we are able * to add one more ref. * * So bump the ref count first, then set the bit. If someone * beat us to it, drop the ref we added. */ refs = atomic_read(&eb->refs); if (refs >= 2 && test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) return; spin_lock(&eb->refs_lock); if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) atomic_inc(&eb->refs); spin_unlock(&eb->refs_lock); } static void mark_extent_buffer_accessed(struct extent_buffer *eb, struct page *accessed) { int num_pages, i; check_buffer_tree_ref(eb); num_pages = num_extent_pages(eb); for (i = 0; i < num_pages; i++) { struct page *p = eb->pages[i]; if (p != accessed) mark_page_accessed(p); } } struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info, u64 start) { struct extent_buffer *eb; rcu_read_lock(); eb = radix_tree_lookup(&fs_info->buffer_radix, start >> PAGE_SHIFT); if (eb && atomic_inc_not_zero(&eb->refs)) { rcu_read_unlock(); /* * Lock our eb's refs_lock to avoid races with * free_extent_buffer. When we get our eb it might be flagged * with EXTENT_BUFFER_STALE and another task running * free_extent_buffer might have seen that flag set, * eb->refs == 2, that the buffer isn't under IO (dirty and * writeback flags not set) and it's still in the tree (flag * EXTENT_BUFFER_TREE_REF set), therefore being in the process * of decrementing the extent buffer's reference count twice. * So here we could race and increment the eb's reference count, * clear its stale flag, mark it as dirty and drop our reference * before the other task finishes executing free_extent_buffer, * which would later result in an attempt to free an extent * buffer that is dirty. */ if (test_bit(EXTENT_BUFFER_STALE, &eb->bflags)) { spin_lock(&eb->refs_lock); spin_unlock(&eb->refs_lock); } mark_extent_buffer_accessed(eb, NULL); return eb; } rcu_read_unlock(); return NULL; } #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info, u64 start) { struct extent_buffer *eb, *exists = NULL; int ret; eb = find_extent_buffer(fs_info, start); if (eb) return eb; eb = alloc_dummy_extent_buffer(fs_info, start); if (!eb) return 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); 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(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 (copy_to_user(dst, kaddr + offset, cur)) { ret = -EFAULT; break; } dst += cur; len -= cur; offset = 0; i++; } return ret; } /* * return 0 if the item is found within a page. * return 1 if the item spans two pages. * return -EINVAL otherwise. */ int map_private_extent_buffer(const struct extent_buffer *eb, unsigned long start, unsigned long min_len, char **map, unsigned long *map_start, unsigned long *map_len) { size_t offset; 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); }
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