diff options
Diffstat (limited to '')
| -rw-r--r-- | fs/btrfs/ordered-data.c | 961 |
1 files changed, 961 insertions, 0 deletions
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c new file mode 100644 index 000000000..87bac9ecd --- /dev/null +++ b/fs/btrfs/ordered-data.c @@ -0,0 +1,961 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2007 Oracle. All rights reserved. + */ + +#include <linux/slab.h> +#include <linux/blkdev.h> +#include <linux/writeback.h> +#include <linux/sched/mm.h> +#include "misc.h" +#include "ctree.h" +#include "transaction.h" +#include "btrfs_inode.h" +#include "extent_io.h" +#include "disk-io.h" +#include "compression.h" +#include "delalloc-space.h" +#include "qgroup.h" + +static struct kmem_cache *btrfs_ordered_extent_cache; + +static u64 entry_end(struct btrfs_ordered_extent *entry) +{ + if (entry->file_offset + entry->num_bytes < entry->file_offset) + return (u64)-1; + return entry->file_offset + entry->num_bytes; +} + +/* returns NULL if the insertion worked, or it returns the node it did find + * in the tree + */ +static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset, + struct rb_node *node) +{ + struct rb_node **p = &root->rb_node; + struct rb_node *parent = NULL; + struct btrfs_ordered_extent *entry; + + while (*p) { + parent = *p; + entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node); + + if (file_offset < entry->file_offset) + p = &(*p)->rb_left; + else if (file_offset >= entry_end(entry)) + p = &(*p)->rb_right; + else + return parent; + } + + rb_link_node(node, parent, p); + rb_insert_color(node, root); + return NULL; +} + +/* + * look for a given offset in the tree, and if it can't be found return the + * first lesser offset + */ +static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset, + struct rb_node **prev_ret) +{ + struct rb_node *n = root->rb_node; + struct rb_node *prev = NULL; + struct rb_node *test; + struct btrfs_ordered_extent *entry; + struct btrfs_ordered_extent *prev_entry = NULL; + + while (n) { + entry = rb_entry(n, struct btrfs_ordered_extent, rb_node); + prev = n; + prev_entry = entry; + + if (file_offset < entry->file_offset) + n = n->rb_left; + else if (file_offset >= entry_end(entry)) + n = n->rb_right; + else + return n; + } + if (!prev_ret) + return NULL; + + while (prev && file_offset >= entry_end(prev_entry)) { + test = rb_next(prev); + if (!test) + break; + prev_entry = rb_entry(test, struct btrfs_ordered_extent, + rb_node); + if (file_offset < entry_end(prev_entry)) + break; + + prev = test; + } + if (prev) + prev_entry = rb_entry(prev, struct btrfs_ordered_extent, + rb_node); + while (prev && file_offset < entry_end(prev_entry)) { + test = rb_prev(prev); + if (!test) + break; + prev_entry = rb_entry(test, struct btrfs_ordered_extent, + rb_node); + prev = test; + } + *prev_ret = prev; + return NULL; +} + +/* + * helper to check if a given offset is inside a given entry + */ +static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset) +{ + if (file_offset < entry->file_offset || + entry->file_offset + entry->num_bytes <= file_offset) + return 0; + return 1; +} + +static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset, + u64 len) +{ + if (file_offset + len <= entry->file_offset || + entry->file_offset + entry->num_bytes <= file_offset) + return 0; + return 1; +} + +/* + * look find the first ordered struct that has this offset, otherwise + * the first one less than this offset + */ +static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree, + u64 file_offset) +{ + struct rb_root *root = &tree->tree; + struct rb_node *prev = NULL; + struct rb_node *ret; + struct btrfs_ordered_extent *entry; + + if (tree->last) { + entry = rb_entry(tree->last, struct btrfs_ordered_extent, + rb_node); + if (offset_in_entry(entry, file_offset)) + return tree->last; + } + ret = __tree_search(root, file_offset, &prev); + if (!ret) + ret = prev; + if (ret) + tree->last = ret; + return ret; +} + +/* + * Allocate and add a new ordered_extent into the per-inode tree. + * + * The tree is given a single reference on the ordered extent that was + * inserted. + */ +static int __btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset, + u64 disk_bytenr, u64 num_bytes, + u64 disk_num_bytes, int type, int dio, + int compress_type) +{ + struct btrfs_root *root = inode->root; + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree; + struct rb_node *node; + struct btrfs_ordered_extent *entry; + int ret; + + if (type == BTRFS_ORDERED_NOCOW || type == BTRFS_ORDERED_PREALLOC) { + /* For nocow write, we can release the qgroup rsv right now */ + ret = btrfs_qgroup_free_data(inode, NULL, file_offset, num_bytes); + if (ret < 0) + return ret; + ret = 0; + } else { + /* + * The ordered extent has reserved qgroup space, release now + * and pass the reserved number for qgroup_record to free. + */ + ret = btrfs_qgroup_release_data(inode, file_offset, num_bytes); + if (ret < 0) + return ret; + } + entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS); + if (!entry) + return -ENOMEM; + + entry->file_offset = file_offset; + entry->disk_bytenr = disk_bytenr; + entry->num_bytes = num_bytes; + entry->disk_num_bytes = disk_num_bytes; + entry->bytes_left = num_bytes; + entry->inode = igrab(&inode->vfs_inode); + entry->compress_type = compress_type; + entry->truncated_len = (u64)-1; + entry->qgroup_rsv = ret; + if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE) + set_bit(type, &entry->flags); + + if (dio) { + percpu_counter_add_batch(&fs_info->dio_bytes, num_bytes, + fs_info->delalloc_batch); + set_bit(BTRFS_ORDERED_DIRECT, &entry->flags); + } + + /* one ref for the tree */ + refcount_set(&entry->refs, 1); + init_waitqueue_head(&entry->wait); + INIT_LIST_HEAD(&entry->list); + INIT_LIST_HEAD(&entry->log_list); + INIT_LIST_HEAD(&entry->root_extent_list); + INIT_LIST_HEAD(&entry->work_list); + init_completion(&entry->completion); + + trace_btrfs_ordered_extent_add(inode, entry); + + spin_lock_irq(&tree->lock); + node = tree_insert(&tree->tree, file_offset, + &entry->rb_node); + if (node) + btrfs_panic(fs_info, -EEXIST, + "inconsistency in ordered tree at offset %llu", + file_offset); + spin_unlock_irq(&tree->lock); + + spin_lock(&root->ordered_extent_lock); + list_add_tail(&entry->root_extent_list, + &root->ordered_extents); + root->nr_ordered_extents++; + if (root->nr_ordered_extents == 1) { + spin_lock(&fs_info->ordered_root_lock); + BUG_ON(!list_empty(&root->ordered_root)); + list_add_tail(&root->ordered_root, &fs_info->ordered_roots); + spin_unlock(&fs_info->ordered_root_lock); + } + spin_unlock(&root->ordered_extent_lock); + + /* + * We don't need the count_max_extents here, we can assume that all of + * that work has been done at higher layers, so this is truly the + * smallest the extent is going to get. + */ + spin_lock(&inode->lock); + btrfs_mod_outstanding_extents(inode, 1); + spin_unlock(&inode->lock); + + return 0; +} + +int btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset, + u64 disk_bytenr, u64 num_bytes, u64 disk_num_bytes, + int type) +{ + return __btrfs_add_ordered_extent(inode, file_offset, disk_bytenr, + num_bytes, disk_num_bytes, type, 0, + BTRFS_COMPRESS_NONE); +} + +int btrfs_add_ordered_extent_dio(struct btrfs_inode *inode, u64 file_offset, + u64 disk_bytenr, u64 num_bytes, + u64 disk_num_bytes, int type) +{ + return __btrfs_add_ordered_extent(inode, file_offset, disk_bytenr, + num_bytes, disk_num_bytes, type, 1, + BTRFS_COMPRESS_NONE); +} + +int btrfs_add_ordered_extent_compress(struct btrfs_inode *inode, u64 file_offset, + u64 disk_bytenr, u64 num_bytes, + u64 disk_num_bytes, int type, + int compress_type) +{ + return __btrfs_add_ordered_extent(inode, file_offset, disk_bytenr, + num_bytes, disk_num_bytes, type, 0, + compress_type); +} + +/* + * Add a struct btrfs_ordered_sum into the list of checksums to be inserted + * when an ordered extent is finished. If the list covers more than one + * ordered extent, it is split across multiples. + */ +void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry, + struct btrfs_ordered_sum *sum) +{ + struct btrfs_ordered_inode_tree *tree; + + tree = &BTRFS_I(entry->inode)->ordered_tree; + spin_lock_irq(&tree->lock); + list_add_tail(&sum->list, &entry->list); + spin_unlock_irq(&tree->lock); +} + +/* + * this is used to account for finished IO across a given range + * of the file. The IO may span ordered extents. If + * a given ordered_extent is completely done, 1 is returned, otherwise + * 0. + * + * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used + * to make sure this function only returns 1 once for a given ordered extent. + * + * file_offset is updated to one byte past the range that is recorded as + * complete. This allows you to walk forward in the file. + */ +int btrfs_dec_test_first_ordered_pending(struct btrfs_inode *inode, + struct btrfs_ordered_extent **cached, + u64 *file_offset, u64 io_size, int uptodate) +{ + struct btrfs_fs_info *fs_info = inode->root->fs_info; + struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree; + struct rb_node *node; + struct btrfs_ordered_extent *entry = NULL; + int ret; + unsigned long flags; + u64 dec_end; + u64 dec_start; + u64 to_dec; + + spin_lock_irqsave(&tree->lock, flags); + node = tree_search(tree, *file_offset); + if (!node) { + ret = 1; + goto out; + } + + entry = rb_entry(node, struct btrfs_ordered_extent, rb_node); + if (!offset_in_entry(entry, *file_offset)) { + ret = 1; + goto out; + } + + dec_start = max(*file_offset, entry->file_offset); + dec_end = min(*file_offset + io_size, + entry->file_offset + entry->num_bytes); + *file_offset = dec_end; + if (dec_start > dec_end) { + btrfs_crit(fs_info, "bad ordering dec_start %llu end %llu", + dec_start, dec_end); + } + to_dec = dec_end - dec_start; + if (to_dec > entry->bytes_left) { + btrfs_crit(fs_info, + "bad ordered accounting left %llu size %llu", + entry->bytes_left, to_dec); + } + entry->bytes_left -= to_dec; + if (!uptodate) + set_bit(BTRFS_ORDERED_IOERR, &entry->flags); + + if (entry->bytes_left == 0) { + ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags); + /* test_and_set_bit implies a barrier */ + cond_wake_up_nomb(&entry->wait); + } else { + ret = 1; + } +out: + if (!ret && cached && entry) { + *cached = entry; + refcount_inc(&entry->refs); + } + spin_unlock_irqrestore(&tree->lock, flags); + return ret == 0; +} + +/* + * this is used to account for finished IO across a given range + * of the file. The IO should not span ordered extents. If + * a given ordered_extent is completely done, 1 is returned, otherwise + * 0. + * + * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used + * to make sure this function only returns 1 once for a given ordered extent. + */ +int btrfs_dec_test_ordered_pending(struct btrfs_inode *inode, + struct btrfs_ordered_extent **cached, + u64 file_offset, u64 io_size, int uptodate) +{ + struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree; + struct rb_node *node; + struct btrfs_ordered_extent *entry = NULL; + unsigned long flags; + int ret; + + spin_lock_irqsave(&tree->lock, flags); + if (cached && *cached) { + entry = *cached; + goto have_entry; + } + + node = tree_search(tree, file_offset); + if (!node) { + ret = 1; + goto out; + } + + entry = rb_entry(node, struct btrfs_ordered_extent, rb_node); +have_entry: + if (!offset_in_entry(entry, file_offset)) { + ret = 1; + goto out; + } + + if (io_size > entry->bytes_left) { + btrfs_crit(inode->root->fs_info, + "bad ordered accounting left %llu size %llu", + entry->bytes_left, io_size); + } + entry->bytes_left -= io_size; + if (!uptodate) + set_bit(BTRFS_ORDERED_IOERR, &entry->flags); + + if (entry->bytes_left == 0) { + ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags); + /* test_and_set_bit implies a barrier */ + cond_wake_up_nomb(&entry->wait); + } else { + ret = 1; + } +out: + if (!ret && cached && entry) { + *cached = entry; + refcount_inc(&entry->refs); + } + spin_unlock_irqrestore(&tree->lock, flags); + return ret == 0; +} + +/* + * used to drop a reference on an ordered extent. This will free + * the extent if the last reference is dropped + */ +void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry) +{ + struct list_head *cur; + struct btrfs_ordered_sum *sum; + + trace_btrfs_ordered_extent_put(BTRFS_I(entry->inode), entry); + + if (refcount_dec_and_test(&entry->refs)) { + ASSERT(list_empty(&entry->root_extent_list)); + ASSERT(list_empty(&entry->log_list)); + ASSERT(RB_EMPTY_NODE(&entry->rb_node)); + if (entry->inode) + btrfs_add_delayed_iput(entry->inode); + while (!list_empty(&entry->list)) { + cur = entry->list.next; + sum = list_entry(cur, struct btrfs_ordered_sum, list); + list_del(&sum->list); + kvfree(sum); + } + kmem_cache_free(btrfs_ordered_extent_cache, entry); + } +} + +/* + * remove an ordered extent from the tree. No references are dropped + * and waiters are woken up. + */ +void btrfs_remove_ordered_extent(struct btrfs_inode *btrfs_inode, + struct btrfs_ordered_extent *entry) +{ + struct btrfs_ordered_inode_tree *tree; + struct btrfs_root *root = btrfs_inode->root; + struct btrfs_fs_info *fs_info = root->fs_info; + struct rb_node *node; + bool pending; + + /* This is paired with btrfs_add_ordered_extent. */ + spin_lock(&btrfs_inode->lock); + btrfs_mod_outstanding_extents(btrfs_inode, -1); + spin_unlock(&btrfs_inode->lock); + if (root != fs_info->tree_root) + btrfs_delalloc_release_metadata(btrfs_inode, entry->num_bytes, + false); + + if (test_bit(BTRFS_ORDERED_DIRECT, &entry->flags)) + percpu_counter_add_batch(&fs_info->dio_bytes, -entry->num_bytes, + fs_info->delalloc_batch); + + tree = &btrfs_inode->ordered_tree; + spin_lock_irq(&tree->lock); + node = &entry->rb_node; + rb_erase(node, &tree->tree); + RB_CLEAR_NODE(node); + if (tree->last == node) + tree->last = NULL; + set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags); + pending = test_and_clear_bit(BTRFS_ORDERED_PENDING, &entry->flags); + spin_unlock_irq(&tree->lock); + + /* + * The current running transaction is waiting on us, we need to let it + * know that we're complete and wake it up. + */ + if (pending) { + struct btrfs_transaction *trans; + + /* + * The checks for trans are just a formality, it should be set, + * but if it isn't we don't want to deref/assert under the spin + * lock, so be nice and check if trans is set, but ASSERT() so + * if it isn't set a developer will notice. + */ + spin_lock(&fs_info->trans_lock); + trans = fs_info->running_transaction; + if (trans) + refcount_inc(&trans->use_count); + spin_unlock(&fs_info->trans_lock); + + ASSERT(trans); + if (trans) { + if (atomic_dec_and_test(&trans->pending_ordered)) + wake_up(&trans->pending_wait); + btrfs_put_transaction(trans); + } + } + + spin_lock(&root->ordered_extent_lock); + list_del_init(&entry->root_extent_list); + root->nr_ordered_extents--; + + trace_btrfs_ordered_extent_remove(btrfs_inode, entry); + + if (!root->nr_ordered_extents) { + spin_lock(&fs_info->ordered_root_lock); + BUG_ON(list_empty(&root->ordered_root)); + list_del_init(&root->ordered_root); + spin_unlock(&fs_info->ordered_root_lock); + } + spin_unlock(&root->ordered_extent_lock); + wake_up(&entry->wait); +} + +static void btrfs_run_ordered_extent_work(struct btrfs_work *work) +{ + struct btrfs_ordered_extent *ordered; + + ordered = container_of(work, struct btrfs_ordered_extent, flush_work); + btrfs_start_ordered_extent(ordered, 1); + complete(&ordered->completion); +} + +/* + * wait for all the ordered extents in a root. This is done when balancing + * space between drives. + */ +u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr, + const u64 range_start, const u64 range_len) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + LIST_HEAD(splice); + LIST_HEAD(skipped); + LIST_HEAD(works); + struct btrfs_ordered_extent *ordered, *next; + u64 count = 0; + const u64 range_end = range_start + range_len; + + mutex_lock(&root->ordered_extent_mutex); + spin_lock(&root->ordered_extent_lock); + list_splice_init(&root->ordered_extents, &splice); + while (!list_empty(&splice) && nr) { + ordered = list_first_entry(&splice, struct btrfs_ordered_extent, + root_extent_list); + + if (range_end <= ordered->disk_bytenr || + ordered->disk_bytenr + ordered->disk_num_bytes <= range_start) { + list_move_tail(&ordered->root_extent_list, &skipped); + cond_resched_lock(&root->ordered_extent_lock); + continue; + } + + list_move_tail(&ordered->root_extent_list, + &root->ordered_extents); + refcount_inc(&ordered->refs); + spin_unlock(&root->ordered_extent_lock); + + btrfs_init_work(&ordered->flush_work, + btrfs_run_ordered_extent_work, NULL, NULL); + list_add_tail(&ordered->work_list, &works); + btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work); + + cond_resched(); + spin_lock(&root->ordered_extent_lock); + if (nr != U64_MAX) + nr--; + count++; + } + list_splice_tail(&skipped, &root->ordered_extents); + list_splice_tail(&splice, &root->ordered_extents); + spin_unlock(&root->ordered_extent_lock); + + list_for_each_entry_safe(ordered, next, &works, work_list) { + list_del_init(&ordered->work_list); + wait_for_completion(&ordered->completion); + btrfs_put_ordered_extent(ordered); + cond_resched(); + } + mutex_unlock(&root->ordered_extent_mutex); + + return count; +} + +void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr, + const u64 range_start, const u64 range_len) +{ + struct btrfs_root *root; + struct list_head splice; + u64 done; + + INIT_LIST_HEAD(&splice); + + mutex_lock(&fs_info->ordered_operations_mutex); + spin_lock(&fs_info->ordered_root_lock); + list_splice_init(&fs_info->ordered_roots, &splice); + while (!list_empty(&splice) && nr) { + root = list_first_entry(&splice, struct btrfs_root, + ordered_root); + root = btrfs_grab_root(root); + BUG_ON(!root); + list_move_tail(&root->ordered_root, + &fs_info->ordered_roots); + spin_unlock(&fs_info->ordered_root_lock); + + done = btrfs_wait_ordered_extents(root, nr, + range_start, range_len); + btrfs_put_root(root); + + spin_lock(&fs_info->ordered_root_lock); + if (nr != U64_MAX) { + nr -= done; + } + } + list_splice_tail(&splice, &fs_info->ordered_roots); + spin_unlock(&fs_info->ordered_root_lock); + mutex_unlock(&fs_info->ordered_operations_mutex); +} + +/* + * Used to start IO or wait for a given ordered extent to finish. + * + * If wait is one, this effectively waits on page writeback for all the pages + * in the extent, and it waits on the io completion code to insert + * metadata into the btree corresponding to the extent + */ +void btrfs_start_ordered_extent(struct btrfs_ordered_extent *entry, int wait) +{ + u64 start = entry->file_offset; + u64 end = start + entry->num_bytes - 1; + struct btrfs_inode *inode = BTRFS_I(entry->inode); + + trace_btrfs_ordered_extent_start(inode, entry); + + /* + * pages in the range can be dirty, clean or writeback. We + * start IO on any dirty ones so the wait doesn't stall waiting + * for the flusher thread to find them + */ + if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags)) + filemap_fdatawrite_range(inode->vfs_inode.i_mapping, start, end); + if (wait) { + wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE, + &entry->flags)); + } +} + +/* + * Used to wait on ordered extents across a large range of bytes. + */ +int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len) +{ + int ret = 0; + int ret_wb = 0; + u64 end; + u64 orig_end; + struct btrfs_ordered_extent *ordered; + + if (start + len < start) { + orig_end = INT_LIMIT(loff_t); + } else { + orig_end = start + len - 1; + if (orig_end > INT_LIMIT(loff_t)) + orig_end = INT_LIMIT(loff_t); + } + + /* start IO across the range first to instantiate any delalloc + * extents + */ + ret = btrfs_fdatawrite_range(inode, start, orig_end); + if (ret) + return ret; + + /* + * If we have a writeback error don't return immediately. Wait first + * for any ordered extents that haven't completed yet. This is to make + * sure no one can dirty the same page ranges and call writepages() + * before the ordered extents complete - to avoid failures (-EEXIST) + * when adding the new ordered extents to the ordered tree. + */ + ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end); + + end = orig_end; + while (1) { + ordered = btrfs_lookup_first_ordered_extent(BTRFS_I(inode), end); + if (!ordered) + break; + if (ordered->file_offset > orig_end) { + btrfs_put_ordered_extent(ordered); + break; + } + if (ordered->file_offset + ordered->num_bytes <= start) { + btrfs_put_ordered_extent(ordered); + break; + } + btrfs_start_ordered_extent(ordered, 1); + end = ordered->file_offset; + /* + * If the ordered extent had an error save the error but don't + * exit without waiting first for all other ordered extents in + * the range to complete. + */ + if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags)) + ret = -EIO; + btrfs_put_ordered_extent(ordered); + if (end == 0 || end == start) + break; + end--; + } + return ret_wb ? ret_wb : ret; +} + +/* + * find an ordered extent corresponding to file_offset. return NULL if + * nothing is found, otherwise take a reference on the extent and return it + */ +struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct btrfs_inode *inode, + u64 file_offset) +{ + struct btrfs_ordered_inode_tree *tree; + struct rb_node *node; + struct btrfs_ordered_extent *entry = NULL; + + tree = &inode->ordered_tree; + spin_lock_irq(&tree->lock); + node = tree_search(tree, file_offset); + if (!node) + goto out; + + entry = rb_entry(node, struct btrfs_ordered_extent, rb_node); + if (!offset_in_entry(entry, file_offset)) + entry = NULL; + if (entry) + refcount_inc(&entry->refs); +out: + spin_unlock_irq(&tree->lock); + return entry; +} + +/* Since the DIO code tries to lock a wide area we need to look for any ordered + * extents that exist in the range, rather than just the start of the range. + */ +struct btrfs_ordered_extent *btrfs_lookup_ordered_range( + struct btrfs_inode *inode, u64 file_offset, u64 len) +{ + struct btrfs_ordered_inode_tree *tree; + struct rb_node *node; + struct btrfs_ordered_extent *entry = NULL; + + tree = &inode->ordered_tree; + spin_lock_irq(&tree->lock); + node = tree_search(tree, file_offset); + if (!node) { + node = tree_search(tree, file_offset + len); + if (!node) + goto out; + } + + while (1) { + entry = rb_entry(node, struct btrfs_ordered_extent, rb_node); + if (range_overlaps(entry, file_offset, len)) + break; + + if (entry->file_offset >= file_offset + len) { + entry = NULL; + break; + } + entry = NULL; + node = rb_next(node); + if (!node) + break; + } +out: + if (entry) + refcount_inc(&entry->refs); + spin_unlock_irq(&tree->lock); + return entry; +} + +/* + * Adds all ordered extents to the given list. The list ends up sorted by the + * file_offset of the ordered extents. + */ +void btrfs_get_ordered_extents_for_logging(struct btrfs_inode *inode, + struct list_head *list) +{ + struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree; + struct rb_node *n; + + ASSERT(inode_is_locked(&inode->vfs_inode)); + + spin_lock_irq(&tree->lock); + for (n = rb_first(&tree->tree); n; n = rb_next(n)) { + struct btrfs_ordered_extent *ordered; + + ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node); + + if (test_bit(BTRFS_ORDERED_LOGGED, &ordered->flags)) + continue; + + ASSERT(list_empty(&ordered->log_list)); + list_add_tail(&ordered->log_list, list); + refcount_inc(&ordered->refs); + } + spin_unlock_irq(&tree->lock); +} + +/* + * lookup and return any extent before 'file_offset'. NULL is returned + * if none is found + */ +struct btrfs_ordered_extent * +btrfs_lookup_first_ordered_extent(struct btrfs_inode *inode, u64 file_offset) +{ + struct btrfs_ordered_inode_tree *tree; + struct rb_node *node; + struct btrfs_ordered_extent *entry = NULL; + + tree = &inode->ordered_tree; + spin_lock_irq(&tree->lock); + node = tree_search(tree, file_offset); + if (!node) + goto out; + + entry = rb_entry(node, struct btrfs_ordered_extent, rb_node); + refcount_inc(&entry->refs); +out: + spin_unlock_irq(&tree->lock); + return entry; +} + +/* + * search the ordered extents for one corresponding to 'offset' and + * try to find a checksum. This is used because we allow pages to + * be reclaimed before their checksum is actually put into the btree + */ +int btrfs_find_ordered_sum(struct btrfs_inode *inode, u64 offset, + u64 disk_bytenr, u8 *sum, int len) +{ + struct btrfs_fs_info *fs_info = inode->root->fs_info; + struct btrfs_ordered_sum *ordered_sum; + struct btrfs_ordered_extent *ordered; + struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree; + unsigned long num_sectors; + unsigned long i; + u32 sectorsize = btrfs_inode_sectorsize(inode); + const u8 blocksize_bits = inode->vfs_inode.i_sb->s_blocksize_bits; + const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy); + int index = 0; + + ordered = btrfs_lookup_ordered_extent(inode, offset); + if (!ordered) + return 0; + + spin_lock_irq(&tree->lock); + list_for_each_entry_reverse(ordered_sum, &ordered->list, list) { + if (disk_bytenr >= ordered_sum->bytenr && + disk_bytenr < ordered_sum->bytenr + ordered_sum->len) { + i = (disk_bytenr - ordered_sum->bytenr) >> blocksize_bits; + num_sectors = ordered_sum->len >> blocksize_bits; + num_sectors = min_t(int, len - index, num_sectors - i); + memcpy(sum + index, ordered_sum->sums + i * csum_size, + num_sectors * csum_size); + + index += (int)num_sectors * csum_size; + if (index == len) + goto out; + disk_bytenr += num_sectors * sectorsize; + } + } +out: + spin_unlock_irq(&tree->lock); + btrfs_put_ordered_extent(ordered); + return index; +} + +/* + * btrfs_flush_ordered_range - Lock the passed range and ensures all pending + * ordered extents in it are run to completion. + * + * @inode: Inode whose ordered tree is to be searched + * @start: Beginning of range to flush + * @end: Last byte of range to lock + * @cached_state: If passed, will return the extent state responsible for the + * locked range. It's the caller's responsibility to free the cached state. + * + * This function always returns with the given range locked, ensuring after it's + * called no order extent can be pending. + */ +void btrfs_lock_and_flush_ordered_range(struct btrfs_inode *inode, u64 start, + u64 end, + struct extent_state **cached_state) +{ + struct btrfs_ordered_extent *ordered; + struct extent_state *cache = NULL; + struct extent_state **cachedp = &cache; + + if (cached_state) + cachedp = cached_state; + + while (1) { + lock_extent_bits(&inode->io_tree, start, end, cachedp); + ordered = btrfs_lookup_ordered_range(inode, start, + end - start + 1); + if (!ordered) { + /* + * If no external cached_state has been passed then + * decrement the extra ref taken for cachedp since we + * aren't exposing it outside of this function + */ + if (!cached_state) + refcount_dec(&cache->refs); + break; + } + unlock_extent_cached(&inode->io_tree, start, end, cachedp); + btrfs_start_ordered_extent(ordered, 1); + btrfs_put_ordered_extent(ordered); + } +} + +int __init ordered_data_init(void) +{ + btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent", + sizeof(struct btrfs_ordered_extent), 0, + SLAB_MEM_SPREAD, + NULL); + if (!btrfs_ordered_extent_cache) + return -ENOMEM; + + return 0; +} + +void __cold ordered_data_exit(void) +{ + kmem_cache_destroy(btrfs_ordered_extent_cache); +} |