/* * Copyright (C) 2007 Oracle. All rights reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public * License v2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public * License along with this program; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 021110-1307, USA. */ #include <linux/slab.h> #include <linux/blkdev.h> #include <linux/writeback.h> #include <linux/pagevec.h> #include "ctree.h" #include "transaction.h" #include "btrfs_inode.h" #include "extent_io.h" #include "disk-io.h" static struct kmem_cache *btrfs_ordered_extent_cache; static u64 entry_end(struct btrfs_ordered_extent *entry) { if (entry->file_offset + entry->len < entry->file_offset) return (u64)-1; return entry->file_offset + entry->len; } /* 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; } static void ordered_data_tree_panic(struct inode *inode, int errno, u64 offset) { struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); btrfs_panic(fs_info, errno, "Inconsistency in ordered tree at offset " "%llu", offset); } /* * 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->len <= 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->len <= 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. * file_offset is the logical offset in the file * * start is the disk block number of an extent already reserved in the * extent allocation tree * * len is the length of the extent * * The tree is given a single reference on the ordered extent that was * inserted. */ static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset, u64 start, u64 len, u64 disk_len, int type, int dio, int compress_type) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_ordered_inode_tree *tree; struct rb_node *node; struct btrfs_ordered_extent *entry; tree = &BTRFS_I(inode)->ordered_tree; entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS); if (!entry) return -ENOMEM; entry->file_offset = file_offset; entry->start = start; entry->len = len; entry->disk_len = disk_len; entry->bytes_left = len; entry->inode = igrab(inode); entry->compress_type = compress_type; entry->truncated_len = (u64)-1; if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE) set_bit(type, &entry->flags); if (dio) set_bit(BTRFS_ORDERED_DIRECT, &entry->flags); /* one ref for the tree */ atomic_set(&entry->refs, 1); init_waitqueue_head(&entry->wait); INIT_LIST_HEAD(&entry->list); INIT_LIST_HEAD(&entry->root_extent_list); INIT_LIST_HEAD(&entry->work_list); init_completion(&entry->completion); INIT_LIST_HEAD(&entry->log_list); INIT_LIST_HEAD(&entry->trans_list); trace_btrfs_ordered_extent_add(inode, entry); spin_lock_irq(&tree->lock); node = tree_insert(&tree->tree, file_offset, &entry->rb_node); if (node) ordered_data_tree_panic(inode, -EEXIST, 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(&root->fs_info->ordered_root_lock); BUG_ON(!list_empty(&root->ordered_root)); list_add_tail(&root->ordered_root, &root->fs_info->ordered_roots); spin_unlock(&root->fs_info->ordered_root_lock); } spin_unlock(&root->ordered_extent_lock); return 0; } int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset, u64 start, u64 len, u64 disk_len, int type) { return __btrfs_add_ordered_extent(inode, file_offset, start, len, disk_len, type, 0, BTRFS_COMPRESS_NONE); } int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset, u64 start, u64 len, u64 disk_len, int type) { return __btrfs_add_ordered_extent(inode, file_offset, start, len, disk_len, type, 1, BTRFS_COMPRESS_NONE); } int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset, u64 start, u64 len, u64 disk_len, int type, int compress_type) { return __btrfs_add_ordered_extent(inode, file_offset, start, len, disk_len, 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 inode *inode, struct btrfs_ordered_extent *entry, struct btrfs_ordered_sum *sum) { struct btrfs_ordered_inode_tree *tree; tree = &BTRFS_I(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 inode *inode, struct btrfs_ordered_extent **cached, u64 *file_offset, u64 io_size, int uptodate) { struct btrfs_ordered_inode_tree *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; tree = &BTRFS_I(inode)->ordered_tree; 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->len); *file_offset = dec_end; if (dec_start > dec_end) { btrfs_crit(BTRFS_I(inode)->root->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(BTRFS_I(inode)->root->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); if (waitqueue_active(&entry->wait)) wake_up(&entry->wait); } else { ret = 1; } out: if (!ret && cached && entry) { *cached = entry; atomic_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 inode *inode, struct btrfs_ordered_extent **cached, u64 file_offset, u64 io_size, int uptodate) { struct btrfs_ordered_inode_tree *tree; struct rb_node *node; struct btrfs_ordered_extent *entry = NULL; unsigned long flags; int ret; tree = &BTRFS_I(inode)->ordered_tree; 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(BTRFS_I(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); if (waitqueue_active(&entry->wait)) wake_up(&entry->wait); } else { ret = 1; } out: if (!ret && cached && entry) { *cached = entry; atomic_inc(&entry->refs); } spin_unlock_irqrestore(&tree->lock, flags); return ret == 0; } /* Needs to either be called under a log transaction or the log_mutex */ void btrfs_get_logged_extents(struct inode *inode, struct list_head *logged_list, const loff_t start, const loff_t end) { struct btrfs_ordered_inode_tree *tree; struct btrfs_ordered_extent *ordered; struct rb_node *n; struct rb_node *prev; tree = &BTRFS_I(inode)->ordered_tree; spin_lock_irq(&tree->lock); n = __tree_search(&tree->tree, end, &prev); if (!n) n = prev; for (; n; n = rb_prev(n)) { ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node); if (ordered->file_offset > end) continue; if (entry_end(ordered) <= start) break; if (test_and_set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags)) continue; list_add(&ordered->log_list, logged_list); atomic_inc(&ordered->refs); } spin_unlock_irq(&tree->lock); } void btrfs_put_logged_extents(struct list_head *logged_list) { struct btrfs_ordered_extent *ordered; while (!list_empty(logged_list)) { ordered = list_first_entry(logged_list, struct btrfs_ordered_extent, log_list); list_del_init(&ordered->log_list); btrfs_put_ordered_extent(ordered); } } void btrfs_submit_logged_extents(struct list_head *logged_list, struct btrfs_root *log) { int index = log->log_transid % 2; spin_lock_irq(&log->log_extents_lock[index]); list_splice_tail(logged_list, &log->logged_list[index]); spin_unlock_irq(&log->log_extents_lock[index]); } void btrfs_wait_logged_extents(struct btrfs_trans_handle *trans, struct btrfs_root *log, u64 transid) { struct btrfs_ordered_extent *ordered; int index = transid % 2; spin_lock_irq(&log->log_extents_lock[index]); while (!list_empty(&log->logged_list[index])) { ordered = list_first_entry(&log->logged_list[index], struct btrfs_ordered_extent, log_list); list_del_init(&ordered->log_list); spin_unlock_irq(&log->log_extents_lock[index]); if (!test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags) && !test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) { struct inode *inode = ordered->inode; u64 start = ordered->file_offset; u64 end = ordered->file_offset + ordered->len - 1; WARN_ON(!inode); filemap_fdatawrite_range(inode->i_mapping, start, end); } wait_event(ordered->wait, test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags)); /* * If our ordered extent completed it means it updated the * fs/subvol and csum trees already, so no need to make the * current transaction's commit wait for it, as we end up * holding memory unnecessarily and delaying the inode's iput * until the transaction commit (we schedule an iput for the * inode when the ordered extent's refcount drops to 0), which * prevents it from being evictable until the transaction * commits. */ if (test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) btrfs_put_ordered_extent(ordered); else list_add_tail(&ordered->trans_list, &trans->ordered); spin_lock_irq(&log->log_extents_lock[index]); } spin_unlock_irq(&log->log_extents_lock[index]); } void btrfs_free_logged_extents(struct btrfs_root *log, u64 transid) { struct btrfs_ordered_extent *ordered; int index = transid % 2; spin_lock_irq(&log->log_extents_lock[index]); while (!list_empty(&log->logged_list[index])) { ordered = list_first_entry(&log->logged_list[index], struct btrfs_ordered_extent, log_list); list_del_init(&ordered->log_list); spin_unlock_irq(&log->log_extents_lock[index]); btrfs_put_ordered_extent(ordered); spin_lock_irq(&log->log_extents_lock[index]); } spin_unlock_irq(&log->log_extents_lock[index]); } /* * 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(entry->inode, entry); if (atomic_dec_and_test(&entry->refs)) { ASSERT(list_empty(&entry->log_list)); ASSERT(list_empty(&entry->trans_list)); ASSERT(list_empty(&entry->root_extent_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); kfree(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 inode *inode, struct btrfs_ordered_extent *entry) { struct btrfs_ordered_inode_tree *tree; struct btrfs_root *root = BTRFS_I(inode)->root; struct rb_node *node; tree = &BTRFS_I(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); spin_unlock_irq(&tree->lock); spin_lock(&root->ordered_extent_lock); list_del_init(&entry->root_extent_list); root->nr_ordered_extents--; trace_btrfs_ordered_extent_remove(inode, entry); if (!root->nr_ordered_extents) { spin_lock(&root->fs_info->ordered_root_lock); BUG_ON(list_empty(&root->ordered_root)); list_del_init(&root->ordered_root); spin_unlock(&root->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->inode, ordered, 1); complete(&ordered->completion); } /* * wait for all the ordered extents in a root. This is done when balancing * space between drives. */ int btrfs_wait_ordered_extents(struct btrfs_root *root, int nr) { struct list_head splice, works; struct btrfs_ordered_extent *ordered, *next; int count = 0; INIT_LIST_HEAD(&splice); INIT_LIST_HEAD(&works); 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); list_move_tail(&ordered->root_extent_list, &root->ordered_extents); atomic_inc(&ordered->refs); spin_unlock(&root->ordered_extent_lock); btrfs_init_work(&ordered->flush_work, btrfs_flush_delalloc_helper, btrfs_run_ordered_extent_work, NULL, NULL); list_add_tail(&ordered->work_list, &works); btrfs_queue_work(root->fs_info->flush_workers, &ordered->flush_work); cond_resched(); spin_lock(&root->ordered_extent_lock); if (nr != -1) nr--; count++; } 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, int nr) { struct btrfs_root *root; struct list_head splice; int 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_fs_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); btrfs_put_fs_root(root); spin_lock(&fs_info->ordered_root_lock); if (nr != -1) { nr -= done; WARN_ON(nr < 0); } } 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 inode *inode, struct btrfs_ordered_extent *entry, int wait) { u64 start = entry->file_offset; u64 end = start + entry->len - 1; 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->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(inode, end); if (!ordered) break; if (ordered->file_offset > orig_end) { btrfs_put_ordered_extent(ordered); break; } if (ordered->file_offset + ordered->len <= start) { btrfs_put_ordered_extent(ordered); break; } btrfs_start_ordered_extent(inode, ordered, 1); end = ordered->file_offset; if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags)) ret = -EIO; btrfs_put_ordered_extent(ordered); if (ret || 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 inode *inode, u64 file_offset) { struct btrfs_ordered_inode_tree *tree; struct rb_node *node; struct btrfs_ordered_extent *entry = NULL; tree = &BTRFS_I(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) atomic_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 inode *inode, u64 file_offset, u64 len) { struct btrfs_ordered_inode_tree *tree; struct rb_node *node; struct btrfs_ordered_extent *entry = NULL; tree = &BTRFS_I(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) atomic_inc(&entry->refs); spin_unlock_irq(&tree->lock); return entry; } bool btrfs_have_ordered_extents_in_range(struct inode *inode, u64 file_offset, u64 len) { struct btrfs_ordered_extent *oe; oe = btrfs_lookup_ordered_range(inode, file_offset, len); if (oe) { btrfs_put_ordered_extent(oe); return true; } return false; } /* * 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 inode *inode, u64 file_offset) { struct btrfs_ordered_inode_tree *tree; struct rb_node *node; struct btrfs_ordered_extent *entry = NULL; tree = &BTRFS_I(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); atomic_inc(&entry->refs); out: spin_unlock_irq(&tree->lock); return entry; } /* * After an extent is done, call this to conditionally update the on disk * i_size. i_size is updated to cover any fully written part of the file. */ int btrfs_ordered_update_i_size(struct inode *inode, u64 offset, struct btrfs_ordered_extent *ordered) { struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree; u64 disk_i_size; u64 new_i_size; u64 i_size = i_size_read(inode); struct rb_node *node; struct rb_node *prev = NULL; struct btrfs_ordered_extent *test; int ret = 1; spin_lock_irq(&tree->lock); if (ordered) { offset = entry_end(ordered); if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags)) offset = min(offset, ordered->file_offset + ordered->truncated_len); } else { offset = ALIGN(offset, BTRFS_I(inode)->root->sectorsize); } disk_i_size = BTRFS_I(inode)->disk_i_size; /* truncate file */ if (disk_i_size > i_size) { BTRFS_I(inode)->disk_i_size = i_size; ret = 0; goto out; } /* * if the disk i_size is already at the inode->i_size, or * this ordered extent is inside the disk i_size, we're done */ if (disk_i_size == i_size) goto out; /* * We still need to update disk_i_size if outstanding_isize is greater * than disk_i_size. */ if (offset <= disk_i_size && (!ordered || ordered->outstanding_isize <= disk_i_size)) goto out; /* * walk backward from this ordered extent to disk_i_size. * if we find an ordered extent then we can't update disk i_size * yet */ if (ordered) { node = rb_prev(&ordered->rb_node); } else { prev = tree_search(tree, offset); /* * we insert file extents without involving ordered struct, * so there should be no ordered struct cover this offset */ if (prev) { test = rb_entry(prev, struct btrfs_ordered_extent, rb_node); BUG_ON(offset_in_entry(test, offset)); } node = prev; } for (; node; node = rb_prev(node)) { test = rb_entry(node, struct btrfs_ordered_extent, rb_node); /* We treat this entry as if it doesnt exist */ if (test_bit(BTRFS_ORDERED_UPDATED_ISIZE, &test->flags)) continue; if (test->file_offset + test->len <= disk_i_size) break; if (test->file_offset >= i_size) break; if (entry_end(test) > disk_i_size) { /* * we don't update disk_i_size now, so record this * undealt i_size. Or we will not know the real * i_size. */ if (test->outstanding_isize < offset) test->outstanding_isize = offset; if (ordered && ordered->outstanding_isize > test->outstanding_isize) test->outstanding_isize = ordered->outstanding_isize; goto out; } } new_i_size = min_t(u64, offset, i_size); /* * Some ordered extents may completed before the current one, and * we hold the real i_size in ->outstanding_isize. */ if (ordered && ordered->outstanding_isize > new_i_size) new_i_size = min_t(u64, ordered->outstanding_isize, i_size); BTRFS_I(inode)->disk_i_size = new_i_size; ret = 0; out: /* * We need to do this because we can't remove ordered extents until * after the i_disk_size has been updated and then the inode has been * updated to reflect the change, so we need to tell anybody who finds * this ordered extent that we've already done all the real work, we * just haven't completed all the other work. */ if (ordered) set_bit(BTRFS_ORDERED_UPDATED_ISIZE, &ordered->flags); spin_unlock_irq(&tree->lock); return ret; } /* * 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 inode *inode, u64 offset, u64 disk_bytenr, u32 *sum, int len) { struct btrfs_ordered_sum *ordered_sum; struct btrfs_ordered_extent *ordered; struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree; unsigned long num_sectors; unsigned long i; u32 sectorsize = BTRFS_I(inode)->root->sectorsize; 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) >> inode->i_sb->s_blocksize_bits; num_sectors = ordered_sum->len >> inode->i_sb->s_blocksize_bits; num_sectors = min_t(int, len - index, num_sectors - i); memcpy(sum + index, ordered_sum->sums + i, num_sectors); index += (int)num_sectors; if (index == len) goto out; disk_bytenr += num_sectors * sectorsize; } } out: spin_unlock_irq(&tree->lock); btrfs_put_ordered_extent(ordered); return index; } int __init ordered_data_init(void) { btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent", sizeof(struct btrfs_ordered_extent), 0, SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); if (!btrfs_ordered_extent_cache) return -ENOMEM; return 0; } void ordered_data_exit(void) { if (btrfs_ordered_extent_cache) kmem_cache_destroy(btrfs_ordered_extent_cache); }