From c216775458a2ee345d9412a2770c2916acfb5d30 Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Thu, 12 Nov 2009 09:34:21 +0000 Subject: Btrfs: Fix disk_i_size update corner case There are some cases file extents are inserted without involving ordered struct. In these cases, we update disk_i_size directly, without checking pending ordered extent and DELALLOC bit. This patch extends btrfs_ordered_update_i_size() to handle these cases. Signed-off-by: Yan Zheng Signed-off-by: Chris Mason --- fs/btrfs/ordered-data.c | 105 +++++++++++++++++++++++++++++++++++++----------- 1 file changed, 81 insertions(+), 24 deletions(-) (limited to 'fs/btrfs/ordered-data.c') diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c index 5799bc46a30..9b16073bb87 100644 --- a/fs/btrfs/ordered-data.c +++ b/fs/btrfs/ordered-data.c @@ -291,16 +291,16 @@ int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry) /* * remove an ordered extent from the tree. No references are dropped - * but, anyone waiting on this extent is woken up. + * and you must wake_up entry->wait. You must hold the tree mutex + * while you call this function. */ -int btrfs_remove_ordered_extent(struct inode *inode, +static int __btrfs_remove_ordered_extent(struct inode *inode, struct btrfs_ordered_extent *entry) { struct btrfs_ordered_inode_tree *tree; struct rb_node *node; tree = &BTRFS_I(inode)->ordered_tree; - mutex_lock(&tree->mutex); node = &entry->rb_node; rb_erase(node, &tree->tree); tree->last = NULL; @@ -326,9 +326,26 @@ int btrfs_remove_ordered_extent(struct inode *inode, } spin_unlock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock); + return 0; +} + +/* + * remove an ordered extent from the tree. No references are dropped + * but any waiters are woken. + */ +int btrfs_remove_ordered_extent(struct inode *inode, + struct btrfs_ordered_extent *entry) +{ + struct btrfs_ordered_inode_tree *tree; + int ret; + + tree = &BTRFS_I(inode)->ordered_tree; + mutex_lock(&tree->mutex); + ret = __btrfs_remove_ordered_extent(inode, entry); mutex_unlock(&tree->mutex); wake_up(&entry->wait); - return 0; + + return ret; } /* @@ -589,7 +606,7 @@ out: * 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, +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; @@ -597,18 +614,30 @@ int btrfs_ordered_update_i_size(struct inode *inode, u64 disk_i_size; u64 new_i_size; u64 i_size_test; + u64 i_size = i_size_read(inode); struct rb_node *node; + struct rb_node *prev = NULL; struct btrfs_ordered_extent *test; + int ret = 1; + + if (ordered) + offset = entry_end(ordered); mutex_lock(&tree->mutex); 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 >= inode->i_size || - ordered->file_offset + ordered->len <= disk_i_size) { + if (disk_i_size == i_size || offset <= disk_i_size) { goto out; } @@ -616,8 +645,7 @@ int btrfs_ordered_update_i_size(struct inode *inode, * we can't update the disk_isize if there are delalloc bytes * between disk_i_size and this ordered extent */ - if (test_range_bit(io_tree, disk_i_size, - ordered->file_offset + ordered->len - 1, + if (test_range_bit(io_tree, disk_i_size, offset - 1, EXTENT_DELALLOC, 0, NULL)) { goto out; } @@ -626,20 +654,32 @@ int btrfs_ordered_update_i_size(struct inode *inode, * if we find an ordered extent then we can't update disk i_size * yet */ - node = &ordered->rb_node; - while (1) { - node = rb_prev(node); - if (!node) - break; + 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; + } + while (node) { test = rb_entry(node, struct btrfs_ordered_extent, rb_node); if (test->file_offset + test->len <= disk_i_size) break; - if (test->file_offset >= inode->i_size) + if (test->file_offset >= i_size) break; if (test->file_offset >= disk_i_size) goto out; + node = rb_prev(node); } - new_i_size = min_t(u64, entry_end(ordered), i_size_read(inode)); + new_i_size = min_t(u64, offset, i_size); /* * at this point, we know we can safely update i_size to at least @@ -647,7 +687,14 @@ int btrfs_ordered_update_i_size(struct inode *inode, * walk forward and see if ios from higher up in the file have * finished. */ - node = rb_next(&ordered->rb_node); + if (ordered) { + node = rb_next(&ordered->rb_node); + } else { + if (prev) + node = rb_next(prev); + else + node = rb_first(&tree->tree); + } i_size_test = 0; if (node) { /* @@ -655,10 +702,10 @@ int btrfs_ordered_update_i_size(struct inode *inode, * between our ordered extent and the next one. */ test = rb_entry(node, struct btrfs_ordered_extent, rb_node); - if (test->file_offset > entry_end(ordered)) + if (test->file_offset > offset) i_size_test = test->file_offset; } else { - i_size_test = i_size_read(inode); + i_size_test = i_size; } /* @@ -667,15 +714,25 @@ int btrfs_ordered_update_i_size(struct inode *inode, * are no delalloc bytes in this area, it is safe to update * disk_i_size to the end of the region. */ - if (i_size_test > entry_end(ordered) && - !test_range_bit(io_tree, entry_end(ordered), i_size_test - 1, - EXTENT_DELALLOC, 0, NULL)) { - new_i_size = min_t(u64, i_size_test, i_size_read(inode)); + if (i_size_test > offset && + !test_range_bit(io_tree, offset, i_size_test - 1, + EXTENT_DELALLOC, 0, NULL)) { + new_i_size = min_t(u64, i_size_test, i_size); } BTRFS_I(inode)->disk_i_size = new_i_size; + ret = 0; out: + /* + * we need to remove the ordered extent with the tree lock held + * so that other people calling this function don't find our fully + * processed ordered entry and skip updating the i_size + */ + if (ordered) + __btrfs_remove_ordered_extent(inode, ordered); mutex_unlock(&tree->mutex); - return 0; + if (ordered) + wake_up(&ordered->wait); + return ret; } /* -- cgit v1.2.3