From 085e59de0d15d3105cff8bbbd9b34802798359c9 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Wed, 27 Apr 2022 11:16:31 +0800 Subject: [PATCH] btrfs: check the root node for uptodate before returning it stable inclusion from stable-v5.10.94 commit e7764bccae77d3620113576ed18abd5233ba07a6 bugzilla: https://gitee.com/openeuler/kernel/issues/I531X9 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=e7764bccae77d3620113576ed18abd5233ba07a6 -------------------------------- commit 120de408e4b97504a2d9b5ca534b383de2c73d49 upstream. Now that we clear the extent buffer uptodate if we fail to write it out we need to check to see if our root node is uptodate before we search down it. Otherwise we could return stale data (or potentially corrupt data that was caught by the write verification step) and think that the path is OK to search down. CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Nikolay Borisov Signed-off-by: Josef Bacik Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman Signed-off-by: Zheng Zengkai Acked-by: Xie XiuQi --- fs/btrfs/ctree.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 519cf145f9bd..5addd1e36a8e 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -2589,12 +2589,9 @@ static struct extent_buffer *btrfs_search_slot_get_root(struct btrfs_root *root, { struct btrfs_fs_info *fs_info = root->fs_info; struct extent_buffer *b; - int root_lock; + int root_lock = 0; int level = 0; - /* We try very hard to do read locks on the root */ - root_lock = BTRFS_READ_LOCK; - if (p->search_commit_root) { /* * The commit roots are read only so we always do read locks, @@ -2632,6 +2629,9 @@ static struct extent_buffer *btrfs_search_slot_get_root(struct btrfs_root *root, goto out; } + /* We try very hard to do read locks on the root */ + root_lock = BTRFS_READ_LOCK; + /* * If the level is set to maximum, we can skip trying to get the read * lock. @@ -2658,6 +2658,17 @@ static struct extent_buffer *btrfs_search_slot_get_root(struct btrfs_root *root, level = btrfs_header_level(b); out: + /* + * The root may have failed to write out at some point, and thus is no + * longer valid, return an error in this case. + */ + if (!extent_buffer_uptodate(b)) { + if (root_lock) + btrfs_tree_unlock_rw(b, root_lock); + free_extent_buffer(b); + return ERR_PTR(-EIO); + } + p->nodes[level] = b; if (!p->skip_locking) p->locks[level] = root_lock; -- GitLab