From: Qu Wenruo wqu@suse.com
mainline inclusion from mainline-5.2-rc1 commit ff2ac107fae2440b6877c615c0ac788d2a106ed7 category: bugfix bugzilla: NA CVE: CVE-2019-19036 ---------------------------
Commit 1ba98d086fe3 ("Btrfs: detect corruption when non-root leaf has zero item") introduced comprehensive root owner checker.
However it's pretty expensive tree search to locate the owner root, especially when it get reused by mandatory read and write time tree-checker.
This patch will remove that check, and completely rely on owner based empty leaf check, which is much faster and still works fine for most case.
And since we skip the old root owner check, now write time tree check can be merged with btrfs_check_leaf_full().
Signed-off-by: Qu Wenruo wqu@suse.com Signed-off-by: David Sterba dsterba@suse.com Conflict: fs/btrfs/tree-checker.c Signed-off-by: Yufen Yu yuyufen@huawei.com Reviewed-by: zhangyi (F) yi.zhang@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- fs/btrfs/tree-checker.c | 24 ------------------------ 1 file changed, 24 deletions(-)
diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c index 3ec712c..f1ae228 100644 --- a/fs/btrfs/tree-checker.c +++ b/fs/btrfs/tree-checker.c @@ -495,7 +495,6 @@ static int check_leaf(struct btrfs_fs_info *fs_info, struct extent_buffer *leaf, */ if (nritems == 0 && !btrfs_header_flag(leaf, BTRFS_HEADER_FLAG_RELOC)) { u64 owner = btrfs_header_owner(leaf); - struct btrfs_root *check_root;
/* These trees must never be empty */ if (owner == BTRFS_ROOT_TREE_OBJECTID || @@ -509,29 +508,6 @@ static int check_leaf(struct btrfs_fs_info *fs_info, struct extent_buffer *leaf, owner); return -EUCLEAN; } - key.objectid = owner; - key.type = BTRFS_ROOT_ITEM_KEY; - key.offset = (u64)-1; - - check_root = btrfs_get_fs_root(fs_info, &key, false); - /* - * The only reason we also check NULL here is that during - * open_ctree() some roots has not yet been set up. - */ - if (!IS_ERR_OR_NULL(check_root)) { - struct extent_buffer *eb; - - eb = btrfs_root_node(check_root); - /* if leaf is the root, then it's fine */ - if (leaf != eb) { - generic_err(fs_info, leaf, 0, - "invalid nritems, have %u should not be 0 for non-root leaf", - nritems); - free_extent_buffer(eb); - return -EUCLEAN; - } - free_extent_buffer(eb); - } return 0; }