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authorQu Wenruo <wqu@suse.com>2018-03-29 04:08:11 +0300
committerDavid Sterba <dsterba@suse.com>2018-03-31 03:01:06 +0300
commit581c1760415c48cca9349b198bba52dd38750765 (patch)
tree90e5aa035bfcab9a05fdec79eaa4ce90dc7aa267 /fs/btrfs/backref.c
parent3c0efdf03b2d127f0e40e30db4e7aa0429b1b79a (diff)
downloadlinux-581c1760415c48cca9349b198bba52dd38750765.tar.xz
btrfs: Validate child tree block's level and first key
We have several reports about node pointer points to incorrect child tree blocks, which could have even wrong owner and level but still with valid generation and checksum. Although btrfs check could handle it and print error message like: leaf parent key incorrect 60670574592 Kernel doesn't have enough check on this type of corruption correctly. At least add such check to read_tree_block() and btrfs_read_buffer(), where we need two new parameters @level and @first_key to verify the child tree block. The new @level check is mandatory and all call sites are already modified to extract expected level from its call chain. While @first_key is optional, the following call sites are skipping such check: 1) Root node/leaf As ROOT_ITEM doesn't contain the first key, skip @first_key check. 2) Direct backref Only parent bytenr and level is known and we need to resolve the key all by ourselves, skip @first_key check. Another note of this verification is, it needs extra info from nodeptr or ROOT_ITEM, so it can't fit into current tree-checker framework, which is limited to node/leaf boundary. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/backref.c')
-rw-r--r--fs/btrfs/backref.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 6007dd6b799e..571024bc632e 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -738,7 +738,8 @@ static int add_missing_keys(struct btrfs_fs_info *fs_info,
BUG_ON(ref->key_for_search.type);
BUG_ON(!ref->wanted_disk_byte);
- eb = read_tree_block(fs_info, ref->wanted_disk_byte, 0);
+ eb = read_tree_block(fs_info, ref->wanted_disk_byte, 0,
+ ref->level - 1, NULL);
if (IS_ERR(eb)) {
free_pref(ref);
return PTR_ERR(eb);
@@ -1288,7 +1289,8 @@ again:
ref->level == 0) {
struct extent_buffer *eb;
- eb = read_tree_block(fs_info, ref->parent, 0);
+ eb = read_tree_block(fs_info, ref->parent, 0,
+ ref->level, NULL);
if (IS_ERR(eb)) {
ret = PTR_ERR(eb);
goto out;