diff options
author | Qu Wenruo <wqu@suse.com> | 2024-07-15 16:07:07 +0930 |
---|---|---|
committer | David Sterba <dsterba@suse.com> | 2024-07-25 23:54:06 +0200 |
commit | f333a3c7e8323499aa65038e77fe8f3199d4e283 (patch) | |
tree | 4f0c972b1192d04891ba1664f7f149f650f07cf8 /fs | |
parent | c3ece6b7ffb4a7c00e8d53cbf4026a32b6127914 (diff) |
btrfs: tree-checker: validate dref root and objectid
[CORRUPTION]
There is a bug report that btrfs flips RO due to a corruption in the
extent tree, the involved dumps looks like this:
item 188 key (402811572224 168 4096) itemoff 14598 itemsize 79
extent refs 3 gen 3678544 flags 1
ref#0: extent data backref root 13835058055282163977 objectid 281473384125923 offset 81432576 count 1
ref#1: shared data backref parent 1947073626112 count 1
ref#2: shared data backref parent 1156030103552 count 1
BTRFS critical (device vdc1: state EA): unable to find ref byte nr 402811572224 parent 0 root 265 owner 28703026 offset 81432576 slot 189
BTRFS error (device vdc1: state EA): failed to run delayed ref for logical 402811572224 num_bytes 4096 type 178 action 2 ref_mod 1: -2
[CAUSE]
The corrupted entry is ref#0 of item 188.
The root number 13835058055282163977 is beyond the upper limit for root
items (the current limit is 1 << 48), and the objectid also looks
suspicious.
Only the offset and count is correct.
[ENHANCEMENT]
Although it's still unknown why we have such many bytes corrupted
randomly, we can still enhance the tree-checker for data backrefs by:
- Validate the root value
For now there should only be 3 types of roots can have data backref:
* subvolume trees
* data reloc trees
* root tree
Only for v1 space cache
- validate the objectid value
The objectid should be a valid inode number.
Hopefully we can catch such problem in the future with the new checkers.
Reported-by: Kai Krakow <hurikhan77@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CAMthOuPjg5RDT-G_LXeBBUUtzt3cq=JywF+D1_h+JYxe=WKp-Q@mail.gmail.com/#t
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/btrfs/tree-checker.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c index 6388786fd8b5..18bb0c930db4 100644 --- a/fs/btrfs/tree-checker.c +++ b/fs/btrfs/tree-checker.c @@ -1289,6 +1289,19 @@ static void extent_err(const struct extent_buffer *eb, int slot, va_end(args); } +static bool is_valid_dref_root(u64 rootid) +{ + /* + * The following tree root objectids are allowed to have a data backref: + * - subvolume trees + * - data reloc tree + * - tree root + * For v1 space cache + */ + return is_fstree(rootid) || rootid == BTRFS_DATA_RELOC_TREE_OBJECTID || + rootid == BTRFS_ROOT_TREE_OBJECTID; +} + static int check_extent_item(struct extent_buffer *leaf, struct btrfs_key *key, int slot, struct btrfs_key *prev_key) @@ -1441,6 +1454,8 @@ static int check_extent_item(struct extent_buffer *leaf, struct btrfs_extent_data_ref *dref; struct btrfs_shared_data_ref *sref; u64 seq; + u64 dref_root; + u64 dref_objectid; u64 dref_offset; u64 inline_offset; u8 inline_type; @@ -1484,11 +1499,26 @@ static int check_extent_item(struct extent_buffer *leaf, */ case BTRFS_EXTENT_DATA_REF_KEY: dref = (struct btrfs_extent_data_ref *)(&iref->offset); + dref_root = btrfs_extent_data_ref_root(leaf, dref); + dref_objectid = btrfs_extent_data_ref_objectid(leaf, dref); dref_offset = btrfs_extent_data_ref_offset(leaf, dref); seq = hash_extent_data_ref( btrfs_extent_data_ref_root(leaf, dref), btrfs_extent_data_ref_objectid(leaf, dref), btrfs_extent_data_ref_offset(leaf, dref)); + if (unlikely(!is_valid_dref_root(dref_root))) { + extent_err(leaf, slot, + "invalid data ref root value %llu", + dref_root); + return -EUCLEAN; + } + if (unlikely(dref_objectid < BTRFS_FIRST_FREE_OBJECTID || + dref_objectid > BTRFS_LAST_FREE_OBJECTID)) { + extent_err(leaf, slot, + "invalid data ref objectid value %llu", + dref_root); + return -EUCLEAN; + } if (unlikely(!IS_ALIGNED(dref_offset, fs_info->sectorsize))) { extent_err(leaf, slot, @@ -1627,6 +1657,8 @@ static int check_extent_data_ref(struct extent_buffer *leaf, return -EUCLEAN; } for (; ptr < end; ptr += sizeof(*dref)) { + u64 root; + u64 objectid; u64 offset; /* @@ -1634,7 +1666,22 @@ static int check_extent_data_ref(struct extent_buffer *leaf, * overflow from the leaf due to hash collisions. */ dref = (struct btrfs_extent_data_ref *)ptr; + root = btrfs_extent_data_ref_root(leaf, dref); + objectid = btrfs_extent_data_ref_objectid(leaf, dref); offset = btrfs_extent_data_ref_offset(leaf, dref); + if (unlikely(!is_valid_dref_root(root))) { + extent_err(leaf, slot, + "invalid extent data backref root value %llu", + root); + return -EUCLEAN; + } + if (unlikely(objectid < BTRFS_FIRST_FREE_OBJECTID || + objectid > BTRFS_LAST_FREE_OBJECTID)) { + extent_err(leaf, slot, + "invalid extent data backref objectid value %llu", + root); + return -EUCLEAN; + } if (unlikely(!IS_ALIGNED(offset, leaf->fs_info->sectorsize))) { extent_err(leaf, slot, "invalid extent data backref offset, have %llu expect aligned to %u", |