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| author |   Qu Wenruo <wqu@suse.com> | 2020-09-22 10:37:01 +0800 |
|---|---|---|
| committer |   David Sterba <dsterba@suse.com> | 2020-10-07 12:13:23 +0200 |
| commit | 1465af12e254a68706e110846f59cf0f09683184 (patch) | |
| tree | 1720a50ff0d674e104c28f5653194c20f65855dd /fs/btrfs/tree-checker.c | |
| parent | btrfs: use unaligned helpers for stack and header set/get helpers (diff) | |
| download | linux-dev-1465af12e254a68706e110846f59cf0f09683184.tar.xz linux-dev-1465af12e254a68706e110846f59cf0f09683184.zip | |
btrfs: tree-checker: fix false alert caused by legacy btrfs root item
Commit 259ee7754b67 ("btrfs: tree-checker: Add ROOT_ITEM check")
introduced btrfs root item size check, however btrfs root item has two
versions, the legacy one which just ends before generation_v2 member, is
smaller than current btrfs root item size.
This caused btrfs kernel to reject valid but old tree root leaves.
Fix this problem by also allowing legacy root item, since kernel can
already handle them pretty well and upgrade to newer root item format
when needed.
Reported-by: Martin Steigerwald <martin@lichtvoll.de>
Fixes: 259ee7754b67 ("btrfs: tree-checker: Add ROOT_ITEM check")
CC: stable@vger.kernel.org # 5.4+
Tested-By: Martin Steigerwald <martin@lichtvoll.de>
Reviewed-by: Josef Bacik <josef@toxicpanda.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/btrfs/tree-checker.c')
| -rw-r--r-- | fs/btrfs/tree-checker.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c index 7b1fee630f97..f0ffd5ee77bd 100644 --- a/fs/btrfs/tree-checker.c +++ b/fs/btrfs/tree-checker.c @@ -1035,7 +1035,7 @@ static int check_root_item(struct extent_buffer *leaf, struct btrfs_key *key, int slot) { struct btrfs_fs_info *fs_info = leaf->fs_info; - struct btrfs_root_item ri; + struct btrfs_root_item ri = { 0 }; const u64 valid_root_flags = BTRFS_ROOT_SUBVOL_RDONLY | BTRFS_ROOT_SUBVOL_DEAD; int ret; @@ -1044,14 +1044,21 @@ static int check_root_item(struct extent_buffer *leaf, struct btrfs_key *key, if (ret < 0) return ret; - if (btrfs_item_size_nr(leaf, slot) != sizeof(ri)) { + if (btrfs_item_size_nr(leaf, slot) != sizeof(ri) && + btrfs_item_size_nr(leaf, slot) != btrfs_legacy_root_item_size()) { generic_err(leaf, slot, - "invalid root item size, have %u expect %zu", - btrfs_item_size_nr(leaf, slot), sizeof(ri)); + "invalid root item size, have %u expect %zu or %u", + btrfs_item_size_nr(leaf, slot), sizeof(ri), + btrfs_legacy_root_item_size()); } + /* + * For legacy root item, the members starting at generation_v2 will be + * all filled with 0. + * And since we allow geneartion_v2 as 0, it will still pass the check. + */ read_extent_buffer(leaf, &ri, btrfs_item_ptr_offset(leaf, slot), - sizeof(ri)); + btrfs_item_size_nr(leaf, slot)); /* Generation related */ if (btrfs_root_generation(&ri) > |