From 52e71eb95cc73e544f36041973bd3c4cd460a4fb Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Tue, 10 Mar 2026 08:49:25 +1030 Subject: btrfs: tree-checker: introduce checks for FREE_SPACE_INFO Introduce checks for FREE_SPACE_INFO item, which include: - Key alignment check The objectid is the logical bytenr of the chunk/bg, and offset is the length of the chunk/bg, thus they should all be aligned to the fs block size. - Item size check The FREE_SPACE_INFO should a fix size. - Flags check The flags member should have no other flags than BTRFS_FREE_SPACE_USING_BITMAPS. For future expansion, introduce a new macro BTRFS_FREE_SPACE_FLAGS_MASK for such checks. And since we're here, the BTRFS_FREE_SPACE_USING_BITMAPS should not use unsigned long long, as the flags is only 32 bits wide. So fix that to use unsigned long. - Extent count check That member shows how many free space bitmap/extent items there are inside the chunk/bg. We know the chunk size (from key->offset), thus there should be at most (key->offset >> sectorsize_bits) blocks inside the chunk. Use that value as the upper limit and if that counter is larger than that, there is a high chance it's a bitflip in high bits. Reviewed-by: Johannes Thumshirn Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba --- include/uapi/linux/btrfs_tree.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h index f7843e6bb978..cc3b9f7dccaf 100644 --- a/include/uapi/linux/btrfs_tree.h +++ b/include/uapi/linux/btrfs_tree.h @@ -1245,7 +1245,8 @@ struct btrfs_free_space_info { __le32 flags; } __attribute__ ((__packed__)); -#define BTRFS_FREE_SPACE_USING_BITMAPS (1ULL << 0) +#define BTRFS_FREE_SPACE_USING_BITMAPS (1UL << 0) +#define BTRFS_FREE_SPACE_FLAGS_MASK (BTRFS_FREE_SPACE_USING_BITMAPS) #define BTRFS_QGROUP_LEVEL_SHIFT 48 static inline __u16 btrfs_qgroup_level(__u64 qgroupid) -- cgit v1.2.3