From b61aad18b38aa34f168abc5a1c29342583c4994c Mon Sep 17 00:00:00 2001 From: Anand Jain Date: Mon, 31 Jul 2023 19:16:32 +0800 Subject: [PATCH] btrfs: add a helper to read the superblock metadata_uuid [ Upstream commit 4844c3664a72d36cc79752cb651c78860b14c240 ] In some cases, we need to read the FSID from the superblock when the metadata_uuid is not set, and otherwise, read the metadata_uuid. So, add a helper. Reviewed-by: Johannes Thumshirn Tested-by: Guilherme G. Piccoli Signed-off-by: Anand Jain Reviewed-by: David Sterba Signed-off-by: David Sterba Stable-dep-of: 6bfe3959b0e7 ("btrfs: compare the correct fsid/metadata_uuid in btrfs_validate_super") Signed-off-by: Sasha Levin --- fs/btrfs/volumes.c | 8 ++++++++ fs/btrfs/volumes.h | 1 + 2 files changed, 9 insertions(+) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 0d4afeacb237..f9192dcb9208 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -895,6 +895,14 @@ error_brelse: return -EINVAL; } +u8 *btrfs_sb_fsid_ptr(struct btrfs_super_block *sb) +{ + bool has_metadata_uuid = (btrfs_super_incompat_flags(sb) & + BTRFS_FEATURE_INCOMPAT_METADATA_UUID); + + return has_metadata_uuid ? sb->metadata_uuid : sb->fsid; +} + /* * Handle scanned device having its CHANGING_FSID_V2 flag set and the fs_devices * being created with a disk that has already completed its fsid change. diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index fd8fdaa4b0cd..762c0a375498 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -582,5 +582,6 @@ const char *btrfs_bg_type_to_raid_name(u64 flags); int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info); bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr); +u8 *btrfs_sb_fsid_ptr(struct btrfs_super_block *sb); #endif