From 4844c3664a72d36cc79752cb651c78860b14c240 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 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 --- 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 bfdfecee1afe..2669206e6f15 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -681,6 +681,14 @@ error_free_page: 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. Such diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index a59898d51e9e..2128a032c3b7 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -747,5 +747,6 @@ int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info); bool btrfs_repair_one_zone(struct btrfs_fs_info *fs_info, u64 logical); bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr); +u8 *btrfs_sb_fsid_ptr(struct btrfs_super_block *sb); #endif