Commit 4844c366 authored by Anand Jain's avatar Anand Jain Committed by David Sterba
Browse files

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: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: default avatarGuilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: default avatarAnand Jain <anand.jain@oracle.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 182741d2

fs/btrfs/volumes.c

+8 −0
Original line number Diff line number Diff line
@@ -681,6 +681,14 @@ static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices, 
	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

fs/btrfs/volumes.h

+1 −0
Original line number Diff line number Diff line
@@ -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