Commit a3c54b0b authored by Anand Jain's avatar Anand Jain Committed by David Sterba
Browse files

btrfs: simplify how changed fsid and metadata_uuid is checked 



We often check if the metadata_uuid is not the same as fsid, and then we
check if the given fsid matches the metadata_uuid. This patch refactors
this logic into function match_fsid_changed and utilize it.

Signed-off-by: default avatarAnand Jain <anand.jain@oracle.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 1a898345

fs/btrfs/volumes.c

+26 −21
Original line number Diff line number Diff line
@@ -457,6 +457,19 @@ static noinline struct btrfs_fs_devices *find_fsid( 
	return NULL;

}



/*

 * First check if the metadata_uuid is different from the fsid in the given

 * fs_devices. Then check if the given fsid is the same as the metadata_uuid

 * in the fs_devices. If it is, return true; otherwise, return false.

 */

static inline bool check_fsid_changed(const struct btrfs_fs_devices *fs_devices,

				      const u8 *fsid)

{

	return memcmp(fs_devices->fsid, fs_devices->metadata_uuid,

		      BTRFS_FSID_SIZE) != 0 &&

	       memcmp(fs_devices->metadata_uuid, fsid, BTRFS_FSID_SIZE) == 0;

}



static struct btrfs_fs_devices *find_fsid_with_metadata_uuid(

				struct btrfs_super_block *disk_super)

{
@@ -485,14 +498,12 @@ static struct btrfs_fs_devices *find_fsid_with_metadata_uuid( 
	 * CHANGING_FSID_V2 flag set.

	 */

	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {

		if (fs_devices->fsid_change &&

		    memcmp(fs_devices->metadata_uuid,

			   fs_devices->fsid, BTRFS_FSID_SIZE) != 0 &&

		    memcmp(disk_super->metadata_uuid, fs_devices->metadata_uuid,

			   BTRFS_FSID_SIZE) == 0) {

		if (!fs_devices->fsid_change)

			continue;



		if (check_fsid_changed(fs_devices, disk_super->metadata_uuid))

			return fs_devices;

	}

	}



	return find_fsid(disk_super->fsid, disk_super->metadata_uuid);

}
@@ -682,18 +693,16 @@ static struct btrfs_fs_devices *find_fsid_inprogress( 
	struct btrfs_fs_devices *fs_devices;



	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {

		if (memcmp(fs_devices->metadata_uuid, fs_devices->fsid,

			   BTRFS_FSID_SIZE) != 0 &&

		    memcmp(fs_devices->metadata_uuid, disk_super->fsid,

			   BTRFS_FSID_SIZE) == 0 && !fs_devices->fsid_change) {

		if (fs_devices->fsid_change)

			continue;



		if (check_fsid_changed(fs_devices,  disk_super->fsid))

			return fs_devices;

	}

	}



	return find_fsid(disk_super->fsid, NULL);

}





static struct btrfs_fs_devices *find_fsid_changed(

					struct btrfs_super_block *disk_super)

{
@@ -710,10 +719,7 @@ static struct btrfs_fs_devices *find_fsid_changed( 
	 */

	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {

		/* Changed UUIDs */

		if (memcmp(fs_devices->metadata_uuid, fs_devices->fsid,

			   BTRFS_FSID_SIZE) != 0 &&

		    memcmp(fs_devices->metadata_uuid, disk_super->metadata_uuid,

			   BTRFS_FSID_SIZE) == 0 &&

		if (check_fsid_changed(fs_devices, disk_super->metadata_uuid) &&

		    memcmp(fs_devices->fsid, disk_super->fsid,

			   BTRFS_FSID_SIZE) != 0)

			return fs_devices;
@@ -744,11 +750,10 @@ static struct btrfs_fs_devices *find_fsid_reverted_metadata( 
	 * fs_devices equal to the FSID of the disk.

	 */

	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {

		if (memcmp(fs_devices->fsid, fs_devices->metadata_uuid,

			   BTRFS_FSID_SIZE) != 0 &&

		    memcmp(fs_devices->metadata_uuid, disk_super->fsid,

			   BTRFS_FSID_SIZE) == 0 &&

		    fs_devices->fsid_change)

		if (!fs_devices->fsid_change)

			continue;



		if (check_fsid_changed(fs_devices, disk_super->fsid))

			return fs_devices;

	}