Commit 1a898345 authored by Anand Jain's avatar Anand Jain Committed by David Sterba
Browse files

btrfs: simplify fsid and metadata_uuid comparisons 



Refactor the functions find_fsid() and find_fsid_with_metadata_uuid(),
as they currently share a common set of code to compare the fsid and
metadata_uuid. Create a common helper function, match_fsid_fs_devices().

Signed-off-by: default avatarAnand Jain <anand.jain@oracle.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 413fb1bc

fs/btrfs/volumes.c

+23 −15
Original line number Diff line number Diff line
@@ -427,6 +427,21 @@ void __exit btrfs_cleanup_fs_uuids(void) 
	}

}



static bool match_fsid_fs_devices(const struct btrfs_fs_devices *fs_devices,

				  const u8 *fsid, const u8 *metadata_fsid)

{

	if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) != 0)

		return false;



	if (!metadata_fsid)

		return true;



	if (memcmp(metadata_fsid, fs_devices->metadata_uuid, BTRFS_FSID_SIZE) != 0)

		return false;



	return true;

}



static noinline struct btrfs_fs_devices *find_fsid(

		const u8 *fsid, const u8 *metadata_fsid)

{
@@ -436,16 +451,9 @@ static noinline struct btrfs_fs_devices *find_fsid( 


	/* Handle non-split brain cases */

	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {

		if (metadata_fsid) {

			if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0

			    && memcmp(metadata_fsid, fs_devices->metadata_uuid,

				      BTRFS_FSID_SIZE) == 0)

				return fs_devices;

		} else {

			if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)

		if (match_fsid_fs_devices(fs_devices, fsid, metadata_fsid))

			return fs_devices;

	}

	}

	return NULL;

}
@@ -462,14 +470,14 @@ static struct btrfs_fs_devices *find_fsid_with_metadata_uuid( 
	 * at all and the CHANGING_FSID_V2 flag set.

	 */

	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {

		if (fs_devices->fsid_change &&

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

			   BTRFS_FSID_SIZE) == 0 &&

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

			   BTRFS_FSID_SIZE) == 0) {

		if (!fs_devices->fsid_change)

			continue;



		if (match_fsid_fs_devices(fs_devices, disk_super->metadata_uuid,

					  fs_devices->fsid))

			return fs_devices;

	}

	}



	/*

	 * Handle scanned device having completed its fsid change but

	 * belonging to a fs_devices that was created by a device that