Commit c6730a0e authored by Su Yue's avatar Su Yue Committed by David Sterba
Browse files

btrfs: Factor out metadata_uuid code from find_fsid. 



find_fsid became rather hairy with the introduction of metadata uuid
changing feature. Alleviate this by factoring out the metadata uuid
specific code in a dedicated function which deals with finding
correct fsid for a device with changed uuid.

Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Signed-off-by: default avatarSu Yue <Damenly_Su@gmx.com>
Signed-off-by: default avatarNikolay Borisov <nborisov@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent c0d81c7c

fs/btrfs/volumes.c

+42 −35
Original line number Diff line number Diff line
@@ -441,7 +441,27 @@ static noinline struct btrfs_fs_devices *find_fsid( 


	ASSERT(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)

				return fs_devices;

		}

	}

	return NULL;

}



static struct btrfs_fs_devices *find_fsid_with_metadata_uuid(

				struct btrfs_super_block *disk_super)

{



	struct btrfs_fs_devices *fs_devices;



	/*

	 * Handle scanned device having completed its fsid change but

	 * belonging to a fs_devices that was created by first scanning
@@ -450,7 +470,7 @@ static noinline struct btrfs_fs_devices *find_fsid( 
	 */

	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {

		if (fs_devices->fsid_change &&

			    memcmp(metadata_fsid, fs_devices->fsid,

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

			   BTRFS_FSID_SIZE) == 0 &&

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

			   BTRFS_FSID_SIZE) == 0) {
@@ -467,28 +487,16 @@ static noinline struct btrfs_fs_devices *find_fsid( 
		if (fs_devices->fsid_change &&

		    memcmp(fs_devices->metadata_uuid,

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

			    memcmp(metadata_fsid, fs_devices->metadata_uuid,

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

			   BTRFS_FSID_SIZE) == 0) {

			return fs_devices;

		}

	}

	}



	/* 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)

				return fs_devices;

		}

	}

	return NULL;

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

}





static int

btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,

		      int flush, struct block_device **bdev,
@@ -744,8 +752,7 @@ static noinline struct btrfs_device *device_list_add(const char *path, 
		else

			fs_devices = find_fsid_changed(disk_super);

	} else if (has_metadata_uuid) {

		fs_devices = find_fsid(disk_super->fsid,

				       disk_super->metadata_uuid);

		fs_devices = find_fsid_with_metadata_uuid(disk_super);

	} else {

		fs_devices = find_fsid(disk_super->fsid, NULL);

	}