btrfs-progs: tune: factor out metadata UUID change to own file

Signed-off-by: David Sterba <dsterba@suse.com>

Makefile

@@ -234,7 +234,7 @@ convert_objects = convert/main.o convert/common.o convert/source-fs.o \
 		  mkfs/common.o
 mkfs_objects = mkfs/main.o mkfs/common.o mkfs/rootdir.o
 image_objects = image/main.o image/sanitize.o
-tune_objects = tune/main.o tune/seeding.o tune/change-uuid.o
+tune_objects = tune/main.o tune/seeding.o tune/change-uuid.o tune/change-metadata-uuid.o
 all_objects = $(objects) $(cmds_objects) $(libbtrfs_objects) $(convert_objects) \
 	      $(mkfs_objects) $(image_objects) $(tune_objects) $(libbtrfsutil_objects)
 

tune/change-metadata-uuid.c

@@ -0,0 +1,113 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include "kerncompat.h"
+#include <stdbool.h>
+#include <string.h>
+#include <uuid/uuid.h>
+#include "kernel-shared/ctree.h"
+#include "kernel-shared/transaction.h"
+#include "common/messages.h"
+#include "tune/tune.h"
+#include "ioctl.h"
+
+int set_metadata_uuid(struct btrfs_root *root, const char *uuid_string)
+{
+	struct btrfs_super_block *disk_super;
+	uuid_t new_fsid, unused1, unused2;
+	struct btrfs_trans_handle *trans;
+	bool new_uuid = true;
+	u64 incompat_flags;
+	bool uuid_changed;
+	u64 super_flags;
+	int ret;
+
+	disk_super = root->fs_info->super_copy;
+	super_flags = btrfs_super_flags(disk_super);
+	incompat_flags = btrfs_super_incompat_flags(disk_super);
+	uuid_changed = incompat_flags & BTRFS_FEATURE_INCOMPAT_METADATA_UUID;
+
+	if (super_flags & BTRFS_SUPER_FLAG_SEEDING) {
+		error("cannot set metadata UUID on a seed device");
+		return 1;
+	}
+
+	if (check_unfinished_fsid_change(root->fs_info, unused1, unused2)) {
+		error("UUID rewrite in progress, cannot change fsid");
+		return 1;
+	}
+
+	if (uuid_string)
+		uuid_parse(uuid_string, new_fsid);
+	else
+		uuid_generate(new_fsid);
+
+	new_uuid = (memcmp(new_fsid, disk_super->fsid, BTRFS_FSID_SIZE) != 0);
+
+	/* Step 1 sets the in progress flag */
+	trans = btrfs_start_transaction(root, 1);
+	super_flags |= BTRFS_SUPER_FLAG_CHANGING_FSID_V2;
+	btrfs_set_super_flags(disk_super, super_flags);
+	ret = btrfs_commit_transaction(trans, root);
+	if (ret < 0)
+		return ret;
+
+	if (new_uuid && uuid_changed && memcmp(disk_super->metadata_uuid,
+					       new_fsid, BTRFS_FSID_SIZE) == 0) {
+		/*
+		 * Changing fsid to be the same as metadata uuid, so just
+		 * disable the flag
+		 */
+		memcpy(disk_super->fsid, &new_fsid, BTRFS_FSID_SIZE);
+		incompat_flags &= ~BTRFS_FEATURE_INCOMPAT_METADATA_UUID;
+		btrfs_set_super_incompat_flags(disk_super, incompat_flags);
+		memset(disk_super->metadata_uuid, 0, BTRFS_FSID_SIZE);
+	} else if (new_uuid && uuid_changed && memcmp(disk_super->metadata_uuid,
+						new_fsid, BTRFS_FSID_SIZE)) {
+		/*
+		 * Changing fsid on an already changed FS, in this case we
+		 * only change the fsid and don't touch metadata uuid as it
+		 * has already the correct value
+		 */
+		memcpy(disk_super->fsid, &new_fsid, BTRFS_FSID_SIZE);
+	} else if (new_uuid && !uuid_changed) {
+		/*
+		 * First time changing the fsid, copy the fsid to metadata_uuid
+		 */
+		incompat_flags |= BTRFS_FEATURE_INCOMPAT_METADATA_UUID;
+		btrfs_set_super_incompat_flags(disk_super, incompat_flags);
+		memcpy(disk_super->metadata_uuid, disk_super->fsid,
+		       BTRFS_FSID_SIZE);
+		memcpy(disk_super->fsid, &new_fsid, BTRFS_FSID_SIZE);
+	} else {
+		/* Setting the same fsid as current, do nothing */
+		return 0;
+	}
+
+	trans = btrfs_start_transaction(root, 1);
+
+	/*
+	 * Step 2 is to write the metadata_uuid, set the incompat flag and
+	 * clear the in progress flag
+	 */
+	super_flags &= ~BTRFS_SUPER_FLAG_CHANGING_FSID_V2;
+	btrfs_set_super_flags(disk_super, super_flags);
+
+	/* Then actually copy the metadata uuid and set the incompat bit */
+
+	return btrfs_commit_transaction(trans, root);
+}
+

tune/main.c

@@ -47,93 +47,6 @@
 static char *device;
 static int force = 0;
 
-static int set_metadata_uuid(struct btrfs_root *root, const char *uuid_string)
-{
-	struct btrfs_super_block *disk_super;
-	uuid_t new_fsid, unused1, unused2;
-	struct btrfs_trans_handle *trans;
-	bool new_uuid = true;
-	u64 incompat_flags;
-	bool uuid_changed;
-	u64 super_flags;
-	int ret;
-
-	disk_super = root->fs_info->super_copy;
-	super_flags = btrfs_super_flags(disk_super);
-	incompat_flags = btrfs_super_incompat_flags(disk_super);
-	uuid_changed = incompat_flags & BTRFS_FEATURE_INCOMPAT_METADATA_UUID;
-
-	if (super_flags & BTRFS_SUPER_FLAG_SEEDING) {
-		error("cannot set metadata UUID on a seed device");
-		return 1;
-	}
-
-	if (check_unfinished_fsid_change(root->fs_info, unused1, unused2)) {
-		error("UUID rewrite in progress, cannot change fsid");
-		return 1;
-	}
-
-	if (uuid_string)
-		uuid_parse(uuid_string, new_fsid);
-	else
-		uuid_generate(new_fsid);
-
-	new_uuid = (memcmp(new_fsid, disk_super->fsid, BTRFS_FSID_SIZE) != 0);
-
-	/* Step 1 sets the in progress flag */
-	trans = btrfs_start_transaction(root, 1);
-	super_flags |= BTRFS_SUPER_FLAG_CHANGING_FSID_V2;
-	btrfs_set_super_flags(disk_super, super_flags);
-	ret = btrfs_commit_transaction(trans, root);
-	if (ret < 0)
-		return ret;
-
-	if (new_uuid && uuid_changed && memcmp(disk_super->metadata_uuid,
-					       new_fsid, BTRFS_FSID_SIZE) == 0) {
-		/*
-		 * Changing fsid to be the same as metadata uuid, so just
-		 * disable the flag
-		 */
-		memcpy(disk_super->fsid, &new_fsid, BTRFS_FSID_SIZE);
-		incompat_flags &= ~BTRFS_FEATURE_INCOMPAT_METADATA_UUID;
-		btrfs_set_super_incompat_flags(disk_super, incompat_flags);
-		memset(disk_super->metadata_uuid, 0, BTRFS_FSID_SIZE);
-	} else if (new_uuid && uuid_changed && memcmp(disk_super->metadata_uuid,
-						new_fsid, BTRFS_FSID_SIZE)) {
-		/*
-		 * Changing fsid on an already changed FS, in this case we
-		 * only change the fsid and don't touch metadata uuid as it
-		 * has already the correct value
-		 */
-		memcpy(disk_super->fsid, &new_fsid, BTRFS_FSID_SIZE);
-	} else if (new_uuid && !uuid_changed) {
-		/*
-		 * First time changing the fsid, copy the fsid to metadata_uuid
-		 */
-		incompat_flags |= BTRFS_FEATURE_INCOMPAT_METADATA_UUID;
-		btrfs_set_super_incompat_flags(disk_super, incompat_flags);
-		memcpy(disk_super->metadata_uuid, disk_super->fsid,
-		       BTRFS_FSID_SIZE);
-		memcpy(disk_super->fsid, &new_fsid, BTRFS_FSID_SIZE);
-	} else {
-		/* Setting the same fsid as current, do nothing */
-		return 0;
-	}
-
-	trans = btrfs_start_transaction(root, 1);
-
-	/*
-	 * Step 2 is to write the metadata_uuid, set the incompat flag and
-	 * clear the in progress flag
-	 */
-	super_flags &= ~BTRFS_SUPER_FLAG_CHANGING_FSID_V2;
-	btrfs_set_super_flags(disk_super, super_flags);
-
-	/* Then actually copy the metadata uuid and set the incompat bit */
-
-	return btrfs_commit_transaction(trans, root);
-}
-
 static int delete_csum_items(struct btrfs_trans_handle *trans,
 			     struct btrfs_fs_info *fs_info)
 {

tune/tune.h

@@ -25,5 +25,6 @@ int update_seeding_flag(struct btrfs_root *root, const char *device, int set_fla
 int check_unfinished_fsid_change(struct btrfs_fs_info *fs_info,
 				 uuid_t fsid_ret, uuid_t chunk_id_ret);
 int change_uuid(struct btrfs_fs_info *fs_info, const char *new_fsid_str);
+int set_metadata_uuid(struct btrfs_root *root, const char *uuid_string);
 
 #endif