dm: push error reporting down to dm_register_target()

Simplifies each DM target's init method by making dm_register_target()
responsible for its error reporting (on behalf of targets).

Signed-off-by: Yangtao Li <[e-mail]>
Signed-off-by: Mike Snitzer <[e-mail]>

drivers/md/dm-cache-target.c

···
 
 	r = dm_register_target(&cache_target);
 	if (r) {
-		DMERR("cache target registration failed: %d", r);
 		kmem_cache_destroy(migration_cache);
 		return r;
 	}

drivers/md/dm-clone-target.c

···
 
 	r = dm_register_target(&clone_target);
 	if (r < 0) {
-		DMERR("Failed to register clone target");
 		kmem_cache_destroy(_hydration_cache);
 		return r;
 	}

drivers/md/dm-crypt.c

···
 
 static int __init dm_crypt_init(void)
 {
-	int r;
-
-	r = dm_register_target(&crypt_target);
-	if (r < 0)
-		DMERR("register failed %d", r);
-
-	return r;
+	return dm_register_target(&crypt_target);
 }
 
 static void __exit dm_crypt_exit(void)

drivers/md/dm-delay.c

···
 
 static int __init dm_delay_init(void)
 {
-	int r;
-
-	r = dm_register_target(&delay_target);
-	if (r < 0) {
-		DMERR("register failed %d", r);
-		goto bad_register;
-	}
-
-	return 0;
-
-bad_register:
-	return r;
+	return dm_register_target(&delay_target);
 }
 
 static void __exit dm_delay_exit(void)

drivers/md/dm-dust.c

···
 
 static int __init dm_dust_init(void)
 {
-	int r = dm_register_target(&dust_target);
-
-	if (r < 0)
-		DMERR("dm_register_target failed %d", r);
-
-	return r;
+	return dm_register_target(&dust_target);
 }
 
 static void __exit dm_dust_exit(void)

drivers/md/dm-ebs-target.c

···
 
 static int __init dm_ebs_init(void)
 {
-	int r = dm_register_target(&ebs_target);
-
-	if (r < 0)
-		DMERR("register failed %d", r);
-
-	return r;
+	return dm_register_target(&ebs_target);
 }
 
 static void dm_ebs_exit(void)

drivers/md/dm-era-target.c

···
 
 static int __init dm_era_init(void)
 {
-	int r;
-
-	r = dm_register_target(&era_target);
-	if (r) {
-		DMERR("era target registration failed: %d", r);
-		return r;
-	}
-
-	return 0;
+	return dm_register_target(&era_target);
 }
 
 static void __exit dm_era_exit(void)

drivers/md/dm-flakey.c

···
 
 static int __init dm_flakey_init(void)
 {
-	int r = dm_register_target(&flakey_target);
-
-	if (r < 0)
-		DMERR("register failed %d", r);
-
-	return r;
+	return dm_register_target(&flakey_target);
 }
 
 static void __exit dm_flakey_exit(void)

drivers/md/dm-integrity.c

···
 
 	r = dm_register_target(&integrity_target);
 	if (r < 0) {
-		DMERR("register failed %d", r);
 		kmem_cache_destroy(journal_io_cache);
 		return r;
 	}

drivers/md/dm-log-writes.c

···
 
 static int __init dm_log_writes_init(void)
 {
-	int r = dm_register_target(&log_writes_target);
-
-	if (r < 0)
-		DMERR("register failed %d", r);
-
-	return r;
+	return dm_register_target(&log_writes_target);
 }
 
 static void __exit dm_log_writes_exit(void)

drivers/md/dm-mpath.c

···
 	}
 
 	r = dm_register_target(&multipath_target);
-	if (r < 0) {
-		DMERR("request-based register failed %d", r);
-		r = -EINVAL;
+	if (r < 0)
 		goto bad_register_target;
-	}
 
 	return 0;
 

drivers/md/dm-raid1.c

···
 
 static int __init dm_mirror_init(void)
 {
-	int r = -ENOMEM;
+	int r;
 
 	dm_raid1_wq = alloc_workqueue("dm_raid1_wq", 0, 0);
 	if (!dm_raid1_wq)
-		goto bad_target;
+		return -ENOMEM;
 
 	r = dm_register_target(&mirror_target);
 	if (r < 0) {
 		destroy_workqueue(dm_raid1_wq);
-		goto bad_target;
+		return r;
 	}
 
 	return 0;
-
-bad_target:
-	DMERR("Failed to register mirror target");
-	return r;
 }
 
 static void __exit dm_mirror_exit(void)

drivers/md/dm-snap.c

···
 	}
 
 	r = dm_register_target(&snapshot_target);
-	if (r < 0) {
-		DMERR("snapshot target register failed %d", r);
+	if (r < 0)
 		goto bad_register_snapshot_target;
-	}
 
 	r = dm_register_target(&origin_target);
-	if (r < 0) {
-		DMERR("Origin target register failed %d", r);
+	if (r < 0)
 		goto bad_register_origin_target;
-	}
 
 	r = dm_register_target(&merge_target);
-	if (r < 0) {
-		DMERR("Merge target register failed %d", r);
+	if (r < 0)
 		goto bad_register_merge_target;
-	}
 
 	return 0;
 

drivers/md/dm-switch.c

···
 
 static int __init dm_switch_init(void)
 {
-	int r;
-
-	r = dm_register_target(&switch_target);
-	if (r < 0)
-		DMERR("dm_register_target() failed %d", r);
-
-	return r;
+	return dm_register_target(&switch_target);
 }
 
 static void __exit dm_switch_exit(void)

drivers/md/dm-target.c

···
 	int rv = 0;
 
 	down_write(&_lock);
-	if (__find_target_type(tt->name))
+	if (__find_target_type(tt->name)) {
+		DMERR("%s: '%s' target already registered",
+		      __func__, tt->name);
 		rv = -EEXIST;
-	else
+	} else {
 		list_add(&tt->list, &_targets);
-
+	}
 	up_write(&_lock);
+
 	return rv;
 }
 EXPORT_SYMBOL(dm_register_target);

drivers/md/dm-verity-target.c

···
 
 static int __init dm_verity_init(void)
 {
-	int r;
-
-	r = dm_register_target(&verity_target);
-	if (r < 0)
-		DMERR("register failed %d", r);
-
-	return r;
+	return dm_register_target(&verity_target);
 }
 
 static void __exit dm_verity_exit(void)

drivers/md/dm-writecache.c

···
 
 static int __init dm_writecache_init(void)
 {
-	int r;
-
-	r = dm_register_target(&writecache_target);
-	if (r < 0) {
-		DMERR("register failed %d", r);
-		return r;
-	}
-
-	return 0;
+	return dm_register_target(&writecache_target);
 }
 
 static void __exit dm_writecache_exit(void)

drivers/md/dm-zero.c

···
 
 static int __init dm_zero_init(void)
 {
-	int r = dm_register_target(&zero_target);
-
-	if (r < 0)
-		DMERR("register failed %d", r);
-
-	return r;
+	return dm_register_target(&zero_target);
 }
 
 static void __exit dm_zero_exit(void)