gfs2: Clean up freeing struct gfs2_sbd

Add a free_sbd function for freeing a struct gfs2_sbd.  Use that for
freeing a super-block descriptor, either directly or via kobject_put.
Free sd_lkstats inside the kobject release function: that way,
gfs2_put_super will no longer leak sd_lkstats.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

fs/gfs2/ops_fstype.c

@@ -61,6 +61,13 @@ static void gfs2_tune_init(struct gfs2_tune *gt)
 	gt->gt_complain_secs = 10;
 }
 
+void free_sbd(struct gfs2_sbd *sdp)
+{
+	if (sdp->sd_lkstats)
+		free_percpu(sdp->sd_lkstats);
+	kfree(sdp);
+}
+
 static struct gfs2_sbd *init_sbd(struct super_block *sb)
 {
 	struct gfs2_sbd *sdp;
@@ -72,10 +79,8 @@ static struct gfs2_sbd *init_sbd(struct super_block *sb)
 
 	sdp->sd_vfs = sb;
 	sdp->sd_lkstats = alloc_percpu(struct gfs2_pcpu_lkstats);
-	if (!sdp->sd_lkstats) {
-		kfree(sdp);
-		return NULL;
-	}
+	if (!sdp->sd_lkstats)
+		goto fail;
 	sb->s_fs_info = sdp;
 
 	set_bit(SDF_NOJOURNALID, &sdp->sd_flags);
@@ -134,8 +139,11 @@ static struct gfs2_sbd *init_sbd(struct super_block *sb)
 	mutex_init(&sdp->sd_freeze_mutex);
 
 	return sdp;
-}
 
+fail:
+	free_sbd(sdp);
+	return NULL;
+}
 
 /**
  * gfs2_check_sb - Check superblock
@@ -1086,8 +1094,7 @@ static int fill_super(struct super_block *sb, struct gfs2_args *args, int silent
 	if (error) {
 		/* In this case, we haven't initialized sysfs, so we have to
 		   manually free the sdp. */
-		free_percpu(sdp->sd_lkstats);
-		kfree(sdp);
+		free_sbd(sdp);
 		sb->s_fs_info = NULL;
 		return error;
 	}
@@ -1190,7 +1197,6 @@ static int fill_super(struct super_block *sb, struct gfs2_args *args, int silent
 	gfs2_lm_unmount(sdp);
 fail_debug:
 	gfs2_delete_debugfs_file(sdp);
-	free_percpu(sdp->sd_lkstats);
 	/* gfs2_sys_fs_del must be the last thing we do, since it causes
 	 * sysfs to call function gfs2_sbd_release, which frees sdp. */
 	gfs2_sys_fs_del(sdp);
@@ -1370,7 +1376,6 @@ static void gfs2_kill_sb(struct super_block *sb)
 	sdp->sd_root_dir = NULL;
 	sdp->sd_master_dir = NULL;
 	shrink_dcache_sb(sb);
-	free_percpu(sdp->sd_lkstats);
 	kill_block_super(sb);
 }
 

fs/gfs2/super.h

@@ -44,6 +44,8 @@ extern void update_statfs(struct gfs2_sbd *sdp, struct buffer_head *m_bh,
 extern int gfs2_statfs_sync(struct super_block *sb, int type);
 extern void gfs2_freeze_func(struct work_struct *work);
 
+extern void free_sbd(struct gfs2_sbd *sdp);
+
 extern struct file_system_type gfs2_fs_type;
 extern struct file_system_type gfs2meta_fs_type;
 extern const struct export_operations gfs2_export_ops;

fs/gfs2/sys.c

@@ -301,7 +301,7 @@ static void gfs2_sbd_release(struct kobject *kobj)
 {
 	struct gfs2_sbd *sdp = container_of(kobj, struct gfs2_sbd, sd_kobj);
 
-	kfree(sdp);
+	free_sbd(sdp);
 }
 
 static struct kobj_type gfs2_ktype = {
@@ -679,7 +679,6 @@ int gfs2_sys_fs_add(struct gfs2_sbd *sdp)
 fail_tune:
 	sysfs_remove_group(&sdp->sd_kobj, &tune_group);
 fail_reg:
-	free_percpu(sdp->sd_lkstats);
 	fs_err(sdp, "error %d adding sysfs files\n", error);
 	kobject_put(&sdp->sd_kobj);
 	sb->s_fs_info = NULL;