[PATCH] MD: md, fix lock imbalance

[Jiri Slaby <jirislaby@gmail.com>]

Add unlock and put to one of fail paths in md_alloc.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
---
 drivers/md/md.c |   26 +++++++++++++++-----------
 1 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 0f11fd1..6264933 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3833,7 +3833,7 @@ static int md_alloc(dev_t dev, char *name)
 	int partitioned;
 	int shift;
 	int unit;
-	int error;
+	int error, ret;
 
 	if (!mddev)
 		return -ENODEV;
@@ -3849,9 +3849,8 @@ static int md_alloc(dev_t dev, char *name)
 
 	mutex_lock(&disks_mutex);
 	if (mddev->gendisk) {
-		mutex_unlock(&disks_mutex);
-		mddev_put(mddev);
-		return -EEXIST;
+		ret = -EEXIST;
+		goto unlock;
 	}
 
 	if (name) {
@@ -3864,16 +3863,16 @@ static int md_alloc(dev_t dev, char *name)
 			if (mddev2->gendisk &&
 			    strcmp(mddev2->gendisk->disk_name, name) == 0) {
 				spin_unlock(&all_mddevs_lock);
-				return -EEXIST;
+				ret = -EEXIST;
+				goto unlock;
 			}
 		spin_unlock(&all_mddevs_lock);
 	}
 
 	mddev->queue = blk_alloc_queue(GFP_KERNEL);
 	if (!mddev->queue) {
-		mutex_unlock(&disks_mutex);
-		mddev_put(mddev);
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto unlock;
 	}
 	mddev->queue->queuedata = mddev;
 
@@ -3887,8 +3886,8 @@ static int md_alloc(dev_t dev, char *name)
 		mutex_unlock(&disks_mutex);
 		blk_cleanup_queue(mddev->queue);
 		mddev->queue = NULL;
-		mddev_put(mddev);
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto put;
 	}
 	disk->major = MAJOR(mddev->unit);
 	disk->first_minor = unit << shift;
@@ -3918,8 +3917,13 @@ static int md_alloc(dev_t dev, char *name)
 		kobject_uevent(&mddev->kobj, KOBJ_ADD);
 		mddev->sysfs_state = sysfs_get_dirent(mddev->kobj.sd, "array_state");
 	}
+	ret = 0;
+put:
 	mddev_put(mddev);
-	return 0;
+	return ret;
+unlock:
+	mutex_unlock(&disks_mutex);
+	goto put;
 }
 
 static struct kobject *md_probe(dev_t dev, int *part, void *data)
-- 
1.6.3.2