md: properly unwind when failing to add the kobject in md_alloc

Add proper error handling to delete the gendisk when failing to add
the md kobject and clean up the error unwinding in general.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 946bbed..c6b15ff 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -5672,7 +5672,7 @@ static int md_alloc(dev_t dev, char *name)
                            strcmp(mddev2->gendisk->disk_name, name) == 0) {
                                spin_unlock(&all_mddevs_lock);
                                error = -EEXIST;
-                               goto abort;
+                               goto out_unlock_disks_mutex;
                        }
                spin_unlock(&all_mddevs_lock);
        }
@@ -5685,7 +5685,7 @@ static int md_alloc(dev_t dev, char *name)
        error = -ENOMEM;
        disk = blk_alloc_disk(NUMA_NO_NODE);
        if (!disk)
-               goto abort;
+               goto out_unlock_disks_mutex;
 
        disk->major = MAJOR(mddev->unit);
        disk->first_minor = unit << shift;
@@ -5710,26 +5710,23 @@ static int md_alloc(dev_t dev, char *name)
        disk->events |= DISK_EVENT_MEDIA_CHANGE;
        mddev->gendisk = disk;
        error = add_disk(disk);
-       if (error) {
-               blk_cleanup_disk(disk);
-               goto abort;
-       }
+       if (error)
+               goto out_cleanup_disk;
 
        error = kobject_add(&mddev->kobj, &disk_to_dev(disk)->kobj, "%s", "md");
-       if (error) {
-               /* This isn't possible, but as kobject_init_and_add is marked
-                * __must_check, we must do something with the result
-                */
-               pr_debug("md: cannot register %s/md - name in use\n",
-                        disk->disk_name);
-               error = 0;
-       }
- abort:
-       if (!error && mddev->kobj.sd) {
-               kobject_uevent(&mddev->kobj, KOBJ_ADD);
-               mddev->sysfs_state = sysfs_get_dirent_safe(mddev->kobj.sd, "array_state");
-               mddev->sysfs_level = sysfs_get_dirent_safe(mddev->kobj.sd, "level");
-       }
+       if (error)
+               goto out_del_gendisk;
+
+       kobject_uevent(&mddev->kobj, KOBJ_ADD);
+       mddev->sysfs_state = sysfs_get_dirent_safe(mddev->kobj.sd, "array_state");
+       mddev->sysfs_level = sysfs_get_dirent_safe(mddev->kobj.sd, "level");
+       goto out_unlock_disks_mutex;
+
+out_del_gendisk:
+       del_gendisk(disk);
+out_cleanup_disk:
+       blk_cleanup_disk(disk);
+out_unlock_disks_mutex:
        mutex_unlock(&disks_mutex);
        mddev_put(mddev);
        return error;