zram: destroy all devices on error recovery path in zram_init()

commit 39a9b8ac9333e4268ecff7da6c9d1ab3823ff243 upstream.

On error recovery path of zram_init(), it leaks the zram device object
causing the failure. So change create_device() to free allocated
resources on error path.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c
index 785a947..72d8060 100644 (file)
--- a/drivers/staging/zram/zram_drv.c
+++ b/drivers/staging/zram/zram_drv.c
@@ -715,7 +715,7 @@ static const struct block_device_operations zram_devops = {
 
 static int create_device(struct zram *zram, int device_id)
 {
-       int ret = 0;
+       int ret = -ENOMEM;
 
        init_rwsem(&zram->lock);
        init_rwsem(&zram->init_lock);
@@ -725,7 +725,6 @@ static int create_device(struct zram *zram, int device_id)
        if (!zram->queue) {
                pr_err("Error allocating disk queue for device %d\n",
                        device_id);
-               ret = -ENOMEM;
                goto out;
        }
 
@@ -735,11 +734,9 @@ static int create_device(struct zram *zram, int device_id)
         /* gendisk structure */
        zram->disk = alloc_disk(1);
        if (!zram->disk) {
-               blk_cleanup_queue(zram->queue);
                pr_warning("Error allocating disk structure for device %d\n",
                        device_id);
-               ret = -ENOMEM;
-               goto out;
+               goto out_free_queue;
        }
 
        zram->disk->major = zram_major;
@@ -768,11 +765,17 @@ static int create_device(struct zram *zram, int device_id)
                                &zram_disk_attr_group);
        if (ret < 0) {
                pr_warning("Error creating sysfs group");
-               goto out;
+               goto out_free_disk;
        }
 
        zram->init_done = 0;
+       return 0;
 
+out_free_disk:
+       del_gendisk(zram->disk);
+       put_disk(zram->disk);
+out_free_queue:
+       blk_cleanup_queue(zram->queue);
 out:
        return ret;
 }