null_blk: Fix error path in module initialization

Module couldn't release resource properly during the initialization. To
fix this issue, we will clean up the proper resource before returning.

Signed-off-by: Minfei Huang <mnfhuang@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index 7981b7407305383b76bd76ca21d29047299ed445..8162475d96b55471befacf889acf8dfa28e274ea 100644 (file)
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -766,7 +766,9 @@ out:
 
 static int __init null_init(void)
 {
+       int ret = 0;
        unsigned int i;
+       struct nullb *nullb;
 
        if (bs > PAGE_SIZE) {
                pr_warn("null_blk: invalid block size\n");
@@ -808,22 +810,29 @@ static int __init null_init(void)
                                                                0, 0, NULL);
                if (!ppa_cache) {
                        pr_err("null_blk: unable to create ppa cache\n");
-                       return -ENOMEM;
+                       ret = -ENOMEM;
+                       goto err_ppa;
                }
        }
 
        for (i = 0; i < nr_devices; i++) {
-               if (null_add_dev()) {
-                       unregister_blkdev(null_major, "nullb");
-                       goto err_ppa;
-               }
+               ret = null_add_dev();
+               if (ret)
+                       goto err_dev;
        }
 
        pr_info("null: module loaded\n");
        return 0;
-err_ppa:
+
+err_dev:
+       while (!list_empty(&nullb_list)) {
+               nullb = list_entry(nullb_list.next, struct nullb, list);
+               null_del_dev(nullb);
+       }
        kmem_cache_destroy(ppa_cache);
-       return -EINVAL;
+err_ppa:
+       unregister_blkdev(null_major, "nullb");
+       return ret;
 }
 
 static void __exit null_exit(void)