[PATCH] null_blk: Fix error path in module initialization

From: Minfei Huang
Date: Thu Nov 26 2015 - 08:46:30 EST


From: Minfei Huang <mnfhuang@xxxxxxxxx>

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@xxxxxxxxx>
---
drivers/block/null_blk.c | 24 +++++++++++++++++-------
1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index 5c8ba54..ec99568 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -780,7 +780,9 @@ 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");
@@ -835,22 +837,30 @@ 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_dev:
+ while (!list_empty(&nullb_list)) {
+ nullb = list_entry(nullb_list.next, struct nullb, list);
+ null_del_dev(nullb);
+ }
+ if (use_lightnvm)
+ kmem_cache_destroy(ppa_cache);
err_ppa:
- kmem_cache_destroy(ppa_cache);
- return -EINVAL;
+ unregister_blkdev(null_major, "nullb");
+ return ret;
}

static void __exit null_exit(void)
--
1.8.3.1

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