btrfs: add error handling for scrub_workers_get()

Although it is a rare case, we'd better free previous allocated
memory on error.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 9f2feabe99f211f9c8eb5d489c44c85f54754c27..94db0fa5225a9fd493163fc117cd25d8b01b7343 100644 (file)
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -3571,7 +3571,6 @@ static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
 static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
                                                int is_dev_replace)
 {
-       int ret = 0;
        unsigned int flags = WQ_FREEZABLE | WQ_UNBOUND;
        int max_active = fs_info->thread_pool_size;
 
@@ -3584,34 +3583,36 @@ static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
                        fs_info->scrub_workers =
                                btrfs_alloc_workqueue("btrfs-scrub", flags,
                                                      max_active, 4);
-               if (!fs_info->scrub_workers) {
-                       ret = -ENOMEM;
-                       goto out;
-               }
+               if (!fs_info->scrub_workers)
+                       goto fail_scrub_workers;
+
                fs_info->scrub_wr_completion_workers =
                        btrfs_alloc_workqueue("btrfs-scrubwrc", flags,
                                              max_active, 2);
-               if (!fs_info->scrub_wr_completion_workers) {
-                       ret = -ENOMEM;
-                       goto out;
-               }
+               if (!fs_info->scrub_wr_completion_workers)
+                       goto fail_scrub_wr_completion_workers;
+
                fs_info->scrub_nocow_workers =
                        btrfs_alloc_workqueue("btrfs-scrubnc", flags, 1, 0);
-               if (!fs_info->scrub_nocow_workers) {
-                       ret = -ENOMEM;
-                       goto out;
-               }
+               if (!fs_info->scrub_nocow_workers)
+                       goto fail_scrub_nocow_workers;
                fs_info->scrub_parity_workers =
                        btrfs_alloc_workqueue("btrfs-scrubparity", flags,
                                              max_active, 2);
-               if (!fs_info->scrub_parity_workers) {
-                       ret = -ENOMEM;
-                       goto out;
-               }
+               if (!fs_info->scrub_parity_workers)
+                       goto fail_scrub_parity_workers;
        }
        ++fs_info->scrub_workers_refcnt;
-out:
-       return ret;
+       return 0;
+
+fail_scrub_parity_workers:
+       btrfs_destroy_workqueue(fs_info->scrub_nocow_workers);
+fail_scrub_nocow_workers:
+       btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
+fail_scrub_wr_completion_workers:
+       btrfs_destroy_workqueue(fs_info->scrub_workers);
+fail_scrub_workers:
+       return -ENOMEM;
 }
 
 static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info)