Btrfs: check return value for kthread_run() correctly

kthread_run() returns the kthread or ERR_PTR(-ENOMEM), not NULL.

Signed-off-by: Qinghuang Feng <qhfeng.kernel@gmail.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 37e12f6..0d8ccd6 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1739,13 +1739,13 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
        fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
                                               "btrfs-cleaner");
-       if (!fs_info->cleaner_kthread)
+       if (IS_ERR(fs_info->cleaner_kthread))
                goto fail_csum_root;
 
        fs_info->transaction_kthread = kthread_run(transaction_kthread,
                                                   tree_root,
                                                   "btrfs-transaction");
-       if (!fs_info->transaction_kthread)
+       if (IS_ERR(fs_info->transaction_kthread))
                goto fail_cleaner;
 
        if (btrfs_super_log_root(disk_super) != 0) {