md/md-linear: Fix a NULL vs IS_ERR() bug in linear_add()

commit 62c552070a980363d55a6082b432ebd1cade7a6e upstream.

The linear_conf() returns error pointers, it doesn't return NULL.  Update
the error checking to match.

Fixes: 127186cfb184 ("md: reintroduce md-linear")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/add654be-759f-4b2d-93ba-a3726dae380c@stanley.mountain
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/md/md-linear.c b/drivers/md/md-linear.c
index 53bc3fda9edb2cde4121133cb7fa57f7e06feed9..a382929ce7bab43d953efa3babc0df7f19e8d2cd 100644 (file)
--- a/drivers/md/md-linear.c
+++ b/drivers/md/md-linear.c
@@ -204,8 +204,8 @@ static int linear_add(struct mddev *mddev, struct md_rdev *rdev)
        rdev->saved_raid_disk = -1;
 
        newconf = linear_conf(mddev, mddev->raid_disks + 1);
-       if (!newconf)
-               return -ENOMEM;
+       if (IS_ERR(newconf))
+               return PTR_ERR(newconf);
 
        /* newconf->raid_disks already keeps a copy of * the increased
         * value of mddev->raid_disks, WARN_ONCE() is just used to make