Re: [patch] ceph: checking for IS_ERR instead of NULL

[Ilya Dryomov]

On Tue, Jan 26, 2016 at 10:24 AM, Dan Carpenter
<dan.carpenter@xxxxxxxxxx> wrote:
> ceph_osdc_alloc_request() returns NULL on error, it never returns error
> pointers.
>
> Fixes: 5be0389dac66 ('ceph: re-send AIO write request when getting -EOLDSNAP error')
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
>
> diff --git a/fs/ceph/file.c b/fs/ceph/file.c
> index d37efdd..a52cf9b 100644
> --- a/fs/ceph/file.c
> +++ b/fs/ceph/file.c
> @@ -698,8 +698,8 @@ static void ceph_aio_retry_work(struct work_struct *work)
>
>         req = ceph_osdc_alloc_request(orig_req->r_osdc, snapc, 2,
>                         false, GFP_NOFS);
> -       if (IS_ERR(req)) {
> -               ret = PTR_ERR(req);
> +       if (!req) {
> +               ret = -ENOMEM;
>                 req = orig_req;
>                 goto out;
>         }

Applied, thanks Dan.

Zheng, I have an related concern: where do you put snapc (refcount is
bumped a few lines above) if ceph_osdc_alloc_request() fails?  It looks
like it's leaked to me.

The BUG_ON(ret == -EOLDSNAPC) also seems a bit bogus, given that ret is
either -ENOMEM or ceph_osdc_start_request() retval.

                Ilya