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Subject: Re: [SMBDIRECT][PATCH] missing rc checks while waiting for SMB3 over
 RDMA events
To:     Steve French <smfrench@gmail.com>, Long Li <longli@microsoft.com>
Cc:     CIFS <linux-cifs@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
References: <CAH2r5msOSLaZT42-jFMjJrB1YiYTZBzdM18ieqQY2v=YwXzcrA@mail.gmail.com>
From:   Tom Talpey <tom@talpey.com>
Message-ID: <1241844c-c9ab-2055-a363-80db63a4dd22@talpey.com>
Date:   Tue, 22 Jun 2021 11:18:42 -0400
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On 6/21/2021 5:32 PM, Steve French wrote:
>      There were two places where we weren't checking for error
>      (e.g. ERESTARTSYS) while waiting for rdma resolution.
> 
>      Addresses-Coverity: 1462165 ("Unchecked return value")
>     Signed-off-by: Steve French <stfrench@microsoft.com>
> 
> diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c
> index 10dfe5006792..ae07732f750f 100644
> --- a/fs/cifs/smbdirect.c
> +++ b/fs/cifs/smbdirect.c
> @@ -572,8 +572,11 @@ static struct rdma_cm_id *smbd_create_id(
>                  log_rdma_event(ERR, "rdma_resolve_addr() failed %i\n", rc);
>                  goto out;
>          }
> -       wait_for_completion_interruptible_timeout(
> +       rc = wait_for_completion_interruptible_timeout(
>                  &info->ri_done, msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT));
> +       /* -ERESTARTSYS, returned when interrupted, is the only rc mentioned */

Suggest the same comment text as the one below, this one seems uncertain.

> +       if (rc < 0)
> +               goto out;
>          rc = info->ri_rc;
>          if (rc) {
>                  log_rdma_event(ERR, "rdma_resolve_addr() completed %i\n", rc);
> @@ -586,8 +589,10 @@ static struct rdma_cm_id *smbd_create_id(
>                  log_rdma_event(ERR, "rdma_resolve_route() failed %i\n", rc);
>                  goto out;
>          }
> -       wait_for_completion_interruptible_timeout(
> +       rc = wait_for_completion_interruptible_timeout(
>                  &info->ri_done, msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT));
> +       if (rc < 0)  /* e.g. if interrupted and returns -ERESTARTSYS */

delete "and"?

> +               goto out

Missing a semicolon.     ^^^

>          rc = info->ri_rc;
>          if (rc) {
>                  log_rdma_event(ERR, "rdma_resolve_route() completed %i\n", rc);
> 
> 

One meta-comment. There's no message logged for these ERESTARTSYS cases.
That might be confusing in the log, if they lead to failure.

Reviewed-By: Tom Talpey <tom@talpey.com>

Tom.