> -----Original Message-----
> From: linux-kernel-ow...@vger.kernel.org <linux-kernel-ow...@vger.kernel.org> 
> On Behalf
> Of Long Li
> Sent: Tuesday, April 17, 2018 12:17 PM
> To: Steve French <sfre...@samba.org>; linux-c...@vger.kernel.org; samba-
> techni...@lists.samba.org; linux-kernel@vger.kernel.org; 
> linux-r...@vger.kernel.org
> Cc: Long Li <lon...@microsoft.com>; sta...@vger.kernel.org
> Subject: [Patch v2 1/6] cifs: smbd: Check for iov length on sending the last 
> iov
> 
> From: Long Li <lon...@microsoft.com>
> 
> When sending the last iov that breaks into smaller buffers to fit the
> transfer size, it's necessary to check if this is the last iov.
> 
> If this is the latest iov, stop and proceed to send pages.
> 
> Signed-off-by: Long Li <lon...@microsoft.com>
> Cc: sta...@vger.kernel.org

Reviewed-by: Michael Kelley <mikel...@microsoft.com>

But a question unrelated to this change arose during my review:  At the
beginning and end of smbd_send(), the field smbd_send_pending is
incremented and decremented, respectively.   The increment/decrement
are not done as atomic operations.  Is this code guaranteed to be single
threaded?  If not, the count could become corrupted, and
smbd_destroy_rdma_work(), which waits for the count to become zero,
could hang.  A similar question applies to smbd_recv_pending in smbd_recv().

> ---
>  fs/cifs/smbdirect.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c
> index 90e673c..b5c6c0d 100644
> --- a/fs/cifs/smbdirect.c
> +++ b/fs/cifs/smbdirect.c
> @@ -2197,6 +2197,8 @@ int smbd_send(struct smbd_connection *info, struct 
> smb_rqst *rqst)
>                                               goto done;
>                               }
>                               i++;
> +                             if (i == rqst->rq_nvec)
> +                                     break;
>                       }
>                       start = i;
>                       buflen = 0;
> --
> 2.7.4

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