From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurence Oberman Subject: Re: [PATCH 1/2] scsi: add a max_segment_size limitation to struct Scsi_Host Date: Mon, 11 Apr 2016 19:22:30 -0400 (EDT) Message-ID: <1375441901.28363505.1460416950062.JavaMail.zimbra@redhat.com> References: <1460414846-29540-1-git-send-email-hch@lst.de> <1460414846-29540-2-git-send-email-hch@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mx4-phx2.redhat.com ([209.132.183.25]:55734 "EHLO mx4-phx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752652AbcDKXWc (ORCPT ); Mon, 11 Apr 2016 19:22:32 -0400 In-Reply-To: <1460414846-29540-2-git-send-email-hch@lst.de> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Christoph Hellwig Cc: linux-rdma@vger.kernel.org, linux-scsi@vger.kernel.org This looks fine to me. I am pulling this in to my SRP initiator and target testing ongoing at the moment so will be testing. Up to now this has likely not affected me but I am pulling in all RDMA patches to test. Reviewed-by: Laurence Oberman Laurence Oberman Principal Software Maintenance Engineer Red Hat Global Support Services ----- Original Message ----- From: "Christoph Hellwig" To: linux-rdma@vger.kernel.org, linux-scsi@vger.kernel.org Sent: Monday, April 11, 2016 6:47:25 PM Subject: [PATCH 1/2] scsi: add a max_segment_size limitation to struct Scsi_Host RDMA drivers need segments that aren't larger than a single HCA page for memory registrations to work properly, so wire up this limitation in the host. While we could just call blk_queue_max_segment_size from ->slave_configure, that would override the global limit based on the DMA device, so let's do it the traditional way by adding a field to the Scsi_Host structure. Signed-off-by: Christoph Hellwig --- drivers/scsi/scsi_lib.c | 3 ++- include/scsi/scsi_host.h | 1 + 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 8106515..04c660d 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -2120,7 +2120,8 @@ static void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q) blk_queue_segment_boundary(q, shost->dma_boundary); dma_set_seg_boundary(dev, shost->dma_boundary); - blk_queue_max_segment_size(q, dma_get_max_seg_size(dev)); + blk_queue_max_segment_size(q, + min(shost->max_segment_size, dma_get_max_seg_size(dev))); if (!shost->use_clustering) q->limits.cluster = 0; diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index fcfa3d7..f11d3fe 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -621,6 +621,7 @@ struct Scsi_Host { short unsigned int sg_tablesize; short unsigned int sg_prot_tablesize; unsigned int max_sectors; + unsigned int max_segment_size; unsigned long dma_boundary; /* * In scsi-mq mode, the number of hardware queues supported by the LLD. -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html