From patchwork Fri Jun 30 15:25:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13298389 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F08A8EB64DA for ; Fri, 30 Jun 2023 15:28:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232682AbjF3P20 (ORCPT ); Fri, 30 Jun 2023 11:28:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42894 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233083AbjF3P1R (ORCPT ); Fri, 30 Jun 2023 11:27:17 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 12FAA421F for ; Fri, 30 Jun 2023 08:26:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1688138767; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=dTUg/mVQyhhJfywizixeKkySOuaXp8UTsLqq+KCOGUE=; b=atmb6SIuYUSvBo+G6C6nrT2ln1MQB8vvMXrdE5f5BHzb1Vj9dSVl8KLCbivwX++4xDfr5v YGWpW+zfRD8uYLILdshyZWJ324rgRglywpv68QewDRYrkP2VbWrWPn8Atf+DgAW164CUyN 3fi0J8DQtk/m5xRU95Y4iIx/FUfsU1s= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-342-ykgDuP25MHy7G1d5_4sdcQ-1; Fri, 30 Jun 2023 11:26:03 -0400 X-MC-Unique: ykgDuP25MHy7G1d5_4sdcQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 21B6D1C0512E; Fri, 30 Jun 2023 15:26:02 +0000 (UTC) Received: from warthog.procyon.org.uk.com (unknown [10.42.28.195]) by smtp.corp.redhat.com (Postfix) with ESMTP id DF05540C6CCD; Fri, 30 Jun 2023 15:25:59 +0000 (UTC) From: David Howells To: Jens Axboe , Al Viro , Christoph Hellwig Cc: David Howells , Matthew Wilcox , Jan Kara , Jeff Layton , David Hildenbrand , Jason Gunthorpe , Logan Gunthorpe , Hillf Danton , Christian Brauner , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, "James E . J . Bottomley" , "Martin K . Petersen" , Christoph Hellwig , linux-scsi@vger.kernel.org Subject: [RFC PATCH 11/11] scsi: Use extract_iter_to_sg() Date: Fri, 30 Jun 2023 16:25:24 +0100 Message-ID: <20230630152524.661208-12-dhowells@redhat.com> In-Reply-To: <20230630152524.661208-1-dhowells@redhat.com> References: <20230630152524.661208-1-dhowells@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Use extract_iter_to_sg() to build a scatterlist from an iterator. Signed-off-by: David Howells cc: James E.J. Bottomley cc: Martin K. Petersen cc: Christoph Hellwig cc: linux-scsi@vger.kernel.org --- drivers/vhost/scsi.c | 79 +++++++++++++------------------------------- 1 file changed, 23 insertions(+), 56 deletions(-) diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index bb10fa4bb4f6..7bb41e2a0d64 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -75,6 +75,9 @@ struct vhost_scsi_cmd { u32 tvc_prot_sgl_count; /* Saved unpacked SCSI LUN for vhost_scsi_target_queue_cmd() */ u32 tvc_lun; + /* Cleanup modes for scatterlists */ + unsigned int tvc_need_unpin; + unsigned int tvc_prot_need_unpin; /* Pointer to the SGL formatted memory from virtio-scsi */ struct scatterlist *tvc_sgl; struct scatterlist *tvc_prot_sgl; @@ -327,14 +330,13 @@ static void vhost_scsi_release_cmd_res(struct se_cmd *se_cmd) struct vhost_scsi_inflight *inflight = tv_cmd->inflight; int i; - if (tv_cmd->tvc_sgl_count) { + if (tv_cmd->tvc_need_unpin && tv_cmd->tvc_sgl_count) for (i = 0; i < tv_cmd->tvc_sgl_count; i++) - put_page(sg_page(&tv_cmd->tvc_sgl[i])); - } - if (tv_cmd->tvc_prot_sgl_count) { + unpin_user_page(sg_page(&tv_cmd->tvc_sgl[i])); + + if (tv_cmd->tvc_prot_need_unpin && tv_cmd->tvc_prot_sgl_count) for (i = 0; i < tv_cmd->tvc_prot_sgl_count; i++) - put_page(sg_page(&tv_cmd->tvc_prot_sgl[i])); - } + unpin_user_page(sg_page(&tv_cmd->tvc_prot_sgl[i])); sbitmap_clear_bit(&svq->scsi_tags, se_cmd->map_tag); vhost_scsi_put_inflight(inflight); @@ -606,38 +608,6 @@ vhost_scsi_get_cmd(struct vhost_virtqueue *vq, struct vhost_scsi_tpg *tpg, return cmd; } -/* - * Map a user memory range into a scatterlist - * - * Returns the number of scatterlist entries used or -errno on error. - */ -static int -vhost_scsi_map_to_sgl(struct vhost_scsi_cmd *cmd, - struct iov_iter *iter, - struct scatterlist *sgl, - bool write) -{ - struct page **pages = cmd->tvc_upages; - struct scatterlist *sg = sgl; - ssize_t bytes; - size_t offset; - unsigned int npages = 0; - - bytes = iov_iter_get_pages2(iter, pages, LONG_MAX, - VHOST_SCSI_PREALLOC_UPAGES, &offset); - /* No pages were pinned */ - if (bytes <= 0) - return bytes < 0 ? bytes : -EFAULT; - - while (bytes) { - unsigned n = min_t(unsigned, PAGE_SIZE - offset, bytes); - sg_set_page(sg++, pages[npages++], n, offset); - bytes -= n; - offset = 0; - } - return npages; -} - static int vhost_scsi_calc_sgls(struct iov_iter *iter, size_t bytes, int max_sgls) { @@ -661,24 +631,19 @@ vhost_scsi_calc_sgls(struct iov_iter *iter, size_t bytes, int max_sgls) static int vhost_scsi_iov_to_sgl(struct vhost_scsi_cmd *cmd, bool write, struct iov_iter *iter, - struct scatterlist *sg, int sg_count) + struct scatterlist *sg, int sg_count, + unsigned int *need_unpin) { - struct scatterlist *p = sg; - int ret; + struct sg_table sgt = { .sgl = sg }; + ssize_t ret; - while (iov_iter_count(iter)) { - ret = vhost_scsi_map_to_sgl(cmd, iter, sg, write); - if (ret < 0) { - while (p < sg) { - struct page *page = sg_page(p++); - if (page) - put_page(page); - } - return ret; - } - sg += ret; - } - return 0; + ret = extract_iter_to_sg(iter, LONG_MAX, &sgt, sg_count, + write ? WRITE_FROM_ITER : READ_INTO_ITER); + if (ret > 0) + sg_mark_end(sg + sgt.nents - 1); + + *need_unpin = iov_iter_extract_will_pin(iter); + return ret; } static int @@ -702,7 +667,8 @@ vhost_scsi_mapal(struct vhost_scsi_cmd *cmd, ret = vhost_scsi_iov_to_sgl(cmd, write, prot_iter, cmd->tvc_prot_sgl, - cmd->tvc_prot_sgl_count); + cmd->tvc_prot_sgl_count, + &cmd->tvc_prot_need_unpin); if (ret < 0) { cmd->tvc_prot_sgl_count = 0; return ret; @@ -719,7 +685,8 @@ vhost_scsi_mapal(struct vhost_scsi_cmd *cmd, cmd->tvc_sgl, cmd->tvc_sgl_count); ret = vhost_scsi_iov_to_sgl(cmd, write, data_iter, - cmd->tvc_sgl, cmd->tvc_sgl_count); + cmd->tvc_sgl, cmd->tvc_sgl_count, + &cmd->tvc_need_unpin); if (ret < 0) { cmd->tvc_sgl_count = 0; return ret;