From patchwork Tue Nov 1 16:31:28 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13027222 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 0BF98C433FE for ; Tue, 1 Nov 2022 16:33:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231166AbiKAQdQ (ORCPT ); Tue, 1 Nov 2022 12:33:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34522 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231179AbiKAQcf (ORCPT ); Tue, 1 Nov 2022 12:32:35 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EF0621CFD9 for ; Tue, 1 Nov 2022 09:31:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1667320294; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=wJkBi5kdUIPghoooABzqD0pHZYV0NGlqarhZvc8P+dQ=; b=AYMH6FZ8HyC7TplPEeUiW7iRdsydHJFmc2k5HQNH0MWnc+ASgAUI10LJuWpQu94Mfw+8Bh 6bPwT0nCOK6pyfknXuUPAl5DkbxjcHvyAHgIySgp0EHCvgmdEsejJV6L9LgIAltTtvoKAV UVcXS08rKjEGxkc138exccWk1zESk9Y= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-383-d7wZGBjFPdGcca0aqL8Img-1; Tue, 01 Nov 2022 12:31:31 -0400 X-MC-Unique: d7wZGBjFPdGcca0aqL8Img-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 9B36D833A06; Tue, 1 Nov 2022 16:31:30 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.73]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0381F1121320; Tue, 1 Nov 2022 16:31:28 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [RFC PATCH 06/12] cifs: Add a function to build an RDMA SGE list from an iterator From: David Howells To: Steve French , Al Viro Cc: Steve French , Shyam Prasad N , Rohith Surabattula , Jeff Layton , linux-cifs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-rdma@vger.kernel.org, dhowells@redhat.com, Shyam Prasad N , Rohith Surabattula , Tom Talpey , Christoph Hellwig , Matthew Wilcox , Jeff Layton , linux-cifs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Tue, 01 Nov 2022 16:31:28 +0000 Message-ID: <166732028840.3186319.8512284239779728860.stgit@warthog.procyon.org.uk> In-Reply-To: <166732024173.3186319.18204305072070871546.stgit@warthog.procyon.org.uk> References: <166732024173.3186319.18204305072070871546.stgit@warthog.procyon.org.uk> User-Agent: StGit/1.5 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Add a function to add elements onto an RDMA SGE list representing page fragments extracted from a BVEC-, KVEC- or XARRAY-type iterator and DMA mapped until the maximum number of elements is reached. Nothing is done to make sure the pages remain present - that must be done by the caller. Signed-off-by: David Howells cc: Steve French cc: Shyam Prasad N cc: Rohith Surabattula cc: Jeff Layton cc: linux-cifs@vger.kernel.org cc: linux-fsdevel@vger.kernel.org cc: linux-rdma@vger.kernel.org --- fs/cifs/smbdirect.c | 224 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 224 insertions(+) diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c index 90789aaa6567..18fb440a02c3 100644 --- a/fs/cifs/smbdirect.c +++ b/fs/cifs/smbdirect.c @@ -44,6 +44,17 @@ static int smbd_post_send_page(struct smbd_connection *info, static void destroy_mr_list(struct smbd_connection *info); static int allocate_mr_list(struct smbd_connection *info); +struct smb_extract_to_rdma { + struct ib_sge *sge; + unsigned int nr_sge; + unsigned int max_sge; + struct ib_device *device; + u32 local_dma_lkey; + enum dma_data_direction direction; +}; +static ssize_t smb_extract_iter_to_rdma(struct iov_iter *iter, size_t len, + struct smb_extract_to_rdma *rdma); + /* SMBD version number */ #define SMBD_V1 0x0100 @@ -2489,3 +2500,216 @@ int smbd_deregister_mr(struct smbd_mr *smbdirect_mr) return rc; } + +static bool smb_set_sge(struct smb_extract_to_rdma *rdma, + struct page *lowest_page, size_t off, size_t len) +{ + struct ib_sge *sge = &rdma->sge[rdma->nr_sge]; + u64 addr; + + addr = ib_dma_map_page(rdma->device, lowest_page, + off, len, rdma->direction); + if (ib_dma_mapping_error(rdma->device, addr)) + return false; + + sge->addr = addr; + sge->length = len; + sge->lkey = rdma->local_dma_lkey; + rdma->nr_sge++; + return true; +} + +/* + * Extract page fragments from a BVEC-class iterator and add them to an RDMA + * element list. The pages are not pinned. + */ +static ssize_t smb_extract_bvec_to_rdma(struct iov_iter *iter, + struct smb_extract_to_rdma *rdma, + ssize_t maxsize) +{ + const struct bio_vec *bv = iter->bvec; + unsigned long start = iter->iov_offset; + unsigned int i, sge_max = rdma->max_sge; + ssize_t ret = 0; + + for (i = 0; i < iter->nr_segs; i++) { + size_t off, len; + + len = bv[i].bv_len; + if (start >= len) { + start -= len; + continue; + } + + len = min_t(size_t, maxsize, len - start); + off = bv[i].bv_offset + start; + + if (!smb_set_sge(rdma, bv[i].bv_page, off, len)) + return -EIO; + sge_max--; + + ret += len; + maxsize -= len; + if (maxsize <= 0 || sge_max == 0) + break; + start = 0; + } + + return ret; +} + +/* + * Extract fragments from a KVEC-class iterator and add them to an RDMA list. + * This can deal with vmalloc'd buffers as well as kmalloc'd or static buffers. + * The pages are not pinned. + */ +static ssize_t smb_extract_kvec_to_rdma(struct iov_iter *iter, + struct smb_extract_to_rdma *rdma, + ssize_t maxsize) +{ + const struct kvec *kv = iter->kvec; + unsigned long start = iter->iov_offset; + unsigned int i, sge_max = rdma->max_sge; + ssize_t ret = 0; + + for (i = 0; i < iter->nr_segs; i++) { + struct page *page; + unsigned long kaddr; + size_t off, len, seg; + + len = kv[i].iov_len; + if (start >= len) { + start -= len; + continue; + } + + kaddr = (unsigned long)kv[i].iov_base + start; + off = kaddr & ~PAGE_MASK; + len = min_t(size_t, maxsize, len - start); + kaddr &= PAGE_MASK; + + maxsize -= len; + ret += len; + do { + seg = min_t(size_t, len, PAGE_SIZE - off); + + if (is_vmalloc_or_module_addr((void *)kaddr)) + page = vmalloc_to_page((void *)kaddr); + else + page = virt_to_page(kaddr); + + if (!smb_set_sge(rdma, page, off, len)) + return -EIO; + sge_max--; + + len -= seg; + kaddr += PAGE_SIZE; + off = 0; + } while (len > 0 && sge_max > 0); + + if (maxsize <= 0 || sge_max == 0) + break; + start = 0; + } + + return ret; +} + +/* + * Extract folio fragments from an XARRAY-class iterator and add them to an + * RDMA list. The folios are not pinned. + */ +static ssize_t smb_extract_xarray_to_rdma(struct iov_iter *iter, + struct smb_extract_to_rdma *rdma, + ssize_t maxsize) +{ + struct xarray *xa = iter->xarray; + struct folio *folio; + unsigned int sge_max = rdma->max_sge; + loff_t start = iter->xarray_start + iter->iov_offset; + pgoff_t index = start / PAGE_SIZE; + ssize_t ret; + size_t off, len; + XA_STATE(xas, xa, index); + + rcu_read_lock(); + + xas_for_each(&xas, folio, ULONG_MAX) { + if (xas_retry(&xas, folio)) + continue; + if (WARN_ON(xa_is_value(folio))) + break; + if (WARN_ON(folio_test_hugetlb(folio))) + break; + + off = offset_in_folio(folio, start); + len = min_t(size_t, maxsize, folio_size(folio) - off); + + if (!smb_set_sge(rdma, folio_page(folio, 0), off, len)) { + rcu_read_lock(); + return -EIO; + } + sge_max--; + + maxsize -= len; + ret += len; + if (maxsize <= 0 || sge_max == 0) + break; + } + + rcu_read_unlock(); + return ret; +} + +/* + * Extract page fragments from up to the given amount of the source iterator + * and build up an RDMA list that refers to all of those bits. The RDMA list + * is appended to, up to the maximum number of elements set in the parameter + * block. + * + * The extracted page fragments are not pinned or ref'd in any way; if an + * IOVEC/UBUF-type iterator is to be used, it should be converted to a + * BVEC-type iterator and the pages pinned, ref'd or otherwise held in some + * way. + */ +static ssize_t smb_extract_iter_to_rdma(struct iov_iter *iter, size_t len, + struct smb_extract_to_rdma *rdma) +{ + ssize_t ret; + int before = rdma->nr_sge; + + if (iov_iter_is_discard(iter) || + iov_iter_is_pipe(iter) || + user_backed_iter(iter)) { + WARN_ON_ONCE(1); + return -EIO; + } + + switch (iov_iter_type(iter)) { + case ITER_BVEC: + ret = smb_extract_bvec_to_rdma(iter, rdma, len); + break; + case ITER_KVEC: + ret = smb_extract_kvec_to_rdma(iter, rdma, len); + break; + case ITER_XARRAY: + ret = smb_extract_xarray_to_rdma(iter, rdma, len); + break; + default: + BUG(); + } + + if (ret > 0) { + iov_iter_advance(iter, ret); + } else if (ret < 0) { + while (rdma->nr_sge > before) { + struct ib_sge *sge = &rdma->sge[rdma->nr_sge--]; + + ib_dma_unmap_single(rdma->device, sge->addr, sge->length, + rdma->direction); + sge->addr = 0; + } + } + + return ret; +} From patchwork Tue Nov 1 16:32:05 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13027223 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 8A604C43217 for ; Tue, 1 Nov 2022 16:35:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230100AbiKAQfA (ORCPT ); Tue, 1 Nov 2022 12:35:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35562 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231313AbiKAQdz (ORCPT ); Tue, 1 Nov 2022 12:33:55 -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 023EB1D642 for ; Tue, 1 Nov 2022 09:32:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1667320329; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=6P7/llVoRVswYjqvNRXAGnL+tR0OiKnMSoeQk+0UX2U=; b=UZ6R0/gjoaeyf7N59Qlt5q2y4K/9i1tlBlzZyotErbv3f+VN4EDK0GXRnBc0zmDzCdkFz+ HGi1apM7BfDoCfugHmhJR8U67dJ48gxO1BPZuQQftCM7aMxmqXTJJoBuVCUnGbs/MCmyNy fwnLnQV+OH3S6SLPY4ZxJ5Sq4Arwt/U= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-436-g5JkT2nmMBmOLcb12MnIVg-1; Tue, 01 Nov 2022 12:32:08 -0400 X-MC-Unique: g5JkT2nmMBmOLcb12MnIVg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 64A58857D0E; Tue, 1 Nov 2022 16:32:07 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.73]) by smtp.corp.redhat.com (Postfix) with ESMTP id C17EB1121320; Tue, 1 Nov 2022 16:32:05 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [RFC PATCH 11/12] cifs: Build the RDMA SGE list directly from an iterator From: David Howells To: Steve French , Al Viro Cc: Steve French , Shyam Prasad N , Rohith Surabattula , Jeff Layton , linux-cifs@vger.kernel.org, linux-rdma@vger.kernel.org, dhowells@redhat.com, Shyam Prasad N , Rohith Surabattula , Tom Talpey , Christoph Hellwig , Matthew Wilcox , Jeff Layton , linux-cifs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Tue, 01 Nov 2022 16:32:05 +0000 Message-ID: <166732032518.3186319.1859601819981624629.stgit@warthog.procyon.org.uk> In-Reply-To: <166732024173.3186319.18204305072070871546.stgit@warthog.procyon.org.uk> References: <166732024173.3186319.18204305072070871546.stgit@warthog.procyon.org.uk> User-Agent: StGit/1.5 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org In the depths of the cifs RDMA code, extract part of an iov iterator directly into an SGE list without going through an intermediate scatterlist. Note that this doesn't support extraction from an IOBUF- or UBUF-type iterator (ie. user-supplied buffer). The assumption is that the higher layers will extract those to a BVEC-type iterator first and do whatever is required to stop the pages from going away. Signed-off-by: David Howells cc: Steve French cc: Shyam Prasad N cc: Rohith Surabattula cc: Jeff Layton cc: linux-cifs@vger.kernel.org cc: linux-rdma@vger.kernel.org --- fs/cifs/smbdirect.c | 89 ++++++++++++++++++--------------------------------- 1 file changed, 32 insertions(+), 57 deletions(-) diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c index 4ee4f040f3db..3f1f952a1e6b 100644 --- a/fs/cifs/smbdirect.c +++ b/fs/cifs/smbdirect.c @@ -828,16 +828,16 @@ static int smbd_post_send(struct smbd_connection *info, return rc; } -static int smbd_post_send_sgl(struct smbd_connection *info, - struct scatterlist *sgl, int data_length, int remaining_data_length) +static int smbd_post_send_iter(struct smbd_connection *info, + struct iov_iter *iter, + int *_remaining_data_length) { - int num_sgs; int i, rc; int header_length; + int data_length; struct smbd_request *request; struct smbd_data_transfer *packet; int new_credits; - struct scatterlist *sg; wait_credit: /* Wait for send credits. A SMBD packet needs one credit */ @@ -881,6 +881,30 @@ static int smbd_post_send_sgl(struct smbd_connection *info, } request->info = info; + memset(request->sge, 0, sizeof(request->sge)); + + /* Fill in the data payload to find out how much data we can add */ + if (iter) { + struct smb_extract_to_rdma extract = { + .nr_sge = 1, + .max_sge = SMBDIRECT_MAX_SEND_SGE, + .sge = request->sge, + .device = info->id->device, + .local_dma_lkey = info->pd->local_dma_lkey, + .direction = DMA_TO_DEVICE, + }; + + rc = smb_extract_iter_to_rdma(iter, *_remaining_data_length, + &extract); + if (rc < 0) + goto err_dma; + data_length = rc; + request->num_sge = extract.nr_sge; + *_remaining_data_length -= data_length; + } else { + data_length = 0; + request->num_sge = 1; + } /* Fill in the packet header */ packet = smbd_request_payload(request); @@ -902,7 +926,7 @@ static int smbd_post_send_sgl(struct smbd_connection *info, else packet->data_offset = cpu_to_le32(24); packet->data_length = cpu_to_le32(data_length); - packet->remaining_data_length = cpu_to_le32(remaining_data_length); + packet->remaining_data_length = cpu_to_le32(*_remaining_data_length); packet->padding = 0; log_outgoing(INFO, "credits_requested=%d credits_granted=%d data_offset=%d data_length=%d remaining_data_length=%d\n", @@ -918,7 +942,6 @@ static int smbd_post_send_sgl(struct smbd_connection *info, if (!data_length) header_length = offsetof(struct smbd_data_transfer, padding); - request->num_sge = 1; request->sge[0].addr = ib_dma_map_single(info->id->device, (void *)packet, header_length, @@ -932,23 +955,6 @@ static int smbd_post_send_sgl(struct smbd_connection *info, request->sge[0].length = header_length; request->sge[0].lkey = info->pd->local_dma_lkey; - /* Fill in the packet data payload */ - num_sgs = sgl ? sg_nents(sgl) : 0; - for_each_sg(sgl, sg, num_sgs, i) { - request->sge[i+1].addr = - ib_dma_map_page(info->id->device, sg_page(sg), - sg->offset, sg->length, DMA_TO_DEVICE); - if (ib_dma_mapping_error( - info->id->device, request->sge[i+1].addr)) { - rc = -EIO; - request->sge[i+1].addr = 0; - goto err_dma; - } - request->sge[i+1].length = sg->length; - request->sge[i+1].lkey = info->pd->local_dma_lkey; - request->num_sge++; - } - rc = smbd_post_send(info, request); if (!rc) return 0; @@ -987,8 +993,10 @@ static int smbd_post_send_sgl(struct smbd_connection *info, */ static int smbd_post_send_empty(struct smbd_connection *info) { + int remaining_data_length = 0; + info->count_send_empty++; - return smbd_post_send_sgl(info, NULL, 0, 0); + return smbd_post_send_iter(info, NULL, &remaining_data_length); } /* @@ -1932,39 +1940,6 @@ int smbd_recv(struct smbd_connection *info, struct msghdr *msg) return rc; } -/* - * Send the contents of an iterator - * @iter: The iterator to send - * @_remaining_data_length: remaining data to send in this payload - */ -static int smbd_post_send_iter(struct smbd_connection *info, - struct iov_iter *iter, - int *_remaining_data_length) -{ - struct scatterlist sgl[SMBDIRECT_MAX_SEND_SGE - 1]; - unsigned int max_payload = info->max_send_size - sizeof(struct smbd_data_transfer); - ssize_t rc; - - do { - struct sg_table sgtable = { .sgl = sgl }; - size_t maxlen = min_t(size_t, *_remaining_data_length, max_payload); - - sg_init_table(sgtable.sgl, ARRAY_SIZE(sgl)); - rc = netfs_extract_iter_to_sg(iter, maxlen, - &sgtable, ARRAY_SIZE(sgl)); - if (rc < 0) - break; - if (WARN_ON_ONCE(sgtable.nents == 0)) - return -EIO; - - sg_mark_end(&sgl[sgtable.nents - 1]); - *_remaining_data_length -= rc; - rc = smbd_post_send_sgl(info, sgl, rc, *_remaining_data_length); - } while (rc == 0 && iov_iter_count(iter) > 0); - - return rc; -} - /* * Send data to transport * Each rqst is transported as a SMBDirect payload