From patchwork Thu Feb 16 21:47:32 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13144048 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 B3A96C61DA4 for ; Thu, 16 Feb 2023 21:49:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230252AbjBPVtd (ORCPT ); Thu, 16 Feb 2023 16:49:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36352 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230152AbjBPVtX (ORCPT ); Thu, 16 Feb 2023 16:49:23 -0500 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 EE47C46144 for ; Thu, 16 Feb 2023 13:48:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1676584105; 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=XQdifRk6LoRlY8bBJqWjSiNz8KoUNxlUmZ1XJ6Y/O6c=; b=fLJiXt7BJTbwHvwH7sfyKzWmDGLOi0gbj66BY7I+XlQBn36EHA8IakyNP2b1jKsiIb2fDh zComy44VMMOsIk7iYSG5Akyejk9YhKo9R46YwmSitgyOtqklSzAcfOQSs2ZD5Ql+tLpgKI HtFtKikHCRJnACfXGC3ST579gsRGQmk= 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-558-TZxIysogMpWNukeCTYhZIA-1; Thu, 16 Feb 2023 16:48:19 -0500 X-MC-Unique: TZxIysogMpWNukeCTYhZIA-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 0DF2F3C10146; Thu, 16 Feb 2023 21:48:19 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.24]) by smtp.corp.redhat.com (Postfix) with ESMTP id D6ECD1121314; Thu, 16 Feb 2023 21:48:16 +0000 (UTC) From: David Howells To: Steve French Cc: David Howells , Jens Axboe , Al Viro , Shyam Prasad N , Rohith Surabattula , Tom Talpey , Stefan Metzmacher , Christoph Hellwig , Matthew Wilcox , Jeff Layton , linux-cifs@vger.kernel.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Christoph Hellwig , John Hubbard , Logan Gunthorpe Subject: [PATCH 04/17] iov_iter: Define flags to qualify page extraction. Date: Thu, 16 Feb 2023 21:47:32 +0000 Message-Id: <20230216214745.3985496-5-dhowells@redhat.com> In-Reply-To: <20230216214745.3985496-1-dhowells@redhat.com> References: <20230216214745.3985496-1-dhowells@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org Define flags to qualify page extraction to pass into iov_iter_*_pages*() rather than passing in FOLL_* flags. For now only a flag to allow peer-to-peer DMA is supported. Signed-off-by: David Howells Reviewed-by: Christoph Hellwig Reviewed-by: John Hubbard Reviewed-by: Jens Axboe cc: Al Viro cc: Logan Gunthorpe cc: linux-fsdevel@vger.kernel.org cc: linux-block@vger.kernel.org --- block/bio.c | 6 +++--- block/blk-map.c | 8 ++++---- include/linux/uio.h | 10 ++++++++-- lib/iov_iter.c | 14 ++++++++------ 4 files changed, 23 insertions(+), 15 deletions(-) diff --git a/block/bio.c b/block/bio.c index ab59a491a883..b97f3991c904 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1245,11 +1245,11 @@ static int bio_iov_add_zone_append_page(struct bio *bio, struct page *page, */ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) { + iov_iter_extraction_t extraction_flags = 0; unsigned short nr_pages = bio->bi_max_vecs - bio->bi_vcnt; unsigned short entries_left = bio->bi_max_vecs - bio->bi_vcnt; struct bio_vec *bv = bio->bi_io_vec + bio->bi_vcnt; struct page **pages = (struct page **)bv; - unsigned int gup_flags = 0; ssize_t size, left; unsigned len, i = 0; size_t offset, trim; @@ -1264,7 +1264,7 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) pages += entries_left * (PAGE_PTRS_PER_BVEC - 1); if (bio->bi_bdev && blk_queue_pci_p2pdma(bio->bi_bdev->bd_disk->queue)) - gup_flags |= FOLL_PCI_P2PDMA; + extraction_flags |= ITER_ALLOW_P2PDMA; /* * Each segment in the iov is required to be a block size multiple. @@ -1275,7 +1275,7 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) */ size = iov_iter_get_pages(iter, pages, UINT_MAX - bio->bi_iter.bi_size, - nr_pages, &offset, gup_flags); + nr_pages, &offset, extraction_flags); if (unlikely(size <= 0)) return size ? size : -EFAULT; diff --git a/block/blk-map.c b/block/blk-map.c index 19940c978c73..080dd60485be 100644 --- a/block/blk-map.c +++ b/block/blk-map.c @@ -265,9 +265,9 @@ static struct bio *blk_rq_map_bio_alloc(struct request *rq, static int bio_map_user_iov(struct request *rq, struct iov_iter *iter, gfp_t gfp_mask) { + iov_iter_extraction_t extraction_flags = 0; unsigned int max_sectors = queue_max_hw_sectors(rq->q); unsigned int nr_vecs = iov_iter_npages(iter, BIO_MAX_VECS); - unsigned int gup_flags = 0; struct bio *bio; int ret; int j; @@ -280,7 +280,7 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter, return -ENOMEM; if (blk_queue_pci_p2pdma(rq->q)) - gup_flags |= FOLL_PCI_P2PDMA; + extraction_flags |= ITER_ALLOW_P2PDMA; while (iov_iter_count(iter)) { struct page **pages, *stack_pages[UIO_FASTIOV]; @@ -291,10 +291,10 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter, if (nr_vecs <= ARRAY_SIZE(stack_pages)) { pages = stack_pages; bytes = iov_iter_get_pages(iter, pages, LONG_MAX, - nr_vecs, &offs, gup_flags); + nr_vecs, &offs, extraction_flags); } else { bytes = iov_iter_get_pages_alloc(iter, &pages, - LONG_MAX, &offs, gup_flags); + LONG_MAX, &offs, extraction_flags); } if (unlikely(bytes <= 0)) { ret = bytes ? bytes : -EFAULT; diff --git a/include/linux/uio.h b/include/linux/uio.h index 9f158238edba..eec6ed8a627a 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -13,6 +13,8 @@ struct page; struct pipe_inode_info; +typedef unsigned int __bitwise iov_iter_extraction_t; + struct kvec { void *iov_base; /* and that should *never* hold a userland pointer */ size_t iov_len; @@ -252,12 +254,12 @@ void iov_iter_xarray(struct iov_iter *i, unsigned int direction, struct xarray * loff_t start, size_t count); ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages, size_t maxsize, unsigned maxpages, size_t *start, - unsigned gup_flags); + iov_iter_extraction_t extraction_flags); ssize_t iov_iter_get_pages2(struct iov_iter *i, struct page **pages, size_t maxsize, unsigned maxpages, size_t *start); ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages, size_t maxsize, size_t *start, - unsigned gup_flags); + iov_iter_extraction_t extraction_flags); ssize_t iov_iter_get_pages_alloc2(struct iov_iter *i, struct page ***pages, size_t maxsize, size_t *start); int iov_iter_npages(const struct iov_iter *i, int maxpages); @@ -360,4 +362,8 @@ static inline void iov_iter_ubuf(struct iov_iter *i, unsigned int direction, }; } +/* Flags for iov_iter_get/extract_pages*() */ +/* Allow P2PDMA on the extracted pages */ +#define ITER_ALLOW_P2PDMA ((__force iov_iter_extraction_t)0x01) + #endif diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 47c484551c59..9d4949ea9b27 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1426,9 +1426,9 @@ static struct page *first_bvec_segment(const struct iov_iter *i, static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages, size_t maxsize, unsigned int maxpages, size_t *start, - unsigned int gup_flags) + iov_iter_extraction_t extraction_flags) { - unsigned int n; + unsigned int n, gup_flags = 0; if (maxsize > i->count) maxsize = i->count; @@ -1436,6 +1436,8 @@ static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i, return 0; if (maxsize > MAX_RW_COUNT) maxsize = MAX_RW_COUNT; + if (extraction_flags & ITER_ALLOW_P2PDMA) + gup_flags |= FOLL_PCI_P2PDMA; if (likely(user_backed_iter(i))) { unsigned long addr; @@ -1489,14 +1491,14 @@ static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i, ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages, size_t maxsize, unsigned maxpages, - size_t *start, unsigned gup_flags) + size_t *start, iov_iter_extraction_t extraction_flags) { if (!maxpages) return 0; BUG_ON(!pages); return __iov_iter_get_pages_alloc(i, &pages, maxsize, maxpages, - start, gup_flags); + start, extraction_flags); } EXPORT_SYMBOL_GPL(iov_iter_get_pages); @@ -1509,14 +1511,14 @@ EXPORT_SYMBOL(iov_iter_get_pages2); ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages, size_t maxsize, - size_t *start, unsigned gup_flags) + size_t *start, iov_iter_extraction_t extraction_flags) { ssize_t len; *pages = NULL; len = __iov_iter_get_pages_alloc(i, pages, maxsize, ~0U, start, - gup_flags); + extraction_flags); if (len <= 0) { kvfree(*pages); *pages = NULL;