From patchwork Thu Feb 9 10:29:53 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 54853 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:adf:eb09:0:0:0:0:0 with SMTP id s9csp256251wrn; Thu, 9 Feb 2023 02:35:22 -0800 (PST) X-Google-Smtp-Source: AK7set9iL8HtNawsOkIu6ffBUmdQ/kN92P3TKKGYTdXCh/fAne3ioOGcsi4G0gi26V3gIlCo4WFN X-Received: by 2002:a05:6a20:669e:b0:be:ea27:3c24 with SMTP id o30-20020a056a20669e00b000beea273c24mr10361793pzh.41.1675938922455; Thu, 09 Feb 2023 02:35:22 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1675938922; cv=none; d=google.com; s=arc-20160816; b=VaXvKJptZveuE5p4ocOhMiz5dss5OXV7Lvrbob8CIRlQXMIuFKjxq2amz/cahjfl/V ZMKvA9gQZpK9bNBRBxUbmc/tJ054V9jHvLn5j5JMm9VHuFpFGHzyVW5+HihMbf/CCj9s Vly0kQn9BFRUaOigl+SDK/6IfBngLx4QjXWQm/zxkgYoGiz0NMhB4F0bgVd1pi2Q3h4r +GCqUuoB1b0WWQAhX1wk4h95I3pVFvcAldFjWZw/DbsAjpHxmlcgvQIPsNnQi3lWB/Xh JFWp5tKLiW3qcwdCdvufvq+2PFXpu3IVK1/mesDXgdFL9hLSIKleMKW5v/q6qufNZBIr J0Kg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=YX3eOMnEnHmNO2fsUm7QGJ9rpDZ86GbDPShQEUjns7k=; b=FBZftgWvZ6jFwUBG8wZOUvq4J3iRTf1GJXP1Arzl3DqR4/mWTwdpdb3uIFehL/QNLA i0seVjyWabAuH993/Dk0sNRkgkA46sm+v+DugsY4hCsSDXLA4Ot/L+kX/mbRbMa/HNH4 somMMycJeJ8HaTBsD1vmPP2aOQJtX5cH1CepUpM92bCYV7I0elPE4IUEdsjlc17jx1YK Vmo44O1XDAdkrva8/ESdFPR4smeK3mYLJ3yypSbal/ycHyFGIwTm8zxsEEGyE6UKZWLR 370iB8vtNMi0YLCvwDy/7qeJvAops9tb1zLlHdc6cGvdBGXVlcAZu1pT9Fw+k8BSPtM+ uJnQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=UwNpya8K; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id n25-20020a637219000000b004e493d57bd3si1473751pgc.543.2023.02.09.02.35.09; Thu, 09 Feb 2023 02:35:22 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=UwNpya8K; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230002AbjBIKdt (ORCPT + 99 others); Thu, 9 Feb 2023 05:33:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52020 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229689AbjBIKc3 (ORCPT ); Thu, 9 Feb 2023 05:32:29 -0500 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 2995934C2E for ; Thu, 9 Feb 2023 02:30:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1675938635; 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=YX3eOMnEnHmNO2fsUm7QGJ9rpDZ86GbDPShQEUjns7k=; b=UwNpya8KEL5/ZFtVj1/3+5HoUmubVFIlb1nudzrivlPHIV9Oki1Ym9CSOsy74+xP7lMclo d0pWgHa1YH90mc9lj/JGRplCK9xFPAq2ZPuL/hdvHZAUWCOKNw9/2GU8tDMr+gZxcIWMhh jgsKWwjeQw6C9atZWOZQtJxlNmTnZAI= 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-331-cAnVFdLZOYyXeog1AF3Bew-1; Thu, 09 Feb 2023 05:30:30 -0500 X-MC-Unique: cAnVFdLZOYyXeog1AF3Bew-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 0FFD885D064; Thu, 9 Feb 2023 10:30:28 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.24]) by smtp.corp.redhat.com (Postfix) with ESMTP id 207EC1121315; Thu, 9 Feb 2023 10:30:26 +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 , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Christoph Hellwig , John Hubbard Subject: [PATCH v13 11/12] block: Convert bio_iov_iter_get_pages to use iov_iter_extract_pages Date: Thu, 9 Feb 2023 10:29:53 +0000 Message-Id: <20230209102954.528942-12-dhowells@redhat.com> In-Reply-To: <20230209102954.528942-1-dhowells@redhat.com> References: <20230209102954.528942-1-dhowells@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1757349331490429660?= X-GMAIL-MSGID: =?utf-8?q?1757349331490429660?= This will pin pages or leave them unaltered rather than getting a ref on them as appropriate to the iterator. The pages need to be pinned for DIO rather than having refs taken on them to prevent VM copy-on-write from malfunctioning during a concurrent fork() (the result of the I/O could otherwise end up being affected by/visible to the child process). Signed-off-by: David Howells Reviewed-by: Christoph Hellwig Reviewed-by: John Hubbard cc: Al Viro cc: Jens Axboe cc: Jan Kara cc: Matthew Wilcox cc: Logan Gunthorpe cc: linux-block@vger.kernel.org --- Notes: ver #10) - Drop bio_set_cleanup_mode(), open coding it instead. ver #8) - Split the patch up a bit [hch]. - We should only be using pinned/non-pinned pages and not ref'd pages, so adjust the comments appropriately. ver #7) - Don't treat BIO_PAGE_REFFED/PINNED as being the same as FOLL_GET/PIN. ver #5) - Transcribe the FOLL_* flags returned by iov_iter_extract_pages() to BIO_* flags and got rid of bi_cleanup_mode. - Replaced BIO_NO_PAGE_REF to BIO_PAGE_REFFED in the preceding patch. block/bio.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) diff --git a/block/bio.c b/block/bio.c index 547e38883934..fc57f0aa098e 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1212,7 +1212,7 @@ static int bio_iov_add_page(struct bio *bio, struct page *page, } if (same_page) - put_page(page); + bio_release_page(bio, page); return 0; } @@ -1226,7 +1226,7 @@ static int bio_iov_add_zone_append_page(struct bio *bio, struct page *page, queue_max_zone_append_sectors(q), &same_page) != len) return -EINVAL; if (same_page) - put_page(page); + bio_release_page(bio, page); return 0; } @@ -1237,10 +1237,10 @@ static int bio_iov_add_zone_append_page(struct bio *bio, struct page *page, * @bio: bio to add pages to * @iter: iov iterator describing the region to be mapped * - * Pins pages from *iter and appends them to @bio's bvec array. The - * pages will have to be released using put_page() when done. - * For multi-segment *iter, this function only adds pages from the - * next non-empty segment of the iov iterator. + * Extracts pages from *iter and appends them to @bio's bvec array. The pages + * will have to be cleaned up in the way indicated by the BIO_PAGE_PINNED flag. + * For a multi-segment *iter, this function only adds pages from the next + * non-empty segment of the iov iterator. */ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) { @@ -1272,9 +1272,9 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) * result to ensure the bio's total size is correct. The remainder of * the iov data will be picked up in the next bio iteration. */ - size = iov_iter_get_pages(iter, pages, - UINT_MAX - bio->bi_iter.bi_size, - nr_pages, &offset, extraction_flags); + size = iov_iter_extract_pages(iter, &pages, + UINT_MAX - bio->bi_iter.bi_size, + nr_pages, extraction_flags, &offset); if (unlikely(size <= 0)) return size ? size : -EFAULT; @@ -1307,7 +1307,7 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) iov_iter_revert(iter, left); out: while (i < nr_pages) - put_page(pages[i++]); + bio_release_page(bio, pages[i++]); return ret; } @@ -1342,7 +1342,8 @@ int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) return 0; } - bio_set_flag(bio, BIO_PAGE_REFFED); + if (iov_iter_extract_will_pin(iter)) + bio_set_flag(bio, BIO_PAGE_PINNED); do { ret = __bio_iov_iter_get_pages(bio, iter); } while (!ret && iov_iter_count(iter) && !bio_full(bio, 0));