From patchwork Thu Jan 26 14:16:26 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13117199 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8E7CC61D97 for ; Thu, 26 Jan 2023 14:17:03 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 78F276B0080; Thu, 26 Jan 2023 09:17:03 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 73E426B0081; Thu, 26 Jan 2023 09:17:03 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 606DB8E0001; Thu, 26 Jan 2023 09:17:03 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 518156B0080 for ; Thu, 26 Jan 2023 09:17:03 -0500 (EST) Received: from smtpin06.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 22448AB462 for ; Thu, 26 Jan 2023 14:17:03 +0000 (UTC) X-FDA: 80397151926.06.F7739EC Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf14.hostedemail.com (Postfix) with ESMTP id 534CA100017 for ; Thu, 26 Jan 2023 14:17:01 +0000 (UTC) Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=RO2vMiL3; spf=pass (imf14.hostedemail.com: domain of dhowells@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=dhowells@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1674742621; a=rsa-sha256; cv=none; b=VeoB77kBv4keMXGVR/Iw8R7ocCfgmV4ynO5QeOmel21SRXlV0Kr0NzuyM8obFF2BLMUbkS gC0coEFZeMm6C2CiEkoJN27KSVJ4QhF9jyibrfLZwXPOgoGRD7eJKHNDZbkefDWjXMpw8u UBv0qEvfQdKC2TAdXY81aOBSP3GcoNw= ARC-Authentication-Results: i=1; imf14.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=RO2vMiL3; spf=pass (imf14.hostedemail.com: domain of dhowells@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=dhowells@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1674742621; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=7RYncx3d2QCFno76YxQ26A3gARIW2WsBk/g5n5z32ew=; b=dIBDv8sHwAgT3F6AFYPvy43qfCXPFvcg30mZS/08xd8/OEzL7iLvdE4beBb2QZ1LiVmRSS aAzvVMB9nx3L9G9yOLjHs1zPe1er3g5jwC2nAlNnQPDxra9O+7ItXN9AwuqgpmROZYNUuN +hchkzFh8iAlW+qiW1cmmmj4X44JnoE= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1674742620; 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=7RYncx3d2QCFno76YxQ26A3gARIW2WsBk/g5n5z32ew=; b=RO2vMiL3XB5fy5j06VapbtYiaTUQ8ADrEQozUND+3v1ZQhXNEKvnhA64hLZ+0Zd94T6V1Q zxiU5QId4ZoVS8fjnt7qbWEN5awHb2tQQEZZrTRD5oSvK/0DCG+2b1cdoRGpC/5NzHiGv4 lmKUhkp533ELlV2tQ4O0ukw1XsRL7tk= 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-567-vMncZTdFMO2Ma3wz53HZSA-1; Thu, 26 Jan 2023 09:16:56 -0500 X-MC-Unique: vMncZTdFMO2Ma3wz53HZSA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 6072B886C60; Thu, 26 Jan 2023 14:16:55 +0000 (UTC) Received: from warthog.procyon.org.uk.com (unknown [10.33.36.97]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5BCAA2166B26; Thu, 26 Jan 2023 14:16:53 +0000 (UTC) From: David Howells To: Al Viro , Christoph Hellwig Cc: David Howells , Matthew Wilcox , Jens Axboe , Jan Kara , Jeff Layton , David Hildenbrand , Jason Gunthorpe , Logan Gunthorpe , 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 v11 8/8] block: convert bio_map_user_iov to use iov_iter_extract_pages Date: Thu, 26 Jan 2023 14:16:26 +0000 Message-Id: <20230126141626.2809643-9-dhowells@redhat.com> In-Reply-To: <20230126141626.2809643-1-dhowells@redhat.com> References: <20230126141626.2809643-1-dhowells@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 X-Rspam-User: X-Rspamd-Queue-Id: 534CA100017 X-Rspamd-Server: rspam01 X-Stat-Signature: shhf7k6mu5m3ebro3bsw9u71bp747jez X-HE-Tag: 1674742621-543314 X-HE-Meta: U2FsdGVkX1/46B5G7bdpCLUZtS5eWjgyvd3nrkFzP4oz+bL/ZldS+OvUVAlwXrK/FmXQLbIRh55s0msyZenUIIBAn8hOO4attY8YoXPRiTNZHegHgTCLTaXVJC81guRl6c75kq2pYJpOoOSLlDJOfjeAQgxM9ztBnl7qy8lYXzakJEe6thdsgxxywL2YnykEGouEUag3AMwFkNlvJEs2eK5+I7WuN0uVmjQmcy4K7AxHgDT3IgL5p9XNVuCTFyV5c3Myra+zB3d3Nycjbg/hPF0poqo5Xtl5LsjMsg0rNCUYd1f0AKIkmFHwOc9ARplsJEurp5akWsaMLjqJao1wNEnAQIDqVMVMCEWY2cZMUR+fCtUOvO8nuAGv7SWnrrrNdVVhIiaiGx+p/t3HAAnaj2IE81jibSjiC6usrCk5GFNacq6JLAnVLb7oUy7ov7bIIeZiSw3Tu6olsuO2HaLhA1WQ3A4/e3H4ccZBtsFZ1E/un3Y4JM7bggIeaiZrH+JL0RXVnv/fG0iOfBvVSjLjJGLd8ePf6UEH7UWM9WKvmmNGEzehbwVY+toWXeBALXMVNhYhQ8bMdiMs7NcU747wXaK8VJHNOwc2iaTkkM0r7rk5I6clpbDPbm0p1vBIZAl7YHF7rYymhf8/EpvVVu97fri/izb1c3vMoOhdNRK/3C3f6Pp9nC8VynPbDvaYJLcJcjliSn2vXWaX1uUkY5XkdJVvUg2UZf1kiW2zpsY5E9e0a0qBo6coys3kYM1gy+MQPIwwX7m/xuowlFTzyoDqtA+90Bd/hXObbdIo787Jl/Af878zU6Ujczqa6/bRZCLD6rm3E2F5x1rdGkm7waKigJBOmYdRnIXiUr0N8nKgD38PDeYnX+N0uCJsbvCMt8ItXD+BEwF0x5lPfwRsuGheit0s4VcAGRUIB8v+5sDyRBgIOxp5/JvfOvgxWoYe1LS8ET1Y6dCOu+QzRwUtTko S4kYeF0u 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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 visible to/affected by 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/blk-map.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-) diff --git a/block/blk-map.c b/block/blk-map.c index f1f70b50388d..0f1593e144da 100644 --- a/block/blk-map.c +++ b/block/blk-map.c @@ -281,22 +281,21 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter, if (blk_queue_pci_p2pdma(rq->q)) extraction_flags |= ITER_ALLOW_P2PDMA; + if (iov_iter_extract_will_pin(iter)) + bio_set_flag(bio, BIO_PAGE_PINNED); - bio_set_flag(bio, BIO_PAGE_REFFED); while (iov_iter_count(iter)) { - struct page **pages, *stack_pages[UIO_FASTIOV]; + struct page *stack_pages[UIO_FASTIOV]; + struct page **pages = stack_pages; ssize_t bytes; size_t offs; int npages; - if (nr_vecs <= ARRAY_SIZE(stack_pages)) { - pages = stack_pages; - bytes = iov_iter_get_pages(iter, pages, LONG_MAX, - nr_vecs, &offs, extraction_flags); - } else { - bytes = iov_iter_get_pages_alloc(iter, &pages, - LONG_MAX, &offs, extraction_flags); - } + if (nr_vecs > ARRAY_SIZE(stack_pages)) + pages = NULL; + + bytes = iov_iter_extract_pages(iter, &pages, LONG_MAX, + nr_vecs, extraction_flags, &offs); if (unlikely(bytes <= 0)) { ret = bytes ? bytes : -EFAULT; goto out_unmap; @@ -318,7 +317,7 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter, if (!bio_add_hw_page(rq->q, bio, page, n, offs, max_sectors, &same_page)) { if (same_page) - put_page(page); + bio_release_page(bio, page); break; } @@ -330,7 +329,7 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter, * release the pages we didn't map into the bio, if any */ while (j < npages) - put_page(pages[j++]); + bio_release_page(bio, pages[j++]); if (pages != stack_pages) kvfree(pages); /* couldn't stuff something into bio? */