From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 40D95C43603 for ; Tue, 10 Dec 2019 16:25:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id EC9FC2073B for ; Tue, 10 Dec 2019 16:25:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="eQQkP4Qn" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EC9FC2073B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C71336B2D3C; Tue, 10 Dec 2019 11:25:05 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id BFB076B2D3D; Tue, 10 Dec 2019 11:25:05 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B0F9B6B2D3E; Tue, 10 Dec 2019 11:25:05 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0146.hostedemail.com [216.40.44.146]) by kanga.kvack.org (Postfix) with ESMTP id 9C30B6B2D3C for ; Tue, 10 Dec 2019 11:25:05 -0500 (EST) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id 561C652A3 for ; Tue, 10 Dec 2019 16:25:05 +0000 (UTC) X-FDA: 76249756170.12.crow16_f48207f4bf29 X-HE-Tag: crow16_f48207f4bf29 X-Filterd-Recvd-Size: 8236 Received: from mail-il1-f194.google.com (mail-il1-f194.google.com [209.85.166.194]) by imf19.hostedemail.com (Postfix) with ESMTP for ; Tue, 10 Dec 2019 16:25:04 +0000 (UTC) Received: by mail-il1-f194.google.com with SMTP id r81so16682081ilk.0 for ; Tue, 10 Dec 2019 08:25:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=c6xGL0+Pvg+YsVb4S081GX/xoxEhKO3Eq64Kq716fjY=; b=eQQkP4QniithxoS/TSUmlbKRATm/UWwPjKu5OwiUIOCJnp7KCYci+TRhGXB2cQgZHU vHFvXlmoWh1qn7u+pFpAtwDxLp41TidswikH0e6NbtPVWF29qmIQ3bdsEWqXZPZmIR9Z 6gY4C4Rasj5MSB0KWqLtkVkQSIkuBLs++jKv9q0NmceTz08mPxux8e8dfYP3hE7jkQdD q6U/WDMVmItC5Vvi0A3vdrBcdTdTCtY0d8UoKfyKioyzQdB3d68aBCRrzFpgwT5qs3k6 kgD/FAXk3Ij9DJsVFyjkMVDgc80SniX11+vaw8WiF+SqbnwSBW41klh453qhmAf+Q5r1 CQ4A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=c6xGL0+Pvg+YsVb4S081GX/xoxEhKO3Eq64Kq716fjY=; b=DnOm2TGovEfqyEUvci8aTnA27tKhlshZGvZFEBsT1JBu8YXrQonzyYQdRO/dYBmd2e KdMW7Ep4zosafX5faD95S4Bc6MK4vu5K/f0qN4CPlHOe9TyADpEOKnT7TCJkbdBh/zgK 1alCV8C/hvnOwrlOFnNSuNrt5nF4xPbknA6aS9ZJi+Ta11vTuCWFZ2+SeMgg2cOUUXzk Sqlb5BUPd5i7ElUrbu5SRx+M1OHyg+IEcRphqzQi8wz6VlpLp8DvK7iBCYlB3mxhg4OE rEIN33YA/0gUpBr0Rkm77isUk3uxehtZouYvxp9gadtL/o9hSGAyLUI+54PxKE+C4YGb /+qA== X-Gm-Message-State: APjAAAVi/A7qAEL6M/hzxv6vvRiRo+e6KM5QfhYAli9FBeWC67AiNt5F rPku1fgNWs+u6DH9MebqOHMR3whNfDDp3Q== X-Google-Smtp-Source: APXvYqwqBizrk9IOVrpYwJOag6Se2wpP/F4l2DgMAcpgdzdYcJmV/WSCppXecARpMQ2a9wTOWWefmA== X-Received: by 2002:a92:3d49:: with SMTP id k70mr33109866ila.246.1575995103774; Tue, 10 Dec 2019 08:25:03 -0800 (PST) Received: from x1.thefacebook.com ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id y11sm791174iol.23.2019.12.10.08.25.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 10 Dec 2019 08:25:03 -0800 (PST) From: Jens Axboe To: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org Cc: Jens Axboe Subject: [PATCH 5/5] iomap: support RWF_UNCACHED for buffered writes Date: Tue, 10 Dec 2019 09:24:54 -0700 Message-Id: <20191210162454.8608-6-axboe@kernel.dk> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191210162454.8608-1-axboe@kernel.dk> References: <20191210162454.8608-1-axboe@kernel.dk> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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 adds support for RWF_UNCACHED for file systems using iomap to perform buffered writes. We use the generic infrastructure for this, by tracking pages we created and calling write_drop_cached_pages() to issue writeback and prune those pages. Signed-off-by: Jens Axboe --- fs/iomap/buffered-io.c | 58 ++++++++++++++++++++++++++++++++++-------- include/linux/iomap.h | 1 + 2 files changed, 49 insertions(+), 10 deletions(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 9b5b770ca4c7..c8d36b280ff2 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -566,6 +566,7 @@ EXPORT_SYMBOL_GPL(iomap_migrate_page); =20 enum { IOMAP_WRITE_F_UNSHARE =3D (1 << 0), + IOMAP_WRITE_F_UNCACHED =3D (1 << 1), }; =20 static void @@ -643,6 +644,7 @@ iomap_write_begin(struct inode *inode, loff_t pos, un= signed len, unsigned flags, struct page **pagep, struct iomap *iomap, struct iomap *srcmap) { const struct iomap_page_ops *page_ops =3D iomap->page_ops; + unsigned aop_flags; struct page *page; int status =3D 0; =20 @@ -659,8 +661,11 @@ iomap_write_begin(struct inode *inode, loff_t pos, u= nsigned len, unsigned flags, return status; } =20 + aop_flags =3D AOP_FLAG_NOFS; + if (flags & IOMAP_UNCACHED) + aop_flags |=3D AOP_FLAG_UNCACHED; page =3D grab_cache_page_write_begin(inode->i_mapping, pos >> PAGE_SHIF= T, - AOP_FLAG_NOFS); + aop_flags); if (!page) { status =3D -ENOMEM; goto out_no_page; @@ -670,9 +675,14 @@ iomap_write_begin(struct inode *inode, loff_t pos, u= nsigned len, unsigned flags, iomap_read_inline_data(inode, page, srcmap); else if (iomap->flags & IOMAP_F_BUFFER_HEAD) status =3D __block_write_begin_int(page, pos, len, NULL, srcmap); - else - status =3D __iomap_write_begin(inode, pos, len, flags, page, + else { + unsigned wb_flags =3D 0; + + if (flags & IOMAP_UNCACHED) + wb_flags =3D IOMAP_WRITE_F_UNCACHED; + status =3D __iomap_write_begin(inode, pos, len, wb_flags, page, srcmap); + } =20 if (unlikely(status)) goto out_unlock; @@ -796,19 +806,25 @@ iomap_write_end(struct inode *inode, loff_t pos, un= signed len, unsigned copied, return ret; } =20 +#define GPW_PAGE_BATCH 16 + static loff_t iomap_write_actor(struct inode *inode, loff_t pos, loff_t length, void *= data, unsigned flags, struct iomap *iomap, struct iomap *srcmap) { + struct address_space *mapping =3D inode->i_mapping; + struct page *drop_pages[GPW_PAGE_BATCH]; struct iov_iter *i =3D data; long status =3D 0; ssize_t written =3D 0; + unsigned drop_nr =3D 0; =20 do { struct page *page; unsigned long offset; /* Offset into pagecache page */ unsigned long bytes; /* Bytes to write to page */ size_t copied; /* Bytes copied from user */ + bool drop_page =3D false; /* drop page after IO */ =20 offset =3D offset_in_page(pos); bytes =3D min_t(unsigned long, PAGE_SIZE - offset, @@ -832,10 +848,17 @@ iomap_write_actor(struct inode *inode, loff_t pos, = loff_t length, void *data, break; } =20 - status =3D iomap_write_begin(inode, pos, bytes, 0, &page, iomap, - srcmap); - if (unlikely(status)) +retry: + status =3D iomap_write_begin(inode, pos, bytes, flags, &page, + iomap, srcmap); + if (unlikely(status)) { + if (status =3D=3D -ENOMEM && (flags & IOMAP_UNCACHED)) { + drop_page =3D true; + flags &=3D ~IOMAP_UNCACHED; + goto retry; + } break; + } =20 if (mapping_writably_mapped(inode->i_mapping)) flush_dcache_page(page); @@ -866,13 +889,24 @@ iomap_write_actor(struct inode *inode, loff_t pos, = loff_t length, void *data, iov_iter_single_seg_count(i)); goto again; } + + if (drop_page && + ((pos >> PAGE_SHIFT) !=3D ((pos + copied) >> PAGE_SHIFT))) { + drop_pages[drop_nr] =3D page; + if (++drop_nr =3D=3D GPW_PAGE_BATCH) + write_drop_cached_pages(drop_pages, mapping, + &drop_nr); + } else + balance_dirty_pages_ratelimited(inode->i_mapping); + pos +=3D copied; written +=3D copied; length -=3D copied; - - balance_dirty_pages_ratelimited(inode->i_mapping); } while (iov_iter_count(i) && length); =20 + if (drop_nr) + write_drop_cached_pages(drop_pages, mapping, &drop_nr); + return written ? written : status; } =20 @@ -882,10 +916,14 @@ iomap_file_buffered_write(struct kiocb *iocb, struc= t iov_iter *iter, { struct inode *inode =3D iocb->ki_filp->f_mapping->host; loff_t pos =3D iocb->ki_pos, ret =3D 0, written =3D 0; + unsigned flags =3D IOMAP_WRITE; + + if (iocb->ki_flags & IOCB_UNCACHED) + flags |=3D IOMAP_UNCACHED; =20 while (iov_iter_count(iter)) { - ret =3D iomap_apply(inode, pos, iov_iter_count(iter), - IOMAP_WRITE, ops, iter, iomap_write_actor); + ret =3D iomap_apply(inode, pos, iov_iter_count(iter), flags, + ops, iter, iomap_write_actor); if (ret <=3D 0) break; pos +=3D ret; diff --git a/include/linux/iomap.h b/include/linux/iomap.h index 61fcaa3904d4..833dd43507ac 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -121,6 +121,7 @@ struct iomap_page_ops { #define IOMAP_FAULT (1 << 3) /* mapping for page fault */ #define IOMAP_DIRECT (1 << 4) /* direct I/O */ #define IOMAP_NOWAIT (1 << 5) /* do not block */ +#define IOMAP_UNCACHED (1 << 6) =20 struct iomap_ops { /* --=20 2.24.0