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=-9.5 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,URIBL_BLOCKED,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 77D0DC2D0CA for ; Wed, 11 Dec 2019 15:29:59 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 317F124682 for ; Wed, 11 Dec 2019 15:29:59 +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="b7eZVja6" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 317F124682 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 A38986B329F; Wed, 11 Dec 2019 10:29:56 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 9E9896B32A0; Wed, 11 Dec 2019 10:29:56 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8D79A6B32A1; Wed, 11 Dec 2019 10:29:56 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0122.hostedemail.com [216.40.44.122]) by kanga.kvack.org (Postfix) with ESMTP id 7981E6B329F for ; Wed, 11 Dec 2019 10:29:56 -0500 (EST) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with SMTP id 10409180AD804 for ; Wed, 11 Dec 2019 15:29:56 +0000 (UTC) X-FDA: 76253245992.20.moon29_1c763500b6f5c X-HE-Tag: moon29_1c763500b6f5c X-Filterd-Recvd-Size: 6173 Received: from mail-pl1-f195.google.com (mail-pl1-f195.google.com [209.85.214.195]) by imf34.hostedemail.com (Postfix) with ESMTP for ; Wed, 11 Dec 2019 15:29:55 +0000 (UTC) Received: by mail-pl1-f195.google.com with SMTP id c23so1553820plz.4 for ; Wed, 11 Dec 2019 07:29:55 -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=es9BSJvoDpT3WZtR0L+ZV+Or+1xGCPbWn6QJpLr3Xx4=; b=b7eZVja6aKMDWQsCKiYnvs5qkkMtb4DoRhvZH0mwJvk9LESKsse6xmT3WWlILNTvSh v88npyxYy5/e7tLfGcgiIVXEYnv46FT50sPnEQt69UhDuyJOSuVNzLSlAXpUWTdkrJku nBpk9ZFk1qOaWPCwwhIIUbpQcT9k4a3aWUlDts7fPgZxFfbctK2wZluabjrrFqSzFkdb ugqNIWkF1i16/QrpWLX9gvSlMh+w4/NfxFGOtFaxQnCkEmSB/wopkF4l1CCYgv3FmwBY 8JMlN5D7vigbmAU/36SNoC65YkKfas3+j+3P0Mey+EpgI+uJdC4zZ8pPIn6ofe48cSq8 fYrw== 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=es9BSJvoDpT3WZtR0L+ZV+Or+1xGCPbWn6QJpLr3Xx4=; b=P7oQyUlX48ZcrbPM6pb1XZGP1Tm6j71ytfLv5AiiTupONIvXLZ9wqWam7iJ+6qS9eX ydiEqDnjnGrfM5dRGo6y7G9jR+v9TMVPRj4ea/u/jnrwI2+cmSSvY8dd0WmpUXRw1unx uDCPRWqRdFgKuhUx2YghLyoz/CXMReJ9/S1mmjnkwZD+SXsn/unl9I8GXj0/jOx/Brqs tJQ4mPF5o4K6xTFREfBNsD8ZRDhgDADRZjY84z+5FbHhMVkHeTVNRsc8Zql3r5sCyjP2 SVnaTYsytSNciThS+CQcpZ4BxLTt9HxoD/CUziWs9AQBAVLreRohaZXlpXpnElcwz0pu 12Dg== X-Gm-Message-State: APjAAAUC6Xo6RAO2sOYxF6ocTZ1O6bpQrPy/1JVBHjGWawfUf5/2SgYc UdReOA7W2pQvc7R8Fv+XEBIOXbg61Rw= X-Google-Smtp-Source: APXvYqwO4KCx+Py7lrwxvyOY5WGp+WpfJGvARNpLtItIFsqOyOUndXtXBekGEuoMQQchwtmsNvTWrg== X-Received: by 2002:a17:902:8d8a:: with SMTP id v10mr3929048plo.282.1576078193740; Wed, 11 Dec 2019 07:29:53 -0800 (PST) Received: from x1.thefacebook.com ([2620:10d:c090:180::50da]) by smtp.gmail.com with ESMTPSA id n26sm3661882pgd.46.2019.12.11.07.29.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 11 Dec 2019 07:29:52 -0800 (PST) From: Jens Axboe To: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org Cc: willy@infradead.org, clm@fb.com, torvalds@linux-foundation.org, david@fromorbit.com, Jens Axboe Subject: [PATCH 3/5] mm: make buffered writes work with RWF_UNCACHED Date: Wed, 11 Dec 2019 08:29:41 -0700 Message-Id: <20191211152943.2933-4-axboe@kernel.dk> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191211152943.2933-1-axboe@kernel.dk> References: <20191211152943.2933-1-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: If RWF_UNCACHED is set for io_uring (or pwritev2(2)), we'll drop the cache instantiated for buffered writes. If new pages aren't instantiated, we leave them alone. This provides similar semantics to reads with RWF_UNCACHED set. Signed-off-by: Jens Axboe --- include/linux/fs.h | 1 + mm/filemap.c | 41 +++++++++++++++++++++++++++++++++++++++-- 2 files changed, 40 insertions(+), 2 deletions(-) diff --git a/include/linux/fs.h b/include/linux/fs.h index bf58db1bc032..5ea5fc167524 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -285,6 +285,7 @@ enum positive_aop_returns { #define AOP_FLAG_NOFS 0x0002 /* used by filesystem to direct * helper code (eg buffer layer) * to clear GFP_FS from alloc */ +#define AOP_FLAG_UNCACHED 0x0004 =20 /* * oh the beauties of C type declarations. diff --git a/mm/filemap.c b/mm/filemap.c index fe37bd2b2630..4dadd1a4ca7c 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -3287,10 +3287,12 @@ struct page *grab_cache_page_write_begin(struct a= ddress_space *mapping, pgoff_t index, unsigned flags) { struct page *page; - int fgp_flags =3D FGP_LOCK|FGP_WRITE|FGP_CREAT; + int fgp_flags =3D FGP_LOCK|FGP_WRITE; =20 if (flags & AOP_FLAG_NOFS) fgp_flags |=3D FGP_NOFS; + if (!(flags & AOP_FLAG_UNCACHED)) + fgp_flags |=3D FGP_CREAT; =20 page =3D pagecache_get_page(mapping, index, fgp_flags, mapping_gfp_mask(mapping)); @@ -3311,6 +3313,9 @@ ssize_t generic_perform_write(struct file *file, ssize_t written =3D 0; unsigned int flags =3D 0; =20 + if (iocb->ki_flags & IOCB_UNCACHED) + flags |=3D AOP_FLAG_UNCACHED; + do { struct page *page; unsigned long offset; /* Offset into pagecache page */ @@ -3343,10 +3348,16 @@ ssize_t generic_perform_write(struct file *file, break; } =20 +retry: status =3D a_ops->write_begin(file, mapping, pos, bytes, flags, &page, &fsdata); - if (unlikely(status < 0)) + if (unlikely(status < 0)) { + if (status =3D=3D -ENOMEM && (flags & AOP_FLAG_UNCACHED)) { + flags &=3D ~AOP_FLAG_UNCACHED; + goto retry; + } break; + } =20 if (mapping_writably_mapped(mapping)) flush_dcache_page(page); @@ -3382,6 +3393,32 @@ ssize_t generic_perform_write(struct file *file, balance_dirty_pages_ratelimited(mapping); } while (iov_iter_count(i)); =20 + if (written && (iocb->ki_flags & IOCB_UNCACHED)) { + loff_t end; + + pos =3D iocb->ki_pos; + end =3D pos + written; + + status =3D filemap_write_and_wait_range(mapping, pos, end); + if (status) + goto out; + + /* + * No pages were created for this range, we're done + */ + if (flags & AOP_FLAG_UNCACHED) + goto out; + + /* + * Try to invalidate cache pages for the range we just wrote. + * We don't care if invalidation fails as the write has still + * worked and leaving clean uptodate pages in the page cache + * isn't a corruption vector for uncached IO. + */ + invalidate_inode_pages2_range(mapping, + pos >> PAGE_SHIFT, end >> PAGE_SHIFT); + } +out: return written ? written : status; } EXPORT_SYMBOL(generic_perform_write); --=20 2.24.0