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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 9DC6EC55178 for ; Tue, 27 Oct 2020 15:01:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4AD6E20715 for ; Tue, 27 Oct 2020 15:01:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603810864; bh=NEdFkFp1HTWa8b0HGnfZPUuQLWzTa0Fb2pVQZ0f0wFc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Q/yk7MigVKwo9D+WCrKC8pDRjKS16y4SIIAhjaMQ/GhNQr1dD5uAXWoJf7f9wqtyg re3QOxqX0+K+7M+mcM6kXDa195eQbMRU7La0lG2GyEh/dYzQm1Zz18SbPCKFHES7Yo frdxvfkAOrmV1s9YQUHDIaR/WoE2Z3XXYSMkA2Sc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1775683AbgJ0PBA (ORCPT ); Tue, 27 Oct 2020 11:01:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:58666 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1782878AbgJ0O5i (ORCPT ); Tue, 27 Oct 2020 10:57:38 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D9F94204FD; Tue, 27 Oct 2020 14:57:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603810657; bh=NEdFkFp1HTWa8b0HGnfZPUuQLWzTa0Fb2pVQZ0f0wFc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dhZ+X/OIUEMGplnCRwYvG5uxHQOcgLjvyY7R4W50CIDwliJDBQBHwy/RLOHXpqfoQ eti27DXGFDvhvejqMY92xJxKM/lavJ0v2NTHOPteGZUmf/onRaki0d7pE+ShsS7IGe /wUePxq7Vqzkv0LYtO1Yqa0e5bmNOuhTUxcg1uF4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Matthew Wilcox (Oracle)" , "Darrick J. Wong" , Christoph Hellwig , Sasha Levin Subject: [PATCH 5.8 210/633] iomap: Mark read blocks uptodate in write_begin Date: Tue, 27 Oct 2020 14:49:13 +0100 Message-Id: <20201027135532.532477028@linuxfoundation.org> X-Mailer: git-send-email 2.29.1 In-Reply-To: <20201027135522.655719020@linuxfoundation.org> References: <20201027135522.655719020@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Matthew Wilcox (Oracle) [ Upstream commit 14284fedf59f1647264f4603d64418cf1fcd3eb0 ] When bringing (portions of) a page uptodate, we were marking blocks that were zeroed as being uptodate, but not blocks that were read from storage. Like the previous commit, this problem was found with generic/127 and a kernel which failed readahead I/Os. This bug causes writes to be silently lost when working with flaky storage. Fixes: 9dc55f1389f9 ("iomap: add support for sub-pagesize buffered I/O without buffer heads") Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Signed-off-by: Sasha Levin --- fs/iomap/buffered-io.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index c95454784df48..897ab9a26a74c 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -574,7 +574,6 @@ __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, int flags, loff_t block_start = pos & ~(block_size - 1); loff_t block_end = (pos + len + block_size - 1) & ~(block_size - 1); unsigned from = offset_in_page(pos), to = from + len, poff, plen; - int status; if (PageUptodate(page)) return 0; @@ -595,14 +594,13 @@ __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, int flags, if (WARN_ON_ONCE(flags & IOMAP_WRITE_F_UNSHARE)) return -EIO; zero_user_segments(page, poff, from, to, poff + plen); - iomap_set_range_uptodate(page, poff, plen); - continue; + } else { + int status = iomap_read_page_sync(block_start, page, + poff, plen, srcmap); + if (status) + return status; } - - status = iomap_read_page_sync(block_start, page, poff, plen, - srcmap); - if (status) - return status; + iomap_set_range_uptodate(page, poff, plen); } while ((block_start += plen) < block_end); return 0; -- 2.25.1