From patchwork Tue May 25 13:50:50 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 12278937 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,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 D2DEDC4724A for ; Tue, 25 May 2021 13:51:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B922B6140F for ; Tue, 25 May 2021 13:51:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233626AbhEYNwz (ORCPT ); Tue, 25 May 2021 09:52:55 -0400 Received: from mx2.suse.de ([195.135.220.15]:42784 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233438AbhEYNwj (ORCPT ); Tue, 25 May 2021 09:52:39 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1621950662; h=from:from:reply-to: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=jZlfk4vwF2p32yW05HQcA1IZqYim5+F109uIplXVw+8=; b=DRHNjtVyi2P6ez+bSS1jJfysTJfmXmuAc7XaBIitSzh1v+NvVKFi/bS6NgZ9EQnzxGxZLQ RQYD2oowFxeZBnkgdxqt5tTtXVYuiKBPC0w8egFh1kAA8P1jUsRdS9alqol2+nMZqEXqey Kl+tANswz9b7fD0NioVdMnX5SE2EAf4= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1621950662; h=from:from:reply-to: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=jZlfk4vwF2p32yW05HQcA1IZqYim5+F109uIplXVw+8=; b=9rURY4pla4pmyo+OPI1H2/hqtWG7wnDmBHyn2VRduoODR8GrNGuKuKRNMWAy3XEbVdDMtd l2WgpuM9iITZKtAA== Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 47E04AF27; Tue, 25 May 2021 13:51:02 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 45E1F1F2CBE; Tue, 25 May 2021 15:51:00 +0200 (CEST) From: Jan Kara To: Cc: Christoph Hellwig , Dave Chinner , ceph-devel@vger.kernel.org, Chao Yu , Damien Le Moal , "Darrick J. Wong" , Jaegeuk Kim , Jeff Layton , Johannes Thumshirn , linux-cifs@vger.kernel.org, , linux-f2fs-devel@lists.sourceforge.net, , , Miklos Szeredi , Steve French , Ted Tso , Matthew Wilcox , Jan Kara Subject: [PATCH 13/13] cifs: Fix race between hole punch and page fault Date: Tue, 25 May 2021 15:50:50 +0200 Message-Id: <20210525135100.11221-13-jack@suse.cz> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210525125652.20457-1-jack@suse.cz> References: <20210525125652.20457-1-jack@suse.cz> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Cifs has a following race between hole punching and page fault: CPU1 CPU2 smb3_fallocate() smb3_punch_hole() truncate_pagecache_range() filemap_fault() - loads old data into the page cache SMB2_ioctl(..., FSCTL_SET_ZERO_DATA, ...) And now we have stale data in the page cache. Fix the problem by locking out faults (as well as reads) using mapping->invalidate_lock while hole punch is running. CC: Steve French CC: linux-cifs@vger.kernel.org Signed-off-by: Jan Kara --- fs/cifs/smb2ops.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index dd0eb665b680..b0a0f8b34add 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -3579,6 +3579,7 @@ static long smb3_punch_hole(struct file *file, struct cifs_tcon *tcon, return rc; } + down_write(&inode->i_mapping->invalidate_lock); /* * We implement the punch hole through ioctl, so we need remove the page * caches first, otherwise the data may be inconsistent with the server. @@ -3596,6 +3597,7 @@ static long smb3_punch_hole(struct file *file, struct cifs_tcon *tcon, sizeof(struct file_zero_data_information), CIFSMaxBufSize, NULL, NULL); free_xid(xid); + up_write(&inode->i_mapping->invalidate_lock); return rc; }