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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 A1A0CC32757 for ; Sat, 10 Aug 2019 20:45:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 78B4F2166E for ; Sat, 10 Aug 2019 20:45:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726928AbfHJUoJ (ORCPT ); Sat, 10 Aug 2019 16:44:09 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:55332 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726901AbfHJUoI (ORCPT ); Sat, 10 Aug 2019 16:44:08 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hwYDd-00053u-3S; Sat, 10 Aug 2019 21:44:05 +0100 Received: from ben by deadeye with local (Exim 4.92) (envelope-from ) id 1hwYDK-0003cf-Qz; Sat, 10 Aug 2019 21:43:46 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Nikolay Borisov" , "Anand Jain" , "David Sterba" Date: Sat, 10 Aug 2019 21:40:07 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 065/157] btrfs: prop: fix vanished compression property after failed set In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 3.16.72-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Anand Jain commit 272e5326c7837697882ce3162029ba893059b616 upstream. The compression property resets to NULL, instead of the old value if we fail to set the new compression parameter. $ btrfs prop get /btrfs compression compression=lzo $ btrfs prop set /btrfs compression zli ERROR: failed to set compression for /btrfs: Invalid argument $ btrfs prop get /btrfs compression This is because the compression property ->validate() is successful for 'zli' as the strncmp() used the length passed from the userspace. Fix it by using the expected string length in strncmp(). Fixes: 63541927c8d1 ("Btrfs: add support for inode properties") Fixes: 5c1aab1dd544 ("btrfs: Add zstd support") Reviewed-by: Nikolay Borisov Signed-off-by: Anand Jain Reviewed-by: David Sterba Signed-off-by: David Sterba [bwh: Backported to 3.16: "zstd" is not supported] Signed-off-by: Ben Hutchings --- --- a/fs/btrfs/props.c +++ b/fs/btrfs/props.c @@ -378,9 +378,9 @@ int btrfs_subvol_inherit_props(struct bt static int prop_compression_validate(const char *value, size_t len) { - if (!strncmp("lzo", value, len)) + if (!strncmp("lzo", value, 3)) return 0; - else if (!strncmp("zlib", value, len)) + else if (!strncmp("zlib", value, 4)) return 0; return -EINVAL;