From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([59.151.112.132]:54633 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752979AbbIYIIb (ORCPT ); Fri, 25 Sep 2015 04:08:31 -0400 Subject: Re: [PATCH 3/5] btrfs: Do per-chunk degraded check for remount To: Anand Jain , References: <1442801443-5132-1-git-send-email-quwenruo@cn.fujitsu.com> <1442801443-5132-4-git-send-email-quwenruo@cn.fujitsu.com> <5604EF8B.5060503@oracle.com> From: Qu Wenruo Message-ID: <560500F8.9070105@cn.fujitsu.com> Date: Fri, 25 Sep 2015 16:08:24 +0800 MIME-Version: 1.0 In-Reply-To: <5604EF8B.5060503@oracle.com> Content-Type: text/plain; charset="utf-8"; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: Anand Jain wrote on 2015/09/25 14:54 +0800: > > > On 09/21/2015 10:10 AM, Qu Wenruo wrote: >> Just the same for mount time check, use new btrfs_check_degraded() to do >> per chunk check. >> >> Signed-off-by: Qu Wenruo >> --- >> fs/btrfs/super.c | 11 +++++++---- >> 1 file changed, 7 insertions(+), 4 deletions(-) >> >> diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c >> index c389c13..720c044 100644 >> --- a/fs/btrfs/super.c >> +++ b/fs/btrfs/super.c >> @@ -1681,11 +1681,14 @@ static int btrfs_remount(struct super_block >> *sb, int *flags, char *data) >> goto restore; >> } >> >> - if (fs_info->fs_devices->missing_devices > >> - fs_info->num_tolerated_disk_barrier_failures && >> - !(*flags & MS_RDONLY)) { >> + ret = btrfs_check_degradable(fs_info, *flags); >> + if (ret < 0) { >> + btrfs_error(fs_info, ret, >> + "degraded writable remount failed"); > > btrfs_erorr() which is an error handling routine, isn't appropriate > here, mainly because as we are in the remount context, I am not sure if > you meant to change the fs state to readonly (on error) in the remount > context ? or Instead btrfs_err() which is an error reporting/logging > would be appropriate. > > btrfs_erorr() and btrfs_err() are way different in action but very easy > have an oversight and use the wrong one. the below patch changed it.. > > Btrfs: consolidate btrfs_error() to btrfs_std_error() > > Thanks, Anand Thanks for pointing this out. I was quite unsure about using btrfs_info/warn/error. In this case, I just wan't to output a dmesg info to let user know exactly what caused the mount failed. Original code output nothing but "failed to open chunk tree", which is quite confusing for end user. I was planning to use btrfs_info, but at least this is really an error message, but only to info user the real cause. Maybe btrfs_warn will be a better choice? Thanks, Qu > > >> + goto restore; >> + } else if (ret > 0 && !btrfs_test_opt(root, DEGRADED)) { >> btrfs_warn(fs_info, >> - "too many missing devices, writeable remount is not >> allowed"); >> + "some device missing, but still degraded mountable, >> please remount with -o degraded option"); >> ret = -EACCES; >> goto restore; >> } >>