Re: [PATCH] Btrfs: don't delay inode ref updates during log replay

[Qu Wenruo <quwenruo@cn.fujitsu.com>]

Great! The root cause of missing file is fixed!

Thanks a lot!
Qu
-------- Original Message --------
Subject: Re: [PATCH] Btrfs: don't delay inode ref updates during log replay
From: Marc MERLIN <marc@merlins.org>
To: Chris Mason <clm@fb.com>, Qu Wenruo <quwenruo@cn.fujitsu.com>, Roman 
Mamedov <rm@romanrm.net>, Btrfs BTRFS <linux-btrfs@vger.kernel.org>
Date: 2015年01月02日 06:58
> Chris, you rule, I applied this to 3.16.7 and my problem went away.
>
> Tested-By: Marc MERLIN <marc@merlins.org>
>
> Happy new year! :)
>
> Marc
>
> On Wed, Dec 31, 2014 at 01:30:13PM -0500, Chris Mason wrote:
>> Commit 1d52c78afbb (Btrfs: try not to ENOSPC on log replay) added a
>> check to skip delayed inode updates during log replay because it
>> confuses the enospc code.  But the delayed processing will end up
>> skipping delayed refs from log replay because the inode itself wasn't
>> put through the delayed code.
>>
>> This can end up triggering a warning at commit time:
>>
>> WARNING: CPU: 2 PID: 778 at fs/btrfs/delayed-inode.c:1410 btrfs_assert_delayed_root_empty+0x32/0x34()
>>
>> Which is repeated for each commit because we never process the delayed ref.
>>
>> The fix used here is to change btrfs_delayed_delete_inode_ref to return
>> an error if we're current in log replay.  The caller will do the ref
>> deletion immediately and everything will work properly.
>>
>> This bug can cause lost files, whick fsck will find.  --repair on
>> btrfs-progs 3.18 will fix them
>>
>> Signed-off-by: Chris Mason <clm@fb.com>
>> cc: stable@vger.kernel.org # v3.18 and any stable series that picked 1d52c78afbbf80b58299e076a159617d6b42fe3c
>>
>> diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
>> index 054577b..de4e70f 100644
>> --- a/fs/btrfs/delayed-inode.c
>> +++ b/fs/btrfs/delayed-inode.c
>> @@ -1857,6 +1857,14 @@ int btrfs_delayed_delete_inode_ref(struct inode *inode)
>>   {
>>   	struct btrfs_delayed_node *delayed_node;
>>   
>> +	/*
>> +	 * we don't do delayed inode updates during log recovery because it
>> +	 * leads to enospc problems.  This means we also can't do
>> +	 * delayed inode refs
>> +	 */
>> +	if (BTRFS_I(inode)->root->fs_info->log_root_recovering)
>> +		return -EAGAIN;
>> +
>>   	delayed_node = btrfs_get_or_create_delayed_node(inode);
>>   	if (IS_ERR(delayed_node))
>>   		return PTR_ERR(delayed_node);
>> --
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