Re: [PATCH] Btrfs: don't do async reclaim during log replay V2

[Miao Xie <miaox@cn.fujitsu.com>]

Ping..

On Thu, 23 Oct 2014 16:44:54 +0800, Miao Xie wrote:
> On Thu, 18 Sep 2014 11:27:17 -0400, Josef Bacik wrote:
>> Trying to reproduce a log enospc bug I hit a panic in the async reclaim code
>> during log replay.  This is because we use fs_info->fs_root as our root for
>> shrinking and such.  Technically we can use whatever root we want, but let's
>> just not allow async reclaim while we're doing log replay.  Thanks,
> 
> Why not move the code of fs_root initialization to the front of log replay?
> I think it is better than the fix way in this patch because the async reclaimer
> can help us do some work.
> 
> Thanks
> Miao
> 
>>
>> Signed-off-by: Josef Bacik <jbacik@fb.com>
>> ---
>> V1->V2: use fs_info->log_root_recovering instead, didn't notice this existed
>> before.
>>
>>  fs/btrfs/extent-tree.c | 8 +++++++-
>>  1 file changed, 7 insertions(+), 1 deletion(-)
>>
>> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
>> index 28a27d5..44d0497 100644
>> --- a/fs/btrfs/extent-tree.c
>> +++ b/fs/btrfs/extent-tree.c
>> @@ -4513,7 +4513,13 @@ again:
>>  		space_info->flush = 1;
>>  	} else if (!ret && space_info->flags & BTRFS_BLOCK_GROUP_METADATA) {
>>  		used += orig_bytes;
>> -		if (need_do_async_reclaim(space_info, root->fs_info, used) &&
>> +		/*
>> +		 * We will do the space reservation dance during log replay,
>> +		 * which means we won't have fs_info->fs_root set, so don't do
>> +		 * the async reclaim as we will panic.
>> +		 */
>> +		if (!root->fs_info->log_root_recovering &&
>> +		    need_do_async_reclaim(space_info, root->fs_info, used) &&
>>  		    !work_busy(&root->fs_info->async_reclaim_work))
>>  			queue_work(system_unbound_wq,
>>  				   &root->fs_info->async_reclaim_work);
>>
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>