On Fri, 10 Oct 2014 15:13:31 +0800, Eryu Guan wrote:
> On Thu, Sep 25, 2014 at 06:28:14PM +0800, Eryu Guan wrote:
>> device replace could fail due to another running scrub process, but this
>> failure doesn't get returned to userspace.
>>
>> The following steps could reproduce this issue
>>
>>      mkfs -t btrfs -f /dev/sdb1 /dev/sdb2
>>      mount /dev/sdb1 /mnt/btrfs
>>      while true; do
>>              btrfs scrub start -B /mnt/btrfs >/dev/null 2>&1
>>      done &
>>      btrfs replace start -Bf /dev/sdb2 /dev/sdb3 /mnt/btrfs
>>      # if this replace succeeded, do the following and repeat until
>>      # you see this log in dmesg
>>      # BTRFS: btrfs_scrub_dev(/dev/sdb2, 2, /dev/sdb3) failed -115
>>      #btrfs replace start -Bf /dev/sdb3 /dev/sdb2 /mnt/btrfs
>>
>>      # once you see the error log in dmesg, check return value of
>>      # replace
>>      echo $?
>>
>> Also only WARN_ON if the return code is not -EINPROGRESS.
>>
>> Signed-off-by: Eryu Guan <guane...@gmail.com>
> 
> Ping, any comments on this patch?
> 
> Thanks,
> Eryu
>> ---
>>  fs/btrfs/dev-replace.c | 8 +++++---
>>  1 file changed, 5 insertions(+), 3 deletions(-)
>>
>> diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
>> index eea26e1..44d32ab 100644
>> --- a/fs/btrfs/dev-replace.c
>> +++ b/fs/btrfs/dev-replace.c
>> @@ -418,9 +418,11 @@ int btrfs_dev_replace_start(struct btrfs_root *root,
>>                            &dev_replace->scrub_progress, 0, 1);
>>  
>>      ret = btrfs_dev_replace_finishing(root->fs_info, ret);
>> -    WARN_ON(ret);
>> +    /* don't warn if EINPROGRESS, someone else might be running scrub */
>> +    if (ret != -EINPROGRESS)
>> +            WARN_ON(ret);

picky comment

I prefer WARN_ON(ret && ret != -EINPROGRESS).

>>  
>> -    return 0;
>> +    return ret;

here we will return -EINPROGRESS if scrub is running, I think it better that
we assign some special number to args->result, and then return 0, just like
the case the device replace is running.

Thanks
Miao

>>  
>>  leave:
>>      dev_replace->srcdev = NULL;
>> @@ -538,7 +540,7 @@ static int btrfs_dev_replace_finishing(struct 
>> btrfs_fs_info *fs_info,
>>                      btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
>>              mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
>>  
>> -            return 0;
>> +            return scrub_ret;
>>      }
>>  
>>      printk_in_rcu(KERN_INFO
>> -- 
>> 1.8.3.1
>>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majord...@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to