On 2/6/14, 12:43 AM, Dave Chinner wrote:
> On Thu, Jan 30, 2014 at 03:54:16PM -0500, Brian Foster wrote:
>> On 01/30/2014 03:30 PM, Eric Sandeen wrote:
>>> On 1/30/14, 2:26 PM, Brian Foster wrote:
>>>>> diff --git a/fs/xfs/xfs_sb.c b/fs/xfs/xfs_sb.c
>>>>>> index 511cce9..b575317 100644
>>>>>> --- a/fs/xfs/xfs_sb.c
>>>>>> +++ b/fs/xfs/xfs_sb.c
>>>>>> @@ -617,6 +617,8 @@ xfs_sb_read_verify(
>>>>>> /* Only fail bad secondaries on a known V5
>>>>>> filesystem */
>>>>>> if (bp->b_bn != XFS_SB_DADDR &&
>>>>>> xfs_sb_version_hascrc(&mp->m_sb)) {
>>>>>> + XFS_CORRUPTION_ERROR(__func__,
>>>>>> XFS_ERRLEVEL_LOW,
>>>>>> + mp, bp->b_addr);
>>>>>> error = EFSCORRUPTED;
>>>>>> goto out_error;
>>>>>> }
>>>>>> @@ -625,12 +627,8 @@ xfs_sb_read_verify(
>>>>>> error = xfs_sb_verify(bp, true);
>>>>>>
>>>>>> out_error:
>>>>>> - if (error) {
>>>>>> - if (error != EWRONGFS)
>>>>>> - XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW,
>>>>>> - mp, bp->b_addr);
>>>>>> + if (error)
>>>>>> xfs_buf_ioerror(bp, error);
>>>>>> - }
>>>>>> }
>>>> ... but why not leave the corruption output here in out_error, change
>>>> the check to (error == EFSCORRUPTED) and remove the now duplicate
>>>> corruption message in xfs_mount_validate_sb() (or replace it with a
>>>> warn/notice message)? This would catch the other EFSCORRUPTED returns in
>>>> a consistent manner, including another potential duplicate in the write
>>>> verifier. I guess we'd lose a little specificity between the crc failure
>>>> and sb validation, but we could add a warn/notice for the former too.
>>>>
>>>> Brian
>>>>
>>>
>>> Well, I went back and forth on this. It's probably philosophical. ;)
>>>
>>> Should we emit the corruption error at the point of corruption detection,
>>> or at a higher level? I guess my concern was that while *this* caller
>>> might catch the return & yell, if another caller got added it might not.
>>>
>>> Putting it at the point of detection seemed foolproof in that regard.
>>>
>>
>> Yeah, that makes sense too. If we were consistent, that model would
>> suggest the write verifier corruption message could go and we'd embed
>> corruption errors along with the other associated EFSCORRUPTED returns
>> (at least where the resulting message is appropriate) in
>> xfs_mount_validate_sb().
>>
>> Either way seems reasonable to me. I guess if all the remaining
>> situations are in fact real corruption situations, the point of
>> detection approach is probably more resilient. It would still be nice to
>> make the verifiers consistent in that though. ;)
>
> And the conclusion to this discussion is ...?
I think Brian has some valid points, I'll take another look at it.
Thanks,
-Eric
> Cheers,
>
> Dave.
>
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