Re: [PATCH 3/3 v4] btrfs-progs: disable using backup superblock by default

[Eric Sandeen <sandeen@redhat.com>]

On 3/14/13 9:47 AM, Eric Sandeen wrote:
> On 3/14/13 3:56 AM, Anand Jain wrote:
>>
>>
>> On 03/14/2013 12:36 PM, Eric Sandeen wrote:
>>> On 3/13/13 10:05 PM, Anand Jain wrote:
>>>
>>> <maybe a little more commit log would be good?>
>>>
>>> So here is what confuses me now. :)
>>>
>>> *every* caller of btrfs_read_dev_super() is now called with
>>> 0 for the flags variable, so it never reads the backup
>>> under any circumstance.
>>>
>>> If it's always called w/ 0, what is the point of the argument?
>>> Is there another patch you have planned that would use this argument
>>> later?
>>
>>  Thanks for the review. yes true. as of now it (BTRFS_SCAN_BACKUP_SB)
>>  only serves the purpose if in future should we need it.
>>  purpose is something like a user initiated thread which
>>  should to go to the backup-SB if primary-SB is not found ?.
>>  Or I can drop BTRFS_SCAN_BACKUP_SB idea depending on how
>>  it is convenient as a whole.
> 
> See what others think, perhaps, but if nobody is using it, I think
> it should just go away.  I'd call it "dead code." :)
> 
> But I am surprised that none of the commands which accept alternate
> superblock locations find their way into btrfs_read_dev_super() -
> that seems odd to me.  Is it re-implemented or open-coded in other
> places?

So to be clearer, rather than removing the code right away, maybe
it's worth a look to see if the other commands which *want* backup
superblocks should be using this same code.  Then you'd have a reason
for your new flag.  :)

-Eric

> -Eric
> 
> 
>> Thanks,  Anand
>>
>>