Re: [PATCH 1/3 v4] btrfs-progs: use kernel for mounted disk for show

[Anand Jain <Anand.Jain@oracle.com>]

On 10/21/13 10:44 PM, Josef Bacik wrote:
> On Tue, Oct 15, 2013 at 07:13:33PM +0200, David Sterba wrote:
>> On Tue, Oct 08, 2013 at 11:41:38AM +0800, Anand Jain wrote:
>>> As of now btrfs filesystem show reads directly from
>>> disks. So sometimes output can be stale, mainly when
>>> user wants to cross verify their operation like,
>>> label or device delete or add... etc. so this
>>> patch will read from the kernel ioctl if it finds
>>> that disk is mounted.
>>
>> Sorry for holding this patch back for so long, I wanted to find out why
>> the output is different before and after. The reason is simple, for my
>> convenience I've added the user to the 'disk' group so I can access the
>> block devices without root. This patch stops to read the block devs
>> directly and uses the ioctl BTRFS_IOC_FS_INFO which gives me a silent
>> EPERM. If I run show with sudo, then all filesystems show up as
>> expected.
>>
>
> This patch needs to be dropped (I imagine the whole series too) as it breaks
> xfstests btrfs/003.  If I do btrfs fi show on a mounted fs I get this
>
> [root@destiny btrfs-progs]# btrfs fi show /dev/sdc
> Btrfs v0.20-rc1-483-ge0173f6
> [root@destiny btrfs-progs]#
>
> Chris this is in integration, so maybe a revert?  Thanks,

  That would be less productive approach as a whole.
  I have sent out the fix for this. Kindly find it.

---
[PATCH 1/2] btrfs-progs: make get_btrfs_mount callable
[PATCH 2/2] btrfs-progs: filesystem show of specified mounted disk 
should work
---

Thanks, Anand