[RFC] WARNING: dev_open(xxx) called while suspended

[Takahiro Yasui <tyasui@redhat.com>]

On 02/19/10 11:44, Alasdair G Kergon wrote:
> On Fri, Feb 19, 2010 at 11:20:09AM -0500, Takahiro Yasui wrote:
>> warning message.
>>   WARNING: dev_open(xxx) called while suspended
>> Can I suppress it by lvm configuration or something?
>  
> No - if the message appears, it's means there's a bug that must be fixed:-)

The rough sequence of lvconvert is

  1. construct new VG/LV data structure
  2. vg_write()
  3. suspend_lv()
      memlock_count++
  4. vg_commit()
      remove_commit_cached_metadata()  => Invalidate lvmcache

  5. resume_lv()
       _lv_resume()
         lv_from_lvid()
           fmt_from_vgname()
             label_read() => WARNING is displayed
      memlock_count--

By adding remove_commit_cached_metadata(), lvmcache is invalidated and
devices were scanned in resume_lv() with memlock_count != 0.

Can we move remove_commit_cached_metadata() just before memlock_count--?

Thanks,
Taka