Re: [dm-devel] [PATCH] deadlock with suspend and quotas

[Eric Sandeen <sandeen redhat com>]

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On 11/29/11 7:32 AM, Jan Kara wrote:
> On Tue 29-11-11 13:18:11, Alasdair G Kergon wrote:
>> On Tue, Nov 29, 2011 at 02:09:13PM +0100, Jan Kara wrote:
>>>   Hmm, then why do these operations suspend the filesystem if they
>>> apparently don't need it? Sorry for my ignorance, I never seriously worked
>>> with LVM code...
>>
>> They don't suspend it if they don't need to.
>>
>> dm-ioctl.h:
>> /*
>>  * Set this to avoid attempting to freeze any filesystem when suspending.
>>  */
>> #define DM_SKIP_LOCKFS_FLAG     (1 << 10) /* In */
>   Thanks. I was now checking in detail and indeed FIFREEZE fails if
> ->freeze_fs is not set. And only xfs, ext3, ext4, reiserfs, jfs, nilfs2,
> and gfs2 provide this function. So I was correct in assuming that when
> filesystem supports FIFREEZE it must make sure no modifications happen to
> the filesystem. So I believe that my original plan for sync to skip frozen
> filesystem is correct.

Jan, FWIW I agree with this as well.

- -Eric
 
> 								Honza

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