* Re: lock i_mutex for fallocate? [not found] <4E5ED2D5.8040302@linux.vnet.ibm.com> @ 2011-09-01 1:12 ` Allison Henderson 2011-09-01 17:59 ` Josef Bacik 0 siblings, 1 reply; 2+ messages in thread From: Allison Henderson @ 2011-09-01 1:12 UTC (permalink / raw) To: linux-kernel, linux-fsdevel; +Cc: Ext4 Developers List, Andreas Dilger Oh, I meant for this to go to linux-fsdevel instead of linux-kernel, but all feedback is welcome! :) On 08/31/2011 05:33 PM, Allison Henderson wrote: > Hi All, > > In ext4 punch hole, we realized that the punch hole operation needs to > be done under i_mutex just like truncate. i_mutex for truncate is held > in the vfs layer, so we dont need to lock it at the file system layer, > but vfs does not lock i_mutex for fallocate. We can lock i_mutex for > fallocate at the fs layer, but question was raised then: should i_mutex > for fallocate be held in the vfs layer instead? I do not know if other > file systems need i_mutex to be locked for fallocate, or if they might > be locking it already, so I am doing some investigating on this idea, > and also the appropriate use of i_mutex in general. Can someone provide > some insight this topic? Thx! > > Allison Henderson ^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: lock i_mutex for fallocate? 2011-09-01 1:12 ` lock i_mutex for fallocate? Allison Henderson @ 2011-09-01 17:59 ` Josef Bacik 0 siblings, 0 replies; 2+ messages in thread From: Josef Bacik @ 2011-09-01 17:59 UTC (permalink / raw) To: Allison Henderson Cc: linux-kernel, linux-fsdevel, Ext4 Developers List, Andreas Dilger On Wed, Aug 31, 2011 at 06:12:04PM -0700, Allison Henderson wrote: > Oh, I meant for this to go to linux-fsdevel instead of linux-kernel, but > all feedback is welcome! :) > > On 08/31/2011 05:33 PM, Allison Henderson wrote: >> Hi All, >> >> In ext4 punch hole, we realized that the punch hole operation needs to >> be done under i_mutex just like truncate. i_mutex for truncate is held >> in the vfs layer, so we dont need to lock it at the file system layer, >> but vfs does not lock i_mutex for fallocate. We can lock i_mutex for >> fallocate at the fs layer, but question was raised then: should i_mutex >> for fallocate be held in the vfs layer instead? I do not know if other >> file systems need i_mutex to be locked for fallocate, or if they might >> be locking it already, so I am doing some investigating on this idea, >> and also the appropriate use of i_mutex in general. Can someone provide >> some insight this topic? Thx! >> Btrfs has range locking for our extents, so we don't really need to be holding the i_mutex, even tho it appears we do it anyway. So I'd rather this not be moved to VFS for us who can do more fine grained locking. Thanks, Josef ^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2011-09-01 17:59 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
[not found] <4E5ED2D5.8040302@linux.vnet.ibm.com>
2011-09-01 1:12 ` lock i_mutex for fallocate? Allison Henderson
2011-09-01 17:59 ` Josef Bacik
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).