iput() in reclaim context

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, 20 May 2008, Andrew Morton wrote:
> On Wed, 21 May 2008 10:15:32 +0400 Evgeniy Polyakov <johnpol@xxxxxxxxxxx> wrote:
> > On Tue, May 20, 2008 at 04:28:16PM -0700, Andrew Morton (akpm@xxxxxxxxxxxxxxxxxxxx) wrote:
> > > It's more than efficiency.  There are lots and lots of things we cannot
> > > do in direct-reclaim context.
> > > 
> > > ...
> > > 
> > > c) Cannot run iput().  Or at least, we couldn't five or six years
> > >    ago.  afaik nobody has investigated whether the situation is now
> > >    better or worse.

I happened to notice your remark in the buffer heads defrag thread.
Do you remember what that limitation was about?

Because just a few months ago I discovered a shmem race which I fixed
by doing igrab+iput in shmem_writepage, in the reclaim context.  Feeling
guilty now: I'd better investigate, but would welcome a starting pointer.

(If I'm lucky, it'll be that the generic code in vmscan.c cannot
use iput, but particular filesystems might themselves be safe to.)

Thanks,
Hugh
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]
  Powered by Linux