lkml.org 
[lkml]   [2010]   [Oct]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: fs: Inode cache scalability V3
On Wed, Oct 13, 2010 at 05:46:09PM -0400, Christoph Hellwig wrote:
> On Wed, Oct 13, 2010 at 11:58:45AM -0400, Christoph Hellwig wrote:
> >
> > It's 100% reproducible on my kvm VM. The bug is the assert_spin_locked
> > in redirty_tail. I really can't find a way how we reach it without
> > d_lock so this really confuses me.
>
> We are for some reason getting a block device inode that is on the
> dirty list of a bdi that it doesn't point to. Still trying to figure
> out how exactly that happens.

It's because __blkdev_put reset the bdi on the mapping, and bdev inodes
are still special cased to not use s_bdi unlike everybody else. So
we keep switch between different bdis that get locked.

I wonder what's a good workaround for that. Just flushing out all
dirty state of a block device inode on last close would fix, but we'd
still have all the dragons hidden underneath until we finally sort
out the bdi reference mess.



\
 
 \ /
  Last update: 2010-10-14 01:39    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site