Re: writeback: bad unlock balance detected in 3.5-rc1

From: Jan Kara
Date: Fri Jun 08 2012 - 16:50:28 EST


On Sat 09-06-12 00:45:35, Wu Fengguang wrote:
> On Fri, Jun 08, 2012 at 05:07:36PM +0200, Jan Kara wrote:
> > On Fri 08-06-12 10:36:13, Ted Tso wrote:
> > >
> > > I can reproduce this fairly easily by using ext4 w/o a journal, running
> > > under KVM with 1024megs memory, with fsstress (xfstests #13):
>
> Good catch, thanks!
>
> > Argh, I wonder how come I didn't hit this. Does attached patch fix the
> > problem?
>
> > diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
> > index 8d2fb8c..41a3ccf 100644
> > --- a/fs/fs-writeback.c
> > +++ b/fs/fs-writeback.c
> > @@ -664,6 +664,7 @@ static long writeback_sb_inodes(struct super_block *sb,
> > /* Wait for I_SYNC. This function drops i_lock... */
> > inode_sleep_on_writeback(inode);
> > /* Inode may be gone, start again */
> > + spin_lock(&wb->list_lock);
> > continue;
> > }
>
> That looks like the fix. So I pushed it to writeback-for-next.
> Thanks for the quick fixing!
Attached is a version with proper sign-off and changelog. Just in case
you didn't create one yourself already.

Honza
--
Jan Kara <jack@xxxxxxx>
SUSE Labs, CR