Re: -tip: origin tree boot crash

[Ingo Molnar <mingo@elte.hu>]

* Ingo Molnar <mingo@elte.hu> wrote:

> 
> * Al Viro <viro@ZenIV.linux.org.uk> wrote:
> 
> > On Thu, Dec 17, 2009 at 10:02:50AM +0100, Ingo Molnar wrote:
> > > 
> > > Today's -tip crashes during bootup on one of my testsystems, and i've bisected 
> > > it back to this commit:
> > > 
> > > | 5fe878ae7f82fbf0830dbfaee4c5ca18f3aee442 is the first bad commit
> > > | commit 5fe878ae7f82fbf0830dbfaee4c5ca18f3aee442
> > > | Author: Christoph Hellwig <hch@lst.de>
> > > | Date:   Tue Dec 15 16:47:50 2009 -0800
> > > |
> > > |    direct-io: cleanup blockdev_direct_IO locking
> > > |
> > > |    Currently the locking in blockdev_direct_IO is a mess, we have three
> > > |    different locking types and very confusing checks for some of them.  The
> > > |    most complicated one is DIO_OWN_LOCKING for reads, which happens to not
> > > |    actually be used.
> > > 
> > > I have no bootlog available currently. The kernel config is attached.
> > > 
> > > I've reverted the patch from -tip for now.
> > 
> > How about this:
> > 
> > diff --git a/fs/direct-io.c b/fs/direct-io.c
> > index 4012885..e82adc2 100644
> > --- a/fs/direct-io.c
> > +++ b/fs/direct-io.c
> > @@ -1206,7 +1206,7 @@ __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
> >  	 * NOTE: filesystems with their own locking have to handle this
> >  	 * on their own.
> >  	 */
> > -	if (dio->flags & DIO_LOCKING) {
> > +	if (flags & DIO_LOCKING) {
> >  		if (unlikely((rw & WRITE) && retval < 0)) {
> >  			loff_t isize = i_size_read(inode);
> >  			if (end > isize)
> 
> thanks, will check this.

Fixes the crash, thanks Al!

Tested-by: Ingo Molnar <mingo@elte.hu>

	Ingo