Re: -tip: origin tree boot crash

[Al Viro <viro@ZenIV.linux.org.uk>]

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)