Re: 2.6.34-rc3-git6: Reported regressions from 2.6.33

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

On Wed, Apr 07, 2010 at 03:04:46PM -0700, Linus Torvalds wrote:

> > Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=15674
> > Subject		: [2.6.34-rc2 NFS4 oops] open error path failure...
> > Submitter	: Daniel J Blueman <daniel.blueman@gmail.com>
> > Date		: 2010-03-29 18:36 (10 days old)
> > Message-ID	: <6278d2221003291136p6481fe8emfb039403343c082@mail.gmail.com>
> > References	: http://marc.info/?l=linux-kernel&m=126988782722711&w=2
> 
> This smells like the same LOOKUP_DIRECTORY thing as the first entry, but.. 

No, it's not the same thing; the fix is to have nfs ->d_revalidate()
return an error on failing open attempt (in insane codepath that has
->d_revalidate() handling open()).  Confirmed to work by reporter...

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index d79a7b3..fe0cd9e 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2068,8 +2068,7 @@ nfs4_open_revalidate(struct inode *dir, struct dentry *dentry, int openflags, st
 			case -EDQUOT:
 			case -ENOSPC:
 			case -EROFS:
-				lookup_instantiate_filp(nd, (struct dentry *)state, NULL);
-				return 1;
+				return PTR_ERR(state);
 			default:
 				goto out_drop;
 		}