Re: 2.6.24-rc2-mm1

[Jan Blunck <jblunck@suse.de>]

On Thu, Nov 15, Torsten Kaiser wrote:

> While the next bisect proved that these patches are innocent, I'm
> still blaming you for my problems. ;)

 :(

> The only thing that looks suspicious to me in that patch is the
> following change in nfs4_atomic_open(), nfs4_open_revalidate() and
> nfs4_proc_create()
> 
> -	struct path path = {
> -		.mnt = nd->mnt,
> -		.dentry = dentry,
> -	};
> +	struct path path = nd->path;
> 
> This changes the path.dentry from the explizit parameter 'dentry' to
> the embedded dentry from the parameter 'nd'.

Ouch! You are totally right. This really looks wrong and I even don't remember
how that went into the patch. Can you test if the following patch fixes the
problem? (BTW: thanks for the detailed analysis)

Thanks,
Jan

---

Subject: Embed a struct path into struct nameidata breakes NFSv4

I accidently break NFSv4. Here is the original report by Torsten Kaiser:

 > > Breaks nfsv4 in a rather funny way:
 > >
 > > treogen ~ # cd /usr/portage/x
 > > treogen x # touch bla
 > > touch: cannot touch `bla': File exists
 > > treogen x # mkdir bla
 > > treogen x # touch bla/bla
 > > touch: cannot touch `bla/bla': File exists
 > > treogen x # ls -lad *
 > > drwxr-xr-x 2 root root 6 Nov 14 20:03 bla
 > > treogen x # ls -la *
 > > total 0
 > > drwxr-xr-x 2 root root  6 Nov 14 20:03 .
 > > drwxr-xr-x 3 root root 16 Nov 14 20:03 ..
 > > treogen x #
                                  
Signed-off-by: Jan Blunck <jblunck@suse.de>
---
 fs/nfs/nfs4proc.c |   15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

Index: b/fs/nfs/nfs4proc.c
===================================================================
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1372,7 +1372,10 @@ out_close:
 struct dentry *
 nfs4_atomic_open(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
 {
-	struct path path = nd->path;
+	struct path path = {
+		.mnt = nd->path.mnt,
+		.dentry = dentry,
+	};
 	struct iattr attr;
 	struct rpc_cred *cred;
 	struct nfs4_state *state;
@@ -1411,7 +1414,10 @@ nfs4_atomic_open(struct inode *dir, stru
 int
 nfs4_open_revalidate(struct inode *dir, struct dentry *dentry, int openflags, struct nameidata *nd)
 {
-	struct path path = nd->path;
+	struct path path = {
+		.mnt = nd->path.mnt,
+		.dentry = dentry,
+	};
 	struct rpc_cred *cred;
 	struct nfs4_state *state;
 
@@ -1860,7 +1866,10 @@ static int
 nfs4_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
                  int flags, struct nameidata *nd)
 {
-	struct path path = nd->path;
+	struct path path = {
+		.mnt = nd->path.mnt,
+		.dentry = dentry,
+	};
 	struct nfs4_state *state;
 	struct rpc_cred *cred;
 	int status = 0;