[PATCH] knfsd: Fix stale file handle problem with subtree_checking.

A recent commit (7fc90ec93a5eb71f4b08403baf5ba7176b3ec6b1) moved the
call to nfsd_setuser out of the 'find a dentry for a filehandle' branch
of fh_verify so that it would always be called.

This had the unfortunately side-effect of moving *after* the call to
decode_fh, so the prober fsuid was not set when nfsd_acceptable was called,
the 'permission' check did the wrong thing.

This patch moves the nfsd_setuser call back where it was, and add as call
in the other branch of the if.

Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 13 insertions, 7 deletions

diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
index ecc439d256..501d838845 100644
--- a/fs/nfsd/nfsfh.c
+++ b/fs/nfsd/nfsfh.c
@@ -187,6 +187,11 @@ fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
                         goto out;
                 }
 
+                /* Set user creds for this exportpoint */
+                error = nfserrno(nfsd_setuser(rqstp, exp));
+                if (error)
+                        goto out;
+
                 /*
                  * Look up the dentry using the NFS file handle.
                  */
@@ -241,16 +246,17 @@ fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
                 dprintk("nfsd: fh_verify - just checking\n");
                 dentry = fhp->fh_dentry;
                 exp = fhp->fh_export;
+                /* Set user creds for this exportpoint; necessary even
+                 * in the "just checking" case because this may be a
+                 * filehandle that was created by fh_compose, and that
+                 * is about to be used in another nfsv4 compound
+                 * operation */
+                error = nfserrno(nfsd_setuser(rqstp, exp));
+                if (error)
+                        goto out;
         }
         cache_get(&exp->h);
 
-        /* Set user creds for this exportpoint; necessary even in the "just
-         * checking" case because this may be a filehandle that was created by
-         * fh_compose, and that is about to be used in another nfsv4 compound
-         * operation */
-        error = nfserrno(nfsd_setuser(rqstp, exp));
-        if (error)
-                goto out;
 
         error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
         if (error)