[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>

diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
index ecc439d..501d838 100644 (file)
--- 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)