nfsd: fix b0rken error value for setattr on read-only mount

BugLink: http://bugs.launchpad.net/bugs/996109

commit 96f6f98501196d46ce52c2697dd758d9300c63f5 upstream.

..._want_write() returns -EROFS on failure, _not_ an NFS error value.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 0b8830c9de7..d06a02c1b1a 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -812,6 +812,7 @@ nfsd4_setattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
               struct nfsd4_setattr *setattr)
 {
         __be32 status = nfs_ok;
+        int err;
 
         if (setattr->sa_iattr.ia_valid & ATTR_SIZE) {
                 nfs4_lock_state();
@@ -823,9 +824,9 @@ nfsd4_setattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                         return status;
                 }
         }
-        status = mnt_want_write(cstate->current_fh.fh_export->ex_path.mnt);
-        if (status)
-                return status;
+        err = mnt_want_write(cstate->current_fh.fh_export->ex_path.mnt);
+        if (err)
+                return nfserrno(err);
         status = nfs_ok;
 
         status = check_attr_support(rqstp, cstate, setattr->sa_bmval,