nfsd: lock_rename() needs both directories to live on the same fs

commit 1aee9158bc978f91701c5992e395efbc6da2de3c upstream.

... checking that after lock_rename() is too late.  Incidentally,
NFSv2 had no nfserr_xdev...

Fixes: aa387d6ce153 "nfsd: fix EXDEV checking in rename"
Cc: stable@vger.kernel.org # v3.9+
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index a64065ad8851d1bfa539d29b47355424a8f80b48..43bfdbb9a60175f198c2d2a738e981b87cbf343c 100644 (file)
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1665,6 +1665,12 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
        if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
                goto out;
 
+       err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev;
+       if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
+               goto out;
+       if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry)
+               goto out;
+
        host_err = fh_want_write(ffhp);
        if (host_err) {
                err = nfserrno(host_err);
@@ -1698,12 +1704,6 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
        if (ndentry == trap)
                goto out_dput_new;
 
-       host_err = -EXDEV;
-       if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
-               goto out_dput_new;
-       if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry)
-               goto out_dput_new;
-
        host_err = vfs_rename(fdir, odentry, tdir, ndentry, NULL, 0);
        if (!host_err) {
                host_err = commit_metadata(tfhp);