fix NFS4 handling of mountpoint stat
Al Viro [Sat, 30 Jan 2010 21:11:21 +0000 (16:11 -0500)]
RFC says we need to follow the chain of mounts if there's more
than one stacked on that point.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/nfsd/nfs4xdr.c

index a8587e9..bbf72d8 100644 (file)
@@ -2121,9 +2121,15 @@ out_acl:
                 * and this is the root of a cross-mounted filesystem.
                 */
                if (ignore_crossmnt == 0 &&
-                   exp->ex_path.mnt->mnt_root->d_inode == dentry->d_inode) {
-                       err = vfs_getattr(exp->ex_path.mnt->mnt_parent,
-                               exp->ex_path.mnt->mnt_mountpoint, &stat);
+                   dentry == exp->ex_path.mnt->mnt_root) {
+                       struct path path = exp->ex_path;
+                       path_get(&path);
+                       while (follow_up(&path)) {
+                               if (path.dentry != path.mnt->mnt_root)
+                                       break;
+                       }
+                       err = vfs_getattr(path.mnt, path.dentry, &stat);
+                       path_put(&path);
                        if (err)
                                goto out_nfserr;
                }