9p: don't use __getname/__putname for uname/aname

These are generally very small strings. We don't need an entire 4k
allocation for each. Instead, just free and reallocate them on an
as-needed basis.

Note: This patch is untested since I don't have a 9p server available at
the moment. It's mainly something I noticed while doing some
getname/putname cleanup work.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

fs/9p/v9fs.c

@@ -184,10 +184,20 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 			v9ses->afid = option;
 			break;
 		case Opt_uname:
-			match_strlcpy(v9ses->uname, &args[0], PATH_MAX);
+			kfree(v9ses->uname);
+			v9ses->uname = match_strdup(&args[0]);
+			if (!v9ses->uname) {
+				ret = -ENOMEM;
+				goto free_and_return;
+			}
 			break;
 		case Opt_remotename:
-			match_strlcpy(v9ses->aname, &args[0], PATH_MAX);
+			kfree(v9ses->aname);
+			v9ses->aname = match_strdup(&args[0]);
+			if (!v9ses->aname) {
+				ret = -ENOMEM;
+				goto free_and_return;
+			}
 			break;
 		case Opt_nodevmap:
 			v9ses->nodev = 1;
@@ -287,21 +297,21 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 	struct p9_fid *fid;
 	int rc;
 
-	v9ses->uname = __getname();
+	v9ses->uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL);
 	if (!v9ses->uname)
 		return ERR_PTR(-ENOMEM);
 
-	v9ses->aname = __getname();
+	v9ses->aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL);
 	if (!v9ses->aname) {
-		__putname(v9ses->uname);
+		kfree(v9ses->uname);
 		return ERR_PTR(-ENOMEM);
 	}
 	init_rwsem(&v9ses->rename_sem);
 
 	rc = bdi_setup_and_register(&v9ses->bdi, "9p", BDI_CAP_MAP_COPY);
 	if (rc) {
-		__putname(v9ses->aname);
-		__putname(v9ses->uname);
+		kfree(v9ses->aname);
+		kfree(v9ses->uname);
 		return ERR_PTR(rc);
 	}
 
@@ -309,8 +319,6 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 	list_add(&v9ses->slist, &v9fs_sessionlist);
 	spin_unlock(&v9fs_sessionlist_lock);
 
-	strcpy(v9ses->uname, V9FS_DEFUSER);
-	strcpy(v9ses->aname, V9FS_DEFANAME);
 	v9ses->uid = ~0;
 	v9ses->dfltuid = V9FS_DEFUID;
 	v9ses->dfltgid = V9FS_DEFGID;
@@ -412,8 +420,8 @@ void v9fs_session_close(struct v9fs_session_info *v9ses)
 		kfree(v9ses->cachetag);
 	}
 #endif
-	__putname(v9ses->uname);
-	__putname(v9ses->aname);
+	kfree(v9ses->uname);
+	kfree(v9ses->aname);
 
 	bdi_destroy(&v9ses->bdi);