Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c
index 48db9a9..674d22b 100644
--- a/fs/9p/vfs_dir.c
+++ b/fs/9p/vfs_dir.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * linux/fs/9p/vfs_dir.c
  *
@@ -5,22 +6,6 @@
  *
  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License version 2
- *  as published by the Free Software Foundation.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to:
- *  Free Software Foundation
- *  51 Franklin Street, Fifth Floor
- *  Boston, MA  02111-1301  USA
- *
  */
 
 #include <linux/module.h>
@@ -105,7 +90,6 @@
 	int err = 0;
 	struct p9_fid *fid;
 	int buflen;
-	int reclen = 0;
 	struct p9_rdir *rdir;
 	struct kvec kvec;
 
@@ -124,7 +108,7 @@
 		if (rdir->tail == rdir->head) {
 			struct iov_iter to;
 			int n;
-			iov_iter_kvec(&to, READ | ITER_KVEC, &kvec, 1, buflen);
+			iov_iter_kvec(&to, READ, &kvec, 1, buflen);
 			n = p9_client_read(file->private_data, ctx->pos, &to,
 					   &err);
 			if (err)
@@ -138,11 +122,10 @@
 		while (rdir->head < rdir->tail) {
 			err = p9stat_read(fid->clnt, rdir->buf + rdir->head,
 					  rdir->tail - rdir->head, &st);
-			if (err) {
+			if (err <= 0) {
 				p9_debug(P9_DEBUG_VFS, "returned %d\n", err);
 				return -EIO;
 			}
-			reclen = st.size+2;
 
 			over = !dir_emit(ctx, st.name, strlen(st.name),
 					 v9fs_qid2ino(&st.qid), dt_type(&st));
@@ -150,8 +133,8 @@
 			if (over)
 				return 0;
 
-			rdir->head += reclen;
-			ctx->pos += reclen;
+			rdir->head += err;
+			ctx->pos += err;
 		}
 	}
 }