Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/fs/cifs/cifsroot.c b/fs/cifs/cifsroot.c
new file mode 100644
index 0000000..37edbfb
--- /dev/null
+++ b/fs/cifs/cifsroot.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SMB root file system support
+ *
+ * Copyright (c) 2019 Paulo Alcantara <palcantara@suse.de>
+ */
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/types.h>
+#include <linux/ctype.h>
+#include <linux/string.h>
+#include <linux/root_dev.h>
+#include <linux/kernel.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <net/ipconfig.h>
+
+#define DEFAULT_MNT_OPTS \
+ "vers=1.0,cifsacl,mfsymlinks,rsize=1048576,wsize=65536,uid=0,gid=0," \
+ "hard,rootfs"
+
+static char root_dev[2048] __initdata = "";
+static char root_opts[1024] __initdata = DEFAULT_MNT_OPTS;
+
+static __be32 __init parse_srvaddr(char *start, char *end)
+{
+ /* TODO: ipv6 support */
+ char addr[sizeof("aaa.bbb.ccc.ddd")];
+ int i = 0;
+
+ while (start < end && i < sizeof(addr) - 1) {
+ if (isdigit(*start) || *start == '.')
+ addr[i++] = *start;
+ start++;
+ }
+ addr[i] = '\0';
+ return in_aton(addr);
+}
+
+/* cifsroot=//<server-ip>/<share>[,options] */
+static int __init cifs_root_setup(char *line)
+{
+ char *s;
+ int len;
+ __be32 srvaddr = htonl(INADDR_NONE);
+
+ ROOT_DEV = Root_CIFS;
+
+ if (strlen(line) > 3 && line[0] == '/' && line[1] == '/') {
+ s = strchr(&line[2], '/');
+ if (!s || s[1] == '\0')
+ return 1;
+
+ /* make s point to ',' or '\0' at end of line */
+ s = strchrnul(s, ',');
+ /* len is strlen(unc) + '\0' */
+ len = s - line + 1;
+ if (len > sizeof(root_dev)) {
+ printk(KERN_ERR "Root-CIFS: UNC path too long\n");
+ return 1;
+ }
+ strlcpy(root_dev, line, len);
+ srvaddr = parse_srvaddr(&line[2], s);
+ if (*s) {
+ int n = snprintf(root_opts,
+ sizeof(root_opts), "%s,%s",
+ DEFAULT_MNT_OPTS, s + 1);
+ if (n >= sizeof(root_opts)) {
+ printk(KERN_ERR "Root-CIFS: mount options string too long\n");
+ root_opts[sizeof(root_opts)-1] = '\0';
+ return 1;
+ }
+ }
+ }
+
+ root_server_addr = srvaddr;
+
+ return 1;
+}
+
+__setup("cifsroot=", cifs_root_setup);
+
+int __init cifs_root_data(char **dev, char **opts)
+{
+ if (!root_dev[0] || root_server_addr == htonl(INADDR_NONE)) {
+ printk(KERN_ERR "Root-CIFS: no SMB server address\n");
+ return -1;
+ }
+
+ *dev = root_dev;
+ *opts = root_opts;
+
+ return 0;
+}