1 files changed, 36 insertions, 29 deletions

diff --git a/fs/filesystems.c b/fs/filesystems.c
index a920ad2629ac..95e5256821a5 100644
--- a/fs/filesystems.c
+++ b/fs/filesystems.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  linux/fs/filesystems.c
  *
@@ -15,6 +16,7 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
+#include <linux/fs_parser.h>
 
 /*
  * Handling of filesystem drivers list.
@@ -72,6 +74,10 @@ int register_filesystem(struct file_system_type * fs)
 	int res = 0;
 	struct file_system_type ** p;
 
+	if (fs->parameters &&
+	    !fs_validate_description(fs->name, fs->parameters))
+		return -EINVAL;
+
 	BUG_ON(strchr(fs->name, '.'));
 	if (fs->next)
 		return -EBUSY;
@@ -150,15 +156,19 @@ static int fs_index(const char __user * __name)
 static int fs_name(unsigned int index, char __user * buf)
 {
 	struct file_system_type * tmp;
-	int len, res;
+	int len, res = -EINVAL;
 
 	read_lock(&file_systems_lock);
-	for (tmp = file_systems; tmp; tmp = tmp->next, index--)
-		if (index <= 0 && try_module_get(tmp->owner))
+	for (tmp = file_systems; tmp; tmp = tmp->next, index--) {
+		if (index == 0) {
+			if (try_module_get(tmp->owner))
+				res = 0;
 			break;
+		}
+	}
 	read_unlock(&file_systems_lock);
-	if (!tmp)
-		return -EINVAL;
+	if (res)
+		return res;
 
 	/* OK, we got the reference, so we can safely block */
 	len = strlen(tmp->name) + 1;
@@ -203,21 +213,28 @@ SYSCALL_DEFINE3(sysfs, int, option, unsigned long, arg1, unsigned long, arg2)
 }
 #endif
 
-int __init get_filesystem_list(char *buf)
+int __init list_bdev_fs_names(char *buf, size_t size)
 {
-	int len = 0;
-	struct file_system_type * tmp;
+	struct file_system_type *p;
+	size_t len;
+	int count = 0;
 
 	read_lock(&file_systems_lock);
-	tmp = file_systems;
-	while (tmp && len < PAGE_SIZE - 80) {
-		len += sprintf(buf+len, "%s\t%s\n",
-			(tmp->fs_flags & FS_REQUIRES_DEV) ? "" : "nodev",
-			tmp->name);
-		tmp = tmp->next;
+	for (p = file_systems; p; p = p->next) {
+		if (!(p->fs_flags & FS_REQUIRES_DEV))
+			continue;
+		len = strlen(p->name) + 1;
+		if (len > size) {
+			pr_warn("%s: truncating file system list\n", __func__);
+			break;
+		}
+		memcpy(buf, p->name, len);
+		buf += len;
+		size -= len;
+		count++;
 	}
 	read_unlock(&file_systems_lock);
-	return len;
+	return count;
 }
 
 #ifdef CONFIG_PROC_FS
@@ -237,21 +254,9 @@ static int filesystems_proc_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-static int filesystems_proc_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, filesystems_proc_show, NULL);
-}
-
-static const struct file_operations filesystems_proc_fops = {
-	.open		= filesystems_proc_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
-
 static int __init proc_filesystems_init(void)
 {
-	proc_create("filesystems", 0, NULL, &filesystems_proc_fops);
+	proc_create_single("filesystems", 0, NULL, filesystems_proc_show);
 	return 0;
 }
 module_init(proc_filesystems_init);
@@ -278,7 +283,9 @@ struct file_system_type *get_fs_type(const char *name)
 	fs = __get_fs_type(name, len);
 	if (!fs && (request_module("fs-%.*s", len, name) == 0)) {
 		fs = __get_fs_type(name, len);
-		WARN_ONCE(!fs, "request_module fs-%.*s succeeded, but still no fs?\n", len, name);
+		if (!fs)
+			pr_warn_once("request_module fs-%.*s succeeded, but still no fs?\n",
+				     len, name);
 	}
 
 	if (dot && fs && !(fs->fs_flags & FS_HAS_SUBTYPE)) {