1 files changed, 71 insertions, 18 deletions

diff --git a/fs/filesystems.c b/fs/filesystems.c
index e3fa77c6ed5..5797d45a78c 100644
--- a/fs/filesystems.c
+++ b/fs/filesystems.c
@@ -8,11 +8,12 @@
 
 #include <linux/syscalls.h>
 #include <linux/fs.h>
-#include <linux/slab.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
 #include <linux/kmod.h>
 #include <linux/init.h>
 #include <linux/module.h>
-#include <linux/sched.h>	/* for 'current' */
+#include <linux/slab.h>
 #include <asm/uaccess.h>
 
 /*
@@ -42,11 +43,12 @@ void put_filesystem(struct file_system_type *fs)
 	module_put(fs->owner);
 }
 
-static struct file_system_type **find_filesystem(const char *name)
+static struct file_system_type **find_filesystem(const char *name, unsigned len)
 {
 	struct file_system_type **p;
 	for (p=&file_systems; *p; p=&(*p)->next)
-		if (strcmp((*p)->name,name) == 0)
+		if (strlen((*p)->name) == len &&
+		    strncmp((*p)->name, name, len) == 0)
 			break;
 	return p;
 }
@@ -69,11 +71,11 @@ int register_filesystem(struct file_system_type * fs)
 	int res = 0;
 	struct file_system_type ** p;
 
+	BUG_ON(strchr(fs->name, '.'));
 	if (fs->next)
 		return -EBUSY;
-	INIT_LIST_HEAD(&fs->fs_supers);
 	write_lock(&file_systems_lock);
-	p = find_filesystem(fs->name);
+	p = find_filesystem(fs->name, strlen(fs->name));
 	if (*p)
 		res = -EBUSY;
 	else
@@ -107,20 +109,23 @@ int unregister_filesystem(struct file_system_type * fs)
 			*tmp = fs->next;
 			fs->next = NULL;
 			write_unlock(&file_systems_lock);
+			synchronize_rcu();
 			return 0;
 		}
 		tmp = &(*tmp)->next;
 	}
 	write_unlock(&file_systems_lock);
+
 	return -EINVAL;
 }
 
 EXPORT_SYMBOL(unregister_filesystem);
 
+#ifdef CONFIG_SYSFS_SYSCALL
 static int fs_index(const char __user * __name)
 {
 	struct file_system_type * tmp;
-	char * name;
+	struct filename *name;
 	int err, index;
 
 	name = getname(__name);
@@ -131,7 +136,7 @@ static int fs_index(const char __user * __name)
 	err = -EINVAL;
 	read_lock(&file_systems_lock);
 	for (tmp=file_systems, index=0 ; tmp ; tmp=tmp->next, index++) {
-		if (strcmp(tmp->name,name) == 0) {
+		if (strcmp(tmp->name, name->name) == 0) {
 			err = index;
 			break;
 		}
@@ -176,7 +181,7 @@ static int fs_maxindex(void)
 /*
  * Whee.. Weird sysv syscall. 
  */
-asmlinkage long sys_sysfs(int option, unsigned long arg1, unsigned long arg2)
+SYSCALL_DEFINE3(sysfs, int, option, unsigned long, arg1, unsigned long, arg2)
 {
 	int retval = -EINVAL;
 
@@ -195,8 +200,9 @@ asmlinkage long sys_sysfs(int option, unsigned long arg1, unsigned long arg2)
 	}
 	return retval;
 }
+#endif
 
-int get_filesystem_list(char * buf)
+int __init get_filesystem_list(char *buf)
 {
 	int len = 0;
 	struct file_system_type * tmp;
@@ -213,21 +219,68 @@ int get_filesystem_list(char * buf)
 	return len;
 }
 
-struct file_system_type *get_fs_type(const char *name)
+#ifdef CONFIG_PROC_FS
+static int filesystems_proc_show(struct seq_file *m, void *v)
+{
+	struct file_system_type * tmp;
+
+	read_lock(&file_systems_lock);
+	tmp = file_systems;
+	while (tmp) {
+		seq_printf(m, "%s\t%s\n",
+			(tmp->fs_flags & FS_REQUIRES_DEV) ? "" : "nodev",
+			tmp->name);
+		tmp = tmp->next;
+	}
+	read_unlock(&file_systems_lock);
+	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);
+	return 0;
+}
+module_init(proc_filesystems_init);
+#endif
+
+static struct file_system_type *__get_fs_type(const char *name, int len)
 {
 	struct file_system_type *fs;
 
 	read_lock(&file_systems_lock);
-	fs = *(find_filesystem(name));
+	fs = *(find_filesystem(name, len));
 	if (fs && !try_module_get(fs->owner))
 		fs = NULL;
 	read_unlock(&file_systems_lock);
-	if (!fs && (request_module("%s", name) == 0)) {
-		read_lock(&file_systems_lock);
-		fs = *(find_filesystem(name));
-		if (fs && !try_module_get(fs->owner))
-			fs = NULL;
-		read_unlock(&file_systems_lock);
+	return fs;
+}
+
+struct file_system_type *get_fs_type(const char *name)
+{
+	struct file_system_type *fs;
+	const char *dot = strchr(name, '.');
+	int len = dot ? dot - name : strlen(name);
+
+	fs = __get_fs_type(name, len);
+	if (!fs && (request_module("fs-%.*s", len, name) == 0))
+		fs = __get_fs_type(name, len);
+
+	if (dot && fs && !(fs->fs_flags & FS_HAS_SUBTYPE)) {
+		put_filesystem(fs);
+		fs = NULL;
 	}
 	return fs;
 }