vfs: move getname() from callers to do_mount()

It would make more sense to pass char __user * instead of
char * in callers of do_mount() and do getname() inside do_mount().

Suggested-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Seunghun Lee <waydi1@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 9 insertions, 30 deletions

diff --git a/fs/compat.c b/fs/compat.c
index 6205c24..b13df99 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -794,7 +794,6 @@ COMPAT_SYSCALL_DEFINE5(mount, const char __user *, dev_name,
 	char *kernel_type;
 	unsigned long data_page;
 	char *kernel_dev;
-	struct filename *dir;
 	int retval;
 
 	kernel_type = copy_mount_string(type);
@@ -802,19 +801,14 @@ COMPAT_SYSCALL_DEFINE5(mount, const char __user *, dev_name,
 	if (IS_ERR(kernel_type))
 		goto out;
 
-	dir = getname(dir_name);
-	retval = PTR_ERR(dir);
-	if (IS_ERR(dir))
-		goto out1;
-
 	kernel_dev = copy_mount_string(dev_name);
 	retval = PTR_ERR(kernel_dev);
 	if (IS_ERR(kernel_dev))
-		goto out2;
+		goto out1;
 
 	retval = copy_mount_options(data, &data_page);
 	if (retval < 0)
-		goto out3;
+		goto out2;
 
 	retval = -EINVAL;
 
@@ -823,19 +817,17 @@ COMPAT_SYSCALL_DEFINE5(mount, const char __user *, dev_name,
 			do_ncp_super_data_conv((void *)data_page);
 		} else if (!strcmp(kernel_type, NFS4_NAME)) {
 			if (do_nfs4_super_data_conv((void *) data_page))
-				goto out4;
+				goto out3;
 		}
 	}
 
-	retval = do_mount(kernel_dev, dir->name, kernel_type,
+	retval = do_mount(kernel_dev, dir_name, kernel_type,
 			flags, (void*)data_page);
 
- out4:
-	free_page(data_page);
  out3:
-	kfree(kernel_dev);
+	free_page(data_page);
  out2:
-	putname(dir);
+	kfree(kernel_dev);
  out1:
 	kfree(kernel_type);
  out:
diff --git a/fs/namespace.c b/fs/namespace.c
index abd3abb..348562f 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -2533,7 +2533,7 @@ char *copy_mount_string(const void __user *data)
  * Therefore, if this magic number is present, it carries no information
  * and must be discarded.
  */
-long do_mount(const char *dev_name, const char *dir_name,
+long do_mount(const char *dev_name, const char __user *dir_name,
 		const char *type_page, unsigned long flags, void *data_page)
 {
 	struct path path;
@@ -2545,15 +2545,11 @@ long do_mount(const char *dev_name, const char *dir_name,
 		flags &= ~MS_MGC_MSK;
 
 	/* Basic sanity checks */
-
-	if (!dir_name || !*dir_name || !memchr(dir_name, 0, PAGE_SIZE))
-		return -EINVAL;
-
 	if (data_page)
 		((char *)data_page)[PAGE_SIZE - 1] = 0;
 
 	/* ... and get the mountpoint */
-	retval = kern_path(dir_name, LOOKUP_FOLLOW, &path);
+	retval = user_path(dir_name, &path);
 	if (retval)
 		return retval;
 
@@ -2778,7 +2774,6 @@ SYSCALL_DEFINE5(mount, char __user *, dev_name, char __user *, dir_name,
 {
 	int ret;
 	char *kernel_type;
-	struct filename *kernel_dir;
 	char *kernel_dev;
 	unsigned long data_page;
 
@@ -2787,12 +2782,6 @@ SYSCALL_DEFINE5(mount, char __user *, dev_name, char __user *, dir_name,
 	if (IS_ERR(kernel_type))
 		goto out_type;
 
-	kernel_dir = getname(dir_name);
-	if (IS_ERR(kernel_dir)) {
-		ret = PTR_ERR(kernel_dir);
-		goto out_dir;
-	}
-
 	kernel_dev = copy_mount_string(dev_name);
 	ret = PTR_ERR(kernel_dev);
 	if (IS_ERR(kernel_dev))
@@ -2802,15 +2791,13 @@ SYSCALL_DEFINE5(mount, char __user *, dev_name, char __user *, dir_name,
 	if (ret < 0)
 		goto out_data;
 
-	ret = do_mount(kernel_dev, kernel_dir->name, kernel_type, flags,
+	ret = do_mount(kernel_dev, dir_name, kernel_type, flags,
 		(void *) data_page);
 
 	free_page(data_page);
 out_data:
 	kfree(kernel_dev);
 out_dev:
-	putname(kernel_dir);
-out_dir:
 	kfree(kernel_type);
 out_type:
 	return ret;