commit cf31e70d6cf93f19fe9bf1144966ef40991ac723
author Al Viro <viro@zeniv.linux.org.uk> Mon Jan 02 22:28:36 2012 -0500
committer Al Viro <viro@zeniv.linux.org.uk> Tue Jan 03 22:53:07 2012 -0500
tree 39cdc07b9d46b17ef882ddeb5041f4faec808662
parent c972b4bc8331b432f51a5f1bc3ca7e020172717f

vfs: new helper - vfs_ustat()

... and bury user_get_super()/statfs_by_dentry() - they are
purely internal now.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/compat.c

diff --git a/fs/compat.c b/fs/compat.c
index c987875..9db5a60 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -342,16 +342,9 @@
  */
 asmlinkage long compat_sys_ustat(unsigned dev, struct compat_ustat __user *u)
 {
-	struct super_block *sb;
 	struct compat_ustat tmp;
 	struct kstatfs sbuf;
-	int err;
-
-	sb = user_get_super(new_decode_dev(dev));
-	if (!sb)
-		return -EINVAL;
-	err = statfs_by_dentry(sb->s_root, &sbuf);
-	drop_super(sb);
+	int err = vfs_ustat(new_decode_dev(dev), &sbuf);
 	if (err)
 		return err;
 

fs/internal.h

diff --git a/fs/internal.h b/fs/internal.h
index 839d3f9..7b1cb15 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -78,6 +78,7 @@
 extern bool grab_super_passive(struct super_block *sb);
 extern struct dentry *mount_fs(struct file_system_type *,
 			       int, const char *, void *);
+extern struct super_block *user_get_super(dev_t);
 
 /*
  * open.c

fs/statfs.c

diff --git a/fs/statfs.c b/fs/statfs.c
index 9cf04a1..2aa6a22 100644
--- a/fs/statfs.c
+++ b/fs/statfs.c
@@ -7,6 +7,7 @@
 #include <linux/statfs.h>
 #include <linux/security.h>
 #include <linux/uaccess.h>
+#include "internal.h"
 
 static int flags_by_mnt(int mnt_flags)
 {
@@ -45,7 +46,7 @@
 		flags_by_sb(mnt->mnt_sb->s_flags);
 }
 
-int statfs_by_dentry(struct dentry *dentry, struct kstatfs *buf)
+static int statfs_by_dentry(struct dentry *dentry, struct kstatfs *buf)
 {
 	int retval;
 
@@ -205,19 +206,23 @@
 	return error;
 }
 
-SYSCALL_DEFINE2(ustat, unsigned, dev, struct ustat __user *, ubuf)
+int vfs_ustat(dev_t dev, struct kstatfs *sbuf)
 {
-	struct super_block *s;
-	struct ustat tmp;
-	struct kstatfs sbuf;
+	struct super_block *s = user_get_super(dev);
 	int err;
-
-	s = user_get_super(new_decode_dev(dev));
 	if (!s)
 		return -EINVAL;
 
-	err = statfs_by_dentry(s->s_root, &sbuf);
+	err = statfs_by_dentry(s->s_root, sbuf);
 	drop_super(s);
+	return err;
+}
+
+SYSCALL_DEFINE2(ustat, unsigned, dev, struct ustat __user *, ubuf)
+{
+	struct ustat tmp;
+	struct kstatfs sbuf;
+	int err = vfs_ustat(new_decode_dev(dev), &sbuf);
 	if (err)
 		return err;