[PATCH] sysfs ->follow_link() switched to new scheme

Signed-off-by: Al Viro <viro@parcelfarce.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/sysfs/symlink.c

@@ -5,12 +5,14 @@
 #include <linux/fs.h>
 #include <linux/module.h>
 #include <linux/kobject.h>
+#include <linux/namei.h>
 
 #include "sysfs.h"
 
 static struct inode_operations sysfs_symlink_inode_operations = {
-	.readlink = sysfs_readlink,
+	.readlink = generic_readlink,
 	.follow_link = sysfs_follow_link,
+	.put_link = sysfs_put_link,
 };
 
 static int init_symlink(struct inode * inode)
@@ -140,38 +142,21 @@ static int sysfs_getlink(struct dentry *dentry, char * path)
 
 }
 
-int sysfs_readlink(struct dentry *dentry, char __user *buffer, int buflen)
+int sysfs_follow_link(struct dentry *dentry, struct nameidata *nd)
 {
-	int error = 0;
+	int error = -ENOMEM;
 	unsigned long page = get_zeroed_page(GFP_KERNEL);
-
-	if (!page)
-		return -ENOMEM;
-
-	error = sysfs_getlink(dentry, (char *) page);
-	if (!error)
-	        error = vfs_readlink(dentry, buffer, buflen, (char *) page);
-
-	free_page(page);
-
-	return error;
+	if (page)
+		error = sysfs_getlink(dentry, (char *) page); 
+	nd_set_link(nd, error ? ERR_PTR(error) : (char *)page);
+	return 0;
 }
 
-int sysfs_follow_link(struct dentry *dentry, struct nameidata *nd)
+void sysfs_put_link(struct dentry *dentry, struct nameidata *nd)
 {
-	int error = 0;
-	unsigned long page = get_zeroed_page(GFP_KERNEL);
-
-	if (!page)
-		return -ENOMEM;
-
-	error = sysfs_getlink(dentry, (char *) page); 
-	if (!error)
-	        error = vfs_follow_link(nd, (char *) page);
-
-	free_page(page);
-
-	return error;
+	char *page = nd_get_link(nd);
+	if (!IS_ERR(page))
+		free_page((unsigned long)page);
 }
 
 EXPORT_SYMBOL(sysfs_create_link);

fs/sysfs/sysfs.h

@@ -12,8 +12,8 @@ extern void sysfs_hash_and_remove(struct dentry * dir, const char * name);
 extern int sysfs_create_subdir(struct kobject *, const char *, struct dentry **);
 extern void sysfs_remove_subdir(struct dentry *);
 
-extern int sysfs_readlink(struct dentry *, char __user *, int );
 extern int sysfs_follow_link(struct dentry *, struct nameidata *);
+extern void sysfs_put_link(struct dentry *, struct nameidata *);
 extern struct rw_semaphore sysfs_rename_sem;
 
 static inline struct kobject *sysfs_get_kobject(struct dentry *dentry)