1 files changed, 46 insertions, 4 deletions

diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index c5081ad77026..b93ec51fa7ac 100644
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -11,6 +11,7 @@
  */
 
 #include <linux/fs.h>
+#include <linux/gfp.h>
 #include <linux/mount.h>
 #include <linux/module.h>
 #include <linux/kobject.h>
@@ -123,6 +124,44 @@ void sysfs_remove_link(struct kobject * kobj, const char * name)
         sysfs_hash_and_remove(parent_sd, name);
 }
 
+/**
+ *      sysfs_rename_link - rename symlink in object's directory.
+ *      @kobj:  object we're acting for.
+ *      @targ:  object we're pointing to.
+ *      @old:   previous name of the symlink.
+ *      @new:   new name of the symlink.
+ *
+ *      A helper function for the common rename symlink idiom.
+ */
+int sysfs_rename_link(struct kobject *kobj, struct kobject *targ,
+                        const char *old, const char *new)
+{
+        struct sysfs_dirent *parent_sd, *sd = NULL;
+        int result;
+
+        if (!kobj)
+                parent_sd = &sysfs_root;
+        else
+                parent_sd = kobj->sd;
+
+        result = -ENOENT;
+        sd = sysfs_get_dirent(parent_sd, old);
+        if (!sd)
+                goto out;
+
+        result = -EINVAL;
+        if (sysfs_type(sd) != SYSFS_KOBJ_LINK)
+                goto out;
+        if (sd->s_symlink.target_sd->s_dir.kobj != targ)
+                goto out;
+
+        result = sysfs_rename(sd, parent_sd, new);
+
+out:
+        sysfs_put(sd);
+        return result;
+}
+
 static int sysfs_get_target_path(struct sysfs_dirent *parent_sd,
                                  struct sysfs_dirent *target_sd, char *path)
 {
@@ -210,10 +249,13 @@ static void sysfs_put_link(struct dentry *dentry, struct nameidata *nd, void *co
 }
 
 const struct inode_operations sysfs_symlink_inode_operations = {
-        .setxattr = sysfs_setxattr,
-        .readlink = generic_readlink,
-        .follow_link = sysfs_follow_link,
-        .put_link = sysfs_put_link,
+        .setxattr       = sysfs_setxattr,
+        .readlink       = generic_readlink,
+        .follow_link    = sysfs_follow_link,
+        .put_link       = sysfs_put_link,
+        .setattr        = sysfs_setattr,
+        .getattr        = sysfs_getattr,
+        .permission     = sysfs_permission,
 };