4 files changed, 92 insertions, 13 deletions

diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c
index 2df555c66d57..aec3d5c98c94 100644
--- a/fs/sysfs/group.c
+++ b/fs/sysfs/group.c
@@ -205,6 +205,48 @@ void sysfs_unmerge_group(struct kobject *kobj,
 }
 EXPORT_SYMBOL_GPL(sysfs_unmerge_group);
 
+/**
+ * sysfs_add_link_to_group - add a symlink to an attribute group.
+ * @kobj:	The kobject containing the group.
+ * @group_name:	The name of the group.
+ * @target:	The target kobject of the symlink to create.
+ * @link_name:	The name of the symlink to create.
+ */
+int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
+			    struct kobject *target, const char *link_name)
+{
+	struct sysfs_dirent *dir_sd;
+	int error = 0;
+
+	dir_sd = sysfs_get_dirent(kobj->sd, NULL, group_name);
+	if (!dir_sd)
+		return -ENOENT;
+
+	error = sysfs_create_link_sd(dir_sd, target, link_name);
+	sysfs_put(dir_sd);
+
+	return error;
+}
+EXPORT_SYMBOL_GPL(sysfs_add_link_to_group);
+
+/**
+ * sysfs_remove_link_from_group - remove a symlink from an attribute group.
+ * @kobj:	The kobject containing the group.
+ * @group_name:	The name of the group.
+ * @link_name:	The name of the symlink to remove.
+ */
+void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
+				  const char *link_name)
+{
+	struct sysfs_dirent *dir_sd;
+
+	dir_sd = sysfs_get_dirent(kobj->sd, NULL, group_name);
+	if (dir_sd) {
+		sysfs_hash_and_remove(dir_sd, NULL, link_name);
+		sysfs_put(dir_sd);
+	}
+}
+EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group);
 
 EXPORT_SYMBOL_GPL(sysfs_create_group);
 EXPORT_SYMBOL_GPL(sysfs_update_group);
diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index 3c9eb5624f5e..8c940df97a52 100644
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -21,26 +21,17 @@
 
 #include "sysfs.h"
 
-static int sysfs_do_create_link(struct kobject *kobj, struct kobject *target,
-				const char *name, int warn)
+static int sysfs_do_create_link_sd(struct sysfs_dirent *parent_sd,
+				   struct kobject *target,
+				   const char *name, int warn)
 {
-	struct sysfs_dirent *parent_sd = NULL;
 	struct sysfs_dirent *target_sd = NULL;
 	struct sysfs_dirent *sd = NULL;
 	struct sysfs_addrm_cxt acxt;
 	enum kobj_ns_type ns_type;
 	int error;
 
-	BUG_ON(!name);
-
-	if (!kobj)
-		parent_sd = &sysfs_root;
-	else
-		parent_sd = kobj->sd;
-
-	error = -EFAULT;
-	if (!parent_sd)
-		goto out_put;
+	BUG_ON(!name || !parent_sd);
 
 	/* target->sd can go away beneath us but is protected with
 	 * sysfs_assoc_lock.  Fetch target_sd from it.
@@ -96,6 +87,34 @@ static int sysfs_do_create_link(struct kobject *kobj, struct kobject *target,
 }
 
 /**
+ *	sysfs_create_link_sd - create symlink to a given object.
+ *	@sd:		directory we're creating the link in.
+ *	@target:	object we're pointing to.
+ *	@name:		name of the symlink.
+ */
+int sysfs_create_link_sd(struct sysfs_dirent *sd, struct kobject *target,
+			 const char *name)
+{
+	return sysfs_do_create_link_sd(sd, target, name, 1);
+}
+
+static int sysfs_do_create_link(struct kobject *kobj, struct kobject *target,
+				const char *name, int warn)
+{
+	struct sysfs_dirent *parent_sd = NULL;
+
+	if (!kobj)
+		parent_sd = &sysfs_root;
+	else
+		parent_sd = kobj->sd;
+
+	if (!parent_sd)
+		return -EFAULT;
+
+	return sysfs_do_create_link_sd(parent_sd, target, name, warn);
+}
+
+/**
  *	sysfs_create_link - create symlink between two objects.
  *	@kobj:	object whose directory we're creating the link in.
  *	@target:	object we're pointing to.
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index d73c0932bbd6..d1e4043eb0c3 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -240,3 +240,5 @@ void unmap_bin_file(struct sysfs_dirent *attr_sd);
  * symlink.c
  */
 extern const struct inode_operations sysfs_symlink_inode_operations;
+int sysfs_create_link_sd(struct sysfs_dirent *sd, struct kobject *target,
+			 const char *name);
diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
index 381f06db2fe5..e2cee22f578a 100644
--- a/include/linux/sysfs.h
+++ b/include/linux/sysfs.h
@@ -181,6 +181,10 @@ int sysfs_merge_group(struct kobject *kobj,
 		       const struct attribute_group *grp);
 void sysfs_unmerge_group(struct kobject *kobj,
 		       const struct attribute_group *grp);
+int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
+			    struct kobject *target, const char *link_name);
+void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
+				  const char *link_name);
 
 void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr);
 void sysfs_notify_dirent(struct sysfs_dirent *sd);
@@ -326,6 +330,18 @@ static inline void sysfs_unmerge_group(struct kobject *kobj,
 {
 }
 
+static inline int sysfs_add_link_to_group(struct kobject *kobj,
+		const char *group_name, struct kobject *target,
+		const char *link_name)
+{
+	return 0;
+}
+
+static inline void sysfs_remove_link_from_group(struct kobject *kobj,
+		const char *group_name, const char *link_name)
+{
+}
+
 static inline void sysfs_notify(struct kobject *kobj, const char *dir,
 				const char *attr)
 {