@@ -367,15 +367,15 @@ void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group);
/**
- * __compat_only_sysfs_link_entry_to_kobj - add a symlink to a kobject pointing
- * to a group or an attribute
+ * sysfs_add_group_link - add a symlink to a kobject pointing to a group or
+ * an attribute
* @kobj: The kobject containing the group.
* @target_kobj: The target kobject.
* @target_name: The name of the target group or attribute.
+ * @link_name: The name of the link to the target group or attribute.
*/
-int __compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,
- struct kobject *target_kobj,
- const char *target_name)
+int sysfs_add_group_link(struct kobject *kobj, struct kobject *target_kobj,
+ const char *target_name, const char *link_name)
{
struct kernfs_node *target;
struct kernfs_node *entry;
@@ -400,12 +400,28 @@ int __compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,
return -ENOENT;
}
- link = kernfs_create_link(kobj->sd, target_name, entry);
+ link = kernfs_create_link(kobj->sd, link_name, entry);
if (IS_ERR(link) && PTR_ERR(link) == -EEXIST)
- sysfs_warn_dup(kobj->sd, target_name);
+ sysfs_warn_dup(kobj->sd, link_name);
kernfs_put(entry);
kernfs_put(target);
return IS_ERR(link) ? PTR_ERR(link) : 0;
}
+EXPORT_SYMBOL_GPL(sysfs_add_group_link);
+
+/**
+ * __compat_only_sysfs_link_entry_to_kobj - add a symlink to a kobject pointing
+ * to a group or an attribute
+ * @kobj: The kobject containing the group.
+ * @target_kobj: The target kobject.
+ * @target_name: The name of the target group or attribute.
+ */
+int __compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,
+ struct kobject *target_kobj,
+ const char *target_name)
+{
+ return sysfs_add_group_link(kobj, target_kobj, target_name,
+ target_name);
+}
EXPORT_SYMBOL_GPL(__compat_only_sysfs_link_entry_to_kobj);
@@ -278,6 +278,8 @@ 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);
+int sysfs_add_group_link(struct kobject *kobj, struct kobject *target_kobj,
+ const char *target_name, const char *link_name);
int __compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,
struct kobject *target_kobj,
const char *target_name);
The current __compat_only_sysfs_link_entry_to_kobj() code allows us to create symbolic links in sysfs to groups or attributes. Something like: /sys/.../entry1/groupA -> /sys/.../entry2/groupA This patch extends this functionality with a new sysfs_add_group_link() call that allows the link to have a different name than the group or attribute, so: /sys/.../entry1/link_name -> /sys/.../entry2/groupA __compat_only_sysfs_link_entry_to_kobj() now just calls sysfs_add_group_link(), passing in the same name for both the group/attribute and for the link name. This is needed by the ACPI HMAT enabling work because we want to have a group of performance attributes that live in a memory target. This group represents the performance between the (initiator,target) pair, and in the target the attribute group is named "via_mem_initX" to represent this pairing: # tree mem_tgt2/via_mem_init0/ mem_tgt2/via_mem_init0/ ├── mem_init0 -> ../../mem_init0 ├── mem_tgt2 -> ../../mem_tgt2 ├── read_bw_MBps ├── read_lat_nsec ├── write_bw_MBps └── write_lat_nsec We then want to link to this attribute group from the initiator, but change the name to "via_mem_tgtX" since we're now looking at it from the initiator's perspective: # ls -l mem_init0/via_mem_tgt2 lrwxrwxrwx. 1 root root 0 Jun 1 10:00 mem_init0/via_mem_tgt2 -> ../mem_tgt2/via_mem_init0 Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> --- fs/sysfs/group.c | 30 +++++++++++++++++++++++------- include/linux/sysfs.h | 2 ++ 2 files changed, 25 insertions(+), 7 deletions(-)