Added a new function __compat_only_sysfs_link_group_to_kobj() that adds
a symlink from attribute or group to a kobject. This needed for
maintaining backwards compatibility with PPI attributes in the TPM
driver.
Signed-off-by: Jarkko Sakkinen <jarkko.sakki...@linux.intel.com>
---
fs/sysfs/group.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/sysfs.h | 11 +++++++++++
2 files changed, 55 insertions(+)
diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c
index 39a0199..e123659 100644
--- a/fs/sysfs/group.c
+++ b/fs/sysfs/group.c
@@ -352,3 +352,47 @@ 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
+ * @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)
+{
+ struct kernfs_node *target;
+ struct kernfs_node *entry;
+ struct kernfs_node *link;
+
+ /*
+ * We don't own @target_kobj and it may be removed at any time.
+ * Synchronize using sysfs_symlink_target_lock. See sysfs_remove_dir()
+ * for details.
+ */
+ spin_lock(&sysfs_symlink_target_lock);
+ target = target_kobj->sd;
+ if (target)
+ kernfs_get(target);
+ spin_unlock(&sysfs_symlink_target_lock);
+ if (!target)
+ return -ENOENT;
+
+ entry = kernfs_find_and_get(target_kobj->sd, target_name);
+ if (!entry) {
+ kernfs_put(target);
+ return -ENOENT;
+ }
+
+ link = kernfs_create_link(kobj->sd, target_name, entry);
+ if (IS_ERR(link) && PTR_ERR(link) == -EEXIST)
+ sysfs_warn_dup(kobj->sd, target_name);
+
+ kernfs_put(entry);
+ kernfs_put(target);
+ return IS_ERR(link) ? PTR_ERR(link) : 0;
+}
+EXPORT_SYMBOL_GPL(__compat_only_sysfs_link_entry_to_kobj);
diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
index 9f65758..ea090ea 100644
--- a/include/linux/sysfs.h
+++ b/include/linux/sysfs.h
@@ -268,6 +268,9 @@ 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 __compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,
+ struct kobject *target_kobj,
+ const char *target_name);
void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr);
@@ -451,6 +454,14 @@ static inline void sysfs_remove_link_from_group(struct
kobject *kobj,
{
}
+static inline int __compat_only_sysfs_link_entry_to_kobj(
+ struct kobject *kobj,
+ struct kobject *target_kobj,
+ const char *target_name)
+{
+ return 0;
+}
+
static inline void sysfs_notify(struct kobject *kobj, const char *dir,
const char *attr)
{
--
2.5.0
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