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authorJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>2015-04-22 19:36:06 +0300
committerPeter Huewe <peterhuewe@gmx.de>2015-10-19 01:01:19 +0200
commit37c1c04cca920de8a68285751b2c7b3d937ad50c (patch)
tree3765e559cc8cce4341f9e26400c23d0f1b1ee487 /fs/sysfs
parent399235dc6e95400a1322a9999e92073bc572f0c8 (diff)
downloadlinux-37c1c04cca920de8a68285751b2c7b3d937ad50c.tar.bz2
sysfs: added __compat_only_sysfs_link_entry_to_kobj()
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.sakkinen@linux.intel.com> Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Diffstat (limited to 'fs/sysfs')
-rw-r--r--fs/sysfs/group.c44
1 files changed, 44 insertions, 0 deletions
diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c
index 39a019936768..e1236594fffe 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);