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-rw-r--r--lib/kobject.c93
1 files changed, 89 insertions, 4 deletions
diff --git a/lib/kobject.c b/lib/kobject.c
index 084f7b1..7a1c203 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -13,11 +13,33 @@
*/
#include <linux/kobject.h>
+#include <linux/kobj_completion.h>
#include <linux/string.h>
#include <linux/export.h>
#include <linux/stat.h>
#include <linux/slab.h>
+/**
+ * kobject_namespace - return @kobj's namespace tag
+ * @kobj: kobject in question
+ *
+ * Returns namespace tag of @kobj if its parent has namespace ops enabled
+ * and thus @kobj should have a namespace tag associated with it. Returns
+ * %NULL otherwise.
+ */
+const void *kobject_namespace(struct kobject *kobj)
+{
+ const struct kobj_ns_type_operations *ns_ops = kobj_ns_ops(kobj);
+ const void *ns;
+
+ if (!ns_ops || ns_ops->type == KOBJ_NS_TYPE_NONE)
+ return NULL;
+
+ ns = kobj->ktype->namespace(kobj);
+ WARN_ON(!ns); /* @kobj in a namespace is required to have !NULL tag */
+ return ns;
+}
+
/*
* populate_dir - populate directory with attributes.
* @kobj: object we're working on.
@@ -46,13 +68,21 @@ static int populate_dir(struct kobject *kobj)
static int create_dir(struct kobject *kobj)
{
- int error = 0;
- error = sysfs_create_dir(kobj);
+ int error;
+
+ error = sysfs_create_dir_ns(kobj, kobject_namespace(kobj));
if (!error) {
error = populate_dir(kobj);
if (error)
sysfs_remove_dir(kobj);
}
+
+ /*
+ * @kobj->sd may be deleted by an ancestor going away. Hold an
+ * extra reference so that it stays until @kobj is gone.
+ */
+ sysfs_get(kobj->sd);
+
return error;
}
@@ -428,7 +458,7 @@ int kobject_rename(struct kobject *kobj, const char *new_name)
goto out;
}
- error = sysfs_rename_dir(kobj, new_name);
+ error = sysfs_rename_dir_ns(kobj, new_name, kobject_namespace(kobj));
if (error)
goto out;
@@ -472,6 +502,7 @@ int kobject_move(struct kobject *kobj, struct kobject *new_parent)
if (kobj->kset)
new_parent = kobject_get(&kobj->kset->kobj);
}
+
/* old object path */
devpath = kobject_get_path(kobj, GFP_KERNEL);
if (!devpath) {
@@ -486,7 +517,7 @@ int kobject_move(struct kobject *kobj, struct kobject *new_parent)
sprintf(devpath_string, "DEVPATH_OLD=%s", devpath);
envp[0] = devpath_string;
envp[1] = NULL;
- error = sysfs_move_dir(kobj, new_parent);
+ error = sysfs_move_dir_ns(kobj, new_parent, kobject_namespace(kobj));
if (error)
goto out;
old_parent = kobj->parent;
@@ -508,10 +539,15 @@ out:
*/
void kobject_del(struct kobject *kobj)
{
+ struct sysfs_dirent *sd;
+
if (!kobj)
return;
+ sd = kobj->sd;
sysfs_remove_dir(kobj);
+ sysfs_put(sd);
+
kobj->state_in_sysfs = 0;
kobj_kset_leave(kobj);
kobject_put(kobj->parent);
@@ -727,6 +763,55 @@ const struct sysfs_ops kobj_sysfs_ops = {
};
/**
+ * kobj_completion_init - initialize a kobj_completion object.
+ * @kc: kobj_completion
+ * @ktype: type of kobject to initialize
+ *
+ * kobj_completion structures can be embedded within structures with different
+ * lifetime rules. During the release of the enclosing object, we can
+ * wait on the release of the kobject so that we don't free it while it's
+ * still busy.
+ */
+void kobj_completion_init(struct kobj_completion *kc, struct kobj_type *ktype)
+{
+ init_completion(&kc->kc_unregister);
+ kobject_init(&kc->kc_kobj, ktype);
+}
+EXPORT_SYMBOL_GPL(kobj_completion_init);
+
+/**
+ * kobj_completion_release - release a kobj_completion object
+ * @kobj: kobject embedded in kobj_completion
+ *
+ * Used with kobject_release to notify waiters that the kobject has been
+ * released.
+ */
+void kobj_completion_release(struct kobject *kobj)
+{
+ struct kobj_completion *kc = kobj_to_kobj_completion(kobj);
+ complete(&kc->kc_unregister);
+}
+EXPORT_SYMBOL_GPL(kobj_completion_release);
+
+/**
+ * kobj_completion_del_and_wait - release the kobject and wait for it
+ * @kc: kobj_completion object to release
+ *
+ * Delete the kobject from sysfs and drop the reference count. Then wait
+ * until any other outstanding references are also dropped. This routine
+ * is only necessary once other references may have been taken on the
+ * kobject. Typically this happens when the kobject has been published
+ * to sysfs via kobject_add.
+ */
+void kobj_completion_del_and_wait(struct kobj_completion *kc)
+{
+ kobject_del(&kc->kc_kobj);
+ kobject_put(&kc->kc_kobj);
+ wait_for_completion(&kc->kc_unregister);
+}
+EXPORT_SYMBOL_GPL(kobj_completion_del_and_wait);
+
+/**
* kset_register - initialize and add a kset.
* @k: kset.
*/
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