[RFC 1/6] sysfs-kobject.patch
From: Maneesh Soni
Date: Mon Oct 06 2003 - 04:01:44 EST
o This patch adds new fields to struct kobject for providing
parent-child-sibling based hierarchy. Using these links we can traverse
the hierarchy in both directions. All these fields are intialised in
kobject_init and modified accordingly in kobject_add and kobject_del.
o The new fields attr, and attr_groups link the attributes and attribute
groups to the kobject. These are linked using the new structures
kobject_attr and kobject_attr_group as we cannot link the struct attribute
directly to the kobject because these are generally embedded in other
struct and are referenced with offsets.
o All the lists are protected by the read-write semaphore k_rwsem.
o All the subsystems are linked in the kobj_subsystem_list which is protected
using spinlock kobj_subsystem_lock.
include/linux/kobject.h | 33 ++++++++++++++++++++++++++++++
lib/kobject.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 84 insertions(+), 1 deletion(-)
diff -puN include/linux/kobject.h~sysfs-kobject include/linux/kobject.h
--- linux-2.6.0-test6/include/linux/kobject.h~sysfs-kobject 2003-10-06 11:48:37.000000000 +0530
+++ linux-2.6.0-test6-maneesh/include/linux/kobject.h 2003-10-06 11:48:51.000000000 +0530
@@ -32,6 +32,12 @@ struct kobject {
struct kset * kset;
struct kobj_type * ktype;
struct dentry * dentry;
+ struct list_head k_sibling;
+ struct list_head k_children;
+ struct list_head attr;
+ struct list_head attr_group;
+ struct rw_semaphore k_rwsem;
+ char *k_symlink;
};
extern int kobject_set_name(struct kobject *, const char *, ...)
@@ -57,6 +63,29 @@ extern struct kobject * kobject_get(stru
extern void kobject_put(struct kobject *);
+struct kobject_attr {
+ struct list_head list;
+ int flags;
+ union {
+ const struct attribute * attr;
+ const struct bin_attribute * bin_attr;
+ } attr_u;
+};
+
+#define KOBJ_TEXT_ATTR 0x0001
+#define KOBJ_BINARY_ATTR 0x0002
+
+static inline const struct attribute *
+kobject_attr(struct kobject_attr * k_attr)
+{
+ return ((k_attr->flags & KOBJ_TEXT_ATTR) ? k_attr->attr_u.attr : &k_attr->attr_u.bin_attr->attr);
+}
+
+struct kobject_attr_group {
+ struct list_head list;
+ const struct attribute_group * attr_group;
+};
+
struct kobj_type {
void (*release)(struct kobject *);
struct sysfs_ops * sysfs_ops;
@@ -140,8 +169,12 @@ extern struct kobject * kset_find_obj(st
struct subsystem {
struct kset kset;
struct rw_semaphore rwsem;
+ struct list_head next;
};
+extern spinlock_t kobj_subsystem_lock;
+extern struct list_head kobj_subsystem_list;
+
#define decl_subsys(_name,_type,_hotplug_ops) \
struct subsystem _name##_subsys = { \
.kset = { \
diff -puN lib/kobject.c~sysfs-kobject lib/kobject.c
--- linux-2.6.0-test6/lib/kobject.c~sysfs-kobject 2003-10-06 11:48:44.000000000 +0530
+++ linux-2.6.0-test6-maneesh/lib/kobject.c 2003-10-06 11:51:51.000000000 +0530
@@ -17,6 +17,9 @@
#include <linux/module.h>
#include <linux/stat.h>
+spinlock_t kobj_subsystem_lock = SPIN_LOCK_UNLOCKED;
+LIST_HEAD(kobj_subsystem_list);
+
/**
* populate_dir - populate directory with attributes.
* @kobj: object we're working on.
@@ -216,6 +219,12 @@ void kobject_init(struct kobject * kobj)
atomic_set(&kobj->refcount,1);
INIT_LIST_HEAD(&kobj->entry);
kobj->kset = kset_get(kobj->kset);
+ kobj->dentry = NULL;
+ init_rwsem(&kobj->k_rwsem);
+ INIT_LIST_HEAD(&kobj->k_children);
+ INIT_LIST_HEAD(&kobj->attr);
+ INIT_LIST_HEAD(&kobj->attr_group);
+ kobj->k_symlink = NULL;
}
@@ -236,8 +245,12 @@ static void unlink(struct kobject * kobj
list_del_init(&kobj->entry);
up_write(&kobj->kset->subsys->rwsem);
}
- if (kobj->parent)
+ if (kobj->parent) {
+ down_write(&kobj->parent->k_rwsem);
+ list_del_init(&kobj->k_sibling);
+ up_write(&kobj->parent->k_rwsem);
kobject_put(kobj->parent);
+ }
kobject_put(kobj);
}
@@ -273,6 +286,15 @@ int kobject_add(struct kobject * kobj)
}
kobj->parent = parent;
+ if (kobj->parent) {
+ down_write(&parent->k_rwsem);
+ list_add(&kobj->k_sibling, &kobj->parent->k_children);
+ up_write(&parent->k_rwsem);
+ }
+ else {
+ INIT_LIST_HEAD(&kobj->k_sibling);
+ }
+
error = create_dir(kobj);
if (error)
unlink(kobj);
@@ -443,11 +465,32 @@ void kobject_cleanup(struct kobject * ko
{
struct kobj_type * t = get_ktype(kobj);
struct kset * s = kobj->kset;
+ struct list_head * tmp = kobj->attr.next;
pr_debug("kobject %s: cleaning up\n",kobject_name(kobj));
+
+ down_write(&kobj->k_rwsem);
if (kobj->k_name != kobj->name)
kfree(kobj->k_name);
kobj->k_name = NULL;
+
+ while (tmp != &kobj->attr) {
+ struct kobject_attr * k_attr;
+ k_attr = list_entry(tmp, struct kobject_attr, list);
+ tmp = tmp->next;
+ list_del(&k_attr->list);
+ kfree(k_attr);
+ }
+ tmp = kobj->attr_group.next;
+ while (tmp != &kobj->attr_group) {
+ struct kobject_attr_group * k_attr_group;
+ k_attr_group = list_entry(tmp, struct kobject_attr_group, list);
+ tmp = tmp->next;
+ list_del(&k_attr_group->list);
+ kfree(k_attr_group);
+ }
+ up_write(&kobj->k_rwsem);
+
if (t && t->release)
t->release(kobj);
if (s)
@@ -557,6 +600,7 @@ void subsystem_init(struct subsystem * s
{
init_rwsem(&s->rwsem);
kset_init(&s->kset);
+ INIT_LIST_HEAD(&s->next);
}
/**
@@ -578,6 +622,9 @@ int subsystem_register(struct subsystem
if (!(error = kset_add(&s->kset))) {
if (!s->kset.subsys)
s->kset.subsys = s;
+ spin_lock(&kobj_subsystem_lock);
+ list_add(&s->next, &kobj_subsystem_list);
+ spin_unlock(&kobj_subsystem_lock);
}
return error;
}
@@ -585,6 +632,9 @@ int subsystem_register(struct subsystem
void subsystem_unregister(struct subsystem * s)
{
pr_debug("subsystem %s: unregistering\n",s->kset.kobj.name);
+ spin_lock(&kobj_subsystem_lock);
+ list_del_init(&s->next);
+ spin_unlock(&kobj_subsystem_lock);
kset_unregister(&s->kset);
}
_
--
Maneesh Soni
Linux Technology Center,
IBM Software Lab, Bangalore, India
email: maneesh@xxxxxxxxxx
Phone: 91-80-5044999 Fax: 91-80-5268553
T/L : 9243696
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