[PATCH 49/54] Driver Core: kill subsys_attribute and default sysfs ops

Greg Kroah-Hartman
2007-11-03T00:16:47Z

From: Kay Sievers <kay.sievers@vrfy.org>

Remove the no longer needed subsys_attributes, they are all converted to
the more sensical kobj_attributes.

There is no longer a magic fallback in sysfs attribute operations, all
kobjects which create simple attributes need explicitely a ktype
assigned, which tells the core what was intended here.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
fs/sysfs/file.c | 63 +++++++---------------------------------------
include/linux/kobject.h | 9 ------
lib/kobject.c | 21 ---------------
3 files changed, 10 insertions(+), 83 deletions(-)

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 4d6fba0..fb5a1c2 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -20,43 +20,6 @@

#include "sysfs.h"

-#define to_sattr(a) container_of(a,struct subsys_attribute, attr)
-
-/*
- * Subsystem file operations.
- * These operations allow subsystems to have files that can be
- * read/written.
- */
-static ssize_t
-subsys_attr_show(struct kobject * kobj, struct attribute * attr, char * page)
-{
- struct kset *kset = to_kset(kobj);
- struct subsys_attribute * sattr = to_sattr(attr);
- ssize_t ret = -EIO;
-
- if (sattr->show)
- ret = sattr->show(kset, page);
- return ret;
-}
-
-static ssize_t
-subsys_attr_store(struct kobject * kobj, struct attribute * attr,
- const char * page, size_t count)
-{
- struct kset *kset = to_kset(kobj);
- struct subsys_attribute * sattr = to_sattr(attr);
- ssize_t ret = -EIO;
-
- if (sattr->store)
- ret = sattr->store(kset, page, count);
- return ret;
-}
-
-static struct sysfs_ops subsys_sysfs_ops = {
- .show = subsys_attr_show,
- .store = subsys_attr_store,
-};
-
/*
* There's one sysfs_buffer for each open file and one
* sysfs_open_dirent for each sysfs_dirent with one or more open
@@ -350,29 +313,23 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
{
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
- struct sysfs_buffer * buffer;
- struct sysfs_ops * ops = NULL;
- int error;
+ struct sysfs_buffer *buffer;
+ struct sysfs_ops *ops;
+ int error = -EACCES;

/* need attr_sd for attr and ops, its parent for kobj */
if (!sysfs_get_active_two(attr_sd))
return -ENODEV;

- /* if the kobject has no ktype, then we assume that it is a subsystem
- * itself, and use ops for it.
- */
- if (kobj->ktype)
+ /* every kobject with an attribute needs a ktype assigned */
+ if (kobj->ktype && kobj->ktype->sysfs_ops)
ops = kobj->ktype->sysfs_ops;
- else
- ops = &subsys_sysfs_ops;
-
- error = -EACCES;
-
- /* No sysfs operations, either from having no subsystem,
- * or the subsystem have no operations.
- */
- if (!ops)
+ else {
+ printk(KERN_ERR "missing sysfs attribute operations for "
+ "kobject: %s\n", kobject_name(kobj));
+ WARN_ON(1);
goto err_out;
+ }

/* File needs write support.
* The inode's perms must say it's ok,
diff --git a/include/linux/kobject.h b/include/linux/kobject.h
index 3aa8108..05c8ef8 100644
--- a/include/linux/kobject.h
+++ b/include/linux/kobject.h
@@ -210,15 +210,6 @@ extern struct kset *firmware_kset;
extern int __must_check subsystem_register(struct kset *);
extern void subsystem_unregister(struct kset *);

-struct subsys_attribute {
- struct attribute attr;
- ssize_t (*show)(struct kset *, char *);
- ssize_t (*store)(struct kset *, const char *, size_t);
-};
-
-extern int __must_check subsys_create_file(struct kset *,
- struct subsys_attribute *);
-
#if defined(CONFIG_HOTPLUG)
int kobject_uevent(struct kobject *kobj, enum kobject_action action);
int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
diff --git a/lib/kobject.c b/lib/kobject.c
index dda6614..c768e0c 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -671,26 +671,6 @@ void subsystem_unregister(struct kset *s)
kset_unregister(s);
}

-/**
- * subsystem_create_file - export sysfs attribute file.
- * @s: subsystem.
- * @a: subsystem attribute descriptor.
- */
-
-int subsys_create_file(struct kset *s, struct subsys_attribute *a)
-{
- int error = 0;
-
- if (!s || !a)
- return -EINVAL;
-
- if (kset_get(s)) {
- error = sysfs_create_file(&s->kobj, &a->attr);
- kset_put(s);
- }
- return error;
-}
-
static void kset_release(struct kobject *kobj)
{
struct kset *kset = container_of(kobj, struct kset, kobj);
@@ -795,4 +775,3 @@ EXPORT_SYMBOL(kset_unregister);

EXPORT_SYMBOL(subsystem_register);
EXPORT_SYMBOL(subsystem_unregister);
-EXPORT_SYMBOL(subsys_create_file);
--
1.5.3.4