Re: [PATCH REPOST 2.6.10-rc2 4/4] module sysfs: module parameters reimplemented using attr group

From: Tejun Heo
Date: Tue Nov 23 2004 - 01:33:14 EST


Signed-off-by: Tejun Heo <tj@xxxxxxxxxxx>


Index: linux-export/include/linux/module.h
===================================================================
--- linux-export.orig/include/linux/module.h 2004-11-23 15:08:15.000000000 +0900
+++ linux-export/include/linux/module.h 2004-11-23 15:08:22.000000000 +0900
@@ -238,7 +238,7 @@ struct module_sect_attrs
struct module_sect_attr attrs[0];
};

-struct param_kobject;
+struct module_param_attrs;

struct module
{
@@ -252,7 +252,7 @@ struct module

/* Sysfs stuff. */
struct module_kobject mkobj;
- struct param_kobject *params_kobject;
+ struct module_param_attrs *param_attrs;

/* Exported symbols */
const struct kernel_symbol *syms;
Index: linux-export/kernel/params.c
===================================================================
--- linux-export.orig/kernel/params.c 2004-11-23 15:08:11.000000000 +0900
+++ linux-export/kernel/params.c 2004-11-23 15:08:22.000000000 +0900
@@ -357,26 +357,23 @@ extern struct kernel_param __start___par

struct param_attribute
{
- struct attribute attr;
+ struct module_attribute mattr;
struct kernel_param *param;
};

-struct param_kobject
+struct module_param_attrs
{
- struct kobject kobj;
-
- unsigned int num_attributes;
- struct param_attribute attr[0];
+ struct attribute_group grp;
+ struct param_attribute attrs[0];
};

-#define to_param_attr(n) container_of(n, struct param_attribute, attr);
+#define to_param_attr(n) container_of(n, struct param_attribute, mattr);

-static ssize_t param_attr_show(struct kobject *kobj,
- struct attribute *attr,
- char *buf)
+static ssize_t param_attr_show(struct module_attribute *mattr,
+ struct module *mod, char *buf)
{
int count;
- struct param_attribute *attribute = to_param_attr(attr);
+ struct param_attribute *attribute = to_param_attr(mattr);

if (!attribute->param->get)
return -EPERM;
@@ -390,12 +387,12 @@ static ssize_t param_attr_show(struct ko
}

/* sysfs always hands a nul-terminated string in buf. We rely on that. */
-static ssize_t param_attr_store(struct kobject *kobj,
- struct attribute *attr,
+static ssize_t param_attr_store(struct module_attribute *mattr,
+ struct module *owner,
const char *buf, size_t len)
{
int err;
- struct param_attribute *attribute = to_param_attr(attr);
+ struct param_attribute *attribute = to_param_attr(mattr);

if (!attribute->param->set)
return -EPERM;
@@ -406,27 +403,6 @@ static ssize_t param_attr_store(struct k
return err;
}

-
-static struct sysfs_ops param_sysfs_ops = {
- .show = param_attr_show,
- .store = param_attr_store,
-};
-
-static void param_kobj_release(struct kobject *kobj)
-{
- kfree(container_of(kobj, struct param_kobject, kobj));
-}
-
-static struct kobj_type param_ktype = {
- .sysfs_ops = &param_sysfs_ops,
- .release = &param_kobj_release,
-};
-
-static struct kset param_kset = {
- .subsys = &module_subsys,
- .ktype = &param_ktype,
-};
-
#ifdef CONFIG_MODULES
#define __modinit
#else
@@ -434,54 +410,6 @@ static struct kset param_kset = {
#endif

/*
- * param_add_attribute - actually adds an parameter to sysfs
- * @mod: owner of parameter
- * @pk: param_kobject the attribute shall be assigned to.
- * One per module, one per KBUILD_MODNAME.
- * @kp: kernel_param to be added
- * @skip: offset where the parameter name start in kp->name.
- * Needed for built-in modules
- *
- * Fill in data into appropriate &pk->attr[], and create sysfs file.
- */
-static __modinit int param_add_attribute(struct module *mod,
- struct param_kobject *pk,
- struct kernel_param *kp,
- unsigned int skip)
-{
- struct param_attribute *a;
- int err;
-
- a = &pk->attr[pk->num_attributes];
- a->attr.name = (char *) &kp->name[skip];
- a->attr.owner = mod;
- a->attr.mode = kp->perm;
- a->param = kp;
- err = sysfs_create_file(&pk->kobj, &a->attr);
- if (!err)
- pk->num_attributes++;
- return err;
-}
-
-/*
- * param_sysfs_remove - remove sysfs support for one module or KBUILD_MODNAME
- * @pk: struct param_kobject which is to be removed
- *
- * Called when an error in registration occurs or a module is removed
- * from the system.
- */
-static __modinit void param_sysfs_remove(struct param_kobject *pk)
-{
- unsigned int i;
- for (i = 0; i < pk->num_attributes; i++)
- sysfs_remove_file(&pk->kobj,&pk->attr[i].attr);
-
- /* Calls param_kobj_release */
- kobject_unregister(&pk->kobj);
-}
-
-
-/*
* param_sysfs_setup - setup sysfs support for one module or KBUILD_MODNAME
* @mk: struct module_kobject (contains parent kobject)
* @kparam: array of struct kernel_param, the actual parameter definitions
@@ -492,15 +420,17 @@ static __modinit void param_sysfs_remove
* in sysfs. A pointer to the param_kobject is returned on success,
* NULL if there's no parameter to export, or other ERR_PTR(err).
*/
-static __modinit struct param_kobject *
+static __modinit struct module_param_attrs *
param_sysfs_setup(struct module_kobject *mk,
struct kernel_param *kparam,
unsigned int num_params,
unsigned int name_skip)
{
- struct param_kobject *pk;
+ struct module_param_attrs *mp;
unsigned int valid_attrs = 0;
- unsigned int i;
+ unsigned int i, size[2];
+ struct param_attribute *pattr;
+ struct attribute **gattr;
int err;

for (i=0; i<num_params; i++) {
@@ -511,42 +441,39 @@ param_sysfs_setup(struct module_kobject
if (!valid_attrs)
return NULL;

- pk = kmalloc(sizeof(struct param_kobject)
- + sizeof(struct param_attribute) * valid_attrs,
- GFP_KERNEL);
- if (!pk)
+ size[0] = ALIGN(sizeof(*mp) +
+ valid_attrs * sizeof(mp->attrs[0]),
+ sizeof(mp->grp.attrs[0]));
+ size[1] = (valid_attrs + 1) * sizeof(mp->grp.attrs[0]);
+
+ mp = kmalloc(size[0] + size[1], GFP_KERNEL);
+ if (!mp)
return ERR_PTR(-ENOMEM);
- memset(pk, 0, sizeof(struct param_kobject)
- + sizeof(struct param_attribute) * valid_attrs);

- err = kobject_set_name(&pk->kobj, "parameters");
- if (err)
- goto out;
-
- pk->kobj.kset = &param_kset;
- pk->kobj.parent = &mk->kobj;
- err = kobject_register(&pk->kobj);
- if (err)
- goto out;
+ mp->grp.name = "parameters";
+ mp->grp.attrs = (void *)mp + size[0];

+ pattr = &mp->attrs[0];
+ gattr = &mp->grp.attrs[0];
for (i = 0; i < num_params; i++) {
- if (kparam[i].perm) {
- err = param_add_attribute(mk->mod, pk,
- &kparam[i], name_skip);
- if (err)
- goto out_unreg;
+ struct kernel_param *kp = &kparam[i];
+ if (kp->perm) {
+ pattr->param = kp;
+ pattr->mattr.show = param_attr_show;
+ pattr->mattr.store = param_attr_store;
+ pattr->mattr.attr.name = (char *)&kp->name[name_skip];
+ pattr->mattr.attr.owner = mk->mod;
+ pattr->mattr.attr.mode = kp->perm;
+ *(gattr++) = &(pattr++)->mattr.attr;
}
}
+ *gattr = NULL;

- return pk;
-
-out_unreg:
- param_sysfs_remove(pk);
- return ERR_PTR(err);
-
-out:
- kfree(pk);
- return ERR_PTR(err);
+ if ((err = sysfs_create_group(&mk->kobj, &mp->grp))) {
+ kfree(mp);
+ return ERR_PTR(err);
+ }
+ return mp;
}


@@ -565,13 +492,13 @@ int module_param_sysfs_setup(struct modu
struct kernel_param *kparam,
unsigned int num_params)
{
- struct param_kobject *pk;
+ struct module_param_attrs *mp;

- pk = param_sysfs_setup(&mod->mkobj, kparam, num_params, 0);
- if (IS_ERR(pk))
- return PTR_ERR(pk);
+ mp = param_sysfs_setup(&mod->mkobj, kparam, num_params, 0);
+ if (IS_ERR(mp))
+ return PTR_ERR(mp);

- mod->params_kobject = pk;
+ mod->param_attrs = mp;
return 0;
}

@@ -584,9 +511,13 @@ int module_param_sysfs_setup(struct modu
*/
void module_param_sysfs_remove(struct module *mod)
{
- if (mod->params_kobject) {
- param_sysfs_remove(mod->params_kobject);
- mod->params_kobject = NULL;
+ if (mod->param_attrs) {
+ sysfs_remove_group(&mod->mkobj.kobj,
+ &mod->param_attrs->grp);
+ /* We are positive that no one is using any param
+ * attrs at this point. Deallocate immediately. */
+ kfree(mod->param_attrs);
+ mod->param_attrs = NULL;
}
}
#endif
@@ -724,8 +655,6 @@ decl_subsys(module, &module_ktype, NULL)
static int __init param_sysfs_init(void)
{
subsystem_register(&module_subsys);
- kobject_set_name(&param_kset.kobj, "parameters");
- kset_init(&param_kset);

param_sysfs_builtin();

-
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