Re: [PATCH] sysfs: add filter function to groups

James Bottomley
2007-10-31T14:38:21Z

On Tue, 2007-10-30 at 20:55 -0700, Greg KH wrote:
> OSame problem here, if grp->is_visible is not set, sysfs_add_file() would
> never be called, right?
>
> Other than the logic problem (I think), I have no issue with this idea
> at all. Care to redo this so it works?

It's a fair cop govenor ... new patch attached.

James

---
Index: BUILD-2.6/fs/sysfs/group.c
===================================================================
--- BUILD-2.6.orig/fs/sysfs/group.c 2007-10-28 17:27:04.000000000 -0500
+++ BUILD-2.6/fs/sysfs/group.c 2007-10-31 09:29:14.000000000 -0500
@@ -16,25 +16,31 @@
#include "sysfs.h"

-static void remove_files(struct sysfs_dirent *dir_sd,
+static void remove_files(struct sysfs_dirent *dir_sd, struct kobject *kobj,
const struct attribute_group *grp)
{
struct attribute *const* attr;
+ int i;

- for (attr = grp->attrs; *attr; attr++)
- sysfs_hash_and_remove(dir_sd, (*attr)->name);
+ for (i = 0, attr = grp->attrs; *attr; i++, attr++)
+ if (!grp->is_visible ||
+ grp->is_visible(kobj, *attr, i))
+ sysfs_hash_and_remove(dir_sd, (*attr)->name);
}

-static int create_files(struct sysfs_dirent *dir_sd,
+static int create_files(struct sysfs_dirent *dir_sd, struct kobject *kobj,
const struct attribute_group *grp)
{
struct attribute *const* attr;
- int error = 0;
+ int error = 0, i;

- for (attr = grp->attrs; *attr && !error; attr++)
- error = sysfs_add_file(dir_sd, *attr, SYSFS_KOBJ_ATTR);
+ for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++)
+ if (!grp->is_visible ||
+ grp->is_visible(kobj, *attr, i))
+ error |=
+ sysfs_add_file(dir_sd, *attr, SYSFS_KOBJ_ATTR);
if (error)
- remove_files(dir_sd, grp);
+ remove_files(dir_sd, kobj, grp);
return error;
}

@@ -54,7 +60,7 @@ int sysfs_create_group(struct kobject *
} else
sd = kobj->sd;
sysfs_get(sd);
- error = create_files(sd, grp);
+ error = create_files(sd, kobj, grp);
if (error) {
if (grp->name)
sysfs_remove_subdir(sd);
@@ -75,7 +81,7 @@ void sysfs_remove_group(struct kobject *
} else
sd = sysfs_get(dir_sd);

- remove_files(sd, grp);
+ remove_files(sd, kobj, grp);
if (grp->name)
sysfs_remove_subdir(sd);

Index: BUILD-2.6/include/linux/sysfs.h
===================================================================
--- BUILD-2.6.orig/include/linux/sysfs.h 2007-10-28 17:20:06.000000000 -0500
+++ BUILD-2.6/include/linux/sysfs.h 2007-10-30 13:24:06.000000000 -0500
@@ -32,6 +32,8 @@ struct attribute {

struct attribute_group {
const char *name;
+ int (*is_visible)(struct kobject *,
+ struct attribute *, int);
struct attribute **attrs;
};

Index: BUILD-2.6/kernel/params.c
===================================================================
--- BUILD-2.6.orig/kernel/params.c 2007-10-29 01:18:43.000000000 -0500
+++ BUILD-2.6/kernel/params.c 2007-10-29 01:18:49.000000000 -0500
@@ -472,7 +472,7 @@ param_sysfs_setup(struct module_kobject
sizeof(mp->grp.attrs[0]));
size[1] = (valid_attrs + 1) * sizeof(mp->grp.attrs[0]);

- mp = kmalloc(size[0] + size[1], GFP_KERNEL);
+ mp = kzalloc(size[0] + size[1], GFP_KERNEL);
if (!mp)
return ERR_PTR(-ENOMEM);