[SCSI] sysfs: add filter function to groups
This patch allows the various users of attribute_groups to selectively
allow the appearance of group attributes. The primary consumer of
this will be the transport classes in which we currently have
elaborate attribute selection algorithms to do this same thing.
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c
index d197237..0871c3d 100644
--- a/fs/sysfs/group.c
+++ b/fs/sysfs/group.c
@@ -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 @@
} 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 @@
} else
sd = sysfs_get(dir_sd);
- remove_files(sd, grp);
+ remove_files(sd, kobj, grp);
if (grp->name)
sysfs_remove_subdir(sd);
diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
index 149ab62..8027104 100644
--- a/include/linux/sysfs.h
+++ b/include/linux/sysfs.h
@@ -32,6 +32,8 @@
struct attribute_group {
const char *name;
+ int (*is_visible)(struct kobject *,
+ struct attribute *, int);
struct attribute **attrs;
};
diff --git a/kernel/params.c b/kernel/params.c
index 7686417..dfef464 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -472,7 +472,7 @@
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);