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-rw-r--r--fs/sysfs/group.c45
-rw-r--r--include/linux/sysfs.h63
2 files changed, 87 insertions, 21 deletions
diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c
index 138676463336..ccb275cdabcb 100644
--- a/fs/sysfs/group.c
+++ b/fs/sysfs/group.c
@@ -31,6 +31,17 @@ static void remove_files(struct kernfs_node *parent,
kernfs_remove_by_name(parent, (*bin_attr)->attr.name);
}
+static umode_t __first_visible(const struct attribute_group *grp, struct kobject *kobj)
+{
+ if (grp->attrs && grp->is_visible)
+ return grp->is_visible(kobj, grp->attrs[0], 0);
+
+ if (grp->bin_attrs && grp->is_bin_visible)
+ return grp->is_bin_visible(kobj, grp->bin_attrs[0], 0);
+
+ return 0;
+}
+
static int create_files(struct kernfs_node *parent, struct kobject *kobj,
kuid_t uid, kgid_t gid,
const struct attribute_group *grp, int update)
@@ -52,6 +63,7 @@ static int create_files(struct kernfs_node *parent, struct kobject *kobj,
kernfs_remove_by_name(parent, (*attr)->name);
if (grp->is_visible) {
mode = grp->is_visible(kobj, *attr, i);
+ mode &= ~SYSFS_GROUP_INVISIBLE;
if (!mode)
continue;
}
@@ -81,6 +93,7 @@ static int create_files(struct kernfs_node *parent, struct kobject *kobj,
(*bin_attr)->attr.name);
if (grp->is_bin_visible) {
mode = grp->is_bin_visible(kobj, *bin_attr, i);
+ mode &= ~SYSFS_GROUP_INVISIBLE;
if (!mode)
continue;
}
@@ -127,16 +140,31 @@ static int internal_create_group(struct kobject *kobj, int update,
kobject_get_ownership(kobj, &uid, &gid);
if (grp->name) {
+ umode_t mode = __first_visible(grp, kobj);
+
+ if (mode & SYSFS_GROUP_INVISIBLE)
+ mode = 0;
+ else
+ mode = S_IRWXU | S_IRUGO | S_IXUGO;
+
if (update) {
kn = kernfs_find_and_get(kobj->sd, grp->name);
if (!kn) {
- pr_warn("Can't update unknown attr grp name: %s/%s\n",
- kobj->name, grp->name);
- return -EINVAL;
+ pr_debug("attr grp %s/%s not created yet\n",
+ kobj->name, grp->name);
+ /* may have been invisible prior to this update */
+ update = 0;
+ } else if (!mode) {
+ sysfs_remove_group(kobj, grp);
+ kernfs_put(kn);
+ return 0;
}
- } else {
- kn = kernfs_create_dir_ns(kobj->sd, grp->name,
- S_IRWXU | S_IRUGO | S_IXUGO,
+ }
+
+ if (!update) {
+ if (!mode)
+ return 0;
+ kn = kernfs_create_dir_ns(kobj->sd, grp->name, mode,
uid, gid, kobj, NULL);
if (IS_ERR(kn)) {
if (PTR_ERR(kn) == -EEXIST)
@@ -279,9 +307,8 @@ void sysfs_remove_group(struct kobject *kobj,
if (grp->name) {
kn = kernfs_find_and_get(parent, grp->name);
if (!kn) {
- WARN(!kn, KERN_WARNING
- "sysfs group '%s' not found for kobject '%s'\n",
- grp->name, kobject_name(kobj));
+ pr_debug("sysfs group '%s' not found for kobject '%s'\n",
+ grp->name, kobject_name(kobj));
return;
}
} else {
diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
index b717a70219f6..a42642b277dd 100644
--- a/include/linux/sysfs.h
+++ b/include/linux/sysfs.h
@@ -61,22 +61,32 @@ do { \
/**
* struct attribute_group - data structure used to declare an attribute group.
* @name: Optional: Attribute group name
- * If specified, the attribute group will be created in
- * a new subdirectory with this name.
+ * If specified, the attribute group will be created in a
+ * new subdirectory with this name. Additionally when a
+ * group is named, @is_visible and @is_bin_visible may
+ * return SYSFS_GROUP_INVISIBLE to control visibility of
+ * the directory itself.
* @is_visible: Optional: Function to return permissions associated with an
- * attribute of the group. Will be called repeatedly for each
- * non-binary attribute in the group. Only read/write
+ * attribute of the group. Will be called repeatedly for
+ * each non-binary attribute in the group. Only read/write
* permissions as well as SYSFS_PREALLOC are accepted. Must
- * return 0 if an attribute is not visible. The returned value
- * will replace static permissions defined in struct attribute.
+ * return 0 if an attribute is not visible. The returned
+ * value will replace static permissions defined in struct
+ * attribute. Use SYSFS_GROUP_VISIBLE() when assigning this
+ * callback to specify separate _group_visible() and
+ * _attr_visible() handlers.
* @is_bin_visible:
* Optional: Function to return permissions associated with a
* binary attribute of the group. Will be called repeatedly
* for each binary attribute in the group. Only read/write
- * permissions as well as SYSFS_PREALLOC are accepted. Must
- * return 0 if a binary attribute is not visible. The returned
- * value will replace static permissions defined in
- * struct bin_attribute.
+ * permissions as well as SYSFS_PREALLOC (and the
+ * visibility flags for named groups) are accepted. Must
+ * return 0 if a binary attribute is not visible. The
+ * returned value will replace static permissions defined
+ * in struct bin_attribute. If @is_visible is not set, Use
+ * SYSFS_GROUP_VISIBLE() when assigning this callback to
+ * specify separate _group_visible() and _attr_visible()
+ * handlers.
* @attrs: Pointer to NULL terminated list of attributes.
* @bin_attrs: Pointer to NULL terminated list of binary attributes.
* Either attrs or bin_attrs or both must be provided.
@@ -91,13 +101,42 @@ struct attribute_group {
struct bin_attribute **bin_attrs;
};
+#define SYSFS_PREALLOC 010000
+#define SYSFS_GROUP_INVISIBLE 020000
+
+/*
+ * The first call to is_visible() in the create / update path may
+ * indicate visibility for the entire group
+ */
+#define DEFINE_SYSFS_GROUP_VISIBLE(name) \
+ static inline umode_t sysfs_group_visible_##name( \
+ struct kobject *kobj, struct attribute *attr, int n) \
+ { \
+ if (n == 0 && !name##_group_visible(kobj)) \
+ return SYSFS_GROUP_INVISIBLE; \
+ return name##_attr_visible(kobj, attr, n); \
+ }
+
+/*
+ * Same as DEFINE_SYSFS_GROUP_VISIBLE, but for groups with only binary
+ * attributes
+ */
+#define DEFINE_SYSFS_BIN_GROUP_VISIBLE(name) \
+ static inline umode_t sysfs_group_visible_##name( \
+ struct kobject *kobj, struct bin_attribute *attr, int n) \
+ { \
+ if (n == 0 && !name##_group_visible(kobj)) \
+ return SYSFS_GROUP_INVISIBLE; \
+ return name##_attr_visible(kobj, attr, n); \
+ }
+
+#define SYSFS_GROUP_VISIBLE(fn) sysfs_group_visible_##fn
+
/*
* Use these macros to make defining attributes easier.
* See include/linux/device.h for examples..
*/
-#define SYSFS_PREALLOC 010000
-
#define __ATTR(_name, _mode, _show, _store) { \
.attr = {.name = __stringify(_name), \
.mode = VERIFY_OCTAL_PERMISSIONS(_mode) }, \
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-17 04:41:44 +0000