We don't want to hardcode default groups at subsystem
creation time. We export:
* configfs_register_group
* configfs_unregister_group
to allow drivers to programatically create/destroy groups
later, after module init time.
This is needed for IIO configfs support.
Suggested-by: Lars-Peter Clausen <l...@metafoo.de>
Signed-off-by: Daniel Baluta <daniel.bal...@intel.com>
---
fs/configfs/dir.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/configfs.h | 4 ++++
2 files changed, 54 insertions(+)
diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index c81ce7f..1f5337c 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -1636,6 +1636,56 @@ const struct file_operations configfs_dir_operations = {
.iterate = configfs_readdir,
};
+int configfs_register_group(struct config_group *parent_group,
+ struct config_group *group)
+{
+ struct configfs_subsystem *subsys = parent_group->cg_subsys;
+ struct dentry *parent;
+ int ret;
+
+ mutex_lock(&subsys->su_mutex);
+ link_group(parent_group, group);
+ mutex_unlock(&subsys->su_mutex);
+
+ parent = parent_group->cg_item.ci_dentry;
+
+ mutex_lock_nested(&d_inode(parent)->i_mutex, I_MUTEX_PARENT);
+ ret = create_default_group(parent_group, group);
+ if (!ret) {
+ spin_lock(&configfs_dirent_lock);
+ configfs_dir_set_ready(group->cg_item.ci_dentry->d_fsdata);
+ spin_unlock(&configfs_dirent_lock);
+ }
+ mutex_unlock(&d_inode(parent)->i_mutex);
+ return ret;
+}
+EXPORT_SYMBOL(configfs_register_group);
+
+void configfs_unregister_group(struct config_group *group)
+{
+ struct configfs_subsystem *subsys = group->cg_subsys;
+ struct dentry *dentry = group->cg_item.ci_dentry;
+ struct dentry *parent = group->cg_item.ci_parent->ci_dentry;
+
+ mutex_lock_nested(&d_inode(parent)->i_mutex, I_MUTEX_PARENT);
+ spin_lock(&configfs_dirent_lock);
+ configfs_detach_prep(dentry, NULL);
+ spin_unlock(&configfs_dirent_lock);
+
+ configfs_detach_group(&group->cg_item);
+ d_inode(dentry)->i_flags |= S_DEAD;
+ dont_mount(dentry);
+ d_delete(dentry);
+ mutex_unlock(&d_inode(parent)->i_mutex);
+
+ dput(dentry);
+
+ mutex_lock(&subsys->su_mutex);
+ unlink_group(group);
+ mutex_unlock(&subsys->su_mutex);
+}
+EXPORT_SYMBOL(configfs_unregister_group);
+
int configfs_register_subsystem(struct configfs_subsystem *subsys)
{
int err;
diff --git a/include/linux/configfs.h b/include/linux/configfs.h
index 63a36e8..c40b8143 100644
--- a/include/linux/configfs.h
+++ b/include/linux/configfs.h
@@ -252,6 +252,10 @@ static inline struct configfs_subsystem
*to_configfs_subsystem(struct config_gro
int configfs_register_subsystem(struct configfs_subsystem *subsys);
void configfs_unregister_subsystem(struct configfs_subsystem *subsys);
+int configfs_register_group(struct config_group *parent_group,
+ struct config_group *group);
+void configfs_unregister_group(struct config_group *group);
+
/* These functions can sleep and can alloc with GFP_KERNEL */
/* WARNING: These cannot be called underneath configfs callbacks!! */
int configfs_depend_item(struct configfs_subsystem *subsys, struct config_item
*target);
--
1.9.1
--
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