linux/fs/sysfs/sysfs.h

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/* SPDX-License-Identifier: GPL-2.0 */
/*
* fs/sysfs/sysfs.h - sysfs internal header file
*
* Copyright (c) 2001-3 Patrick Mochel
* Copyright (c) 2007 SUSE Linux Products GmbH
* Copyright (c) 2007 Tejun Heo <teheo@suse.de>
*/
#ifndef __SYSFS_INTERNAL_H
#define __SYSFS_INTERNAL_H
#include <linux/sysfs.h>
sysfs: restructure add/remove paths and fix inode update The original add/remove code had the following problems. * parent's timestamps are updated on dentry instantiation. this is incorrect with reclaimable files. * updating parent's timestamps isn't synchronized. * parent nlink update assumes the inode is accessible which won't be true once directory dentries are made reclaimable. This patch restructures add/remove paths to resolve the above problems. Add/removal are done in the following steps. 1. sysfs_addrm_start() : acquire locks including sysfs_mutex and other resources. 2-a. sysfs_add_one() : add new sd. linking the new sd into the children list is caller's responsibility. 2-b. sysfs_remove_one() : remove a sd. unlinking the sd from the children list is caller's responsibility. 3. sysfs_addrm_finish() : release all resources and clean up. Steps 2-a and/or 2-b can be repeated multiple times. Parent's inode is looked up during sysfs_addrm_start(). If available (always at the moment), it's pinned and nlink is updated as sd's are added and removed. Timestamps are updated during finish if any sd has been added or removed. If parent's inode is not available during start, sysfs_mutex ensures that parent inode is not created till add/remove is complete. All the complexity is contained inside the helper functions. Especially, dentry/inode handling is properly hidden from the rest of sysfs which now mostly operate on sysfs_dirents. As an added bonus, codes which use these helpers to add and remove sysfs_dirents are now more structured and simpler. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-06-13 19:27:24 +00:00
/*
* mount.c
*/
extern struct kernfs_node *sysfs_root_kn;
/*
* dir.c
*/
extern spinlock_t sysfs_symlink_target_lock;
void sysfs_warn_dup(struct kernfs_node *parent, const char *name);
/*
* file.c
*/
int sysfs_add_file_mode_ns(struct kernfs_node *parent,
const struct attribute *attr, umode_t amode, kuid_t uid,
kgid_t gid, const void *ns);
int sysfs_add_bin_file_mode_ns(struct kernfs_node *parent,
const struct bin_attribute *battr, umode_t mode,
kuid_t uid, kgid_t gid, const void *ns);
/*
* symlink.c
*/
int sysfs_create_link_sd(struct kernfs_node *kn, struct kobject *target,
const char *name);
#endif /* __SYSFS_INTERNAL_H */