1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 * fs/kernfs/kernfs-internal.h - kernfs internal header file
  4 *
  5 * Copyright (c) 2001-3 Patrick Mochel
  6 * Copyright (c) 2007 SUSE Linux Products GmbH
  7 * Copyright (c) 2007, 2013 Tejun Heo <teheo@suse.de>
  8 */
  9
 10#ifndef __KERNFS_INTERNAL_H
 11#define __KERNFS_INTERNAL_H
 12
 13#include <linux/lockdep.h>
 14#include <linux/fs.h>
 15#include <linux/mutex.h>
 16#include <linux/rwsem.h>
 17#include <linux/xattr.h>
 18
 19#include <linux/kernfs.h>
 20#include <linux/fs_context.h>
 21
 22struct kernfs_iattrs {
 23	kuid_t			ia_uid;
 24	kgid_t			ia_gid;
 25	struct timespec64	ia_atime;
 26	struct timespec64	ia_mtime;
 27	struct timespec64	ia_ctime;
 28
 29	struct simple_xattrs	xattrs;
 30	atomic_t		nr_user_xattrs;
 31	atomic_t		user_xattr_size;
 32};
 33
 34struct kernfs_root {
 35	/* published fields */
 36	struct kernfs_node	*kn;
 37	unsigned int		flags;	/* KERNFS_ROOT_* flags */
 38
 39	/* private fields, do not use outside kernfs proper */
 40	struct idr		ino_idr;
 41	u32			last_id_lowbits;
 42	u32			id_highbits;
 43	struct kernfs_syscall_ops *syscall_ops;
 44
 45	/* list of kernfs_super_info of this root, protected by kernfs_rwsem */
 46	struct list_head	supers;
 47
 48	wait_queue_head_t	deactivate_waitq;
 49	struct rw_semaphore	kernfs_rwsem;
 50	struct rw_semaphore	kernfs_iattr_rwsem;
 51	struct rw_semaphore	kernfs_supers_rwsem;
 52
 53	struct rcu_head		rcu;
 54};
 55
 56/* +1 to avoid triggering overflow warning when negating it */
 57#define KN_DEACTIVATED_BIAS		(INT_MIN + 1)
 58
 59/* KERNFS_TYPE_MASK and types are defined in include/linux/kernfs.h */
 60
 61/**
 62 * kernfs_root - find out the kernfs_root a kernfs_node belongs to
 63 * @kn: kernfs_node of interest
 64 *
 65 * Return: the kernfs_root @kn belongs to.
 66 */
 67static inline struct kernfs_root *kernfs_root(struct kernfs_node *kn)
 68{
 69	/* if parent exists, it's always a dir; otherwise, @sd is a dir */
 70	if (kn->parent)
 71		kn = kn->parent;
 72	return kn->dir.root;
 73}
 74
 75/*
 76 * mount.c
 77 */
 78struct kernfs_super_info {
 79	struct super_block	*sb;
 80
 81	/*
 82	 * The root associated with this super_block.  Each super_block is
 83	 * identified by the root and ns it's associated with.
 84	 */
 85	struct kernfs_root	*root;
 86
 87	/*
 88	 * Each sb is associated with one namespace tag, currently the
 89	 * network namespace of the task which mounted this kernfs
 90	 * instance.  If multiple tags become necessary, make the following
 91	 * an array and compare kernfs_node tag against every entry.
 92	 */
 93	const void		*ns;
 94
 95	/* anchored at kernfs_root->supers, protected by kernfs_rwsem */
 96	struct list_head	node;
 97};
 98#define kernfs_info(SB) ((struct kernfs_super_info *)(SB->s_fs_info))
 99
100static inline struct kernfs_node *kernfs_dentry_node(struct dentry *dentry)
101{
102	if (d_really_is_negative(dentry))
103		return NULL;
104	return d_inode(dentry)->i_private;
105}
106
107static inline void kernfs_set_rev(struct kernfs_node *parent,
108				  struct dentry *dentry)
109{
110	dentry->d_time = parent->dir.rev;
111}
112
113static inline void kernfs_inc_rev(struct kernfs_node *parent)
114{
115	parent->dir.rev++;
116}
117
118static inline bool kernfs_dir_changed(struct kernfs_node *parent,
119				      struct dentry *dentry)
120{
121	if (parent->dir.rev != dentry->d_time)
122		return true;
123	return false;
124}
125
126extern const struct super_operations kernfs_sops;
127extern struct kmem_cache *kernfs_node_cache, *kernfs_iattrs_cache;
128
129/*
130 * inode.c
131 */
132extern const struct xattr_handler * const kernfs_xattr_handlers[];
133void kernfs_evict_inode(struct inode *inode);
134int kernfs_iop_permission(struct mnt_idmap *idmap,
135			  struct inode *inode, int mask);
136int kernfs_iop_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
137		       struct iattr *iattr);
138int kernfs_iop_getattr(struct mnt_idmap *idmap,
139		       const struct path *path, struct kstat *stat,
140		       u32 request_mask, unsigned int query_flags);
141ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size);
142int __kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr);
143
144/*
145 * dir.c
146 */
147extern const struct dentry_operations kernfs_dops;
148extern const struct file_operations kernfs_dir_fops;
149extern const struct inode_operations kernfs_dir_iops;
150
151struct kernfs_node *kernfs_get_active(struct kernfs_node *kn);
152void kernfs_put_active(struct kernfs_node *kn);
153int kernfs_add_one(struct kernfs_node *kn);
154struct kernfs_node *kernfs_new_node(struct kernfs_node *parent,
155				    const char *name, umode_t mode,
156				    kuid_t uid, kgid_t gid,
157				    unsigned flags);
158
159/*
160 * file.c
161 */
162extern const struct file_operations kernfs_file_fops;
163
164bool kernfs_should_drain_open_files(struct kernfs_node *kn);
165void kernfs_drain_open_files(struct kernfs_node *kn);
166
167/*
168 * symlink.c
169 */
170extern const struct inode_operations kernfs_symlink_iops;
171
172/*
173 * kernfs locks
174 */
175extern struct kernfs_global_locks *kernfs_locks;
176#endif	/* __KERNFS_INTERNAL_H */