LXR linux/fs/kernfs/kernfs-internal.h

   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
  34/* +1 to avoid triggering overflow warning when negating it */
  35#define KN_DEACTIVATED_BIAS             (INT_MIN + 1)
  36
  37/* KERNFS_TYPE_MASK and types are defined in include/linux/kernfs.h */
  38
  39/**
  40 * kernfs_root - find out the kernfs_root a kernfs_node belongs to
  41 * @kn: kernfs_node of interest
  42 *
  43 * Return the kernfs_root @kn belongs to.
  44 */
  45static inline struct kernfs_root *kernfs_root(struct kernfs_node *kn)
  46{
  47        /* if parent exists, it's always a dir; otherwise, @sd is a dir */
  48        if (kn->parent)
  49                kn = kn->parent;
  50        return kn->dir.root;
  51}
  52
  53/*
  54 * mount.c
  55 */
  56struct kernfs_super_info {
  57        struct super_block      *sb;
  58
  59        /*
  60         * The root associated with this super_block.  Each super_block is
  61         * identified by the root and ns it's associated with.
  62         */
  63        struct kernfs_root      *root;
  64
  65        /*
  66         * Each sb is associated with one namespace tag, currently the
  67         * network namespace of the task which mounted this kernfs
  68         * instance.  If multiple tags become necessary, make the following
  69         * an array and compare kernfs_node tag against every entry.
  70         */
  71        const void              *ns;
  72
  73        /* anchored at kernfs_root->supers, protected by kernfs_rwsem */
  74        struct list_head        node;
  75};
  76#define kernfs_info(SB) ((struct kernfs_super_info *)(SB->s_fs_info))
  77
  78static inline struct kernfs_node *kernfs_dentry_node(struct dentry *dentry)
  79{
  80        if (d_really_is_negative(dentry))
  81                return NULL;
  82        return d_inode(dentry)->i_private;
  83}
  84
  85static inline void kernfs_set_rev(struct kernfs_node *parent,
  86                                  struct dentry *dentry)
  87{
  88        dentry->d_time = parent->dir.rev;
  89}
  90
  91static inline void kernfs_inc_rev(struct kernfs_node *parent)
  92{
  93        parent->dir.rev++;
  94}
  95
  96static inline bool kernfs_dir_changed(struct kernfs_node *parent,
  97                                      struct dentry *dentry)
  98{
  99        if (parent->dir.rev != dentry->d_time)
 100                return true;
 101        return false;
 102}
 103
 104extern const struct super_operations kernfs_sops;
 105extern struct kmem_cache *kernfs_node_cache, *kernfs_iattrs_cache;
 106
 107/*
 108 * inode.c
 109 */
 110extern const struct xattr_handler *kernfs_xattr_handlers[];
 111void kernfs_evict_inode(struct inode *inode);
 112int kernfs_iop_permission(struct user_namespace *mnt_userns,
 113                          struct inode *inode, int mask);
 114int kernfs_iop_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 115                       struct iattr *iattr);
 116int kernfs_iop_getattr(struct user_namespace *mnt_userns,
 117                       const struct path *path, struct kstat *stat,
 118                       u32 request_mask, unsigned int query_flags);
 119ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size);
 120int __kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr);
 121
 122/*
 123 * dir.c
 124 */
 125extern struct rw_semaphore kernfs_rwsem;
 126extern const struct dentry_operations kernfs_dops;
 127extern const struct file_operations kernfs_dir_fops;
 128extern const struct inode_operations kernfs_dir_iops;
 129
 130struct kernfs_node *kernfs_get_active(struct kernfs_node *kn);
 131void kernfs_put_active(struct kernfs_node *kn);
 132int kernfs_add_one(struct kernfs_node *kn);
 133struct kernfs_node *kernfs_new_node(struct kernfs_node *parent,
 134                                    const char *name, umode_t mode,
 135                                    kuid_t uid, kgid_t gid,
 136                                    unsigned flags);
 137
 138/*
 139 * file.c
 140 */
 141extern const struct file_operations kernfs_file_fops;
 142
 143void kernfs_drain_open_files(struct kernfs_node *kn);
 144
 145/*
 146 * symlink.c
 147 */
 148extern const struct inode_operations kernfs_symlink_iops;
 149
 150#endif  /* __KERNFS_INTERNAL_H */
 151