LXR linux/fs/configfs/configfs

   1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2/* -*- mode: c; c-basic-offset:8; -*-
   3 * vim: noexpandtab sw=8 ts=8 sts=0:
   4 *
   5 * configfs_internal.h - Internal stuff for configfs
   6 *
   7 * Based on sysfs:
   8 *      sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
   9 *
  10 * configfs Copyright (C) 2005 Oracle.  All rights reserved.
  11 */
  12
  13#ifdef pr_fmt
  14#undef pr_fmt
  15#endif
  16
  17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  18
  19#include <linux/slab.h>
  20#include <linux/list.h>
  21#include <linux/spinlock.h>
  22
  23struct configfs_fragment {
  24        atomic_t frag_count;
  25        struct rw_semaphore frag_sem;
  26        bool frag_dead;
  27};
  28
  29void put_fragment(struct configfs_fragment *);
  30struct configfs_fragment *get_fragment(struct configfs_fragment *);
  31
  32struct configfs_dirent {
  33        atomic_t                s_count;
  34        int                     s_dependent_count;
  35        struct list_head        s_sibling;
  36        struct list_head        s_children;
  37        int                     s_links;
  38        void                    * s_element;
  39        int                     s_type;
  40        umode_t                 s_mode;
  41        struct dentry           * s_dentry;
  42        struct iattr            * s_iattr;
  43#ifdef CONFIG_LOCKDEP
  44        int                     s_depth;
  45#endif
  46        struct configfs_fragment *s_frag;
  47};
  48
  49#define CONFIGFS_ROOT           0x0001
  50#define CONFIGFS_DIR            0x0002
  51#define CONFIGFS_ITEM_ATTR      0x0004
  52#define CONFIGFS_ITEM_BIN_ATTR  0x0008
  53#define CONFIGFS_ITEM_LINK      0x0020
  54#define CONFIGFS_USET_DIR       0x0040
  55#define CONFIGFS_USET_DEFAULT   0x0080
  56#define CONFIGFS_USET_DROPPING  0x0100
  57#define CONFIGFS_USET_IN_MKDIR  0x0200
  58#define CONFIGFS_USET_CREATING  0x0400
  59#define CONFIGFS_NOT_PINNED     (CONFIGFS_ITEM_ATTR | CONFIGFS_ITEM_BIN_ATTR)
  60
  61extern struct mutex configfs_symlink_mutex;
  62extern spinlock_t configfs_dirent_lock;
  63
  64extern struct kmem_cache *configfs_dir_cachep;
  65
  66extern int configfs_is_root(struct config_item *item);
  67
  68extern struct inode * configfs_new_inode(umode_t mode, struct configfs_dirent *, struct super_block *);
  69extern struct inode *configfs_create(struct dentry *, umode_t mode);
  70
  71extern int configfs_create_file(struct config_item *, const struct configfs_attribute *);
  72extern int configfs_create_bin_file(struct config_item *,
  73                                    const struct configfs_bin_attribute *);
  74extern int configfs_make_dirent(struct configfs_dirent *, struct dentry *,
  75                                void *, umode_t, int, struct configfs_fragment *);
  76extern int configfs_dirent_is_ready(struct configfs_dirent *);
  77
  78extern void configfs_hash_and_remove(struct dentry * dir, const char * name);
  79
  80extern const unsigned char * configfs_get_name(struct configfs_dirent *sd);
  81extern void configfs_drop_dentry(struct configfs_dirent *sd, struct dentry *parent);
  82extern int configfs_setattr(struct dentry *dentry, struct iattr *iattr);
  83
  84extern struct dentry *configfs_pin_fs(void);
  85extern void configfs_release_fs(void);
  86
  87extern const struct file_operations configfs_dir_operations;
  88extern const struct file_operations configfs_file_operations;
  89extern const struct file_operations configfs_bin_file_operations;
  90extern const struct inode_operations configfs_dir_inode_operations;
  91extern const struct inode_operations configfs_root_inode_operations;
  92extern const struct inode_operations configfs_symlink_inode_operations;
  93extern const struct dentry_operations configfs_dentry_ops;
  94
  95extern int configfs_symlink(struct inode *dir, struct dentry *dentry,
  96                            const char *symname);
  97extern int configfs_unlink(struct inode *dir, struct dentry *dentry);
  98
  99int configfs_create_link(struct configfs_dirent *target, struct dentry *parent,
 100                struct dentry *dentry, char *body);
 101
 102static inline struct config_item * to_item(struct dentry * dentry)
 103{
 104        struct configfs_dirent * sd = dentry->d_fsdata;
 105        return ((struct config_item *) sd->s_element);
 106}
 107
 108static inline struct configfs_attribute * to_attr(struct dentry * dentry)
 109{
 110        struct configfs_dirent * sd = dentry->d_fsdata;
 111        return ((struct configfs_attribute *) sd->s_element);
 112}
 113
 114static inline struct configfs_bin_attribute *to_bin_attr(struct dentry *dentry)
 115{
 116        struct configfs_attribute *attr = to_attr(dentry);
 117
 118        return container_of(attr, struct configfs_bin_attribute, cb_attr);
 119}
 120
 121static inline struct config_item *configfs_get_config_item(struct dentry *dentry)
 122{
 123        struct config_item * item = NULL;
 124
 125        spin_lock(&dentry->d_lock);
 126        if (!d_unhashed(dentry)) {
 127                struct configfs_dirent * sd = dentry->d_fsdata;
 128                item = config_item_get(sd->s_element);
 129        }
 130        spin_unlock(&dentry->d_lock);
 131
 132        return item;
 133}
 134
 135static inline void release_configfs_dirent(struct configfs_dirent * sd)
 136{
 137        if (!(sd->s_type & CONFIGFS_ROOT)) {
 138                kfree(sd->s_iattr);
 139                put_fragment(sd->s_frag);
 140                kmem_cache_free(configfs_dir_cachep, sd);
 141        }
 142}
 143
 144static inline struct configfs_dirent * configfs_get(struct configfs_dirent * sd)
 145{
 146        if (sd) {
 147                WARN_ON(!atomic_read(&sd->s_count));
 148                atomic_inc(&sd->s_count);
 149        }
 150        return sd;
 151}
 152
 153static inline void configfs_put(struct configfs_dirent * sd)
 154{
 155        WARN_ON(!atomic_read(&sd->s_count));
 156        if (atomic_dec_and_test(&sd->s_count))
 157                release_configfs_dirent(sd);
 158}
 159
 160