fs/configfs/configfs_internal.h

   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
  23 struct configfs_dirent {
  24         atomic_t                s_count;
  25         int                     s_dependent_count;
  26         struct list_head        s_sibling;
  27         struct list_head        s_children;
  28         struct list_head        s_links;
  29         void                    * s_element;
  30         int                     s_type;
  31         umode_t                 s_mode;
  32         struct dentry           * s_dentry;
  33         struct iattr            * s_iattr;
  34 #ifdef CONFIG_LOCKDEP
  35         int                     s_depth;
  36 #endif
  37 };
  38
  39 #define CONFIGFS_ROOT           0x0001
  40 #define CONFIGFS_DIR            0x0002
  41 #define CONFIGFS_ITEM_ATTR      0x0004
  42 #define CONFIGFS_ITEM_BIN_ATTR  0x0008
  43 #define CONFIGFS_ITEM_LINK      0x0020
  44 #define CONFIGFS_USET_DIR       0x0040
  45 #define CONFIGFS_USET_DEFAULT   0x0080
  46 #define CONFIGFS_USET_DROPPING  0x0100
  47 #define CONFIGFS_USET_IN_MKDIR  0x0200
  48 #define CONFIGFS_USET_CREATING  0x0400
  49 #define CONFIGFS_NOT_PINNED     (CONFIGFS_ITEM_ATTR | CONFIGFS_ITEM_BIN_ATTR)
  50
  51 extern struct mutex configfs_symlink_mutex;
  52 extern spinlock_t configfs_dirent_lock;
  53
  54 extern struct kmem_cache *configfs_dir_cachep;
  55
  56 extern int configfs_is_root(struct config_item *item);
  57
  58 extern struct inode * configfs_new_inode(umode_t mode, struct configfs_dirent *, struct super_block *);
  59 extern int configfs_create(struct dentry *, umode_t mode, void (*init)(struct inode *));
  60
  61 extern int configfs_create_file(struct config_item *, const struct configfs_attribute *);
  62 extern int configfs_create_bin_file(struct config_item *,
  63                                     const struct configfs_bin_attribute *);
  64 extern int configfs_make_dirent(struct configfs_dirent *,
  65                                 struct dentry *, void *, umode_t, int);
  66 extern int configfs_dirent_is_ready(struct configfs_dirent *);
  67
  68 extern void configfs_hash_and_remove(struct dentry * dir, const char * name);
  69
  70 extern const unsigned char * configfs_get_name(struct configfs_dirent *sd);
  71 extern void configfs_drop_dentry(struct configfs_dirent *sd, struct dentry *parent);
  72 extern int configfs_setattr(struct dentry *dentry, struct iattr *iattr);
  73
  74 extern struct dentry *configfs_pin_fs(void);
  75 extern void configfs_release_fs(void);
  76
  77 extern struct rw_semaphore configfs_rename_sem;
  78 extern const struct file_operations configfs_dir_operations;
  79 extern const struct file_operations configfs_file_operations;
  80 extern const struct file_operations configfs_bin_file_operations;
  81 extern const struct inode_operations configfs_dir_inode_operations;
  82 extern const struct inode_operations configfs_root_inode_operations;
  83 extern const struct inode_operations configfs_symlink_inode_operations;
  84 extern const struct dentry_operations configfs_dentry_ops;
  85
  86 extern int configfs_symlink(struct inode *dir, struct dentry *dentry,
  87                             const char *symname);
  88 extern int configfs_unlink(struct inode *dir, struct dentry *dentry);
  89
  90 struct configfs_symlink {
  91         struct list_head sl_list;
  92         struct config_item *sl_target;
  93 };
  94
  95 extern int configfs_create_link(struct configfs_symlink *sl,
  96                                 struct dentry *parent,
  97                                 struct dentry *dentry);
  98
  99 static inline struct config_item * to_item(struct dentry * dentry)
 100 {
 101         struct configfs_dirent * sd = dentry->d_fsdata;
 102         return ((struct config_item *) sd->s_element);
 103 }
 104
 105 static inline struct configfs_attribute * to_attr(struct dentry * dentry)
 106 {
 107         struct configfs_dirent * sd = dentry->d_fsdata;
 108         return ((struct configfs_attribute *) sd->s_element);
 109 }
 110
 111 static inline struct configfs_bin_attribute *to_bin_attr(struct dentry *dentry)
 112 {
 113         struct configfs_attribute *attr = to_attr(dentry);
 114
 115         return container_of(attr, struct configfs_bin_attribute, cb_attr);
 116 }
 117
 118 static inline struct config_item *configfs_get_config_item(struct dentry *dentry)
 119 {
 120         struct config_item * item = NULL;
 121
 122         spin_lock(&dentry->d_lock);
 123         if (!d_unhashed(dentry)) {
 124                 struct configfs_dirent * sd = dentry->d_fsdata;
 125                 if (sd->s_type & CONFIGFS_ITEM_LINK) {
 126                         struct configfs_symlink * sl = sd->s_element;
 127                         item = config_item_get(sl->sl_target);
 128                 } else
 129                         item = config_item_get(sd->s_element);
 130         }
 131         spin_unlock(&dentry->d_lock);
 132
 133         return item;
 134 }
 135
 136 static inline void release_configfs_dirent(struct configfs_dirent * sd)
 137 {
 138         if (!(sd->s_type & CONFIGFS_ROOT)) {
 139                 kfree(sd->s_iattr);
 140                 kmem_cache_free(configfs_dir_cachep, sd);
 141         }
 142 }
 143
 144 static 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
 153 static 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