fs/configfs/configfs_internal.h

   1 /* -*- mode: c; c-basic-offset:8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * configfs_internal.h - Internal stuff for configfs
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public
  17  * License along with this program; if not, write to the
  18  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19  * Boston, MA 021110-1307, USA.
  20  *
  21  * Based on sysfs:
  22  *      sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
  23  *
  24  * configfs Copyright (C) 2005 Oracle.  All rights reserved.
  25  */
  26
  27 #ifdef pr_fmt
  28 #undef pr_fmt
  29 #endif
  30
  31 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  32
  33 #include <linux/slab.h>
  34 #include <linux/list.h>
  35 #include <linux/spinlock.h>
  36
  37 struct configfs_fragment {
  38         atomic_t frag_count;
  39         struct rw_semaphore frag_sem;
  40         bool frag_dead;
  41 };
  42
  43 void put_fragment(struct configfs_fragment *);
  44 struct configfs_fragment *get_fragment(struct configfs_fragment *);
  45
  46 struct configfs_dirent {
  47         atomic_t                s_count;
  48         int                     s_dependent_count;
  49         struct list_head        s_sibling;
  50         struct list_head        s_children;
  51         struct list_head        s_links;
  52         void                    * s_element;
  53         int                     s_type;
  54         umode_t                 s_mode;
  55         struct dentry           * s_dentry;
  56         struct iattr            * s_iattr;
  57 #ifdef CONFIG_LOCKDEP
  58         int                     s_depth;
  59 #endif
  60         struct configfs_fragment *s_frag;
  61 };
  62
  63 #define CONFIGFS_ROOT           0x0001
  64 #define CONFIGFS_DIR            0x0002
  65 #define CONFIGFS_ITEM_ATTR      0x0004
  66 #define CONFIGFS_ITEM_BIN_ATTR  0x0008
  67 #define CONFIGFS_ITEM_LINK      0x0020
  68 #define CONFIGFS_USET_DIR       0x0040
  69 #define CONFIGFS_USET_DEFAULT   0x0080
  70 #define CONFIGFS_USET_DROPPING  0x0100
  71 #define CONFIGFS_USET_IN_MKDIR  0x0200
  72 #define CONFIGFS_USET_CREATING  0x0400
  73 #define CONFIGFS_NOT_PINNED     (CONFIGFS_ITEM_ATTR | CONFIGFS_ITEM_BIN_ATTR)
  74
  75 extern struct mutex configfs_symlink_mutex;
  76 extern spinlock_t configfs_dirent_lock;
  77
  78 extern struct kmem_cache *configfs_dir_cachep;
  79
  80 extern int configfs_is_root(struct config_item *item);
  81
  82 extern struct inode * configfs_new_inode(umode_t mode, struct configfs_dirent *, struct super_block *);
  83 extern int configfs_create(struct dentry *, umode_t mode, void (*init)(struct inode *));
  84
  85 extern int configfs_create_file(struct config_item *, const struct configfs_attribute *);
  86 extern int configfs_create_bin_file(struct config_item *,
  87                                     const struct configfs_bin_attribute *);
  88 extern int configfs_make_dirent(struct configfs_dirent *, struct dentry *,
  89                                 void *, umode_t, int, struct configfs_fragment *);
  90 extern int configfs_dirent_is_ready(struct configfs_dirent *);
  91
  92 extern void configfs_hash_and_remove(struct dentry * dir, const char * name);
  93
  94 extern const unsigned char * configfs_get_name(struct configfs_dirent *sd);
  95 extern void configfs_drop_dentry(struct configfs_dirent *sd, struct dentry *parent);
  96 extern int configfs_setattr(struct dentry *dentry, struct iattr *iattr);
  97
  98 extern struct dentry *configfs_pin_fs(void);
  99 extern void configfs_release_fs(void);
 100
 101 extern struct rw_semaphore configfs_rename_sem;
 102 extern const struct file_operations configfs_dir_operations;
 103 extern const struct file_operations configfs_file_operations;
 104 extern const struct file_operations configfs_bin_file_operations;
 105 extern const struct inode_operations configfs_dir_inode_operations;
 106 extern const struct inode_operations configfs_root_inode_operations;
 107 extern const struct inode_operations configfs_symlink_inode_operations;
 108 extern const struct dentry_operations configfs_dentry_ops;
 109
 110 extern int configfs_symlink(struct inode *dir, struct dentry *dentry,
 111                             const char *symname);
 112 extern int configfs_unlink(struct inode *dir, struct dentry *dentry);
 113
 114 struct configfs_symlink {
 115         struct list_head sl_list;
 116         struct config_item *sl_target;
 117 };
 118
 119 extern int configfs_create_link(struct configfs_symlink *sl,
 120                                 struct dentry *parent,
 121                                 struct dentry *dentry);
 122
 123 static inline struct config_item * to_item(struct dentry * dentry)
 124 {
 125         struct configfs_dirent * sd = dentry->d_fsdata;
 126         return ((struct config_item *) sd->s_element);
 127 }
 128
 129 static inline struct configfs_attribute * to_attr(struct dentry * dentry)
 130 {
 131         struct configfs_dirent * sd = dentry->d_fsdata;
 132         return ((struct configfs_attribute *) sd->s_element);
 133 }
 134
 135 static inline struct configfs_bin_attribute *to_bin_attr(struct dentry *dentry)
 136 {
 137         struct configfs_attribute *attr = to_attr(dentry);
 138
 139         return container_of(attr, struct configfs_bin_attribute, cb_attr);
 140 }
 141
 142 static inline struct config_item *configfs_get_config_item(struct dentry *dentry)
 143 {
 144         struct config_item * item = NULL;
 145
 146         spin_lock(&dentry->d_lock);
 147         if (!d_unhashed(dentry)) {
 148                 struct configfs_dirent * sd = dentry->d_fsdata;
 149                 if (sd->s_type & CONFIGFS_ITEM_LINK) {
 150                         struct configfs_symlink * sl = sd->s_element;
 151                         item = config_item_get(sl->sl_target);
 152                 } else
 153                         item = config_item_get(sd->s_element);
 154         }
 155         spin_unlock(&dentry->d_lock);
 156
 157         return item;
 158 }
 159
 160 static inline void release_configfs_dirent(struct configfs_dirent * sd)
 161 {
 162         if (!(sd->s_type & CONFIGFS_ROOT)) {
 163                 kfree(sd->s_iattr);
 164                 put_fragment(sd->s_frag);
 165                 kmem_cache_free(configfs_dir_cachep, sd);
 166         }
 167 }
 168
 169 static inline struct configfs_dirent * configfs_get(struct configfs_dirent * sd)
 170 {
 171         if (sd) {
 172                 WARN_ON(!atomic_read(&sd->s_count));
 173                 atomic_inc(&sd->s_count);
 174         }
 175         return sd;
 176 }
 177
 178 static inline void configfs_put(struct configfs_dirent * sd)
 179 {
 180         WARN_ON(!atomic_read(&sd->s_count));
 181         if (atomic_dec_and_test(&sd->s_count))
 182                 release_configfs_dirent(sd);
 183 }
 184