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_dirent {
  38         atomic_t                s_count;
  39         int                     s_dependent_count;
  40         struct list_head        s_sibling;
  41         struct list_head        s_children;
  42         struct list_head        s_links;
  43         void                    * s_element;
  44         int                     s_type;
  45         umode_t                 s_mode;
  46         struct dentry           * s_dentry;
  47         struct iattr            * s_iattr;
  48 #ifdef CONFIG_LOCKDEP
  49         int                     s_depth;
  50 #endif
  51 };
  52
  53 #define CONFIGFS_ROOT           0x0001
  54 #define CONFIGFS_DIR            0x0002
  55 #define CONFIGFS_ITEM_ATTR      0x0004
  56 #define CONFIGFS_ITEM_BIN_ATTR  0x0008
  57 #define CONFIGFS_ITEM_LINK      0x0020
  58 #define CONFIGFS_USET_DIR       0x0040
  59 #define CONFIGFS_USET_DEFAULT   0x0080
  60 #define CONFIGFS_USET_DROPPING  0x0100
  61 #define CONFIGFS_USET_IN_MKDIR  0x0200
  62 #define CONFIGFS_USET_CREATING  0x0400
  63 #define CONFIGFS_NOT_PINNED     (CONFIGFS_ITEM_ATTR | CONFIGFS_ITEM_BIN_ATTR)
  64
  65 extern struct mutex configfs_symlink_mutex;
  66 extern spinlock_t configfs_dirent_lock;
  67
  68 extern struct kmem_cache *configfs_dir_cachep;
  69
  70 extern int configfs_is_root(struct config_item *item);
  71
  72 extern struct inode * configfs_new_inode(umode_t mode, struct configfs_dirent *, struct super_block *);
  73 extern int configfs_create(struct dentry *, umode_t mode, void (*init)(struct inode *));
  74
  75 extern int configfs_create_file(struct config_item *, const struct configfs_attribute *);
  76 extern int configfs_create_bin_file(struct config_item *,
  77                                     const struct configfs_bin_attribute *);
  78 extern int configfs_make_dirent(struct configfs_dirent *,
  79                                 struct dentry *, void *, umode_t, int);
  80 extern int configfs_dirent_is_ready(struct configfs_dirent *);
  81
  82 extern void configfs_hash_and_remove(struct dentry * dir, const char * name);
  83
  84 extern const unsigned char * configfs_get_name(struct configfs_dirent *sd);
  85 extern void configfs_drop_dentry(struct configfs_dirent *sd, struct dentry *parent);
  86 extern int configfs_setattr(struct dentry *dentry, struct iattr *iattr);
  87
  88 extern struct dentry *configfs_pin_fs(void);
  89 extern void configfs_release_fs(void);
  90
  91 extern struct rw_semaphore configfs_rename_sem;
  92 extern const struct file_operations configfs_dir_operations;
  93 extern const struct file_operations configfs_file_operations;
  94 extern const struct file_operations configfs_bin_file_operations;
  95 extern const struct inode_operations configfs_dir_inode_operations;
  96 extern const struct inode_operations configfs_root_inode_operations;
  97 extern const struct inode_operations configfs_symlink_inode_operations;
  98 extern const struct dentry_operations configfs_dentry_ops;
  99
 100 extern int configfs_symlink(struct inode *dir, struct dentry *dentry,
 101                             const char *symname);
 102 extern int configfs_unlink(struct inode *dir, struct dentry *dentry);
 103
 104 struct configfs_symlink {
 105         struct list_head sl_list;
 106         struct config_item *sl_target;
 107 };
 108
 109 extern int configfs_create_link(struct configfs_symlink *sl,
 110                                 struct dentry *parent,
 111                                 struct dentry *dentry);
 112
 113 static inline struct config_item * to_item(struct dentry * dentry)
 114 {
 115         struct configfs_dirent * sd = dentry->d_fsdata;
 116         return ((struct config_item *) sd->s_element);
 117 }
 118
 119 static inline struct configfs_attribute * to_attr(struct dentry * dentry)
 120 {
 121         struct configfs_dirent * sd = dentry->d_fsdata;
 122         return ((struct configfs_attribute *) sd->s_element);
 123 }
 124
 125 static inline struct configfs_bin_attribute *to_bin_attr(struct dentry *dentry)
 126 {
 127         struct configfs_attribute *attr = to_attr(dentry);
 128
 129         return container_of(attr, struct configfs_bin_attribute, cb_attr);
 130 }
 131
 132 static inline struct config_item *configfs_get_config_item(struct dentry *dentry)
 133 {
 134         struct config_item * item = NULL;
 135
 136         spin_lock(&dentry->d_lock);
 137         if (!d_unhashed(dentry)) {
 138                 struct configfs_dirent * sd = dentry->d_fsdata;
 139                 if (sd->s_type & CONFIGFS_ITEM_LINK) {
 140                         struct configfs_symlink * sl = sd->s_element;
 141                         item = config_item_get(sl->sl_target);
 142                 } else
 143                         item = config_item_get(sd->s_element);
 144         }
 145         spin_unlock(&dentry->d_lock);
 146
 147         return item;
 148 }
 149
 150 static inline void release_configfs_dirent(struct configfs_dirent * sd)
 151 {
 152         if (!(sd->s_type & CONFIGFS_ROOT)) {
 153                 kfree(sd->s_iattr);
 154                 kmem_cache_free(configfs_dir_cachep, sd);
 155         }
 156 }
 157
 158 static inline struct configfs_dirent * configfs_get(struct configfs_dirent * sd)
 159 {
 160         if (sd) {
 161                 WARN_ON(!atomic_read(&sd->s_count));
 162                 atomic_inc(&sd->s_count);
 163         }
 164         return sd;
 165 }
 166
 167 static inline void configfs_put(struct configfs_dirent * sd)
 168 {
 169         WARN_ON(!atomic_read(&sd->s_count));
 170         if (atomic_dec_and_test(&sd->s_count))
 171                 release_configfs_dirent(sd);
 172 }
 173