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 #include <linux/slab.h>
  28 #include <linux/list.h>
  29 #include <linux/spinlock.h>
  30
  31 struct configfs_dirent {
  32         atomic_t                s_count;
  33         int                     s_dependent_count;
  34         struct list_head        s_sibling;
  35         struct list_head        s_children;
  36         struct list_head        s_links;
  37         void                    * s_element;
  38         int                     s_type;
  39         umode_t                 s_mode;
  40         struct dentry           * s_dentry;
  41         struct iattr            * s_iattr;
  42 };
  43
  44 #define CONFIGFS_ROOT           0x0001
  45 #define CONFIGFS_DIR            0x0002
  46 #define CONFIGFS_ITEM_ATTR      0x0004
  47 #define CONFIGFS_ITEM_LINK      0x0020
  48 #define CONFIGFS_USET_DIR       0x0040
  49 #define CONFIGFS_USET_DEFAULT   0x0080
  50 #define CONFIGFS_USET_DROPPING  0x0100
  51 #define CONFIGFS_USET_IN_MKDIR  0x0200
  52 #define CONFIGFS_NOT_PINNED     (CONFIGFS_ITEM_ATTR)
  53
  54 extern spinlock_t configfs_dirent_lock;
  55
  56 extern struct vfsmount * configfs_mount;
  57 extern struct kmem_cache *configfs_dir_cachep;
  58
  59 extern int configfs_is_root(struct config_item *item);
  60
  61 extern struct inode * configfs_new_inode(mode_t mode, struct configfs_dirent *);
  62 extern int configfs_create(struct dentry *, int mode, int (*init)(struct inode *));
  63 extern int configfs_inode_init(void);
  64 extern void configfs_inode_exit(void);
  65
  66 extern int configfs_create_file(struct config_item *, const struct configfs_attribute *);
  67 extern int configfs_make_dirent(struct configfs_dirent *,
  68                                 struct dentry *, void *, umode_t, int);
  69
  70 extern int configfs_add_file(struct dentry *, const struct configfs_attribute *, int);
  71 extern void configfs_hash_and_remove(struct dentry * dir, const char * name);
  72
  73 extern const unsigned char * configfs_get_name(struct configfs_dirent *sd);
  74 extern void configfs_drop_dentry(struct configfs_dirent *sd, struct dentry *parent);
  75 extern int configfs_setattr(struct dentry *dentry, struct iattr *iattr);
  76
  77 extern int configfs_pin_fs(void);
  78 extern void configfs_release_fs(void);
  79
  80 extern struct rw_semaphore configfs_rename_sem;
  81 extern struct super_block * configfs_sb;
  82 extern const struct file_operations configfs_dir_operations;
  83 extern const struct file_operations configfs_file_operations;
  84 extern const struct file_operations bin_fops;
  85 extern const struct inode_operations configfs_dir_inode_operations;
  86 extern const struct inode_operations configfs_symlink_inode_operations;
  87
  88 extern int configfs_symlink(struct inode *dir, struct dentry *dentry,
  89                             const char *symname);
  90 extern int configfs_unlink(struct inode *dir, struct dentry *dentry);
  91
  92 struct configfs_symlink {
  93         struct list_head sl_list;
  94         struct config_item *sl_target;
  95 };
  96
  97 extern int configfs_create_link(struct configfs_symlink *sl,
  98                                 struct dentry *parent,
  99                                 struct dentry *dentry);
 100
 101 static inline struct config_item * to_item(struct dentry * dentry)
 102 {
 103         struct configfs_dirent * sd = dentry->d_fsdata;
 104         return ((struct config_item *) sd->s_element);
 105 }
 106
 107 static inline struct configfs_attribute * to_attr(struct dentry * dentry)
 108 {
 109         struct configfs_dirent * sd = dentry->d_fsdata;
 110         return ((struct configfs_attribute *) sd->s_element);
 111 }
 112
 113 static inline struct config_item *configfs_get_config_item(struct dentry *dentry)
 114 {
 115         struct config_item * item = NULL;
 116
 117         spin_lock(&dcache_lock);
 118         if (!d_unhashed(dentry)) {
 119                 struct configfs_dirent * sd = dentry->d_fsdata;
 120                 if (sd->s_type & CONFIGFS_ITEM_LINK) {
 121                         struct configfs_symlink * sl = sd->s_element;
 122                         item = config_item_get(sl->sl_target);
 123                 } else
 124                         item = config_item_get(sd->s_element);
 125         }
 126         spin_unlock(&dcache_lock);
 127
 128         return item;
 129 }
 130
 131 static inline void release_configfs_dirent(struct configfs_dirent * sd)
 132 {
 133         if (!(sd->s_type & CONFIGFS_ROOT)) {
 134                 kfree(sd->s_iattr);
 135                 kmem_cache_free(configfs_dir_cachep, sd);
 136         }
 137 }
 138
 139 static inline struct configfs_dirent * configfs_get(struct configfs_dirent * sd)
 140 {
 141         if (sd) {
 142                 WARN_ON(!atomic_read(&sd->s_count));
 143                 atomic_inc(&sd->s_count);
 144         }
 145         return sd;
 146 }
 147
 148 static inline void configfs_put(struct configfs_dirent * sd)
 149 {
 150         WARN_ON(!atomic_read(&sd->s_count));
 151         if (atomic_dec_and_test(&sd->s_count))
 152                 release_configfs_dirent(sd);
 153 }
 154