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