LXR linux/fs/configfs/configfs

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