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#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
  37struct 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_LINK      0x0020
  57#define CONFIGFS_USET_DIR       0x0040
  58#define CONFIGFS_USET_DEFAULT   0x0080
  59#define CONFIGFS_USET_DROPPING  0x0100
  60#define CONFIGFS_USET_IN_MKDIR  0x0200
  61#define CONFIGFS_USET_CREATING  0x0400
  62#define CONFIGFS_NOT_PINNED     (CONFIGFS_ITEM_ATTR)
  63
  64extern struct mutex configfs_symlink_mutex;
  65extern spinlock_t configfs_dirent_lock;
  66
  67extern struct kmem_cache *configfs_dir_cachep;
  68
  69extern int configfs_is_root(struct config_item *item);
  70
  71extern struct inode * configfs_new_inode(umode_t mode, struct configfs_dirent *, struct super_block *);
  72extern int configfs_create(struct dentry *, umode_t mode, void (*init)(struct inode *));
  73
  74extern int configfs_create_file(struct config_item *, const struct configfs_attribute *);
  75extern int configfs_make_dirent(struct configfs_dirent *,
  76                                struct dentry *, void *, umode_t, int);
  77extern int configfs_dirent_is_ready(struct configfs_dirent *);
  78
  79extern void configfs_hash_and_remove(struct dentry * dir, const char * name);
  80
  81extern const unsigned char * configfs_get_name(struct configfs_dirent *sd);
  82extern void configfs_drop_dentry(struct configfs_dirent *sd, struct dentry *parent);
  83extern int configfs_setattr(struct dentry *dentry, struct iattr *iattr);
  84
  85extern struct dentry *configfs_pin_fs(void);
  86extern void configfs_release_fs(void);
  87
  88extern struct rw_semaphore configfs_rename_sem;
  89extern const struct file_operations configfs_dir_operations;
  90extern const struct file_operations configfs_file_operations;
  91extern const struct file_operations bin_fops;
  92extern const struct inode_operations configfs_dir_inode_operations;
  93extern const struct inode_operations configfs_root_inode_operations;
  94extern const struct inode_operations configfs_symlink_inode_operations;
  95extern const struct dentry_operations configfs_dentry_ops;
  96
  97extern int configfs_symlink(struct inode *dir, struct dentry *dentry,
  98                            const char *symname);
  99extern int configfs_unlink(struct inode *dir, struct dentry *dentry);
 100
 101struct configfs_symlink {
 102        struct list_head sl_list;
 103        struct config_item *sl_target;
 104};
 105
 106extern int configfs_create_link(struct configfs_symlink *sl,
 107                                struct dentry *parent,
 108                                struct dentry *dentry);
 109
 110static inline struct config_item * to_item(struct dentry * dentry)
 111{
 112        struct configfs_dirent * sd = dentry->d_fsdata;
 113        return ((struct config_item *) sd->s_element);
 114}
 115
 116static inline struct configfs_attribute * to_attr(struct dentry * dentry)
 117{
 118        struct configfs_dirent * sd = dentry->d_fsdata;
 119        return ((struct configfs_attribute *) sd->s_element);
 120}
 121
 122static inline struct config_item *configfs_get_config_item(struct dentry *dentry)
 123{
 124        struct config_item * item = NULL;
 125
 126        spin_lock(&dentry->d_lock);
 127        if (!d_unhashed(dentry)) {
 128                struct configfs_dirent * sd = dentry->d_fsdata;
 129                if (sd->s_type & CONFIGFS_ITEM_LINK) {
 130                        struct configfs_symlink * sl = sd->s_element;
 131                        item = config_item_get(sl->sl_target);
 132                } else
 133                        item = config_item_get(sd->s_element);
 134        }
 135        spin_unlock(&dentry->d_lock);
 136
 137        return item;
 138}
 139
 140static inline void release_configfs_dirent(struct configfs_dirent * sd)
 141{
 142        if (!(sd->s_type & CONFIGFS_ROOT)) {
 143                kfree(sd->s_iattr);
 144                kmem_cache_free(configfs_dir_cachep, sd);
 145        }
 146}
 147
 148static inline struct configfs_dirent * configfs_get(struct configfs_dirent * sd)
 149{
 150        if (sd) {
 151                WARN_ON(!atomic_read(&sd->s_count));
 152                atomic_inc(&sd->s_count);
 153        }
 154        return sd;
 155}
 156
 157static inline void configfs_put(struct configfs_dirent * sd)
 158{
 159        WARN_ON(!atomic_read(&sd->s_count));
 160        if (atomic_dec_and_test(&sd->s_count))
 161                release_configfs_dirent(sd);
 162}
 163
 164