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