uspace/srv/vfs/vfs.h

   1 /*
   2  * Copyright (c) 2008 Jakub Jermar
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * - Redistributions of source code must retain the above copyright
  10  *   notice, this list of conditions and the following disclaimer.
  11  * - Redistributions in binary form must reproduce the above copyright
  12  *   notice, this list of conditions and the following disclaimer in the
  13  *   documentation and/or other materials provided with the distribution.
  14  * - The name of the author may not be used to endorse or promote products
  15  *   derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /** @addtogroup fs
  30  * @{
  31  */
  32
  33 #ifndef VFS_VFS_H_
  34 #define VFS_VFS_H_
  35
  36 #include <async.h>
  37 #include <adt/list.h>
  38 #include <adt/hash_table.h>
  39 #include <fibril_synch.h>
  40 #include <sys/types.h>
  41 #include <loc.h>
  42 #include <stdbool.h>
  43 #include <ipc/vfs.h>
  44 #include <task.h>
  45
  46 #ifndef dprintf
  47         #define dprintf(...)
  48 #endif
  49
  50 /**
  51  * A structure like this will be allocated for each registered file system.
  52  */
  53 typedef struct {
  54         link_t fs_link;
  55         vfs_info_t vfs_info;
  56         fs_handle_t fs_handle;
  57         async_sess_t *sess;
  58 } fs_info_t;
  59
  60 /**
  61  * VFS_PAIR uniquely represents a file system instance.
  62  */
  63 #define VFS_PAIR \
  64         fs_handle_t fs_handle; \
  65         service_id_t service_id;
  66
  67 /**
  68  * VFS_TRIPLET uniquely identifies a file system node (e.g. directory, file) but
  69  * doesn't contain any state. For a stateful structure, see vfs_node_t.
  70  *
  71  * @note        fs_handle, service_id and index are meant to be returned in one
  72  *              IPC reply.
  73  */
  74 #define VFS_TRIPLET \
  75         VFS_PAIR; \
  76         fs_index_t index;
  77
  78 typedef struct {
  79         VFS_PAIR;
  80 } vfs_pair_t;
  81
  82 typedef struct {
  83         VFS_TRIPLET;
  84 } vfs_triplet_t;
  85
  86 typedef enum vfs_node_type {
  87         VFS_NODE_UNKNOWN,
  88         VFS_NODE_FILE,
  89         VFS_NODE_DIRECTORY,
  90 } vfs_node_type_t;
  91
  92 typedef struct {
  93         vfs_triplet_t triplet;
  94         vfs_node_type_t type;
  95         aoff64_t size;
  96         unsigned int lnkcnt;
  97 } vfs_lookup_res_t;
  98
  99 /**
 100  * Instances of this type represent an active, in-memory VFS node and any state
 101  * which may be associated with it.
 102  */
 103 typedef struct {
 104         VFS_TRIPLET;            /**< Identity of the node. */
 105
 106         /**
 107          * Usage counter.  This includes, but is not limited to, all vfs_file_t
 108          * structures that reference this node.
 109          */
 110         unsigned refcnt;
 111
 112         /** Number of names this node has in the file system namespace. */
 113         unsigned lnkcnt;
 114
 115         ht_link_t nh_link;              /**< Node hash-table link. */
 116
 117         vfs_node_type_t type;   /**< Partial info about the node type. */
 118
 119         aoff64_t size;          /**< Cached size if the node is a file. */
 120
 121         /**
 122          * Holding this rwlock prevents modifications of the node's contents.
 123          */
 124         fibril_rwlock_t contents_rwlock;
 125 } vfs_node_t;
 126
 127 /**
 128  * Instances of this type represent an open file. If the file is opened by more
 129  * than one task, there will be a separate structure allocated for each task.
 130  */
 131 typedef struct {
 132         /** Serializes access to this open file. */
 133         fibril_mutex_t lock;
 134
 135         vfs_node_t *node;
 136
 137         /** Number of file handles referencing this file. */
 138         unsigned refcnt;
 139
 140         /** Append on write. */
 141         bool append;
 142
 143         /** Current absolute position in the file. */
 144         aoff64_t pos;
 145 } vfs_file_t;
 146
 147 extern fibril_mutex_t nodes_mutex;
 148
 149 extern fibril_condvar_t fs_list_cv;
 150 extern fibril_mutex_t fs_list_lock;
 151 extern list_t fs_list;          /**< List of registered file systems. */
 152
 153 extern fibril_mutex_t fs_mntlist_lock;
 154 extern list_t fs_mntlist;       /**< List of mounted file systems. */
 155
 156 extern vfs_pair_t rootfs;       /**< Root file system. */
 157
 158 /** Each instance of this type describes one path lookup in progress. */
 159 typedef struct {
 160         link_t  plb_link;       /**< Active PLB entries list link. */
 161         unsigned index;         /**< Index of the first character in PLB. */
 162         size_t len;             /**< Number of characters in this PLB entry. */
 163 } plb_entry_t;
 164
 165 extern fibril_mutex_t plb_mutex;/**< Mutex protecting plb and plb_entries. */
 166 extern uint8_t *plb;            /**< Path Lookup Buffer */
 167 extern list_t plb_entries;      /**< List of active PLB entries. */
 168
 169 /** Holding this rwlock prevents changes in file system namespace. */
 170 extern fibril_rwlock_t namespace_rwlock;
 171
 172 extern async_exch_t *vfs_exchange_grab(fs_handle_t);
 173 extern void vfs_exchange_release(async_exch_t *);
 174
 175 extern fs_handle_t fs_name_to_handle(unsigned int instance, char *, bool);
 176 extern vfs_info_t *fs_handle_to_info(fs_handle_t);
 177
 178 extern int vfs_lookup_internal(char *, int, vfs_lookup_res_t *,
 179     vfs_pair_t *, ...);
 180
 181 extern bool vfs_nodes_init(void);
 182 extern vfs_node_t *vfs_node_get(vfs_lookup_res_t *);
 183 extern void vfs_node_put(vfs_node_t *);
 184 extern void vfs_node_forget(vfs_node_t *);
 185 extern unsigned vfs_nodes_refcount_sum_get(fs_handle_t, service_id_t);
 186
 187
 188 #define MAX_OPEN_FILES  128
 189
 190 extern void *vfs_client_data_create(void);
 191 extern void vfs_client_data_destroy(void *);
 192
 193 extern void vfs_pass_handle(task_id_t, task_id_t, int);
 194 extern int vfs_wait_handle_internal(void);
 195
 196 extern vfs_file_t *vfs_file_get(int);
 197 extern void vfs_file_put(vfs_file_t *);
 198 extern int vfs_fd_assign(vfs_file_t *, int);
 199 extern int vfs_fd_alloc(bool desc);
 200 extern int vfs_fd_free(int);
 201
 202 extern void vfs_node_addref(vfs_node_t *);
 203 extern void vfs_node_delref(vfs_node_t *);
 204 extern int vfs_open_node_remote(vfs_node_t *);
 205
 206 extern void vfs_register(ipc_callid_t, ipc_call_t *);
 207 extern void vfs_mount(ipc_callid_t, ipc_call_t *);
 208 extern void vfs_unmount(ipc_callid_t, ipc_call_t *);
 209 extern void vfs_open(ipc_callid_t, ipc_call_t *);
 210 extern void vfs_sync(ipc_callid_t, ipc_call_t *);
 211 extern void vfs_dup(ipc_callid_t, ipc_call_t *);
 212 extern void vfs_close(ipc_callid_t, ipc_call_t *);
 213 extern void vfs_read(ipc_callid_t, ipc_call_t *);
 214 extern void vfs_write(ipc_callid_t, ipc_call_t *);
 215 extern void vfs_seek(ipc_callid_t, ipc_call_t *);
 216 extern void vfs_truncate(ipc_callid_t, ipc_call_t *);
 217 extern void vfs_fstat(ipc_callid_t, ipc_call_t *);
 218 extern void vfs_stat(ipc_callid_t, ipc_call_t *);
 219 extern void vfs_mkdir(ipc_callid_t, ipc_call_t *);
 220 extern void vfs_unlink(ipc_callid_t, ipc_call_t *);
 221 extern void vfs_rename(ipc_callid_t, ipc_call_t *);
 222 extern void vfs_wait_handle(ipc_callid_t, ipc_call_t *);
 223 extern void vfs_get_mtab(ipc_callid_t, ipc_call_t *);
 224 extern void vfs_statfs(ipc_callid_t, ipc_call_t *);
 225
 226 #endif
 227
 228 /**
 229  * @}
 230  */