source: mainline/uspace/srv/vfs/vfs.h@ ac23b9d3

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since ac23b9d3 was 1090b8c, checked in by Jiri Svoboda <jirik.svoboda@…>, 16 years ago

C binding for devmap. Gets rid of duplicate code.
  • Property mode set to 100644
File size: 7.9 KB
Line 
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 <ipc/ipc.h>
37#include <libadt/list.h>
38#include <futex.h>
39#include <rwlock.h>
40#include <sys/types.h>
41#include <devmap.h>
42#include <bool.h>
43
44// FIXME: according to CONFIG_DEBUG
45// #define dprintf(...) printf(__VA_ARGS__)
46
47#define dprintf(...)
48
49#define VFS_FIRST IPC_FIRST_USER_METHOD
50
51/* Basic types. */
52typedef int16_t fs_handle_t;
53typedef uint32_t fs_index_t;
54
55typedef enum {
56 VFS_READ = VFS_FIRST,
57 VFS_WRITE,
58 VFS_TRUNCATE,
59 VFS_MOUNT,
60 VFS_UNMOUNT,
61 VFS_LAST_CMN, /* keep this the last member of this enum */
62} vfs_request_cmn_t;
63
64typedef enum {
65 VFS_LOOKUP = VFS_LAST_CMN,
66 VFS_MOUNTED,
67 VFS_DESTROY,
68 VFS_LAST_CLNT, /* keep this the last member of this enum */
69} vfs_request_clnt_t;
70
71typedef enum {
72 VFS_REGISTER = VFS_LAST_CMN,
73 VFS_OPEN,
74 VFS_CLOSE,
75 VFS_SEEK,
76 VFS_MKDIR,
77 VFS_UNLINK,
78 VFS_RENAME,
79 VFS_LAST_SRV, /* keep this the last member of this enum */
80} vfs_request_srv_t;
81
82#define FS_NAME_MAXLEN 20
83
84/**
85 * A structure like this is passed to VFS by each individual FS upon its
86 * registration. It assosiates a human-readable identifier with each
87 * registered FS.
88 */
89typedef struct {
90 /** Unique identifier of the fs. */
91 char name[FS_NAME_MAXLEN + 1];
92} vfs_info_t;
93
94/**
95 * A structure like this will be allocated for each registered file system.
96 */
97typedef struct {
98 link_t fs_link;
99 vfs_info_t vfs_info;
100 fs_handle_t fs_handle;
101 futex_t phone_futex; /**< Phone serializing futex. */
102 ipcarg_t phone;
103} fs_info_t;
104
105/**
106 * VFS_PAIR uniquely represents a file system instance.
107 */
108#define VFS_PAIR \
109 fs_handle_t fs_handle; \
110 dev_handle_t dev_handle;
111
112/**
113 * VFS_TRIPLET uniquely identifies a file system node (e.g. directory, file) but
114 * doesn't contain any state. For a stateful structure, see vfs_node_t.
115 *
116 * @note fs_handle, dev_handle and index are meant to be returned in one
117 * IPC reply.
118 */
119#define VFS_TRIPLET \
120 VFS_PAIR; \
121 fs_index_t index;
122
123typedef struct {
124 VFS_PAIR;
125} vfs_pair_t;
126
127typedef struct {
128 VFS_TRIPLET;
129} vfs_triplet_t;
130
131/*
132 * Lookup flags.
133 */
134/**
135 * No lookup flags used.
136 */
137#define L_NONE 0
138/**
139 * Lookup will succeed only if the object is a regular file. If L_CREATE is
140 * specified, an empty file will be created. This flag is mutually exclusive
141 * with L_DIRECTORY.
142 */
143#define L_FILE 1
144/**
145 * Lookup wil succeed only if the object is a directory. If L_CREATE is
146 * specified, an empty directory will be created. This flag is mutually
147 * exclusive with L_FILE.
148 */
149#define L_DIRECTORY 2
150/**
151 * When used with L_CREATE, L_EXCLUSIVE will cause the lookup to fail if the
152 * object already exists. L_EXCLUSIVE is implied when L_DIRECTORY is used.
153 */
154#define L_EXCLUSIVE 4
155/**
156 * L_CREATE is used for creating both regular files and directories.
157 */
158#define L_CREATE 8
159/**
160 * L_LINK is used for linking to an already existing nodes.
161 */
162#define L_LINK 16
163/**
164 * L_UNLINK is used to remove leaves from the file system namespace. This flag
165 * cannot be passed directly by the client, but will be set by VFS during
166 * VFS_UNLINK.
167 */
168#define L_UNLINK 32
169
170typedef enum vfs_node_type {
171 VFS_NODE_UNKNOWN,
172 VFS_NODE_FILE,
173 VFS_NODE_DIRECTORY,
174} vfs_node_type_t;
175
176typedef struct {
177 vfs_triplet_t triplet;
178 vfs_node_type_t type;
179 size_t size;
180 unsigned lnkcnt;
181} vfs_lookup_res_t;
182
183/**
184 * Instances of this type represent an active, in-memory VFS node and any state
185 * which may be associated with it.
186 */
187typedef struct {
188 VFS_TRIPLET; /**< Identity of the node. */
189
190 /**
191 * Usage counter. This includes, but is not limited to, all vfs_file_t
192 * structures that reference this node.
193 */
194 unsigned refcnt;
195
196 /** Number of names this node has in the file system namespace. */
197 unsigned lnkcnt;
198
199 link_t nh_link; /**< Node hash-table link. */
200
201 vfs_node_type_t type; /**< Partial info about the node type. */
202
203 size_t size; /**< Cached size if the node is a file. */
204
205 /**
206 * Holding this rwlock prevents modifications of the node's contents.
207 */
208 rwlock_t contents_rwlock;
209} vfs_node_t;
210
211/**
212 * Instances of this type represent an open file. If the file is opened by more
213 * than one task, there will be a separate structure allocated for each task.
214 */
215typedef struct {
216 /** Serializes access to this open file. */
217 futex_t lock;
218
219 vfs_node_t *node;
220
221 /** Number of file handles referencing this file. */
222 unsigned refcnt;
223
224 /** Append on write. */
225 bool append;
226
227 /** Current position in the file. */
228 off_t pos;
229} vfs_file_t;
230
231extern futex_t nodes_futex;
232
233extern link_t fs_head; /**< List of registered file systems. */
234
235extern vfs_pair_t rootfs; /**< Root file system. */
236
237#define MAX_PATH_LEN (64 * 1024)
238
239#define PLB_SIZE (2 * MAX_PATH_LEN)
240
241/** Each instance of this type describes one path lookup in progress. */
242typedef struct {
243 link_t plb_link; /**< Active PLB entries list link. */
244 unsigned index; /**< Index of the first character in PLB. */
245 size_t len; /**< Number of characters in this PLB entry. */
246} plb_entry_t;
247
248extern futex_t plb_futex; /**< Futex protecting plb and plb_head. */
249extern uint8_t *plb; /**< Path Lookup Buffer */
250extern link_t plb_head; /**< List of active PLB entries. */
251
252#define MAX_MNTOPTS_LEN 256
253
254/** Holding this rwlock prevents changes in file system namespace. */
255extern rwlock_t namespace_rwlock;
256
257extern int vfs_grab_phone(fs_handle_t);
258extern void vfs_release_phone(int);
259
260extern fs_handle_t fs_name_to_handle(char *, bool);
261
262extern int vfs_lookup_internal(char *, int, vfs_lookup_res_t *, vfs_pair_t *,
263 ...);
264
265extern bool vfs_nodes_init(void);
266extern vfs_node_t *vfs_node_get(vfs_lookup_res_t *);
267extern void vfs_node_put(vfs_node_t *);
268
269#define MAX_OPEN_FILES 128
270
271extern bool vfs_files_init(void);
272extern vfs_file_t *vfs_file_get(int);
273extern int vfs_fd_alloc(void);
274extern int vfs_fd_free(int);
275
276extern void vfs_file_addref(vfs_file_t *);
277extern void vfs_file_delref(vfs_file_t *);
278
279extern void vfs_node_addref(vfs_node_t *);
280extern void vfs_node_delref(vfs_node_t *);
281
282extern void vfs_process_pending_mount(void);
283extern void vfs_register(ipc_callid_t, ipc_call_t *);
284extern void vfs_mount(ipc_callid_t, ipc_call_t *);
285extern void vfs_open(ipc_callid_t, ipc_call_t *);
286extern void vfs_close(ipc_callid_t, ipc_call_t *);
287extern void vfs_read(ipc_callid_t, ipc_call_t *);
288extern void vfs_write(ipc_callid_t, ipc_call_t *);
289extern void vfs_seek(ipc_callid_t, ipc_call_t *);
290extern void vfs_truncate(ipc_callid_t, ipc_call_t *);
291extern void vfs_mkdir(ipc_callid_t, ipc_call_t *);
292extern void vfs_unlink(ipc_callid_t, ipc_call_t *);
293extern void vfs_rename(ipc_callid_t, ipc_call_t *);
294
295#endif
296
297/**
298 * @}
299 */
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