source: mainline/uspace/srv/vfs/vfs.h@ e3fa92aa

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since e3fa92aa was af7383f3, checked in by Jakub Jermar <jakub@…>, 16 years ago

Handle pending mounts using only one fibril.
  • Property mode set to 100644
File size: 6.2 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 <adt/list.h>
38#include <fibril_sync.h>
39#include <futex.h>
40#include <sys/types.h>
41#include <devmap.h>
42#include <bool.h>
43#include <ipc/vfs.h>
44
45// FIXME: according to CONFIG_DEBUG
46// #define dprintf(...) printf(__VA_ARGS__)
47
48#define dprintf(...)
49
50/**
51 * A structure like this will be allocated for each registered file system.
52 */
53typedef struct {
54 link_t fs_link;
55 vfs_info_t vfs_info;
56 fs_handle_t fs_handle;
57 fibril_mutex_t phone_lock;
58 ipcarg_t phone;
59} fs_info_t;
60
61/**
62 * VFS_PAIR uniquely represents a file system instance.
63 */
64#define VFS_PAIR \
65 fs_handle_t fs_handle; \
66 dev_handle_t dev_handle;
67
68/**
69 * VFS_TRIPLET uniquely identifies a file system node (e.g. directory, file) but
70 * doesn't contain any state. For a stateful structure, see vfs_node_t.
71 *
72 * @note fs_handle, dev_handle and index are meant to be returned in one
73 * IPC reply.
74 */
75#define VFS_TRIPLET \
76 VFS_PAIR; \
77 fs_index_t index;
78
79typedef struct {
80 VFS_PAIR;
81} vfs_pair_t;
82
83typedef struct {
84 VFS_TRIPLET;
85} vfs_triplet_t;
86
87typedef enum vfs_node_type {
88 VFS_NODE_UNKNOWN,
89 VFS_NODE_FILE,
90 VFS_NODE_DIRECTORY,
91} vfs_node_type_t;
92
93typedef struct {
94 vfs_triplet_t triplet;
95 vfs_node_type_t type;
96 size_t size;
97 unsigned lnkcnt;
98} vfs_lookup_res_t;
99
100/**
101 * Instances of this type represent an active, in-memory VFS node and any state
102 * which may be associated with it.
103 */
104typedef struct {
105 VFS_TRIPLET; /**< Identity of the node. */
106
107 /**
108 * Usage counter. This includes, but is not limited to, all vfs_file_t
109 * structures that reference this node.
110 */
111 unsigned refcnt;
112
113 /** Number of names this node has in the file system namespace. */
114 unsigned lnkcnt;
115
116 link_t nh_link; /**< Node hash-table link. */
117
118 vfs_node_type_t type; /**< Partial info about the node type. */
119
120 size_t size; /**< Cached size if the node is a file. */
121
122 /**
123 * Holding this rwlock prevents modifications of the node's contents.
124 */
125 fibril_rwlock_t contents_rwlock;
126} vfs_node_t;
127
128/**
129 * Instances of this type represent an open file. If the file is opened by more
130 * than one task, there will be a separate structure allocated for each task.
131 */
132typedef struct {
133 /** Serializes access to this open file. */
134 fibril_mutex_t lock;
135
136 vfs_node_t *node;
137
138 /** Number of file handles referencing this file. */
139 unsigned refcnt;
140
141 /** Append on write. */
142 bool append;
143
144 /** Current position in the file. */
145 off_t pos;
146} vfs_file_t;
147
148extern futex_t nodes_futex;
149
150extern link_t fs_head; /**< List of registered file systems. */
151
152extern vfs_pair_t rootfs; /**< Root file system. */
153
154/** Each instance of this type describes one path lookup in progress. */
155typedef struct {
156 link_t plb_link; /**< Active PLB entries list link. */
157 unsigned index; /**< Index of the first character in PLB. */
158 size_t len; /**< Number of characters in this PLB entry. */
159} plb_entry_t;
160
161extern futex_t plb_futex; /**< Futex protecting plb and plb_head. */
162extern uint8_t *plb; /**< Path Lookup Buffer */
163extern link_t plb_head; /**< List of active PLB entries. */
164
165#define MAX_MNTOPTS_LEN 256
166
167/** Holding this rwlock prevents changes in file system namespace. */
168extern fibril_rwlock_t namespace_rwlock;
169
170extern int vfs_grab_phone(fs_handle_t);
171extern void vfs_release_phone(int);
172
173extern fibril_mutex_t fs_head_lock;
174extern bool pending_new_fs;
175extern fibril_condvar_t pending_cv;
176
177extern fs_handle_t fs_name_to_handle(char *, bool);
178
179extern int vfs_lookup_internal(char *, int, vfs_lookup_res_t *,
180 vfs_pair_t *, ...);
181extern int vfs_open_node_internal(vfs_lookup_res_t *);
182
183extern bool vfs_nodes_init(void);
184extern vfs_node_t *vfs_node_get(vfs_lookup_res_t *);
185extern void vfs_node_put(vfs_node_t *);
186
187#define MAX_OPEN_FILES 128
188
189extern bool vfs_files_init(void);
190extern vfs_file_t *vfs_file_get(int);
191extern int vfs_fd_alloc(void);
192extern int vfs_fd_free(int);
193
194extern void vfs_file_addref(vfs_file_t *);
195extern void vfs_file_delref(vfs_file_t *);
196
197extern void vfs_node_addref(vfs_node_t *);
198extern void vfs_node_delref(vfs_node_t *);
199
200extern void vfs_process_pending_mount(void);
201extern void vfs_register(ipc_callid_t, ipc_call_t *);
202extern void vfs_mount(ipc_callid_t, ipc_call_t *);
203extern void vfs_open(ipc_callid_t, ipc_call_t *);
204extern void vfs_open_node(ipc_callid_t, ipc_call_t *);
205extern void vfs_device(ipc_callid_t, ipc_call_t *);
206extern void vfs_sync(ipc_callid_t, ipc_call_t *);
207extern void vfs_node(ipc_callid_t, ipc_call_t *);
208extern void vfs_close(ipc_callid_t, ipc_call_t *);
209extern void vfs_read(ipc_callid_t, ipc_call_t *);
210extern void vfs_write(ipc_callid_t, ipc_call_t *);
211extern void vfs_seek(ipc_callid_t, ipc_call_t *);
212extern void vfs_truncate(ipc_callid_t, ipc_call_t *);
213extern void vfs_mkdir(ipc_callid_t, ipc_call_t *);
214extern void vfs_unlink(ipc_callid_t, ipc_call_t *);
215extern void vfs_rename(ipc_callid_t, ipc_call_t *);
216
217#endif
218
219/**
220 * @}
221 */
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