Subversion Repositories HelenOS

Rev

Rev 2687 | Rev 2691 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
2520 jermar 1
/*
2682 jermar 2
 * Copyright (c) 2008 Jakub Jermar
2520 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
 
2523 jermar 36
#include <ipc/ipc.h>
2529 jermar 37
#include <libadt/list.h>
2540 jermar 38
#include <atomic.h>
2680 jermar 39
#include <rwlock.h>
2542 jermar 40
#include <sys/types.h>
2550 cejka 41
#include <bool.h>
2523 jermar 42
 
2535 jermar 43
#define dprintf(...)    printf(__VA_ARGS__)
44
 
2550 cejka 45
#define VFS_FIRST   IPC_FIRST_USER_METHOD
2523 jermar 46
 
2526 jermar 47
#define IPC_METHOD_TO_VFS_OP(m) ((m) - VFS_FIRST)   
48
 
2520 jermar 49
typedef enum {
2690 jermar 50
    VFS_OPEN = VFS_FIRST,
2523 jermar 51
    VFS_CLOSE,
52
    VFS_READ,
53
    VFS_WRITE,
2690 jermar 54
    VFS_TRUNCATE,
2593 jermar 55
    VFS_RENAME,
2690 jermar 56
    VFS_OPENDIR,
57
    VFS_READDIR,
58
    VFS_CLOSEDIR,
2593 jermar 59
    VFS_UNLINK,
2690 jermar 60
    VFS_MOUNT,
61
    VFS_UNMOUNT,
62
    VFS_LAST_CMN,   /* keep this the last member of this enum */
63
} vfs_request_cmn_t;
2520 jermar 64
 
2690 jermar 65
typedef enum {
66
    VFS_LOOKUP = VFS_LAST_CMN,
67
    VFS_LAST_CLNT,  /* keep this the last member of this enum */
68
} vfs_request_clnt_t;
2521 jermar 69
 
2690 jermar 70
typedef enum {
71
    VFS_REGISTER = VFS_LAST_CMN,
72
    VFS_SEEK,
73
    VFS_LAST_SRV,   /* keep this the last member of this enum */
74
} vfs_request_srv_t;
75
 
76
 
2521 jermar 77
/**
78
 * An instance of this structure is associated with a particular FS operation.
79
 * It tells VFS if the FS supports the operation or maybe if a default one
80
 * should be used.
81
 */
82
typedef enum {
2523 jermar 83
    VFS_OP_NULL = 0,
2521 jermar 84
    VFS_OP_DEFAULT,
85
    VFS_OP_DEFINED
86
} vfs_op_t;
87
 
88
#define FS_NAME_MAXLEN  20
89
 
90
/**
91
 * A structure like this is passed to VFS by each individual FS upon its
92
 * registration. It assosiates a human-readable identifier with each
93
 * registered FS. More importantly, through this structure, the FS announces
94
 * what operations it supports.
95
 */
96
typedef struct {
2523 jermar 97
    /** Unique identifier of the fs. */
2641 jermar 98
    char name[FS_NAME_MAXLEN + 1];
2523 jermar 99
 
100
    /** Operations. */
2690 jermar 101
    vfs_op_t ops[VFS_LAST_CLNT - VFS_FIRST];
2521 jermar 102
} vfs_info_t;
103
 
2540 jermar 104
/**
105
 * A structure like this will be allocated for each registered file system.
106
 */
2526 jermar 107
typedef struct {
108
    link_t fs_link;
109
    vfs_info_t vfs_info;
2546 jermar 110
    int fs_handle;
111
    atomic_t phone_futex;   /**< Phone serializing futex. */
2527 jermar 112
    ipcarg_t phone;
2526 jermar 113
} fs_info_t;
114
 
2540 jermar 115
/**
2587 jermar 116
 * VFS_PAIR uniquely represents a file system instance.
117
 */
118
#define VFS_PAIR    \
119
    int fs_handle;  \
120
    int dev_handle; 
121
 
122
/**
123
 * VFS_TRIPLET uniquely identifies a file system node (e.g. directory, file) but
124
 * doesn't contain any state. For a stateful structure, see vfs_node_t.
2540 jermar 125
 *
126
 * @note    fs_handle, dev_handle and index are meant to be returned in one
127
 *      IPC reply.
128
 */
2587 jermar 129
#define VFS_TRIPLET \
130
    VFS_PAIR;   \
131
    uint64_t index;
132
 
2540 jermar 133
typedef struct {
2587 jermar 134
    VFS_PAIR;
135
} vfs_pair_t;
136
 
137
typedef struct {
138
    VFS_TRIPLET;
139
} vfs_triplet_t;
140
 
141
/**
142
 * Instances of this type represent an active, in-memory VFS node and any state
143
 * which may be associated with it.
144
 */
145
typedef struct {
146
    VFS_TRIPLET;        /**< Identity of the node. */
2593 jermar 147
    unsigned refcnt;    /**< Usage counter. */
148
    link_t nh_link;     /**< Node hash-table link. */
2684 jermar 149
    size_t size;        /**< Cached size of the file. */
2679 jermar 150
 
2682 jermar 151
    /**
152
     * Holding this rwlock prevents modifications of the node's contents.
153
     */
154
    rwlock_t contents_rwlock;
2540 jermar 155
} vfs_node_t;
156
 
157
/**
158
 * Instances of this type represent an open file. If the file is opened by more
159
 * than one task, there will be a separate structure allocated for each task.
160
 */
161
typedef struct {
2683 jermar 162
    /** Serializes access to this open file. */
163
    futex_t lock;
164
 
2540 jermar 165
    vfs_node_t *node;
166
 
167
    /** Number of file handles referencing this file. */
2593 jermar 168
    unsigned refcnt;
2540 jermar 169
 
170
    /** Current position in the file. */
171
    off_t pos;
172
} vfs_file_t;
173
 
2542 jermar 174
extern link_t fs_head;      /**< List of registered file systems. */
2535 jermar 175
 
2587 jermar 176
extern vfs_triplet_t rootfs;    /**< Root node of the root file system. */
2535 jermar 177
 
2542 jermar 178
#define MAX_PATH_LEN        (64 * 1024)
179
 
180
#define PLB_SIZE        (2 * MAX_PATH_LEN)
181
 
182
/** Each instance of this type describes one path lookup in progress. */
183
typedef struct {
184
    link_t  plb_link;   /**< Active PLB entries list link. */
185
    unsigned index;     /**< Index of the first character in PLB. */
186
    size_t len;     /**< Number of characters in this PLB entry. */
187
} plb_entry_t;
188
 
189
extern atomic_t plb_futex;  /**< Futex protecting plb and plb_head. */
190
extern uint8_t *plb;        /**< Path Lookup Buffer */
191
extern link_t plb_head;     /**< List of active PLB entries. */
192
 
2681 jermar 193
/** Holding this rwlock prevents changes in file system namespace. */
194
extern rwlock_t namespace_rwlock;
2593 jermar 195
 
2546 jermar 196
extern int vfs_grab_phone(int);
197
extern void vfs_release_phone(int);
198
 
2552 jermar 199
extern int fs_name_to_handle(char *, bool);
2548 jermar 200
 
2687 jermar 201
extern int vfs_lookup_internal(char *, size_t, vfs_triplet_t *, size_t *,
202
    vfs_pair_t *);
2593 jermar 203
 
2596 jermar 204
extern bool vfs_nodes_init(void);
2687 jermar 205
extern vfs_node_t *vfs_node_get(vfs_triplet_t *, size_t);
2593 jermar 206
extern void vfs_node_put(vfs_node_t *);
2544 jermar 207
 
2596 jermar 208
#define MAX_OPEN_FILES  128
209
 
2593 jermar 210
extern bool vfs_files_init(void);
211
extern vfs_file_t *vfs_file_get(int);
212
extern int vfs_fd_alloc(void);
213
extern void vfs_fd_free(int);
214
 
215
extern void vfs_file_addref(vfs_file_t *);
216
extern void vfs_file_delref(vfs_file_t *);
217
 
218
extern void vfs_node_addref(vfs_node_t *);
219
extern void vfs_node_delref(vfs_node_t *);
220
 
2542 jermar 221
extern void vfs_register(ipc_callid_t, ipc_call_t *);
2544 jermar 222
extern void vfs_mount(ipc_callid_t, ipc_call_t *);
2560 jermar 223
extern void vfs_open(ipc_callid_t, ipc_call_t *);
2625 jermar 224
extern void vfs_read(ipc_callid_t, ipc_call_t *);
2666 jermar 225
extern void vfs_write(ipc_callid_t, ipc_call_t *);
2684 jermar 226
extern void vfs_seek(ipc_callid_t, ipc_call_t *);
2542 jermar 227
 
2520 jermar 228
#endif
229
 
230
/**
231
 * @}
2523 jermar 232
 */