Subversion Repositories HelenOS

Rev

Rev 2593 | Rev 2625 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
2520 jermar 1
/*
2
 * Copyright (c) 2007 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
 
2523 jermar 36
#include <ipc/ipc.h>
2529 jermar 37
#include <libadt/list.h>
2540 jermar 38
#include <atomic.h>
2542 jermar 39
#include <sys/types.h>
2550 cejka 40
#include <bool.h>
2523 jermar 41
 
2535 jermar 42
#define dprintf(...)    printf(__VA_ARGS__)
43
 
2550 cejka 44
#define VFS_FIRST   IPC_FIRST_USER_METHOD
2523 jermar 45
 
2526 jermar 46
#define IPC_METHOD_TO_VFS_OP(m) ((m) - VFS_FIRST)   
47
 
2520 jermar 48
typedef enum {
2523 jermar 49
    VFS_REGISTER = VFS_FIRST,
2520 jermar 50
    VFS_MOUNT,
51
    VFS_UNMOUNT,
2527 jermar 52
    VFS_LOOKUP,
2521 jermar 53
    VFS_OPEN,
2523 jermar 54
    VFS_CREATE,
55
    VFS_CLOSE,
56
    VFS_READ,
57
    VFS_WRITE,
58
    VFS_SEEK,
2593 jermar 59
    VFS_RENAME,
60
    VFS_UNLINK,
2521 jermar 61
    VFS_LAST,       /* keep this the last member of the enum */
2520 jermar 62
} vfs_request_t;
63
 
2521 jermar 64
 
65
/**
66
 * An instance of this structure is associated with a particular FS operation.
67
 * It tells VFS if the FS supports the operation or maybe if a default one
68
 * should be used.
69
 */
70
typedef enum {
2523 jermar 71
    VFS_OP_NULL = 0,
2521 jermar 72
    VFS_OP_DEFAULT,
73
    VFS_OP_DEFINED
74
} vfs_op_t;
75
 
76
#define FS_NAME_MAXLEN  20
77
 
78
/**
79
 * A structure like this is passed to VFS by each individual FS upon its
80
 * registration. It assosiates a human-readable identifier with each
81
 * registered FS. More importantly, through this structure, the FS announces
82
 * what operations it supports.
83
 */
84
typedef struct {
2523 jermar 85
    /** Unique identifier of the fs. */
2526 jermar 86
    char name[FS_NAME_MAXLEN];
2523 jermar 87
 
88
    /** Operations. */
89
    vfs_op_t ops[VFS_LAST - VFS_FIRST];
2521 jermar 90
} vfs_info_t;
91
 
2540 jermar 92
/**
93
 * A structure like this will be allocated for each registered file system.
94
 */
2526 jermar 95
typedef struct {
96
    link_t fs_link;
97
    vfs_info_t vfs_info;
2546 jermar 98
    int fs_handle;
99
    atomic_t phone_futex;   /**< Phone serializing futex. */
2527 jermar 100
    ipcarg_t phone;
2526 jermar 101
} fs_info_t;
102
 
2540 jermar 103
/**
2587 jermar 104
 * VFS_PAIR uniquely represents a file system instance.
105
 */
106
#define VFS_PAIR    \
107
    int fs_handle;  \
108
    int dev_handle; 
109
 
110
/**
111
 * VFS_TRIPLET uniquely identifies a file system node (e.g. directory, file) but
112
 * doesn't contain any state. For a stateful structure, see vfs_node_t.
2540 jermar 113
 *
114
 * @note    fs_handle, dev_handle and index are meant to be returned in one
115
 *      IPC reply.
116
 */
2587 jermar 117
#define VFS_TRIPLET \
118
    VFS_PAIR;   \
119
    uint64_t index;
120
 
2540 jermar 121
typedef struct {
2587 jermar 122
    VFS_PAIR;
123
} vfs_pair_t;
124
 
125
typedef struct {
126
    VFS_TRIPLET;
127
} vfs_triplet_t;
128
 
129
/**
130
 * Instances of this type represent an active, in-memory VFS node and any state
131
 * which may be associated with it.
132
 */
133
typedef struct {
134
    VFS_TRIPLET;        /**< Identity of the node. */
2593 jermar 135
    unsigned refcnt;    /**< Usage counter. */
136
    link_t nh_link;     /**< Node hash-table link. */
2540 jermar 137
} vfs_node_t;
138
 
139
/**
140
 * Instances of this type represent an open file. If the file is opened by more
141
 * than one task, there will be a separate structure allocated for each task.
142
 */
143
typedef struct {
144
    vfs_node_t *node;
145
 
146
    /** Number of file handles referencing this file. */
2593 jermar 147
    unsigned refcnt;
2540 jermar 148
 
149
    /** Current position in the file. */
150
    off_t pos;
151
} vfs_file_t;
152
 
2542 jermar 153
extern link_t fs_head;      /**< List of registered file systems. */
2535 jermar 154
 
2587 jermar 155
extern vfs_triplet_t rootfs;    /**< Root node of the root file system. */
2535 jermar 156
 
2542 jermar 157
#define MAX_PATH_LEN        (64 * 1024)
158
 
159
#define PLB_SIZE        (2 * MAX_PATH_LEN)
160
 
161
/** Each instance of this type describes one path lookup in progress. */
162
typedef struct {
163
    link_t  plb_link;   /**< Active PLB entries list link. */
164
    unsigned index;     /**< Index of the first character in PLB. */
165
    size_t len;     /**< Number of characters in this PLB entry. */
166
} plb_entry_t;
167
 
168
extern atomic_t plb_futex;  /**< Futex protecting plb and plb_head. */
169
extern uint8_t *plb;        /**< Path Lookup Buffer */
170
extern link_t plb_head;     /**< List of active PLB entries. */
171
 
2593 jermar 172
extern atomic_t unlink_futex;   /**< VFS_{CREATE|OPEN|UNLINK} serialization. */
173
 
2546 jermar 174
extern int vfs_grab_phone(int);
175
extern void vfs_release_phone(int);
176
 
2552 jermar 177
extern int fs_name_to_handle(char *, bool);
2548 jermar 178
 
2587 jermar 179
extern int vfs_lookup_internal(char *, size_t, vfs_triplet_t *, vfs_pair_t *);
2593 jermar 180
 
2596 jermar 181
extern bool vfs_nodes_init(void);
2590 jermar 182
extern vfs_node_t *vfs_node_get(vfs_triplet_t *);
2593 jermar 183
extern void vfs_node_put(vfs_node_t *);
2544 jermar 184
 
2596 jermar 185
#define MAX_OPEN_FILES  128
186
 
2593 jermar 187
extern bool vfs_files_init(void);
188
extern vfs_file_t *vfs_file_get(int);
189
extern int vfs_fd_alloc(void);
190
extern void vfs_fd_free(int);
191
 
192
extern void vfs_file_addref(vfs_file_t *);
193
extern void vfs_file_delref(vfs_file_t *);
194
 
195
extern void vfs_node_addref(vfs_node_t *);
196
extern void vfs_node_delref(vfs_node_t *);
197
 
2542 jermar 198
extern void vfs_register(ipc_callid_t, ipc_call_t *);
2544 jermar 199
extern void vfs_mount(ipc_callid_t, ipc_call_t *);
2560 jermar 200
extern void vfs_open(ipc_callid_t, ipc_call_t *);
2542 jermar 201
 
2520 jermar 202
#endif
203
 
204
/**
205
 * @}
2523 jermar 206
 */