Subversion Repositories HelenOS

Rev

Rev 2856 | Rev 2876 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
2627 jermar 1
/*
2789 jermar 2
 * Copyright (c) 2008 Jakub Jermar
2627 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 FAT_FAT_H_
34
#define FAT_FAT_H_
35
 
36
#include <ipc/ipc.h>
2643 jermar 37
#include <libfs.h>
2627 jermar 38
#include <atomic.h>
39
#include <sys/types.h>
40
#include <bool.h>
2789 jermar 41
#include "../../vfs/vfs.h"
2627 jermar 42
 
43
#define dprintf(...)    printf(__VA_ARGS__)
44
 
2628 jermar 45
typedef struct {
46
    uint8_t     ji[3];      /**< Jump instruction. */
47
    uint8_t     oem_name[8];
48
    /* BIOS Parameter Block */
49
    uint16_t    bps;        /**< Bytes per sector. */
50
    uint8_t     spc;        /**< Sectors per cluster. */
2789 jermar 51
    uint16_t    rscnt;      /**< Reserved sector count. */
2628 jermar 52
    uint8_t     fatcnt;     /**< Number of FATs. */
53
    uint16_t    root_ent_max;   /**< Maximum number of root directory
54
                         entries. */
2789 jermar 55
    uint16_t    totsec16;   /**< Total sectors. 16-bit version. */
2628 jermar 56
    uint8_t     mdesc;      /**< Media descriptor. */
57
    uint16_t    sec_per_fat;    /**< Sectors per FAT12/FAT16. */
58
    uint16_t    sec_per_track;  /**< Sectors per track. */
59
    uint16_t    headcnt;    /**< Number of heads. */
60
    uint32_t    hidden_sec; /**< Hidden sectors. */
2831 jermar 61
    uint32_t    totsec32;   /**< Total sectors. 32-bit version. */
2628 jermar 62
 
63
    union {
64
        struct {
65
            /* FAT12/FAT16 only: Extended BIOS Parameter Block */
66
            /** Physical drive number. */
67
            uint8_t     pdn;
68
            uint8_t     reserved;
69
            /** Extended boot signature. */
70
            uint8_t     ebs;
71
            /** Serial number. */
72
            uint32_t    id;
73
            /** Volume label. */
74
            uint8_t     label[11];
75
            /** FAT type. */
76
            uint8_t     type[8];
77
            /** Boot code. */
78
            uint8_t     boot_code[448];
79
            /** Boot sector signature. */
80
            uint16_t    signature;
81
        } __attribute__ ((packed));
82
        struct {
83
            /* FAT32 only */
84
            /** Sectors per FAT. */
85
            uint32_t    sectors_per_fat;
86
            /** FAT flags. */
87
            uint16_t    flags;
88
            /** Version. */
89
            uint16_t    version;
90
            /** Cluster number of root directory. */
91
            uint32_t    root_cluster;
92
            /** Sector number of file system information sector. */
93
            uint16_t    fsinfo_sec;
94
            /** Sector number of boot sector copy. */
95
            uint16_t    bscopy_sec;
96
            uint8_t     reserved1[12];
97
            /** Physical drive number. */
98
            uint8_t     pdn;
99
            uint8_t     reserved2;
100
            /** Extended boot signature. */
101
            uint8_t     ebs;
102
            /** Serial number. */
103
            uint32_t    id;
104
            /** Volume label. */
2789 jermar 105
            uint8_t     label[11];
2628 jermar 106
            /** FAT type. */
107
            uint8_t     type[8];
108
            /** Boot code. */
109
            uint8_t     boot_code[420];
110
            /** Signature. */
111
            uint16_t    signature;
112
        } __attribute__ ((packed));
113
    };
2629 jermar 114
} __attribute__ ((packed)) fat_bs_t;
2628 jermar 115
 
2793 jermar 116
#define FAT_ATTR_RDONLY     (1 << 0)
117
#define FAT_ATTR_VOLLABEL   (1 << 3)
118
#define FAT_ATTR_SUBDIR     (1 << 4)
119
 
2629 jermar 120
typedef struct {
121
    uint8_t     name[8];
122
    uint8_t     ext[3];
123
    uint8_t     attr;
124
    uint8_t     reserved;
125
    uint8_t     ctime_fine;
126
    uint16_t    ctime;
127
    uint16_t    cdate;
128
    uint16_t    adate;
129
    union {
130
        uint16_t    eaidx;      /* FAT12/FAT16 */
131
        uint16_t    firstc_hi;  /* FAT32 */
132
    };
133
    uint16_t    mtime;
134
    uint16_t    mdate;
135
    union {
136
        uint16_t    firstc;     /* FAT12/FAT16 */
137
        uint16_t    firstc_lo;  /* FAT32 */
138
    };
139
    uint32_t    size;
140
} __attribute__ ((packed)) fat_dentry_t;
141
 
2864 jermar 142
typedef uint16_t fat_cluster_t;
143
 
2789 jermar 144
typedef enum {
2831 jermar 145
    FAT_INVALID,
2789 jermar 146
    FAT_DIRECTORY,
147
    FAT_FILE
148
} fat_node_type_t;
149
 
2864 jermar 150
struct fat_node;
151
 
152
/** FAT index structure.
153
 *
154
 * This structure exists to help us to overcome certain limitations of the FAT
155
 * file system design.  The problem with FAT is that it is hard to find
156
 * an entity which could represent a VFS index.  There are two candidates:
157
 *
158
 * a) number of the node's first cluster
159
 * b) the pair of the parent directory's first cluster and the dentry index
160
 *    within the parent directory
161
 *
162
 * We need VFS indices to be:
163
 * A) unique
164
 * B) stable in time, at least until the next mount
165
 *
166
 * Unfortunately a) does not meet the A) criterion because zero-length files
167
 * will have the first cluster field cleared.  And b) does not meet the B)
168
 * criterion because unlink() and rename() will both free up the original
169
 * dentry, which contains all the essential info about the file.
170
 *
171
 * Therefore, a completely opaque indices are used and the FAT server maintains
172
 * a mapping between them and otherwise nice b) variant.  On rename(), the VFS
173
 * index stays unaltered, while the internal FAT "physical tree address"
174
 * changes.  The unlink case is also handled this way thanks to an in-core node
175
 * pointer embedded in the index structure.
176
 */
177
typedef struct {
178
    dev_handle_t    dev_handle;
179
    fs_index_t  index;
180
    /**
181
     * Parent first cluster.
182
     * Zero is used if this node is not linked, in which case nodep must
183
     * contain a pointer to the in-core node structure.
184
     * One is used when the parent is the root directory.
185
     */
186
    fat_cluster_t   pfc;
187
    /** Parent directory entry index. */
188
    unsigned    pdi;
189
    /** Pointer to in-core node instance. */
190
    struct fat_node *nodep;
191
} fat_idx_t;
192
 
2789 jermar 193
/** FAT in-core node. */
2864 jermar 194
typedef struct fat_node {
2789 jermar 195
    fat_node_type_t     type;
2864 jermar 196
    fat_idx_t       *idx;
197
    /**
198
     *  Node's first cluster.
199
     *  Zero is used for zero-length nodes.
200
     *  One is used to mark root directory.
201
     */
202
    fat_cluster_t       firstc;
2789 jermar 203
    /** FAT in-core node hash table link. */
204
    link_t          fin_link;
2831 jermar 205
    /** FAT in-core node free list link. */
206
    link_t          ffn_link;
2789 jermar 207
    size_t          size;
208
    unsigned        lnkcnt;
2831 jermar 209
    unsigned        refcnt;
210
    bool            dirty;
2789 jermar 211
} fat_node_t;
212
 
2643 jermar 213
extern fs_reg_t fat_reg;
2627 jermar 214
 
2638 jermar 215
extern void fat_lookup(ipc_callid_t, ipc_call_t *);
216
 
2627 jermar 217
#endif
218
 
219
/**
220
 * @}
221
 */