source: mainline/uspace/srv/fs/fat/fat.h@ f563126

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since f563126 was f563126, checked in by Martin Decky <martin@…>, 16 years ago

make uspace pass compilation with clang
  • Property mode set to 100644
File size: 7.2 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 FAT_FAT_H_
34#define FAT_FAT_H_
35
36#include "fat_fat.h"
37#include <ipc/ipc.h>
38#include <fibril_sync.h>
39#include <libfs.h>
40#include <atomic.h>
41#include <sys/types.h>
42#include <bool.h>
43#include "../../vfs/vfs.h"
44
45#ifndef dprintf
46#define dprintf(...) printf(__VA_ARGS__)
47#endif
48
49#define min(a, b) ((a) < (b) ? (a) : (b))
50
51#define BS_BLOCK 0
52#define BS_SIZE 512
53
54typedef struct fat_bs {
55 uint8_t ji[3]; /**< Jump instruction. */
56 uint8_t oem_name[8];
57 /* BIOS Parameter Block */
58 uint16_t bps; /**< Bytes per sector. */
59 uint8_t spc; /**< Sectors per cluster. */
60 uint16_t rscnt; /**< Reserved sector count. */
61 uint8_t fatcnt; /**< Number of FATs. */
62 uint16_t root_ent_max; /**< Maximum number of root directory
63 entries. */
64 uint16_t totsec16; /**< Total sectors. 16-bit version. */
65 uint8_t mdesc; /**< Media descriptor. */
66 uint16_t sec_per_fat; /**< Sectors per FAT12/FAT16. */
67 uint16_t sec_per_track; /**< Sectors per track. */
68 uint16_t headcnt; /**< Number of heads. */
69 uint32_t hidden_sec; /**< Hidden sectors. */
70 uint32_t totsec32; /**< Total sectors. 32-bit version. */
71
72 union {
73 struct {
74 /* FAT12/FAT16 only: Extended BIOS Parameter Block */
75 /** Physical drive number. */
76 uint8_t pdn;
77 uint8_t reserved;
78 /** Extended boot signature. */
79 uint8_t ebs;
80 /** Serial number. */
81 uint32_t id;
82 /** Volume label. */
83 uint8_t label[11];
84 /** FAT type. */
85 uint8_t type[8];
86 /** Boot code. */
87 uint8_t boot_code[448];
88 /** Boot sector signature. */
89 uint16_t signature;
90 } __attribute__ ((packed));
91 struct fat32 {
92 /* FAT32 only */
93 /** Sectors per FAT. */
94 uint32_t sectors_per_fat;
95 /** FAT flags. */
96 uint16_t flags;
97 /** Version. */
98 uint16_t version;
99 /** Cluster number of root directory. */
100 uint32_t root_cluster;
101 /** Sector number of file system information sector. */
102 uint16_t fsinfo_sec;
103 /** Sector number of boot sector copy. */
104 uint16_t bscopy_sec;
105 uint8_t reserved1[12];
106 /** Physical drive number. */
107 uint8_t pdn;
108 uint8_t reserved2;
109 /** Extended boot signature. */
110 uint8_t ebs;
111 /** Serial number. */
112 uint32_t id;
113 /** Volume label. */
114 uint8_t label[11];
115 /** FAT type. */
116 uint8_t type[8];
117 /** Boot code. */
118 uint8_t boot_code[420];
119 /** Signature. */
120 uint16_t signature;
121 } __attribute__ ((packed));
122 };
123} __attribute__ ((packed)) fat_bs_t;
124
125typedef enum {
126 FAT_INVALID,
127 FAT_DIRECTORY,
128 FAT_FILE
129} fat_node_type_t;
130
131struct fat_node;
132
133/** FAT index structure.
134 *
135 * This structure exists to help us to overcome certain limitations of the FAT
136 * file system design. The problem with FAT is that it is hard to find
137 * an entity which could represent a VFS index. There are two candidates:
138 *
139 * a) number of the node's first cluster
140 * b) the pair of the parent directory's first cluster and the dentry index
141 * within the parent directory
142 *
143 * We need VFS indices to be:
144 * A) unique
145 * B) stable in time, at least until the next mount
146 *
147 * Unfortunately a) does not meet the A) criterion because zero-length files
148 * will have the first cluster field cleared. And b) does not meet the B)
149 * criterion because unlink() and rename() will both free up the original
150 * dentry, which contains all the essential info about the file.
151 *
152 * Therefore, a completely opaque indices are used and the FAT server maintains
153 * a mapping between them and otherwise nice b) variant. On rename(), the VFS
154 * index stays unaltered, while the internal FAT "physical tree address"
155 * changes. The unlink case is also handled this way thanks to an in-core node
156 * pointer embedded in the index structure.
157 */
158typedef struct {
159 /** Used indices (position) hash table link. */
160 link_t uph_link;
161 /** Used indices (index) hash table link. */
162 link_t uih_link;
163
164 fibril_mutex_t lock;
165 dev_handle_t dev_handle;
166 fs_index_t index;
167 /**
168 * Parent node's first cluster.
169 * Zero is used if this node is not linked, in which case nodep must
170 * contain a pointer to the in-core node structure.
171 * One is used when the parent is the root directory.
172 */
173 fat_cluster_t pfc;
174 /** Directory entry index within the parent node. */
175 unsigned pdi;
176 /** Pointer to in-core node instance. */
177 struct fat_node *nodep;
178} fat_idx_t;
179
180/** FAT in-core node. */
181typedef struct fat_node {
182 /** Back pointer to the FS node. */
183 fs_node_t *bp;
184
185 fibril_mutex_t lock;
186 fat_node_type_t type;
187 fat_idx_t *idx;
188 /**
189 * Node's first cluster.
190 * Zero is used for zero-length nodes.
191 * One is used to mark root directory.
192 */
193 fat_cluster_t firstc;
194 /** FAT in-core node free list link. */
195 link_t ffn_link;
196 size_t size;
197 unsigned lnkcnt;
198 unsigned refcnt;
199 bool dirty;
200} fat_node_t;
201
202extern fs_reg_t fat_reg;
203
204extern void fat_mounted(ipc_callid_t, ipc_call_t *);
205extern void fat_mount(ipc_callid_t, ipc_call_t *);
206extern void fat_lookup(ipc_callid_t, ipc_call_t *);
207extern void fat_read(ipc_callid_t, ipc_call_t *);
208extern void fat_write(ipc_callid_t, ipc_call_t *);
209extern void fat_truncate(ipc_callid_t, ipc_call_t *);
210extern void fat_stat(ipc_callid_t, ipc_call_t *);
211extern void fat_close(ipc_callid_t, ipc_call_t *);
212extern void fat_destroy(ipc_callid_t, ipc_call_t *);
213extern void fat_open_node(ipc_callid_t, ipc_call_t *);
214extern void fat_stat(ipc_callid_t, ipc_call_t *);
215extern void fat_sync(ipc_callid_t, ipc_call_t *);
216
217extern int fat_idx_get_new(fat_idx_t **, dev_handle_t);
218extern fat_idx_t *fat_idx_get_by_pos(dev_handle_t, fat_cluster_t, unsigned);
219extern fat_idx_t *fat_idx_get_by_index(dev_handle_t, fs_index_t);
220extern void fat_idx_destroy(fat_idx_t *);
221extern void fat_idx_hashin(fat_idx_t *);
222extern void fat_idx_hashout(fat_idx_t *);
223
224extern int fat_idx_init(void);
225extern void fat_idx_fini(void);
226extern int fat_idx_init_by_dev_handle(dev_handle_t);
227extern void fat_idx_fini_by_dev_handle(dev_handle_t);
228
229#endif
230
231/**
232 * @}
233 */
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