source: mainline/uspace/srv/fs/fat/fat.h@ 7accfac

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 7accfac was ffa2c8ef, checked in by Martin Decky <martin@…>, 15 years ago

do not intermix low-level IPC methods with async framework methods

  • Property mode set to 100644
File size: 8.2 KB
RevLine 
[be815bc]1/*
[5e790e6]2 * Copyright (c) 2008 Jakub Jermar
[be815bc]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
[0f57d0e]36#include "fat_fat.h"
[1e4cada]37#include <fibril_synch.h>
[efd4a72]38#include <libfs.h>
[be815bc]39#include <atomic.h>
40#include <sys/types.h>
41#include <bool.h>
[5e790e6]42#include "../../vfs/vfs.h"
[be815bc]43
[b7b6753]44#ifndef dprintf
[be815bc]45#define dprintf(...) printf(__VA_ARGS__)
[b7b6753]46#endif
[be815bc]47
[0f57d0e]48#define min(a, b) ((a) < (b) ? (a) : (b))
49
[7a23d60]50/*
51 * Convenience macros for accessing some frequently used boot sector members.
52 */
53#define BPS(bs) uint16_t_le2host((bs)->bps)
54#define SPC(bs) (bs)->spc
55#define RSCNT(bs) uint16_t_le2host((bs)->rscnt)
56#define FATCNT(bs) (bs)->fatcnt
57#define SF(bs) uint16_t_le2host((bs)->sec_per_fat)
58#define RDE(bs) uint16_t_le2host((bs)->root_ent_max)
59#define TS(bs) (uint16_t_le2host((bs)->totsec16) != 0 ? \
60 uint16_t_le2host((bs)->totsec16) : \
61 uint32_t_le2host(bs->totsec32))
62
[0f57d0e]63#define BS_BLOCK 0
64#define BS_SIZE 512
65
[cb682eb]66typedef struct fat_bs {
[5af627fc]67 uint8_t ji[3]; /**< Jump instruction. */
68 uint8_t oem_name[8];
69 /* BIOS Parameter Block */
70 uint16_t bps; /**< Bytes per sector. */
71 uint8_t spc; /**< Sectors per cluster. */
[5e790e6]72 uint16_t rscnt; /**< Reserved sector count. */
[5af627fc]73 uint8_t fatcnt; /**< Number of FATs. */
74 uint16_t root_ent_max; /**< Maximum number of root directory
75 entries. */
[5e790e6]76 uint16_t totsec16; /**< Total sectors. 16-bit version. */
[5af627fc]77 uint8_t mdesc; /**< Media descriptor. */
78 uint16_t sec_per_fat; /**< Sectors per FAT12/FAT16. */
79 uint16_t sec_per_track; /**< Sectors per track. */
80 uint16_t headcnt; /**< Number of heads. */
81 uint32_t hidden_sec; /**< Hidden sectors. */
[e1e3b26]82 uint32_t totsec32; /**< Total sectors. 32-bit version. */
[5af627fc]83
84 union {
85 struct {
86 /* FAT12/FAT16 only: Extended BIOS Parameter Block */
87 /** Physical drive number. */
88 uint8_t pdn;
89 uint8_t reserved;
90 /** Extended boot signature. */
91 uint8_t ebs;
92 /** Serial number. */
93 uint32_t id;
94 /** Volume label. */
95 uint8_t label[11];
96 /** FAT type. */
97 uint8_t type[8];
98 /** Boot code. */
99 uint8_t boot_code[448];
100 /** Boot sector signature. */
101 uint16_t signature;
102 } __attribute__ ((packed));
[ed903174]103 struct {
[5af627fc]104 /* FAT32 only */
105 /** Sectors per FAT. */
106 uint32_t sectors_per_fat;
107 /** FAT flags. */
108 uint16_t flags;
109 /** Version. */
110 uint16_t version;
111 /** Cluster number of root directory. */
112 uint32_t root_cluster;
113 /** Sector number of file system information sector. */
114 uint16_t fsinfo_sec;
115 /** Sector number of boot sector copy. */
116 uint16_t bscopy_sec;
117 uint8_t reserved1[12];
118 /** Physical drive number. */
119 uint8_t pdn;
120 uint8_t reserved2;
121 /** Extended boot signature. */
122 uint8_t ebs;
123 /** Serial number. */
124 uint32_t id;
125 /** Volume label. */
[5e790e6]126 uint8_t label[11];
[5af627fc]127 /** FAT type. */
128 uint8_t type[8];
129 /** Boot code. */
130 uint8_t boot_code[420];
131 /** Signature. */
132 uint16_t signature;
[ed903174]133 } fat32 __attribute__ ((packed));
134 };
[263e1ec]135} __attribute__ ((packed)) fat_bs_t;
136
[5e790e6]137typedef enum {
[e1e3b26]138 FAT_INVALID,
[5e790e6]139 FAT_DIRECTORY,
140 FAT_FILE
141} fat_node_type_t;
142
[869e546]143struct fat_node;
144
145/** FAT index structure.
146 *
147 * This structure exists to help us to overcome certain limitations of the FAT
148 * file system design. The problem with FAT is that it is hard to find
149 * an entity which could represent a VFS index. There are two candidates:
150 *
151 * a) number of the node's first cluster
152 * b) the pair of the parent directory's first cluster and the dentry index
153 * within the parent directory
154 *
155 * We need VFS indices to be:
156 * A) unique
157 * B) stable in time, at least until the next mount
158 *
159 * Unfortunately a) does not meet the A) criterion because zero-length files
160 * will have the first cluster field cleared. And b) does not meet the B)
161 * criterion because unlink() and rename() will both free up the original
162 * dentry, which contains all the essential info about the file.
163 *
164 * Therefore, a completely opaque indices are used and the FAT server maintains
165 * a mapping between them and otherwise nice b) variant. On rename(), the VFS
166 * index stays unaltered, while the internal FAT "physical tree address"
167 * changes. The unlink case is also handled this way thanks to an in-core node
168 * pointer embedded in the index structure.
169 */
[5e790e6]170typedef struct {
[4797132]171 /** Used indices (position) hash table link. */
172 link_t uph_link;
173 /** Used indices (index) hash table link. */
174 link_t uih_link;
[9a5ccfb3]175
[6ebe721]176 fibril_mutex_t lock;
[991f645]177 devmap_handle_t devmap_handle;
[869e546]178 fs_index_t index;
179 /**
[9a5ccfb3]180 * Parent node's first cluster.
[869e546]181 * Zero is used if this node is not linked, in which case nodep must
182 * contain a pointer to the in-core node structure.
183 * One is used when the parent is the root directory.
184 */
185 fat_cluster_t pfc;
[9a5ccfb3]186 /** Directory entry index within the parent node. */
[869e546]187 unsigned pdi;
188 /** Pointer to in-core node instance. */
189 struct fat_node *nodep;
190} fat_idx_t;
191
192/** FAT in-core node. */
193typedef struct fat_node {
[b6035ba]194 /** Back pointer to the FS node. */
195 fs_node_t *bp;
196
[6ebe721]197 fibril_mutex_t lock;
[5e790e6]198 fat_node_type_t type;
[869e546]199 fat_idx_t *idx;
200 /**
201 * Node's first cluster.
202 * Zero is used for zero-length nodes.
203 * One is used to mark root directory.
204 */
205 fat_cluster_t firstc;
[e1e3b26]206 /** FAT in-core node free list link. */
207 link_t ffn_link;
[ed903174]208 aoff64_t size;
[5e790e6]209 unsigned lnkcnt;
[e1e3b26]210 unsigned refcnt;
211 bool dirty;
[377cce8]212
213 /*
[dba4a23]214 * Cache of the node's last and "current" cluster to avoid some
215 * unnecessary FAT walks.
[377cce8]216 */
[dba4a23]217 /* Node's last cluster in FAT. */
218 bool lastc_cached_valid;
219 fat_cluster_t lastc_cached_value;
220 /* Node's "current" cluster, i.e. where the last I/O took place. */
221 bool currc_cached_valid;
222 aoff64_t currc_cached_bn;
223 fat_cluster_t currc_cached_value;
[5e790e6]224} fat_node_t;
225
[efd4a72]226extern fs_reg_t fat_reg;
[be815bc]227
[cde485d]228extern void fat_mounted(ipc_callid_t, ipc_call_t *);
229extern void fat_mount(ipc_callid_t, ipc_call_t *);
[3c11713]230extern void fat_unmounted(ipc_callid_t, ipc_call_t *);
231extern void fat_unmount(ipc_callid_t, ipc_call_t *);
[6364d3c]232extern void fat_lookup(ipc_callid_t, ipc_call_t *);
[4bf40f6]233extern void fat_read(ipc_callid_t, ipc_call_t *);
[c947dda]234extern void fat_write(ipc_callid_t, ipc_call_t *);
[6c71a1f]235extern void fat_truncate(ipc_callid_t, ipc_call_t *);
[852b801]236extern void fat_stat(ipc_callid_t, ipc_call_t *);
[c20aa06]237extern void fat_close(ipc_callid_t, ipc_call_t *);
[50e5b25]238extern void fat_destroy(ipc_callid_t, ipc_call_t *);
[c20aa06]239extern void fat_open_node(ipc_callid_t, ipc_call_t *);
[852b801]240extern void fat_stat(ipc_callid_t, ipc_call_t *);
[c20aa06]241extern void fat_sync(ipc_callid_t, ipc_call_t *);
[6364d3c]242
[991f645]243extern int fat_idx_get_new(fat_idx_t **, devmap_handle_t);
244extern fat_idx_t *fat_idx_get_by_pos(devmap_handle_t, fat_cluster_t, unsigned);
245extern fat_idx_t *fat_idx_get_by_index(devmap_handle_t, fs_index_t);
[48eb7a14]246extern void fat_idx_destroy(fat_idx_t *);
[0fdd6bb]247extern void fat_idx_hashin(fat_idx_t *);
[a31c1ccf]248extern void fat_idx_hashout(fat_idx_t *);
[297f1197]249
[cde485d]250extern int fat_idx_init(void);
251extern void fat_idx_fini(void);
[991f645]252extern int fat_idx_init_by_devmap_handle(devmap_handle_t);
253extern void fat_idx_fini_by_devmap_handle(devmap_handle_t);
[cde485d]254
[be815bc]255#endif
256
257/**
258 * @}
259 */
Note: See TracBrowser for help on using the repository browser.