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Rev | Author | Line No. | Line |
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2627 | jermar | 1 | /* |
2793 | jermar | 2 | * Copyright (c) 2008 Jakub Jermar |
2627 | jermar | 3 | * All rights reserved. |
4 | * |
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5 | * Redistribution and use in source and binary forms, with or without |
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6 | * modification, are permitted provided that the following conditions |
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7 | * are met: |
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8 | * |
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9 | * - Redistributions of source code must retain the above copyright |
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10 | * notice, this list of conditions and the following disclaimer. |
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11 | * - Redistributions in binary form must reproduce the above copyright |
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12 | * notice, this list of conditions and the following disclaimer in the |
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13 | * documentation and/or other materials provided with the distribution. |
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14 | * - The name of the author may not be used to endorse or promote products |
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15 | * derived from this software without specific prior written permission. |
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16 | * |
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17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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27 | */ |
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28 | |||
29 | /** @addtogroup fs |
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30 | * @{ |
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31 | */ |
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32 | |||
33 | /** |
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34 | * @file fat_ops.c |
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35 | * @brief Implementation of VFS operations for the FAT file system server. |
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36 | */ |
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37 | |||
38 | #include "fat.h" |
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2638 | jermar | 39 | #include "../../vfs/vfs.h" |
2793 | jermar | 40 | #include <libfs.h> |
2627 | jermar | 41 | #include <ipc/ipc.h> |
3257 | jermar | 42 | #include <ipc/services.h> |
43 | #include <ipc/devmap.h> |
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2627 | jermar | 44 | #include <async.h> |
45 | #include <errno.h> |
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2793 | jermar | 46 | #include <string.h> |
2798 | jermar | 47 | #include <byteorder.h> |
2831 | jermar | 48 | #include <libadt/hash_table.h> |
49 | #include <libadt/list.h> |
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50 | #include <assert.h> |
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2856 | jermar | 51 | #include <futex.h> |
3257 | jermar | 52 | #include <sys/mman.h> |
3499 | jermar | 53 | #include <align.h> |
2627 | jermar | 54 | |
2843 | jermar | 55 | #define BS_BLOCK 0 |
3253 | jermar | 56 | #define BS_SIZE 512 |
2843 | jermar | 57 | |
2951 | jermar | 58 | /** Futex protecting the list of cached free FAT nodes. */ |
59 | static futex_t ffn_futex = FUTEX_INITIALIZER; |
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2843 | jermar | 60 | |
2951 | jermar | 61 | /** List of cached free FAT nodes. */ |
62 | static LIST_INITIALIZE(ffn_head); |
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63 | |||
2638 | jermar | 64 | #define FAT_NAME_LEN 8 |
65 | #define FAT_EXT_LEN 3 |
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66 | |||
67 | #define FAT_PAD ' ' |
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68 | |||
69 | #define FAT_DENTRY_UNUSED 0x00 |
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70 | #define FAT_DENTRY_E5_ESC 0x05 |
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71 | #define FAT_DENTRY_DOT 0x2e |
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72 | #define FAT_DENTRY_ERASED 0xe5 |
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73 | |||
3308 | jermar | 74 | #define min(a, b) ((a) < (b) ? (a) : (b)) |
75 | |||
2793 | jermar | 76 | static void dentry_name_canonify(fat_dentry_t *d, char *buf) |
2638 | jermar | 77 | { |
2793 | jermar | 78 | int i; |
2639 | jermar | 79 | |
2793 | jermar | 80 | for (i = 0; i < FAT_NAME_LEN; i++) { |
3272 | jermar | 81 | if (d->name[i] == FAT_PAD) |
2793 | jermar | 82 | break; |
83 | if (d->name[i] == FAT_DENTRY_E5_ESC) |
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84 | *buf++ = 0xe5; |
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85 | else |
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86 | *buf++ = d->name[i]; |
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87 | } |
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88 | if (d->ext[0] != FAT_PAD) |
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89 | *buf++ = '.'; |
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90 | for (i = 0; i < FAT_EXT_LEN; i++) { |
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91 | if (d->ext[i] == FAT_PAD) { |
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92 | *buf = '\0'; |
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93 | return; |
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94 | } |
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95 | if (d->ext[i] == FAT_DENTRY_E5_ESC) |
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96 | *buf++ = 0xe5; |
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97 | else |
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98 | *buf++ = d->ext[i]; |
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99 | } |
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3272 | jermar | 100 | *buf = '\0'; |
2793 | jermar | 101 | } |
102 | |||
3257 | jermar | 103 | static int dev_phone = -1; /* FIXME */ |
104 | static void *dev_buffer = NULL; /* FIXME */ |
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105 | |||
2910 | jermar | 106 | /* TODO move somewhere else */ |
2822 | jermar | 107 | typedef struct { |
108 | void *data; |
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3257 | jermar | 109 | size_t size; |
3499 | jermar | 110 | bool dirty; |
2822 | jermar | 111 | } block_t; |
112 | |||
3253 | jermar | 113 | static block_t *block_get(dev_handle_t dev_handle, off_t offset, size_t bs) |
2793 | jermar | 114 | { |
3257 | jermar | 115 | /* FIXME */ |
116 | block_t *b; |
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117 | off_t bufpos = 0; |
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118 | size_t buflen = 0; |
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3272 | jermar | 119 | off_t pos = offset * bs; |
3257 | jermar | 120 | |
121 | assert(dev_phone != -1); |
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122 | assert(dev_buffer); |
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123 | |||
124 | b = malloc(sizeof(block_t)); |
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125 | if (!b) |
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126 | return NULL; |
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127 | |||
128 | b->data = malloc(bs); |
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129 | if (!b->data) { |
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130 | free(b); |
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131 | return NULL; |
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132 | } |
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133 | b->size = bs; |
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134 | |||
3272 | jermar | 135 | if (!libfs_blockread(dev_phone, dev_buffer, &bufpos, &buflen, &pos, |
3257 | jermar | 136 | b->data, bs, bs)) { |
137 | free(b->data); |
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138 | free(b); |
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139 | return NULL; |
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140 | } |
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141 | |||
142 | return b; |
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2793 | jermar | 143 | } |
144 | |||
2822 | jermar | 145 | static void block_put(block_t *block) |
2793 | jermar | 146 | { |
3257 | jermar | 147 | /* FIXME */ |
148 | free(block->data); |
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149 | free(block); |
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2793 | jermar | 150 | } |
151 | |||
2859 | jermar | 152 | #define FAT_BS(b) ((fat_bs_t *)((b)->data)) |
153 | |||
2864 | jermar | 154 | #define FAT_CLST_RES0 0x0000 |
3119 | jermar | 155 | #define FAT_CLST_RES1 0x0001 |
2859 | jermar | 156 | #define FAT_CLST_FIRST 0x0002 |
157 | #define FAT_CLST_BAD 0xfff7 |
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158 | #define FAT_CLST_LAST1 0xfff8 |
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159 | #define FAT_CLST_LAST8 0xffff |
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160 | |||
3119 | jermar | 161 | /* internally used to mark root directory's parent */ |
162 | #define FAT_CLST_ROOTPAR FAT_CLST_RES0 |
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163 | /* internally used to mark root directory */ |
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164 | #define FAT_CLST_ROOT FAT_CLST_RES1 |
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165 | |||
2891 | jermar | 166 | #define fat_block_get(np, off) \ |
167 | _fat_block_get((np)->idx->dev_handle, (np)->firstc, (off)) |
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168 | |||
169 | static block_t * |
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2893 | jermar | 170 | _fat_block_get(dev_handle_t dev_handle, fat_cluster_t firstc, off_t offset) |
2859 | jermar | 171 | { |
172 | block_t *bb; |
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173 | block_t *b; |
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174 | unsigned bps; |
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175 | unsigned spc; |
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176 | unsigned rscnt; /* block address of the first FAT */ |
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177 | unsigned fatcnt; |
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178 | unsigned rde; |
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179 | unsigned rds; /* root directory size */ |
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180 | unsigned sf; |
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181 | unsigned ssa; /* size of the system area */ |
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182 | unsigned clusters; |
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2893 | jermar | 183 | fat_cluster_t clst = firstc; |
2859 | jermar | 184 | unsigned i; |
185 | |||
3253 | jermar | 186 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
2859 | jermar | 187 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
188 | spc = FAT_BS(bb)->spc; |
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189 | rscnt = uint16_t_le2host(FAT_BS(bb)->rscnt); |
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190 | fatcnt = FAT_BS(bb)->fatcnt; |
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191 | rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max); |
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192 | sf = uint16_t_le2host(FAT_BS(bb)->sec_per_fat); |
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193 | block_put(bb); |
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194 | |||
195 | rds = (sizeof(fat_dentry_t) * rde) / bps; |
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196 | rds += ((sizeof(fat_dentry_t) * rde) % bps != 0); |
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197 | ssa = rscnt + fatcnt * sf + rds; |
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198 | |||
3119 | jermar | 199 | if (firstc == FAT_CLST_ROOT) { |
2859 | jermar | 200 | /* root directory special case */ |
201 | assert(offset < rds); |
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3253 | jermar | 202 | b = block_get(dev_handle, rscnt + fatcnt * sf + offset, bps); |
2859 | jermar | 203 | return b; |
204 | } |
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205 | |||
206 | clusters = offset / spc; |
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207 | for (i = 0; i < clusters; i++) { |
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208 | unsigned fsec; /* sector offset relative to FAT1 */ |
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209 | unsigned fidx; /* FAT1 entry index */ |
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210 | |||
211 | assert(clst >= FAT_CLST_FIRST && clst < FAT_CLST_BAD); |
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2864 | jermar | 212 | fsec = (clst * sizeof(fat_cluster_t)) / bps; |
213 | fidx = clst % (bps / sizeof(fat_cluster_t)); |
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2859 | jermar | 214 | /* read FAT1 */ |
3253 | jermar | 215 | b = block_get(dev_handle, rscnt + fsec, bps); |
2864 | jermar | 216 | clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]); |
2859 | jermar | 217 | assert(clst != FAT_CLST_BAD); |
218 | assert(clst < FAT_CLST_LAST1); |
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219 | block_put(b); |
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220 | } |
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221 | |||
2891 | jermar | 222 | b = block_get(dev_handle, ssa + (clst - FAT_CLST_FIRST) * spc + |
3253 | jermar | 223 | offset % spc, bps); |
2859 | jermar | 224 | |
225 | return b; |
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226 | } |
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227 | |||
3325 | jermar | 228 | /** Return number of blocks allocated to a file. |
229 | * |
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230 | * @param dev_handle Device handle of the device with the file. |
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231 | * @param firstc First cluster of the file. |
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232 | * |
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233 | * @return Number of blocks allocated to the file. |
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234 | */ |
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235 | static uint16_t |
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236 | _fat_blcks_get(dev_handle_t dev_handle, fat_cluster_t firstc) |
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237 | { |
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238 | block_t *bb; |
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239 | block_t *b; |
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240 | unsigned bps; |
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241 | unsigned spc; |
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242 | unsigned rscnt; /* block address of the first FAT */ |
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243 | unsigned clusters = 0; |
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244 | fat_cluster_t clst = firstc; |
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245 | |||
246 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
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247 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
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248 | spc = FAT_BS(bb)->spc; |
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249 | rscnt = uint16_t_le2host(FAT_BS(bb)->rscnt); |
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250 | block_put(bb); |
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251 | |||
252 | if (firstc == FAT_CLST_RES0) { |
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253 | /* No space allocated to the file. */ |
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254 | return 0; |
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255 | } |
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256 | |||
257 | while (clst < FAT_CLST_LAST1) { |
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258 | unsigned fsec; /* sector offset relative to FAT1 */ |
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259 | unsigned fidx; /* FAT1 entry index */ |
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260 | |||
261 | assert(clst >= FAT_CLST_FIRST); |
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262 | fsec = (clst * sizeof(fat_cluster_t)) / bps; |
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263 | fidx = clst % (bps / sizeof(fat_cluster_t)); |
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264 | /* read FAT1 */ |
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265 | b = block_get(dev_handle, rscnt + fsec, bps); |
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266 | clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]); |
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267 | assert(clst != FAT_CLST_BAD); |
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268 | block_put(b); |
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269 | clusters++; |
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270 | } |
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271 | |||
272 | return clusters * spc; |
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273 | } |
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274 | |||
2831 | jermar | 275 | static void fat_node_initialize(fat_node_t *node) |
2793 | jermar | 276 | { |
2951 | jermar | 277 | futex_initialize(&node->lock, 1); |
2864 | jermar | 278 | node->idx = NULL; |
2831 | jermar | 279 | node->type = 0; |
280 | link_initialize(&node->ffn_link); |
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281 | node->size = 0; |
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282 | node->lnkcnt = 0; |
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283 | node->refcnt = 0; |
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284 | node->dirty = false; |
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2793 | jermar | 285 | } |
286 | |||
2843 | jermar | 287 | static uint16_t fat_bps_get(dev_handle_t dev_handle) |
288 | { |
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289 | block_t *bb; |
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290 | uint16_t bps; |
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291 | |||
3253 | jermar | 292 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
2843 | jermar | 293 | assert(bb != NULL); |
2859 | jermar | 294 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
2843 | jermar | 295 | block_put(bb); |
296 | |||
297 | return bps; |
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298 | } |
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299 | |||
2845 | jermar | 300 | typedef enum { |
301 | FAT_DENTRY_SKIP, |
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302 | FAT_DENTRY_LAST, |
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303 | FAT_DENTRY_VALID |
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304 | } fat_dentry_clsf_t; |
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305 | |||
306 | static fat_dentry_clsf_t fat_classify_dentry(fat_dentry_t *d) |
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307 | { |
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308 | if (d->attr & FAT_ATTR_VOLLABEL) { |
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309 | /* volume label entry */ |
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310 | return FAT_DENTRY_SKIP; |
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311 | } |
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312 | if (d->name[0] == FAT_DENTRY_ERASED) { |
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313 | /* not-currently-used entry */ |
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314 | return FAT_DENTRY_SKIP; |
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315 | } |
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316 | if (d->name[0] == FAT_DENTRY_UNUSED) { |
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317 | /* never used entry */ |
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318 | return FAT_DENTRY_LAST; |
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319 | } |
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320 | if (d->name[0] == FAT_DENTRY_DOT) { |
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321 | /* |
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322 | * Most likely '.' or '..'. |
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323 | * It cannot occur in a regular file name. |
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324 | */ |
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325 | return FAT_DENTRY_SKIP; |
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326 | } |
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327 | return FAT_DENTRY_VALID; |
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328 | } |
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329 | |||
2893 | jermar | 330 | static void fat_node_sync(fat_node_t *node) |
2831 | jermar | 331 | { |
332 | /* TODO */ |
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333 | } |
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334 | |||
2951 | jermar | 335 | /** Internal version of fat_node_get(). |
336 | * |
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337 | * @param idxp Locked index structure. |
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338 | */ |
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339 | static void *fat_node_get_core(fat_idx_t *idxp) |
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2831 | jermar | 340 | { |
2891 | jermar | 341 | block_t *b; |
342 | fat_dentry_t *d; |
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3312 | jermar | 343 | fat_node_t *nodep = NULL; |
2891 | jermar | 344 | unsigned bps; |
345 | unsigned dps; |
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346 | |||
2951 | jermar | 347 | if (idxp->nodep) { |
2891 | jermar | 348 | /* |
349 | * We are lucky. |
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350 | * The node is already instantiated in memory. |
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351 | */ |
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2951 | jermar | 352 | futex_down(&idxp->nodep->lock); |
353 | if (!idxp->nodep->refcnt++) |
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3312 | jermar | 354 | list_remove(&idxp->nodep->ffn_link); |
2951 | jermar | 355 | futex_up(&idxp->nodep->lock); |
356 | return idxp->nodep; |
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2891 | jermar | 357 | } |
358 | |||
359 | /* |
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360 | * We must instantiate the node from the file system. |
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361 | */ |
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362 | |||
2951 | jermar | 363 | assert(idxp->pfc); |
2891 | jermar | 364 | |
2951 | jermar | 365 | futex_down(&ffn_futex); |
2893 | jermar | 366 | if (!list_empty(&ffn_head)) { |
2951 | jermar | 367 | /* Try to use a cached free node structure. */ |
368 | fat_idx_t *idxp_tmp; |
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2893 | jermar | 369 | nodep = list_get_instance(ffn_head.next, fat_node_t, ffn_link); |
2951 | jermar | 370 | if (futex_trydown(&nodep->lock) == ESYNCH_WOULD_BLOCK) |
371 | goto skip_cache; |
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372 | idxp_tmp = nodep->idx; |
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373 | if (futex_trydown(&idxp_tmp->lock) == ESYNCH_WOULD_BLOCK) { |
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374 | futex_up(&nodep->lock); |
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375 | goto skip_cache; |
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376 | } |
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377 | list_remove(&nodep->ffn_link); |
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378 | futex_up(&ffn_futex); |
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2893 | jermar | 379 | if (nodep->dirty) |
380 | fat_node_sync(nodep); |
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2951 | jermar | 381 | idxp_tmp->nodep = NULL; |
382 | futex_up(&nodep->lock); |
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383 | futex_up(&idxp_tmp->lock); |
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2893 | jermar | 384 | } else { |
2951 | jermar | 385 | skip_cache: |
2893 | jermar | 386 | /* Try to allocate a new node structure. */ |
2951 | jermar | 387 | futex_up(&ffn_futex); |
2893 | jermar | 388 | nodep = (fat_node_t *)malloc(sizeof(fat_node_t)); |
389 | if (!nodep) |
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390 | return NULL; |
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391 | } |
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2891 | jermar | 392 | fat_node_initialize(nodep); |
393 | |||
2951 | jermar | 394 | bps = fat_bps_get(idxp->dev_handle); |
2891 | jermar | 395 | dps = bps / sizeof(fat_dentry_t); |
396 | |||
2893 | jermar | 397 | /* Read the block that contains the dentry of interest. */ |
2951 | jermar | 398 | b = _fat_block_get(idxp->dev_handle, idxp->pfc, |
399 | (idxp->pdi * sizeof(fat_dentry_t)) / bps); |
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2891 | jermar | 400 | assert(b); |
401 | |||
2951 | jermar | 402 | d = ((fat_dentry_t *)b->data) + (idxp->pdi % dps); |
2893 | jermar | 403 | if (d->attr & FAT_ATTR_SUBDIR) { |
404 | /* |
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405 | * The only directory which does not have this bit set is the |
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406 | * root directory itself. The root directory node is handled |
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407 | * and initialized elsewhere. |
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408 | */ |
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409 | nodep->type = FAT_DIRECTORY; |
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3282 | jermar | 410 | /* |
3325 | jermar | 411 | * Unfortunately, the 'size' field of the FAT dentry is not |
412 | * defined for the directory entry type. We must determine the |
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413 | * size of the directory by walking the FAT. |
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3282 | jermar | 414 | */ |
3325 | jermar | 415 | nodep->size = bps * _fat_blcks_get(idxp->dev_handle, |
416 | uint16_t_le2host(d->firstc)); |
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2893 | jermar | 417 | } else { |
418 | nodep->type = FAT_FILE; |
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3282 | jermar | 419 | nodep->size = uint32_t_le2host(d->size); |
2893 | jermar | 420 | } |
421 | nodep->firstc = uint16_t_le2host(d->firstc); |
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422 | nodep->lnkcnt = 1; |
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423 | nodep->refcnt = 1; |
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424 | |||
425 | block_put(b); |
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426 | |||
427 | /* Link the idx structure with the node structure. */ |
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2951 | jermar | 428 | nodep->idx = idxp; |
429 | idxp->nodep = nodep; |
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2893 | jermar | 430 | |
431 | return nodep; |
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2831 | jermar | 432 | } |
433 | |||
2951 | jermar | 434 | /** Instantiate a FAT in-core node. */ |
435 | static void *fat_node_get(dev_handle_t dev_handle, fs_index_t index) |
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436 | { |
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437 | void *node; |
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438 | fat_idx_t *idxp; |
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439 | |||
440 | idxp = fat_idx_get_by_index(dev_handle, index); |
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441 | if (!idxp) |
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442 | return NULL; |
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443 | /* idxp->lock held */ |
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444 | node = fat_node_get_core(idxp); |
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445 | futex_up(&idxp->lock); |
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446 | return node; |
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447 | } |
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448 | |||
2852 | jermar | 449 | static void fat_node_put(void *node) |
450 | { |
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2910 | jermar | 451 | fat_node_t *nodep = (fat_node_t *)node; |
452 | |||
2951 | jermar | 453 | futex_down(&nodep->lock); |
2910 | jermar | 454 | if (!--nodep->refcnt) { |
2951 | jermar | 455 | futex_down(&ffn_futex); |
2910 | jermar | 456 | list_append(&nodep->ffn_link, &ffn_head); |
2951 | jermar | 457 | futex_up(&ffn_futex); |
2910 | jermar | 458 | } |
2951 | jermar | 459 | futex_up(&nodep->lock); |
2852 | jermar | 460 | } |
461 | |||
2857 | jermar | 462 | static void *fat_create(int flags) |
463 | { |
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464 | return NULL; /* not supported at the moment */ |
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465 | } |
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466 | |||
2858 | jermar | 467 | static int fat_destroy(void *node) |
2857 | jermar | 468 | { |
2858 | jermar | 469 | return ENOTSUP; /* not supported at the moment */ |
2857 | jermar | 470 | } |
471 | |||
472 | static bool fat_link(void *prnt, void *chld, const char *name) |
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473 | { |
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474 | return false; /* not supported at the moment */ |
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475 | } |
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476 | |||
477 | static int fat_unlink(void *prnt, void *chld) |
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478 | { |
||
479 | return ENOTSUP; /* not supported at the moment */ |
||
480 | } |
||
481 | |||
2793 | jermar | 482 | static void *fat_match(void *prnt, const char *component) |
483 | { |
||
484 | fat_node_t *parentp = (fat_node_t *)prnt; |
||
485 | char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1]; |
||
2822 | jermar | 486 | unsigned i, j; |
2828 | jermar | 487 | unsigned bps; /* bytes per sector */ |
2822 | jermar | 488 | unsigned dps; /* dentries per sector */ |
489 | unsigned blocks; |
||
2793 | jermar | 490 | fat_dentry_t *d; |
2822 | jermar | 491 | block_t *b; |
2793 | jermar | 492 | |
2953 | jermar | 493 | futex_down(&parentp->idx->lock); |
2864 | jermar | 494 | bps = fat_bps_get(parentp->idx->dev_handle); |
2828 | jermar | 495 | dps = bps / sizeof(fat_dentry_t); |
496 | blocks = parentp->size / bps + (parentp->size % bps != 0); |
||
2822 | jermar | 497 | for (i = 0; i < blocks; i++) { |
498 | unsigned dentries; |
||
2793 | jermar | 499 | |
2864 | jermar | 500 | b = fat_block_get(parentp, i); |
2822 | jermar | 501 | dentries = (i == blocks - 1) ? |
502 | parentp->size % sizeof(fat_dentry_t) : |
||
503 | dps; |
||
504 | for (j = 0; j < dentries; j++) { |
||
505 | d = ((fat_dentry_t *)b->data) + j; |
||
2845 | jermar | 506 | switch (fat_classify_dentry(d)) { |
507 | case FAT_DENTRY_SKIP: |
||
2822 | jermar | 508 | continue; |
2845 | jermar | 509 | case FAT_DENTRY_LAST: |
2822 | jermar | 510 | block_put(b); |
2953 | jermar | 511 | futex_up(&parentp->idx->lock); |
2822 | jermar | 512 | return NULL; |
2845 | jermar | 513 | default: |
514 | case FAT_DENTRY_VALID: |
||
515 | dentry_name_canonify(d, name); |
||
516 | break; |
||
2822 | jermar | 517 | } |
3272 | jermar | 518 | if (stricmp(name, component) == 0) { |
2822 | jermar | 519 | /* hit */ |
2951 | jermar | 520 | void *node; |
2953 | jermar | 521 | /* |
522 | * Assume tree hierarchy for locking. We |
||
523 | * already have the parent and now we are going |
||
524 | * to lock the child. Never lock in the oposite |
||
525 | * order. |
||
526 | */ |
||
2890 | jermar | 527 | fat_idx_t *idx = fat_idx_get_by_pos( |
2881 | jermar | 528 | parentp->idx->dev_handle, parentp->firstc, |
2864 | jermar | 529 | i * dps + j); |
2953 | jermar | 530 | futex_up(&parentp->idx->lock); |
2890 | jermar | 531 | if (!idx) { |
532 | /* |
||
533 | * Can happen if memory is low or if we |
||
534 | * run out of 32-bit indices. |
||
535 | */ |
||
536 | block_put(b); |
||
537 | return NULL; |
||
538 | } |
||
2951 | jermar | 539 | node = fat_node_get_core(idx); |
540 | futex_up(&idx->lock); |
||
2822 | jermar | 541 | block_put(b); |
542 | return node; |
||
543 | } |
||
2793 | jermar | 544 | } |
2822 | jermar | 545 | block_put(b); |
2639 | jermar | 546 | } |
2953 | jermar | 547 | futex_up(&parentp->idx->lock); |
2793 | jermar | 548 | return NULL; |
2638 | jermar | 549 | } |
550 | |||
2831 | jermar | 551 | static fs_index_t fat_index_get(void *node) |
552 | { |
||
553 | fat_node_t *fnodep = (fat_node_t *)node; |
||
554 | if (!fnodep) |
||
555 | return 0; |
||
2864 | jermar | 556 | return fnodep->idx->index; |
2831 | jermar | 557 | } |
558 | |||
559 | static size_t fat_size_get(void *node) |
||
560 | { |
||
561 | return ((fat_node_t *)node)->size; |
||
562 | } |
||
563 | |||
564 | static unsigned fat_lnkcnt_get(void *node) |
||
565 | { |
||
566 | return ((fat_node_t *)node)->lnkcnt; |
||
567 | } |
||
568 | |||
2845 | jermar | 569 | static bool fat_has_children(void *node) |
570 | { |
||
571 | fat_node_t *nodep = (fat_node_t *)node; |
||
572 | unsigned bps; |
||
573 | unsigned dps; |
||
574 | unsigned blocks; |
||
575 | block_t *b; |
||
576 | unsigned i, j; |
||
577 | |||
578 | if (nodep->type != FAT_DIRECTORY) |
||
579 | return false; |
||
580 | |||
2951 | jermar | 581 | futex_down(&nodep->idx->lock); |
2864 | jermar | 582 | bps = fat_bps_get(nodep->idx->dev_handle); |
2845 | jermar | 583 | dps = bps / sizeof(fat_dentry_t); |
584 | |||
585 | blocks = nodep->size / bps + (nodep->size % bps != 0); |
||
586 | |||
587 | for (i = 0; i < blocks; i++) { |
||
588 | unsigned dentries; |
||
589 | fat_dentry_t *d; |
||
590 | |||
2864 | jermar | 591 | b = fat_block_get(nodep, i); |
2845 | jermar | 592 | dentries = (i == blocks - 1) ? |
593 | nodep->size % sizeof(fat_dentry_t) : |
||
594 | dps; |
||
595 | for (j = 0; j < dentries; j++) { |
||
596 | d = ((fat_dentry_t *)b->data) + j; |
||
597 | switch (fat_classify_dentry(d)) { |
||
598 | case FAT_DENTRY_SKIP: |
||
599 | continue; |
||
600 | case FAT_DENTRY_LAST: |
||
601 | block_put(b); |
||
2951 | jermar | 602 | futex_up(&nodep->idx->lock); |
2845 | jermar | 603 | return false; |
604 | default: |
||
605 | case FAT_DENTRY_VALID: |
||
606 | block_put(b); |
||
2951 | jermar | 607 | futex_up(&nodep->idx->lock); |
2845 | jermar | 608 | return true; |
609 | } |
||
610 | block_put(b); |
||
2951 | jermar | 611 | futex_up(&nodep->idx->lock); |
2845 | jermar | 612 | return true; |
613 | } |
||
614 | block_put(b); |
||
615 | } |
||
616 | |||
2951 | jermar | 617 | futex_up(&nodep->idx->lock); |
2845 | jermar | 618 | return false; |
619 | } |
||
620 | |||
2844 | jermar | 621 | static void *fat_root_get(dev_handle_t dev_handle) |
622 | { |
||
3119 | jermar | 623 | return fat_node_get(dev_handle, 0); |
2844 | jermar | 624 | } |
625 | |||
626 | static char fat_plb_get_char(unsigned pos) |
||
627 | { |
||
628 | return fat_reg.plb_ro[pos % PLB_SIZE]; |
||
629 | } |
||
630 | |||
2831 | jermar | 631 | static bool fat_is_directory(void *node) |
632 | { |
||
633 | return ((fat_node_t *)node)->type == FAT_DIRECTORY; |
||
634 | } |
||
635 | |||
636 | static bool fat_is_file(void *node) |
||
637 | { |
||
638 | return ((fat_node_t *)node)->type == FAT_FILE; |
||
639 | } |
||
640 | |||
2793 | jermar | 641 | /** libfs operations */ |
642 | libfs_ops_t fat_libfs_ops = { |
||
643 | .match = fat_match, |
||
644 | .node_get = fat_node_get, |
||
2852 | jermar | 645 | .node_put = fat_node_put, |
2857 | jermar | 646 | .create = fat_create, |
647 | .destroy = fat_destroy, |
||
648 | .link = fat_link, |
||
649 | .unlink = fat_unlink, |
||
2831 | jermar | 650 | .index_get = fat_index_get, |
651 | .size_get = fat_size_get, |
||
652 | .lnkcnt_get = fat_lnkcnt_get, |
||
2845 | jermar | 653 | .has_children = fat_has_children, |
2844 | jermar | 654 | .root_get = fat_root_get, |
655 | .plb_get_char = fat_plb_get_char, |
||
2831 | jermar | 656 | .is_directory = fat_is_directory, |
657 | .is_file = fat_is_file |
||
2793 | jermar | 658 | }; |
659 | |||
3110 | jermar | 660 | void fat_mounted(ipc_callid_t rid, ipc_call_t *request) |
661 | { |
||
662 | dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request); |
||
3119 | jermar | 663 | block_t *bb; |
3257 | jermar | 664 | uint16_t bps; |
3119 | jermar | 665 | uint16_t rde; |
3110 | jermar | 666 | int rc; |
667 | |||
3257 | jermar | 668 | /* |
669 | * For now, we don't bother to remember dev_handle, dev_phone or |
||
670 | * dev_buffer in some data structure. We use global variables because we |
||
671 | * know there will be at most one mount on this file system. |
||
672 | * Of course, this is a huge TODO item. |
||
673 | */ |
||
674 | dev_buffer = mmap(NULL, BS_SIZE, PROTO_READ | PROTO_WRITE, |
||
675 | MAP_ANONYMOUS | MAP_PRIVATE, 0, 0); |
||
676 | |||
677 | if (!dev_buffer) { |
||
678 | ipc_answer_0(rid, ENOMEM); |
||
679 | return; |
||
680 | } |
||
681 | |||
682 | dev_phone = ipc_connect_me_to(PHONE_NS, SERVICE_DEVMAP, |
||
683 | DEVMAP_CONNECT_TO_DEVICE, dev_handle); |
||
684 | |||
685 | if (dev_phone < 0) { |
||
686 | munmap(dev_buffer, BS_SIZE); |
||
687 | ipc_answer_0(rid, dev_phone); |
||
688 | return; |
||
689 | } |
||
690 | |||
691 | rc = ipc_share_out_start(dev_phone, dev_buffer, |
||
692 | AS_AREA_READ | AS_AREA_WRITE); |
||
693 | if (rc != EOK) { |
||
694 | munmap(dev_buffer, BS_SIZE); |
||
695 | ipc_answer_0(rid, rc); |
||
696 | return; |
||
697 | } |
||
698 | |||
3119 | jermar | 699 | /* Read the number of root directory entries. */ |
3253 | jermar | 700 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
3257 | jermar | 701 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
3119 | jermar | 702 | rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max); |
703 | block_put(bb); |
||
704 | |||
3257 | jermar | 705 | if (bps != BS_SIZE) { |
706 | munmap(dev_buffer, BS_SIZE); |
||
707 | ipc_answer_0(rid, ENOTSUP); |
||
708 | return; |
||
709 | } |
||
710 | |||
3110 | jermar | 711 | rc = fat_idx_init_by_dev_handle(dev_handle); |
712 | if (rc != EOK) { |
||
3257 | jermar | 713 | munmap(dev_buffer, BS_SIZE); |
3110 | jermar | 714 | ipc_answer_0(rid, rc); |
715 | return; |
||
716 | } |
||
717 | |||
3119 | jermar | 718 | /* Initialize the root node. */ |
719 | fat_node_t *rootp = (fat_node_t *)malloc(sizeof(fat_node_t)); |
||
720 | if (!rootp) { |
||
3257 | jermar | 721 | munmap(dev_buffer, BS_SIZE); |
3119 | jermar | 722 | fat_idx_fini_by_dev_handle(dev_handle); |
723 | ipc_answer_0(rid, ENOMEM); |
||
724 | return; |
||
725 | } |
||
726 | fat_node_initialize(rootp); |
||
727 | |||
728 | fat_idx_t *ridxp = fat_idx_get_by_pos(dev_handle, FAT_CLST_ROOTPAR, 0); |
||
729 | if (!ridxp) { |
||
3257 | jermar | 730 | munmap(dev_buffer, BS_SIZE); |
3119 | jermar | 731 | free(rootp); |
732 | fat_idx_fini_by_dev_handle(dev_handle); |
||
733 | ipc_answer_0(rid, ENOMEM); |
||
734 | return; |
||
735 | } |
||
736 | assert(ridxp->index == 0); |
||
737 | /* ridxp->lock held */ |
||
738 | |||
739 | rootp->type = FAT_DIRECTORY; |
||
740 | rootp->firstc = FAT_CLST_ROOT; |
||
741 | rootp->refcnt = 1; |
||
3352 | jermar | 742 | rootp->lnkcnt = 0; /* FS root is not linked */ |
3119 | jermar | 743 | rootp->size = rde * sizeof(fat_dentry_t); |
744 | rootp->idx = ridxp; |
||
745 | ridxp->nodep = rootp; |
||
746 | |||
747 | futex_up(&ridxp->lock); |
||
748 | |||
3352 | jermar | 749 | ipc_answer_3(rid, EOK, ridxp->index, rootp->size, rootp->lnkcnt); |
3110 | jermar | 750 | } |
751 | |||
752 | void fat_mount(ipc_callid_t rid, ipc_call_t *request) |
||
753 | { |
||
754 | ipc_answer_0(rid, ENOTSUP); |
||
755 | } |
||
756 | |||
2627 | jermar | 757 | void fat_lookup(ipc_callid_t rid, ipc_call_t *request) |
758 | { |
||
2793 | jermar | 759 | libfs_lookup(&fat_libfs_ops, fat_reg.fs_handle, rid, request); |
2627 | jermar | 760 | } |
761 | |||
3307 | jermar | 762 | void fat_read(ipc_callid_t rid, ipc_call_t *request) |
763 | { |
||
764 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
||
765 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
||
766 | off_t pos = (off_t)IPC_GET_ARG3(*request); |
||
767 | fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
||
3308 | jermar | 768 | uint16_t bps = fat_bps_get(dev_handle); |
769 | size_t bytes; |
||
3335 | jermar | 770 | block_t *b; |
3308 | jermar | 771 | |
3307 | jermar | 772 | if (!nodep) { |
773 | ipc_answer_0(rid, ENOENT); |
||
774 | return; |
||
775 | } |
||
776 | |||
777 | ipc_callid_t callid; |
||
778 | size_t len; |
||
3314 | jermar | 779 | if (!ipc_data_read_receive(&callid, &len)) { |
3307 | jermar | 780 | fat_node_put(nodep); |
781 | ipc_answer_0(callid, EINVAL); |
||
782 | ipc_answer_0(rid, EINVAL); |
||
783 | return; |
||
784 | } |
||
785 | |||
786 | if (nodep->type == FAT_FILE) { |
||
3335 | jermar | 787 | /* |
788 | * Our strategy for regular file reads is to read one block at |
||
789 | * most and make use of the possibility to return less data than |
||
790 | * requested. This keeps the code very simple. |
||
791 | */ |
||
3308 | jermar | 792 | bytes = min(len, bps - pos % bps); |
793 | b = fat_block_get(nodep, pos / bps); |
||
794 | (void) ipc_data_read_finalize(callid, b->data + pos % bps, |
||
795 | bytes); |
||
796 | block_put(b); |
||
3307 | jermar | 797 | } else { |
3335 | jermar | 798 | unsigned bnum; |
799 | off_t spos = pos; |
||
800 | char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1]; |
||
801 | fat_dentry_t *d; |
||
802 | |||
3307 | jermar | 803 | assert(nodep->type == FAT_DIRECTORY); |
3335 | jermar | 804 | assert(nodep->size % bps == 0); |
805 | assert(bps % sizeof(fat_dentry_t) == 0); |
||
806 | |||
807 | /* |
||
808 | * Our strategy for readdir() is to use the position pointer as |
||
809 | * an index into the array of all dentries. On entry, it points |
||
810 | * to the first unread dentry. If we skip any dentries, we bump |
||
811 | * the position pointer accordingly. |
||
812 | */ |
||
813 | bnum = (pos * sizeof(fat_dentry_t)) / bps; |
||
814 | while (bnum < nodep->size / bps) { |
||
815 | off_t o; |
||
816 | |||
817 | b = fat_block_get(nodep, bnum); |
||
818 | for (o = pos % (bps / sizeof(fat_dentry_t)); |
||
819 | o < bps / sizeof(fat_dentry_t); |
||
820 | o++, pos++) { |
||
821 | d = ((fat_dentry_t *)b->data) + o; |
||
822 | switch (fat_classify_dentry(d)) { |
||
823 | case FAT_DENTRY_SKIP: |
||
824 | continue; |
||
825 | case FAT_DENTRY_LAST: |
||
826 | block_put(b); |
||
827 | goto miss; |
||
828 | default: |
||
829 | case FAT_DENTRY_VALID: |
||
830 | dentry_name_canonify(d, name); |
||
831 | block_put(b); |
||
832 | goto hit; |
||
833 | } |
||
834 | } |
||
835 | block_put(b); |
||
836 | bnum++; |
||
837 | } |
||
838 | miss: |
||
3307 | jermar | 839 | fat_node_put(nodep); |
3335 | jermar | 840 | ipc_answer_0(callid, ENOENT); |
841 | ipc_answer_1(rid, ENOENT, 0); |
||
3307 | jermar | 842 | return; |
3335 | jermar | 843 | hit: |
844 | (void) ipc_data_read_finalize(callid, name, strlen(name) + 1); |
||
845 | bytes = (pos - spos) + 1; |
||
3307 | jermar | 846 | } |
847 | |||
848 | fat_node_put(nodep); |
||
3308 | jermar | 849 | ipc_answer_1(rid, EOK, (ipcarg_t)bytes); |
3307 | jermar | 850 | } |
851 | |||
3500 | jermar | 852 | static void |
853 | fat_fill_gap(fat_node_t *nodep, fat_cluster_t mclst, off_t pos) |
||
3499 | jermar | 854 | { |
855 | /* TODO */ |
||
856 | } |
||
857 | |||
3500 | jermar | 858 | static int |
859 | fat_alloc_clusters(unsigned nclsts, fat_cluster_t *mcl, fat_cluster_t *lcl) |
||
860 | { |
||
861 | return ENOTSUP; /* TODO */ |
||
862 | } |
||
863 | |||
864 | static void |
||
865 | fat_append_clusters(fat_node_t *nodep, fat_cluster_t mcl) |
||
866 | { |
||
867 | } |
||
868 | |||
3497 | jermar | 869 | void fat_write(ipc_callid_t rid, ipc_call_t *request) |
870 | { |
||
3499 | jermar | 871 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
872 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
||
873 | off_t pos = (off_t)IPC_GET_ARG3(*request); |
||
874 | fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
||
875 | size_t bytes; |
||
876 | block_t *b, *bb; |
||
877 | uint16_t bps; |
||
878 | unsigned spc; |
||
879 | off_t clst_boundary; |
||
880 | |||
881 | if (!nodep) { |
||
882 | ipc_answer_0(rid, ENOENT); |
||
883 | return; |
||
884 | } |
||
885 | |||
886 | /* XXX remove me when you are ready */ |
||
887 | { |
||
888 | ipc_answer_0(rid, ENOTSUP); |
||
889 | fat_node_put(nodep); |
||
890 | return; |
||
891 | } |
||
892 | |||
893 | ipc_callid_t callid; |
||
894 | size_t len; |
||
895 | if (!ipc_data_write_receive(&callid, &len)) { |
||
896 | fat_node_put(nodep); |
||
897 | ipc_answer_0(callid, EINVAL); |
||
898 | ipc_answer_0(rid, EINVAL); |
||
899 | return; |
||
900 | } |
||
901 | |||
902 | /* |
||
903 | * In all scenarios, we will attempt to write out only one block worth |
||
904 | * of data at maximum. There might be some more efficient approaches, |
||
905 | * but this one greatly simplifies fat_write(). Note that we can afford |
||
906 | * to do this because the client must be ready to handle the return |
||
907 | * value signalizing a smaller number of bytes written. |
||
908 | */ |
||
909 | bytes = min(len, bps - pos % bps); |
||
910 | |||
911 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
||
912 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
||
913 | spc = FAT_BS(bb)->spc; |
||
914 | block_put(bb); |
||
915 | |||
916 | clst_boundary = ROUND_UP(nodep->size, bps * spc); |
||
917 | if (pos < clst_boundary) { |
||
918 | /* |
||
919 | * This is the easier case - we are either overwriting already |
||
920 | * existing contents or writing behind the EOF, but still within |
||
921 | * the limits of the last cluster. The node size may grow to the |
||
922 | * next block size boundary. |
||
923 | */ |
||
3500 | jermar | 924 | fat_fill_gap(nodep, FAT_CLST_RES0, pos); |
3499 | jermar | 925 | b = fat_block_get(nodep, pos / bps); |
926 | (void) ipc_data_write_finalize(callid, b->data + pos % bps, |
||
927 | bytes); |
||
928 | b->dirty = true; /* need to sync block */ |
||
3500 | jermar | 929 | block_put(b); |
3499 | jermar | 930 | if (pos + bytes > nodep->size) { |
931 | nodep->size = pos + bytes; |
||
932 | nodep->dirty = true; /* need to sync node */ |
||
933 | } |
||
934 | fat_node_put(nodep); |
||
935 | ipc_answer_1(rid, EOK, bytes); |
||
936 | return; |
||
937 | } else { |
||
938 | /* |
||
939 | * This is the more difficult case. We must allocate new |
||
940 | * clusters for the node and zero them out. |
||
941 | */ |
||
3500 | jermar | 942 | int status; |
3499 | jermar | 943 | unsigned nclsts; |
3500 | jermar | 944 | fat_cluster_t mcl, lcl; |
945 | |||
3499 | jermar | 946 | nclsts = (ROUND_UP(pos + bytes, bps * spc) - clst_boundary) / |
3500 | jermar | 947 | bps * spc; |
948 | /* create an independent chain of nclsts clusters in all FATs */ |
||
949 | status = fat_alloc_clusters(nclsts, &mcl, &lcl); |
||
950 | if (status != EOK) { |
||
951 | /* could not allocate a chain of nclsts clusters */ |
||
952 | fat_node_put(nodep); |
||
953 | ipc_answer_0(callid, status); |
||
954 | ipc_answer_0(rid, status); |
||
955 | return; |
||
956 | } |
||
957 | /* zero fill any gaps */ |
||
958 | fat_fill_gap(nodep, mcl, pos); |
||
959 | b = _fat_block_get(dev_handle, lcl, (pos / bps) % spc); |
||
960 | (void) ipc_data_write_finalize(callid, b->data + pos % bps, |
||
961 | bytes); |
||
962 | b->dirty = true; |
||
963 | block_put(b); |
||
964 | /* |
||
965 | * Append the cluster chain starting in mcl to the end of the |
||
966 | * node's cluster chain. |
||
967 | */ |
||
968 | fat_append_clusters(nodep, mcl); |
||
969 | nodep->size = pos + bytes; |
||
970 | nodep->dirty = true; |
||
971 | fat_node_put(nodep); |
||
972 | ipc_answer_1(rid, EOK, bytes); |
||
973 | return; |
||
3499 | jermar | 974 | } |
3497 | jermar | 975 | } |
976 | |||
2627 | jermar | 977 | /** |
978 | * @} |
||
979 | */ |