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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 | |||
3503 | jermar | 152 | #define FAT1 0 |
153 | |||
2859 | jermar | 154 | #define FAT_BS(b) ((fat_bs_t *)((b)->data)) |
155 | |||
2864 | jermar | 156 | #define FAT_CLST_RES0 0x0000 |
3119 | jermar | 157 | #define FAT_CLST_RES1 0x0001 |
2859 | jermar | 158 | #define FAT_CLST_FIRST 0x0002 |
159 | #define FAT_CLST_BAD 0xfff7 |
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160 | #define FAT_CLST_LAST1 0xfff8 |
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161 | #define FAT_CLST_LAST8 0xffff |
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162 | |||
3119 | jermar | 163 | /* internally used to mark root directory's parent */ |
164 | #define FAT_CLST_ROOTPAR FAT_CLST_RES0 |
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165 | /* internally used to mark root directory */ |
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166 | #define FAT_CLST_ROOT FAT_CLST_RES1 |
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167 | |||
2891 | jermar | 168 | #define fat_block_get(np, off) \ |
169 | _fat_block_get((np)->idx->dev_handle, (np)->firstc, (off)) |
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170 | |||
171 | static block_t * |
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2893 | jermar | 172 | _fat_block_get(dev_handle_t dev_handle, fat_cluster_t firstc, off_t offset) |
2859 | jermar | 173 | { |
174 | block_t *bb; |
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175 | block_t *b; |
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176 | unsigned bps; |
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177 | unsigned spc; |
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178 | unsigned rscnt; /* block address of the first FAT */ |
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179 | unsigned fatcnt; |
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180 | unsigned rde; |
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181 | unsigned rds; /* root directory size */ |
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182 | unsigned sf; |
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183 | unsigned ssa; /* size of the system area */ |
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184 | unsigned clusters; |
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2893 | jermar | 185 | fat_cluster_t clst = firstc; |
2859 | jermar | 186 | unsigned i; |
187 | |||
3253 | jermar | 188 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
2859 | jermar | 189 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
190 | spc = FAT_BS(bb)->spc; |
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191 | rscnt = uint16_t_le2host(FAT_BS(bb)->rscnt); |
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192 | fatcnt = FAT_BS(bb)->fatcnt; |
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193 | rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max); |
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194 | sf = uint16_t_le2host(FAT_BS(bb)->sec_per_fat); |
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195 | block_put(bb); |
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196 | |||
197 | rds = (sizeof(fat_dentry_t) * rde) / bps; |
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198 | rds += ((sizeof(fat_dentry_t) * rde) % bps != 0); |
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199 | ssa = rscnt + fatcnt * sf + rds; |
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200 | |||
3119 | jermar | 201 | if (firstc == FAT_CLST_ROOT) { |
2859 | jermar | 202 | /* root directory special case */ |
203 | assert(offset < rds); |
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3253 | jermar | 204 | b = block_get(dev_handle, rscnt + fatcnt * sf + offset, bps); |
2859 | jermar | 205 | return b; |
206 | } |
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207 | |||
208 | clusters = offset / spc; |
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209 | for (i = 0; i < clusters; i++) { |
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210 | unsigned fsec; /* sector offset relative to FAT1 */ |
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211 | unsigned fidx; /* FAT1 entry index */ |
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212 | |||
213 | assert(clst >= FAT_CLST_FIRST && clst < FAT_CLST_BAD); |
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2864 | jermar | 214 | fsec = (clst * sizeof(fat_cluster_t)) / bps; |
215 | fidx = clst % (bps / sizeof(fat_cluster_t)); |
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2859 | jermar | 216 | /* read FAT1 */ |
3253 | jermar | 217 | b = block_get(dev_handle, rscnt + fsec, bps); |
2864 | jermar | 218 | clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]); |
2859 | jermar | 219 | assert(clst != FAT_CLST_BAD); |
220 | assert(clst < FAT_CLST_LAST1); |
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221 | block_put(b); |
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222 | } |
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223 | |||
2891 | jermar | 224 | b = block_get(dev_handle, ssa + (clst - FAT_CLST_FIRST) * spc + |
3253 | jermar | 225 | offset % spc, bps); |
2859 | jermar | 226 | |
227 | return b; |
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228 | } |
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229 | |||
3325 | jermar | 230 | /** Return number of blocks allocated to a file. |
231 | * |
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232 | * @param dev_handle Device handle of the device with the file. |
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233 | * @param firstc First cluster of the file. |
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234 | * |
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235 | * @return Number of blocks allocated to the file. |
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236 | */ |
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237 | static uint16_t |
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238 | _fat_blcks_get(dev_handle_t dev_handle, fat_cluster_t firstc) |
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239 | { |
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240 | block_t *bb; |
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241 | block_t *b; |
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242 | unsigned bps; |
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243 | unsigned spc; |
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244 | unsigned rscnt; /* block address of the first FAT */ |
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245 | unsigned clusters = 0; |
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246 | fat_cluster_t clst = firstc; |
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247 | |||
248 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
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249 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
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250 | spc = FAT_BS(bb)->spc; |
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251 | rscnt = uint16_t_le2host(FAT_BS(bb)->rscnt); |
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252 | block_put(bb); |
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253 | |||
254 | if (firstc == FAT_CLST_RES0) { |
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255 | /* No space allocated to the file. */ |
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256 | return 0; |
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257 | } |
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258 | |||
259 | while (clst < FAT_CLST_LAST1) { |
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260 | unsigned fsec; /* sector offset relative to FAT1 */ |
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261 | unsigned fidx; /* FAT1 entry index */ |
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262 | |||
263 | assert(clst >= FAT_CLST_FIRST); |
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264 | fsec = (clst * sizeof(fat_cluster_t)) / bps; |
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265 | fidx = clst % (bps / sizeof(fat_cluster_t)); |
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266 | /* read FAT1 */ |
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267 | b = block_get(dev_handle, rscnt + fsec, bps); |
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268 | clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]); |
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269 | assert(clst != FAT_CLST_BAD); |
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270 | block_put(b); |
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271 | clusters++; |
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272 | } |
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273 | |||
274 | return clusters * spc; |
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275 | } |
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276 | |||
2831 | jermar | 277 | static void fat_node_initialize(fat_node_t *node) |
2793 | jermar | 278 | { |
2951 | jermar | 279 | futex_initialize(&node->lock, 1); |
2864 | jermar | 280 | node->idx = NULL; |
2831 | jermar | 281 | node->type = 0; |
282 | link_initialize(&node->ffn_link); |
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283 | node->size = 0; |
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284 | node->lnkcnt = 0; |
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285 | node->refcnt = 0; |
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286 | node->dirty = false; |
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2793 | jermar | 287 | } |
288 | |||
2843 | jermar | 289 | static uint16_t fat_bps_get(dev_handle_t dev_handle) |
290 | { |
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291 | block_t *bb; |
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292 | uint16_t bps; |
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293 | |||
3253 | jermar | 294 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
2843 | jermar | 295 | assert(bb != NULL); |
2859 | jermar | 296 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
2843 | jermar | 297 | block_put(bb); |
298 | |||
299 | return bps; |
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300 | } |
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301 | |||
2845 | jermar | 302 | typedef enum { |
303 | FAT_DENTRY_SKIP, |
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304 | FAT_DENTRY_LAST, |
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305 | FAT_DENTRY_VALID |
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306 | } fat_dentry_clsf_t; |
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307 | |||
308 | static fat_dentry_clsf_t fat_classify_dentry(fat_dentry_t *d) |
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309 | { |
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310 | if (d->attr & FAT_ATTR_VOLLABEL) { |
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311 | /* volume label entry */ |
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312 | return FAT_DENTRY_SKIP; |
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313 | } |
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314 | if (d->name[0] == FAT_DENTRY_ERASED) { |
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315 | /* not-currently-used entry */ |
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316 | return FAT_DENTRY_SKIP; |
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317 | } |
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318 | if (d->name[0] == FAT_DENTRY_UNUSED) { |
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319 | /* never used entry */ |
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320 | return FAT_DENTRY_LAST; |
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321 | } |
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322 | if (d->name[0] == FAT_DENTRY_DOT) { |
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323 | /* |
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324 | * Most likely '.' or '..'. |
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325 | * It cannot occur in a regular file name. |
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326 | */ |
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327 | return FAT_DENTRY_SKIP; |
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328 | } |
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329 | return FAT_DENTRY_VALID; |
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330 | } |
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331 | |||
2893 | jermar | 332 | static void fat_node_sync(fat_node_t *node) |
2831 | jermar | 333 | { |
334 | /* TODO */ |
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335 | } |
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336 | |||
2951 | jermar | 337 | /** Internal version of fat_node_get(). |
338 | * |
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339 | * @param idxp Locked index structure. |
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340 | */ |
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341 | static void *fat_node_get_core(fat_idx_t *idxp) |
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2831 | jermar | 342 | { |
2891 | jermar | 343 | block_t *b; |
344 | fat_dentry_t *d; |
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3312 | jermar | 345 | fat_node_t *nodep = NULL; |
2891 | jermar | 346 | unsigned bps; |
347 | unsigned dps; |
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348 | |||
2951 | jermar | 349 | if (idxp->nodep) { |
2891 | jermar | 350 | /* |
351 | * We are lucky. |
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352 | * The node is already instantiated in memory. |
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353 | */ |
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2951 | jermar | 354 | futex_down(&idxp->nodep->lock); |
355 | if (!idxp->nodep->refcnt++) |
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3312 | jermar | 356 | list_remove(&idxp->nodep->ffn_link); |
2951 | jermar | 357 | futex_up(&idxp->nodep->lock); |
358 | return idxp->nodep; |
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2891 | jermar | 359 | } |
360 | |||
361 | /* |
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362 | * We must instantiate the node from the file system. |
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363 | */ |
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364 | |||
2951 | jermar | 365 | assert(idxp->pfc); |
2891 | jermar | 366 | |
2951 | jermar | 367 | futex_down(&ffn_futex); |
2893 | jermar | 368 | if (!list_empty(&ffn_head)) { |
2951 | jermar | 369 | /* Try to use a cached free node structure. */ |
370 | fat_idx_t *idxp_tmp; |
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2893 | jermar | 371 | nodep = list_get_instance(ffn_head.next, fat_node_t, ffn_link); |
2951 | jermar | 372 | if (futex_trydown(&nodep->lock) == ESYNCH_WOULD_BLOCK) |
373 | goto skip_cache; |
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374 | idxp_tmp = nodep->idx; |
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375 | if (futex_trydown(&idxp_tmp->lock) == ESYNCH_WOULD_BLOCK) { |
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376 | futex_up(&nodep->lock); |
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377 | goto skip_cache; |
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378 | } |
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379 | list_remove(&nodep->ffn_link); |
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380 | futex_up(&ffn_futex); |
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2893 | jermar | 381 | if (nodep->dirty) |
382 | fat_node_sync(nodep); |
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2951 | jermar | 383 | idxp_tmp->nodep = NULL; |
384 | futex_up(&nodep->lock); |
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385 | futex_up(&idxp_tmp->lock); |
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2893 | jermar | 386 | } else { |
2951 | jermar | 387 | skip_cache: |
2893 | jermar | 388 | /* Try to allocate a new node structure. */ |
2951 | jermar | 389 | futex_up(&ffn_futex); |
2893 | jermar | 390 | nodep = (fat_node_t *)malloc(sizeof(fat_node_t)); |
391 | if (!nodep) |
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392 | return NULL; |
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393 | } |
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2891 | jermar | 394 | fat_node_initialize(nodep); |
395 | |||
2951 | jermar | 396 | bps = fat_bps_get(idxp->dev_handle); |
2891 | jermar | 397 | dps = bps / sizeof(fat_dentry_t); |
398 | |||
2893 | jermar | 399 | /* Read the block that contains the dentry of interest. */ |
2951 | jermar | 400 | b = _fat_block_get(idxp->dev_handle, idxp->pfc, |
401 | (idxp->pdi * sizeof(fat_dentry_t)) / bps); |
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2891 | jermar | 402 | assert(b); |
403 | |||
2951 | jermar | 404 | d = ((fat_dentry_t *)b->data) + (idxp->pdi % dps); |
2893 | jermar | 405 | if (d->attr & FAT_ATTR_SUBDIR) { |
406 | /* |
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407 | * The only directory which does not have this bit set is the |
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408 | * root directory itself. The root directory node is handled |
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409 | * and initialized elsewhere. |
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410 | */ |
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411 | nodep->type = FAT_DIRECTORY; |
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3282 | jermar | 412 | /* |
3325 | jermar | 413 | * Unfortunately, the 'size' field of the FAT dentry is not |
414 | * defined for the directory entry type. We must determine the |
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415 | * size of the directory by walking the FAT. |
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3282 | jermar | 416 | */ |
3325 | jermar | 417 | nodep->size = bps * _fat_blcks_get(idxp->dev_handle, |
418 | uint16_t_le2host(d->firstc)); |
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2893 | jermar | 419 | } else { |
420 | nodep->type = FAT_FILE; |
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3282 | jermar | 421 | nodep->size = uint32_t_le2host(d->size); |
2893 | jermar | 422 | } |
423 | nodep->firstc = uint16_t_le2host(d->firstc); |
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424 | nodep->lnkcnt = 1; |
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425 | nodep->refcnt = 1; |
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426 | |||
427 | block_put(b); |
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428 | |||
429 | /* Link the idx structure with the node structure. */ |
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2951 | jermar | 430 | nodep->idx = idxp; |
431 | idxp->nodep = nodep; |
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2893 | jermar | 432 | |
433 | return nodep; |
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2831 | jermar | 434 | } |
435 | |||
2951 | jermar | 436 | /** Instantiate a FAT in-core node. */ |
437 | static void *fat_node_get(dev_handle_t dev_handle, fs_index_t index) |
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438 | { |
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439 | void *node; |
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440 | fat_idx_t *idxp; |
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441 | |||
442 | idxp = fat_idx_get_by_index(dev_handle, index); |
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443 | if (!idxp) |
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444 | return NULL; |
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445 | /* idxp->lock held */ |
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446 | node = fat_node_get_core(idxp); |
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447 | futex_up(&idxp->lock); |
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448 | return node; |
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449 | } |
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450 | |||
2852 | jermar | 451 | static void fat_node_put(void *node) |
452 | { |
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2910 | jermar | 453 | fat_node_t *nodep = (fat_node_t *)node; |
454 | |||
2951 | jermar | 455 | futex_down(&nodep->lock); |
2910 | jermar | 456 | if (!--nodep->refcnt) { |
2951 | jermar | 457 | futex_down(&ffn_futex); |
2910 | jermar | 458 | list_append(&nodep->ffn_link, &ffn_head); |
2951 | jermar | 459 | futex_up(&ffn_futex); |
2910 | jermar | 460 | } |
2951 | jermar | 461 | futex_up(&nodep->lock); |
2852 | jermar | 462 | } |
463 | |||
2857 | jermar | 464 | static void *fat_create(int flags) |
465 | { |
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466 | return NULL; /* not supported at the moment */ |
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467 | } |
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468 | |||
2858 | jermar | 469 | static int fat_destroy(void *node) |
2857 | jermar | 470 | { |
2858 | jermar | 471 | return ENOTSUP; /* not supported at the moment */ |
2857 | jermar | 472 | } |
473 | |||
474 | static bool fat_link(void *prnt, void *chld, const char *name) |
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475 | { |
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476 | return false; /* not supported at the moment */ |
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477 | } |
||
478 | |||
479 | static int fat_unlink(void *prnt, void *chld) |
||
480 | { |
||
481 | return ENOTSUP; /* not supported at the moment */ |
||
482 | } |
||
483 | |||
2793 | jermar | 484 | static void *fat_match(void *prnt, const char *component) |
485 | { |
||
486 | fat_node_t *parentp = (fat_node_t *)prnt; |
||
487 | char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1]; |
||
2822 | jermar | 488 | unsigned i, j; |
2828 | jermar | 489 | unsigned bps; /* bytes per sector */ |
2822 | jermar | 490 | unsigned dps; /* dentries per sector */ |
491 | unsigned blocks; |
||
2793 | jermar | 492 | fat_dentry_t *d; |
2822 | jermar | 493 | block_t *b; |
2793 | jermar | 494 | |
2953 | jermar | 495 | futex_down(&parentp->idx->lock); |
2864 | jermar | 496 | bps = fat_bps_get(parentp->idx->dev_handle); |
2828 | jermar | 497 | dps = bps / sizeof(fat_dentry_t); |
498 | blocks = parentp->size / bps + (parentp->size % bps != 0); |
||
2822 | jermar | 499 | for (i = 0; i < blocks; i++) { |
500 | unsigned dentries; |
||
2793 | jermar | 501 | |
2864 | jermar | 502 | b = fat_block_get(parentp, i); |
2822 | jermar | 503 | dentries = (i == blocks - 1) ? |
504 | parentp->size % sizeof(fat_dentry_t) : |
||
505 | dps; |
||
506 | for (j = 0; j < dentries; j++) { |
||
507 | d = ((fat_dentry_t *)b->data) + j; |
||
2845 | jermar | 508 | switch (fat_classify_dentry(d)) { |
509 | case FAT_DENTRY_SKIP: |
||
2822 | jermar | 510 | continue; |
2845 | jermar | 511 | case FAT_DENTRY_LAST: |
2822 | jermar | 512 | block_put(b); |
2953 | jermar | 513 | futex_up(&parentp->idx->lock); |
2822 | jermar | 514 | return NULL; |
2845 | jermar | 515 | default: |
516 | case FAT_DENTRY_VALID: |
||
517 | dentry_name_canonify(d, name); |
||
518 | break; |
||
2822 | jermar | 519 | } |
3272 | jermar | 520 | if (stricmp(name, component) == 0) { |
2822 | jermar | 521 | /* hit */ |
2951 | jermar | 522 | void *node; |
2953 | jermar | 523 | /* |
524 | * Assume tree hierarchy for locking. We |
||
525 | * already have the parent and now we are going |
||
526 | * to lock the child. Never lock in the oposite |
||
527 | * order. |
||
528 | */ |
||
2890 | jermar | 529 | fat_idx_t *idx = fat_idx_get_by_pos( |
2881 | jermar | 530 | parentp->idx->dev_handle, parentp->firstc, |
2864 | jermar | 531 | i * dps + j); |
2953 | jermar | 532 | futex_up(&parentp->idx->lock); |
2890 | jermar | 533 | if (!idx) { |
534 | /* |
||
535 | * Can happen if memory is low or if we |
||
536 | * run out of 32-bit indices. |
||
537 | */ |
||
538 | block_put(b); |
||
539 | return NULL; |
||
540 | } |
||
2951 | jermar | 541 | node = fat_node_get_core(idx); |
542 | futex_up(&idx->lock); |
||
2822 | jermar | 543 | block_put(b); |
544 | return node; |
||
545 | } |
||
2793 | jermar | 546 | } |
2822 | jermar | 547 | block_put(b); |
2639 | jermar | 548 | } |
2953 | jermar | 549 | futex_up(&parentp->idx->lock); |
2793 | jermar | 550 | return NULL; |
2638 | jermar | 551 | } |
552 | |||
2831 | jermar | 553 | static fs_index_t fat_index_get(void *node) |
554 | { |
||
555 | fat_node_t *fnodep = (fat_node_t *)node; |
||
556 | if (!fnodep) |
||
557 | return 0; |
||
2864 | jermar | 558 | return fnodep->idx->index; |
2831 | jermar | 559 | } |
560 | |||
561 | static size_t fat_size_get(void *node) |
||
562 | { |
||
563 | return ((fat_node_t *)node)->size; |
||
564 | } |
||
565 | |||
566 | static unsigned fat_lnkcnt_get(void *node) |
||
567 | { |
||
568 | return ((fat_node_t *)node)->lnkcnt; |
||
569 | } |
||
570 | |||
2845 | jermar | 571 | static bool fat_has_children(void *node) |
572 | { |
||
573 | fat_node_t *nodep = (fat_node_t *)node; |
||
574 | unsigned bps; |
||
575 | unsigned dps; |
||
576 | unsigned blocks; |
||
577 | block_t *b; |
||
578 | unsigned i, j; |
||
579 | |||
580 | if (nodep->type != FAT_DIRECTORY) |
||
581 | return false; |
||
582 | |||
2951 | jermar | 583 | futex_down(&nodep->idx->lock); |
2864 | jermar | 584 | bps = fat_bps_get(nodep->idx->dev_handle); |
2845 | jermar | 585 | dps = bps / sizeof(fat_dentry_t); |
586 | |||
587 | blocks = nodep->size / bps + (nodep->size % bps != 0); |
||
588 | |||
589 | for (i = 0; i < blocks; i++) { |
||
590 | unsigned dentries; |
||
591 | fat_dentry_t *d; |
||
592 | |||
2864 | jermar | 593 | b = fat_block_get(nodep, i); |
2845 | jermar | 594 | dentries = (i == blocks - 1) ? |
595 | nodep->size % sizeof(fat_dentry_t) : |
||
596 | dps; |
||
597 | for (j = 0; j < dentries; j++) { |
||
598 | d = ((fat_dentry_t *)b->data) + j; |
||
599 | switch (fat_classify_dentry(d)) { |
||
600 | case FAT_DENTRY_SKIP: |
||
601 | continue; |
||
602 | case FAT_DENTRY_LAST: |
||
603 | block_put(b); |
||
2951 | jermar | 604 | futex_up(&nodep->idx->lock); |
2845 | jermar | 605 | return false; |
606 | default: |
||
607 | case FAT_DENTRY_VALID: |
||
608 | block_put(b); |
||
2951 | jermar | 609 | futex_up(&nodep->idx->lock); |
2845 | jermar | 610 | return true; |
611 | } |
||
612 | block_put(b); |
||
2951 | jermar | 613 | futex_up(&nodep->idx->lock); |
2845 | jermar | 614 | return true; |
615 | } |
||
616 | block_put(b); |
||
617 | } |
||
618 | |||
2951 | jermar | 619 | futex_up(&nodep->idx->lock); |
2845 | jermar | 620 | return false; |
621 | } |
||
622 | |||
2844 | jermar | 623 | static void *fat_root_get(dev_handle_t dev_handle) |
624 | { |
||
3119 | jermar | 625 | return fat_node_get(dev_handle, 0); |
2844 | jermar | 626 | } |
627 | |||
628 | static char fat_plb_get_char(unsigned pos) |
||
629 | { |
||
630 | return fat_reg.plb_ro[pos % PLB_SIZE]; |
||
631 | } |
||
632 | |||
2831 | jermar | 633 | static bool fat_is_directory(void *node) |
634 | { |
||
635 | return ((fat_node_t *)node)->type == FAT_DIRECTORY; |
||
636 | } |
||
637 | |||
638 | static bool fat_is_file(void *node) |
||
639 | { |
||
640 | return ((fat_node_t *)node)->type == FAT_FILE; |
||
641 | } |
||
642 | |||
2793 | jermar | 643 | /** libfs operations */ |
644 | libfs_ops_t fat_libfs_ops = { |
||
645 | .match = fat_match, |
||
646 | .node_get = fat_node_get, |
||
2852 | jermar | 647 | .node_put = fat_node_put, |
2857 | jermar | 648 | .create = fat_create, |
649 | .destroy = fat_destroy, |
||
650 | .link = fat_link, |
||
651 | .unlink = fat_unlink, |
||
2831 | jermar | 652 | .index_get = fat_index_get, |
653 | .size_get = fat_size_get, |
||
654 | .lnkcnt_get = fat_lnkcnt_get, |
||
2845 | jermar | 655 | .has_children = fat_has_children, |
2844 | jermar | 656 | .root_get = fat_root_get, |
657 | .plb_get_char = fat_plb_get_char, |
||
2831 | jermar | 658 | .is_directory = fat_is_directory, |
659 | .is_file = fat_is_file |
||
2793 | jermar | 660 | }; |
661 | |||
3110 | jermar | 662 | void fat_mounted(ipc_callid_t rid, ipc_call_t *request) |
663 | { |
||
664 | dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request); |
||
3119 | jermar | 665 | block_t *bb; |
3257 | jermar | 666 | uint16_t bps; |
3119 | jermar | 667 | uint16_t rde; |
3110 | jermar | 668 | int rc; |
669 | |||
3257 | jermar | 670 | /* |
671 | * For now, we don't bother to remember dev_handle, dev_phone or |
||
672 | * dev_buffer in some data structure. We use global variables because we |
||
673 | * know there will be at most one mount on this file system. |
||
674 | * Of course, this is a huge TODO item. |
||
675 | */ |
||
676 | dev_buffer = mmap(NULL, BS_SIZE, PROTO_READ | PROTO_WRITE, |
||
677 | MAP_ANONYMOUS | MAP_PRIVATE, 0, 0); |
||
678 | |||
679 | if (!dev_buffer) { |
||
680 | ipc_answer_0(rid, ENOMEM); |
||
681 | return; |
||
682 | } |
||
683 | |||
684 | dev_phone = ipc_connect_me_to(PHONE_NS, SERVICE_DEVMAP, |
||
685 | DEVMAP_CONNECT_TO_DEVICE, dev_handle); |
||
686 | |||
687 | if (dev_phone < 0) { |
||
688 | munmap(dev_buffer, BS_SIZE); |
||
689 | ipc_answer_0(rid, dev_phone); |
||
690 | return; |
||
691 | } |
||
692 | |||
693 | rc = ipc_share_out_start(dev_phone, dev_buffer, |
||
694 | AS_AREA_READ | AS_AREA_WRITE); |
||
695 | if (rc != EOK) { |
||
696 | munmap(dev_buffer, BS_SIZE); |
||
697 | ipc_answer_0(rid, rc); |
||
698 | return; |
||
699 | } |
||
700 | |||
3119 | jermar | 701 | /* Read the number of root directory entries. */ |
3253 | jermar | 702 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
3257 | jermar | 703 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
3119 | jermar | 704 | rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max); |
705 | block_put(bb); |
||
706 | |||
3257 | jermar | 707 | if (bps != BS_SIZE) { |
708 | munmap(dev_buffer, BS_SIZE); |
||
709 | ipc_answer_0(rid, ENOTSUP); |
||
710 | return; |
||
711 | } |
||
712 | |||
3110 | jermar | 713 | rc = fat_idx_init_by_dev_handle(dev_handle); |
714 | if (rc != EOK) { |
||
3257 | jermar | 715 | munmap(dev_buffer, BS_SIZE); |
3110 | jermar | 716 | ipc_answer_0(rid, rc); |
717 | return; |
||
718 | } |
||
719 | |||
3119 | jermar | 720 | /* Initialize the root node. */ |
721 | fat_node_t *rootp = (fat_node_t *)malloc(sizeof(fat_node_t)); |
||
722 | if (!rootp) { |
||
3257 | jermar | 723 | munmap(dev_buffer, BS_SIZE); |
3119 | jermar | 724 | fat_idx_fini_by_dev_handle(dev_handle); |
725 | ipc_answer_0(rid, ENOMEM); |
||
726 | return; |
||
727 | } |
||
728 | fat_node_initialize(rootp); |
||
729 | |||
730 | fat_idx_t *ridxp = fat_idx_get_by_pos(dev_handle, FAT_CLST_ROOTPAR, 0); |
||
731 | if (!ridxp) { |
||
3257 | jermar | 732 | munmap(dev_buffer, BS_SIZE); |
3119 | jermar | 733 | free(rootp); |
734 | fat_idx_fini_by_dev_handle(dev_handle); |
||
735 | ipc_answer_0(rid, ENOMEM); |
||
736 | return; |
||
737 | } |
||
738 | assert(ridxp->index == 0); |
||
739 | /* ridxp->lock held */ |
||
740 | |||
741 | rootp->type = FAT_DIRECTORY; |
||
742 | rootp->firstc = FAT_CLST_ROOT; |
||
743 | rootp->refcnt = 1; |
||
3352 | jermar | 744 | rootp->lnkcnt = 0; /* FS root is not linked */ |
3119 | jermar | 745 | rootp->size = rde * sizeof(fat_dentry_t); |
746 | rootp->idx = ridxp; |
||
747 | ridxp->nodep = rootp; |
||
748 | |||
749 | futex_up(&ridxp->lock); |
||
750 | |||
3352 | jermar | 751 | ipc_answer_3(rid, EOK, ridxp->index, rootp->size, rootp->lnkcnt); |
3110 | jermar | 752 | } |
753 | |||
754 | void fat_mount(ipc_callid_t rid, ipc_call_t *request) |
||
755 | { |
||
756 | ipc_answer_0(rid, ENOTSUP); |
||
757 | } |
||
758 | |||
2627 | jermar | 759 | void fat_lookup(ipc_callid_t rid, ipc_call_t *request) |
760 | { |
||
2793 | jermar | 761 | libfs_lookup(&fat_libfs_ops, fat_reg.fs_handle, rid, request); |
2627 | jermar | 762 | } |
763 | |||
3307 | jermar | 764 | void fat_read(ipc_callid_t rid, ipc_call_t *request) |
765 | { |
||
766 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
||
767 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
||
768 | off_t pos = (off_t)IPC_GET_ARG3(*request); |
||
769 | fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
||
3308 | jermar | 770 | uint16_t bps = fat_bps_get(dev_handle); |
771 | size_t bytes; |
||
3335 | jermar | 772 | block_t *b; |
3308 | jermar | 773 | |
3307 | jermar | 774 | if (!nodep) { |
775 | ipc_answer_0(rid, ENOENT); |
||
776 | return; |
||
777 | } |
||
778 | |||
779 | ipc_callid_t callid; |
||
780 | size_t len; |
||
3314 | jermar | 781 | if (!ipc_data_read_receive(&callid, &len)) { |
3307 | jermar | 782 | fat_node_put(nodep); |
783 | ipc_answer_0(callid, EINVAL); |
||
784 | ipc_answer_0(rid, EINVAL); |
||
785 | return; |
||
786 | } |
||
787 | |||
788 | if (nodep->type == FAT_FILE) { |
||
3335 | jermar | 789 | /* |
790 | * Our strategy for regular file reads is to read one block at |
||
791 | * most and make use of the possibility to return less data than |
||
792 | * requested. This keeps the code very simple. |
||
793 | */ |
||
3308 | jermar | 794 | bytes = min(len, bps - pos % bps); |
795 | b = fat_block_get(nodep, pos / bps); |
||
796 | (void) ipc_data_read_finalize(callid, b->data + pos % bps, |
||
797 | bytes); |
||
798 | block_put(b); |
||
3307 | jermar | 799 | } else { |
3335 | jermar | 800 | unsigned bnum; |
801 | off_t spos = pos; |
||
802 | char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1]; |
||
803 | fat_dentry_t *d; |
||
804 | |||
3307 | jermar | 805 | assert(nodep->type == FAT_DIRECTORY); |
3335 | jermar | 806 | assert(nodep->size % bps == 0); |
807 | assert(bps % sizeof(fat_dentry_t) == 0); |
||
808 | |||
809 | /* |
||
810 | * Our strategy for readdir() is to use the position pointer as |
||
811 | * an index into the array of all dentries. On entry, it points |
||
812 | * to the first unread dentry. If we skip any dentries, we bump |
||
813 | * the position pointer accordingly. |
||
814 | */ |
||
815 | bnum = (pos * sizeof(fat_dentry_t)) / bps; |
||
816 | while (bnum < nodep->size / bps) { |
||
817 | off_t o; |
||
818 | |||
819 | b = fat_block_get(nodep, bnum); |
||
820 | for (o = pos % (bps / sizeof(fat_dentry_t)); |
||
821 | o < bps / sizeof(fat_dentry_t); |
||
822 | o++, pos++) { |
||
823 | d = ((fat_dentry_t *)b->data) + o; |
||
824 | switch (fat_classify_dentry(d)) { |
||
825 | case FAT_DENTRY_SKIP: |
||
826 | continue; |
||
827 | case FAT_DENTRY_LAST: |
||
828 | block_put(b); |
||
829 | goto miss; |
||
830 | default: |
||
831 | case FAT_DENTRY_VALID: |
||
832 | dentry_name_canonify(d, name); |
||
833 | block_put(b); |
||
834 | goto hit; |
||
835 | } |
||
836 | } |
||
837 | block_put(b); |
||
838 | bnum++; |
||
839 | } |
||
840 | miss: |
||
3307 | jermar | 841 | fat_node_put(nodep); |
3335 | jermar | 842 | ipc_answer_0(callid, ENOENT); |
843 | ipc_answer_1(rid, ENOENT, 0); |
||
3307 | jermar | 844 | return; |
3335 | jermar | 845 | hit: |
846 | (void) ipc_data_read_finalize(callid, name, strlen(name) + 1); |
||
847 | bytes = (pos - spos) + 1; |
||
3307 | jermar | 848 | } |
849 | |||
850 | fat_node_put(nodep); |
||
3308 | jermar | 851 | ipc_answer_1(rid, EOK, (ipcarg_t)bytes); |
3307 | jermar | 852 | } |
853 | |||
3501 | jermar | 854 | /** Fill the gap between EOF and a new file position. |
855 | * |
||
856 | * @param nodep FAT node with the gap. |
||
857 | * @param mcl First cluster in an independent cluster chain that will |
||
858 | * be later appended to the end of the node's own cluster |
||
859 | * chain. If pos is still in the last allocated cluster, |
||
860 | * this argument is ignored. |
||
861 | * @param pos Position in the last node block. |
||
862 | */ |
||
3500 | jermar | 863 | static void |
3501 | jermar | 864 | fat_fill_gap(fat_node_t *nodep, fat_cluster_t mcl, off_t pos) |
3499 | jermar | 865 | { |
3501 | jermar | 866 | uint16_t bps; |
867 | unsigned spc; |
||
868 | block_t *bb, *b; |
||
869 | off_t o, boundary; |
||
870 | |||
871 | bb = block_get(nodep->idx->dev_handle, BS_BLOCK, BS_SIZE); |
||
872 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
||
873 | spc = FAT_BS(bb)->spc; |
||
874 | block_put(bb); |
||
875 | |||
876 | boundary = ROUND_UP(nodep->size, bps * spc); |
||
877 | |||
878 | /* zero out already allocated space */ |
||
879 | for (o = nodep->size - 1; o < pos && o < boundary; |
||
880 | o = ALIGN_DOWN(o + bps, bps)) { |
||
881 | b = fat_block_get(nodep, o / bps); |
||
882 | memset(b->data + o % bps, 0, bps - o % bps); |
||
883 | b->dirty = true; /* need to sync node */ |
||
884 | block_put(b); |
||
885 | } |
||
886 | |||
887 | if (o >= pos) |
||
888 | return; |
||
889 | |||
890 | /* zero out the initial part of the new cluster chain */ |
||
891 | for (o = boundary; o < pos; o += bps) { |
||
892 | b = _fat_block_get(nodep->idx->dev_handle, mcl, |
||
893 | (o - boundary) / bps); |
||
894 | memset(b->data, 0, min(bps, pos - o)); |
||
3503 | jermar | 895 | b->dirty = true; /* need to sync node */ |
3501 | jermar | 896 | block_put(b); |
897 | } |
||
3499 | jermar | 898 | } |
899 | |||
3503 | jermar | 900 | static void |
901 | fat_mark_cluster(dev_handle_t dev_handle, unsigned fatno, fat_cluster_t clst, |
||
902 | fat_cluster_t value) |
||
903 | { |
||
904 | /* TODO */ |
||
905 | } |
||
906 | |||
907 | static void |
||
908 | fat_alloc_shadow_clusters(dev_handle_t dev_handle, fat_cluster_t *lifo, |
||
909 | unsigned nclsts) |
||
910 | { |
||
911 | /* TODO */ |
||
912 | } |
||
913 | |||
3500 | jermar | 914 | static int |
3503 | jermar | 915 | fat_alloc_clusters(dev_handle_t dev_handle, unsigned nclsts, fat_cluster_t *mcl, |
916 | fat_cluster_t *lcl) |
||
3500 | jermar | 917 | { |
3503 | jermar | 918 | uint16_t bps; |
919 | uint16_t rscnt; |
||
920 | uint16_t sf; |
||
921 | block_t *bb, *blk; |
||
922 | fat_cluster_t *lifo; /* stack for storing free cluster numbers */ |
||
923 | unsigned found = 0; /* top of the free cluster number stack */ |
||
924 | unsigned b, c, cl; |
||
925 | |||
926 | lifo = (fat_cluster_t *) malloc(nclsts * sizeof(fat_cluster_t)); |
||
927 | if (lifo) |
||
928 | return ENOMEM; |
||
929 | |||
930 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
||
931 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
||
932 | rscnt = uint16_t_le2host(FAT_BS(bb)->rscnt); |
||
933 | sf = uint16_t_le2host(FAT_BS(bb)->sec_per_fat); |
||
934 | block_put(bb); |
||
935 | |||
936 | /* |
||
937 | * Search FAT1 for unused clusters. |
||
938 | */ |
||
939 | for (b = 0, cl = 0; b < sf; blk++) { |
||
940 | blk = block_get(dev_handle, rscnt + b, bps); |
||
941 | for (c = 0; c < bps / sizeof(fat_cluster_t); c++, cl++) { |
||
942 | fat_cluster_t *clst = (fat_cluster_t *)blk->data + c; |
||
943 | if (*clst == FAT_CLST_RES0) { |
||
944 | /* |
||
945 | * The cluster is free. Put it into our stack |
||
946 | * of found clusters and mark it as non-free. |
||
947 | */ |
||
948 | lifo[found] = cl; |
||
949 | if (found == 0) |
||
950 | *clst = FAT_CLST_LAST1; |
||
951 | else |
||
952 | *clst = lifo[found - 1]; |
||
953 | blk->dirty = true; /* need to sync block */ |
||
954 | if (++found == nclsts) { |
||
955 | /* we are almost done */ |
||
956 | block_put(blk); |
||
957 | /* update the shadow copies of FAT */ |
||
958 | fat_alloc_shadow_clusters(dev_handle, |
||
959 | lifo, nclsts); |
||
960 | *mcl = lifo[found - 1]; |
||
961 | *lcl = lifo[0]; |
||
962 | free(lifo); |
||
963 | return EOK; |
||
964 | } |
||
965 | } |
||
966 | } |
||
967 | block_put(blk); |
||
968 | } |
||
969 | |||
970 | /* |
||
971 | * We could not find enough clusters. Now we need to free the clusters |
||
972 | * we have allocated so far. |
||
973 | */ |
||
974 | while (found--) |
||
975 | fat_mark_cluster(dev_handle, FAT1, lifo[found], FAT_CLST_RES0); |
||
976 | |||
977 | free(lifo); |
||
978 | return ENOSPC; |
||
3500 | jermar | 979 | } |
980 | |||
981 | static void |
||
982 | fat_append_clusters(fat_node_t *nodep, fat_cluster_t mcl) |
||
983 | { |
||
984 | } |
||
985 | |||
3497 | jermar | 986 | void fat_write(ipc_callid_t rid, ipc_call_t *request) |
987 | { |
||
3499 | jermar | 988 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
989 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
||
990 | off_t pos = (off_t)IPC_GET_ARG3(*request); |
||
991 | fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
||
992 | size_t bytes; |
||
993 | block_t *b, *bb; |
||
994 | uint16_t bps; |
||
995 | unsigned spc; |
||
3501 | jermar | 996 | off_t boundary; |
3499 | jermar | 997 | |
998 | if (!nodep) { |
||
999 | ipc_answer_0(rid, ENOENT); |
||
1000 | return; |
||
1001 | } |
||
1002 | |||
1003 | /* XXX remove me when you are ready */ |
||
1004 | { |
||
1005 | ipc_answer_0(rid, ENOTSUP); |
||
1006 | fat_node_put(nodep); |
||
1007 | return; |
||
1008 | } |
||
1009 | |||
1010 | ipc_callid_t callid; |
||
1011 | size_t len; |
||
1012 | if (!ipc_data_write_receive(&callid, &len)) { |
||
1013 | fat_node_put(nodep); |
||
1014 | ipc_answer_0(callid, EINVAL); |
||
1015 | ipc_answer_0(rid, EINVAL); |
||
1016 | return; |
||
1017 | } |
||
1018 | |||
1019 | /* |
||
1020 | * In all scenarios, we will attempt to write out only one block worth |
||
1021 | * of data at maximum. There might be some more efficient approaches, |
||
1022 | * but this one greatly simplifies fat_write(). Note that we can afford |
||
1023 | * to do this because the client must be ready to handle the return |
||
1024 | * value signalizing a smaller number of bytes written. |
||
1025 | */ |
||
1026 | bytes = min(len, bps - pos % bps); |
||
1027 | |||
1028 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
||
1029 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
||
1030 | spc = FAT_BS(bb)->spc; |
||
1031 | block_put(bb); |
||
1032 | |||
3501 | jermar | 1033 | boundary = ROUND_UP(nodep->size, bps * spc); |
1034 | if (pos < boundary) { |
||
3499 | jermar | 1035 | /* |
1036 | * This is the easier case - we are either overwriting already |
||
1037 | * existing contents or writing behind the EOF, but still within |
||
1038 | * the limits of the last cluster. The node size may grow to the |
||
1039 | * next block size boundary. |
||
1040 | */ |
||
3500 | jermar | 1041 | fat_fill_gap(nodep, FAT_CLST_RES0, pos); |
3499 | jermar | 1042 | b = fat_block_get(nodep, pos / bps); |
1043 | (void) ipc_data_write_finalize(callid, b->data + pos % bps, |
||
1044 | bytes); |
||
1045 | b->dirty = true; /* need to sync block */ |
||
3500 | jermar | 1046 | block_put(b); |
3499 | jermar | 1047 | if (pos + bytes > nodep->size) { |
1048 | nodep->size = pos + bytes; |
||
1049 | nodep->dirty = true; /* need to sync node */ |
||
1050 | } |
||
1051 | fat_node_put(nodep); |
||
1052 | ipc_answer_1(rid, EOK, bytes); |
||
1053 | return; |
||
1054 | } else { |
||
1055 | /* |
||
1056 | * This is the more difficult case. We must allocate new |
||
1057 | * clusters for the node and zero them out. |
||
1058 | */ |
||
3500 | jermar | 1059 | int status; |
3499 | jermar | 1060 | unsigned nclsts; |
3500 | jermar | 1061 | fat_cluster_t mcl, lcl; |
1062 | |||
3501 | jermar | 1063 | nclsts = (ROUND_UP(pos + bytes, bps * spc) - boundary) / |
3500 | jermar | 1064 | bps * spc; |
1065 | /* create an independent chain of nclsts clusters in all FATs */ |
||
3503 | jermar | 1066 | status = fat_alloc_clusters(dev_handle, nclsts, &mcl, &lcl); |
3500 | jermar | 1067 | if (status != EOK) { |
1068 | /* could not allocate a chain of nclsts clusters */ |
||
1069 | fat_node_put(nodep); |
||
1070 | ipc_answer_0(callid, status); |
||
1071 | ipc_answer_0(rid, status); |
||
1072 | return; |
||
1073 | } |
||
1074 | /* zero fill any gaps */ |
||
1075 | fat_fill_gap(nodep, mcl, pos); |
||
1076 | b = _fat_block_get(dev_handle, lcl, (pos / bps) % spc); |
||
1077 | (void) ipc_data_write_finalize(callid, b->data + pos % bps, |
||
1078 | bytes); |
||
3501 | jermar | 1079 | b->dirty = true; /* need to sync block */ |
3500 | jermar | 1080 | block_put(b); |
1081 | /* |
||
1082 | * Append the cluster chain starting in mcl to the end of the |
||
1083 | * node's cluster chain. |
||
1084 | */ |
||
1085 | fat_append_clusters(nodep, mcl); |
||
1086 | nodep->size = pos + bytes; |
||
3501 | jermar | 1087 | nodep->dirty = true; /* need to sync node */ |
3500 | jermar | 1088 | fat_node_put(nodep); |
1089 | ipc_answer_1(rid, EOK, bytes); |
||
1090 | return; |
||
3499 | jermar | 1091 | } |
3497 | jermar | 1092 | } |
1093 | |||
2627 | jermar | 1094 | /** |
1095 | * @} |
||
1096 | */ |