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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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3535 | svoboda | 39 | #include "fat_dentry.h" |
40 | #include "fat_fat.h" |
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2638 | jermar | 41 | #include "../../vfs/vfs.h" |
2793 | jermar | 42 | #include <libfs.h> |
3535 | svoboda | 43 | #include <libblock.h> |
2627 | jermar | 44 | #include <ipc/ipc.h> |
3403 | svoboda | 45 | #include <ipc/services.h> |
46 | #include <ipc/devmap.h> |
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2627 | jermar | 47 | #include <async.h> |
48 | #include <errno.h> |
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2793 | jermar | 49 | #include <string.h> |
2798 | jermar | 50 | #include <byteorder.h> |
2831 | jermar | 51 | #include <libadt/hash_table.h> |
52 | #include <libadt/list.h> |
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53 | #include <assert.h> |
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2856 | jermar | 54 | #include <futex.h> |
3403 | svoboda | 55 | #include <sys/mman.h> |
3535 | svoboda | 56 | #include <align.h> |
2627 | jermar | 57 | |
3009 | svoboda | 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 | |
3009 | svoboda | 61 | /** List of cached free FAT nodes. */ |
62 | static LIST_INITIALIZE(ffn_head); |
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63 | |||
2831 | jermar | 64 | static void fat_node_initialize(fat_node_t *node) |
2793 | jermar | 65 | { |
3009 | svoboda | 66 | futex_initialize(&node->lock, 1); |
2864 | jermar | 67 | node->idx = NULL; |
2831 | jermar | 68 | node->type = 0; |
69 | link_initialize(&node->ffn_link); |
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70 | node->size = 0; |
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71 | node->lnkcnt = 0; |
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72 | node->refcnt = 0; |
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73 | node->dirty = false; |
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2793 | jermar | 74 | } |
75 | |||
3535 | svoboda | 76 | static void fat_node_sync(fat_node_t *node) |
2843 | jermar | 77 | { |
3535 | svoboda | 78 | block_t *b; |
79 | fat_bs_t *bs; |
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80 | fat_dentry_t *d; |
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2843 | jermar | 81 | uint16_t bps; |
3535 | svoboda | 82 | unsigned dps; |
2843 | jermar | 83 | |
3535 | svoboda | 84 | assert(node->dirty); |
2843 | jermar | 85 | |
3535 | svoboda | 86 | bs = block_bb_get(node->idx->dev_handle); |
87 | bps = uint16_t_le2host(bs->bps); |
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88 | dps = bps / sizeof(fat_dentry_t); |
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89 | |||
90 | /* Read the block that contains the dentry of interest. */ |
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91 | b = _fat_block_get(bs, node->idx->dev_handle, node->idx->pfc, |
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92 | (node->idx->pdi * sizeof(fat_dentry_t)) / bps); |
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2843 | jermar | 93 | |
3535 | svoboda | 94 | d = ((fat_dentry_t *)b->data) + (node->idx->pdi % dps); |
2845 | jermar | 95 | |
3535 | svoboda | 96 | d->firstc = host2uint16_t_le(node->firstc); |
97 | if (node->type == FAT_FILE) |
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98 | d->size = host2uint32_t_le(node->size); |
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99 | /* TODO: update other fields? (e.g time fields, attr field) */ |
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100 | |||
101 | b->dirty = true; /* need to sync block */ |
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102 | block_put(b); |
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2845 | jermar | 103 | } |
104 | |||
3588 | svoboda | 105 | static fat_node_t *fat_node_get_new(void) |
106 | { |
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107 | fat_node_t *nodep; |
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108 | |||
109 | futex_down(&ffn_futex); |
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110 | if (!list_empty(&ffn_head)) { |
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111 | /* Try to use a cached free node structure. */ |
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112 | fat_idx_t *idxp_tmp; |
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113 | nodep = list_get_instance(ffn_head.next, fat_node_t, ffn_link); |
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114 | if (futex_trydown(&nodep->lock) == ESYNCH_WOULD_BLOCK) |
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115 | goto skip_cache; |
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116 | idxp_tmp = nodep->idx; |
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117 | if (futex_trydown(&idxp_tmp->lock) == ESYNCH_WOULD_BLOCK) { |
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118 | futex_up(&nodep->lock); |
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119 | goto skip_cache; |
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120 | } |
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121 | list_remove(&nodep->ffn_link); |
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122 | futex_up(&ffn_futex); |
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123 | if (nodep->dirty) |
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124 | fat_node_sync(nodep); |
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125 | idxp_tmp->nodep = NULL; |
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126 | futex_up(&nodep->lock); |
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127 | futex_up(&idxp_tmp->lock); |
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128 | } else { |
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129 | skip_cache: |
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130 | /* Try to allocate a new node structure. */ |
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131 | futex_up(&ffn_futex); |
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132 | nodep = (fat_node_t *)malloc(sizeof(fat_node_t)); |
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133 | if (!nodep) |
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134 | return NULL; |
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135 | } |
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136 | fat_node_initialize(nodep); |
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137 | |||
138 | return nodep; |
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139 | } |
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140 | |||
3009 | svoboda | 141 | /** Internal version of fat_node_get(). |
142 | * |
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143 | * @param idxp Locked index structure. |
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144 | */ |
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145 | static void *fat_node_get_core(fat_idx_t *idxp) |
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2831 | jermar | 146 | { |
2891 | jermar | 147 | block_t *b; |
3535 | svoboda | 148 | fat_bs_t *bs; |
2891 | jermar | 149 | fat_dentry_t *d; |
3403 | svoboda | 150 | fat_node_t *nodep = NULL; |
2891 | jermar | 151 | unsigned bps; |
3561 | svoboda | 152 | unsigned spc; |
2891 | jermar | 153 | unsigned dps; |
154 | |||
3009 | svoboda | 155 | if (idxp->nodep) { |
2891 | jermar | 156 | /* |
157 | * We are lucky. |
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158 | * The node is already instantiated in memory. |
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159 | */ |
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3009 | svoboda | 160 | futex_down(&idxp->nodep->lock); |
161 | if (!idxp->nodep->refcnt++) |
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3403 | svoboda | 162 | list_remove(&idxp->nodep->ffn_link); |
3009 | svoboda | 163 | futex_up(&idxp->nodep->lock); |
164 | return idxp->nodep; |
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2891 | jermar | 165 | } |
166 | |||
167 | /* |
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168 | * We must instantiate the node from the file system. |
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169 | */ |
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170 | |||
3009 | svoboda | 171 | assert(idxp->pfc); |
2891 | jermar | 172 | |
3588 | svoboda | 173 | nodep = fat_node_get_new(); |
174 | if (!nodep) |
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175 | return NULL; |
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2891 | jermar | 176 | |
3535 | svoboda | 177 | bs = block_bb_get(idxp->dev_handle); |
178 | bps = uint16_t_le2host(bs->bps); |
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3561 | svoboda | 179 | spc = bs->spc; |
2891 | jermar | 180 | dps = bps / sizeof(fat_dentry_t); |
181 | |||
2893 | jermar | 182 | /* Read the block that contains the dentry of interest. */ |
3535 | svoboda | 183 | b = _fat_block_get(bs, idxp->dev_handle, idxp->pfc, |
3009 | svoboda | 184 | (idxp->pdi * sizeof(fat_dentry_t)) / bps); |
2891 | jermar | 185 | assert(b); |
186 | |||
3009 | svoboda | 187 | d = ((fat_dentry_t *)b->data) + (idxp->pdi % dps); |
2893 | jermar | 188 | if (d->attr & FAT_ATTR_SUBDIR) { |
189 | /* |
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190 | * The only directory which does not have this bit set is the |
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191 | * root directory itself. The root directory node is handled |
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192 | * and initialized elsewhere. |
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193 | */ |
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194 | nodep->type = FAT_DIRECTORY; |
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3403 | svoboda | 195 | /* |
196 | * Unfortunately, the 'size' field of the FAT dentry is not |
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197 | * defined for the directory entry type. We must determine the |
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198 | * size of the directory by walking the FAT. |
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199 | */ |
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3561 | svoboda | 200 | nodep->size = bps * spc * fat_clusters_get(bs, idxp->dev_handle, |
201 | uint16_t_le2host(d->firstc)); |
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2893 | jermar | 202 | } else { |
203 | nodep->type = FAT_FILE; |
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3403 | svoboda | 204 | nodep->size = uint32_t_le2host(d->size); |
2893 | jermar | 205 | } |
206 | nodep->firstc = uint16_t_le2host(d->firstc); |
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207 | nodep->lnkcnt = 1; |
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208 | nodep->refcnt = 1; |
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209 | |||
210 | block_put(b); |
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211 | |||
212 | /* Link the idx structure with the node structure. */ |
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3009 | svoboda | 213 | nodep->idx = idxp; |
214 | idxp->nodep = nodep; |
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2893 | jermar | 215 | |
216 | return nodep; |
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2831 | jermar | 217 | } |
218 | |||
3009 | svoboda | 219 | /** Instantiate a FAT in-core node. */ |
220 | static void *fat_node_get(dev_handle_t dev_handle, fs_index_t index) |
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221 | { |
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222 | void *node; |
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223 | fat_idx_t *idxp; |
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224 | |||
225 | idxp = fat_idx_get_by_index(dev_handle, index); |
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226 | if (!idxp) |
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227 | return NULL; |
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228 | /* idxp->lock held */ |
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229 | node = fat_node_get_core(idxp); |
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230 | futex_up(&idxp->lock); |
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231 | return node; |
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232 | } |
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233 | |||
2852 | jermar | 234 | static void fat_node_put(void *node) |
235 | { |
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2910 | jermar | 236 | fat_node_t *nodep = (fat_node_t *)node; |
237 | |||
3009 | svoboda | 238 | futex_down(&nodep->lock); |
2910 | jermar | 239 | if (!--nodep->refcnt) { |
3009 | svoboda | 240 | futex_down(&ffn_futex); |
2910 | jermar | 241 | list_append(&nodep->ffn_link, &ffn_head); |
3009 | svoboda | 242 | futex_up(&ffn_futex); |
2910 | jermar | 243 | } |
3009 | svoboda | 244 | futex_up(&nodep->lock); |
2852 | jermar | 245 | } |
246 | |||
3588 | svoboda | 247 | static void *fat_create(dev_handle_t dev_handle, int flags) |
2857 | jermar | 248 | { |
249 | return NULL; /* not supported at the moment */ |
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250 | } |
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251 | |||
2858 | jermar | 252 | static int fat_destroy(void *node) |
2857 | jermar | 253 | { |
2858 | jermar | 254 | return ENOTSUP; /* not supported at the moment */ |
2857 | jermar | 255 | } |
256 | |||
257 | static bool fat_link(void *prnt, void *chld, const char *name) |
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258 | { |
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259 | return false; /* not supported at the moment */ |
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260 | } |
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261 | |||
262 | static int fat_unlink(void *prnt, void *chld) |
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263 | { |
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264 | return ENOTSUP; /* not supported at the moment */ |
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265 | } |
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266 | |||
2793 | jermar | 267 | static void *fat_match(void *prnt, const char *component) |
268 | { |
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3535 | svoboda | 269 | fat_bs_t *bs; |
2793 | jermar | 270 | fat_node_t *parentp = (fat_node_t *)prnt; |
271 | char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1]; |
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2822 | jermar | 272 | unsigned i, j; |
2828 | jermar | 273 | unsigned bps; /* bytes per sector */ |
2822 | jermar | 274 | unsigned dps; /* dentries per sector */ |
275 | unsigned blocks; |
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2793 | jermar | 276 | fat_dentry_t *d; |
2822 | jermar | 277 | block_t *b; |
2793 | jermar | 278 | |
3009 | svoboda | 279 | futex_down(&parentp->idx->lock); |
3535 | svoboda | 280 | bs = block_bb_get(parentp->idx->dev_handle); |
281 | bps = uint16_t_le2host(bs->bps); |
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2828 | jermar | 282 | dps = bps / sizeof(fat_dentry_t); |
3535 | svoboda | 283 | blocks = parentp->size / bps; |
2822 | jermar | 284 | for (i = 0; i < blocks; i++) { |
3535 | svoboda | 285 | b = fat_block_get(bs, parentp, i); |
286 | for (j = 0; j < dps; j++) { |
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2822 | jermar | 287 | d = ((fat_dentry_t *)b->data) + j; |
2845 | jermar | 288 | switch (fat_classify_dentry(d)) { |
289 | case FAT_DENTRY_SKIP: |
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2822 | jermar | 290 | continue; |
2845 | jermar | 291 | case FAT_DENTRY_LAST: |
2822 | jermar | 292 | block_put(b); |
3009 | svoboda | 293 | futex_up(&parentp->idx->lock); |
2822 | jermar | 294 | return NULL; |
2845 | jermar | 295 | default: |
296 | case FAT_DENTRY_VALID: |
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297 | dentry_name_canonify(d, name); |
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298 | break; |
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2822 | jermar | 299 | } |
3403 | svoboda | 300 | if (stricmp(name, component) == 0) { |
2822 | jermar | 301 | /* hit */ |
3009 | svoboda | 302 | void *node; |
303 | /* |
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304 | * Assume tree hierarchy for locking. We |
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305 | * already have the parent and now we are going |
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306 | * to lock the child. Never lock in the oposite |
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307 | * order. |
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308 | */ |
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2890 | jermar | 309 | fat_idx_t *idx = fat_idx_get_by_pos( |
2881 | jermar | 310 | parentp->idx->dev_handle, parentp->firstc, |
2864 | jermar | 311 | i * dps + j); |
3009 | svoboda | 312 | futex_up(&parentp->idx->lock); |
2890 | jermar | 313 | if (!idx) { |
314 | /* |
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315 | * Can happen if memory is low or if we |
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316 | * run out of 32-bit indices. |
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317 | */ |
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318 | block_put(b); |
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319 | return NULL; |
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320 | } |
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3009 | svoboda | 321 | node = fat_node_get_core(idx); |
322 | futex_up(&idx->lock); |
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2822 | jermar | 323 | block_put(b); |
324 | return node; |
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325 | } |
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2793 | jermar | 326 | } |
2822 | jermar | 327 | block_put(b); |
2639 | jermar | 328 | } |
3535 | svoboda | 329 | |
3009 | svoboda | 330 | futex_up(&parentp->idx->lock); |
2793 | jermar | 331 | return NULL; |
2638 | jermar | 332 | } |
333 | |||
2831 | jermar | 334 | static fs_index_t fat_index_get(void *node) |
335 | { |
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336 | fat_node_t *fnodep = (fat_node_t *)node; |
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337 | if (!fnodep) |
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338 | return 0; |
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2864 | jermar | 339 | return fnodep->idx->index; |
2831 | jermar | 340 | } |
341 | |||
342 | static size_t fat_size_get(void *node) |
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343 | { |
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344 | return ((fat_node_t *)node)->size; |
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345 | } |
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346 | |||
347 | static unsigned fat_lnkcnt_get(void *node) |
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348 | { |
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349 | return ((fat_node_t *)node)->lnkcnt; |
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350 | } |
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351 | |||
2845 | jermar | 352 | static bool fat_has_children(void *node) |
353 | { |
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3535 | svoboda | 354 | fat_bs_t *bs; |
2845 | jermar | 355 | fat_node_t *nodep = (fat_node_t *)node; |
356 | unsigned bps; |
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357 | unsigned dps; |
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358 | unsigned blocks; |
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359 | block_t *b; |
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360 | unsigned i, j; |
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361 | |||
362 | if (nodep->type != FAT_DIRECTORY) |
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363 | return false; |
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3535 | svoboda | 364 | |
3009 | svoboda | 365 | futex_down(&nodep->idx->lock); |
3535 | svoboda | 366 | bs = block_bb_get(nodep->idx->dev_handle); |
367 | bps = uint16_t_le2host(bs->bps); |
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2845 | jermar | 368 | dps = bps / sizeof(fat_dentry_t); |
369 | |||
3535 | svoboda | 370 | blocks = nodep->size / bps; |
2845 | jermar | 371 | |
372 | for (i = 0; i < blocks; i++) { |
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373 | fat_dentry_t *d; |
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374 | |||
3535 | svoboda | 375 | b = fat_block_get(bs, nodep, i); |
376 | for (j = 0; j < dps; j++) { |
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2845 | jermar | 377 | d = ((fat_dentry_t *)b->data) + j; |
378 | switch (fat_classify_dentry(d)) { |
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379 | case FAT_DENTRY_SKIP: |
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380 | continue; |
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381 | case FAT_DENTRY_LAST: |
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382 | block_put(b); |
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3009 | svoboda | 383 | futex_up(&nodep->idx->lock); |
2845 | jermar | 384 | return false; |
385 | default: |
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386 | case FAT_DENTRY_VALID: |
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387 | block_put(b); |
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3009 | svoboda | 388 | futex_up(&nodep->idx->lock); |
2845 | jermar | 389 | return true; |
390 | } |
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391 | block_put(b); |
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3009 | svoboda | 392 | futex_up(&nodep->idx->lock); |
2845 | jermar | 393 | return true; |
394 | } |
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395 | block_put(b); |
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396 | } |
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397 | |||
3009 | svoboda | 398 | futex_up(&nodep->idx->lock); |
2845 | jermar | 399 | return false; |
400 | } |
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401 | |||
2844 | jermar | 402 | static void *fat_root_get(dev_handle_t dev_handle) |
403 | { |
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3153 | svoboda | 404 | return fat_node_get(dev_handle, 0); |
2844 | jermar | 405 | } |
406 | |||
407 | static char fat_plb_get_char(unsigned pos) |
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408 | { |
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409 | return fat_reg.plb_ro[pos % PLB_SIZE]; |
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410 | } |
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411 | |||
2831 | jermar | 412 | static bool fat_is_directory(void *node) |
413 | { |
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414 | return ((fat_node_t *)node)->type == FAT_DIRECTORY; |
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415 | } |
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416 | |||
417 | static bool fat_is_file(void *node) |
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418 | { |
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419 | return ((fat_node_t *)node)->type == FAT_FILE; |
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420 | } |
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421 | |||
2793 | jermar | 422 | /** libfs operations */ |
423 | libfs_ops_t fat_libfs_ops = { |
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424 | .match = fat_match, |
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425 | .node_get = fat_node_get, |
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2852 | jermar | 426 | .node_put = fat_node_put, |
2857 | jermar | 427 | .create = fat_create, |
428 | .destroy = fat_destroy, |
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429 | .link = fat_link, |
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430 | .unlink = fat_unlink, |
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2831 | jermar | 431 | .index_get = fat_index_get, |
432 | .size_get = fat_size_get, |
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433 | .lnkcnt_get = fat_lnkcnt_get, |
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2845 | jermar | 434 | .has_children = fat_has_children, |
2844 | jermar | 435 | .root_get = fat_root_get, |
436 | .plb_get_char = fat_plb_get_char, |
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2831 | jermar | 437 | .is_directory = fat_is_directory, |
438 | .is_file = fat_is_file |
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2793 | jermar | 439 | }; |
440 | |||
3153 | svoboda | 441 | void fat_mounted(ipc_callid_t rid, ipc_call_t *request) |
442 | { |
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443 | dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request); |
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3535 | svoboda | 444 | fat_bs_t *bs; |
3403 | svoboda | 445 | uint16_t bps; |
3153 | svoboda | 446 | uint16_t rde; |
447 | int rc; |
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448 | |||
3535 | svoboda | 449 | /* initialize libblock */ |
3561 | svoboda | 450 | rc = block_init(dev_handle, BS_SIZE); |
3403 | svoboda | 451 | if (rc != EOK) { |
3561 | svoboda | 452 | ipc_answer_0(rid, rc); |
3403 | svoboda | 453 | return; |
454 | } |
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455 | |||
3561 | svoboda | 456 | /* prepare the boot block */ |
457 | rc = block_bb_read(dev_handle, BS_BLOCK * BS_SIZE, BS_SIZE); |
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458 | if (rc != EOK) { |
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459 | block_fini(dev_handle); |
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460 | ipc_answer_0(rid, rc); |
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461 | return; |
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462 | } |
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463 | |||
3535 | svoboda | 464 | /* get the buffer with the boot sector */ |
465 | bs = block_bb_get(dev_handle); |
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466 | |||
3153 | svoboda | 467 | /* Read the number of root directory entries. */ |
3535 | svoboda | 468 | bps = uint16_t_le2host(bs->bps); |
469 | rde = uint16_t_le2host(bs->root_ent_max); |
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3153 | svoboda | 470 | |
3403 | svoboda | 471 | if (bps != BS_SIZE) { |
3535 | svoboda | 472 | block_fini(dev_handle); |
3403 | svoboda | 473 | ipc_answer_0(rid, ENOTSUP); |
474 | return; |
||
475 | } |
||
476 | |||
3561 | svoboda | 477 | /* Initialize the block cache */ |
478 | rc = block_cache_init(dev_handle, bps, 0 /* XXX */); |
||
479 | if (rc != EOK) { |
||
480 | block_fini(dev_handle); |
||
481 | ipc_answer_0(rid, rc); |
||
482 | return; |
||
483 | } |
||
484 | |||
3153 | svoboda | 485 | rc = fat_idx_init_by_dev_handle(dev_handle); |
486 | if (rc != EOK) { |
||
3535 | svoboda | 487 | block_fini(dev_handle); |
3153 | svoboda | 488 | ipc_answer_0(rid, rc); |
489 | return; |
||
490 | } |
||
491 | |||
492 | /* Initialize the root node. */ |
||
493 | fat_node_t *rootp = (fat_node_t *)malloc(sizeof(fat_node_t)); |
||
494 | if (!rootp) { |
||
3535 | svoboda | 495 | block_fini(dev_handle); |
3153 | svoboda | 496 | fat_idx_fini_by_dev_handle(dev_handle); |
497 | ipc_answer_0(rid, ENOMEM); |
||
498 | return; |
||
499 | } |
||
500 | fat_node_initialize(rootp); |
||
501 | |||
502 | fat_idx_t *ridxp = fat_idx_get_by_pos(dev_handle, FAT_CLST_ROOTPAR, 0); |
||
503 | if (!ridxp) { |
||
3535 | svoboda | 504 | block_fini(dev_handle); |
3153 | svoboda | 505 | free(rootp); |
506 | fat_idx_fini_by_dev_handle(dev_handle); |
||
507 | ipc_answer_0(rid, ENOMEM); |
||
508 | return; |
||
509 | } |
||
510 | assert(ridxp->index == 0); |
||
511 | /* ridxp->lock held */ |
||
512 | |||
513 | rootp->type = FAT_DIRECTORY; |
||
514 | rootp->firstc = FAT_CLST_ROOT; |
||
515 | rootp->refcnt = 1; |
||
3403 | svoboda | 516 | rootp->lnkcnt = 0; /* FS root is not linked */ |
3153 | svoboda | 517 | rootp->size = rde * sizeof(fat_dentry_t); |
518 | rootp->idx = ridxp; |
||
519 | ridxp->nodep = rootp; |
||
520 | |||
521 | futex_up(&ridxp->lock); |
||
522 | |||
3403 | svoboda | 523 | ipc_answer_3(rid, EOK, ridxp->index, rootp->size, rootp->lnkcnt); |
3153 | svoboda | 524 | } |
525 | |||
526 | void fat_mount(ipc_callid_t rid, ipc_call_t *request) |
||
527 | { |
||
528 | ipc_answer_0(rid, ENOTSUP); |
||
529 | } |
||
530 | |||
2627 | jermar | 531 | void fat_lookup(ipc_callid_t rid, ipc_call_t *request) |
532 | { |
||
2793 | jermar | 533 | libfs_lookup(&fat_libfs_ops, fat_reg.fs_handle, rid, request); |
2627 | jermar | 534 | } |
535 | |||
3403 | svoboda | 536 | void fat_read(ipc_callid_t rid, ipc_call_t *request) |
537 | { |
||
538 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
||
539 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
||
540 | off_t pos = (off_t)IPC_GET_ARG3(*request); |
||
541 | fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
||
3535 | svoboda | 542 | fat_bs_t *bs; |
543 | uint16_t bps; |
||
3403 | svoboda | 544 | size_t bytes; |
545 | block_t *b; |
||
546 | |||
547 | if (!nodep) { |
||
548 | ipc_answer_0(rid, ENOENT); |
||
549 | return; |
||
550 | } |
||
551 | |||
552 | ipc_callid_t callid; |
||
553 | size_t len; |
||
554 | if (!ipc_data_read_receive(&callid, &len)) { |
||
555 | fat_node_put(nodep); |
||
556 | ipc_answer_0(callid, EINVAL); |
||
557 | ipc_answer_0(rid, EINVAL); |
||
558 | return; |
||
559 | } |
||
560 | |||
3535 | svoboda | 561 | bs = block_bb_get(dev_handle); |
562 | bps = uint16_t_le2host(bs->bps); |
||
563 | |||
3403 | svoboda | 564 | if (nodep->type == FAT_FILE) { |
565 | /* |
||
566 | * Our strategy for regular file reads is to read one block at |
||
567 | * most and make use of the possibility to return less data than |
||
568 | * requested. This keeps the code very simple. |
||
569 | */ |
||
3535 | svoboda | 570 | if (pos >= nodep->size) { |
571 | /* reading beyond the EOF */ |
||
572 | bytes = 0; |
||
573 | (void) ipc_data_read_finalize(callid, NULL, 0); |
||
574 | } else { |
||
575 | bytes = min(len, bps - pos % bps); |
||
576 | bytes = min(bytes, nodep->size - pos); |
||
577 | b = fat_block_get(bs, nodep, pos / bps); |
||
578 | (void) ipc_data_read_finalize(callid, b->data + pos % bps, |
||
579 | bytes); |
||
580 | block_put(b); |
||
581 | } |
||
3403 | svoboda | 582 | } else { |
583 | unsigned bnum; |
||
584 | off_t spos = pos; |
||
585 | char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1]; |
||
586 | fat_dentry_t *d; |
||
587 | |||
588 | assert(nodep->type == FAT_DIRECTORY); |
||
589 | assert(nodep->size % bps == 0); |
||
590 | assert(bps % sizeof(fat_dentry_t) == 0); |
||
591 | |||
592 | /* |
||
593 | * Our strategy for readdir() is to use the position pointer as |
||
594 | * an index into the array of all dentries. On entry, it points |
||
595 | * to the first unread dentry. If we skip any dentries, we bump |
||
596 | * the position pointer accordingly. |
||
597 | */ |
||
598 | bnum = (pos * sizeof(fat_dentry_t)) / bps; |
||
599 | while (bnum < nodep->size / bps) { |
||
600 | off_t o; |
||
601 | |||
3535 | svoboda | 602 | b = fat_block_get(bs, nodep, bnum); |
3403 | svoboda | 603 | for (o = pos % (bps / sizeof(fat_dentry_t)); |
604 | o < bps / sizeof(fat_dentry_t); |
||
605 | o++, pos++) { |
||
606 | d = ((fat_dentry_t *)b->data) + o; |
||
607 | switch (fat_classify_dentry(d)) { |
||
608 | case FAT_DENTRY_SKIP: |
||
609 | continue; |
||
610 | case FAT_DENTRY_LAST: |
||
611 | block_put(b); |
||
612 | goto miss; |
||
613 | default: |
||
614 | case FAT_DENTRY_VALID: |
||
615 | dentry_name_canonify(d, name); |
||
616 | block_put(b); |
||
617 | goto hit; |
||
618 | } |
||
619 | } |
||
620 | block_put(b); |
||
621 | bnum++; |
||
622 | } |
||
623 | miss: |
||
624 | fat_node_put(nodep); |
||
625 | ipc_answer_0(callid, ENOENT); |
||
626 | ipc_answer_1(rid, ENOENT, 0); |
||
627 | return; |
||
628 | hit: |
||
629 | (void) ipc_data_read_finalize(callid, name, strlen(name) + 1); |
||
630 | bytes = (pos - spos) + 1; |
||
631 | } |
||
632 | |||
633 | fat_node_put(nodep); |
||
634 | ipc_answer_1(rid, EOK, (ipcarg_t)bytes); |
||
635 | } |
||
636 | |||
3535 | svoboda | 637 | void fat_write(ipc_callid_t rid, ipc_call_t *request) |
638 | { |
||
639 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
||
640 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
||
641 | off_t pos = (off_t)IPC_GET_ARG3(*request); |
||
642 | fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
||
643 | fat_bs_t *bs; |
||
644 | size_t bytes; |
||
645 | block_t *b; |
||
646 | uint16_t bps; |
||
647 | unsigned spc; |
||
3588 | svoboda | 648 | unsigned bpc; /* bytes per cluster */ |
3535 | svoboda | 649 | off_t boundary; |
650 | |||
651 | if (!nodep) { |
||
652 | ipc_answer_0(rid, ENOENT); |
||
653 | return; |
||
654 | } |
||
655 | |||
656 | ipc_callid_t callid; |
||
657 | size_t len; |
||
658 | if (!ipc_data_write_receive(&callid, &len)) { |
||
659 | fat_node_put(nodep); |
||
660 | ipc_answer_0(callid, EINVAL); |
||
661 | ipc_answer_0(rid, EINVAL); |
||
662 | return; |
||
663 | } |
||
664 | |||
3588 | svoboda | 665 | bs = block_bb_get(dev_handle); |
666 | bps = uint16_t_le2host(bs->bps); |
||
667 | spc = bs->spc; |
||
668 | bpc = bps * spc; |
||
669 | |||
3535 | svoboda | 670 | /* |
671 | * In all scenarios, we will attempt to write out only one block worth |
||
672 | * of data at maximum. There might be some more efficient approaches, |
||
673 | * but this one greatly simplifies fat_write(). Note that we can afford |
||
674 | * to do this because the client must be ready to handle the return |
||
675 | * value signalizing a smaller number of bytes written. |
||
676 | */ |
||
677 | bytes = min(len, bps - pos % bps); |
||
678 | |||
3588 | svoboda | 679 | boundary = ROUND_UP(nodep->size, bpc); |
3535 | svoboda | 680 | if (pos < boundary) { |
681 | /* |
||
682 | * This is the easier case - we are either overwriting already |
||
683 | * existing contents or writing behind the EOF, but still within |
||
684 | * the limits of the last cluster. The node size may grow to the |
||
685 | * next block size boundary. |
||
686 | */ |
||
687 | fat_fill_gap(bs, nodep, FAT_CLST_RES0, pos); |
||
688 | b = fat_block_get(bs, nodep, pos / bps); |
||
689 | (void) ipc_data_write_finalize(callid, b->data + pos % bps, |
||
690 | bytes); |
||
691 | b->dirty = true; /* need to sync block */ |
||
692 | block_put(b); |
||
693 | if (pos + bytes > nodep->size) { |
||
694 | nodep->size = pos + bytes; |
||
695 | nodep->dirty = true; /* need to sync node */ |
||
696 | } |
||
3588 | svoboda | 697 | ipc_answer_2(rid, EOK, bytes, nodep->size); |
3535 | svoboda | 698 | fat_node_put(nodep); |
699 | return; |
||
700 | } else { |
||
701 | /* |
||
702 | * This is the more difficult case. We must allocate new |
||
703 | * clusters for the node and zero them out. |
||
704 | */ |
||
705 | int status; |
||
706 | unsigned nclsts; |
||
3561 | svoboda | 707 | fat_cluster_t mcl, lcl; |
708 | |||
3588 | svoboda | 709 | nclsts = (ROUND_UP(pos + bytes, bpc) - boundary) / bpc; |
3535 | svoboda | 710 | /* create an independent chain of nclsts clusters in all FATs */ |
3588 | svoboda | 711 | status = fat_alloc_clusters(bs, dev_handle, nclsts, &mcl, &lcl); |
3535 | svoboda | 712 | if (status != EOK) { |
713 | /* could not allocate a chain of nclsts clusters */ |
||
714 | fat_node_put(nodep); |
||
715 | ipc_answer_0(callid, status); |
||
716 | ipc_answer_0(rid, status); |
||
717 | return; |
||
718 | } |
||
719 | /* zero fill any gaps */ |
||
720 | fat_fill_gap(bs, nodep, mcl, pos); |
||
3561 | svoboda | 721 | b = _fat_block_get(bs, dev_handle, lcl, (pos / bps) % spc); |
3535 | svoboda | 722 | (void) ipc_data_write_finalize(callid, b->data + pos % bps, |
723 | bytes); |
||
724 | b->dirty = true; /* need to sync block */ |
||
725 | block_put(b); |
||
726 | /* |
||
727 | * Append the cluster chain starting in mcl to the end of the |
||
728 | * node's cluster chain. |
||
729 | */ |
||
730 | fat_append_clusters(bs, nodep, mcl); |
||
731 | nodep->size = pos + bytes; |
||
732 | nodep->dirty = true; /* need to sync node */ |
||
3588 | svoboda | 733 | ipc_answer_2(rid, EOK, bytes, nodep->size); |
3535 | svoboda | 734 | fat_node_put(nodep); |
735 | return; |
||
736 | } |
||
737 | } |
||
738 | |||
3561 | svoboda | 739 | void fat_truncate(ipc_callid_t rid, ipc_call_t *request) |
740 | { |
||
741 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
||
742 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
||
743 | size_t size = (off_t)IPC_GET_ARG3(*request); |
||
744 | fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
||
3588 | svoboda | 745 | fat_bs_t *bs; |
746 | uint16_t bps; |
||
747 | uint8_t spc; |
||
748 | unsigned bpc; /* bytes per cluster */ |
||
3561 | svoboda | 749 | int rc; |
750 | |||
751 | if (!nodep) { |
||
752 | ipc_answer_0(rid, ENOENT); |
||
753 | return; |
||
754 | } |
||
755 | |||
3588 | svoboda | 756 | bs = block_bb_get(dev_handle); |
757 | bps = uint16_t_le2host(bs->bps); |
||
758 | spc = bs->spc; |
||
759 | bpc = bps * spc; |
||
760 | |||
3561 | svoboda | 761 | if (nodep->size == size) { |
762 | rc = EOK; |
||
763 | } else if (nodep->size < size) { |
||
764 | /* |
||
3588 | svoboda | 765 | * The standard says we have the freedom to grow the node. |
3561 | svoboda | 766 | * For now, we simply return an error. |
767 | */ |
||
768 | rc = EINVAL; |
||
3588 | svoboda | 769 | } else if (ROUND_UP(nodep->size, bpc) == ROUND_UP(size, bpc)) { |
770 | /* |
||
771 | * The node will be shrunk, but no clusters will be deallocated. |
||
772 | */ |
||
773 | nodep->size = size; |
||
774 | nodep->dirty = true; /* need to sync node */ |
||
775 | rc = EOK; |
||
3561 | svoboda | 776 | } else { |
777 | /* |
||
3588 | svoboda | 778 | * The node will be shrunk, clusters will be deallocated. |
3561 | svoboda | 779 | */ |
3588 | svoboda | 780 | if (size == 0) { |
781 | fat_chop_clusters(bs, nodep, FAT_CLST_RES0); |
||
782 | } else { |
||
783 | fat_cluster_t lastc; |
||
784 | (void) fat_cluster_walk(bs, dev_handle, nodep->firstc, |
||
785 | &lastc, (size - 1) / bpc); |
||
786 | fat_chop_clusters(bs, nodep, lastc); |
||
787 | } |
||
788 | nodep->size = size; |
||
789 | nodep->dirty = true; /* need to sync node */ |
||
790 | rc = EOK; |
||
3561 | svoboda | 791 | } |
792 | fat_node_put(nodep); |
||
793 | ipc_answer_0(rid, rc); |
||
794 | return; |
||
795 | } |
||
796 | |||
2627 | jermar | 797 | /** |
798 | * @} |
||
799 | */ |