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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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3505 | jermar | 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> |
3521 | jermar | 43 | #include <libblock.h> |
2627 | jermar | 44 | #include <ipc/ipc.h> |
3257 | jermar | 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> |
3257 | jermar | 55 | #include <sys/mman.h> |
3499 | jermar | 56 | #include <align.h> |
2627 | 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 | |||
2831 | jermar | 64 | static void fat_node_initialize(fat_node_t *node) |
2793 | jermar | 65 | { |
2951 | jermar | 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 | |||
2893 | jermar | 76 | static void fat_node_sync(fat_node_t *node) |
2831 | jermar | 77 | { |
3530 | jermar | 78 | block_t *b; |
79 | fat_bs_t *bs; |
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3519 | jermar | 80 | fat_dentry_t *d; |
81 | uint16_t bps; |
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82 | unsigned dps; |
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83 | |||
84 | assert(node->dirty); |
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85 | |||
3530 | jermar | 86 | bs = block_bb_get(node->idx->dev_handle); |
87 | bps = uint16_t_le2host(bs->bps); |
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3519 | jermar | 88 | dps = bps / sizeof(fat_dentry_t); |
89 | |||
90 | /* Read the block that contains the dentry of interest. */ |
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3530 | jermar | 91 | b = _fat_block_get(bs, node->idx->dev_handle, node->idx->pfc, |
3595 | jermar | 92 | (node->idx->pdi * sizeof(fat_dentry_t)) / bps, BLOCK_FLAGS_NONE); |
3519 | jermar | 93 | |
94 | d = ((fat_dentry_t *)b->data) + (node->idx->pdi % dps); |
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95 | |||
96 | d->firstc = host2uint16_t_le(node->firstc); |
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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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2831 | jermar | 103 | } |
104 | |||
3574 | jermar | 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 | |||
2951 | jermar | 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 | { |
3530 | jermar | 147 | block_t *b; |
148 | fat_bs_t *bs; |
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2891 | jermar | 149 | fat_dentry_t *d; |
3312 | jermar | 150 | fat_node_t *nodep = NULL; |
2891 | jermar | 151 | unsigned bps; |
3550 | jermar | 152 | unsigned spc; |
2891 | jermar | 153 | unsigned dps; |
154 | |||
2951 | jermar | 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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2951 | jermar | 160 | futex_down(&idxp->nodep->lock); |
161 | if (!idxp->nodep->refcnt++) |
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3312 | jermar | 162 | list_remove(&idxp->nodep->ffn_link); |
2951 | jermar | 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 | |||
2951 | jermar | 171 | assert(idxp->pfc); |
2891 | jermar | 172 | |
3574 | jermar | 173 | nodep = fat_node_get_new(); |
174 | if (!nodep) |
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175 | return NULL; |
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2891 | jermar | 176 | |
3530 | jermar | 177 | bs = block_bb_get(idxp->dev_handle); |
178 | bps = uint16_t_le2host(bs->bps); |
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3550 | jermar | 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. */ |
3530 | jermar | 183 | b = _fat_block_get(bs, idxp->dev_handle, idxp->pfc, |
3595 | jermar | 184 | (idxp->pdi * sizeof(fat_dentry_t)) / bps, BLOCK_FLAGS_NONE); |
2891 | jermar | 185 | assert(b); |
186 | |||
2951 | jermar | 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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3282 | jermar | 195 | /* |
3325 | jermar | 196 | * Unfortunately, the 'size' field of the FAT dentry is not |
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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3282 | jermar | 199 | */ |
3550 | jermar | 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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3282 | jermar | 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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2951 | jermar | 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 | |||
2951 | jermar | 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; |
3609 | jermar | 237 | bool destroy = false; |
2910 | jermar | 238 | |
2951 | jermar | 239 | futex_down(&nodep->lock); |
2910 | jermar | 240 | if (!--nodep->refcnt) { |
3609 | jermar | 241 | if (nodep->idx) { |
242 | futex_down(&ffn_futex); |
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243 | list_append(&nodep->ffn_link, &ffn_head); |
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244 | futex_up(&ffn_futex); |
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245 | } else { |
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246 | /* |
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247 | * The node does not have any index structure associated |
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248 | * with itself. This can only mean that we are releasing |
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249 | * the node after a failed attempt to allocate the index |
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250 | * structure for it. |
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251 | */ |
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252 | destroy = true; |
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253 | } |
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2910 | jermar | 254 | } |
2951 | jermar | 255 | futex_up(&nodep->lock); |
3609 | jermar | 256 | if (destroy) |
257 | free(node); |
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2852 | jermar | 258 | } |
259 | |||
3609 | jermar | 260 | static void *fat_create_node(dev_handle_t dev_handle, int flags) |
2857 | jermar | 261 | { |
3609 | jermar | 262 | fat_idx_t *idxp; |
263 | fat_node_t *nodep; |
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264 | |||
265 | nodep = fat_node_get_new(); |
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266 | if (!nodep) |
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267 | return NULL; |
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268 | idxp = fat_idx_get_new(dev_handle); |
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269 | if (!idxp) { |
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270 | fat_node_put(nodep); |
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271 | return NULL; |
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272 | } |
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273 | /* idxp->lock held */ |
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274 | if (flags & L_DIRECTORY) { |
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275 | nodep->type = FAT_DIRECTORY; |
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276 | } else { |
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277 | nodep->type = FAT_FILE; |
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278 | } |
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279 | nodep->size = 0; |
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280 | nodep->firstc = FAT_CLST_RES0; |
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281 | nodep->lnkcnt = 0; /* not linked anywhere */ |
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282 | nodep->refcnt = 1; |
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283 | |||
284 | nodep->idx = idxp; |
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285 | idxp->nodep = nodep; |
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286 | |||
287 | futex_up(&idxp->lock); |
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288 | return nodep; |
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2857 | jermar | 289 | } |
290 | |||
3609 | jermar | 291 | static int fat_destroy_node(void *node) |
2857 | jermar | 292 | { |
2858 | jermar | 293 | return ENOTSUP; /* not supported at the moment */ |
2857 | jermar | 294 | } |
295 | |||
296 | static bool fat_link(void *prnt, void *chld, const char *name) |
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297 | { |
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298 | return false; /* not supported at the moment */ |
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299 | } |
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300 | |||
301 | static int fat_unlink(void *prnt, void *chld) |
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302 | { |
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303 | return ENOTSUP; /* not supported at the moment */ |
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304 | } |
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305 | |||
2793 | jermar | 306 | static void *fat_match(void *prnt, const char *component) |
307 | { |
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3530 | jermar | 308 | fat_bs_t *bs; |
2793 | jermar | 309 | fat_node_t *parentp = (fat_node_t *)prnt; |
310 | char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1]; |
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2822 | jermar | 311 | unsigned i, j; |
2828 | jermar | 312 | unsigned bps; /* bytes per sector */ |
2822 | jermar | 313 | unsigned dps; /* dentries per sector */ |
314 | unsigned blocks; |
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2793 | jermar | 315 | fat_dentry_t *d; |
3530 | jermar | 316 | block_t *b; |
2793 | jermar | 317 | |
2953 | jermar | 318 | futex_down(&parentp->idx->lock); |
3530 | jermar | 319 | bs = block_bb_get(parentp->idx->dev_handle); |
320 | bps = uint16_t_le2host(bs->bps); |
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2828 | jermar | 321 | dps = bps / sizeof(fat_dentry_t); |
3526 | jermar | 322 | blocks = parentp->size / bps; |
2822 | jermar | 323 | for (i = 0; i < blocks; i++) { |
3595 | jermar | 324 | b = fat_block_get(bs, parentp, i, BLOCK_FLAGS_NONE); |
3526 | jermar | 325 | for (j = 0; j < dps; j++) { |
2822 | jermar | 326 | d = ((fat_dentry_t *)b->data) + j; |
2845 | jermar | 327 | switch (fat_classify_dentry(d)) { |
328 | case FAT_DENTRY_SKIP: |
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2822 | jermar | 329 | continue; |
2845 | jermar | 330 | case FAT_DENTRY_LAST: |
2822 | jermar | 331 | block_put(b); |
2953 | jermar | 332 | futex_up(&parentp->idx->lock); |
2822 | jermar | 333 | return NULL; |
2845 | jermar | 334 | default: |
335 | case FAT_DENTRY_VALID: |
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336 | dentry_name_canonify(d, name); |
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337 | break; |
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2822 | jermar | 338 | } |
3272 | jermar | 339 | if (stricmp(name, component) == 0) { |
2822 | jermar | 340 | /* hit */ |
2951 | jermar | 341 | void *node; |
2953 | jermar | 342 | /* |
343 | * Assume tree hierarchy for locking. We |
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344 | * already have the parent and now we are going |
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345 | * to lock the child. Never lock in the oposite |
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346 | * order. |
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347 | */ |
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2890 | jermar | 348 | fat_idx_t *idx = fat_idx_get_by_pos( |
2881 | jermar | 349 | parentp->idx->dev_handle, parentp->firstc, |
2864 | jermar | 350 | i * dps + j); |
2953 | jermar | 351 | futex_up(&parentp->idx->lock); |
2890 | jermar | 352 | if (!idx) { |
353 | /* |
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354 | * Can happen if memory is low or if we |
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355 | * run out of 32-bit indices. |
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356 | */ |
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357 | block_put(b); |
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358 | return NULL; |
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359 | } |
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2951 | jermar | 360 | node = fat_node_get_core(idx); |
361 | futex_up(&idx->lock); |
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2822 | jermar | 362 | block_put(b); |
363 | return node; |
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364 | } |
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2793 | jermar | 365 | } |
2822 | jermar | 366 | block_put(b); |
2639 | jermar | 367 | } |
3516 | jermar | 368 | |
2953 | jermar | 369 | futex_up(&parentp->idx->lock); |
2793 | jermar | 370 | return NULL; |
2638 | jermar | 371 | } |
372 | |||
2831 | jermar | 373 | static fs_index_t fat_index_get(void *node) |
374 | { |
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375 | fat_node_t *fnodep = (fat_node_t *)node; |
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376 | if (!fnodep) |
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377 | return 0; |
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2864 | jermar | 378 | return fnodep->idx->index; |
2831 | jermar | 379 | } |
380 | |||
381 | static size_t fat_size_get(void *node) |
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382 | { |
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383 | return ((fat_node_t *)node)->size; |
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384 | } |
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385 | |||
386 | static unsigned fat_lnkcnt_get(void *node) |
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387 | { |
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388 | return ((fat_node_t *)node)->lnkcnt; |
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389 | } |
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390 | |||
2845 | jermar | 391 | static bool fat_has_children(void *node) |
392 | { |
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3530 | jermar | 393 | fat_bs_t *bs; |
2845 | jermar | 394 | fat_node_t *nodep = (fat_node_t *)node; |
395 | unsigned bps; |
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396 | unsigned dps; |
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397 | unsigned blocks; |
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3530 | jermar | 398 | block_t *b; |
2845 | jermar | 399 | unsigned i, j; |
400 | |||
401 | if (nodep->type != FAT_DIRECTORY) |
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402 | return false; |
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3526 | jermar | 403 | |
2951 | jermar | 404 | futex_down(&nodep->idx->lock); |
3530 | jermar | 405 | bs = block_bb_get(nodep->idx->dev_handle); |
406 | bps = uint16_t_le2host(bs->bps); |
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2845 | jermar | 407 | dps = bps / sizeof(fat_dentry_t); |
408 | |||
3526 | jermar | 409 | blocks = nodep->size / bps; |
2845 | jermar | 410 | |
411 | for (i = 0; i < blocks; i++) { |
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412 | fat_dentry_t *d; |
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413 | |||
3595 | jermar | 414 | b = fat_block_get(bs, nodep, i, BLOCK_FLAGS_NONE); |
3526 | jermar | 415 | for (j = 0; j < dps; j++) { |
2845 | jermar | 416 | d = ((fat_dentry_t *)b->data) + j; |
417 | switch (fat_classify_dentry(d)) { |
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418 | case FAT_DENTRY_SKIP: |
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419 | continue; |
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420 | case FAT_DENTRY_LAST: |
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421 | block_put(b); |
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2951 | jermar | 422 | futex_up(&nodep->idx->lock); |
2845 | jermar | 423 | return false; |
424 | default: |
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425 | case FAT_DENTRY_VALID: |
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426 | block_put(b); |
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2951 | jermar | 427 | futex_up(&nodep->idx->lock); |
2845 | jermar | 428 | return true; |
429 | } |
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430 | block_put(b); |
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2951 | jermar | 431 | futex_up(&nodep->idx->lock); |
2845 | jermar | 432 | return true; |
433 | } |
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434 | block_put(b); |
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435 | } |
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436 | |||
2951 | jermar | 437 | futex_up(&nodep->idx->lock); |
2845 | jermar | 438 | return false; |
439 | } |
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440 | |||
2844 | jermar | 441 | static void *fat_root_get(dev_handle_t dev_handle) |
442 | { |
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3119 | jermar | 443 | return fat_node_get(dev_handle, 0); |
2844 | jermar | 444 | } |
445 | |||
446 | static char fat_plb_get_char(unsigned pos) |
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447 | { |
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448 | return fat_reg.plb_ro[pos % PLB_SIZE]; |
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449 | } |
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450 | |||
2831 | jermar | 451 | static bool fat_is_directory(void *node) |
452 | { |
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453 | return ((fat_node_t *)node)->type == FAT_DIRECTORY; |
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454 | } |
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455 | |||
456 | static bool fat_is_file(void *node) |
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457 | { |
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458 | return ((fat_node_t *)node)->type == FAT_FILE; |
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459 | } |
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460 | |||
2793 | jermar | 461 | /** libfs operations */ |
462 | libfs_ops_t fat_libfs_ops = { |
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463 | .match = fat_match, |
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464 | .node_get = fat_node_get, |
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2852 | jermar | 465 | .node_put = fat_node_put, |
3609 | jermar | 466 | .create = fat_create_node, |
467 | .destroy = fat_destroy_node, |
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2857 | jermar | 468 | .link = fat_link, |
469 | .unlink = fat_unlink, |
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2831 | jermar | 470 | .index_get = fat_index_get, |
471 | .size_get = fat_size_get, |
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472 | .lnkcnt_get = fat_lnkcnt_get, |
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2845 | jermar | 473 | .has_children = fat_has_children, |
2844 | jermar | 474 | .root_get = fat_root_get, |
475 | .plb_get_char = fat_plb_get_char, |
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2831 | jermar | 476 | .is_directory = fat_is_directory, |
477 | .is_file = fat_is_file |
||
2793 | jermar | 478 | }; |
479 | |||
3110 | jermar | 480 | void fat_mounted(ipc_callid_t rid, ipc_call_t *request) |
481 | { |
||
482 | dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request); |
||
3530 | jermar | 483 | fat_bs_t *bs; |
3257 | jermar | 484 | uint16_t bps; |
3119 | jermar | 485 | uint16_t rde; |
3110 | jermar | 486 | int rc; |
487 | |||
3530 | jermar | 488 | /* initialize libblock */ |
3537 | jermar | 489 | rc = block_init(dev_handle, BS_SIZE); |
3257 | jermar | 490 | if (rc != EOK) { |
3537 | jermar | 491 | ipc_answer_0(rid, rc); |
3257 | jermar | 492 | return; |
493 | } |
||
494 | |||
3537 | jermar | 495 | /* prepare the boot block */ |
496 | rc = block_bb_read(dev_handle, BS_BLOCK * BS_SIZE, BS_SIZE); |
||
497 | if (rc != EOK) { |
||
498 | block_fini(dev_handle); |
||
499 | ipc_answer_0(rid, rc); |
||
500 | return; |
||
501 | } |
||
502 | |||
3530 | jermar | 503 | /* get the buffer with the boot sector */ |
504 | bs = block_bb_get(dev_handle); |
||
505 | |||
3119 | jermar | 506 | /* Read the number of root directory entries. */ |
3530 | jermar | 507 | bps = uint16_t_le2host(bs->bps); |
508 | rde = uint16_t_le2host(bs->root_ent_max); |
||
3119 | jermar | 509 | |
3257 | jermar | 510 | if (bps != BS_SIZE) { |
3530 | jermar | 511 | block_fini(dev_handle); |
3257 | jermar | 512 | ipc_answer_0(rid, ENOTSUP); |
513 | return; |
||
514 | } |
||
515 | |||
3539 | jermar | 516 | /* Initialize the block cache */ |
517 | rc = block_cache_init(dev_handle, bps, 0 /* XXX */); |
||
518 | if (rc != EOK) { |
||
519 | block_fini(dev_handle); |
||
520 | ipc_answer_0(rid, rc); |
||
521 | return; |
||
522 | } |
||
523 | |||
3110 | jermar | 524 | rc = fat_idx_init_by_dev_handle(dev_handle); |
525 | if (rc != EOK) { |
||
3530 | jermar | 526 | block_fini(dev_handle); |
3110 | jermar | 527 | ipc_answer_0(rid, rc); |
528 | return; |
||
529 | } |
||
530 | |||
3119 | jermar | 531 | /* Initialize the root node. */ |
532 | fat_node_t *rootp = (fat_node_t *)malloc(sizeof(fat_node_t)); |
||
533 | if (!rootp) { |
||
3530 | jermar | 534 | block_fini(dev_handle); |
3119 | jermar | 535 | fat_idx_fini_by_dev_handle(dev_handle); |
536 | ipc_answer_0(rid, ENOMEM); |
||
537 | return; |
||
538 | } |
||
539 | fat_node_initialize(rootp); |
||
540 | |||
541 | fat_idx_t *ridxp = fat_idx_get_by_pos(dev_handle, FAT_CLST_ROOTPAR, 0); |
||
542 | if (!ridxp) { |
||
3530 | jermar | 543 | block_fini(dev_handle); |
3119 | jermar | 544 | free(rootp); |
545 | fat_idx_fini_by_dev_handle(dev_handle); |
||
546 | ipc_answer_0(rid, ENOMEM); |
||
547 | return; |
||
548 | } |
||
549 | assert(ridxp->index == 0); |
||
550 | /* ridxp->lock held */ |
||
551 | |||
552 | rootp->type = FAT_DIRECTORY; |
||
553 | rootp->firstc = FAT_CLST_ROOT; |
||
554 | rootp->refcnt = 1; |
||
3352 | jermar | 555 | rootp->lnkcnt = 0; /* FS root is not linked */ |
3119 | jermar | 556 | rootp->size = rde * sizeof(fat_dentry_t); |
557 | rootp->idx = ridxp; |
||
558 | ridxp->nodep = rootp; |
||
559 | |||
560 | futex_up(&ridxp->lock); |
||
561 | |||
3352 | jermar | 562 | ipc_answer_3(rid, EOK, ridxp->index, rootp->size, rootp->lnkcnt); |
3110 | jermar | 563 | } |
564 | |||
565 | void fat_mount(ipc_callid_t rid, ipc_call_t *request) |
||
566 | { |
||
567 | ipc_answer_0(rid, ENOTSUP); |
||
568 | } |
||
569 | |||
2627 | jermar | 570 | void fat_lookup(ipc_callid_t rid, ipc_call_t *request) |
571 | { |
||
2793 | jermar | 572 | libfs_lookup(&fat_libfs_ops, fat_reg.fs_handle, rid, request); |
2627 | jermar | 573 | } |
574 | |||
3307 | jermar | 575 | void fat_read(ipc_callid_t rid, ipc_call_t *request) |
576 | { |
||
577 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
||
578 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
||
579 | off_t pos = (off_t)IPC_GET_ARG3(*request); |
||
580 | fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
||
3530 | jermar | 581 | fat_bs_t *bs; |
3516 | jermar | 582 | uint16_t bps; |
3308 | jermar | 583 | size_t bytes; |
3530 | jermar | 584 | block_t *b; |
3308 | jermar | 585 | |
3307 | jermar | 586 | if (!nodep) { |
587 | ipc_answer_0(rid, ENOENT); |
||
588 | return; |
||
589 | } |
||
590 | |||
591 | ipc_callid_t callid; |
||
592 | size_t len; |
||
3314 | jermar | 593 | if (!ipc_data_read_receive(&callid, &len)) { |
3307 | jermar | 594 | fat_node_put(nodep); |
595 | ipc_answer_0(callid, EINVAL); |
||
596 | ipc_answer_0(rid, EINVAL); |
||
597 | return; |
||
598 | } |
||
599 | |||
3530 | jermar | 600 | bs = block_bb_get(dev_handle); |
601 | bps = uint16_t_le2host(bs->bps); |
||
3516 | jermar | 602 | |
3307 | jermar | 603 | if (nodep->type == FAT_FILE) { |
3335 | jermar | 604 | /* |
605 | * Our strategy for regular file reads is to read one block at |
||
606 | * most and make use of the possibility to return less data than |
||
607 | * requested. This keeps the code very simple. |
||
608 | */ |
||
3532 | jermar | 609 | if (pos >= nodep->size) { |
3533 | jermar | 610 | /* reading beyond the EOF */ |
611 | bytes = 0; |
||
3532 | jermar | 612 | (void) ipc_data_read_finalize(callid, NULL, 0); |
613 | } else { |
||
614 | bytes = min(len, bps - pos % bps); |
||
615 | bytes = min(bytes, nodep->size - pos); |
||
3595 | jermar | 616 | b = fat_block_get(bs, nodep, pos / bps, |
617 | BLOCK_FLAGS_NONE); |
||
3532 | jermar | 618 | (void) ipc_data_read_finalize(callid, b->data + pos % bps, |
619 | bytes); |
||
620 | block_put(b); |
||
621 | } |
||
3307 | jermar | 622 | } else { |
3335 | jermar | 623 | unsigned bnum; |
624 | off_t spos = pos; |
||
625 | char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1]; |
||
626 | fat_dentry_t *d; |
||
627 | |||
3307 | jermar | 628 | assert(nodep->type == FAT_DIRECTORY); |
3335 | jermar | 629 | assert(nodep->size % bps == 0); |
630 | assert(bps % sizeof(fat_dentry_t) == 0); |
||
631 | |||
632 | /* |
||
633 | * Our strategy for readdir() is to use the position pointer as |
||
634 | * an index into the array of all dentries. On entry, it points |
||
635 | * to the first unread dentry. If we skip any dentries, we bump |
||
636 | * the position pointer accordingly. |
||
637 | */ |
||
638 | bnum = (pos * sizeof(fat_dentry_t)) / bps; |
||
639 | while (bnum < nodep->size / bps) { |
||
640 | off_t o; |
||
641 | |||
3595 | jermar | 642 | b = fat_block_get(bs, nodep, bnum, BLOCK_FLAGS_NONE); |
3335 | jermar | 643 | for (o = pos % (bps / sizeof(fat_dentry_t)); |
644 | o < bps / sizeof(fat_dentry_t); |
||
645 | o++, pos++) { |
||
646 | d = ((fat_dentry_t *)b->data) + o; |
||
647 | switch (fat_classify_dentry(d)) { |
||
648 | case FAT_DENTRY_SKIP: |
||
649 | continue; |
||
650 | case FAT_DENTRY_LAST: |
||
651 | block_put(b); |
||
652 | goto miss; |
||
653 | default: |
||
654 | case FAT_DENTRY_VALID: |
||
655 | dentry_name_canonify(d, name); |
||
656 | block_put(b); |
||
657 | goto hit; |
||
658 | } |
||
659 | } |
||
660 | block_put(b); |
||
661 | bnum++; |
||
662 | } |
||
663 | miss: |
||
3307 | jermar | 664 | fat_node_put(nodep); |
3335 | jermar | 665 | ipc_answer_0(callid, ENOENT); |
666 | ipc_answer_1(rid, ENOENT, 0); |
||
3307 | jermar | 667 | return; |
3335 | jermar | 668 | hit: |
669 | (void) ipc_data_read_finalize(callid, name, strlen(name) + 1); |
||
670 | bytes = (pos - spos) + 1; |
||
3307 | jermar | 671 | } |
672 | |||
673 | fat_node_put(nodep); |
||
3308 | jermar | 674 | ipc_answer_1(rid, EOK, (ipcarg_t)bytes); |
3307 | jermar | 675 | } |
676 | |||
3497 | jermar | 677 | void fat_write(ipc_callid_t rid, ipc_call_t *request) |
678 | { |
||
3499 | jermar | 679 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
680 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
||
681 | off_t pos = (off_t)IPC_GET_ARG3(*request); |
||
682 | fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
||
3530 | jermar | 683 | fat_bs_t *bs; |
3499 | jermar | 684 | size_t bytes; |
3530 | jermar | 685 | block_t *b; |
3499 | jermar | 686 | uint16_t bps; |
687 | unsigned spc; |
||
3572 | jermar | 688 | unsigned bpc; /* bytes per cluster */ |
3501 | jermar | 689 | off_t boundary; |
3595 | jermar | 690 | int flags = BLOCK_FLAGS_NONE; |
3499 | jermar | 691 | |
692 | if (!nodep) { |
||
693 | ipc_answer_0(rid, ENOENT); |
||
694 | return; |
||
695 | } |
||
696 | |||
697 | ipc_callid_t callid; |
||
698 | size_t len; |
||
699 | if (!ipc_data_write_receive(&callid, &len)) { |
||
700 | fat_node_put(nodep); |
||
701 | ipc_answer_0(callid, EINVAL); |
||
702 | ipc_answer_0(rid, EINVAL); |
||
703 | return; |
||
704 | } |
||
705 | |||
3572 | jermar | 706 | bs = block_bb_get(dev_handle); |
707 | bps = uint16_t_le2host(bs->bps); |
||
708 | spc = bs->spc; |
||
709 | bpc = bps * spc; |
||
710 | |||
3499 | jermar | 711 | /* |
712 | * In all scenarios, we will attempt to write out only one block worth |
||
713 | * of data at maximum. There might be some more efficient approaches, |
||
714 | * but this one greatly simplifies fat_write(). Note that we can afford |
||
715 | * to do this because the client must be ready to handle the return |
||
716 | * value signalizing a smaller number of bytes written. |
||
717 | */ |
||
718 | bytes = min(len, bps - pos % bps); |
||
3595 | jermar | 719 | if (bytes == bps) |
720 | flags |= BLOCK_FLAGS_NOREAD; |
||
3499 | jermar | 721 | |
3572 | jermar | 722 | boundary = ROUND_UP(nodep->size, bpc); |
3501 | jermar | 723 | if (pos < boundary) { |
3499 | jermar | 724 | /* |
725 | * This is the easier case - we are either overwriting already |
||
726 | * existing contents or writing behind the EOF, but still within |
||
727 | * the limits of the last cluster. The node size may grow to the |
||
728 | * next block size boundary. |
||
729 | */ |
||
3530 | jermar | 730 | fat_fill_gap(bs, nodep, FAT_CLST_RES0, pos); |
3595 | jermar | 731 | b = fat_block_get(bs, nodep, pos / bps, flags); |
3499 | jermar | 732 | (void) ipc_data_write_finalize(callid, b->data + pos % bps, |
733 | bytes); |
||
734 | b->dirty = true; /* need to sync block */ |
||
3500 | jermar | 735 | block_put(b); |
3499 | jermar | 736 | if (pos + bytes > nodep->size) { |
737 | nodep->size = pos + bytes; |
||
738 | nodep->dirty = true; /* need to sync node */ |
||
739 | } |
||
3573 | jermar | 740 | ipc_answer_2(rid, EOK, bytes, nodep->size); |
3499 | jermar | 741 | fat_node_put(nodep); |
742 | return; |
||
743 | } else { |
||
744 | /* |
||
745 | * This is the more difficult case. We must allocate new |
||
746 | * clusters for the node and zero them out. |
||
747 | */ |
||
3500 | jermar | 748 | int status; |
3499 | jermar | 749 | unsigned nclsts; |
3548 | jermar | 750 | fat_cluster_t mcl, lcl; |
751 | |||
3572 | jermar | 752 | nclsts = (ROUND_UP(pos + bytes, bpc) - boundary) / bpc; |
3500 | jermar | 753 | /* create an independent chain of nclsts clusters in all FATs */ |
3572 | jermar | 754 | status = fat_alloc_clusters(bs, dev_handle, nclsts, &mcl, &lcl); |
3500 | jermar | 755 | if (status != EOK) { |
756 | /* could not allocate a chain of nclsts clusters */ |
||
757 | fat_node_put(nodep); |
||
758 | ipc_answer_0(callid, status); |
||
759 | ipc_answer_0(rid, status); |
||
760 | return; |
||
761 | } |
||
762 | /* zero fill any gaps */ |
||
3530 | jermar | 763 | fat_fill_gap(bs, nodep, mcl, pos); |
3595 | jermar | 764 | b = _fat_block_get(bs, dev_handle, lcl, (pos / bps) % spc, |
765 | flags); |
||
3500 | jermar | 766 | (void) ipc_data_write_finalize(callid, b->data + pos % bps, |
767 | bytes); |
||
3501 | jermar | 768 | b->dirty = true; /* need to sync block */ |
3500 | jermar | 769 | block_put(b); |
770 | /* |
||
771 | * Append the cluster chain starting in mcl to the end of the |
||
772 | * node's cluster chain. |
||
773 | */ |
||
3530 | jermar | 774 | fat_append_clusters(bs, nodep, mcl); |
3500 | jermar | 775 | nodep->size = pos + bytes; |
3501 | jermar | 776 | nodep->dirty = true; /* need to sync node */ |
3573 | jermar | 777 | ipc_answer_2(rid, EOK, bytes, nodep->size); |
3500 | jermar | 778 | fat_node_put(nodep); |
779 | return; |
||
3499 | jermar | 780 | } |
3497 | jermar | 781 | } |
782 | |||
3546 | jermar | 783 | void fat_truncate(ipc_callid_t rid, ipc_call_t *request) |
784 | { |
||
3548 | jermar | 785 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
786 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
||
787 | size_t size = (off_t)IPC_GET_ARG3(*request); |
||
788 | fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
||
3572 | jermar | 789 | fat_bs_t *bs; |
790 | uint16_t bps; |
||
791 | uint8_t spc; |
||
792 | unsigned bpc; /* bytes per cluster */ |
||
3548 | jermar | 793 | int rc; |
794 | |||
795 | if (!nodep) { |
||
796 | ipc_answer_0(rid, ENOENT); |
||
797 | return; |
||
798 | } |
||
799 | |||
3572 | jermar | 800 | bs = block_bb_get(dev_handle); |
801 | bps = uint16_t_le2host(bs->bps); |
||
802 | spc = bs->spc; |
||
803 | bpc = bps * spc; |
||
804 | |||
3548 | jermar | 805 | if (nodep->size == size) { |
806 | rc = EOK; |
||
807 | } else if (nodep->size < size) { |
||
808 | /* |
||
3572 | jermar | 809 | * The standard says we have the freedom to grow the node. |
3548 | jermar | 810 | * For now, we simply return an error. |
811 | */ |
||
812 | rc = EINVAL; |
||
3572 | jermar | 813 | } else if (ROUND_UP(nodep->size, bpc) == ROUND_UP(size, bpc)) { |
814 | /* |
||
815 | * The node will be shrunk, but no clusters will be deallocated. |
||
816 | */ |
||
817 | nodep->size = size; |
||
818 | nodep->dirty = true; /* need to sync node */ |
||
819 | rc = EOK; |
||
3548 | jermar | 820 | } else { |
821 | /* |
||
3572 | jermar | 822 | * The node will be shrunk, clusters will be deallocated. |
3548 | jermar | 823 | */ |
3572 | jermar | 824 | if (size == 0) { |
825 | fat_chop_clusters(bs, nodep, FAT_CLST_RES0); |
||
826 | } else { |
||
827 | fat_cluster_t lastc; |
||
828 | (void) fat_cluster_walk(bs, dev_handle, nodep->firstc, |
||
829 | &lastc, (size - 1) / bpc); |
||
830 | fat_chop_clusters(bs, nodep, lastc); |
||
831 | } |
||
832 | nodep->size = size; |
||
833 | nodep->dirty = true; /* need to sync node */ |
||
834 | rc = EOK; |
||
3548 | jermar | 835 | } |
836 | fat_node_put(nodep); |
||
837 | ipc_answer_0(rid, rc); |
||
838 | return; |
||
3546 | jermar | 839 | } |
840 | |||
2627 | jermar | 841 | /** |
842 | * @} |
||
843 | */ |