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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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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> |
2627 | jermar | 43 | #include <ipc/ipc.h> |
3257 | jermar | 44 | #include <ipc/services.h> |
45 | #include <ipc/devmap.h> |
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2627 | jermar | 46 | #include <async.h> |
47 | #include <errno.h> |
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2793 | jermar | 48 | #include <string.h> |
2798 | jermar | 49 | #include <byteorder.h> |
2831 | jermar | 50 | #include <libadt/hash_table.h> |
51 | #include <libadt/list.h> |
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52 | #include <assert.h> |
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2856 | jermar | 53 | #include <futex.h> |
3257 | jermar | 54 | #include <sys/mman.h> |
3499 | jermar | 55 | #include <align.h> |
2627 | jermar | 56 | |
2951 | jermar | 57 | /** Futex protecting the list of cached free FAT nodes. */ |
58 | static futex_t ffn_futex = FUTEX_INITIALIZER; |
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2843 | jermar | 59 | |
2951 | jermar | 60 | /** List of cached free FAT nodes. */ |
61 | static LIST_INITIALIZE(ffn_head); |
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62 | |||
3257 | jermar | 63 | static int dev_phone = -1; /* FIXME */ |
64 | static void *dev_buffer = NULL; /* FIXME */ |
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65 | |||
3506 | jermar | 66 | block_t *block_get(dev_handle_t dev_handle, off_t offset, size_t bs) |
2793 | jermar | 67 | { |
3257 | jermar | 68 | /* FIXME */ |
69 | block_t *b; |
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70 | off_t bufpos = 0; |
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71 | size_t buflen = 0; |
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3272 | jermar | 72 | off_t pos = offset * bs; |
3257 | jermar | 73 | |
74 | assert(dev_phone != -1); |
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75 | assert(dev_buffer); |
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76 | |||
77 | b = malloc(sizeof(block_t)); |
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78 | if (!b) |
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79 | return NULL; |
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80 | |||
81 | b->data = malloc(bs); |
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82 | if (!b->data) { |
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83 | free(b); |
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84 | return NULL; |
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85 | } |
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86 | b->size = bs; |
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87 | |||
3272 | jermar | 88 | if (!libfs_blockread(dev_phone, dev_buffer, &bufpos, &buflen, &pos, |
3257 | jermar | 89 | b->data, bs, bs)) { |
90 | free(b->data); |
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91 | free(b); |
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92 | return NULL; |
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93 | } |
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94 | |||
95 | return b; |
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2793 | jermar | 96 | } |
97 | |||
3506 | jermar | 98 | void block_put(block_t *block) |
2793 | jermar | 99 | { |
3257 | jermar | 100 | /* FIXME */ |
101 | free(block->data); |
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102 | free(block); |
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2793 | jermar | 103 | } |
104 | |||
2831 | jermar | 105 | static void fat_node_initialize(fat_node_t *node) |
2793 | jermar | 106 | { |
2951 | jermar | 107 | futex_initialize(&node->lock, 1); |
2864 | jermar | 108 | node->idx = NULL; |
2831 | jermar | 109 | node->type = 0; |
110 | link_initialize(&node->ffn_link); |
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111 | node->size = 0; |
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112 | node->lnkcnt = 0; |
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113 | node->refcnt = 0; |
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114 | node->dirty = false; |
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2793 | jermar | 115 | } |
116 | |||
2893 | jermar | 117 | static void fat_node_sync(fat_node_t *node) |
2831 | jermar | 118 | { |
119 | /* TODO */ |
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120 | } |
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121 | |||
2951 | jermar | 122 | /** Internal version of fat_node_get(). |
123 | * |
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124 | * @param idxp Locked index structure. |
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125 | */ |
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126 | static void *fat_node_get_core(fat_idx_t *idxp) |
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2831 | jermar | 127 | { |
2891 | jermar | 128 | block_t *b; |
129 | fat_dentry_t *d; |
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3312 | jermar | 130 | fat_node_t *nodep = NULL; |
2891 | jermar | 131 | unsigned bps; |
132 | unsigned dps; |
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133 | |||
2951 | jermar | 134 | if (idxp->nodep) { |
2891 | jermar | 135 | /* |
136 | * We are lucky. |
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137 | * The node is already instantiated in memory. |
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138 | */ |
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2951 | jermar | 139 | futex_down(&idxp->nodep->lock); |
140 | if (!idxp->nodep->refcnt++) |
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3312 | jermar | 141 | list_remove(&idxp->nodep->ffn_link); |
2951 | jermar | 142 | futex_up(&idxp->nodep->lock); |
143 | return idxp->nodep; |
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2891 | jermar | 144 | } |
145 | |||
146 | /* |
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147 | * We must instantiate the node from the file system. |
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148 | */ |
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149 | |||
2951 | jermar | 150 | assert(idxp->pfc); |
2891 | jermar | 151 | |
2951 | jermar | 152 | futex_down(&ffn_futex); |
2893 | jermar | 153 | if (!list_empty(&ffn_head)) { |
2951 | jermar | 154 | /* Try to use a cached free node structure. */ |
155 | fat_idx_t *idxp_tmp; |
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2893 | jermar | 156 | nodep = list_get_instance(ffn_head.next, fat_node_t, ffn_link); |
2951 | jermar | 157 | if (futex_trydown(&nodep->lock) == ESYNCH_WOULD_BLOCK) |
158 | goto skip_cache; |
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159 | idxp_tmp = nodep->idx; |
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160 | if (futex_trydown(&idxp_tmp->lock) == ESYNCH_WOULD_BLOCK) { |
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161 | futex_up(&nodep->lock); |
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162 | goto skip_cache; |
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163 | } |
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164 | list_remove(&nodep->ffn_link); |
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165 | futex_up(&ffn_futex); |
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2893 | jermar | 166 | if (nodep->dirty) |
167 | fat_node_sync(nodep); |
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2951 | jermar | 168 | idxp_tmp->nodep = NULL; |
169 | futex_up(&nodep->lock); |
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170 | futex_up(&idxp_tmp->lock); |
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2893 | jermar | 171 | } else { |
2951 | jermar | 172 | skip_cache: |
2893 | jermar | 173 | /* Try to allocate a new node structure. */ |
2951 | jermar | 174 | futex_up(&ffn_futex); |
2893 | jermar | 175 | nodep = (fat_node_t *)malloc(sizeof(fat_node_t)); |
176 | if (!nodep) |
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177 | return NULL; |
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178 | } |
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2891 | jermar | 179 | fat_node_initialize(nodep); |
180 | |||
2951 | jermar | 181 | bps = fat_bps_get(idxp->dev_handle); |
2891 | jermar | 182 | dps = bps / sizeof(fat_dentry_t); |
183 | |||
2893 | jermar | 184 | /* Read the block that contains the dentry of interest. */ |
2951 | jermar | 185 | b = _fat_block_get(idxp->dev_handle, idxp->pfc, |
186 | (idxp->pdi * sizeof(fat_dentry_t)) / bps); |
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2891 | jermar | 187 | assert(b); |
188 | |||
2951 | jermar | 189 | d = ((fat_dentry_t *)b->data) + (idxp->pdi % dps); |
2893 | jermar | 190 | if (d->attr & FAT_ATTR_SUBDIR) { |
191 | /* |
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192 | * The only directory which does not have this bit set is the |
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193 | * root directory itself. The root directory node is handled |
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194 | * and initialized elsewhere. |
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195 | */ |
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196 | nodep->type = FAT_DIRECTORY; |
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3282 | jermar | 197 | /* |
3325 | jermar | 198 | * Unfortunately, the 'size' field of the FAT dentry is not |
199 | * defined for the directory entry type. We must determine the |
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200 | * size of the directory by walking the FAT. |
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3282 | jermar | 201 | */ |
3325 | jermar | 202 | nodep->size = bps * _fat_blcks_get(idxp->dev_handle, |
3513 | jermar | 203 | uint16_t_le2host(d->firstc), NULL); |
2893 | jermar | 204 | } else { |
205 | nodep->type = FAT_FILE; |
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3282 | jermar | 206 | nodep->size = uint32_t_le2host(d->size); |
2893 | jermar | 207 | } |
208 | nodep->firstc = uint16_t_le2host(d->firstc); |
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209 | nodep->lnkcnt = 1; |
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210 | nodep->refcnt = 1; |
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211 | |||
212 | block_put(b); |
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213 | |||
214 | /* Link the idx structure with the node structure. */ |
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2951 | jermar | 215 | nodep->idx = idxp; |
216 | idxp->nodep = nodep; |
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2893 | jermar | 217 | |
218 | return nodep; |
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2831 | jermar | 219 | } |
220 | |||
2951 | jermar | 221 | /** Instantiate a FAT in-core node. */ |
222 | static void *fat_node_get(dev_handle_t dev_handle, fs_index_t index) |
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223 | { |
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224 | void *node; |
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225 | fat_idx_t *idxp; |
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226 | |||
227 | idxp = fat_idx_get_by_index(dev_handle, index); |
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228 | if (!idxp) |
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229 | return NULL; |
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230 | /* idxp->lock held */ |
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231 | node = fat_node_get_core(idxp); |
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232 | futex_up(&idxp->lock); |
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233 | return node; |
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234 | } |
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235 | |||
2852 | jermar | 236 | static void fat_node_put(void *node) |
237 | { |
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2910 | jermar | 238 | fat_node_t *nodep = (fat_node_t *)node; |
239 | |||
2951 | jermar | 240 | futex_down(&nodep->lock); |
2910 | jermar | 241 | if (!--nodep->refcnt) { |
2951 | jermar | 242 | futex_down(&ffn_futex); |
2910 | jermar | 243 | list_append(&nodep->ffn_link, &ffn_head); |
2951 | jermar | 244 | futex_up(&ffn_futex); |
2910 | jermar | 245 | } |
2951 | jermar | 246 | futex_up(&nodep->lock); |
2852 | jermar | 247 | } |
248 | |||
2857 | jermar | 249 | static void *fat_create(int flags) |
250 | { |
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251 | return NULL; /* not supported at the moment */ |
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252 | } |
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253 | |||
2858 | jermar | 254 | static int fat_destroy(void *node) |
2857 | jermar | 255 | { |
2858 | jermar | 256 | return ENOTSUP; /* not supported at the moment */ |
2857 | jermar | 257 | } |
258 | |||
259 | static bool fat_link(void *prnt, void *chld, const char *name) |
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260 | { |
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261 | return false; /* not supported at the moment */ |
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262 | } |
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263 | |||
264 | static int fat_unlink(void *prnt, void *chld) |
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265 | { |
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266 | return ENOTSUP; /* not supported at the moment */ |
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267 | } |
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268 | |||
2793 | jermar | 269 | static void *fat_match(void *prnt, const char *component) |
270 | { |
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271 | fat_node_t *parentp = (fat_node_t *)prnt; |
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272 | char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1]; |
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2822 | jermar | 273 | unsigned i, j; |
2828 | jermar | 274 | unsigned bps; /* bytes per sector */ |
2822 | jermar | 275 | unsigned dps; /* dentries per sector */ |
276 | unsigned blocks; |
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2793 | jermar | 277 | fat_dentry_t *d; |
2822 | jermar | 278 | block_t *b; |
2793 | jermar | 279 | |
2953 | jermar | 280 | futex_down(&parentp->idx->lock); |
2864 | jermar | 281 | bps = fat_bps_get(parentp->idx->dev_handle); |
2828 | jermar | 282 | dps = bps / sizeof(fat_dentry_t); |
283 | blocks = parentp->size / bps + (parentp->size % bps != 0); |
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2822 | jermar | 284 | for (i = 0; i < blocks; i++) { |
285 | unsigned dentries; |
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2793 | jermar | 286 | |
2864 | jermar | 287 | b = fat_block_get(parentp, i); |
2822 | jermar | 288 | dentries = (i == blocks - 1) ? |
289 | parentp->size % sizeof(fat_dentry_t) : |
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290 | dps; |
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291 | for (j = 0; j < dentries; j++) { |
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292 | d = ((fat_dentry_t *)b->data) + j; |
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2845 | jermar | 293 | switch (fat_classify_dentry(d)) { |
294 | case FAT_DENTRY_SKIP: |
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2822 | jermar | 295 | continue; |
2845 | jermar | 296 | case FAT_DENTRY_LAST: |
2822 | jermar | 297 | block_put(b); |
2953 | jermar | 298 | futex_up(&parentp->idx->lock); |
2822 | jermar | 299 | return NULL; |
2845 | jermar | 300 | default: |
301 | case FAT_DENTRY_VALID: |
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302 | dentry_name_canonify(d, name); |
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303 | break; |
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2822 | jermar | 304 | } |
3272 | jermar | 305 | if (stricmp(name, component) == 0) { |
2822 | jermar | 306 | /* hit */ |
2951 | jermar | 307 | void *node; |
2953 | jermar | 308 | /* |
309 | * Assume tree hierarchy for locking. We |
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310 | * already have the parent and now we are going |
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311 | * to lock the child. Never lock in the oposite |
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312 | * order. |
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313 | */ |
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2890 | jermar | 314 | fat_idx_t *idx = fat_idx_get_by_pos( |
2881 | jermar | 315 | parentp->idx->dev_handle, parentp->firstc, |
2864 | jermar | 316 | i * dps + j); |
2953 | jermar | 317 | futex_up(&parentp->idx->lock); |
2890 | jermar | 318 | if (!idx) { |
319 | /* |
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320 | * Can happen if memory is low or if we |
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321 | * run out of 32-bit indices. |
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322 | */ |
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323 | block_put(b); |
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324 | return NULL; |
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325 | } |
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2951 | jermar | 326 | node = fat_node_get_core(idx); |
327 | futex_up(&idx->lock); |
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2822 | jermar | 328 | block_put(b); |
329 | return node; |
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330 | } |
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2793 | jermar | 331 | } |
2822 | jermar | 332 | block_put(b); |
2639 | jermar | 333 | } |
2953 | jermar | 334 | futex_up(&parentp->idx->lock); |
2793 | jermar | 335 | return NULL; |
2638 | jermar | 336 | } |
337 | |||
2831 | jermar | 338 | static fs_index_t fat_index_get(void *node) |
339 | { |
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340 | fat_node_t *fnodep = (fat_node_t *)node; |
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341 | if (!fnodep) |
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342 | return 0; |
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2864 | jermar | 343 | return fnodep->idx->index; |
2831 | jermar | 344 | } |
345 | |||
346 | static size_t fat_size_get(void *node) |
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347 | { |
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348 | return ((fat_node_t *)node)->size; |
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349 | } |
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350 | |||
351 | static unsigned fat_lnkcnt_get(void *node) |
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352 | { |
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353 | return ((fat_node_t *)node)->lnkcnt; |
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354 | } |
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355 | |||
2845 | jermar | 356 | static bool fat_has_children(void *node) |
357 | { |
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358 | fat_node_t *nodep = (fat_node_t *)node; |
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359 | unsigned bps; |
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360 | unsigned dps; |
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361 | unsigned blocks; |
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362 | block_t *b; |
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363 | unsigned i, j; |
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364 | |||
365 | if (nodep->type != FAT_DIRECTORY) |
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366 | return false; |
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367 | |||
2951 | jermar | 368 | futex_down(&nodep->idx->lock); |
2864 | jermar | 369 | bps = fat_bps_get(nodep->idx->dev_handle); |
2845 | jermar | 370 | dps = bps / sizeof(fat_dentry_t); |
371 | |||
372 | blocks = nodep->size / bps + (nodep->size % bps != 0); |
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373 | |||
374 | for (i = 0; i < blocks; i++) { |
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375 | unsigned dentries; |
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376 | fat_dentry_t *d; |
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377 | |||
2864 | jermar | 378 | b = fat_block_get(nodep, i); |
2845 | jermar | 379 | dentries = (i == blocks - 1) ? |
380 | nodep->size % sizeof(fat_dentry_t) : |
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381 | dps; |
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382 | for (j = 0; j < dentries; j++) { |
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383 | d = ((fat_dentry_t *)b->data) + j; |
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384 | switch (fat_classify_dentry(d)) { |
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385 | case FAT_DENTRY_SKIP: |
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386 | continue; |
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387 | case FAT_DENTRY_LAST: |
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388 | block_put(b); |
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2951 | jermar | 389 | futex_up(&nodep->idx->lock); |
2845 | jermar | 390 | return false; |
391 | default: |
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392 | case FAT_DENTRY_VALID: |
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393 | block_put(b); |
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2951 | jermar | 394 | futex_up(&nodep->idx->lock); |
2845 | jermar | 395 | return true; |
396 | } |
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397 | block_put(b); |
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2951 | jermar | 398 | futex_up(&nodep->idx->lock); |
2845 | jermar | 399 | return true; |
400 | } |
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401 | block_put(b); |
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402 | } |
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403 | |||
2951 | jermar | 404 | futex_up(&nodep->idx->lock); |
2845 | jermar | 405 | return false; |
406 | } |
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407 | |||
2844 | jermar | 408 | static void *fat_root_get(dev_handle_t dev_handle) |
409 | { |
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3119 | jermar | 410 | return fat_node_get(dev_handle, 0); |
2844 | jermar | 411 | } |
412 | |||
413 | static char fat_plb_get_char(unsigned pos) |
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414 | { |
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415 | return fat_reg.plb_ro[pos % PLB_SIZE]; |
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416 | } |
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417 | |||
2831 | jermar | 418 | static bool fat_is_directory(void *node) |
419 | { |
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420 | return ((fat_node_t *)node)->type == FAT_DIRECTORY; |
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421 | } |
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422 | |||
423 | static bool fat_is_file(void *node) |
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424 | { |
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425 | return ((fat_node_t *)node)->type == FAT_FILE; |
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426 | } |
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427 | |||
2793 | jermar | 428 | /** libfs operations */ |
429 | libfs_ops_t fat_libfs_ops = { |
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430 | .match = fat_match, |
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431 | .node_get = fat_node_get, |
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2852 | jermar | 432 | .node_put = fat_node_put, |
2857 | jermar | 433 | .create = fat_create, |
434 | .destroy = fat_destroy, |
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435 | .link = fat_link, |
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436 | .unlink = fat_unlink, |
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2831 | jermar | 437 | .index_get = fat_index_get, |
438 | .size_get = fat_size_get, |
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439 | .lnkcnt_get = fat_lnkcnt_get, |
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2845 | jermar | 440 | .has_children = fat_has_children, |
2844 | jermar | 441 | .root_get = fat_root_get, |
442 | .plb_get_char = fat_plb_get_char, |
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2831 | jermar | 443 | .is_directory = fat_is_directory, |
444 | .is_file = fat_is_file |
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2793 | jermar | 445 | }; |
446 | |||
3110 | jermar | 447 | void fat_mounted(ipc_callid_t rid, ipc_call_t *request) |
448 | { |
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449 | dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request); |
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3119 | jermar | 450 | block_t *bb; |
3257 | jermar | 451 | uint16_t bps; |
3119 | jermar | 452 | uint16_t rde; |
3110 | jermar | 453 | int rc; |
454 | |||
3257 | jermar | 455 | /* |
456 | * For now, we don't bother to remember dev_handle, dev_phone or |
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457 | * dev_buffer in some data structure. We use global variables because we |
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458 | * know there will be at most one mount on this file system. |
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459 | * Of course, this is a huge TODO item. |
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460 | */ |
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461 | dev_buffer = mmap(NULL, BS_SIZE, PROTO_READ | PROTO_WRITE, |
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462 | MAP_ANONYMOUS | MAP_PRIVATE, 0, 0); |
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463 | |||
464 | if (!dev_buffer) { |
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465 | ipc_answer_0(rid, ENOMEM); |
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466 | return; |
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467 | } |
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468 | |||
469 | dev_phone = ipc_connect_me_to(PHONE_NS, SERVICE_DEVMAP, |
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470 | DEVMAP_CONNECT_TO_DEVICE, dev_handle); |
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471 | |||
472 | if (dev_phone < 0) { |
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473 | munmap(dev_buffer, BS_SIZE); |
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474 | ipc_answer_0(rid, dev_phone); |
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475 | return; |
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476 | } |
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477 | |||
478 | rc = ipc_share_out_start(dev_phone, dev_buffer, |
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479 | AS_AREA_READ | AS_AREA_WRITE); |
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480 | if (rc != EOK) { |
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481 | munmap(dev_buffer, BS_SIZE); |
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482 | ipc_answer_0(rid, rc); |
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483 | return; |
||
484 | } |
||
485 | |||
3119 | jermar | 486 | /* Read the number of root directory entries. */ |
3253 | jermar | 487 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
3257 | jermar | 488 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
3119 | jermar | 489 | rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max); |
490 | block_put(bb); |
||
491 | |||
3257 | jermar | 492 | if (bps != BS_SIZE) { |
493 | munmap(dev_buffer, BS_SIZE); |
||
494 | ipc_answer_0(rid, ENOTSUP); |
||
495 | return; |
||
496 | } |
||
497 | |||
3110 | jermar | 498 | rc = fat_idx_init_by_dev_handle(dev_handle); |
499 | if (rc != EOK) { |
||
3257 | jermar | 500 | munmap(dev_buffer, BS_SIZE); |
3110 | jermar | 501 | ipc_answer_0(rid, rc); |
502 | return; |
||
503 | } |
||
504 | |||
3119 | jermar | 505 | /* Initialize the root node. */ |
506 | fat_node_t *rootp = (fat_node_t *)malloc(sizeof(fat_node_t)); |
||
507 | if (!rootp) { |
||
3257 | jermar | 508 | munmap(dev_buffer, BS_SIZE); |
3119 | jermar | 509 | fat_idx_fini_by_dev_handle(dev_handle); |
510 | ipc_answer_0(rid, ENOMEM); |
||
511 | return; |
||
512 | } |
||
513 | fat_node_initialize(rootp); |
||
514 | |||
515 | fat_idx_t *ridxp = fat_idx_get_by_pos(dev_handle, FAT_CLST_ROOTPAR, 0); |
||
516 | if (!ridxp) { |
||
3257 | jermar | 517 | munmap(dev_buffer, BS_SIZE); |
3119 | jermar | 518 | free(rootp); |
519 | fat_idx_fini_by_dev_handle(dev_handle); |
||
520 | ipc_answer_0(rid, ENOMEM); |
||
521 | return; |
||
522 | } |
||
523 | assert(ridxp->index == 0); |
||
524 | /* ridxp->lock held */ |
||
525 | |||
526 | rootp->type = FAT_DIRECTORY; |
||
527 | rootp->firstc = FAT_CLST_ROOT; |
||
528 | rootp->refcnt = 1; |
||
3352 | jermar | 529 | rootp->lnkcnt = 0; /* FS root is not linked */ |
3119 | jermar | 530 | rootp->size = rde * sizeof(fat_dentry_t); |
531 | rootp->idx = ridxp; |
||
532 | ridxp->nodep = rootp; |
||
533 | |||
534 | futex_up(&ridxp->lock); |
||
535 | |||
3352 | jermar | 536 | ipc_answer_3(rid, EOK, ridxp->index, rootp->size, rootp->lnkcnt); |
3110 | jermar | 537 | } |
538 | |||
539 | void fat_mount(ipc_callid_t rid, ipc_call_t *request) |
||
540 | { |
||
541 | ipc_answer_0(rid, ENOTSUP); |
||
542 | } |
||
543 | |||
2627 | jermar | 544 | void fat_lookup(ipc_callid_t rid, ipc_call_t *request) |
545 | { |
||
2793 | jermar | 546 | libfs_lookup(&fat_libfs_ops, fat_reg.fs_handle, rid, request); |
2627 | jermar | 547 | } |
548 | |||
3307 | jermar | 549 | void fat_read(ipc_callid_t rid, ipc_call_t *request) |
550 | { |
||
551 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
||
552 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
||
553 | off_t pos = (off_t)IPC_GET_ARG3(*request); |
||
554 | fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
||
3308 | jermar | 555 | uint16_t bps = fat_bps_get(dev_handle); |
556 | size_t bytes; |
||
3335 | jermar | 557 | block_t *b; |
3308 | jermar | 558 | |
3307 | jermar | 559 | if (!nodep) { |
560 | ipc_answer_0(rid, ENOENT); |
||
561 | return; |
||
562 | } |
||
563 | |||
564 | ipc_callid_t callid; |
||
565 | size_t len; |
||
3314 | jermar | 566 | if (!ipc_data_read_receive(&callid, &len)) { |
3307 | jermar | 567 | fat_node_put(nodep); |
568 | ipc_answer_0(callid, EINVAL); |
||
569 | ipc_answer_0(rid, EINVAL); |
||
570 | return; |
||
571 | } |
||
572 | |||
573 | if (nodep->type == FAT_FILE) { |
||
3335 | jermar | 574 | /* |
575 | * Our strategy for regular file reads is to read one block at |
||
576 | * most and make use of the possibility to return less data than |
||
577 | * requested. This keeps the code very simple. |
||
578 | */ |
||
3308 | jermar | 579 | bytes = min(len, bps - pos % bps); |
580 | b = fat_block_get(nodep, pos / bps); |
||
581 | (void) ipc_data_read_finalize(callid, b->data + pos % bps, |
||
582 | bytes); |
||
583 | block_put(b); |
||
3307 | jermar | 584 | } else { |
3335 | jermar | 585 | unsigned bnum; |
586 | off_t spos = pos; |
||
587 | char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1]; |
||
588 | fat_dentry_t *d; |
||
589 | |||
3307 | jermar | 590 | assert(nodep->type == FAT_DIRECTORY); |
3335 | jermar | 591 | assert(nodep->size % bps == 0); |
592 | assert(bps % sizeof(fat_dentry_t) == 0); |
||
593 | |||
594 | /* |
||
595 | * Our strategy for readdir() is to use the position pointer as |
||
596 | * an index into the array of all dentries. On entry, it points |
||
597 | * to the first unread dentry. If we skip any dentries, we bump |
||
598 | * the position pointer accordingly. |
||
599 | */ |
||
600 | bnum = (pos * sizeof(fat_dentry_t)) / bps; |
||
601 | while (bnum < nodep->size / bps) { |
||
602 | off_t o; |
||
603 | |||
604 | b = fat_block_get(nodep, bnum); |
||
605 | for (o = pos % (bps / sizeof(fat_dentry_t)); |
||
606 | o < bps / sizeof(fat_dentry_t); |
||
607 | o++, pos++) { |
||
608 | d = ((fat_dentry_t *)b->data) + o; |
||
609 | switch (fat_classify_dentry(d)) { |
||
610 | case FAT_DENTRY_SKIP: |
||
611 | continue; |
||
612 | case FAT_DENTRY_LAST: |
||
613 | block_put(b); |
||
614 | goto miss; |
||
615 | default: |
||
616 | case FAT_DENTRY_VALID: |
||
617 | dentry_name_canonify(d, name); |
||
618 | block_put(b); |
||
619 | goto hit; |
||
620 | } |
||
621 | } |
||
622 | block_put(b); |
||
623 | bnum++; |
||
624 | } |
||
625 | miss: |
||
3307 | jermar | 626 | fat_node_put(nodep); |
3335 | jermar | 627 | ipc_answer_0(callid, ENOENT); |
628 | ipc_answer_1(rid, ENOENT, 0); |
||
3307 | jermar | 629 | return; |
3335 | jermar | 630 | hit: |
631 | (void) ipc_data_read_finalize(callid, name, strlen(name) + 1); |
||
632 | bytes = (pos - spos) + 1; |
||
3307 | jermar | 633 | } |
634 | |||
635 | fat_node_put(nodep); |
||
3308 | jermar | 636 | ipc_answer_1(rid, EOK, (ipcarg_t)bytes); |
3307 | jermar | 637 | } |
638 | |||
3497 | jermar | 639 | void fat_write(ipc_callid_t rid, ipc_call_t *request) |
640 | { |
||
3499 | jermar | 641 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
642 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
||
643 | off_t pos = (off_t)IPC_GET_ARG3(*request); |
||
644 | fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
||
645 | size_t bytes; |
||
646 | block_t *b, *bb; |
||
647 | uint16_t bps; |
||
648 | unsigned spc; |
||
3501 | jermar | 649 | off_t boundary; |
3499 | jermar | 650 | |
651 | if (!nodep) { |
||
652 | ipc_answer_0(rid, ENOENT); |
||
653 | return; |
||
654 | } |
||
655 | |||
656 | /* XXX remove me when you are ready */ |
||
657 | { |
||
658 | ipc_answer_0(rid, ENOTSUP); |
||
659 | fat_node_put(nodep); |
||
660 | return; |
||
661 | } |
||
662 | |||
663 | ipc_callid_t callid; |
||
664 | size_t len; |
||
665 | if (!ipc_data_write_receive(&callid, &len)) { |
||
666 | fat_node_put(nodep); |
||
667 | ipc_answer_0(callid, EINVAL); |
||
668 | ipc_answer_0(rid, EINVAL); |
||
669 | return; |
||
670 | } |
||
671 | |||
672 | /* |
||
673 | * In all scenarios, we will attempt to write out only one block worth |
||
674 | * of data at maximum. There might be some more efficient approaches, |
||
675 | * but this one greatly simplifies fat_write(). Note that we can afford |
||
676 | * to do this because the client must be ready to handle the return |
||
677 | * value signalizing a smaller number of bytes written. |
||
678 | */ |
||
679 | bytes = min(len, bps - pos % bps); |
||
680 | |||
681 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
||
682 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
||
683 | spc = FAT_BS(bb)->spc; |
||
684 | block_put(bb); |
||
685 | |||
3501 | jermar | 686 | boundary = ROUND_UP(nodep->size, bps * spc); |
687 | if (pos < boundary) { |
||
3499 | jermar | 688 | /* |
689 | * This is the easier case - we are either overwriting already |
||
690 | * existing contents or writing behind the EOF, but still within |
||
691 | * the limits of the last cluster. The node size may grow to the |
||
692 | * next block size boundary. |
||
693 | */ |
||
3500 | jermar | 694 | fat_fill_gap(nodep, FAT_CLST_RES0, pos); |
3499 | jermar | 695 | b = fat_block_get(nodep, pos / bps); |
696 | (void) ipc_data_write_finalize(callid, b->data + pos % bps, |
||
697 | bytes); |
||
698 | b->dirty = true; /* need to sync block */ |
||
3500 | jermar | 699 | block_put(b); |
3499 | jermar | 700 | if (pos + bytes > nodep->size) { |
701 | nodep->size = pos + bytes; |
||
702 | nodep->dirty = true; /* need to sync node */ |
||
703 | } |
||
704 | fat_node_put(nodep); |
||
705 | ipc_answer_1(rid, EOK, bytes); |
||
706 | return; |
||
707 | } else { |
||
708 | /* |
||
709 | * This is the more difficult case. We must allocate new |
||
710 | * clusters for the node and zero them out. |
||
711 | */ |
||
3500 | jermar | 712 | int status; |
3499 | jermar | 713 | unsigned nclsts; |
3500 | jermar | 714 | fat_cluster_t mcl, lcl; |
715 | |||
3501 | jermar | 716 | nclsts = (ROUND_UP(pos + bytes, bps * spc) - boundary) / |
3500 | jermar | 717 | bps * spc; |
718 | /* create an independent chain of nclsts clusters in all FATs */ |
||
3503 | jermar | 719 | status = fat_alloc_clusters(dev_handle, nclsts, &mcl, &lcl); |
3500 | jermar | 720 | if (status != EOK) { |
721 | /* could not allocate a chain of nclsts clusters */ |
||
722 | fat_node_put(nodep); |
||
723 | ipc_answer_0(callid, status); |
||
724 | ipc_answer_0(rid, status); |
||
725 | return; |
||
726 | } |
||
727 | /* zero fill any gaps */ |
||
728 | fat_fill_gap(nodep, mcl, pos); |
||
729 | b = _fat_block_get(dev_handle, lcl, (pos / bps) % spc); |
||
730 | (void) ipc_data_write_finalize(callid, b->data + pos % bps, |
||
731 | bytes); |
||
3501 | jermar | 732 | b->dirty = true; /* need to sync block */ |
3500 | jermar | 733 | block_put(b); |
734 | /* |
||
735 | * Append the cluster chain starting in mcl to the end of the |
||
736 | * node's cluster chain. |
||
737 | */ |
||
738 | fat_append_clusters(nodep, mcl); |
||
739 | nodep->size = pos + bytes; |
||
3501 | jermar | 740 | nodep->dirty = true; /* need to sync node */ |
3500 | jermar | 741 | fat_node_put(nodep); |
742 | ipc_answer_1(rid, EOK, bytes); |
||
743 | return; |
||
3499 | jermar | 744 | } |
3497 | jermar | 745 | } |
746 | |||
2627 | jermar | 747 | /** |
748 | * @} |
||
749 | */ |