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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> |
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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3629 | jermar | 97 | if (node->type == FAT_FILE) { |
3519 | jermar | 98 | d->size = host2uint32_t_le(node->size); |
3629 | jermar | 99 | } else if (node->type == FAT_DIRECTORY) { |
100 | d->attr = FAT_ATTR_SUBDIR; |
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101 | } |
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3519 | jermar | 102 | |
3629 | jermar | 103 | /* TODO: update other fields? (e.g time fields) */ |
104 | |||
3519 | jermar | 105 | b->dirty = true; /* need to sync block */ |
106 | block_put(b); |
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2831 | jermar | 107 | } |
108 | |||
3574 | jermar | 109 | static fat_node_t *fat_node_get_new(void) |
110 | { |
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111 | fat_node_t *nodep; |
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112 | |||
113 | futex_down(&ffn_futex); |
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114 | if (!list_empty(&ffn_head)) { |
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115 | /* Try to use a cached free node structure. */ |
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116 | fat_idx_t *idxp_tmp; |
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117 | nodep = list_get_instance(ffn_head.next, fat_node_t, ffn_link); |
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118 | if (futex_trydown(&nodep->lock) == ESYNCH_WOULD_BLOCK) |
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119 | goto skip_cache; |
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120 | idxp_tmp = nodep->idx; |
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121 | if (futex_trydown(&idxp_tmp->lock) == ESYNCH_WOULD_BLOCK) { |
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122 | futex_up(&nodep->lock); |
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123 | goto skip_cache; |
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124 | } |
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125 | list_remove(&nodep->ffn_link); |
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126 | futex_up(&ffn_futex); |
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127 | if (nodep->dirty) |
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128 | fat_node_sync(nodep); |
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129 | idxp_tmp->nodep = NULL; |
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130 | futex_up(&nodep->lock); |
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131 | futex_up(&idxp_tmp->lock); |
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132 | } else { |
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133 | skip_cache: |
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134 | /* Try to allocate a new node structure. */ |
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135 | futex_up(&ffn_futex); |
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136 | nodep = (fat_node_t *)malloc(sizeof(fat_node_t)); |
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137 | if (!nodep) |
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138 | return NULL; |
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139 | } |
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140 | fat_node_initialize(nodep); |
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141 | |||
142 | return nodep; |
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143 | } |
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144 | |||
2951 | jermar | 145 | /** Internal version of fat_node_get(). |
146 | * |
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147 | * @param idxp Locked index structure. |
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148 | */ |
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149 | static void *fat_node_get_core(fat_idx_t *idxp) |
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2831 | jermar | 150 | { |
3530 | jermar | 151 | block_t *b; |
152 | fat_bs_t *bs; |
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2891 | jermar | 153 | fat_dentry_t *d; |
3312 | jermar | 154 | fat_node_t *nodep = NULL; |
2891 | jermar | 155 | unsigned bps; |
3550 | jermar | 156 | unsigned spc; |
2891 | jermar | 157 | unsigned dps; |
158 | |||
2951 | jermar | 159 | if (idxp->nodep) { |
2891 | jermar | 160 | /* |
161 | * We are lucky. |
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162 | * The node is already instantiated in memory. |
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163 | */ |
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2951 | jermar | 164 | futex_down(&idxp->nodep->lock); |
165 | if (!idxp->nodep->refcnt++) |
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3312 | jermar | 166 | list_remove(&idxp->nodep->ffn_link); |
2951 | jermar | 167 | futex_up(&idxp->nodep->lock); |
168 | return idxp->nodep; |
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2891 | jermar | 169 | } |
170 | |||
171 | /* |
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172 | * We must instantiate the node from the file system. |
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173 | */ |
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174 | |||
2951 | jermar | 175 | assert(idxp->pfc); |
2891 | jermar | 176 | |
3574 | jermar | 177 | nodep = fat_node_get_new(); |
178 | if (!nodep) |
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179 | return NULL; |
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2891 | jermar | 180 | |
3530 | jermar | 181 | bs = block_bb_get(idxp->dev_handle); |
182 | bps = uint16_t_le2host(bs->bps); |
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3550 | jermar | 183 | spc = bs->spc; |
2891 | jermar | 184 | dps = bps / sizeof(fat_dentry_t); |
185 | |||
2893 | jermar | 186 | /* Read the block that contains the dentry of interest. */ |
3530 | jermar | 187 | b = _fat_block_get(bs, idxp->dev_handle, idxp->pfc, |
3595 | jermar | 188 | (idxp->pdi * sizeof(fat_dentry_t)) / bps, BLOCK_FLAGS_NONE); |
2891 | jermar | 189 | assert(b); |
190 | |||
2951 | jermar | 191 | d = ((fat_dentry_t *)b->data) + (idxp->pdi % dps); |
2893 | jermar | 192 | if (d->attr & FAT_ATTR_SUBDIR) { |
193 | /* |
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194 | * The only directory which does not have this bit set is the |
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195 | * root directory itself. The root directory node is handled |
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196 | * and initialized elsewhere. |
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197 | */ |
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198 | nodep->type = FAT_DIRECTORY; |
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3282 | jermar | 199 | /* |
3325 | jermar | 200 | * Unfortunately, the 'size' field of the FAT dentry is not |
201 | * defined for the directory entry type. We must determine the |
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202 | * size of the directory by walking the FAT. |
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3282 | jermar | 203 | */ |
3550 | jermar | 204 | nodep->size = bps * spc * fat_clusters_get(bs, idxp->dev_handle, |
205 | uint16_t_le2host(d->firstc)); |
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2893 | jermar | 206 | } else { |
207 | nodep->type = FAT_FILE; |
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3282 | jermar | 208 | nodep->size = uint32_t_le2host(d->size); |
2893 | jermar | 209 | } |
210 | nodep->firstc = uint16_t_le2host(d->firstc); |
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211 | nodep->lnkcnt = 1; |
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212 | nodep->refcnt = 1; |
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213 | |||
214 | block_put(b); |
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215 | |||
216 | /* Link the idx structure with the node structure. */ |
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2951 | jermar | 217 | nodep->idx = idxp; |
218 | idxp->nodep = nodep; |
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2893 | jermar | 219 | |
220 | return nodep; |
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2831 | jermar | 221 | } |
222 | |||
3621 | jermar | 223 | /* |
224 | * Forward declarations of FAT libfs operations. |
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225 | */ |
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226 | static void *fat_node_get(dev_handle_t, fs_index_t); |
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227 | static void fat_node_put(void *); |
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228 | static void *fat_create_node(dev_handle_t, int); |
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229 | static int fat_destroy_node(void *); |
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3625 | jermar | 230 | static int fat_link(void *, void *, const char *); |
3621 | jermar | 231 | static int fat_unlink(void *, void *); |
232 | static void *fat_match(void *, const char *); |
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233 | static fs_index_t fat_index_get(void *); |
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234 | static size_t fat_size_get(void *); |
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235 | static unsigned fat_lnkcnt_get(void *); |
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236 | static bool fat_has_children(void *); |
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237 | static void *fat_root_get(dev_handle_t); |
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238 | static char fat_plb_get_char(unsigned); |
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239 | static bool fat_is_directory(void *); |
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240 | static bool fat_is_file(void *node); |
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241 | |||
242 | /* |
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243 | * FAT libfs operations. |
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244 | */ |
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245 | |||
2951 | jermar | 246 | /** Instantiate a FAT in-core node. */ |
3621 | jermar | 247 | void *fat_node_get(dev_handle_t dev_handle, fs_index_t index) |
2951 | jermar | 248 | { |
249 | void *node; |
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250 | fat_idx_t *idxp; |
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251 | |||
252 | idxp = fat_idx_get_by_index(dev_handle, index); |
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253 | if (!idxp) |
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254 | return NULL; |
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255 | /* idxp->lock held */ |
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256 | node = fat_node_get_core(idxp); |
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257 | futex_up(&idxp->lock); |
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258 | return node; |
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259 | } |
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260 | |||
3621 | jermar | 261 | void fat_node_put(void *node) |
2852 | jermar | 262 | { |
2910 | jermar | 263 | fat_node_t *nodep = (fat_node_t *)node; |
3609 | jermar | 264 | bool destroy = false; |
2910 | jermar | 265 | |
2951 | jermar | 266 | futex_down(&nodep->lock); |
2910 | jermar | 267 | if (!--nodep->refcnt) { |
3609 | jermar | 268 | if (nodep->idx) { |
269 | futex_down(&ffn_futex); |
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270 | list_append(&nodep->ffn_link, &ffn_head); |
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271 | futex_up(&ffn_futex); |
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272 | } else { |
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273 | /* |
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274 | * The node does not have any index structure associated |
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275 | * with itself. This can only mean that we are releasing |
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276 | * the node after a failed attempt to allocate the index |
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277 | * structure for it. |
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278 | */ |
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279 | destroy = true; |
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280 | } |
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2910 | jermar | 281 | } |
2951 | jermar | 282 | futex_up(&nodep->lock); |
3609 | jermar | 283 | if (destroy) |
284 | free(node); |
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2852 | jermar | 285 | } |
286 | |||
3621 | jermar | 287 | void *fat_create_node(dev_handle_t dev_handle, int flags) |
2857 | jermar | 288 | { |
3609 | jermar | 289 | fat_idx_t *idxp; |
290 | fat_node_t *nodep; |
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3633 | jermar | 291 | fat_bs_t *bs; |
292 | fat_cluster_t mcl, lcl; |
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293 | uint16_t bps; |
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294 | int rc; |
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3609 | jermar | 295 | |
3633 | jermar | 296 | bs = block_bb_get(dev_handle); |
297 | bps = uint16_t_le2host(bs->bps); |
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298 | if (flags & L_DIRECTORY) { |
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299 | /* allocate a cluster */ |
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300 | rc = fat_alloc_clusters(bs, dev_handle, 1, &mcl, &lcl); |
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301 | if (rc != EOK) |
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302 | return NULL; |
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303 | } |
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304 | |||
3609 | jermar | 305 | nodep = fat_node_get_new(); |
3633 | jermar | 306 | if (!nodep) { |
307 | fat_free_clusters(bs, dev_handle, mcl); |
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3609 | jermar | 308 | return NULL; |
3633 | jermar | 309 | } |
3609 | jermar | 310 | idxp = fat_idx_get_new(dev_handle); |
311 | if (!idxp) { |
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3633 | jermar | 312 | fat_free_clusters(bs, dev_handle, mcl); |
3609 | jermar | 313 | fat_node_put(nodep); |
314 | return NULL; |
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315 | } |
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316 | /* idxp->lock held */ |
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317 | if (flags & L_DIRECTORY) { |
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3633 | jermar | 318 | int i; |
319 | block_t *b; |
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320 | |||
321 | /* |
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322 | * Populate the new cluster with unused dentries. |
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323 | */ |
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324 | for (i = 0; i < bs->spc; i++) { |
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325 | b = _fat_block_get(bs, dev_handle, mcl, i, |
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326 | BLOCK_FLAGS_NOREAD); |
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327 | /* mark all dentries as never-used */ |
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328 | memset(b->data, 0, bps); |
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329 | b->dirty = false; |
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330 | block_put(b); |
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331 | } |
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3609 | jermar | 332 | nodep->type = FAT_DIRECTORY; |
3633 | jermar | 333 | nodep->firstc = mcl; |
334 | nodep->size = bps * bs->spc; |
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3609 | jermar | 335 | } else { |
336 | nodep->type = FAT_FILE; |
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3633 | jermar | 337 | nodep->firstc = FAT_CLST_RES0; |
338 | nodep->size = 0; |
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3609 | jermar | 339 | } |
340 | nodep->lnkcnt = 0; /* not linked anywhere */ |
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341 | nodep->refcnt = 1; |
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3633 | jermar | 342 | nodep->dirty = true; |
3609 | jermar | 343 | |
344 | nodep->idx = idxp; |
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345 | idxp->nodep = nodep; |
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346 | |||
347 | futex_up(&idxp->lock); |
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348 | return nodep; |
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2857 | jermar | 349 | } |
350 | |||
3621 | jermar | 351 | int fat_destroy_node(void *node) |
2857 | jermar | 352 | { |
3621 | jermar | 353 | fat_node_t *nodep = (fat_node_t *)node; |
354 | fat_bs_t *bs; |
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355 | |||
356 | /* |
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357 | * The node is not reachable from the file system. This means that the |
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358 | * link count should be zero and that the index structure cannot be |
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359 | * found in the position hash. Obviously, we don't need to lock the node |
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360 | * nor its index structure. |
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361 | */ |
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362 | assert(nodep->lnkcnt == 0); |
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363 | |||
364 | /* |
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365 | * The node may not have any children. |
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366 | */ |
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367 | assert(fat_has_children(node) == false); |
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368 | |||
369 | bs = block_bb_get(nodep->idx->dev_handle); |
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370 | if (nodep->firstc != FAT_CLST_RES0) { |
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371 | assert(nodep->size); |
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372 | /* Free all clusters allocated to the node. */ |
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373 | fat_free_clusters(bs, nodep->idx->dev_handle, nodep->firstc); |
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374 | } |
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375 | |||
376 | fat_idx_destroy(nodep->idx); |
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377 | free(nodep); |
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378 | return EOK; |
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2857 | jermar | 379 | } |
380 | |||
3625 | jermar | 381 | int fat_link(void *prnt, void *chld, const char *name) |
2857 | jermar | 382 | { |
3628 | jermar | 383 | fat_node_t *parentp = (fat_node_t *)prnt; |
384 | fat_node_t *childp = (fat_node_t *)chld; |
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385 | fat_dentry_t *d; |
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386 | fat_bs_t *bs; |
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387 | block_t *b; |
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388 | int i, j; |
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389 | uint16_t bps; |
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390 | unsigned dps; |
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391 | unsigned blocks; |
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3700 | jermar | 392 | fat_cluster_t mcl, lcl; |
393 | int rc; |
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3628 | jermar | 394 | |
395 | futex_down(&childp->lock); |
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396 | if (childp->lnkcnt == 1) { |
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397 | /* |
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398 | * On FAT, we don't support multiple hard links. |
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399 | */ |
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400 | futex_up(&childp->lock); |
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401 | return EMLINK; |
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402 | } |
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403 | assert(childp->lnkcnt == 0); |
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404 | futex_up(&childp->lock); |
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405 | |||
406 | if (!fat_dentry_name_verify(name)) { |
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407 | /* |
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408 | * Attempt to create unsupported name. |
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409 | */ |
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410 | return ENOTSUP; |
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411 | } |
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412 | |||
413 | /* |
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414 | * Get us an unused parent node's dentry or grow the parent and allocate |
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415 | * a new one. |
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416 | */ |
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417 | |||
418 | futex_down(&parentp->idx->lock); |
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419 | bs = block_bb_get(parentp->idx->dev_handle); |
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420 | bps = uint16_t_le2host(bs->bps); |
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421 | dps = bps / sizeof(fat_dentry_t); |
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422 | |||
423 | blocks = parentp->size / bps; |
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424 | |||
425 | for (i = 0; i < blocks; i++) { |
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426 | b = fat_block_get(bs, parentp, i, BLOCK_FLAGS_NONE); |
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427 | for (j = 0; j < dps; j++) { |
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428 | d = ((fat_dentry_t *)b->data) + j; |
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429 | switch (fat_classify_dentry(d)) { |
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430 | case FAT_DENTRY_SKIP: |
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431 | case FAT_DENTRY_VALID: |
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432 | /* skipping used and meta entries */ |
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433 | continue; |
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434 | case FAT_DENTRY_FREE: |
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435 | case FAT_DENTRY_LAST: |
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436 | /* found an empty slot */ |
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437 | goto hit; |
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438 | } |
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439 | } |
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440 | block_put(b); |
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441 | } |
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442 | |||
443 | /* |
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444 | * We need to grow the parent in order to create a new unused dentry. |
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445 | */ |
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3700 | jermar | 446 | if (parentp->idx->pfc == FAT_CLST_ROOT) { |
447 | /* Can't grow the root directory. */ |
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448 | futex_up(&parentp->idx->lock); |
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449 | return ENOSPC; |
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450 | } |
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451 | rc = fat_alloc_clusters(bs, parentp->idx->dev_handle, 1, &mcl, &lcl); |
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452 | if (rc != EOK) { |
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453 | futex_up(&parentp->idx->lock); |
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454 | return rc; |
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455 | } |
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456 | fat_append_clusters(bs, parentp, mcl); |
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457 | b = fat_block_get(bs, parentp, i, BLOCK_FLAGS_NOREAD); |
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458 | d = (fat_dentry_t *)b->data; |
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459 | /* |
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460 | * Clear all dentries in the block except for the first one (the first |
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461 | * dentry will be cleared in the next step). |
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462 | */ |
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463 | memset(d + 1, 0, bps - sizeof(fat_dentry_t)); |
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3628 | jermar | 464 | |
465 | hit: |
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466 | /* |
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467 | * At this point we only establish the link between the parent and the |
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468 | * child. The dentry, except of the name and the extension, will remain |
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3700 | jermar | 469 | * uninitialized until the corresponding node is synced. Thus the valid |
470 | * dentry data is kept in the child node structure. |
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3628 | jermar | 471 | */ |
472 | memset(d, 0, sizeof(fat_dentry_t)); |
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473 | fat_dentry_name_set(d, name); |
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474 | b->dirty = true; /* need to sync block */ |
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475 | block_put(b); |
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476 | futex_up(&parentp->idx->lock); |
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477 | |||
478 | futex_down(&childp->idx->lock); |
||
3660 | jermar | 479 | |
480 | /* |
||
481 | * If possible, create the Sub-directory Identifier Entry and the |
||
482 | * Sub-directory Parent Pointer Entry (i.e. "." and ".."). These entries |
||
483 | * are not mandatory according to Standard ECMA-107 and HelenOS VFS does |
||
484 | * not use them anyway, so this is rather a sign of our good will. |
||
485 | */ |
||
486 | b = fat_block_get(bs, childp, 0, BLOCK_FLAGS_NONE); |
||
487 | d = (fat_dentry_t *)b->data; |
||
488 | if (fat_classify_dentry(d) == FAT_DENTRY_LAST || |
||
489 | strcmp(d->name, FAT_NAME_DOT) == 0) { |
||
490 | memset(d, 0, sizeof(fat_dentry_t)); |
||
491 | strcpy(d->name, FAT_NAME_DOT); |
||
492 | strcpy(d->ext, FAT_EXT_PAD); |
||
493 | d->attr = FAT_ATTR_SUBDIR; |
||
494 | d->firstc = host2uint16_t_le(childp->firstc); |
||
495 | /* TODO: initialize also the date/time members. */ |
||
496 | } |
||
497 | d++; |
||
498 | if (fat_classify_dentry(d) == FAT_DENTRY_LAST || |
||
499 | strcmp(d->name, FAT_NAME_DOT_DOT) == 0) { |
||
500 | memset(d, 0, sizeof(fat_dentry_t)); |
||
501 | strcpy(d->name, FAT_NAME_DOT_DOT); |
||
502 | strcpy(d->ext, FAT_EXT_PAD); |
||
503 | d->attr = FAT_ATTR_SUBDIR; |
||
504 | d->firstc = (parentp->firstc == FAT_CLST_ROOT) ? |
||
505 | host2uint16_t_le(FAT_CLST_RES0) : |
||
506 | host2uint16_t_le(parentp->firstc); |
||
507 | /* TODO: initialize also the date/time members. */ |
||
508 | } |
||
509 | b->dirty = true; /* need to sync block */ |
||
510 | block_put(b); |
||
511 | |||
3628 | jermar | 512 | childp->idx->pfc = parentp->firstc; |
513 | childp->idx->pdi = i * dps + j; |
||
514 | futex_up(&childp->idx->lock); |
||
515 | |||
516 | futex_down(&childp->lock); |
||
517 | childp->lnkcnt = 1; |
||
518 | childp->dirty = true; /* need to sync node */ |
||
519 | futex_up(&childp->lock); |
||
520 | |||
521 | /* |
||
522 | * Hash in the index structure into the position hash. |
||
523 | */ |
||
524 | fat_idx_hashin(childp->idx); |
||
525 | |||
526 | return EOK; |
||
2857 | jermar | 527 | } |
528 | |||
3621 | jermar | 529 | int fat_unlink(void *prnt, void *chld) |
2857 | jermar | 530 | { |
3638 | jermar | 531 | fat_node_t *parentp = (fat_node_t *)prnt; |
532 | fat_node_t *childp = (fat_node_t *)chld; |
||
533 | fat_bs_t *bs; |
||
534 | fat_dentry_t *d; |
||
535 | uint16_t bps; |
||
536 | block_t *b; |
||
537 | |||
538 | futex_down(&parentp->lock); |
||
539 | futex_down(&childp->lock); |
||
540 | assert(childp->lnkcnt == 1); |
||
541 | futex_down(&childp->idx->lock); |
||
542 | bs = block_bb_get(childp->idx->dev_handle); |
||
543 | bps = uint16_t_le2host(bs->bps); |
||
544 | |||
545 | b = _fat_block_get(bs, childp->idx->dev_handle, childp->idx->pfc, |
||
546 | (childp->idx->pdi * sizeof(fat_dentry_t)) / bps, |
||
547 | BLOCK_FLAGS_NONE); |
||
548 | d = (fat_dentry_t *)b->data + |
||
549 | (childp->idx->pdi % (bps / sizeof(fat_dentry_t))); |
||
550 | /* mark the dentry as not-currently-used */ |
||
551 | d->name[0] = FAT_DENTRY_ERASED; |
||
552 | b->dirty = true; /* need to sync block */ |
||
553 | block_put(b); |
||
554 | |||
555 | /* remove the index structure from the position hash */ |
||
556 | fat_idx_hashout(childp->idx); |
||
557 | /* clear position information */ |
||
558 | childp->idx->pfc = FAT_CLST_RES0; |
||
559 | childp->idx->pdi = 0; |
||
560 | futex_up(&childp->idx->lock); |
||
561 | childp->lnkcnt = 0; |
||
562 | childp->dirty = true; |
||
563 | futex_up(&childp->lock); |
||
564 | futex_up(&parentp->lock); |
||
565 | |||
566 | return EOK; |
||
2857 | jermar | 567 | } |
568 | |||
3621 | jermar | 569 | void *fat_match(void *prnt, const char *component) |
2793 | jermar | 570 | { |
3530 | jermar | 571 | fat_bs_t *bs; |
2793 | jermar | 572 | fat_node_t *parentp = (fat_node_t *)prnt; |
573 | char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1]; |
||
2822 | jermar | 574 | unsigned i, j; |
2828 | jermar | 575 | unsigned bps; /* bytes per sector */ |
2822 | jermar | 576 | unsigned dps; /* dentries per sector */ |
577 | unsigned blocks; |
||
2793 | jermar | 578 | fat_dentry_t *d; |
3530 | jermar | 579 | block_t *b; |
2793 | jermar | 580 | |
2953 | jermar | 581 | futex_down(&parentp->idx->lock); |
3530 | jermar | 582 | bs = block_bb_get(parentp->idx->dev_handle); |
583 | bps = uint16_t_le2host(bs->bps); |
||
2828 | jermar | 584 | dps = bps / sizeof(fat_dentry_t); |
3526 | jermar | 585 | blocks = parentp->size / bps; |
2822 | jermar | 586 | for (i = 0; i < blocks; i++) { |
3595 | jermar | 587 | b = fat_block_get(bs, parentp, i, BLOCK_FLAGS_NONE); |
3526 | jermar | 588 | for (j = 0; j < dps; j++) { |
2822 | jermar | 589 | d = ((fat_dentry_t *)b->data) + j; |
2845 | jermar | 590 | switch (fat_classify_dentry(d)) { |
591 | case FAT_DENTRY_SKIP: |
||
3628 | jermar | 592 | case FAT_DENTRY_FREE: |
2822 | jermar | 593 | continue; |
2845 | jermar | 594 | case FAT_DENTRY_LAST: |
2822 | jermar | 595 | block_put(b); |
2953 | jermar | 596 | futex_up(&parentp->idx->lock); |
2822 | jermar | 597 | return NULL; |
2845 | jermar | 598 | default: |
599 | case FAT_DENTRY_VALID: |
||
3628 | jermar | 600 | fat_dentry_name_get(d, name); |
2845 | jermar | 601 | break; |
2822 | jermar | 602 | } |
3634 | jermar | 603 | if (fat_dentry_namecmp(name, component) == 0) { |
2822 | jermar | 604 | /* hit */ |
2951 | jermar | 605 | void *node; |
2953 | jermar | 606 | /* |
607 | * Assume tree hierarchy for locking. We |
||
608 | * already have the parent and now we are going |
||
609 | * to lock the child. Never lock in the oposite |
||
610 | * order. |
||
611 | */ |
||
2890 | jermar | 612 | fat_idx_t *idx = fat_idx_get_by_pos( |
2881 | jermar | 613 | parentp->idx->dev_handle, parentp->firstc, |
2864 | jermar | 614 | i * dps + j); |
2953 | jermar | 615 | futex_up(&parentp->idx->lock); |
2890 | jermar | 616 | if (!idx) { |
617 | /* |
||
618 | * Can happen if memory is low or if we |
||
619 | * run out of 32-bit indices. |
||
620 | */ |
||
621 | block_put(b); |
||
622 | return NULL; |
||
623 | } |
||
2951 | jermar | 624 | node = fat_node_get_core(idx); |
625 | futex_up(&idx->lock); |
||
2822 | jermar | 626 | block_put(b); |
627 | return node; |
||
628 | } |
||
2793 | jermar | 629 | } |
2822 | jermar | 630 | block_put(b); |
2639 | jermar | 631 | } |
3516 | jermar | 632 | |
2953 | jermar | 633 | futex_up(&parentp->idx->lock); |
2793 | jermar | 634 | return NULL; |
2638 | jermar | 635 | } |
636 | |||
3621 | jermar | 637 | fs_index_t fat_index_get(void *node) |
2831 | jermar | 638 | { |
639 | fat_node_t *fnodep = (fat_node_t *)node; |
||
640 | if (!fnodep) |
||
641 | return 0; |
||
2864 | jermar | 642 | return fnodep->idx->index; |
2831 | jermar | 643 | } |
644 | |||
3621 | jermar | 645 | size_t fat_size_get(void *node) |
2831 | jermar | 646 | { |
647 | return ((fat_node_t *)node)->size; |
||
648 | } |
||
649 | |||
3621 | jermar | 650 | unsigned fat_lnkcnt_get(void *node) |
2831 | jermar | 651 | { |
652 | return ((fat_node_t *)node)->lnkcnt; |
||
653 | } |
||
654 | |||
3621 | jermar | 655 | bool fat_has_children(void *node) |
2845 | jermar | 656 | { |
3530 | jermar | 657 | fat_bs_t *bs; |
2845 | jermar | 658 | fat_node_t *nodep = (fat_node_t *)node; |
659 | unsigned bps; |
||
660 | unsigned dps; |
||
661 | unsigned blocks; |
||
3530 | jermar | 662 | block_t *b; |
2845 | jermar | 663 | unsigned i, j; |
664 | |||
665 | if (nodep->type != FAT_DIRECTORY) |
||
666 | return false; |
||
3526 | jermar | 667 | |
2951 | jermar | 668 | futex_down(&nodep->idx->lock); |
3530 | jermar | 669 | bs = block_bb_get(nodep->idx->dev_handle); |
670 | bps = uint16_t_le2host(bs->bps); |
||
2845 | jermar | 671 | dps = bps / sizeof(fat_dentry_t); |
672 | |||
3526 | jermar | 673 | blocks = nodep->size / bps; |
2845 | jermar | 674 | |
675 | for (i = 0; i < blocks; i++) { |
||
676 | fat_dentry_t *d; |
||
677 | |||
3595 | jermar | 678 | b = fat_block_get(bs, nodep, i, BLOCK_FLAGS_NONE); |
3526 | jermar | 679 | for (j = 0; j < dps; j++) { |
2845 | jermar | 680 | d = ((fat_dentry_t *)b->data) + j; |
681 | switch (fat_classify_dentry(d)) { |
||
682 | case FAT_DENTRY_SKIP: |
||
3628 | jermar | 683 | case FAT_DENTRY_FREE: |
2845 | jermar | 684 | continue; |
685 | case FAT_DENTRY_LAST: |
||
686 | block_put(b); |
||
2951 | jermar | 687 | futex_up(&nodep->idx->lock); |
2845 | jermar | 688 | return false; |
689 | default: |
||
690 | case FAT_DENTRY_VALID: |
||
691 | block_put(b); |
||
2951 | jermar | 692 | futex_up(&nodep->idx->lock); |
2845 | jermar | 693 | return true; |
694 | } |
||
695 | block_put(b); |
||
2951 | jermar | 696 | futex_up(&nodep->idx->lock); |
2845 | jermar | 697 | return true; |
698 | } |
||
699 | block_put(b); |
||
700 | } |
||
701 | |||
2951 | jermar | 702 | futex_up(&nodep->idx->lock); |
2845 | jermar | 703 | return false; |
704 | } |
||
705 | |||
3621 | jermar | 706 | void *fat_root_get(dev_handle_t dev_handle) |
2844 | jermar | 707 | { |
3119 | jermar | 708 | return fat_node_get(dev_handle, 0); |
2844 | jermar | 709 | } |
710 | |||
3621 | jermar | 711 | char fat_plb_get_char(unsigned pos) |
2844 | jermar | 712 | { |
713 | return fat_reg.plb_ro[pos % PLB_SIZE]; |
||
714 | } |
||
715 | |||
3621 | jermar | 716 | bool fat_is_directory(void *node) |
2831 | jermar | 717 | { |
718 | return ((fat_node_t *)node)->type == FAT_DIRECTORY; |
||
719 | } |
||
720 | |||
3621 | jermar | 721 | bool fat_is_file(void *node) |
2831 | jermar | 722 | { |
723 | return ((fat_node_t *)node)->type == FAT_FILE; |
||
724 | } |
||
725 | |||
2793 | jermar | 726 | /** libfs operations */ |
727 | libfs_ops_t fat_libfs_ops = { |
||
728 | .match = fat_match, |
||
729 | .node_get = fat_node_get, |
||
2852 | jermar | 730 | .node_put = fat_node_put, |
3609 | jermar | 731 | .create = fat_create_node, |
732 | .destroy = fat_destroy_node, |
||
2857 | jermar | 733 | .link = fat_link, |
734 | .unlink = fat_unlink, |
||
2831 | jermar | 735 | .index_get = fat_index_get, |
736 | .size_get = fat_size_get, |
||
737 | .lnkcnt_get = fat_lnkcnt_get, |
||
2845 | jermar | 738 | .has_children = fat_has_children, |
2844 | jermar | 739 | .root_get = fat_root_get, |
740 | .plb_get_char = fat_plb_get_char, |
||
2831 | jermar | 741 | .is_directory = fat_is_directory, |
742 | .is_file = fat_is_file |
||
2793 | jermar | 743 | }; |
744 | |||
3625 | jermar | 745 | /* |
746 | * VFS operations. |
||
747 | */ |
||
748 | |||
3110 | jermar | 749 | void fat_mounted(ipc_callid_t rid, ipc_call_t *request) |
750 | { |
||
751 | dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request); |
||
3530 | jermar | 752 | fat_bs_t *bs; |
3257 | jermar | 753 | uint16_t bps; |
3119 | jermar | 754 | uint16_t rde; |
3110 | jermar | 755 | int rc; |
756 | |||
3530 | jermar | 757 | /* initialize libblock */ |
3537 | jermar | 758 | rc = block_init(dev_handle, BS_SIZE); |
3257 | jermar | 759 | if (rc != EOK) { |
3537 | jermar | 760 | ipc_answer_0(rid, rc); |
3257 | jermar | 761 | return; |
762 | } |
||
763 | |||
3537 | jermar | 764 | /* prepare the boot block */ |
765 | rc = block_bb_read(dev_handle, BS_BLOCK * BS_SIZE, BS_SIZE); |
||
766 | if (rc != EOK) { |
||
767 | block_fini(dev_handle); |
||
768 | ipc_answer_0(rid, rc); |
||
769 | return; |
||
770 | } |
||
771 | |||
3530 | jermar | 772 | /* get the buffer with the boot sector */ |
773 | bs = block_bb_get(dev_handle); |
||
774 | |||
3119 | jermar | 775 | /* Read the number of root directory entries. */ |
3530 | jermar | 776 | bps = uint16_t_le2host(bs->bps); |
777 | rde = uint16_t_le2host(bs->root_ent_max); |
||
3119 | jermar | 778 | |
3257 | jermar | 779 | if (bps != BS_SIZE) { |
3530 | jermar | 780 | block_fini(dev_handle); |
3257 | jermar | 781 | ipc_answer_0(rid, ENOTSUP); |
782 | return; |
||
783 | } |
||
784 | |||
3539 | jermar | 785 | /* Initialize the block cache */ |
786 | rc = block_cache_init(dev_handle, bps, 0 /* XXX */); |
||
787 | if (rc != EOK) { |
||
788 | block_fini(dev_handle); |
||
789 | ipc_answer_0(rid, rc); |
||
790 | return; |
||
791 | } |
||
792 | |||
3110 | jermar | 793 | rc = fat_idx_init_by_dev_handle(dev_handle); |
794 | if (rc != EOK) { |
||
3530 | jermar | 795 | block_fini(dev_handle); |
3110 | jermar | 796 | ipc_answer_0(rid, rc); |
797 | return; |
||
798 | } |
||
799 | |||
3119 | jermar | 800 | /* Initialize the root node. */ |
801 | fat_node_t *rootp = (fat_node_t *)malloc(sizeof(fat_node_t)); |
||
802 | if (!rootp) { |
||
3530 | jermar | 803 | block_fini(dev_handle); |
3119 | jermar | 804 | fat_idx_fini_by_dev_handle(dev_handle); |
805 | ipc_answer_0(rid, ENOMEM); |
||
806 | return; |
||
807 | } |
||
808 | fat_node_initialize(rootp); |
||
809 | |||
810 | fat_idx_t *ridxp = fat_idx_get_by_pos(dev_handle, FAT_CLST_ROOTPAR, 0); |
||
811 | if (!ridxp) { |
||
3530 | jermar | 812 | block_fini(dev_handle); |
3119 | jermar | 813 | free(rootp); |
814 | fat_idx_fini_by_dev_handle(dev_handle); |
||
815 | ipc_answer_0(rid, ENOMEM); |
||
816 | return; |
||
817 | } |
||
818 | assert(ridxp->index == 0); |
||
819 | /* ridxp->lock held */ |
||
820 | |||
821 | rootp->type = FAT_DIRECTORY; |
||
822 | rootp->firstc = FAT_CLST_ROOT; |
||
823 | rootp->refcnt = 1; |
||
3352 | jermar | 824 | rootp->lnkcnt = 0; /* FS root is not linked */ |
3119 | jermar | 825 | rootp->size = rde * sizeof(fat_dentry_t); |
826 | rootp->idx = ridxp; |
||
827 | ridxp->nodep = rootp; |
||
828 | |||
829 | futex_up(&ridxp->lock); |
||
830 | |||
3352 | jermar | 831 | ipc_answer_3(rid, EOK, ridxp->index, rootp->size, rootp->lnkcnt); |
3110 | jermar | 832 | } |
833 | |||
834 | void fat_mount(ipc_callid_t rid, ipc_call_t *request) |
||
835 | { |
||
836 | ipc_answer_0(rid, ENOTSUP); |
||
837 | } |
||
838 | |||
2627 | jermar | 839 | void fat_lookup(ipc_callid_t rid, ipc_call_t *request) |
840 | { |
||
2793 | jermar | 841 | libfs_lookup(&fat_libfs_ops, fat_reg.fs_handle, rid, request); |
2627 | jermar | 842 | } |
843 | |||
3307 | jermar | 844 | void fat_read(ipc_callid_t rid, ipc_call_t *request) |
845 | { |
||
846 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
||
847 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
||
848 | off_t pos = (off_t)IPC_GET_ARG3(*request); |
||
849 | fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
||
3530 | jermar | 850 | fat_bs_t *bs; |
3516 | jermar | 851 | uint16_t bps; |
3308 | jermar | 852 | size_t bytes; |
3530 | jermar | 853 | block_t *b; |
3308 | jermar | 854 | |
3307 | jermar | 855 | if (!nodep) { |
856 | ipc_answer_0(rid, ENOENT); |
||
857 | return; |
||
858 | } |
||
859 | |||
860 | ipc_callid_t callid; |
||
861 | size_t len; |
||
3314 | jermar | 862 | if (!ipc_data_read_receive(&callid, &len)) { |
3307 | jermar | 863 | fat_node_put(nodep); |
864 | ipc_answer_0(callid, EINVAL); |
||
865 | ipc_answer_0(rid, EINVAL); |
||
866 | return; |
||
867 | } |
||
868 | |||
3530 | jermar | 869 | bs = block_bb_get(dev_handle); |
870 | bps = uint16_t_le2host(bs->bps); |
||
3516 | jermar | 871 | |
3307 | jermar | 872 | if (nodep->type == FAT_FILE) { |
3335 | jermar | 873 | /* |
874 | * Our strategy for regular file reads is to read one block at |
||
875 | * most and make use of the possibility to return less data than |
||
876 | * requested. This keeps the code very simple. |
||
877 | */ |
||
3532 | jermar | 878 | if (pos >= nodep->size) { |
3533 | jermar | 879 | /* reading beyond the EOF */ |
880 | bytes = 0; |
||
3532 | jermar | 881 | (void) ipc_data_read_finalize(callid, NULL, 0); |
882 | } else { |
||
883 | bytes = min(len, bps - pos % bps); |
||
884 | bytes = min(bytes, nodep->size - pos); |
||
3595 | jermar | 885 | b = fat_block_get(bs, nodep, pos / bps, |
886 | BLOCK_FLAGS_NONE); |
||
3532 | jermar | 887 | (void) ipc_data_read_finalize(callid, b->data + pos % bps, |
888 | bytes); |
||
889 | block_put(b); |
||
890 | } |
||
3307 | jermar | 891 | } else { |
3335 | jermar | 892 | unsigned bnum; |
893 | off_t spos = pos; |
||
894 | char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1]; |
||
895 | fat_dentry_t *d; |
||
896 | |||
3307 | jermar | 897 | assert(nodep->type == FAT_DIRECTORY); |
3335 | jermar | 898 | assert(nodep->size % bps == 0); |
899 | assert(bps % sizeof(fat_dentry_t) == 0); |
||
900 | |||
901 | /* |
||
902 | * Our strategy for readdir() is to use the position pointer as |
||
903 | * an index into the array of all dentries. On entry, it points |
||
904 | * to the first unread dentry. If we skip any dentries, we bump |
||
905 | * the position pointer accordingly. |
||
906 | */ |
||
907 | bnum = (pos * sizeof(fat_dentry_t)) / bps; |
||
908 | while (bnum < nodep->size / bps) { |
||
909 | off_t o; |
||
910 | |||
3595 | jermar | 911 | b = fat_block_get(bs, nodep, bnum, BLOCK_FLAGS_NONE); |
3335 | jermar | 912 | for (o = pos % (bps / sizeof(fat_dentry_t)); |
913 | o < bps / sizeof(fat_dentry_t); |
||
914 | o++, pos++) { |
||
915 | d = ((fat_dentry_t *)b->data) + o; |
||
916 | switch (fat_classify_dentry(d)) { |
||
917 | case FAT_DENTRY_SKIP: |
||
3628 | jermar | 918 | case FAT_DENTRY_FREE: |
3335 | jermar | 919 | continue; |
920 | case FAT_DENTRY_LAST: |
||
921 | block_put(b); |
||
922 | goto miss; |
||
923 | default: |
||
924 | case FAT_DENTRY_VALID: |
||
3628 | jermar | 925 | fat_dentry_name_get(d, name); |
3335 | jermar | 926 | block_put(b); |
927 | goto hit; |
||
928 | } |
||
929 | } |
||
930 | block_put(b); |
||
931 | bnum++; |
||
932 | } |
||
933 | miss: |
||
3307 | jermar | 934 | fat_node_put(nodep); |
3335 | jermar | 935 | ipc_answer_0(callid, ENOENT); |
936 | ipc_answer_1(rid, ENOENT, 0); |
||
3307 | jermar | 937 | return; |
3335 | jermar | 938 | hit: |
939 | (void) ipc_data_read_finalize(callid, name, strlen(name) + 1); |
||
940 | bytes = (pos - spos) + 1; |
||
3307 | jermar | 941 | } |
942 | |||
943 | fat_node_put(nodep); |
||
3308 | jermar | 944 | ipc_answer_1(rid, EOK, (ipcarg_t)bytes); |
3307 | jermar | 945 | } |
946 | |||
3497 | jermar | 947 | void fat_write(ipc_callid_t rid, ipc_call_t *request) |
948 | { |
||
3499 | jermar | 949 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
950 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
||
951 | off_t pos = (off_t)IPC_GET_ARG3(*request); |
||
952 | fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
||
3530 | jermar | 953 | fat_bs_t *bs; |
3499 | jermar | 954 | size_t bytes; |
3530 | jermar | 955 | block_t *b; |
3499 | jermar | 956 | uint16_t bps; |
957 | unsigned spc; |
||
3572 | jermar | 958 | unsigned bpc; /* bytes per cluster */ |
3501 | jermar | 959 | off_t boundary; |
3595 | jermar | 960 | int flags = BLOCK_FLAGS_NONE; |
3499 | jermar | 961 | |
962 | if (!nodep) { |
||
963 | ipc_answer_0(rid, ENOENT); |
||
964 | return; |
||
965 | } |
||
966 | |||
967 | ipc_callid_t callid; |
||
968 | size_t len; |
||
969 | if (!ipc_data_write_receive(&callid, &len)) { |
||
970 | fat_node_put(nodep); |
||
971 | ipc_answer_0(callid, EINVAL); |
||
972 | ipc_answer_0(rid, EINVAL); |
||
973 | return; |
||
974 | } |
||
975 | |||
3572 | jermar | 976 | bs = block_bb_get(dev_handle); |
977 | bps = uint16_t_le2host(bs->bps); |
||
978 | spc = bs->spc; |
||
979 | bpc = bps * spc; |
||
980 | |||
3499 | jermar | 981 | /* |
982 | * In all scenarios, we will attempt to write out only one block worth |
||
983 | * of data at maximum. There might be some more efficient approaches, |
||
984 | * but this one greatly simplifies fat_write(). Note that we can afford |
||
985 | * to do this because the client must be ready to handle the return |
||
986 | * value signalizing a smaller number of bytes written. |
||
987 | */ |
||
988 | bytes = min(len, bps - pos % bps); |
||
3595 | jermar | 989 | if (bytes == bps) |
990 | flags |= BLOCK_FLAGS_NOREAD; |
||
3499 | jermar | 991 | |
3572 | jermar | 992 | boundary = ROUND_UP(nodep->size, bpc); |
3501 | jermar | 993 | if (pos < boundary) { |
3499 | jermar | 994 | /* |
995 | * This is the easier case - we are either overwriting already |
||
996 | * existing contents or writing behind the EOF, but still within |
||
997 | * the limits of the last cluster. The node size may grow to the |
||
998 | * next block size boundary. |
||
999 | */ |
||
3530 | jermar | 1000 | fat_fill_gap(bs, nodep, FAT_CLST_RES0, pos); |
3595 | jermar | 1001 | b = fat_block_get(bs, nodep, pos / bps, flags); |
3499 | jermar | 1002 | (void) ipc_data_write_finalize(callid, b->data + pos % bps, |
1003 | bytes); |
||
1004 | b->dirty = true; /* need to sync block */ |
||
3500 | jermar | 1005 | block_put(b); |
3499 | jermar | 1006 | if (pos + bytes > nodep->size) { |
1007 | nodep->size = pos + bytes; |
||
1008 | nodep->dirty = true; /* need to sync node */ |
||
1009 | } |
||
3573 | jermar | 1010 | ipc_answer_2(rid, EOK, bytes, nodep->size); |
3499 | jermar | 1011 | fat_node_put(nodep); |
1012 | return; |
||
1013 | } else { |
||
1014 | /* |
||
1015 | * This is the more difficult case. We must allocate new |
||
1016 | * clusters for the node and zero them out. |
||
1017 | */ |
||
3500 | jermar | 1018 | int status; |
3499 | jermar | 1019 | unsigned nclsts; |
3548 | jermar | 1020 | fat_cluster_t mcl, lcl; |
1021 | |||
3572 | jermar | 1022 | nclsts = (ROUND_UP(pos + bytes, bpc) - boundary) / bpc; |
3500 | jermar | 1023 | /* create an independent chain of nclsts clusters in all FATs */ |
3572 | jermar | 1024 | status = fat_alloc_clusters(bs, dev_handle, nclsts, &mcl, &lcl); |
3500 | jermar | 1025 | if (status != EOK) { |
1026 | /* could not allocate a chain of nclsts clusters */ |
||
1027 | fat_node_put(nodep); |
||
1028 | ipc_answer_0(callid, status); |
||
1029 | ipc_answer_0(rid, status); |
||
1030 | return; |
||
1031 | } |
||
1032 | /* zero fill any gaps */ |
||
3530 | jermar | 1033 | fat_fill_gap(bs, nodep, mcl, pos); |
3595 | jermar | 1034 | b = _fat_block_get(bs, dev_handle, lcl, (pos / bps) % spc, |
1035 | flags); |
||
3500 | jermar | 1036 | (void) ipc_data_write_finalize(callid, b->data + pos % bps, |
1037 | bytes); |
||
3501 | jermar | 1038 | b->dirty = true; /* need to sync block */ |
3500 | jermar | 1039 | block_put(b); |
1040 | /* |
||
1041 | * Append the cluster chain starting in mcl to the end of the |
||
1042 | * node's cluster chain. |
||
1043 | */ |
||
3530 | jermar | 1044 | fat_append_clusters(bs, nodep, mcl); |
3500 | jermar | 1045 | nodep->size = pos + bytes; |
3501 | jermar | 1046 | nodep->dirty = true; /* need to sync node */ |
3573 | jermar | 1047 | ipc_answer_2(rid, EOK, bytes, nodep->size); |
3500 | jermar | 1048 | fat_node_put(nodep); |
1049 | return; |
||
3499 | jermar | 1050 | } |
3497 | jermar | 1051 | } |
1052 | |||
3546 | jermar | 1053 | void fat_truncate(ipc_callid_t rid, ipc_call_t *request) |
1054 | { |
||
3548 | jermar | 1055 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
1056 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
||
1057 | size_t size = (off_t)IPC_GET_ARG3(*request); |
||
1058 | fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
||
3572 | jermar | 1059 | fat_bs_t *bs; |
1060 | uint16_t bps; |
||
1061 | uint8_t spc; |
||
1062 | unsigned bpc; /* bytes per cluster */ |
||
3548 | jermar | 1063 | int rc; |
1064 | |||
1065 | if (!nodep) { |
||
1066 | ipc_answer_0(rid, ENOENT); |
||
1067 | return; |
||
1068 | } |
||
1069 | |||
3572 | jermar | 1070 | bs = block_bb_get(dev_handle); |
1071 | bps = uint16_t_le2host(bs->bps); |
||
1072 | spc = bs->spc; |
||
1073 | bpc = bps * spc; |
||
1074 | |||
3548 | jermar | 1075 | if (nodep->size == size) { |
1076 | rc = EOK; |
||
1077 | } else if (nodep->size < size) { |
||
1078 | /* |
||
3572 | jermar | 1079 | * The standard says we have the freedom to grow the node. |
3548 | jermar | 1080 | * For now, we simply return an error. |
1081 | */ |
||
1082 | rc = EINVAL; |
||
3572 | jermar | 1083 | } else if (ROUND_UP(nodep->size, bpc) == ROUND_UP(size, bpc)) { |
1084 | /* |
||
1085 | * The node will be shrunk, but no clusters will be deallocated. |
||
1086 | */ |
||
1087 | nodep->size = size; |
||
1088 | nodep->dirty = true; /* need to sync node */ |
||
1089 | rc = EOK; |
||
3548 | jermar | 1090 | } else { |
1091 | /* |
||
3572 | jermar | 1092 | * The node will be shrunk, clusters will be deallocated. |
3548 | jermar | 1093 | */ |
3572 | jermar | 1094 | if (size == 0) { |
1095 | fat_chop_clusters(bs, nodep, FAT_CLST_RES0); |
||
1096 | } else { |
||
1097 | fat_cluster_t lastc; |
||
1098 | (void) fat_cluster_walk(bs, dev_handle, nodep->firstc, |
||
1099 | &lastc, (size - 1) / bpc); |
||
1100 | fat_chop_clusters(bs, nodep, lastc); |
||
1101 | } |
||
1102 | nodep->size = size; |
||
1103 | nodep->dirty = true; /* need to sync node */ |
||
1104 | rc = EOK; |
||
3548 | jermar | 1105 | } |
1106 | fat_node_put(nodep); |
||
1107 | ipc_answer_0(rid, rc); |
||
1108 | return; |
||
3546 | jermar | 1109 | } |
1110 | |||
3621 | jermar | 1111 | void fat_destroy(ipc_callid_t rid, ipc_call_t *request) |
1112 | { |
||
1113 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
||
1114 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
||
1115 | int rc; |
||
1116 | |||
1117 | fat_node_t *nodep = fat_node_get(dev_handle, index); |
||
1118 | if (!nodep) { |
||
1119 | ipc_answer_0(rid, ENOENT); |
||
1120 | return; |
||
1121 | } |
||
1122 | |||
1123 | rc = fat_destroy_node(nodep); |
||
1124 | ipc_answer_0(rid, rc); |
||
1125 | } |
||
1126 | |||
2627 | jermar | 1127 | /** |
1128 | * @} |
||
1129 | */ |