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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 | * We don't create the '.' and '..' entries, since they are |
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324 | * optional and HelenOS VFS does not need them. |
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325 | */ |
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326 | for (i = 0; i < bs->spc; i++) { |
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327 | b = _fat_block_get(bs, dev_handle, mcl, i, |
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328 | BLOCK_FLAGS_NOREAD); |
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329 | /* mark all dentries as never-used */ |
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330 | memset(b->data, 0, bps); |
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331 | b->dirty = false; |
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332 | block_put(b); |
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333 | } |
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3609 | jermar | 334 | nodep->type = FAT_DIRECTORY; |
3633 | jermar | 335 | nodep->firstc = mcl; |
336 | nodep->size = bps * bs->spc; |
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3609 | jermar | 337 | } else { |
338 | nodep->type = FAT_FILE; |
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3633 | jermar | 339 | nodep->firstc = FAT_CLST_RES0; |
340 | nodep->size = 0; |
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3609 | jermar | 341 | } |
342 | nodep->lnkcnt = 0; /* not linked anywhere */ |
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343 | nodep->refcnt = 1; |
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3633 | jermar | 344 | nodep->dirty = true; |
3609 | jermar | 345 | |
346 | nodep->idx = idxp; |
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347 | idxp->nodep = nodep; |
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348 | |||
349 | futex_up(&idxp->lock); |
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350 | return nodep; |
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2857 | jermar | 351 | } |
352 | |||
3621 | jermar | 353 | int fat_destroy_node(void *node) |
2857 | jermar | 354 | { |
3621 | jermar | 355 | fat_node_t *nodep = (fat_node_t *)node; |
356 | fat_bs_t *bs; |
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357 | |||
358 | /* |
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359 | * The node is not reachable from the file system. This means that the |
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360 | * link count should be zero and that the index structure cannot be |
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361 | * found in the position hash. Obviously, we don't need to lock the node |
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362 | * nor its index structure. |
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363 | */ |
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364 | assert(nodep->lnkcnt == 0); |
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365 | |||
366 | /* |
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367 | * The node may not have any children. |
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368 | */ |
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369 | assert(fat_has_children(node) == false); |
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370 | |||
371 | bs = block_bb_get(nodep->idx->dev_handle); |
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372 | if (nodep->firstc != FAT_CLST_RES0) { |
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373 | assert(nodep->size); |
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374 | /* Free all clusters allocated to the node. */ |
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375 | fat_free_clusters(bs, nodep->idx->dev_handle, nodep->firstc); |
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376 | } |
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377 | |||
378 | fat_idx_destroy(nodep->idx); |
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379 | free(nodep); |
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380 | return EOK; |
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2857 | jermar | 381 | } |
382 | |||
3625 | jermar | 383 | int fat_link(void *prnt, void *chld, const char *name) |
2857 | jermar | 384 | { |
3628 | jermar | 385 | fat_node_t *parentp = (fat_node_t *)prnt; |
386 | fat_node_t *childp = (fat_node_t *)chld; |
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387 | fat_dentry_t *d; |
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388 | fat_bs_t *bs; |
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389 | block_t *b; |
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390 | int i, j; |
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391 | uint16_t bps; |
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392 | unsigned dps; |
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393 | unsigned blocks; |
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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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446 | futex_up(&parentp->idx->lock); |
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447 | return ENOTSUP; /* XXX */ |
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448 | |||
449 | hit: |
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450 | /* |
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451 | * At this point we only establish the link between the parent and the |
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452 | * child. The dentry, except of the name and the extension, will remain |
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453 | * uninitialized until the the corresponding node is synced. Thus the |
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454 | * valid dentry data is kept in the child node structure. |
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455 | */ |
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456 | memset(d, 0, sizeof(fat_dentry_t)); |
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457 | fat_dentry_name_set(d, name); |
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458 | b->dirty = true; /* need to sync block */ |
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459 | block_put(b); |
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460 | futex_up(&parentp->idx->lock); |
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461 | |||
462 | futex_down(&childp->idx->lock); |
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463 | childp->idx->pfc = parentp->firstc; |
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464 | childp->idx->pdi = i * dps + j; |
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465 | futex_up(&childp->idx->lock); |
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466 | |||
467 | futex_down(&childp->lock); |
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468 | childp->lnkcnt = 1; |
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469 | childp->dirty = true; /* need to sync node */ |
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470 | futex_up(&childp->lock); |
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471 | |||
472 | /* |
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473 | * Hash in the index structure into the position hash. |
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474 | */ |
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475 | fat_idx_hashin(childp->idx); |
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476 | |||
477 | return EOK; |
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2857 | jermar | 478 | } |
479 | |||
3621 | jermar | 480 | int fat_unlink(void *prnt, void *chld) |
2857 | jermar | 481 | { |
3638 | jermar | 482 | fat_node_t *parentp = (fat_node_t *)prnt; |
483 | fat_node_t *childp = (fat_node_t *)chld; |
||
484 | fat_bs_t *bs; |
||
485 | fat_dentry_t *d; |
||
486 | uint16_t bps; |
||
487 | block_t *b; |
||
488 | |||
489 | futex_down(&parentp->lock); |
||
490 | futex_down(&childp->lock); |
||
491 | assert(childp->lnkcnt == 1); |
||
492 | futex_down(&childp->idx->lock); |
||
493 | bs = block_bb_get(childp->idx->dev_handle); |
||
494 | bps = uint16_t_le2host(bs->bps); |
||
495 | |||
496 | b = _fat_block_get(bs, childp->idx->dev_handle, childp->idx->pfc, |
||
497 | (childp->idx->pdi * sizeof(fat_dentry_t)) / bps, |
||
498 | BLOCK_FLAGS_NONE); |
||
499 | d = (fat_dentry_t *)b->data + |
||
500 | (childp->idx->pdi % (bps / sizeof(fat_dentry_t))); |
||
501 | /* mark the dentry as not-currently-used */ |
||
502 | d->name[0] = FAT_DENTRY_ERASED; |
||
503 | b->dirty = true; /* need to sync block */ |
||
504 | block_put(b); |
||
505 | |||
506 | /* remove the index structure from the position hash */ |
||
507 | fat_idx_hashout(childp->idx); |
||
508 | /* clear position information */ |
||
509 | childp->idx->pfc = FAT_CLST_RES0; |
||
510 | childp->idx->pdi = 0; |
||
511 | futex_up(&childp->idx->lock); |
||
512 | childp->lnkcnt = 0; |
||
513 | childp->dirty = true; |
||
514 | futex_up(&childp->lock); |
||
515 | futex_up(&parentp->lock); |
||
516 | |||
517 | return EOK; |
||
2857 | jermar | 518 | } |
519 | |||
3621 | jermar | 520 | void *fat_match(void *prnt, const char *component) |
2793 | jermar | 521 | { |
3530 | jermar | 522 | fat_bs_t *bs; |
2793 | jermar | 523 | fat_node_t *parentp = (fat_node_t *)prnt; |
524 | char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1]; |
||
2822 | jermar | 525 | unsigned i, j; |
2828 | jermar | 526 | unsigned bps; /* bytes per sector */ |
2822 | jermar | 527 | unsigned dps; /* dentries per sector */ |
528 | unsigned blocks; |
||
2793 | jermar | 529 | fat_dentry_t *d; |
3530 | jermar | 530 | block_t *b; |
2793 | jermar | 531 | |
2953 | jermar | 532 | futex_down(&parentp->idx->lock); |
3530 | jermar | 533 | bs = block_bb_get(parentp->idx->dev_handle); |
534 | bps = uint16_t_le2host(bs->bps); |
||
2828 | jermar | 535 | dps = bps / sizeof(fat_dentry_t); |
3526 | jermar | 536 | blocks = parentp->size / bps; |
2822 | jermar | 537 | for (i = 0; i < blocks; i++) { |
3595 | jermar | 538 | b = fat_block_get(bs, parentp, i, BLOCK_FLAGS_NONE); |
3526 | jermar | 539 | for (j = 0; j < dps; j++) { |
2822 | jermar | 540 | d = ((fat_dentry_t *)b->data) + j; |
2845 | jermar | 541 | switch (fat_classify_dentry(d)) { |
542 | case FAT_DENTRY_SKIP: |
||
3628 | jermar | 543 | case FAT_DENTRY_FREE: |
2822 | jermar | 544 | continue; |
2845 | jermar | 545 | case FAT_DENTRY_LAST: |
2822 | jermar | 546 | block_put(b); |
2953 | jermar | 547 | futex_up(&parentp->idx->lock); |
2822 | jermar | 548 | return NULL; |
2845 | jermar | 549 | default: |
550 | case FAT_DENTRY_VALID: |
||
3628 | jermar | 551 | fat_dentry_name_get(d, name); |
2845 | jermar | 552 | break; |
2822 | jermar | 553 | } |
3634 | jermar | 554 | if (fat_dentry_namecmp(name, component) == 0) { |
2822 | jermar | 555 | /* hit */ |
2951 | jermar | 556 | void *node; |
2953 | jermar | 557 | /* |
558 | * Assume tree hierarchy for locking. We |
||
559 | * already have the parent and now we are going |
||
560 | * to lock the child. Never lock in the oposite |
||
561 | * order. |
||
562 | */ |
||
2890 | jermar | 563 | fat_idx_t *idx = fat_idx_get_by_pos( |
2881 | jermar | 564 | parentp->idx->dev_handle, parentp->firstc, |
2864 | jermar | 565 | i * dps + j); |
2953 | jermar | 566 | futex_up(&parentp->idx->lock); |
2890 | jermar | 567 | if (!idx) { |
568 | /* |
||
569 | * Can happen if memory is low or if we |
||
570 | * run out of 32-bit indices. |
||
571 | */ |
||
572 | block_put(b); |
||
573 | return NULL; |
||
574 | } |
||
2951 | jermar | 575 | node = fat_node_get_core(idx); |
576 | futex_up(&idx->lock); |
||
2822 | jermar | 577 | block_put(b); |
578 | return node; |
||
579 | } |
||
2793 | jermar | 580 | } |
2822 | jermar | 581 | block_put(b); |
2639 | jermar | 582 | } |
3516 | jermar | 583 | |
2953 | jermar | 584 | futex_up(&parentp->idx->lock); |
2793 | jermar | 585 | return NULL; |
2638 | jermar | 586 | } |
587 | |||
3621 | jermar | 588 | fs_index_t fat_index_get(void *node) |
2831 | jermar | 589 | { |
590 | fat_node_t *fnodep = (fat_node_t *)node; |
||
591 | if (!fnodep) |
||
592 | return 0; |
||
2864 | jermar | 593 | return fnodep->idx->index; |
2831 | jermar | 594 | } |
595 | |||
3621 | jermar | 596 | size_t fat_size_get(void *node) |
2831 | jermar | 597 | { |
598 | return ((fat_node_t *)node)->size; |
||
599 | } |
||
600 | |||
3621 | jermar | 601 | unsigned fat_lnkcnt_get(void *node) |
2831 | jermar | 602 | { |
603 | return ((fat_node_t *)node)->lnkcnt; |
||
604 | } |
||
605 | |||
3621 | jermar | 606 | bool fat_has_children(void *node) |
2845 | jermar | 607 | { |
3530 | jermar | 608 | fat_bs_t *bs; |
2845 | jermar | 609 | fat_node_t *nodep = (fat_node_t *)node; |
610 | unsigned bps; |
||
611 | unsigned dps; |
||
612 | unsigned blocks; |
||
3530 | jermar | 613 | block_t *b; |
2845 | jermar | 614 | unsigned i, j; |
615 | |||
616 | if (nodep->type != FAT_DIRECTORY) |
||
617 | return false; |
||
3526 | jermar | 618 | |
2951 | jermar | 619 | futex_down(&nodep->idx->lock); |
3530 | jermar | 620 | bs = block_bb_get(nodep->idx->dev_handle); |
621 | bps = uint16_t_le2host(bs->bps); |
||
2845 | jermar | 622 | dps = bps / sizeof(fat_dentry_t); |
623 | |||
3526 | jermar | 624 | blocks = nodep->size / bps; |
2845 | jermar | 625 | |
626 | for (i = 0; i < blocks; i++) { |
||
627 | fat_dentry_t *d; |
||
628 | |||
3595 | jermar | 629 | b = fat_block_get(bs, nodep, i, BLOCK_FLAGS_NONE); |
3526 | jermar | 630 | for (j = 0; j < dps; j++) { |
2845 | jermar | 631 | d = ((fat_dentry_t *)b->data) + j; |
632 | switch (fat_classify_dentry(d)) { |
||
633 | case FAT_DENTRY_SKIP: |
||
3628 | jermar | 634 | case FAT_DENTRY_FREE: |
2845 | jermar | 635 | continue; |
636 | case FAT_DENTRY_LAST: |
||
637 | block_put(b); |
||
2951 | jermar | 638 | futex_up(&nodep->idx->lock); |
2845 | jermar | 639 | return false; |
640 | default: |
||
641 | case FAT_DENTRY_VALID: |
||
642 | block_put(b); |
||
2951 | jermar | 643 | futex_up(&nodep->idx->lock); |
2845 | jermar | 644 | return true; |
645 | } |
||
646 | block_put(b); |
||
2951 | jermar | 647 | futex_up(&nodep->idx->lock); |
2845 | jermar | 648 | return true; |
649 | } |
||
650 | block_put(b); |
||
651 | } |
||
652 | |||
2951 | jermar | 653 | futex_up(&nodep->idx->lock); |
2845 | jermar | 654 | return false; |
655 | } |
||
656 | |||
3621 | jermar | 657 | void *fat_root_get(dev_handle_t dev_handle) |
2844 | jermar | 658 | { |
3119 | jermar | 659 | return fat_node_get(dev_handle, 0); |
2844 | jermar | 660 | } |
661 | |||
3621 | jermar | 662 | char fat_plb_get_char(unsigned pos) |
2844 | jermar | 663 | { |
664 | return fat_reg.plb_ro[pos % PLB_SIZE]; |
||
665 | } |
||
666 | |||
3621 | jermar | 667 | bool fat_is_directory(void *node) |
2831 | jermar | 668 | { |
669 | return ((fat_node_t *)node)->type == FAT_DIRECTORY; |
||
670 | } |
||
671 | |||
3621 | jermar | 672 | bool fat_is_file(void *node) |
2831 | jermar | 673 | { |
674 | return ((fat_node_t *)node)->type == FAT_FILE; |
||
675 | } |
||
676 | |||
2793 | jermar | 677 | /** libfs operations */ |
678 | libfs_ops_t fat_libfs_ops = { |
||
679 | .match = fat_match, |
||
680 | .node_get = fat_node_get, |
||
2852 | jermar | 681 | .node_put = fat_node_put, |
3609 | jermar | 682 | .create = fat_create_node, |
683 | .destroy = fat_destroy_node, |
||
2857 | jermar | 684 | .link = fat_link, |
685 | .unlink = fat_unlink, |
||
2831 | jermar | 686 | .index_get = fat_index_get, |
687 | .size_get = fat_size_get, |
||
688 | .lnkcnt_get = fat_lnkcnt_get, |
||
2845 | jermar | 689 | .has_children = fat_has_children, |
2844 | jermar | 690 | .root_get = fat_root_get, |
691 | .plb_get_char = fat_plb_get_char, |
||
2831 | jermar | 692 | .is_directory = fat_is_directory, |
693 | .is_file = fat_is_file |
||
2793 | jermar | 694 | }; |
695 | |||
3625 | jermar | 696 | /* |
697 | * VFS operations. |
||
698 | */ |
||
699 | |||
3110 | jermar | 700 | void fat_mounted(ipc_callid_t rid, ipc_call_t *request) |
701 | { |
||
702 | dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request); |
||
3530 | jermar | 703 | fat_bs_t *bs; |
3257 | jermar | 704 | uint16_t bps; |
3119 | jermar | 705 | uint16_t rde; |
3110 | jermar | 706 | int rc; |
707 | |||
3530 | jermar | 708 | /* initialize libblock */ |
3537 | jermar | 709 | rc = block_init(dev_handle, BS_SIZE); |
3257 | jermar | 710 | if (rc != EOK) { |
3537 | jermar | 711 | ipc_answer_0(rid, rc); |
3257 | jermar | 712 | return; |
713 | } |
||
714 | |||
3537 | jermar | 715 | /* prepare the boot block */ |
716 | rc = block_bb_read(dev_handle, BS_BLOCK * BS_SIZE, BS_SIZE); |
||
717 | if (rc != EOK) { |
||
718 | block_fini(dev_handle); |
||
719 | ipc_answer_0(rid, rc); |
||
720 | return; |
||
721 | } |
||
722 | |||
3530 | jermar | 723 | /* get the buffer with the boot sector */ |
724 | bs = block_bb_get(dev_handle); |
||
725 | |||
3119 | jermar | 726 | /* Read the number of root directory entries. */ |
3530 | jermar | 727 | bps = uint16_t_le2host(bs->bps); |
728 | rde = uint16_t_le2host(bs->root_ent_max); |
||
3119 | jermar | 729 | |
3257 | jermar | 730 | if (bps != BS_SIZE) { |
3530 | jermar | 731 | block_fini(dev_handle); |
3257 | jermar | 732 | ipc_answer_0(rid, ENOTSUP); |
733 | return; |
||
734 | } |
||
735 | |||
3539 | jermar | 736 | /* Initialize the block cache */ |
737 | rc = block_cache_init(dev_handle, bps, 0 /* XXX */); |
||
738 | if (rc != EOK) { |
||
739 | block_fini(dev_handle); |
||
740 | ipc_answer_0(rid, rc); |
||
741 | return; |
||
742 | } |
||
743 | |||
3110 | jermar | 744 | rc = fat_idx_init_by_dev_handle(dev_handle); |
745 | if (rc != EOK) { |
||
3530 | jermar | 746 | block_fini(dev_handle); |
3110 | jermar | 747 | ipc_answer_0(rid, rc); |
748 | return; |
||
749 | } |
||
750 | |||
3119 | jermar | 751 | /* Initialize the root node. */ |
752 | fat_node_t *rootp = (fat_node_t *)malloc(sizeof(fat_node_t)); |
||
753 | if (!rootp) { |
||
3530 | jermar | 754 | block_fini(dev_handle); |
3119 | jermar | 755 | fat_idx_fini_by_dev_handle(dev_handle); |
756 | ipc_answer_0(rid, ENOMEM); |
||
757 | return; |
||
758 | } |
||
759 | fat_node_initialize(rootp); |
||
760 | |||
761 | fat_idx_t *ridxp = fat_idx_get_by_pos(dev_handle, FAT_CLST_ROOTPAR, 0); |
||
762 | if (!ridxp) { |
||
3530 | jermar | 763 | block_fini(dev_handle); |
3119 | jermar | 764 | free(rootp); |
765 | fat_idx_fini_by_dev_handle(dev_handle); |
||
766 | ipc_answer_0(rid, ENOMEM); |
||
767 | return; |
||
768 | } |
||
769 | assert(ridxp->index == 0); |
||
770 | /* ridxp->lock held */ |
||
771 | |||
772 | rootp->type = FAT_DIRECTORY; |
||
773 | rootp->firstc = FAT_CLST_ROOT; |
||
774 | rootp->refcnt = 1; |
||
3352 | jermar | 775 | rootp->lnkcnt = 0; /* FS root is not linked */ |
3119 | jermar | 776 | rootp->size = rde * sizeof(fat_dentry_t); |
777 | rootp->idx = ridxp; |
||
778 | ridxp->nodep = rootp; |
||
779 | |||
780 | futex_up(&ridxp->lock); |
||
781 | |||
3352 | jermar | 782 | ipc_answer_3(rid, EOK, ridxp->index, rootp->size, rootp->lnkcnt); |
3110 | jermar | 783 | } |
784 | |||
785 | void fat_mount(ipc_callid_t rid, ipc_call_t *request) |
||
786 | { |
||
787 | ipc_answer_0(rid, ENOTSUP); |
||
788 | } |
||
789 | |||
2627 | jermar | 790 | void fat_lookup(ipc_callid_t rid, ipc_call_t *request) |
791 | { |
||
2793 | jermar | 792 | libfs_lookup(&fat_libfs_ops, fat_reg.fs_handle, rid, request); |
2627 | jermar | 793 | } |
794 | |||
3307 | jermar | 795 | void fat_read(ipc_callid_t rid, ipc_call_t *request) |
796 | { |
||
797 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
||
798 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
||
799 | off_t pos = (off_t)IPC_GET_ARG3(*request); |
||
800 | fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
||
3530 | jermar | 801 | fat_bs_t *bs; |
3516 | jermar | 802 | uint16_t bps; |
3308 | jermar | 803 | size_t bytes; |
3530 | jermar | 804 | block_t *b; |
3308 | jermar | 805 | |
3307 | jermar | 806 | if (!nodep) { |
807 | ipc_answer_0(rid, ENOENT); |
||
808 | return; |
||
809 | } |
||
810 | |||
811 | ipc_callid_t callid; |
||
812 | size_t len; |
||
3314 | jermar | 813 | if (!ipc_data_read_receive(&callid, &len)) { |
3307 | jermar | 814 | fat_node_put(nodep); |
815 | ipc_answer_0(callid, EINVAL); |
||
816 | ipc_answer_0(rid, EINVAL); |
||
817 | return; |
||
818 | } |
||
819 | |||
3530 | jermar | 820 | bs = block_bb_get(dev_handle); |
821 | bps = uint16_t_le2host(bs->bps); |
||
3516 | jermar | 822 | |
3307 | jermar | 823 | if (nodep->type == FAT_FILE) { |
3335 | jermar | 824 | /* |
825 | * Our strategy for regular file reads is to read one block at |
||
826 | * most and make use of the possibility to return less data than |
||
827 | * requested. This keeps the code very simple. |
||
828 | */ |
||
3532 | jermar | 829 | if (pos >= nodep->size) { |
3533 | jermar | 830 | /* reading beyond the EOF */ |
831 | bytes = 0; |
||
3532 | jermar | 832 | (void) ipc_data_read_finalize(callid, NULL, 0); |
833 | } else { |
||
834 | bytes = min(len, bps - pos % bps); |
||
835 | bytes = min(bytes, nodep->size - pos); |
||
3595 | jermar | 836 | b = fat_block_get(bs, nodep, pos / bps, |
837 | BLOCK_FLAGS_NONE); |
||
3532 | jermar | 838 | (void) ipc_data_read_finalize(callid, b->data + pos % bps, |
839 | bytes); |
||
840 | block_put(b); |
||
841 | } |
||
3307 | jermar | 842 | } else { |
3335 | jermar | 843 | unsigned bnum; |
844 | off_t spos = pos; |
||
845 | char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1]; |
||
846 | fat_dentry_t *d; |
||
847 | |||
3307 | jermar | 848 | assert(nodep->type == FAT_DIRECTORY); |
3335 | jermar | 849 | assert(nodep->size % bps == 0); |
850 | assert(bps % sizeof(fat_dentry_t) == 0); |
||
851 | |||
852 | /* |
||
853 | * Our strategy for readdir() is to use the position pointer as |
||
854 | * an index into the array of all dentries. On entry, it points |
||
855 | * to the first unread dentry. If we skip any dentries, we bump |
||
856 | * the position pointer accordingly. |
||
857 | */ |
||
858 | bnum = (pos * sizeof(fat_dentry_t)) / bps; |
||
859 | while (bnum < nodep->size / bps) { |
||
860 | off_t o; |
||
861 | |||
3595 | jermar | 862 | b = fat_block_get(bs, nodep, bnum, BLOCK_FLAGS_NONE); |
3335 | jermar | 863 | for (o = pos % (bps / sizeof(fat_dentry_t)); |
864 | o < bps / sizeof(fat_dentry_t); |
||
865 | o++, pos++) { |
||
866 | d = ((fat_dentry_t *)b->data) + o; |
||
867 | switch (fat_classify_dentry(d)) { |
||
868 | case FAT_DENTRY_SKIP: |
||
3628 | jermar | 869 | case FAT_DENTRY_FREE: |
3335 | jermar | 870 | continue; |
871 | case FAT_DENTRY_LAST: |
||
872 | block_put(b); |
||
873 | goto miss; |
||
874 | default: |
||
875 | case FAT_DENTRY_VALID: |
||
3628 | jermar | 876 | fat_dentry_name_get(d, name); |
3335 | jermar | 877 | block_put(b); |
878 | goto hit; |
||
879 | } |
||
880 | } |
||
881 | block_put(b); |
||
882 | bnum++; |
||
883 | } |
||
884 | miss: |
||
3307 | jermar | 885 | fat_node_put(nodep); |
3335 | jermar | 886 | ipc_answer_0(callid, ENOENT); |
887 | ipc_answer_1(rid, ENOENT, 0); |
||
3307 | jermar | 888 | return; |
3335 | jermar | 889 | hit: |
890 | (void) ipc_data_read_finalize(callid, name, strlen(name) + 1); |
||
891 | bytes = (pos - spos) + 1; |
||
3307 | jermar | 892 | } |
893 | |||
894 | fat_node_put(nodep); |
||
3308 | jermar | 895 | ipc_answer_1(rid, EOK, (ipcarg_t)bytes); |
3307 | jermar | 896 | } |
897 | |||
3497 | jermar | 898 | void fat_write(ipc_callid_t rid, ipc_call_t *request) |
899 | { |
||
3499 | jermar | 900 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
901 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
||
902 | off_t pos = (off_t)IPC_GET_ARG3(*request); |
||
903 | fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
||
3530 | jermar | 904 | fat_bs_t *bs; |
3499 | jermar | 905 | size_t bytes; |
3530 | jermar | 906 | block_t *b; |
3499 | jermar | 907 | uint16_t bps; |
908 | unsigned spc; |
||
3572 | jermar | 909 | unsigned bpc; /* bytes per cluster */ |
3501 | jermar | 910 | off_t boundary; |
3595 | jermar | 911 | int flags = BLOCK_FLAGS_NONE; |
3499 | jermar | 912 | |
913 | if (!nodep) { |
||
914 | ipc_answer_0(rid, ENOENT); |
||
915 | return; |
||
916 | } |
||
917 | |||
918 | ipc_callid_t callid; |
||
919 | size_t len; |
||
920 | if (!ipc_data_write_receive(&callid, &len)) { |
||
921 | fat_node_put(nodep); |
||
922 | ipc_answer_0(callid, EINVAL); |
||
923 | ipc_answer_0(rid, EINVAL); |
||
924 | return; |
||
925 | } |
||
926 | |||
3572 | jermar | 927 | bs = block_bb_get(dev_handle); |
928 | bps = uint16_t_le2host(bs->bps); |
||
929 | spc = bs->spc; |
||
930 | bpc = bps * spc; |
||
931 | |||
3499 | jermar | 932 | /* |
933 | * In all scenarios, we will attempt to write out only one block worth |
||
934 | * of data at maximum. There might be some more efficient approaches, |
||
935 | * but this one greatly simplifies fat_write(). Note that we can afford |
||
936 | * to do this because the client must be ready to handle the return |
||
937 | * value signalizing a smaller number of bytes written. |
||
938 | */ |
||
939 | bytes = min(len, bps - pos % bps); |
||
3595 | jermar | 940 | if (bytes == bps) |
941 | flags |= BLOCK_FLAGS_NOREAD; |
||
3499 | jermar | 942 | |
3572 | jermar | 943 | boundary = ROUND_UP(nodep->size, bpc); |
3501 | jermar | 944 | if (pos < boundary) { |
3499 | jermar | 945 | /* |
946 | * This is the easier case - we are either overwriting already |
||
947 | * existing contents or writing behind the EOF, but still within |
||
948 | * the limits of the last cluster. The node size may grow to the |
||
949 | * next block size boundary. |
||
950 | */ |
||
3530 | jermar | 951 | fat_fill_gap(bs, nodep, FAT_CLST_RES0, pos); |
3595 | jermar | 952 | b = fat_block_get(bs, nodep, pos / bps, flags); |
3499 | jermar | 953 | (void) ipc_data_write_finalize(callid, b->data + pos % bps, |
954 | bytes); |
||
955 | b->dirty = true; /* need to sync block */ |
||
3500 | jermar | 956 | block_put(b); |
3499 | jermar | 957 | if (pos + bytes > nodep->size) { |
958 | nodep->size = pos + bytes; |
||
959 | nodep->dirty = true; /* need to sync node */ |
||
960 | } |
||
3573 | jermar | 961 | ipc_answer_2(rid, EOK, bytes, nodep->size); |
3499 | jermar | 962 | fat_node_put(nodep); |
963 | return; |
||
964 | } else { |
||
965 | /* |
||
966 | * This is the more difficult case. We must allocate new |
||
967 | * clusters for the node and zero them out. |
||
968 | */ |
||
3500 | jermar | 969 | int status; |
3499 | jermar | 970 | unsigned nclsts; |
3548 | jermar | 971 | fat_cluster_t mcl, lcl; |
972 | |||
3572 | jermar | 973 | nclsts = (ROUND_UP(pos + bytes, bpc) - boundary) / bpc; |
3500 | jermar | 974 | /* create an independent chain of nclsts clusters in all FATs */ |
3572 | jermar | 975 | status = fat_alloc_clusters(bs, dev_handle, nclsts, &mcl, &lcl); |
3500 | jermar | 976 | if (status != EOK) { |
977 | /* could not allocate a chain of nclsts clusters */ |
||
978 | fat_node_put(nodep); |
||
979 | ipc_answer_0(callid, status); |
||
980 | ipc_answer_0(rid, status); |
||
981 | return; |
||
982 | } |
||
983 | /* zero fill any gaps */ |
||
3530 | jermar | 984 | fat_fill_gap(bs, nodep, mcl, pos); |
3595 | jermar | 985 | b = _fat_block_get(bs, dev_handle, lcl, (pos / bps) % spc, |
986 | flags); |
||
3500 | jermar | 987 | (void) ipc_data_write_finalize(callid, b->data + pos % bps, |
988 | bytes); |
||
3501 | jermar | 989 | b->dirty = true; /* need to sync block */ |
3500 | jermar | 990 | block_put(b); |
991 | /* |
||
992 | * Append the cluster chain starting in mcl to the end of the |
||
993 | * node's cluster chain. |
||
994 | */ |
||
3530 | jermar | 995 | fat_append_clusters(bs, nodep, mcl); |
3500 | jermar | 996 | nodep->size = pos + bytes; |
3501 | jermar | 997 | nodep->dirty = true; /* need to sync node */ |
3573 | jermar | 998 | ipc_answer_2(rid, EOK, bytes, nodep->size); |
3500 | jermar | 999 | fat_node_put(nodep); |
1000 | return; |
||
3499 | jermar | 1001 | } |
3497 | jermar | 1002 | } |
1003 | |||
3546 | jermar | 1004 | void fat_truncate(ipc_callid_t rid, ipc_call_t *request) |
1005 | { |
||
3548 | jermar | 1006 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
1007 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
||
1008 | size_t size = (off_t)IPC_GET_ARG3(*request); |
||
1009 | fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
||
3572 | jermar | 1010 | fat_bs_t *bs; |
1011 | uint16_t bps; |
||
1012 | uint8_t spc; |
||
1013 | unsigned bpc; /* bytes per cluster */ |
||
3548 | jermar | 1014 | int rc; |
1015 | |||
1016 | if (!nodep) { |
||
1017 | ipc_answer_0(rid, ENOENT); |
||
1018 | return; |
||
1019 | } |
||
1020 | |||
3572 | jermar | 1021 | bs = block_bb_get(dev_handle); |
1022 | bps = uint16_t_le2host(bs->bps); |
||
1023 | spc = bs->spc; |
||
1024 | bpc = bps * spc; |
||
1025 | |||
3548 | jermar | 1026 | if (nodep->size == size) { |
1027 | rc = EOK; |
||
1028 | } else if (nodep->size < size) { |
||
1029 | /* |
||
3572 | jermar | 1030 | * The standard says we have the freedom to grow the node. |
3548 | jermar | 1031 | * For now, we simply return an error. |
1032 | */ |
||
1033 | rc = EINVAL; |
||
3572 | jermar | 1034 | } else if (ROUND_UP(nodep->size, bpc) == ROUND_UP(size, bpc)) { |
1035 | /* |
||
1036 | * The node will be shrunk, but no clusters will be deallocated. |
||
1037 | */ |
||
1038 | nodep->size = size; |
||
1039 | nodep->dirty = true; /* need to sync node */ |
||
1040 | rc = EOK; |
||
3548 | jermar | 1041 | } else { |
1042 | /* |
||
3572 | jermar | 1043 | * The node will be shrunk, clusters will be deallocated. |
3548 | jermar | 1044 | */ |
3572 | jermar | 1045 | if (size == 0) { |
1046 | fat_chop_clusters(bs, nodep, FAT_CLST_RES0); |
||
1047 | } else { |
||
1048 | fat_cluster_t lastc; |
||
1049 | (void) fat_cluster_walk(bs, dev_handle, nodep->firstc, |
||
1050 | &lastc, (size - 1) / bpc); |
||
1051 | fat_chop_clusters(bs, nodep, lastc); |
||
1052 | } |
||
1053 | nodep->size = size; |
||
1054 | nodep->dirty = true; /* need to sync node */ |
||
1055 | rc = EOK; |
||
3548 | jermar | 1056 | } |
1057 | fat_node_put(nodep); |
||
1058 | ipc_answer_0(rid, rc); |
||
1059 | return; |
||
3546 | jermar | 1060 | } |
1061 | |||
3621 | jermar | 1062 | void fat_destroy(ipc_callid_t rid, ipc_call_t *request) |
1063 | { |
||
1064 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
||
1065 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
||
1066 | int rc; |
||
1067 | |||
1068 | fat_node_t *nodep = fat_node_get(dev_handle, index); |
||
1069 | if (!nodep) { |
||
1070 | ipc_answer_0(rid, ENOENT); |
||
1071 | return; |
||
1072 | } |
||
1073 | |||
1074 | rc = fat_destroy_node(nodep); |
||
1075 | ipc_answer_0(rid, rc); |
||
1076 | } |
||
1077 | |||
2627 | jermar | 1078 | /** |
1079 | * @} |
||
1080 | */ |