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1 | /* |
1 | /* |
2 | * Copyright (c) 2008 Jakub Jermar |
2 | * Copyright (c) 2008 Jakub Jermar |
3 | * All rights reserved. |
3 | * All rights reserved. |
4 | * |
4 | * |
5 | * Redistribution and use in source and binary forms, with or without |
5 | * Redistribution and use in source and binary forms, with or without |
6 | * modification, are permitted provided that the following conditions |
6 | * modification, are permitted provided that the following conditions |
7 | * are met: |
7 | * are met: |
8 | * |
8 | * |
9 | * - Redistributions of source code must retain the above copyright |
9 | * - Redistributions of source code must retain the above copyright |
10 | * notice, this list of conditions and the following disclaimer. |
10 | * notice, this list of conditions and the following disclaimer. |
11 | * - Redistributions in binary form must reproduce the above copyright |
11 | * - Redistributions in binary form must reproduce the above copyright |
12 | * notice, this list of conditions and the following disclaimer in the |
12 | * notice, this list of conditions and the following disclaimer in the |
13 | * documentation and/or other materials provided with the distribution. |
13 | * documentation and/or other materials provided with the distribution. |
14 | * - The name of the author may not be used to endorse or promote products |
14 | * - The name of the author may not be used to endorse or promote products |
15 | * derived from this software without specific prior written permission. |
15 | * derived from this software without specific prior written permission. |
16 | * |
16 | * |
17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
27 | */ |
27 | */ |
28 | 28 | ||
29 | /** @addtogroup fs |
29 | /** @addtogroup fs |
30 | * @{ |
30 | * @{ |
31 | */ |
31 | */ |
32 | 32 | ||
33 | /** |
33 | /** |
34 | * @file fat_fat.c |
34 | * @file fat_fat.c |
35 | * @brief Functions that manipulate the File Allocation Tables. |
35 | * @brief Functions that manipulate the File Allocation Tables. |
36 | */ |
36 | */ |
37 | 37 | ||
38 | #include "fat_fat.h" |
38 | #include "fat_fat.h" |
39 | #include "fat_dentry.h" |
39 | #include "fat_dentry.h" |
40 | #include "fat.h" |
40 | #include "fat.h" |
41 | #include "../../vfs/vfs.h" |
41 | #include "../../vfs/vfs.h" |
42 | #include <libfs.h> |
42 | #include <libfs.h> |
43 | #include <errno.h> |
43 | #include <errno.h> |
44 | #include <byteorder.h> |
44 | #include <byteorder.h> |
45 | #include <align.h> |
45 | #include <align.h> |
46 | #include <assert.h> |
46 | #include <assert.h> |
47 | #include <futex.h> |
47 | #include <futex.h> |
48 | 48 | ||
49 | /** |
49 | /** |
50 | * The fat_alloc_lock futex protects all copies of the File Allocation Table |
50 | * The fat_alloc_lock futex protects all copies of the File Allocation Table |
51 | * during allocation of clusters. The lock does not have to be held durring |
51 | * during allocation of clusters. The lock does not have to be held durring |
52 | * deallocation of clusters. |
52 | * deallocation of clusters. |
53 | */ |
53 | */ |
54 | static futex_t fat_alloc_lock = FUTEX_INITIALIZER; |
54 | static futex_t fat_alloc_lock = FUTEX_INITIALIZER; |
55 | 55 | ||
- | 56 | /** Read block from file located on a FAT file system. |
|
- | 57 | * |
|
- | 58 | * @param bs Buffer holding the boot sector of the file system. |
|
- | 59 | * @param dev_handle Device handle of the file system. |
|
- | 60 | * @param firstc First cluster used by the file. Can be zero if the file |
|
- | 61 | * is empty. |
|
- | 62 | * @param offset Offset in blocks. |
|
- | 63 | * |
|
- | 64 | * @return Block structure holding the requested block. |
|
- | 65 | */ |
|
56 | block_t * |
66 | block_t * |
57 | _fat_block_get(fat_bs_t *bs, dev_handle_t dev_handle, fat_cluster_t firstc, |
67 | _fat_block_get(fat_bs_t *bs, dev_handle_t dev_handle, fat_cluster_t firstc, |
58 | off_t offset) |
68 | off_t offset) |
59 | { |
69 | { |
60 | block_t *b; |
70 | block_t *b; |
61 | unsigned bps; |
71 | unsigned bps; |
62 | unsigned spc; |
72 | unsigned spc; |
63 | unsigned rscnt; /* block address of the first FAT */ |
73 | unsigned rscnt; /* block address of the first FAT */ |
64 | unsigned fatcnt; |
74 | unsigned fatcnt; |
65 | unsigned rde; |
75 | unsigned rde; |
66 | unsigned rds; /* root directory size */ |
76 | unsigned rds; /* root directory size */ |
67 | unsigned sf; |
77 | unsigned sf; |
68 | unsigned ssa; /* size of the system area */ |
78 | unsigned ssa; /* size of the system area */ |
69 | unsigned clusters; |
79 | unsigned clusters; |
70 | fat_cluster_t clst = firstc; |
80 | fat_cluster_t clst = firstc; |
71 | unsigned i; |
81 | unsigned i; |
72 | 82 | ||
73 | bps = uint16_t_le2host(bs->bps); |
83 | bps = uint16_t_le2host(bs->bps); |
74 | spc = bs->spc; |
84 | spc = bs->spc; |
75 | rscnt = uint16_t_le2host(bs->rscnt); |
85 | rscnt = uint16_t_le2host(bs->rscnt); |
76 | fatcnt = bs->fatcnt; |
86 | fatcnt = bs->fatcnt; |
77 | rde = uint16_t_le2host(bs->root_ent_max); |
87 | rde = uint16_t_le2host(bs->root_ent_max); |
78 | sf = uint16_t_le2host(bs->sec_per_fat); |
88 | sf = uint16_t_le2host(bs->sec_per_fat); |
79 | 89 | ||
80 | rds = (sizeof(fat_dentry_t) * rde) / bps; |
90 | rds = (sizeof(fat_dentry_t) * rde) / bps; |
81 | rds += ((sizeof(fat_dentry_t) * rde) % bps != 0); |
91 | rds += ((sizeof(fat_dentry_t) * rde) % bps != 0); |
82 | ssa = rscnt + fatcnt * sf + rds; |
92 | ssa = rscnt + fatcnt * sf + rds; |
83 | 93 | ||
84 | if (firstc == FAT_CLST_ROOT) { |
94 | if (firstc == FAT_CLST_ROOT) { |
85 | /* root directory special case */ |
95 | /* root directory special case */ |
86 | assert(offset < rds); |
96 | assert(offset < rds); |
87 | b = block_get(dev_handle, rscnt + fatcnt * sf + offset, bps); |
97 | b = block_get(dev_handle, rscnt + fatcnt * sf + offset, bps); |
88 | return b; |
98 | return b; |
89 | } |
99 | } |
90 | 100 | ||
91 | clusters = offset / spc; |
101 | clusters = offset / spc; |
92 | for (i = 0; i < clusters; i++) { |
102 | for (i = 0; i < clusters; i++) { |
93 | unsigned fsec; /* sector offset relative to FAT1 */ |
103 | unsigned fsec; /* sector offset relative to FAT1 */ |
94 | unsigned fidx; /* FAT1 entry index */ |
104 | unsigned fidx; /* FAT1 entry index */ |
95 | 105 | ||
96 | assert(clst >= FAT_CLST_FIRST && clst < FAT_CLST_BAD); |
106 | assert(clst >= FAT_CLST_FIRST && clst < FAT_CLST_BAD); |
97 | fsec = (clst * sizeof(fat_cluster_t)) / bps; |
107 | fsec = (clst * sizeof(fat_cluster_t)) / bps; |
98 | fidx = clst % (bps / sizeof(fat_cluster_t)); |
108 | fidx = clst % (bps / sizeof(fat_cluster_t)); |
99 | /* read FAT1 */ |
109 | /* read FAT1 */ |
100 | b = block_get(dev_handle, rscnt + fsec, bps); |
110 | b = block_get(dev_handle, rscnt + fsec, bps); |
101 | clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]); |
111 | clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]); |
102 | assert(clst != FAT_CLST_BAD); |
112 | assert(clst != FAT_CLST_BAD); |
103 | assert(clst < FAT_CLST_LAST1); |
113 | assert(clst < FAT_CLST_LAST1); |
104 | block_put(b); |
114 | block_put(b); |
105 | } |
115 | } |
106 | 116 | ||
107 | b = block_get(dev_handle, ssa + (clst - FAT_CLST_FIRST) * spc + |
117 | b = block_get(dev_handle, ssa + (clst - FAT_CLST_FIRST) * spc + |
108 | offset % spc, bps); |
118 | offset % spc, bps); |
109 | 119 | ||
110 | return b; |
120 | return b; |
111 | } |
121 | } |
112 | 122 | ||
113 | /** Return number of blocks allocated to a file. |
123 | /** Return number of blocks allocated to a file. |
114 | * |
124 | * |
115 | * @param bs Buffer holding the boot sector for the file. |
125 | * @param bs Buffer holding the boot sector for the file. |
116 | * @param dev_handle Device handle of the device with the file. |
126 | * @param dev_handle Device handle of the device with the file. |
117 | * @param firstc First cluster of the file. |
127 | * @param firstc First cluster of the file. |
118 | * @param lastc If non-NULL, output argument holding the |
128 | * @param lastc If non-NULL, output argument holding the |
119 | * last cluster. |
129 | * last cluster. |
120 | * |
130 | * |
121 | * @return Number of blocks allocated to the file. |
131 | * @return Number of blocks allocated to the file. |
122 | */ |
132 | */ |
123 | uint16_t |
133 | uint16_t |
124 | _fat_blcks_get(fat_bs_t *bs, dev_handle_t dev_handle, fat_cluster_t firstc, |
134 | _fat_blcks_get(fat_bs_t *bs, dev_handle_t dev_handle, fat_cluster_t firstc, |
125 | fat_cluster_t *lastc) |
135 | fat_cluster_t *lastc) |
126 | { |
136 | { |
127 | block_t *b; |
137 | block_t *b; |
128 | unsigned bps; |
138 | unsigned bps; |
129 | unsigned spc; |
139 | unsigned spc; |
130 | unsigned rscnt; /* block address of the first FAT */ |
140 | unsigned rscnt; /* block address of the first FAT */ |
131 | unsigned clusters = 0; |
141 | unsigned clusters = 0; |
132 | fat_cluster_t clst = firstc; |
142 | fat_cluster_t clst = firstc; |
133 | 143 | ||
134 | bps = uint16_t_le2host(bs->bps); |
144 | bps = uint16_t_le2host(bs->bps); |
135 | spc = bs->spc; |
145 | spc = bs->spc; |
136 | rscnt = uint16_t_le2host(bs->rscnt); |
146 | rscnt = uint16_t_le2host(bs->rscnt); |
137 | 147 | ||
138 | if (firstc == FAT_CLST_RES0) { |
148 | if (firstc == FAT_CLST_RES0) { |
139 | /* No space allocated to the file. */ |
149 | /* No space allocated to the file. */ |
140 | if (lastc) |
150 | if (lastc) |
141 | *lastc = firstc; |
151 | *lastc = firstc; |
142 | return 0; |
152 | return 0; |
143 | } |
153 | } |
144 | 154 | ||
145 | while (clst < FAT_CLST_LAST1) { |
155 | while (clst < FAT_CLST_LAST1) { |
146 | unsigned fsec; /* sector offset relative to FAT1 */ |
156 | unsigned fsec; /* sector offset relative to FAT1 */ |
147 | unsigned fidx; /* FAT1 entry index */ |
157 | unsigned fidx; /* FAT1 entry index */ |
148 | 158 | ||
149 | assert(clst >= FAT_CLST_FIRST); |
159 | assert(clst >= FAT_CLST_FIRST); |
150 | if (lastc) |
160 | if (lastc) |
151 | *lastc = clst; /* remember the last cluster */ |
161 | *lastc = clst; /* remember the last cluster */ |
152 | fsec = (clst * sizeof(fat_cluster_t)) / bps; |
162 | fsec = (clst * sizeof(fat_cluster_t)) / bps; |
153 | fidx = clst % (bps / sizeof(fat_cluster_t)); |
163 | fidx = clst % (bps / sizeof(fat_cluster_t)); |
154 | /* read FAT1 */ |
164 | /* read FAT1 */ |
155 | b = block_get(dev_handle, rscnt + fsec, bps); |
165 | b = block_get(dev_handle, rscnt + fsec, bps); |
156 | clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]); |
166 | clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]); |
157 | assert(clst != FAT_CLST_BAD); |
167 | assert(clst != FAT_CLST_BAD); |
158 | block_put(b); |
168 | block_put(b); |
159 | clusters++; |
169 | clusters++; |
160 | } |
170 | } |
161 | 171 | ||
162 | if (lastc) |
172 | if (lastc) |
163 | *lastc = clst; |
173 | *lastc = clst; |
164 | return clusters * spc; |
174 | return clusters * spc; |
165 | } |
175 | } |
166 | 176 | ||
167 | /** Fill the gap between EOF and a new file position. |
177 | /** Fill the gap between EOF and a new file position. |
168 | * |
178 | * |
169 | * @param bs Buffer holding the boot sector for nodep. |
179 | * @param bs Buffer holding the boot sector for nodep. |
170 | * @param nodep FAT node with the gap. |
180 | * @param nodep FAT node with the gap. |
171 | * @param mcl First cluster in an independent cluster chain that will |
181 | * @param mcl First cluster in an independent cluster chain that will |
172 | * be later appended to the end of the node's own cluster |
182 | * be later appended to the end of the node's own cluster |
173 | * chain. If pos is still in the last allocated cluster, |
183 | * chain. If pos is still in the last allocated cluster, |
174 | * this argument is ignored. |
184 | * this argument is ignored. |
175 | * @param pos Position in the last node block. |
185 | * @param pos Position in the last node block. |
176 | */ |
186 | */ |
177 | void fat_fill_gap(fat_bs_t *bs, fat_node_t *nodep, fat_cluster_t mcl, off_t pos) |
187 | void fat_fill_gap(fat_bs_t *bs, fat_node_t *nodep, fat_cluster_t mcl, off_t pos) |
178 | { |
188 | { |
179 | uint16_t bps; |
189 | uint16_t bps; |
180 | unsigned spc; |
190 | unsigned spc; |
181 | block_t *b; |
191 | block_t *b; |
182 | off_t o, boundary; |
192 | off_t o, boundary; |
183 | 193 | ||
184 | bps = uint16_t_le2host(bs->bps); |
194 | bps = uint16_t_le2host(bs->bps); |
185 | spc = bs->spc; |
195 | spc = bs->spc; |
186 | 196 | ||
187 | boundary = ROUND_UP(nodep->size, bps * spc); |
197 | boundary = ROUND_UP(nodep->size, bps * spc); |
188 | 198 | ||
189 | /* zero out already allocated space */ |
199 | /* zero out already allocated space */ |
190 | for (o = nodep->size - 1; o < pos && o < boundary; |
200 | for (o = nodep->size - 1; o < pos && o < boundary; |
191 | o = ALIGN_DOWN(o + bps, bps)) { |
201 | o = ALIGN_DOWN(o + bps, bps)) { |
192 | b = fat_block_get(bs, nodep, o / bps); |
202 | b = fat_block_get(bs, nodep, o / bps); |
193 | memset(b->data + o % bps, 0, bps - o % bps); |
203 | memset(b->data + o % bps, 0, bps - o % bps); |
194 | b->dirty = true; /* need to sync node */ |
204 | b->dirty = true; /* need to sync node */ |
195 | block_put(b); |
205 | block_put(b); |
196 | } |
206 | } |
197 | 207 | ||
198 | if (o >= pos) |
208 | if (o >= pos) |
199 | return; |
209 | return; |
200 | 210 | ||
201 | /* zero out the initial part of the new cluster chain */ |
211 | /* zero out the initial part of the new cluster chain */ |
202 | for (o = boundary; o < pos; o += bps) { |
212 | for (o = boundary; o < pos; o += bps) { |
203 | b = _fat_block_get(bs, nodep->idx->dev_handle, mcl, |
213 | b = _fat_block_get(bs, nodep->idx->dev_handle, mcl, |
204 | (o - boundary) / bps); |
214 | (o - boundary) / bps); |
205 | memset(b->data, 0, min(bps, pos - o)); |
215 | memset(b->data, 0, min(bps, pos - o)); |
206 | b->dirty = true; /* need to sync node */ |
216 | b->dirty = true; /* need to sync node */ |
207 | block_put(b); |
217 | block_put(b); |
208 | } |
218 | } |
209 | } |
219 | } |
210 | 220 | ||
- | 221 | /** Mark cluster in one instance of FAT. |
|
- | 222 | * |
|
- | 223 | * @param bs Buffer holding the boot sector for the file system. |
|
- | 224 | * @param dev_handle Device handle for the file system. |
|
- | 225 | * @param fatno Number of the FAT instance where to make the change. |
|
- | 226 | * @param clst Cluster which is to be marked. |
|
- | 227 | * @param value Value mark the cluster with. |
|
- | 228 | */ |
|
211 | void |
229 | void |
212 | fat_mark_cluster(fat_bs_t *bs, dev_handle_t dev_handle, unsigned fatno, |
230 | fat_mark_cluster(fat_bs_t *bs, dev_handle_t dev_handle, unsigned fatno, |
213 | fat_cluster_t clst, fat_cluster_t value) |
231 | fat_cluster_t clst, fat_cluster_t value) |
214 | { |
232 | { |
215 | block_t *b; |
233 | block_t *b; |
216 | uint16_t bps; |
234 | uint16_t bps; |
217 | uint16_t rscnt; |
235 | uint16_t rscnt; |
218 | uint16_t sf; |
236 | uint16_t sf; |
219 | fat_cluster_t *cp; |
237 | fat_cluster_t *cp; |
220 | 238 | ||
221 | bps = uint16_t_le2host(bs->bps); |
239 | bps = uint16_t_le2host(bs->bps); |
222 | rscnt = uint16_t_le2host(bs->rscnt); |
240 | rscnt = uint16_t_le2host(bs->rscnt); |
223 | sf = uint16_t_le2host(bs->sec_per_fat); |
241 | sf = uint16_t_le2host(bs->sec_per_fat); |
224 | 242 | ||
225 | assert(fatno < bs->fatcnt); |
243 | assert(fatno < bs->fatcnt); |
226 | b = block_get(dev_handle, rscnt + sf * fatno + |
244 | b = block_get(dev_handle, rscnt + sf * fatno + |
227 | (clst * sizeof(fat_cluster_t)) / bps, bps); |
245 | (clst * sizeof(fat_cluster_t)) / bps, bps); |
228 | cp = (fat_cluster_t *)b->data + clst % (bps / sizeof(fat_cluster_t)); |
246 | cp = (fat_cluster_t *)b->data + clst % (bps / sizeof(fat_cluster_t)); |
229 | *cp = host2uint16_t_le(value); |
247 | *cp = host2uint16_t_le(value); |
230 | b->dirty = true; /* need to sync block */ |
248 | b->dirty = true; /* need to sync block */ |
231 | block_put(b); |
249 | block_put(b); |
232 | } |
250 | } |
233 | 251 | ||
- | 252 | /** Replay the allocatoin of clusters in all shadow instances of FAT. |
|
- | 253 | * |
|
- | 254 | * @param bs Buffer holding the boot sector of the file system. |
|
- | 255 | * @param dev_handle Device handle of the file system. |
|
- | 256 | * @param lifo Chain of allocated clusters. |
|
- | 257 | * @param nclsts Number of clusters in the lifo chain. |
|
- | 258 | */ |
|
234 | void fat_alloc_shadow_clusters(fat_bs_t *bs, dev_handle_t dev_handle, |
259 | void fat_alloc_shadow_clusters(fat_bs_t *bs, dev_handle_t dev_handle, |
235 | fat_cluster_t *lifo, unsigned nclsts) |
260 | fat_cluster_t *lifo, unsigned nclsts) |
236 | { |
261 | { |
237 | uint8_t fatno; |
262 | uint8_t fatno; |
238 | unsigned c; |
263 | unsigned c; |
239 | 264 | ||
240 | for (fatno = FAT1 + 1; fatno < bs->fatcnt; fatno++) { |
265 | for (fatno = FAT1 + 1; fatno < bs->fatcnt; fatno++) { |
241 | for (c = 0; c < nclsts; c++) { |
266 | for (c = 0; c < nclsts; c++) { |
242 | fat_mark_cluster(bs, dev_handle, fatno, lifo[c], |
267 | fat_mark_cluster(bs, dev_handle, fatno, lifo[c], |
243 | c == 0 ? FAT_CLST_LAST1 : lifo[c - 1]); |
268 | c == 0 ? FAT_CLST_LAST1 : lifo[c - 1]); |
244 | } |
269 | } |
245 | } |
270 | } |
246 | } |
271 | } |
247 | 272 | ||
- | 273 | /** Allocate clusters in FAT1. |
|
- | 274 | * |
|
- | 275 | * This function will attempt to allocate the requested number of clusters in |
|
- | 276 | * the first FAT instance. The FAT will be altered so that the allocated |
|
- | 277 | * clusters form an independent chain (i.e. a chain which does not belong to any |
|
- | 278 | * file yet). |
|
- | 279 | * |
|
- | 280 | * @param bs Buffer holding the boot sector of the file system. |
|
- | 281 | * @param dev_handle Device handle of the file system. |
|
- | 282 | * @param nclsts Number of clusters to allocate. |
|
- | 283 | * @param mcl Output parameter where the first cluster in the chain |
|
- | 284 | * will be returned. |
|
- | 285 | * @param lcl Output parameter where the last cluster in the chain |
|
- | 286 | * will be returned. |
|
- | 287 | * |
|
- | 288 | * @return EOK on success, a negative error code otherwise. |
|
- | 289 | */ |
|
248 | int |
290 | int |
249 | fat_alloc_clusters(fat_bs_t *bs, dev_handle_t dev_handle, unsigned nclsts, |
291 | fat_alloc_clusters(fat_bs_t *bs, dev_handle_t dev_handle, unsigned nclsts, |
250 | fat_cluster_t *mcl, fat_cluster_t *lcl) |
292 | fat_cluster_t *mcl, fat_cluster_t *lcl) |
251 | { |
293 | { |
252 | uint16_t bps; |
294 | uint16_t bps; |
253 | uint16_t rscnt; |
295 | uint16_t rscnt; |
254 | uint16_t sf; |
296 | uint16_t sf; |
255 | block_t *blk; |
297 | block_t *blk; |
256 | fat_cluster_t *lifo; /* stack for storing free cluster numbers */ |
298 | fat_cluster_t *lifo; /* stack for storing free cluster numbers */ |
257 | unsigned found = 0; /* top of the free cluster number stack */ |
299 | unsigned found = 0; /* top of the free cluster number stack */ |
258 | unsigned b, c, cl; |
300 | unsigned b, c, cl; |
259 | 301 | ||
260 | lifo = (fat_cluster_t *) malloc(nclsts * sizeof(fat_cluster_t)); |
302 | lifo = (fat_cluster_t *) malloc(nclsts * sizeof(fat_cluster_t)); |
261 | if (lifo) |
303 | if (lifo) |
262 | return ENOMEM; |
304 | return ENOMEM; |
263 | 305 | ||
264 | bps = uint16_t_le2host(bs->bps); |
306 | bps = uint16_t_le2host(bs->bps); |
265 | rscnt = uint16_t_le2host(bs->rscnt); |
307 | rscnt = uint16_t_le2host(bs->rscnt); |
266 | sf = uint16_t_le2host(bs->sec_per_fat); |
308 | sf = uint16_t_le2host(bs->sec_per_fat); |
267 | 309 | ||
268 | /* |
310 | /* |
269 | * Search FAT1 for unused clusters. |
311 | * Search FAT1 for unused clusters. |
270 | */ |
312 | */ |
271 | futex_down(&fat_alloc_lock); |
313 | futex_down(&fat_alloc_lock); |
272 | for (b = 0, cl = 0; b < sf; blk++) { |
314 | for (b = 0, cl = 0; b < sf; blk++) { |
273 | blk = block_get(dev_handle, rscnt + b, bps); |
315 | blk = block_get(dev_handle, rscnt + b, bps); |
274 | for (c = 0; c < bps / sizeof(fat_cluster_t); c++, cl++) { |
316 | for (c = 0; c < bps / sizeof(fat_cluster_t); c++, cl++) { |
275 | fat_cluster_t *clst = (fat_cluster_t *)blk->data + c; |
317 | fat_cluster_t *clst = (fat_cluster_t *)blk->data + c; |
276 | if (uint16_t_le2host(*clst) == FAT_CLST_RES0) { |
318 | if (uint16_t_le2host(*clst) == FAT_CLST_RES0) { |
277 | /* |
319 | /* |
278 | * The cluster is free. Put it into our stack |
320 | * The cluster is free. Put it into our stack |
279 | * of found clusters and mark it as non-free. |
321 | * of found clusters and mark it as non-free. |
280 | */ |
322 | */ |
281 | lifo[found] = cl; |
323 | lifo[found] = cl; |
282 | *clst = (found == 0) ? |
324 | *clst = (found == 0) ? |
283 | host2uint16_t_le(FAT_CLST_LAST1) : |
325 | host2uint16_t_le(FAT_CLST_LAST1) : |
284 | host2uint16_t_le(lifo[found - 1]); |
326 | host2uint16_t_le(lifo[found - 1]); |
285 | blk->dirty = true; /* need to sync block */ |
327 | blk->dirty = true; /* need to sync block */ |
286 | if (++found == nclsts) { |
328 | if (++found == nclsts) { |
287 | /* we are almost done */ |
329 | /* we are almost done */ |
288 | block_put(blk); |
330 | block_put(blk); |
289 | /* update the shadow copies of FAT */ |
331 | /* update the shadow copies of FAT */ |
290 | fat_alloc_shadow_clusters(bs, |
332 | fat_alloc_shadow_clusters(bs, |
291 | dev_handle, lifo, nclsts); |
333 | dev_handle, lifo, nclsts); |
292 | *mcl = lifo[found - 1]; |
334 | *mcl = lifo[found - 1]; |
293 | *lcl = lifo[0]; |
335 | *lcl = lifo[0]; |
294 | free(lifo); |
336 | free(lifo); |
295 | futex_up(&fat_alloc_lock); |
337 | futex_up(&fat_alloc_lock); |
296 | return EOK; |
338 | return EOK; |
297 | } |
339 | } |
298 | } |
340 | } |
299 | } |
341 | } |
300 | block_put(blk); |
342 | block_put(blk); |
301 | } |
343 | } |
302 | futex_up(&fat_alloc_lock); |
344 | futex_up(&fat_alloc_lock); |
303 | 345 | ||
304 | /* |
346 | /* |
305 | * We could not find enough clusters. Now we need to free the clusters |
347 | * We could not find enough clusters. Now we need to free the clusters |
306 | * we have allocated so far. |
348 | * we have allocated so far. |
307 | */ |
349 | */ |
308 | while (found--) { |
350 | while (found--) { |
309 | fat_mark_cluster(bs, dev_handle, FAT1, lifo[found], |
351 | fat_mark_cluster(bs, dev_handle, FAT1, lifo[found], |
310 | FAT_CLST_RES0); |
352 | FAT_CLST_RES0); |
311 | } |
353 | } |
312 | 354 | ||
313 | free(lifo); |
355 | free(lifo); |
314 | return ENOSPC; |
356 | return ENOSPC; |
315 | } |
357 | } |
316 | 358 | ||
- | 359 | /** Append a cluster chain to the last file cluster in all FATs. |
|
- | 360 | * |
|
- | 361 | * @param bs Buffer holding boot sector of the file system. |
|
- | 362 | * @param nodep Node representing the file. |
|
- | 363 | * @param mcl First cluster of the cluster chain to append. |
|
- | 364 | */ |
|
317 | void fat_append_clusters(fat_bs_t *bs, fat_node_t *nodep, fat_cluster_t mcl) |
365 | void fat_append_clusters(fat_bs_t *bs, fat_node_t *nodep, fat_cluster_t mcl) |
318 | { |
366 | { |
319 | dev_handle_t dev_handle = nodep->idx->dev_handle; |
367 | dev_handle_t dev_handle = nodep->idx->dev_handle; |
320 | fat_cluster_t lcl; |
368 | fat_cluster_t lcl; |
321 | uint8_t fatno; |
369 | uint8_t fatno; |
322 | 370 | ||
323 | if (_fat_blcks_get(bs, dev_handle, nodep->firstc, &lcl) == 0) { |
371 | if (_fat_blcks_get(bs, dev_handle, nodep->firstc, &lcl) == 0) { |
324 | nodep->firstc = host2uint16_t_le(mcl); |
372 | nodep->firstc = host2uint16_t_le(mcl); |
325 | nodep->dirty = true; /* need to sync node */ |
373 | nodep->dirty = true; /* need to sync node */ |
326 | return; |
374 | return; |
327 | } |
375 | } |
328 | 376 | ||
329 | for (fatno = FAT1; fatno < bs->fatcnt; fatno++) |
377 | for (fatno = FAT1; fatno < bs->fatcnt; fatno++) |
330 | fat_mark_cluster(bs, nodep->idx->dev_handle, fatno, lcl, mcl); |
378 | fat_mark_cluster(bs, nodep->idx->dev_handle, fatno, lcl, mcl); |
331 | } |
379 | } |
332 | 380 | ||
333 | /** |
381 | /** |
334 | * @} |
382 | * @} |
335 | */ |
383 | */ |
336 | 384 |