Rev 3497 | Rev 3500 | Go to most recent revision | Only display areas with differences | Ignore whitespace | Details | Blame | Last modification | View Log | RSS feed
| Rev 3497 | Rev 3499 | ||
|---|---|---|---|
| 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_ops.c |
34 | * @file fat_ops.c |
| 35 | * @brief Implementation of VFS operations for the FAT file system server. |
35 | * @brief Implementation of VFS operations for the FAT file system server. |
| 36 | */ |
36 | */ |
| 37 | 37 | ||
| 38 | #include "fat.h" |
38 | #include "fat.h" |
| 39 | #include "../../vfs/vfs.h" |
39 | #include "../../vfs/vfs.h" |
| 40 | #include <libfs.h> |
40 | #include <libfs.h> |
| 41 | #include <ipc/ipc.h> |
41 | #include <ipc/ipc.h> |
| 42 | #include <ipc/services.h> |
42 | #include <ipc/services.h> |
| 43 | #include <ipc/devmap.h> |
43 | #include <ipc/devmap.h> |
| 44 | #include <async.h> |
44 | #include <async.h> |
| 45 | #include <errno.h> |
45 | #include <errno.h> |
| 46 | #include <string.h> |
46 | #include <string.h> |
| 47 | #include <byteorder.h> |
47 | #include <byteorder.h> |
| 48 | #include <libadt/hash_table.h> |
48 | #include <libadt/hash_table.h> |
| 49 | #include <libadt/list.h> |
49 | #include <libadt/list.h> |
| 50 | #include <assert.h> |
50 | #include <assert.h> |
| 51 | #include <futex.h> |
51 | #include <futex.h> |
| 52 | #include <sys/mman.h> |
52 | #include <sys/mman.h> |
| - | 53 | #include <align.h> |
|
| 53 | 54 | ||
| 54 | #define BS_BLOCK 0 |
55 | #define BS_BLOCK 0 |
| 55 | #define BS_SIZE 512 |
56 | #define BS_SIZE 512 |
| 56 | 57 | ||
| 57 | /** Futex protecting the list of cached free FAT nodes. */ |
58 | /** Futex protecting the list of cached free FAT nodes. */ |
| 58 | static futex_t ffn_futex = FUTEX_INITIALIZER; |
59 | static futex_t ffn_futex = FUTEX_INITIALIZER; |
| 59 | 60 | ||
| 60 | /** List of cached free FAT nodes. */ |
61 | /** List of cached free FAT nodes. */ |
| 61 | static LIST_INITIALIZE(ffn_head); |
62 | static LIST_INITIALIZE(ffn_head); |
| 62 | 63 | ||
| 63 | #define FAT_NAME_LEN 8 |
64 | #define FAT_NAME_LEN 8 |
| 64 | #define FAT_EXT_LEN 3 |
65 | #define FAT_EXT_LEN 3 |
| 65 | 66 | ||
| 66 | #define FAT_PAD ' ' |
67 | #define FAT_PAD ' ' |
| 67 | 68 | ||
| 68 | #define FAT_DENTRY_UNUSED 0x00 |
69 | #define FAT_DENTRY_UNUSED 0x00 |
| 69 | #define FAT_DENTRY_E5_ESC 0x05 |
70 | #define FAT_DENTRY_E5_ESC 0x05 |
| 70 | #define FAT_DENTRY_DOT 0x2e |
71 | #define FAT_DENTRY_DOT 0x2e |
| 71 | #define FAT_DENTRY_ERASED 0xe5 |
72 | #define FAT_DENTRY_ERASED 0xe5 |
| 72 | 73 | ||
| 73 | #define min(a, b) ((a) < (b) ? (a) : (b)) |
74 | #define min(a, b) ((a) < (b) ? (a) : (b)) |
| 74 | 75 | ||
| 75 | static void dentry_name_canonify(fat_dentry_t *d, char *buf) |
76 | static void dentry_name_canonify(fat_dentry_t *d, char *buf) |
| 76 | { |
77 | { |
| 77 | int i; |
78 | int i; |
| 78 | 79 | ||
| 79 | for (i = 0; i < FAT_NAME_LEN; i++) { |
80 | for (i = 0; i < FAT_NAME_LEN; i++) { |
| 80 | if (d->name[i] == FAT_PAD) |
81 | if (d->name[i] == FAT_PAD) |
| 81 | break; |
82 | break; |
| 82 | if (d->name[i] == FAT_DENTRY_E5_ESC) |
83 | if (d->name[i] == FAT_DENTRY_E5_ESC) |
| 83 | *buf++ = 0xe5; |
84 | *buf++ = 0xe5; |
| 84 | else |
85 | else |
| 85 | *buf++ = d->name[i]; |
86 | *buf++ = d->name[i]; |
| 86 | } |
87 | } |
| 87 | if (d->ext[0] != FAT_PAD) |
88 | if (d->ext[0] != FAT_PAD) |
| 88 | *buf++ = '.'; |
89 | *buf++ = '.'; |
| 89 | for (i = 0; i < FAT_EXT_LEN; i++) { |
90 | for (i = 0; i < FAT_EXT_LEN; i++) { |
| 90 | if (d->ext[i] == FAT_PAD) { |
91 | if (d->ext[i] == FAT_PAD) { |
| 91 | *buf = '\0'; |
92 | *buf = '\0'; |
| 92 | return; |
93 | return; |
| 93 | } |
94 | } |
| 94 | if (d->ext[i] == FAT_DENTRY_E5_ESC) |
95 | if (d->ext[i] == FAT_DENTRY_E5_ESC) |
| 95 | *buf++ = 0xe5; |
96 | *buf++ = 0xe5; |
| 96 | else |
97 | else |
| 97 | *buf++ = d->ext[i]; |
98 | *buf++ = d->ext[i]; |
| 98 | } |
99 | } |
| 99 | *buf = '\0'; |
100 | *buf = '\0'; |
| 100 | } |
101 | } |
| 101 | 102 | ||
| 102 | static int dev_phone = -1; /* FIXME */ |
103 | static int dev_phone = -1; /* FIXME */ |
| 103 | static void *dev_buffer = NULL; /* FIXME */ |
104 | static void *dev_buffer = NULL; /* FIXME */ |
| 104 | 105 | ||
| 105 | /* TODO move somewhere else */ |
106 | /* TODO move somewhere else */ |
| 106 | typedef struct { |
107 | typedef struct { |
| 107 | void *data; |
108 | void *data; |
| 108 | size_t size; |
109 | size_t size; |
| - | 110 | bool dirty; |
|
| 109 | } block_t; |
111 | } block_t; |
| 110 | 112 | ||
| 111 | static block_t *block_get(dev_handle_t dev_handle, off_t offset, size_t bs) |
113 | static block_t *block_get(dev_handle_t dev_handle, off_t offset, size_t bs) |
| 112 | { |
114 | { |
| 113 | /* FIXME */ |
115 | /* FIXME */ |
| 114 | block_t *b; |
116 | block_t *b; |
| 115 | off_t bufpos = 0; |
117 | off_t bufpos = 0; |
| 116 | size_t buflen = 0; |
118 | size_t buflen = 0; |
| 117 | off_t pos = offset * bs; |
119 | off_t pos = offset * bs; |
| 118 | 120 | ||
| 119 | assert(dev_phone != -1); |
121 | assert(dev_phone != -1); |
| 120 | assert(dev_buffer); |
122 | assert(dev_buffer); |
| 121 | 123 | ||
| 122 | b = malloc(sizeof(block_t)); |
124 | b = malloc(sizeof(block_t)); |
| 123 | if (!b) |
125 | if (!b) |
| 124 | return NULL; |
126 | return NULL; |
| 125 | 127 | ||
| 126 | b->data = malloc(bs); |
128 | b->data = malloc(bs); |
| 127 | if (!b->data) { |
129 | if (!b->data) { |
| 128 | free(b); |
130 | free(b); |
| 129 | return NULL; |
131 | return NULL; |
| 130 | } |
132 | } |
| 131 | b->size = bs; |
133 | b->size = bs; |
| 132 | 134 | ||
| 133 | if (!libfs_blockread(dev_phone, dev_buffer, &bufpos, &buflen, &pos, |
135 | if (!libfs_blockread(dev_phone, dev_buffer, &bufpos, &buflen, &pos, |
| 134 | b->data, bs, bs)) { |
136 | b->data, bs, bs)) { |
| 135 | free(b->data); |
137 | free(b->data); |
| 136 | free(b); |
138 | free(b); |
| 137 | return NULL; |
139 | return NULL; |
| 138 | } |
140 | } |
| 139 | 141 | ||
| 140 | return b; |
142 | return b; |
| 141 | } |
143 | } |
| 142 | 144 | ||
| 143 | static void block_put(block_t *block) |
145 | static void block_put(block_t *block) |
| 144 | { |
146 | { |
| 145 | /* FIXME */ |
147 | /* FIXME */ |
| 146 | free(block->data); |
148 | free(block->data); |
| 147 | free(block); |
149 | free(block); |
| 148 | } |
150 | } |
| 149 | 151 | ||
| 150 | #define FAT_BS(b) ((fat_bs_t *)((b)->data)) |
152 | #define FAT_BS(b) ((fat_bs_t *)((b)->data)) |
| 151 | 153 | ||
| 152 | #define FAT_CLST_RES0 0x0000 |
154 | #define FAT_CLST_RES0 0x0000 |
| 153 | #define FAT_CLST_RES1 0x0001 |
155 | #define FAT_CLST_RES1 0x0001 |
| 154 | #define FAT_CLST_FIRST 0x0002 |
156 | #define FAT_CLST_FIRST 0x0002 |
| 155 | #define FAT_CLST_BAD 0xfff7 |
157 | #define FAT_CLST_BAD 0xfff7 |
| 156 | #define FAT_CLST_LAST1 0xfff8 |
158 | #define FAT_CLST_LAST1 0xfff8 |
| 157 | #define FAT_CLST_LAST8 0xffff |
159 | #define FAT_CLST_LAST8 0xffff |
| 158 | 160 | ||
| 159 | /* internally used to mark root directory's parent */ |
161 | /* internally used to mark root directory's parent */ |
| 160 | #define FAT_CLST_ROOTPAR FAT_CLST_RES0 |
162 | #define FAT_CLST_ROOTPAR FAT_CLST_RES0 |
| 161 | /* internally used to mark root directory */ |
163 | /* internally used to mark root directory */ |
| 162 | #define FAT_CLST_ROOT FAT_CLST_RES1 |
164 | #define FAT_CLST_ROOT FAT_CLST_RES1 |
| 163 | 165 | ||
| 164 | #define fat_block_get(np, off) \ |
166 | #define fat_block_get(np, off) \ |
| 165 | _fat_block_get((np)->idx->dev_handle, (np)->firstc, (off)) |
167 | _fat_block_get((np)->idx->dev_handle, (np)->firstc, (off)) |
| 166 | 168 | ||
| 167 | static block_t * |
169 | static block_t * |
| 168 | _fat_block_get(dev_handle_t dev_handle, fat_cluster_t firstc, off_t offset) |
170 | _fat_block_get(dev_handle_t dev_handle, fat_cluster_t firstc, off_t offset) |
| 169 | { |
171 | { |
| 170 | block_t *bb; |
172 | block_t *bb; |
| 171 | block_t *b; |
173 | block_t *b; |
| 172 | unsigned bps; |
174 | unsigned bps; |
| 173 | unsigned spc; |
175 | unsigned spc; |
| 174 | unsigned rscnt; /* block address of the first FAT */ |
176 | unsigned rscnt; /* block address of the first FAT */ |
| 175 | unsigned fatcnt; |
177 | unsigned fatcnt; |
| 176 | unsigned rde; |
178 | unsigned rde; |
| 177 | unsigned rds; /* root directory size */ |
179 | unsigned rds; /* root directory size */ |
| 178 | unsigned sf; |
180 | unsigned sf; |
| 179 | unsigned ssa; /* size of the system area */ |
181 | unsigned ssa; /* size of the system area */ |
| 180 | unsigned clusters; |
182 | unsigned clusters; |
| 181 | fat_cluster_t clst = firstc; |
183 | fat_cluster_t clst = firstc; |
| 182 | unsigned i; |
184 | unsigned i; |
| 183 | 185 | ||
| 184 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
186 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
| 185 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
187 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
| 186 | spc = FAT_BS(bb)->spc; |
188 | spc = FAT_BS(bb)->spc; |
| 187 | rscnt = uint16_t_le2host(FAT_BS(bb)->rscnt); |
189 | rscnt = uint16_t_le2host(FAT_BS(bb)->rscnt); |
| 188 | fatcnt = FAT_BS(bb)->fatcnt; |
190 | fatcnt = FAT_BS(bb)->fatcnt; |
| 189 | rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max); |
191 | rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max); |
| 190 | sf = uint16_t_le2host(FAT_BS(bb)->sec_per_fat); |
192 | sf = uint16_t_le2host(FAT_BS(bb)->sec_per_fat); |
| 191 | block_put(bb); |
193 | block_put(bb); |
| 192 | 194 | ||
| 193 | rds = (sizeof(fat_dentry_t) * rde) / bps; |
195 | rds = (sizeof(fat_dentry_t) * rde) / bps; |
| 194 | rds += ((sizeof(fat_dentry_t) * rde) % bps != 0); |
196 | rds += ((sizeof(fat_dentry_t) * rde) % bps != 0); |
| 195 | ssa = rscnt + fatcnt * sf + rds; |
197 | ssa = rscnt + fatcnt * sf + rds; |
| 196 | 198 | ||
| 197 | if (firstc == FAT_CLST_ROOT) { |
199 | if (firstc == FAT_CLST_ROOT) { |
| 198 | /* root directory special case */ |
200 | /* root directory special case */ |
| 199 | assert(offset < rds); |
201 | assert(offset < rds); |
| 200 | b = block_get(dev_handle, rscnt + fatcnt * sf + offset, bps); |
202 | b = block_get(dev_handle, rscnt + fatcnt * sf + offset, bps); |
| 201 | return b; |
203 | return b; |
| 202 | } |
204 | } |
| 203 | 205 | ||
| 204 | clusters = offset / spc; |
206 | clusters = offset / spc; |
| 205 | for (i = 0; i < clusters; i++) { |
207 | for (i = 0; i < clusters; i++) { |
| 206 | unsigned fsec; /* sector offset relative to FAT1 */ |
208 | unsigned fsec; /* sector offset relative to FAT1 */ |
| 207 | unsigned fidx; /* FAT1 entry index */ |
209 | unsigned fidx; /* FAT1 entry index */ |
| 208 | 210 | ||
| 209 | assert(clst >= FAT_CLST_FIRST && clst < FAT_CLST_BAD); |
211 | assert(clst >= FAT_CLST_FIRST && clst < FAT_CLST_BAD); |
| 210 | fsec = (clst * sizeof(fat_cluster_t)) / bps; |
212 | fsec = (clst * sizeof(fat_cluster_t)) / bps; |
| 211 | fidx = clst % (bps / sizeof(fat_cluster_t)); |
213 | fidx = clst % (bps / sizeof(fat_cluster_t)); |
| 212 | /* read FAT1 */ |
214 | /* read FAT1 */ |
| 213 | b = block_get(dev_handle, rscnt + fsec, bps); |
215 | b = block_get(dev_handle, rscnt + fsec, bps); |
| 214 | clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]); |
216 | clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]); |
| 215 | assert(clst != FAT_CLST_BAD); |
217 | assert(clst != FAT_CLST_BAD); |
| 216 | assert(clst < FAT_CLST_LAST1); |
218 | assert(clst < FAT_CLST_LAST1); |
| 217 | block_put(b); |
219 | block_put(b); |
| 218 | } |
220 | } |
| 219 | 221 | ||
| 220 | b = block_get(dev_handle, ssa + (clst - FAT_CLST_FIRST) * spc + |
222 | b = block_get(dev_handle, ssa + (clst - FAT_CLST_FIRST) * spc + |
| 221 | offset % spc, bps); |
223 | offset % spc, bps); |
| 222 | 224 | ||
| 223 | return b; |
225 | return b; |
| 224 | } |
226 | } |
| 225 | 227 | ||
| 226 | /** Return number of blocks allocated to a file. |
228 | /** Return number of blocks allocated to a file. |
| 227 | * |
229 | * |
| 228 | * @param dev_handle Device handle of the device with the file. |
230 | * @param dev_handle Device handle of the device with the file. |
| 229 | * @param firstc First cluster of the file. |
231 | * @param firstc First cluster of the file. |
| 230 | * |
232 | * |
| 231 | * @return Number of blocks allocated to the file. |
233 | * @return Number of blocks allocated to the file. |
| 232 | */ |
234 | */ |
| 233 | static uint16_t |
235 | static uint16_t |
| 234 | _fat_blcks_get(dev_handle_t dev_handle, fat_cluster_t firstc) |
236 | _fat_blcks_get(dev_handle_t dev_handle, fat_cluster_t firstc) |
| 235 | { |
237 | { |
| 236 | block_t *bb; |
238 | block_t *bb; |
| 237 | block_t *b; |
239 | block_t *b; |
| 238 | unsigned bps; |
240 | unsigned bps; |
| 239 | unsigned spc; |
241 | unsigned spc; |
| 240 | unsigned rscnt; /* block address of the first FAT */ |
242 | unsigned rscnt; /* block address of the first FAT */ |
| 241 | unsigned clusters = 0; |
243 | unsigned clusters = 0; |
| 242 | fat_cluster_t clst = firstc; |
244 | fat_cluster_t clst = firstc; |
| 243 | 245 | ||
| 244 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
246 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
| 245 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
247 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
| 246 | spc = FAT_BS(bb)->spc; |
248 | spc = FAT_BS(bb)->spc; |
| 247 | rscnt = uint16_t_le2host(FAT_BS(bb)->rscnt); |
249 | rscnt = uint16_t_le2host(FAT_BS(bb)->rscnt); |
| 248 | block_put(bb); |
250 | block_put(bb); |
| 249 | 251 | ||
| 250 | if (firstc == FAT_CLST_RES0) { |
252 | if (firstc == FAT_CLST_RES0) { |
| 251 | /* No space allocated to the file. */ |
253 | /* No space allocated to the file. */ |
| 252 | return 0; |
254 | return 0; |
| 253 | } |
255 | } |
| 254 | 256 | ||
| 255 | while (clst < FAT_CLST_LAST1) { |
257 | while (clst < FAT_CLST_LAST1) { |
| 256 | unsigned fsec; /* sector offset relative to FAT1 */ |
258 | unsigned fsec; /* sector offset relative to FAT1 */ |
| 257 | unsigned fidx; /* FAT1 entry index */ |
259 | unsigned fidx; /* FAT1 entry index */ |
| 258 | 260 | ||
| 259 | assert(clst >= FAT_CLST_FIRST); |
261 | assert(clst >= FAT_CLST_FIRST); |
| 260 | fsec = (clst * sizeof(fat_cluster_t)) / bps; |
262 | fsec = (clst * sizeof(fat_cluster_t)) / bps; |
| 261 | fidx = clst % (bps / sizeof(fat_cluster_t)); |
263 | fidx = clst % (bps / sizeof(fat_cluster_t)); |
| 262 | /* read FAT1 */ |
264 | /* read FAT1 */ |
| 263 | b = block_get(dev_handle, rscnt + fsec, bps); |
265 | b = block_get(dev_handle, rscnt + fsec, bps); |
| 264 | clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]); |
266 | clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]); |
| 265 | assert(clst != FAT_CLST_BAD); |
267 | assert(clst != FAT_CLST_BAD); |
| 266 | block_put(b); |
268 | block_put(b); |
| 267 | clusters++; |
269 | clusters++; |
| 268 | } |
270 | } |
| 269 | 271 | ||
| 270 | return clusters * spc; |
272 | return clusters * spc; |
| 271 | } |
273 | } |
| 272 | 274 | ||
| 273 | static void fat_node_initialize(fat_node_t *node) |
275 | static void fat_node_initialize(fat_node_t *node) |
| 274 | { |
276 | { |
| 275 | futex_initialize(&node->lock, 1); |
277 | futex_initialize(&node->lock, 1); |
| 276 | node->idx = NULL; |
278 | node->idx = NULL; |
| 277 | node->type = 0; |
279 | node->type = 0; |
| 278 | link_initialize(&node->ffn_link); |
280 | link_initialize(&node->ffn_link); |
| 279 | node->size = 0; |
281 | node->size = 0; |
| 280 | node->lnkcnt = 0; |
282 | node->lnkcnt = 0; |
| 281 | node->refcnt = 0; |
283 | node->refcnt = 0; |
| 282 | node->dirty = false; |
284 | node->dirty = false; |
| 283 | } |
285 | } |
| 284 | 286 | ||
| 285 | static uint16_t fat_bps_get(dev_handle_t dev_handle) |
287 | static uint16_t fat_bps_get(dev_handle_t dev_handle) |
| 286 | { |
288 | { |
| 287 | block_t *bb; |
289 | block_t *bb; |
| 288 | uint16_t bps; |
290 | uint16_t bps; |
| 289 | 291 | ||
| 290 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
292 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
| 291 | assert(bb != NULL); |
293 | assert(bb != NULL); |
| 292 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
294 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
| 293 | block_put(bb); |
295 | block_put(bb); |
| 294 | 296 | ||
| 295 | return bps; |
297 | return bps; |
| 296 | } |
298 | } |
| 297 | 299 | ||
| 298 | typedef enum { |
300 | typedef enum { |
| 299 | FAT_DENTRY_SKIP, |
301 | FAT_DENTRY_SKIP, |
| 300 | FAT_DENTRY_LAST, |
302 | FAT_DENTRY_LAST, |
| 301 | FAT_DENTRY_VALID |
303 | FAT_DENTRY_VALID |
| 302 | } fat_dentry_clsf_t; |
304 | } fat_dentry_clsf_t; |
| 303 | 305 | ||
| 304 | static fat_dentry_clsf_t fat_classify_dentry(fat_dentry_t *d) |
306 | static fat_dentry_clsf_t fat_classify_dentry(fat_dentry_t *d) |
| 305 | { |
307 | { |
| 306 | if (d->attr & FAT_ATTR_VOLLABEL) { |
308 | if (d->attr & FAT_ATTR_VOLLABEL) { |
| 307 | /* volume label entry */ |
309 | /* volume label entry */ |
| 308 | return FAT_DENTRY_SKIP; |
310 | return FAT_DENTRY_SKIP; |
| 309 | } |
311 | } |
| 310 | if (d->name[0] == FAT_DENTRY_ERASED) { |
312 | if (d->name[0] == FAT_DENTRY_ERASED) { |
| 311 | /* not-currently-used entry */ |
313 | /* not-currently-used entry */ |
| 312 | return FAT_DENTRY_SKIP; |
314 | return FAT_DENTRY_SKIP; |
| 313 | } |
315 | } |
| 314 | if (d->name[0] == FAT_DENTRY_UNUSED) { |
316 | if (d->name[0] == FAT_DENTRY_UNUSED) { |
| 315 | /* never used entry */ |
317 | /* never used entry */ |
| 316 | return FAT_DENTRY_LAST; |
318 | return FAT_DENTRY_LAST; |
| 317 | } |
319 | } |
| 318 | if (d->name[0] == FAT_DENTRY_DOT) { |
320 | if (d->name[0] == FAT_DENTRY_DOT) { |
| 319 | /* |
321 | /* |
| 320 | * Most likely '.' or '..'. |
322 | * Most likely '.' or '..'. |
| 321 | * It cannot occur in a regular file name. |
323 | * It cannot occur in a regular file name. |
| 322 | */ |
324 | */ |
| 323 | return FAT_DENTRY_SKIP; |
325 | return FAT_DENTRY_SKIP; |
| 324 | } |
326 | } |
| 325 | return FAT_DENTRY_VALID; |
327 | return FAT_DENTRY_VALID; |
| 326 | } |
328 | } |
| 327 | 329 | ||
| 328 | static void fat_node_sync(fat_node_t *node) |
330 | static void fat_node_sync(fat_node_t *node) |
| 329 | { |
331 | { |
| 330 | /* TODO */ |
332 | /* TODO */ |
| 331 | } |
333 | } |
| 332 | 334 | ||
| 333 | /** Internal version of fat_node_get(). |
335 | /** Internal version of fat_node_get(). |
| 334 | * |
336 | * |
| 335 | * @param idxp Locked index structure. |
337 | * @param idxp Locked index structure. |
| 336 | */ |
338 | */ |
| 337 | static void *fat_node_get_core(fat_idx_t *idxp) |
339 | static void *fat_node_get_core(fat_idx_t *idxp) |
| 338 | { |
340 | { |
| 339 | block_t *b; |
341 | block_t *b; |
| 340 | fat_dentry_t *d; |
342 | fat_dentry_t *d; |
| 341 | fat_node_t *nodep = NULL; |
343 | fat_node_t *nodep = NULL; |
| 342 | unsigned bps; |
344 | unsigned bps; |
| 343 | unsigned dps; |
345 | unsigned dps; |
| 344 | 346 | ||
| 345 | if (idxp->nodep) { |
347 | if (idxp->nodep) { |
| 346 | /* |
348 | /* |
| 347 | * We are lucky. |
349 | * We are lucky. |
| 348 | * The node is already instantiated in memory. |
350 | * The node is already instantiated in memory. |
| 349 | */ |
351 | */ |
| 350 | futex_down(&idxp->nodep->lock); |
352 | futex_down(&idxp->nodep->lock); |
| 351 | if (!idxp->nodep->refcnt++) |
353 | if (!idxp->nodep->refcnt++) |
| 352 | list_remove(&idxp->nodep->ffn_link); |
354 | list_remove(&idxp->nodep->ffn_link); |
| 353 | futex_up(&idxp->nodep->lock); |
355 | futex_up(&idxp->nodep->lock); |
| 354 | return idxp->nodep; |
356 | return idxp->nodep; |
| 355 | } |
357 | } |
| 356 | 358 | ||
| 357 | /* |
359 | /* |
| 358 | * We must instantiate the node from the file system. |
360 | * We must instantiate the node from the file system. |
| 359 | */ |
361 | */ |
| 360 | 362 | ||
| 361 | assert(idxp->pfc); |
363 | assert(idxp->pfc); |
| 362 | 364 | ||
| 363 | futex_down(&ffn_futex); |
365 | futex_down(&ffn_futex); |
| 364 | if (!list_empty(&ffn_head)) { |
366 | if (!list_empty(&ffn_head)) { |
| 365 | /* Try to use a cached free node structure. */ |
367 | /* Try to use a cached free node structure. */ |
| 366 | fat_idx_t *idxp_tmp; |
368 | fat_idx_t *idxp_tmp; |
| 367 | nodep = list_get_instance(ffn_head.next, fat_node_t, ffn_link); |
369 | nodep = list_get_instance(ffn_head.next, fat_node_t, ffn_link); |
| 368 | if (futex_trydown(&nodep->lock) == ESYNCH_WOULD_BLOCK) |
370 | if (futex_trydown(&nodep->lock) == ESYNCH_WOULD_BLOCK) |
| 369 | goto skip_cache; |
371 | goto skip_cache; |
| 370 | idxp_tmp = nodep->idx; |
372 | idxp_tmp = nodep->idx; |
| 371 | if (futex_trydown(&idxp_tmp->lock) == ESYNCH_WOULD_BLOCK) { |
373 | if (futex_trydown(&idxp_tmp->lock) == ESYNCH_WOULD_BLOCK) { |
| 372 | futex_up(&nodep->lock); |
374 | futex_up(&nodep->lock); |
| 373 | goto skip_cache; |
375 | goto skip_cache; |
| 374 | } |
376 | } |
| 375 | list_remove(&nodep->ffn_link); |
377 | list_remove(&nodep->ffn_link); |
| 376 | futex_up(&ffn_futex); |
378 | futex_up(&ffn_futex); |
| 377 | if (nodep->dirty) |
379 | if (nodep->dirty) |
| 378 | fat_node_sync(nodep); |
380 | fat_node_sync(nodep); |
| 379 | idxp_tmp->nodep = NULL; |
381 | idxp_tmp->nodep = NULL; |
| 380 | futex_up(&nodep->lock); |
382 | futex_up(&nodep->lock); |
| 381 | futex_up(&idxp_tmp->lock); |
383 | futex_up(&idxp_tmp->lock); |
| 382 | } else { |
384 | } else { |
| 383 | skip_cache: |
385 | skip_cache: |
| 384 | /* Try to allocate a new node structure. */ |
386 | /* Try to allocate a new node structure. */ |
| 385 | futex_up(&ffn_futex); |
387 | futex_up(&ffn_futex); |
| 386 | nodep = (fat_node_t *)malloc(sizeof(fat_node_t)); |
388 | nodep = (fat_node_t *)malloc(sizeof(fat_node_t)); |
| 387 | if (!nodep) |
389 | if (!nodep) |
| 388 | return NULL; |
390 | return NULL; |
| 389 | } |
391 | } |
| 390 | fat_node_initialize(nodep); |
392 | fat_node_initialize(nodep); |
| 391 | 393 | ||
| 392 | bps = fat_bps_get(idxp->dev_handle); |
394 | bps = fat_bps_get(idxp->dev_handle); |
| 393 | dps = bps / sizeof(fat_dentry_t); |
395 | dps = bps / sizeof(fat_dentry_t); |
| 394 | 396 | ||
| 395 | /* Read the block that contains the dentry of interest. */ |
397 | /* Read the block that contains the dentry of interest. */ |
| 396 | b = _fat_block_get(idxp->dev_handle, idxp->pfc, |
398 | b = _fat_block_get(idxp->dev_handle, idxp->pfc, |
| 397 | (idxp->pdi * sizeof(fat_dentry_t)) / bps); |
399 | (idxp->pdi * sizeof(fat_dentry_t)) / bps); |
| 398 | assert(b); |
400 | assert(b); |
| 399 | 401 | ||
| 400 | d = ((fat_dentry_t *)b->data) + (idxp->pdi % dps); |
402 | d = ((fat_dentry_t *)b->data) + (idxp->pdi % dps); |
| 401 | if (d->attr & FAT_ATTR_SUBDIR) { |
403 | if (d->attr & FAT_ATTR_SUBDIR) { |
| 402 | /* |
404 | /* |
| 403 | * The only directory which does not have this bit set is the |
405 | * The only directory which does not have this bit set is the |
| 404 | * root directory itself. The root directory node is handled |
406 | * root directory itself. The root directory node is handled |
| 405 | * and initialized elsewhere. |
407 | * and initialized elsewhere. |
| 406 | */ |
408 | */ |
| 407 | nodep->type = FAT_DIRECTORY; |
409 | nodep->type = FAT_DIRECTORY; |
| 408 | /* |
410 | /* |
| 409 | * Unfortunately, the 'size' field of the FAT dentry is not |
411 | * Unfortunately, the 'size' field of the FAT dentry is not |
| 410 | * defined for the directory entry type. We must determine the |
412 | * defined for the directory entry type. We must determine the |
| 411 | * size of the directory by walking the FAT. |
413 | * size of the directory by walking the FAT. |
| 412 | */ |
414 | */ |
| 413 | nodep->size = bps * _fat_blcks_get(idxp->dev_handle, |
415 | nodep->size = bps * _fat_blcks_get(idxp->dev_handle, |
| 414 | uint16_t_le2host(d->firstc)); |
416 | uint16_t_le2host(d->firstc)); |
| 415 | } else { |
417 | } else { |
| 416 | nodep->type = FAT_FILE; |
418 | nodep->type = FAT_FILE; |
| 417 | nodep->size = uint32_t_le2host(d->size); |
419 | nodep->size = uint32_t_le2host(d->size); |
| 418 | } |
420 | } |
| 419 | nodep->firstc = uint16_t_le2host(d->firstc); |
421 | nodep->firstc = uint16_t_le2host(d->firstc); |
| 420 | nodep->lnkcnt = 1; |
422 | nodep->lnkcnt = 1; |
| 421 | nodep->refcnt = 1; |
423 | nodep->refcnt = 1; |
| 422 | 424 | ||
| 423 | block_put(b); |
425 | block_put(b); |
| 424 | 426 | ||
| 425 | /* Link the idx structure with the node structure. */ |
427 | /* Link the idx structure with the node structure. */ |
| 426 | nodep->idx = idxp; |
428 | nodep->idx = idxp; |
| 427 | idxp->nodep = nodep; |
429 | idxp->nodep = nodep; |
| 428 | 430 | ||
| 429 | return nodep; |
431 | return nodep; |
| 430 | } |
432 | } |
| 431 | 433 | ||
| 432 | /** Instantiate a FAT in-core node. */ |
434 | /** Instantiate a FAT in-core node. */ |
| 433 | static void *fat_node_get(dev_handle_t dev_handle, fs_index_t index) |
435 | static void *fat_node_get(dev_handle_t dev_handle, fs_index_t index) |
| 434 | { |
436 | { |
| 435 | void *node; |
437 | void *node; |
| 436 | fat_idx_t *idxp; |
438 | fat_idx_t *idxp; |
| 437 | 439 | ||
| 438 | idxp = fat_idx_get_by_index(dev_handle, index); |
440 | idxp = fat_idx_get_by_index(dev_handle, index); |
| 439 | if (!idxp) |
441 | if (!idxp) |
| 440 | return NULL; |
442 | return NULL; |
| 441 | /* idxp->lock held */ |
443 | /* idxp->lock held */ |
| 442 | node = fat_node_get_core(idxp); |
444 | node = fat_node_get_core(idxp); |
| 443 | futex_up(&idxp->lock); |
445 | futex_up(&idxp->lock); |
| 444 | return node; |
446 | return node; |
| 445 | } |
447 | } |
| 446 | 448 | ||
| 447 | static void fat_node_put(void *node) |
449 | static void fat_node_put(void *node) |
| 448 | { |
450 | { |
| 449 | fat_node_t *nodep = (fat_node_t *)node; |
451 | fat_node_t *nodep = (fat_node_t *)node; |
| 450 | 452 | ||
| 451 | futex_down(&nodep->lock); |
453 | futex_down(&nodep->lock); |
| 452 | if (!--nodep->refcnt) { |
454 | if (!--nodep->refcnt) { |
| 453 | futex_down(&ffn_futex); |
455 | futex_down(&ffn_futex); |
| 454 | list_append(&nodep->ffn_link, &ffn_head); |
456 | list_append(&nodep->ffn_link, &ffn_head); |
| 455 | futex_up(&ffn_futex); |
457 | futex_up(&ffn_futex); |
| 456 | } |
458 | } |
| 457 | futex_up(&nodep->lock); |
459 | futex_up(&nodep->lock); |
| 458 | } |
460 | } |
| 459 | 461 | ||
| 460 | static void *fat_create(int flags) |
462 | static void *fat_create(int flags) |
| 461 | { |
463 | { |
| 462 | return NULL; /* not supported at the moment */ |
464 | return NULL; /* not supported at the moment */ |
| 463 | } |
465 | } |
| 464 | 466 | ||
| 465 | static int fat_destroy(void *node) |
467 | static int fat_destroy(void *node) |
| 466 | { |
468 | { |
| 467 | return ENOTSUP; /* not supported at the moment */ |
469 | return ENOTSUP; /* not supported at the moment */ |
| 468 | } |
470 | } |
| 469 | 471 | ||
| 470 | static bool fat_link(void *prnt, void *chld, const char *name) |
472 | static bool fat_link(void *prnt, void *chld, const char *name) |
| 471 | { |
473 | { |
| 472 | return false; /* not supported at the moment */ |
474 | return false; /* not supported at the moment */ |
| 473 | } |
475 | } |
| 474 | 476 | ||
| 475 | static int fat_unlink(void *prnt, void *chld) |
477 | static int fat_unlink(void *prnt, void *chld) |
| 476 | { |
478 | { |
| 477 | return ENOTSUP; /* not supported at the moment */ |
479 | return ENOTSUP; /* not supported at the moment */ |
| 478 | } |
480 | } |
| 479 | 481 | ||
| 480 | static void *fat_match(void *prnt, const char *component) |
482 | static void *fat_match(void *prnt, const char *component) |
| 481 | { |
483 | { |
| 482 | fat_node_t *parentp = (fat_node_t *)prnt; |
484 | fat_node_t *parentp = (fat_node_t *)prnt; |
| 483 | char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1]; |
485 | char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1]; |
| 484 | unsigned i, j; |
486 | unsigned i, j; |
| 485 | unsigned bps; /* bytes per sector */ |
487 | unsigned bps; /* bytes per sector */ |
| 486 | unsigned dps; /* dentries per sector */ |
488 | unsigned dps; /* dentries per sector */ |
| 487 | unsigned blocks; |
489 | unsigned blocks; |
| 488 | fat_dentry_t *d; |
490 | fat_dentry_t *d; |
| 489 | block_t *b; |
491 | block_t *b; |
| 490 | 492 | ||
| 491 | futex_down(&parentp->idx->lock); |
493 | futex_down(&parentp->idx->lock); |
| 492 | bps = fat_bps_get(parentp->idx->dev_handle); |
494 | bps = fat_bps_get(parentp->idx->dev_handle); |
| 493 | dps = bps / sizeof(fat_dentry_t); |
495 | dps = bps / sizeof(fat_dentry_t); |
| 494 | blocks = parentp->size / bps + (parentp->size % bps != 0); |
496 | blocks = parentp->size / bps + (parentp->size % bps != 0); |
| 495 | for (i = 0; i < blocks; i++) { |
497 | for (i = 0; i < blocks; i++) { |
| 496 | unsigned dentries; |
498 | unsigned dentries; |
| 497 | 499 | ||
| 498 | b = fat_block_get(parentp, i); |
500 | b = fat_block_get(parentp, i); |
| 499 | dentries = (i == blocks - 1) ? |
501 | dentries = (i == blocks - 1) ? |
| 500 | parentp->size % sizeof(fat_dentry_t) : |
502 | parentp->size % sizeof(fat_dentry_t) : |
| 501 | dps; |
503 | dps; |
| 502 | for (j = 0; j < dentries; j++) { |
504 | for (j = 0; j < dentries; j++) { |
| 503 | d = ((fat_dentry_t *)b->data) + j; |
505 | d = ((fat_dentry_t *)b->data) + j; |
| 504 | switch (fat_classify_dentry(d)) { |
506 | switch (fat_classify_dentry(d)) { |
| 505 | case FAT_DENTRY_SKIP: |
507 | case FAT_DENTRY_SKIP: |
| 506 | continue; |
508 | continue; |
| 507 | case FAT_DENTRY_LAST: |
509 | case FAT_DENTRY_LAST: |
| 508 | block_put(b); |
510 | block_put(b); |
| 509 | futex_up(&parentp->idx->lock); |
511 | futex_up(&parentp->idx->lock); |
| 510 | return NULL; |
512 | return NULL; |
| 511 | default: |
513 | default: |
| 512 | case FAT_DENTRY_VALID: |
514 | case FAT_DENTRY_VALID: |
| 513 | dentry_name_canonify(d, name); |
515 | dentry_name_canonify(d, name); |
| 514 | break; |
516 | break; |
| 515 | } |
517 | } |
| 516 | if (stricmp(name, component) == 0) { |
518 | if (stricmp(name, component) == 0) { |
| 517 | /* hit */ |
519 | /* hit */ |
| 518 | void *node; |
520 | void *node; |
| 519 | /* |
521 | /* |
| 520 | * Assume tree hierarchy for locking. We |
522 | * Assume tree hierarchy for locking. We |
| 521 | * already have the parent and now we are going |
523 | * already have the parent and now we are going |
| 522 | * to lock the child. Never lock in the oposite |
524 | * to lock the child. Never lock in the oposite |
| 523 | * order. |
525 | * order. |
| 524 | */ |
526 | */ |
| 525 | fat_idx_t *idx = fat_idx_get_by_pos( |
527 | fat_idx_t *idx = fat_idx_get_by_pos( |
| 526 | parentp->idx->dev_handle, parentp->firstc, |
528 | parentp->idx->dev_handle, parentp->firstc, |
| 527 | i * dps + j); |
529 | i * dps + j); |
| 528 | futex_up(&parentp->idx->lock); |
530 | futex_up(&parentp->idx->lock); |
| 529 | if (!idx) { |
531 | if (!idx) { |
| 530 | /* |
532 | /* |
| 531 | * Can happen if memory is low or if we |
533 | * Can happen if memory is low or if we |
| 532 | * run out of 32-bit indices. |
534 | * run out of 32-bit indices. |
| 533 | */ |
535 | */ |
| 534 | block_put(b); |
536 | block_put(b); |
| 535 | return NULL; |
537 | return NULL; |
| 536 | } |
538 | } |
| 537 | node = fat_node_get_core(idx); |
539 | node = fat_node_get_core(idx); |
| 538 | futex_up(&idx->lock); |
540 | futex_up(&idx->lock); |
| 539 | block_put(b); |
541 | block_put(b); |
| 540 | return node; |
542 | return node; |
| 541 | } |
543 | } |
| 542 | } |
544 | } |
| 543 | block_put(b); |
545 | block_put(b); |
| 544 | } |
546 | } |
| 545 | futex_up(&parentp->idx->lock); |
547 | futex_up(&parentp->idx->lock); |
| 546 | return NULL; |
548 | return NULL; |
| 547 | } |
549 | } |
| 548 | 550 | ||
| 549 | static fs_index_t fat_index_get(void *node) |
551 | static fs_index_t fat_index_get(void *node) |
| 550 | { |
552 | { |
| 551 | fat_node_t *fnodep = (fat_node_t *)node; |
553 | fat_node_t *fnodep = (fat_node_t *)node; |
| 552 | if (!fnodep) |
554 | if (!fnodep) |
| 553 | return 0; |
555 | return 0; |
| 554 | return fnodep->idx->index; |
556 | return fnodep->idx->index; |
| 555 | } |
557 | } |
| 556 | 558 | ||
| 557 | static size_t fat_size_get(void *node) |
559 | static size_t fat_size_get(void *node) |
| 558 | { |
560 | { |
| 559 | return ((fat_node_t *)node)->size; |
561 | return ((fat_node_t *)node)->size; |
| 560 | } |
562 | } |
| 561 | 563 | ||
| 562 | static unsigned fat_lnkcnt_get(void *node) |
564 | static unsigned fat_lnkcnt_get(void *node) |
| 563 | { |
565 | { |
| 564 | return ((fat_node_t *)node)->lnkcnt; |
566 | return ((fat_node_t *)node)->lnkcnt; |
| 565 | } |
567 | } |
| 566 | 568 | ||
| 567 | static bool fat_has_children(void *node) |
569 | static bool fat_has_children(void *node) |
| 568 | { |
570 | { |
| 569 | fat_node_t *nodep = (fat_node_t *)node; |
571 | fat_node_t *nodep = (fat_node_t *)node; |
| 570 | unsigned bps; |
572 | unsigned bps; |
| 571 | unsigned dps; |
573 | unsigned dps; |
| 572 | unsigned blocks; |
574 | unsigned blocks; |
| 573 | block_t *b; |
575 | block_t *b; |
| 574 | unsigned i, j; |
576 | unsigned i, j; |
| 575 | 577 | ||
| 576 | if (nodep->type != FAT_DIRECTORY) |
578 | if (nodep->type != FAT_DIRECTORY) |
| 577 | return false; |
579 | return false; |
| 578 | 580 | ||
| 579 | futex_down(&nodep->idx->lock); |
581 | futex_down(&nodep->idx->lock); |
| 580 | bps = fat_bps_get(nodep->idx->dev_handle); |
582 | bps = fat_bps_get(nodep->idx->dev_handle); |
| 581 | dps = bps / sizeof(fat_dentry_t); |
583 | dps = bps / sizeof(fat_dentry_t); |
| 582 | 584 | ||
| 583 | blocks = nodep->size / bps + (nodep->size % bps != 0); |
585 | blocks = nodep->size / bps + (nodep->size % bps != 0); |
| 584 | 586 | ||
| 585 | for (i = 0; i < blocks; i++) { |
587 | for (i = 0; i < blocks; i++) { |
| 586 | unsigned dentries; |
588 | unsigned dentries; |
| 587 | fat_dentry_t *d; |
589 | fat_dentry_t *d; |
| 588 | 590 | ||
| 589 | b = fat_block_get(nodep, i); |
591 | b = fat_block_get(nodep, i); |
| 590 | dentries = (i == blocks - 1) ? |
592 | dentries = (i == blocks - 1) ? |
| 591 | nodep->size % sizeof(fat_dentry_t) : |
593 | nodep->size % sizeof(fat_dentry_t) : |
| 592 | dps; |
594 | dps; |
| 593 | for (j = 0; j < dentries; j++) { |
595 | for (j = 0; j < dentries; j++) { |
| 594 | d = ((fat_dentry_t *)b->data) + j; |
596 | d = ((fat_dentry_t *)b->data) + j; |
| 595 | switch (fat_classify_dentry(d)) { |
597 | switch (fat_classify_dentry(d)) { |
| 596 | case FAT_DENTRY_SKIP: |
598 | case FAT_DENTRY_SKIP: |
| 597 | continue; |
599 | continue; |
| 598 | case FAT_DENTRY_LAST: |
600 | case FAT_DENTRY_LAST: |
| 599 | block_put(b); |
601 | block_put(b); |
| 600 | futex_up(&nodep->idx->lock); |
602 | futex_up(&nodep->idx->lock); |
| 601 | return false; |
603 | return false; |
| 602 | default: |
604 | default: |
| 603 | case FAT_DENTRY_VALID: |
605 | case FAT_DENTRY_VALID: |
| 604 | block_put(b); |
606 | block_put(b); |
| 605 | futex_up(&nodep->idx->lock); |
607 | futex_up(&nodep->idx->lock); |
| 606 | return true; |
608 | return true; |
| 607 | } |
609 | } |
| 608 | block_put(b); |
610 | block_put(b); |
| 609 | futex_up(&nodep->idx->lock); |
611 | futex_up(&nodep->idx->lock); |
| 610 | return true; |
612 | return true; |
| 611 | } |
613 | } |
| 612 | block_put(b); |
614 | block_put(b); |
| 613 | } |
615 | } |
| 614 | 616 | ||
| 615 | futex_up(&nodep->idx->lock); |
617 | futex_up(&nodep->idx->lock); |
| 616 | return false; |
618 | return false; |
| 617 | } |
619 | } |
| 618 | 620 | ||
| 619 | static void *fat_root_get(dev_handle_t dev_handle) |
621 | static void *fat_root_get(dev_handle_t dev_handle) |
| 620 | { |
622 | { |
| 621 | return fat_node_get(dev_handle, 0); |
623 | return fat_node_get(dev_handle, 0); |
| 622 | } |
624 | } |
| 623 | 625 | ||
| 624 | static char fat_plb_get_char(unsigned pos) |
626 | static char fat_plb_get_char(unsigned pos) |
| 625 | { |
627 | { |
| 626 | return fat_reg.plb_ro[pos % PLB_SIZE]; |
628 | return fat_reg.plb_ro[pos % PLB_SIZE]; |
| 627 | } |
629 | } |
| 628 | 630 | ||
| 629 | static bool fat_is_directory(void *node) |
631 | static bool fat_is_directory(void *node) |
| 630 | { |
632 | { |
| 631 | return ((fat_node_t *)node)->type == FAT_DIRECTORY; |
633 | return ((fat_node_t *)node)->type == FAT_DIRECTORY; |
| 632 | } |
634 | } |
| 633 | 635 | ||
| 634 | static bool fat_is_file(void *node) |
636 | static bool fat_is_file(void *node) |
| 635 | { |
637 | { |
| 636 | return ((fat_node_t *)node)->type == FAT_FILE; |
638 | return ((fat_node_t *)node)->type == FAT_FILE; |
| 637 | } |
639 | } |
| 638 | 640 | ||
| 639 | /** libfs operations */ |
641 | /** libfs operations */ |
| 640 | libfs_ops_t fat_libfs_ops = { |
642 | libfs_ops_t fat_libfs_ops = { |
| 641 | .match = fat_match, |
643 | .match = fat_match, |
| 642 | .node_get = fat_node_get, |
644 | .node_get = fat_node_get, |
| 643 | .node_put = fat_node_put, |
645 | .node_put = fat_node_put, |
| 644 | .create = fat_create, |
646 | .create = fat_create, |
| 645 | .destroy = fat_destroy, |
647 | .destroy = fat_destroy, |
| 646 | .link = fat_link, |
648 | .link = fat_link, |
| 647 | .unlink = fat_unlink, |
649 | .unlink = fat_unlink, |
| 648 | .index_get = fat_index_get, |
650 | .index_get = fat_index_get, |
| 649 | .size_get = fat_size_get, |
651 | .size_get = fat_size_get, |
| 650 | .lnkcnt_get = fat_lnkcnt_get, |
652 | .lnkcnt_get = fat_lnkcnt_get, |
| 651 | .has_children = fat_has_children, |
653 | .has_children = fat_has_children, |
| 652 | .root_get = fat_root_get, |
654 | .root_get = fat_root_get, |
| 653 | .plb_get_char = fat_plb_get_char, |
655 | .plb_get_char = fat_plb_get_char, |
| 654 | .is_directory = fat_is_directory, |
656 | .is_directory = fat_is_directory, |
| 655 | .is_file = fat_is_file |
657 | .is_file = fat_is_file |
| 656 | }; |
658 | }; |
| 657 | 659 | ||
| 658 | void fat_mounted(ipc_callid_t rid, ipc_call_t *request) |
660 | void fat_mounted(ipc_callid_t rid, ipc_call_t *request) |
| 659 | { |
661 | { |
| 660 | dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request); |
662 | dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request); |
| 661 | block_t *bb; |
663 | block_t *bb; |
| 662 | uint16_t bps; |
664 | uint16_t bps; |
| 663 | uint16_t rde; |
665 | uint16_t rde; |
| 664 | int rc; |
666 | int rc; |
| 665 | 667 | ||
| 666 | /* |
668 | /* |
| 667 | * For now, we don't bother to remember dev_handle, dev_phone or |
669 | * For now, we don't bother to remember dev_handle, dev_phone or |
| 668 | * dev_buffer in some data structure. We use global variables because we |
670 | * dev_buffer in some data structure. We use global variables because we |
| 669 | * know there will be at most one mount on this file system. |
671 | * know there will be at most one mount on this file system. |
| 670 | * Of course, this is a huge TODO item. |
672 | * Of course, this is a huge TODO item. |
| 671 | */ |
673 | */ |
| 672 | dev_buffer = mmap(NULL, BS_SIZE, PROTO_READ | PROTO_WRITE, |
674 | dev_buffer = mmap(NULL, BS_SIZE, PROTO_READ | PROTO_WRITE, |
| 673 | MAP_ANONYMOUS | MAP_PRIVATE, 0, 0); |
675 | MAP_ANONYMOUS | MAP_PRIVATE, 0, 0); |
| 674 | 676 | ||
| 675 | if (!dev_buffer) { |
677 | if (!dev_buffer) { |
| 676 | ipc_answer_0(rid, ENOMEM); |
678 | ipc_answer_0(rid, ENOMEM); |
| 677 | return; |
679 | return; |
| 678 | } |
680 | } |
| 679 | 681 | ||
| 680 | dev_phone = ipc_connect_me_to(PHONE_NS, SERVICE_DEVMAP, |
682 | dev_phone = ipc_connect_me_to(PHONE_NS, SERVICE_DEVMAP, |
| 681 | DEVMAP_CONNECT_TO_DEVICE, dev_handle); |
683 | DEVMAP_CONNECT_TO_DEVICE, dev_handle); |
| 682 | 684 | ||
| 683 | if (dev_phone < 0) { |
685 | if (dev_phone < 0) { |
| 684 | munmap(dev_buffer, BS_SIZE); |
686 | munmap(dev_buffer, BS_SIZE); |
| 685 | ipc_answer_0(rid, dev_phone); |
687 | ipc_answer_0(rid, dev_phone); |
| 686 | return; |
688 | return; |
| 687 | } |
689 | } |
| 688 | 690 | ||
| 689 | rc = ipc_share_out_start(dev_phone, dev_buffer, |
691 | rc = ipc_share_out_start(dev_phone, dev_buffer, |
| 690 | AS_AREA_READ | AS_AREA_WRITE); |
692 | AS_AREA_READ | AS_AREA_WRITE); |
| 691 | if (rc != EOK) { |
693 | if (rc != EOK) { |
| 692 | munmap(dev_buffer, BS_SIZE); |
694 | munmap(dev_buffer, BS_SIZE); |
| 693 | ipc_answer_0(rid, rc); |
695 | ipc_answer_0(rid, rc); |
| 694 | return; |
696 | return; |
| 695 | } |
697 | } |
| 696 | 698 | ||
| 697 | /* Read the number of root directory entries. */ |
699 | /* Read the number of root directory entries. */ |
| 698 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
700 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
| 699 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
701 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
| 700 | rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max); |
702 | rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max); |
| 701 | block_put(bb); |
703 | block_put(bb); |
| 702 | 704 | ||
| 703 | if (bps != BS_SIZE) { |
705 | if (bps != BS_SIZE) { |
| 704 | munmap(dev_buffer, BS_SIZE); |
706 | munmap(dev_buffer, BS_SIZE); |
| 705 | ipc_answer_0(rid, ENOTSUP); |
707 | ipc_answer_0(rid, ENOTSUP); |
| 706 | return; |
708 | return; |
| 707 | } |
709 | } |
| 708 | 710 | ||
| 709 | rc = fat_idx_init_by_dev_handle(dev_handle); |
711 | rc = fat_idx_init_by_dev_handle(dev_handle); |
| 710 | if (rc != EOK) { |
712 | if (rc != EOK) { |
| 711 | munmap(dev_buffer, BS_SIZE); |
713 | munmap(dev_buffer, BS_SIZE); |
| 712 | ipc_answer_0(rid, rc); |
714 | ipc_answer_0(rid, rc); |
| 713 | return; |
715 | return; |
| 714 | } |
716 | } |
| 715 | 717 | ||
| 716 | /* Initialize the root node. */ |
718 | /* Initialize the root node. */ |
| 717 | fat_node_t *rootp = (fat_node_t *)malloc(sizeof(fat_node_t)); |
719 | fat_node_t *rootp = (fat_node_t *)malloc(sizeof(fat_node_t)); |
| 718 | if (!rootp) { |
720 | if (!rootp) { |
| 719 | munmap(dev_buffer, BS_SIZE); |
721 | munmap(dev_buffer, BS_SIZE); |
| 720 | fat_idx_fini_by_dev_handle(dev_handle); |
722 | fat_idx_fini_by_dev_handle(dev_handle); |
| 721 | ipc_answer_0(rid, ENOMEM); |
723 | ipc_answer_0(rid, ENOMEM); |
| 722 | return; |
724 | return; |
| 723 | } |
725 | } |
| 724 | fat_node_initialize(rootp); |
726 | fat_node_initialize(rootp); |
| 725 | 727 | ||
| 726 | fat_idx_t *ridxp = fat_idx_get_by_pos(dev_handle, FAT_CLST_ROOTPAR, 0); |
728 | fat_idx_t *ridxp = fat_idx_get_by_pos(dev_handle, FAT_CLST_ROOTPAR, 0); |
| 727 | if (!ridxp) { |
729 | if (!ridxp) { |
| 728 | munmap(dev_buffer, BS_SIZE); |
730 | munmap(dev_buffer, BS_SIZE); |
| 729 | free(rootp); |
731 | free(rootp); |
| 730 | fat_idx_fini_by_dev_handle(dev_handle); |
732 | fat_idx_fini_by_dev_handle(dev_handle); |
| 731 | ipc_answer_0(rid, ENOMEM); |
733 | ipc_answer_0(rid, ENOMEM); |
| 732 | return; |
734 | return; |
| 733 | } |
735 | } |
| 734 | assert(ridxp->index == 0); |
736 | assert(ridxp->index == 0); |
| 735 | /* ridxp->lock held */ |
737 | /* ridxp->lock held */ |
| 736 | 738 | ||
| 737 | rootp->type = FAT_DIRECTORY; |
739 | rootp->type = FAT_DIRECTORY; |
| 738 | rootp->firstc = FAT_CLST_ROOT; |
740 | rootp->firstc = FAT_CLST_ROOT; |
| 739 | rootp->refcnt = 1; |
741 | rootp->refcnt = 1; |
| 740 | rootp->lnkcnt = 0; /* FS root is not linked */ |
742 | rootp->lnkcnt = 0; /* FS root is not linked */ |
| 741 | rootp->size = rde * sizeof(fat_dentry_t); |
743 | rootp->size = rde * sizeof(fat_dentry_t); |
| 742 | rootp->idx = ridxp; |
744 | rootp->idx = ridxp; |
| 743 | ridxp->nodep = rootp; |
745 | ridxp->nodep = rootp; |
| 744 | 746 | ||
| 745 | futex_up(&ridxp->lock); |
747 | futex_up(&ridxp->lock); |
| 746 | 748 | ||
| 747 | ipc_answer_3(rid, EOK, ridxp->index, rootp->size, rootp->lnkcnt); |
749 | ipc_answer_3(rid, EOK, ridxp->index, rootp->size, rootp->lnkcnt); |
| 748 | } |
750 | } |
| 749 | 751 | ||
| 750 | void fat_mount(ipc_callid_t rid, ipc_call_t *request) |
752 | void fat_mount(ipc_callid_t rid, ipc_call_t *request) |
| 751 | { |
753 | { |
| 752 | ipc_answer_0(rid, ENOTSUP); |
754 | ipc_answer_0(rid, ENOTSUP); |
| 753 | } |
755 | } |
| 754 | 756 | ||
| 755 | void fat_lookup(ipc_callid_t rid, ipc_call_t *request) |
757 | void fat_lookup(ipc_callid_t rid, ipc_call_t *request) |
| 756 | { |
758 | { |
| 757 | libfs_lookup(&fat_libfs_ops, fat_reg.fs_handle, rid, request); |
759 | libfs_lookup(&fat_libfs_ops, fat_reg.fs_handle, rid, request); |
| 758 | } |
760 | } |
| 759 | 761 | ||
| 760 | void fat_read(ipc_callid_t rid, ipc_call_t *request) |
762 | void fat_read(ipc_callid_t rid, ipc_call_t *request) |
| 761 | { |
763 | { |
| 762 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
764 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
| 763 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
765 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
| 764 | off_t pos = (off_t)IPC_GET_ARG3(*request); |
766 | off_t pos = (off_t)IPC_GET_ARG3(*request); |
| 765 | fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
767 | fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
| 766 | uint16_t bps = fat_bps_get(dev_handle); |
768 | uint16_t bps = fat_bps_get(dev_handle); |
| 767 | size_t bytes; |
769 | size_t bytes; |
| 768 | block_t *b; |
770 | block_t *b; |
| 769 | 771 | ||
| 770 | if (!nodep) { |
772 | if (!nodep) { |
| 771 | ipc_answer_0(rid, ENOENT); |
773 | ipc_answer_0(rid, ENOENT); |
| 772 | return; |
774 | return; |
| 773 | } |
775 | } |
| 774 | 776 | ||
| 775 | ipc_callid_t callid; |
777 | ipc_callid_t callid; |
| 776 | size_t len; |
778 | size_t len; |
| 777 | if (!ipc_data_read_receive(&callid, &len)) { |
779 | if (!ipc_data_read_receive(&callid, &len)) { |
| 778 | fat_node_put(nodep); |
780 | fat_node_put(nodep); |
| 779 | ipc_answer_0(callid, EINVAL); |
781 | ipc_answer_0(callid, EINVAL); |
| 780 | ipc_answer_0(rid, EINVAL); |
782 | ipc_answer_0(rid, EINVAL); |
| 781 | return; |
783 | return; |
| 782 | } |
784 | } |
| 783 | 785 | ||
| 784 | if (nodep->type == FAT_FILE) { |
786 | if (nodep->type == FAT_FILE) { |
| 785 | /* |
787 | /* |
| 786 | * Our strategy for regular file reads is to read one block at |
788 | * Our strategy for regular file reads is to read one block at |
| 787 | * most and make use of the possibility to return less data than |
789 | * most and make use of the possibility to return less data than |
| 788 | * requested. This keeps the code very simple. |
790 | * requested. This keeps the code very simple. |
| 789 | */ |
791 | */ |
| 790 | bytes = min(len, bps - pos % bps); |
792 | bytes = min(len, bps - pos % bps); |
| 791 | b = fat_block_get(nodep, pos / bps); |
793 | b = fat_block_get(nodep, pos / bps); |
| 792 | (void) ipc_data_read_finalize(callid, b->data + pos % bps, |
794 | (void) ipc_data_read_finalize(callid, b->data + pos % bps, |
| 793 | bytes); |
795 | bytes); |
| 794 | block_put(b); |
796 | block_put(b); |
| 795 | } else { |
797 | } else { |
| 796 | unsigned bnum; |
798 | unsigned bnum; |
| 797 | off_t spos = pos; |
799 | off_t spos = pos; |
| 798 | char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1]; |
800 | char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1]; |
| 799 | fat_dentry_t *d; |
801 | fat_dentry_t *d; |
| 800 | 802 | ||
| 801 | assert(nodep->type == FAT_DIRECTORY); |
803 | assert(nodep->type == FAT_DIRECTORY); |
| 802 | assert(nodep->size % bps == 0); |
804 | assert(nodep->size % bps == 0); |
| 803 | assert(bps % sizeof(fat_dentry_t) == 0); |
805 | assert(bps % sizeof(fat_dentry_t) == 0); |
| 804 | 806 | ||
| 805 | /* |
807 | /* |
| 806 | * Our strategy for readdir() is to use the position pointer as |
808 | * Our strategy for readdir() is to use the position pointer as |
| 807 | * an index into the array of all dentries. On entry, it points |
809 | * an index into the array of all dentries. On entry, it points |
| 808 | * to the first unread dentry. If we skip any dentries, we bump |
810 | * to the first unread dentry. If we skip any dentries, we bump |
| 809 | * the position pointer accordingly. |
811 | * the position pointer accordingly. |
| 810 | */ |
812 | */ |
| 811 | bnum = (pos * sizeof(fat_dentry_t)) / bps; |
813 | bnum = (pos * sizeof(fat_dentry_t)) / bps; |
| 812 | while (bnum < nodep->size / bps) { |
814 | while (bnum < nodep->size / bps) { |
| 813 | off_t o; |
815 | off_t o; |
| 814 | 816 | ||
| 815 | b = fat_block_get(nodep, bnum); |
817 | b = fat_block_get(nodep, bnum); |
| 816 | for (o = pos % (bps / sizeof(fat_dentry_t)); |
818 | for (o = pos % (bps / sizeof(fat_dentry_t)); |
| 817 | o < bps / sizeof(fat_dentry_t); |
819 | o < bps / sizeof(fat_dentry_t); |
| 818 | o++, pos++) { |
820 | o++, pos++) { |
| 819 | d = ((fat_dentry_t *)b->data) + o; |
821 | d = ((fat_dentry_t *)b->data) + o; |
| 820 | switch (fat_classify_dentry(d)) { |
822 | switch (fat_classify_dentry(d)) { |
| 821 | case FAT_DENTRY_SKIP: |
823 | case FAT_DENTRY_SKIP: |
| 822 | continue; |
824 | continue; |
| 823 | case FAT_DENTRY_LAST: |
825 | case FAT_DENTRY_LAST: |
| 824 | block_put(b); |
826 | block_put(b); |
| 825 | goto miss; |
827 | goto miss; |
| 826 | default: |
828 | default: |
| 827 | case FAT_DENTRY_VALID: |
829 | case FAT_DENTRY_VALID: |
| 828 | dentry_name_canonify(d, name); |
830 | dentry_name_canonify(d, name); |
| 829 | block_put(b); |
831 | block_put(b); |
| 830 | goto hit; |
832 | goto hit; |
| 831 | } |
833 | } |
| 832 | } |
834 | } |
| 833 | block_put(b); |
835 | block_put(b); |
| 834 | bnum++; |
836 | bnum++; |
| 835 | } |
837 | } |
| 836 | miss: |
838 | miss: |
| 837 | fat_node_put(nodep); |
839 | fat_node_put(nodep); |
| 838 | ipc_answer_0(callid, ENOENT); |
840 | ipc_answer_0(callid, ENOENT); |
| 839 | ipc_answer_1(rid, ENOENT, 0); |
841 | ipc_answer_1(rid, ENOENT, 0); |
| 840 | return; |
842 | return; |
| 841 | hit: |
843 | hit: |
| 842 | (void) ipc_data_read_finalize(callid, name, strlen(name) + 1); |
844 | (void) ipc_data_read_finalize(callid, name, strlen(name) + 1); |
| 843 | bytes = (pos - spos) + 1; |
845 | bytes = (pos - spos) + 1; |
| 844 | } |
846 | } |
| 845 | 847 | ||
| 846 | fat_node_put(nodep); |
848 | fat_node_put(nodep); |
| 847 | ipc_answer_1(rid, EOK, (ipcarg_t)bytes); |
849 | ipc_answer_1(rid, EOK, (ipcarg_t)bytes); |
| 848 | } |
850 | } |
| 849 | 851 | ||
| - | 852 | static void fat_fill_gap(fat_node_t *nodep, off_t start, off_t stop) |
|
| - | 853 | { |
|
| - | 854 | /* TODO */ |
|
| - | 855 | } |
|
| - | 856 | ||
| 850 | void fat_write(ipc_callid_t rid, ipc_call_t *request) |
857 | void fat_write(ipc_callid_t rid, ipc_call_t *request) |
| 851 | { |
858 | { |
| - | 859 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
|
| - | 860 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
|
| - | 861 | off_t pos = (off_t)IPC_GET_ARG3(*request); |
|
| - | 862 | fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
|
| - | 863 | size_t bytes; |
|
| - | 864 | block_t *b, *bb; |
|
| - | 865 | uint16_t bps; |
|
| - | 866 | unsigned spc; |
|
| - | 867 | off_t clst_boundary; |
|
| - | 868 | ||
| - | 869 | if (!nodep) { |
|
| - | 870 | ipc_answer_0(rid, ENOENT); |
|
| - | 871 | return; |
|
| - | 872 | } |
|
| - | 873 | ||
| - | 874 | /* XXX remove me when you are ready */ |
|
| - | 875 | { |
|
| 852 | ipc_answer_0(rid, ENOTSUP); |
876 | ipc_answer_0(rid, ENOTSUP); |
| - | 877 | fat_node_put(nodep); |
|
| - | 878 | return; |
|
| - | 879 | } |
|
| - | 880 | ||
| - | 881 | ipc_callid_t callid; |
|
| - | 882 | size_t len; |
|
| - | 883 | if (!ipc_data_write_receive(&callid, &len)) { |
|
| - | 884 | fat_node_put(nodep); |
|
| - | 885 | ipc_answer_0(callid, EINVAL); |
|
| - | 886 | ipc_answer_0(rid, EINVAL); |
|
| - | 887 | return; |
|
| - | 888 | } |
|
| - | 889 | ||
| - | 890 | /* |
|
| - | 891 | * In all scenarios, we will attempt to write out only one block worth |
|
| - | 892 | * of data at maximum. There might be some more efficient approaches, |
|
| - | 893 | * but this one greatly simplifies fat_write(). Note that we can afford |
|
| - | 894 | * to do this because the client must be ready to handle the return |
|
| - | 895 | * value signalizing a smaller number of bytes written. |
|
| - | 896 | */ |
|
| - | 897 | bytes = min(len, bps - pos % bps); |
|
| - | 898 | ||
| - | 899 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
|
| - | 900 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
|
| - | 901 | spc = FAT_BS(bb)->spc; |
|
| - | 902 | block_put(bb); |
|
| - | 903 | ||
| - | 904 | clst_boundary = ROUND_UP(nodep->size, bps * spc); |
|
| - | 905 | if (pos < clst_boundary) { |
|
| - | 906 | /* |
|
| - | 907 | * This is the easier case - we are either overwriting already |
|
| - | 908 | * existing contents or writing behind the EOF, but still within |
|
| - | 909 | * the limits of the last cluster. The node size may grow to the |
|
| - | 910 | * next block size boundary. |
|
| - | 911 | */ |
|
| - | 912 | if (pos > nodep->size) |
|
| - | 913 | fat_fill_gap(nodep, nodep->size, pos); |
|
| - | 914 | b = fat_block_get(nodep, pos / bps); |
|
| - | 915 | (void) ipc_data_write_finalize(callid, b->data + pos % bps, |
|
| - | 916 | bytes); |
|
| - | 917 | b->dirty = true; /* need to sync block */ |
|
| - | 918 | if (pos + bytes > nodep->size) { |
|
| - | 919 | nodep->size = pos + bytes; |
|
| - | 920 | nodep->dirty = true; /* need to sync node */ |
|
| - | 921 | } |
|
| - | 922 | block_put(b); |
|
| - | 923 | fat_node_put(nodep); |
|
| - | 924 | ipc_answer_1(rid, EOK, bytes); |
|
| - | 925 | return; |
|
| - | 926 | } else { |
|
| - | 927 | /* |
|
| - | 928 | * This is the more difficult case. We must allocate new |
|
| - | 929 | * clusters for the node and zero them out. |
|
| - | 930 | */ |
|
| - | 931 | unsigned nclsts; |
|
| - | 932 | ||
| - | 933 | nclsts = (ROUND_UP(pos + bytes, bps * spc) - clst_boundary) / |
|
| - | 934 | bps * spc; |
|
| - | 935 | ||
| - | 936 | } |
|
| - | 937 | ||
| 853 | } |
938 | } |
| 854 | 939 | ||
| 855 | /** |
940 | /** |
| 856 | * @} |
941 | * @} |
| 857 | */ |
942 | */ |
| 858 | 943 | ||