Rev 2666 | Rev 2673 | Go to most recent revision | Only display areas with differences | Regard whitespace | Details | Blame | Last modification | View Log | RSS feed
Rev 2666 | Rev 2667 | ||
---|---|---|---|
1 | /* |
1 | /* |
2 | * Copyright (c) 2007 Jakub Jermar |
2 | * Copyright (c) 2007 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 tmpfs_ops.c |
34 | * @file tmpfs_ops.c |
35 | * @brief Implementation of VFS operations for the TMPFS file system |
35 | * @brief Implementation of VFS operations for the TMPFS file system |
36 | * server. |
36 | * server. |
37 | */ |
37 | */ |
38 | 38 | ||
39 | #include "tmpfs.h" |
39 | #include "tmpfs.h" |
40 | #include "../../vfs/vfs.h" |
40 | #include "../../vfs/vfs.h" |
41 | #include <ipc/ipc.h> |
41 | #include <ipc/ipc.h> |
42 | #include <async.h> |
42 | #include <async.h> |
43 | #include <errno.h> |
43 | #include <errno.h> |
44 | #include <atomic.h> |
44 | #include <atomic.h> |
45 | #include <stdlib.h> |
45 | #include <stdlib.h> |
46 | #include <string.h> |
46 | #include <string.h> |
47 | #include <stdio.h> |
47 | #include <stdio.h> |
48 | #include <sys/types.h> |
48 | #include <sys/types.h> |
49 | #include <libadt/hash_table.h> |
49 | #include <libadt/hash_table.h> |
50 | #include <as.h> |
50 | #include <as.h> |
51 | 51 | ||
52 | #define min(a, b) ((a) < (b) ? (a) : (b)) |
52 | #define min(a, b) ((a) < (b) ? (a) : (b)) |
53 | #define max(a, b) ((a) > (b) ? (a) : (b)) |
53 | #define max(a, b) ((a) > (b) ? (a) : (b)) |
54 | 54 | ||
55 | #define PLB_GET_CHAR(i) (tmpfs_reg.plb_ro[(i) % PLB_SIZE]) |
55 | #define PLB_GET_CHAR(i) (tmpfs_reg.plb_ro[(i) % PLB_SIZE]) |
56 | 56 | ||
57 | #define DENTRIES_BUCKETS 256 |
57 | #define DENTRIES_BUCKETS 256 |
58 | 58 | ||
59 | /* |
59 | /* |
60 | * Hash table of all directory entries. |
60 | * Hash table of all directory entries. |
61 | */ |
61 | */ |
62 | hash_table_t dentries; |
62 | hash_table_t dentries; |
63 | 63 | ||
64 | static hash_index_t dentries_hash(unsigned long *key) |
64 | static hash_index_t dentries_hash(unsigned long *key) |
65 | { |
65 | { |
66 | return *key % DENTRIES_BUCKETS; |
66 | return *key % DENTRIES_BUCKETS; |
67 | } |
67 | } |
68 | 68 | ||
69 | static int dentries_compare(unsigned long *key, hash_count_t keys, |
69 | static int dentries_compare(unsigned long *key, hash_count_t keys, |
70 | link_t *item) |
70 | link_t *item) |
71 | { |
71 | { |
72 | tmpfs_dentry_t *dentry = hash_table_get_instance(item, tmpfs_dentry_t, |
72 | tmpfs_dentry_t *dentry = hash_table_get_instance(item, tmpfs_dentry_t, |
73 | dh_link); |
73 | dh_link); |
74 | return dentry->index == *key; |
74 | return dentry->index == *key; |
75 | } |
75 | } |
76 | 76 | ||
77 | static void dentries_remove_callback(link_t *item) |
77 | static void dentries_remove_callback(link_t *item) |
78 | { |
78 | { |
79 | } |
79 | } |
80 | 80 | ||
81 | /** TMPFS dentries hash table operations. */ |
81 | /** TMPFS dentries hash table operations. */ |
82 | hash_table_operations_t dentries_ops = { |
82 | hash_table_operations_t dentries_ops = { |
83 | .hash = dentries_hash, |
83 | .hash = dentries_hash, |
84 | .compare = dentries_compare, |
84 | .compare = dentries_compare, |
85 | .remove_callback = dentries_remove_callback |
85 | .remove_callback = dentries_remove_callback |
86 | }; |
86 | }; |
87 | 87 | ||
88 | unsigned tmpfs_next_index = 1; |
88 | unsigned tmpfs_next_index = 1; |
89 | 89 | ||
90 | static void tmpfs_dentry_initialize(tmpfs_dentry_t *dentry) |
90 | static void tmpfs_dentry_initialize(tmpfs_dentry_t *dentry) |
91 | { |
91 | { |
92 | dentry->index = 0; |
92 | dentry->index = 0; |
93 | dentry->parent = NULL; |
93 | dentry->parent = NULL; |
94 | dentry->sibling = NULL; |
94 | dentry->sibling = NULL; |
95 | dentry->child = NULL; |
95 | dentry->child = NULL; |
96 | dentry->name = NULL; |
96 | dentry->name = NULL; |
97 | dentry->type = TMPFS_NONE; |
97 | dentry->type = TMPFS_NONE; |
98 | dentry->size = 0; |
98 | dentry->size = 0; |
99 | dentry->data = NULL; |
99 | dentry->data = NULL; |
100 | link_initialize(&dentry->dh_link); |
100 | link_initialize(&dentry->dh_link); |
101 | } |
101 | } |
102 | 102 | ||
103 | /* |
103 | /* |
104 | * For now, we don't distinguish between different dev_handles/instances. All |
104 | * For now, we don't distinguish between different dev_handles/instances. All |
105 | * requests resolve to the only instance, rooted in the following variable. |
105 | * requests resolve to the only instance, rooted in the following variable. |
106 | */ |
106 | */ |
107 | static tmpfs_dentry_t *root; |
107 | static tmpfs_dentry_t *root; |
108 | 108 | ||
109 | static bool tmpfs_init(void) |
109 | static bool tmpfs_init(void) |
110 | { |
110 | { |
111 | if (!hash_table_create(&dentries, DENTRIES_BUCKETS, 1, &dentries_ops)) |
111 | if (!hash_table_create(&dentries, DENTRIES_BUCKETS, 1, &dentries_ops)) |
112 | return false; |
112 | return false; |
113 | 113 | ||
114 | root = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t)); |
114 | root = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t)); |
115 | if (!root) |
115 | if (!root) |
116 | return false; |
116 | return false; |
117 | tmpfs_dentry_initialize(root); |
117 | tmpfs_dentry_initialize(root); |
118 | root->index = tmpfs_next_index++; |
118 | root->index = tmpfs_next_index++; |
119 | root->name = ""; |
119 | root->name = ""; |
120 | root->type = TMPFS_DIRECTORY; |
120 | root->type = TMPFS_DIRECTORY; |
121 | hash_table_insert(&dentries, &root->index, &root->dh_link); |
121 | hash_table_insert(&dentries, &root->index, &root->dh_link); |
122 | 122 | ||
123 | /* |
123 | /* |
124 | * This is only for debugging. Once we can create files and directories |
124 | * This is only for debugging. Once we can create files and directories |
125 | * using VFS, we can get rid of this. |
125 | * using VFS, we can get rid of this. |
126 | */ |
126 | */ |
127 | tmpfs_dentry_t *d; |
127 | tmpfs_dentry_t *d; |
128 | d = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t)); |
128 | d = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t)); |
129 | if (!d) { |
129 | if (!d) { |
130 | free(root); |
130 | free(root); |
131 | root = NULL; |
131 | root = NULL; |
132 | return false; |
132 | return false; |
133 | } |
133 | } |
134 | tmpfs_dentry_initialize(d); |
134 | tmpfs_dentry_initialize(d); |
135 | d->index = tmpfs_next_index++; |
135 | d->index = tmpfs_next_index++; |
136 | root->child = d; |
136 | root->child = d; |
137 | d->parent = root; |
137 | d->parent = root; |
138 | d->type = TMPFS_DIRECTORY; |
138 | d->type = TMPFS_DIRECTORY; |
139 | d->name = "dir1"; |
139 | d->name = "dir1"; |
140 | hash_table_insert(&dentries, &d->index, &d->dh_link); |
140 | hash_table_insert(&dentries, &d->index, &d->dh_link); |
141 | 141 | ||
142 | d = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t)); |
142 | d = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t)); |
143 | if (!d) { |
143 | if (!d) { |
144 | free(root->child); |
144 | free(root->child); |
145 | free(root); |
145 | free(root); |
146 | root = NULL; |
146 | root = NULL; |
147 | return false; |
147 | return false; |
148 | } |
148 | } |
149 | tmpfs_dentry_initialize(d); |
149 | tmpfs_dentry_initialize(d); |
150 | d->index = tmpfs_next_index++; |
150 | d->index = tmpfs_next_index++; |
151 | root->child->sibling = d; |
151 | root->child->sibling = d; |
152 | d->parent = root; |
152 | d->parent = root; |
153 | d->type = TMPFS_DIRECTORY; |
153 | d->type = TMPFS_DIRECTORY; |
154 | d->name = "dir2"; |
154 | d->name = "dir2"; |
155 | hash_table_insert(&dentries, &d->index, &d->dh_link); |
155 | hash_table_insert(&dentries, &d->index, &d->dh_link); |
156 | 156 | ||
157 | d = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t)); |
157 | d = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t)); |
158 | if (!d) { |
158 | if (!d) { |
159 | free(root->child->sibling); |
159 | free(root->child->sibling); |
160 | free(root->child); |
160 | free(root->child); |
161 | free(root); |
161 | free(root); |
162 | root = NULL; |
162 | root = NULL; |
163 | return false; |
163 | return false; |
164 | } |
164 | } |
165 | tmpfs_dentry_initialize(d); |
165 | tmpfs_dentry_initialize(d); |
166 | d->index = tmpfs_next_index++; |
166 | d->index = tmpfs_next_index++; |
167 | root->child->child = d; |
167 | root->child->child = d; |
168 | d->parent = root->child; |
168 | d->parent = root->child; |
169 | d->type = TMPFS_FILE; |
169 | d->type = TMPFS_FILE; |
170 | d->name = "file1"; |
170 | d->name = "file1"; |
171 | d->data = "This is the contents of /dir1/file1.\n"; |
171 | d->data = "This is the contents of /dir1/file1.\n"; |
172 | d->size = strlen(d->data); |
172 | d->size = strlen(d->data); |
173 | hash_table_insert(&dentries, &d->index, &d->dh_link); |
173 | hash_table_insert(&dentries, &d->index, &d->dh_link); |
174 | 174 | ||
175 | d = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t)); |
175 | d = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t)); |
176 | if (!d) { |
176 | if (!d) { |
177 | free(root->child->sibling); |
177 | free(root->child->sibling); |
178 | free(root->child->child); |
178 | free(root->child->child); |
179 | free(root->child); |
179 | free(root->child); |
180 | free(root); |
180 | free(root); |
181 | root = NULL; |
181 | root = NULL; |
182 | return false; |
182 | return false; |
183 | } |
183 | } |
184 | tmpfs_dentry_initialize(d); |
184 | tmpfs_dentry_initialize(d); |
185 | d->index = tmpfs_next_index++; |
185 | d->index = tmpfs_next_index++; |
186 | root->child->sibling->child = d; |
186 | root->child->sibling->child = d; |
187 | d->parent = root->child->sibling; |
187 | d->parent = root->child->sibling; |
188 | d->type = TMPFS_FILE; |
188 | d->type = TMPFS_FILE; |
189 | d->name = "file2"; |
189 | d->name = "file2"; |
190 | d->data = "This is the contents of /dir2/file2.\n"; |
190 | d->data = "This is the contents of /dir2/file2.\n"; |
191 | d->size = strlen(d->data); |
191 | d->size = strlen(d->data); |
192 | hash_table_insert(&dentries, &d->index, &d->dh_link); |
192 | hash_table_insert(&dentries, &d->index, &d->dh_link); |
193 | 193 | ||
194 | return true; |
194 | return true; |
195 | } |
195 | } |
196 | 196 | ||
197 | /** Compare one component of path to a directory entry. |
197 | /** Compare one component of path to a directory entry. |
198 | * |
198 | * |
199 | * @param dentry Directory entry to compare the path component with. |
199 | * @param dentry Directory entry to compare the path component with. |
200 | * @param start Index into PLB where the path component starts. |
200 | * @param start Index into PLB where the path component starts. |
201 | * @param last Index of the last character of the path in PLB. |
201 | * @param last Index of the last character of the path in PLB. |
202 | * |
202 | * |
203 | * @return Zero on failure or delta such that (index + delta) % |
203 | * @return Zero on failure or delta such that (index + delta) % |
204 | * PLB_SIZE points to the first unprocessed character in |
204 | * PLB_SIZE points to the first unprocessed character in |
205 | * PLB which comprises the path. |
205 | * PLB which comprises the path. |
206 | */ |
206 | */ |
207 | static unsigned match_path_component(tmpfs_dentry_t *dentry, unsigned start, |
207 | static unsigned match_path_component(tmpfs_dentry_t *dentry, unsigned start, |
208 | unsigned last) |
208 | unsigned last) |
209 | { |
209 | { |
210 | int i, j; |
210 | int i, j; |
211 | size_t namelen; |
211 | size_t namelen; |
212 | 212 | ||
213 | namelen = strlen(dentry->name); |
213 | namelen = strlen(dentry->name); |
214 | 214 | ||
215 | if (last < start) |
215 | if (last < start) |
216 | last += PLB_SIZE; |
216 | last += PLB_SIZE; |
217 | 217 | ||
218 | for (i = 0, j = start; i < namelen && j <= last; i++, j++) { |
218 | for (i = 0, j = start; i < namelen && j <= last; i++, j++) { |
219 | if (dentry->name[i] != PLB_GET_CHAR(j)) |
219 | if (dentry->name[i] != PLB_GET_CHAR(j)) |
220 | return 0; |
220 | return 0; |
221 | } |
221 | } |
222 | 222 | ||
223 | if (i != namelen) |
223 | if (i != namelen) |
224 | return 0; |
224 | return 0; |
225 | if (j < last && PLB_GET_CHAR(j) != '/') |
225 | if (j < last && PLB_GET_CHAR(j) != '/') |
226 | return 0; |
226 | return 0; |
227 | if (j == last) |
227 | if (j == last) |
228 | return 0; |
228 | return 0; |
229 | 229 | ||
230 | return (j - start); |
230 | return (j - start); |
231 | } |
231 | } |
232 | 232 | ||
233 | void tmpfs_lookup(ipc_callid_t rid, ipc_call_t *request) |
233 | void tmpfs_lookup(ipc_callid_t rid, ipc_call_t *request) |
234 | { |
234 | { |
235 | unsigned next = IPC_GET_ARG1(*request); |
235 | unsigned next = IPC_GET_ARG1(*request); |
236 | unsigned last = IPC_GET_ARG2(*request); |
236 | unsigned last = IPC_GET_ARG2(*request); |
237 | int dev_handle = IPC_GET_ARG3(*request); |
237 | int dev_handle = IPC_GET_ARG3(*request); |
238 | 238 | ||
239 | if (last < next) |
239 | if (last < next) |
240 | last += PLB_SIZE; |
240 | last += PLB_SIZE; |
241 | 241 | ||
242 | if (!root && !tmpfs_init()) { |
242 | if (!root && !tmpfs_init()) { |
243 | ipc_answer_0(rid, ENOMEM); |
243 | ipc_answer_0(rid, ENOMEM); |
244 | return; |
244 | return; |
245 | } |
245 | } |
246 | 246 | ||
247 | tmpfs_dentry_t *dtmp = root->child; |
247 | tmpfs_dentry_t *dtmp = root->child; |
248 | tmpfs_dentry_t *dcur = root; |
248 | tmpfs_dentry_t *dcur = root; |
249 | 249 | ||
250 | bool hit = true; |
250 | bool hit = true; |
251 | 251 | ||
252 | if (PLB_GET_CHAR(next) == '/') |
252 | if (PLB_GET_CHAR(next) == '/') |
253 | next++; /* eat slash */ |
253 | next++; /* eat slash */ |
254 | 254 | ||
255 | while (next <= last) { |
255 | while (next <= last) { |
256 | unsigned delta; |
256 | unsigned delta; |
257 | hit = false; |
257 | hit = false; |
258 | do { |
258 | do { |
259 | delta = match_path_component(dtmp, next, last); |
259 | delta = match_path_component(dtmp, next, last); |
260 | if (!delta) { |
260 | if (!delta) { |
261 | dtmp = dtmp->sibling; |
261 | dtmp = dtmp->sibling; |
262 | } else { |
262 | } else { |
263 | hit = true; |
263 | hit = true; |
264 | next += delta; |
264 | next += delta; |
265 | next++; /* eat slash */ |
265 | next++; /* eat slash */ |
266 | dcur = dtmp; |
266 | dcur = dtmp; |
267 | dtmp = dtmp->child; |
267 | dtmp = dtmp->child; |
268 | } |
268 | } |
269 | } while (delta == 0 && dtmp); |
269 | } while (delta == 0 && dtmp); |
270 | if (!hit) { |
270 | if (!hit) { |
271 | ipc_answer_3(rid, ENOENT, tmpfs_reg.fs_handle, |
271 | ipc_answer_3(rid, ENOENT, tmpfs_reg.fs_handle, |
272 | dev_handle, dcur->index); |
272 | dev_handle, dcur->index); |
273 | return; |
273 | return; |
274 | } |
274 | } |
275 | } |
275 | } |
276 | 276 | ||
277 | ipc_answer_3(rid, EOK, tmpfs_reg.fs_handle, dev_handle, dcur->index); |
277 | ipc_answer_3(rid, EOK, tmpfs_reg.fs_handle, dev_handle, dcur->index); |
278 | } |
278 | } |
279 | 279 | ||
280 | void tmpfs_read(ipc_callid_t rid, ipc_call_t *request) |
280 | void tmpfs_read(ipc_callid_t rid, ipc_call_t *request) |
281 | { |
281 | { |
282 | int dev_handle = IPC_GET_ARG1(*request); |
282 | int dev_handle = IPC_GET_ARG1(*request); |
283 | unsigned long index = IPC_GET_ARG2(*request); |
283 | unsigned long index = IPC_GET_ARG2(*request); |
284 | off_t pos = IPC_GET_ARG3(*request); |
284 | off_t pos = IPC_GET_ARG3(*request); |
285 | 285 | ||
286 | /* |
286 | /* |
287 | * Lookup the respective dentry. |
287 | * Lookup the respective dentry. |
288 | */ |
288 | */ |
289 | link_t *hlp; |
289 | link_t *hlp; |
290 | hlp = hash_table_find(&dentries, &index); |
290 | hlp = hash_table_find(&dentries, &index); |
291 | if (!hlp) { |
291 | if (!hlp) { |
292 | ipc_answer_0(rid, ENOENT); |
292 | ipc_answer_0(rid, ENOENT); |
293 | return; |
293 | return; |
294 | } |
294 | } |
295 | tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t, |
295 | tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t, |
296 | dh_link); |
296 | dh_link); |
297 | 297 | ||
298 | /* |
298 | /* |
299 | * Receive the read request. |
299 | * Receive the read request. |
300 | */ |
300 | */ |
301 | ipc_callid_t callid; |
301 | ipc_callid_t callid; |
302 | size_t size; |
302 | size_t size; |
303 | if (!ipc_data_read_receive(&callid, &size)) { |
303 | if (!ipc_data_read_receive(&callid, &size)) { |
304 | ipc_answer_0(callid, EINVAL); |
304 | ipc_answer_0(callid, EINVAL); |
305 | ipc_answer_0(rid, EINVAL); |
305 | ipc_answer_0(rid, EINVAL); |
306 | return; |
306 | return; |
307 | } |
307 | } |
308 | 308 | ||
309 | size_t bytes = max(0, min(dentry->size - pos, size)); |
309 | size_t bytes = max(0, min(dentry->size - pos, size)); |
310 | (void) ipc_data_read_deliver(callid, dentry->data + pos, bytes); |
310 | (void) ipc_data_read_deliver(callid, dentry->data + pos, bytes); |
311 | 311 | ||
312 | /* |
312 | /* |
313 | * Answer the VFS_READ call. |
313 | * Answer the VFS_READ call. |
314 | */ |
314 | */ |
315 | ipc_answer_1(rid, EOK, bytes); |
315 | ipc_answer_1(rid, EOK, bytes); |
316 | } |
316 | } |
317 | 317 | ||
318 | void tmpfs_write(ipc_callid_t rid, ipc_call_t *request) |
318 | void tmpfs_write(ipc_callid_t rid, ipc_call_t *request) |
319 | { |
319 | { |
320 | int dev_handle = IPC_GET_ARG1(*request); |
320 | int dev_handle = IPC_GET_ARG1(*request); |
321 | unsigned long index = IPC_GET_ARG2(*request); |
321 | unsigned long index = IPC_GET_ARG2(*request); |
322 | off_t pos = IPC_GET_ARG3(*request); |
322 | off_t pos = IPC_GET_ARG3(*request); |
323 | 323 | ||
324 | /* |
324 | /* |
325 | * Lookup the respective dentry. |
325 | * Lookup the respective dentry. |
326 | */ |
326 | */ |
327 | link_t *hlp; |
327 | link_t *hlp; |
328 | hlp = hash_table_find(&dentries, &index); |
328 | hlp = hash_table_find(&dentries, &index); |
329 | if (!hlp) { |
329 | if (!hlp) { |
330 | ipc_answer_0(rid, ENOENT); |
330 | ipc_answer_0(rid, ENOENT); |
331 | return; |
331 | return; |
332 | } |
332 | } |
333 | tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t, |
333 | tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t, |
334 | dh_link); |
334 | dh_link); |
335 | 335 | ||
336 | /* |
336 | /* |
337 | * Receive the write request. |
337 | * Receive the write request. |
338 | */ |
338 | */ |
339 | ipc_callid_t callid; |
339 | ipc_callid_t callid; |
340 | size_t size; |
340 | size_t size; |
341 | if (!ipc_data_write_receive(&callid, NULL, &size)) { |
341 | if (!ipc_data_write_receive(&callid, NULL, &size)) { |
342 | ipc_answer_0(callid, EINVAL); |
342 | ipc_answer_0(callid, EINVAL); |
343 | ipc_answer_0(rid, EINVAL); |
343 | ipc_answer_0(rid, EINVAL); |
344 | return; |
344 | return; |
345 | } |
345 | } |
346 | 346 | ||
347 | /* |
347 | /* |
- | 348 | * Check whether the file needs to grow. |
|
- | 349 | */ |
|
- | 350 | if (pos + size <= dentry->size) { |
|
- | 351 | /* The file size is not changing. */ |
|
- | 352 | (void) ipc_data_write_deliver(callid, dentry->data + pos, size); |
|
- | 353 | ipc_answer_1(rid, EOK, size); |
|
- | 354 | return; |
|
- | 355 | } |
|
- | 356 | size_t delta = (pos + size) - dentry->size; |
|
- | 357 | /* |
|
348 | * At this point, we are deliberately extremely straightforward and |
358 | * At this point, we are deliberately extremely straightforward and |
349 | * simply realloc the contents of the file on every write. In the end, |
359 | * simply realloc the contents of the file on every write that grows the |
350 | * the situation might not be as bad as it may look: our heap allocator |
360 | * file. In the end, the situation might not be as bad as it may look: |
351 | * can save us and just grow the block whenever possible. |
361 | * our heap allocator can save us and just grow the block whenever |
- | 362 | * possible. |
|
352 | */ |
363 | */ |
353 | void *newdata = realloc(dentry->data, size); |
364 | void *newdata = realloc(dentry->data, dentry->size + delta); |
354 | if (!newdata) { |
365 | if (!newdata) { |
355 | ipc_answer_0(callid, ENOMEM); |
366 | ipc_answer_0(callid, ENOMEM); |
356 | ipc_answer_1(rid, EOK, 0); |
367 | ipc_answer_1(rid, EOK, 0); |
357 | return; |
368 | return; |
358 | } |
369 | } |
359 | dentry->size = size; |
370 | dentry->size += delta; |
360 | dentry->data = newdata; |
371 | dentry->data = newdata; |
361 | (void) ipc_data_write_deliver(callid, dentry->data + pos, size); |
372 | (void) ipc_data_write_deliver(callid, dentry->data + pos, size); |
362 | - | ||
363 | /* |
- | |
364 | * Answer the VFS_WRITE call. |
- | |
365 | */ |
- | |
366 | ipc_answer_1(rid, EOK, size); |
373 | ipc_answer_1(rid, EOK, size); |
367 | } |
374 | } |
368 | 375 | ||
369 | /** |
376 | /** |
370 | * @} |
377 | * @} |
371 | */ |
378 | */ |
372 | 379 |