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8667d434 DH |
1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* Daemon interface | |
3 | * | |
4 | * Copyright (C) 2007, 2021 Red Hat, Inc. All Rights Reserved. | |
5 | * Written by David Howells (dhowells@redhat.com) | |
6 | */ | |
7 | ||
8 | #include <linux/module.h> | |
9 | #include <linux/init.h> | |
10 | #include <linux/sched.h> | |
11 | #include <linux/completion.h> | |
12 | #include <linux/slab.h> | |
13 | #include <linux/fs.h> | |
14 | #include <linux/file.h> | |
15 | #include <linux/namei.h> | |
16 | #include <linux/poll.h> | |
17 | #include <linux/mount.h> | |
18 | #include <linux/statfs.h> | |
19 | #include <linux/ctype.h> | |
20 | #include <linux/string.h> | |
21 | #include <linux/fs_struct.h> | |
22 | #include "internal.h" | |
23 | ||
24 | static int cachefiles_daemon_open(struct inode *, struct file *); | |
25 | static int cachefiles_daemon_release(struct inode *, struct file *); | |
26 | static ssize_t cachefiles_daemon_read(struct file *, char __user *, size_t, | |
27 | loff_t *); | |
28 | static ssize_t cachefiles_daemon_write(struct file *, const char __user *, | |
29 | size_t, loff_t *); | |
30 | static __poll_t cachefiles_daemon_poll(struct file *, | |
31 | struct poll_table_struct *); | |
32 | static int cachefiles_daemon_frun(struct cachefiles_cache *, char *); | |
33 | static int cachefiles_daemon_fcull(struct cachefiles_cache *, char *); | |
34 | static int cachefiles_daemon_fstop(struct cachefiles_cache *, char *); | |
35 | static int cachefiles_daemon_brun(struct cachefiles_cache *, char *); | |
36 | static int cachefiles_daemon_bcull(struct cachefiles_cache *, char *); | |
37 | static int cachefiles_daemon_bstop(struct cachefiles_cache *, char *); | |
38 | static int cachefiles_daemon_cull(struct cachefiles_cache *, char *); | |
39 | static int cachefiles_daemon_debug(struct cachefiles_cache *, char *); | |
40 | static int cachefiles_daemon_dir(struct cachefiles_cache *, char *); | |
41 | static int cachefiles_daemon_inuse(struct cachefiles_cache *, char *); | |
42 | static int cachefiles_daemon_secctx(struct cachefiles_cache *, char *); | |
43 | static int cachefiles_daemon_tag(struct cachefiles_cache *, char *); | |
44 | static int cachefiles_daemon_bind(struct cachefiles_cache *, char *); | |
45 | static void cachefiles_daemon_unbind(struct cachefiles_cache *); | |
46 | ||
47 | static unsigned long cachefiles_open; | |
48 | ||
49 | const struct file_operations cachefiles_daemon_fops = { | |
50 | .owner = THIS_MODULE, | |
51 | .open = cachefiles_daemon_open, | |
52 | .release = cachefiles_daemon_release, | |
53 | .read = cachefiles_daemon_read, | |
54 | .write = cachefiles_daemon_write, | |
55 | .poll = cachefiles_daemon_poll, | |
56 | .llseek = noop_llseek, | |
57 | }; | |
58 | ||
59 | struct cachefiles_daemon_cmd { | |
60 | char name[8]; | |
61 | int (*handler)(struct cachefiles_cache *cache, char *args); | |
62 | }; | |
63 | ||
64 | static const struct cachefiles_daemon_cmd cachefiles_daemon_cmds[] = { | |
65 | { "bind", cachefiles_daemon_bind }, | |
66 | { "brun", cachefiles_daemon_brun }, | |
67 | { "bcull", cachefiles_daemon_bcull }, | |
68 | { "bstop", cachefiles_daemon_bstop }, | |
69 | { "cull", cachefiles_daemon_cull }, | |
70 | { "debug", cachefiles_daemon_debug }, | |
71 | { "dir", cachefiles_daemon_dir }, | |
72 | { "frun", cachefiles_daemon_frun }, | |
73 | { "fcull", cachefiles_daemon_fcull }, | |
74 | { "fstop", cachefiles_daemon_fstop }, | |
75 | { "inuse", cachefiles_daemon_inuse }, | |
76 | { "secctx", cachefiles_daemon_secctx }, | |
77 | { "tag", cachefiles_daemon_tag }, | |
c8383054 JX |
78 | #ifdef CONFIG_CACHEFILES_ONDEMAND |
79 | { "copen", cachefiles_ondemand_copen }, | |
e73fa11a | 80 | { "restore", cachefiles_ondemand_restore }, |
c8383054 | 81 | #endif |
8667d434 DH |
82 | { "", NULL } |
83 | }; | |
84 | ||
85 | ||
86 | /* | |
87 | * Prepare a cache for caching. | |
88 | */ | |
89 | static int cachefiles_daemon_open(struct inode *inode, struct file *file) | |
90 | { | |
91 | struct cachefiles_cache *cache; | |
92 | ||
93 | _enter(""); | |
94 | ||
95 | /* only the superuser may do this */ | |
96 | if (!capable(CAP_SYS_ADMIN)) | |
97 | return -EPERM; | |
98 | ||
99 | /* the cachefiles device may only be open once at a time */ | |
100 | if (xchg(&cachefiles_open, 1) == 1) | |
101 | return -EBUSY; | |
102 | ||
103 | /* allocate a cache record */ | |
104 | cache = kzalloc(sizeof(struct cachefiles_cache), GFP_KERNEL); | |
105 | if (!cache) { | |
106 | cachefiles_open = 0; | |
107 | return -ENOMEM; | |
108 | } | |
109 | ||
110 | mutex_init(&cache->daemon_mutex); | |
111 | init_waitqueue_head(&cache->daemon_pollwq); | |
fe2140e2 | 112 | INIT_LIST_HEAD(&cache->volumes); |
1f08c925 | 113 | INIT_LIST_HEAD(&cache->object_list); |
fe2140e2 | 114 | spin_lock_init(&cache->object_list_lock); |
d11b0b04 | 115 | refcount_set(&cache->unbind_pincount, 1); |
c8383054 JX |
116 | xa_init_flags(&cache->reqs, XA_FLAGS_ALLOC); |
117 | xa_init_flags(&cache->ondemand_ids, XA_FLAGS_ALLOC1); | |
8667d434 DH |
118 | |
119 | /* set default caching limits | |
120 | * - limit at 1% free space and/or free files | |
121 | * - cull below 5% free space and/or free files | |
122 | * - cease culling above 7% free space and/or free files | |
123 | */ | |
124 | cache->frun_percent = 7; | |
125 | cache->fcull_percent = 5; | |
126 | cache->fstop_percent = 1; | |
127 | cache->brun_percent = 7; | |
128 | cache->bcull_percent = 5; | |
129 | cache->bstop_percent = 1; | |
130 | ||
131 | file->private_data = cache; | |
132 | cache->cachefilesd = file; | |
133 | return 0; | |
134 | } | |
135 | ||
c8383054 JX |
136 | static void cachefiles_flush_reqs(struct cachefiles_cache *cache) |
137 | { | |
138 | struct xarray *xa = &cache->reqs; | |
139 | struct cachefiles_req *req; | |
140 | unsigned long index; | |
141 | ||
142 | /* | |
143 | * Make sure the following two operations won't be reordered. | |
144 | * 1) set CACHEFILES_DEAD bit | |
145 | * 2) flush requests in the xarray | |
146 | * Otherwise the request may be enqueued after xarray has been | |
147 | * flushed, leaving the orphan request never being completed. | |
148 | * | |
149 | * CPU 1 CPU 2 | |
150 | * ===== ===== | |
151 | * flush requests in the xarray | |
152 | * test CACHEFILES_DEAD bit | |
153 | * enqueue the request | |
154 | * set CACHEFILES_DEAD bit | |
155 | */ | |
156 | smp_mb(); | |
157 | ||
158 | xa_lock(xa); | |
159 | xa_for_each(xa, index, req) { | |
160 | req->error = -EIO; | |
161 | complete(&req->done); | |
162 | } | |
163 | xa_unlock(xa); | |
164 | ||
165 | xa_destroy(&cache->reqs); | |
166 | xa_destroy(&cache->ondemand_ids); | |
167 | } | |
168 | ||
d11b0b04 JX |
169 | void cachefiles_put_unbind_pincount(struct cachefiles_cache *cache) |
170 | { | |
171 | if (refcount_dec_and_test(&cache->unbind_pincount)) { | |
172 | cachefiles_daemon_unbind(cache); | |
173 | cachefiles_open = 0; | |
174 | kfree(cache); | |
175 | } | |
176 | } | |
177 | ||
178 | void cachefiles_get_unbind_pincount(struct cachefiles_cache *cache) | |
179 | { | |
180 | refcount_inc(&cache->unbind_pincount); | |
181 | } | |
182 | ||
8667d434 DH |
183 | /* |
184 | * Release a cache. | |
185 | */ | |
186 | static int cachefiles_daemon_release(struct inode *inode, struct file *file) | |
187 | { | |
188 | struct cachefiles_cache *cache = file->private_data; | |
189 | ||
190 | _enter(""); | |
191 | ||
192 | ASSERT(cache); | |
193 | ||
194 | set_bit(CACHEFILES_DEAD, &cache->flags); | |
195 | ||
c8383054 JX |
196 | if (cachefiles_in_ondemand_mode(cache)) |
197 | cachefiles_flush_reqs(cache); | |
8667d434 DH |
198 | |
199 | /* clean up the control file interface */ | |
200 | cache->cachefilesd = NULL; | |
201 | file->private_data = NULL; | |
8667d434 | 202 | |
d11b0b04 | 203 | cachefiles_put_unbind_pincount(cache); |
8667d434 DH |
204 | |
205 | _leave(""); | |
206 | return 0; | |
207 | } | |
208 | ||
c8383054 JX |
209 | static ssize_t cachefiles_do_daemon_read(struct cachefiles_cache *cache, |
210 | char __user *_buffer, size_t buflen) | |
8667d434 | 211 | { |
8667d434 DH |
212 | unsigned long long b_released; |
213 | unsigned f_released; | |
214 | char buffer[256]; | |
215 | int n; | |
216 | ||
8667d434 | 217 | /* check how much space the cache has */ |
3929eca7 | 218 | cachefiles_has_space(cache, 0, 0, cachefiles_has_space_check); |
8667d434 DH |
219 | |
220 | /* summarise */ | |
221 | f_released = atomic_xchg(&cache->f_released, 0); | |
222 | b_released = atomic_long_xchg(&cache->b_released, 0); | |
223 | clear_bit(CACHEFILES_STATE_CHANGED, &cache->flags); | |
224 | ||
225 | n = snprintf(buffer, sizeof(buffer), | |
226 | "cull=%c" | |
227 | " frun=%llx" | |
228 | " fcull=%llx" | |
229 | " fstop=%llx" | |
230 | " brun=%llx" | |
231 | " bcull=%llx" | |
232 | " bstop=%llx" | |
233 | " freleased=%x" | |
234 | " breleased=%llx", | |
235 | test_bit(CACHEFILES_CULLING, &cache->flags) ? '1' : '0', | |
236 | (unsigned long long) cache->frun, | |
237 | (unsigned long long) cache->fcull, | |
238 | (unsigned long long) cache->fstop, | |
239 | (unsigned long long) cache->brun, | |
240 | (unsigned long long) cache->bcull, | |
241 | (unsigned long long) cache->bstop, | |
242 | f_released, | |
243 | b_released); | |
244 | ||
245 | if (n > buflen) | |
246 | return -EMSGSIZE; | |
247 | ||
248 | if (copy_to_user(_buffer, buffer, n) != 0) | |
249 | return -EFAULT; | |
250 | ||
251 | return n; | |
252 | } | |
253 | ||
c8383054 JX |
254 | /* |
255 | * Read the cache state. | |
256 | */ | |
257 | static ssize_t cachefiles_daemon_read(struct file *file, char __user *_buffer, | |
258 | size_t buflen, loff_t *pos) | |
259 | { | |
260 | struct cachefiles_cache *cache = file->private_data; | |
261 | ||
262 | //_enter(",,%zu,", buflen); | |
263 | ||
264 | if (!test_bit(CACHEFILES_READY, &cache->flags)) | |
265 | return 0; | |
266 | ||
267 | if (cachefiles_in_ondemand_mode(cache)) | |
268 | return cachefiles_ondemand_daemon_read(cache, _buffer, buflen); | |
269 | else | |
270 | return cachefiles_do_daemon_read(cache, _buffer, buflen); | |
271 | } | |
272 | ||
8667d434 DH |
273 | /* |
274 | * Take a command from cachefilesd, parse it and act on it. | |
275 | */ | |
276 | static ssize_t cachefiles_daemon_write(struct file *file, | |
277 | const char __user *_data, | |
278 | size_t datalen, | |
279 | loff_t *pos) | |
280 | { | |
281 | const struct cachefiles_daemon_cmd *cmd; | |
282 | struct cachefiles_cache *cache = file->private_data; | |
283 | ssize_t ret; | |
284 | char *data, *args, *cp; | |
285 | ||
286 | //_enter(",,%zu,", datalen); | |
287 | ||
288 | ASSERT(cache); | |
289 | ||
290 | if (test_bit(CACHEFILES_DEAD, &cache->flags)) | |
291 | return -EIO; | |
292 | ||
293 | if (datalen > PAGE_SIZE - 1) | |
294 | return -EOPNOTSUPP; | |
295 | ||
296 | /* drag the command string into the kernel so we can parse it */ | |
297 | data = memdup_user_nul(_data, datalen); | |
298 | if (IS_ERR(data)) | |
299 | return PTR_ERR(data); | |
300 | ||
301 | ret = -EINVAL; | |
302 | if (memchr(data, '\0', datalen)) | |
303 | goto error; | |
304 | ||
305 | /* strip any newline */ | |
306 | cp = memchr(data, '\n', datalen); | |
307 | if (cp) { | |
308 | if (cp == data) | |
309 | goto error; | |
310 | ||
311 | *cp = '\0'; | |
312 | } | |
313 | ||
314 | /* parse the command */ | |
315 | ret = -EOPNOTSUPP; | |
316 | ||
317 | for (args = data; *args; args++) | |
318 | if (isspace(*args)) | |
319 | break; | |
320 | if (*args) { | |
321 | if (args == data) | |
322 | goto error; | |
323 | *args = '\0'; | |
324 | args = skip_spaces(++args); | |
325 | } | |
326 | ||
327 | /* run the appropriate command handler */ | |
328 | for (cmd = cachefiles_daemon_cmds; cmd->name[0]; cmd++) | |
329 | if (strcmp(cmd->name, data) == 0) | |
330 | goto found_command; | |
331 | ||
332 | error: | |
333 | kfree(data); | |
334 | //_leave(" = %zd", ret); | |
335 | return ret; | |
336 | ||
337 | found_command: | |
338 | mutex_lock(&cache->daemon_mutex); | |
339 | ||
340 | ret = -EIO; | |
341 | if (!test_bit(CACHEFILES_DEAD, &cache->flags)) | |
342 | ret = cmd->handler(cache, args); | |
343 | ||
344 | mutex_unlock(&cache->daemon_mutex); | |
345 | ||
346 | if (ret == 0) | |
347 | ret = datalen; | |
348 | goto error; | |
349 | } | |
350 | ||
351 | /* | |
352 | * Poll for culling state | |
353 | * - use EPOLLOUT to indicate culling state | |
354 | */ | |
355 | static __poll_t cachefiles_daemon_poll(struct file *file, | |
356 | struct poll_table_struct *poll) | |
357 | { | |
358 | struct cachefiles_cache *cache = file->private_data; | |
b817e22b JZ |
359 | XA_STATE(xas, &cache->reqs, 0); |
360 | struct cachefiles_req *req; | |
8667d434 DH |
361 | __poll_t mask; |
362 | ||
363 | poll_wait(file, &cache->daemon_pollwq, poll); | |
364 | mask = 0; | |
365 | ||
c8383054 | 366 | if (cachefiles_in_ondemand_mode(cache)) { |
b817e22b JZ |
367 | if (!xa_empty(&cache->reqs)) { |
368 | rcu_read_lock(); | |
369 | xas_for_each_marked(&xas, req, ULONG_MAX, CACHEFILES_REQ_NEW) { | |
370 | if (!cachefiles_ondemand_is_reopening_read(req)) { | |
371 | mask |= EPOLLIN; | |
372 | break; | |
373 | } | |
374 | } | |
375 | rcu_read_unlock(); | |
376 | } | |
c8383054 JX |
377 | } else { |
378 | if (test_bit(CACHEFILES_STATE_CHANGED, &cache->flags)) | |
379 | mask |= EPOLLIN; | |
380 | } | |
8667d434 DH |
381 | |
382 | if (test_bit(CACHEFILES_CULLING, &cache->flags)) | |
383 | mask |= EPOLLOUT; | |
384 | ||
385 | return mask; | |
386 | } | |
387 | ||
388 | /* | |
389 | * Give a range error for cache space constraints | |
390 | * - can be tail-called | |
391 | */ | |
392 | static int cachefiles_daemon_range_error(struct cachefiles_cache *cache, | |
393 | char *args) | |
394 | { | |
395 | pr_err("Free space limits must be in range 0%%<=stop<cull<run<100%%\n"); | |
396 | ||
397 | return -EINVAL; | |
398 | } | |
399 | ||
400 | /* | |
401 | * Set the percentage of files at which to stop culling | |
402 | * - command: "frun <N>%" | |
403 | */ | |
404 | static int cachefiles_daemon_frun(struct cachefiles_cache *cache, char *args) | |
405 | { | |
406 | unsigned long frun; | |
407 | ||
408 | _enter(",%s", args); | |
409 | ||
410 | if (!*args) | |
411 | return -EINVAL; | |
412 | ||
413 | frun = simple_strtoul(args, &args, 10); | |
414 | if (args[0] != '%' || args[1] != '\0') | |
415 | return -EINVAL; | |
416 | ||
417 | if (frun <= cache->fcull_percent || frun >= 100) | |
418 | return cachefiles_daemon_range_error(cache, args); | |
419 | ||
420 | cache->frun_percent = frun; | |
421 | return 0; | |
422 | } | |
423 | ||
424 | /* | |
425 | * Set the percentage of files at which to start culling | |
426 | * - command: "fcull <N>%" | |
427 | */ | |
428 | static int cachefiles_daemon_fcull(struct cachefiles_cache *cache, char *args) | |
429 | { | |
430 | unsigned long fcull; | |
431 | ||
432 | _enter(",%s", args); | |
433 | ||
434 | if (!*args) | |
435 | return -EINVAL; | |
436 | ||
437 | fcull = simple_strtoul(args, &args, 10); | |
438 | if (args[0] != '%' || args[1] != '\0') | |
439 | return -EINVAL; | |
440 | ||
441 | if (fcull <= cache->fstop_percent || fcull >= cache->frun_percent) | |
442 | return cachefiles_daemon_range_error(cache, args); | |
443 | ||
444 | cache->fcull_percent = fcull; | |
445 | return 0; | |
446 | } | |
447 | ||
448 | /* | |
449 | * Set the percentage of files at which to stop allocating | |
450 | * - command: "fstop <N>%" | |
451 | */ | |
452 | static int cachefiles_daemon_fstop(struct cachefiles_cache *cache, char *args) | |
453 | { | |
454 | unsigned long fstop; | |
455 | ||
456 | _enter(",%s", args); | |
457 | ||
458 | if (!*args) | |
459 | return -EINVAL; | |
460 | ||
461 | fstop = simple_strtoul(args, &args, 10); | |
462 | if (args[0] != '%' || args[1] != '\0') | |
463 | return -EINVAL; | |
464 | ||
465 | if (fstop >= cache->fcull_percent) | |
466 | return cachefiles_daemon_range_error(cache, args); | |
467 | ||
468 | cache->fstop_percent = fstop; | |
469 | return 0; | |
470 | } | |
471 | ||
472 | /* | |
473 | * Set the percentage of blocks at which to stop culling | |
474 | * - command: "brun <N>%" | |
475 | */ | |
476 | static int cachefiles_daemon_brun(struct cachefiles_cache *cache, char *args) | |
477 | { | |
478 | unsigned long brun; | |
479 | ||
480 | _enter(",%s", args); | |
481 | ||
482 | if (!*args) | |
483 | return -EINVAL; | |
484 | ||
485 | brun = simple_strtoul(args, &args, 10); | |
486 | if (args[0] != '%' || args[1] != '\0') | |
487 | return -EINVAL; | |
488 | ||
489 | if (brun <= cache->bcull_percent || brun >= 100) | |
490 | return cachefiles_daemon_range_error(cache, args); | |
491 | ||
492 | cache->brun_percent = brun; | |
493 | return 0; | |
494 | } | |
495 | ||
496 | /* | |
497 | * Set the percentage of blocks at which to start culling | |
498 | * - command: "bcull <N>%" | |
499 | */ | |
500 | static int cachefiles_daemon_bcull(struct cachefiles_cache *cache, char *args) | |
501 | { | |
502 | unsigned long bcull; | |
503 | ||
504 | _enter(",%s", args); | |
505 | ||
506 | if (!*args) | |
507 | return -EINVAL; | |
508 | ||
509 | bcull = simple_strtoul(args, &args, 10); | |
510 | if (args[0] != '%' || args[1] != '\0') | |
511 | return -EINVAL; | |
512 | ||
513 | if (bcull <= cache->bstop_percent || bcull >= cache->brun_percent) | |
514 | return cachefiles_daemon_range_error(cache, args); | |
515 | ||
516 | cache->bcull_percent = bcull; | |
517 | return 0; | |
518 | } | |
519 | ||
520 | /* | |
521 | * Set the percentage of blocks at which to stop allocating | |
522 | * - command: "bstop <N>%" | |
523 | */ | |
524 | static int cachefiles_daemon_bstop(struct cachefiles_cache *cache, char *args) | |
525 | { | |
526 | unsigned long bstop; | |
527 | ||
528 | _enter(",%s", args); | |
529 | ||
530 | if (!*args) | |
531 | return -EINVAL; | |
532 | ||
533 | bstop = simple_strtoul(args, &args, 10); | |
534 | if (args[0] != '%' || args[1] != '\0') | |
535 | return -EINVAL; | |
536 | ||
537 | if (bstop >= cache->bcull_percent) | |
538 | return cachefiles_daemon_range_error(cache, args); | |
539 | ||
540 | cache->bstop_percent = bstop; | |
541 | return 0; | |
542 | } | |
543 | ||
544 | /* | |
545 | * Set the cache directory | |
546 | * - command: "dir <name>" | |
547 | */ | |
548 | static int cachefiles_daemon_dir(struct cachefiles_cache *cache, char *args) | |
549 | { | |
550 | char *dir; | |
551 | ||
552 | _enter(",%s", args); | |
553 | ||
554 | if (!*args) { | |
555 | pr_err("Empty directory specified\n"); | |
556 | return -EINVAL; | |
557 | } | |
558 | ||
559 | if (cache->rootdirname) { | |
560 | pr_err("Second cache directory specified\n"); | |
561 | return -EEXIST; | |
562 | } | |
563 | ||
564 | dir = kstrdup(args, GFP_KERNEL); | |
565 | if (!dir) | |
566 | return -ENOMEM; | |
567 | ||
568 | cache->rootdirname = dir; | |
569 | return 0; | |
570 | } | |
571 | ||
572 | /* | |
573 | * Set the cache security context | |
574 | * - command: "secctx <ctx>" | |
575 | */ | |
576 | static int cachefiles_daemon_secctx(struct cachefiles_cache *cache, char *args) | |
577 | { | |
578 | char *secctx; | |
579 | ||
580 | _enter(",%s", args); | |
581 | ||
582 | if (!*args) { | |
583 | pr_err("Empty security context specified\n"); | |
584 | return -EINVAL; | |
585 | } | |
586 | ||
587 | if (cache->secctx) { | |
588 | pr_err("Second security context specified\n"); | |
589 | return -EINVAL; | |
590 | } | |
591 | ||
592 | secctx = kstrdup(args, GFP_KERNEL); | |
593 | if (!secctx) | |
594 | return -ENOMEM; | |
595 | ||
596 | cache->secctx = secctx; | |
597 | return 0; | |
598 | } | |
599 | ||
600 | /* | |
601 | * Set the cache tag | |
602 | * - command: "tag <name>" | |
603 | */ | |
604 | static int cachefiles_daemon_tag(struct cachefiles_cache *cache, char *args) | |
605 | { | |
606 | char *tag; | |
607 | ||
608 | _enter(",%s", args); | |
609 | ||
610 | if (!*args) { | |
611 | pr_err("Empty tag specified\n"); | |
612 | return -EINVAL; | |
613 | } | |
614 | ||
615 | if (cache->tag) | |
616 | return -EEXIST; | |
617 | ||
618 | tag = kstrdup(args, GFP_KERNEL); | |
619 | if (!tag) | |
620 | return -ENOMEM; | |
621 | ||
622 | cache->tag = tag; | |
623 | return 0; | |
624 | } | |
625 | ||
626 | /* | |
627 | * Request a node in the cache be culled from the current working directory | |
628 | * - command: "cull <name>" | |
629 | */ | |
630 | static int cachefiles_daemon_cull(struct cachefiles_cache *cache, char *args) | |
631 | { | |
632 | struct path path; | |
633 | const struct cred *saved_cred; | |
634 | int ret; | |
635 | ||
636 | _enter(",%s", args); | |
637 | ||
638 | if (strchr(args, '/')) | |
639 | goto inval; | |
640 | ||
641 | if (!test_bit(CACHEFILES_READY, &cache->flags)) { | |
642 | pr_err("cull applied to unready cache\n"); | |
643 | return -EIO; | |
644 | } | |
645 | ||
646 | if (test_bit(CACHEFILES_DEAD, &cache->flags)) { | |
647 | pr_err("cull applied to dead cache\n"); | |
648 | return -EIO; | |
649 | } | |
650 | ||
651 | get_fs_pwd(current->fs, &path); | |
652 | ||
653 | if (!d_can_lookup(path.dentry)) | |
654 | goto notdir; | |
655 | ||
656 | cachefiles_begin_secure(cache, &saved_cred); | |
07a90e97 | 657 | ret = cachefiles_cull(cache, path.dentry, args); |
8667d434 DH |
658 | cachefiles_end_secure(cache, saved_cred); |
659 | ||
660 | path_put(&path); | |
661 | _leave(" = %d", ret); | |
662 | return ret; | |
663 | ||
664 | notdir: | |
665 | path_put(&path); | |
666 | pr_err("cull command requires dirfd to be a directory\n"); | |
667 | return -ENOTDIR; | |
668 | ||
669 | inval: | |
670 | pr_err("cull command requires dirfd and filename\n"); | |
671 | return -EINVAL; | |
672 | } | |
673 | ||
674 | /* | |
675 | * Set debugging mode | |
676 | * - command: "debug <mask>" | |
677 | */ | |
678 | static int cachefiles_daemon_debug(struct cachefiles_cache *cache, char *args) | |
679 | { | |
680 | unsigned long mask; | |
681 | ||
682 | _enter(",%s", args); | |
683 | ||
684 | mask = simple_strtoul(args, &args, 0); | |
685 | if (args[0] != '\0') | |
686 | goto inval; | |
687 | ||
688 | cachefiles_debug = mask; | |
689 | _leave(" = 0"); | |
690 | return 0; | |
691 | ||
692 | inval: | |
693 | pr_err("debug command requires mask\n"); | |
694 | return -EINVAL; | |
695 | } | |
696 | ||
697 | /* | |
698 | * Find out whether an object in the current working directory is in use or not | |
699 | * - command: "inuse <name>" | |
700 | */ | |
701 | static int cachefiles_daemon_inuse(struct cachefiles_cache *cache, char *args) | |
702 | { | |
703 | struct path path; | |
704 | const struct cred *saved_cred; | |
705 | int ret; | |
706 | ||
707 | //_enter(",%s", args); | |
708 | ||
709 | if (strchr(args, '/')) | |
710 | goto inval; | |
711 | ||
712 | if (!test_bit(CACHEFILES_READY, &cache->flags)) { | |
713 | pr_err("inuse applied to unready cache\n"); | |
714 | return -EIO; | |
715 | } | |
716 | ||
717 | if (test_bit(CACHEFILES_DEAD, &cache->flags)) { | |
718 | pr_err("inuse applied to dead cache\n"); | |
719 | return -EIO; | |
720 | } | |
721 | ||
722 | get_fs_pwd(current->fs, &path); | |
723 | ||
724 | if (!d_can_lookup(path.dentry)) | |
725 | goto notdir; | |
726 | ||
727 | cachefiles_begin_secure(cache, &saved_cred); | |
07a90e97 | 728 | ret = cachefiles_check_in_use(cache, path.dentry, args); |
8667d434 DH |
729 | cachefiles_end_secure(cache, saved_cred); |
730 | ||
731 | path_put(&path); | |
732 | //_leave(" = %d", ret); | |
733 | return ret; | |
734 | ||
735 | notdir: | |
736 | path_put(&path); | |
737 | pr_err("inuse command requires dirfd to be a directory\n"); | |
738 | return -ENOTDIR; | |
739 | ||
740 | inval: | |
741 | pr_err("inuse command requires dirfd and filename\n"); | |
742 | return -EINVAL; | |
743 | } | |
744 | ||
745 | /* | |
746 | * Bind a directory as a cache | |
747 | */ | |
748 | static int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args) | |
749 | { | |
750 | _enter("{%u,%u,%u,%u,%u,%u},%s", | |
751 | cache->frun_percent, | |
752 | cache->fcull_percent, | |
753 | cache->fstop_percent, | |
754 | cache->brun_percent, | |
755 | cache->bcull_percent, | |
756 | cache->bstop_percent, | |
757 | args); | |
758 | ||
759 | if (cache->fstop_percent >= cache->fcull_percent || | |
760 | cache->fcull_percent >= cache->frun_percent || | |
761 | cache->frun_percent >= 100) | |
762 | return -ERANGE; | |
763 | ||
764 | if (cache->bstop_percent >= cache->bcull_percent || | |
765 | cache->bcull_percent >= cache->brun_percent || | |
766 | cache->brun_percent >= 100) | |
767 | return -ERANGE; | |
768 | ||
8667d434 DH |
769 | if (!cache->rootdirname) { |
770 | pr_err("No cache directory specified\n"); | |
771 | return -EINVAL; | |
772 | } | |
773 | ||
774 | /* Don't permit already bound caches to be re-bound */ | |
775 | if (test_bit(CACHEFILES_READY, &cache->flags)) { | |
776 | pr_err("Cache already bound\n"); | |
777 | return -EBUSY; | |
778 | } | |
779 | ||
4e4f1788 JX |
780 | if (IS_ENABLED(CONFIG_CACHEFILES_ONDEMAND)) { |
781 | if (!strcmp(args, "ondemand")) { | |
782 | set_bit(CACHEFILES_ONDEMAND_MODE, &cache->flags); | |
783 | } else if (*args) { | |
784 | pr_err("Invalid argument to the 'bind' command\n"); | |
785 | return -EINVAL; | |
786 | } | |
787 | } else if (*args) { | |
788 | pr_err("'bind' command doesn't take an argument\n"); | |
789 | return -EINVAL; | |
790 | } | |
791 | ||
c7ca7315 JX |
792 | /* Make sure we have copies of the tag string */ |
793 | if (!cache->tag) { | |
794 | /* | |
795 | * The tag string is released by the fops->release() | |
796 | * function, so we don't release it on error here | |
797 | */ | |
798 | cache->tag = kstrdup("CacheFiles", GFP_KERNEL); | |
799 | if (!cache->tag) | |
800 | return -ENOMEM; | |
801 | } | |
802 | ||
ecd1a5f6 | 803 | return cachefiles_add_cache(cache); |
8667d434 DH |
804 | } |
805 | ||
806 | /* | |
807 | * Unbind a cache. | |
808 | */ | |
809 | static void cachefiles_daemon_unbind(struct cachefiles_cache *cache) | |
810 | { | |
811 | _enter(""); | |
812 | ||
d1065b0a DH |
813 | if (test_bit(CACHEFILES_READY, &cache->flags)) |
814 | cachefiles_withdraw_cache(cache); | |
8667d434 | 815 | |
d1065b0a DH |
816 | cachefiles_put_directory(cache->graveyard); |
817 | cachefiles_put_directory(cache->store); | |
8667d434 | 818 | mntput(cache->mnt); |
e21a2f17 | 819 | put_cred(cache->cache_cred); |
8667d434 DH |
820 | |
821 | kfree(cache->rootdirname); | |
822 | kfree(cache->secctx); | |
823 | kfree(cache->tag); | |
824 | ||
825 | _leave(""); | |
826 | } |