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