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99ccbd22 MT |
1 | /* |
2 | * Ceph cache definitions. | |
3 | * | |
4 | * Copyright (C) 2013 by Adfin Solutions, Inc. All Rights Reserved. | |
5 | * Written by Milosz Tanski (milosz@adfin.com) | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 | |
9 | * as published by the Free Software Foundation. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program; if not, write to: | |
18 | * Free Software Foundation | |
19 | * 51 Franklin Street, Fifth Floor | |
20 | * Boston, MA 02111-1301 USA | |
21 | * | |
22 | */ | |
23 | ||
99ccbd22 MT |
24 | #include "super.h" |
25 | #include "cache.h" | |
26 | ||
27 | struct ceph_aux_inode { | |
f6973c09 | 28 | u64 version; |
99ccbd22 MT |
29 | struct timespec mtime; |
30 | loff_t size; | |
31 | }; | |
32 | ||
33 | struct fscache_netfs ceph_cache_netfs = { | |
34 | .name = "ceph", | |
35 | .version = 0, | |
36 | }; | |
37 | ||
1d8f8360 YZ |
38 | static DEFINE_MUTEX(ceph_fscache_lock); |
39 | static LIST_HEAD(ceph_fscache_list); | |
40 | ||
41 | struct ceph_fscache_entry { | |
42 | struct list_head list; | |
43 | struct fscache_cookie *fscache; | |
44 | struct ceph_fsid fsid; | |
45 | size_t uniq_len; | |
46 | char uniquifier[0]; | |
47 | }; | |
48 | ||
99ccbd22 MT |
49 | static uint16_t ceph_fscache_session_get_key(const void *cookie_netfs_data, |
50 | void *buffer, uint16_t maxbuf) | |
51 | { | |
52 | const struct ceph_fs_client* fsc = cookie_netfs_data; | |
1d8f8360 YZ |
53 | const char *fscache_uniq = fsc->mount_options->fscache_uniq; |
54 | uint16_t fsid_len, uniq_len; | |
99ccbd22 | 55 | |
1d8f8360 YZ |
56 | fsid_len = sizeof(fsc->client->fsid); |
57 | uniq_len = fscache_uniq ? strlen(fscache_uniq) : 0; | |
58 | if (fsid_len + uniq_len > maxbuf) | |
99ccbd22 MT |
59 | return 0; |
60 | ||
1d8f8360 YZ |
61 | memcpy(buffer, &fsc->client->fsid, fsid_len); |
62 | if (uniq_len) | |
63 | memcpy(buffer + fsid_len, fscache_uniq, uniq_len); | |
64 | ||
65 | return fsid_len + uniq_len; | |
99ccbd22 MT |
66 | } |
67 | ||
68 | static const struct fscache_cookie_def ceph_fscache_fsid_object_def = { | |
69 | .name = "CEPH.fsid", | |
70 | .type = FSCACHE_COOKIE_TYPE_INDEX, | |
71 | .get_key = ceph_fscache_session_get_key, | |
72 | }; | |
73 | ||
971f0bde | 74 | int ceph_fscache_register(void) |
99ccbd22 MT |
75 | { |
76 | return fscache_register_netfs(&ceph_cache_netfs); | |
77 | } | |
78 | ||
971f0bde | 79 | void ceph_fscache_unregister(void) |
99ccbd22 MT |
80 | { |
81 | fscache_unregister_netfs(&ceph_cache_netfs); | |
82 | } | |
83 | ||
84 | int ceph_fscache_register_fs(struct ceph_fs_client* fsc) | |
85 | { | |
1d8f8360 YZ |
86 | const struct ceph_fsid *fsid = &fsc->client->fsid; |
87 | const char *fscache_uniq = fsc->mount_options->fscache_uniq; | |
88 | size_t uniq_len = fscache_uniq ? strlen(fscache_uniq) : 0; | |
89 | struct ceph_fscache_entry *ent; | |
90 | int err = 0; | |
91 | ||
92 | mutex_lock(&ceph_fscache_lock); | |
93 | list_for_each_entry(ent, &ceph_fscache_list, list) { | |
94 | if (memcmp(&ent->fsid, fsid, sizeof(*fsid))) | |
95 | continue; | |
96 | if (ent->uniq_len != uniq_len) | |
97 | continue; | |
98 | if (uniq_len && memcmp(ent->uniquifier, fscache_uniq, uniq_len)) | |
99 | continue; | |
100 | ||
101 | pr_err("fscache cookie already registered for fsid %pU\n", fsid); | |
102 | pr_err(" use fsc=%%s mount option to specify a uniquifier\n"); | |
103 | err = -EBUSY; | |
104 | goto out_unlock; | |
105 | } | |
106 | ||
107 | ent = kzalloc(sizeof(*ent) + uniq_len, GFP_KERNEL); | |
108 | if (!ent) { | |
109 | err = -ENOMEM; | |
110 | goto out_unlock; | |
111 | } | |
112 | ||
99ccbd22 MT |
113 | fsc->fscache = fscache_acquire_cookie(ceph_cache_netfs.primary_index, |
114 | &ceph_fscache_fsid_object_def, | |
94d30ae9 | 115 | fsc, true); |
99ccbd22 | 116 | |
1d8f8360 YZ |
117 | if (fsc->fscache) { |
118 | memcpy(&ent->fsid, fsid, sizeof(*fsid)); | |
119 | if (uniq_len > 0) { | |
120 | memcpy(&ent->uniquifier, fscache_uniq, uniq_len); | |
121 | ent->uniq_len = uniq_len; | |
122 | } | |
123 | ent->fscache = fsc->fscache; | |
124 | list_add_tail(&ent->list, &ceph_fscache_list); | |
125 | } else { | |
126 | kfree(ent); | |
127 | pr_err("unable to register fscache cookie for fsid %pU\n", | |
128 | fsid); | |
129 | /* all other fs ignore this error */ | |
130 | } | |
131 | out_unlock: | |
132 | mutex_unlock(&ceph_fscache_lock); | |
133 | return err; | |
99ccbd22 MT |
134 | } |
135 | ||
136 | static uint16_t ceph_fscache_inode_get_key(const void *cookie_netfs_data, | |
137 | void *buffer, uint16_t maxbuf) | |
138 | { | |
139 | const struct ceph_inode_info* ci = cookie_netfs_data; | |
140 | uint16_t klen; | |
141 | ||
1291fb95 | 142 | /* use ceph virtual inode (id + snapshot) */ |
99ccbd22 MT |
143 | klen = sizeof(ci->i_vino); |
144 | if (klen > maxbuf) | |
145 | return 0; | |
146 | ||
147 | memcpy(buffer, &ci->i_vino, klen); | |
148 | return klen; | |
149 | } | |
150 | ||
151 | static uint16_t ceph_fscache_inode_get_aux(const void *cookie_netfs_data, | |
152 | void *buffer, uint16_t bufmax) | |
153 | { | |
154 | struct ceph_aux_inode aux; | |
155 | const struct ceph_inode_info* ci = cookie_netfs_data; | |
156 | const struct inode* inode = &ci->vfs_inode; | |
157 | ||
158 | memset(&aux, 0, sizeof(aux)); | |
f6973c09 | 159 | aux.version = ci->i_version; |
99ccbd22 | 160 | aux.mtime = inode->i_mtime; |
99c88e69 | 161 | aux.size = i_size_read(inode); |
99ccbd22 MT |
162 | |
163 | memcpy(buffer, &aux, sizeof(aux)); | |
164 | ||
165 | return sizeof(aux); | |
166 | } | |
167 | ||
168 | static void ceph_fscache_inode_get_attr(const void *cookie_netfs_data, | |
169 | uint64_t *size) | |
170 | { | |
171 | const struct ceph_inode_info* ci = cookie_netfs_data; | |
99c88e69 | 172 | *size = i_size_read(&ci->vfs_inode); |
99ccbd22 MT |
173 | } |
174 | ||
175 | static enum fscache_checkaux ceph_fscache_inode_check_aux( | |
176 | void *cookie_netfs_data, const void *data, uint16_t dlen) | |
177 | { | |
178 | struct ceph_aux_inode aux; | |
179 | struct ceph_inode_info* ci = cookie_netfs_data; | |
180 | struct inode* inode = &ci->vfs_inode; | |
181 | ||
182 | if (dlen != sizeof(aux)) | |
183 | return FSCACHE_CHECKAUX_OBSOLETE; | |
184 | ||
185 | memset(&aux, 0, sizeof(aux)); | |
f6973c09 | 186 | aux.version = ci->i_version; |
99ccbd22 | 187 | aux.mtime = inode->i_mtime; |
99c88e69 | 188 | aux.size = i_size_read(inode); |
99ccbd22 MT |
189 | |
190 | if (memcmp(data, &aux, sizeof(aux)) != 0) | |
191 | return FSCACHE_CHECKAUX_OBSOLETE; | |
192 | ||
193 | dout("ceph inode 0x%p cached okay", ci); | |
194 | return FSCACHE_CHECKAUX_OKAY; | |
195 | } | |
196 | ||
197 | static void ceph_fscache_inode_now_uncached(void* cookie_netfs_data) | |
198 | { | |
199 | struct ceph_inode_info* ci = cookie_netfs_data; | |
200 | struct pagevec pvec; | |
201 | pgoff_t first; | |
202 | int loop, nr_pages; | |
203 | ||
204 | pagevec_init(&pvec, 0); | |
205 | first = 0; | |
206 | ||
207 | dout("ceph inode 0x%p now uncached", ci); | |
208 | ||
209 | while (1) { | |
210 | nr_pages = pagevec_lookup(&pvec, ci->vfs_inode.i_mapping, first, | |
211 | PAGEVEC_SIZE - pagevec_count(&pvec)); | |
212 | ||
213 | if (!nr_pages) | |
214 | break; | |
215 | ||
216 | for (loop = 0; loop < nr_pages; loop++) | |
217 | ClearPageFsCache(pvec.pages[loop]); | |
218 | ||
219 | first = pvec.pages[nr_pages - 1]->index + 1; | |
220 | ||
221 | pvec.nr = nr_pages; | |
222 | pagevec_release(&pvec); | |
223 | cond_resched(); | |
224 | } | |
225 | } | |
226 | ||
227 | static const struct fscache_cookie_def ceph_fscache_inode_object_def = { | |
228 | .name = "CEPH.inode", | |
229 | .type = FSCACHE_COOKIE_TYPE_DATAFILE, | |
230 | .get_key = ceph_fscache_inode_get_key, | |
231 | .get_attr = ceph_fscache_inode_get_attr, | |
232 | .get_aux = ceph_fscache_inode_get_aux, | |
233 | .check_aux = ceph_fscache_inode_check_aux, | |
234 | .now_uncached = ceph_fscache_inode_now_uncached, | |
235 | }; | |
236 | ||
46b59b2b | 237 | void ceph_fscache_register_inode_cookie(struct inode *inode) |
99ccbd22 | 238 | { |
46b59b2b YZ |
239 | struct ceph_inode_info *ci = ceph_inode(inode); |
240 | struct ceph_fs_client *fsc = ceph_inode_to_client(inode); | |
99ccbd22 MT |
241 | |
242 | /* No caching for filesystem */ | |
243 | if (fsc->fscache == NULL) | |
244 | return; | |
245 | ||
246 | /* Only cache for regular files that are read only */ | |
46b59b2b | 247 | if (!S_ISREG(inode->i_mode)) |
99ccbd22 MT |
248 | return; |
249 | ||
46b59b2b YZ |
250 | inode_lock_nested(inode, I_MUTEX_CHILD); |
251 | if (!ci->fscache) { | |
252 | ci->fscache = fscache_acquire_cookie(fsc->fscache, | |
253 | &ceph_fscache_inode_object_def, | |
254 | ci, false); | |
255 | } | |
5955102c | 256 | inode_unlock(inode); |
99ccbd22 MT |
257 | } |
258 | ||
259 | void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci) | |
260 | { | |
261 | struct fscache_cookie* cookie; | |
262 | ||
263 | if ((cookie = ci->fscache) == NULL) | |
264 | return; | |
265 | ||
266 | ci->fscache = NULL; | |
267 | ||
268 | fscache_uncache_all_inode_pages(cookie, &ci->vfs_inode); | |
269 | fscache_relinquish_cookie(cookie, 0); | |
270 | } | |
271 | ||
46b59b2b YZ |
272 | static bool ceph_fscache_can_enable(void *data) |
273 | { | |
274 | struct inode *inode = data; | |
275 | return !inode_is_open_for_write(inode); | |
276 | } | |
277 | ||
278 | void ceph_fscache_file_set_cookie(struct inode *inode, struct file *filp) | |
279 | { | |
280 | struct ceph_inode_info *ci = ceph_inode(inode); | |
281 | ||
282 | if (!fscache_cookie_valid(ci->fscache)) | |
283 | return; | |
284 | ||
285 | if (inode_is_open_for_write(inode)) { | |
286 | dout("fscache_file_set_cookie %p %p disabling cache\n", | |
287 | inode, filp); | |
288 | fscache_disable_cookie(ci->fscache, false); | |
289 | fscache_uncache_all_inode_pages(ci->fscache, inode); | |
290 | } else { | |
291 | fscache_enable_cookie(ci->fscache, ceph_fscache_can_enable, | |
292 | inode); | |
293 | if (fscache_cookie_enabled(ci->fscache)) { | |
0fbc5360 | 294 | dout("fscache_file_set_cookie %p %p enabling cache\n", |
46b59b2b YZ |
295 | inode, filp); |
296 | } | |
297 | } | |
298 | } | |
299 | ||
99ccbd22 MT |
300 | static void ceph_vfs_readpage_complete(struct page *page, void *data, int error) |
301 | { | |
302 | if (!error) | |
303 | SetPageUptodate(page); | |
304 | } | |
305 | ||
306 | static void ceph_vfs_readpage_complete_unlock(struct page *page, void *data, int error) | |
307 | { | |
308 | if (!error) | |
309 | SetPageUptodate(page); | |
310 | ||
311 | unlock_page(page); | |
312 | } | |
313 | ||
3b33f692 | 314 | static inline bool cache_valid(struct ceph_inode_info *ci) |
99ccbd22 | 315 | { |
f7f7e7a0 | 316 | return ci->i_fscache_gen == ci->i_rdcache_gen; |
99ccbd22 MT |
317 | } |
318 | ||
319 | ||
320 | /* Atempt to read from the fscache, | |
321 | * | |
322 | * This function is called from the readpage_nounlock context. DO NOT attempt to | |
323 | * unlock the page here (or in the callback). | |
324 | */ | |
325 | int ceph_readpage_from_fscache(struct inode *inode, struct page *page) | |
326 | { | |
327 | struct ceph_inode_info *ci = ceph_inode(inode); | |
328 | int ret; | |
329 | ||
330 | if (!cache_valid(ci)) | |
331 | return -ENOBUFS; | |
332 | ||
333 | ret = fscache_read_or_alloc_page(ci->fscache, page, | |
334 | ceph_vfs_readpage_complete, NULL, | |
335 | GFP_KERNEL); | |
336 | ||
337 | switch (ret) { | |
338 | case 0: /* Page found */ | |
339 | dout("page read submitted\n"); | |
340 | return 0; | |
341 | case -ENOBUFS: /* Pages were not found, and can't be */ | |
342 | case -ENODATA: /* Pages were not found */ | |
343 | dout("page/inode not in cache\n"); | |
344 | return ret; | |
345 | default: | |
346 | dout("%s: unknown error ret = %i\n", __func__, ret); | |
347 | return ret; | |
348 | } | |
349 | } | |
350 | ||
351 | int ceph_readpages_from_fscache(struct inode *inode, | |
352 | struct address_space *mapping, | |
353 | struct list_head *pages, | |
354 | unsigned *nr_pages) | |
355 | { | |
356 | struct ceph_inode_info *ci = ceph_inode(inode); | |
357 | int ret; | |
358 | ||
359 | if (!cache_valid(ci)) | |
360 | return -ENOBUFS; | |
361 | ||
362 | ret = fscache_read_or_alloc_pages(ci->fscache, mapping, pages, nr_pages, | |
363 | ceph_vfs_readpage_complete_unlock, | |
364 | NULL, mapping_gfp_mask(mapping)); | |
365 | ||
366 | switch (ret) { | |
367 | case 0: /* All pages found */ | |
368 | dout("all-page read submitted\n"); | |
369 | return 0; | |
370 | case -ENOBUFS: /* Some pages were not found, and can't be */ | |
371 | case -ENODATA: /* some pages were not found */ | |
372 | dout("page/inode not in cache\n"); | |
373 | return ret; | |
374 | default: | |
375 | dout("%s: unknown error ret = %i\n", __func__, ret); | |
376 | return ret; | |
377 | } | |
378 | } | |
379 | ||
380 | void ceph_readpage_to_fscache(struct inode *inode, struct page *page) | |
381 | { | |
382 | struct ceph_inode_info *ci = ceph_inode(inode); | |
383 | int ret; | |
384 | ||
9b8dd1e8 MT |
385 | if (!PageFsCache(page)) |
386 | return; | |
387 | ||
99ccbd22 MT |
388 | if (!cache_valid(ci)) |
389 | return; | |
390 | ||
391 | ret = fscache_write_page(ci->fscache, page, GFP_KERNEL); | |
392 | if (ret) | |
393 | fscache_uncache_page(ci->fscache, page); | |
394 | } | |
395 | ||
396 | void ceph_invalidate_fscache_page(struct inode* inode, struct page *page) | |
397 | { | |
398 | struct ceph_inode_info *ci = ceph_inode(inode); | |
399 | ||
ffc79664 MT |
400 | if (!PageFsCache(page)) |
401 | return; | |
402 | ||
99ccbd22 MT |
403 | fscache_wait_on_page_write(ci->fscache, page); |
404 | fscache_uncache_page(ci->fscache, page); | |
405 | } | |
406 | ||
407 | void ceph_fscache_unregister_fs(struct ceph_fs_client* fsc) | |
408 | { | |
1d8f8360 YZ |
409 | if (fscache_cookie_valid(fsc->fscache)) { |
410 | struct ceph_fscache_entry *ent; | |
411 | bool found = false; | |
412 | ||
413 | mutex_lock(&ceph_fscache_lock); | |
414 | list_for_each_entry(ent, &ceph_fscache_list, list) { | |
415 | if (ent->fscache == fsc->fscache) { | |
416 | list_del(&ent->list); | |
417 | kfree(ent); | |
418 | found = true; | |
419 | break; | |
420 | } | |
421 | } | |
422 | WARN_ON_ONCE(!found); | |
423 | mutex_unlock(&ceph_fscache_lock); | |
424 | ||
425 | __fscache_relinquish_cookie(fsc->fscache, 0); | |
426 | } | |
99ccbd22 MT |
427 | fsc->fscache = NULL; |
428 | } | |
429 | ||
f7f7e7a0 YZ |
430 | /* |
431 | * caller should hold CEPH_CAP_FILE_{RD,CACHE} | |
432 | */ | |
433 | void ceph_fscache_revalidate_cookie(struct ceph_inode_info *ci) | |
99ccbd22 | 434 | { |
f7f7e7a0 | 435 | if (cache_valid(ci)) |
e81568eb MT |
436 | return; |
437 | ||
f7f7e7a0 YZ |
438 | /* resue i_truncate_mutex. There should be no pending |
439 | * truncate while the caller holds CEPH_CAP_FILE_RD */ | |
440 | mutex_lock(&ci->i_truncate_mutex); | |
441 | if (!cache_valid(ci)) { | |
442 | if (fscache_check_consistency(ci->fscache)) | |
443 | fscache_invalidate(ci->fscache); | |
444 | spin_lock(&ci->i_ceph_lock); | |
445 | ci->i_fscache_gen = ci->i_rdcache_gen; | |
446 | spin_unlock(&ci->i_ceph_lock); | |
99ccbd22 | 447 | } |
f7f7e7a0 | 448 | mutex_unlock(&ci->i_truncate_mutex); |
99ccbd22 | 449 | } |