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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 | ||
38 | static uint16_t ceph_fscache_session_get_key(const void *cookie_netfs_data, | |
39 | void *buffer, uint16_t maxbuf) | |
40 | { | |
41 | const struct ceph_fs_client* fsc = cookie_netfs_data; | |
42 | uint16_t klen; | |
43 | ||
44 | klen = sizeof(fsc->client->fsid); | |
45 | if (klen > maxbuf) | |
46 | return 0; | |
47 | ||
48 | memcpy(buffer, &fsc->client->fsid, klen); | |
49 | return klen; | |
50 | } | |
51 | ||
52 | static const struct fscache_cookie_def ceph_fscache_fsid_object_def = { | |
53 | .name = "CEPH.fsid", | |
54 | .type = FSCACHE_COOKIE_TYPE_INDEX, | |
55 | .get_key = ceph_fscache_session_get_key, | |
56 | }; | |
57 | ||
971f0bde | 58 | int ceph_fscache_register(void) |
99ccbd22 MT |
59 | { |
60 | return fscache_register_netfs(&ceph_cache_netfs); | |
61 | } | |
62 | ||
971f0bde | 63 | void ceph_fscache_unregister(void) |
99ccbd22 MT |
64 | { |
65 | fscache_unregister_netfs(&ceph_cache_netfs); | |
66 | } | |
67 | ||
68 | int ceph_fscache_register_fs(struct ceph_fs_client* fsc) | |
69 | { | |
70 | fsc->fscache = fscache_acquire_cookie(ceph_cache_netfs.primary_index, | |
71 | &ceph_fscache_fsid_object_def, | |
94d30ae9 | 72 | fsc, true); |
f7f7e7a0 | 73 | if (!fsc->fscache) |
679f0b82 | 74 | pr_err("Unable to register fsid: %p fscache cookie\n", fsc); |
99ccbd22 MT |
75 | |
76 | return 0; | |
77 | } | |
78 | ||
79 | static uint16_t ceph_fscache_inode_get_key(const void *cookie_netfs_data, | |
80 | void *buffer, uint16_t maxbuf) | |
81 | { | |
82 | const struct ceph_inode_info* ci = cookie_netfs_data; | |
83 | uint16_t klen; | |
84 | ||
1291fb95 | 85 | /* use ceph virtual inode (id + snapshot) */ |
99ccbd22 MT |
86 | klen = sizeof(ci->i_vino); |
87 | if (klen > maxbuf) | |
88 | return 0; | |
89 | ||
90 | memcpy(buffer, &ci->i_vino, klen); | |
91 | return klen; | |
92 | } | |
93 | ||
94 | static uint16_t ceph_fscache_inode_get_aux(const void *cookie_netfs_data, | |
95 | void *buffer, uint16_t bufmax) | |
96 | { | |
97 | struct ceph_aux_inode aux; | |
98 | const struct ceph_inode_info* ci = cookie_netfs_data; | |
99 | const struct inode* inode = &ci->vfs_inode; | |
100 | ||
101 | memset(&aux, 0, sizeof(aux)); | |
f6973c09 | 102 | aux.version = ci->i_version; |
99ccbd22 | 103 | aux.mtime = inode->i_mtime; |
99c88e69 | 104 | aux.size = i_size_read(inode); |
99ccbd22 MT |
105 | |
106 | memcpy(buffer, &aux, sizeof(aux)); | |
107 | ||
108 | return sizeof(aux); | |
109 | } | |
110 | ||
111 | static void ceph_fscache_inode_get_attr(const void *cookie_netfs_data, | |
112 | uint64_t *size) | |
113 | { | |
114 | const struct ceph_inode_info* ci = cookie_netfs_data; | |
99c88e69 | 115 | *size = i_size_read(&ci->vfs_inode); |
99ccbd22 MT |
116 | } |
117 | ||
118 | static enum fscache_checkaux ceph_fscache_inode_check_aux( | |
119 | void *cookie_netfs_data, const void *data, uint16_t dlen) | |
120 | { | |
121 | struct ceph_aux_inode aux; | |
122 | struct ceph_inode_info* ci = cookie_netfs_data; | |
123 | struct inode* inode = &ci->vfs_inode; | |
124 | ||
125 | if (dlen != sizeof(aux)) | |
126 | return FSCACHE_CHECKAUX_OBSOLETE; | |
127 | ||
128 | memset(&aux, 0, sizeof(aux)); | |
f6973c09 | 129 | aux.version = ci->i_version; |
99ccbd22 | 130 | aux.mtime = inode->i_mtime; |
99c88e69 | 131 | aux.size = i_size_read(inode); |
99ccbd22 MT |
132 | |
133 | if (memcmp(data, &aux, sizeof(aux)) != 0) | |
134 | return FSCACHE_CHECKAUX_OBSOLETE; | |
135 | ||
136 | dout("ceph inode 0x%p cached okay", ci); | |
137 | return FSCACHE_CHECKAUX_OKAY; | |
138 | } | |
139 | ||
140 | static void ceph_fscache_inode_now_uncached(void* cookie_netfs_data) | |
141 | { | |
142 | struct ceph_inode_info* ci = cookie_netfs_data; | |
143 | struct pagevec pvec; | |
144 | pgoff_t first; | |
145 | int loop, nr_pages; | |
146 | ||
147 | pagevec_init(&pvec, 0); | |
148 | first = 0; | |
149 | ||
150 | dout("ceph inode 0x%p now uncached", ci); | |
151 | ||
152 | while (1) { | |
153 | nr_pages = pagevec_lookup(&pvec, ci->vfs_inode.i_mapping, first, | |
154 | PAGEVEC_SIZE - pagevec_count(&pvec)); | |
155 | ||
156 | if (!nr_pages) | |
157 | break; | |
158 | ||
159 | for (loop = 0; loop < nr_pages; loop++) | |
160 | ClearPageFsCache(pvec.pages[loop]); | |
161 | ||
162 | first = pvec.pages[nr_pages - 1]->index + 1; | |
163 | ||
164 | pvec.nr = nr_pages; | |
165 | pagevec_release(&pvec); | |
166 | cond_resched(); | |
167 | } | |
168 | } | |
169 | ||
170 | static const struct fscache_cookie_def ceph_fscache_inode_object_def = { | |
171 | .name = "CEPH.inode", | |
172 | .type = FSCACHE_COOKIE_TYPE_DATAFILE, | |
173 | .get_key = ceph_fscache_inode_get_key, | |
174 | .get_attr = ceph_fscache_inode_get_attr, | |
175 | .get_aux = ceph_fscache_inode_get_aux, | |
176 | .check_aux = ceph_fscache_inode_check_aux, | |
177 | .now_uncached = ceph_fscache_inode_now_uncached, | |
178 | }; | |
179 | ||
46b59b2b | 180 | void ceph_fscache_register_inode_cookie(struct inode *inode) |
99ccbd22 | 181 | { |
46b59b2b YZ |
182 | struct ceph_inode_info *ci = ceph_inode(inode); |
183 | struct ceph_fs_client *fsc = ceph_inode_to_client(inode); | |
99ccbd22 MT |
184 | |
185 | /* No caching for filesystem */ | |
186 | if (fsc->fscache == NULL) | |
187 | return; | |
188 | ||
189 | /* Only cache for regular files that are read only */ | |
46b59b2b | 190 | if (!S_ISREG(inode->i_mode)) |
99ccbd22 MT |
191 | return; |
192 | ||
46b59b2b YZ |
193 | inode_lock_nested(inode, I_MUTEX_CHILD); |
194 | if (!ci->fscache) { | |
195 | ci->fscache = fscache_acquire_cookie(fsc->fscache, | |
196 | &ceph_fscache_inode_object_def, | |
197 | ci, false); | |
198 | } | |
5955102c | 199 | inode_unlock(inode); |
99ccbd22 MT |
200 | } |
201 | ||
202 | void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci) | |
203 | { | |
204 | struct fscache_cookie* cookie; | |
205 | ||
206 | if ((cookie = ci->fscache) == NULL) | |
207 | return; | |
208 | ||
209 | ci->fscache = NULL; | |
210 | ||
211 | fscache_uncache_all_inode_pages(cookie, &ci->vfs_inode); | |
212 | fscache_relinquish_cookie(cookie, 0); | |
213 | } | |
214 | ||
46b59b2b YZ |
215 | static bool ceph_fscache_can_enable(void *data) |
216 | { | |
217 | struct inode *inode = data; | |
218 | return !inode_is_open_for_write(inode); | |
219 | } | |
220 | ||
221 | void ceph_fscache_file_set_cookie(struct inode *inode, struct file *filp) | |
222 | { | |
223 | struct ceph_inode_info *ci = ceph_inode(inode); | |
224 | ||
225 | if (!fscache_cookie_valid(ci->fscache)) | |
226 | return; | |
227 | ||
228 | if (inode_is_open_for_write(inode)) { | |
229 | dout("fscache_file_set_cookie %p %p disabling cache\n", | |
230 | inode, filp); | |
231 | fscache_disable_cookie(ci->fscache, false); | |
232 | fscache_uncache_all_inode_pages(ci->fscache, inode); | |
233 | } else { | |
234 | fscache_enable_cookie(ci->fscache, ceph_fscache_can_enable, | |
235 | inode); | |
236 | if (fscache_cookie_enabled(ci->fscache)) { | |
237 | dout("fscache_file_set_cookie %p %p enabing cache\n", | |
238 | inode, filp); | |
239 | } | |
240 | } | |
241 | } | |
242 | ||
99ccbd22 MT |
243 | static void ceph_vfs_readpage_complete(struct page *page, void *data, int error) |
244 | { | |
245 | if (!error) | |
246 | SetPageUptodate(page); | |
247 | } | |
248 | ||
249 | static void ceph_vfs_readpage_complete_unlock(struct page *page, void *data, int error) | |
250 | { | |
251 | if (!error) | |
252 | SetPageUptodate(page); | |
253 | ||
254 | unlock_page(page); | |
255 | } | |
256 | ||
3b33f692 | 257 | static inline bool cache_valid(struct ceph_inode_info *ci) |
99ccbd22 | 258 | { |
f7f7e7a0 | 259 | return ci->i_fscache_gen == ci->i_rdcache_gen; |
99ccbd22 MT |
260 | } |
261 | ||
262 | ||
263 | /* Atempt to read from the fscache, | |
264 | * | |
265 | * This function is called from the readpage_nounlock context. DO NOT attempt to | |
266 | * unlock the page here (or in the callback). | |
267 | */ | |
268 | int ceph_readpage_from_fscache(struct inode *inode, struct page *page) | |
269 | { | |
270 | struct ceph_inode_info *ci = ceph_inode(inode); | |
271 | int ret; | |
272 | ||
273 | if (!cache_valid(ci)) | |
274 | return -ENOBUFS; | |
275 | ||
276 | ret = fscache_read_or_alloc_page(ci->fscache, page, | |
277 | ceph_vfs_readpage_complete, NULL, | |
278 | GFP_KERNEL); | |
279 | ||
280 | switch (ret) { | |
281 | case 0: /* Page found */ | |
282 | dout("page read submitted\n"); | |
283 | return 0; | |
284 | case -ENOBUFS: /* Pages were not found, and can't be */ | |
285 | case -ENODATA: /* Pages were not found */ | |
286 | dout("page/inode not in cache\n"); | |
287 | return ret; | |
288 | default: | |
289 | dout("%s: unknown error ret = %i\n", __func__, ret); | |
290 | return ret; | |
291 | } | |
292 | } | |
293 | ||
294 | int ceph_readpages_from_fscache(struct inode *inode, | |
295 | struct address_space *mapping, | |
296 | struct list_head *pages, | |
297 | unsigned *nr_pages) | |
298 | { | |
299 | struct ceph_inode_info *ci = ceph_inode(inode); | |
300 | int ret; | |
301 | ||
302 | if (!cache_valid(ci)) | |
303 | return -ENOBUFS; | |
304 | ||
305 | ret = fscache_read_or_alloc_pages(ci->fscache, mapping, pages, nr_pages, | |
306 | ceph_vfs_readpage_complete_unlock, | |
307 | NULL, mapping_gfp_mask(mapping)); | |
308 | ||
309 | switch (ret) { | |
310 | case 0: /* All pages found */ | |
311 | dout("all-page read submitted\n"); | |
312 | return 0; | |
313 | case -ENOBUFS: /* Some pages were not found, and can't be */ | |
314 | case -ENODATA: /* some pages were not found */ | |
315 | dout("page/inode not in cache\n"); | |
316 | return ret; | |
317 | default: | |
318 | dout("%s: unknown error ret = %i\n", __func__, ret); | |
319 | return ret; | |
320 | } | |
321 | } | |
322 | ||
323 | void ceph_readpage_to_fscache(struct inode *inode, struct page *page) | |
324 | { | |
325 | struct ceph_inode_info *ci = ceph_inode(inode); | |
326 | int ret; | |
327 | ||
9b8dd1e8 MT |
328 | if (!PageFsCache(page)) |
329 | return; | |
330 | ||
99ccbd22 MT |
331 | if (!cache_valid(ci)) |
332 | return; | |
333 | ||
334 | ret = fscache_write_page(ci->fscache, page, GFP_KERNEL); | |
335 | if (ret) | |
336 | fscache_uncache_page(ci->fscache, page); | |
337 | } | |
338 | ||
339 | void ceph_invalidate_fscache_page(struct inode* inode, struct page *page) | |
340 | { | |
341 | struct ceph_inode_info *ci = ceph_inode(inode); | |
342 | ||
ffc79664 MT |
343 | if (!PageFsCache(page)) |
344 | return; | |
345 | ||
99ccbd22 MT |
346 | fscache_wait_on_page_write(ci->fscache, page); |
347 | fscache_uncache_page(ci->fscache, page); | |
348 | } | |
349 | ||
350 | void ceph_fscache_unregister_fs(struct ceph_fs_client* fsc) | |
351 | { | |
99ccbd22 MT |
352 | fscache_relinquish_cookie(fsc->fscache, 0); |
353 | fsc->fscache = NULL; | |
354 | } | |
355 | ||
f7f7e7a0 YZ |
356 | /* |
357 | * caller should hold CEPH_CAP_FILE_{RD,CACHE} | |
358 | */ | |
359 | void ceph_fscache_revalidate_cookie(struct ceph_inode_info *ci) | |
99ccbd22 | 360 | { |
f7f7e7a0 | 361 | if (cache_valid(ci)) |
e81568eb MT |
362 | return; |
363 | ||
f7f7e7a0 YZ |
364 | /* resue i_truncate_mutex. There should be no pending |
365 | * truncate while the caller holds CEPH_CAP_FILE_RD */ | |
366 | mutex_lock(&ci->i_truncate_mutex); | |
367 | if (!cache_valid(ci)) { | |
368 | if (fscache_check_consistency(ci->fscache)) | |
369 | fscache_invalidate(ci->fscache); | |
370 | spin_lock(&ci->i_ceph_lock); | |
371 | ci->i_fscache_gen = ci->i_rdcache_gen; | |
372 | spin_unlock(&ci->i_ceph_lock); | |
99ccbd22 | 373 | } |
f7f7e7a0 | 374 | mutex_unlock(&ci->i_truncate_mutex); |
99ccbd22 | 375 | } |