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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
24#include "super.h"
25#include "cache.h"
26
27struct ceph_aux_inode {
28 struct timespec mtime;
29 loff_t size;
30};
31
32struct fscache_netfs ceph_cache_netfs = {
33 .name = "ceph",
34 .version = 0,
35};
36
37static uint16_t ceph_fscache_session_get_key(const void *cookie_netfs_data,
38 void *buffer, uint16_t maxbuf)
39{
40 const struct ceph_fs_client* fsc = cookie_netfs_data;
41 uint16_t klen;
42
43 klen = sizeof(fsc->client->fsid);
44 if (klen > maxbuf)
45 return 0;
46
47 memcpy(buffer, &fsc->client->fsid, klen);
48 return klen;
49}
50
51static const struct fscache_cookie_def ceph_fscache_fsid_object_def = {
52 .name = "CEPH.fsid",
53 .type = FSCACHE_COOKIE_TYPE_INDEX,
54 .get_key = ceph_fscache_session_get_key,
55};
56
57int ceph_fscache_register(void)
58{
59 return fscache_register_netfs(&ceph_cache_netfs);
60}
61
62void ceph_fscache_unregister(void)
63{
64 fscache_unregister_netfs(&ceph_cache_netfs);
65}
66
67int ceph_fscache_register_fs(struct ceph_fs_client* fsc)
68{
69 fsc->fscache = fscache_acquire_cookie(ceph_cache_netfs.primary_index,
70 &ceph_fscache_fsid_object_def,
71 fsc, true);
72
73 if (fsc->fscache == NULL) {
74 pr_err("Unable to resgister fsid: %p fscache cookie", fsc);
75 return 0;
76 }
77
78 fsc->revalidate_wq = alloc_workqueue("ceph-revalidate", 0, 1);
79 if (fsc->revalidate_wq == NULL)
80 return -ENOMEM;
81
82 return 0;
83}
84
85static uint16_t ceph_fscache_inode_get_key(const void *cookie_netfs_data,
86 void *buffer, uint16_t maxbuf)
87{
88 const struct ceph_inode_info* ci = cookie_netfs_data;
89 uint16_t klen;
90
91 /* use ceph virtual inode (id + snaphot) */
92 klen = sizeof(ci->i_vino);
93 if (klen > maxbuf)
94 return 0;
95
96 memcpy(buffer, &ci->i_vino, klen);
97 return klen;
98}
99
100static uint16_t ceph_fscache_inode_get_aux(const void *cookie_netfs_data,
101 void *buffer, uint16_t bufmax)
102{
103 struct ceph_aux_inode aux;
104 const struct ceph_inode_info* ci = cookie_netfs_data;
105 const struct inode* inode = &ci->vfs_inode;
106
107 memset(&aux, 0, sizeof(aux));
108 aux.mtime = inode->i_mtime;
109 aux.size = inode->i_size;
110
111 memcpy(buffer, &aux, sizeof(aux));
112
113 return sizeof(aux);
114}
115
116static void ceph_fscache_inode_get_attr(const void *cookie_netfs_data,
117 uint64_t *size)
118{
119 const struct ceph_inode_info* ci = cookie_netfs_data;
120 const struct inode* inode = &ci->vfs_inode;
121
122 *size = inode->i_size;
123}
124
125static enum fscache_checkaux ceph_fscache_inode_check_aux(
126 void *cookie_netfs_data, const void *data, uint16_t dlen)
127{
128 struct ceph_aux_inode aux;
129 struct ceph_inode_info* ci = cookie_netfs_data;
130 struct inode* inode = &ci->vfs_inode;
131
132 if (dlen != sizeof(aux))
133 return FSCACHE_CHECKAUX_OBSOLETE;
134
135 memset(&aux, 0, sizeof(aux));
136 aux.mtime = inode->i_mtime;
137 aux.size = inode->i_size;
138
139 if (memcmp(data, &aux, sizeof(aux)) != 0)
140 return FSCACHE_CHECKAUX_OBSOLETE;
141
142 dout("ceph inode 0x%p cached okay", ci);
143 return FSCACHE_CHECKAUX_OKAY;
144}
145
146static void ceph_fscache_inode_now_uncached(void* cookie_netfs_data)
147{
148 struct ceph_inode_info* ci = cookie_netfs_data;
149 struct pagevec pvec;
150 pgoff_t first;
151 int loop, nr_pages;
152
153 pagevec_init(&pvec, 0);
154 first = 0;
155
156 dout("ceph inode 0x%p now uncached", ci);
157
158 while (1) {
159 nr_pages = pagevec_lookup(&pvec, ci->vfs_inode.i_mapping, first,
160 PAGEVEC_SIZE - pagevec_count(&pvec));
161
162 if (!nr_pages)
163 break;
164
165 for (loop = 0; loop < nr_pages; loop++)
166 ClearPageFsCache(pvec.pages[loop]);
167
168 first = pvec.pages[nr_pages - 1]->index + 1;
169
170 pvec.nr = nr_pages;
171 pagevec_release(&pvec);
172 cond_resched();
173 }
174}
175
176static const struct fscache_cookie_def ceph_fscache_inode_object_def = {
177 .name = "CEPH.inode",
178 .type = FSCACHE_COOKIE_TYPE_DATAFILE,
179 .get_key = ceph_fscache_inode_get_key,
180 .get_attr = ceph_fscache_inode_get_attr,
181 .get_aux = ceph_fscache_inode_get_aux,
182 .check_aux = ceph_fscache_inode_check_aux,
183 .now_uncached = ceph_fscache_inode_now_uncached,
184};
185
186void ceph_fscache_register_inode_cookie(struct ceph_fs_client* fsc,
187 struct ceph_inode_info* ci)
188{
189 struct inode* inode = &ci->vfs_inode;
190
191 /* No caching for filesystem */
192 if (fsc->fscache == NULL)
193 return;
194
195 /* Only cache for regular files that are read only */
196 if ((ci->vfs_inode.i_mode & S_IFREG) == 0)
197 return;
198
199 /* Avoid multiple racing open requests */
200 mutex_lock(&inode->i_mutex);
201
202 if (ci->fscache)
203 goto done;
204
205 ci->fscache = fscache_acquire_cookie(fsc->fscache,
206 &ceph_fscache_inode_object_def,
207 ci, true);
208 fscache_check_consistency(ci->fscache);
209done:
210 mutex_unlock(&inode->i_mutex);
211
212}
213
214void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci)
215{
216 struct fscache_cookie* cookie;
217
218 if ((cookie = ci->fscache) == NULL)
219 return;
220
221 ci->fscache = NULL;
222
223 fscache_uncache_all_inode_pages(cookie, &ci->vfs_inode);
224 fscache_relinquish_cookie(cookie, 0);
225}
226
227static void ceph_vfs_readpage_complete(struct page *page, void *data, int error)
228{
229 if (!error)
230 SetPageUptodate(page);
231}
232
233static void ceph_vfs_readpage_complete_unlock(struct page *page, void *data, int error)
234{
235 if (!error)
236 SetPageUptodate(page);
237
238 unlock_page(page);
239}
240
241static inline int cache_valid(struct ceph_inode_info *ci)
242{
243 return ((ceph_caps_issued(ci) & CEPH_CAP_FILE_CACHE) &&
244 (ci->i_fscache_gen == ci->i_rdcache_gen));
245}
246
247
248/* Atempt to read from the fscache,
249 *
250 * This function is called from the readpage_nounlock context. DO NOT attempt to
251 * unlock the page here (or in the callback).
252 */
253int ceph_readpage_from_fscache(struct inode *inode, struct page *page)
254{
255 struct ceph_inode_info *ci = ceph_inode(inode);
256 int ret;
257
258 if (!cache_valid(ci))
259 return -ENOBUFS;
260
261 ret = fscache_read_or_alloc_page(ci->fscache, page,
262 ceph_vfs_readpage_complete, NULL,
263 GFP_KERNEL);
264
265 switch (ret) {
266 case 0: /* Page found */
267 dout("page read submitted\n");
268 return 0;
269 case -ENOBUFS: /* Pages were not found, and can't be */
270 case -ENODATA: /* Pages were not found */
271 dout("page/inode not in cache\n");
272 return ret;
273 default:
274 dout("%s: unknown error ret = %i\n", __func__, ret);
275 return ret;
276 }
277}
278
279int ceph_readpages_from_fscache(struct inode *inode,
280 struct address_space *mapping,
281 struct list_head *pages,
282 unsigned *nr_pages)
283{
284 struct ceph_inode_info *ci = ceph_inode(inode);
285 int ret;
286
287 if (!cache_valid(ci))
288 return -ENOBUFS;
289
290 ret = fscache_read_or_alloc_pages(ci->fscache, mapping, pages, nr_pages,
291 ceph_vfs_readpage_complete_unlock,
292 NULL, mapping_gfp_mask(mapping));
293
294 switch (ret) {
295 case 0: /* All pages found */
296 dout("all-page read submitted\n");
297 return 0;
298 case -ENOBUFS: /* Some pages were not found, and can't be */
299 case -ENODATA: /* some pages were not found */
300 dout("page/inode not in cache\n");
301 return ret;
302 default:
303 dout("%s: unknown error ret = %i\n", __func__, ret);
304 return ret;
305 }
306}
307
308void ceph_readpage_to_fscache(struct inode *inode, struct page *page)
309{
310 struct ceph_inode_info *ci = ceph_inode(inode);
311 int ret;
312
313 if (!PageFsCache(page))
314 return;
315
316 if (!cache_valid(ci))
317 return;
318
319 ret = fscache_write_page(ci->fscache, page, GFP_KERNEL);
320 if (ret)
321 fscache_uncache_page(ci->fscache, page);
322}
323
324void ceph_invalidate_fscache_page(struct inode* inode, struct page *page)
325{
326 struct ceph_inode_info *ci = ceph_inode(inode);
327
328 if (!PageFsCache(page))
329 return;
330
331 fscache_wait_on_page_write(ci->fscache, page);
332 fscache_uncache_page(ci->fscache, page);
333}
334
335void ceph_fscache_unregister_fs(struct ceph_fs_client* fsc)
336{
337 if (fsc->revalidate_wq)
338 destroy_workqueue(fsc->revalidate_wq);
339
340 fscache_relinquish_cookie(fsc->fscache, 0);
341 fsc->fscache = NULL;
342}
343
344static void ceph_revalidate_work(struct work_struct *work)
345{
346 int issued;
347 u32 orig_gen;
348 struct ceph_inode_info *ci = container_of(work, struct ceph_inode_info,
349 i_revalidate_work);
350 struct inode *inode = &ci->vfs_inode;
351
352 spin_lock(&ci->i_ceph_lock);
353 issued = __ceph_caps_issued(ci, NULL);
354 orig_gen = ci->i_rdcache_gen;
355 spin_unlock(&ci->i_ceph_lock);
356
357 if (!(issued & CEPH_CAP_FILE_CACHE)) {
358 dout("revalidate_work lost cache before validation %p\n",
359 inode);
360 goto out;
361 }
362
363 if (!fscache_check_consistency(ci->fscache))
364 fscache_invalidate(ci->fscache);
365
366 spin_lock(&ci->i_ceph_lock);
367 /* Update the new valid generation (backwards sanity check too) */
368 if (orig_gen > ci->i_fscache_gen) {
369 ci->i_fscache_gen = orig_gen;
370 }
371 spin_unlock(&ci->i_ceph_lock);
372
373out:
374 iput(&ci->vfs_inode);
375}
376
377void ceph_queue_revalidate(struct inode *inode)
378{
379 struct ceph_fs_client *fsc = ceph_sb_to_client(inode->i_sb);
380 struct ceph_inode_info *ci = ceph_inode(inode);
381
382 if (fsc->revalidate_wq == NULL || ci->fscache == NULL)
383 return;
384
385 ihold(inode);
386
387 if (queue_work(ceph_sb_to_client(inode->i_sb)->revalidate_wq,
388 &ci->i_revalidate_work)) {
389 dout("ceph_queue_revalidate %p\n", inode);
390 } else {
391 dout("ceph_queue_revalidate %p failed\n)", inode);
392 iput(inode);
393 }
394}
395
396void ceph_fscache_inode_init(struct ceph_inode_info *ci)
397{
398 ci->fscache = NULL;
399 /* The first load is verifed cookie open time */
400 ci->i_fscache_gen = 1;
401 INIT_WORK(&ci->i_revalidate_work, ceph_revalidate_work);
402}
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
24#include "super.h"
25#include "cache.h"
26
27struct ceph_aux_inode {
28 u64 version;
29 struct timespec mtime;
30 loff_t size;
31};
32
33struct fscache_netfs ceph_cache_netfs = {
34 .name = "ceph",
35 .version = 0,
36};
37
38static 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
52static 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
58int ceph_fscache_register(void)
59{
60 return fscache_register_netfs(&ceph_cache_netfs);
61}
62
63void ceph_fscache_unregister(void)
64{
65 fscache_unregister_netfs(&ceph_cache_netfs);
66}
67
68int 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,
72 fsc, true);
73 if (!fsc->fscache)
74 pr_err("Unable to register fsid: %p fscache cookie\n", fsc);
75
76 return 0;
77}
78
79static 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
85 /* use ceph virtual inode (id + snapshot) */
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
94static 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));
102 aux.version = ci->i_version;
103 aux.mtime = inode->i_mtime;
104 aux.size = i_size_read(inode);
105
106 memcpy(buffer, &aux, sizeof(aux));
107
108 return sizeof(aux);
109}
110
111static 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;
115 *size = i_size_read(&ci->vfs_inode);
116}
117
118static 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));
129 aux.version = ci->i_version;
130 aux.mtime = inode->i_mtime;
131 aux.size = i_size_read(inode);
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
140static 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
170static 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
180void ceph_fscache_register_inode_cookie(struct inode *inode)
181{
182 struct ceph_inode_info *ci = ceph_inode(inode);
183 struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
184
185 /* No caching for filesystem */
186 if (fsc->fscache == NULL)
187 return;
188
189 /* Only cache for regular files that are read only */
190 if (!S_ISREG(inode->i_mode))
191 return;
192
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 }
199 inode_unlock(inode);
200}
201
202void 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
215static bool ceph_fscache_can_enable(void *data)
216{
217 struct inode *inode = data;
218 return !inode_is_open_for_write(inode);
219}
220
221void 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
243static void ceph_vfs_readpage_complete(struct page *page, void *data, int error)
244{
245 if (!error)
246 SetPageUptodate(page);
247}
248
249static 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
257static inline bool cache_valid(struct ceph_inode_info *ci)
258{
259 return ci->i_fscache_gen == ci->i_rdcache_gen;
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 */
268int 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
294int 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
323void ceph_readpage_to_fscache(struct inode *inode, struct page *page)
324{
325 struct ceph_inode_info *ci = ceph_inode(inode);
326 int ret;
327
328 if (!PageFsCache(page))
329 return;
330
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
339void ceph_invalidate_fscache_page(struct inode* inode, struct page *page)
340{
341 struct ceph_inode_info *ci = ceph_inode(inode);
342
343 if (!PageFsCache(page))
344 return;
345
346 fscache_wait_on_page_write(ci->fscache, page);
347 fscache_uncache_page(ci->fscache, page);
348}
349
350void ceph_fscache_unregister_fs(struct ceph_fs_client* fsc)
351{
352 fscache_relinquish_cookie(fsc->fscache, 0);
353 fsc->fscache = NULL;
354}
355
356/*
357 * caller should hold CEPH_CAP_FILE_{RD,CACHE}
358 */
359void ceph_fscache_revalidate_cookie(struct ceph_inode_info *ci)
360{
361 if (cache_valid(ci))
362 return;
363
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);
373 }
374 mutex_unlock(&ci->i_truncate_mutex);
375}