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Milosz Tanski99ccbd22013-08-21 17:29:54 -04001/*
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
Milosz Tanski99ccbd22013-08-21 17:29:54 -040024#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
Milosz Tanski971f0bd2013-09-06 15:13:18 +000057int ceph_fscache_register(void)
Milosz Tanski99ccbd22013-08-21 17:29:54 -040058{
59 return fscache_register_netfs(&ceph_cache_netfs);
60}
61
Milosz Tanski971f0bd2013-09-06 15:13:18 +000062void ceph_fscache_unregister(void)
Milosz Tanski99ccbd22013-08-21 17:29:54 -040063{
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);
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);
208done:
209 mutex_unlock(&inode->i_mutex);
210
211}
212
213void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci)
214{
215 struct fscache_cookie* cookie;
216
217 if ((cookie = ci->fscache) == NULL)
218 return;
219
220 ci->fscache = NULL;
221
222 fscache_uncache_all_inode_pages(cookie, &ci->vfs_inode);
223 fscache_relinquish_cookie(cookie, 0);
224}
225
226static void ceph_vfs_readpage_complete(struct page *page, void *data, int error)
227{
228 if (!error)
229 SetPageUptodate(page);
230}
231
232static void ceph_vfs_readpage_complete_unlock(struct page *page, void *data, int error)
233{
234 if (!error)
235 SetPageUptodate(page);
236
237 unlock_page(page);
238}
239
240static inline int cache_valid(struct ceph_inode_info *ci)
241{
242 return ((ceph_caps_issued(ci) & CEPH_CAP_FILE_CACHE) &&
243 (ci->i_fscache_gen == ci->i_rdcache_gen));
244}
245
246
247/* Atempt to read from the fscache,
248 *
249 * This function is called from the readpage_nounlock context. DO NOT attempt to
250 * unlock the page here (or in the callback).
251 */
252int ceph_readpage_from_fscache(struct inode *inode, struct page *page)
253{
254 struct ceph_inode_info *ci = ceph_inode(inode);
255 int ret;
256
257 if (!cache_valid(ci))
258 return -ENOBUFS;
259
260 ret = fscache_read_or_alloc_page(ci->fscache, page,
261 ceph_vfs_readpage_complete, NULL,
262 GFP_KERNEL);
263
264 switch (ret) {
265 case 0: /* Page found */
266 dout("page read submitted\n");
267 return 0;
268 case -ENOBUFS: /* Pages were not found, and can't be */
269 case -ENODATA: /* Pages were not found */
270 dout("page/inode not in cache\n");
271 return ret;
272 default:
273 dout("%s: unknown error ret = %i\n", __func__, ret);
274 return ret;
275 }
276}
277
278int ceph_readpages_from_fscache(struct inode *inode,
279 struct address_space *mapping,
280 struct list_head *pages,
281 unsigned *nr_pages)
282{
283 struct ceph_inode_info *ci = ceph_inode(inode);
284 int ret;
285
286 if (!cache_valid(ci))
287 return -ENOBUFS;
288
289 ret = fscache_read_or_alloc_pages(ci->fscache, mapping, pages, nr_pages,
290 ceph_vfs_readpage_complete_unlock,
291 NULL, mapping_gfp_mask(mapping));
292
293 switch (ret) {
294 case 0: /* All pages found */
295 dout("all-page read submitted\n");
296 return 0;
297 case -ENOBUFS: /* Some pages were not found, and can't be */
298 case -ENODATA: /* some pages were not found */
299 dout("page/inode not in cache\n");
300 return ret;
301 default:
302 dout("%s: unknown error ret = %i\n", __func__, ret);
303 return ret;
304 }
305}
306
307void ceph_readpage_to_fscache(struct inode *inode, struct page *page)
308{
309 struct ceph_inode_info *ci = ceph_inode(inode);
310 int ret;
311
Milosz Tanski9b8dd1e2013-09-03 19:11:01 -0400312 if (!PageFsCache(page))
313 return;
314
Milosz Tanski99ccbd22013-08-21 17:29:54 -0400315 if (!cache_valid(ci))
316 return;
317
318 ret = fscache_write_page(ci->fscache, page, GFP_KERNEL);
319 if (ret)
320 fscache_uncache_page(ci->fscache, page);
321}
322
323void ceph_invalidate_fscache_page(struct inode* inode, struct page *page)
324{
325 struct ceph_inode_info *ci = ceph_inode(inode);
326
327 fscache_wait_on_page_write(ci->fscache, page);
328 fscache_uncache_page(ci->fscache, page);
329}
330
331void ceph_fscache_unregister_fs(struct ceph_fs_client* fsc)
332{
333 if (fsc->revalidate_wq)
334 destroy_workqueue(fsc->revalidate_wq);
335
336 fscache_relinquish_cookie(fsc->fscache, 0);
337 fsc->fscache = NULL;
338}
339
340static void ceph_revalidate_work(struct work_struct *work)
341{
342 int issued;
343 u32 orig_gen;
344 struct ceph_inode_info *ci = container_of(work, struct ceph_inode_info,
345 i_revalidate_work);
346 struct inode *inode = &ci->vfs_inode;
347
348 spin_lock(&ci->i_ceph_lock);
349 issued = __ceph_caps_issued(ci, NULL);
350 orig_gen = ci->i_rdcache_gen;
351 spin_unlock(&ci->i_ceph_lock);
352
353 if (!(issued & CEPH_CAP_FILE_CACHE)) {
354 dout("revalidate_work lost cache before validation %p\n",
355 inode);
356 goto out;
357 }
358
359 if (!fscache_check_consistency(ci->fscache))
360 fscache_invalidate(ci->fscache);
361
362 spin_lock(&ci->i_ceph_lock);
363 /* Update the new valid generation (backwards sanity check too) */
364 if (orig_gen > ci->i_fscache_gen) {
365 ci->i_fscache_gen = orig_gen;
366 }
367 spin_unlock(&ci->i_ceph_lock);
368
369out:
370 iput(&ci->vfs_inode);
371}
372
373void ceph_queue_revalidate(struct inode *inode)
374{
Milosz Tanskie81568e2013-09-05 18:29:03 +0000375 struct ceph_fs_client *fsc = ceph_sb_to_client(inode->i_sb);
Milosz Tanski99ccbd22013-08-21 17:29:54 -0400376 struct ceph_inode_info *ci = ceph_inode(inode);
377
Milosz Tanskie81568e2013-09-05 18:29:03 +0000378 if (fsc->revalidate_wq == NULL || ci->fscache == NULL)
379 return;
380
Milosz Tanski99ccbd22013-08-21 17:29:54 -0400381 ihold(inode);
382
383 if (queue_work(ceph_sb_to_client(inode->i_sb)->revalidate_wq,
384 &ci->i_revalidate_work)) {
385 dout("ceph_queue_revalidate %p\n", inode);
386 } else {
387 dout("ceph_queue_revalidate %p failed\n)", inode);
388 iput(inode);
389 }
390}
391
392void ceph_fscache_inode_init(struct ceph_inode_info *ci)
393{
394 ci->fscache = NULL;
395 /* The first load is verifed cookie open time */
396 ci->i_fscache_gen = 1;
397 INIT_WORK(&ci->i_revalidate_work, ceph_revalidate_work);
398}