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1/*
2 * V9FS cache definitions.
3 *
4 * Copyright (C) 2009 by Abhishek Kulkarni <adkulkar@umail.iu.edu>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2
8 * as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to:
17 * Free Software Foundation
18 * 51 Franklin Street, Fifth Floor
19 * Boston, MA 02111-1301 USA
20 *
21 */
22
23#include <linux/jiffies.h>
24#include <linux/file.h>
25#include <linux/slab.h>
26#include <linux/stat.h>
27#include <linux/sched.h>
28#include <linux/fs.h>
29#include <net/9p/9p.h>
30
31#include "v9fs.h"
32#include "cache.h"
33
34#define CACHETAG_LEN 11
35
36struct fscache_netfs v9fs_cache_netfs = {
37 .name = "9p",
38 .version = 0,
39};
40
41/**
42 * v9fs_random_cachetag - Generate a random tag to be associated
43 * with a new cache session.
44 *
45 * The value of jiffies is used for a fairly randomly cache tag.
46 */
47
48static
49int v9fs_random_cachetag(struct v9fs_session_info *v9ses)
50{
51 v9ses->cachetag = kmalloc(CACHETAG_LEN, GFP_KERNEL);
52 if (!v9ses->cachetag)
53 return -ENOMEM;
54
55 return scnprintf(v9ses->cachetag, CACHETAG_LEN, "%lu", jiffies);
56}
57
58static uint16_t v9fs_cache_session_get_key(const void *cookie_netfs_data,
59 void *buffer, uint16_t bufmax)
60{
61 struct v9fs_session_info *v9ses;
62 uint16_t klen = 0;
63
64 v9ses = (struct v9fs_session_info *)cookie_netfs_data;
65 p9_debug(P9_DEBUG_FSC, "session %p buf %p size %u\n",
66 v9ses, buffer, bufmax);
67
68 if (v9ses->cachetag)
69 klen = strlen(v9ses->cachetag);
70
71 if (klen > bufmax)
72 return 0;
73
74 memcpy(buffer, v9ses->cachetag, klen);
75 p9_debug(P9_DEBUG_FSC, "cache session tag %s\n", v9ses->cachetag);
76 return klen;
77}
78
79const struct fscache_cookie_def v9fs_cache_session_index_def = {
80 .name = "9P.session",
81 .type = FSCACHE_COOKIE_TYPE_INDEX,
82 .get_key = v9fs_cache_session_get_key,
83};
84
85void v9fs_cache_session_get_cookie(struct v9fs_session_info *v9ses)
86{
87 /* If no cache session tag was specified, we generate a random one. */
88 if (!v9ses->cachetag)
89 v9fs_random_cachetag(v9ses);
90
91 v9ses->fscache = fscache_acquire_cookie(v9fs_cache_netfs.primary_index,
92 &v9fs_cache_session_index_def,
93 v9ses, true);
94 p9_debug(P9_DEBUG_FSC, "session %p get cookie %p\n",
95 v9ses, v9ses->fscache);
96}
97
98void v9fs_cache_session_put_cookie(struct v9fs_session_info *v9ses)
99{
100 p9_debug(P9_DEBUG_FSC, "session %p put cookie %p\n",
101 v9ses, v9ses->fscache);
102 fscache_relinquish_cookie(v9ses->fscache, 0);
103 v9ses->fscache = NULL;
104}
105
106
107static uint16_t v9fs_cache_inode_get_key(const void *cookie_netfs_data,
108 void *buffer, uint16_t bufmax)
109{
110 const struct v9fs_inode *v9inode = cookie_netfs_data;
111 memcpy(buffer, &v9inode->qid.path, sizeof(v9inode->qid.path));
112 p9_debug(P9_DEBUG_FSC, "inode %p get key %llu\n",
113 &v9inode->vfs_inode, v9inode->qid.path);
114 return sizeof(v9inode->qid.path);
115}
116
117static void v9fs_cache_inode_get_attr(const void *cookie_netfs_data,
118 uint64_t *size)
119{
120 const struct v9fs_inode *v9inode = cookie_netfs_data;
121 *size = i_size_read(&v9inode->vfs_inode);
122
123 p9_debug(P9_DEBUG_FSC, "inode %p get attr %llu\n",
124 &v9inode->vfs_inode, *size);
125}
126
127static uint16_t v9fs_cache_inode_get_aux(const void *cookie_netfs_data,
128 void *buffer, uint16_t buflen)
129{
130 const struct v9fs_inode *v9inode = cookie_netfs_data;
131 memcpy(buffer, &v9inode->qid.version, sizeof(v9inode->qid.version));
132 p9_debug(P9_DEBUG_FSC, "inode %p get aux %u\n",
133 &v9inode->vfs_inode, v9inode->qid.version);
134 return sizeof(v9inode->qid.version);
135}
136
137static enum
138fscache_checkaux v9fs_cache_inode_check_aux(void *cookie_netfs_data,
139 const void *buffer,
140 uint16_t buflen)
141{
142 const struct v9fs_inode *v9inode = cookie_netfs_data;
143
144 if (buflen != sizeof(v9inode->qid.version))
145 return FSCACHE_CHECKAUX_OBSOLETE;
146
147 if (memcmp(buffer, &v9inode->qid.version,
148 sizeof(v9inode->qid.version)))
149 return FSCACHE_CHECKAUX_OBSOLETE;
150
151 return FSCACHE_CHECKAUX_OKAY;
152}
153
154static void v9fs_cache_inode_now_uncached(void *cookie_netfs_data)
155{
156 struct v9fs_inode *v9inode = cookie_netfs_data;
157 struct pagevec pvec;
158 pgoff_t first;
159 int loop, nr_pages;
160
161 pagevec_init(&pvec, 0);
162 first = 0;
163
164 for (;;) {
165 nr_pages = pagevec_lookup(&pvec, v9inode->vfs_inode.i_mapping,
166 first,
167 PAGEVEC_SIZE - pagevec_count(&pvec));
168 if (!nr_pages)
169 break;
170
171 for (loop = 0; loop < nr_pages; loop++)
172 ClearPageFsCache(pvec.pages[loop]);
173
174 first = pvec.pages[nr_pages - 1]->index + 1;
175
176 pvec.nr = nr_pages;
177 pagevec_release(&pvec);
178 cond_resched();
179 }
180}
181
182const struct fscache_cookie_def v9fs_cache_inode_index_def = {
183 .name = "9p.inode",
184 .type = FSCACHE_COOKIE_TYPE_DATAFILE,
185 .get_key = v9fs_cache_inode_get_key,
186 .get_attr = v9fs_cache_inode_get_attr,
187 .get_aux = v9fs_cache_inode_get_aux,
188 .check_aux = v9fs_cache_inode_check_aux,
189 .now_uncached = v9fs_cache_inode_now_uncached,
190};
191
192void v9fs_cache_inode_get_cookie(struct inode *inode)
193{
194 struct v9fs_inode *v9inode;
195 struct v9fs_session_info *v9ses;
196
197 if (!S_ISREG(inode->i_mode))
198 return;
199
200 v9inode = V9FS_I(inode);
201 if (v9inode->fscache)
202 return;
203
204 v9ses = v9fs_inode2v9ses(inode);
205 v9inode->fscache = fscache_acquire_cookie(v9ses->fscache,
206 &v9fs_cache_inode_index_def,
207 v9inode, true);
208
209 p9_debug(P9_DEBUG_FSC, "inode %p get cookie %p\n",
210 inode, v9inode->fscache);
211}
212
213void v9fs_cache_inode_put_cookie(struct inode *inode)
214{
215 struct v9fs_inode *v9inode = V9FS_I(inode);
216
217 if (!v9inode->fscache)
218 return;
219 p9_debug(P9_DEBUG_FSC, "inode %p put cookie %p\n",
220 inode, v9inode->fscache);
221
222 fscache_relinquish_cookie(v9inode->fscache, 0);
223 v9inode->fscache = NULL;
224}
225
226void v9fs_cache_inode_flush_cookie(struct inode *inode)
227{
228 struct v9fs_inode *v9inode = V9FS_I(inode);
229
230 if (!v9inode->fscache)
231 return;
232 p9_debug(P9_DEBUG_FSC, "inode %p flush cookie %p\n",
233 inode, v9inode->fscache);
234
235 fscache_relinquish_cookie(v9inode->fscache, 1);
236 v9inode->fscache = NULL;
237}
238
239void v9fs_cache_inode_set_cookie(struct inode *inode, struct file *filp)
240{
241 struct v9fs_inode *v9inode = V9FS_I(inode);
242
243 if (!v9inode->fscache)
244 return;
245
246 mutex_lock(&v9inode->fscache_lock);
247
248 if ((filp->f_flags & O_ACCMODE) != O_RDONLY)
249 v9fs_cache_inode_flush_cookie(inode);
250 else
251 v9fs_cache_inode_get_cookie(inode);
252
253 mutex_unlock(&v9inode->fscache_lock);
254}
255
256void v9fs_cache_inode_reset_cookie(struct inode *inode)
257{
258 struct v9fs_inode *v9inode = V9FS_I(inode);
259 struct v9fs_session_info *v9ses;
260 struct fscache_cookie *old;
261
262 if (!v9inode->fscache)
263 return;
264
265 old = v9inode->fscache;
266
267 mutex_lock(&v9inode->fscache_lock);
268 fscache_relinquish_cookie(v9inode->fscache, 1);
269
270 v9ses = v9fs_inode2v9ses(inode);
271 v9inode->fscache = fscache_acquire_cookie(v9ses->fscache,
272 &v9fs_cache_inode_index_def,
273 v9inode, true);
274 p9_debug(P9_DEBUG_FSC, "inode %p revalidating cookie old %p new %p\n",
275 inode, old, v9inode->fscache);
276
277 mutex_unlock(&v9inode->fscache_lock);
278}
279
280int __v9fs_fscache_release_page(struct page *page, gfp_t gfp)
281{
282 struct inode *inode = page->mapping->host;
283 struct v9fs_inode *v9inode = V9FS_I(inode);
284
285 BUG_ON(!v9inode->fscache);
286
287 return fscache_maybe_release_page(v9inode->fscache, page, gfp);
288}
289
290void __v9fs_fscache_invalidate_page(struct page *page)
291{
292 struct inode *inode = page->mapping->host;
293 struct v9fs_inode *v9inode = V9FS_I(inode);
294
295 BUG_ON(!v9inode->fscache);
296
297 if (PageFsCache(page)) {
298 fscache_wait_on_page_write(v9inode->fscache, page);
299 BUG_ON(!PageLocked(page));
300 fscache_uncache_page(v9inode->fscache, page);
301 }
302}
303
304static void v9fs_vfs_readpage_complete(struct page *page, void *data,
305 int error)
306{
307 if (!error)
308 SetPageUptodate(page);
309
310 unlock_page(page);
311}
312
313/**
314 * __v9fs_readpage_from_fscache - read a page from cache
315 *
316 * Returns 0 if the pages are in cache and a BIO is submitted,
317 * 1 if the pages are not in cache and -error otherwise.
318 */
319
320int __v9fs_readpage_from_fscache(struct inode *inode, struct page *page)
321{
322 int ret;
323 const struct v9fs_inode *v9inode = V9FS_I(inode);
324
325 p9_debug(P9_DEBUG_FSC, "inode %p page %p\n", inode, page);
326 if (!v9inode->fscache)
327 return -ENOBUFS;
328
329 ret = fscache_read_or_alloc_page(v9inode->fscache,
330 page,
331 v9fs_vfs_readpage_complete,
332 NULL,
333 GFP_KERNEL);
334 switch (ret) {
335 case -ENOBUFS:
336 case -ENODATA:
337 p9_debug(P9_DEBUG_FSC, "page/inode not in cache %d\n", ret);
338 return 1;
339 case 0:
340 p9_debug(P9_DEBUG_FSC, "BIO submitted\n");
341 return ret;
342 default:
343 p9_debug(P9_DEBUG_FSC, "ret %d\n", ret);
344 return ret;
345 }
346}
347
348/**
349 * __v9fs_readpages_from_fscache - read multiple pages from cache
350 *
351 * Returns 0 if the pages are in cache and a BIO is submitted,
352 * 1 if the pages are not in cache and -error otherwise.
353 */
354
355int __v9fs_readpages_from_fscache(struct inode *inode,
356 struct address_space *mapping,
357 struct list_head *pages,
358 unsigned *nr_pages)
359{
360 int ret;
361 const struct v9fs_inode *v9inode = V9FS_I(inode);
362
363 p9_debug(P9_DEBUG_FSC, "inode %p pages %u\n", inode, *nr_pages);
364 if (!v9inode->fscache)
365 return -ENOBUFS;
366
367 ret = fscache_read_or_alloc_pages(v9inode->fscache,
368 mapping, pages, nr_pages,
369 v9fs_vfs_readpage_complete,
370 NULL,
371 mapping_gfp_mask(mapping));
372 switch (ret) {
373 case -ENOBUFS:
374 case -ENODATA:
375 p9_debug(P9_DEBUG_FSC, "pages/inodes not in cache %d\n", ret);
376 return 1;
377 case 0:
378 BUG_ON(!list_empty(pages));
379 BUG_ON(*nr_pages != 0);
380 p9_debug(P9_DEBUG_FSC, "BIO submitted\n");
381 return ret;
382 default:
383 p9_debug(P9_DEBUG_FSC, "ret %d\n", ret);
384 return ret;
385 }
386}
387
388/**
389 * __v9fs_readpage_to_fscache - write a page to the cache
390 *
391 */
392
393void __v9fs_readpage_to_fscache(struct inode *inode, struct page *page)
394{
395 int ret;
396 const struct v9fs_inode *v9inode = V9FS_I(inode);
397
398 p9_debug(P9_DEBUG_FSC, "inode %p page %p\n", inode, page);
399 ret = fscache_write_page(v9inode->fscache, page, GFP_KERNEL);
400 p9_debug(P9_DEBUG_FSC, "ret = %d\n", ret);
401 if (ret != 0)
402 v9fs_uncache_page(inode, page);
403}
404
405/*
406 * wait for a page to complete writing to the cache
407 */
408void __v9fs_fscache_wait_on_page_write(struct inode *inode, struct page *page)
409{
410 const struct v9fs_inode *v9inode = V9FS_I(inode);
411 p9_debug(P9_DEBUG_FSC, "inode %p page %p\n", inode, page);
412 if (PageFsCache(page))
413 fscache_wait_on_page_write(v9inode->fscache, page);
414}
1/*
2 * V9FS cache definitions.
3 *
4 * Copyright (C) 2009 by Abhishek Kulkarni <adkulkar@umail.iu.edu>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2
8 * as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to:
17 * Free Software Foundation
18 * 51 Franklin Street, Fifth Floor
19 * Boston, MA 02111-1301 USA
20 *
21 */
22
23#include <linux/jiffies.h>
24#include <linux/file.h>
25#include <linux/slab.h>
26#include <linux/stat.h>
27#include <linux/sched.h>
28#include <linux/fs.h>
29#include <net/9p/9p.h>
30
31#include "v9fs.h"
32#include "cache.h"
33
34#define CACHETAG_LEN 11
35
36struct fscache_netfs v9fs_cache_netfs = {
37 .name = "9p",
38 .version = 0,
39};
40
41/**
42 * v9fs_random_cachetag - Generate a random tag to be associated
43 * with a new cache session.
44 *
45 * The value of jiffies is used for a fairly randomly cache tag.
46 */
47
48static
49int v9fs_random_cachetag(struct v9fs_session_info *v9ses)
50{
51 v9ses->cachetag = kmalloc(CACHETAG_LEN, GFP_KERNEL);
52 if (!v9ses->cachetag)
53 return -ENOMEM;
54
55 return scnprintf(v9ses->cachetag, CACHETAG_LEN, "%lu", jiffies);
56}
57
58const struct fscache_cookie_def v9fs_cache_session_index_def = {
59 .name = "9P.session",
60 .type = FSCACHE_COOKIE_TYPE_INDEX,
61};
62
63void v9fs_cache_session_get_cookie(struct v9fs_session_info *v9ses)
64{
65 /* If no cache session tag was specified, we generate a random one. */
66 if (!v9ses->cachetag) {
67 if (v9fs_random_cachetag(v9ses) < 0) {
68 v9ses->fscache = NULL;
69 return;
70 }
71 }
72
73 v9ses->fscache = fscache_acquire_cookie(v9fs_cache_netfs.primary_index,
74 &v9fs_cache_session_index_def,
75 v9ses->cachetag,
76 strlen(v9ses->cachetag),
77 NULL, 0,
78 v9ses, 0, true);
79 p9_debug(P9_DEBUG_FSC, "session %p get cookie %p\n",
80 v9ses, v9ses->fscache);
81}
82
83void v9fs_cache_session_put_cookie(struct v9fs_session_info *v9ses)
84{
85 p9_debug(P9_DEBUG_FSC, "session %p put cookie %p\n",
86 v9ses, v9ses->fscache);
87 fscache_relinquish_cookie(v9ses->fscache, NULL, false);
88 v9ses->fscache = NULL;
89}
90
91static enum
92fscache_checkaux v9fs_cache_inode_check_aux(void *cookie_netfs_data,
93 const void *buffer,
94 uint16_t buflen,
95 loff_t object_size)
96{
97 const struct v9fs_inode *v9inode = cookie_netfs_data;
98
99 if (buflen != sizeof(v9inode->qid.version))
100 return FSCACHE_CHECKAUX_OBSOLETE;
101
102 if (memcmp(buffer, &v9inode->qid.version,
103 sizeof(v9inode->qid.version)))
104 return FSCACHE_CHECKAUX_OBSOLETE;
105
106 return FSCACHE_CHECKAUX_OKAY;
107}
108
109const struct fscache_cookie_def v9fs_cache_inode_index_def = {
110 .name = "9p.inode",
111 .type = FSCACHE_COOKIE_TYPE_DATAFILE,
112 .check_aux = v9fs_cache_inode_check_aux,
113};
114
115void v9fs_cache_inode_get_cookie(struct inode *inode)
116{
117 struct v9fs_inode *v9inode;
118 struct v9fs_session_info *v9ses;
119
120 if (!S_ISREG(inode->i_mode))
121 return;
122
123 v9inode = V9FS_I(inode);
124 if (v9inode->fscache)
125 return;
126
127 v9ses = v9fs_inode2v9ses(inode);
128 v9inode->fscache = fscache_acquire_cookie(v9ses->fscache,
129 &v9fs_cache_inode_index_def,
130 &v9inode->qid.path,
131 sizeof(v9inode->qid.path),
132 &v9inode->qid.version,
133 sizeof(v9inode->qid.version),
134 v9inode,
135 i_size_read(&v9inode->vfs_inode),
136 true);
137
138 p9_debug(P9_DEBUG_FSC, "inode %p get cookie %p\n",
139 inode, v9inode->fscache);
140}
141
142void v9fs_cache_inode_put_cookie(struct inode *inode)
143{
144 struct v9fs_inode *v9inode = V9FS_I(inode);
145
146 if (!v9inode->fscache)
147 return;
148 p9_debug(P9_DEBUG_FSC, "inode %p put cookie %p\n",
149 inode, v9inode->fscache);
150
151 fscache_relinquish_cookie(v9inode->fscache, &v9inode->qid.version,
152 false);
153 v9inode->fscache = NULL;
154}
155
156void v9fs_cache_inode_flush_cookie(struct inode *inode)
157{
158 struct v9fs_inode *v9inode = V9FS_I(inode);
159
160 if (!v9inode->fscache)
161 return;
162 p9_debug(P9_DEBUG_FSC, "inode %p flush cookie %p\n",
163 inode, v9inode->fscache);
164
165 fscache_relinquish_cookie(v9inode->fscache, NULL, true);
166 v9inode->fscache = NULL;
167}
168
169void v9fs_cache_inode_set_cookie(struct inode *inode, struct file *filp)
170{
171 struct v9fs_inode *v9inode = V9FS_I(inode);
172
173 if (!v9inode->fscache)
174 return;
175
176 mutex_lock(&v9inode->fscache_lock);
177
178 if ((filp->f_flags & O_ACCMODE) != O_RDONLY)
179 v9fs_cache_inode_flush_cookie(inode);
180 else
181 v9fs_cache_inode_get_cookie(inode);
182
183 mutex_unlock(&v9inode->fscache_lock);
184}
185
186void v9fs_cache_inode_reset_cookie(struct inode *inode)
187{
188 struct v9fs_inode *v9inode = V9FS_I(inode);
189 struct v9fs_session_info *v9ses;
190 struct fscache_cookie *old;
191
192 if (!v9inode->fscache)
193 return;
194
195 old = v9inode->fscache;
196
197 mutex_lock(&v9inode->fscache_lock);
198 fscache_relinquish_cookie(v9inode->fscache, NULL, true);
199
200 v9ses = v9fs_inode2v9ses(inode);
201 v9inode->fscache = fscache_acquire_cookie(v9ses->fscache,
202 &v9fs_cache_inode_index_def,
203 &v9inode->qid.path,
204 sizeof(v9inode->qid.path),
205 &v9inode->qid.version,
206 sizeof(v9inode->qid.version),
207 v9inode,
208 i_size_read(&v9inode->vfs_inode),
209 true);
210 p9_debug(P9_DEBUG_FSC, "inode %p revalidating cookie old %p new %p\n",
211 inode, old, v9inode->fscache);
212
213 mutex_unlock(&v9inode->fscache_lock);
214}
215
216int __v9fs_fscache_release_page(struct page *page, gfp_t gfp)
217{
218 struct inode *inode = page->mapping->host;
219 struct v9fs_inode *v9inode = V9FS_I(inode);
220
221 BUG_ON(!v9inode->fscache);
222
223 return fscache_maybe_release_page(v9inode->fscache, page, gfp);
224}
225
226void __v9fs_fscache_invalidate_page(struct page *page)
227{
228 struct inode *inode = page->mapping->host;
229 struct v9fs_inode *v9inode = V9FS_I(inode);
230
231 BUG_ON(!v9inode->fscache);
232
233 if (PageFsCache(page)) {
234 fscache_wait_on_page_write(v9inode->fscache, page);
235 BUG_ON(!PageLocked(page));
236 fscache_uncache_page(v9inode->fscache, page);
237 }
238}
239
240static void v9fs_vfs_readpage_complete(struct page *page, void *data,
241 int error)
242{
243 if (!error)
244 SetPageUptodate(page);
245
246 unlock_page(page);
247}
248
249/**
250 * __v9fs_readpage_from_fscache - read a page from cache
251 *
252 * Returns 0 if the pages are in cache and a BIO is submitted,
253 * 1 if the pages are not in cache and -error otherwise.
254 */
255
256int __v9fs_readpage_from_fscache(struct inode *inode, struct page *page)
257{
258 int ret;
259 const struct v9fs_inode *v9inode = V9FS_I(inode);
260
261 p9_debug(P9_DEBUG_FSC, "inode %p page %p\n", inode, page);
262 if (!v9inode->fscache)
263 return -ENOBUFS;
264
265 ret = fscache_read_or_alloc_page(v9inode->fscache,
266 page,
267 v9fs_vfs_readpage_complete,
268 NULL,
269 GFP_KERNEL);
270 switch (ret) {
271 case -ENOBUFS:
272 case -ENODATA:
273 p9_debug(P9_DEBUG_FSC, "page/inode not in cache %d\n", ret);
274 return 1;
275 case 0:
276 p9_debug(P9_DEBUG_FSC, "BIO submitted\n");
277 return ret;
278 default:
279 p9_debug(P9_DEBUG_FSC, "ret %d\n", ret);
280 return ret;
281 }
282}
283
284/**
285 * __v9fs_readpages_from_fscache - read multiple pages from cache
286 *
287 * Returns 0 if the pages are in cache and a BIO is submitted,
288 * 1 if the pages are not in cache and -error otherwise.
289 */
290
291int __v9fs_readpages_from_fscache(struct inode *inode,
292 struct address_space *mapping,
293 struct list_head *pages,
294 unsigned *nr_pages)
295{
296 int ret;
297 const struct v9fs_inode *v9inode = V9FS_I(inode);
298
299 p9_debug(P9_DEBUG_FSC, "inode %p pages %u\n", inode, *nr_pages);
300 if (!v9inode->fscache)
301 return -ENOBUFS;
302
303 ret = fscache_read_or_alloc_pages(v9inode->fscache,
304 mapping, pages, nr_pages,
305 v9fs_vfs_readpage_complete,
306 NULL,
307 mapping_gfp_mask(mapping));
308 switch (ret) {
309 case -ENOBUFS:
310 case -ENODATA:
311 p9_debug(P9_DEBUG_FSC, "pages/inodes not in cache %d\n", ret);
312 return 1;
313 case 0:
314 BUG_ON(!list_empty(pages));
315 BUG_ON(*nr_pages != 0);
316 p9_debug(P9_DEBUG_FSC, "BIO submitted\n");
317 return ret;
318 default:
319 p9_debug(P9_DEBUG_FSC, "ret %d\n", ret);
320 return ret;
321 }
322}
323
324/**
325 * __v9fs_readpage_to_fscache - write a page to the cache
326 *
327 */
328
329void __v9fs_readpage_to_fscache(struct inode *inode, struct page *page)
330{
331 int ret;
332 const struct v9fs_inode *v9inode = V9FS_I(inode);
333
334 p9_debug(P9_DEBUG_FSC, "inode %p page %p\n", inode, page);
335 ret = fscache_write_page(v9inode->fscache, page,
336 i_size_read(&v9inode->vfs_inode), GFP_KERNEL);
337 p9_debug(P9_DEBUG_FSC, "ret = %d\n", ret);
338 if (ret != 0)
339 v9fs_uncache_page(inode, page);
340}
341
342/*
343 * wait for a page to complete writing to the cache
344 */
345void __v9fs_fscache_wait_on_page_write(struct inode *inode, struct page *page)
346{
347 const struct v9fs_inode *v9inode = V9FS_I(inode);
348 p9_debug(P9_DEBUG_FSC, "inode %p page %p\n", inode, page);
349 if (PageFsCache(page))
350 fscache_wait_on_page_write(v9inode->fscache, page);
351}