Commit | Line | Data |
---|---|---|
60e78d2c AK |
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> | |
5a0e3ad6 | 25 | #include <linux/slab.h> |
60e78d2c AK |
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 | ||
60e78d2c AK |
36 | struct fscache_netfs v9fs_cache_netfs = { |
37 | .name = "9p", | |
38 | .version = 0, | |
39 | }; | |
40 | ||
60e78d2c AK |
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 | ||
48 | static | |
49 | int 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 | ||
58 | static 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_DPRINTK(P9_DEBUG_FSC, "session %p buf %p size %u", v9ses, | |
66 | 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_DPRINTK(P9_DEBUG_FSC, "cache session tag %s", v9ses->cachetag); | |
76 | return klen; | |
77 | } | |
78 | ||
79 | const struct fscache_cookie_def v9fs_cache_session_index_def = { | |
a78ce05d AK |
80 | .name = "9P.session", |
81 | .type = FSCACHE_COOKIE_TYPE_INDEX, | |
82 | .get_key = v9fs_cache_session_get_key, | |
60e78d2c AK |
83 | }; |
84 | ||
85 | void 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); | |
94 | P9_DPRINTK(P9_DEBUG_FSC, "session %p get cookie %p", v9ses, | |
95 | v9ses->fscache); | |
96 | } | |
97 | ||
98 | void v9fs_cache_session_put_cookie(struct v9fs_session_info *v9ses) | |
99 | { | |
100 | P9_DPRINTK(P9_DEBUG_FSC, "session %p put cookie %p", v9ses, | |
101 | v9ses->fscache); | |
102 | fscache_relinquish_cookie(v9ses->fscache, 0); | |
103 | v9ses->fscache = NULL; | |
104 | } | |
105 | ||
106 | ||
107 | static uint16_t v9fs_cache_inode_get_key(const void *cookie_netfs_data, | |
108 | void *buffer, uint16_t bufmax) | |
109 | { | |
a78ce05d AK |
110 | const struct v9fs_inode *v9inode = cookie_netfs_data; |
111 | memcpy(buffer, &v9inode->fscache_key->path, | |
112 | sizeof(v9inode->fscache_key->path)); | |
113 | P9_DPRINTK(P9_DEBUG_FSC, "inode %p get key %llu", &v9inode->vfs_inode, | |
114 | v9inode->fscache_key->path); | |
115 | return sizeof(v9inode->fscache_key->path); | |
60e78d2c AK |
116 | } |
117 | ||
118 | static void v9fs_cache_inode_get_attr(const void *cookie_netfs_data, | |
119 | uint64_t *size) | |
120 | { | |
a78ce05d AK |
121 | const struct v9fs_inode *v9inode = cookie_netfs_data; |
122 | *size = i_size_read(&v9inode->vfs_inode); | |
60e78d2c | 123 | |
a78ce05d | 124 | P9_DPRINTK(P9_DEBUG_FSC, "inode %p get attr %llu", &v9inode->vfs_inode, |
60e78d2c AK |
125 | *size); |
126 | } | |
127 | ||
128 | static uint16_t v9fs_cache_inode_get_aux(const void *cookie_netfs_data, | |
129 | void *buffer, uint16_t buflen) | |
130 | { | |
a78ce05d AK |
131 | const struct v9fs_inode *v9inode = cookie_netfs_data; |
132 | memcpy(buffer, &v9inode->fscache_key->version, | |
133 | sizeof(v9inode->fscache_key->version)); | |
134 | P9_DPRINTK(P9_DEBUG_FSC, "inode %p get aux %u", &v9inode->vfs_inode, | |
135 | v9inode->fscache_key->version); | |
136 | return sizeof(v9inode->fscache_key->version); | |
60e78d2c AK |
137 | } |
138 | ||
139 | static enum | |
140 | fscache_checkaux v9fs_cache_inode_check_aux(void *cookie_netfs_data, | |
141 | const void *buffer, | |
142 | uint16_t buflen) | |
143 | { | |
a78ce05d | 144 | const struct v9fs_inode *v9inode = cookie_netfs_data; |
60e78d2c | 145 | |
a78ce05d | 146 | if (buflen != sizeof(v9inode->fscache_key->version)) |
60e78d2c AK |
147 | return FSCACHE_CHECKAUX_OBSOLETE; |
148 | ||
a78ce05d AK |
149 | if (memcmp(buffer, &v9inode->fscache_key->version, |
150 | sizeof(v9inode->fscache_key->version))) | |
60e78d2c AK |
151 | return FSCACHE_CHECKAUX_OBSOLETE; |
152 | ||
153 | return FSCACHE_CHECKAUX_OKAY; | |
154 | } | |
155 | ||
156 | static void v9fs_cache_inode_now_uncached(void *cookie_netfs_data) | |
157 | { | |
a78ce05d | 158 | struct v9fs_inode *v9inode = cookie_netfs_data; |
60e78d2c AK |
159 | struct pagevec pvec; |
160 | pgoff_t first; | |
161 | int loop, nr_pages; | |
162 | ||
163 | pagevec_init(&pvec, 0); | |
164 | first = 0; | |
165 | ||
166 | for (;;) { | |
a78ce05d | 167 | nr_pages = pagevec_lookup(&pvec, v9inode->vfs_inode.i_mapping, |
60e78d2c AK |
168 | first, |
169 | PAGEVEC_SIZE - pagevec_count(&pvec)); | |
170 | if (!nr_pages) | |
171 | break; | |
172 | ||
173 | for (loop = 0; loop < nr_pages; loop++) | |
174 | ClearPageFsCache(pvec.pages[loop]); | |
175 | ||
176 | first = pvec.pages[nr_pages - 1]->index + 1; | |
177 | ||
178 | pvec.nr = nr_pages; | |
179 | pagevec_release(&pvec); | |
180 | cond_resched(); | |
181 | } | |
182 | } | |
183 | ||
184 | const struct fscache_cookie_def v9fs_cache_inode_index_def = { | |
185 | .name = "9p.inode", | |
186 | .type = FSCACHE_COOKIE_TYPE_DATAFILE, | |
187 | .get_key = v9fs_cache_inode_get_key, | |
188 | .get_attr = v9fs_cache_inode_get_attr, | |
189 | .get_aux = v9fs_cache_inode_get_aux, | |
190 | .check_aux = v9fs_cache_inode_check_aux, | |
191 | .now_uncached = v9fs_cache_inode_now_uncached, | |
192 | }; | |
193 | ||
194 | void v9fs_cache_inode_get_cookie(struct inode *inode) | |
195 | { | |
a78ce05d | 196 | struct v9fs_inode *v9inode; |
60e78d2c AK |
197 | struct v9fs_session_info *v9ses; |
198 | ||
199 | if (!S_ISREG(inode->i_mode)) | |
200 | return; | |
201 | ||
a78ce05d AK |
202 | v9inode = V9FS_I(inode); |
203 | if (v9inode->fscache) | |
60e78d2c AK |
204 | return; |
205 | ||
206 | v9ses = v9fs_inode2v9ses(inode); | |
a78ce05d | 207 | v9inode->fscache = fscache_acquire_cookie(v9ses->fscache, |
60e78d2c | 208 | &v9fs_cache_inode_index_def, |
a78ce05d | 209 | v9inode); |
60e78d2c AK |
210 | |
211 | P9_DPRINTK(P9_DEBUG_FSC, "inode %p get cookie %p", inode, | |
a78ce05d | 212 | v9inode->fscache); |
60e78d2c AK |
213 | } |
214 | ||
215 | void v9fs_cache_inode_put_cookie(struct inode *inode) | |
216 | { | |
a78ce05d | 217 | struct v9fs_inode *v9inode = V9FS_I(inode); |
60e78d2c | 218 | |
a78ce05d | 219 | if (!v9inode->fscache) |
60e78d2c AK |
220 | return; |
221 | P9_DPRINTK(P9_DEBUG_FSC, "inode %p put cookie %p", inode, | |
a78ce05d | 222 | v9inode->fscache); |
60e78d2c | 223 | |
a78ce05d AK |
224 | fscache_relinquish_cookie(v9inode->fscache, 0); |
225 | v9inode->fscache = NULL; | |
60e78d2c AK |
226 | } |
227 | ||
228 | void v9fs_cache_inode_flush_cookie(struct inode *inode) | |
229 | { | |
a78ce05d | 230 | struct v9fs_inode *v9inode = V9FS_I(inode); |
60e78d2c | 231 | |
a78ce05d | 232 | if (!v9inode->fscache) |
60e78d2c AK |
233 | return; |
234 | P9_DPRINTK(P9_DEBUG_FSC, "inode %p flush cookie %p", inode, | |
a78ce05d | 235 | v9inode->fscache); |
60e78d2c | 236 | |
a78ce05d AK |
237 | fscache_relinquish_cookie(v9inode->fscache, 1); |
238 | v9inode->fscache = NULL; | |
60e78d2c AK |
239 | } |
240 | ||
241 | void v9fs_cache_inode_set_cookie(struct inode *inode, struct file *filp) | |
242 | { | |
a78ce05d | 243 | struct v9fs_inode *v9inode = V9FS_I(inode); |
60e78d2c AK |
244 | struct p9_fid *fid; |
245 | ||
a78ce05d | 246 | if (!v9inode->fscache) |
60e78d2c AK |
247 | return; |
248 | ||
a78ce05d | 249 | spin_lock(&v9inode->fscache_lock); |
60e78d2c AK |
250 | fid = filp->private_data; |
251 | if ((filp->f_flags & O_ACCMODE) != O_RDONLY) | |
252 | v9fs_cache_inode_flush_cookie(inode); | |
253 | else | |
254 | v9fs_cache_inode_get_cookie(inode); | |
255 | ||
a78ce05d | 256 | spin_unlock(&v9inode->fscache_lock); |
60e78d2c AK |
257 | } |
258 | ||
259 | void v9fs_cache_inode_reset_cookie(struct inode *inode) | |
260 | { | |
a78ce05d | 261 | struct v9fs_inode *v9inode = V9FS_I(inode); |
60e78d2c AK |
262 | struct v9fs_session_info *v9ses; |
263 | struct fscache_cookie *old; | |
264 | ||
a78ce05d | 265 | if (!v9inode->fscache) |
60e78d2c AK |
266 | return; |
267 | ||
a78ce05d | 268 | old = v9inode->fscache; |
60e78d2c | 269 | |
a78ce05d AK |
270 | spin_lock(&v9inode->fscache_lock); |
271 | fscache_relinquish_cookie(v9inode->fscache, 1); | |
60e78d2c AK |
272 | |
273 | v9ses = v9fs_inode2v9ses(inode); | |
a78ce05d | 274 | v9inode->fscache = fscache_acquire_cookie(v9ses->fscache, |
60e78d2c | 275 | &v9fs_cache_inode_index_def, |
a78ce05d | 276 | v9inode); |
60e78d2c | 277 | P9_DPRINTK(P9_DEBUG_FSC, "inode %p revalidating cookie old %p new %p", |
a78ce05d | 278 | inode, old, v9inode->fscache); |
60e78d2c | 279 | |
a78ce05d | 280 | spin_unlock(&v9inode->fscache_lock); |
60e78d2c AK |
281 | } |
282 | ||
283 | int __v9fs_fscache_release_page(struct page *page, gfp_t gfp) | |
284 | { | |
285 | struct inode *inode = page->mapping->host; | |
a78ce05d | 286 | struct v9fs_inode *v9inode = V9FS_I(inode); |
60e78d2c | 287 | |
a78ce05d | 288 | BUG_ON(!v9inode->fscache); |
60e78d2c | 289 | |
a78ce05d | 290 | return fscache_maybe_release_page(v9inode->fscache, page, gfp); |
60e78d2c AK |
291 | } |
292 | ||
293 | void __v9fs_fscache_invalidate_page(struct page *page) | |
294 | { | |
295 | struct inode *inode = page->mapping->host; | |
a78ce05d | 296 | struct v9fs_inode *v9inode = V9FS_I(inode); |
60e78d2c | 297 | |
a78ce05d | 298 | BUG_ON(!v9inode->fscache); |
60e78d2c AK |
299 | |
300 | if (PageFsCache(page)) { | |
a78ce05d | 301 | fscache_wait_on_page_write(v9inode->fscache, page); |
60e78d2c | 302 | BUG_ON(!PageLocked(page)); |
a78ce05d | 303 | fscache_uncache_page(v9inode->fscache, page); |
60e78d2c AK |
304 | } |
305 | } | |
306 | ||
307 | static void v9fs_vfs_readpage_complete(struct page *page, void *data, | |
308 | int error) | |
309 | { | |
310 | if (!error) | |
311 | SetPageUptodate(page); | |
312 | ||
313 | unlock_page(page); | |
314 | } | |
315 | ||
316 | /** | |
317 | * __v9fs_readpage_from_fscache - read a page from cache | |
318 | * | |
319 | * Returns 0 if the pages are in cache and a BIO is submitted, | |
320 | * 1 if the pages are not in cache and -error otherwise. | |
321 | */ | |
322 | ||
323 | int __v9fs_readpage_from_fscache(struct inode *inode, struct page *page) | |
324 | { | |
325 | int ret; | |
a78ce05d | 326 | const struct v9fs_inode *v9inode = V9FS_I(inode); |
60e78d2c AK |
327 | |
328 | P9_DPRINTK(P9_DEBUG_FSC, "inode %p page %p", inode, page); | |
a78ce05d | 329 | if (!v9inode->fscache) |
60e78d2c AK |
330 | return -ENOBUFS; |
331 | ||
a78ce05d | 332 | ret = fscache_read_or_alloc_page(v9inode->fscache, |
60e78d2c AK |
333 | page, |
334 | v9fs_vfs_readpage_complete, | |
335 | NULL, | |
336 | GFP_KERNEL); | |
337 | switch (ret) { | |
338 | case -ENOBUFS: | |
339 | case -ENODATA: | |
340 | P9_DPRINTK(P9_DEBUG_FSC, "page/inode not in cache %d", ret); | |
341 | return 1; | |
342 | case 0: | |
343 | P9_DPRINTK(P9_DEBUG_FSC, "BIO submitted"); | |
344 | return ret; | |
345 | default: | |
346 | P9_DPRINTK(P9_DEBUG_FSC, "ret %d", ret); | |
347 | return ret; | |
348 | } | |
349 | } | |
350 | ||
351 | /** | |
352 | * __v9fs_readpages_from_fscache - read multiple pages from cache | |
353 | * | |
354 | * Returns 0 if the pages are in cache and a BIO is submitted, | |
355 | * 1 if the pages are not in cache and -error otherwise. | |
356 | */ | |
357 | ||
358 | int __v9fs_readpages_from_fscache(struct inode *inode, | |
359 | struct address_space *mapping, | |
360 | struct list_head *pages, | |
361 | unsigned *nr_pages) | |
362 | { | |
363 | int ret; | |
a78ce05d | 364 | const struct v9fs_inode *v9inode = V9FS_I(inode); |
60e78d2c AK |
365 | |
366 | P9_DPRINTK(P9_DEBUG_FSC, "inode %p pages %u", inode, *nr_pages); | |
a78ce05d | 367 | if (!v9inode->fscache) |
60e78d2c AK |
368 | return -ENOBUFS; |
369 | ||
a78ce05d | 370 | ret = fscache_read_or_alloc_pages(v9inode->fscache, |
60e78d2c AK |
371 | mapping, pages, nr_pages, |
372 | v9fs_vfs_readpage_complete, | |
373 | NULL, | |
374 | mapping_gfp_mask(mapping)); | |
375 | switch (ret) { | |
376 | case -ENOBUFS: | |
377 | case -ENODATA: | |
378 | P9_DPRINTK(P9_DEBUG_FSC, "pages/inodes not in cache %d", ret); | |
379 | return 1; | |
380 | case 0: | |
381 | BUG_ON(!list_empty(pages)); | |
382 | BUG_ON(*nr_pages != 0); | |
383 | P9_DPRINTK(P9_DEBUG_FSC, "BIO submitted"); | |
384 | return ret; | |
385 | default: | |
386 | P9_DPRINTK(P9_DEBUG_FSC, "ret %d", ret); | |
387 | return ret; | |
388 | } | |
389 | } | |
390 | ||
391 | /** | |
392 | * __v9fs_readpage_to_fscache - write a page to the cache | |
393 | * | |
394 | */ | |
395 | ||
396 | void __v9fs_readpage_to_fscache(struct inode *inode, struct page *page) | |
397 | { | |
398 | int ret; | |
a78ce05d | 399 | const struct v9fs_inode *v9inode = V9FS_I(inode); |
60e78d2c AK |
400 | |
401 | P9_DPRINTK(P9_DEBUG_FSC, "inode %p page %p", inode, page); | |
a78ce05d | 402 | ret = fscache_write_page(v9inode->fscache, page, GFP_KERNEL); |
60e78d2c AK |
403 | P9_DPRINTK(P9_DEBUG_FSC, "ret = %d", ret); |
404 | if (ret != 0) | |
405 | v9fs_uncache_page(inode, page); | |
406 | } | |
2efda799 AK |
407 | |
408 | /* | |
409 | * wait for a page to complete writing to the cache | |
410 | */ | |
411 | void __v9fs_fscache_wait_on_page_write(struct inode *inode, struct page *page) | |
412 | { | |
a78ce05d | 413 | const struct v9fs_inode *v9inode = V9FS_I(inode); |
2efda799 AK |
414 | P9_DPRINTK(P9_DEBUG_FSC, "inode %p page %p", inode, page); |
415 | if (PageFsCache(page)) | |
a78ce05d | 416 | fscache_wait_on_page_write(v9inode->fscache, page); |
2efda799 | 417 | } |