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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
43
44
45
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_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
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
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
98void 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
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->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);
116}
117
118static void v9fs_cache_inode_get_attr(const void *cookie_netfs_data,
119 uint64_t *size)
120{
121 const struct v9fs_inode *v9inode = cookie_netfs_data;
122 *size = i_size_read(&v9inode->vfs_inode);
123
124 P9_DPRINTK(P9_DEBUG_FSC, "inode %p get attr %llu", &v9inode->vfs_inode,
125 *size);
126}
127
128static uint16_t v9fs_cache_inode_get_aux(const void *cookie_netfs_data,
129 void *buffer, uint16_t buflen)
130{
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);
137}
138
139static enum
140fscache_checkaux v9fs_cache_inode_check_aux(void *cookie_netfs_data,
141 const void *buffer,
142 uint16_t buflen)
143{
144 const struct v9fs_inode *v9inode = cookie_netfs_data;
145
146 if (buflen != sizeof(v9inode->fscache_key->version))
147 return FSCACHE_CHECKAUX_OBSOLETE;
148
149 if (memcmp(buffer, &v9inode->fscache_key->version,
150 sizeof(v9inode->fscache_key->version)))
151 return FSCACHE_CHECKAUX_OBSOLETE;
152
153 return FSCACHE_CHECKAUX_OKAY;
154}
155
156static void v9fs_cache_inode_now_uncached(void *cookie_netfs_data)
157{
158 struct v9fs_inode *v9inode = cookie_netfs_data;
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 (;;) {
167 nr_pages = pagevec_lookup(&pvec, v9inode->vfs_inode.i_mapping,
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
184const 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
194void v9fs_cache_inode_get_cookie(struct inode *inode)
195{
196 struct v9fs_inode *v9inode;
197 struct v9fs_session_info *v9ses;
198
199 if (!S_ISREG(inode->i_mode))
200 return;
201
202 v9inode = V9FS_I(inode);
203 if (v9inode->fscache)
204 return;
205
206 v9ses = v9fs_inode2v9ses(inode);
207 v9inode->fscache = fscache_acquire_cookie(v9ses->fscache,
208 &v9fs_cache_inode_index_def,
209 v9inode);
210
211 P9_DPRINTK(P9_DEBUG_FSC, "inode %p get cookie %p", inode,
212 v9inode->fscache);
213}
214
215void v9fs_cache_inode_put_cookie(struct inode *inode)
216{
217 struct v9fs_inode *v9inode = V9FS_I(inode);
218
219 if (!v9inode->fscache)
220 return;
221 P9_DPRINTK(P9_DEBUG_FSC, "inode %p put cookie %p", inode,
222 v9inode->fscache);
223
224 fscache_relinquish_cookie(v9inode->fscache, 0);
225 v9inode->fscache = NULL;
226}
227
228void v9fs_cache_inode_flush_cookie(struct inode *inode)
229{
230 struct v9fs_inode *v9inode = V9FS_I(inode);
231
232 if (!v9inode->fscache)
233 return;
234 P9_DPRINTK(P9_DEBUG_FSC, "inode %p flush cookie %p", inode,
235 v9inode->fscache);
236
237 fscache_relinquish_cookie(v9inode->fscache, 1);
238 v9inode->fscache = NULL;
239}
240
241void v9fs_cache_inode_set_cookie(struct inode *inode, struct file *filp)
242{
243 struct v9fs_inode *v9inode = V9FS_I(inode);
244 struct p9_fid *fid;
245
246 if (!v9inode->fscache)
247 return;
248
249 spin_lock(&v9inode->fscache_lock);
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
256 spin_unlock(&v9inode->fscache_lock);
257}
258
259void v9fs_cache_inode_reset_cookie(struct inode *inode)
260{
261 struct v9fs_inode *v9inode = V9FS_I(inode);
262 struct v9fs_session_info *v9ses;
263 struct fscache_cookie *old;
264
265 if (!v9inode->fscache)
266 return;
267
268 old = v9inode->fscache;
269
270 spin_lock(&v9inode->fscache_lock);
271 fscache_relinquish_cookie(v9inode->fscache, 1);
272
273 v9ses = v9fs_inode2v9ses(inode);
274 v9inode->fscache = fscache_acquire_cookie(v9ses->fscache,
275 &v9fs_cache_inode_index_def,
276 v9inode);
277 P9_DPRINTK(P9_DEBUG_FSC, "inode %p revalidating cookie old %p new %p",
278 inode, old, v9inode->fscache);
279
280 spin_unlock(&v9inode->fscache_lock);
281}
282
283int __v9fs_fscache_release_page(struct page *page, gfp_t gfp)
284{
285 struct inode *inode = page->mapping->host;
286 struct v9fs_inode *v9inode = V9FS_I(inode);
287
288 BUG_ON(!v9inode->fscache);
289
290 return fscache_maybe_release_page(v9inode->fscache, page, gfp);
291}
292
293void __v9fs_fscache_invalidate_page(struct page *page)
294{
295 struct inode *inode = page->mapping->host;
296 struct v9fs_inode *v9inode = V9FS_I(inode);
297
298 BUG_ON(!v9inode->fscache);
299
300 if (PageFsCache(page)) {
301 fscache_wait_on_page_write(v9inode->fscache, page);
302 BUG_ON(!PageLocked(page));
303 fscache_uncache_page(v9inode->fscache, page);
304 }
305}
306
307static 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
318
319
320
321
322
323int __v9fs_readpage_from_fscache(struct inode *inode, struct page *page)
324{
325 int ret;
326 const struct v9fs_inode *v9inode = V9FS_I(inode);
327
328 P9_DPRINTK(P9_DEBUG_FSC, "inode %p page %p", inode, page);
329 if (!v9inode->fscache)
330 return -ENOBUFS;
331
332 ret = fscache_read_or_alloc_page(v9inode->fscache,
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
353
354
355
356
357
358int __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;
364 const struct v9fs_inode *v9inode = V9FS_I(inode);
365
366 P9_DPRINTK(P9_DEBUG_FSC, "inode %p pages %u", inode, *nr_pages);
367 if (!v9inode->fscache)
368 return -ENOBUFS;
369
370 ret = fscache_read_or_alloc_pages(v9inode->fscache,
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
393
394
395
396void __v9fs_readpage_to_fscache(struct inode *inode, struct page *page)
397{
398 int ret;
399 const struct v9fs_inode *v9inode = V9FS_I(inode);
400
401 P9_DPRINTK(P9_DEBUG_FSC, "inode %p page %p", inode, page);
402 ret = fscache_write_page(v9inode->fscache, page, GFP_KERNEL);
403 P9_DPRINTK(P9_DEBUG_FSC, "ret = %d", ret);
404 if (ret != 0)
405 v9fs_uncache_page(inode, page);
406}
407
408
409
410
411void __v9fs_fscache_wait_on_page_write(struct inode *inode, struct page *page)
412{
413 const struct v9fs_inode *v9inode = V9FS_I(inode);
414 P9_DPRINTK(P9_DEBUG_FSC, "inode %p page %p", inode, page);
415 if (PageFsCache(page))
416 fscache_wait_on_page_write(v9inode->fscache, page);
417}
418
