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1f327613 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
60e78d2c AK |
2 | /* |
3 | * V9FS cache definitions. | |
4 | * | |
5 | * Copyright (C) 2009 by Abhishek Kulkarni <adkulkar@umail.iu.edu> | |
60e78d2c AK |
6 | */ |
7 | ||
8 | #include <linux/jiffies.h> | |
9 | #include <linux/file.h> | |
5a0e3ad6 | 10 | #include <linux/slab.h> |
60e78d2c AK |
11 | #include <linux/stat.h> |
12 | #include <linux/sched.h> | |
13 | #include <linux/fs.h> | |
14 | #include <net/9p/9p.h> | |
15 | ||
16 | #include "v9fs.h" | |
17 | #include "cache.h" | |
18 | ||
19 | #define CACHETAG_LEN 11 | |
20 | ||
60e78d2c AK |
21 | struct fscache_netfs v9fs_cache_netfs = { |
22 | .name = "9p", | |
23 | .version = 0, | |
24 | }; | |
25 | ||
60e78d2c AK |
26 | /** |
27 | * v9fs_random_cachetag - Generate a random tag to be associated | |
28 | * with a new cache session. | |
29 | * | |
30 | * The value of jiffies is used for a fairly randomly cache tag. | |
31 | */ | |
32 | ||
33 | static | |
34 | int v9fs_random_cachetag(struct v9fs_session_info *v9ses) | |
35 | { | |
36 | v9ses->cachetag = kmalloc(CACHETAG_LEN, GFP_KERNEL); | |
37 | if (!v9ses->cachetag) | |
38 | return -ENOMEM; | |
39 | ||
40 | return scnprintf(v9ses->cachetag, CACHETAG_LEN, "%lu", jiffies); | |
41 | } | |
42 | ||
60e78d2c | 43 | const struct fscache_cookie_def v9fs_cache_session_index_def = { |
a78ce05d AK |
44 | .name = "9P.session", |
45 | .type = FSCACHE_COOKIE_TYPE_INDEX, | |
60e78d2c AK |
46 | }; |
47 | ||
48 | void v9fs_cache_session_get_cookie(struct v9fs_session_info *v9ses) | |
49 | { | |
50 | /* If no cache session tag was specified, we generate a random one. */ | |
402cb8dd DH |
51 | if (!v9ses->cachetag) { |
52 | if (v9fs_random_cachetag(v9ses) < 0) { | |
53 | v9ses->fscache = NULL; | |
962a991c BV |
54 | kfree(v9ses->cachetag); |
55 | v9ses->cachetag = NULL; | |
402cb8dd DH |
56 | return; |
57 | } | |
58 | } | |
60e78d2c AK |
59 | |
60 | v9ses->fscache = fscache_acquire_cookie(v9fs_cache_netfs.primary_index, | |
61 | &v9fs_cache_session_index_def, | |
402cb8dd DH |
62 | v9ses->cachetag, |
63 | strlen(v9ses->cachetag), | |
64 | NULL, 0, | |
ee1235a9 | 65 | v9ses, 0, true); |
5d385153 JP |
66 | p9_debug(P9_DEBUG_FSC, "session %p get cookie %p\n", |
67 | v9ses, v9ses->fscache); | |
60e78d2c AK |
68 | } |
69 | ||
70 | void v9fs_cache_session_put_cookie(struct v9fs_session_info *v9ses) | |
71 | { | |
5d385153 JP |
72 | p9_debug(P9_DEBUG_FSC, "session %p put cookie %p\n", |
73 | v9ses, v9ses->fscache); | |
402cb8dd | 74 | fscache_relinquish_cookie(v9ses->fscache, NULL, false); |
60e78d2c AK |
75 | v9ses->fscache = NULL; |
76 | } | |
77 | ||
60e78d2c AK |
78 | static enum |
79 | fscache_checkaux v9fs_cache_inode_check_aux(void *cookie_netfs_data, | |
80 | const void *buffer, | |
ee1235a9 DH |
81 | uint16_t buflen, |
82 | loff_t object_size) | |
60e78d2c | 83 | { |
a78ce05d | 84 | const struct v9fs_inode *v9inode = cookie_netfs_data; |
60e78d2c | 85 | |
fd2421f5 | 86 | if (buflen != sizeof(v9inode->qid.version)) |
60e78d2c AK |
87 | return FSCACHE_CHECKAUX_OBSOLETE; |
88 | ||
fd2421f5 AK |
89 | if (memcmp(buffer, &v9inode->qid.version, |
90 | sizeof(v9inode->qid.version))) | |
60e78d2c AK |
91 | return FSCACHE_CHECKAUX_OBSOLETE; |
92 | ||
93 | return FSCACHE_CHECKAUX_OKAY; | |
94 | } | |
95 | ||
60e78d2c AK |
96 | const struct fscache_cookie_def v9fs_cache_inode_index_def = { |
97 | .name = "9p.inode", | |
98 | .type = FSCACHE_COOKIE_TYPE_DATAFILE, | |
60e78d2c | 99 | .check_aux = v9fs_cache_inode_check_aux, |
60e78d2c AK |
100 | }; |
101 | ||
102 | void v9fs_cache_inode_get_cookie(struct inode *inode) | |
103 | { | |
a78ce05d | 104 | struct v9fs_inode *v9inode; |
60e78d2c AK |
105 | struct v9fs_session_info *v9ses; |
106 | ||
107 | if (!S_ISREG(inode->i_mode)) | |
108 | return; | |
109 | ||
a78ce05d AK |
110 | v9inode = V9FS_I(inode); |
111 | if (v9inode->fscache) | |
60e78d2c AK |
112 | return; |
113 | ||
114 | v9ses = v9fs_inode2v9ses(inode); | |
a78ce05d | 115 | v9inode->fscache = fscache_acquire_cookie(v9ses->fscache, |
60e78d2c | 116 | &v9fs_cache_inode_index_def, |
402cb8dd DH |
117 | &v9inode->qid.path, |
118 | sizeof(v9inode->qid.path), | |
119 | &v9inode->qid.version, | |
120 | sizeof(v9inode->qid.version), | |
ee1235a9 DH |
121 | v9inode, |
122 | i_size_read(&v9inode->vfs_inode), | |
123 | true); | |
60e78d2c | 124 | |
5d385153 JP |
125 | p9_debug(P9_DEBUG_FSC, "inode %p get cookie %p\n", |
126 | inode, v9inode->fscache); | |
60e78d2c AK |
127 | } |
128 | ||
129 | void v9fs_cache_inode_put_cookie(struct inode *inode) | |
130 | { | |
a78ce05d | 131 | struct v9fs_inode *v9inode = V9FS_I(inode); |
60e78d2c | 132 | |
a78ce05d | 133 | if (!v9inode->fscache) |
60e78d2c | 134 | return; |
5d385153 JP |
135 | p9_debug(P9_DEBUG_FSC, "inode %p put cookie %p\n", |
136 | inode, v9inode->fscache); | |
60e78d2c | 137 | |
402cb8dd DH |
138 | fscache_relinquish_cookie(v9inode->fscache, &v9inode->qid.version, |
139 | false); | |
a78ce05d | 140 | v9inode->fscache = NULL; |
60e78d2c AK |
141 | } |
142 | ||
143 | void v9fs_cache_inode_flush_cookie(struct inode *inode) | |
144 | { | |
a78ce05d | 145 | struct v9fs_inode *v9inode = V9FS_I(inode); |
60e78d2c | 146 | |
a78ce05d | 147 | if (!v9inode->fscache) |
60e78d2c | 148 | return; |
5d385153 JP |
149 | p9_debug(P9_DEBUG_FSC, "inode %p flush cookie %p\n", |
150 | inode, v9inode->fscache); | |
60e78d2c | 151 | |
402cb8dd | 152 | fscache_relinquish_cookie(v9inode->fscache, NULL, true); |
a78ce05d | 153 | v9inode->fscache = NULL; |
60e78d2c AK |
154 | } |
155 | ||
156 | void v9fs_cache_inode_set_cookie(struct inode *inode, struct file *filp) | |
157 | { | |
a78ce05d | 158 | struct v9fs_inode *v9inode = V9FS_I(inode); |
60e78d2c | 159 | |
a78ce05d | 160 | if (!v9inode->fscache) |
60e78d2c AK |
161 | return; |
162 | ||
8f5fed1e | 163 | mutex_lock(&v9inode->fscache_lock); |
bd126e5e | 164 | |
60e78d2c AK |
165 | if ((filp->f_flags & O_ACCMODE) != O_RDONLY) |
166 | v9fs_cache_inode_flush_cookie(inode); | |
167 | else | |
168 | v9fs_cache_inode_get_cookie(inode); | |
169 | ||
8f5fed1e | 170 | mutex_unlock(&v9inode->fscache_lock); |
60e78d2c AK |
171 | } |
172 | ||
173 | void v9fs_cache_inode_reset_cookie(struct inode *inode) | |
174 | { | |
a78ce05d | 175 | struct v9fs_inode *v9inode = V9FS_I(inode); |
60e78d2c AK |
176 | struct v9fs_session_info *v9ses; |
177 | struct fscache_cookie *old; | |
178 | ||
a78ce05d | 179 | if (!v9inode->fscache) |
60e78d2c AK |
180 | return; |
181 | ||
a78ce05d | 182 | old = v9inode->fscache; |
60e78d2c | 183 | |
8f5fed1e | 184 | mutex_lock(&v9inode->fscache_lock); |
402cb8dd | 185 | fscache_relinquish_cookie(v9inode->fscache, NULL, true); |
60e78d2c AK |
186 | |
187 | v9ses = v9fs_inode2v9ses(inode); | |
a78ce05d | 188 | v9inode->fscache = fscache_acquire_cookie(v9ses->fscache, |
60e78d2c | 189 | &v9fs_cache_inode_index_def, |
402cb8dd DH |
190 | &v9inode->qid.path, |
191 | sizeof(v9inode->qid.path), | |
192 | &v9inode->qid.version, | |
193 | sizeof(v9inode->qid.version), | |
ee1235a9 DH |
194 | v9inode, |
195 | i_size_read(&v9inode->vfs_inode), | |
196 | true); | |
5d385153 JP |
197 | p9_debug(P9_DEBUG_FSC, "inode %p revalidating cookie old %p new %p\n", |
198 | inode, old, v9inode->fscache); | |
60e78d2c | 199 | |
8f5fed1e | 200 | mutex_unlock(&v9inode->fscache_lock); |
60e78d2c AK |
201 | } |
202 | ||
203 | int __v9fs_fscache_release_page(struct page *page, gfp_t gfp) | |
204 | { | |
205 | struct inode *inode = page->mapping->host; | |
a78ce05d | 206 | struct v9fs_inode *v9inode = V9FS_I(inode); |
60e78d2c | 207 | |
a78ce05d | 208 | BUG_ON(!v9inode->fscache); |
60e78d2c | 209 | |
a78ce05d | 210 | return fscache_maybe_release_page(v9inode->fscache, page, gfp); |
60e78d2c AK |
211 | } |
212 | ||
213 | void __v9fs_fscache_invalidate_page(struct page *page) | |
214 | { | |
215 | struct inode *inode = page->mapping->host; | |
a78ce05d | 216 | struct v9fs_inode *v9inode = V9FS_I(inode); |
60e78d2c | 217 | |
a78ce05d | 218 | BUG_ON(!v9inode->fscache); |
60e78d2c AK |
219 | |
220 | if (PageFsCache(page)) { | |
a78ce05d | 221 | fscache_wait_on_page_write(v9inode->fscache, page); |
60e78d2c | 222 | BUG_ON(!PageLocked(page)); |
a78ce05d | 223 | fscache_uncache_page(v9inode->fscache, page); |
60e78d2c AK |
224 | } |
225 | } | |
226 | ||
227 | static void v9fs_vfs_readpage_complete(struct page *page, void *data, | |
228 | int error) | |
229 | { | |
230 | if (!error) | |
231 | SetPageUptodate(page); | |
232 | ||
233 | unlock_page(page); | |
234 | } | |
235 | ||
236 | /** | |
237 | * __v9fs_readpage_from_fscache - read a page from cache | |
238 | * | |
239 | * Returns 0 if the pages are in cache and a BIO is submitted, | |
240 | * 1 if the pages are not in cache and -error otherwise. | |
241 | */ | |
242 | ||
243 | int __v9fs_readpage_from_fscache(struct inode *inode, struct page *page) | |
244 | { | |
245 | int ret; | |
a78ce05d | 246 | const struct v9fs_inode *v9inode = V9FS_I(inode); |
60e78d2c | 247 | |
5d385153 | 248 | p9_debug(P9_DEBUG_FSC, "inode %p page %p\n", inode, page); |
a78ce05d | 249 | if (!v9inode->fscache) |
60e78d2c AK |
250 | return -ENOBUFS; |
251 | ||
a78ce05d | 252 | ret = fscache_read_or_alloc_page(v9inode->fscache, |
60e78d2c AK |
253 | page, |
254 | v9fs_vfs_readpage_complete, | |
255 | NULL, | |
256 | GFP_KERNEL); | |
257 | switch (ret) { | |
258 | case -ENOBUFS: | |
259 | case -ENODATA: | |
5d385153 | 260 | p9_debug(P9_DEBUG_FSC, "page/inode not in cache %d\n", ret); |
60e78d2c AK |
261 | return 1; |
262 | case 0: | |
5d385153 | 263 | p9_debug(P9_DEBUG_FSC, "BIO submitted\n"); |
60e78d2c AK |
264 | return ret; |
265 | default: | |
5d385153 | 266 | p9_debug(P9_DEBUG_FSC, "ret %d\n", ret); |
60e78d2c AK |
267 | return ret; |
268 | } | |
269 | } | |
270 | ||
271 | /** | |
272 | * __v9fs_readpages_from_fscache - read multiple pages from cache | |
273 | * | |
274 | * Returns 0 if the pages are in cache and a BIO is submitted, | |
275 | * 1 if the pages are not in cache and -error otherwise. | |
276 | */ | |
277 | ||
278 | int __v9fs_readpages_from_fscache(struct inode *inode, | |
279 | struct address_space *mapping, | |
280 | struct list_head *pages, | |
281 | unsigned *nr_pages) | |
282 | { | |
283 | int ret; | |
a78ce05d | 284 | const struct v9fs_inode *v9inode = V9FS_I(inode); |
60e78d2c | 285 | |
5d385153 | 286 | p9_debug(P9_DEBUG_FSC, "inode %p pages %u\n", inode, *nr_pages); |
a78ce05d | 287 | if (!v9inode->fscache) |
60e78d2c AK |
288 | return -ENOBUFS; |
289 | ||
a78ce05d | 290 | ret = fscache_read_or_alloc_pages(v9inode->fscache, |
60e78d2c AK |
291 | mapping, pages, nr_pages, |
292 | v9fs_vfs_readpage_complete, | |
293 | NULL, | |
294 | mapping_gfp_mask(mapping)); | |
295 | switch (ret) { | |
296 | case -ENOBUFS: | |
297 | case -ENODATA: | |
5d385153 | 298 | p9_debug(P9_DEBUG_FSC, "pages/inodes not in cache %d\n", ret); |
60e78d2c AK |
299 | return 1; |
300 | case 0: | |
301 | BUG_ON(!list_empty(pages)); | |
302 | BUG_ON(*nr_pages != 0); | |
5d385153 | 303 | p9_debug(P9_DEBUG_FSC, "BIO submitted\n"); |
60e78d2c AK |
304 | return ret; |
305 | default: | |
5d385153 | 306 | p9_debug(P9_DEBUG_FSC, "ret %d\n", ret); |
60e78d2c AK |
307 | return ret; |
308 | } | |
309 | } | |
310 | ||
311 | /** | |
312 | * __v9fs_readpage_to_fscache - write a page to the cache | |
313 | * | |
314 | */ | |
315 | ||
316 | void __v9fs_readpage_to_fscache(struct inode *inode, struct page *page) | |
317 | { | |
318 | int ret; | |
a78ce05d | 319 | const struct v9fs_inode *v9inode = V9FS_I(inode); |
60e78d2c | 320 | |
5d385153 | 321 | p9_debug(P9_DEBUG_FSC, "inode %p page %p\n", inode, page); |
ee1235a9 DH |
322 | ret = fscache_write_page(v9inode->fscache, page, |
323 | i_size_read(&v9inode->vfs_inode), GFP_KERNEL); | |
5d385153 | 324 | p9_debug(P9_DEBUG_FSC, "ret = %d\n", ret); |
60e78d2c AK |
325 | if (ret != 0) |
326 | v9fs_uncache_page(inode, page); | |
327 | } | |
2efda799 AK |
328 | |
329 | /* | |
330 | * wait for a page to complete writing to the cache | |
331 | */ | |
332 | void __v9fs_fscache_wait_on_page_write(struct inode *inode, struct page *page) | |
333 | { | |
a78ce05d | 334 | const struct v9fs_inode *v9inode = V9FS_I(inode); |
5d385153 | 335 | p9_debug(P9_DEBUG_FSC, "inode %p page %p\n", inode, page); |
2efda799 | 336 | if (PageFsCache(page)) |
a78ce05d | 337 | fscache_wait_on_page_write(v9inode->fscache, page); |
2efda799 | 338 | } |