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Commit | Line | Data |
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14727281 DH |
1 | /* NFS filesystem cache interface |
2 | * | |
3 | * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved. | |
4 | * Written by David Howells ([email protected]) | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public Licence | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the Licence, or (at your option) any later version. | |
10 | */ | |
11 | ||
12 | #include <linux/init.h> | |
13 | #include <linux/kernel.h> | |
14 | #include <linux/sched.h> | |
15 | #include <linux/mm.h> | |
16 | #include <linux/nfs_fs.h> | |
17 | #include <linux/nfs_fs_sb.h> | |
18 | #include <linux/in6.h> | |
19 | #include <linux/seq_file.h> | |
5a0e3ad6 | 20 | #include <linux/slab.h> |
14727281 DH |
21 | |
22 | #include "internal.h" | |
545db45f | 23 | #include "iostat.h" |
14727281 DH |
24 | #include "fscache.h" |
25 | ||
26 | #define NFSDBG_FACILITY NFSDBG_FSCACHE | |
27 | ||
08734048 DH |
28 | static struct rb_root nfs_fscache_keys = RB_ROOT; |
29 | static DEFINE_SPINLOCK(nfs_fscache_keys_lock); | |
30 | ||
14727281 DH |
31 | /* |
32 | * Get the per-client index cookie for an NFS client if the appropriate mount | |
33 | * flag was set | |
34 | * - We always try and get an index cookie for the client, but get filehandle | |
35 | * cookies on a per-superblock basis, depending on the mount flags | |
36 | */ | |
37 | void nfs_fscache_get_client_cookie(struct nfs_client *clp) | |
38 | { | |
39 | /* create a cache index for looking up filehandles */ | |
40 | clp->fscache = fscache_acquire_cookie(nfs_fscache_netfs.primary_index, | |
41 | &nfs_fscache_server_index_def, | |
94d30ae9 | 42 | clp, true); |
14727281 DH |
43 | dfprintk(FSCACHE, "NFS: get client cookie (0x%p/0x%p)\n", |
44 | clp, clp->fscache); | |
45 | } | |
46 | ||
47 | /* | |
48 | * Dispose of a per-client cookie | |
49 | */ | |
50 | void nfs_fscache_release_client_cookie(struct nfs_client *clp) | |
51 | { | |
52 | dfprintk(FSCACHE, "NFS: releasing client cookie (0x%p/0x%p)\n", | |
53 | clp, clp->fscache); | |
54 | ||
55 | fscache_relinquish_cookie(clp->fscache, 0); | |
56 | clp->fscache = NULL; | |
57 | } | |
08734048 DH |
58 | |
59 | /* | |
60 | * Get the cache cookie for an NFS superblock. We have to handle | |
61 | * uniquification here because the cache doesn't do it for us. | |
2df54806 DH |
62 | * |
63 | * The default uniquifier is just an empty string, but it may be overridden | |
64 | * either by the 'fsc=xxx' option to mount, or by inheriting it from the parent | |
65 | * superblock across an automount point of some nature. | |
08734048 | 66 | */ |
2311b943 | 67 | void nfs_fscache_get_super_cookie(struct super_block *sb, const char *uniq, int ulen) |
08734048 DH |
68 | { |
69 | struct nfs_fscache_key *key, *xkey; | |
70 | struct nfs_server *nfss = NFS_SB(sb); | |
71 | struct rb_node **p, *parent; | |
2311b943 | 72 | int diff; |
2df54806 DH |
73 | |
74 | if (!uniq) { | |
75 | uniq = ""; | |
76 | ulen = 1; | |
77 | } | |
78 | ||
08734048 DH |
79 | key = kzalloc(sizeof(*key) + ulen, GFP_KERNEL); |
80 | if (!key) | |
81 | return; | |
82 | ||
83 | key->nfs_client = nfss->nfs_client; | |
84 | key->key.super.s_flags = sb->s_flags & NFS_MS_MASK; | |
85 | key->key.nfs_server.flags = nfss->flags; | |
86 | key->key.nfs_server.rsize = nfss->rsize; | |
87 | key->key.nfs_server.wsize = nfss->wsize; | |
88 | key->key.nfs_server.acregmin = nfss->acregmin; | |
89 | key->key.nfs_server.acregmax = nfss->acregmax; | |
90 | key->key.nfs_server.acdirmin = nfss->acdirmin; | |
91 | key->key.nfs_server.acdirmax = nfss->acdirmax; | |
92 | key->key.nfs_server.fsid = nfss->fsid; | |
93 | key->key.rpc_auth.au_flavor = nfss->client->cl_auth->au_flavor; | |
94 | ||
95 | key->key.uniq_len = ulen; | |
96 | memcpy(key->key.uniquifier, uniq, ulen); | |
97 | ||
98 | spin_lock(&nfs_fscache_keys_lock); | |
99 | p = &nfs_fscache_keys.rb_node; | |
100 | parent = NULL; | |
101 | while (*p) { | |
102 | parent = *p; | |
103 | xkey = rb_entry(parent, struct nfs_fscache_key, node); | |
104 | ||
105 | if (key->nfs_client < xkey->nfs_client) | |
106 | goto go_left; | |
107 | if (key->nfs_client > xkey->nfs_client) | |
108 | goto go_right; | |
109 | ||
110 | diff = memcmp(&key->key, &xkey->key, sizeof(key->key)); | |
111 | if (diff < 0) | |
112 | goto go_left; | |
113 | if (diff > 0) | |
114 | goto go_right; | |
115 | ||
116 | if (key->key.uniq_len == 0) | |
117 | goto non_unique; | |
118 | diff = memcmp(key->key.uniquifier, | |
119 | xkey->key.uniquifier, | |
120 | key->key.uniq_len); | |
121 | if (diff < 0) | |
122 | goto go_left; | |
123 | if (diff > 0) | |
124 | goto go_right; | |
125 | goto non_unique; | |
126 | ||
127 | go_left: | |
128 | p = &(*p)->rb_left; | |
129 | continue; | |
130 | go_right: | |
131 | p = &(*p)->rb_right; | |
132 | } | |
133 | ||
134 | rb_link_node(&key->node, parent, p); | |
135 | rb_insert_color(&key->node, &nfs_fscache_keys); | |
136 | spin_unlock(&nfs_fscache_keys_lock); | |
137 | nfss->fscache_key = key; | |
138 | ||
139 | /* create a cache index for looking up filehandles */ | |
140 | nfss->fscache = fscache_acquire_cookie(nfss->nfs_client->fscache, | |
141 | &nfs_fscache_super_index_def, | |
94d30ae9 | 142 | nfss, true); |
08734048 DH |
143 | dfprintk(FSCACHE, "NFS: get superblock cookie (0x%p/0x%p)\n", |
144 | nfss, nfss->fscache); | |
145 | return; | |
146 | ||
147 | non_unique: | |
148 | spin_unlock(&nfs_fscache_keys_lock); | |
149 | kfree(key); | |
150 | nfss->fscache_key = NULL; | |
151 | nfss->fscache = NULL; | |
152 | printk(KERN_WARNING "NFS:" | |
153 | " Cache request denied due to non-unique superblock keys\n"); | |
154 | } | |
155 | ||
156 | /* | |
157 | * release a per-superblock cookie | |
158 | */ | |
159 | void nfs_fscache_release_super_cookie(struct super_block *sb) | |
160 | { | |
161 | struct nfs_server *nfss = NFS_SB(sb); | |
162 | ||
163 | dfprintk(FSCACHE, "NFS: releasing superblock cookie (0x%p/0x%p)\n", | |
164 | nfss, nfss->fscache); | |
165 | ||
166 | fscache_relinquish_cookie(nfss->fscache, 0); | |
167 | nfss->fscache = NULL; | |
168 | ||
169 | if (nfss->fscache_key) { | |
170 | spin_lock(&nfs_fscache_keys_lock); | |
171 | rb_erase(&nfss->fscache_key->node, &nfs_fscache_keys); | |
172 | spin_unlock(&nfs_fscache_keys_lock); | |
173 | kfree(nfss->fscache_key); | |
174 | nfss->fscache_key = NULL; | |
175 | } | |
176 | } | |
ef79c097 DH |
177 | |
178 | /* | |
179 | * Initialise the per-inode cache cookie pointer for an NFS inode. | |
180 | */ | |
f1fe29b4 | 181 | void nfs_fscache_init_inode(struct inode *inode) |
ef79c097 | 182 | { |
ef79c097 DH |
183 | struct nfs_inode *nfsi = NFS_I(inode); |
184 | ||
f1fe29b4 DH |
185 | nfsi->fscache = NULL; |
186 | if (!S_ISREG(inode->i_mode)) | |
ef79c097 | 187 | return; |
f1fe29b4 DH |
188 | nfsi->fscache = fscache_acquire_cookie(NFS_SB(inode->i_sb)->fscache, |
189 | &nfs_fscache_inode_object_def, | |
190 | nfsi, false); | |
ef79c097 DH |
191 | } |
192 | ||
193 | /* | |
194 | * Release a per-inode cookie. | |
195 | */ | |
f1fe29b4 | 196 | void nfs_fscache_clear_inode(struct inode *inode) |
ef79c097 DH |
197 | { |
198 | struct nfs_inode *nfsi = NFS_I(inode); | |
f1fe29b4 | 199 | struct fscache_cookie *cookie = nfs_i_fscache(inode); |
ef79c097 | 200 | |
f1fe29b4 | 201 | dfprintk(FSCACHE, "NFS: clear cookie (0x%p/0x%p)\n", nfsi, cookie); |
ef79c097 | 202 | |
f1fe29b4 | 203 | fscache_relinquish_cookie(cookie, false); |
ef79c097 DH |
204 | nfsi->fscache = NULL; |
205 | } | |
206 | ||
f1fe29b4 | 207 | static bool nfs_fscache_can_enable(void *data) |
ef79c097 | 208 | { |
f1fe29b4 | 209 | struct inode *inode = data; |
ef79c097 | 210 | |
f1fe29b4 | 211 | return !inode_is_open_for_write(inode); |
ef79c097 DH |
212 | } |
213 | ||
214 | /* | |
f1fe29b4 DH |
215 | * Enable or disable caching for a file that is being opened as appropriate. |
216 | * The cookie is allocated when the inode is initialised, but is not enabled at | |
217 | * that time. Enablement is deferred to file-open time to avoid stat() and | |
218 | * access() thrashing the cache. | |
219 | * | |
220 | * For now, with NFS, only regular files that are open read-only will be able | |
221 | * to use the cache. | |
222 | * | |
223 | * We enable the cache for an inode if we open it read-only and it isn't | |
224 | * currently open for writing. We disable the cache if the inode is open | |
225 | * write-only. | |
226 | * | |
227 | * The caller uses the file struct to pin i_writecount on the inode before | |
228 | * calling us when a file is opened for writing, so we can make use of that. | |
229 | * | |
230 | * Note that this may be invoked multiple times in parallel by parallel | |
231 | * nfs_open() functions. | |
ef79c097 | 232 | */ |
f1fe29b4 | 233 | void nfs_fscache_open_file(struct inode *inode, struct file *filp) |
ef79c097 DH |
234 | { |
235 | struct nfs_inode *nfsi = NFS_I(inode); | |
f1fe29b4 | 236 | struct fscache_cookie *cookie = nfs_i_fscache(inode); |
ef79c097 | 237 | |
f1fe29b4 DH |
238 | if (!fscache_cookie_valid(cookie)) |
239 | return; | |
ef79c097 | 240 | |
f1fe29b4 DH |
241 | if (inode_is_open_for_write(inode)) { |
242 | dfprintk(FSCACHE, "NFS: nfsi 0x%p disabling cache\n", nfsi); | |
243 | clear_bit(NFS_INO_FSCACHE, &nfsi->flags); | |
244 | fscache_disable_cookie(cookie, true); | |
245 | fscache_uncache_all_inode_pages(cookie, inode); | |
246 | } else { | |
247 | dfprintk(FSCACHE, "NFS: nfsi 0x%p enabling cache\n", nfsi); | |
248 | fscache_enable_cookie(cookie, nfs_fscache_can_enable, inode); | |
249 | if (fscache_cookie_enabled(cookie)) | |
250 | set_bit(NFS_INO_FSCACHE, &NFS_I(inode)->flags); | |
ef79c097 | 251 | } |
ef79c097 | 252 | } |
f1fe29b4 | 253 | EXPORT_SYMBOL_GPL(nfs_fscache_open_file); |
545db45f DH |
254 | |
255 | /* | |
256 | * Release the caching state associated with a page, if the page isn't busy | |
257 | * interacting with the cache. | |
258 | * - Returns true (can release page) or false (page busy). | |
259 | */ | |
260 | int nfs_fscache_release_page(struct page *page, gfp_t gfp) | |
261 | { | |
545db45f | 262 | if (PageFsCache(page)) { |
f1fe29b4 | 263 | struct fscache_cookie *cookie = nfs_i_fscache(page->mapping->host); |
2c174009 TM |
264 | |
265 | BUG_ON(!cookie); | |
545db45f | 266 | dfprintk(FSCACHE, "NFS: fscache releasepage (0x%p/0x%p/0x%p)\n", |
f1fe29b4 | 267 | cookie, page, NFS_I(page->mapping->host)); |
545db45f | 268 | |
201a1542 DH |
269 | if (!fscache_maybe_release_page(cookie, page, gfp)) |
270 | return 0; | |
271 | ||
e9f456ca LR |
272 | nfs_inc_fscache_stats(page->mapping->host, |
273 | NFSIOS_FSCACHE_PAGES_UNCACHED); | |
545db45f DH |
274 | } |
275 | ||
276 | return 1; | |
277 | } | |
278 | ||
279 | /* | |
280 | * Release the caching state associated with a page if undergoing complete page | |
281 | * invalidation. | |
282 | */ | |
283 | void __nfs_fscache_invalidate_page(struct page *page, struct inode *inode) | |
284 | { | |
f1fe29b4 | 285 | struct fscache_cookie *cookie = nfs_i_fscache(inode); |
545db45f DH |
286 | |
287 | BUG_ON(!cookie); | |
288 | ||
289 | dfprintk(FSCACHE, "NFS: fscache invalidatepage (0x%p/0x%p/0x%p)\n", | |
f1fe29b4 | 290 | cookie, page, NFS_I(inode)); |
545db45f DH |
291 | |
292 | fscache_wait_on_page_write(cookie, page); | |
293 | ||
294 | BUG_ON(!PageLocked(page)); | |
295 | fscache_uncache_page(cookie, page); | |
e9f456ca LR |
296 | nfs_inc_fscache_stats(page->mapping->host, |
297 | NFSIOS_FSCACHE_PAGES_UNCACHED); | |
545db45f | 298 | } |
9a9fc1c0 DH |
299 | |
300 | /* | |
301 | * Handle completion of a page being read from the cache. | |
302 | * - Called in process (keventd) context. | |
303 | */ | |
304 | static void nfs_readpage_from_fscache_complete(struct page *page, | |
305 | void *context, | |
306 | int error) | |
307 | { | |
308 | dfprintk(FSCACHE, | |
309 | "NFS: readpage_from_fscache_complete (0x%p/0x%p/%d)\n", | |
310 | page, context, error); | |
311 | ||
312 | /* if the read completes with an error, we just unlock the page and let | |
313 | * the VM reissue the readpage */ | |
314 | if (!error) { | |
315 | SetPageUptodate(page); | |
316 | unlock_page(page); | |
317 | } else { | |
318 | error = nfs_readpage_async(context, page->mapping->host, page); | |
319 | if (error) | |
320 | unlock_page(page); | |
321 | } | |
322 | } | |
323 | ||
324 | /* | |
325 | * Retrieve a page from fscache | |
326 | */ | |
327 | int __nfs_readpage_from_fscache(struct nfs_open_context *ctx, | |
328 | struct inode *inode, struct page *page) | |
329 | { | |
330 | int ret; | |
331 | ||
332 | dfprintk(FSCACHE, | |
333 | "NFS: readpage_from_fscache(fsc:%p/p:%p(i:%lx f:%lx)/0x%p)\n", | |
f1fe29b4 | 334 | nfs_i_fscache(inode), page, page->index, page->flags, inode); |
9a9fc1c0 | 335 | |
f1fe29b4 | 336 | ret = fscache_read_or_alloc_page(nfs_i_fscache(inode), |
9a9fc1c0 DH |
337 | page, |
338 | nfs_readpage_from_fscache_complete, | |
339 | ctx, | |
340 | GFP_KERNEL); | |
341 | ||
342 | switch (ret) { | |
343 | case 0: /* read BIO submitted (page in fscache) */ | |
344 | dfprintk(FSCACHE, | |
345 | "NFS: readpage_from_fscache: BIO submitted\n"); | |
e9f456ca | 346 | nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_OK); |
9a9fc1c0 DH |
347 | return ret; |
348 | ||
349 | case -ENOBUFS: /* inode not in cache */ | |
350 | case -ENODATA: /* page not in cache */ | |
e9f456ca | 351 | nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL); |
9a9fc1c0 DH |
352 | dfprintk(FSCACHE, |
353 | "NFS: readpage_from_fscache %d\n", ret); | |
354 | return 1; | |
355 | ||
356 | default: | |
357 | dfprintk(FSCACHE, "NFS: readpage_from_fscache %d\n", ret); | |
e9f456ca | 358 | nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL); |
9a9fc1c0 DH |
359 | } |
360 | return ret; | |
361 | } | |
362 | ||
363 | /* | |
364 | * Retrieve a set of pages from fscache | |
365 | */ | |
366 | int __nfs_readpages_from_fscache(struct nfs_open_context *ctx, | |
367 | struct inode *inode, | |
368 | struct address_space *mapping, | |
369 | struct list_head *pages, | |
370 | unsigned *nr_pages) | |
371 | { | |
0f15c53d CL |
372 | unsigned npages = *nr_pages; |
373 | int ret; | |
9a9fc1c0 DH |
374 | |
375 | dfprintk(FSCACHE, "NFS: nfs_getpages_from_fscache (0x%p/%u/0x%p)\n", | |
f1fe29b4 | 376 | nfs_i_fscache(inode), npages, inode); |
9a9fc1c0 | 377 | |
f1fe29b4 | 378 | ret = fscache_read_or_alloc_pages(nfs_i_fscache(inode), |
9a9fc1c0 DH |
379 | mapping, pages, nr_pages, |
380 | nfs_readpage_from_fscache_complete, | |
381 | ctx, | |
382 | mapping_gfp_mask(mapping)); | |
383 | if (*nr_pages < npages) | |
384 | nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_OK, | |
385 | npages); | |
386 | if (*nr_pages > 0) | |
387 | nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL, | |
388 | *nr_pages); | |
389 | ||
390 | switch (ret) { | |
391 | case 0: /* read submitted to the cache for all pages */ | |
392 | BUG_ON(!list_empty(pages)); | |
393 | BUG_ON(*nr_pages != 0); | |
394 | dfprintk(FSCACHE, | |
395 | "NFS: nfs_getpages_from_fscache: submitted\n"); | |
396 | ||
397 | return ret; | |
398 | ||
399 | case -ENOBUFS: /* some pages aren't cached and can't be */ | |
400 | case -ENODATA: /* some pages aren't cached */ | |
401 | dfprintk(FSCACHE, | |
402 | "NFS: nfs_getpages_from_fscache: no page: %d\n", ret); | |
403 | return 1; | |
404 | ||
405 | default: | |
406 | dfprintk(FSCACHE, | |
407 | "NFS: nfs_getpages_from_fscache: ret %d\n", ret); | |
408 | } | |
409 | ||
410 | return ret; | |
411 | } | |
7f8e05f6 DH |
412 | |
413 | /* | |
414 | * Store a newly fetched page in fscache | |
415 | * - PG_fscache must be set on the page | |
416 | */ | |
417 | void __nfs_readpage_to_fscache(struct inode *inode, struct page *page, int sync) | |
418 | { | |
419 | int ret; | |
420 | ||
421 | dfprintk(FSCACHE, | |
422 | "NFS: readpage_to_fscache(fsc:%p/p:%p(i:%lx f:%lx)/%d)\n", | |
f1fe29b4 | 423 | nfs_i_fscache(inode), page, page->index, page->flags, sync); |
7f8e05f6 | 424 | |
f1fe29b4 | 425 | ret = fscache_write_page(nfs_i_fscache(inode), page, GFP_KERNEL); |
7f8e05f6 DH |
426 | dfprintk(FSCACHE, |
427 | "NFS: readpage_to_fscache: p:%p(i:%lu f:%lx) ret %d\n", | |
428 | page, page->index, page->flags, ret); | |
429 | ||
430 | if (ret != 0) { | |
f1fe29b4 | 431 | fscache_uncache_page(nfs_i_fscache(inode), page); |
e9f456ca LR |
432 | nfs_inc_fscache_stats(inode, |
433 | NFSIOS_FSCACHE_PAGES_WRITTEN_FAIL); | |
434 | nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_UNCACHED); | |
7f8e05f6 | 435 | } else { |
e9f456ca LR |
436 | nfs_inc_fscache_stats(inode, |
437 | NFSIOS_FSCACHE_PAGES_WRITTEN_OK); | |
7f8e05f6 DH |
438 | } |
439 | } |