Commit | Line | Data |
---|---|---|
08e0e7c8 | 1 | /* AFS filesystem file handling |
1da177e4 | 2 | * |
08e0e7c8 | 3 | * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved. |
1da177e4 LT |
4 | * Written by David Howells (dhowells@redhat.com) |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | */ | |
11 | ||
12 | #include <linux/kernel.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/init.h> | |
1da177e4 LT |
15 | #include <linux/fs.h> |
16 | #include <linux/pagemap.h> | |
31143d5d | 17 | #include <linux/writeback.h> |
5a0e3ad6 | 18 | #include <linux/gfp.h> |
91b467e0 | 19 | #include <linux/task_io_accounting_ops.h> |
1da177e4 LT |
20 | #include "internal.h" |
21 | ||
416351f2 | 22 | static int afs_readpage(struct file *file, struct page *page); |
d47992f8 LC |
23 | static void afs_invalidatepage(struct page *page, unsigned int offset, |
24 | unsigned int length); | |
416351f2 | 25 | static int afs_releasepage(struct page *page, gfp_t gfp_flags); |
1da177e4 | 26 | |
9b3f26c9 DH |
27 | static int afs_readpages(struct file *filp, struct address_space *mapping, |
28 | struct list_head *pages, unsigned nr_pages); | |
29 | ||
00d3b7a4 DH |
30 | const struct file_operations afs_file_operations = { |
31 | .open = afs_open, | |
58fed94d | 32 | .flush = afs_flush, |
00d3b7a4 DH |
33 | .release = afs_release, |
34 | .llseek = generic_file_llseek, | |
aad4f8bb | 35 | .read_iter = generic_file_read_iter, |
50b5551d | 36 | .write_iter = afs_file_write, |
00d3b7a4 | 37 | .mmap = generic_file_readonly_mmap, |
5ffc4ef4 | 38 | .splice_read = generic_file_splice_read, |
31143d5d | 39 | .fsync = afs_fsync, |
e8d6c554 DH |
40 | .lock = afs_lock, |
41 | .flock = afs_flock, | |
00d3b7a4 DH |
42 | }; |
43 | ||
754661f1 | 44 | const struct inode_operations afs_file_inode_operations = { |
416351f2 | 45 | .getattr = afs_getattr, |
31143d5d | 46 | .setattr = afs_setattr, |
00d3b7a4 | 47 | .permission = afs_permission, |
d3e3b7ea | 48 | .listxattr = afs_listxattr, |
1da177e4 LT |
49 | }; |
50 | ||
f5e54d6e | 51 | const struct address_space_operations afs_fs_aops = { |
416351f2 | 52 | .readpage = afs_readpage, |
9b3f26c9 | 53 | .readpages = afs_readpages, |
31143d5d DH |
54 | .set_page_dirty = afs_set_page_dirty, |
55 | .launder_page = afs_launder_page, | |
416351f2 DH |
56 | .releasepage = afs_releasepage, |
57 | .invalidatepage = afs_invalidatepage, | |
15b4650e NP |
58 | .write_begin = afs_write_begin, |
59 | .write_end = afs_write_end, | |
31143d5d DH |
60 | .writepage = afs_writepage, |
61 | .writepages = afs_writepages, | |
1da177e4 LT |
62 | }; |
63 | ||
4343d008 DH |
64 | /* |
65 | * Discard a pin on a writeback key. | |
66 | */ | |
67 | void afs_put_wb_key(struct afs_wb_key *wbk) | |
68 | { | |
69 | if (refcount_dec_and_test(&wbk->usage)) { | |
70 | key_put(wbk->key); | |
71 | kfree(wbk); | |
72 | } | |
73 | } | |
74 | ||
75 | /* | |
76 | * Cache key for writeback. | |
77 | */ | |
78 | int afs_cache_wb_key(struct afs_vnode *vnode, struct afs_file *af) | |
79 | { | |
80 | struct afs_wb_key *wbk, *p; | |
81 | ||
82 | wbk = kzalloc(sizeof(struct afs_wb_key), GFP_KERNEL); | |
83 | if (!wbk) | |
84 | return -ENOMEM; | |
85 | refcount_set(&wbk->usage, 2); | |
86 | wbk->key = af->key; | |
87 | ||
88 | spin_lock(&vnode->wb_lock); | |
89 | list_for_each_entry(p, &vnode->wb_keys, vnode_link) { | |
90 | if (p->key == wbk->key) | |
91 | goto found; | |
92 | } | |
93 | ||
94 | key_get(wbk->key); | |
95 | list_add_tail(&wbk->vnode_link, &vnode->wb_keys); | |
96 | spin_unlock(&vnode->wb_lock); | |
97 | af->wb = wbk; | |
98 | return 0; | |
99 | ||
100 | found: | |
101 | refcount_inc(&p->usage); | |
102 | spin_unlock(&vnode->wb_lock); | |
103 | af->wb = p; | |
104 | kfree(wbk); | |
105 | return 0; | |
106 | } | |
107 | ||
00d3b7a4 DH |
108 | /* |
109 | * open an AFS file or directory and attach a key to it | |
110 | */ | |
111 | int afs_open(struct inode *inode, struct file *file) | |
112 | { | |
113 | struct afs_vnode *vnode = AFS_FS_I(inode); | |
215804a9 | 114 | struct afs_file *af; |
00d3b7a4 | 115 | struct key *key; |
260a9803 | 116 | int ret; |
00d3b7a4 | 117 | |
416351f2 | 118 | _enter("{%x:%u},", vnode->fid.vid, vnode->fid.vnode); |
00d3b7a4 DH |
119 | |
120 | key = afs_request_key(vnode->volume->cell); | |
121 | if (IS_ERR(key)) { | |
215804a9 DH |
122 | ret = PTR_ERR(key); |
123 | goto error; | |
00d3b7a4 DH |
124 | } |
125 | ||
215804a9 DH |
126 | af = kzalloc(sizeof(*af), GFP_KERNEL); |
127 | if (!af) { | |
128 | ret = -ENOMEM; | |
129 | goto error_key; | |
260a9803 | 130 | } |
4343d008 | 131 | af->key = key; |
260a9803 | 132 | |
215804a9 DH |
133 | ret = afs_validate(vnode, key); |
134 | if (ret < 0) | |
135 | goto error_af; | |
136 | ||
4343d008 DH |
137 | if (file->f_mode & FMODE_WRITE) { |
138 | ret = afs_cache_wb_key(vnode, af); | |
139 | if (ret < 0) | |
140 | goto error_af; | |
141 | } | |
142 | ||
215804a9 | 143 | file->private_data = af; |
00d3b7a4 DH |
144 | _leave(" = 0"); |
145 | return 0; | |
215804a9 DH |
146 | |
147 | error_af: | |
148 | kfree(af); | |
149 | error_key: | |
150 | key_put(key); | |
151 | error: | |
152 | _leave(" = %d", ret); | |
153 | return ret; | |
00d3b7a4 DH |
154 | } |
155 | ||
156 | /* | |
157 | * release an AFS file or directory and discard its key | |
158 | */ | |
159 | int afs_release(struct inode *inode, struct file *file) | |
160 | { | |
161 | struct afs_vnode *vnode = AFS_FS_I(inode); | |
215804a9 | 162 | struct afs_file *af = file->private_data; |
00d3b7a4 | 163 | |
416351f2 | 164 | _enter("{%x:%u},", vnode->fid.vid, vnode->fid.vnode); |
00d3b7a4 | 165 | |
215804a9 | 166 | file->private_data = NULL; |
4343d008 DH |
167 | if (af->wb) |
168 | afs_put_wb_key(af->wb); | |
215804a9 DH |
169 | key_put(af->key); |
170 | kfree(af); | |
4343d008 | 171 | afs_prune_wb_keys(vnode); |
00d3b7a4 DH |
172 | _leave(" = 0"); |
173 | return 0; | |
174 | } | |
175 | ||
196ee9cd DH |
176 | /* |
177 | * Dispose of a ref to a read record. | |
178 | */ | |
179 | void afs_put_read(struct afs_read *req) | |
180 | { | |
181 | int i; | |
182 | ||
183 | if (atomic_dec_and_test(&req->usage)) { | |
184 | for (i = 0; i < req->nr_pages; i++) | |
185 | if (req->pages[i]) | |
186 | put_page(req->pages[i]); | |
187 | kfree(req); | |
188 | } | |
189 | } | |
190 | ||
6566abdb | 191 | #ifdef CONFIG_AFS_FSCACHE |
1da177e4 LT |
192 | /* |
193 | * deal with notification that a page was read from the cache | |
194 | */ | |
9b3f26c9 DH |
195 | static void afs_file_readpage_read_complete(struct page *page, |
196 | void *data, | |
197 | int error) | |
1da177e4 | 198 | { |
9b3f26c9 | 199 | _enter("%p,%p,%d", page, data, error); |
1da177e4 | 200 | |
9b3f26c9 DH |
201 | /* if the read completes with an error, we just unlock the page and let |
202 | * the VM reissue the readpage */ | |
203 | if (!error) | |
1da177e4 LT |
204 | SetPageUptodate(page); |
205 | unlock_page(page); | |
ec26815a | 206 | } |
6566abdb | 207 | #endif |
1da177e4 | 208 | |
d2ddc776 DH |
209 | /* |
210 | * Fetch file data from the volume. | |
211 | */ | |
212 | int afs_fetch_data(struct afs_vnode *vnode, struct key *key, struct afs_read *desc) | |
213 | { | |
214 | struct afs_fs_cursor fc; | |
215 | int ret; | |
216 | ||
217 | _enter("%s{%x:%u.%u},%x,,,", | |
218 | vnode->volume->name, | |
219 | vnode->fid.vid, | |
220 | vnode->fid.vnode, | |
221 | vnode->fid.unique, | |
222 | key_serial(key)); | |
223 | ||
224 | ret = -ERESTARTSYS; | |
225 | if (afs_begin_vnode_operation(&fc, vnode, key)) { | |
226 | while (afs_select_fileserver(&fc)) { | |
227 | fc.cb_break = vnode->cb_break + vnode->cb_s_break; | |
228 | afs_fs_fetch_data(&fc, desc); | |
229 | } | |
230 | ||
231 | afs_check_for_remote_deletion(&fc, fc.vnode); | |
232 | afs_vnode_commit_status(&fc, vnode, fc.cb_break); | |
233 | ret = afs_end_vnode_operation(&fc); | |
234 | } | |
235 | ||
236 | _leave(" = %d", ret); | |
237 | return ret; | |
238 | } | |
239 | ||
1da177e4 | 240 | /* |
f6d335c0 | 241 | * read page from file, directory or symlink, given a key to use |
1da177e4 | 242 | */ |
f6d335c0 | 243 | int afs_page_filler(void *data, struct page *page) |
1da177e4 | 244 | { |
f6d335c0 AV |
245 | struct inode *inode = page->mapping->host; |
246 | struct afs_vnode *vnode = AFS_FS_I(inode); | |
196ee9cd | 247 | struct afs_read *req; |
f6d335c0 | 248 | struct key *key = data; |
1da177e4 LT |
249 | int ret; |
250 | ||
00d3b7a4 | 251 | _enter("{%x},{%lu},{%lu}", key_serial(key), inode->i_ino, page->index); |
1da177e4 | 252 | |
cd7619d6 | 253 | BUG_ON(!PageLocked(page)); |
1da177e4 LT |
254 | |
255 | ret = -ESTALE; | |
08e0e7c8 | 256 | if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) |
1da177e4 LT |
257 | goto error; |
258 | ||
1da177e4 | 259 | /* is it cached? */ |
9b3f26c9 DH |
260 | #ifdef CONFIG_AFS_FSCACHE |
261 | ret = fscache_read_or_alloc_page(vnode->cache, | |
1da177e4 LT |
262 | page, |
263 | afs_file_readpage_read_complete, | |
264 | NULL, | |
265 | GFP_KERNEL); | |
266 | #else | |
267 | ret = -ENOBUFS; | |
268 | #endif | |
1da177e4 | 269 | switch (ret) { |
1da177e4 LT |
270 | /* read BIO submitted (page in cache) */ |
271 | case 0: | |
272 | break; | |
273 | ||
9b3f26c9 | 274 | /* page not yet cached */ |
1da177e4 | 275 | case -ENODATA: |
9b3f26c9 DH |
276 | _debug("cache said ENODATA"); |
277 | goto go_on; | |
278 | ||
279 | /* page will not be cached */ | |
280 | case -ENOBUFS: | |
281 | _debug("cache said ENOBUFS"); | |
1da177e4 | 282 | default: |
9b3f26c9 | 283 | go_on: |
196ee9cd DH |
284 | req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *), |
285 | GFP_KERNEL); | |
286 | if (!req) | |
287 | goto enomem; | |
288 | ||
6db3ac3c DH |
289 | /* We request a full page. If the page is a partial one at the |
290 | * end of the file, the server will return a short read and the | |
291 | * unmarshalling code will clear the unfilled space. | |
292 | */ | |
196ee9cd DH |
293 | atomic_set(&req->usage, 1); |
294 | req->pos = (loff_t)page->index << PAGE_SHIFT; | |
6db3ac3c | 295 | req->len = PAGE_SIZE; |
196ee9cd DH |
296 | req->nr_pages = 1; |
297 | req->pages[0] = page; | |
298 | get_page(page); | |
1da177e4 LT |
299 | |
300 | /* read the contents of the file from the server into the | |
301 | * page */ | |
d2ddc776 | 302 | ret = afs_fetch_data(vnode, key, req); |
196ee9cd | 303 | afs_put_read(req); |
dab17c1a DH |
304 | |
305 | if (ret >= 0 && S_ISDIR(inode->i_mode) && | |
306 | !afs_dir_check_page(inode, page)) | |
307 | ret = -EIO; | |
308 | ||
1da177e4 | 309 | if (ret < 0) { |
08e0e7c8 | 310 | if (ret == -ENOENT) { |
1da177e4 LT |
311 | _debug("got NOENT from server" |
312 | " - marking file deleted and stale"); | |
08e0e7c8 | 313 | set_bit(AFS_VNODE_DELETED, &vnode->flags); |
1da177e4 LT |
314 | ret = -ESTALE; |
315 | } | |
9b3f26c9 DH |
316 | |
317 | #ifdef CONFIG_AFS_FSCACHE | |
318 | fscache_uncache_page(vnode->cache, page); | |
1da177e4 | 319 | #endif |
9b3f26c9 | 320 | BUG_ON(PageFsCache(page)); |
68ae849d DH |
321 | |
322 | if (ret == -EINTR || | |
323 | ret == -ENOMEM || | |
324 | ret == -ERESTARTSYS || | |
325 | ret == -EAGAIN) | |
326 | goto error; | |
327 | goto io_error; | |
1da177e4 LT |
328 | } |
329 | ||
330 | SetPageUptodate(page); | |
331 | ||
9b3f26c9 DH |
332 | /* send the page to the cache */ |
333 | #ifdef CONFIG_AFS_FSCACHE | |
334 | if (PageFsCache(page) && | |
335 | fscache_write_page(vnode->cache, page, GFP_KERNEL) != 0) { | |
336 | fscache_uncache_page(vnode->cache, page); | |
337 | BUG_ON(PageFsCache(page)); | |
1da177e4 | 338 | } |
1da177e4 | 339 | #endif |
9b3f26c9 | 340 | unlock_page(page); |
1da177e4 LT |
341 | } |
342 | ||
343 | _leave(" = 0"); | |
344 | return 0; | |
345 | ||
68ae849d DH |
346 | io_error: |
347 | SetPageError(page); | |
348 | goto error; | |
196ee9cd DH |
349 | enomem: |
350 | ret = -ENOMEM; | |
08e0e7c8 | 351 | error: |
1da177e4 | 352 | unlock_page(page); |
1da177e4 LT |
353 | _leave(" = %d", ret); |
354 | return ret; | |
ec26815a | 355 | } |
1da177e4 | 356 | |
f6d335c0 AV |
357 | /* |
358 | * read page from file, directory or symlink, given a file to nominate the key | |
359 | * to be used | |
360 | */ | |
361 | static int afs_readpage(struct file *file, struct page *page) | |
362 | { | |
363 | struct key *key; | |
364 | int ret; | |
365 | ||
366 | if (file) { | |
215804a9 | 367 | key = afs_file_key(file); |
f6d335c0 AV |
368 | ASSERT(key != NULL); |
369 | ret = afs_page_filler(key, page); | |
370 | } else { | |
371 | struct inode *inode = page->mapping->host; | |
d2ddc776 | 372 | key = afs_request_key(AFS_FS_S(inode->i_sb)->cell); |
f6d335c0 AV |
373 | if (IS_ERR(key)) { |
374 | ret = PTR_ERR(key); | |
375 | } else { | |
376 | ret = afs_page_filler(key, page); | |
377 | key_put(key); | |
378 | } | |
379 | } | |
380 | return ret; | |
381 | } | |
382 | ||
91b467e0 DH |
383 | /* |
384 | * Make pages available as they're filled. | |
385 | */ | |
386 | static void afs_readpages_page_done(struct afs_call *call, struct afs_read *req) | |
387 | { | |
51c89e6a | 388 | #ifdef CONFIG_AFS_FSCACHE |
97e3043a | 389 | struct afs_vnode *vnode = call->reply[0]; |
51c89e6a | 390 | #endif |
91b467e0 DH |
391 | struct page *page = req->pages[req->index]; |
392 | ||
393 | req->pages[req->index] = NULL; | |
394 | SetPageUptodate(page); | |
395 | ||
396 | /* send the page to the cache */ | |
397 | #ifdef CONFIG_AFS_FSCACHE | |
398 | if (PageFsCache(page) && | |
399 | fscache_write_page(vnode->cache, page, GFP_KERNEL) != 0) { | |
400 | fscache_uncache_page(vnode->cache, page); | |
401 | BUG_ON(PageFsCache(page)); | |
402 | } | |
403 | #endif | |
404 | unlock_page(page); | |
405 | put_page(page); | |
406 | } | |
407 | ||
408 | /* | |
409 | * Read a contiguous set of pages. | |
410 | */ | |
411 | static int afs_readpages_one(struct file *file, struct address_space *mapping, | |
412 | struct list_head *pages) | |
413 | { | |
414 | struct afs_vnode *vnode = AFS_FS_I(mapping->host); | |
415 | struct afs_read *req; | |
416 | struct list_head *p; | |
417 | struct page *first, *page; | |
215804a9 | 418 | struct key *key = afs_file_key(file); |
91b467e0 DH |
419 | pgoff_t index; |
420 | int ret, n, i; | |
421 | ||
422 | /* Count the number of contiguous pages at the front of the list. Note | |
423 | * that the list goes prev-wards rather than next-wards. | |
424 | */ | |
425 | first = list_entry(pages->prev, struct page, lru); | |
426 | index = first->index + 1; | |
427 | n = 1; | |
428 | for (p = first->lru.prev; p != pages; p = p->prev) { | |
429 | page = list_entry(p, struct page, lru); | |
430 | if (page->index != index) | |
431 | break; | |
432 | index++; | |
433 | n++; | |
434 | } | |
435 | ||
436 | req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *) * n, | |
437 | GFP_NOFS); | |
438 | if (!req) | |
439 | return -ENOMEM; | |
440 | ||
441 | atomic_set(&req->usage, 1); | |
442 | req->page_done = afs_readpages_page_done; | |
443 | req->pos = first->index; | |
444 | req->pos <<= PAGE_SHIFT; | |
445 | ||
446 | /* Transfer the pages to the request. We add them in until one fails | |
447 | * to add to the LRU and then we stop (as that'll make a hole in the | |
448 | * contiguous run. | |
449 | * | |
450 | * Note that it's possible for the file size to change whilst we're | |
451 | * doing this, but we rely on the server returning less than we asked | |
452 | * for if the file shrank. We also rely on this to deal with a partial | |
453 | * page at the end of the file. | |
454 | */ | |
455 | do { | |
456 | page = list_entry(pages->prev, struct page, lru); | |
457 | list_del(&page->lru); | |
458 | index = page->index; | |
459 | if (add_to_page_cache_lru(page, mapping, index, | |
460 | readahead_gfp_mask(mapping))) { | |
461 | #ifdef CONFIG_AFS_FSCACHE | |
462 | fscache_uncache_page(vnode->cache, page); | |
463 | #endif | |
464 | put_page(page); | |
465 | break; | |
466 | } | |
467 | ||
468 | req->pages[req->nr_pages++] = page; | |
469 | req->len += PAGE_SIZE; | |
470 | } while (req->nr_pages < n); | |
471 | ||
472 | if (req->nr_pages == 0) { | |
473 | kfree(req); | |
474 | return 0; | |
475 | } | |
476 | ||
d2ddc776 | 477 | ret = afs_fetch_data(vnode, key, req); |
91b467e0 DH |
478 | if (ret < 0) |
479 | goto error; | |
480 | ||
481 | task_io_account_read(PAGE_SIZE * req->nr_pages); | |
482 | afs_put_read(req); | |
483 | return 0; | |
484 | ||
485 | error: | |
486 | if (ret == -ENOENT) { | |
487 | _debug("got NOENT from server" | |
488 | " - marking file deleted and stale"); | |
489 | set_bit(AFS_VNODE_DELETED, &vnode->flags); | |
490 | ret = -ESTALE; | |
491 | } | |
492 | ||
493 | for (i = 0; i < req->nr_pages; i++) { | |
494 | page = req->pages[i]; | |
495 | if (page) { | |
496 | #ifdef CONFIG_AFS_FSCACHE | |
497 | fscache_uncache_page(vnode->cache, page); | |
498 | #endif | |
499 | SetPageError(page); | |
500 | unlock_page(page); | |
501 | } | |
502 | } | |
503 | ||
504 | afs_put_read(req); | |
505 | return ret; | |
506 | } | |
507 | ||
1da177e4 | 508 | /* |
9b3f26c9 | 509 | * read a set of pages |
1da177e4 | 510 | */ |
9b3f26c9 DH |
511 | static int afs_readpages(struct file *file, struct address_space *mapping, |
512 | struct list_head *pages, unsigned nr_pages) | |
1da177e4 | 513 | { |
215804a9 | 514 | struct key *key = afs_file_key(file); |
9b3f26c9 DH |
515 | struct afs_vnode *vnode; |
516 | int ret = 0; | |
1da177e4 | 517 | |
f6d335c0 AV |
518 | _enter("{%d},{%lu},,%d", |
519 | key_serial(key), mapping->host->i_ino, nr_pages); | |
520 | ||
521 | ASSERT(key != NULL); | |
1da177e4 | 522 | |
9b3f26c9 | 523 | vnode = AFS_FS_I(mapping->host); |
ad2a8e60 | 524 | if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) { |
9b3f26c9 DH |
525 | _leave(" = -ESTALE"); |
526 | return -ESTALE; | |
527 | } | |
1da177e4 | 528 | |
9b3f26c9 DH |
529 | /* attempt to read as many of the pages as possible */ |
530 | #ifdef CONFIG_AFS_FSCACHE | |
531 | ret = fscache_read_or_alloc_pages(vnode->cache, | |
532 | mapping, | |
533 | pages, | |
534 | &nr_pages, | |
535 | afs_file_readpage_read_complete, | |
536 | NULL, | |
537 | mapping_gfp_mask(mapping)); | |
538 | #else | |
539 | ret = -ENOBUFS; | |
540 | #endif | |
541 | ||
542 | switch (ret) { | |
543 | /* all pages are being read from the cache */ | |
544 | case 0: | |
545 | BUG_ON(!list_empty(pages)); | |
546 | BUG_ON(nr_pages != 0); | |
547 | _leave(" = 0 [reading all]"); | |
548 | return 0; | |
549 | ||
550 | /* there were pages that couldn't be read from the cache */ | |
551 | case -ENODATA: | |
552 | case -ENOBUFS: | |
553 | break; | |
554 | ||
555 | /* other error */ | |
556 | default: | |
557 | _leave(" = %d", ret); | |
558 | return ret; | |
1da177e4 LT |
559 | } |
560 | ||
91b467e0 DH |
561 | while (!list_empty(pages)) { |
562 | ret = afs_readpages_one(file, mapping, pages); | |
563 | if (ret < 0) | |
564 | break; | |
565 | } | |
9b3f26c9 DH |
566 | |
567 | _leave(" = %d [netting]", ret); | |
568 | return ret; | |
ec26815a | 569 | } |
1da177e4 | 570 | |
1da177e4 | 571 | /* |
9b3f26c9 DH |
572 | * invalidate part or all of a page |
573 | * - release a page and clean up its private data if offset is 0 (indicating | |
574 | * the entire page) | |
575 | */ | |
d47992f8 LC |
576 | static void afs_invalidatepage(struct page *page, unsigned int offset, |
577 | unsigned int length) | |
9b3f26c9 | 578 | { |
d47992f8 | 579 | _enter("{%lu},%u,%u", page->index, offset, length); |
9b3f26c9 DH |
580 | |
581 | BUG_ON(!PageLocked(page)); | |
582 | ||
583 | /* we clean up only if the entire page is being invalidated */ | |
09cbfeaf | 584 | if (offset == 0 && length == PAGE_SIZE) { |
9b3f26c9 DH |
585 | #ifdef CONFIG_AFS_FSCACHE |
586 | if (PageFsCache(page)) { | |
587 | struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); | |
588 | fscache_wait_on_page_write(vnode->cache, page); | |
589 | fscache_uncache_page(vnode->cache, page); | |
9b3f26c9 DH |
590 | } |
591 | #endif | |
592 | ||
593 | if (PagePrivate(page)) { | |
4343d008 DH |
594 | set_page_private(page, 0); |
595 | ClearPagePrivate(page); | |
9b3f26c9 DH |
596 | } |
597 | } | |
598 | ||
599 | _leave(""); | |
600 | } | |
601 | ||
602 | /* | |
603 | * release a page and clean up its private state if it's not busy | |
604 | * - return true if the page can now be released, false if not | |
1da177e4 | 605 | */ |
416351f2 | 606 | static int afs_releasepage(struct page *page, gfp_t gfp_flags) |
1da177e4 | 607 | { |
416351f2 | 608 | struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); |
1da177e4 | 609 | |
416351f2 DH |
610 | _enter("{{%x:%u}[%lu],%lx},%x", |
611 | vnode->fid.vid, vnode->fid.vnode, page->index, page->flags, | |
612 | gfp_flags); | |
1da177e4 | 613 | |
9b3f26c9 DH |
614 | /* deny if page is being written to the cache and the caller hasn't |
615 | * elected to wait */ | |
616 | #ifdef CONFIG_AFS_FSCACHE | |
201a1542 DH |
617 | if (!fscache_maybe_release_page(vnode->cache, page, gfp_flags)) { |
618 | _leave(" = F [cache busy]"); | |
619 | return 0; | |
9b3f26c9 DH |
620 | } |
621 | #endif | |
622 | ||
1da177e4 | 623 | if (PagePrivate(page)) { |
4343d008 | 624 | set_page_private(page, 0); |
1da177e4 | 625 | ClearPagePrivate(page); |
1da177e4 LT |
626 | } |
627 | ||
9b3f26c9 DH |
628 | /* indicate that the page can be released */ |
629 | _leave(" = T"); | |
630 | return 1; | |
ec26815a | 631 | } |