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