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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> |
f86196ea | 20 | #include <linux/mm.h> |
1da177e4 LT |
21 | #include "internal.h" |
22 | ||
1cf7a151 | 23 | static int afs_file_mmap(struct file *file, struct vm_area_struct *vma); |
416351f2 | 24 | static int afs_readpage(struct file *file, struct page *page); |
d47992f8 LC |
25 | static void afs_invalidatepage(struct page *page, unsigned int offset, |
26 | unsigned int length); | |
416351f2 | 27 | static int afs_releasepage(struct page *page, gfp_t gfp_flags); |
1da177e4 | 28 | |
9b3f26c9 DH |
29 | static int afs_readpages(struct file *filp, struct address_space *mapping, |
30 | struct list_head *pages, unsigned nr_pages); | |
31 | ||
00d3b7a4 DH |
32 | const struct file_operations afs_file_operations = { |
33 | .open = afs_open, | |
34 | .release = afs_release, | |
35 | .llseek = generic_file_llseek, | |
aad4f8bb | 36 | .read_iter = generic_file_read_iter, |
50b5551d | 37 | .write_iter = afs_file_write, |
1cf7a151 | 38 | .mmap = afs_file_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 | ||
1cf7a151 DH |
65 | static const struct vm_operations_struct afs_vm_ops = { |
66 | .fault = filemap_fault, | |
67 | .map_pages = filemap_map_pages, | |
68 | .page_mkwrite = afs_page_mkwrite, | |
69 | }; | |
70 | ||
4343d008 DH |
71 | /* |
72 | * Discard a pin on a writeback key. | |
73 | */ | |
74 | void afs_put_wb_key(struct afs_wb_key *wbk) | |
75 | { | |
76 | if (refcount_dec_and_test(&wbk->usage)) { | |
77 | key_put(wbk->key); | |
78 | kfree(wbk); | |
79 | } | |
80 | } | |
81 | ||
82 | /* | |
83 | * Cache key for writeback. | |
84 | */ | |
85 | int afs_cache_wb_key(struct afs_vnode *vnode, struct afs_file *af) | |
86 | { | |
87 | struct afs_wb_key *wbk, *p; | |
88 | ||
89 | wbk = kzalloc(sizeof(struct afs_wb_key), GFP_KERNEL); | |
90 | if (!wbk) | |
91 | return -ENOMEM; | |
92 | refcount_set(&wbk->usage, 2); | |
93 | wbk->key = af->key; | |
94 | ||
95 | spin_lock(&vnode->wb_lock); | |
96 | list_for_each_entry(p, &vnode->wb_keys, vnode_link) { | |
97 | if (p->key == wbk->key) | |
98 | goto found; | |
99 | } | |
100 | ||
101 | key_get(wbk->key); | |
102 | list_add_tail(&wbk->vnode_link, &vnode->wb_keys); | |
103 | spin_unlock(&vnode->wb_lock); | |
104 | af->wb = wbk; | |
105 | return 0; | |
106 | ||
107 | found: | |
108 | refcount_inc(&p->usage); | |
109 | spin_unlock(&vnode->wb_lock); | |
110 | af->wb = p; | |
111 | kfree(wbk); | |
112 | return 0; | |
113 | } | |
114 | ||
00d3b7a4 DH |
115 | /* |
116 | * open an AFS file or directory and attach a key to it | |
117 | */ | |
118 | int afs_open(struct inode *inode, struct file *file) | |
119 | { | |
120 | struct afs_vnode *vnode = AFS_FS_I(inode); | |
215804a9 | 121 | struct afs_file *af; |
00d3b7a4 | 122 | struct key *key; |
260a9803 | 123 | int ret; |
00d3b7a4 | 124 | |
3b6492df | 125 | _enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode); |
00d3b7a4 DH |
126 | |
127 | key = afs_request_key(vnode->volume->cell); | |
128 | if (IS_ERR(key)) { | |
215804a9 DH |
129 | ret = PTR_ERR(key); |
130 | goto error; | |
00d3b7a4 DH |
131 | } |
132 | ||
215804a9 DH |
133 | af = kzalloc(sizeof(*af), GFP_KERNEL); |
134 | if (!af) { | |
135 | ret = -ENOMEM; | |
136 | goto error_key; | |
260a9803 | 137 | } |
4343d008 | 138 | af->key = key; |
260a9803 | 139 | |
215804a9 DH |
140 | ret = afs_validate(vnode, key); |
141 | if (ret < 0) | |
142 | goto error_af; | |
143 | ||
4343d008 DH |
144 | if (file->f_mode & FMODE_WRITE) { |
145 | ret = afs_cache_wb_key(vnode, af); | |
146 | if (ret < 0) | |
147 | goto error_af; | |
148 | } | |
5a813276 DH |
149 | |
150 | if (file->f_flags & O_TRUNC) | |
151 | set_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags); | |
4343d008 | 152 | |
215804a9 | 153 | file->private_data = af; |
00d3b7a4 DH |
154 | _leave(" = 0"); |
155 | return 0; | |
215804a9 DH |
156 | |
157 | error_af: | |
158 | kfree(af); | |
159 | error_key: | |
160 | key_put(key); | |
161 | error: | |
162 | _leave(" = %d", ret); | |
163 | return ret; | |
00d3b7a4 DH |
164 | } |
165 | ||
166 | /* | |
167 | * release an AFS file or directory and discard its key | |
168 | */ | |
169 | int afs_release(struct inode *inode, struct file *file) | |
170 | { | |
171 | struct afs_vnode *vnode = AFS_FS_I(inode); | |
215804a9 | 172 | struct afs_file *af = file->private_data; |
00d3b7a4 | 173 | |
3b6492df | 174 | _enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode); |
00d3b7a4 | 175 | |
5a813276 DH |
176 | if ((file->f_mode & FMODE_WRITE)) |
177 | return vfs_fsync(file, 0); | |
178 | ||
215804a9 | 179 | file->private_data = NULL; |
4343d008 DH |
180 | if (af->wb) |
181 | afs_put_wb_key(af->wb); | |
215804a9 DH |
182 | key_put(af->key); |
183 | kfree(af); | |
4343d008 | 184 | afs_prune_wb_keys(vnode); |
00d3b7a4 DH |
185 | _leave(" = 0"); |
186 | return 0; | |
187 | } | |
188 | ||
196ee9cd DH |
189 | /* |
190 | * Dispose of a ref to a read record. | |
191 | */ | |
192 | void afs_put_read(struct afs_read *req) | |
193 | { | |
194 | int i; | |
195 | ||
f3ddee8d | 196 | if (refcount_dec_and_test(&req->usage)) { |
196ee9cd DH |
197 | for (i = 0; i < req->nr_pages; i++) |
198 | if (req->pages[i]) | |
199 | put_page(req->pages[i]); | |
f3ddee8d DH |
200 | if (req->pages != req->array) |
201 | kfree(req->pages); | |
196ee9cd DH |
202 | kfree(req); |
203 | } | |
204 | } | |
205 | ||
6566abdb | 206 | #ifdef CONFIG_AFS_FSCACHE |
1da177e4 LT |
207 | /* |
208 | * deal with notification that a page was read from the cache | |
209 | */ | |
9b3f26c9 DH |
210 | static void afs_file_readpage_read_complete(struct page *page, |
211 | void *data, | |
212 | int error) | |
1da177e4 | 213 | { |
9b3f26c9 | 214 | _enter("%p,%p,%d", page, data, error); |
1da177e4 | 215 | |
9b3f26c9 DH |
216 | /* if the read completes with an error, we just unlock the page and let |
217 | * the VM reissue the readpage */ | |
218 | if (!error) | |
1da177e4 LT |
219 | SetPageUptodate(page); |
220 | unlock_page(page); | |
ec26815a | 221 | } |
6566abdb | 222 | #endif |
1da177e4 | 223 | |
d2ddc776 DH |
224 | /* |
225 | * Fetch file data from the volume. | |
226 | */ | |
227 | int afs_fetch_data(struct afs_vnode *vnode, struct key *key, struct afs_read *desc) | |
228 | { | |
229 | struct afs_fs_cursor fc; | |
230 | int ret; | |
231 | ||
3b6492df | 232 | _enter("%s{%llx:%llu.%u},%x,,,", |
d2ddc776 DH |
233 | vnode->volume->name, |
234 | vnode->fid.vid, | |
235 | vnode->fid.vnode, | |
236 | vnode->fid.unique, | |
237 | key_serial(key)); | |
238 | ||
239 | ret = -ERESTARTSYS; | |
240 | if (afs_begin_vnode_operation(&fc, vnode, key)) { | |
241 | while (afs_select_fileserver(&fc)) { | |
68251f0a | 242 | fc.cb_break = afs_calc_vnode_cb_break(vnode); |
d2ddc776 DH |
243 | afs_fs_fetch_data(&fc, desc); |
244 | } | |
245 | ||
246 | afs_check_for_remote_deletion(&fc, fc.vnode); | |
247 | afs_vnode_commit_status(&fc, vnode, fc.cb_break); | |
248 | ret = afs_end_vnode_operation(&fc); | |
249 | } | |
250 | ||
76a5cb6f DH |
251 | if (ret == 0) { |
252 | afs_stat_v(vnode, n_fetches); | |
253 | atomic_long_add(desc->actual_len, | |
254 | &afs_v2net(vnode)->n_fetch_bytes); | |
255 | } | |
256 | ||
d2ddc776 DH |
257 | _leave(" = %d", ret); |
258 | return ret; | |
259 | } | |
260 | ||
1da177e4 | 261 | /* |
f6d335c0 | 262 | * read page from file, directory or symlink, given a key to use |
1da177e4 | 263 | */ |
f6d335c0 | 264 | int afs_page_filler(void *data, struct page *page) |
1da177e4 | 265 | { |
f6d335c0 AV |
266 | struct inode *inode = page->mapping->host; |
267 | struct afs_vnode *vnode = AFS_FS_I(inode); | |
196ee9cd | 268 | struct afs_read *req; |
f6d335c0 | 269 | struct key *key = data; |
1da177e4 LT |
270 | int ret; |
271 | ||
00d3b7a4 | 272 | _enter("{%x},{%lu},{%lu}", key_serial(key), inode->i_ino, page->index); |
1da177e4 | 273 | |
cd7619d6 | 274 | BUG_ON(!PageLocked(page)); |
1da177e4 LT |
275 | |
276 | ret = -ESTALE; | |
08e0e7c8 | 277 | if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) |
1da177e4 LT |
278 | goto error; |
279 | ||
1da177e4 | 280 | /* is it cached? */ |
9b3f26c9 DH |
281 | #ifdef CONFIG_AFS_FSCACHE |
282 | ret = fscache_read_or_alloc_page(vnode->cache, | |
1da177e4 LT |
283 | page, |
284 | afs_file_readpage_read_complete, | |
285 | NULL, | |
286 | GFP_KERNEL); | |
287 | #else | |
288 | ret = -ENOBUFS; | |
289 | #endif | |
1da177e4 | 290 | switch (ret) { |
1da177e4 LT |
291 | /* read BIO submitted (page in cache) */ |
292 | case 0: | |
293 | break; | |
294 | ||
9b3f26c9 | 295 | /* page not yet cached */ |
1da177e4 | 296 | case -ENODATA: |
9b3f26c9 DH |
297 | _debug("cache said ENODATA"); |
298 | goto go_on; | |
299 | ||
300 | /* page will not be cached */ | |
301 | case -ENOBUFS: | |
302 | _debug("cache said ENOBUFS"); | |
1da177e4 | 303 | default: |
9b3f26c9 | 304 | go_on: |
196ee9cd DH |
305 | req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *), |
306 | GFP_KERNEL); | |
307 | if (!req) | |
308 | goto enomem; | |
309 | ||
6db3ac3c DH |
310 | /* We request a full page. If the page is a partial one at the |
311 | * end of the file, the server will return a short read and the | |
312 | * unmarshalling code will clear the unfilled space. | |
313 | */ | |
f3ddee8d | 314 | refcount_set(&req->usage, 1); |
196ee9cd | 315 | req->pos = (loff_t)page->index << PAGE_SHIFT; |
6db3ac3c | 316 | req->len = PAGE_SIZE; |
196ee9cd | 317 | req->nr_pages = 1; |
f3ddee8d | 318 | req->pages = req->array; |
196ee9cd DH |
319 | req->pages[0] = page; |
320 | get_page(page); | |
1da177e4 LT |
321 | |
322 | /* read the contents of the file from the server into the | |
323 | * page */ | |
d2ddc776 | 324 | ret = afs_fetch_data(vnode, key, req); |
196ee9cd | 325 | afs_put_read(req); |
dab17c1a | 326 | |
1da177e4 | 327 | if (ret < 0) { |
08e0e7c8 | 328 | if (ret == -ENOENT) { |
1da177e4 LT |
329 | _debug("got NOENT from server" |
330 | " - marking file deleted and stale"); | |
08e0e7c8 | 331 | set_bit(AFS_VNODE_DELETED, &vnode->flags); |
1da177e4 LT |
332 | ret = -ESTALE; |
333 | } | |
9b3f26c9 DH |
334 | |
335 | #ifdef CONFIG_AFS_FSCACHE | |
336 | fscache_uncache_page(vnode->cache, page); | |
1da177e4 | 337 | #endif |
9b3f26c9 | 338 | BUG_ON(PageFsCache(page)); |
68ae849d DH |
339 | |
340 | if (ret == -EINTR || | |
341 | ret == -ENOMEM || | |
342 | ret == -ERESTARTSYS || | |
343 | ret == -EAGAIN) | |
344 | goto error; | |
345 | goto io_error; | |
1da177e4 LT |
346 | } |
347 | ||
348 | SetPageUptodate(page); | |
349 | ||
9b3f26c9 DH |
350 | /* send the page to the cache */ |
351 | #ifdef CONFIG_AFS_FSCACHE | |
352 | if (PageFsCache(page) && | |
ee1235a9 DH |
353 | fscache_write_page(vnode->cache, page, vnode->status.size, |
354 | GFP_KERNEL) != 0) { | |
9b3f26c9 DH |
355 | fscache_uncache_page(vnode->cache, page); |
356 | BUG_ON(PageFsCache(page)); | |
1da177e4 | 357 | } |
1da177e4 | 358 | #endif |
9b3f26c9 | 359 | unlock_page(page); |
1da177e4 LT |
360 | } |
361 | ||
362 | _leave(" = 0"); | |
363 | return 0; | |
364 | ||
68ae849d DH |
365 | io_error: |
366 | SetPageError(page); | |
367 | goto error; | |
196ee9cd DH |
368 | enomem: |
369 | ret = -ENOMEM; | |
08e0e7c8 | 370 | error: |
1da177e4 | 371 | unlock_page(page); |
1da177e4 LT |
372 | _leave(" = %d", ret); |
373 | return ret; | |
ec26815a | 374 | } |
1da177e4 | 375 | |
f6d335c0 AV |
376 | /* |
377 | * read page from file, directory or symlink, given a file to nominate the key | |
378 | * to be used | |
379 | */ | |
380 | static int afs_readpage(struct file *file, struct page *page) | |
381 | { | |
382 | struct key *key; | |
383 | int ret; | |
384 | ||
385 | if (file) { | |
215804a9 | 386 | key = afs_file_key(file); |
f6d335c0 AV |
387 | ASSERT(key != NULL); |
388 | ret = afs_page_filler(key, page); | |
389 | } else { | |
390 | struct inode *inode = page->mapping->host; | |
d2ddc776 | 391 | key = afs_request_key(AFS_FS_S(inode->i_sb)->cell); |
f6d335c0 AV |
392 | if (IS_ERR(key)) { |
393 | ret = PTR_ERR(key); | |
394 | } else { | |
395 | ret = afs_page_filler(key, page); | |
396 | key_put(key); | |
397 | } | |
398 | } | |
399 | return ret; | |
400 | } | |
401 | ||
91b467e0 DH |
402 | /* |
403 | * Make pages available as they're filled. | |
404 | */ | |
405 | static void afs_readpages_page_done(struct afs_call *call, struct afs_read *req) | |
406 | { | |
51c89e6a | 407 | #ifdef CONFIG_AFS_FSCACHE |
97e3043a | 408 | struct afs_vnode *vnode = call->reply[0]; |
51c89e6a | 409 | #endif |
91b467e0 DH |
410 | struct page *page = req->pages[req->index]; |
411 | ||
412 | req->pages[req->index] = NULL; | |
413 | SetPageUptodate(page); | |
414 | ||
415 | /* send the page to the cache */ | |
416 | #ifdef CONFIG_AFS_FSCACHE | |
417 | if (PageFsCache(page) && | |
ee1235a9 DH |
418 | fscache_write_page(vnode->cache, page, vnode->status.size, |
419 | GFP_KERNEL) != 0) { | |
91b467e0 DH |
420 | fscache_uncache_page(vnode->cache, page); |
421 | BUG_ON(PageFsCache(page)); | |
422 | } | |
423 | #endif | |
424 | unlock_page(page); | |
425 | put_page(page); | |
426 | } | |
427 | ||
428 | /* | |
429 | * Read a contiguous set of pages. | |
430 | */ | |
431 | static int afs_readpages_one(struct file *file, struct address_space *mapping, | |
432 | struct list_head *pages) | |
433 | { | |
434 | struct afs_vnode *vnode = AFS_FS_I(mapping->host); | |
435 | struct afs_read *req; | |
436 | struct list_head *p; | |
437 | struct page *first, *page; | |
215804a9 | 438 | struct key *key = afs_file_key(file); |
91b467e0 DH |
439 | pgoff_t index; |
440 | int ret, n, i; | |
441 | ||
442 | /* Count the number of contiguous pages at the front of the list. Note | |
443 | * that the list goes prev-wards rather than next-wards. | |
444 | */ | |
f86196ea | 445 | first = lru_to_page(pages); |
91b467e0 DH |
446 | index = first->index + 1; |
447 | n = 1; | |
448 | for (p = first->lru.prev; p != pages; p = p->prev) { | |
449 | page = list_entry(p, struct page, lru); | |
450 | if (page->index != index) | |
451 | break; | |
452 | index++; | |
453 | n++; | |
454 | } | |
455 | ||
456 | req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *) * n, | |
457 | GFP_NOFS); | |
458 | if (!req) | |
459 | return -ENOMEM; | |
460 | ||
f3ddee8d | 461 | refcount_set(&req->usage, 1); |
91b467e0 DH |
462 | req->page_done = afs_readpages_page_done; |
463 | req->pos = first->index; | |
464 | req->pos <<= PAGE_SHIFT; | |
f3ddee8d | 465 | req->pages = req->array; |
91b467e0 DH |
466 | |
467 | /* Transfer the pages to the request. We add them in until one fails | |
468 | * to add to the LRU and then we stop (as that'll make a hole in the | |
469 | * contiguous run. | |
470 | * | |
471 | * Note that it's possible for the file size to change whilst we're | |
472 | * doing this, but we rely on the server returning less than we asked | |
473 | * for if the file shrank. We also rely on this to deal with a partial | |
474 | * page at the end of the file. | |
475 | */ | |
476 | do { | |
f86196ea | 477 | page = lru_to_page(pages); |
91b467e0 DH |
478 | list_del(&page->lru); |
479 | index = page->index; | |
480 | if (add_to_page_cache_lru(page, mapping, index, | |
481 | readahead_gfp_mask(mapping))) { | |
482 | #ifdef CONFIG_AFS_FSCACHE | |
483 | fscache_uncache_page(vnode->cache, page); | |
484 | #endif | |
485 | put_page(page); | |
486 | break; | |
487 | } | |
488 | ||
489 | req->pages[req->nr_pages++] = page; | |
490 | req->len += PAGE_SIZE; | |
491 | } while (req->nr_pages < n); | |
492 | ||
493 | if (req->nr_pages == 0) { | |
494 | kfree(req); | |
495 | return 0; | |
496 | } | |
497 | ||
d2ddc776 | 498 | ret = afs_fetch_data(vnode, key, req); |
91b467e0 DH |
499 | if (ret < 0) |
500 | goto error; | |
501 | ||
502 | task_io_account_read(PAGE_SIZE * req->nr_pages); | |
503 | afs_put_read(req); | |
504 | return 0; | |
505 | ||
506 | error: | |
507 | if (ret == -ENOENT) { | |
508 | _debug("got NOENT from server" | |
509 | " - marking file deleted and stale"); | |
510 | set_bit(AFS_VNODE_DELETED, &vnode->flags); | |
511 | ret = -ESTALE; | |
512 | } | |
513 | ||
514 | for (i = 0; i < req->nr_pages; i++) { | |
515 | page = req->pages[i]; | |
516 | if (page) { | |
517 | #ifdef CONFIG_AFS_FSCACHE | |
518 | fscache_uncache_page(vnode->cache, page); | |
519 | #endif | |
520 | SetPageError(page); | |
521 | unlock_page(page); | |
522 | } | |
523 | } | |
524 | ||
525 | afs_put_read(req); | |
526 | return ret; | |
527 | } | |
528 | ||
1da177e4 | 529 | /* |
9b3f26c9 | 530 | * read a set of pages |
1da177e4 | 531 | */ |
9b3f26c9 DH |
532 | static int afs_readpages(struct file *file, struct address_space *mapping, |
533 | struct list_head *pages, unsigned nr_pages) | |
1da177e4 | 534 | { |
215804a9 | 535 | struct key *key = afs_file_key(file); |
9b3f26c9 DH |
536 | struct afs_vnode *vnode; |
537 | int ret = 0; | |
1da177e4 | 538 | |
f6d335c0 AV |
539 | _enter("{%d},{%lu},,%d", |
540 | key_serial(key), mapping->host->i_ino, nr_pages); | |
541 | ||
542 | ASSERT(key != NULL); | |
1da177e4 | 543 | |
9b3f26c9 | 544 | vnode = AFS_FS_I(mapping->host); |
ad2a8e60 | 545 | if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) { |
9b3f26c9 DH |
546 | _leave(" = -ESTALE"); |
547 | return -ESTALE; | |
548 | } | |
1da177e4 | 549 | |
9b3f26c9 DH |
550 | /* attempt to read as many of the pages as possible */ |
551 | #ifdef CONFIG_AFS_FSCACHE | |
552 | ret = fscache_read_or_alloc_pages(vnode->cache, | |
553 | mapping, | |
554 | pages, | |
555 | &nr_pages, | |
556 | afs_file_readpage_read_complete, | |
557 | NULL, | |
558 | mapping_gfp_mask(mapping)); | |
559 | #else | |
560 | ret = -ENOBUFS; | |
561 | #endif | |
562 | ||
563 | switch (ret) { | |
564 | /* all pages are being read from the cache */ | |
565 | case 0: | |
566 | BUG_ON(!list_empty(pages)); | |
567 | BUG_ON(nr_pages != 0); | |
568 | _leave(" = 0 [reading all]"); | |
569 | return 0; | |
570 | ||
571 | /* there were pages that couldn't be read from the cache */ | |
572 | case -ENODATA: | |
573 | case -ENOBUFS: | |
574 | break; | |
575 | ||
576 | /* other error */ | |
577 | default: | |
578 | _leave(" = %d", ret); | |
579 | return ret; | |
1da177e4 LT |
580 | } |
581 | ||
91b467e0 DH |
582 | while (!list_empty(pages)) { |
583 | ret = afs_readpages_one(file, mapping, pages); | |
584 | if (ret < 0) | |
585 | break; | |
586 | } | |
9b3f26c9 DH |
587 | |
588 | _leave(" = %d [netting]", ret); | |
589 | return ret; | |
ec26815a | 590 | } |
1da177e4 | 591 | |
1da177e4 | 592 | /* |
9b3f26c9 DH |
593 | * invalidate part or all of a page |
594 | * - release a page and clean up its private data if offset is 0 (indicating | |
595 | * the entire page) | |
596 | */ | |
d47992f8 LC |
597 | static void afs_invalidatepage(struct page *page, unsigned int offset, |
598 | unsigned int length) | |
9b3f26c9 | 599 | { |
13524ab3 DH |
600 | struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); |
601 | unsigned long priv; | |
602 | ||
d47992f8 | 603 | _enter("{%lu},%u,%u", page->index, offset, length); |
9b3f26c9 DH |
604 | |
605 | BUG_ON(!PageLocked(page)); | |
606 | ||
607 | /* we clean up only if the entire page is being invalidated */ | |
09cbfeaf | 608 | if (offset == 0 && length == PAGE_SIZE) { |
9b3f26c9 DH |
609 | #ifdef CONFIG_AFS_FSCACHE |
610 | if (PageFsCache(page)) { | |
611 | struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); | |
612 | fscache_wait_on_page_write(vnode->cache, page); | |
613 | fscache_uncache_page(vnode->cache, page); | |
9b3f26c9 DH |
614 | } |
615 | #endif | |
616 | ||
617 | if (PagePrivate(page)) { | |
13524ab3 DH |
618 | priv = page_private(page); |
619 | trace_afs_page_dirty(vnode, tracepoint_string("inval"), | |
620 | page->index, priv); | |
4343d008 DH |
621 | set_page_private(page, 0); |
622 | ClearPagePrivate(page); | |
9b3f26c9 DH |
623 | } |
624 | } | |
625 | ||
626 | _leave(""); | |
627 | } | |
628 | ||
629 | /* | |
630 | * release a page and clean up its private state if it's not busy | |
631 | * - return true if the page can now be released, false if not | |
1da177e4 | 632 | */ |
416351f2 | 633 | static int afs_releasepage(struct page *page, gfp_t gfp_flags) |
1da177e4 | 634 | { |
416351f2 | 635 | struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); |
13524ab3 | 636 | unsigned long priv; |
1da177e4 | 637 | |
3b6492df | 638 | _enter("{{%llx:%llu}[%lu],%lx},%x", |
416351f2 DH |
639 | vnode->fid.vid, vnode->fid.vnode, page->index, page->flags, |
640 | gfp_flags); | |
1da177e4 | 641 | |
9b3f26c9 DH |
642 | /* deny if page is being written to the cache and the caller hasn't |
643 | * elected to wait */ | |
644 | #ifdef CONFIG_AFS_FSCACHE | |
201a1542 DH |
645 | if (!fscache_maybe_release_page(vnode->cache, page, gfp_flags)) { |
646 | _leave(" = F [cache busy]"); | |
647 | return 0; | |
9b3f26c9 DH |
648 | } |
649 | #endif | |
650 | ||
1da177e4 | 651 | if (PagePrivate(page)) { |
13524ab3 DH |
652 | priv = page_private(page); |
653 | trace_afs_page_dirty(vnode, tracepoint_string("rel"), | |
654 | page->index, priv); | |
4343d008 | 655 | set_page_private(page, 0); |
1da177e4 | 656 | ClearPagePrivate(page); |
1da177e4 LT |
657 | } |
658 | ||
9b3f26c9 DH |
659 | /* indicate that the page can be released */ |
660 | _leave(" = T"); | |
661 | return 1; | |
ec26815a | 662 | } |
1cf7a151 DH |
663 | |
664 | /* | |
665 | * Handle setting up a memory mapping on an AFS file. | |
666 | */ | |
667 | static int afs_file_mmap(struct file *file, struct vm_area_struct *vma) | |
668 | { | |
669 | int ret; | |
670 | ||
671 | ret = generic_file_mmap(file, vma); | |
672 | if (ret == 0) | |
673 | vma->vm_ops = &afs_vm_ops; | |
674 | return ret; | |
675 | } |