Commit | Line | Data |
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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
08e0e7c8 | 2 | /* AFS filesystem file handling |
1da177e4 | 3 | * |
08e0e7c8 | 4 | * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved. |
1da177e4 | 5 | * Written by David Howells (dhowells@redhat.com) |
1da177e4 LT |
6 | */ |
7 | ||
8 | #include <linux/kernel.h> | |
9 | #include <linux/module.h> | |
10 | #include <linux/init.h> | |
1da177e4 LT |
11 | #include <linux/fs.h> |
12 | #include <linux/pagemap.h> | |
31143d5d | 13 | #include <linux/writeback.h> |
5a0e3ad6 | 14 | #include <linux/gfp.h> |
91b467e0 | 15 | #include <linux/task_io_accounting_ops.h> |
f86196ea | 16 | #include <linux/mm.h> |
1da177e4 LT |
17 | #include "internal.h" |
18 | ||
1cf7a151 | 19 | static int afs_file_mmap(struct file *file, struct vm_area_struct *vma); |
416351f2 | 20 | static int afs_readpage(struct file *file, struct page *page); |
d47992f8 LC |
21 | static void afs_invalidatepage(struct page *page, unsigned int offset, |
22 | unsigned int length); | |
416351f2 | 23 | static int afs_releasepage(struct page *page, gfp_t gfp_flags); |
1da177e4 | 24 | |
9b3f26c9 DH |
25 | static int afs_readpages(struct file *filp, struct address_space *mapping, |
26 | struct list_head *pages, unsigned nr_pages); | |
27 | ||
00d3b7a4 DH |
28 | const struct file_operations afs_file_operations = { |
29 | .open = afs_open, | |
30 | .release = afs_release, | |
31 | .llseek = generic_file_llseek, | |
aad4f8bb | 32 | .read_iter = generic_file_read_iter, |
50b5551d | 33 | .write_iter = afs_file_write, |
1cf7a151 | 34 | .mmap = afs_file_mmap, |
5ffc4ef4 | 35 | .splice_read = generic_file_splice_read, |
06a17bbe | 36 | .splice_write = iter_file_splice_write, |
31143d5d | 37 | .fsync = afs_fsync, |
e8d6c554 DH |
38 | .lock = afs_lock, |
39 | .flock = afs_flock, | |
00d3b7a4 DH |
40 | }; |
41 | ||
754661f1 | 42 | const struct inode_operations afs_file_inode_operations = { |
416351f2 | 43 | .getattr = afs_getattr, |
31143d5d | 44 | .setattr = afs_setattr, |
00d3b7a4 | 45 | .permission = afs_permission, |
1da177e4 LT |
46 | }; |
47 | ||
f5e54d6e | 48 | const struct address_space_operations afs_fs_aops = { |
416351f2 | 49 | .readpage = afs_readpage, |
9b3f26c9 | 50 | .readpages = afs_readpages, |
31143d5d DH |
51 | .set_page_dirty = afs_set_page_dirty, |
52 | .launder_page = afs_launder_page, | |
416351f2 DH |
53 | .releasepage = afs_releasepage, |
54 | .invalidatepage = afs_invalidatepage, | |
15b4650e NP |
55 | .write_begin = afs_write_begin, |
56 | .write_end = afs_write_end, | |
31143d5d DH |
57 | .writepage = afs_writepage, |
58 | .writepages = afs_writepages, | |
1da177e4 LT |
59 | }; |
60 | ||
1cf7a151 DH |
61 | static const struct vm_operations_struct afs_vm_ops = { |
62 | .fault = filemap_fault, | |
63 | .map_pages = filemap_map_pages, | |
64 | .page_mkwrite = afs_page_mkwrite, | |
65 | }; | |
66 | ||
4343d008 DH |
67 | /* |
68 | * Discard a pin on a writeback key. | |
69 | */ | |
70 | void afs_put_wb_key(struct afs_wb_key *wbk) | |
71 | { | |
e49c7b2f | 72 | if (wbk && refcount_dec_and_test(&wbk->usage)) { |
4343d008 DH |
73 | key_put(wbk->key); |
74 | kfree(wbk); | |
75 | } | |
76 | } | |
77 | ||
78 | /* | |
79 | * Cache key for writeback. | |
80 | */ | |
81 | int afs_cache_wb_key(struct afs_vnode *vnode, struct afs_file *af) | |
82 | { | |
83 | struct afs_wb_key *wbk, *p; | |
84 | ||
85 | wbk = kzalloc(sizeof(struct afs_wb_key), GFP_KERNEL); | |
86 | if (!wbk) | |
87 | return -ENOMEM; | |
88 | refcount_set(&wbk->usage, 2); | |
89 | wbk->key = af->key; | |
90 | ||
91 | spin_lock(&vnode->wb_lock); | |
92 | list_for_each_entry(p, &vnode->wb_keys, vnode_link) { | |
93 | if (p->key == wbk->key) | |
94 | goto found; | |
95 | } | |
96 | ||
97 | key_get(wbk->key); | |
98 | list_add_tail(&wbk->vnode_link, &vnode->wb_keys); | |
99 | spin_unlock(&vnode->wb_lock); | |
100 | af->wb = wbk; | |
101 | return 0; | |
102 | ||
103 | found: | |
104 | refcount_inc(&p->usage); | |
105 | spin_unlock(&vnode->wb_lock); | |
106 | af->wb = p; | |
107 | kfree(wbk); | |
108 | return 0; | |
109 | } | |
110 | ||
00d3b7a4 DH |
111 | /* |
112 | * open an AFS file or directory and attach a key to it | |
113 | */ | |
114 | int afs_open(struct inode *inode, struct file *file) | |
115 | { | |
116 | struct afs_vnode *vnode = AFS_FS_I(inode); | |
215804a9 | 117 | struct afs_file *af; |
00d3b7a4 | 118 | struct key *key; |
260a9803 | 119 | int ret; |
00d3b7a4 | 120 | |
3b6492df | 121 | _enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode); |
00d3b7a4 DH |
122 | |
123 | key = afs_request_key(vnode->volume->cell); | |
124 | if (IS_ERR(key)) { | |
215804a9 DH |
125 | ret = PTR_ERR(key); |
126 | goto error; | |
00d3b7a4 DH |
127 | } |
128 | ||
215804a9 DH |
129 | af = kzalloc(sizeof(*af), GFP_KERNEL); |
130 | if (!af) { | |
131 | ret = -ENOMEM; | |
132 | goto error_key; | |
260a9803 | 133 | } |
4343d008 | 134 | af->key = key; |
260a9803 | 135 | |
215804a9 DH |
136 | ret = afs_validate(vnode, key); |
137 | if (ret < 0) | |
138 | goto error_af; | |
139 | ||
4343d008 DH |
140 | if (file->f_mode & FMODE_WRITE) { |
141 | ret = afs_cache_wb_key(vnode, af); | |
142 | if (ret < 0) | |
143 | goto error_af; | |
144 | } | |
5a813276 DH |
145 | |
146 | if (file->f_flags & O_TRUNC) | |
147 | set_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags); | |
4343d008 | 148 | |
215804a9 | 149 | file->private_data = af; |
00d3b7a4 DH |
150 | _leave(" = 0"); |
151 | return 0; | |
215804a9 DH |
152 | |
153 | error_af: | |
154 | kfree(af); | |
155 | error_key: | |
156 | key_put(key); | |
157 | error: | |
158 | _leave(" = %d", ret); | |
159 | return ret; | |
00d3b7a4 DH |
160 | } |
161 | ||
162 | /* | |
163 | * release an AFS file or directory and discard its key | |
164 | */ | |
165 | int afs_release(struct inode *inode, struct file *file) | |
166 | { | |
167 | struct afs_vnode *vnode = AFS_FS_I(inode); | |
215804a9 | 168 | struct afs_file *af = file->private_data; |
a1b879ee | 169 | int ret = 0; |
00d3b7a4 | 170 | |
3b6492df | 171 | _enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode); |
00d3b7a4 | 172 | |
5a813276 | 173 | if ((file->f_mode & FMODE_WRITE)) |
a1b879ee | 174 | ret = vfs_fsync(file, 0); |
5a813276 | 175 | |
215804a9 | 176 | file->private_data = NULL; |
4343d008 DH |
177 | if (af->wb) |
178 | afs_put_wb_key(af->wb); | |
215804a9 DH |
179 | key_put(af->key); |
180 | kfree(af); | |
4343d008 | 181 | afs_prune_wb_keys(vnode); |
a1b879ee DH |
182 | _leave(" = %d", ret); |
183 | return ret; | |
00d3b7a4 DH |
184 | } |
185 | ||
c4508464 DH |
186 | /* |
187 | * Handle completion of a read operation. | |
188 | */ | |
189 | static void afs_file_read_done(struct afs_read *req) | |
190 | { | |
191 | struct afs_vnode *vnode = req->vnode; | |
192 | struct page *page; | |
193 | pgoff_t index = req->pos >> PAGE_SHIFT; | |
194 | pgoff_t last = index + req->nr_pages - 1; | |
195 | ||
196 | XA_STATE(xas, &vnode->vfs_inode.i_mapping->i_pages, index); | |
197 | ||
198 | if (iov_iter_count(req->iter) > 0) { | |
199 | /* The read was short - clear the excess buffer. */ | |
200 | _debug("afterclear %zx %zx %llx/%llx", | |
201 | req->iter->iov_offset, | |
202 | iov_iter_count(req->iter), | |
203 | req->actual_len, req->len); | |
204 | iov_iter_zero(iov_iter_count(req->iter), req->iter); | |
205 | } | |
206 | ||
207 | rcu_read_lock(); | |
208 | xas_for_each(&xas, page, last) { | |
209 | page_endio(page, false, 0); | |
210 | put_page(page); | |
211 | } | |
212 | rcu_read_unlock(); | |
213 | ||
214 | task_io_account_read(req->len); | |
215 | req->cleanup = NULL; | |
216 | } | |
217 | ||
218 | /* | |
219 | * Dispose of our locks and refs on the pages if the read failed. | |
220 | */ | |
221 | static void afs_file_read_cleanup(struct afs_read *req) | |
222 | { | |
223 | struct page *page; | |
224 | pgoff_t index = req->pos >> PAGE_SHIFT; | |
225 | pgoff_t last = index + req->nr_pages - 1; | |
226 | ||
227 | if (req->iter) { | |
228 | XA_STATE(xas, &req->vnode->vfs_inode.i_mapping->i_pages, index); | |
229 | ||
230 | _enter("%lu,%u,%zu", index, req->nr_pages, iov_iter_count(req->iter)); | |
231 | ||
232 | rcu_read_lock(); | |
233 | xas_for_each(&xas, page, last) { | |
234 | BUG_ON(xa_is_value(page)); | |
235 | BUG_ON(PageCompound(page)); | |
236 | ||
237 | page_endio(page, false, req->error); | |
238 | put_page(page); | |
239 | } | |
240 | rcu_read_unlock(); | |
241 | } | |
242 | } | |
243 | ||
196ee9cd DH |
244 | /* |
245 | * Dispose of a ref to a read record. | |
246 | */ | |
247 | void afs_put_read(struct afs_read *req) | |
248 | { | |
f3ddee8d | 249 | if (refcount_dec_and_test(&req->usage)) { |
c4508464 DH |
250 | if (req->cleanup) |
251 | req->cleanup(req); | |
c69bf479 | 252 | key_put(req->key); |
196ee9cd DH |
253 | kfree(req); |
254 | } | |
255 | } | |
256 | ||
e49c7b2f DH |
257 | static void afs_fetch_data_success(struct afs_operation *op) |
258 | { | |
259 | struct afs_vnode *vnode = op->file[0].vnode; | |
260 | ||
261 | _enter("op=%08x", op->debug_id); | |
e49c7b2f DH |
262 | afs_vnode_commit_status(op, &op->file[0]); |
263 | afs_stat_v(vnode, n_fetches); | |
264 | atomic_long_add(op->fetch.req->actual_len, &op->net->n_fetch_bytes); | |
265 | } | |
266 | ||
267 | static void afs_fetch_data_put(struct afs_operation *op) | |
268 | { | |
c4508464 | 269 | op->fetch.req->error = op->error; |
e49c7b2f DH |
270 | afs_put_read(op->fetch.req); |
271 | } | |
272 | ||
273 | static const struct afs_operation_ops afs_fetch_data_operation = { | |
274 | .issue_afs_rpc = afs_fs_fetch_data, | |
275 | .issue_yfs_rpc = yfs_fs_fetch_data, | |
276 | .success = afs_fetch_data_success, | |
728279a5 | 277 | .aborted = afs_check_for_remote_deletion, |
e49c7b2f DH |
278 | .put = afs_fetch_data_put, |
279 | }; | |
280 | ||
d2ddc776 DH |
281 | /* |
282 | * Fetch file data from the volume. | |
283 | */ | |
c69bf479 | 284 | int afs_fetch_data(struct afs_vnode *vnode, struct afs_read *req) |
d2ddc776 | 285 | { |
e49c7b2f | 286 | struct afs_operation *op; |
d2ddc776 | 287 | |
3b6492df | 288 | _enter("%s{%llx:%llu.%u},%x,,,", |
d2ddc776 DH |
289 | vnode->volume->name, |
290 | vnode->fid.vid, | |
291 | vnode->fid.vnode, | |
292 | vnode->fid.unique, | |
c69bf479 | 293 | key_serial(req->key)); |
d2ddc776 | 294 | |
c69bf479 | 295 | op = afs_alloc_operation(req->key, vnode->volume); |
e49c7b2f DH |
296 | if (IS_ERR(op)) |
297 | return PTR_ERR(op); | |
a58823ac | 298 | |
e49c7b2f | 299 | afs_op_set_vnode(op, 0, vnode); |
d2ddc776 | 300 | |
e49c7b2f DH |
301 | op->fetch.req = afs_get_read(req); |
302 | op->ops = &afs_fetch_data_operation; | |
303 | return afs_do_sync_operation(op); | |
d2ddc776 DH |
304 | } |
305 | ||
1da177e4 | 306 | /* |
f6d335c0 | 307 | * read page from file, directory or symlink, given a key to use |
1da177e4 | 308 | */ |
c4508464 | 309 | static int afs_page_filler(struct key *key, struct page *page) |
1da177e4 | 310 | { |
f6d335c0 AV |
311 | struct inode *inode = page->mapping->host; |
312 | struct afs_vnode *vnode = AFS_FS_I(inode); | |
196ee9cd | 313 | struct afs_read *req; |
1da177e4 LT |
314 | int ret; |
315 | ||
00d3b7a4 | 316 | _enter("{%x},{%lu},{%lu}", key_serial(key), inode->i_ino, page->index); |
1da177e4 | 317 | |
cd7619d6 | 318 | BUG_ON(!PageLocked(page)); |
1da177e4 LT |
319 | |
320 | ret = -ESTALE; | |
08e0e7c8 | 321 | if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) |
1da177e4 LT |
322 | goto error; |
323 | ||
c4508464 | 324 | req = kzalloc(sizeof(struct afs_read), GFP_KERNEL); |
03ffae90 DH |
325 | if (!req) |
326 | goto enomem; | |
1da177e4 | 327 | |
03ffae90 | 328 | refcount_set(&req->usage, 1); |
c4508464 DH |
329 | req->vnode = vnode; |
330 | req->key = key_get(key); | |
331 | req->pos = (loff_t)page->index << PAGE_SHIFT; | |
332 | req->len = PAGE_SIZE; | |
333 | req->nr_pages = 1; | |
334 | req->done = afs_file_read_done; | |
335 | req->cleanup = afs_file_read_cleanup; | |
336 | ||
03ffae90 | 337 | get_page(page); |
c4508464 DH |
338 | iov_iter_xarray(&req->def_iter, READ, &page->mapping->i_pages, |
339 | req->pos, req->len); | |
340 | req->iter = &req->def_iter; | |
03ffae90 | 341 | |
c69bf479 | 342 | ret = afs_fetch_data(vnode, req); |
c4508464 DH |
343 | if (ret < 0) |
344 | goto fetch_error; | |
03ffae90 | 345 | |
c4508464 | 346 | afs_put_read(req); |
1da177e4 LT |
347 | _leave(" = 0"); |
348 | return 0; | |
349 | ||
c4508464 DH |
350 | fetch_error: |
351 | switch (ret) { | |
352 | case -EINTR: | |
353 | case -ENOMEM: | |
354 | case -ERESTARTSYS: | |
355 | case -EAGAIN: | |
356 | afs_put_read(req); | |
357 | goto error; | |
358 | case -ENOENT: | |
359 | _debug("got NOENT from server - marking file deleted and stale"); | |
360 | set_bit(AFS_VNODE_DELETED, &vnode->flags); | |
361 | ret = -ESTALE; | |
362 | /* Fall through */ | |
363 | default: | |
364 | page_endio(page, false, ret); | |
365 | afs_put_read(req); | |
366 | _leave(" = %d", ret); | |
367 | return ret; | |
368 | } | |
369 | ||
196ee9cd DH |
370 | enomem: |
371 | ret = -ENOMEM; | |
08e0e7c8 | 372 | error: |
1da177e4 | 373 | unlock_page(page); |
1da177e4 LT |
374 | _leave(" = %d", ret); |
375 | return ret; | |
ec26815a | 376 | } |
1da177e4 | 377 | |
f6d335c0 AV |
378 | /* |
379 | * read page from file, directory or symlink, given a file to nominate the key | |
380 | * to be used | |
381 | */ | |
382 | static int afs_readpage(struct file *file, struct page *page) | |
383 | { | |
384 | struct key *key; | |
385 | int ret; | |
386 | ||
387 | if (file) { | |
215804a9 | 388 | key = afs_file_key(file); |
f6d335c0 AV |
389 | ASSERT(key != NULL); |
390 | ret = afs_page_filler(key, page); | |
391 | } else { | |
392 | struct inode *inode = page->mapping->host; | |
d2ddc776 | 393 | key = afs_request_key(AFS_FS_S(inode->i_sb)->cell); |
f6d335c0 AV |
394 | if (IS_ERR(key)) { |
395 | ret = PTR_ERR(key); | |
396 | } else { | |
397 | ret = afs_page_filler(key, page); | |
398 | key_put(key); | |
399 | } | |
400 | } | |
401 | return ret; | |
402 | } | |
403 | ||
91b467e0 DH |
404 | /* |
405 | * Read a contiguous set of pages. | |
406 | */ | |
407 | static int afs_readpages_one(struct file *file, struct address_space *mapping, | |
408 | struct list_head *pages) | |
409 | { | |
410 | struct afs_vnode *vnode = AFS_FS_I(mapping->host); | |
411 | struct afs_read *req; | |
412 | struct list_head *p; | |
413 | struct page *first, *page; | |
91b467e0 | 414 | pgoff_t index; |
c4508464 | 415 | int ret, n; |
91b467e0 DH |
416 | |
417 | /* Count the number of contiguous pages at the front of the list. Note | |
418 | * that the list goes prev-wards rather than next-wards. | |
419 | */ | |
f86196ea | 420 | first = lru_to_page(pages); |
91b467e0 DH |
421 | index = first->index + 1; |
422 | n = 1; | |
423 | for (p = first->lru.prev; p != pages; p = p->prev) { | |
424 | page = list_entry(p, struct page, lru); | |
425 | if (page->index != index) | |
426 | break; | |
427 | index++; | |
428 | n++; | |
429 | } | |
430 | ||
c4508464 | 431 | req = kzalloc(sizeof(struct afs_read), GFP_NOFS); |
91b467e0 DH |
432 | if (!req) |
433 | return -ENOMEM; | |
434 | ||
f3ddee8d | 435 | refcount_set(&req->usage, 1); |
a58823ac | 436 | req->vnode = vnode; |
c69bf479 | 437 | req->key = key_get(afs_file_key(file)); |
c4508464 DH |
438 | req->done = afs_file_read_done; |
439 | req->cleanup = afs_file_read_cleanup; | |
91b467e0 DH |
440 | req->pos = first->index; |
441 | req->pos <<= PAGE_SHIFT; | |
442 | ||
c4508464 DH |
443 | /* Add pages to the LRU until it fails. We keep the pages ref'd and |
444 | * locked until the read is complete. | |
91b467e0 DH |
445 | * |
446 | * Note that it's possible for the file size to change whilst we're | |
447 | * doing this, but we rely on the server returning less than we asked | |
448 | * for if the file shrank. We also rely on this to deal with a partial | |
449 | * page at the end of the file. | |
450 | */ | |
451 | do { | |
f86196ea | 452 | page = lru_to_page(pages); |
91b467e0 DH |
453 | list_del(&page->lru); |
454 | index = page->index; | |
455 | if (add_to_page_cache_lru(page, mapping, index, | |
456 | readahead_gfp_mask(mapping))) { | |
91b467e0 DH |
457 | put_page(page); |
458 | break; | |
459 | } | |
460 | ||
c4508464 | 461 | req->nr_pages++; |
91b467e0 DH |
462 | } while (req->nr_pages < n); |
463 | ||
464 | if (req->nr_pages == 0) { | |
c69bf479 | 465 | afs_put_read(req); |
91b467e0 DH |
466 | return 0; |
467 | } | |
468 | ||
c4508464 DH |
469 | req->len = req->nr_pages * PAGE_SIZE; |
470 | iov_iter_xarray(&req->def_iter, READ, &file->f_mapping->i_pages, | |
471 | req->pos, req->len); | |
472 | req->iter = &req->def_iter; | |
473 | ||
c69bf479 | 474 | ret = afs_fetch_data(vnode, req); |
91b467e0 DH |
475 | if (ret < 0) |
476 | goto error; | |
477 | ||
91b467e0 DH |
478 | afs_put_read(req); |
479 | return 0; | |
480 | ||
481 | error: | |
482 | if (ret == -ENOENT) { | |
c4508464 | 483 | _debug("got NOENT from server - marking file deleted and stale"); |
91b467e0 DH |
484 | set_bit(AFS_VNODE_DELETED, &vnode->flags); |
485 | ret = -ESTALE; | |
486 | } | |
487 | ||
91b467e0 DH |
488 | afs_put_read(req); |
489 | return ret; | |
490 | } | |
491 | ||
1da177e4 | 492 | /* |
9b3f26c9 | 493 | * read a set of pages |
1da177e4 | 494 | */ |
9b3f26c9 DH |
495 | static int afs_readpages(struct file *file, struct address_space *mapping, |
496 | struct list_head *pages, unsigned nr_pages) | |
1da177e4 | 497 | { |
215804a9 | 498 | struct key *key = afs_file_key(file); |
9b3f26c9 DH |
499 | struct afs_vnode *vnode; |
500 | int ret = 0; | |
1da177e4 | 501 | |
f6d335c0 AV |
502 | _enter("{%d},{%lu},,%d", |
503 | key_serial(key), mapping->host->i_ino, nr_pages); | |
504 | ||
505 | ASSERT(key != NULL); | |
1da177e4 | 506 | |
9b3f26c9 | 507 | vnode = AFS_FS_I(mapping->host); |
ad2a8e60 | 508 | if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) { |
9b3f26c9 DH |
509 | _leave(" = -ESTALE"); |
510 | return -ESTALE; | |
511 | } | |
1da177e4 | 512 | |
9b3f26c9 | 513 | /* attempt to read as many of the pages as possible */ |
91b467e0 DH |
514 | while (!list_empty(pages)) { |
515 | ret = afs_readpages_one(file, mapping, pages); | |
516 | if (ret < 0) | |
517 | break; | |
518 | } | |
9b3f26c9 DH |
519 | |
520 | _leave(" = %d [netting]", ret); | |
521 | return ret; | |
ec26815a | 522 | } |
1da177e4 | 523 | |
f86726a6 DH |
524 | /* |
525 | * Adjust the dirty region of the page on truncation or full invalidation, | |
526 | * getting rid of the markers altogether if the region is entirely invalidated. | |
527 | */ | |
528 | static void afs_invalidate_dirty(struct page *page, unsigned int offset, | |
529 | unsigned int length) | |
530 | { | |
531 | struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); | |
532 | unsigned long priv; | |
533 | unsigned int f, t, end = offset + length; | |
534 | ||
535 | priv = page_private(page); | |
536 | ||
537 | /* we clean up only if the entire page is being invalidated */ | |
538 | if (offset == 0 && length == thp_size(page)) | |
539 | goto full_invalidate; | |
540 | ||
541 | /* If the page was dirtied by page_mkwrite(), the PTE stays writable | |
542 | * and we don't get another notification to tell us to expand it | |
543 | * again. | |
544 | */ | |
545 | if (afs_is_page_dirty_mmapped(priv)) | |
546 | return; | |
547 | ||
548 | /* We may need to shorten the dirty region */ | |
67d78a6f DH |
549 | f = afs_page_dirty_from(page, priv); |
550 | t = afs_page_dirty_to(page, priv); | |
f86726a6 DH |
551 | |
552 | if (t <= offset || f >= end) | |
553 | return; /* Doesn't overlap */ | |
554 | ||
555 | if (f < offset && t > end) | |
556 | return; /* Splits the dirty region - just absorb it */ | |
557 | ||
558 | if (f >= offset && t <= end) | |
559 | goto undirty; | |
560 | ||
561 | if (f < offset) | |
562 | t = offset; | |
563 | else | |
564 | f = end; | |
565 | if (f == t) | |
566 | goto undirty; | |
567 | ||
67d78a6f | 568 | priv = afs_page_dirty(page, f, t); |
f86726a6 | 569 | set_page_private(page, priv); |
67d78a6f | 570 | trace_afs_page_dirty(vnode, tracepoint_string("trunc"), page); |
f86726a6 DH |
571 | return; |
572 | ||
573 | undirty: | |
67d78a6f | 574 | trace_afs_page_dirty(vnode, tracepoint_string("undirty"), page); |
f86726a6 DH |
575 | clear_page_dirty_for_io(page); |
576 | full_invalidate: | |
67d78a6f DH |
577 | detach_page_private(page); |
578 | trace_afs_page_dirty(vnode, tracepoint_string("inval"), page); | |
f86726a6 DH |
579 | } |
580 | ||
1da177e4 | 581 | /* |
9b3f26c9 DH |
582 | * invalidate part or all of a page |
583 | * - release a page and clean up its private data if offset is 0 (indicating | |
584 | * the entire page) | |
585 | */ | |
d47992f8 LC |
586 | static void afs_invalidatepage(struct page *page, unsigned int offset, |
587 | unsigned int length) | |
9b3f26c9 | 588 | { |
d47992f8 | 589 | _enter("{%lu},%u,%u", page->index, offset, length); |
9b3f26c9 DH |
590 | |
591 | BUG_ON(!PageLocked(page)); | |
592 | ||
f86726a6 DH |
593 | if (PagePrivate(page)) |
594 | afs_invalidate_dirty(page, offset, length); | |
9b3f26c9 DH |
595 | |
596 | _leave(""); | |
597 | } | |
598 | ||
599 | /* | |
600 | * release a page and clean up its private state if it's not busy | |
601 | * - return true if the page can now be released, false if not | |
1da177e4 | 602 | */ |
416351f2 | 603 | static int afs_releasepage(struct page *page, gfp_t gfp_flags) |
1da177e4 | 604 | { |
416351f2 | 605 | struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); |
1da177e4 | 606 | |
3b6492df | 607 | _enter("{{%llx:%llu}[%lu],%lx},%x", |
416351f2 DH |
608 | vnode->fid.vid, vnode->fid.vnode, page->index, page->flags, |
609 | gfp_flags); | |
1da177e4 | 610 | |
9b3f26c9 DH |
611 | /* deny if page is being written to the cache and the caller hasn't |
612 | * elected to wait */ | |
1da177e4 | 613 | if (PagePrivate(page)) { |
67d78a6f DH |
614 | detach_page_private(page); |
615 | trace_afs_page_dirty(vnode, tracepoint_string("rel"), page); | |
1da177e4 LT |
616 | } |
617 | ||
9b3f26c9 DH |
618 | /* indicate that the page can be released */ |
619 | _leave(" = T"); | |
620 | return 1; | |
ec26815a | 621 | } |
1cf7a151 DH |
622 | |
623 | /* | |
624 | * Handle setting up a memory mapping on an AFS file. | |
625 | */ | |
626 | static int afs_file_mmap(struct file *file, struct vm_area_struct *vma) | |
627 | { | |
628 | int ret; | |
629 | ||
630 | ret = generic_file_mmap(file, vma); | |
631 | if (ret == 0) | |
632 | vma->vm_ops = &afs_vm_ops; | |
633 | return ret; | |
634 | } |