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12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/fs.h>
16#include <linux/pagemap.h>
17#include <linux/writeback.h>
18#include <linux/gfp.h>
19#include <linux/task_io_accounting_ops.h>
20#include "internal.h"
21
22static int afs_file_mmap(struct file *file, struct vm_area_struct *vma);
23static int afs_readpage(struct file *file, struct page *page);
24static void afs_invalidatepage(struct page *page, unsigned int offset,
25 unsigned int length);
26static int afs_releasepage(struct page *page, gfp_t gfp_flags);
27
28static int afs_readpages(struct file *filp, struct address_space *mapping,
29 struct list_head *pages, unsigned nr_pages);
30
31const struct file_operations afs_file_operations = {
32 .open = afs_open,
33 .release = afs_release,
34 .llseek = generic_file_llseek,
35 .read_iter = generic_file_read_iter,
36 .write_iter = afs_file_write,
37 .mmap = afs_file_mmap,
38 .splice_read = generic_file_splice_read,
39 .fsync = afs_fsync,
40 .lock = afs_lock,
41 .flock = afs_flock,
42};
43
44const struct inode_operations afs_file_inode_operations = {
45 .getattr = afs_getattr,
46 .setattr = afs_setattr,
47 .permission = afs_permission,
48 .listxattr = afs_listxattr,
49};
50
51const struct address_space_operations afs_fs_aops = {
52 .readpage = afs_readpage,
53 .readpages = afs_readpages,
54 .set_page_dirty = afs_set_page_dirty,
55 .launder_page = afs_launder_page,
56 .releasepage = afs_releasepage,
57 .invalidatepage = afs_invalidatepage,
58 .write_begin = afs_write_begin,
59 .write_end = afs_write_end,
60 .writepage = afs_writepage,
61 .writepages = afs_writepages,
62};
63
64static const struct vm_operations_struct afs_vm_ops = {
65 .fault = filemap_fault,
66 .map_pages = filemap_map_pages,
67 .page_mkwrite = afs_page_mkwrite,
68};
69
70
71
72
73void afs_put_wb_key(struct afs_wb_key *wbk)
74{
75 if (refcount_dec_and_test(&wbk->usage)) {
76 key_put(wbk->key);
77 kfree(wbk);
78 }
79}
80
81
82
83
84int afs_cache_wb_key(struct afs_vnode *vnode, struct afs_file *af)
85{
86 struct afs_wb_key *wbk, *p;
87
88 wbk = kzalloc(sizeof(struct afs_wb_key), GFP_KERNEL);
89 if (!wbk)
90 return -ENOMEM;
91 refcount_set(&wbk->usage, 2);
92 wbk->key = af->key;
93
94 spin_lock(&vnode->wb_lock);
95 list_for_each_entry(p, &vnode->wb_keys, vnode_link) {
96 if (p->key == wbk->key)
97 goto found;
98 }
99
100 key_get(wbk->key);
101 list_add_tail(&wbk->vnode_link, &vnode->wb_keys);
102 spin_unlock(&vnode->wb_lock);
103 af->wb = wbk;
104 return 0;
105
106found:
107 refcount_inc(&p->usage);
108 spin_unlock(&vnode->wb_lock);
109 af->wb = p;
110 kfree(wbk);
111 return 0;
112}
113
114
115
116
117int afs_open(struct inode *inode, struct file *file)
118{
119 struct afs_vnode *vnode = AFS_FS_I(inode);
120 struct afs_file *af;
121 struct key *key;
122 int ret;
123
124 _enter("{%x:%u},", vnode->fid.vid, vnode->fid.vnode);
125
126 key = afs_request_key(vnode->volume->cell);
127 if (IS_ERR(key)) {
128 ret = PTR_ERR(key);
129 goto error;
130 }
131
132 af = kzalloc(sizeof(*af), GFP_KERNEL);
133 if (!af) {
134 ret = -ENOMEM;
135 goto error_key;
136 }
137 af->key = key;
138
139 ret = afs_validate(vnode, key);
140 if (ret < 0)
141 goto error_af;
142
143 if (file->f_mode & FMODE_WRITE) {
144 ret = afs_cache_wb_key(vnode, af);
145 if (ret < 0)
146 goto error_af;
147 }
148
149 if (file->f_flags & O_TRUNC)
150 set_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags);
151
152 file->private_data = af;
153 _leave(" = 0");
154 return 0;
155
156error_af:
157 kfree(af);
158error_key:
159 key_put(key);
160error:
161 _leave(" = %d", ret);
162 return ret;
163}
164
165
166
167
168int afs_release(struct inode *inode, struct file *file)
169{
170 struct afs_vnode *vnode = AFS_FS_I(inode);
171 struct afs_file *af = file->private_data;
172
173 _enter("{%x:%u},", vnode->fid.vid, vnode->fid.vnode);
174
175 if ((file->f_mode & FMODE_WRITE))
176 return vfs_fsync(file, 0);
177
178 file->private_data = NULL;
179 if (af->wb)
180 afs_put_wb_key(af->wb);
181 key_put(af->key);
182 kfree(af);
183 afs_prune_wb_keys(vnode);
184 _leave(" = 0");
185 return 0;
186}
187
188
189
190
191void afs_put_read(struct afs_read *req)
192{
193 int i;
194
195 if (refcount_dec_and_test(&req->usage)) {
196 for (i = 0; i < req->nr_pages; i++)
197 if (req->pages[i])
198 put_page(req->pages[i]);
199 if (req->pages != req->array)
200 kfree(req->pages);
201 kfree(req);
202 }
203}
204
205#ifdef CONFIG_AFS_FSCACHE
206
207
208
209static void afs_file_readpage_read_complete(struct page *page,
210 void *data,
211 int error)
212{
213 _enter("%p,%p,%d", page, data, error);
214
215
216
217 if (!error)
218 SetPageUptodate(page);
219 unlock_page(page);
220}
221#endif
222
223
224
225
226int afs_fetch_data(struct afs_vnode *vnode, struct key *key, struct afs_read *desc)
227{
228 struct afs_fs_cursor fc;
229 int ret;
230
231 _enter("%s{%x:%u.%u},%x,,,",
232 vnode->volume->name,
233 vnode->fid.vid,
234 vnode->fid.vnode,
235 vnode->fid.unique,
236 key_serial(key));
237
238 ret = -ERESTARTSYS;
239 if (afs_begin_vnode_operation(&fc, vnode, key)) {
240 while (afs_select_fileserver(&fc)) {
241 fc.cb_break = afs_calc_vnode_cb_break(vnode);
242 afs_fs_fetch_data(&fc, desc);
243 }
244
245 afs_check_for_remote_deletion(&fc, fc.vnode);
246 afs_vnode_commit_status(&fc, vnode, fc.cb_break);
247 ret = afs_end_vnode_operation(&fc);
248 }
249
250 if (ret == 0) {
251 afs_stat_v(vnode, n_fetches);
252 atomic_long_add(desc->actual_len,
253 &afs_v2net(vnode)->n_fetch_bytes);
254 }
255
256 _leave(" = %d", ret);
257 return ret;
258}
259
260
261
262
263int afs_page_filler(void *data, struct page *page)
264{
265 struct inode *inode = page->mapping->host;
266 struct afs_vnode *vnode = AFS_FS_I(inode);
267 struct afs_read *req;
268 struct key *key = data;
269 int ret;
270
271 _enter("{%x},{%lu},{%lu}", key_serial(key), inode->i_ino, page->index);
272
273 BUG_ON(!PageLocked(page));
274
275 ret = -ESTALE;
276 if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
277 goto error;
278
279
280#ifdef CONFIG_AFS_FSCACHE
281 ret = fscache_read_or_alloc_page(vnode->cache,
282 page,
283 afs_file_readpage_read_complete,
284 NULL,
285 GFP_KERNEL);
286#else
287 ret = -ENOBUFS;
288#endif
289 switch (ret) {
290
291 case 0:
292 break;
293
294
295 case -ENODATA:
296 _debug("cache said ENODATA");
297 goto go_on;
298
299
300 case -ENOBUFS:
301 _debug("cache said ENOBUFS");
302 default:
303 go_on:
304 req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *),
305 GFP_KERNEL);
306 if (!req)
307 goto enomem;
308
309
310
311
312
313 refcount_set(&req->usage, 1);
314 req->pos = (loff_t)page->index << PAGE_SHIFT;
315 req->len = PAGE_SIZE;
316 req->nr_pages = 1;
317 req->pages = req->array;
318 req->pages[0] = page;
319 get_page(page);
320
321
322
323 ret = afs_fetch_data(vnode, key, req);
324 afs_put_read(req);
325
326 if (ret < 0) {
327 if (ret == -ENOENT) {
328 _debug("got NOENT from server"
329 " - marking file deleted and stale");
330 set_bit(AFS_VNODE_DELETED, &vnode->flags);
331 ret = -ESTALE;
332 }
333
334#ifdef CONFIG_AFS_FSCACHE
335 fscache_uncache_page(vnode->cache, page);
336#endif
337 BUG_ON(PageFsCache(page));
338
339 if (ret == -EINTR ||
340 ret == -ENOMEM ||
341 ret == -ERESTARTSYS ||
342 ret == -EAGAIN)
343 goto error;
344 goto io_error;
345 }
346
347 SetPageUptodate(page);
348
349
350#ifdef CONFIG_AFS_FSCACHE
351 if (PageFsCache(page) &&
352 fscache_write_page(vnode->cache, page, vnode->status.size,
353 GFP_KERNEL) != 0) {
354 fscache_uncache_page(vnode->cache, page);
355 BUG_ON(PageFsCache(page));
356 }
357#endif
358 unlock_page(page);
359 }
360
361 _leave(" = 0");
362 return 0;
363
364io_error:
365 SetPageError(page);
366 goto error;
367enomem:
368 ret = -ENOMEM;
369error:
370 unlock_page(page);
371 _leave(" = %d", ret);
372 return ret;
373}
374
375
376
377
378
379static int afs_readpage(struct file *file, struct page *page)
380{
381 struct key *key;
382 int ret;
383
384 if (file) {
385 key = afs_file_key(file);
386 ASSERT(key != NULL);
387 ret = afs_page_filler(key, page);
388 } else {
389 struct inode *inode = page->mapping->host;
390 key = afs_request_key(AFS_FS_S(inode->i_sb)->cell);
391 if (IS_ERR(key)) {
392 ret = PTR_ERR(key);
393 } else {
394 ret = afs_page_filler(key, page);
395 key_put(key);
396 }
397 }
398 return ret;
399}
400
401
402
403
404static void afs_readpages_page_done(struct afs_call *call, struct afs_read *req)
405{
406#ifdef CONFIG_AFS_FSCACHE
407 struct afs_vnode *vnode = call->reply[0];
408#endif
409 struct page *page = req->pages[req->index];
410
411 req->pages[req->index] = NULL;
412 SetPageUptodate(page);
413
414
415#ifdef CONFIG_AFS_FSCACHE
416 if (PageFsCache(page) &&
417 fscache_write_page(vnode->cache, page, vnode->status.size,
418 GFP_KERNEL) != 0) {
419 fscache_uncache_page(vnode->cache, page);
420 BUG_ON(PageFsCache(page));
421 }
422#endif
423 unlock_page(page);
424 put_page(page);
425}
426
427
428
429
430static int afs_readpages_one(struct file *file, struct address_space *mapping,
431 struct list_head *pages)
432{
433 struct afs_vnode *vnode = AFS_FS_I(mapping->host);
434 struct afs_read *req;
435 struct list_head *p;
436 struct page *first, *page;
437 struct key *key = afs_file_key(file);
438 pgoff_t index;
439 int ret, n, i;
440
441
442
443
444 first = list_entry(pages->prev, struct page, lru);
445 index = first->index + 1;
446 n = 1;
447 for (p = first->lru.prev; p != pages; p = p->prev) {
448 page = list_entry(p, struct page, lru);
449 if (page->index != index)
450 break;
451 index++;
452 n++;
453 }
454
455 req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *) * n,
456 GFP_NOFS);
457 if (!req)
458 return -ENOMEM;
459
460 refcount_set(&req->usage, 1);
461 req->page_done = afs_readpages_page_done;
462 req->pos = first->index;
463 req->pos <<= PAGE_SHIFT;
464 req->pages = req->array;
465
466
467
468
469
470
471
472
473
474
475 do {
476 page = list_entry(pages->prev, struct page, lru);
477 list_del(&page->lru);
478 index = page->index;
479 if (add_to_page_cache_lru(page, mapping, index,
480 readahead_gfp_mask(mapping))) {
481#ifdef CONFIG_AFS_FSCACHE
482 fscache_uncache_page(vnode->cache, page);
483#endif
484 put_page(page);
485 break;
486 }
487
488 req->pages[req->nr_pages++] = page;
489 req->len += PAGE_SIZE;
490 } while (req->nr_pages < n);
491
492 if (req->nr_pages == 0) {
493 kfree(req);
494 return 0;
495 }
496
497 ret = afs_fetch_data(vnode, key, req);
498 if (ret < 0)
499 goto error;
500
501 task_io_account_read(PAGE_SIZE * req->nr_pages);
502 afs_put_read(req);
503 return 0;
504
505error:
506 if (ret == -ENOENT) {
507 _debug("got NOENT from server"
508 " - marking file deleted and stale");
509 set_bit(AFS_VNODE_DELETED, &vnode->flags);
510 ret = -ESTALE;
511 }
512
513 for (i = 0; i < req->nr_pages; i++) {
514 page = req->pages[i];
515 if (page) {
516#ifdef CONFIG_AFS_FSCACHE
517 fscache_uncache_page(vnode->cache, page);
518#endif
519 SetPageError(page);
520 unlock_page(page);
521 }
522 }
523
524 afs_put_read(req);
525 return ret;
526}
527
528
529
530
531static int afs_readpages(struct file *file, struct address_space *mapping,
532 struct list_head *pages, unsigned nr_pages)
533{
534 struct key *key = afs_file_key(file);
535 struct afs_vnode *vnode;
536 int ret = 0;
537
538 _enter("{%d},{%lu},,%d",
539 key_serial(key), mapping->host->i_ino, nr_pages);
540
541 ASSERT(key != NULL);
542
543 vnode = AFS_FS_I(mapping->host);
544 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
545 _leave(" = -ESTALE");
546 return -ESTALE;
547 }
548
549
550#ifdef CONFIG_AFS_FSCACHE
551 ret = fscache_read_or_alloc_pages(vnode->cache,
552 mapping,
553 pages,
554 &nr_pages,
555 afs_file_readpage_read_complete,
556 NULL,
557 mapping_gfp_mask(mapping));
558#else
559 ret = -ENOBUFS;
560#endif
561
562 switch (ret) {
563
564 case 0:
565 BUG_ON(!list_empty(pages));
566 BUG_ON(nr_pages != 0);
567 _leave(" = 0 [reading all]");
568 return 0;
569
570
571 case -ENODATA:
572 case -ENOBUFS:
573 break;
574
575
576 default:
577 _leave(" = %d", ret);
578 return ret;
579 }
580
581 while (!list_empty(pages)) {
582 ret = afs_readpages_one(file, mapping, pages);
583 if (ret < 0)
584 break;
585 }
586
587 _leave(" = %d [netting]", ret);
588 return ret;
589}
590
591
592
593
594
595
596static void afs_invalidatepage(struct page *page, unsigned int offset,
597 unsigned int length)
598{
599 struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
600 unsigned long priv;
601
602 _enter("{%lu},%u,%u", page->index, offset, length);
603
604 BUG_ON(!PageLocked(page));
605
606
607 if (offset == 0 && length == PAGE_SIZE) {
608#ifdef CONFIG_AFS_FSCACHE
609 if (PageFsCache(page)) {
610 struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
611 fscache_wait_on_page_write(vnode->cache, page);
612 fscache_uncache_page(vnode->cache, page);
613 }
614#endif
615
616 if (PagePrivate(page)) {
617 priv = page_private(page);
618 trace_afs_page_dirty(vnode, tracepoint_string("inval"),
619 page->index, priv);
620 set_page_private(page, 0);
621 ClearPagePrivate(page);
622 }
623 }
624
625 _leave("");
626}
627
628
629
630
631
632static int afs_releasepage(struct page *page, gfp_t gfp_flags)
633{
634 struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
635 unsigned long priv;
636
637 _enter("{{%x:%u}[%lu],%lx},%x",
638 vnode->fid.vid, vnode->fid.vnode, page->index, page->flags,
639 gfp_flags);
640
641
642
643#ifdef CONFIG_AFS_FSCACHE
644 if (!fscache_maybe_release_page(vnode->cache, page, gfp_flags)) {
645 _leave(" = F [cache busy]");
646 return 0;
647 }
648#endif
649
650 if (PagePrivate(page)) {
651 priv = page_private(page);
652 trace_afs_page_dirty(vnode, tracepoint_string("rel"),
653 page->index, priv);
654 set_page_private(page, 0);
655 ClearPagePrivate(page);
656 }
657
658
659 _leave(" = T");
660 return 1;
661}
662
663
664
665
666static int afs_file_mmap(struct file *file, struct vm_area_struct *vma)
667{
668 int ret;
669
670 ret = generic_file_mmap(file, vma);
671 if (ret == 0)
672 vma->vm_ops = &afs_vm_ops;
673 return ret;
674}
675