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12#include <linux/slab.h>
13#include <linux/file.h>
14#include <linux/sched.h>
15#include <linux/sunrpc/clnt.h>
16#include <linux/nfs.h>
17#include <linux/nfs3.h>
18#include <linux/nfs4.h>
19#include <linux/nfs_page.h>
20#include <linux/nfs_fs.h>
21#include <linux/nfs_mount.h>
22#include <linux/export.h>
23
24#include "internal.h"
25#include "pnfs.h"
26
27#define NFSDBG_FACILITY NFSDBG_PAGECACHE
28
29static struct kmem_cache *nfs_page_cachep;
30static const struct rpc_call_ops nfs_pgio_common_ops;
31
32static bool nfs_pgarray_set(struct nfs_page_array *p, unsigned int pagecount)
33{
34 p->npages = pagecount;
35 if (pagecount <= ARRAY_SIZE(p->page_array))
36 p->pagevec = p->page_array;
37 else {
38 p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_KERNEL);
39 if (!p->pagevec)
40 p->npages = 0;
41 }
42 return p->pagevec != NULL;
43}
44
45void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
46 struct nfs_pgio_header *hdr,
47 void (*release)(struct nfs_pgio_header *hdr))
48{
49 hdr->req = nfs_list_entry(desc->pg_list.next);
50 hdr->inode = desc->pg_inode;
51 hdr->cred = hdr->req->wb_context->cred;
52 hdr->io_start = req_offset(hdr->req);
53 hdr->good_bytes = desc->pg_count;
54 hdr->dreq = desc->pg_dreq;
55 hdr->layout_private = desc->pg_layout_private;
56 hdr->release = release;
57 hdr->completion_ops = desc->pg_completion_ops;
58 if (hdr->completion_ops->init_hdr)
59 hdr->completion_ops->init_hdr(hdr);
60}
61EXPORT_SYMBOL_GPL(nfs_pgheader_init);
62
63void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos)
64{
65 spin_lock(&hdr->lock);
66 if (pos < hdr->io_start + hdr->good_bytes) {
67 set_bit(NFS_IOHDR_ERROR, &hdr->flags);
68 clear_bit(NFS_IOHDR_EOF, &hdr->flags);
69 hdr->good_bytes = pos - hdr->io_start;
70 hdr->error = error;
71 }
72 spin_unlock(&hdr->lock);
73}
74
75static inline struct nfs_page *
76nfs_page_alloc(void)
77{
78 struct nfs_page *p = kmem_cache_zalloc(nfs_page_cachep, GFP_NOIO);
79 if (p)
80 INIT_LIST_HEAD(&p->wb_list);
81 return p;
82}
83
84static inline void
85nfs_page_free(struct nfs_page *p)
86{
87 kmem_cache_free(nfs_page_cachep, p);
88}
89
90static void
91nfs_iocounter_inc(struct nfs_io_counter *c)
92{
93 atomic_inc(&c->io_count);
94}
95
96static void
97nfs_iocounter_dec(struct nfs_io_counter *c)
98{
99 if (atomic_dec_and_test(&c->io_count)) {
100 clear_bit(NFS_IO_INPROGRESS, &c->flags);
101 smp_mb__after_atomic();
102 wake_up_bit(&c->flags, NFS_IO_INPROGRESS);
103 }
104}
105
106static int
107__nfs_iocounter_wait(struct nfs_io_counter *c)
108{
109 wait_queue_head_t *wq = bit_waitqueue(&c->flags, NFS_IO_INPROGRESS);
110 DEFINE_WAIT_BIT(q, &c->flags, NFS_IO_INPROGRESS);
111 int ret = 0;
112
113 do {
114 prepare_to_wait(wq, &q.wait, TASK_KILLABLE);
115 set_bit(NFS_IO_INPROGRESS, &c->flags);
116 if (atomic_read(&c->io_count) == 0)
117 break;
118 ret = nfs_wait_bit_killable(&q.key);
119 } while (atomic_read(&c->io_count) != 0 && !ret);
120 finish_wait(wq, &q.wait);
121 return ret;
122}
123
124
125
126
127
128
129
130
131int
132nfs_iocounter_wait(struct nfs_io_counter *c)
133{
134 if (atomic_read(&c->io_count) == 0)
135 return 0;
136 return __nfs_iocounter_wait(c);
137}
138
139
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151
152
153int
154nfs_page_group_lock(struct nfs_page *req, bool nonblock)
155{
156 struct nfs_page *head = req->wb_head;
157
158 WARN_ON_ONCE(head != head->wb_head);
159
160 if (!test_and_set_bit(PG_HEADLOCK, &head->wb_flags))
161 return 0;
162
163 if (!nonblock)
164 return wait_on_bit_lock(&head->wb_flags, PG_HEADLOCK,
165 TASK_UNINTERRUPTIBLE);
166
167 return -EAGAIN;
168}
169
170
171
172
173
174
175
176void
177nfs_page_group_lock_wait(struct nfs_page *req)
178{
179 struct nfs_page *head = req->wb_head;
180
181 WARN_ON_ONCE(head != head->wb_head);
182
183 wait_on_bit(&head->wb_flags, PG_HEADLOCK,
184 TASK_UNINTERRUPTIBLE);
185}
186
187
188
189
190
191void
192nfs_page_group_unlock(struct nfs_page *req)
193{
194 struct nfs_page *head = req->wb_head;
195
196 WARN_ON_ONCE(head != head->wb_head);
197
198 smp_mb__before_atomic();
199 clear_bit(PG_HEADLOCK, &head->wb_flags);
200 smp_mb__after_atomic();
201 wake_up_bit(&head->wb_flags, PG_HEADLOCK);
202}
203
204
205
206
207
208
209static bool
210nfs_page_group_sync_on_bit_locked(struct nfs_page *req, unsigned int bit)
211{
212 struct nfs_page *head = req->wb_head;
213 struct nfs_page *tmp;
214
215 WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &head->wb_flags));
216 WARN_ON_ONCE(test_and_set_bit(bit, &req->wb_flags));
217
218 tmp = req->wb_this_page;
219 while (tmp != req) {
220 if (!test_bit(bit, &tmp->wb_flags))
221 return false;
222 tmp = tmp->wb_this_page;
223 }
224
225
226 tmp = req;
227 do {
228 clear_bit(bit, &tmp->wb_flags);
229 tmp = tmp->wb_this_page;
230 } while (tmp != req);
231
232 return true;
233}
234
235
236
237
238
239
240
241bool nfs_page_group_sync_on_bit(struct nfs_page *req, unsigned int bit)
242{
243 bool ret;
244
245 nfs_page_group_lock(req, false);
246 ret = nfs_page_group_sync_on_bit_locked(req, bit);
247 nfs_page_group_unlock(req);
248
249 return ret;
250}
251
252
253
254
255
256
257
258static inline void
259nfs_page_group_init(struct nfs_page *req, struct nfs_page *prev)
260{
261 WARN_ON_ONCE(prev == req);
262
263 if (!prev) {
264
265 req->wb_head = req;
266 req->wb_this_page = req;
267 } else {
268
269 WARN_ON_ONCE(prev->wb_this_page != prev->wb_head);
270 WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &prev->wb_head->wb_flags));
271 req->wb_head = prev->wb_head;
272 req->wb_this_page = prev->wb_this_page;
273 prev->wb_this_page = req;
274
275
276
277 kref_get(&req->wb_head->wb_kref);
278
279
280
281
282 if (test_bit(PG_INODE_REF, &prev->wb_head->wb_flags)) {
283 set_bit(PG_INODE_REF, &req->wb_flags);
284 kref_get(&req->wb_kref);
285 }
286 }
287}
288
289
290
291
292
293
294
295
296static void
297nfs_page_group_destroy(struct kref *kref)
298{
299 struct nfs_page *req = container_of(kref, struct nfs_page, wb_kref);
300 struct nfs_page *tmp, *next;
301
302
303 if (req->wb_head != req)
304 nfs_release_request(req->wb_head);
305
306 if (!nfs_page_group_sync_on_bit(req, PG_TEARDOWN))
307 return;
308
309 tmp = req;
310 do {
311 next = tmp->wb_this_page;
312
313 tmp->wb_this_page = tmp;
314 tmp->wb_head = tmp;
315 nfs_free_request(tmp);
316 tmp = next;
317 } while (tmp != req);
318}
319
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327
328
329
330
331
332struct nfs_page *
333nfs_create_request(struct nfs_open_context *ctx, struct page *page,
334 struct nfs_page *last, unsigned int offset,
335 unsigned int count)
336{
337 struct nfs_page *req;
338 struct nfs_lock_context *l_ctx;
339
340 if (test_bit(NFS_CONTEXT_BAD, &ctx->flags))
341 return ERR_PTR(-EBADF);
342
343 req = nfs_page_alloc();
344 if (req == NULL)
345 return ERR_PTR(-ENOMEM);
346
347
348 l_ctx = nfs_get_lock_context(ctx);
349 if (IS_ERR(l_ctx)) {
350 nfs_page_free(req);
351 return ERR_CAST(l_ctx);
352 }
353 req->wb_lock_context = l_ctx;
354 nfs_iocounter_inc(&l_ctx->io_count);
355
356
357
358
359 req->wb_page = page;
360 req->wb_index = page_file_index(page);
361 page_cache_get(page);
362 req->wb_offset = offset;
363 req->wb_pgbase = offset;
364 req->wb_bytes = count;
365 req->wb_context = get_nfs_open_context(ctx);
366 kref_init(&req->wb_kref);
367 nfs_page_group_init(req, last);
368 return req;
369}
370
371
372
373
374
375void nfs_unlock_request(struct nfs_page *req)
376{
377 if (!NFS_WBACK_BUSY(req)) {
378 printk(KERN_ERR "NFS: Invalid unlock attempted\n");
379 BUG();
380 }
381 smp_mb__before_atomic();
382 clear_bit(PG_BUSY, &req->wb_flags);
383 smp_mb__after_atomic();
384 wake_up_bit(&req->wb_flags, PG_BUSY);
385}
386
387
388
389
390
391void nfs_unlock_and_release_request(struct nfs_page *req)
392{
393 nfs_unlock_request(req);
394 nfs_release_request(req);
395}
396
397
398
399
400
401
402
403
404static void nfs_clear_request(struct nfs_page *req)
405{
406 struct page *page = req->wb_page;
407 struct nfs_open_context *ctx = req->wb_context;
408 struct nfs_lock_context *l_ctx = req->wb_lock_context;
409
410 if (page != NULL) {
411 page_cache_release(page);
412 req->wb_page = NULL;
413 }
414 if (l_ctx != NULL) {
415 nfs_iocounter_dec(&l_ctx->io_count);
416 nfs_put_lock_context(l_ctx);
417 req->wb_lock_context = NULL;
418 }
419 if (ctx != NULL) {
420 put_nfs_open_context(ctx);
421 req->wb_context = NULL;
422 }
423}
424
425
426
427
428
429
430
431void nfs_free_request(struct nfs_page *req)
432{
433 WARN_ON_ONCE(req->wb_this_page != req);
434
435
436 WARN_ON_ONCE(test_bit(PG_TEARDOWN, &req->wb_flags));
437 WARN_ON_ONCE(test_bit(PG_UNLOCKPAGE, &req->wb_flags));
438 WARN_ON_ONCE(test_bit(PG_UPTODATE, &req->wb_flags));
439 WARN_ON_ONCE(test_bit(PG_WB_END, &req->wb_flags));
440 WARN_ON_ONCE(test_bit(PG_REMOVE, &req->wb_flags));
441
442
443 nfs_clear_request(req);
444 nfs_page_free(req);
445}
446
447void nfs_release_request(struct nfs_page *req)
448{
449 kref_put(&req->wb_kref, nfs_page_group_destroy);
450}
451
452
453
454
455
456
457
458
459int
460nfs_wait_on_request(struct nfs_page *req)
461{
462 return wait_on_bit_io(&req->wb_flags, PG_BUSY,
463 TASK_UNINTERRUPTIBLE);
464}
465
466
467
468
469
470
471
472
473
474
475size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
476 struct nfs_page *prev, struct nfs_page *req)
477{
478 if (desc->pg_count > desc->pg_bsize) {
479
480 WARN_ON_ONCE(1);
481 return 0;
482 }
483
484 return min(desc->pg_bsize - desc->pg_count, (size_t)req->wb_bytes);
485}
486EXPORT_SYMBOL_GPL(nfs_generic_pg_test);
487
488struct nfs_pgio_header *nfs_pgio_header_alloc(const struct nfs_rw_ops *ops)
489{
490 struct nfs_pgio_header *hdr = ops->rw_alloc_header();
491
492 if (hdr) {
493 INIT_LIST_HEAD(&hdr->pages);
494 spin_lock_init(&hdr->lock);
495 hdr->rw_ops = ops;
496 }
497 return hdr;
498}
499EXPORT_SYMBOL_GPL(nfs_pgio_header_alloc);
500
501
502
503
504
505void nfs_pgio_header_free(struct nfs_pgio_header *hdr)
506{
507 hdr->rw_ops->rw_free_header(hdr);
508}
509EXPORT_SYMBOL_GPL(nfs_pgio_header_free);
510
511
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513
514
515
516
517
518
519void nfs_pgio_data_destroy(struct nfs_pgio_header *hdr)
520{
521 put_nfs_open_context(hdr->args.context);
522 if (hdr->page_array.pagevec != hdr->page_array.page_array)
523 kfree(hdr->page_array.pagevec);
524}
525EXPORT_SYMBOL_GPL(nfs_pgio_data_destroy);
526
527
528
529
530
531
532
533
534
535static void nfs_pgio_rpcsetup(struct nfs_pgio_header *hdr,
536 unsigned int count, unsigned int offset,
537 int how, struct nfs_commit_info *cinfo)
538{
539 struct nfs_page *req = hdr->req;
540
541
542
543
544 hdr->args.fh = NFS_FH(hdr->inode);
545 hdr->args.offset = req_offset(req) + offset;
546
547 hdr->mds_offset = hdr->args.offset;
548 hdr->args.pgbase = req->wb_pgbase + offset;
549 hdr->args.pages = hdr->page_array.pagevec;
550 hdr->args.count = count;
551 hdr->args.context = get_nfs_open_context(req->wb_context);
552 hdr->args.lock_context = req->wb_lock_context;
553 hdr->args.stable = NFS_UNSTABLE;
554 switch (how & (FLUSH_STABLE | FLUSH_COND_STABLE)) {
555 case 0:
556 break;
557 case FLUSH_COND_STABLE:
558 if (nfs_reqs_to_commit(cinfo))
559 break;
560 default:
561 hdr->args.stable = NFS_FILE_SYNC;
562 }
563
564 hdr->res.fattr = &hdr->fattr;
565 hdr->res.count = count;
566 hdr->res.eof = 0;
567 hdr->res.verf = &hdr->verf;
568 nfs_fattr_init(&hdr->fattr);
569}
570
571
572
573
574
575
576static void nfs_pgio_prepare(struct rpc_task *task, void *calldata)
577{
578 struct nfs_pgio_header *hdr = calldata;
579 int err;
580 err = NFS_PROTO(hdr->inode)->pgio_rpc_prepare(task, hdr);
581 if (err)
582 rpc_exit(task, err);
583}
584
585int nfs_initiate_pgio(struct rpc_clnt *clnt, struct nfs_pgio_header *hdr,
586 const struct rpc_call_ops *call_ops, int how, int flags)
587{
588 struct rpc_task *task;
589 struct rpc_message msg = {
590 .rpc_argp = &hdr->args,
591 .rpc_resp = &hdr->res,
592 .rpc_cred = hdr->cred,
593 };
594 struct rpc_task_setup task_setup_data = {
595 .rpc_client = clnt,
596 .task = &hdr->task,
597 .rpc_message = &msg,
598 .callback_ops = call_ops,
599 .callback_data = hdr,
600 .workqueue = nfsiod_workqueue,
601 .flags = RPC_TASK_ASYNC | flags,
602 };
603 int ret = 0;
604
605 hdr->rw_ops->rw_initiate(hdr, &msg, &task_setup_data, how);
606
607 dprintk("NFS: %5u initiated pgio call "
608 "(req %s/%llu, %u bytes @ offset %llu)\n",
609 hdr->task.tk_pid,
610 hdr->inode->i_sb->s_id,
611 (unsigned long long)NFS_FILEID(hdr->inode),
612 hdr->args.count,
613 (unsigned long long)hdr->args.offset);
614
615 task = rpc_run_task(&task_setup_data);
616 if (IS_ERR(task)) {
617 ret = PTR_ERR(task);
618 goto out;
619 }
620 if (how & FLUSH_SYNC) {
621 ret = rpc_wait_for_completion_task(task);
622 if (ret == 0)
623 ret = task->tk_status;
624 }
625 rpc_put_task(task);
626out:
627 return ret;
628}
629EXPORT_SYMBOL_GPL(nfs_initiate_pgio);
630
631
632
633
634
635
636static int nfs_pgio_error(struct nfs_pageio_descriptor *desc,
637 struct nfs_pgio_header *hdr)
638{
639 set_bit(NFS_IOHDR_REDO, &hdr->flags);
640 nfs_pgio_data_destroy(hdr);
641 hdr->completion_ops->completion(hdr);
642 desc->pg_completion_ops->error_cleanup(&desc->pg_list);
643 return -ENOMEM;
644}
645
646
647
648
649
650static void nfs_pgio_release(void *calldata)
651{
652 struct nfs_pgio_header *hdr = calldata;
653 if (hdr->rw_ops->rw_release)
654 hdr->rw_ops->rw_release(hdr);
655 nfs_pgio_data_destroy(hdr);
656 hdr->completion_ops->completion(hdr);
657}
658
659
660
661
662
663
664
665
666
667void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
668 struct inode *inode,
669 const struct nfs_pageio_ops *pg_ops,
670 const struct nfs_pgio_completion_ops *compl_ops,
671 const struct nfs_rw_ops *rw_ops,
672 size_t bsize,
673 int io_flags)
674{
675 INIT_LIST_HEAD(&desc->pg_list);
676 desc->pg_bytes_written = 0;
677 desc->pg_count = 0;
678 desc->pg_bsize = bsize;
679 desc->pg_base = 0;
680 desc->pg_moreio = 0;
681 desc->pg_recoalesce = 0;
682 desc->pg_inode = inode;
683 desc->pg_ops = pg_ops;
684 desc->pg_completion_ops = compl_ops;
685 desc->pg_rw_ops = rw_ops;
686 desc->pg_ioflags = io_flags;
687 desc->pg_error = 0;
688 desc->pg_lseg = NULL;
689 desc->pg_dreq = NULL;
690 desc->pg_layout_private = NULL;
691}
692EXPORT_SYMBOL_GPL(nfs_pageio_init);
693
694
695
696
697
698
699static void nfs_pgio_result(struct rpc_task *task, void *calldata)
700{
701 struct nfs_pgio_header *hdr = calldata;
702 struct inode *inode = hdr->inode;
703
704 dprintk("NFS: %s: %5u, (status %d)\n", __func__,
705 task->tk_pid, task->tk_status);
706
707 if (hdr->rw_ops->rw_done(task, hdr, inode) != 0)
708 return;
709 if (task->tk_status < 0)
710 nfs_set_pgio_error(hdr, task->tk_status, hdr->args.offset);
711 else
712 hdr->rw_ops->rw_result(task, hdr);
713}
714
715
716
717
718
719
720
721
722
723int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
724 struct nfs_pgio_header *hdr)
725{
726 struct nfs_page *req;
727 struct page **pages,
728 *last_page;
729 struct list_head *head = &desc->pg_list;
730 struct nfs_commit_info cinfo;
731 unsigned int pagecount, pageused;
732
733 pagecount = nfs_page_array_len(desc->pg_base, desc->pg_count);
734 if (!nfs_pgarray_set(&hdr->page_array, pagecount))
735 return nfs_pgio_error(desc, hdr);
736
737 nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq);
738 pages = hdr->page_array.pagevec;
739 last_page = NULL;
740 pageused = 0;
741 while (!list_empty(head)) {
742 req = nfs_list_entry(head->next);
743 nfs_list_remove_request(req);
744 nfs_list_add_request(req, &hdr->pages);
745
746 if (WARN_ON_ONCE(pageused >= pagecount))
747 return nfs_pgio_error(desc, hdr);
748
749 if (!last_page || last_page != req->wb_page) {
750 *pages++ = last_page = req->wb_page;
751 pageused++;
752 }
753 }
754 if (WARN_ON_ONCE(pageused != pagecount))
755 return nfs_pgio_error(desc, hdr);
756
757 if ((desc->pg_ioflags & FLUSH_COND_STABLE) &&
758 (desc->pg_moreio || nfs_reqs_to_commit(&cinfo)))
759 desc->pg_ioflags &= ~FLUSH_COND_STABLE;
760
761
762 nfs_pgio_rpcsetup(hdr, desc->pg_count, 0, desc->pg_ioflags, &cinfo);
763 desc->pg_rpc_callops = &nfs_pgio_common_ops;
764 return 0;
765}
766EXPORT_SYMBOL_GPL(nfs_generic_pgio);
767
768static int nfs_generic_pg_pgios(struct nfs_pageio_descriptor *desc)
769{
770 struct nfs_pgio_header *hdr;
771 int ret;
772
773 hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
774 if (!hdr) {
775 desc->pg_completion_ops->error_cleanup(&desc->pg_list);
776 return -ENOMEM;
777 }
778 nfs_pgheader_init(desc, hdr, nfs_pgio_header_free);
779 ret = nfs_generic_pgio(desc, hdr);
780 if (ret == 0)
781 ret = nfs_initiate_pgio(NFS_CLIENT(hdr->inode),
782 hdr, desc->pg_rpc_callops,
783 desc->pg_ioflags, 0);
784 return ret;
785}
786
787static bool nfs_match_open_context(const struct nfs_open_context *ctx1,
788 const struct nfs_open_context *ctx2)
789{
790 return ctx1->cred == ctx2->cred && ctx1->state == ctx2->state;
791}
792
793static bool nfs_match_lock_context(const struct nfs_lock_context *l1,
794 const struct nfs_lock_context *l2)
795{
796 return l1->lockowner.l_owner == l2->lockowner.l_owner
797 && l1->lockowner.l_pid == l2->lockowner.l_pid;
798}
799
800
801
802
803
804
805
806
807
808
809
810
811static bool nfs_can_coalesce_requests(struct nfs_page *prev,
812 struct nfs_page *req,
813 struct nfs_pageio_descriptor *pgio)
814{
815 size_t size;
816
817 if (prev) {
818 if (!nfs_match_open_context(req->wb_context, prev->wb_context))
819 return false;
820 if (req->wb_context->dentry->d_inode->i_flock != NULL &&
821 !nfs_match_lock_context(req->wb_lock_context,
822 prev->wb_lock_context))
823 return false;
824 if (req_offset(req) != req_offset(prev) + prev->wb_bytes)
825 return false;
826 if (req->wb_page == prev->wb_page) {
827 if (req->wb_pgbase != prev->wb_pgbase + prev->wb_bytes)
828 return false;
829 } else {
830 if (req->wb_pgbase != 0 ||
831 prev->wb_pgbase + prev->wb_bytes != PAGE_CACHE_SIZE)
832 return false;
833 }
834 }
835 size = pgio->pg_ops->pg_test(pgio, prev, req);
836 WARN_ON_ONCE(size > req->wb_bytes);
837 if (size && size < req->wb_bytes)
838 req->wb_bytes = size;
839 return size > 0;
840}
841
842
843
844
845
846
847
848
849
850static int nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc,
851 struct nfs_page *req)
852{
853 struct nfs_page *prev = NULL;
854 if (desc->pg_count != 0) {
855 prev = nfs_list_entry(desc->pg_list.prev);
856 } else {
857 if (desc->pg_ops->pg_init)
858 desc->pg_ops->pg_init(desc, req);
859 desc->pg_base = req->wb_pgbase;
860 }
861 if (!nfs_can_coalesce_requests(prev, req, desc))
862 return 0;
863 nfs_list_remove_request(req);
864 nfs_list_add_request(req, &desc->pg_list);
865 desc->pg_count += req->wb_bytes;
866 return 1;
867}
868
869
870
871
872static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc)
873{
874 if (!list_empty(&desc->pg_list)) {
875 int error = desc->pg_ops->pg_doio(desc);
876 if (error < 0)
877 desc->pg_error = error;
878 else
879 desc->pg_bytes_written += desc->pg_count;
880 }
881 if (list_empty(&desc->pg_list)) {
882 desc->pg_count = 0;
883 desc->pg_base = 0;
884 }
885}
886
887
888
889
890
891
892
893
894
895
896
897
898static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
899 struct nfs_page *req)
900{
901 struct nfs_page *subreq;
902 unsigned int bytes_left = 0;
903 unsigned int offset, pgbase;
904
905 nfs_page_group_lock(req, false);
906
907 subreq = req;
908 bytes_left = subreq->wb_bytes;
909 offset = subreq->wb_offset;
910 pgbase = subreq->wb_pgbase;
911
912 do {
913 if (!nfs_pageio_do_add_request(desc, subreq)) {
914
915 WARN_ON_ONCE(subreq->wb_bytes != bytes_left);
916 WARN_ON_ONCE(subreq->wb_offset != offset);
917 WARN_ON_ONCE(subreq->wb_pgbase != pgbase);
918
919 nfs_page_group_unlock(req);
920 desc->pg_moreio = 1;
921 nfs_pageio_doio(desc);
922 if (desc->pg_error < 0)
923 return 0;
924 if (desc->pg_recoalesce)
925 return 0;
926
927 nfs_page_group_lock(req, false);
928 continue;
929 }
930
931
932 WARN_ON_ONCE(subreq->wb_bytes + subreq->wb_pgbase > PAGE_SIZE);
933 WARN_ON_ONCE(subreq->wb_bytes > bytes_left);
934 WARN_ON_ONCE(subreq->wb_bytes == 0);
935
936 bytes_left -= subreq->wb_bytes;
937 offset += subreq->wb_bytes;
938 pgbase += subreq->wb_bytes;
939
940 if (bytes_left) {
941 subreq = nfs_create_request(req->wb_context,
942 req->wb_page,
943 subreq, pgbase, bytes_left);
944 if (IS_ERR(subreq))
945 goto err_ptr;
946 nfs_lock_request(subreq);
947 subreq->wb_offset = offset;
948 subreq->wb_index = req->wb_index;
949 }
950 } while (bytes_left > 0);
951
952 nfs_page_group_unlock(req);
953 return 1;
954err_ptr:
955 desc->pg_error = PTR_ERR(subreq);
956 nfs_page_group_unlock(req);
957 return 0;
958}
959
960static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc)
961{
962 LIST_HEAD(head);
963
964 do {
965 list_splice_init(&desc->pg_list, &head);
966 desc->pg_bytes_written -= desc->pg_count;
967 desc->pg_count = 0;
968 desc->pg_base = 0;
969 desc->pg_recoalesce = 0;
970 desc->pg_moreio = 0;
971
972 while (!list_empty(&head)) {
973 struct nfs_page *req;
974
975 req = list_first_entry(&head, struct nfs_page, wb_list);
976 nfs_list_remove_request(req);
977 if (__nfs_pageio_add_request(desc, req))
978 continue;
979 if (desc->pg_error < 0)
980 return 0;
981 break;
982 }
983 } while (desc->pg_recoalesce);
984 return 1;
985}
986
987int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
988 struct nfs_page *req)
989{
990 int ret;
991
992 do {
993 ret = __nfs_pageio_add_request(desc, req);
994 if (ret)
995 break;
996 if (desc->pg_error < 0)
997 break;
998 ret = nfs_do_recoalesce(desc);
999 } while (ret);
1000 return ret;
1001}
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013int nfs_pageio_resend(struct nfs_pageio_descriptor *desc,
1014 struct nfs_pgio_header *hdr)
1015{
1016 LIST_HEAD(failed);
1017
1018 desc->pg_dreq = hdr->dreq;
1019 while (!list_empty(&hdr->pages)) {
1020 struct nfs_page *req = nfs_list_entry(hdr->pages.next);
1021
1022 nfs_list_remove_request(req);
1023 if (!nfs_pageio_add_request(desc, req))
1024 nfs_list_add_request(req, &failed);
1025 }
1026 nfs_pageio_complete(desc);
1027 if (!list_empty(&failed)) {
1028 list_move(&failed, &hdr->pages);
1029 return -EIO;
1030 }
1031 return 0;
1032}
1033EXPORT_SYMBOL_GPL(nfs_pageio_resend);
1034
1035
1036
1037
1038
1039void nfs_pageio_complete(struct nfs_pageio_descriptor *desc)
1040{
1041 for (;;) {
1042 nfs_pageio_doio(desc);
1043 if (!desc->pg_recoalesce)
1044 break;
1045 if (!nfs_do_recoalesce(desc))
1046 break;
1047 }
1048}
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index)
1062{
1063 if (!list_empty(&desc->pg_list)) {
1064 struct nfs_page *prev = nfs_list_entry(desc->pg_list.prev);
1065 if (index != prev->wb_index + 1)
1066 nfs_pageio_complete(desc);
1067 }
1068}
1069
1070int __init nfs_init_nfspagecache(void)
1071{
1072 nfs_page_cachep = kmem_cache_create("nfs_page",
1073 sizeof(struct nfs_page),
1074 0, SLAB_HWCACHE_ALIGN,
1075 NULL);
1076 if (nfs_page_cachep == NULL)
1077 return -ENOMEM;
1078
1079 return 0;
1080}
1081
1082void nfs_destroy_nfspagecache(void)
1083{
1084 kmem_cache_destroy(nfs_page_cachep);
1085}
1086
1087static const struct rpc_call_ops nfs_pgio_common_ops = {
1088 .rpc_call_prepare = nfs_pgio_prepare,
1089 .rpc_call_done = nfs_pgio_result,
1090 .rpc_release = nfs_pgio_release,
1091};
1092
1093const struct nfs_pageio_ops nfs_pgio_rw_ops = {
1094 .pg_test = nfs_generic_pg_test,
1095 .pg_doio = nfs_generic_pg_pgios,
1096};
1097