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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/fs/nfs/pagelist.c
4 *
5 * A set of helper functions for managing NFS read and write requests.
6 * The main purpose of these routines is to provide support for the
7 * coalescing of several requests into a single RPC call.
8 *
9 * Copyright 2000, 2001 (c) Trond Myklebust <trond.myklebust@fys.uio.no>
10 *
11 */
12
13#include <linux/slab.h>
14#include <linux/file.h>
15#include <linux/sched.h>
16#include <linux/sunrpc/clnt.h>
17#include <linux/nfs.h>
18#include <linux/nfs3.h>
19#include <linux/nfs4.h>
20#include <linux/nfs_fs.h>
21#include <linux/nfs_page.h>
22#include <linux/nfs_mount.h>
23#include <linux/export.h>
24
25#include "internal.h"
26#include "pnfs.h"
27#include "nfstrace.h"
28
29#define NFSDBG_FACILITY NFSDBG_PAGECACHE
30
31static struct kmem_cache *nfs_page_cachep;
32static const struct rpc_call_ops nfs_pgio_common_ops;
33
34static struct nfs_pgio_mirror *
35nfs_pgio_get_mirror(struct nfs_pageio_descriptor *desc, u32 idx)
36{
37 if (desc->pg_ops->pg_get_mirror)
38 return desc->pg_ops->pg_get_mirror(desc, idx);
39 return &desc->pg_mirrors[0];
40}
41
42struct nfs_pgio_mirror *
43nfs_pgio_current_mirror(struct nfs_pageio_descriptor *desc)
44{
45 return nfs_pgio_get_mirror(desc, desc->pg_mirror_idx);
46}
47EXPORT_SYMBOL_GPL(nfs_pgio_current_mirror);
48
49static u32
50nfs_pgio_set_current_mirror(struct nfs_pageio_descriptor *desc, u32 idx)
51{
52 if (desc->pg_ops->pg_set_mirror)
53 return desc->pg_ops->pg_set_mirror(desc, idx);
54 return desc->pg_mirror_idx;
55}
56
57void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
58 struct nfs_pgio_header *hdr,
59 void (*release)(struct nfs_pgio_header *hdr))
60{
61 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
62
63
64 hdr->req = nfs_list_entry(mirror->pg_list.next);
65 hdr->inode = desc->pg_inode;
66 hdr->cred = nfs_req_openctx(hdr->req)->cred;
67 hdr->io_start = req_offset(hdr->req);
68 hdr->good_bytes = mirror->pg_count;
69 hdr->io_completion = desc->pg_io_completion;
70 hdr->dreq = desc->pg_dreq;
71 hdr->release = release;
72 hdr->completion_ops = desc->pg_completion_ops;
73 if (hdr->completion_ops->init_hdr)
74 hdr->completion_ops->init_hdr(hdr);
75
76 hdr->pgio_mirror_idx = desc->pg_mirror_idx;
77}
78EXPORT_SYMBOL_GPL(nfs_pgheader_init);
79
80void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos)
81{
82 unsigned int new = pos - hdr->io_start;
83
84 trace_nfs_pgio_error(hdr, error, pos);
85 if (hdr->good_bytes > new) {
86 hdr->good_bytes = new;
87 clear_bit(NFS_IOHDR_EOF, &hdr->flags);
88 if (!test_and_set_bit(NFS_IOHDR_ERROR, &hdr->flags))
89 hdr->error = error;
90 }
91}
92
93static inline struct nfs_page *
94nfs_page_alloc(void)
95{
96 struct nfs_page *p = kmem_cache_zalloc(nfs_page_cachep, GFP_KERNEL);
97 if (p)
98 INIT_LIST_HEAD(&p->wb_list);
99 return p;
100}
101
102static inline void
103nfs_page_free(struct nfs_page *p)
104{
105 kmem_cache_free(nfs_page_cachep, p);
106}
107
108/**
109 * nfs_iocounter_wait - wait for i/o to complete
110 * @l_ctx: nfs_lock_context with io_counter to use
111 *
112 * returns -ERESTARTSYS if interrupted by a fatal signal.
113 * Otherwise returns 0 once the io_count hits 0.
114 */
115int
116nfs_iocounter_wait(struct nfs_lock_context *l_ctx)
117{
118 return wait_var_event_killable(&l_ctx->io_count,
119 !atomic_read(&l_ctx->io_count));
120}
121
122/**
123 * nfs_async_iocounter_wait - wait on a rpc_waitqueue for I/O
124 * to complete
125 * @task: the rpc_task that should wait
126 * @l_ctx: nfs_lock_context with io_counter to check
127 *
128 * Returns true if there is outstanding I/O to wait on and the
129 * task has been put to sleep.
130 */
131bool
132nfs_async_iocounter_wait(struct rpc_task *task, struct nfs_lock_context *l_ctx)
133{
134 struct inode *inode = d_inode(l_ctx->open_context->dentry);
135 bool ret = false;
136
137 if (atomic_read(&l_ctx->io_count) > 0) {
138 rpc_sleep_on(&NFS_SERVER(inode)->uoc_rpcwaitq, task, NULL);
139 ret = true;
140 }
141
142 if (atomic_read(&l_ctx->io_count) == 0) {
143 rpc_wake_up_queued_task(&NFS_SERVER(inode)->uoc_rpcwaitq, task);
144 ret = false;
145 }
146
147 return ret;
148}
149EXPORT_SYMBOL_GPL(nfs_async_iocounter_wait);
150
151/*
152 * nfs_page_lock_head_request - page lock the head of the page group
153 * @req: any member of the page group
154 */
155struct nfs_page *
156nfs_page_group_lock_head(struct nfs_page *req)
157{
158 struct nfs_page *head = req->wb_head;
159
160 while (!nfs_lock_request(head)) {
161 int ret = nfs_wait_on_request(head);
162 if (ret < 0)
163 return ERR_PTR(ret);
164 }
165 if (head != req)
166 kref_get(&head->wb_kref);
167 return head;
168}
169
170/*
171 * nfs_unroll_locks - unlock all newly locked reqs and wait on @req
172 * @head: head request of page group, must be holding head lock
173 * @req: request that couldn't lock and needs to wait on the req bit lock
174 *
175 * This is a helper function for nfs_lock_and_join_requests
176 * returns 0 on success, < 0 on error.
177 */
178static void
179nfs_unroll_locks(struct nfs_page *head, struct nfs_page *req)
180{
181 struct nfs_page *tmp;
182
183 /* relinquish all the locks successfully grabbed this run */
184 for (tmp = head->wb_this_page ; tmp != req; tmp = tmp->wb_this_page) {
185 if (!kref_read(&tmp->wb_kref))
186 continue;
187 nfs_unlock_and_release_request(tmp);
188 }
189}
190
191/*
192 * nfs_page_group_lock_subreq - try to lock a subrequest
193 * @head: head request of page group
194 * @subreq: request to lock
195 *
196 * This is a helper function for nfs_lock_and_join_requests which
197 * must be called with the head request and page group both locked.
198 * On error, it returns with the page group unlocked.
199 */
200static int
201nfs_page_group_lock_subreq(struct nfs_page *head, struct nfs_page *subreq)
202{
203 int ret;
204
205 if (!kref_get_unless_zero(&subreq->wb_kref))
206 return 0;
207 while (!nfs_lock_request(subreq)) {
208 nfs_page_group_unlock(head);
209 ret = nfs_wait_on_request(subreq);
210 if (!ret)
211 ret = nfs_page_group_lock(head);
212 if (ret < 0) {
213 nfs_unroll_locks(head, subreq);
214 nfs_release_request(subreq);
215 return ret;
216 }
217 }
218 return 0;
219}
220
221/*
222 * nfs_page_group_lock_subrequests - try to lock the subrequests
223 * @head: head request of page group
224 *
225 * This is a helper function for nfs_lock_and_join_requests which
226 * must be called with the head request locked.
227 */
228int nfs_page_group_lock_subrequests(struct nfs_page *head)
229{
230 struct nfs_page *subreq;
231 int ret;
232
233 ret = nfs_page_group_lock(head);
234 if (ret < 0)
235 return ret;
236 /* lock each request in the page group */
237 for (subreq = head->wb_this_page; subreq != head;
238 subreq = subreq->wb_this_page) {
239 ret = nfs_page_group_lock_subreq(head, subreq);
240 if (ret < 0)
241 return ret;
242 }
243 nfs_page_group_unlock(head);
244 return 0;
245}
246
247/*
248 * nfs_page_set_headlock - set the request PG_HEADLOCK
249 * @req: request that is to be locked
250 *
251 * this lock must be held when modifying req->wb_head
252 *
253 * return 0 on success, < 0 on error
254 */
255int
256nfs_page_set_headlock(struct nfs_page *req)
257{
258 if (!test_and_set_bit(PG_HEADLOCK, &req->wb_flags))
259 return 0;
260
261 set_bit(PG_CONTENDED1, &req->wb_flags);
262 smp_mb__after_atomic();
263 return wait_on_bit_lock(&req->wb_flags, PG_HEADLOCK,
264 TASK_UNINTERRUPTIBLE);
265}
266
267/*
268 * nfs_page_clear_headlock - clear the request PG_HEADLOCK
269 * @req: request that is to be locked
270 */
271void
272nfs_page_clear_headlock(struct nfs_page *req)
273{
274 smp_mb__before_atomic();
275 clear_bit(PG_HEADLOCK, &req->wb_flags);
276 smp_mb__after_atomic();
277 if (!test_bit(PG_CONTENDED1, &req->wb_flags))
278 return;
279 wake_up_bit(&req->wb_flags, PG_HEADLOCK);
280}
281
282/*
283 * nfs_page_group_lock - lock the head of the page group
284 * @req: request in group that is to be locked
285 *
286 * this lock must be held when traversing or modifying the page
287 * group list
288 *
289 * return 0 on success, < 0 on error
290 */
291int
292nfs_page_group_lock(struct nfs_page *req)
293{
294 int ret;
295
296 ret = nfs_page_set_headlock(req);
297 if (ret || req->wb_head == req)
298 return ret;
299 return nfs_page_set_headlock(req->wb_head);
300}
301
302/*
303 * nfs_page_group_unlock - unlock the head of the page group
304 * @req: request in group that is to be unlocked
305 */
306void
307nfs_page_group_unlock(struct nfs_page *req)
308{
309 if (req != req->wb_head)
310 nfs_page_clear_headlock(req->wb_head);
311 nfs_page_clear_headlock(req);
312}
313
314/*
315 * nfs_page_group_sync_on_bit_locked
316 *
317 * must be called with page group lock held
318 */
319static bool
320nfs_page_group_sync_on_bit_locked(struct nfs_page *req, unsigned int bit)
321{
322 struct nfs_page *head = req->wb_head;
323 struct nfs_page *tmp;
324
325 WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &head->wb_flags));
326 WARN_ON_ONCE(test_and_set_bit(bit, &req->wb_flags));
327
328 tmp = req->wb_this_page;
329 while (tmp != req) {
330 if (!test_bit(bit, &tmp->wb_flags))
331 return false;
332 tmp = tmp->wb_this_page;
333 }
334
335 /* true! reset all bits */
336 tmp = req;
337 do {
338 clear_bit(bit, &tmp->wb_flags);
339 tmp = tmp->wb_this_page;
340 } while (tmp != req);
341
342 return true;
343}
344
345/*
346 * nfs_page_group_sync_on_bit - set bit on current request, but only
347 * return true if the bit is set for all requests in page group
348 * @req - request in page group
349 * @bit - PG_* bit that is used to sync page group
350 */
351bool nfs_page_group_sync_on_bit(struct nfs_page *req, unsigned int bit)
352{
353 bool ret;
354
355 nfs_page_group_lock(req);
356 ret = nfs_page_group_sync_on_bit_locked(req, bit);
357 nfs_page_group_unlock(req);
358
359 return ret;
360}
361
362/*
363 * nfs_page_group_init - Initialize the page group linkage for @req
364 * @req - a new nfs request
365 * @prev - the previous request in page group, or NULL if @req is the first
366 * or only request in the group (the head).
367 */
368static inline void
369nfs_page_group_init(struct nfs_page *req, struct nfs_page *prev)
370{
371 struct inode *inode;
372 WARN_ON_ONCE(prev == req);
373
374 if (!prev) {
375 /* a head request */
376 req->wb_head = req;
377 req->wb_this_page = req;
378 } else {
379 /* a subrequest */
380 WARN_ON_ONCE(prev->wb_this_page != prev->wb_head);
381 WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &prev->wb_head->wb_flags));
382 req->wb_head = prev->wb_head;
383 req->wb_this_page = prev->wb_this_page;
384 prev->wb_this_page = req;
385
386 /* All subrequests take a ref on the head request until
387 * nfs_page_group_destroy is called */
388 kref_get(&req->wb_head->wb_kref);
389
390 /* grab extra ref and bump the request count if head request
391 * has extra ref from the write/commit path to handle handoff
392 * between write and commit lists. */
393 if (test_bit(PG_INODE_REF, &prev->wb_head->wb_flags)) {
394 inode = page_file_mapping(req->wb_page)->host;
395 set_bit(PG_INODE_REF, &req->wb_flags);
396 kref_get(&req->wb_kref);
397 atomic_long_inc(&NFS_I(inode)->nrequests);
398 }
399 }
400}
401
402/*
403 * nfs_page_group_destroy - sync the destruction of page groups
404 * @req - request that no longer needs the page group
405 *
406 * releases the page group reference from each member once all
407 * members have called this function.
408 */
409static void
410nfs_page_group_destroy(struct kref *kref)
411{
412 struct nfs_page *req = container_of(kref, struct nfs_page, wb_kref);
413 struct nfs_page *head = req->wb_head;
414 struct nfs_page *tmp, *next;
415
416 if (!nfs_page_group_sync_on_bit(req, PG_TEARDOWN))
417 goto out;
418
419 tmp = req;
420 do {
421 next = tmp->wb_this_page;
422 /* unlink and free */
423 tmp->wb_this_page = tmp;
424 tmp->wb_head = tmp;
425 nfs_free_request(tmp);
426 tmp = next;
427 } while (tmp != req);
428out:
429 /* subrequests must release the ref on the head request */
430 if (head != req)
431 nfs_release_request(head);
432}
433
434static struct nfs_page *
435__nfs_create_request(struct nfs_lock_context *l_ctx, struct page *page,
436 unsigned int pgbase, unsigned int offset,
437 unsigned int count)
438{
439 struct nfs_page *req;
440 struct nfs_open_context *ctx = l_ctx->open_context;
441
442 if (test_bit(NFS_CONTEXT_BAD, &ctx->flags))
443 return ERR_PTR(-EBADF);
444 /* try to allocate the request struct */
445 req = nfs_page_alloc();
446 if (req == NULL)
447 return ERR_PTR(-ENOMEM);
448
449 req->wb_lock_context = l_ctx;
450 refcount_inc(&l_ctx->count);
451 atomic_inc(&l_ctx->io_count);
452
453 /* Initialize the request struct. Initially, we assume a
454 * long write-back delay. This will be adjusted in
455 * update_nfs_request below if the region is not locked. */
456 req->wb_page = page;
457 if (page) {
458 req->wb_index = page_index(page);
459 get_page(page);
460 }
461 req->wb_offset = offset;
462 req->wb_pgbase = pgbase;
463 req->wb_bytes = count;
464 kref_init(&req->wb_kref);
465 req->wb_nio = 0;
466 return req;
467}
468
469/**
470 * nfs_create_request - Create an NFS read/write request.
471 * @ctx: open context to use
472 * @page: page to write
473 * @offset: starting offset within the page for the write
474 * @count: number of bytes to read/write
475 *
476 * The page must be locked by the caller. This makes sure we never
477 * create two different requests for the same page.
478 * User should ensure it is safe to sleep in this function.
479 */
480struct nfs_page *
481nfs_create_request(struct nfs_open_context *ctx, struct page *page,
482 unsigned int offset, unsigned int count)
483{
484 struct nfs_lock_context *l_ctx = nfs_get_lock_context(ctx);
485 struct nfs_page *ret;
486
487 if (IS_ERR(l_ctx))
488 return ERR_CAST(l_ctx);
489 ret = __nfs_create_request(l_ctx, page, offset, offset, count);
490 if (!IS_ERR(ret))
491 nfs_page_group_init(ret, NULL);
492 nfs_put_lock_context(l_ctx);
493 return ret;
494}
495
496static struct nfs_page *
497nfs_create_subreq(struct nfs_page *req,
498 unsigned int pgbase,
499 unsigned int offset,
500 unsigned int count)
501{
502 struct nfs_page *last;
503 struct nfs_page *ret;
504
505 ret = __nfs_create_request(req->wb_lock_context, req->wb_page,
506 pgbase, offset, count);
507 if (!IS_ERR(ret)) {
508 /* find the last request */
509 for (last = req->wb_head;
510 last->wb_this_page != req->wb_head;
511 last = last->wb_this_page)
512 ;
513
514 nfs_lock_request(ret);
515 ret->wb_index = req->wb_index;
516 nfs_page_group_init(ret, last);
517 ret->wb_nio = req->wb_nio;
518 }
519 return ret;
520}
521
522/**
523 * nfs_unlock_request - Unlock request and wake up sleepers.
524 * @req: pointer to request
525 */
526void nfs_unlock_request(struct nfs_page *req)
527{
528 if (!NFS_WBACK_BUSY(req)) {
529 printk(KERN_ERR "NFS: Invalid unlock attempted\n");
530 BUG();
531 }
532 smp_mb__before_atomic();
533 clear_bit(PG_BUSY, &req->wb_flags);
534 smp_mb__after_atomic();
535 if (!test_bit(PG_CONTENDED2, &req->wb_flags))
536 return;
537 wake_up_bit(&req->wb_flags, PG_BUSY);
538}
539
540/**
541 * nfs_unlock_and_release_request - Unlock request and release the nfs_page
542 * @req: pointer to request
543 */
544void nfs_unlock_and_release_request(struct nfs_page *req)
545{
546 nfs_unlock_request(req);
547 nfs_release_request(req);
548}
549
550/*
551 * nfs_clear_request - Free up all resources allocated to the request
552 * @req:
553 *
554 * Release page and open context resources associated with a read/write
555 * request after it has completed.
556 */
557static void nfs_clear_request(struct nfs_page *req)
558{
559 struct page *page = req->wb_page;
560 struct nfs_lock_context *l_ctx = req->wb_lock_context;
561 struct nfs_open_context *ctx;
562
563 if (page != NULL) {
564 put_page(page);
565 req->wb_page = NULL;
566 }
567 if (l_ctx != NULL) {
568 if (atomic_dec_and_test(&l_ctx->io_count)) {
569 wake_up_var(&l_ctx->io_count);
570 ctx = l_ctx->open_context;
571 if (test_bit(NFS_CONTEXT_UNLOCK, &ctx->flags))
572 rpc_wake_up(&NFS_SERVER(d_inode(ctx->dentry))->uoc_rpcwaitq);
573 }
574 nfs_put_lock_context(l_ctx);
575 req->wb_lock_context = NULL;
576 }
577}
578
579/**
580 * nfs_free_request - Release the count on an NFS read/write request
581 * @req: request to release
582 *
583 * Note: Should never be called with the spinlock held!
584 */
585void nfs_free_request(struct nfs_page *req)
586{
587 WARN_ON_ONCE(req->wb_this_page != req);
588
589 /* extra debug: make sure no sync bits are still set */
590 WARN_ON_ONCE(test_bit(PG_TEARDOWN, &req->wb_flags));
591 WARN_ON_ONCE(test_bit(PG_UNLOCKPAGE, &req->wb_flags));
592 WARN_ON_ONCE(test_bit(PG_UPTODATE, &req->wb_flags));
593 WARN_ON_ONCE(test_bit(PG_WB_END, &req->wb_flags));
594 WARN_ON_ONCE(test_bit(PG_REMOVE, &req->wb_flags));
595
596 /* Release struct file and open context */
597 nfs_clear_request(req);
598 nfs_page_free(req);
599}
600
601void nfs_release_request(struct nfs_page *req)
602{
603 kref_put(&req->wb_kref, nfs_page_group_destroy);
604}
605EXPORT_SYMBOL_GPL(nfs_release_request);
606
607/**
608 * nfs_wait_on_request - Wait for a request to complete.
609 * @req: request to wait upon.
610 *
611 * Interruptible by fatal signals only.
612 * The user is responsible for holding a count on the request.
613 */
614int
615nfs_wait_on_request(struct nfs_page *req)
616{
617 if (!test_bit(PG_BUSY, &req->wb_flags))
618 return 0;
619 set_bit(PG_CONTENDED2, &req->wb_flags);
620 smp_mb__after_atomic();
621 return wait_on_bit_io(&req->wb_flags, PG_BUSY,
622 TASK_UNINTERRUPTIBLE);
623}
624EXPORT_SYMBOL_GPL(nfs_wait_on_request);
625
626/*
627 * nfs_generic_pg_test - determine if requests can be coalesced
628 * @desc: pointer to descriptor
629 * @prev: previous request in desc, or NULL
630 * @req: this request
631 *
632 * Returns zero if @req cannot be coalesced into @desc, otherwise it returns
633 * the size of the request.
634 */
635size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
636 struct nfs_page *prev, struct nfs_page *req)
637{
638 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
639
640
641 if (mirror->pg_count > mirror->pg_bsize) {
642 /* should never happen */
643 WARN_ON_ONCE(1);
644 return 0;
645 }
646
647 /*
648 * Limit the request size so that we can still allocate a page array
649 * for it without upsetting the slab allocator.
650 */
651 if (((mirror->pg_count + req->wb_bytes) >> PAGE_SHIFT) *
652 sizeof(struct page *) > PAGE_SIZE)
653 return 0;
654
655 return min(mirror->pg_bsize - mirror->pg_count, (size_t)req->wb_bytes);
656}
657EXPORT_SYMBOL_GPL(nfs_generic_pg_test);
658
659struct nfs_pgio_header *nfs_pgio_header_alloc(const struct nfs_rw_ops *ops)
660{
661 struct nfs_pgio_header *hdr = ops->rw_alloc_header();
662
663 if (hdr) {
664 INIT_LIST_HEAD(&hdr->pages);
665 hdr->rw_ops = ops;
666 }
667 return hdr;
668}
669EXPORT_SYMBOL_GPL(nfs_pgio_header_alloc);
670
671/**
672 * nfs_pgio_data_destroy - make @hdr suitable for reuse
673 *
674 * Frees memory and releases refs from nfs_generic_pgio, so that it may
675 * be called again.
676 *
677 * @hdr: A header that has had nfs_generic_pgio called
678 */
679static void nfs_pgio_data_destroy(struct nfs_pgio_header *hdr)
680{
681 if (hdr->args.context)
682 put_nfs_open_context(hdr->args.context);
683 if (hdr->page_array.pagevec != hdr->page_array.page_array)
684 kfree(hdr->page_array.pagevec);
685}
686
687/*
688 * nfs_pgio_header_free - Free a read or write header
689 * @hdr: The header to free
690 */
691void nfs_pgio_header_free(struct nfs_pgio_header *hdr)
692{
693 nfs_pgio_data_destroy(hdr);
694 hdr->rw_ops->rw_free_header(hdr);
695}
696EXPORT_SYMBOL_GPL(nfs_pgio_header_free);
697
698/**
699 * nfs_pgio_rpcsetup - Set up arguments for a pageio call
700 * @hdr: The pageio hdr
701 * @count: Number of bytes to read
702 * @how: How to commit data (writes only)
703 * @cinfo: Commit information for the call (writes only)
704 */
705static void nfs_pgio_rpcsetup(struct nfs_pgio_header *hdr,
706 unsigned int count,
707 int how, struct nfs_commit_info *cinfo)
708{
709 struct nfs_page *req = hdr->req;
710
711 /* Set up the RPC argument and reply structs
712 * NB: take care not to mess about with hdr->commit et al. */
713
714 hdr->args.fh = NFS_FH(hdr->inode);
715 hdr->args.offset = req_offset(req);
716 /* pnfs_set_layoutcommit needs this */
717 hdr->mds_offset = hdr->args.offset;
718 hdr->args.pgbase = req->wb_pgbase;
719 hdr->args.pages = hdr->page_array.pagevec;
720 hdr->args.count = count;
721 hdr->args.context = get_nfs_open_context(nfs_req_openctx(req));
722 hdr->args.lock_context = req->wb_lock_context;
723 hdr->args.stable = NFS_UNSTABLE;
724 switch (how & (FLUSH_STABLE | FLUSH_COND_STABLE)) {
725 case 0:
726 break;
727 case FLUSH_COND_STABLE:
728 if (nfs_reqs_to_commit(cinfo))
729 break;
730 fallthrough;
731 default:
732 hdr->args.stable = NFS_FILE_SYNC;
733 }
734
735 hdr->res.fattr = &hdr->fattr;
736 hdr->res.count = 0;
737 hdr->res.eof = 0;
738 hdr->res.verf = &hdr->verf;
739 nfs_fattr_init(&hdr->fattr);
740}
741
742/**
743 * nfs_pgio_prepare - Prepare pageio hdr to go over the wire
744 * @task: The current task
745 * @calldata: pageio header to prepare
746 */
747static void nfs_pgio_prepare(struct rpc_task *task, void *calldata)
748{
749 struct nfs_pgio_header *hdr = calldata;
750 int err;
751 err = NFS_PROTO(hdr->inode)->pgio_rpc_prepare(task, hdr);
752 if (err)
753 rpc_exit(task, err);
754}
755
756int nfs_initiate_pgio(struct rpc_clnt *clnt, struct nfs_pgio_header *hdr,
757 const struct cred *cred, const struct nfs_rpc_ops *rpc_ops,
758 const struct rpc_call_ops *call_ops, int how, int flags)
759{
760 struct rpc_task *task;
761 struct rpc_message msg = {
762 .rpc_argp = &hdr->args,
763 .rpc_resp = &hdr->res,
764 .rpc_cred = cred,
765 };
766 struct rpc_task_setup task_setup_data = {
767 .rpc_client = clnt,
768 .task = &hdr->task,
769 .rpc_message = &msg,
770 .callback_ops = call_ops,
771 .callback_data = hdr,
772 .workqueue = nfsiod_workqueue,
773 .flags = RPC_TASK_ASYNC | flags,
774 };
775
776 hdr->rw_ops->rw_initiate(hdr, &msg, rpc_ops, &task_setup_data, how);
777
778 dprintk("NFS: initiated pgio call "
779 "(req %s/%llu, %u bytes @ offset %llu)\n",
780 hdr->inode->i_sb->s_id,
781 (unsigned long long)NFS_FILEID(hdr->inode),
782 hdr->args.count,
783 (unsigned long long)hdr->args.offset);
784
785 task = rpc_run_task(&task_setup_data);
786 if (IS_ERR(task))
787 return PTR_ERR(task);
788 rpc_put_task(task);
789 return 0;
790}
791EXPORT_SYMBOL_GPL(nfs_initiate_pgio);
792
793/**
794 * nfs_pgio_error - Clean up from a pageio error
795 * @hdr: pageio header
796 */
797static void nfs_pgio_error(struct nfs_pgio_header *hdr)
798{
799 set_bit(NFS_IOHDR_REDO, &hdr->flags);
800 hdr->completion_ops->completion(hdr);
801}
802
803/**
804 * nfs_pgio_release - Release pageio data
805 * @calldata: The pageio header to release
806 */
807static void nfs_pgio_release(void *calldata)
808{
809 struct nfs_pgio_header *hdr = calldata;
810 hdr->completion_ops->completion(hdr);
811}
812
813static void nfs_pageio_mirror_init(struct nfs_pgio_mirror *mirror,
814 unsigned int bsize)
815{
816 INIT_LIST_HEAD(&mirror->pg_list);
817 mirror->pg_bytes_written = 0;
818 mirror->pg_count = 0;
819 mirror->pg_bsize = bsize;
820 mirror->pg_base = 0;
821 mirror->pg_recoalesce = 0;
822}
823
824/**
825 * nfs_pageio_init - initialise a page io descriptor
826 * @desc: pointer to descriptor
827 * @inode: pointer to inode
828 * @pg_ops: pointer to pageio operations
829 * @compl_ops: pointer to pageio completion operations
830 * @rw_ops: pointer to nfs read/write operations
831 * @bsize: io block size
832 * @io_flags: extra parameters for the io function
833 */
834void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
835 struct inode *inode,
836 const struct nfs_pageio_ops *pg_ops,
837 const struct nfs_pgio_completion_ops *compl_ops,
838 const struct nfs_rw_ops *rw_ops,
839 size_t bsize,
840 int io_flags)
841{
842 desc->pg_moreio = 0;
843 desc->pg_inode = inode;
844 desc->pg_ops = pg_ops;
845 desc->pg_completion_ops = compl_ops;
846 desc->pg_rw_ops = rw_ops;
847 desc->pg_ioflags = io_flags;
848 desc->pg_error = 0;
849 desc->pg_lseg = NULL;
850 desc->pg_io_completion = NULL;
851 desc->pg_dreq = NULL;
852 desc->pg_bsize = bsize;
853
854 desc->pg_mirror_count = 1;
855 desc->pg_mirror_idx = 0;
856
857 desc->pg_mirrors_dynamic = NULL;
858 desc->pg_mirrors = desc->pg_mirrors_static;
859 nfs_pageio_mirror_init(&desc->pg_mirrors[0], bsize);
860 desc->pg_maxretrans = 0;
861}
862
863/**
864 * nfs_pgio_result - Basic pageio error handling
865 * @task: The task that ran
866 * @calldata: Pageio header to check
867 */
868static void nfs_pgio_result(struct rpc_task *task, void *calldata)
869{
870 struct nfs_pgio_header *hdr = calldata;
871 struct inode *inode = hdr->inode;
872
873 dprintk("NFS: %s: %5u, (status %d)\n", __func__,
874 task->tk_pid, task->tk_status);
875
876 if (hdr->rw_ops->rw_done(task, hdr, inode) != 0)
877 return;
878 if (task->tk_status < 0)
879 nfs_set_pgio_error(hdr, task->tk_status, hdr->args.offset);
880 else
881 hdr->rw_ops->rw_result(task, hdr);
882}
883
884/*
885 * Create an RPC task for the given read or write request and kick it.
886 * The page must have been locked by the caller.
887 *
888 * It may happen that the page we're passed is not marked dirty.
889 * This is the case if nfs_updatepage detects a conflicting request
890 * that has been written but not committed.
891 */
892int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
893 struct nfs_pgio_header *hdr)
894{
895 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
896
897 struct nfs_page *req;
898 struct page **pages,
899 *last_page;
900 struct list_head *head = &mirror->pg_list;
901 struct nfs_commit_info cinfo;
902 struct nfs_page_array *pg_array = &hdr->page_array;
903 unsigned int pagecount, pageused;
904 gfp_t gfp_flags = GFP_KERNEL;
905
906 pagecount = nfs_page_array_len(mirror->pg_base, mirror->pg_count);
907 pg_array->npages = pagecount;
908
909 if (pagecount <= ARRAY_SIZE(pg_array->page_array))
910 pg_array->pagevec = pg_array->page_array;
911 else {
912 pg_array->pagevec = kcalloc(pagecount, sizeof(struct page *), gfp_flags);
913 if (!pg_array->pagevec) {
914 pg_array->npages = 0;
915 nfs_pgio_error(hdr);
916 desc->pg_error = -ENOMEM;
917 return desc->pg_error;
918 }
919 }
920
921 nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq);
922 pages = hdr->page_array.pagevec;
923 last_page = NULL;
924 pageused = 0;
925 while (!list_empty(head)) {
926 req = nfs_list_entry(head->next);
927 nfs_list_move_request(req, &hdr->pages);
928
929 if (!last_page || last_page != req->wb_page) {
930 pageused++;
931 if (pageused > pagecount)
932 break;
933 *pages++ = last_page = req->wb_page;
934 }
935 }
936 if (WARN_ON_ONCE(pageused != pagecount)) {
937 nfs_pgio_error(hdr);
938 desc->pg_error = -EINVAL;
939 return desc->pg_error;
940 }
941
942 if ((desc->pg_ioflags & FLUSH_COND_STABLE) &&
943 (desc->pg_moreio || nfs_reqs_to_commit(&cinfo)))
944 desc->pg_ioflags &= ~FLUSH_COND_STABLE;
945
946 /* Set up the argument struct */
947 nfs_pgio_rpcsetup(hdr, mirror->pg_count, desc->pg_ioflags, &cinfo);
948 desc->pg_rpc_callops = &nfs_pgio_common_ops;
949 return 0;
950}
951EXPORT_SYMBOL_GPL(nfs_generic_pgio);
952
953static int nfs_generic_pg_pgios(struct nfs_pageio_descriptor *desc)
954{
955 struct nfs_pgio_header *hdr;
956 int ret;
957 unsigned short task_flags = 0;
958
959 hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
960 if (!hdr) {
961 desc->pg_error = -ENOMEM;
962 return desc->pg_error;
963 }
964 nfs_pgheader_init(desc, hdr, nfs_pgio_header_free);
965 ret = nfs_generic_pgio(desc, hdr);
966 if (ret == 0) {
967 if (NFS_SERVER(hdr->inode)->nfs_client->cl_minorversion)
968 task_flags = RPC_TASK_MOVEABLE;
969 ret = nfs_initiate_pgio(NFS_CLIENT(hdr->inode),
970 hdr,
971 hdr->cred,
972 NFS_PROTO(hdr->inode),
973 desc->pg_rpc_callops,
974 desc->pg_ioflags,
975 RPC_TASK_CRED_NOREF | task_flags);
976 }
977 return ret;
978}
979
980static struct nfs_pgio_mirror *
981nfs_pageio_alloc_mirrors(struct nfs_pageio_descriptor *desc,
982 unsigned int mirror_count)
983{
984 struct nfs_pgio_mirror *ret;
985 unsigned int i;
986
987 kfree(desc->pg_mirrors_dynamic);
988 desc->pg_mirrors_dynamic = NULL;
989 if (mirror_count == 1)
990 return desc->pg_mirrors_static;
991 ret = kmalloc_array(mirror_count, sizeof(*ret), GFP_KERNEL);
992 if (ret != NULL) {
993 for (i = 0; i < mirror_count; i++)
994 nfs_pageio_mirror_init(&ret[i], desc->pg_bsize);
995 desc->pg_mirrors_dynamic = ret;
996 }
997 return ret;
998}
999
1000/*
1001 * nfs_pageio_setup_mirroring - determine if mirroring is to be used
1002 * by calling the pg_get_mirror_count op
1003 */
1004static void nfs_pageio_setup_mirroring(struct nfs_pageio_descriptor *pgio,
1005 struct nfs_page *req)
1006{
1007 unsigned int mirror_count = 1;
1008
1009 if (pgio->pg_ops->pg_get_mirror_count)
1010 mirror_count = pgio->pg_ops->pg_get_mirror_count(pgio, req);
1011 if (mirror_count == pgio->pg_mirror_count || pgio->pg_error < 0)
1012 return;
1013
1014 if (!mirror_count || mirror_count > NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX) {
1015 pgio->pg_error = -EINVAL;
1016 return;
1017 }
1018
1019 pgio->pg_mirrors = nfs_pageio_alloc_mirrors(pgio, mirror_count);
1020 if (pgio->pg_mirrors == NULL) {
1021 pgio->pg_error = -ENOMEM;
1022 pgio->pg_mirrors = pgio->pg_mirrors_static;
1023 mirror_count = 1;
1024 }
1025 pgio->pg_mirror_count = mirror_count;
1026}
1027
1028static void nfs_pageio_cleanup_mirroring(struct nfs_pageio_descriptor *pgio)
1029{
1030 pgio->pg_mirror_count = 1;
1031 pgio->pg_mirror_idx = 0;
1032 pgio->pg_mirrors = pgio->pg_mirrors_static;
1033 kfree(pgio->pg_mirrors_dynamic);
1034 pgio->pg_mirrors_dynamic = NULL;
1035}
1036
1037static bool nfs_match_lock_context(const struct nfs_lock_context *l1,
1038 const struct nfs_lock_context *l2)
1039{
1040 return l1->lockowner == l2->lockowner;
1041}
1042
1043/**
1044 * nfs_coalesce_size - test two requests for compatibility
1045 * @prev: pointer to nfs_page
1046 * @req: pointer to nfs_page
1047 * @pgio: pointer to nfs_pagio_descriptor
1048 *
1049 * The nfs_page structures 'prev' and 'req' are compared to ensure that the
1050 * page data area they describe is contiguous, and that their RPC
1051 * credentials, NFSv4 open state, and lockowners are the same.
1052 *
1053 * Returns size of the request that can be coalesced
1054 */
1055static unsigned int nfs_coalesce_size(struct nfs_page *prev,
1056 struct nfs_page *req,
1057 struct nfs_pageio_descriptor *pgio)
1058{
1059 struct file_lock_context *flctx;
1060
1061 if (prev) {
1062 if (!nfs_match_open_context(nfs_req_openctx(req), nfs_req_openctx(prev)))
1063 return 0;
1064 flctx = d_inode(nfs_req_openctx(req)->dentry)->i_flctx;
1065 if (flctx != NULL &&
1066 !(list_empty_careful(&flctx->flc_posix) &&
1067 list_empty_careful(&flctx->flc_flock)) &&
1068 !nfs_match_lock_context(req->wb_lock_context,
1069 prev->wb_lock_context))
1070 return 0;
1071 if (req_offset(req) != req_offset(prev) + prev->wb_bytes)
1072 return 0;
1073 if (req->wb_page == prev->wb_page) {
1074 if (req->wb_pgbase != prev->wb_pgbase + prev->wb_bytes)
1075 return 0;
1076 } else {
1077 if (req->wb_pgbase != 0 ||
1078 prev->wb_pgbase + prev->wb_bytes != PAGE_SIZE)
1079 return 0;
1080 }
1081 }
1082 return pgio->pg_ops->pg_test(pgio, prev, req);
1083}
1084
1085/**
1086 * nfs_pageio_do_add_request - Attempt to coalesce a request into a page list.
1087 * @desc: destination io descriptor
1088 * @req: request
1089 *
1090 * If the request 'req' was successfully coalesced into the existing list
1091 * of pages 'desc', it returns the size of req.
1092 */
1093static unsigned int
1094nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc,
1095 struct nfs_page *req)
1096{
1097 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
1098 struct nfs_page *prev = NULL;
1099 unsigned int size;
1100
1101 if (list_empty(&mirror->pg_list)) {
1102 if (desc->pg_ops->pg_init)
1103 desc->pg_ops->pg_init(desc, req);
1104 if (desc->pg_error < 0)
1105 return 0;
1106 mirror->pg_base = req->wb_pgbase;
1107 mirror->pg_count = 0;
1108 mirror->pg_recoalesce = 0;
1109 } else
1110 prev = nfs_list_entry(mirror->pg_list.prev);
1111
1112 if (desc->pg_maxretrans && req->wb_nio > desc->pg_maxretrans) {
1113 if (NFS_SERVER(desc->pg_inode)->flags & NFS_MOUNT_SOFTERR)
1114 desc->pg_error = -ETIMEDOUT;
1115 else
1116 desc->pg_error = -EIO;
1117 return 0;
1118 }
1119
1120 size = nfs_coalesce_size(prev, req, desc);
1121 if (size < req->wb_bytes)
1122 return size;
1123 nfs_list_move_request(req, &mirror->pg_list);
1124 mirror->pg_count += req->wb_bytes;
1125 return req->wb_bytes;
1126}
1127
1128/*
1129 * Helper for nfs_pageio_add_request and nfs_pageio_complete
1130 */
1131static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc)
1132{
1133 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
1134
1135 if (!list_empty(&mirror->pg_list)) {
1136 int error = desc->pg_ops->pg_doio(desc);
1137 if (error < 0)
1138 desc->pg_error = error;
1139 if (list_empty(&mirror->pg_list))
1140 mirror->pg_bytes_written += mirror->pg_count;
1141 }
1142}
1143
1144static void
1145nfs_pageio_cleanup_request(struct nfs_pageio_descriptor *desc,
1146 struct nfs_page *req)
1147{
1148 LIST_HEAD(head);
1149
1150 nfs_list_move_request(req, &head);
1151 desc->pg_completion_ops->error_cleanup(&head, desc->pg_error);
1152}
1153
1154/**
1155 * __nfs_pageio_add_request - Attempt to coalesce a request into a page list.
1156 * @desc: destination io descriptor
1157 * @req: request
1158 *
1159 * This may split a request into subrequests which are all part of the
1160 * same page group. If so, it will submit @req as the last one, to ensure
1161 * the pointer to @req is still valid in case of failure.
1162 *
1163 * Returns true if the request 'req' was successfully coalesced into the
1164 * existing list of pages 'desc'.
1165 */
1166static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
1167 struct nfs_page *req)
1168{
1169 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
1170 struct nfs_page *subreq;
1171 unsigned int size, subreq_size;
1172
1173 nfs_page_group_lock(req);
1174
1175 subreq = req;
1176 subreq_size = subreq->wb_bytes;
1177 for(;;) {
1178 size = nfs_pageio_do_add_request(desc, subreq);
1179 if (size == subreq_size) {
1180 /* We successfully submitted a request */
1181 if (subreq == req)
1182 break;
1183 req->wb_pgbase += size;
1184 req->wb_bytes -= size;
1185 req->wb_offset += size;
1186 subreq_size = req->wb_bytes;
1187 subreq = req;
1188 continue;
1189 }
1190 if (WARN_ON_ONCE(subreq != req)) {
1191 nfs_page_group_unlock(req);
1192 nfs_pageio_cleanup_request(desc, subreq);
1193 subreq = req;
1194 subreq_size = req->wb_bytes;
1195 nfs_page_group_lock(req);
1196 }
1197 if (!size) {
1198 /* Can't coalesce any more, so do I/O */
1199 nfs_page_group_unlock(req);
1200 desc->pg_moreio = 1;
1201 nfs_pageio_doio(desc);
1202 if (desc->pg_error < 0 || mirror->pg_recoalesce)
1203 return 0;
1204 /* retry add_request for this subreq */
1205 nfs_page_group_lock(req);
1206 continue;
1207 }
1208 subreq = nfs_create_subreq(req, req->wb_pgbase,
1209 req->wb_offset, size);
1210 if (IS_ERR(subreq))
1211 goto err_ptr;
1212 subreq_size = size;
1213 }
1214
1215 nfs_page_group_unlock(req);
1216 return 1;
1217err_ptr:
1218 desc->pg_error = PTR_ERR(subreq);
1219 nfs_page_group_unlock(req);
1220 return 0;
1221}
1222
1223static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc)
1224{
1225 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
1226 LIST_HEAD(head);
1227
1228 do {
1229 list_splice_init(&mirror->pg_list, &head);
1230
1231 while (!list_empty(&head)) {
1232 struct nfs_page *req;
1233
1234 req = list_first_entry(&head, struct nfs_page, wb_list);
1235 if (__nfs_pageio_add_request(desc, req))
1236 continue;
1237 if (desc->pg_error < 0) {
1238 list_splice_tail(&head, &mirror->pg_list);
1239 mirror->pg_recoalesce = 1;
1240 return 0;
1241 }
1242 break;
1243 }
1244 } while (mirror->pg_recoalesce);
1245 return 1;
1246}
1247
1248static int nfs_pageio_add_request_mirror(struct nfs_pageio_descriptor *desc,
1249 struct nfs_page *req)
1250{
1251 int ret;
1252
1253 do {
1254 ret = __nfs_pageio_add_request(desc, req);
1255 if (ret)
1256 break;
1257 if (desc->pg_error < 0)
1258 break;
1259 ret = nfs_do_recoalesce(desc);
1260 } while (ret);
1261
1262 return ret;
1263}
1264
1265static void nfs_pageio_error_cleanup(struct nfs_pageio_descriptor *desc)
1266{
1267 u32 midx;
1268 struct nfs_pgio_mirror *mirror;
1269
1270 if (!desc->pg_error)
1271 return;
1272
1273 for (midx = 0; midx < desc->pg_mirror_count; midx++) {
1274 mirror = nfs_pgio_get_mirror(desc, midx);
1275 desc->pg_completion_ops->error_cleanup(&mirror->pg_list,
1276 desc->pg_error);
1277 }
1278}
1279
1280int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
1281 struct nfs_page *req)
1282{
1283 u32 midx;
1284 unsigned int pgbase, offset, bytes;
1285 struct nfs_page *dupreq;
1286
1287 pgbase = req->wb_pgbase;
1288 offset = req->wb_offset;
1289 bytes = req->wb_bytes;
1290
1291 nfs_pageio_setup_mirroring(desc, req);
1292 if (desc->pg_error < 0)
1293 goto out_failed;
1294
1295 /* Create the mirror instances first, and fire them off */
1296 for (midx = 1; midx < desc->pg_mirror_count; midx++) {
1297 nfs_page_group_lock(req);
1298
1299 dupreq = nfs_create_subreq(req,
1300 pgbase, offset, bytes);
1301
1302 nfs_page_group_unlock(req);
1303 if (IS_ERR(dupreq)) {
1304 desc->pg_error = PTR_ERR(dupreq);
1305 goto out_failed;
1306 }
1307
1308 nfs_pgio_set_current_mirror(desc, midx);
1309 if (!nfs_pageio_add_request_mirror(desc, dupreq))
1310 goto out_cleanup_subreq;
1311 }
1312
1313 nfs_pgio_set_current_mirror(desc, 0);
1314 if (!nfs_pageio_add_request_mirror(desc, req))
1315 goto out_failed;
1316
1317 return 1;
1318
1319out_cleanup_subreq:
1320 nfs_pageio_cleanup_request(desc, dupreq);
1321out_failed:
1322 nfs_pageio_error_cleanup(desc);
1323 return 0;
1324}
1325
1326/*
1327 * nfs_pageio_complete_mirror - Complete I/O on the current mirror of an
1328 * nfs_pageio_descriptor
1329 * @desc: pointer to io descriptor
1330 * @mirror_idx: pointer to mirror index
1331 */
1332static void nfs_pageio_complete_mirror(struct nfs_pageio_descriptor *desc,
1333 u32 mirror_idx)
1334{
1335 struct nfs_pgio_mirror *mirror;
1336 u32 restore_idx;
1337
1338 restore_idx = nfs_pgio_set_current_mirror(desc, mirror_idx);
1339 mirror = nfs_pgio_current_mirror(desc);
1340
1341 for (;;) {
1342 nfs_pageio_doio(desc);
1343 if (desc->pg_error < 0 || !mirror->pg_recoalesce)
1344 break;
1345 if (!nfs_do_recoalesce(desc))
1346 break;
1347 }
1348 nfs_pgio_set_current_mirror(desc, restore_idx);
1349}
1350
1351/*
1352 * nfs_pageio_resend - Transfer requests to new descriptor and resend
1353 * @hdr - the pgio header to move request from
1354 * @desc - the pageio descriptor to add requests to
1355 *
1356 * Try to move each request (nfs_page) from @hdr to @desc then attempt
1357 * to send them.
1358 *
1359 * Returns 0 on success and < 0 on error.
1360 */
1361int nfs_pageio_resend(struct nfs_pageio_descriptor *desc,
1362 struct nfs_pgio_header *hdr)
1363{
1364 LIST_HEAD(pages);
1365
1366 desc->pg_io_completion = hdr->io_completion;
1367 desc->pg_dreq = hdr->dreq;
1368 list_splice_init(&hdr->pages, &pages);
1369 while (!list_empty(&pages)) {
1370 struct nfs_page *req = nfs_list_entry(pages.next);
1371
1372 if (!nfs_pageio_add_request(desc, req))
1373 break;
1374 }
1375 nfs_pageio_complete(desc);
1376 if (!list_empty(&pages)) {
1377 int err = desc->pg_error < 0 ? desc->pg_error : -EIO;
1378 hdr->completion_ops->error_cleanup(&pages, err);
1379 nfs_set_pgio_error(hdr, err, hdr->io_start);
1380 return err;
1381 }
1382 return 0;
1383}
1384EXPORT_SYMBOL_GPL(nfs_pageio_resend);
1385
1386/**
1387 * nfs_pageio_complete - Complete I/O then cleanup an nfs_pageio_descriptor
1388 * @desc: pointer to io descriptor
1389 */
1390void nfs_pageio_complete(struct nfs_pageio_descriptor *desc)
1391{
1392 u32 midx;
1393
1394 for (midx = 0; midx < desc->pg_mirror_count; midx++)
1395 nfs_pageio_complete_mirror(desc, midx);
1396
1397 if (desc->pg_error < 0)
1398 nfs_pageio_error_cleanup(desc);
1399 if (desc->pg_ops->pg_cleanup)
1400 desc->pg_ops->pg_cleanup(desc);
1401 nfs_pageio_cleanup_mirroring(desc);
1402}
1403
1404/**
1405 * nfs_pageio_cond_complete - Conditional I/O completion
1406 * @desc: pointer to io descriptor
1407 * @index: page index
1408 *
1409 * It is important to ensure that processes don't try to take locks
1410 * on non-contiguous ranges of pages as that might deadlock. This
1411 * function should be called before attempting to wait on a locked
1412 * nfs_page. It will complete the I/O if the page index 'index'
1413 * is not contiguous with the existing list of pages in 'desc'.
1414 */
1415void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index)
1416{
1417 struct nfs_pgio_mirror *mirror;
1418 struct nfs_page *prev;
1419 u32 midx;
1420
1421 for (midx = 0; midx < desc->pg_mirror_count; midx++) {
1422 mirror = nfs_pgio_get_mirror(desc, midx);
1423 if (!list_empty(&mirror->pg_list)) {
1424 prev = nfs_list_entry(mirror->pg_list.prev);
1425 if (index != prev->wb_index + 1) {
1426 nfs_pageio_complete(desc);
1427 break;
1428 }
1429 }
1430 }
1431}
1432
1433/*
1434 * nfs_pageio_stop_mirroring - stop using mirroring (set mirror count to 1)
1435 */
1436void nfs_pageio_stop_mirroring(struct nfs_pageio_descriptor *pgio)
1437{
1438 nfs_pageio_complete(pgio);
1439}
1440
1441int __init nfs_init_nfspagecache(void)
1442{
1443 nfs_page_cachep = kmem_cache_create("nfs_page",
1444 sizeof(struct nfs_page),
1445 0, SLAB_HWCACHE_ALIGN,
1446 NULL);
1447 if (nfs_page_cachep == NULL)
1448 return -ENOMEM;
1449
1450 return 0;
1451}
1452
1453void nfs_destroy_nfspagecache(void)
1454{
1455 kmem_cache_destroy(nfs_page_cachep);
1456}
1457
1458static const struct rpc_call_ops nfs_pgio_common_ops = {
1459 .rpc_call_prepare = nfs_pgio_prepare,
1460 .rpc_call_done = nfs_pgio_result,
1461 .rpc_release = nfs_pgio_release,
1462};
1463
1464const struct nfs_pageio_ops nfs_pgio_rw_ops = {
1465 .pg_test = nfs_generic_pg_test,
1466 .pg_doio = nfs_generic_pg_pgios,
1467};
1/*
2 * linux/fs/nfs/pagelist.c
3 *
4 * A set of helper functions for managing NFS read and write requests.
5 * The main purpose of these routines is to provide support for the
6 * coalescing of several requests into a single RPC call.
7 *
8 * Copyright 2000, 2001 (c) Trond Myklebust <trond.myklebust@fys.uio.no>
9 *
10 */
11
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
45struct nfs_pgio_mirror *
46nfs_pgio_current_mirror(struct nfs_pageio_descriptor *desc)
47{
48 return nfs_pgio_has_mirroring(desc) ?
49 &desc->pg_mirrors[desc->pg_mirror_idx] :
50 &desc->pg_mirrors[0];
51}
52EXPORT_SYMBOL_GPL(nfs_pgio_current_mirror);
53
54void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
55 struct nfs_pgio_header *hdr,
56 void (*release)(struct nfs_pgio_header *hdr))
57{
58 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
59
60
61 hdr->req = nfs_list_entry(mirror->pg_list.next);
62 hdr->inode = desc->pg_inode;
63 hdr->cred = hdr->req->wb_context->cred;
64 hdr->io_start = req_offset(hdr->req);
65 hdr->good_bytes = mirror->pg_count;
66 hdr->dreq = desc->pg_dreq;
67 hdr->layout_private = desc->pg_layout_private;
68 hdr->release = release;
69 hdr->completion_ops = desc->pg_completion_ops;
70 if (hdr->completion_ops->init_hdr)
71 hdr->completion_ops->init_hdr(hdr);
72
73 hdr->pgio_mirror_idx = desc->pg_mirror_idx;
74}
75EXPORT_SYMBOL_GPL(nfs_pgheader_init);
76
77void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos)
78{
79 spin_lock(&hdr->lock);
80 if (!test_and_set_bit(NFS_IOHDR_ERROR, &hdr->flags)
81 || pos < hdr->io_start + hdr->good_bytes) {
82 clear_bit(NFS_IOHDR_EOF, &hdr->flags);
83 hdr->good_bytes = pos - hdr->io_start;
84 hdr->error = error;
85 }
86 spin_unlock(&hdr->lock);
87}
88
89static inline struct nfs_page *
90nfs_page_alloc(void)
91{
92 struct nfs_page *p = kmem_cache_zalloc(nfs_page_cachep, GFP_NOIO);
93 if (p)
94 INIT_LIST_HEAD(&p->wb_list);
95 return p;
96}
97
98static inline void
99nfs_page_free(struct nfs_page *p)
100{
101 kmem_cache_free(nfs_page_cachep, p);
102}
103
104/**
105 * nfs_iocounter_wait - wait for i/o to complete
106 * @l_ctx: nfs_lock_context with io_counter to use
107 *
108 * returns -ERESTARTSYS if interrupted by a fatal signal.
109 * Otherwise returns 0 once the io_count hits 0.
110 */
111int
112nfs_iocounter_wait(struct nfs_lock_context *l_ctx)
113{
114 return wait_on_atomic_t(&l_ctx->io_count, nfs_wait_atomic_killable,
115 TASK_KILLABLE);
116}
117
118/*
119 * nfs_page_group_lock - lock the head of the page group
120 * @req - request in group that is to be locked
121 * @nonblock - if true don't block waiting for lock
122 *
123 * this lock must be held if modifying the page group list
124 *
125 * return 0 on success, < 0 on error: -EDELAY if nonblocking or the
126 * result from wait_on_bit_lock
127 *
128 * NOTE: calling with nonblock=false should always have set the
129 * lock bit (see fs/buffer.c and other uses of wait_on_bit_lock
130 * with TASK_UNINTERRUPTIBLE), so there is no need to check the result.
131 */
132int
133nfs_page_group_lock(struct nfs_page *req, bool nonblock)
134{
135 struct nfs_page *head = req->wb_head;
136
137 WARN_ON_ONCE(head != head->wb_head);
138
139 if (!test_and_set_bit(PG_HEADLOCK, &head->wb_flags))
140 return 0;
141
142 if (!nonblock)
143 return wait_on_bit_lock(&head->wb_flags, PG_HEADLOCK,
144 TASK_UNINTERRUPTIBLE);
145
146 return -EAGAIN;
147}
148
149/*
150 * nfs_page_group_lock_wait - wait for the lock to clear, but don't grab it
151 * @req - a request in the group
152 *
153 * This is a blocking call to wait for the group lock to be cleared.
154 */
155void
156nfs_page_group_lock_wait(struct nfs_page *req)
157{
158 struct nfs_page *head = req->wb_head;
159
160 WARN_ON_ONCE(head != head->wb_head);
161
162 wait_on_bit(&head->wb_flags, PG_HEADLOCK,
163 TASK_UNINTERRUPTIBLE);
164}
165
166/*
167 * nfs_page_group_unlock - unlock the head of the page group
168 * @req - request in group that is to be unlocked
169 */
170void
171nfs_page_group_unlock(struct nfs_page *req)
172{
173 struct nfs_page *head = req->wb_head;
174
175 WARN_ON_ONCE(head != head->wb_head);
176
177 smp_mb__before_atomic();
178 clear_bit(PG_HEADLOCK, &head->wb_flags);
179 smp_mb__after_atomic();
180 wake_up_bit(&head->wb_flags, PG_HEADLOCK);
181}
182
183/*
184 * nfs_page_group_sync_on_bit_locked
185 *
186 * must be called with page group lock held
187 */
188static bool
189nfs_page_group_sync_on_bit_locked(struct nfs_page *req, unsigned int bit)
190{
191 struct nfs_page *head = req->wb_head;
192 struct nfs_page *tmp;
193
194 WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &head->wb_flags));
195 WARN_ON_ONCE(test_and_set_bit(bit, &req->wb_flags));
196
197 tmp = req->wb_this_page;
198 while (tmp != req) {
199 if (!test_bit(bit, &tmp->wb_flags))
200 return false;
201 tmp = tmp->wb_this_page;
202 }
203
204 /* true! reset all bits */
205 tmp = req;
206 do {
207 clear_bit(bit, &tmp->wb_flags);
208 tmp = tmp->wb_this_page;
209 } while (tmp != req);
210
211 return true;
212}
213
214/*
215 * nfs_page_group_sync_on_bit - set bit on current request, but only
216 * return true if the bit is set for all requests in page group
217 * @req - request in page group
218 * @bit - PG_* bit that is used to sync page group
219 */
220bool nfs_page_group_sync_on_bit(struct nfs_page *req, unsigned int bit)
221{
222 bool ret;
223
224 nfs_page_group_lock(req, false);
225 ret = nfs_page_group_sync_on_bit_locked(req, bit);
226 nfs_page_group_unlock(req);
227
228 return ret;
229}
230
231/*
232 * nfs_page_group_init - Initialize the page group linkage for @req
233 * @req - a new nfs request
234 * @prev - the previous request in page group, or NULL if @req is the first
235 * or only request in the group (the head).
236 */
237static inline void
238nfs_page_group_init(struct nfs_page *req, struct nfs_page *prev)
239{
240 struct inode *inode;
241 WARN_ON_ONCE(prev == req);
242
243 if (!prev) {
244 /* a head request */
245 req->wb_head = req;
246 req->wb_this_page = req;
247 } else {
248 /* a subrequest */
249 WARN_ON_ONCE(prev->wb_this_page != prev->wb_head);
250 WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &prev->wb_head->wb_flags));
251 req->wb_head = prev->wb_head;
252 req->wb_this_page = prev->wb_this_page;
253 prev->wb_this_page = req;
254
255 /* All subrequests take a ref on the head request until
256 * nfs_page_group_destroy is called */
257 kref_get(&req->wb_head->wb_kref);
258
259 /* grab extra ref and bump the request count if head request
260 * has extra ref from the write/commit path to handle handoff
261 * between write and commit lists. */
262 if (test_bit(PG_INODE_REF, &prev->wb_head->wb_flags)) {
263 inode = page_file_mapping(req->wb_page)->host;
264 set_bit(PG_INODE_REF, &req->wb_flags);
265 kref_get(&req->wb_kref);
266 spin_lock(&inode->i_lock);
267 NFS_I(inode)->nrequests++;
268 spin_unlock(&inode->i_lock);
269 }
270 }
271}
272
273/*
274 * nfs_page_group_destroy - sync the destruction of page groups
275 * @req - request that no longer needs the page group
276 *
277 * releases the page group reference from each member once all
278 * members have called this function.
279 */
280static void
281nfs_page_group_destroy(struct kref *kref)
282{
283 struct nfs_page *req = container_of(kref, struct nfs_page, wb_kref);
284 struct nfs_page *tmp, *next;
285
286 /* subrequests must release the ref on the head request */
287 if (req->wb_head != req)
288 nfs_release_request(req->wb_head);
289
290 if (!nfs_page_group_sync_on_bit(req, PG_TEARDOWN))
291 return;
292
293 tmp = req;
294 do {
295 next = tmp->wb_this_page;
296 /* unlink and free */
297 tmp->wb_this_page = tmp;
298 tmp->wb_head = tmp;
299 nfs_free_request(tmp);
300 tmp = next;
301 } while (tmp != req);
302}
303
304/**
305 * nfs_create_request - Create an NFS read/write request.
306 * @ctx: open context to use
307 * @page: page to write
308 * @last: last nfs request created for this page group or NULL if head
309 * @offset: starting offset within the page for the write
310 * @count: number of bytes to read/write
311 *
312 * The page must be locked by the caller. This makes sure we never
313 * create two different requests for the same page.
314 * User should ensure it is safe to sleep in this function.
315 */
316struct nfs_page *
317nfs_create_request(struct nfs_open_context *ctx, struct page *page,
318 struct nfs_page *last, unsigned int offset,
319 unsigned int count)
320{
321 struct nfs_page *req;
322 struct nfs_lock_context *l_ctx;
323
324 if (test_bit(NFS_CONTEXT_BAD, &ctx->flags))
325 return ERR_PTR(-EBADF);
326 /* try to allocate the request struct */
327 req = nfs_page_alloc();
328 if (req == NULL)
329 return ERR_PTR(-ENOMEM);
330
331 /* get lock context early so we can deal with alloc failures */
332 l_ctx = nfs_get_lock_context(ctx);
333 if (IS_ERR(l_ctx)) {
334 nfs_page_free(req);
335 return ERR_CAST(l_ctx);
336 }
337 req->wb_lock_context = l_ctx;
338 atomic_inc(&l_ctx->io_count);
339
340 /* Initialize the request struct. Initially, we assume a
341 * long write-back delay. This will be adjusted in
342 * update_nfs_request below if the region is not locked. */
343 req->wb_page = page;
344 req->wb_index = page_file_index(page);
345 get_page(page);
346 req->wb_offset = offset;
347 req->wb_pgbase = offset;
348 req->wb_bytes = count;
349 req->wb_context = get_nfs_open_context(ctx);
350 kref_init(&req->wb_kref);
351 nfs_page_group_init(req, last);
352 return req;
353}
354
355/**
356 * nfs_unlock_request - Unlock request and wake up sleepers.
357 * @req:
358 */
359void nfs_unlock_request(struct nfs_page *req)
360{
361 if (!NFS_WBACK_BUSY(req)) {
362 printk(KERN_ERR "NFS: Invalid unlock attempted\n");
363 BUG();
364 }
365 smp_mb__before_atomic();
366 clear_bit(PG_BUSY, &req->wb_flags);
367 smp_mb__after_atomic();
368 wake_up_bit(&req->wb_flags, PG_BUSY);
369}
370
371/**
372 * nfs_unlock_and_release_request - Unlock request and release the nfs_page
373 * @req:
374 */
375void nfs_unlock_and_release_request(struct nfs_page *req)
376{
377 nfs_unlock_request(req);
378 nfs_release_request(req);
379}
380
381/*
382 * nfs_clear_request - Free up all resources allocated to the request
383 * @req:
384 *
385 * Release page and open context resources associated with a read/write
386 * request after it has completed.
387 */
388static void nfs_clear_request(struct nfs_page *req)
389{
390 struct page *page = req->wb_page;
391 struct nfs_open_context *ctx = req->wb_context;
392 struct nfs_lock_context *l_ctx = req->wb_lock_context;
393
394 if (page != NULL) {
395 put_page(page);
396 req->wb_page = NULL;
397 }
398 if (l_ctx != NULL) {
399 if (atomic_dec_and_test(&l_ctx->io_count))
400 wake_up_atomic_t(&l_ctx->io_count);
401 nfs_put_lock_context(l_ctx);
402 req->wb_lock_context = NULL;
403 }
404 if (ctx != NULL) {
405 put_nfs_open_context(ctx);
406 req->wb_context = NULL;
407 }
408}
409
410/**
411 * nfs_release_request - Release the count on an NFS read/write request
412 * @req: request to release
413 *
414 * Note: Should never be called with the spinlock held!
415 */
416void nfs_free_request(struct nfs_page *req)
417{
418 WARN_ON_ONCE(req->wb_this_page != req);
419
420 /* extra debug: make sure no sync bits are still set */
421 WARN_ON_ONCE(test_bit(PG_TEARDOWN, &req->wb_flags));
422 WARN_ON_ONCE(test_bit(PG_UNLOCKPAGE, &req->wb_flags));
423 WARN_ON_ONCE(test_bit(PG_UPTODATE, &req->wb_flags));
424 WARN_ON_ONCE(test_bit(PG_WB_END, &req->wb_flags));
425 WARN_ON_ONCE(test_bit(PG_REMOVE, &req->wb_flags));
426
427 /* Release struct file and open context */
428 nfs_clear_request(req);
429 nfs_page_free(req);
430}
431
432void nfs_release_request(struct nfs_page *req)
433{
434 kref_put(&req->wb_kref, nfs_page_group_destroy);
435}
436
437/**
438 * nfs_wait_on_request - Wait for a request to complete.
439 * @req: request to wait upon.
440 *
441 * Interruptible by fatal signals only.
442 * The user is responsible for holding a count on the request.
443 */
444int
445nfs_wait_on_request(struct nfs_page *req)
446{
447 return wait_on_bit_io(&req->wb_flags, PG_BUSY,
448 TASK_UNINTERRUPTIBLE);
449}
450
451/*
452 * nfs_generic_pg_test - determine if requests can be coalesced
453 * @desc: pointer to descriptor
454 * @prev: previous request in desc, or NULL
455 * @req: this request
456 *
457 * Returns zero if @req can be coalesced into @desc, otherwise it returns
458 * the size of the request.
459 */
460size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
461 struct nfs_page *prev, struct nfs_page *req)
462{
463 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
464
465
466 if (mirror->pg_count > mirror->pg_bsize) {
467 /* should never happen */
468 WARN_ON_ONCE(1);
469 return 0;
470 }
471
472 /*
473 * Limit the request size so that we can still allocate a page array
474 * for it without upsetting the slab allocator.
475 */
476 if (((mirror->pg_count + req->wb_bytes) >> PAGE_SHIFT) *
477 sizeof(struct page *) > PAGE_SIZE)
478 return 0;
479
480 return min(mirror->pg_bsize - mirror->pg_count, (size_t)req->wb_bytes);
481}
482EXPORT_SYMBOL_GPL(nfs_generic_pg_test);
483
484struct nfs_pgio_header *nfs_pgio_header_alloc(const struct nfs_rw_ops *ops)
485{
486 struct nfs_pgio_header *hdr = ops->rw_alloc_header();
487
488 if (hdr) {
489 INIT_LIST_HEAD(&hdr->pages);
490 spin_lock_init(&hdr->lock);
491 hdr->rw_ops = ops;
492 }
493 return hdr;
494}
495EXPORT_SYMBOL_GPL(nfs_pgio_header_alloc);
496
497/*
498 * nfs_pgio_header_free - Free a read or write header
499 * @hdr: The header to free
500 */
501void nfs_pgio_header_free(struct nfs_pgio_header *hdr)
502{
503 hdr->rw_ops->rw_free_header(hdr);
504}
505EXPORT_SYMBOL_GPL(nfs_pgio_header_free);
506
507/**
508 * nfs_pgio_data_destroy - make @hdr suitable for reuse
509 *
510 * Frees memory and releases refs from nfs_generic_pgio, so that it may
511 * be called again.
512 *
513 * @hdr: A header that has had nfs_generic_pgio called
514 */
515void nfs_pgio_data_destroy(struct nfs_pgio_header *hdr)
516{
517 if (hdr->args.context)
518 put_nfs_open_context(hdr->args.context);
519 if (hdr->page_array.pagevec != hdr->page_array.page_array)
520 kfree(hdr->page_array.pagevec);
521}
522EXPORT_SYMBOL_GPL(nfs_pgio_data_destroy);
523
524/**
525 * nfs_pgio_rpcsetup - Set up arguments for a pageio call
526 * @hdr: The pageio hdr
527 * @count: Number of bytes to read
528 * @offset: Initial offset
529 * @how: How to commit data (writes only)
530 * @cinfo: Commit information for the call (writes only)
531 */
532static void nfs_pgio_rpcsetup(struct nfs_pgio_header *hdr,
533 unsigned int count, unsigned int offset,
534 int how, struct nfs_commit_info *cinfo)
535{
536 struct nfs_page *req = hdr->req;
537
538 /* Set up the RPC argument and reply structs
539 * NB: take care not to mess about with hdr->commit et al. */
540
541 hdr->args.fh = NFS_FH(hdr->inode);
542 hdr->args.offset = req_offset(req) + offset;
543 /* pnfs_set_layoutcommit needs this */
544 hdr->mds_offset = hdr->args.offset;
545 hdr->args.pgbase = req->wb_pgbase + offset;
546 hdr->args.pages = hdr->page_array.pagevec;
547 hdr->args.count = count;
548 hdr->args.context = get_nfs_open_context(req->wb_context);
549 hdr->args.lock_context = req->wb_lock_context;
550 hdr->args.stable = NFS_UNSTABLE;
551 switch (how & (FLUSH_STABLE | FLUSH_COND_STABLE)) {
552 case 0:
553 break;
554 case FLUSH_COND_STABLE:
555 if (nfs_reqs_to_commit(cinfo))
556 break;
557 default:
558 hdr->args.stable = NFS_FILE_SYNC;
559 }
560
561 hdr->res.fattr = &hdr->fattr;
562 hdr->res.count = count;
563 hdr->res.eof = 0;
564 hdr->res.verf = &hdr->verf;
565 nfs_fattr_init(&hdr->fattr);
566}
567
568/**
569 * nfs_pgio_prepare - Prepare pageio hdr to go over the wire
570 * @task: The current task
571 * @calldata: pageio header to prepare
572 */
573static void nfs_pgio_prepare(struct rpc_task *task, void *calldata)
574{
575 struct nfs_pgio_header *hdr = calldata;
576 int err;
577 err = NFS_PROTO(hdr->inode)->pgio_rpc_prepare(task, hdr);
578 if (err)
579 rpc_exit(task, err);
580}
581
582int nfs_initiate_pgio(struct rpc_clnt *clnt, struct nfs_pgio_header *hdr,
583 struct rpc_cred *cred, const struct nfs_rpc_ops *rpc_ops,
584 const struct rpc_call_ops *call_ops, int how, int flags)
585{
586 struct rpc_task *task;
587 struct rpc_message msg = {
588 .rpc_argp = &hdr->args,
589 .rpc_resp = &hdr->res,
590 .rpc_cred = cred,
591 };
592 struct rpc_task_setup task_setup_data = {
593 .rpc_client = clnt,
594 .task = &hdr->task,
595 .rpc_message = &msg,
596 .callback_ops = call_ops,
597 .callback_data = hdr,
598 .workqueue = nfsiod_workqueue,
599 .flags = RPC_TASK_ASYNC | flags,
600 };
601 int ret = 0;
602
603 hdr->rw_ops->rw_initiate(hdr, &msg, rpc_ops, &task_setup_data, how);
604
605 dprintk("NFS: initiated pgio call "
606 "(req %s/%llu, %u bytes @ offset %llu)\n",
607 hdr->inode->i_sb->s_id,
608 (unsigned long long)NFS_FILEID(hdr->inode),
609 hdr->args.count,
610 (unsigned long long)hdr->args.offset);
611
612 task = rpc_run_task(&task_setup_data);
613 if (IS_ERR(task)) {
614 ret = PTR_ERR(task);
615 goto out;
616 }
617 if (how & FLUSH_SYNC) {
618 ret = rpc_wait_for_completion_task(task);
619 if (ret == 0)
620 ret = task->tk_status;
621 }
622 rpc_put_task(task);
623out:
624 return ret;
625}
626EXPORT_SYMBOL_GPL(nfs_initiate_pgio);
627
628/**
629 * nfs_pgio_error - Clean up from a pageio error
630 * @desc: IO descriptor
631 * @hdr: pageio header
632 */
633static void nfs_pgio_error(struct nfs_pgio_header *hdr)
634{
635 set_bit(NFS_IOHDR_REDO, &hdr->flags);
636 nfs_pgio_data_destroy(hdr);
637 hdr->completion_ops->completion(hdr);
638}
639
640/**
641 * nfs_pgio_release - Release pageio data
642 * @calldata: The pageio header to release
643 */
644static void nfs_pgio_release(void *calldata)
645{
646 struct nfs_pgio_header *hdr = calldata;
647 nfs_pgio_data_destroy(hdr);
648 hdr->completion_ops->completion(hdr);
649}
650
651static void nfs_pageio_mirror_init(struct nfs_pgio_mirror *mirror,
652 unsigned int bsize)
653{
654 INIT_LIST_HEAD(&mirror->pg_list);
655 mirror->pg_bytes_written = 0;
656 mirror->pg_count = 0;
657 mirror->pg_bsize = bsize;
658 mirror->pg_base = 0;
659 mirror->pg_recoalesce = 0;
660}
661
662/**
663 * nfs_pageio_init - initialise a page io descriptor
664 * @desc: pointer to descriptor
665 * @inode: pointer to inode
666 * @pg_ops: pointer to pageio operations
667 * @compl_ops: pointer to pageio completion operations
668 * @rw_ops: pointer to nfs read/write operations
669 * @bsize: io block size
670 * @io_flags: extra parameters for the io function
671 */
672void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
673 struct inode *inode,
674 const struct nfs_pageio_ops *pg_ops,
675 const struct nfs_pgio_completion_ops *compl_ops,
676 const struct nfs_rw_ops *rw_ops,
677 size_t bsize,
678 int io_flags)
679{
680 struct nfs_pgio_mirror *new;
681 int i;
682
683 desc->pg_moreio = 0;
684 desc->pg_inode = inode;
685 desc->pg_ops = pg_ops;
686 desc->pg_completion_ops = compl_ops;
687 desc->pg_rw_ops = rw_ops;
688 desc->pg_ioflags = io_flags;
689 desc->pg_error = 0;
690 desc->pg_lseg = NULL;
691 desc->pg_dreq = NULL;
692 desc->pg_layout_private = NULL;
693 desc->pg_bsize = bsize;
694
695 desc->pg_mirror_count = 1;
696 desc->pg_mirror_idx = 0;
697
698 if (pg_ops->pg_get_mirror_count) {
699 /* until we have a request, we don't have an lseg and no
700 * idea how many mirrors there will be */
701 new = kcalloc(NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX,
702 sizeof(struct nfs_pgio_mirror), GFP_KERNEL);
703 desc->pg_mirrors_dynamic = new;
704 desc->pg_mirrors = new;
705
706 for (i = 0; i < NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX; i++)
707 nfs_pageio_mirror_init(&desc->pg_mirrors[i], bsize);
708 } else {
709 desc->pg_mirrors_dynamic = NULL;
710 desc->pg_mirrors = desc->pg_mirrors_static;
711 nfs_pageio_mirror_init(&desc->pg_mirrors[0], bsize);
712 }
713}
714EXPORT_SYMBOL_GPL(nfs_pageio_init);
715
716/**
717 * nfs_pgio_result - Basic pageio error handling
718 * @task: The task that ran
719 * @calldata: Pageio header to check
720 */
721static void nfs_pgio_result(struct rpc_task *task, void *calldata)
722{
723 struct nfs_pgio_header *hdr = calldata;
724 struct inode *inode = hdr->inode;
725
726 dprintk("NFS: %s: %5u, (status %d)\n", __func__,
727 task->tk_pid, task->tk_status);
728
729 if (hdr->rw_ops->rw_done(task, hdr, inode) != 0)
730 return;
731 if (task->tk_status < 0)
732 nfs_set_pgio_error(hdr, task->tk_status, hdr->args.offset);
733 else
734 hdr->rw_ops->rw_result(task, hdr);
735}
736
737/*
738 * Create an RPC task for the given read or write request and kick it.
739 * The page must have been locked by the caller.
740 *
741 * It may happen that the page we're passed is not marked dirty.
742 * This is the case if nfs_updatepage detects a conflicting request
743 * that has been written but not committed.
744 */
745int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
746 struct nfs_pgio_header *hdr)
747{
748 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
749
750 struct nfs_page *req;
751 struct page **pages,
752 *last_page;
753 struct list_head *head = &mirror->pg_list;
754 struct nfs_commit_info cinfo;
755 unsigned int pagecount, pageused;
756
757 pagecount = nfs_page_array_len(mirror->pg_base, mirror->pg_count);
758 if (!nfs_pgarray_set(&hdr->page_array, pagecount)) {
759 nfs_pgio_error(hdr);
760 desc->pg_error = -ENOMEM;
761 return desc->pg_error;
762 }
763
764 nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq);
765 pages = hdr->page_array.pagevec;
766 last_page = NULL;
767 pageused = 0;
768 while (!list_empty(head)) {
769 req = nfs_list_entry(head->next);
770 nfs_list_remove_request(req);
771 nfs_list_add_request(req, &hdr->pages);
772
773 if (!last_page || last_page != req->wb_page) {
774 pageused++;
775 if (pageused > pagecount)
776 break;
777 *pages++ = last_page = req->wb_page;
778 }
779 }
780 if (WARN_ON_ONCE(pageused != pagecount)) {
781 nfs_pgio_error(hdr);
782 desc->pg_error = -EINVAL;
783 return desc->pg_error;
784 }
785
786 if ((desc->pg_ioflags & FLUSH_COND_STABLE) &&
787 (desc->pg_moreio || nfs_reqs_to_commit(&cinfo)))
788 desc->pg_ioflags &= ~FLUSH_COND_STABLE;
789
790 /* Set up the argument struct */
791 nfs_pgio_rpcsetup(hdr, mirror->pg_count, 0, desc->pg_ioflags, &cinfo);
792 desc->pg_rpc_callops = &nfs_pgio_common_ops;
793 return 0;
794}
795EXPORT_SYMBOL_GPL(nfs_generic_pgio);
796
797static int nfs_generic_pg_pgios(struct nfs_pageio_descriptor *desc)
798{
799 struct nfs_pgio_header *hdr;
800 int ret;
801
802 hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
803 if (!hdr) {
804 desc->pg_error = -ENOMEM;
805 return desc->pg_error;
806 }
807 nfs_pgheader_init(desc, hdr, nfs_pgio_header_free);
808 ret = nfs_generic_pgio(desc, hdr);
809 if (ret == 0)
810 ret = nfs_initiate_pgio(NFS_CLIENT(hdr->inode),
811 hdr,
812 hdr->cred,
813 NFS_PROTO(hdr->inode),
814 desc->pg_rpc_callops,
815 desc->pg_ioflags, 0);
816 return ret;
817}
818
819/*
820 * nfs_pageio_setup_mirroring - determine if mirroring is to be used
821 * by calling the pg_get_mirror_count op
822 */
823static int nfs_pageio_setup_mirroring(struct nfs_pageio_descriptor *pgio,
824 struct nfs_page *req)
825{
826 int mirror_count = 1;
827
828 if (!pgio->pg_ops->pg_get_mirror_count)
829 return 0;
830
831 mirror_count = pgio->pg_ops->pg_get_mirror_count(pgio, req);
832
833 if (pgio->pg_error < 0)
834 return pgio->pg_error;
835
836 if (!mirror_count || mirror_count > NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX)
837 return -EINVAL;
838
839 if (WARN_ON_ONCE(!pgio->pg_mirrors_dynamic))
840 return -EINVAL;
841
842 pgio->pg_mirror_count = mirror_count;
843
844 return 0;
845}
846
847/*
848 * nfs_pageio_stop_mirroring - stop using mirroring (set mirror count to 1)
849 */
850void nfs_pageio_stop_mirroring(struct nfs_pageio_descriptor *pgio)
851{
852 pgio->pg_mirror_count = 1;
853 pgio->pg_mirror_idx = 0;
854}
855
856static void nfs_pageio_cleanup_mirroring(struct nfs_pageio_descriptor *pgio)
857{
858 pgio->pg_mirror_count = 1;
859 pgio->pg_mirror_idx = 0;
860 pgio->pg_mirrors = pgio->pg_mirrors_static;
861 kfree(pgio->pg_mirrors_dynamic);
862 pgio->pg_mirrors_dynamic = NULL;
863}
864
865static bool nfs_match_lock_context(const struct nfs_lock_context *l1,
866 const struct nfs_lock_context *l2)
867{
868 return l1->lockowner.l_owner == l2->lockowner.l_owner
869 && l1->lockowner.l_pid == l2->lockowner.l_pid;
870}
871
872/**
873 * nfs_can_coalesce_requests - test two requests for compatibility
874 * @prev: pointer to nfs_page
875 * @req: pointer to nfs_page
876 *
877 * The nfs_page structures 'prev' and 'req' are compared to ensure that the
878 * page data area they describe is contiguous, and that their RPC
879 * credentials, NFSv4 open state, and lockowners are the same.
880 *
881 * Return 'true' if this is the case, else return 'false'.
882 */
883static bool nfs_can_coalesce_requests(struct nfs_page *prev,
884 struct nfs_page *req,
885 struct nfs_pageio_descriptor *pgio)
886{
887 size_t size;
888 struct file_lock_context *flctx;
889
890 if (prev) {
891 if (!nfs_match_open_context(req->wb_context, prev->wb_context))
892 return false;
893 flctx = d_inode(req->wb_context->dentry)->i_flctx;
894 if (flctx != NULL &&
895 !(list_empty_careful(&flctx->flc_posix) &&
896 list_empty_careful(&flctx->flc_flock)) &&
897 !nfs_match_lock_context(req->wb_lock_context,
898 prev->wb_lock_context))
899 return false;
900 if (req_offset(req) != req_offset(prev) + prev->wb_bytes)
901 return false;
902 if (req->wb_page == prev->wb_page) {
903 if (req->wb_pgbase != prev->wb_pgbase + prev->wb_bytes)
904 return false;
905 } else {
906 if (req->wb_pgbase != 0 ||
907 prev->wb_pgbase + prev->wb_bytes != PAGE_SIZE)
908 return false;
909 }
910 }
911 size = pgio->pg_ops->pg_test(pgio, prev, req);
912 WARN_ON_ONCE(size > req->wb_bytes);
913 if (size && size < req->wb_bytes)
914 req->wb_bytes = size;
915 return size > 0;
916}
917
918/**
919 * nfs_pageio_do_add_request - Attempt to coalesce a request into a page list.
920 * @desc: destination io descriptor
921 * @req: request
922 *
923 * Returns true if the request 'req' was successfully coalesced into the
924 * existing list of pages 'desc'.
925 */
926static int nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc,
927 struct nfs_page *req)
928{
929 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
930
931 struct nfs_page *prev = NULL;
932
933 if (mirror->pg_count != 0) {
934 prev = nfs_list_entry(mirror->pg_list.prev);
935 } else {
936 if (desc->pg_ops->pg_init)
937 desc->pg_ops->pg_init(desc, req);
938 if (desc->pg_error < 0)
939 return 0;
940 mirror->pg_base = req->wb_pgbase;
941 }
942 if (!nfs_can_coalesce_requests(prev, req, desc))
943 return 0;
944 nfs_list_remove_request(req);
945 nfs_list_add_request(req, &mirror->pg_list);
946 mirror->pg_count += req->wb_bytes;
947 return 1;
948}
949
950/*
951 * Helper for nfs_pageio_add_request and nfs_pageio_complete
952 */
953static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc)
954{
955 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
956
957
958 if (!list_empty(&mirror->pg_list)) {
959 int error = desc->pg_ops->pg_doio(desc);
960 if (error < 0)
961 desc->pg_error = error;
962 else
963 mirror->pg_bytes_written += mirror->pg_count;
964 }
965 if (list_empty(&mirror->pg_list)) {
966 mirror->pg_count = 0;
967 mirror->pg_base = 0;
968 }
969}
970
971/**
972 * nfs_pageio_add_request - Attempt to coalesce a request into a page list.
973 * @desc: destination io descriptor
974 * @req: request
975 *
976 * This may split a request into subrequests which are all part of the
977 * same page group.
978 *
979 * Returns true if the request 'req' was successfully coalesced into the
980 * existing list of pages 'desc'.
981 */
982static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
983 struct nfs_page *req)
984{
985 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
986
987 struct nfs_page *subreq;
988 unsigned int bytes_left = 0;
989 unsigned int offset, pgbase;
990
991 nfs_page_group_lock(req, false);
992
993 subreq = req;
994 bytes_left = subreq->wb_bytes;
995 offset = subreq->wb_offset;
996 pgbase = subreq->wb_pgbase;
997
998 do {
999 if (!nfs_pageio_do_add_request(desc, subreq)) {
1000 /* make sure pg_test call(s) did nothing */
1001 WARN_ON_ONCE(subreq->wb_bytes != bytes_left);
1002 WARN_ON_ONCE(subreq->wb_offset != offset);
1003 WARN_ON_ONCE(subreq->wb_pgbase != pgbase);
1004
1005 nfs_page_group_unlock(req);
1006 desc->pg_moreio = 1;
1007 nfs_pageio_doio(desc);
1008 if (desc->pg_error < 0)
1009 return 0;
1010 if (mirror->pg_recoalesce)
1011 return 0;
1012 /* retry add_request for this subreq */
1013 nfs_page_group_lock(req, false);
1014 continue;
1015 }
1016
1017 /* check for buggy pg_test call(s) */
1018 WARN_ON_ONCE(subreq->wb_bytes + subreq->wb_pgbase > PAGE_SIZE);
1019 WARN_ON_ONCE(subreq->wb_bytes > bytes_left);
1020 WARN_ON_ONCE(subreq->wb_bytes == 0);
1021
1022 bytes_left -= subreq->wb_bytes;
1023 offset += subreq->wb_bytes;
1024 pgbase += subreq->wb_bytes;
1025
1026 if (bytes_left) {
1027 subreq = nfs_create_request(req->wb_context,
1028 req->wb_page,
1029 subreq, pgbase, bytes_left);
1030 if (IS_ERR(subreq))
1031 goto err_ptr;
1032 nfs_lock_request(subreq);
1033 subreq->wb_offset = offset;
1034 subreq->wb_index = req->wb_index;
1035 }
1036 } while (bytes_left > 0);
1037
1038 nfs_page_group_unlock(req);
1039 return 1;
1040err_ptr:
1041 desc->pg_error = PTR_ERR(subreq);
1042 nfs_page_group_unlock(req);
1043 return 0;
1044}
1045
1046static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc)
1047{
1048 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
1049 LIST_HEAD(head);
1050
1051 do {
1052 list_splice_init(&mirror->pg_list, &head);
1053 mirror->pg_bytes_written -= mirror->pg_count;
1054 mirror->pg_count = 0;
1055 mirror->pg_base = 0;
1056 mirror->pg_recoalesce = 0;
1057
1058 while (!list_empty(&head)) {
1059 struct nfs_page *req;
1060
1061 req = list_first_entry(&head, struct nfs_page, wb_list);
1062 nfs_list_remove_request(req);
1063 if (__nfs_pageio_add_request(desc, req))
1064 continue;
1065 if (desc->pg_error < 0) {
1066 list_splice_tail(&head, &mirror->pg_list);
1067 mirror->pg_recoalesce = 1;
1068 return 0;
1069 }
1070 break;
1071 }
1072 } while (mirror->pg_recoalesce);
1073 return 1;
1074}
1075
1076static int nfs_pageio_add_request_mirror(struct nfs_pageio_descriptor *desc,
1077 struct nfs_page *req)
1078{
1079 int ret;
1080
1081 do {
1082 ret = __nfs_pageio_add_request(desc, req);
1083 if (ret)
1084 break;
1085 if (desc->pg_error < 0)
1086 break;
1087 ret = nfs_do_recoalesce(desc);
1088 } while (ret);
1089
1090 return ret;
1091}
1092
1093int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
1094 struct nfs_page *req)
1095{
1096 u32 midx;
1097 unsigned int pgbase, offset, bytes;
1098 struct nfs_page *dupreq, *lastreq;
1099
1100 pgbase = req->wb_pgbase;
1101 offset = req->wb_offset;
1102 bytes = req->wb_bytes;
1103
1104 nfs_pageio_setup_mirroring(desc, req);
1105 if (desc->pg_error < 0)
1106 goto out_failed;
1107
1108 for (midx = 0; midx < desc->pg_mirror_count; midx++) {
1109 if (midx) {
1110 nfs_page_group_lock(req, false);
1111
1112 /* find the last request */
1113 for (lastreq = req->wb_head;
1114 lastreq->wb_this_page != req->wb_head;
1115 lastreq = lastreq->wb_this_page)
1116 ;
1117
1118 dupreq = nfs_create_request(req->wb_context,
1119 req->wb_page, lastreq, pgbase, bytes);
1120
1121 if (IS_ERR(dupreq)) {
1122 nfs_page_group_unlock(req);
1123 desc->pg_error = PTR_ERR(dupreq);
1124 goto out_failed;
1125 }
1126
1127 nfs_lock_request(dupreq);
1128 nfs_page_group_unlock(req);
1129 dupreq->wb_offset = offset;
1130 dupreq->wb_index = req->wb_index;
1131 } else
1132 dupreq = req;
1133
1134 if (nfs_pgio_has_mirroring(desc))
1135 desc->pg_mirror_idx = midx;
1136 if (!nfs_pageio_add_request_mirror(desc, dupreq))
1137 goto out_failed;
1138 }
1139
1140 return 1;
1141
1142out_failed:
1143 /*
1144 * We might have failed before sending any reqs over wire.
1145 * Clean up rest of the reqs in mirror pg_list.
1146 */
1147 if (desc->pg_error) {
1148 struct nfs_pgio_mirror *mirror;
1149 void (*func)(struct list_head *);
1150
1151 /* remember fatal errors */
1152 if (nfs_error_is_fatal(desc->pg_error))
1153 mapping_set_error(desc->pg_inode->i_mapping,
1154 desc->pg_error);
1155
1156 func = desc->pg_completion_ops->error_cleanup;
1157 for (midx = 0; midx < desc->pg_mirror_count; midx++) {
1158 mirror = &desc->pg_mirrors[midx];
1159 func(&mirror->pg_list);
1160 }
1161 }
1162 return 0;
1163}
1164
1165/*
1166 * nfs_pageio_complete_mirror - Complete I/O on the current mirror of an
1167 * nfs_pageio_descriptor
1168 * @desc: pointer to io descriptor
1169 * @mirror_idx: pointer to mirror index
1170 */
1171static void nfs_pageio_complete_mirror(struct nfs_pageio_descriptor *desc,
1172 u32 mirror_idx)
1173{
1174 struct nfs_pgio_mirror *mirror = &desc->pg_mirrors[mirror_idx];
1175 u32 restore_idx = desc->pg_mirror_idx;
1176
1177 if (nfs_pgio_has_mirroring(desc))
1178 desc->pg_mirror_idx = mirror_idx;
1179 for (;;) {
1180 nfs_pageio_doio(desc);
1181 if (!mirror->pg_recoalesce)
1182 break;
1183 if (!nfs_do_recoalesce(desc))
1184 break;
1185 }
1186 desc->pg_mirror_idx = restore_idx;
1187}
1188
1189/*
1190 * nfs_pageio_resend - Transfer requests to new descriptor and resend
1191 * @hdr - the pgio header to move request from
1192 * @desc - the pageio descriptor to add requests to
1193 *
1194 * Try to move each request (nfs_page) from @hdr to @desc then attempt
1195 * to send them.
1196 *
1197 * Returns 0 on success and < 0 on error.
1198 */
1199int nfs_pageio_resend(struct nfs_pageio_descriptor *desc,
1200 struct nfs_pgio_header *hdr)
1201{
1202 LIST_HEAD(failed);
1203
1204 desc->pg_dreq = hdr->dreq;
1205 while (!list_empty(&hdr->pages)) {
1206 struct nfs_page *req = nfs_list_entry(hdr->pages.next);
1207
1208 nfs_list_remove_request(req);
1209 if (!nfs_pageio_add_request(desc, req))
1210 nfs_list_add_request(req, &failed);
1211 }
1212 nfs_pageio_complete(desc);
1213 if (!list_empty(&failed)) {
1214 list_move(&failed, &hdr->pages);
1215 return desc->pg_error < 0 ? desc->pg_error : -EIO;
1216 }
1217 return 0;
1218}
1219EXPORT_SYMBOL_GPL(nfs_pageio_resend);
1220
1221/**
1222 * nfs_pageio_complete - Complete I/O then cleanup an nfs_pageio_descriptor
1223 * @desc: pointer to io descriptor
1224 */
1225void nfs_pageio_complete(struct nfs_pageio_descriptor *desc)
1226{
1227 u32 midx;
1228
1229 for (midx = 0; midx < desc->pg_mirror_count; midx++)
1230 nfs_pageio_complete_mirror(desc, midx);
1231
1232 if (desc->pg_ops->pg_cleanup)
1233 desc->pg_ops->pg_cleanup(desc);
1234 nfs_pageio_cleanup_mirroring(desc);
1235}
1236
1237/**
1238 * nfs_pageio_cond_complete - Conditional I/O completion
1239 * @desc: pointer to io descriptor
1240 * @index: page index
1241 *
1242 * It is important to ensure that processes don't try to take locks
1243 * on non-contiguous ranges of pages as that might deadlock. This
1244 * function should be called before attempting to wait on a locked
1245 * nfs_page. It will complete the I/O if the page index 'index'
1246 * is not contiguous with the existing list of pages in 'desc'.
1247 */
1248void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index)
1249{
1250 struct nfs_pgio_mirror *mirror;
1251 struct nfs_page *prev;
1252 u32 midx;
1253
1254 for (midx = 0; midx < desc->pg_mirror_count; midx++) {
1255 mirror = &desc->pg_mirrors[midx];
1256 if (!list_empty(&mirror->pg_list)) {
1257 prev = nfs_list_entry(mirror->pg_list.prev);
1258 if (index != prev->wb_index + 1)
1259 nfs_pageio_complete_mirror(desc, midx);
1260 }
1261 }
1262}
1263
1264int __init nfs_init_nfspagecache(void)
1265{
1266 nfs_page_cachep = kmem_cache_create("nfs_page",
1267 sizeof(struct nfs_page),
1268 0, SLAB_HWCACHE_ALIGN,
1269 NULL);
1270 if (nfs_page_cachep == NULL)
1271 return -ENOMEM;
1272
1273 return 0;
1274}
1275
1276void nfs_destroy_nfspagecache(void)
1277{
1278 kmem_cache_destroy(nfs_page_cachep);
1279}
1280
1281static const struct rpc_call_ops nfs_pgio_common_ops = {
1282 .rpc_call_prepare = nfs_pgio_prepare,
1283 .rpc_call_done = nfs_pgio_result,
1284 .rpc_release = nfs_pgio_release,
1285};
1286
1287const struct nfs_pageio_ops nfs_pgio_rw_ops = {
1288 .pg_test = nfs_generic_pg_test,
1289 .pg_doio = nfs_generic_pg_pgios,
1290};