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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
32struct nfs_pgio_mirror *
33nfs_pgio_current_mirror(struct nfs_pageio_descriptor *desc)
34{
35 return nfs_pgio_has_mirroring(desc) ?
36 &desc->pg_mirrors[desc->pg_mirror_idx] :
37 &desc->pg_mirrors[0];
38}
39EXPORT_SYMBOL_GPL(nfs_pgio_current_mirror);
40
41void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
42 struct nfs_pgio_header *hdr,
43 void (*release)(struct nfs_pgio_header *hdr))
44{
45 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
46
47
48 hdr->req = nfs_list_entry(mirror->pg_list.next);
49 hdr->inode = desc->pg_inode;
50 hdr->cred = hdr->req->wb_context->cred;
51 hdr->io_start = req_offset(hdr->req);
52 hdr->good_bytes = mirror->pg_count;
53 hdr->io_completion = desc->pg_io_completion;
54 hdr->dreq = desc->pg_dreq;
55 hdr->release = release;
56 hdr->completion_ops = desc->pg_completion_ops;
57 if (hdr->completion_ops->init_hdr)
58 hdr->completion_ops->init_hdr(hdr);
59
60 hdr->pgio_mirror_idx = desc->pg_mirror_idx;
61}
62EXPORT_SYMBOL_GPL(nfs_pgheader_init);
63
64void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos)
65{
66 spin_lock(&hdr->lock);
67 if (!test_and_set_bit(NFS_IOHDR_ERROR, &hdr->flags)
68 || pos < hdr->io_start + hdr->good_bytes) {
69 clear_bit(NFS_IOHDR_EOF, &hdr->flags);
70 hdr->good_bytes = pos - hdr->io_start;
71 hdr->error = error;
72 }
73 spin_unlock(&hdr->lock);
74}
75
76static inline struct nfs_page *
77nfs_page_alloc(void)
78{
79 struct nfs_page *p = kmem_cache_zalloc(nfs_page_cachep, GFP_NOIO);
80 if (p)
81 INIT_LIST_HEAD(&p->wb_list);
82 return p;
83}
84
85static inline void
86nfs_page_free(struct nfs_page *p)
87{
88 kmem_cache_free(nfs_page_cachep, p);
89}
90
91/**
92 * nfs_iocounter_wait - wait for i/o to complete
93 * @l_ctx: nfs_lock_context with io_counter to use
94 *
95 * returns -ERESTARTSYS if interrupted by a fatal signal.
96 * Otherwise returns 0 once the io_count hits 0.
97 */
98int
99nfs_iocounter_wait(struct nfs_lock_context *l_ctx)
100{
101 return wait_var_event_killable(&l_ctx->io_count,
102 !atomic_read(&l_ctx->io_count));
103}
104
105/**
106 * nfs_async_iocounter_wait - wait on a rpc_waitqueue for I/O
107 * to complete
108 * @task: the rpc_task that should wait
109 * @l_ctx: nfs_lock_context with io_counter to check
110 *
111 * Returns true if there is outstanding I/O to wait on and the
112 * task has been put to sleep.
113 */
114bool
115nfs_async_iocounter_wait(struct rpc_task *task, struct nfs_lock_context *l_ctx)
116{
117 struct inode *inode = d_inode(l_ctx->open_context->dentry);
118 bool ret = false;
119
120 if (atomic_read(&l_ctx->io_count) > 0) {
121 rpc_sleep_on(&NFS_SERVER(inode)->uoc_rpcwaitq, task, NULL);
122 ret = true;
123 }
124
125 if (atomic_read(&l_ctx->io_count) == 0) {
126 rpc_wake_up_queued_task(&NFS_SERVER(inode)->uoc_rpcwaitq, task);
127 ret = false;
128 }
129
130 return ret;
131}
132EXPORT_SYMBOL_GPL(nfs_async_iocounter_wait);
133
134/*
135 * nfs_page_group_lock - lock the head of the page group
136 * @req - request in group that is to be locked
137 *
138 * this lock must be held when traversing or modifying the page
139 * group list
140 *
141 * return 0 on success, < 0 on error
142 */
143int
144nfs_page_group_lock(struct nfs_page *req)
145{
146 struct nfs_page *head = req->wb_head;
147
148 WARN_ON_ONCE(head != head->wb_head);
149
150 if (!test_and_set_bit(PG_HEADLOCK, &head->wb_flags))
151 return 0;
152
153 set_bit(PG_CONTENDED1, &head->wb_flags);
154 smp_mb__after_atomic();
155 return wait_on_bit_lock(&head->wb_flags, PG_HEADLOCK,
156 TASK_UNINTERRUPTIBLE);
157}
158
159/*
160 * nfs_page_group_unlock - unlock the head of the page group
161 * @req - request in group that is to be unlocked
162 */
163void
164nfs_page_group_unlock(struct nfs_page *req)
165{
166 struct nfs_page *head = req->wb_head;
167
168 WARN_ON_ONCE(head != head->wb_head);
169
170 smp_mb__before_atomic();
171 clear_bit(PG_HEADLOCK, &head->wb_flags);
172 smp_mb__after_atomic();
173 if (!test_bit(PG_CONTENDED1, &head->wb_flags))
174 return;
175 wake_up_bit(&head->wb_flags, PG_HEADLOCK);
176}
177
178/*
179 * nfs_page_group_sync_on_bit_locked
180 *
181 * must be called with page group lock held
182 */
183static bool
184nfs_page_group_sync_on_bit_locked(struct nfs_page *req, unsigned int bit)
185{
186 struct nfs_page *head = req->wb_head;
187 struct nfs_page *tmp;
188
189 WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &head->wb_flags));
190 WARN_ON_ONCE(test_and_set_bit(bit, &req->wb_flags));
191
192 tmp = req->wb_this_page;
193 while (tmp != req) {
194 if (!test_bit(bit, &tmp->wb_flags))
195 return false;
196 tmp = tmp->wb_this_page;
197 }
198
199 /* true! reset all bits */
200 tmp = req;
201 do {
202 clear_bit(bit, &tmp->wb_flags);
203 tmp = tmp->wb_this_page;
204 } while (tmp != req);
205
206 return true;
207}
208
209/*
210 * nfs_page_group_sync_on_bit - set bit on current request, but only
211 * return true if the bit is set for all requests in page group
212 * @req - request in page group
213 * @bit - PG_* bit that is used to sync page group
214 */
215bool nfs_page_group_sync_on_bit(struct nfs_page *req, unsigned int bit)
216{
217 bool ret;
218
219 nfs_page_group_lock(req);
220 ret = nfs_page_group_sync_on_bit_locked(req, bit);
221 nfs_page_group_unlock(req);
222
223 return ret;
224}
225
226/*
227 * nfs_page_group_init - Initialize the page group linkage for @req
228 * @req - a new nfs request
229 * @prev - the previous request in page group, or NULL if @req is the first
230 * or only request in the group (the head).
231 */
232static inline void
233nfs_page_group_init(struct nfs_page *req, struct nfs_page *prev)
234{
235 struct inode *inode;
236 WARN_ON_ONCE(prev == req);
237
238 if (!prev) {
239 /* a head request */
240 req->wb_head = req;
241 req->wb_this_page = req;
242 } else {
243 /* a subrequest */
244 WARN_ON_ONCE(prev->wb_this_page != prev->wb_head);
245 WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &prev->wb_head->wb_flags));
246 req->wb_head = prev->wb_head;
247 req->wb_this_page = prev->wb_this_page;
248 prev->wb_this_page = req;
249
250 /* All subrequests take a ref on the head request until
251 * nfs_page_group_destroy is called */
252 kref_get(&req->wb_head->wb_kref);
253
254 /* grab extra ref and bump the request count if head request
255 * has extra ref from the write/commit path to handle handoff
256 * between write and commit lists. */
257 if (test_bit(PG_INODE_REF, &prev->wb_head->wb_flags)) {
258 inode = page_file_mapping(req->wb_page)->host;
259 set_bit(PG_INODE_REF, &req->wb_flags);
260 kref_get(&req->wb_kref);
261 atomic_long_inc(&NFS_I(inode)->nrequests);
262 }
263 }
264}
265
266/*
267 * nfs_page_group_destroy - sync the destruction of page groups
268 * @req - request that no longer needs the page group
269 *
270 * releases the page group reference from each member once all
271 * members have called this function.
272 */
273static void
274nfs_page_group_destroy(struct kref *kref)
275{
276 struct nfs_page *req = container_of(kref, struct nfs_page, wb_kref);
277 struct nfs_page *head = req->wb_head;
278 struct nfs_page *tmp, *next;
279
280 if (!nfs_page_group_sync_on_bit(req, PG_TEARDOWN))
281 goto out;
282
283 tmp = req;
284 do {
285 next = tmp->wb_this_page;
286 /* unlink and free */
287 tmp->wb_this_page = tmp;
288 tmp->wb_head = tmp;
289 nfs_free_request(tmp);
290 tmp = next;
291 } while (tmp != req);
292out:
293 /* subrequests must release the ref on the head request */
294 if (head != req)
295 nfs_release_request(head);
296}
297
298/**
299 * nfs_create_request - Create an NFS read/write request.
300 * @ctx: open context to use
301 * @page: page to write
302 * @last: last nfs request created for this page group or NULL if head
303 * @offset: starting offset within the page for the write
304 * @count: number of bytes to read/write
305 *
306 * The page must be locked by the caller. This makes sure we never
307 * create two different requests for the same page.
308 * User should ensure it is safe to sleep in this function.
309 */
310struct nfs_page *
311nfs_create_request(struct nfs_open_context *ctx, struct page *page,
312 struct nfs_page *last, unsigned int offset,
313 unsigned int count)
314{
315 struct nfs_page *req;
316 struct nfs_lock_context *l_ctx;
317
318 if (test_bit(NFS_CONTEXT_BAD, &ctx->flags))
319 return ERR_PTR(-EBADF);
320 /* try to allocate the request struct */
321 req = nfs_page_alloc();
322 if (req == NULL)
323 return ERR_PTR(-ENOMEM);
324
325 /* get lock context early so we can deal with alloc failures */
326 l_ctx = nfs_get_lock_context(ctx);
327 if (IS_ERR(l_ctx)) {
328 nfs_page_free(req);
329 return ERR_CAST(l_ctx);
330 }
331 req->wb_lock_context = l_ctx;
332 atomic_inc(&l_ctx->io_count);
333
334 /* Initialize the request struct. Initially, we assume a
335 * long write-back delay. This will be adjusted in
336 * update_nfs_request below if the region is not locked. */
337 req->wb_page = page;
338 if (page) {
339 req->wb_index = page_index(page);
340 get_page(page);
341 }
342 req->wb_offset = offset;
343 req->wb_pgbase = offset;
344 req->wb_bytes = count;
345 req->wb_context = get_nfs_open_context(ctx);
346 kref_init(&req->wb_kref);
347 nfs_page_group_init(req, last);
348 return req;
349}
350
351/**
352 * nfs_unlock_request - Unlock request and wake up sleepers.
353 * @req:
354 */
355void nfs_unlock_request(struct nfs_page *req)
356{
357 if (!NFS_WBACK_BUSY(req)) {
358 printk(KERN_ERR "NFS: Invalid unlock attempted\n");
359 BUG();
360 }
361 smp_mb__before_atomic();
362 clear_bit(PG_BUSY, &req->wb_flags);
363 smp_mb__after_atomic();
364 if (!test_bit(PG_CONTENDED2, &req->wb_flags))
365 return;
366 wake_up_bit(&req->wb_flags, PG_BUSY);
367}
368
369/**
370 * nfs_unlock_and_release_request - Unlock request and release the nfs_page
371 * @req:
372 */
373void nfs_unlock_and_release_request(struct nfs_page *req)
374{
375 nfs_unlock_request(req);
376 nfs_release_request(req);
377}
378
379/*
380 * nfs_clear_request - Free up all resources allocated to the request
381 * @req:
382 *
383 * Release page and open context resources associated with a read/write
384 * request after it has completed.
385 */
386static void nfs_clear_request(struct nfs_page *req)
387{
388 struct page *page = req->wb_page;
389 struct nfs_open_context *ctx = req->wb_context;
390 struct nfs_lock_context *l_ctx = req->wb_lock_context;
391
392 if (page != NULL) {
393 put_page(page);
394 req->wb_page = NULL;
395 }
396 if (l_ctx != NULL) {
397 if (atomic_dec_and_test(&l_ctx->io_count)) {
398 wake_up_var(&l_ctx->io_count);
399 if (test_bit(NFS_CONTEXT_UNLOCK, &ctx->flags))
400 rpc_wake_up(&NFS_SERVER(d_inode(ctx->dentry))->uoc_rpcwaitq);
401 }
402 nfs_put_lock_context(l_ctx);
403 req->wb_lock_context = NULL;
404 }
405 if (ctx != NULL) {
406 put_nfs_open_context(ctx);
407 req->wb_context = NULL;
408 }
409}
410
411/**
412 * nfs_release_request - Release the count on an NFS read/write request
413 * @req: request to release
414 *
415 * Note: Should never be called with the spinlock held!
416 */
417void nfs_free_request(struct nfs_page *req)
418{
419 WARN_ON_ONCE(req->wb_this_page != req);
420
421 /* extra debug: make sure no sync bits are still set */
422 WARN_ON_ONCE(test_bit(PG_TEARDOWN, &req->wb_flags));
423 WARN_ON_ONCE(test_bit(PG_UNLOCKPAGE, &req->wb_flags));
424 WARN_ON_ONCE(test_bit(PG_UPTODATE, &req->wb_flags));
425 WARN_ON_ONCE(test_bit(PG_WB_END, &req->wb_flags));
426 WARN_ON_ONCE(test_bit(PG_REMOVE, &req->wb_flags));
427
428 /* Release struct file and open context */
429 nfs_clear_request(req);
430 nfs_page_free(req);
431}
432
433void nfs_release_request(struct nfs_page *req)
434{
435 kref_put(&req->wb_kref, nfs_page_group_destroy);
436}
437EXPORT_SYMBOL_GPL(nfs_release_request);
438
439/**
440 * nfs_wait_on_request - Wait for a request to complete.
441 * @req: request to wait upon.
442 *
443 * Interruptible by fatal signals only.
444 * The user is responsible for holding a count on the request.
445 */
446int
447nfs_wait_on_request(struct nfs_page *req)
448{
449 if (!test_bit(PG_BUSY, &req->wb_flags))
450 return 0;
451 set_bit(PG_CONTENDED2, &req->wb_flags);
452 smp_mb__after_atomic();
453 return wait_on_bit_io(&req->wb_flags, PG_BUSY,
454 TASK_UNINTERRUPTIBLE);
455}
456EXPORT_SYMBOL_GPL(nfs_wait_on_request);
457
458/*
459 * nfs_generic_pg_test - determine if requests can be coalesced
460 * @desc: pointer to descriptor
461 * @prev: previous request in desc, or NULL
462 * @req: this request
463 *
464 * Returns zero if @req can be coalesced into @desc, otherwise it returns
465 * the size of the request.
466 */
467size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
468 struct nfs_page *prev, struct nfs_page *req)
469{
470 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
471
472
473 if (mirror->pg_count > mirror->pg_bsize) {
474 /* should never happen */
475 WARN_ON_ONCE(1);
476 return 0;
477 }
478
479 /*
480 * Limit the request size so that we can still allocate a page array
481 * for it without upsetting the slab allocator.
482 */
483 if (((mirror->pg_count + req->wb_bytes) >> PAGE_SHIFT) *
484 sizeof(struct page *) > PAGE_SIZE)
485 return 0;
486
487 return min(mirror->pg_bsize - mirror->pg_count, (size_t)req->wb_bytes);
488}
489EXPORT_SYMBOL_GPL(nfs_generic_pg_test);
490
491struct nfs_pgio_header *nfs_pgio_header_alloc(const struct nfs_rw_ops *ops)
492{
493 struct nfs_pgio_header *hdr = ops->rw_alloc_header();
494
495 if (hdr) {
496 INIT_LIST_HEAD(&hdr->pages);
497 spin_lock_init(&hdr->lock);
498 hdr->rw_ops = ops;
499 }
500 return hdr;
501}
502EXPORT_SYMBOL_GPL(nfs_pgio_header_alloc);
503
504/**
505 * nfs_pgio_data_destroy - make @hdr suitable for reuse
506 *
507 * Frees memory and releases refs from nfs_generic_pgio, so that it may
508 * be called again.
509 *
510 * @hdr: A header that has had nfs_generic_pgio called
511 */
512static void nfs_pgio_data_destroy(struct nfs_pgio_header *hdr)
513{
514 if (hdr->args.context)
515 put_nfs_open_context(hdr->args.context);
516 if (hdr->page_array.pagevec != hdr->page_array.page_array)
517 kfree(hdr->page_array.pagevec);
518}
519
520/*
521 * nfs_pgio_header_free - Free a read or write header
522 * @hdr: The header to free
523 */
524void nfs_pgio_header_free(struct nfs_pgio_header *hdr)
525{
526 nfs_pgio_data_destroy(hdr);
527 hdr->rw_ops->rw_free_header(hdr);
528}
529EXPORT_SYMBOL_GPL(nfs_pgio_header_free);
530
531/**
532 * nfs_pgio_rpcsetup - Set up arguments for a pageio call
533 * @hdr: The pageio hdr
534 * @count: Number of bytes to read
535 * @offset: Initial offset
536 * @how: How to commit data (writes only)
537 * @cinfo: Commit information for the call (writes only)
538 */
539static void nfs_pgio_rpcsetup(struct nfs_pgio_header *hdr,
540 unsigned int count,
541 int how, struct nfs_commit_info *cinfo)
542{
543 struct nfs_page *req = hdr->req;
544
545 /* Set up the RPC argument and reply structs
546 * NB: take care not to mess about with hdr->commit et al. */
547
548 hdr->args.fh = NFS_FH(hdr->inode);
549 hdr->args.offset = req_offset(req);
550 /* pnfs_set_layoutcommit needs this */
551 hdr->mds_offset = hdr->args.offset;
552 hdr->args.pgbase = req->wb_pgbase;
553 hdr->args.pages = hdr->page_array.pagevec;
554 hdr->args.count = count;
555 hdr->args.context = get_nfs_open_context(req->wb_context);
556 hdr->args.lock_context = req->wb_lock_context;
557 hdr->args.stable = NFS_UNSTABLE;
558 switch (how & (FLUSH_STABLE | FLUSH_COND_STABLE)) {
559 case 0:
560 break;
561 case FLUSH_COND_STABLE:
562 if (nfs_reqs_to_commit(cinfo))
563 break;
564 default:
565 hdr->args.stable = NFS_FILE_SYNC;
566 }
567
568 hdr->res.fattr = &hdr->fattr;
569 hdr->res.count = count;
570 hdr->res.eof = 0;
571 hdr->res.verf = &hdr->verf;
572 nfs_fattr_init(&hdr->fattr);
573}
574
575/**
576 * nfs_pgio_prepare - Prepare pageio hdr to go over the wire
577 * @task: The current task
578 * @calldata: pageio header to prepare
579 */
580static void nfs_pgio_prepare(struct rpc_task *task, void *calldata)
581{
582 struct nfs_pgio_header *hdr = calldata;
583 int err;
584 err = NFS_PROTO(hdr->inode)->pgio_rpc_prepare(task, hdr);
585 if (err)
586 rpc_exit(task, err);
587}
588
589int nfs_initiate_pgio(struct rpc_clnt *clnt, struct nfs_pgio_header *hdr,
590 struct rpc_cred *cred, const struct nfs_rpc_ops *rpc_ops,
591 const struct rpc_call_ops *call_ops, int how, int flags)
592{
593 struct rpc_task *task;
594 struct rpc_message msg = {
595 .rpc_argp = &hdr->args,
596 .rpc_resp = &hdr->res,
597 .rpc_cred = cred,
598 };
599 struct rpc_task_setup task_setup_data = {
600 .rpc_client = clnt,
601 .task = &hdr->task,
602 .rpc_message = &msg,
603 .callback_ops = call_ops,
604 .callback_data = hdr,
605 .workqueue = nfsiod_workqueue,
606 .flags = RPC_TASK_ASYNC | flags,
607 };
608 int ret = 0;
609
610 hdr->rw_ops->rw_initiate(hdr, &msg, rpc_ops, &task_setup_data, how);
611
612 dprintk("NFS: initiated pgio call "
613 "(req %s/%llu, %u bytes @ offset %llu)\n",
614 hdr->inode->i_sb->s_id,
615 (unsigned long long)NFS_FILEID(hdr->inode),
616 hdr->args.count,
617 (unsigned long long)hdr->args.offset);
618
619 task = rpc_run_task(&task_setup_data);
620 if (IS_ERR(task)) {
621 ret = PTR_ERR(task);
622 goto out;
623 }
624 if (how & FLUSH_SYNC) {
625 ret = rpc_wait_for_completion_task(task);
626 if (ret == 0)
627 ret = task->tk_status;
628 }
629 rpc_put_task(task);
630out:
631 return ret;
632}
633EXPORT_SYMBOL_GPL(nfs_initiate_pgio);
634
635/**
636 * nfs_pgio_error - Clean up from a pageio error
637 * @desc: IO descriptor
638 * @hdr: pageio header
639 */
640static void nfs_pgio_error(struct nfs_pgio_header *hdr)
641{
642 set_bit(NFS_IOHDR_REDO, &hdr->flags);
643 hdr->completion_ops->completion(hdr);
644}
645
646/**
647 * nfs_pgio_release - Release pageio data
648 * @calldata: The pageio header to release
649 */
650static void nfs_pgio_release(void *calldata)
651{
652 struct nfs_pgio_header *hdr = calldata;
653 hdr->completion_ops->completion(hdr);
654}
655
656static void nfs_pageio_mirror_init(struct nfs_pgio_mirror *mirror,
657 unsigned int bsize)
658{
659 INIT_LIST_HEAD(&mirror->pg_list);
660 mirror->pg_bytes_written = 0;
661 mirror->pg_count = 0;
662 mirror->pg_bsize = bsize;
663 mirror->pg_base = 0;
664 mirror->pg_recoalesce = 0;
665}
666
667/**
668 * nfs_pageio_init - initialise a page io descriptor
669 * @desc: pointer to descriptor
670 * @inode: pointer to inode
671 * @pg_ops: pointer to pageio operations
672 * @compl_ops: pointer to pageio completion operations
673 * @rw_ops: pointer to nfs read/write operations
674 * @bsize: io block size
675 * @io_flags: extra parameters for the io function
676 */
677void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
678 struct inode *inode,
679 const struct nfs_pageio_ops *pg_ops,
680 const struct nfs_pgio_completion_ops *compl_ops,
681 const struct nfs_rw_ops *rw_ops,
682 size_t bsize,
683 int io_flags)
684{
685 desc->pg_moreio = 0;
686 desc->pg_inode = inode;
687 desc->pg_ops = pg_ops;
688 desc->pg_completion_ops = compl_ops;
689 desc->pg_rw_ops = rw_ops;
690 desc->pg_ioflags = io_flags;
691 desc->pg_error = 0;
692 desc->pg_lseg = NULL;
693 desc->pg_io_completion = NULL;
694 desc->pg_dreq = NULL;
695 desc->pg_bsize = bsize;
696
697 desc->pg_mirror_count = 1;
698 desc->pg_mirror_idx = 0;
699
700 desc->pg_mirrors_dynamic = NULL;
701 desc->pg_mirrors = desc->pg_mirrors_static;
702 nfs_pageio_mirror_init(&desc->pg_mirrors[0], bsize);
703}
704
705/**
706 * nfs_pgio_result - Basic pageio error handling
707 * @task: The task that ran
708 * @calldata: Pageio header to check
709 */
710static void nfs_pgio_result(struct rpc_task *task, void *calldata)
711{
712 struct nfs_pgio_header *hdr = calldata;
713 struct inode *inode = hdr->inode;
714
715 dprintk("NFS: %s: %5u, (status %d)\n", __func__,
716 task->tk_pid, task->tk_status);
717
718 if (hdr->rw_ops->rw_done(task, hdr, inode) != 0)
719 return;
720 if (task->tk_status < 0)
721 nfs_set_pgio_error(hdr, task->tk_status, hdr->args.offset);
722 else
723 hdr->rw_ops->rw_result(task, hdr);
724}
725
726/*
727 * Create an RPC task for the given read or write request and kick it.
728 * The page must have been locked by the caller.
729 *
730 * It may happen that the page we're passed is not marked dirty.
731 * This is the case if nfs_updatepage detects a conflicting request
732 * that has been written but not committed.
733 */
734int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
735 struct nfs_pgio_header *hdr)
736{
737 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
738
739 struct nfs_page *req;
740 struct page **pages,
741 *last_page;
742 struct list_head *head = &mirror->pg_list;
743 struct nfs_commit_info cinfo;
744 struct nfs_page_array *pg_array = &hdr->page_array;
745 unsigned int pagecount, pageused;
746 gfp_t gfp_flags = GFP_KERNEL;
747
748 pagecount = nfs_page_array_len(mirror->pg_base, mirror->pg_count);
749 pg_array->npages = pagecount;
750
751 if (pagecount <= ARRAY_SIZE(pg_array->page_array))
752 pg_array->pagevec = pg_array->page_array;
753 else {
754 if (hdr->rw_mode == FMODE_WRITE)
755 gfp_flags = GFP_NOIO;
756 pg_array->pagevec = kcalloc(pagecount, sizeof(struct page *), gfp_flags);
757 if (!pg_array->pagevec) {
758 pg_array->npages = 0;
759 nfs_pgio_error(hdr);
760 desc->pg_error = -ENOMEM;
761 return desc->pg_error;
762 }
763 }
764
765 nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq);
766 pages = hdr->page_array.pagevec;
767 last_page = NULL;
768 pageused = 0;
769 while (!list_empty(head)) {
770 req = nfs_list_entry(head->next);
771 nfs_list_remove_request(req);
772 nfs_list_add_request(req, &hdr->pages);
773
774 if (!last_page || last_page != req->wb_page) {
775 pageused++;
776 if (pageused > pagecount)
777 break;
778 *pages++ = last_page = req->wb_page;
779 }
780 }
781 if (WARN_ON_ONCE(pageused != pagecount)) {
782 nfs_pgio_error(hdr);
783 desc->pg_error = -EINVAL;
784 return desc->pg_error;
785 }
786
787 if ((desc->pg_ioflags & FLUSH_COND_STABLE) &&
788 (desc->pg_moreio || nfs_reqs_to_commit(&cinfo)))
789 desc->pg_ioflags &= ~FLUSH_COND_STABLE;
790
791 /* Set up the argument struct */
792 nfs_pgio_rpcsetup(hdr, mirror->pg_count, desc->pg_ioflags, &cinfo);
793 desc->pg_rpc_callops = &nfs_pgio_common_ops;
794 return 0;
795}
796EXPORT_SYMBOL_GPL(nfs_generic_pgio);
797
798static int nfs_generic_pg_pgios(struct nfs_pageio_descriptor *desc)
799{
800 struct nfs_pgio_header *hdr;
801 int ret;
802
803 hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
804 if (!hdr) {
805 desc->pg_error = -ENOMEM;
806 return desc->pg_error;
807 }
808 nfs_pgheader_init(desc, hdr, nfs_pgio_header_free);
809 ret = nfs_generic_pgio(desc, hdr);
810 if (ret == 0)
811 ret = nfs_initiate_pgio(NFS_CLIENT(hdr->inode),
812 hdr,
813 hdr->cred,
814 NFS_PROTO(hdr->inode),
815 desc->pg_rpc_callops,
816 desc->pg_ioflags, 0);
817 return ret;
818}
819
820static struct nfs_pgio_mirror *
821nfs_pageio_alloc_mirrors(struct nfs_pageio_descriptor *desc,
822 unsigned int mirror_count)
823{
824 struct nfs_pgio_mirror *ret;
825 unsigned int i;
826
827 kfree(desc->pg_mirrors_dynamic);
828 desc->pg_mirrors_dynamic = NULL;
829 if (mirror_count == 1)
830 return desc->pg_mirrors_static;
831 ret = kmalloc_array(mirror_count, sizeof(*ret), GFP_NOFS);
832 if (ret != NULL) {
833 for (i = 0; i < mirror_count; i++)
834 nfs_pageio_mirror_init(&ret[i], desc->pg_bsize);
835 desc->pg_mirrors_dynamic = ret;
836 }
837 return ret;
838}
839
840/*
841 * nfs_pageio_setup_mirroring - determine if mirroring is to be used
842 * by calling the pg_get_mirror_count op
843 */
844static void nfs_pageio_setup_mirroring(struct nfs_pageio_descriptor *pgio,
845 struct nfs_page *req)
846{
847 unsigned int mirror_count = 1;
848
849 if (pgio->pg_ops->pg_get_mirror_count)
850 mirror_count = pgio->pg_ops->pg_get_mirror_count(pgio, req);
851 if (mirror_count == pgio->pg_mirror_count || pgio->pg_error < 0)
852 return;
853
854 if (!mirror_count || mirror_count > NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX) {
855 pgio->pg_error = -EINVAL;
856 return;
857 }
858
859 pgio->pg_mirrors = nfs_pageio_alloc_mirrors(pgio, mirror_count);
860 if (pgio->pg_mirrors == NULL) {
861 pgio->pg_error = -ENOMEM;
862 pgio->pg_mirrors = pgio->pg_mirrors_static;
863 mirror_count = 1;
864 }
865 pgio->pg_mirror_count = mirror_count;
866}
867
868/*
869 * nfs_pageio_stop_mirroring - stop using mirroring (set mirror count to 1)
870 */
871void nfs_pageio_stop_mirroring(struct nfs_pageio_descriptor *pgio)
872{
873 pgio->pg_mirror_count = 1;
874 pgio->pg_mirror_idx = 0;
875}
876
877static void nfs_pageio_cleanup_mirroring(struct nfs_pageio_descriptor *pgio)
878{
879 pgio->pg_mirror_count = 1;
880 pgio->pg_mirror_idx = 0;
881 pgio->pg_mirrors = pgio->pg_mirrors_static;
882 kfree(pgio->pg_mirrors_dynamic);
883 pgio->pg_mirrors_dynamic = NULL;
884}
885
886static bool nfs_match_lock_context(const struct nfs_lock_context *l1,
887 const struct nfs_lock_context *l2)
888{
889 return l1->lockowner == l2->lockowner;
890}
891
892/**
893 * nfs_can_coalesce_requests - test two requests for compatibility
894 * @prev: pointer to nfs_page
895 * @req: pointer to nfs_page
896 *
897 * The nfs_page structures 'prev' and 'req' are compared to ensure that the
898 * page data area they describe is contiguous, and that their RPC
899 * credentials, NFSv4 open state, and lockowners are the same.
900 *
901 * Return 'true' if this is the case, else return 'false'.
902 */
903static bool nfs_can_coalesce_requests(struct nfs_page *prev,
904 struct nfs_page *req,
905 struct nfs_pageio_descriptor *pgio)
906{
907 size_t size;
908 struct file_lock_context *flctx;
909
910 if (prev) {
911 if (!nfs_match_open_context(req->wb_context, prev->wb_context))
912 return false;
913 flctx = d_inode(req->wb_context->dentry)->i_flctx;
914 if (flctx != NULL &&
915 !(list_empty_careful(&flctx->flc_posix) &&
916 list_empty_careful(&flctx->flc_flock)) &&
917 !nfs_match_lock_context(req->wb_lock_context,
918 prev->wb_lock_context))
919 return false;
920 if (req_offset(req) != req_offset(prev) + prev->wb_bytes)
921 return false;
922 if (req->wb_page == prev->wb_page) {
923 if (req->wb_pgbase != prev->wb_pgbase + prev->wb_bytes)
924 return false;
925 } else {
926 if (req->wb_pgbase != 0 ||
927 prev->wb_pgbase + prev->wb_bytes != PAGE_SIZE)
928 return false;
929 }
930 }
931 size = pgio->pg_ops->pg_test(pgio, prev, req);
932 WARN_ON_ONCE(size > req->wb_bytes);
933 if (size && size < req->wb_bytes)
934 req->wb_bytes = size;
935 return size > 0;
936}
937
938/**
939 * nfs_pageio_do_add_request - Attempt to coalesce a request into a page list.
940 * @desc: destination io descriptor
941 * @req: request
942 *
943 * Returns true if the request 'req' was successfully coalesced into the
944 * existing list of pages 'desc'.
945 */
946static int nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc,
947 struct nfs_page *req)
948{
949 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
950
951 struct nfs_page *prev = NULL;
952
953 if (mirror->pg_count != 0) {
954 prev = nfs_list_entry(mirror->pg_list.prev);
955 } else {
956 if (desc->pg_ops->pg_init)
957 desc->pg_ops->pg_init(desc, req);
958 if (desc->pg_error < 0)
959 return 0;
960 mirror->pg_base = req->wb_pgbase;
961 }
962 if (!nfs_can_coalesce_requests(prev, req, desc))
963 return 0;
964 nfs_list_remove_request(req);
965 nfs_list_add_request(req, &mirror->pg_list);
966 mirror->pg_count += req->wb_bytes;
967 return 1;
968}
969
970/*
971 * Helper for nfs_pageio_add_request and nfs_pageio_complete
972 */
973static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc)
974{
975 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
976
977
978 if (!list_empty(&mirror->pg_list)) {
979 int error = desc->pg_ops->pg_doio(desc);
980 if (error < 0)
981 desc->pg_error = error;
982 else
983 mirror->pg_bytes_written += mirror->pg_count;
984 }
985 if (list_empty(&mirror->pg_list)) {
986 mirror->pg_count = 0;
987 mirror->pg_base = 0;
988 }
989}
990
991/**
992 * nfs_pageio_add_request - Attempt to coalesce a request into a page list.
993 * @desc: destination io descriptor
994 * @req: request
995 *
996 * This may split a request into subrequests which are all part of the
997 * same page group.
998 *
999 * Returns true if the request 'req' was successfully coalesced into the
1000 * existing list of pages 'desc'.
1001 */
1002static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
1003 struct nfs_page *req)
1004{
1005 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
1006
1007 struct nfs_page *subreq;
1008 unsigned int bytes_left = 0;
1009 unsigned int offset, pgbase;
1010
1011 nfs_page_group_lock(req);
1012
1013 subreq = req;
1014 bytes_left = subreq->wb_bytes;
1015 offset = subreq->wb_offset;
1016 pgbase = subreq->wb_pgbase;
1017
1018 do {
1019 if (!nfs_pageio_do_add_request(desc, subreq)) {
1020 /* make sure pg_test call(s) did nothing */
1021 WARN_ON_ONCE(subreq->wb_bytes != bytes_left);
1022 WARN_ON_ONCE(subreq->wb_offset != offset);
1023 WARN_ON_ONCE(subreq->wb_pgbase != pgbase);
1024
1025 nfs_page_group_unlock(req);
1026 desc->pg_moreio = 1;
1027 nfs_pageio_doio(desc);
1028 if (desc->pg_error < 0)
1029 return 0;
1030 if (mirror->pg_recoalesce)
1031 return 0;
1032 /* retry add_request for this subreq */
1033 nfs_page_group_lock(req);
1034 continue;
1035 }
1036
1037 /* check for buggy pg_test call(s) */
1038 WARN_ON_ONCE(subreq->wb_bytes + subreq->wb_pgbase > PAGE_SIZE);
1039 WARN_ON_ONCE(subreq->wb_bytes > bytes_left);
1040 WARN_ON_ONCE(subreq->wb_bytes == 0);
1041
1042 bytes_left -= subreq->wb_bytes;
1043 offset += subreq->wb_bytes;
1044 pgbase += subreq->wb_bytes;
1045
1046 if (bytes_left) {
1047 subreq = nfs_create_request(req->wb_context,
1048 req->wb_page,
1049 subreq, pgbase, bytes_left);
1050 if (IS_ERR(subreq))
1051 goto err_ptr;
1052 nfs_lock_request(subreq);
1053 subreq->wb_offset = offset;
1054 subreq->wb_index = req->wb_index;
1055 }
1056 } while (bytes_left > 0);
1057
1058 nfs_page_group_unlock(req);
1059 return 1;
1060err_ptr:
1061 desc->pg_error = PTR_ERR(subreq);
1062 nfs_page_group_unlock(req);
1063 return 0;
1064}
1065
1066static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc)
1067{
1068 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
1069 LIST_HEAD(head);
1070
1071 do {
1072 list_splice_init(&mirror->pg_list, &head);
1073 mirror->pg_bytes_written -= mirror->pg_count;
1074 mirror->pg_count = 0;
1075 mirror->pg_base = 0;
1076 mirror->pg_recoalesce = 0;
1077
1078 while (!list_empty(&head)) {
1079 struct nfs_page *req;
1080
1081 req = list_first_entry(&head, struct nfs_page, wb_list);
1082 nfs_list_remove_request(req);
1083 if (__nfs_pageio_add_request(desc, req))
1084 continue;
1085 if (desc->pg_error < 0) {
1086 list_splice_tail(&head, &mirror->pg_list);
1087 mirror->pg_recoalesce = 1;
1088 return 0;
1089 }
1090 break;
1091 }
1092 } while (mirror->pg_recoalesce);
1093 return 1;
1094}
1095
1096static int nfs_pageio_add_request_mirror(struct nfs_pageio_descriptor *desc,
1097 struct nfs_page *req)
1098{
1099 int ret;
1100
1101 do {
1102 ret = __nfs_pageio_add_request(desc, req);
1103 if (ret)
1104 break;
1105 if (desc->pg_error < 0)
1106 break;
1107 ret = nfs_do_recoalesce(desc);
1108 } while (ret);
1109
1110 return ret;
1111}
1112
1113int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
1114 struct nfs_page *req)
1115{
1116 u32 midx;
1117 unsigned int pgbase, offset, bytes;
1118 struct nfs_page *dupreq, *lastreq;
1119
1120 pgbase = req->wb_pgbase;
1121 offset = req->wb_offset;
1122 bytes = req->wb_bytes;
1123
1124 nfs_pageio_setup_mirroring(desc, req);
1125 if (desc->pg_error < 0)
1126 goto out_failed;
1127
1128 for (midx = 0; midx < desc->pg_mirror_count; midx++) {
1129 if (midx) {
1130 nfs_page_group_lock(req);
1131
1132 /* find the last request */
1133 for (lastreq = req->wb_head;
1134 lastreq->wb_this_page != req->wb_head;
1135 lastreq = lastreq->wb_this_page)
1136 ;
1137
1138 dupreq = nfs_create_request(req->wb_context,
1139 req->wb_page, lastreq, pgbase, bytes);
1140
1141 if (IS_ERR(dupreq)) {
1142 nfs_page_group_unlock(req);
1143 desc->pg_error = PTR_ERR(dupreq);
1144 goto out_failed;
1145 }
1146
1147 nfs_lock_request(dupreq);
1148 nfs_page_group_unlock(req);
1149 dupreq->wb_offset = offset;
1150 dupreq->wb_index = req->wb_index;
1151 } else
1152 dupreq = req;
1153
1154 if (nfs_pgio_has_mirroring(desc))
1155 desc->pg_mirror_idx = midx;
1156 if (!nfs_pageio_add_request_mirror(desc, dupreq))
1157 goto out_failed;
1158 }
1159
1160 return 1;
1161
1162out_failed:
1163 /*
1164 * We might have failed before sending any reqs over wire.
1165 * Clean up rest of the reqs in mirror pg_list.
1166 */
1167 if (desc->pg_error) {
1168 struct nfs_pgio_mirror *mirror;
1169 void (*func)(struct list_head *);
1170
1171 /* remember fatal errors */
1172 if (nfs_error_is_fatal(desc->pg_error))
1173 nfs_context_set_write_error(req->wb_context,
1174 desc->pg_error);
1175
1176 func = desc->pg_completion_ops->error_cleanup;
1177 for (midx = 0; midx < desc->pg_mirror_count; midx++) {
1178 mirror = &desc->pg_mirrors[midx];
1179 func(&mirror->pg_list);
1180 }
1181 }
1182 return 0;
1183}
1184
1185/*
1186 * nfs_pageio_complete_mirror - Complete I/O on the current mirror of an
1187 * nfs_pageio_descriptor
1188 * @desc: pointer to io descriptor
1189 * @mirror_idx: pointer to mirror index
1190 */
1191static void nfs_pageio_complete_mirror(struct nfs_pageio_descriptor *desc,
1192 u32 mirror_idx)
1193{
1194 struct nfs_pgio_mirror *mirror = &desc->pg_mirrors[mirror_idx];
1195 u32 restore_idx = desc->pg_mirror_idx;
1196
1197 if (nfs_pgio_has_mirroring(desc))
1198 desc->pg_mirror_idx = mirror_idx;
1199 for (;;) {
1200 nfs_pageio_doio(desc);
1201 if (!mirror->pg_recoalesce)
1202 break;
1203 if (!nfs_do_recoalesce(desc))
1204 break;
1205 }
1206 desc->pg_mirror_idx = restore_idx;
1207}
1208
1209/*
1210 * nfs_pageio_resend - Transfer requests to new descriptor and resend
1211 * @hdr - the pgio header to move request from
1212 * @desc - the pageio descriptor to add requests to
1213 *
1214 * Try to move each request (nfs_page) from @hdr to @desc then attempt
1215 * to send them.
1216 *
1217 * Returns 0 on success and < 0 on error.
1218 */
1219int nfs_pageio_resend(struct nfs_pageio_descriptor *desc,
1220 struct nfs_pgio_header *hdr)
1221{
1222 LIST_HEAD(failed);
1223
1224 desc->pg_io_completion = hdr->io_completion;
1225 desc->pg_dreq = hdr->dreq;
1226 while (!list_empty(&hdr->pages)) {
1227 struct nfs_page *req = nfs_list_entry(hdr->pages.next);
1228
1229 nfs_list_remove_request(req);
1230 if (!nfs_pageio_add_request(desc, req))
1231 nfs_list_add_request(req, &failed);
1232 }
1233 nfs_pageio_complete(desc);
1234 if (!list_empty(&failed)) {
1235 list_move(&failed, &hdr->pages);
1236 return desc->pg_error < 0 ? desc->pg_error : -EIO;
1237 }
1238 return 0;
1239}
1240EXPORT_SYMBOL_GPL(nfs_pageio_resend);
1241
1242/**
1243 * nfs_pageio_complete - Complete I/O then cleanup an nfs_pageio_descriptor
1244 * @desc: pointer to io descriptor
1245 */
1246void nfs_pageio_complete(struct nfs_pageio_descriptor *desc)
1247{
1248 u32 midx;
1249
1250 for (midx = 0; midx < desc->pg_mirror_count; midx++)
1251 nfs_pageio_complete_mirror(desc, midx);
1252
1253 if (desc->pg_ops->pg_cleanup)
1254 desc->pg_ops->pg_cleanup(desc);
1255 nfs_pageio_cleanup_mirroring(desc);
1256}
1257
1258/**
1259 * nfs_pageio_cond_complete - Conditional I/O completion
1260 * @desc: pointer to io descriptor
1261 * @index: page index
1262 *
1263 * It is important to ensure that processes don't try to take locks
1264 * on non-contiguous ranges of pages as that might deadlock. This
1265 * function should be called before attempting to wait on a locked
1266 * nfs_page. It will complete the I/O if the page index 'index'
1267 * is not contiguous with the existing list of pages in 'desc'.
1268 */
1269void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index)
1270{
1271 struct nfs_pgio_mirror *mirror;
1272 struct nfs_page *prev;
1273 u32 midx;
1274
1275 for (midx = 0; midx < desc->pg_mirror_count; midx++) {
1276 mirror = &desc->pg_mirrors[midx];
1277 if (!list_empty(&mirror->pg_list)) {
1278 prev = nfs_list_entry(mirror->pg_list.prev);
1279 if (index != prev->wb_index + 1) {
1280 nfs_pageio_complete(desc);
1281 break;
1282 }
1283 }
1284 }
1285}
1286
1287int __init nfs_init_nfspagecache(void)
1288{
1289 nfs_page_cachep = kmem_cache_create("nfs_page",
1290 sizeof(struct nfs_page),
1291 0, SLAB_HWCACHE_ALIGN,
1292 NULL);
1293 if (nfs_page_cachep == NULL)
1294 return -ENOMEM;
1295
1296 return 0;
1297}
1298
1299void nfs_destroy_nfspagecache(void)
1300{
1301 kmem_cache_destroy(nfs_page_cachep);
1302}
1303
1304static const struct rpc_call_ops nfs_pgio_common_ops = {
1305 .rpc_call_prepare = nfs_pgio_prepare,
1306 .rpc_call_done = nfs_pgio_result,
1307 .rpc_release = nfs_pgio_release,
1308};
1309
1310const struct nfs_pageio_ops nfs_pgio_rw_ops = {
1311 .pg_test = nfs_generic_pg_test,
1312 .pg_doio = nfs_generic_pg_pgios,
1313};
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#include <linux/filelock.h>
25
26#include "internal.h"
27#include "pnfs.h"
28#include "nfstrace.h"
29#include "fscache.h"
30
31#define NFSDBG_FACILITY NFSDBG_PAGECACHE
32
33static struct kmem_cache *nfs_page_cachep;
34static const struct rpc_call_ops nfs_pgio_common_ops;
35
36struct nfs_page_iter_page {
37 const struct nfs_page *req;
38 size_t count;
39};
40
41static void nfs_page_iter_page_init(struct nfs_page_iter_page *i,
42 const struct nfs_page *req)
43{
44 i->req = req;
45 i->count = 0;
46}
47
48static void nfs_page_iter_page_advance(struct nfs_page_iter_page *i, size_t sz)
49{
50 const struct nfs_page *req = i->req;
51 size_t tmp = i->count + sz;
52
53 i->count = (tmp < req->wb_bytes) ? tmp : req->wb_bytes;
54}
55
56static struct page *nfs_page_iter_page_get(struct nfs_page_iter_page *i)
57{
58 const struct nfs_page *req = i->req;
59 struct page *page;
60
61 if (i->count != req->wb_bytes) {
62 size_t base = i->count + req->wb_pgbase;
63 size_t len = PAGE_SIZE - offset_in_page(base);
64
65 page = nfs_page_to_page(req, base);
66 nfs_page_iter_page_advance(i, len);
67 return page;
68 }
69 return NULL;
70}
71
72static struct nfs_pgio_mirror *
73nfs_pgio_get_mirror(struct nfs_pageio_descriptor *desc, u32 idx)
74{
75 if (desc->pg_ops->pg_get_mirror)
76 return desc->pg_ops->pg_get_mirror(desc, idx);
77 return &desc->pg_mirrors[0];
78}
79
80struct nfs_pgio_mirror *
81nfs_pgio_current_mirror(struct nfs_pageio_descriptor *desc)
82{
83 return nfs_pgio_get_mirror(desc, desc->pg_mirror_idx);
84}
85EXPORT_SYMBOL_GPL(nfs_pgio_current_mirror);
86
87static u32
88nfs_pgio_set_current_mirror(struct nfs_pageio_descriptor *desc, u32 idx)
89{
90 if (desc->pg_ops->pg_set_mirror)
91 return desc->pg_ops->pg_set_mirror(desc, idx);
92 return desc->pg_mirror_idx;
93}
94
95void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
96 struct nfs_pgio_header *hdr,
97 void (*release)(struct nfs_pgio_header *hdr))
98{
99 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
100
101
102 hdr->req = nfs_list_entry(mirror->pg_list.next);
103 hdr->inode = desc->pg_inode;
104 hdr->cred = nfs_req_openctx(hdr->req)->cred;
105 hdr->io_start = req_offset(hdr->req);
106 hdr->good_bytes = mirror->pg_count;
107 hdr->io_completion = desc->pg_io_completion;
108 hdr->dreq = desc->pg_dreq;
109 nfs_netfs_set_pgio_header(hdr, desc);
110 hdr->release = release;
111 hdr->completion_ops = desc->pg_completion_ops;
112 if (hdr->completion_ops->init_hdr)
113 hdr->completion_ops->init_hdr(hdr);
114
115 hdr->pgio_mirror_idx = desc->pg_mirror_idx;
116}
117EXPORT_SYMBOL_GPL(nfs_pgheader_init);
118
119void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos)
120{
121 unsigned int new = pos - hdr->io_start;
122
123 trace_nfs_pgio_error(hdr, error, pos);
124 if (hdr->good_bytes > new) {
125 hdr->good_bytes = new;
126 clear_bit(NFS_IOHDR_EOF, &hdr->flags);
127 if (!test_and_set_bit(NFS_IOHDR_ERROR, &hdr->flags))
128 hdr->error = error;
129 }
130}
131
132static inline struct nfs_page *nfs_page_alloc(void)
133{
134 struct nfs_page *p =
135 kmem_cache_zalloc(nfs_page_cachep, nfs_io_gfp_mask());
136 if (p)
137 INIT_LIST_HEAD(&p->wb_list);
138 return p;
139}
140
141static inline void
142nfs_page_free(struct nfs_page *p)
143{
144 kmem_cache_free(nfs_page_cachep, p);
145}
146
147/**
148 * nfs_iocounter_wait - wait for i/o to complete
149 * @l_ctx: nfs_lock_context with io_counter to use
150 *
151 * returns -ERESTARTSYS if interrupted by a fatal signal.
152 * Otherwise returns 0 once the io_count hits 0.
153 */
154int
155nfs_iocounter_wait(struct nfs_lock_context *l_ctx)
156{
157 return wait_var_event_killable(&l_ctx->io_count,
158 !atomic_read(&l_ctx->io_count));
159}
160
161/**
162 * nfs_async_iocounter_wait - wait on a rpc_waitqueue for I/O
163 * to complete
164 * @task: the rpc_task that should wait
165 * @l_ctx: nfs_lock_context with io_counter to check
166 *
167 * Returns true if there is outstanding I/O to wait on and the
168 * task has been put to sleep.
169 */
170bool
171nfs_async_iocounter_wait(struct rpc_task *task, struct nfs_lock_context *l_ctx)
172{
173 struct inode *inode = d_inode(l_ctx->open_context->dentry);
174 bool ret = false;
175
176 if (atomic_read(&l_ctx->io_count) > 0) {
177 rpc_sleep_on(&NFS_SERVER(inode)->uoc_rpcwaitq, task, NULL);
178 ret = true;
179 }
180
181 if (atomic_read(&l_ctx->io_count) == 0) {
182 rpc_wake_up_queued_task(&NFS_SERVER(inode)->uoc_rpcwaitq, task);
183 ret = false;
184 }
185
186 return ret;
187}
188EXPORT_SYMBOL_GPL(nfs_async_iocounter_wait);
189
190/*
191 * nfs_page_set_headlock - set the request PG_HEADLOCK
192 * @req: request that is to be locked
193 *
194 * this lock must be held when modifying req->wb_head
195 *
196 * return 0 on success, < 0 on error
197 */
198int
199nfs_page_set_headlock(struct nfs_page *req)
200{
201 if (!test_and_set_bit(PG_HEADLOCK, &req->wb_flags))
202 return 0;
203
204 set_bit(PG_CONTENDED1, &req->wb_flags);
205 smp_mb__after_atomic();
206 return wait_on_bit_lock(&req->wb_flags, PG_HEADLOCK,
207 TASK_UNINTERRUPTIBLE);
208}
209
210/*
211 * nfs_page_clear_headlock - clear the request PG_HEADLOCK
212 * @req: request that is to be locked
213 */
214void
215nfs_page_clear_headlock(struct nfs_page *req)
216{
217 clear_bit_unlock(PG_HEADLOCK, &req->wb_flags);
218 smp_mb__after_atomic();
219 if (!test_bit(PG_CONTENDED1, &req->wb_flags))
220 return;
221 wake_up_bit(&req->wb_flags, PG_HEADLOCK);
222}
223
224/*
225 * nfs_page_group_lock - lock the head of the page group
226 * @req: request in group that is to be locked
227 *
228 * this lock must be held when traversing or modifying the page
229 * group list
230 *
231 * return 0 on success, < 0 on error
232 */
233int
234nfs_page_group_lock(struct nfs_page *req)
235{
236 int ret;
237
238 ret = nfs_page_set_headlock(req);
239 if (ret || req->wb_head == req)
240 return ret;
241 return nfs_page_set_headlock(req->wb_head);
242}
243
244/*
245 * nfs_page_group_unlock - unlock the head of the page group
246 * @req: request in group that is to be unlocked
247 */
248void
249nfs_page_group_unlock(struct nfs_page *req)
250{
251 if (req != req->wb_head)
252 nfs_page_clear_headlock(req->wb_head);
253 nfs_page_clear_headlock(req);
254}
255
256/*
257 * nfs_page_group_sync_on_bit_locked
258 *
259 * must be called with page group lock held
260 */
261static bool
262nfs_page_group_sync_on_bit_locked(struct nfs_page *req, unsigned int bit)
263{
264 struct nfs_page *head = req->wb_head;
265 struct nfs_page *tmp;
266
267 WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &head->wb_flags));
268 WARN_ON_ONCE(test_and_set_bit(bit, &req->wb_flags));
269
270 tmp = req->wb_this_page;
271 while (tmp != req) {
272 if (!test_bit(bit, &tmp->wb_flags))
273 return false;
274 tmp = tmp->wb_this_page;
275 }
276
277 /* true! reset all bits */
278 tmp = req;
279 do {
280 clear_bit(bit, &tmp->wb_flags);
281 tmp = tmp->wb_this_page;
282 } while (tmp != req);
283
284 return true;
285}
286
287/*
288 * nfs_page_group_sync_on_bit - set bit on current request, but only
289 * return true if the bit is set for all requests in page group
290 * @req - request in page group
291 * @bit - PG_* bit that is used to sync page group
292 */
293bool nfs_page_group_sync_on_bit(struct nfs_page *req, unsigned int bit)
294{
295 bool ret;
296
297 nfs_page_group_lock(req);
298 ret = nfs_page_group_sync_on_bit_locked(req, bit);
299 nfs_page_group_unlock(req);
300
301 return ret;
302}
303
304/*
305 * nfs_page_group_init - Initialize the page group linkage for @req
306 * @req - a new nfs request
307 * @prev - the previous request in page group, or NULL if @req is the first
308 * or only request in the group (the head).
309 */
310static inline void
311nfs_page_group_init(struct nfs_page *req, struct nfs_page *prev)
312{
313 struct inode *inode;
314 WARN_ON_ONCE(prev == req);
315
316 if (!prev) {
317 /* a head request */
318 req->wb_head = req;
319 req->wb_this_page = req;
320 } else {
321 /* a subrequest */
322 WARN_ON_ONCE(prev->wb_this_page != prev->wb_head);
323 WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &prev->wb_head->wb_flags));
324 req->wb_head = prev->wb_head;
325 req->wb_this_page = prev->wb_this_page;
326 prev->wb_this_page = req;
327
328 /* All subrequests take a ref on the head request until
329 * nfs_page_group_destroy is called */
330 kref_get(&req->wb_head->wb_kref);
331
332 /* grab extra ref and bump the request count if head request
333 * has extra ref from the write/commit path to handle handoff
334 * between write and commit lists. */
335 if (test_bit(PG_INODE_REF, &prev->wb_head->wb_flags)) {
336 inode = nfs_page_to_inode(req);
337 set_bit(PG_INODE_REF, &req->wb_flags);
338 kref_get(&req->wb_kref);
339 atomic_long_inc(&NFS_I(inode)->nrequests);
340 }
341 }
342}
343
344/*
345 * nfs_page_group_destroy - sync the destruction of page groups
346 * @req - request that no longer needs the page group
347 *
348 * releases the page group reference from each member once all
349 * members have called this function.
350 */
351static void
352nfs_page_group_destroy(struct kref *kref)
353{
354 struct nfs_page *req = container_of(kref, struct nfs_page, wb_kref);
355 struct nfs_page *head = req->wb_head;
356 struct nfs_page *tmp, *next;
357
358 if (!nfs_page_group_sync_on_bit(req, PG_TEARDOWN))
359 goto out;
360
361 tmp = req;
362 do {
363 next = tmp->wb_this_page;
364 /* unlink and free */
365 tmp->wb_this_page = tmp;
366 tmp->wb_head = tmp;
367 nfs_free_request(tmp);
368 tmp = next;
369 } while (tmp != req);
370out:
371 /* subrequests must release the ref on the head request */
372 if (head != req)
373 nfs_release_request(head);
374}
375
376static struct nfs_page *nfs_page_create(struct nfs_lock_context *l_ctx,
377 unsigned int pgbase, pgoff_t index,
378 unsigned int offset, unsigned int count)
379{
380 struct nfs_page *req;
381 struct nfs_open_context *ctx = l_ctx->open_context;
382
383 if (test_bit(NFS_CONTEXT_BAD, &ctx->flags))
384 return ERR_PTR(-EBADF);
385 /* try to allocate the request struct */
386 req = nfs_page_alloc();
387 if (req == NULL)
388 return ERR_PTR(-ENOMEM);
389
390 req->wb_lock_context = l_ctx;
391 refcount_inc(&l_ctx->count);
392 atomic_inc(&l_ctx->io_count);
393
394 /* Initialize the request struct. Initially, we assume a
395 * long write-back delay. This will be adjusted in
396 * update_nfs_request below if the region is not locked. */
397 req->wb_pgbase = pgbase;
398 req->wb_index = index;
399 req->wb_offset = offset;
400 req->wb_bytes = count;
401 kref_init(&req->wb_kref);
402 req->wb_nio = 0;
403 return req;
404}
405
406static void nfs_page_assign_folio(struct nfs_page *req, struct folio *folio)
407{
408 if (folio != NULL) {
409 req->wb_folio = folio;
410 folio_get(folio);
411 set_bit(PG_FOLIO, &req->wb_flags);
412 }
413}
414
415static void nfs_page_assign_page(struct nfs_page *req, struct page *page)
416{
417 if (page != NULL) {
418 req->wb_page = page;
419 get_page(page);
420 }
421}
422
423/**
424 * nfs_page_create_from_page - Create an NFS read/write request.
425 * @ctx: open context to use
426 * @page: page to write
427 * @pgbase: starting offset within the page for the write
428 * @offset: file offset for the write
429 * @count: number of bytes to read/write
430 *
431 * The page must be locked by the caller. This makes sure we never
432 * create two different requests for the same page.
433 * User should ensure it is safe to sleep in this function.
434 */
435struct nfs_page *nfs_page_create_from_page(struct nfs_open_context *ctx,
436 struct page *page,
437 unsigned int pgbase, loff_t offset,
438 unsigned int count)
439{
440 struct nfs_lock_context *l_ctx = nfs_get_lock_context(ctx);
441 struct nfs_page *ret;
442
443 if (IS_ERR(l_ctx))
444 return ERR_CAST(l_ctx);
445 ret = nfs_page_create(l_ctx, pgbase, offset >> PAGE_SHIFT,
446 offset_in_page(offset), count);
447 if (!IS_ERR(ret)) {
448 nfs_page_assign_page(ret, page);
449 nfs_page_group_init(ret, NULL);
450 }
451 nfs_put_lock_context(l_ctx);
452 return ret;
453}
454
455/**
456 * nfs_page_create_from_folio - Create an NFS read/write request.
457 * @ctx: open context to use
458 * @folio: folio to write
459 * @offset: starting offset within the folio for the write
460 * @count: number of bytes to read/write
461 *
462 * The page must be locked by the caller. This makes sure we never
463 * create two different requests for the same page.
464 * User should ensure it is safe to sleep in this function.
465 */
466struct nfs_page *nfs_page_create_from_folio(struct nfs_open_context *ctx,
467 struct folio *folio,
468 unsigned int offset,
469 unsigned int count)
470{
471 struct nfs_lock_context *l_ctx = nfs_get_lock_context(ctx);
472 struct nfs_page *ret;
473
474 if (IS_ERR(l_ctx))
475 return ERR_CAST(l_ctx);
476 ret = nfs_page_create(l_ctx, offset, folio->index, offset, count);
477 if (!IS_ERR(ret)) {
478 nfs_page_assign_folio(ret, folio);
479 nfs_page_group_init(ret, NULL);
480 }
481 nfs_put_lock_context(l_ctx);
482 return ret;
483}
484
485static struct nfs_page *
486nfs_create_subreq(struct nfs_page *req,
487 unsigned int pgbase,
488 unsigned int offset,
489 unsigned int count)
490{
491 struct nfs_page *last;
492 struct nfs_page *ret;
493 struct folio *folio = nfs_page_to_folio(req);
494 struct page *page = nfs_page_to_page(req, pgbase);
495
496 ret = nfs_page_create(req->wb_lock_context, pgbase, req->wb_index,
497 offset, count);
498 if (!IS_ERR(ret)) {
499 if (folio)
500 nfs_page_assign_folio(ret, folio);
501 else
502 nfs_page_assign_page(ret, page);
503 /* find the last request */
504 for (last = req->wb_head;
505 last->wb_this_page != req->wb_head;
506 last = last->wb_this_page)
507 ;
508
509 nfs_lock_request(ret);
510 nfs_page_group_init(ret, last);
511 ret->wb_nio = req->wb_nio;
512 }
513 return ret;
514}
515
516/**
517 * nfs_unlock_request - Unlock request and wake up sleepers.
518 * @req: pointer to request
519 */
520void nfs_unlock_request(struct nfs_page *req)
521{
522 clear_bit_unlock(PG_BUSY, &req->wb_flags);
523 smp_mb__after_atomic();
524 if (!test_bit(PG_CONTENDED2, &req->wb_flags))
525 return;
526 wake_up_bit(&req->wb_flags, PG_BUSY);
527}
528
529/**
530 * nfs_unlock_and_release_request - Unlock request and release the nfs_page
531 * @req: pointer to request
532 */
533void nfs_unlock_and_release_request(struct nfs_page *req)
534{
535 nfs_unlock_request(req);
536 nfs_release_request(req);
537}
538
539/*
540 * nfs_clear_request - Free up all resources allocated to the request
541 * @req:
542 *
543 * Release page and open context resources associated with a read/write
544 * request after it has completed.
545 */
546static void nfs_clear_request(struct nfs_page *req)
547{
548 struct folio *folio = nfs_page_to_folio(req);
549 struct page *page = req->wb_page;
550 struct nfs_lock_context *l_ctx = req->wb_lock_context;
551 struct nfs_open_context *ctx;
552
553 if (folio != NULL) {
554 folio_put(folio);
555 req->wb_folio = NULL;
556 clear_bit(PG_FOLIO, &req->wb_flags);
557 } else if (page != NULL) {
558 put_page(page);
559 req->wb_page = NULL;
560 }
561 if (l_ctx != NULL) {
562 if (atomic_dec_and_test(&l_ctx->io_count)) {
563 wake_up_var(&l_ctx->io_count);
564 ctx = l_ctx->open_context;
565 if (test_bit(NFS_CONTEXT_UNLOCK, &ctx->flags))
566 rpc_wake_up(&NFS_SERVER(d_inode(ctx->dentry))->uoc_rpcwaitq);
567 }
568 nfs_put_lock_context(l_ctx);
569 req->wb_lock_context = NULL;
570 }
571}
572
573/**
574 * nfs_free_request - Release the count on an NFS read/write request
575 * @req: request to release
576 *
577 * Note: Should never be called with the spinlock held!
578 */
579void nfs_free_request(struct nfs_page *req)
580{
581 WARN_ON_ONCE(req->wb_this_page != req);
582
583 /* extra debug: make sure no sync bits are still set */
584 WARN_ON_ONCE(test_bit(PG_TEARDOWN, &req->wb_flags));
585 WARN_ON_ONCE(test_bit(PG_UNLOCKPAGE, &req->wb_flags));
586 WARN_ON_ONCE(test_bit(PG_UPTODATE, &req->wb_flags));
587 WARN_ON_ONCE(test_bit(PG_WB_END, &req->wb_flags));
588 WARN_ON_ONCE(test_bit(PG_REMOVE, &req->wb_flags));
589
590 /* Release struct file and open context */
591 nfs_clear_request(req);
592 nfs_page_free(req);
593}
594
595void nfs_release_request(struct nfs_page *req)
596{
597 kref_put(&req->wb_kref, nfs_page_group_destroy);
598}
599EXPORT_SYMBOL_GPL(nfs_release_request);
600
601/*
602 * nfs_generic_pg_test - determine if requests can be coalesced
603 * @desc: pointer to descriptor
604 * @prev: previous request in desc, or NULL
605 * @req: this request
606 *
607 * Returns zero if @req cannot be coalesced into @desc, otherwise it returns
608 * the size of the request.
609 */
610size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
611 struct nfs_page *prev, struct nfs_page *req)
612{
613 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
614
615
616 if (mirror->pg_count > mirror->pg_bsize) {
617 /* should never happen */
618 WARN_ON_ONCE(1);
619 return 0;
620 }
621
622 /*
623 * Limit the request size so that we can still allocate a page array
624 * for it without upsetting the slab allocator.
625 */
626 if (((mirror->pg_count + req->wb_bytes) >> PAGE_SHIFT) *
627 sizeof(struct page *) > PAGE_SIZE)
628 return 0;
629
630 return min(mirror->pg_bsize - mirror->pg_count, (size_t)req->wb_bytes);
631}
632EXPORT_SYMBOL_GPL(nfs_generic_pg_test);
633
634struct nfs_pgio_header *nfs_pgio_header_alloc(const struct nfs_rw_ops *ops)
635{
636 struct nfs_pgio_header *hdr = ops->rw_alloc_header();
637
638 if (hdr) {
639 INIT_LIST_HEAD(&hdr->pages);
640 hdr->rw_ops = ops;
641 }
642 return hdr;
643}
644EXPORT_SYMBOL_GPL(nfs_pgio_header_alloc);
645
646/**
647 * nfs_pgio_data_destroy - make @hdr suitable for reuse
648 *
649 * Frees memory and releases refs from nfs_generic_pgio, so that it may
650 * be called again.
651 *
652 * @hdr: A header that has had nfs_generic_pgio called
653 */
654static void nfs_pgio_data_destroy(struct nfs_pgio_header *hdr)
655{
656 if (hdr->args.context)
657 put_nfs_open_context(hdr->args.context);
658 if (hdr->page_array.pagevec != hdr->page_array.page_array)
659 kfree(hdr->page_array.pagevec);
660}
661
662/*
663 * nfs_pgio_header_free - Free a read or write header
664 * @hdr: The header to free
665 */
666void nfs_pgio_header_free(struct nfs_pgio_header *hdr)
667{
668 nfs_pgio_data_destroy(hdr);
669 hdr->rw_ops->rw_free_header(hdr);
670}
671EXPORT_SYMBOL_GPL(nfs_pgio_header_free);
672
673/**
674 * nfs_pgio_rpcsetup - Set up arguments for a pageio call
675 * @hdr: The pageio hdr
676 * @pgbase: base
677 * @count: Number of bytes to read
678 * @how: How to commit data (writes only)
679 * @cinfo: Commit information for the call (writes only)
680 */
681static void nfs_pgio_rpcsetup(struct nfs_pgio_header *hdr, unsigned int pgbase,
682 unsigned int count, int how,
683 struct nfs_commit_info *cinfo)
684{
685 struct nfs_page *req = hdr->req;
686
687 /* Set up the RPC argument and reply structs
688 * NB: take care not to mess about with hdr->commit et al. */
689
690 hdr->args.fh = NFS_FH(hdr->inode);
691 hdr->args.offset = req_offset(req);
692 /* pnfs_set_layoutcommit needs this */
693 hdr->mds_offset = hdr->args.offset;
694 hdr->args.pgbase = pgbase;
695 hdr->args.pages = hdr->page_array.pagevec;
696 hdr->args.count = count;
697 hdr->args.context = get_nfs_open_context(nfs_req_openctx(req));
698 hdr->args.lock_context = req->wb_lock_context;
699 hdr->args.stable = NFS_UNSTABLE;
700 switch (how & (FLUSH_STABLE | FLUSH_COND_STABLE)) {
701 case 0:
702 break;
703 case FLUSH_COND_STABLE:
704 if (nfs_reqs_to_commit(cinfo))
705 break;
706 fallthrough;
707 default:
708 hdr->args.stable = NFS_FILE_SYNC;
709 }
710
711 hdr->res.fattr = &hdr->fattr;
712 hdr->res.count = 0;
713 hdr->res.eof = 0;
714 hdr->res.verf = &hdr->verf;
715 nfs_fattr_init(&hdr->fattr);
716}
717
718/**
719 * nfs_pgio_prepare - Prepare pageio hdr to go over the wire
720 * @task: The current task
721 * @calldata: pageio header to prepare
722 */
723static void nfs_pgio_prepare(struct rpc_task *task, void *calldata)
724{
725 struct nfs_pgio_header *hdr = calldata;
726 int err;
727 err = NFS_PROTO(hdr->inode)->pgio_rpc_prepare(task, hdr);
728 if (err)
729 rpc_exit(task, err);
730}
731
732int nfs_initiate_pgio(struct rpc_clnt *clnt, struct nfs_pgio_header *hdr,
733 const struct cred *cred, const struct nfs_rpc_ops *rpc_ops,
734 const struct rpc_call_ops *call_ops, int how, int flags,
735 struct nfsd_file *localio)
736{
737 struct rpc_task *task;
738 struct rpc_message msg = {
739 .rpc_argp = &hdr->args,
740 .rpc_resp = &hdr->res,
741 .rpc_cred = cred,
742 };
743 struct rpc_task_setup task_setup_data = {
744 .rpc_client = clnt,
745 .task = &hdr->task,
746 .rpc_message = &msg,
747 .callback_ops = call_ops,
748 .callback_data = hdr,
749 .workqueue = nfsiod_workqueue,
750 .flags = RPC_TASK_ASYNC | flags,
751 };
752
753 if (nfs_server_capable(hdr->inode, NFS_CAP_MOVEABLE))
754 task_setup_data.flags |= RPC_TASK_MOVEABLE;
755
756 hdr->rw_ops->rw_initiate(hdr, &msg, rpc_ops, &task_setup_data, how);
757
758 dprintk("NFS: initiated pgio call "
759 "(req %s/%llu, %u bytes @ offset %llu)\n",
760 hdr->inode->i_sb->s_id,
761 (unsigned long long)NFS_FILEID(hdr->inode),
762 hdr->args.count,
763 (unsigned long long)hdr->args.offset);
764
765 if (localio)
766 return nfs_local_doio(NFS_SERVER(hdr->inode)->nfs_client,
767 localio, hdr, call_ops);
768
769 task = rpc_run_task(&task_setup_data);
770 if (IS_ERR(task))
771 return PTR_ERR(task);
772 rpc_put_task(task);
773 return 0;
774}
775EXPORT_SYMBOL_GPL(nfs_initiate_pgio);
776
777/**
778 * nfs_pgio_error - Clean up from a pageio error
779 * @hdr: pageio header
780 */
781static void nfs_pgio_error(struct nfs_pgio_header *hdr)
782{
783 set_bit(NFS_IOHDR_REDO, &hdr->flags);
784 hdr->completion_ops->completion(hdr);
785}
786
787/**
788 * nfs_pgio_release - Release pageio data
789 * @calldata: The pageio header to release
790 */
791static void nfs_pgio_release(void *calldata)
792{
793 struct nfs_pgio_header *hdr = calldata;
794 hdr->completion_ops->completion(hdr);
795}
796
797static void nfs_pageio_mirror_init(struct nfs_pgio_mirror *mirror,
798 unsigned int bsize)
799{
800 INIT_LIST_HEAD(&mirror->pg_list);
801 mirror->pg_bytes_written = 0;
802 mirror->pg_count = 0;
803 mirror->pg_bsize = bsize;
804 mirror->pg_base = 0;
805 mirror->pg_recoalesce = 0;
806}
807
808/**
809 * nfs_pageio_init - initialise a page io descriptor
810 * @desc: pointer to descriptor
811 * @inode: pointer to inode
812 * @pg_ops: pointer to pageio operations
813 * @compl_ops: pointer to pageio completion operations
814 * @rw_ops: pointer to nfs read/write operations
815 * @bsize: io block size
816 * @io_flags: extra parameters for the io function
817 */
818void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
819 struct inode *inode,
820 const struct nfs_pageio_ops *pg_ops,
821 const struct nfs_pgio_completion_ops *compl_ops,
822 const struct nfs_rw_ops *rw_ops,
823 size_t bsize,
824 int io_flags)
825{
826 desc->pg_moreio = 0;
827 desc->pg_inode = inode;
828 desc->pg_ops = pg_ops;
829 desc->pg_completion_ops = compl_ops;
830 desc->pg_rw_ops = rw_ops;
831 desc->pg_ioflags = io_flags;
832 desc->pg_error = 0;
833 desc->pg_lseg = NULL;
834 desc->pg_io_completion = NULL;
835 desc->pg_dreq = NULL;
836 nfs_netfs_reset_pageio_descriptor(desc);
837 desc->pg_bsize = bsize;
838
839 desc->pg_mirror_count = 1;
840 desc->pg_mirror_idx = 0;
841
842 desc->pg_mirrors_dynamic = NULL;
843 desc->pg_mirrors = desc->pg_mirrors_static;
844 nfs_pageio_mirror_init(&desc->pg_mirrors[0], bsize);
845 desc->pg_maxretrans = 0;
846}
847
848/**
849 * nfs_pgio_result - Basic pageio error handling
850 * @task: The task that ran
851 * @calldata: Pageio header to check
852 */
853static void nfs_pgio_result(struct rpc_task *task, void *calldata)
854{
855 struct nfs_pgio_header *hdr = calldata;
856 struct inode *inode = hdr->inode;
857
858 if (hdr->rw_ops->rw_done(task, hdr, inode) != 0)
859 return;
860 if (task->tk_status < 0)
861 nfs_set_pgio_error(hdr, task->tk_status, hdr->args.offset);
862 else
863 hdr->rw_ops->rw_result(task, hdr);
864}
865
866/*
867 * Create an RPC task for the given read or write request and kick it.
868 * The page must have been locked by the caller.
869 *
870 * It may happen that the page we're passed is not marked dirty.
871 * This is the case if nfs_updatepage detects a conflicting request
872 * that has been written but not committed.
873 */
874int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
875 struct nfs_pgio_header *hdr)
876{
877 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
878
879 struct nfs_page *req;
880 struct page **pages,
881 *last_page;
882 struct list_head *head = &mirror->pg_list;
883 struct nfs_commit_info cinfo;
884 struct nfs_page_array *pg_array = &hdr->page_array;
885 unsigned int pagecount, pageused;
886 unsigned int pg_base = offset_in_page(mirror->pg_base);
887 gfp_t gfp_flags = nfs_io_gfp_mask();
888
889 pagecount = nfs_page_array_len(pg_base, mirror->pg_count);
890 pg_array->npages = pagecount;
891
892 if (pagecount <= ARRAY_SIZE(pg_array->page_array))
893 pg_array->pagevec = pg_array->page_array;
894 else {
895 pg_array->pagevec = kcalloc(pagecount, sizeof(struct page *), gfp_flags);
896 if (!pg_array->pagevec) {
897 pg_array->npages = 0;
898 nfs_pgio_error(hdr);
899 desc->pg_error = -ENOMEM;
900 return desc->pg_error;
901 }
902 }
903
904 nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq);
905 pages = hdr->page_array.pagevec;
906 last_page = NULL;
907 pageused = 0;
908 while (!list_empty(head)) {
909 struct nfs_page_iter_page i;
910 struct page *page;
911
912 req = nfs_list_entry(head->next);
913 nfs_list_move_request(req, &hdr->pages);
914
915 if (req->wb_pgbase == 0)
916 last_page = NULL;
917
918 nfs_page_iter_page_init(&i, req);
919 while ((page = nfs_page_iter_page_get(&i)) != NULL) {
920 if (last_page != page) {
921 pageused++;
922 if (pageused > pagecount)
923 goto full;
924 *pages++ = last_page = page;
925 }
926 }
927 }
928full:
929 if (WARN_ON_ONCE(pageused != pagecount)) {
930 nfs_pgio_error(hdr);
931 desc->pg_error = -EINVAL;
932 return desc->pg_error;
933 }
934
935 if ((desc->pg_ioflags & FLUSH_COND_STABLE) &&
936 (desc->pg_moreio || nfs_reqs_to_commit(&cinfo)))
937 desc->pg_ioflags &= ~FLUSH_COND_STABLE;
938
939 /* Set up the argument struct */
940 nfs_pgio_rpcsetup(hdr, pg_base, mirror->pg_count, desc->pg_ioflags,
941 &cinfo);
942 desc->pg_rpc_callops = &nfs_pgio_common_ops;
943 return 0;
944}
945EXPORT_SYMBOL_GPL(nfs_generic_pgio);
946
947static int nfs_generic_pg_pgios(struct nfs_pageio_descriptor *desc)
948{
949 struct nfs_pgio_header *hdr;
950 int ret;
951 unsigned short task_flags = 0;
952
953 hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
954 if (!hdr) {
955 desc->pg_error = -ENOMEM;
956 return desc->pg_error;
957 }
958 nfs_pgheader_init(desc, hdr, nfs_pgio_header_free);
959 ret = nfs_generic_pgio(desc, hdr);
960 if (ret == 0) {
961 struct nfs_client *clp = NFS_SERVER(hdr->inode)->nfs_client;
962
963 struct nfsd_file *localio =
964 nfs_local_open_fh(clp, hdr->cred,
965 hdr->args.fh, hdr->args.context->mode);
966
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 localio);
977 }
978 return ret;
979}
980
981static struct nfs_pgio_mirror *
982nfs_pageio_alloc_mirrors(struct nfs_pageio_descriptor *desc,
983 unsigned int mirror_count)
984{
985 struct nfs_pgio_mirror *ret;
986 unsigned int i;
987
988 kfree(desc->pg_mirrors_dynamic);
989 desc->pg_mirrors_dynamic = NULL;
990 if (mirror_count == 1)
991 return desc->pg_mirrors_static;
992 ret = kmalloc_array(mirror_count, sizeof(*ret), nfs_io_gfp_mask());
993 if (ret != NULL) {
994 for (i = 0; i < mirror_count; i++)
995 nfs_pageio_mirror_init(&ret[i], desc->pg_bsize);
996 desc->pg_mirrors_dynamic = ret;
997 }
998 return ret;
999}
1000
1001/*
1002 * nfs_pageio_setup_mirroring - determine if mirroring is to be used
1003 * by calling the pg_get_mirror_count op
1004 */
1005static void nfs_pageio_setup_mirroring(struct nfs_pageio_descriptor *pgio,
1006 struct nfs_page *req)
1007{
1008 unsigned int mirror_count = 1;
1009
1010 if (pgio->pg_ops->pg_get_mirror_count)
1011 mirror_count = pgio->pg_ops->pg_get_mirror_count(pgio, req);
1012 if (mirror_count == pgio->pg_mirror_count || pgio->pg_error < 0)
1013 return;
1014
1015 if (!mirror_count || mirror_count > NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX) {
1016 pgio->pg_error = -EINVAL;
1017 return;
1018 }
1019
1020 pgio->pg_mirrors = nfs_pageio_alloc_mirrors(pgio, mirror_count);
1021 if (pgio->pg_mirrors == NULL) {
1022 pgio->pg_error = -ENOMEM;
1023 pgio->pg_mirrors = pgio->pg_mirrors_static;
1024 mirror_count = 1;
1025 }
1026 pgio->pg_mirror_count = mirror_count;
1027}
1028
1029static void nfs_pageio_cleanup_mirroring(struct nfs_pageio_descriptor *pgio)
1030{
1031 pgio->pg_mirror_count = 1;
1032 pgio->pg_mirror_idx = 0;
1033 pgio->pg_mirrors = pgio->pg_mirrors_static;
1034 kfree(pgio->pg_mirrors_dynamic);
1035 pgio->pg_mirrors_dynamic = NULL;
1036}
1037
1038static bool nfs_match_lock_context(const struct nfs_lock_context *l1,
1039 const struct nfs_lock_context *l2)
1040{
1041 return l1->lockowner == l2->lockowner;
1042}
1043
1044static bool nfs_page_is_contiguous(const struct nfs_page *prev,
1045 const struct nfs_page *req)
1046{
1047 size_t prev_end = prev->wb_pgbase + prev->wb_bytes;
1048
1049 if (req_offset(req) != req_offset(prev) + prev->wb_bytes)
1050 return false;
1051 if (req->wb_pgbase == 0)
1052 return prev_end == nfs_page_max_length(prev);
1053 if (req->wb_pgbase == prev_end) {
1054 struct folio *folio = nfs_page_to_folio(req);
1055 if (folio)
1056 return folio == nfs_page_to_folio(prev);
1057 return req->wb_page == prev->wb_page;
1058 }
1059 return false;
1060}
1061
1062/**
1063 * nfs_coalesce_size - test two requests for compatibility
1064 * @prev: pointer to nfs_page
1065 * @req: pointer to nfs_page
1066 * @pgio: pointer to nfs_pagio_descriptor
1067 *
1068 * The nfs_page structures 'prev' and 'req' are compared to ensure that the
1069 * page data area they describe is contiguous, and that their RPC
1070 * credentials, NFSv4 open state, and lockowners are the same.
1071 *
1072 * Returns size of the request that can be coalesced
1073 */
1074static unsigned int nfs_coalesce_size(struct nfs_page *prev,
1075 struct nfs_page *req,
1076 struct nfs_pageio_descriptor *pgio)
1077{
1078 struct file_lock_context *flctx;
1079
1080 if (prev) {
1081 if (!nfs_match_open_context(nfs_req_openctx(req), nfs_req_openctx(prev)))
1082 return 0;
1083 flctx = locks_inode_context(d_inode(nfs_req_openctx(req)->dentry));
1084 if (flctx != NULL &&
1085 !(list_empty_careful(&flctx->flc_posix) &&
1086 list_empty_careful(&flctx->flc_flock)) &&
1087 !nfs_match_lock_context(req->wb_lock_context,
1088 prev->wb_lock_context))
1089 return 0;
1090 if (!nfs_page_is_contiguous(prev, req))
1091 return 0;
1092 }
1093 return pgio->pg_ops->pg_test(pgio, prev, req);
1094}
1095
1096/**
1097 * nfs_pageio_do_add_request - Attempt to coalesce a request into a page list.
1098 * @desc: destination io descriptor
1099 * @req: request
1100 *
1101 * If the request 'req' was successfully coalesced into the existing list
1102 * of pages 'desc', it returns the size of req.
1103 */
1104static unsigned int
1105nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc,
1106 struct nfs_page *req)
1107{
1108 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
1109 struct nfs_page *prev = NULL;
1110 unsigned int size;
1111
1112 if (list_empty(&mirror->pg_list)) {
1113 if (desc->pg_ops->pg_init)
1114 desc->pg_ops->pg_init(desc, req);
1115 if (desc->pg_error < 0)
1116 return 0;
1117 mirror->pg_base = req->wb_pgbase;
1118 mirror->pg_count = 0;
1119 mirror->pg_recoalesce = 0;
1120 } else
1121 prev = nfs_list_entry(mirror->pg_list.prev);
1122
1123 if (desc->pg_maxretrans && req->wb_nio > desc->pg_maxretrans) {
1124 if (NFS_SERVER(desc->pg_inode)->flags & NFS_MOUNT_SOFTERR)
1125 desc->pg_error = -ETIMEDOUT;
1126 else
1127 desc->pg_error = -EIO;
1128 return 0;
1129 }
1130
1131 size = nfs_coalesce_size(prev, req, desc);
1132 if (size < req->wb_bytes)
1133 return size;
1134 nfs_list_move_request(req, &mirror->pg_list);
1135 mirror->pg_count += req->wb_bytes;
1136 return req->wb_bytes;
1137}
1138
1139/*
1140 * Helper for nfs_pageio_add_request and nfs_pageio_complete
1141 */
1142static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc)
1143{
1144 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
1145
1146 if (!list_empty(&mirror->pg_list)) {
1147 int error = desc->pg_ops->pg_doio(desc);
1148 if (error < 0)
1149 desc->pg_error = error;
1150 if (list_empty(&mirror->pg_list))
1151 mirror->pg_bytes_written += mirror->pg_count;
1152 }
1153}
1154
1155static void
1156nfs_pageio_cleanup_request(struct nfs_pageio_descriptor *desc,
1157 struct nfs_page *req)
1158{
1159 LIST_HEAD(head);
1160
1161 nfs_list_move_request(req, &head);
1162 desc->pg_completion_ops->error_cleanup(&head, desc->pg_error);
1163}
1164
1165/**
1166 * __nfs_pageio_add_request - Attempt to coalesce a request into a page list.
1167 * @desc: destination io descriptor
1168 * @req: request
1169 *
1170 * This may split a request into subrequests which are all part of the
1171 * same page group. If so, it will submit @req as the last one, to ensure
1172 * the pointer to @req is still valid in case of failure.
1173 *
1174 * Returns true if the request 'req' was successfully coalesced into the
1175 * existing list of pages 'desc'.
1176 */
1177static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
1178 struct nfs_page *req)
1179{
1180 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
1181 struct nfs_page *subreq;
1182 unsigned int size, subreq_size;
1183
1184 nfs_page_group_lock(req);
1185
1186 subreq = req;
1187 subreq_size = subreq->wb_bytes;
1188 for(;;) {
1189 size = nfs_pageio_do_add_request(desc, subreq);
1190 if (size == subreq_size) {
1191 /* We successfully submitted a request */
1192 if (subreq == req)
1193 break;
1194 req->wb_pgbase += size;
1195 req->wb_bytes -= size;
1196 req->wb_offset += size;
1197 subreq_size = req->wb_bytes;
1198 subreq = req;
1199 continue;
1200 }
1201 if (WARN_ON_ONCE(subreq != req)) {
1202 nfs_page_group_unlock(req);
1203 nfs_pageio_cleanup_request(desc, subreq);
1204 subreq = req;
1205 subreq_size = req->wb_bytes;
1206 nfs_page_group_lock(req);
1207 }
1208 if (!size) {
1209 /* Can't coalesce any more, so do I/O */
1210 nfs_page_group_unlock(req);
1211 desc->pg_moreio = 1;
1212 nfs_pageio_doio(desc);
1213 if (desc->pg_error < 0 || mirror->pg_recoalesce)
1214 return 0;
1215 /* retry add_request for this subreq */
1216 nfs_page_group_lock(req);
1217 continue;
1218 }
1219 subreq = nfs_create_subreq(req, req->wb_pgbase,
1220 req->wb_offset, size);
1221 if (IS_ERR(subreq))
1222 goto err_ptr;
1223 subreq_size = size;
1224 }
1225
1226 nfs_page_group_unlock(req);
1227 return 1;
1228err_ptr:
1229 desc->pg_error = PTR_ERR(subreq);
1230 nfs_page_group_unlock(req);
1231 return 0;
1232}
1233
1234static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc)
1235{
1236 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
1237 LIST_HEAD(head);
1238
1239 do {
1240 list_splice_init(&mirror->pg_list, &head);
1241 mirror->pg_recoalesce = 0;
1242
1243 while (!list_empty(&head)) {
1244 struct nfs_page *req;
1245
1246 req = list_first_entry(&head, struct nfs_page, wb_list);
1247 if (__nfs_pageio_add_request(desc, req))
1248 continue;
1249 if (desc->pg_error < 0) {
1250 list_splice_tail(&head, &mirror->pg_list);
1251 mirror->pg_recoalesce = 1;
1252 return 0;
1253 }
1254 break;
1255 }
1256 } while (mirror->pg_recoalesce);
1257 return 1;
1258}
1259
1260static int nfs_pageio_add_request_mirror(struct nfs_pageio_descriptor *desc,
1261 struct nfs_page *req)
1262{
1263 int ret;
1264
1265 do {
1266 ret = __nfs_pageio_add_request(desc, req);
1267 if (ret)
1268 break;
1269 if (desc->pg_error < 0)
1270 break;
1271 ret = nfs_do_recoalesce(desc);
1272 } while (ret);
1273
1274 return ret;
1275}
1276
1277static void nfs_pageio_error_cleanup(struct nfs_pageio_descriptor *desc)
1278{
1279 u32 midx;
1280 struct nfs_pgio_mirror *mirror;
1281
1282 if (!desc->pg_error)
1283 return;
1284
1285 for (midx = 0; midx < desc->pg_mirror_count; midx++) {
1286 mirror = nfs_pgio_get_mirror(desc, midx);
1287 desc->pg_completion_ops->error_cleanup(&mirror->pg_list,
1288 desc->pg_error);
1289 }
1290}
1291
1292int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
1293 struct nfs_page *req)
1294{
1295 u32 midx;
1296 unsigned int pgbase, offset, bytes;
1297 struct nfs_page *dupreq;
1298
1299 pgbase = req->wb_pgbase;
1300 offset = req->wb_offset;
1301 bytes = req->wb_bytes;
1302
1303 nfs_pageio_setup_mirroring(desc, req);
1304 if (desc->pg_error < 0)
1305 goto out_failed;
1306
1307 /* Create the mirror instances first, and fire them off */
1308 for (midx = 1; midx < desc->pg_mirror_count; midx++) {
1309 nfs_page_group_lock(req);
1310
1311 dupreq = nfs_create_subreq(req,
1312 pgbase, offset, bytes);
1313
1314 nfs_page_group_unlock(req);
1315 if (IS_ERR(dupreq)) {
1316 desc->pg_error = PTR_ERR(dupreq);
1317 goto out_failed;
1318 }
1319
1320 nfs_pgio_set_current_mirror(desc, midx);
1321 if (!nfs_pageio_add_request_mirror(desc, dupreq))
1322 goto out_cleanup_subreq;
1323 }
1324
1325 nfs_pgio_set_current_mirror(desc, 0);
1326 if (!nfs_pageio_add_request_mirror(desc, req))
1327 goto out_failed;
1328
1329 return 1;
1330
1331out_cleanup_subreq:
1332 nfs_pageio_cleanup_request(desc, dupreq);
1333out_failed:
1334 nfs_pageio_error_cleanup(desc);
1335 return 0;
1336}
1337
1338/*
1339 * nfs_pageio_complete_mirror - Complete I/O on the current mirror of an
1340 * nfs_pageio_descriptor
1341 * @desc: pointer to io descriptor
1342 * @mirror_idx: pointer to mirror index
1343 */
1344static void nfs_pageio_complete_mirror(struct nfs_pageio_descriptor *desc,
1345 u32 mirror_idx)
1346{
1347 struct nfs_pgio_mirror *mirror;
1348 u32 restore_idx;
1349
1350 restore_idx = nfs_pgio_set_current_mirror(desc, mirror_idx);
1351 mirror = nfs_pgio_current_mirror(desc);
1352
1353 for (;;) {
1354 nfs_pageio_doio(desc);
1355 if (desc->pg_error < 0 || !mirror->pg_recoalesce)
1356 break;
1357 if (!nfs_do_recoalesce(desc))
1358 break;
1359 }
1360 nfs_pgio_set_current_mirror(desc, restore_idx);
1361}
1362
1363/*
1364 * nfs_pageio_resend - Transfer requests to new descriptor and resend
1365 * @hdr - the pgio header to move request from
1366 * @desc - the pageio descriptor to add requests to
1367 *
1368 * Try to move each request (nfs_page) from @hdr to @desc then attempt
1369 * to send them.
1370 *
1371 * Returns 0 on success and < 0 on error.
1372 */
1373int nfs_pageio_resend(struct nfs_pageio_descriptor *desc,
1374 struct nfs_pgio_header *hdr)
1375{
1376 LIST_HEAD(pages);
1377
1378 desc->pg_io_completion = hdr->io_completion;
1379 desc->pg_dreq = hdr->dreq;
1380 nfs_netfs_set_pageio_descriptor(desc, hdr);
1381 list_splice_init(&hdr->pages, &pages);
1382 while (!list_empty(&pages)) {
1383 struct nfs_page *req = nfs_list_entry(pages.next);
1384
1385 if (!nfs_pageio_add_request(desc, req))
1386 break;
1387 }
1388 nfs_pageio_complete(desc);
1389 if (!list_empty(&pages)) {
1390 int err = desc->pg_error < 0 ? desc->pg_error : -EIO;
1391 hdr->completion_ops->error_cleanup(&pages, err);
1392 nfs_set_pgio_error(hdr, err, hdr->io_start);
1393 return err;
1394 }
1395 return 0;
1396}
1397EXPORT_SYMBOL_GPL(nfs_pageio_resend);
1398
1399/**
1400 * nfs_pageio_complete - Complete I/O then cleanup an nfs_pageio_descriptor
1401 * @desc: pointer to io descriptor
1402 */
1403void nfs_pageio_complete(struct nfs_pageio_descriptor *desc)
1404{
1405 u32 midx;
1406
1407 for (midx = 0; midx < desc->pg_mirror_count; midx++)
1408 nfs_pageio_complete_mirror(desc, midx);
1409
1410 if (desc->pg_error < 0)
1411 nfs_pageio_error_cleanup(desc);
1412 if (desc->pg_ops->pg_cleanup)
1413 desc->pg_ops->pg_cleanup(desc);
1414 nfs_pageio_cleanup_mirroring(desc);
1415}
1416
1417/**
1418 * nfs_pageio_cond_complete - Conditional I/O completion
1419 * @desc: pointer to io descriptor
1420 * @index: page index
1421 *
1422 * It is important to ensure that processes don't try to take locks
1423 * on non-contiguous ranges of pages as that might deadlock. This
1424 * function should be called before attempting to wait on a locked
1425 * nfs_page. It will complete the I/O if the page index 'index'
1426 * is not contiguous with the existing list of pages in 'desc'.
1427 */
1428void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index)
1429{
1430 struct nfs_pgio_mirror *mirror;
1431 struct nfs_page *prev;
1432 struct folio *folio;
1433 u32 midx;
1434
1435 for (midx = 0; midx < desc->pg_mirror_count; midx++) {
1436 mirror = nfs_pgio_get_mirror(desc, midx);
1437 if (!list_empty(&mirror->pg_list)) {
1438 prev = nfs_list_entry(mirror->pg_list.prev);
1439 folio = nfs_page_to_folio(prev);
1440 if (folio) {
1441 if (index == folio_next_index(folio))
1442 continue;
1443 } else if (index == prev->wb_index + 1)
1444 continue;
1445 /*
1446 * We will submit more requests after these. Indicate
1447 * this to the underlying layers.
1448 */
1449 desc->pg_moreio = 1;
1450 nfs_pageio_complete(desc);
1451 break;
1452 }
1453 }
1454}
1455
1456/*
1457 * nfs_pageio_stop_mirroring - stop using mirroring (set mirror count to 1)
1458 */
1459void nfs_pageio_stop_mirroring(struct nfs_pageio_descriptor *pgio)
1460{
1461 nfs_pageio_complete(pgio);
1462}
1463
1464int __init nfs_init_nfspagecache(void)
1465{
1466 nfs_page_cachep = kmem_cache_create("nfs_page",
1467 sizeof(struct nfs_page),
1468 0, SLAB_HWCACHE_ALIGN,
1469 NULL);
1470 if (nfs_page_cachep == NULL)
1471 return -ENOMEM;
1472
1473 return 0;
1474}
1475
1476void nfs_destroy_nfspagecache(void)
1477{
1478 kmem_cache_destroy(nfs_page_cachep);
1479}
1480
1481static const struct rpc_call_ops nfs_pgio_common_ops = {
1482 .rpc_call_prepare = nfs_pgio_prepare,
1483 .rpc_call_done = nfs_pgio_result,
1484 .rpc_release = nfs_pgio_release,
1485};
1486
1487const struct nfs_pageio_ops nfs_pgio_rw_ops = {
1488 .pg_test = nfs_generic_pg_test,
1489 .pg_doio = nfs_generic_pg_pgios,
1490};