1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/fs/nfs/write.c
4 *
5 * Write file data over NFS.
6 *
7 * Copyright (C) 1996, 1997, Olaf Kirch <okir@monad.swb.de>
8 */
9
10#include <linux/types.h>
11#include <linux/slab.h>
12#include <linux/mm.h>
13#include <linux/pagemap.h>
14#include <linux/file.h>
15#include <linux/writeback.h>
16#include <linux/swap.h>
17#include <linux/migrate.h>
18
19#include <linux/sunrpc/clnt.h>
20#include <linux/nfs_fs.h>
21#include <linux/nfs_mount.h>
22#include <linux/nfs_page.h>
23#include <linux/backing-dev.h>
24#include <linux/export.h>
25#include <linux/freezer.h>
26#include <linux/wait.h>
27#include <linux/iversion.h>
28#include <linux/filelock.h>
29
30#include <linux/uaccess.h>
31#include <linux/sched/mm.h>
32
33#include "delegation.h"
34#include "internal.h"
35#include "iostat.h"
36#include "nfs4_fs.h"
37#include "fscache.h"
38#include "pnfs.h"
39
40#include "nfstrace.h"
41
42#define NFSDBG_FACILITY NFSDBG_PAGECACHE
43
44#define MIN_POOL_WRITE (32)
45#define MIN_POOL_COMMIT (4)
46
47struct nfs_io_completion {
48 void (*complete)(void *data);
49 void *data;
50 struct kref refcount;
51};
52
53/*
54 * Local function declarations
55 */
56static void nfs_redirty_request(struct nfs_page *req);
57static const struct rpc_call_ops nfs_commit_ops;
58static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops;
59static const struct nfs_commit_completion_ops nfs_commit_completion_ops;
60static const struct nfs_rw_ops nfs_rw_write_ops;
61static void nfs_inode_remove_request(struct nfs_page *req);
62static void nfs_clear_request_commit(struct nfs_commit_info *cinfo,
63 struct nfs_page *req);
64static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo,
65 struct inode *inode);
66static struct nfs_page *
67nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi,
68 struct folio *folio);
69
70static struct kmem_cache *nfs_wdata_cachep;
71static mempool_t *nfs_wdata_mempool;
72static struct kmem_cache *nfs_cdata_cachep;
73static mempool_t *nfs_commit_mempool;
74
75struct nfs_commit_data *nfs_commitdata_alloc(void)
76{
77 struct nfs_commit_data *p;
78
79 p = kmem_cache_zalloc(k: nfs_cdata_cachep, flags: nfs_io_gfp_mask());
80 if (!p) {
81 p = mempool_alloc(pool: nfs_commit_mempool, GFP_NOWAIT);
82 if (!p)
83 return NULL;
84 memset(p, 0, sizeof(*p));
85 }
86 INIT_LIST_HEAD(list: &p->pages);
87 return p;
88}
89EXPORT_SYMBOL_GPL(nfs_commitdata_alloc);
90
91void nfs_commit_free(struct nfs_commit_data *p)
92{
93 mempool_free(element: p, pool: nfs_commit_mempool);
94}
95EXPORT_SYMBOL_GPL(nfs_commit_free);
96
97static struct nfs_pgio_header *nfs_writehdr_alloc(void)
98{
99 struct nfs_pgio_header *p;
100
101 p = kmem_cache_zalloc(k: nfs_wdata_cachep, flags: nfs_io_gfp_mask());
102 if (!p) {
103 p = mempool_alloc(pool: nfs_wdata_mempool, GFP_NOWAIT);
104 if (!p)
105 return NULL;
106 memset(p, 0, sizeof(*p));
107 }
108 p->rw_mode = FMODE_WRITE;
109 return p;
110}
111
112static void nfs_writehdr_free(struct nfs_pgio_header *hdr)
113{
114 mempool_free(element: hdr, pool: nfs_wdata_mempool);
115}
116
117static struct nfs_io_completion *nfs_io_completion_alloc(gfp_t gfp_flags)
118{
119 return kmalloc(size: sizeof(struct nfs_io_completion), flags: gfp_flags);
120}
121
122static void nfs_io_completion_init(struct nfs_io_completion *ioc,
123 void (*complete)(void *), void *data)
124{
125 ioc->complete = complete;
126 ioc->data = data;
127 kref_init(kref: &ioc->refcount);
128}
129
130static void nfs_io_completion_release(struct kref *kref)
131{
132 struct nfs_io_completion *ioc = container_of(kref,
133 struct nfs_io_completion, refcount);
134 ioc->complete(ioc->data);
135 kfree(objp: ioc);
136}
137
138static void nfs_io_completion_get(struct nfs_io_completion *ioc)
139{
140 if (ioc != NULL)
141 kref_get(kref: &ioc->refcount);
142}
143
144static void nfs_io_completion_put(struct nfs_io_completion *ioc)
145{
146 if (ioc != NULL)
147 kref_put(kref: &ioc->refcount, release: nfs_io_completion_release);
148}
149
150static void
151nfs_page_set_inode_ref(struct nfs_page *req, struct inode *inode)
152{
153 if (!test_and_set_bit(nr: PG_INODE_REF, addr: &req->wb_flags)) {
154 kref_get(kref: &req->wb_kref);
155 atomic_long_inc(v: &NFS_I(inode)->nrequests);
156 }
157}
158
159static int
160nfs_cancel_remove_inode(struct nfs_page *req, struct inode *inode)
161{
162 int ret;
163
164 if (!test_bit(PG_REMOVE, &req->wb_flags))
165 return 0;
166 ret = nfs_page_group_lock(req);
167 if (ret)
168 return ret;
169 if (test_and_clear_bit(nr: PG_REMOVE, addr: &req->wb_flags))
170 nfs_page_set_inode_ref(req, inode);
171 nfs_page_group_unlock(req);
172 return 0;
173}
174
175static struct nfs_page *nfs_folio_private_request(struct folio *folio)
176{
177 return folio_get_private(folio);
178}
179
180/**
181 * nfs_folio_find_private_request - find head request associated with a folio
182 * @folio: pointer to folio
183 *
184 * must be called while holding the inode lock.
185 *
186 * returns matching head request with reference held, or NULL if not found.
187 */
188static struct nfs_page *nfs_folio_find_private_request(struct folio *folio)
189{
190 struct address_space *mapping = folio_file_mapping(folio);
191 struct nfs_page *req;
192
193 if (!folio_test_private(folio))
194 return NULL;
195 spin_lock(lock: &mapping->private_lock);
196 req = nfs_folio_private_request(folio);
197 if (req) {
198 WARN_ON_ONCE(req->wb_head != req);
199 kref_get(kref: &req->wb_kref);
200 }
201 spin_unlock(lock: &mapping->private_lock);
202 return req;
203}
204
205static struct nfs_page *nfs_folio_find_swap_request(struct folio *folio)
206{
207 struct inode *inode = folio_file_mapping(folio)->host;
208 struct nfs_inode *nfsi = NFS_I(inode);
209 struct nfs_page *req = NULL;
210 if (!folio_test_swapcache(folio))
211 return NULL;
212 mutex_lock(&nfsi->commit_mutex);
213 if (folio_test_swapcache(folio)) {
214 req = nfs_page_search_commits_for_head_request_locked(nfsi,
215 folio);
216 if (req) {
217 WARN_ON_ONCE(req->wb_head != req);
218 kref_get(kref: &req->wb_kref);
219 }
220 }
221 mutex_unlock(lock: &nfsi->commit_mutex);
222 return req;
223}
224
225/**
226 * nfs_folio_find_head_request - find head request associated with a folio
227 * @folio: pointer to folio
228 *
229 * returns matching head request with reference held, or NULL if not found.
230 */
231static struct nfs_page *nfs_folio_find_head_request(struct folio *folio)
232{
233 struct nfs_page *req;
234
235 req = nfs_folio_find_private_request(folio);
236 if (!req)
237 req = nfs_folio_find_swap_request(folio);
238 return req;
239}
240
241static struct nfs_page *nfs_folio_find_and_lock_request(struct folio *folio)
242{
243 struct inode *inode = folio_file_mapping(folio)->host;
244 struct nfs_page *req, *head;
245 int ret;
246
247 for (;;) {
248 req = nfs_folio_find_head_request(folio);
249 if (!req)
250 return req;
251 head = nfs_page_group_lock_head(req);
252 if (head != req)
253 nfs_release_request(req);
254 if (IS_ERR(ptr: head))
255 return head;
256 ret = nfs_cancel_remove_inode(req: head, inode);
257 if (ret < 0) {
258 nfs_unlock_and_release_request(head);
259 return ERR_PTR(error: ret);
260 }
261 /* Ensure that nobody removed the request before we locked it */
262 if (head == nfs_folio_private_request(folio))
263 break;
264 if (folio_test_swapcache(folio))
265 break;
266 nfs_unlock_and_release_request(head);
267 }
268 return head;
269}
270
271/* Adjust the file length if we're writing beyond the end */
272static void nfs_grow_file(struct folio *folio, unsigned int offset,
273 unsigned int count)
274{
275 struct inode *inode = folio_file_mapping(folio)->host;
276 loff_t end, i_size;
277 pgoff_t end_index;
278
279 spin_lock(lock: &inode->i_lock);
280 i_size = i_size_read(inode);
281 end_index = ((i_size - 1) >> folio_shift(folio)) << folio_order(folio);
282 if (i_size > 0 && folio_index(folio) < end_index)
283 goto out;
284 end = folio_file_pos(folio) + (loff_t)offset + (loff_t)count;
285 if (i_size >= end)
286 goto out;
287 trace_nfs_size_grow(inode, new_size: end);
288 i_size_write(inode, i_size: end);
289 NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_SIZE;
290 nfs_inc_stats(inode, stat: NFSIOS_EXTENDWRITE);
291out:
292 spin_unlock(lock: &inode->i_lock);
293 nfs_fscache_invalidate(inode, flags: 0);
294}
295
296/* A writeback failed: mark the page as bad, and invalidate the page cache */
297static void nfs_set_pageerror(struct address_space *mapping)
298{
299 struct inode *inode = mapping->host;
300
301 nfs_zap_mapping(inode: mapping->host, mapping);
302 /* Force file size revalidation */
303 spin_lock(lock: &inode->i_lock);
304 nfs_set_cache_invalid(inode, NFS_INO_REVAL_FORCED |
305 NFS_INO_INVALID_CHANGE |
306 NFS_INO_INVALID_SIZE);
307 spin_unlock(lock: &inode->i_lock);
308}
309
310static void nfs_mapping_set_error(struct folio *folio, int error)
311{
312 struct address_space *mapping = folio_file_mapping(folio);
313
314 folio_set_error(folio);
315 filemap_set_wb_err(mapping, err: error);
316 if (mapping->host)
317 errseq_set(eseq: &mapping->host->i_sb->s_wb_err,
318 err: error == -ENOSPC ? -ENOSPC : -EIO);
319 nfs_set_pageerror(mapping);
320}
321
322/*
323 * nfs_page_group_search_locked
324 * @head - head request of page group
325 * @page_offset - offset into page
326 *
327 * Search page group with head @head to find a request that contains the
328 * page offset @page_offset.
329 *
330 * Returns a pointer to the first matching nfs request, or NULL if no
331 * match is found.
332 *
333 * Must be called with the page group lock held
334 */
335static struct nfs_page *
336nfs_page_group_search_locked(struct nfs_page *head, unsigned int page_offset)
337{
338 struct nfs_page *req;
339
340 req = head;
341 do {
342 if (page_offset >= req->wb_pgbase &&
343 page_offset < (req->wb_pgbase + req->wb_bytes))
344 return req;
345
346 req = req->wb_this_page;
347 } while (req != head);
348
349 return NULL;
350}
351
352/*
353 * nfs_page_group_covers_page
354 * @head - head request of page group
355 *
356 * Return true if the page group with head @head covers the whole page,
357 * returns false otherwise
358 */
359static bool nfs_page_group_covers_page(struct nfs_page *req)
360{
361 unsigned int len = nfs_folio_length(folio: nfs_page_to_folio(req));
362 struct nfs_page *tmp;
363 unsigned int pos = 0;
364
365 nfs_page_group_lock(req);
366
367 for (;;) {
368 tmp = nfs_page_group_search_locked(head: req->wb_head, page_offset: pos);
369 if (!tmp)
370 break;
371 pos = tmp->wb_pgbase + tmp->wb_bytes;
372 }
373
374 nfs_page_group_unlock(req);
375 return pos >= len;
376}
377
378/* We can set the PG_uptodate flag if we see that a write request
379 * covers the full page.
380 */
381static void nfs_mark_uptodate(struct nfs_page *req)
382{
383 struct folio *folio = nfs_page_to_folio(req);
384
385 if (folio_test_uptodate(folio))
386 return;
387 if (!nfs_page_group_covers_page(req))
388 return;
389 folio_mark_uptodate(folio);
390}
391
392static int wb_priority(struct writeback_control *wbc)
393{
394 int ret = 0;
395
396 if (wbc->sync_mode == WB_SYNC_ALL)
397 ret = FLUSH_COND_STABLE;
398 return ret;
399}
400
401/*
402 * NFS congestion control
403 */
404
405int nfs_congestion_kb;
406
407#define NFS_CONGESTION_ON_THRESH (nfs_congestion_kb >> (PAGE_SHIFT-10))
408#define NFS_CONGESTION_OFF_THRESH \
409 (NFS_CONGESTION_ON_THRESH - (NFS_CONGESTION_ON_THRESH >> 2))
410
411static void nfs_folio_set_writeback(struct folio *folio)
412{
413 struct nfs_server *nfss = NFS_SERVER(inode: folio_file_mapping(folio)->host);
414
415 folio_start_writeback(folio);
416 if (atomic_long_inc_return(v: &nfss->writeback) > NFS_CONGESTION_ON_THRESH)
417 nfss->write_congested = 1;
418}
419
420static void nfs_folio_end_writeback(struct folio *folio)
421{
422 struct nfs_server *nfss = NFS_SERVER(inode: folio_file_mapping(folio)->host);
423
424 folio_end_writeback(folio);
425 if (atomic_long_dec_return(v: &nfss->writeback) <
426 NFS_CONGESTION_OFF_THRESH)
427 nfss->write_congested = 0;
428}
429
430static void nfs_page_end_writeback(struct nfs_page *req)
431{
432 if (nfs_page_group_sync_on_bit(req, PG_WB_END)) {
433 nfs_unlock_request(req);
434 nfs_folio_end_writeback(folio: nfs_page_to_folio(req));
435 } else
436 nfs_unlock_request(req);
437}
438
439/*
440 * nfs_destroy_unlinked_subrequests - destroy recently unlinked subrequests
441 *
442 * @destroy_list - request list (using wb_this_page) terminated by @old_head
443 * @old_head - the old head of the list
444 *
445 * All subrequests must be locked and removed from all lists, so at this point
446 * they are only "active" in this function, and possibly in nfs_wait_on_request
447 * with a reference held by some other context.
448 */
449static void
450nfs_destroy_unlinked_subrequests(struct nfs_page *destroy_list,
451 struct nfs_page *old_head,
452 struct inode *inode)
453{
454 while (destroy_list) {
455 struct nfs_page *subreq = destroy_list;
456
457 destroy_list = (subreq->wb_this_page == old_head) ?
458 NULL : subreq->wb_this_page;
459
460 /* Note: lock subreq in order to change subreq->wb_head */
461 nfs_page_set_headlock(req: subreq);
462 WARN_ON_ONCE(old_head != subreq->wb_head);
463
464 /* make sure old group is not used */
465 subreq->wb_this_page = subreq;
466 subreq->wb_head = subreq;
467
468 clear_bit(nr: PG_REMOVE, addr: &subreq->wb_flags);
469
470 /* Note: races with nfs_page_group_destroy() */
471 if (!kref_read(kref: &subreq->wb_kref)) {
472 /* Check if we raced with nfs_page_group_destroy() */
473 if (test_and_clear_bit(nr: PG_TEARDOWN, addr: &subreq->wb_flags)) {
474 nfs_page_clear_headlock(req: subreq);
475 nfs_free_request(req: subreq);
476 } else
477 nfs_page_clear_headlock(req: subreq);
478 continue;
479 }
480 nfs_page_clear_headlock(req: subreq);
481
482 nfs_release_request(old_head);
483
484 if (test_and_clear_bit(nr: PG_INODE_REF, addr: &subreq->wb_flags)) {
485 nfs_release_request(subreq);
486 atomic_long_dec(v: &NFS_I(inode)->nrequests);
487 }
488
489 /* subreq is now totally disconnected from page group or any
490 * write / commit lists. last chance to wake any waiters */
491 nfs_unlock_and_release_request(subreq);
492 }
493}
494
495/*
496 * nfs_join_page_group - destroy subrequests of the head req
497 * @head: the page used to lookup the "page group" of nfs_page structures
498 * @inode: Inode to which the request belongs.
499 *
500 * This function joins all sub requests to the head request by first
501 * locking all requests in the group, cancelling any pending operations
502 * and finally updating the head request to cover the whole range covered by
503 * the (former) group. All subrequests are removed from any write or commit
504 * lists, unlinked from the group and destroyed.
505 */
506void nfs_join_page_group(struct nfs_page *head, struct nfs_commit_info *cinfo,
507 struct inode *inode)
508{
509 struct nfs_page *subreq;
510 struct nfs_page *destroy_list = NULL;
511 unsigned int pgbase, off, bytes;
512
513 pgbase = head->wb_pgbase;
514 bytes = head->wb_bytes;
515 off = head->wb_offset;
516 for (subreq = head->wb_this_page; subreq != head;
517 subreq = subreq->wb_this_page) {
518 /* Subrequests should always form a contiguous range */
519 if (pgbase > subreq->wb_pgbase) {
520 off -= pgbase - subreq->wb_pgbase;
521 bytes += pgbase - subreq->wb_pgbase;
522 pgbase = subreq->wb_pgbase;
523 }
524 bytes = max(subreq->wb_pgbase + subreq->wb_bytes
525 - pgbase, bytes);
526 }
527
528 /* Set the head request's range to cover the former page group */
529 head->wb_pgbase = pgbase;
530 head->wb_bytes = bytes;
531 head->wb_offset = off;
532
533 /* Now that all requests are locked, make sure they aren't on any list.
534 * Commit list removal accounting is done after locks are dropped */
535 subreq = head;
536 do {
537 nfs_clear_request_commit(cinfo, req: subreq);
538 subreq = subreq->wb_this_page;
539 } while (subreq != head);
540
541 /* unlink subrequests from head, destroy them later */
542 if (head->wb_this_page != head) {
543 /* destroy list will be terminated by head */
544 destroy_list = head->wb_this_page;
545 head->wb_this_page = head;
546 }
547
548 nfs_destroy_unlinked_subrequests(destroy_list, old_head: head, inode);
549}
550
551/*
552 * nfs_lock_and_join_requests - join all subreqs to the head req
553 * @folio: the folio used to lookup the "page group" of nfs_page structures
554 *
555 * This function joins all sub requests to the head request by first
556 * locking all requests in the group, cancelling any pending operations
557 * and finally updating the head request to cover the whole range covered by
558 * the (former) group. All subrequests are removed from any write or commit
559 * lists, unlinked from the group and destroyed.
560 *
561 * Returns a locked, referenced pointer to the head request - which after
562 * this call is guaranteed to be the only request associated with the page.
563 * Returns NULL if no requests are found for @folio, or a ERR_PTR if an
564 * error was encountered.
565 */
566static struct nfs_page *nfs_lock_and_join_requests(struct folio *folio)
567{
568 struct inode *inode = folio_file_mapping(folio)->host;
569 struct nfs_page *head;
570 struct nfs_commit_info cinfo;
571 int ret;
572
573 nfs_init_cinfo_from_inode(cinfo: &cinfo, inode);
574 /*
575 * A reference is taken only on the head request which acts as a
576 * reference to the whole page group - the group will not be destroyed
577 * until the head reference is released.
578 */
579 head = nfs_folio_find_and_lock_request(folio);
580 if (IS_ERR_OR_NULL(ptr: head))
581 return head;
582
583 /* lock each request in the page group */
584 ret = nfs_page_group_lock_subrequests(head);
585 if (ret < 0) {
586 nfs_unlock_and_release_request(head);
587 return ERR_PTR(error: ret);
588 }
589
590 nfs_join_page_group(head, cinfo: &cinfo, inode);
591
592 return head;
593}
594
595static void nfs_write_error(struct nfs_page *req, int error)
596{
597 trace_nfs_write_error(inode: nfs_page_to_inode(req), req, error);
598 nfs_mapping_set_error(folio: nfs_page_to_folio(req), error);
599 nfs_inode_remove_request(req);
600 nfs_page_end_writeback(req);
601 nfs_release_request(req);
602}
603
604/*
605 * Find an associated nfs write request, and prepare to flush it out
606 * May return an error if the user signalled nfs_wait_on_request().
607 */
608static int nfs_page_async_flush(struct folio *folio,
609 struct writeback_control *wbc,
610 struct nfs_pageio_descriptor *pgio)
611{
612 struct nfs_page *req;
613 int ret = 0;
614
615 req = nfs_lock_and_join_requests(folio);
616 if (!req)
617 goto out;
618 ret = PTR_ERR(ptr: req);
619 if (IS_ERR(ptr: req))
620 goto out;
621
622 nfs_folio_set_writeback(folio);
623 WARN_ON_ONCE(test_bit(PG_CLEAN, &req->wb_flags));
624
625 /* If there is a fatal error that covers this write, just exit */
626 ret = pgio->pg_error;
627 if (nfs_error_is_fatal_on_server(err: ret))
628 goto out_launder;
629
630 ret = 0;
631 if (!nfs_pageio_add_request(pgio, req)) {
632 ret = pgio->pg_error;
633 /*
634 * Remove the problematic req upon fatal errors on the server
635 */
636 if (nfs_error_is_fatal_on_server(err: ret))
637 goto out_launder;
638 if (wbc->sync_mode == WB_SYNC_NONE)
639 ret = AOP_WRITEPAGE_ACTIVATE;
640 folio_redirty_for_writepage(wbc, folio);
641 nfs_redirty_request(req);
642 pgio->pg_error = 0;
643 } else
644 nfs_add_stats(inode: folio_file_mapping(folio)->host,
645 stat: NFSIOS_WRITEPAGES, addend: 1);
646out:
647 return ret;
648out_launder:
649 nfs_write_error(req, error: ret);
650 return 0;
651}
652
653static int nfs_do_writepage(struct folio *folio, struct writeback_control *wbc,
654 struct nfs_pageio_descriptor *pgio)
655{
656 nfs_pageio_cond_complete(pgio, folio_index(folio));
657 return nfs_page_async_flush(folio, wbc, pgio);
658}
659
660/*
661 * Write an mmapped page to the server.
662 */
663static int nfs_writepage_locked(struct folio *folio,
664 struct writeback_control *wbc)
665{
666 struct nfs_pageio_descriptor pgio;
667 struct inode *inode = folio_file_mapping(folio)->host;
668 int err;
669
670 if (wbc->sync_mode == WB_SYNC_NONE &&
671 NFS_SERVER(inode)->write_congested)
672 return AOP_WRITEPAGE_ACTIVATE;
673
674 nfs_inc_stats(inode, stat: NFSIOS_VFSWRITEPAGE);
675 nfs_pageio_init_write(pgio: &pgio, inode, ioflags: 0, force_mds: false,
676 compl_ops: &nfs_async_write_completion_ops);
677 err = nfs_do_writepage(folio, wbc, pgio: &pgio);
678 pgio.pg_error = 0;
679 nfs_pageio_complete(desc: &pgio);
680 return err;
681}
682
683int nfs_writepage(struct page *page, struct writeback_control *wbc)
684{
685 struct folio *folio = page_folio(page);
686 int ret;
687
688 ret = nfs_writepage_locked(folio, wbc);
689 if (ret != AOP_WRITEPAGE_ACTIVATE)
690 unlock_page(page);
691 return ret;
692}
693
694static int nfs_writepages_callback(struct folio *folio,
695 struct writeback_control *wbc, void *data)
696{
697 int ret;
698
699 ret = nfs_do_writepage(folio, wbc, pgio: data);
700 if (ret != AOP_WRITEPAGE_ACTIVATE)
701 folio_unlock(folio);
702 return ret;
703}
704
705static void nfs_io_completion_commit(void *inode)
706{
707 nfs_commit_inode(inode, 0);
708}
709
710int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
711{
712 struct inode *inode = mapping->host;
713 struct nfs_pageio_descriptor pgio;
714 struct nfs_io_completion *ioc = NULL;
715 unsigned int mntflags = NFS_SERVER(inode)->flags;
716 int priority = 0;
717 int err;
718
719 if (wbc->sync_mode == WB_SYNC_NONE &&
720 NFS_SERVER(inode)->write_congested)
721 return 0;
722
723 nfs_inc_stats(inode, stat: NFSIOS_VFSWRITEPAGES);
724
725 if (!(mntflags & NFS_MOUNT_WRITE_EAGER) || wbc->for_kupdate ||
726 wbc->for_background || wbc->for_sync || wbc->for_reclaim) {
727 ioc = nfs_io_completion_alloc(GFP_KERNEL);
728 if (ioc)
729 nfs_io_completion_init(ioc, complete: nfs_io_completion_commit,
730 data: inode);
731 priority = wb_priority(wbc);
732 }
733
734 do {
735 nfs_pageio_init_write(pgio: &pgio, inode, ioflags: priority, force_mds: false,
736 compl_ops: &nfs_async_write_completion_ops);
737 pgio.pg_io_completion = ioc;
738 err = write_cache_pages(mapping, wbc, writepage: nfs_writepages_callback,
739 data: &pgio);
740 pgio.pg_error = 0;
741 nfs_pageio_complete(desc: &pgio);
742 if (err == -EAGAIN && mntflags & NFS_MOUNT_SOFTERR)
743 break;
744 } while (err < 0 && !nfs_error_is_fatal(err));
745 nfs_io_completion_put(ioc);
746
747 if (err < 0)
748 goto out_err;
749 return 0;
750out_err:
751 return err;
752}
753
754/*
755 * Insert a write request into an inode
756 */
757static void nfs_inode_add_request(struct nfs_page *req)
758{
759 struct folio *folio = nfs_page_to_folio(req);
760 struct address_space *mapping = folio_file_mapping(folio);
761 struct nfs_inode *nfsi = NFS_I(inode: mapping->host);
762
763 WARN_ON_ONCE(req->wb_this_page != req);
764
765 /* Lock the request! */
766 nfs_lock_request(req);
767
768 /*
769 * Swap-space should not get truncated. Hence no need to plug the race
770 * with invalidate/truncate.
771 */
772 spin_lock(lock: &mapping->private_lock);
773 if (likely(!folio_test_swapcache(folio))) {
774 set_bit(nr: PG_MAPPED, addr: &req->wb_flags);
775 folio_set_private(folio);
776 folio->private = req;
777 }
778 spin_unlock(lock: &mapping->private_lock);
779 atomic_long_inc(v: &nfsi->nrequests);
780 /* this a head request for a page group - mark it as having an
781 * extra reference so sub groups can follow suit.
782 * This flag also informs pgio layer when to bump nrequests when
783 * adding subrequests. */
784 WARN_ON(test_and_set_bit(PG_INODE_REF, &req->wb_flags));
785 kref_get(kref: &req->wb_kref);
786}
787
788/*
789 * Remove a write request from an inode
790 */
791static void nfs_inode_remove_request(struct nfs_page *req)
792{
793 struct nfs_inode *nfsi = NFS_I(inode: nfs_page_to_inode(req));
794
795 if (nfs_page_group_sync_on_bit(req, PG_REMOVE)) {
796 struct folio *folio = nfs_page_to_folio(req: req->wb_head);
797 struct address_space *mapping = folio_file_mapping(folio);
798
799 spin_lock(lock: &mapping->private_lock);
800 if (likely(folio && !folio_test_swapcache(folio))) {
801 folio->private = NULL;
802 folio_clear_private(folio);
803 clear_bit(nr: PG_MAPPED, addr: &req->wb_head->wb_flags);
804 }
805 spin_unlock(lock: &mapping->private_lock);
806 }
807
808 if (test_and_clear_bit(nr: PG_INODE_REF, addr: &req->wb_flags)) {
809 atomic_long_dec(v: &nfsi->nrequests);
810 nfs_release_request(req);
811 }
812}
813
814static void nfs_mark_request_dirty(struct nfs_page *req)
815{
816 struct folio *folio = nfs_page_to_folio(req);
817 if (folio)
818 filemap_dirty_folio(mapping: folio_mapping(folio), folio);
819}
820
821/*
822 * nfs_page_search_commits_for_head_request_locked
823 *
824 * Search through commit lists on @inode for the head request for @folio.
825 * Must be called while holding the inode (which is cinfo) lock.
826 *
827 * Returns the head request if found, or NULL if not found.
828 */
829static struct nfs_page *
830nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi,
831 struct folio *folio)
832{
833 struct nfs_page *freq, *t;
834 struct nfs_commit_info cinfo;
835 struct inode *inode = &nfsi->vfs_inode;
836
837 nfs_init_cinfo_from_inode(cinfo: &cinfo, inode);
838
839 /* search through pnfs commit lists */
840 freq = pnfs_search_commit_reqs(inode, cinfo: &cinfo, folio);
841 if (freq)
842 return freq->wb_head;
843
844 /* Linearly search the commit list for the correct request */
845 list_for_each_entry_safe(freq, t, &cinfo.mds->list, wb_list) {
846 if (nfs_page_to_folio(req: freq) == folio)
847 return freq->wb_head;
848 }
849
850 return NULL;
851}
852
853/**
854 * nfs_request_add_commit_list_locked - add request to a commit list
855 * @req: pointer to a struct nfs_page
856 * @dst: commit list head
857 * @cinfo: holds list lock and accounting info
858 *
859 * This sets the PG_CLEAN bit, updates the cinfo count of
860 * number of outstanding requests requiring a commit as well as
861 * the MM page stats.
862 *
863 * The caller must hold NFS_I(cinfo->inode)->commit_mutex, and the
864 * nfs_page lock.
865 */
866void
867nfs_request_add_commit_list_locked(struct nfs_page *req, struct list_head *dst,
868 struct nfs_commit_info *cinfo)
869{
870 set_bit(nr: PG_CLEAN, addr: &req->wb_flags);
871 nfs_list_add_request(req, head: dst);
872 atomic_long_inc(v: &cinfo->mds->ncommit);
873}
874EXPORT_SYMBOL_GPL(nfs_request_add_commit_list_locked);
875
876/**
877 * nfs_request_add_commit_list - add request to a commit list
878 * @req: pointer to a struct nfs_page
879 * @cinfo: holds list lock and accounting info
880 *
881 * This sets the PG_CLEAN bit, updates the cinfo count of
882 * number of outstanding requests requiring a commit as well as
883 * the MM page stats.
884 *
885 * The caller must _not_ hold the cinfo->lock, but must be
886 * holding the nfs_page lock.
887 */
888void
889nfs_request_add_commit_list(struct nfs_page *req, struct nfs_commit_info *cinfo)
890{
891 mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
892 nfs_request_add_commit_list_locked(req, &cinfo->mds->list, cinfo);
893 mutex_unlock(lock: &NFS_I(inode: cinfo->inode)->commit_mutex);
894 nfs_folio_mark_unstable(folio: nfs_page_to_folio(req), cinfo);
895}
896EXPORT_SYMBOL_GPL(nfs_request_add_commit_list);
897
898/**
899 * nfs_request_remove_commit_list - Remove request from a commit list
900 * @req: pointer to a nfs_page
901 * @cinfo: holds list lock and accounting info
902 *
903 * This clears the PG_CLEAN bit, and updates the cinfo's count of
904 * number of outstanding requests requiring a commit
905 * It does not update the MM page stats.
906 *
907 * The caller _must_ hold the cinfo->lock and the nfs_page lock.
908 */
909void
910nfs_request_remove_commit_list(struct nfs_page *req,
911 struct nfs_commit_info *cinfo)
912{
913 if (!test_and_clear_bit(nr: PG_CLEAN, addr: &(req)->wb_flags))
914 return;
915 nfs_list_remove_request(req);
916 atomic_long_dec(v: &cinfo->mds->ncommit);
917}
918EXPORT_SYMBOL_GPL(nfs_request_remove_commit_list);
919
920static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo,
921 struct inode *inode)
922{
923 cinfo->inode = inode;
924 cinfo->mds = &NFS_I(inode)->commit_info;
925 cinfo->ds = pnfs_get_ds_info(inode);
926 cinfo->dreq = NULL;
927 cinfo->completion_ops = &nfs_commit_completion_ops;
928}
929
930void nfs_init_cinfo(struct nfs_commit_info *cinfo,
931 struct inode *inode,
932 struct nfs_direct_req *dreq)
933{
934 if (dreq)
935 nfs_init_cinfo_from_dreq(cinfo, dreq);
936 else
937 nfs_init_cinfo_from_inode(cinfo, inode);
938}
939EXPORT_SYMBOL_GPL(nfs_init_cinfo);
940
941/*
942 * Add a request to the inode's commit list.
943 */
944void
945nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg,
946 struct nfs_commit_info *cinfo, u32 ds_commit_idx)
947{
948 if (pnfs_mark_request_commit(req, lseg, cinfo, ds_commit_idx))
949 return;
950 nfs_request_add_commit_list(req, cinfo);
951}
952
953static void nfs_folio_clear_commit(struct folio *folio)
954{
955 if (folio) {
956 long nr = folio_nr_pages(folio);
957
958 node_stat_mod_folio(folio, item: NR_WRITEBACK, nr: -nr);
959 wb_stat_mod(wb: &inode_to_bdi(inode: folio_file_mapping(folio)->host)->wb,
960 item: WB_WRITEBACK, amount: -nr);
961 }
962}
963
964/* Called holding the request lock on @req */
965static void nfs_clear_request_commit(struct nfs_commit_info *cinfo,
966 struct nfs_page *req)
967{
968 if (test_bit(PG_CLEAN, &req->wb_flags)) {
969 struct nfs_open_context *ctx = nfs_req_openctx(req);
970 struct inode *inode = d_inode(dentry: ctx->dentry);
971
972 mutex_lock(&NFS_I(inode)->commit_mutex);
973 if (!pnfs_clear_request_commit(req, cinfo)) {
974 nfs_request_remove_commit_list(req, cinfo);
975 }
976 mutex_unlock(lock: &NFS_I(inode)->commit_mutex);
977 nfs_folio_clear_commit(folio: nfs_page_to_folio(req));
978 }
979}
980
981int nfs_write_need_commit(struct nfs_pgio_header *hdr)
982{
983 if (hdr->verf.committed == NFS_DATA_SYNC)
984 return hdr->lseg == NULL;
985 return hdr->verf.committed != NFS_FILE_SYNC;
986}
987
988static void nfs_async_write_init(struct nfs_pgio_header *hdr)
989{
990 nfs_io_completion_get(ioc: hdr->io_completion);
991}
992
993static void nfs_write_completion(struct nfs_pgio_header *hdr)
994{
995 struct nfs_commit_info cinfo;
996 unsigned long bytes = 0;
997
998 if (test_bit(NFS_IOHDR_REDO, &hdr->flags))
999 goto out;
1000 nfs_init_cinfo_from_inode(cinfo: &cinfo, inode: hdr->inode);
1001 while (!list_empty(head: &hdr->pages)) {
1002 struct nfs_page *req = nfs_list_entry(head: hdr->pages.next);
1003
1004 bytes += req->wb_bytes;
1005 nfs_list_remove_request(req);
1006 if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) &&
1007 (hdr->good_bytes < bytes)) {
1008 trace_nfs_comp_error(inode: hdr->inode, req, error: hdr->error);
1009 nfs_mapping_set_error(folio: nfs_page_to_folio(req),
1010 error: hdr->error);
1011 goto remove_req;
1012 }
1013 if (nfs_write_need_commit(hdr)) {
1014 /* Reset wb_nio, since the write was successful. */
1015 req->wb_nio = 0;
1016 memcpy(&req->wb_verf, &hdr->verf.verifier, sizeof(req->wb_verf));
1017 nfs_mark_request_commit(req, lseg: hdr->lseg, cinfo: &cinfo,
1018 ds_commit_idx: hdr->pgio_mirror_idx);
1019 goto next;
1020 }
1021remove_req:
1022 nfs_inode_remove_request(req);
1023next:
1024 nfs_page_end_writeback(req);
1025 nfs_release_request(req);
1026 }
1027out:
1028 nfs_io_completion_put(ioc: hdr->io_completion);
1029 hdr->release(hdr);
1030}
1031
1032unsigned long
1033nfs_reqs_to_commit(struct nfs_commit_info *cinfo)
1034{
1035 return atomic_long_read(v: &cinfo->mds->ncommit);
1036}
1037
1038/* NFS_I(cinfo->inode)->commit_mutex held by caller */
1039int
1040nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
1041 struct nfs_commit_info *cinfo, int max)
1042{
1043 struct nfs_page *req, *tmp;
1044 int ret = 0;
1045
1046 list_for_each_entry_safe(req, tmp, src, wb_list) {
1047 kref_get(kref: &req->wb_kref);
1048 if (!nfs_lock_request(req)) {
1049 nfs_release_request(req);
1050 continue;
1051 }
1052 nfs_request_remove_commit_list(req, cinfo);
1053 clear_bit(nr: PG_COMMIT_TO_DS, addr: &req->wb_flags);
1054 nfs_list_add_request(req, head: dst);
1055 ret++;
1056 if ((ret == max) && !cinfo->dreq)
1057 break;
1058 cond_resched();
1059 }
1060 return ret;
1061}
1062EXPORT_SYMBOL_GPL(nfs_scan_commit_list);
1063
1064/*
1065 * nfs_scan_commit - Scan an inode for commit requests
1066 * @inode: NFS inode to scan
1067 * @dst: mds destination list
1068 * @cinfo: mds and ds lists of reqs ready to commit
1069 *
1070 * Moves requests from the inode's 'commit' request list.
1071 * The requests are *not* checked to ensure that they form a contiguous set.
1072 */
1073int
1074nfs_scan_commit(struct inode *inode, struct list_head *dst,
1075 struct nfs_commit_info *cinfo)
1076{
1077 int ret = 0;
1078
1079 if (!atomic_long_read(v: &cinfo->mds->ncommit))
1080 return 0;
1081 mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
1082 if (atomic_long_read(v: &cinfo->mds->ncommit) > 0) {
1083 const int max = INT_MAX;
1084
1085 ret = nfs_scan_commit_list(&cinfo->mds->list, dst,
1086 cinfo, max);
1087 ret += pnfs_scan_commit_lists(inode, cinfo, max: max - ret);
1088 }
1089 mutex_unlock(lock: &NFS_I(inode: cinfo->inode)->commit_mutex);
1090 return ret;
1091}
1092
1093/*
1094 * Search for an existing write request, and attempt to update
1095 * it to reflect a new dirty region on a given page.
1096 *
1097 * If the attempt fails, then the existing request is flushed out
1098 * to disk.
1099 */
1100static struct nfs_page *nfs_try_to_update_request(struct folio *folio,
1101 unsigned int offset,
1102 unsigned int bytes)
1103{
1104 struct nfs_page *req;
1105 unsigned int rqend;
1106 unsigned int end;
1107 int error;
1108
1109 end = offset + bytes;
1110
1111 req = nfs_lock_and_join_requests(folio);
1112 if (IS_ERR_OR_NULL(ptr: req))
1113 return req;
1114
1115 rqend = req->wb_offset + req->wb_bytes;
1116 /*
1117 * Tell the caller to flush out the request if
1118 * the offsets are non-contiguous.
1119 * Note: nfs_flush_incompatible() will already
1120 * have flushed out requests having wrong owners.
1121 */
1122 if (offset > rqend || end < req->wb_offset)
1123 goto out_flushme;
1124
1125 /* Okay, the request matches. Update the region */
1126 if (offset < req->wb_offset) {
1127 req->wb_offset = offset;
1128 req->wb_pgbase = offset;
1129 }
1130 if (end > rqend)
1131 req->wb_bytes = end - req->wb_offset;
1132 else
1133 req->wb_bytes = rqend - req->wb_offset;
1134 req->wb_nio = 0;
1135 return req;
1136out_flushme:
1137 /*
1138 * Note: we mark the request dirty here because
1139 * nfs_lock_and_join_requests() cannot preserve
1140 * commit flags, so we have to replay the write.
1141 */
1142 nfs_mark_request_dirty(req);
1143 nfs_unlock_and_release_request(req);
1144 error = nfs_wb_folio(inode: folio_file_mapping(folio)->host, folio);
1145 return (error < 0) ? ERR_PTR(error) : NULL;
1146}
1147
1148/*
1149 * Try to update an existing write request, or create one if there is none.
1150 *
1151 * Note: Should always be called with the Page Lock held to prevent races
1152 * if we have to add a new request. Also assumes that the caller has
1153 * already called nfs_flush_incompatible() if necessary.
1154 */
1155static struct nfs_page *nfs_setup_write_request(struct nfs_open_context *ctx,
1156 struct folio *folio,
1157 unsigned int offset,
1158 unsigned int bytes)
1159{
1160 struct nfs_page *req;
1161
1162 req = nfs_try_to_update_request(folio, offset, bytes);
1163 if (req != NULL)
1164 goto out;
1165 req = nfs_page_create_from_folio(ctx, folio, offset, count: bytes);
1166 if (IS_ERR(ptr: req))
1167 goto out;
1168 nfs_inode_add_request(req);
1169out:
1170 return req;
1171}
1172
1173static int nfs_writepage_setup(struct nfs_open_context *ctx,
1174 struct folio *folio, unsigned int offset,
1175 unsigned int count)
1176{
1177 struct nfs_page *req;
1178
1179 req = nfs_setup_write_request(ctx, folio, offset, bytes: count);
1180 if (IS_ERR(ptr: req))
1181 return PTR_ERR(ptr: req);
1182 /* Update file length */
1183 nfs_grow_file(folio, offset, count);
1184 nfs_mark_uptodate(req);
1185 nfs_mark_request_dirty(req);
1186 nfs_unlock_and_release_request(req);
1187 return 0;
1188}
1189
1190int nfs_flush_incompatible(struct file *file, struct folio *folio)
1191{
1192 struct nfs_open_context *ctx = nfs_file_open_context(filp: file);
1193 struct nfs_lock_context *l_ctx;
1194 struct file_lock_context *flctx = locks_inode_context(inode: file_inode(f: file));
1195 struct nfs_page *req;
1196 int do_flush, status;
1197 /*
1198 * Look for a request corresponding to this page. If there
1199 * is one, and it belongs to another file, we flush it out
1200 * before we try to copy anything into the page. Do this
1201 * due to the lack of an ACCESS-type call in NFSv2.
1202 * Also do the same if we find a request from an existing
1203 * dropped page.
1204 */
1205 do {
1206 req = nfs_folio_find_head_request(folio);
1207 if (req == NULL)
1208 return 0;
1209 l_ctx = req->wb_lock_context;
1210 do_flush = nfs_page_to_folio(req) != folio ||
1211 !nfs_match_open_context(ctx1: nfs_req_openctx(req), ctx2: ctx);
1212 if (l_ctx && flctx &&
1213 !(list_empty_careful(head: &flctx->flc_posix) &&
1214 list_empty_careful(head: &flctx->flc_flock))) {
1215 do_flush |= l_ctx->lockowner != current->files;
1216 }
1217 nfs_release_request(req);
1218 if (!do_flush)
1219 return 0;
1220 status = nfs_wb_folio(inode: folio_file_mapping(folio)->host, folio);
1221 } while (status == 0);
1222 return status;
1223}
1224
1225/*
1226 * Avoid buffered writes when a open context credential's key would
1227 * expire soon.
1228 *
1229 * Returns -EACCES if the key will expire within RPC_KEY_EXPIRE_FAIL.
1230 *
1231 * Return 0 and set a credential flag which triggers the inode to flush
1232 * and performs NFS_FILE_SYNC writes if the key will expired within
1233 * RPC_KEY_EXPIRE_TIMEO.
1234 */
1235int
1236nfs_key_timeout_notify(struct file *filp, struct inode *inode)
1237{
1238 struct nfs_open_context *ctx = nfs_file_open_context(filp);
1239
1240 if (nfs_ctx_key_to_expire(ctx, inode) &&
1241 !rcu_access_pointer(ctx->ll_cred))
1242 /* Already expired! */
1243 return -EACCES;
1244 return 0;
1245}
1246
1247/*
1248 * Test if the open context credential key is marked to expire soon.
1249 */
1250bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx, struct inode *inode)
1251{
1252 struct rpc_auth *auth = NFS_SERVER(inode)->client->cl_auth;
1253 struct rpc_cred *cred, *new, *old = NULL;
1254 struct auth_cred acred = {
1255 .cred = ctx->cred,
1256 };
1257 bool ret = false;
1258
1259 rcu_read_lock();
1260 cred = rcu_dereference(ctx->ll_cred);
1261 if (cred && !(cred->cr_ops->crkey_timeout &&
1262 cred->cr_ops->crkey_timeout(cred)))
1263 goto out;
1264 rcu_read_unlock();
1265
1266 new = auth->au_ops->lookup_cred(auth, &acred, 0);
1267 if (new == cred) {
1268 put_rpccred(new);
1269 return true;
1270 }
1271 if (IS_ERR_OR_NULL(ptr: new)) {
1272 new = NULL;
1273 ret = true;
1274 } else if (new->cr_ops->crkey_timeout &&
1275 new->cr_ops->crkey_timeout(new))
1276 ret = true;
1277
1278 rcu_read_lock();
1279 old = rcu_dereference_protected(xchg(&ctx->ll_cred,
1280 RCU_INITIALIZER(new)), 1);
1281out:
1282 rcu_read_unlock();
1283 put_rpccred(old);
1284 return ret;
1285}
1286
1287/*
1288 * If the page cache is marked as unsafe or invalid, then we can't rely on
1289 * the PageUptodate() flag. In this case, we will need to turn off
1290 * write optimisations that depend on the page contents being correct.
1291 */
1292static bool nfs_folio_write_uptodate(struct folio *folio, unsigned int pagelen)
1293{
1294 struct inode *inode = folio_file_mapping(folio)->host;
1295 struct nfs_inode *nfsi = NFS_I(inode);
1296
1297 if (nfs_have_delegated_attributes(inode))
1298 goto out;
1299 if (nfsi->cache_validity &
1300 (NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_SIZE))
1301 return false;
1302 smp_rmb();
1303 if (test_bit(NFS_INO_INVALIDATING, &nfsi->flags) && pagelen != 0)
1304 return false;
1305out:
1306 if (nfsi->cache_validity & NFS_INO_INVALID_DATA && pagelen != 0)
1307 return false;
1308 return folio_test_uptodate(folio) != 0;
1309}
1310
1311static bool
1312is_whole_file_wrlock(struct file_lock *fl)
1313{
1314 return fl->fl_start == 0 && fl->fl_end == OFFSET_MAX &&
1315 fl->fl_type == F_WRLCK;
1316}
1317
1318/* If we know the page is up to date, and we're not using byte range locks (or
1319 * if we have the whole file locked for writing), it may be more efficient to
1320 * extend the write to cover the entire page in order to avoid fragmentation
1321 * inefficiencies.
1322 *
1323 * If the file is opened for synchronous writes then we can just skip the rest
1324 * of the checks.
1325 */
1326static int nfs_can_extend_write(struct file *file, struct folio *folio,
1327 unsigned int pagelen)
1328{
1329 struct inode *inode = file_inode(f: file);
1330 struct file_lock_context *flctx = locks_inode_context(inode);
1331 struct file_lock *fl;
1332 int ret;
1333
1334 if (file->f_flags & O_DSYNC)
1335 return 0;
1336 if (!nfs_folio_write_uptodate(folio, pagelen))
1337 return 0;
1338 if (NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE))
1339 return 1;
1340 if (!flctx || (list_empty_careful(head: &flctx->flc_flock) &&
1341 list_empty_careful(head: &flctx->flc_posix)))
1342 return 1;
1343
1344 /* Check to see if there are whole file write locks */
1345 ret = 0;
1346 spin_lock(lock: &flctx->flc_lock);
1347 if (!list_empty(head: &flctx->flc_posix)) {
1348 fl = list_first_entry(&flctx->flc_posix, struct file_lock,
1349 fl_list);
1350 if (is_whole_file_wrlock(fl))
1351 ret = 1;
1352 } else if (!list_empty(head: &flctx->flc_flock)) {
1353 fl = list_first_entry(&flctx->flc_flock, struct file_lock,
1354 fl_list);
1355 if (fl->fl_type == F_WRLCK)
1356 ret = 1;
1357 }
1358 spin_unlock(lock: &flctx->flc_lock);
1359 return ret;
1360}
1361
1362/*
1363 * Update and possibly write a cached page of an NFS file.
1364 *
1365 * XXX: Keep an eye on generic_file_read to make sure it doesn't do bad
1366 * things with a page scheduled for an RPC call (e.g. invalidate it).
1367 */
1368int nfs_update_folio(struct file *file, struct folio *folio,
1369 unsigned int offset, unsigned int count)
1370{
1371 struct nfs_open_context *ctx = nfs_file_open_context(filp: file);
1372 struct address_space *mapping = folio_file_mapping(folio);
1373 struct inode *inode = mapping->host;
1374 unsigned int pagelen = nfs_folio_length(folio);
1375 int status = 0;
1376
1377 nfs_inc_stats(inode, stat: NFSIOS_VFSUPDATEPAGE);
1378
1379 dprintk("NFS: nfs_update_folio(%pD2 %d@%lld)\n", file, count,
1380 (long long)(folio_file_pos(folio) + offset));
1381
1382 if (!count)
1383 goto out;
1384
1385 if (nfs_can_extend_write(file, folio, pagelen)) {
1386 count = max(count + offset, pagelen);
1387 offset = 0;
1388 }
1389
1390 status = nfs_writepage_setup(ctx, folio, offset, count);
1391 if (status < 0)
1392 nfs_set_pageerror(mapping);
1393out:
1394 dprintk("NFS: nfs_update_folio returns %d (isize %lld)\n",
1395 status, (long long)i_size_read(inode));
1396 return status;
1397}
1398
1399static int flush_task_priority(int how)
1400{
1401 switch (how & (FLUSH_HIGHPRI|FLUSH_LOWPRI)) {
1402 case FLUSH_HIGHPRI:
1403 return RPC_PRIORITY_HIGH;
1404 case FLUSH_LOWPRI:
1405 return RPC_PRIORITY_LOW;
1406 }
1407 return RPC_PRIORITY_NORMAL;
1408}
1409
1410static void nfs_initiate_write(struct nfs_pgio_header *hdr,
1411 struct rpc_message *msg,
1412 const struct nfs_rpc_ops *rpc_ops,
1413 struct rpc_task_setup *task_setup_data, int how)
1414{
1415 int priority = flush_task_priority(how);
1416
1417 if (IS_SWAPFILE(hdr->inode))
1418 task_setup_data->flags |= RPC_TASK_SWAPPER;
1419 task_setup_data->priority = priority;
1420 rpc_ops->write_setup(hdr, msg, &task_setup_data->rpc_client);
1421 trace_nfs_initiate_write(hdr);
1422}
1423
1424/* If a nfs_flush_* function fails, it should remove reqs from @head and
1425 * call this on each, which will prepare them to be retried on next
1426 * writeback using standard nfs.
1427 */
1428static void nfs_redirty_request(struct nfs_page *req)
1429{
1430 struct nfs_inode *nfsi = NFS_I(inode: nfs_page_to_inode(req));
1431
1432 /* Bump the transmission count */
1433 req->wb_nio++;
1434 nfs_mark_request_dirty(req);
1435 atomic_long_inc(v: &nfsi->redirtied_pages);
1436 nfs_page_end_writeback(req);
1437 nfs_release_request(req);
1438}
1439
1440static void nfs_async_write_error(struct list_head *head, int error)
1441{
1442 struct nfs_page *req;
1443
1444 while (!list_empty(head)) {
1445 req = nfs_list_entry(head: head->next);
1446 nfs_list_remove_request(req);
1447 if (nfs_error_is_fatal_on_server(err: error))
1448 nfs_write_error(req, error);
1449 else
1450 nfs_redirty_request(req);
1451 }
1452}
1453
1454static void nfs_async_write_reschedule_io(struct nfs_pgio_header *hdr)
1455{
1456 nfs_async_write_error(head: &hdr->pages, error: 0);
1457}
1458
1459static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops = {
1460 .init_hdr = nfs_async_write_init,
1461 .error_cleanup = nfs_async_write_error,
1462 .completion = nfs_write_completion,
1463 .reschedule_io = nfs_async_write_reschedule_io,
1464};
1465
1466void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
1467 struct inode *inode, int ioflags, bool force_mds,
1468 const struct nfs_pgio_completion_ops *compl_ops)
1469{
1470 struct nfs_server *server = NFS_SERVER(inode);
1471 const struct nfs_pageio_ops *pg_ops = &nfs_pgio_rw_ops;
1472
1473#ifdef CONFIG_NFS_V4_1
1474 if (server->pnfs_curr_ld && !force_mds)
1475 pg_ops = server->pnfs_curr_ld->pg_write_ops;
1476#endif
1477 nfs_pageio_init(desc: pgio, inode, pg_ops, compl_ops, rw_ops: &nfs_rw_write_ops,
1478 bsize: server->wsize, how: ioflags);
1479}
1480EXPORT_SYMBOL_GPL(nfs_pageio_init_write);
1481
1482void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio)
1483{
1484 struct nfs_pgio_mirror *mirror;
1485
1486 if (pgio->pg_ops && pgio->pg_ops->pg_cleanup)
1487 pgio->pg_ops->pg_cleanup(pgio);
1488
1489 pgio->pg_ops = &nfs_pgio_rw_ops;
1490
1491 nfs_pageio_stop_mirroring(pgio);
1492
1493 mirror = &pgio->pg_mirrors[0];
1494 mirror->pg_bsize = NFS_SERVER(inode: pgio->pg_inode)->wsize;
1495}
1496EXPORT_SYMBOL_GPL(nfs_pageio_reset_write_mds);
1497
1498
1499void nfs_commit_prepare(struct rpc_task *task, void *calldata)
1500{
1501 struct nfs_commit_data *data = calldata;
1502
1503 NFS_PROTO(inode: data->inode)->commit_rpc_prepare(task, data);
1504}
1505
1506static void nfs_writeback_check_extend(struct nfs_pgio_header *hdr,
1507 struct nfs_fattr *fattr)
1508{
1509 struct nfs_pgio_args *argp = &hdr->args;
1510 struct nfs_pgio_res *resp = &hdr->res;
1511 u64 size = argp->offset + resp->count;
1512
1513 if (!(fattr->valid & NFS_ATTR_FATTR_SIZE))
1514 fattr->size = size;
1515 if (nfs_size_to_loff_t(size: fattr->size) < i_size_read(inode: hdr->inode)) {
1516 fattr->valid &= ~NFS_ATTR_FATTR_SIZE;
1517 return;
1518 }
1519 if (size != fattr->size)
1520 return;
1521 /* Set attribute barrier */
1522 nfs_fattr_set_barrier(fattr);
1523 /* ...and update size */
1524 fattr->valid |= NFS_ATTR_FATTR_SIZE;
1525}
1526
1527void nfs_writeback_update_inode(struct nfs_pgio_header *hdr)
1528{
1529 struct nfs_fattr *fattr = &hdr->fattr;
1530 struct inode *inode = hdr->inode;
1531
1532 spin_lock(lock: &inode->i_lock);
1533 nfs_writeback_check_extend(hdr, fattr);
1534 nfs_post_op_update_inode_force_wcc_locked(inode, fattr);
1535 spin_unlock(lock: &inode->i_lock);
1536}
1537EXPORT_SYMBOL_GPL(nfs_writeback_update_inode);
1538
1539/*
1540 * This function is called when the WRITE call is complete.
1541 */
1542static int nfs_writeback_done(struct rpc_task *task,
1543 struct nfs_pgio_header *hdr,
1544 struct inode *inode)
1545{
1546 int status;
1547
1548 /*
1549 * ->write_done will attempt to use post-op attributes to detect
1550 * conflicting writes by other clients. A strict interpretation
1551 * of close-to-open would allow us to continue caching even if
1552 * another writer had changed the file, but some applications
1553 * depend on tighter cache coherency when writing.
1554 */
1555 status = NFS_PROTO(inode)->write_done(task, hdr);
1556 if (status != 0)
1557 return status;
1558
1559 nfs_add_stats(inode, stat: NFSIOS_SERVERWRITTENBYTES, addend: hdr->res.count);
1560 trace_nfs_writeback_done(task, hdr);
1561
1562 if (task->tk_status >= 0) {
1563 enum nfs3_stable_how committed = hdr->res.verf->committed;
1564
1565 if (committed == NFS_UNSTABLE) {
1566 /*
1567 * We have some uncommitted data on the server at
1568 * this point, so ensure that we keep track of that
1569 * fact irrespective of what later writes do.
1570 */
1571 set_bit(nr: NFS_IOHDR_UNSTABLE_WRITES, addr: &hdr->flags);
1572 }
1573
1574 if (committed < hdr->args.stable) {
1575 /* We tried a write call, but the server did not
1576 * commit data to stable storage even though we
1577 * requested it.
1578 * Note: There is a known bug in Tru64 < 5.0 in which
1579 * the server reports NFS_DATA_SYNC, but performs
1580 * NFS_FILE_SYNC. We therefore implement this checking
1581 * as a dprintk() in order to avoid filling syslog.
1582 */
1583 static unsigned long complain;
1584
1585 /* Note this will print the MDS for a DS write */
1586 if (time_before(complain, jiffies)) {
1587 dprintk("NFS: faulty NFS server %s:"
1588 " (committed = %d) != (stable = %d)\n",
1589 NFS_SERVER(inode)->nfs_client->cl_hostname,
1590 committed, hdr->args.stable);
1591 complain = jiffies + 300 * HZ;
1592 }
1593 }
1594 }
1595
1596 /* Deal with the suid/sgid bit corner case */
1597 if (nfs_should_remove_suid(inode)) {
1598 spin_lock(lock: &inode->i_lock);
1599 nfs_set_cache_invalid(inode, NFS_INO_INVALID_MODE);
1600 spin_unlock(lock: &inode->i_lock);
1601 }
1602 return 0;
1603}
1604
1605/*
1606 * This function is called when the WRITE call is complete.
1607 */
1608static void nfs_writeback_result(struct rpc_task *task,
1609 struct nfs_pgio_header *hdr)
1610{
1611 struct nfs_pgio_args *argp = &hdr->args;
1612 struct nfs_pgio_res *resp = &hdr->res;
1613
1614 if (resp->count < argp->count) {
1615 static unsigned long complain;
1616
1617 /* This a short write! */
1618 nfs_inc_stats(inode: hdr->inode, stat: NFSIOS_SHORTWRITE);
1619
1620 /* Has the server at least made some progress? */
1621 if (resp->count == 0) {
1622 if (time_before(complain, jiffies)) {
1623 printk(KERN_WARNING
1624 "NFS: Server wrote zero bytes, expected %u.\n",
1625 argp->count);
1626 complain = jiffies + 300 * HZ;
1627 }
1628 nfs_set_pgio_error(hdr, error: -EIO, pos: argp->offset);
1629 task->tk_status = -EIO;
1630 return;
1631 }
1632
1633 /* For non rpc-based layout drivers, retry-through-MDS */
1634 if (!task->tk_ops) {
1635 hdr->pnfs_error = -EAGAIN;
1636 return;
1637 }
1638
1639 /* Was this an NFSv2 write or an NFSv3 stable write? */
1640 if (resp->verf->committed != NFS_UNSTABLE) {
1641 /* Resend from where the server left off */
1642 hdr->mds_offset += resp->count;
1643 argp->offset += resp->count;
1644 argp->pgbase += resp->count;
1645 argp->count -= resp->count;
1646 } else {
1647 /* Resend as a stable write in order to avoid
1648 * headaches in the case of a server crash.
1649 */
1650 argp->stable = NFS_FILE_SYNC;
1651 }
1652 resp->count = 0;
1653 resp->verf->committed = 0;
1654 rpc_restart_call_prepare(task);
1655 }
1656}
1657
1658static int wait_on_commit(struct nfs_mds_commit_info *cinfo)
1659{
1660 return wait_var_event_killable(&cinfo->rpcs_out,
1661 !atomic_read(&cinfo->rpcs_out));
1662}
1663
1664static void nfs_commit_begin(struct nfs_mds_commit_info *cinfo)
1665{
1666 atomic_inc(v: &cinfo->rpcs_out);
1667}
1668
1669bool nfs_commit_end(struct nfs_mds_commit_info *cinfo)
1670{
1671 if (atomic_dec_and_test(v: &cinfo->rpcs_out)) {
1672 wake_up_var(var: &cinfo->rpcs_out);
1673 return true;
1674 }
1675 return false;
1676}
1677
1678void nfs_commitdata_release(struct nfs_commit_data *data)
1679{
1680 put_nfs_open_context(ctx: data->context);
1681 nfs_commit_free(data);
1682}
1683EXPORT_SYMBOL_GPL(nfs_commitdata_release);
1684
1685int nfs_initiate_commit(struct rpc_clnt *clnt, struct nfs_commit_data *data,
1686 const struct nfs_rpc_ops *nfs_ops,
1687 const struct rpc_call_ops *call_ops,
1688 int how, int flags)
1689{
1690 struct rpc_task *task;
1691 int priority = flush_task_priority(how);
1692 struct rpc_message msg = {
1693 .rpc_argp = &data->args,
1694 .rpc_resp = &data->res,
1695 .rpc_cred = data->cred,
1696 };
1697 struct rpc_task_setup task_setup_data = {
1698 .task = &data->task,
1699 .rpc_client = clnt,
1700 .rpc_message = &msg,
1701 .callback_ops = call_ops,
1702 .callback_data = data,
1703 .workqueue = nfsiod_workqueue,
1704 .flags = RPC_TASK_ASYNC | flags,
1705 .priority = priority,
1706 };
1707
1708 if (nfs_server_capable(inode: data->inode, NFS_CAP_MOVEABLE))
1709 task_setup_data.flags |= RPC_TASK_MOVEABLE;
1710
1711 /* Set up the initial task struct. */
1712 nfs_ops->commit_setup(data, &msg, &task_setup_data.rpc_client);
1713 trace_nfs_initiate_commit(data);
1714
1715 dprintk("NFS: initiated commit call\n");
1716
1717 task = rpc_run_task(&task_setup_data);
1718 if (IS_ERR(ptr: task))
1719 return PTR_ERR(ptr: task);
1720 if (how & FLUSH_SYNC)
1721 rpc_wait_for_completion_task(task);
1722 rpc_put_task(task);
1723 return 0;
1724}
1725EXPORT_SYMBOL_GPL(nfs_initiate_commit);
1726
1727static loff_t nfs_get_lwb(struct list_head *head)
1728{
1729 loff_t lwb = 0;
1730 struct nfs_page *req;
1731
1732 list_for_each_entry(req, head, wb_list)
1733 if (lwb < (req_offset(req) + req->wb_bytes))
1734 lwb = req_offset(req) + req->wb_bytes;
1735
1736 return lwb;
1737}
1738
1739/*
1740 * Set up the argument/result storage required for the RPC call.
1741 */
1742void nfs_init_commit(struct nfs_commit_data *data,
1743 struct list_head *head,
1744 struct pnfs_layout_segment *lseg,
1745 struct nfs_commit_info *cinfo)
1746{
1747 struct nfs_page *first;
1748 struct nfs_open_context *ctx;
1749 struct inode *inode;
1750
1751 /* Set up the RPC argument and reply structs
1752 * NB: take care not to mess about with data->commit et al. */
1753
1754 if (head)
1755 list_splice_init(list: head, head: &data->pages);
1756
1757 first = nfs_list_entry(head: data->pages.next);
1758 ctx = nfs_req_openctx(req: first);
1759 inode = d_inode(dentry: ctx->dentry);
1760
1761 data->inode = inode;
1762 data->cred = ctx->cred;
1763 data->lseg = lseg; /* reference transferred */
1764 /* only set lwb for pnfs commit */
1765 if (lseg)
1766 data->lwb = nfs_get_lwb(head: &data->pages);
1767 data->mds_ops = &nfs_commit_ops;
1768 data->completion_ops = cinfo->completion_ops;
1769 data->dreq = cinfo->dreq;
1770
1771 data->args.fh = NFS_FH(inode: data->inode);
1772 /* Note: we always request a commit of the entire inode */
1773 data->args.offset = 0;
1774 data->args.count = 0;
1775 data->context = get_nfs_open_context(ctx);
1776 data->res.fattr = &data->fattr;
1777 data->res.verf = &data->verf;
1778 nfs_fattr_init(fattr: &data->fattr);
1779 nfs_commit_begin(cinfo: cinfo->mds);
1780}
1781EXPORT_SYMBOL_GPL(nfs_init_commit);
1782
1783void nfs_retry_commit(struct list_head *page_list,
1784 struct pnfs_layout_segment *lseg,
1785 struct nfs_commit_info *cinfo,
1786 u32 ds_commit_idx)
1787{
1788 struct nfs_page *req;
1789
1790 while (!list_empty(head: page_list)) {
1791 req = nfs_list_entry(head: page_list->next);
1792 nfs_list_remove_request(req);
1793 nfs_mark_request_commit(req, lseg, cinfo, ds_commit_idx);
1794 nfs_folio_clear_commit(folio: nfs_page_to_folio(req));
1795 nfs_unlock_and_release_request(req);
1796 }
1797}
1798EXPORT_SYMBOL_GPL(nfs_retry_commit);
1799
1800static void nfs_commit_resched_write(struct nfs_commit_info *cinfo,
1801 struct nfs_page *req)
1802{
1803 struct folio *folio = nfs_page_to_folio(req);
1804
1805 filemap_dirty_folio(mapping: folio_mapping(folio), folio);
1806}
1807
1808/*
1809 * Commit dirty pages
1810 */
1811static int
1812nfs_commit_list(struct inode *inode, struct list_head *head, int how,
1813 struct nfs_commit_info *cinfo)
1814{
1815 struct nfs_commit_data *data;
1816 unsigned short task_flags = 0;
1817
1818 /* another commit raced with us */
1819 if (list_empty(head))
1820 return 0;
1821
1822 data = nfs_commitdata_alloc();
1823 if (!data) {
1824 nfs_retry_commit(head, NULL, cinfo, -1);
1825 return -ENOMEM;
1826 }
1827
1828 /* Set up the argument struct */
1829 nfs_init_commit(data, head, NULL, cinfo);
1830 if (NFS_SERVER(inode)->nfs_client->cl_minorversion)
1831 task_flags = RPC_TASK_MOVEABLE;
1832 return nfs_initiate_commit(NFS_CLIENT(inode), data, NFS_PROTO(inode),
1833 data->mds_ops, how,
1834 RPC_TASK_CRED_NOREF | task_flags);
1835}
1836
1837/*
1838 * COMMIT call returned
1839 */
1840static void nfs_commit_done(struct rpc_task *task, void *calldata)
1841{
1842 struct nfs_commit_data *data = calldata;
1843
1844 /* Call the NFS version-specific code */
1845 NFS_PROTO(inode: data->inode)->commit_done(task, data);
1846 trace_nfs_commit_done(task, data);
1847}
1848
1849static void nfs_commit_release_pages(struct nfs_commit_data *data)
1850{
1851 const struct nfs_writeverf *verf = data->res.verf;
1852 struct nfs_page *req;
1853 int status = data->task.tk_status;
1854 struct nfs_commit_info cinfo;
1855 struct nfs_server *nfss;
1856 struct folio *folio;
1857
1858 while (!list_empty(head: &data->pages)) {
1859 req = nfs_list_entry(head: data->pages.next);
1860 nfs_list_remove_request(req);
1861 folio = nfs_page_to_folio(req);
1862 nfs_folio_clear_commit(folio);
1863
1864 dprintk("NFS: commit (%s/%llu %d@%lld)",
1865 nfs_req_openctx(req)->dentry->d_sb->s_id,
1866 (unsigned long long)NFS_FILEID(d_inode(nfs_req_openctx(req)->dentry)),
1867 req->wb_bytes,
1868 (long long)req_offset(req));
1869 if (status < 0) {
1870 if (folio) {
1871 trace_nfs_commit_error(inode: data->inode, req,
1872 error: status);
1873 nfs_mapping_set_error(folio, error: status);
1874 nfs_inode_remove_request(req);
1875 }
1876 dprintk_cont(", error = %d\n", status);
1877 goto next;
1878 }
1879
1880 /* Okay, COMMIT succeeded, apparently. Check the verifier
1881 * returned by the server against all stored verfs. */
1882 if (nfs_write_match_verf(verf, req)) {
1883 /* We have a match */
1884 if (folio)
1885 nfs_inode_remove_request(req);
1886 dprintk_cont(" OK\n");
1887 goto next;
1888 }
1889 /* We have a mismatch. Write the page again */
1890 dprintk_cont(" mismatch\n");
1891 nfs_mark_request_dirty(req);
1892 atomic_long_inc(v: &NFS_I(inode: data->inode)->redirtied_pages);
1893 next:
1894 nfs_unlock_and_release_request(req);
1895 /* Latency breaker */
1896 cond_resched();
1897 }
1898 nfss = NFS_SERVER(inode: data->inode);
1899 if (atomic_long_read(v: &nfss->writeback) < NFS_CONGESTION_OFF_THRESH)
1900 nfss->write_congested = 0;
1901
1902 nfs_init_cinfo(&cinfo, data->inode, data->dreq);
1903 nfs_commit_end(cinfo: cinfo.mds);
1904}
1905
1906static void nfs_commit_release(void *calldata)
1907{
1908 struct nfs_commit_data *data = calldata;
1909
1910 data->completion_ops->completion(data);
1911 nfs_commitdata_release(calldata);
1912}
1913
1914static const struct rpc_call_ops nfs_commit_ops = {
1915 .rpc_call_prepare = nfs_commit_prepare,
1916 .rpc_call_done = nfs_commit_done,
1917 .rpc_release = nfs_commit_release,
1918};
1919
1920static const struct nfs_commit_completion_ops nfs_commit_completion_ops = {
1921 .completion = nfs_commit_release_pages,
1922 .resched_write = nfs_commit_resched_write,
1923};
1924
1925int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
1926 int how, struct nfs_commit_info *cinfo)
1927{
1928 int status;
1929
1930 status = pnfs_commit_list(inode, mds_pages: head, how, cinfo);
1931 if (status == PNFS_NOT_ATTEMPTED)
1932 status = nfs_commit_list(inode, head, how, cinfo);
1933 return status;
1934}
1935
1936static int __nfs_commit_inode(struct inode *inode, int how,
1937 struct writeback_control *wbc)
1938{
1939 LIST_HEAD(head);
1940 struct nfs_commit_info cinfo;
1941 int may_wait = how & FLUSH_SYNC;
1942 int ret, nscan;
1943
1944 how &= ~FLUSH_SYNC;
1945 nfs_init_cinfo_from_inode(cinfo: &cinfo, inode);
1946 nfs_commit_begin(cinfo: cinfo.mds);
1947 for (;;) {
1948 ret = nscan = nfs_scan_commit(inode, dst: &head, cinfo: &cinfo);
1949 if (ret <= 0)
1950 break;
1951 ret = nfs_generic_commit_list(inode, head: &head, how, cinfo: &cinfo);
1952 if (ret < 0)
1953 break;
1954 ret = 0;
1955 if (wbc && wbc->sync_mode == WB_SYNC_NONE) {
1956 if (nscan < wbc->nr_to_write)
1957 wbc->nr_to_write -= nscan;
1958 else
1959 wbc->nr_to_write = 0;
1960 }
1961 if (nscan < INT_MAX)
1962 break;
1963 cond_resched();
1964 }
1965 nfs_commit_end(cinfo: cinfo.mds);
1966 if (ret || !may_wait)
1967 return ret;
1968 return wait_on_commit(cinfo: cinfo.mds);
1969}
1970
1971int nfs_commit_inode(struct inode *inode, int how)
1972{
1973 return __nfs_commit_inode(inode, how, NULL);
1974}
1975EXPORT_SYMBOL_GPL(nfs_commit_inode);
1976
1977int nfs_write_inode(struct inode *inode, struct writeback_control *wbc)
1978{
1979 struct nfs_inode *nfsi = NFS_I(inode);
1980 int flags = FLUSH_SYNC;
1981 int ret = 0;
1982
1983 if (wbc->sync_mode == WB_SYNC_NONE) {
1984 /* no commits means nothing needs to be done */
1985 if (!atomic_long_read(v: &nfsi->commit_info.ncommit))
1986 goto check_requests_outstanding;
1987
1988 /* Don't commit yet if this is a non-blocking flush and there
1989 * are a lot of outstanding writes for this mapping.
1990 */
1991 if (mapping_tagged(mapping: inode->i_mapping, PAGECACHE_TAG_WRITEBACK))
1992 goto out_mark_dirty;
1993
1994 /* don't wait for the COMMIT response */
1995 flags = 0;
1996 }
1997
1998 ret = __nfs_commit_inode(inode, how: flags, wbc);
1999 if (!ret) {
2000 if (flags & FLUSH_SYNC)
2001 return 0;
2002 } else if (atomic_long_read(v: &nfsi->commit_info.ncommit))
2003 goto out_mark_dirty;
2004
2005check_requests_outstanding:
2006 if (!atomic_read(v: &nfsi->commit_info.rpcs_out))
2007 return ret;
2008out_mark_dirty:
2009 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
2010 return ret;
2011}
2012EXPORT_SYMBOL_GPL(nfs_write_inode);
2013
2014/*
2015 * Wrapper for filemap_write_and_wait_range()
2016 *
2017 * Needed for pNFS in order to ensure data becomes visible to the
2018 * client.
2019 */
2020int nfs_filemap_write_and_wait_range(struct address_space *mapping,
2021 loff_t lstart, loff_t lend)
2022{
2023 int ret;
2024
2025 ret = filemap_write_and_wait_range(mapping, lstart, lend);
2026 if (ret == 0)
2027 ret = pnfs_sync_inode(inode: mapping->host, datasync: true);
2028 return ret;
2029}
2030EXPORT_SYMBOL_GPL(nfs_filemap_write_and_wait_range);
2031
2032/*
2033 * flush the inode to disk.
2034 */
2035int nfs_wb_all(struct inode *inode)
2036{
2037 int ret;
2038
2039 trace_nfs_writeback_inode_enter(inode);
2040
2041 ret = filemap_write_and_wait(mapping: inode->i_mapping);
2042 if (ret)
2043 goto out;
2044 ret = nfs_commit_inode(inode, FLUSH_SYNC);
2045 if (ret < 0)
2046 goto out;
2047 pnfs_sync_inode(inode, datasync: true);
2048 ret = 0;
2049
2050out:
2051 trace_nfs_writeback_inode_exit(inode, error: ret);
2052 return ret;
2053}
2054EXPORT_SYMBOL_GPL(nfs_wb_all);
2055
2056int nfs_wb_folio_cancel(struct inode *inode, struct folio *folio)
2057{
2058 struct nfs_page *req;
2059 int ret = 0;
2060
2061 folio_wait_writeback(folio);
2062
2063 /* blocking call to cancel all requests and join to a single (head)
2064 * request */
2065 req = nfs_lock_and_join_requests(folio);
2066
2067 if (IS_ERR(ptr: req)) {
2068 ret = PTR_ERR(ptr: req);
2069 } else if (req) {
2070 /* all requests from this folio have been cancelled by
2071 * nfs_lock_and_join_requests, so just remove the head
2072 * request from the inode / page_private pointer and
2073 * release it */
2074 nfs_inode_remove_request(req);
2075 nfs_unlock_and_release_request(req);
2076 }
2077
2078 return ret;
2079}
2080
2081/**
2082 * nfs_wb_folio - Write back all requests on one page
2083 * @inode: pointer to page
2084 * @folio: pointer to folio
2085 *
2086 * Assumes that the folio has been locked by the caller, and will
2087 * not unlock it.
2088 */
2089int nfs_wb_folio(struct inode *inode, struct folio *folio)
2090{
2091 loff_t range_start = folio_file_pos(folio);
2092 loff_t range_end = range_start + (loff_t)folio_size(folio) - 1;
2093 struct writeback_control wbc = {
2094 .sync_mode = WB_SYNC_ALL,
2095 .nr_to_write = 0,
2096 .range_start = range_start,
2097 .range_end = range_end,
2098 };
2099 int ret;
2100
2101 trace_nfs_writeback_folio(inode, folio);
2102
2103 for (;;) {
2104 folio_wait_writeback(folio);
2105 if (folio_clear_dirty_for_io(folio)) {
2106 ret = nfs_writepage_locked(folio, wbc: &wbc);
2107 if (ret < 0)
2108 goto out_error;
2109 continue;
2110 }
2111 ret = 0;
2112 if (!folio_test_private(folio))
2113 break;
2114 ret = nfs_commit_inode(inode, FLUSH_SYNC);
2115 if (ret < 0)
2116 goto out_error;
2117 }
2118out_error:
2119 trace_nfs_writeback_folio_done(inode, folio, ret);
2120 return ret;
2121}
2122
2123#ifdef CONFIG_MIGRATION
2124int nfs_migrate_folio(struct address_space *mapping, struct folio *dst,
2125 struct folio *src, enum migrate_mode mode)
2126{
2127 /*
2128 * If the private flag is set, the folio is currently associated with
2129 * an in-progress read or write request. Don't try to migrate it.
2130 *
2131 * FIXME: we could do this in principle, but we'll need a way to ensure
2132 * that we can safely release the inode reference while holding
2133 * the folio lock.
2134 */
2135 if (folio_test_private(folio: src))
2136 return -EBUSY;
2137
2138 if (folio_test_fscache(src)) {
2139 if (mode == MIGRATE_ASYNC)
2140 return -EBUSY;
2141 folio_wait_fscache(folio: src);
2142 }
2143
2144 return migrate_folio(mapping, dst, src, mode);
2145}
2146#endif
2147
2148int __init nfs_init_writepagecache(void)
2149{
2150 nfs_wdata_cachep = kmem_cache_create(name: "nfs_write_data",
2151 size: sizeof(struct nfs_pgio_header),
2152 align: 0, SLAB_HWCACHE_ALIGN,
2153 NULL);
2154 if (nfs_wdata_cachep == NULL)
2155 return -ENOMEM;
2156
2157 nfs_wdata_mempool = mempool_create_slab_pool(MIN_POOL_WRITE,
2158 kc: nfs_wdata_cachep);
2159 if (nfs_wdata_mempool == NULL)
2160 goto out_destroy_write_cache;
2161
2162 nfs_cdata_cachep = kmem_cache_create(name: "nfs_commit_data",
2163 size: sizeof(struct nfs_commit_data),
2164 align: 0, SLAB_HWCACHE_ALIGN,
2165 NULL);
2166 if (nfs_cdata_cachep == NULL)
2167 goto out_destroy_write_mempool;
2168
2169 nfs_commit_mempool = mempool_create_slab_pool(MIN_POOL_COMMIT,
2170 kc: nfs_cdata_cachep);
2171 if (nfs_commit_mempool == NULL)
2172 goto out_destroy_commit_cache;
2173
2174 /*
2175 * NFS congestion size, scale with available memory.
2176 *
2177 * 64MB: 8192k
2178 * 128MB: 11585k
2179 * 256MB: 16384k
2180 * 512MB: 23170k
2181 * 1GB: 32768k
2182 * 2GB: 46340k
2183 * 4GB: 65536k
2184 * 8GB: 92681k
2185 * 16GB: 131072k
2186 *
2187 * This allows larger machines to have larger/more transfers.
2188 * Limit the default to 256M
2189 */
2190 nfs_congestion_kb = (16*int_sqrt(totalram_pages())) << (PAGE_SHIFT-10);
2191 if (nfs_congestion_kb > 256*1024)
2192 nfs_congestion_kb = 256*1024;
2193
2194 return 0;
2195
2196out_destroy_commit_cache:
2197 kmem_cache_destroy(s: nfs_cdata_cachep);
2198out_destroy_write_mempool:
2199 mempool_destroy(pool: nfs_wdata_mempool);
2200out_destroy_write_cache:
2201 kmem_cache_destroy(s: nfs_wdata_cachep);
2202 return -ENOMEM;
2203}
2204
2205void nfs_destroy_writepagecache(void)
2206{
2207 mempool_destroy(pool: nfs_commit_mempool);
2208 kmem_cache_destroy(s: nfs_cdata_cachep);
2209 mempool_destroy(pool: nfs_wdata_mempool);
2210 kmem_cache_destroy(s: nfs_wdata_cachep);
2211}
2212
2213static const struct nfs_rw_ops nfs_rw_write_ops = {
2214 .rw_alloc_header = nfs_writehdr_alloc,
2215 .rw_free_header = nfs_writehdr_free,
2216 .rw_done = nfs_writeback_done,
2217 .rw_result = nfs_writeback_result,
2218 .rw_initiate = nfs_initiate_write,
2219};
2220

source code of linux/fs/nfs/write.c