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
47 struct nfs_io_completion {
48 void (*complete)(void *data);
49 void *data;
50 struct kref refcount;
51 };
52
53 /*
54 * Local function declarations
55 */
56 static void nfs_redirty_request(struct nfs_page *req);
57 static const struct rpc_call_ops nfs_commit_ops;
58 static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops;
59 static const struct nfs_commit_completion_ops nfs_commit_completion_ops;
60 static const struct nfs_rw_ops nfs_rw_write_ops;
61 static void nfs_inode_remove_request(struct nfs_page *req);
62 static void nfs_clear_request_commit(struct nfs_commit_info *cinfo,
63 struct nfs_page *req);
64 static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo,
65 struct inode *inode);
66
67 static struct kmem_cache *nfs_wdata_cachep;
68 static mempool_t *nfs_wdata_mempool;
69 static struct kmem_cache *nfs_cdata_cachep;
70 static mempool_t *nfs_commit_mempool;
71
nfs_commitdata_alloc(void)72 struct nfs_commit_data *nfs_commitdata_alloc(void)
73 {
74 struct nfs_commit_data *p;
75
76 p = kmem_cache_zalloc(nfs_cdata_cachep, nfs_io_gfp_mask());
77 if (!p) {
78 p = mempool_alloc(nfs_commit_mempool, GFP_NOWAIT);
79 if (!p)
80 return NULL;
81 memset(p, 0, sizeof(*p));
82 }
83 INIT_LIST_HEAD(&p->pages);
84 return p;
85 }
86 EXPORT_SYMBOL_GPL(nfs_commitdata_alloc);
87
nfs_commit_free(struct nfs_commit_data * p)88 void nfs_commit_free(struct nfs_commit_data *p)
89 {
90 mempool_free(p, nfs_commit_mempool);
91 }
92 EXPORT_SYMBOL_GPL(nfs_commit_free);
93
nfs_writehdr_alloc(void)94 static struct nfs_pgio_header *nfs_writehdr_alloc(void)
95 {
96 struct nfs_pgio_header *p;
97
98 p = kmem_cache_zalloc(nfs_wdata_cachep, nfs_io_gfp_mask());
99 if (!p) {
100 p = mempool_alloc(nfs_wdata_mempool, GFP_NOWAIT);
101 if (!p)
102 return NULL;
103 memset(p, 0, sizeof(*p));
104 }
105 p->rw_mode = FMODE_WRITE;
106 return p;
107 }
108
nfs_writehdr_free(struct nfs_pgio_header * hdr)109 static void nfs_writehdr_free(struct nfs_pgio_header *hdr)
110 {
111 mempool_free(hdr, nfs_wdata_mempool);
112 }
113
nfs_io_completion_alloc(gfp_t gfp_flags)114 static struct nfs_io_completion *nfs_io_completion_alloc(gfp_t gfp_flags)
115 {
116 return kmalloc(sizeof(struct nfs_io_completion), gfp_flags);
117 }
118
nfs_io_completion_init(struct nfs_io_completion * ioc,void (* complete)(void *),void * data)119 static void nfs_io_completion_init(struct nfs_io_completion *ioc,
120 void (*complete)(void *), void *data)
121 {
122 ioc->complete = complete;
123 ioc->data = data;
124 kref_init(&ioc->refcount);
125 }
126
nfs_io_completion_release(struct kref * kref)127 static void nfs_io_completion_release(struct kref *kref)
128 {
129 struct nfs_io_completion *ioc = container_of(kref,
130 struct nfs_io_completion, refcount);
131 ioc->complete(ioc->data);
132 kfree(ioc);
133 }
134
nfs_io_completion_get(struct nfs_io_completion * ioc)135 static void nfs_io_completion_get(struct nfs_io_completion *ioc)
136 {
137 if (ioc != NULL)
138 kref_get(&ioc->refcount);
139 }
140
nfs_io_completion_put(struct nfs_io_completion * ioc)141 static void nfs_io_completion_put(struct nfs_io_completion *ioc)
142 {
143 if (ioc != NULL)
144 kref_put(&ioc->refcount, nfs_io_completion_release);
145 }
146
147 static void
nfs_page_set_inode_ref(struct nfs_page * req,struct inode * inode)148 nfs_page_set_inode_ref(struct nfs_page *req, struct inode *inode)
149 {
150 if (!test_and_set_bit(PG_INODE_REF, &req->wb_flags)) {
151 kref_get(&req->wb_kref);
152 atomic_long_inc(&NFS_I(inode)->nrequests);
153 }
154 }
155
nfs_cancel_remove_inode(struct nfs_page * req,struct inode * inode)156 static void nfs_cancel_remove_inode(struct nfs_page *req, struct inode *inode)
157 {
158 if (test_and_clear_bit(PG_REMOVE, &req->wb_flags))
159 nfs_page_set_inode_ref(req, inode);
160 }
161
162 /**
163 * nfs_folio_find_head_request - find head request associated with a folio
164 * @folio: pointer to folio
165 *
166 * must be called while holding the inode lock.
167 *
168 * returns matching head request with reference held, or NULL if not found.
169 */
nfs_folio_find_head_request(struct folio * folio)170 static struct nfs_page *nfs_folio_find_head_request(struct folio *folio)
171 {
172 struct address_space *mapping = folio->mapping;
173 struct nfs_page *req;
174
175 if (!folio_test_private(folio))
176 return NULL;
177 spin_lock(&mapping->i_private_lock);
178 req = folio->private;
179 if (req) {
180 WARN_ON_ONCE(req->wb_head != req);
181 kref_get(&req->wb_kref);
182 }
183 spin_unlock(&mapping->i_private_lock);
184 return req;
185 }
186
187 /* Adjust the file length if we're writing beyond the end */
nfs_grow_file(struct folio * folio,unsigned int offset,unsigned int count)188 static void nfs_grow_file(struct folio *folio, unsigned int offset,
189 unsigned int count)
190 {
191 struct inode *inode = folio->mapping->host;
192 loff_t end, i_size;
193 pgoff_t end_index;
194
195 spin_lock(&inode->i_lock);
196 i_size = i_size_read(inode);
197 end_index = ((i_size - 1) >> folio_shift(folio)) << folio_order(folio);
198 if (i_size > 0 && folio->index < end_index)
199 goto out;
200 end = folio_pos(folio) + (loff_t)offset + (loff_t)count;
201 if (i_size >= end)
202 goto out;
203 trace_nfs_size_grow(inode, end);
204 i_size_write(inode, end);
205 NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_SIZE;
206 nfs_inc_stats(inode, NFSIOS_EXTENDWRITE);
207 out:
208 /* Atomically update timestamps if they are delegated to us. */
209 nfs_update_delegated_mtime_locked(inode);
210 spin_unlock(&inode->i_lock);
211 nfs_fscache_invalidate(inode, 0);
212 }
213
214 /* A writeback failed: mark the page as bad, and invalidate the page cache */
nfs_set_pageerror(struct address_space * mapping)215 static void nfs_set_pageerror(struct address_space *mapping)
216 {
217 struct inode *inode = mapping->host;
218
219 nfs_zap_mapping(mapping->host, mapping);
220 /* Force file size revalidation */
221 spin_lock(&inode->i_lock);
222 nfs_set_cache_invalid(inode, NFS_INO_REVAL_FORCED |
223 NFS_INO_INVALID_CHANGE |
224 NFS_INO_INVALID_SIZE);
225 spin_unlock(&inode->i_lock);
226 }
227
nfs_mapping_set_error(struct folio * folio,int error)228 static void nfs_mapping_set_error(struct folio *folio, int error)
229 {
230 struct address_space *mapping = folio->mapping;
231
232 filemap_set_wb_err(mapping, error);
233 if (mapping->host)
234 errseq_set(&mapping->host->i_sb->s_wb_err,
235 error == -ENOSPC ? -ENOSPC : -EIO);
236 nfs_set_pageerror(mapping);
237 }
238
239 /*
240 * nfs_page_covers_folio
241 * @req: struct nfs_page
242 *
243 * Return true if the request covers the whole folio.
244 * Note that the caller should ensure all subrequests have been joined
245 */
nfs_page_group_covers_page(struct nfs_page * req)246 static bool nfs_page_group_covers_page(struct nfs_page *req)
247 {
248 unsigned int len = nfs_folio_length(nfs_page_to_folio(req));
249
250 return req->wb_pgbase == 0 && req->wb_bytes == len;
251 }
252
253 /* We can set the PG_uptodate flag if we see that a write request
254 * covers the full page.
255 */
nfs_mark_uptodate(struct nfs_page * req)256 static void nfs_mark_uptodate(struct nfs_page *req)
257 {
258 struct folio *folio = nfs_page_to_folio(req);
259
260 if (folio_test_uptodate(folio))
261 return;
262 if (!nfs_page_group_covers_page(req))
263 return;
264 folio_mark_uptodate(folio);
265 }
266
wb_priority(struct writeback_control * wbc)267 static int wb_priority(struct writeback_control *wbc)
268 {
269 int ret = 0;
270
271 if (wbc->sync_mode == WB_SYNC_ALL)
272 ret = FLUSH_COND_STABLE;
273 return ret;
274 }
275
276 /*
277 * NFS congestion control
278 */
279
280 int nfs_congestion_kb;
281
282 #define NFS_CONGESTION_ON_THRESH (nfs_congestion_kb >> (PAGE_SHIFT-10))
283 #define NFS_CONGESTION_OFF_THRESH \
284 (NFS_CONGESTION_ON_THRESH - (NFS_CONGESTION_ON_THRESH >> 2))
285
nfs_folio_set_writeback(struct folio * folio)286 static void nfs_folio_set_writeback(struct folio *folio)
287 {
288 struct nfs_server *nfss = NFS_SERVER(folio->mapping->host);
289
290 folio_start_writeback(folio);
291 if (atomic_long_inc_return(&nfss->writeback) > NFS_CONGESTION_ON_THRESH)
292 nfss->write_congested = 1;
293 }
294
nfs_folio_end_writeback(struct folio * folio)295 static void nfs_folio_end_writeback(struct folio *folio)
296 {
297 struct nfs_server *nfss = NFS_SERVER(folio->mapping->host);
298
299 folio_end_writeback_no_dropbehind(folio);
300 if (atomic_long_dec_return(&nfss->writeback) <
301 NFS_CONGESTION_OFF_THRESH) {
302 nfss->write_congested = 0;
303 wake_up_all(&nfss->write_congestion_wait);
304 }
305 }
306
nfs_page_end_writeback(struct nfs_page * req)307 static void nfs_page_end_writeback(struct nfs_page *req)
308 {
309 if (nfs_page_group_sync_on_bit(req, PG_WB_END)) {
310 nfs_unlock_request(req);
311 nfs_folio_end_writeback(nfs_page_to_folio(req));
312 } else
313 nfs_unlock_request(req);
314 }
315
316 /*
317 * nfs_destroy_unlinked_subrequests - destroy recently unlinked subrequests
318 *
319 * @destroy_list - request list (using wb_this_page) terminated by @old_head
320 * @old_head - the old head of the list
321 *
322 * All subrequests must be locked and removed from all lists, so at this point
323 * they are only "active" in this function, and possibly in nfs_wait_on_request
324 * with a reference held by some other context.
325 */
326 static void
nfs_destroy_unlinked_subrequests(struct nfs_page * destroy_list,struct nfs_page * old_head,struct inode * inode)327 nfs_destroy_unlinked_subrequests(struct nfs_page *destroy_list,
328 struct nfs_page *old_head,
329 struct inode *inode)
330 {
331 while (destroy_list) {
332 struct nfs_page *subreq = destroy_list;
333
334 destroy_list = (subreq->wb_this_page == old_head) ?
335 NULL : subreq->wb_this_page;
336
337 /* Note: lock subreq in order to change subreq->wb_head */
338 nfs_page_set_headlock(subreq);
339 WARN_ON_ONCE(old_head != subreq->wb_head);
340
341 /* make sure old group is not used */
342 subreq->wb_this_page = subreq;
343 subreq->wb_head = subreq;
344
345 clear_bit(PG_REMOVE, &subreq->wb_flags);
346
347 /* Note: races with nfs_page_group_destroy() */
348 if (!kref_read(&subreq->wb_kref)) {
349 /* Check if we raced with nfs_page_group_destroy() */
350 if (test_and_clear_bit(PG_TEARDOWN, &subreq->wb_flags)) {
351 nfs_page_clear_headlock(subreq);
352 nfs_free_request(subreq);
353 } else
354 nfs_page_clear_headlock(subreq);
355 continue;
356 }
357 nfs_page_clear_headlock(subreq);
358
359 nfs_release_request(old_head);
360
361 if (test_and_clear_bit(PG_INODE_REF, &subreq->wb_flags)) {
362 nfs_release_request(subreq);
363 atomic_long_dec(&NFS_I(inode)->nrequests);
364 }
365
366 /* subreq is now totally disconnected from page group or any
367 * write / commit lists. last chance to wake any waiters */
368 nfs_unlock_and_release_request(subreq);
369 }
370 }
371
372 /*
373 * nfs_join_page_group - destroy subrequests of the head req
374 * @head: the page used to lookup the "page group" of nfs_page structures
375 * @inode: Inode to which the request belongs.
376 *
377 * This function joins all sub requests to the head request by first
378 * locking all requests in the group, cancelling any pending operations
379 * and finally updating the head request to cover the whole range covered by
380 * the (former) group. All subrequests are removed from any write or commit
381 * lists, unlinked from the group and destroyed.
382 */
nfs_join_page_group(struct nfs_page * head,struct nfs_commit_info * cinfo,struct inode * inode)383 void nfs_join_page_group(struct nfs_page *head, struct nfs_commit_info *cinfo,
384 struct inode *inode)
385 {
386 struct nfs_page *subreq;
387 struct nfs_page *destroy_list = NULL;
388 unsigned int pgbase, off, bytes;
389
390 pgbase = head->wb_pgbase;
391 bytes = head->wb_bytes;
392 off = head->wb_offset;
393 for (subreq = head->wb_this_page; subreq != head;
394 subreq = subreq->wb_this_page) {
395 /* Subrequests should always form a contiguous range */
396 if (pgbase > subreq->wb_pgbase) {
397 off -= pgbase - subreq->wb_pgbase;
398 bytes += pgbase - subreq->wb_pgbase;
399 pgbase = subreq->wb_pgbase;
400 }
401 bytes = max(subreq->wb_pgbase + subreq->wb_bytes
402 - pgbase, bytes);
403 }
404
405 /* Set the head request's range to cover the former page group */
406 head->wb_pgbase = pgbase;
407 head->wb_bytes = bytes;
408 head->wb_offset = off;
409
410 /* Now that all requests are locked, make sure they aren't on any list.
411 * Commit list removal accounting is done after locks are dropped */
412 subreq = head;
413 do {
414 nfs_clear_request_commit(cinfo, subreq);
415 subreq = subreq->wb_this_page;
416 } while (subreq != head);
417
418 /* unlink subrequests from head, destroy them later */
419 if (head->wb_this_page != head) {
420 /* destroy list will be terminated by head */
421 destroy_list = head->wb_this_page;
422 head->wb_this_page = head;
423 }
424
425 nfs_destroy_unlinked_subrequests(destroy_list, head, inode);
426 }
427
428 /**
429 * nfs_wait_on_request - Wait for a request to complete.
430 * @req: request to wait upon.
431 *
432 * Interruptible by fatal signals only.
433 * The user is responsible for holding a count on the request.
434 */
nfs_wait_on_request(struct nfs_page * req)435 static int nfs_wait_on_request(struct nfs_page *req)
436 {
437 if (!test_bit(PG_BUSY, &req->wb_flags))
438 return 0;
439 set_bit(PG_CONTENDED2, &req->wb_flags);
440 smp_mb__after_atomic();
441 return wait_on_bit_io(&req->wb_flags, PG_BUSY,
442 TASK_UNINTERRUPTIBLE);
443 }
444
445 /*
446 * nfs_unroll_locks - unlock all newly locked reqs and wait on @req
447 * @head: head request of page group, must be holding head lock
448 * @req: request that couldn't lock and needs to wait on the req bit lock
449 *
450 * This is a helper function for nfs_lock_and_join_requests
451 * returns 0 on success, < 0 on error.
452 */
453 static void
nfs_unroll_locks(struct nfs_page * head,struct nfs_page * req)454 nfs_unroll_locks(struct nfs_page *head, struct nfs_page *req)
455 {
456 struct nfs_page *tmp;
457
458 /* relinquish all the locks successfully grabbed this run */
459 for (tmp = head->wb_this_page ; tmp != req; tmp = tmp->wb_this_page) {
460 if (!kref_read(&tmp->wb_kref))
461 continue;
462 nfs_unlock_and_release_request(tmp);
463 }
464 }
465
466 /*
467 * nfs_page_group_lock_subreq - try to lock a subrequest
468 * @head: head request of page group
469 * @subreq: request to lock
470 *
471 * This is a helper function for nfs_lock_and_join_requests which
472 * must be called with the head request and page group both locked.
473 * On error, it returns with the page group unlocked.
474 */
475 static int
nfs_page_group_lock_subreq(struct nfs_page * head,struct nfs_page * subreq)476 nfs_page_group_lock_subreq(struct nfs_page *head, struct nfs_page *subreq)
477 {
478 int ret;
479
480 if (!kref_get_unless_zero(&subreq->wb_kref))
481 return 0;
482 while (!nfs_lock_request(subreq)) {
483 nfs_page_group_unlock(head);
484 ret = nfs_wait_on_request(subreq);
485 if (!ret)
486 ret = nfs_page_group_lock(head);
487 if (ret < 0) {
488 nfs_unroll_locks(head, subreq);
489 nfs_release_request(subreq);
490 return ret;
491 }
492 }
493 return 0;
494 }
495
496 /*
497 * nfs_lock_and_join_requests - join all subreqs to the head req
498 * @folio: the folio used to lookup the "page group" of nfs_page structures
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 *
506 * Returns a locked, referenced pointer to the head request - which after
507 * this call is guaranteed to be the only request associated with the page.
508 * Returns NULL if no requests are found for @folio, or a ERR_PTR if an
509 * error was encountered.
510 */
nfs_lock_and_join_requests(struct folio * folio)511 static struct nfs_page *nfs_lock_and_join_requests(struct folio *folio)
512 {
513 struct inode *inode = folio->mapping->host;
514 struct nfs_page *head, *subreq;
515 struct nfs_commit_info cinfo;
516 int ret;
517
518 /*
519 * A reference is taken only on the head request which acts as a
520 * reference to the whole page group - the group will not be destroyed
521 * until the head reference is released.
522 */
523 retry:
524 head = nfs_folio_find_head_request(folio);
525 if (!head)
526 return NULL;
527
528 while (!nfs_lock_request(head)) {
529 ret = nfs_wait_on_request(head);
530 if (ret < 0) {
531 nfs_release_request(head);
532 return ERR_PTR(ret);
533 }
534 }
535
536 ret = nfs_page_group_lock(head);
537 if (ret < 0)
538 goto out_unlock;
539
540 /* Ensure that nobody removed the request before we locked it */
541 if (head != folio->private) {
542 nfs_page_group_unlock(head);
543 nfs_unlock_and_release_request(head);
544 goto retry;
545 }
546
547 nfs_cancel_remove_inode(head, inode);
548
549 /* lock each request in the page group */
550 for (subreq = head->wb_this_page;
551 subreq != head;
552 subreq = subreq->wb_this_page) {
553 ret = nfs_page_group_lock_subreq(head, subreq);
554 if (ret < 0)
555 goto out_unlock;
556 }
557
558 nfs_page_group_unlock(head);
559
560 nfs_init_cinfo_from_inode(&cinfo, inode);
561 nfs_join_page_group(head, &cinfo, inode);
562 return head;
563
564 out_unlock:
565 nfs_unlock_and_release_request(head);
566 return ERR_PTR(ret);
567 }
568
nfs_write_error(struct nfs_page * req,int error)569 static void nfs_write_error(struct nfs_page *req, int error)
570 {
571 trace_nfs_write_error(nfs_page_to_inode(req), req, error);
572 nfs_mapping_set_error(nfs_page_to_folio(req), error);
573 nfs_inode_remove_request(req);
574 nfs_page_end_writeback(req);
575 nfs_release_request(req);
576 }
577
578 /*
579 * Find an associated nfs write request, and prepare to flush it out
580 * May return an error if the user signalled nfs_wait_on_request().
581 */
nfs_do_writepage(struct folio * folio,struct writeback_control * wbc,struct nfs_pageio_descriptor * pgio)582 static int nfs_do_writepage(struct folio *folio, struct writeback_control *wbc,
583 struct nfs_pageio_descriptor *pgio)
584 {
585 struct nfs_page *req;
586 int ret;
587
588 nfs_pageio_cond_complete(pgio, folio->index);
589
590 req = nfs_lock_and_join_requests(folio);
591 if (!req)
592 return 0;
593 if (IS_ERR(req))
594 return PTR_ERR(req);
595
596 trace_nfs_do_writepage(req);
597 nfs_folio_set_writeback(folio);
598 WARN_ON_ONCE(test_bit(PG_CLEAN, &req->wb_flags));
599
600 /* If there is a fatal error that covers this write, just exit */
601 ret = pgio->pg_error;
602 if (nfs_error_is_fatal_on_server(ret))
603 goto out_launder;
604
605 if (!nfs_pageio_add_request(pgio, req)) {
606 ret = pgio->pg_error;
607 /*
608 * Remove the problematic req upon fatal errors on the server
609 */
610 if (nfs_error_is_fatal_on_server(ret))
611 goto out_launder;
612 folio_redirty_for_writepage(wbc, folio);
613 nfs_redirty_request(req);
614 pgio->pg_error = 0;
615 return ret;
616 }
617
618 nfs_add_stats(folio->mapping->host, NFSIOS_WRITEPAGES, 1);
619 return 0;
620
621 out_launder:
622 nfs_write_error(req, ret);
623 return 0;
624 }
625
626 /*
627 * Write an mmapped page to the server.
628 */
nfs_writepage_locked(struct folio * folio,struct writeback_control * wbc)629 static int nfs_writepage_locked(struct folio *folio,
630 struct writeback_control *wbc)
631 {
632 struct nfs_pageio_descriptor pgio;
633 struct inode *inode = folio->mapping->host;
634 int err;
635
636 nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE);
637 nfs_pageio_init_write(&pgio, inode, 0, false,
638 &nfs_async_write_completion_ops);
639 err = nfs_do_writepage(folio, wbc, &pgio);
640 pgio.pg_error = 0;
641 nfs_pageio_complete(&pgio);
642 return err;
643 }
644
nfs_io_completion_commit(void * inode)645 static void nfs_io_completion_commit(void *inode)
646 {
647 nfs_commit_inode(inode, 0);
648 }
649
nfs_writepages(struct address_space * mapping,struct writeback_control * wbc)650 int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
651 {
652 struct inode *inode = mapping->host;
653 struct nfs_pageio_descriptor pgio;
654 struct nfs_io_completion *ioc = NULL;
655 unsigned int mntflags = NFS_SERVER(inode)->flags;
656 struct nfs_server *nfss = NFS_SERVER(inode);
657 int priority = 0;
658 int err;
659
660 trace_nfs_writepages(inode, wbc->range_start, wbc->range_end - wbc->range_start);
661
662 /* Wait with writeback until write congestion eases */
663 if (wbc->sync_mode == WB_SYNC_NONE && nfss->write_congested) {
664 err = wait_event_killable(nfss->write_congestion_wait,
665 nfss->write_congested == 0);
666 if (err)
667 goto out_err;
668 }
669
670 nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES);
671
672 if (!(mntflags & NFS_MOUNT_WRITE_EAGER) || wbc->for_kupdate ||
673 wbc->for_background || wbc->for_sync) {
674 ioc = nfs_io_completion_alloc(GFP_KERNEL);
675 if (ioc)
676 nfs_io_completion_init(ioc, nfs_io_completion_commit,
677 inode);
678 priority = wb_priority(wbc);
679 }
680
681 do {
682 struct folio *folio = NULL;
683
684 nfs_pageio_init_write(&pgio, inode, priority, false,
685 &nfs_async_write_completion_ops);
686 pgio.pg_io_completion = ioc;
687 while ((folio = writeback_iter(mapping, wbc, folio, &err))) {
688 err = nfs_do_writepage(folio, wbc, &pgio);
689 folio_unlock(folio);
690 }
691 pgio.pg_error = 0;
692 nfs_pageio_complete(&pgio);
693 if (err == -EAGAIN && mntflags & NFS_MOUNT_SOFTERR)
694 break;
695 } while (err < 0 && !nfs_error_is_fatal(err));
696 nfs_io_completion_put(ioc);
697
698 if (err > 0)
699 err = 0;
700 out_err:
701 trace_nfs_writepages_done(inode, wbc->range_start, wbc->range_end - wbc->range_start, err);
702 return err;
703 }
704
705 /*
706 * Insert a write request into an inode
707 */
nfs_inode_add_request(struct nfs_page * req)708 static void nfs_inode_add_request(struct nfs_page *req)
709 {
710 struct folio *folio = nfs_page_to_folio(req);
711 struct address_space *mapping = folio->mapping;
712 struct nfs_inode *nfsi = NFS_I(mapping->host);
713
714 WARN_ON_ONCE(req->wb_this_page != req);
715
716 /* Lock the request! */
717 nfs_lock_request(req);
718 spin_lock(&mapping->i_private_lock);
719 set_bit(PG_MAPPED, &req->wb_flags);
720 folio_set_private(folio);
721 folio->private = req;
722 spin_unlock(&mapping->i_private_lock);
723 atomic_long_inc(&nfsi->nrequests);
724 /* this a head request for a page group - mark it as having an
725 * extra reference so sub groups can follow suit.
726 * This flag also informs pgio layer when to bump nrequests when
727 * adding subrequests. */
728 WARN_ON(test_and_set_bit(PG_INODE_REF, &req->wb_flags));
729 kref_get(&req->wb_kref);
730 }
731
732 /*
733 * Remove a write request from an inode
734 */
nfs_inode_remove_request(struct nfs_page * req)735 static void nfs_inode_remove_request(struct nfs_page *req)
736 {
737 struct nfs_inode *nfsi = NFS_I(nfs_page_to_inode(req));
738
739 nfs_page_group_lock(req);
740 if (nfs_page_group_sync_on_bit_locked(req, PG_REMOVE)) {
741 struct folio *folio = nfs_page_to_folio(req->wb_head);
742 struct address_space *mapping = folio->mapping;
743
744 spin_lock(&mapping->i_private_lock);
745 if (likely(folio)) {
746 folio->private = NULL;
747 folio_clear_private(folio);
748 clear_bit(PG_MAPPED, &req->wb_head->wb_flags);
749 }
750 spin_unlock(&mapping->i_private_lock);
751
752 folio_end_dropbehind(folio);
753 }
754 nfs_page_group_unlock(req);
755
756 if (test_and_clear_bit(PG_INODE_REF, &req->wb_flags)) {
757 atomic_long_dec(&nfsi->nrequests);
758 nfs_release_request(req);
759 }
760 }
761
nfs_mark_request_dirty(struct nfs_page * req)762 static void nfs_mark_request_dirty(struct nfs_page *req)
763 {
764 struct folio *folio = nfs_page_to_folio(req);
765 if (folio)
766 filemap_dirty_folio(folio_mapping(folio), folio);
767 }
768
769 /**
770 * nfs_request_add_commit_list_locked - add request to a commit list
771 * @req: pointer to a struct nfs_page
772 * @dst: commit list head
773 * @cinfo: holds list lock and accounting info
774 *
775 * This sets the PG_CLEAN bit, updates the cinfo count of
776 * number of outstanding requests requiring a commit as well as
777 * the MM page stats.
778 *
779 * The caller must hold NFS_I(cinfo->inode)->commit_mutex, and the
780 * nfs_page lock.
781 */
782 void
nfs_request_add_commit_list_locked(struct nfs_page * req,struct list_head * dst,struct nfs_commit_info * cinfo)783 nfs_request_add_commit_list_locked(struct nfs_page *req, struct list_head *dst,
784 struct nfs_commit_info *cinfo)
785 {
786 set_bit(PG_CLEAN, &req->wb_flags);
787 nfs_list_add_request(req, dst);
788 atomic_long_inc(&cinfo->mds->ncommit);
789 }
790 EXPORT_SYMBOL_GPL(nfs_request_add_commit_list_locked);
791
792 /**
793 * nfs_request_add_commit_list - add request to a commit list
794 * @req: pointer to a struct nfs_page
795 * @cinfo: holds list lock and accounting info
796 *
797 * This sets the PG_CLEAN bit, updates the cinfo count of
798 * number of outstanding requests requiring a commit as well as
799 * the MM page stats.
800 *
801 * The caller must _not_ hold the cinfo->lock, but must be
802 * holding the nfs_page lock.
803 */
804 void
nfs_request_add_commit_list(struct nfs_page * req,struct nfs_commit_info * cinfo)805 nfs_request_add_commit_list(struct nfs_page *req, struct nfs_commit_info *cinfo)
806 {
807 mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
808 nfs_request_add_commit_list_locked(req, &cinfo->mds->list, cinfo);
809 mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
810 nfs_folio_mark_unstable(nfs_page_to_folio(req), cinfo);
811 }
812 EXPORT_SYMBOL_GPL(nfs_request_add_commit_list);
813
814 /**
815 * nfs_request_remove_commit_list - Remove request from a commit list
816 * @req: pointer to a nfs_page
817 * @cinfo: holds list lock and accounting info
818 *
819 * This clears the PG_CLEAN bit, and updates the cinfo's count of
820 * number of outstanding requests requiring a commit
821 * It does not update the MM page stats.
822 *
823 * The caller _must_ hold the cinfo->lock and the nfs_page lock.
824 */
825 void
nfs_request_remove_commit_list(struct nfs_page * req,struct nfs_commit_info * cinfo)826 nfs_request_remove_commit_list(struct nfs_page *req,
827 struct nfs_commit_info *cinfo)
828 {
829 if (!test_and_clear_bit(PG_CLEAN, &(req)->wb_flags))
830 return;
831 nfs_list_remove_request(req);
832 atomic_long_dec(&cinfo->mds->ncommit);
833 }
834 EXPORT_SYMBOL_GPL(nfs_request_remove_commit_list);
835
nfs_init_cinfo_from_inode(struct nfs_commit_info * cinfo,struct inode * inode)836 static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo,
837 struct inode *inode)
838 {
839 cinfo->inode = inode;
840 cinfo->mds = &NFS_I(inode)->commit_info;
841 cinfo->ds = pnfs_get_ds_info(inode);
842 cinfo->dreq = NULL;
843 cinfo->completion_ops = &nfs_commit_completion_ops;
844 }
845
nfs_init_cinfo(struct nfs_commit_info * cinfo,struct inode * inode,struct nfs_direct_req * dreq)846 void nfs_init_cinfo(struct nfs_commit_info *cinfo,
847 struct inode *inode,
848 struct nfs_direct_req *dreq)
849 {
850 if (dreq)
851 nfs_init_cinfo_from_dreq(cinfo, dreq);
852 else
853 nfs_init_cinfo_from_inode(cinfo, inode);
854 }
855 EXPORT_SYMBOL_GPL(nfs_init_cinfo);
856
857 /*
858 * Add a request to the inode's commit list.
859 */
860 void
nfs_mark_request_commit(struct nfs_page * req,struct pnfs_layout_segment * lseg,struct nfs_commit_info * cinfo,u32 ds_commit_idx)861 nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg,
862 struct nfs_commit_info *cinfo, u32 ds_commit_idx)
863 {
864 if (pnfs_mark_request_commit(req, lseg, cinfo, ds_commit_idx))
865 return;
866 nfs_request_add_commit_list(req, cinfo);
867 }
868
nfs_folio_clear_commit(struct folio * folio)869 static void nfs_folio_clear_commit(struct folio *folio)
870 {
871 if (folio) {
872 long nr = folio_nr_pages(folio);
873
874 node_stat_mod_folio(folio, NR_WRITEBACK, -nr);
875 wb_stat_mod(&inode_to_bdi(folio->mapping->host)->wb,
876 WB_WRITEBACK, -nr);
877 }
878 }
879
880 /* Called holding the request lock on @req */
nfs_clear_request_commit(struct nfs_commit_info * cinfo,struct nfs_page * req)881 static void nfs_clear_request_commit(struct nfs_commit_info *cinfo,
882 struct nfs_page *req)
883 {
884 if (test_bit(PG_CLEAN, &req->wb_flags)) {
885 struct nfs_open_context *ctx = nfs_req_openctx(req);
886 struct inode *inode = d_inode(ctx->dentry);
887
888 mutex_lock(&NFS_I(inode)->commit_mutex);
889 if (!pnfs_clear_request_commit(req, cinfo)) {
890 nfs_request_remove_commit_list(req, cinfo);
891 }
892 mutex_unlock(&NFS_I(inode)->commit_mutex);
893 nfs_folio_clear_commit(nfs_page_to_folio(req));
894 }
895 }
896
nfs_write_need_commit(struct nfs_pgio_header * hdr)897 int nfs_write_need_commit(struct nfs_pgio_header *hdr)
898 {
899 if (hdr->verf.committed == NFS_DATA_SYNC)
900 return hdr->lseg == NULL;
901 return hdr->verf.committed != NFS_FILE_SYNC;
902 }
903
nfs_async_write_init(struct nfs_pgio_header * hdr)904 static void nfs_async_write_init(struct nfs_pgio_header *hdr)
905 {
906 nfs_io_completion_get(hdr->io_completion);
907 }
908
nfs_write_completion(struct nfs_pgio_header * hdr)909 static void nfs_write_completion(struct nfs_pgio_header *hdr)
910 {
911 struct nfs_commit_info cinfo;
912 unsigned long bytes = 0;
913
914 if (test_bit(NFS_IOHDR_REDO, &hdr->flags))
915 goto out;
916 nfs_init_cinfo_from_inode(&cinfo, hdr->inode);
917 while (!list_empty(&hdr->pages)) {
918 struct nfs_page *req = nfs_list_entry(hdr->pages.next);
919
920 bytes += req->wb_bytes;
921 nfs_list_remove_request(req);
922 if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) &&
923 (hdr->good_bytes < bytes)) {
924 trace_nfs_comp_error(hdr->inode, req, hdr->error);
925 nfs_mapping_set_error(nfs_page_to_folio(req),
926 hdr->error);
927 goto remove_req;
928 }
929 if (nfs_write_need_commit(hdr)) {
930 /* Reset wb_nio, since the write was successful. */
931 req->wb_nio = 0;
932 memcpy(&req->wb_verf, &hdr->verf.verifier, sizeof(req->wb_verf));
933 nfs_mark_request_commit(req, hdr->lseg, &cinfo,
934 hdr->ds_commit_idx);
935 goto next;
936 }
937 remove_req:
938 nfs_inode_remove_request(req);
939 next:
940 nfs_page_end_writeback(req);
941 nfs_release_request(req);
942 }
943 out:
944 nfs_io_completion_put(hdr->io_completion);
945 hdr->release(hdr);
946 }
947
948 unsigned long
nfs_reqs_to_commit(struct nfs_commit_info * cinfo)949 nfs_reqs_to_commit(struct nfs_commit_info *cinfo)
950 {
951 return atomic_long_read(&cinfo->mds->ncommit);
952 }
953
954 /* NFS_I(cinfo->inode)->commit_mutex held by caller */
955 int
nfs_scan_commit_list(struct list_head * src,struct list_head * dst,struct nfs_commit_info * cinfo,int max)956 nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
957 struct nfs_commit_info *cinfo, int max)
958 {
959 struct nfs_page *req, *tmp;
960 int ret = 0;
961
962 list_for_each_entry_safe(req, tmp, src, wb_list) {
963 kref_get(&req->wb_kref);
964 if (!nfs_lock_request(req)) {
965 nfs_release_request(req);
966 continue;
967 }
968 nfs_request_remove_commit_list(req, cinfo);
969 clear_bit(PG_COMMIT_TO_DS, &req->wb_flags);
970 nfs_list_add_request(req, dst);
971 ret++;
972 if ((ret == max) && !cinfo->dreq)
973 break;
974 cond_resched();
975 }
976 return ret;
977 }
978 EXPORT_SYMBOL_GPL(nfs_scan_commit_list);
979
980 /*
981 * nfs_scan_commit - Scan an inode for commit requests
982 * @inode: NFS inode to scan
983 * @dst: mds destination list
984 * @cinfo: mds and ds lists of reqs ready to commit
985 *
986 * Moves requests from the inode's 'commit' request list.
987 * The requests are *not* checked to ensure that they form a contiguous set.
988 */
989 int
nfs_scan_commit(struct inode * inode,struct list_head * dst,struct nfs_commit_info * cinfo)990 nfs_scan_commit(struct inode *inode, struct list_head *dst,
991 struct nfs_commit_info *cinfo)
992 {
993 int ret = 0;
994
995 if (!atomic_long_read(&cinfo->mds->ncommit))
996 return 0;
997 mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
998 if (atomic_long_read(&cinfo->mds->ncommit) > 0) {
999 const int max = INT_MAX;
1000
1001 ret = nfs_scan_commit_list(&cinfo->mds->list, dst,
1002 cinfo, max);
1003 ret += pnfs_scan_commit_lists(inode, cinfo, max - ret);
1004 }
1005 mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
1006 return ret;
1007 }
1008
1009 /*
1010 * Search for an existing write request, and attempt to update
1011 * it to reflect a new dirty region on a given page.
1012 *
1013 * If the attempt fails, then the existing request is flushed out
1014 * to disk.
1015 */
nfs_try_to_update_request(struct folio * folio,unsigned int offset,unsigned int bytes)1016 static struct nfs_page *nfs_try_to_update_request(struct folio *folio,
1017 unsigned int offset,
1018 unsigned int bytes)
1019 {
1020 struct nfs_page *req;
1021 unsigned int rqend;
1022 unsigned int end;
1023 int error;
1024
1025 trace_nfs_try_to_update_request(folio_inode(folio), offset, bytes);
1026 end = offset + bytes;
1027
1028 req = nfs_lock_and_join_requests(folio);
1029 if (IS_ERR_OR_NULL(req))
1030 goto out;
1031
1032 rqend = req->wb_offset + req->wb_bytes;
1033 /*
1034 * Tell the caller to flush out the request if
1035 * the offsets are non-contiguous.
1036 * Note: nfs_flush_incompatible() will already
1037 * have flushed out requests having wrong owners.
1038 */
1039 if (offset > rqend || end < req->wb_offset)
1040 goto out_flushme;
1041
1042 /* Okay, the request matches. Update the region */
1043 if (offset < req->wb_offset) {
1044 req->wb_offset = offset;
1045 req->wb_pgbase = offset;
1046 }
1047 if (end > rqend)
1048 req->wb_bytes = end - req->wb_offset;
1049 else
1050 req->wb_bytes = rqend - req->wb_offset;
1051 req->wb_nio = 0;
1052 out:
1053 trace_nfs_try_to_update_request_done(folio_inode(folio), offset, bytes,
1054 PTR_ERR_OR_ZERO(req));
1055 return req;
1056 out_flushme:
1057 /*
1058 * Note: we mark the request dirty here because
1059 * nfs_lock_and_join_requests() cannot preserve
1060 * commit flags, so we have to replay the write.
1061 */
1062 nfs_mark_request_dirty(req);
1063 nfs_unlock_and_release_request(req);
1064 error = nfs_wb_folio(folio->mapping->host, folio);
1065 trace_nfs_try_to_update_request_done(folio_inode(folio), offset, bytes, error);
1066 return (error < 0) ? ERR_PTR(error) : NULL;
1067 }
1068
1069 /*
1070 * Try to update an existing write request, or create one if there is none.
1071 *
1072 * Note: Should always be called with the Page Lock held to prevent races
1073 * if we have to add a new request. Also assumes that the caller has
1074 * already called nfs_flush_incompatible() if necessary.
1075 */
nfs_setup_write_request(struct nfs_open_context * ctx,struct folio * folio,unsigned int offset,unsigned int bytes)1076 static struct nfs_page *nfs_setup_write_request(struct nfs_open_context *ctx,
1077 struct folio *folio,
1078 unsigned int offset,
1079 unsigned int bytes)
1080 {
1081 struct nfs_page *req;
1082
1083 req = nfs_try_to_update_request(folio, offset, bytes);
1084 if (req != NULL)
1085 goto out;
1086 req = nfs_page_create_from_folio(ctx, folio, offset, bytes);
1087 if (IS_ERR(req))
1088 goto out;
1089 nfs_inode_add_request(req);
1090 out:
1091 return req;
1092 }
1093
nfs_writepage_setup(struct nfs_open_context * ctx,struct folio * folio,unsigned int offset,unsigned int count)1094 static int nfs_writepage_setup(struct nfs_open_context *ctx,
1095 struct folio *folio, unsigned int offset,
1096 unsigned int count)
1097 {
1098 struct nfs_page *req;
1099
1100 req = nfs_setup_write_request(ctx, folio, offset, count);
1101 if (IS_ERR(req))
1102 return PTR_ERR(req);
1103 trace_nfs_writepage_setup(req);
1104 /* Update file length */
1105 nfs_grow_file(folio, offset, count);
1106 nfs_mark_uptodate(req);
1107 nfs_mark_request_dirty(req);
1108 nfs_unlock_and_release_request(req);
1109 return 0;
1110 }
1111
nfs_flush_incompatible(struct file * file,struct folio * folio)1112 int nfs_flush_incompatible(struct file *file, struct folio *folio)
1113 {
1114 struct nfs_open_context *ctx = nfs_file_open_context(file);
1115 struct nfs_lock_context *l_ctx;
1116 struct file_lock_context *flctx = locks_inode_context(file_inode(file));
1117 struct nfs_page *req;
1118 int do_flush, status;
1119 /*
1120 * Look for a request corresponding to this page. If there
1121 * is one, and it belongs to another file, we flush it out
1122 * before we try to copy anything into the page. Do this
1123 * due to the lack of an ACCESS-type call in NFSv2.
1124 * Also do the same if we find a request from an existing
1125 * dropped page.
1126 */
1127 do {
1128 req = nfs_folio_find_head_request(folio);
1129 if (req == NULL)
1130 return 0;
1131 l_ctx = req->wb_lock_context;
1132 do_flush = nfs_page_to_folio(req) != folio ||
1133 !nfs_match_open_context(nfs_req_openctx(req), ctx);
1134 if (l_ctx && flctx &&
1135 !(list_empty_careful(&flctx->flc_posix) &&
1136 list_empty_careful(&flctx->flc_flock))) {
1137 do_flush |= l_ctx->lockowner != current->files;
1138 }
1139 nfs_release_request(req);
1140 if (!do_flush)
1141 return 0;
1142 status = nfs_wb_folio(folio->mapping->host, folio);
1143 } while (status == 0);
1144 return status;
1145 }
1146
1147 /*
1148 * Avoid buffered writes when a open context credential's key would
1149 * expire soon.
1150 *
1151 * Returns -EACCES if the key will expire within RPC_KEY_EXPIRE_FAIL.
1152 *
1153 * Return 0 and set a credential flag which triggers the inode to flush
1154 * and performs NFS_FILE_SYNC writes if the key will expired within
1155 * RPC_KEY_EXPIRE_TIMEO.
1156 */
1157 int
nfs_key_timeout_notify(struct file * filp,struct inode * inode)1158 nfs_key_timeout_notify(struct file *filp, struct inode *inode)
1159 {
1160 struct nfs_open_context *ctx = nfs_file_open_context(filp);
1161
1162 if (nfs_ctx_key_to_expire(ctx, inode) &&
1163 !rcu_access_pointer(ctx->ll_cred))
1164 /* Already expired! */
1165 return -EACCES;
1166 return 0;
1167 }
1168
1169 /*
1170 * Test if the open context credential key is marked to expire soon.
1171 */
nfs_ctx_key_to_expire(struct nfs_open_context * ctx,struct inode * inode)1172 bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx, struct inode *inode)
1173 {
1174 struct rpc_auth *auth = NFS_SERVER(inode)->client->cl_auth;
1175 struct rpc_cred *cred, *new, *old = NULL;
1176 struct auth_cred acred = {
1177 .cred = ctx->cred,
1178 };
1179 bool ret = false;
1180
1181 rcu_read_lock();
1182 cred = rcu_dereference(ctx->ll_cred);
1183 if (cred && !(cred->cr_ops->crkey_timeout &&
1184 cred->cr_ops->crkey_timeout(cred)))
1185 goto out;
1186 rcu_read_unlock();
1187
1188 new = auth->au_ops->lookup_cred(auth, &acred, 0);
1189 if (new == cred) {
1190 put_rpccred(new);
1191 return true;
1192 }
1193 if (IS_ERR_OR_NULL(new)) {
1194 new = NULL;
1195 ret = true;
1196 } else if (new->cr_ops->crkey_timeout &&
1197 new->cr_ops->crkey_timeout(new))
1198 ret = true;
1199
1200 rcu_read_lock();
1201 old = rcu_dereference_protected(xchg(&ctx->ll_cred,
1202 RCU_INITIALIZER(new)), 1);
1203 out:
1204 rcu_read_unlock();
1205 put_rpccred(old);
1206 return ret;
1207 }
1208
1209 /*
1210 * If the page cache is marked as unsafe or invalid, then we can't rely on
1211 * the PageUptodate() flag. In this case, we will need to turn off
1212 * write optimisations that depend on the page contents being correct.
1213 */
nfs_folio_write_uptodate(struct folio * folio,unsigned int pagelen)1214 static bool nfs_folio_write_uptodate(struct folio *folio, unsigned int pagelen)
1215 {
1216 struct inode *inode = folio->mapping->host;
1217 struct nfs_inode *nfsi = NFS_I(inode);
1218
1219 if (nfs_have_delegated_attributes(inode))
1220 goto out;
1221 if (nfsi->cache_validity &
1222 (NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_SIZE))
1223 return false;
1224 smp_rmb();
1225 if (test_bit(NFS_INO_INVALIDATING, &nfsi->flags) && pagelen != 0)
1226 return false;
1227 out:
1228 if (nfsi->cache_validity & NFS_INO_INVALID_DATA && pagelen != 0)
1229 return false;
1230 return folio_test_uptodate(folio) != 0;
1231 }
1232
1233 static bool
is_whole_file_wrlock(struct file_lock * fl)1234 is_whole_file_wrlock(struct file_lock *fl)
1235 {
1236 return fl->fl_start == 0 && fl->fl_end == OFFSET_MAX &&
1237 lock_is_write(fl);
1238 }
1239
1240 /* If we know the page is up to date, and we're not using byte range locks (or
1241 * if we have the whole file locked for writing), it may be more efficient to
1242 * extend the write to cover the entire page in order to avoid fragmentation
1243 * inefficiencies.
1244 *
1245 * If the file is opened for synchronous writes then we can just skip the rest
1246 * of the checks.
1247 */
nfs_can_extend_write(struct file * file,struct folio * folio,unsigned int pagelen)1248 static int nfs_can_extend_write(struct file *file, struct folio *folio,
1249 unsigned int pagelen)
1250 {
1251 struct inode *inode = file_inode(file);
1252 struct file_lock_context *flctx = locks_inode_context(inode);
1253 struct file_lock *fl;
1254 int ret;
1255 unsigned int mntflags = NFS_SERVER(inode)->flags;
1256
1257 if (mntflags & NFS_MOUNT_NO_ALIGNWRITE)
1258 return 0;
1259 if (file->f_flags & O_DSYNC)
1260 return 0;
1261 if (!nfs_folio_write_uptodate(folio, pagelen))
1262 return 0;
1263 if (nfs_have_write_delegation(inode))
1264 return 1;
1265 if (!flctx || (list_empty_careful(&flctx->flc_flock) &&
1266 list_empty_careful(&flctx->flc_posix)))
1267 return 1;
1268
1269 /* Check to see if there are whole file write locks */
1270 ret = 0;
1271 spin_lock(&flctx->flc_lock);
1272 if (!list_empty(&flctx->flc_posix)) {
1273 fl = list_first_entry(&flctx->flc_posix, struct file_lock,
1274 c.flc_list);
1275 if (is_whole_file_wrlock(fl))
1276 ret = 1;
1277 } else if (!list_empty(&flctx->flc_flock)) {
1278 fl = list_first_entry(&flctx->flc_flock, struct file_lock,
1279 c.flc_list);
1280 if (lock_is_write(fl))
1281 ret = 1;
1282 }
1283 spin_unlock(&flctx->flc_lock);
1284 return ret;
1285 }
1286
1287 /*
1288 * Update and possibly write a cached page of an NFS file.
1289 *
1290 * XXX: Keep an eye on generic_file_read to make sure it doesn't do bad
1291 * things with a page scheduled for an RPC call (e.g. invalidate it).
1292 */
nfs_update_folio(struct file * file,struct folio * folio,unsigned int offset,unsigned int count)1293 int nfs_update_folio(struct file *file, struct folio *folio,
1294 unsigned int offset, unsigned int count)
1295 {
1296 struct nfs_open_context *ctx = nfs_file_open_context(file);
1297 struct address_space *mapping = folio->mapping;
1298 struct inode *inode = mapping->host;
1299 unsigned int pagelen = nfs_folio_length(folio);
1300 int status = 0;
1301
1302 nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE);
1303
1304 trace_nfs_update_folio(inode, offset, count);
1305
1306 dprintk("NFS: nfs_update_folio(%pD2 %d@%lld)\n", file, count,
1307 (long long)(folio_pos(folio) + offset));
1308
1309 if (!count)
1310 goto out;
1311
1312 if (nfs_can_extend_write(file, folio, pagelen)) {
1313 unsigned int end = count + offset;
1314
1315 offset = round_down(offset, PAGE_SIZE);
1316 if (end < pagelen)
1317 end = min(round_up(end, PAGE_SIZE), pagelen);
1318 count = end - offset;
1319 }
1320
1321 status = nfs_writepage_setup(ctx, folio, offset, count);
1322 if (status < 0)
1323 nfs_set_pageerror(mapping);
1324 out:
1325 trace_nfs_update_folio_done(inode, offset, count, status);
1326 dprintk("NFS: nfs_update_folio returns %d (isize %lld)\n",
1327 status, (long long)i_size_read(inode));
1328 return status;
1329 }
1330
flush_task_priority(int how)1331 static int flush_task_priority(int how)
1332 {
1333 switch (how & (FLUSH_HIGHPRI|FLUSH_LOWPRI)) {
1334 case FLUSH_HIGHPRI:
1335 return RPC_PRIORITY_HIGH;
1336 case FLUSH_LOWPRI:
1337 return RPC_PRIORITY_LOW;
1338 }
1339 return RPC_PRIORITY_NORMAL;
1340 }
1341
nfs_initiate_write(struct nfs_pgio_header * hdr,struct rpc_message * msg,const struct nfs_rpc_ops * rpc_ops,struct rpc_task_setup * task_setup_data,int how)1342 static void nfs_initiate_write(struct nfs_pgio_header *hdr,
1343 struct rpc_message *msg,
1344 const struct nfs_rpc_ops *rpc_ops,
1345 struct rpc_task_setup *task_setup_data, int how)
1346 {
1347 int priority = flush_task_priority(how);
1348
1349 if (IS_SWAPFILE(hdr->inode))
1350 task_setup_data->flags |= RPC_TASK_SWAPPER;
1351 task_setup_data->priority = priority;
1352 rpc_ops->write_setup(hdr, msg, &task_setup_data->rpc_client);
1353 trace_nfs_initiate_write(hdr);
1354 }
1355
1356 /* If a nfs_flush_* function fails, it should remove reqs from @head and
1357 * call this on each, which will prepare them to be retried on next
1358 * writeback using standard nfs.
1359 */
nfs_redirty_request(struct nfs_page * req)1360 static void nfs_redirty_request(struct nfs_page *req)
1361 {
1362 struct nfs_inode *nfsi = NFS_I(nfs_page_to_inode(req));
1363
1364 /* Bump the transmission count */
1365 req->wb_nio++;
1366 nfs_mark_request_dirty(req);
1367 atomic_long_inc(&nfsi->redirtied_pages);
1368 nfs_page_end_writeback(req);
1369 nfs_release_request(req);
1370 }
1371
nfs_async_write_error(struct list_head * head,int error)1372 static void nfs_async_write_error(struct list_head *head, int error)
1373 {
1374 struct nfs_page *req;
1375
1376 while (!list_empty(head)) {
1377 req = nfs_list_entry(head->next);
1378 nfs_list_remove_request(req);
1379 if (nfs_error_is_fatal_on_server(error))
1380 nfs_write_error(req, error);
1381 else
1382 nfs_redirty_request(req);
1383 }
1384 }
1385
nfs_async_write_reschedule_io(struct nfs_pgio_header * hdr)1386 static void nfs_async_write_reschedule_io(struct nfs_pgio_header *hdr)
1387 {
1388 nfs_async_write_error(&hdr->pages, 0);
1389 }
1390
1391 static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops = {
1392 .init_hdr = nfs_async_write_init,
1393 .error_cleanup = nfs_async_write_error,
1394 .completion = nfs_write_completion,
1395 .reschedule_io = nfs_async_write_reschedule_io,
1396 };
1397
nfs_pageio_init_write(struct nfs_pageio_descriptor * pgio,struct inode * inode,int ioflags,bool force_mds,const struct nfs_pgio_completion_ops * compl_ops)1398 void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
1399 struct inode *inode, int ioflags, bool force_mds,
1400 const struct nfs_pgio_completion_ops *compl_ops)
1401 {
1402 struct nfs_server *server = NFS_SERVER(inode);
1403 const struct nfs_pageio_ops *pg_ops = &nfs_pgio_rw_ops;
1404
1405 #ifdef CONFIG_NFS_V4_1
1406 if (server->pnfs_curr_ld && !force_mds)
1407 pg_ops = server->pnfs_curr_ld->pg_write_ops;
1408 #endif
1409 nfs_pageio_init(pgio, inode, pg_ops, compl_ops, &nfs_rw_write_ops,
1410 server->wsize, ioflags);
1411 }
1412 EXPORT_SYMBOL_GPL(nfs_pageio_init_write);
1413
nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor * pgio)1414 void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio)
1415 {
1416 struct nfs_pgio_mirror *mirror;
1417
1418 if (pgio->pg_ops && pgio->pg_ops->pg_cleanup)
1419 pgio->pg_ops->pg_cleanup(pgio);
1420
1421 pgio->pg_ops = &nfs_pgio_rw_ops;
1422
1423 nfs_pageio_stop_mirroring(pgio);
1424
1425 mirror = &pgio->pg_mirrors[0];
1426 mirror->pg_bsize = NFS_SERVER(pgio->pg_inode)->wsize;
1427 }
1428 EXPORT_SYMBOL_GPL(nfs_pageio_reset_write_mds);
1429
1430
nfs_commit_prepare(struct rpc_task * task,void * calldata)1431 void nfs_commit_prepare(struct rpc_task *task, void *calldata)
1432 {
1433 struct nfs_commit_data *data = calldata;
1434
1435 NFS_PROTO(data->inode)->commit_rpc_prepare(task, data);
1436 }
1437
nfs_writeback_check_extend(struct nfs_pgio_header * hdr,struct nfs_fattr * fattr)1438 static void nfs_writeback_check_extend(struct nfs_pgio_header *hdr,
1439 struct nfs_fattr *fattr)
1440 {
1441 struct nfs_pgio_args *argp = &hdr->args;
1442 struct nfs_pgio_res *resp = &hdr->res;
1443 u64 size = argp->offset + resp->count;
1444
1445 if (!(fattr->valid & NFS_ATTR_FATTR_SIZE))
1446 fattr->size = size;
1447 if (nfs_size_to_loff_t(fattr->size) < i_size_read(hdr->inode)) {
1448 fattr->valid &= ~NFS_ATTR_FATTR_SIZE;
1449 return;
1450 }
1451 if (size != fattr->size)
1452 return;
1453 /* Set attribute barrier */
1454 nfs_fattr_set_barrier(fattr);
1455 /* ...and update size */
1456 fattr->valid |= NFS_ATTR_FATTR_SIZE;
1457 }
1458
nfs_writeback_update_inode(struct nfs_pgio_header * hdr)1459 void nfs_writeback_update_inode(struct nfs_pgio_header *hdr)
1460 {
1461 struct nfs_fattr *fattr = &hdr->fattr;
1462 struct inode *inode = hdr->inode;
1463
1464 if (nfs_have_delegated_mtime(inode)) {
1465 spin_lock(&inode->i_lock);
1466 nfs_set_cache_invalid(inode, NFS_INO_INVALID_BLOCKS);
1467 spin_unlock(&inode->i_lock);
1468 return;
1469 }
1470
1471 spin_lock(&inode->i_lock);
1472 nfs_writeback_check_extend(hdr, fattr);
1473 nfs_post_op_update_inode_force_wcc_locked(inode, fattr);
1474 spin_unlock(&inode->i_lock);
1475 }
1476 EXPORT_SYMBOL_GPL(nfs_writeback_update_inode);
1477
1478 /*
1479 * This function is called when the WRITE call is complete.
1480 */
nfs_writeback_done(struct rpc_task * task,struct nfs_pgio_header * hdr,struct inode * inode)1481 static int nfs_writeback_done(struct rpc_task *task,
1482 struct nfs_pgio_header *hdr,
1483 struct inode *inode)
1484 {
1485 int status;
1486
1487 /*
1488 * ->write_done will attempt to use post-op attributes to detect
1489 * conflicting writes by other clients. A strict interpretation
1490 * of close-to-open would allow us to continue caching even if
1491 * another writer had changed the file, but some applications
1492 * depend on tighter cache coherency when writing.
1493 */
1494 status = NFS_PROTO(inode)->write_done(task, hdr);
1495 if (status != 0)
1496 return status;
1497
1498 nfs_add_stats(inode, NFSIOS_SERVERWRITTENBYTES, hdr->res.count);
1499 trace_nfs_writeback_done(task, hdr);
1500
1501 if (task->tk_status >= 0) {
1502 enum nfs3_stable_how committed = hdr->res.verf->committed;
1503
1504 if (committed == NFS_UNSTABLE) {
1505 /*
1506 * We have some uncommitted data on the server at
1507 * this point, so ensure that we keep track of that
1508 * fact irrespective of what later writes do.
1509 */
1510 set_bit(NFS_IOHDR_UNSTABLE_WRITES, &hdr->flags);
1511 }
1512
1513 if (committed < hdr->args.stable) {
1514 /* We tried a write call, but the server did not
1515 * commit data to stable storage even though we
1516 * requested it.
1517 * Note: There is a known bug in Tru64 < 5.0 in which
1518 * the server reports NFS_DATA_SYNC, but performs
1519 * NFS_FILE_SYNC. We therefore implement this checking
1520 * as a dprintk() in order to avoid filling syslog.
1521 */
1522 static unsigned long complain;
1523
1524 /* Note this will print the MDS for a DS write */
1525 if (time_before(complain, jiffies)) {
1526 dprintk("NFS: faulty NFS server %s:"
1527 " (committed = %d) != (stable = %d)\n",
1528 NFS_SERVER(inode)->nfs_client->cl_hostname,
1529 committed, hdr->args.stable);
1530 complain = jiffies + 300 * HZ;
1531 }
1532 }
1533 }
1534
1535 /* Deal with the suid/sgid bit corner case */
1536 if (nfs_should_remove_suid(inode)) {
1537 spin_lock(&inode->i_lock);
1538 nfs_set_cache_invalid(inode, NFS_INO_INVALID_MODE);
1539 spin_unlock(&inode->i_lock);
1540 }
1541 return 0;
1542 }
1543
1544 /*
1545 * This function is called when the WRITE call is complete.
1546 */
nfs_writeback_result(struct rpc_task * task,struct nfs_pgio_header * hdr)1547 static void nfs_writeback_result(struct rpc_task *task,
1548 struct nfs_pgio_header *hdr)
1549 {
1550 struct nfs_pgio_args *argp = &hdr->args;
1551 struct nfs_pgio_res *resp = &hdr->res;
1552
1553 if (resp->count < argp->count) {
1554 static unsigned long complain;
1555
1556 /* This a short write! */
1557 nfs_inc_stats(hdr->inode, NFSIOS_SHORTWRITE);
1558
1559 /* Has the server at least made some progress? */
1560 if (resp->count == 0) {
1561 if (time_before(complain, jiffies)) {
1562 printk(KERN_WARNING
1563 "NFS: Server wrote zero bytes, expected %u.\n",
1564 argp->count);
1565 complain = jiffies + 300 * HZ;
1566 }
1567 nfs_set_pgio_error(hdr, -EIO, argp->offset);
1568 task->tk_status = -EIO;
1569 return;
1570 }
1571
1572 /* For non rpc-based layout drivers, retry-through-MDS */
1573 if (!task->tk_ops) {
1574 hdr->pnfs_error = -EAGAIN;
1575 return;
1576 }
1577
1578 /* Was this an NFSv2 write or an NFSv3 stable write? */
1579 if (resp->verf->committed != NFS_UNSTABLE) {
1580 /* Resend from where the server left off */
1581 hdr->mds_offset += resp->count;
1582 argp->offset += resp->count;
1583 argp->pgbase += resp->count;
1584 argp->count -= resp->count;
1585 } else {
1586 /* Resend as a stable write in order to avoid
1587 * headaches in the case of a server crash.
1588 */
1589 argp->stable = NFS_FILE_SYNC;
1590 }
1591 resp->count = 0;
1592 resp->verf->committed = 0;
1593 rpc_restart_call_prepare(task);
1594 }
1595 }
1596
wait_on_commit(struct nfs_mds_commit_info * cinfo)1597 static int wait_on_commit(struct nfs_mds_commit_info *cinfo)
1598 {
1599 return wait_var_event_killable(&cinfo->rpcs_out,
1600 !atomic_read(&cinfo->rpcs_out));
1601 }
1602
nfs_commit_begin(struct nfs_mds_commit_info * cinfo)1603 void nfs_commit_begin(struct nfs_mds_commit_info *cinfo)
1604 {
1605 atomic_inc(&cinfo->rpcs_out);
1606 }
1607
nfs_commit_end(struct nfs_mds_commit_info * cinfo)1608 bool nfs_commit_end(struct nfs_mds_commit_info *cinfo)
1609 {
1610 if (atomic_dec_and_test(&cinfo->rpcs_out)) {
1611 wake_up_var(&cinfo->rpcs_out);
1612 return true;
1613 }
1614 return false;
1615 }
1616
nfs_commitdata_release(struct nfs_commit_data * data)1617 void nfs_commitdata_release(struct nfs_commit_data *data)
1618 {
1619 put_nfs_open_context(data->context);
1620 nfs_commit_free(data);
1621 }
1622 EXPORT_SYMBOL_GPL(nfs_commitdata_release);
1623
nfs_initiate_commit(struct rpc_clnt * clnt,struct nfs_commit_data * data,const struct nfs_rpc_ops * nfs_ops,const struct rpc_call_ops * call_ops,int how,int flags,struct nfsd_file * localio)1624 int nfs_initiate_commit(struct rpc_clnt *clnt, struct nfs_commit_data *data,
1625 const struct nfs_rpc_ops *nfs_ops,
1626 const struct rpc_call_ops *call_ops,
1627 int how, int flags,
1628 struct nfsd_file *localio)
1629 {
1630 struct rpc_task *task;
1631 int priority = flush_task_priority(how);
1632 struct rpc_message msg = {
1633 .rpc_argp = &data->args,
1634 .rpc_resp = &data->res,
1635 .rpc_cred = data->cred,
1636 };
1637 struct rpc_task_setup task_setup_data = {
1638 .task = &data->task,
1639 .rpc_client = clnt,
1640 .rpc_message = &msg,
1641 .callback_ops = call_ops,
1642 .callback_data = data,
1643 .workqueue = nfsiod_workqueue,
1644 .flags = RPC_TASK_ASYNC | flags,
1645 .priority = priority,
1646 };
1647
1648 if (nfs_server_capable(data->inode, NFS_CAP_MOVEABLE))
1649 task_setup_data.flags |= RPC_TASK_MOVEABLE;
1650
1651 /* Set up the initial task struct. */
1652 nfs_ops->commit_setup(data, &msg, &task_setup_data.rpc_client);
1653 trace_nfs_initiate_commit(data);
1654
1655 dprintk("NFS: initiated commit call\n");
1656
1657 if (localio)
1658 return nfs_local_commit(localio, data, call_ops, how);
1659
1660 task = rpc_run_task(&task_setup_data);
1661 if (IS_ERR(task))
1662 return PTR_ERR(task);
1663 if (how & FLUSH_SYNC)
1664 rpc_wait_for_completion_task(task);
1665 rpc_put_task(task);
1666 return 0;
1667 }
1668 EXPORT_SYMBOL_GPL(nfs_initiate_commit);
1669
nfs_get_lwb(struct list_head * head)1670 static loff_t nfs_get_lwb(struct list_head *head)
1671 {
1672 loff_t lwb = 0;
1673 struct nfs_page *req;
1674
1675 list_for_each_entry(req, head, wb_list)
1676 if (lwb < (req_offset(req) + req->wb_bytes))
1677 lwb = req_offset(req) + req->wb_bytes;
1678
1679 return lwb;
1680 }
1681
1682 /*
1683 * Set up the argument/result storage required for the RPC call.
1684 */
nfs_init_commit(struct nfs_commit_data * data,struct list_head * head,struct pnfs_layout_segment * lseg,struct nfs_commit_info * cinfo)1685 void nfs_init_commit(struct nfs_commit_data *data,
1686 struct list_head *head,
1687 struct pnfs_layout_segment *lseg,
1688 struct nfs_commit_info *cinfo)
1689 {
1690 struct nfs_page *first;
1691 struct nfs_open_context *ctx;
1692 struct inode *inode;
1693
1694 /* Set up the RPC argument and reply structs
1695 * NB: take care not to mess about with data->commit et al. */
1696
1697 if (head)
1698 list_splice_init(head, &data->pages);
1699
1700 first = nfs_list_entry(data->pages.next);
1701 ctx = nfs_req_openctx(first);
1702 inode = d_inode(ctx->dentry);
1703
1704 data->inode = inode;
1705 data->cred = ctx->cred;
1706 data->lseg = lseg; /* reference transferred */
1707 /* only set lwb for pnfs commit */
1708 if (lseg)
1709 data->lwb = nfs_get_lwb(&data->pages);
1710 data->mds_ops = &nfs_commit_ops;
1711 data->completion_ops = cinfo->completion_ops;
1712 data->dreq = cinfo->dreq;
1713
1714 data->args.fh = NFS_FH(data->inode);
1715 /* Note: we always request a commit of the entire inode */
1716 data->args.offset = 0;
1717 data->args.count = 0;
1718 data->context = get_nfs_open_context(ctx);
1719 data->res.fattr = &data->fattr;
1720 data->res.verf = &data->verf;
1721 nfs_fattr_init(&data->fattr);
1722 nfs_commit_begin(cinfo->mds);
1723 }
1724 EXPORT_SYMBOL_GPL(nfs_init_commit);
1725
nfs_retry_commit(struct list_head * page_list,struct pnfs_layout_segment * lseg,struct nfs_commit_info * cinfo,u32 ds_commit_idx)1726 void nfs_retry_commit(struct list_head *page_list,
1727 struct pnfs_layout_segment *lseg,
1728 struct nfs_commit_info *cinfo,
1729 u32 ds_commit_idx)
1730 {
1731 struct nfs_page *req;
1732
1733 while (!list_empty(page_list)) {
1734 req = nfs_list_entry(page_list->next);
1735 nfs_list_remove_request(req);
1736 nfs_mark_request_commit(req, lseg, cinfo, ds_commit_idx);
1737 nfs_folio_clear_commit(nfs_page_to_folio(req));
1738 nfs_unlock_and_release_request(req);
1739 }
1740 }
1741 EXPORT_SYMBOL_GPL(nfs_retry_commit);
1742
nfs_commit_resched_write(struct nfs_commit_info * cinfo,struct nfs_page * req)1743 static void nfs_commit_resched_write(struct nfs_commit_info *cinfo,
1744 struct nfs_page *req)
1745 {
1746 struct folio *folio = nfs_page_to_folio(req);
1747
1748 filemap_dirty_folio(folio_mapping(folio), folio);
1749 }
1750
1751 /*
1752 * Commit dirty pages
1753 */
1754 static int
nfs_commit_list(struct inode * inode,struct list_head * head,int how,struct nfs_commit_info * cinfo)1755 nfs_commit_list(struct inode *inode, struct list_head *head, int how,
1756 struct nfs_commit_info *cinfo)
1757 {
1758 struct nfs_commit_data *data;
1759 struct nfsd_file *localio;
1760 unsigned short task_flags = 0;
1761
1762 /* another commit raced with us */
1763 if (list_empty(head))
1764 return 0;
1765
1766 data = nfs_commitdata_alloc();
1767 if (!data) {
1768 nfs_retry_commit(head, NULL, cinfo, -1);
1769 return -ENOMEM;
1770 }
1771
1772 /* Set up the argument struct */
1773 nfs_init_commit(data, head, NULL, cinfo);
1774 if (NFS_SERVER(inode)->nfs_client->cl_minorversion)
1775 task_flags = RPC_TASK_MOVEABLE;
1776
1777 localio = nfs_local_open_fh(NFS_SERVER(inode)->nfs_client, data->cred,
1778 data->args.fh, &data->context->nfl,
1779 data->context->mode);
1780 return nfs_initiate_commit(NFS_CLIENT(inode), data, NFS_PROTO(inode),
1781 data->mds_ops, how,
1782 RPC_TASK_CRED_NOREF | task_flags, localio);
1783 }
1784
1785 /*
1786 * COMMIT call returned
1787 */
nfs_commit_done(struct rpc_task * task,void * calldata)1788 static void nfs_commit_done(struct rpc_task *task, void *calldata)
1789 {
1790 struct nfs_commit_data *data = calldata;
1791
1792 /* Call the NFS version-specific code */
1793 NFS_PROTO(data->inode)->commit_done(task, data);
1794 trace_nfs_commit_done(task, data);
1795 }
1796
nfs_commit_release_pages(struct nfs_commit_data * data)1797 static void nfs_commit_release_pages(struct nfs_commit_data *data)
1798 {
1799 const struct nfs_writeverf *verf = data->res.verf;
1800 struct nfs_page *req;
1801 int status = data->task.tk_status;
1802 struct nfs_commit_info cinfo;
1803 struct folio *folio;
1804
1805 while (!list_empty(&data->pages)) {
1806 req = nfs_list_entry(data->pages.next);
1807 nfs_list_remove_request(req);
1808 folio = nfs_page_to_folio(req);
1809 nfs_folio_clear_commit(folio);
1810
1811 dprintk("NFS: commit (%s/%llu %d@%lld)",
1812 nfs_req_openctx(req)->dentry->d_sb->s_id,
1813 (unsigned long long)NFS_FILEID(d_inode(nfs_req_openctx(req)->dentry)),
1814 req->wb_bytes,
1815 (long long)req_offset(req));
1816 if (status < 0) {
1817 if (folio) {
1818 trace_nfs_commit_error(data->inode, req,
1819 status);
1820 nfs_mapping_set_error(folio, status);
1821 nfs_inode_remove_request(req);
1822 }
1823 dprintk(", error = %d\n", status);
1824 goto next;
1825 }
1826
1827 /* Okay, COMMIT succeeded, apparently. Check the verifier
1828 * returned by the server against all stored verfs. */
1829 if (nfs_write_match_verf(verf, req)) {
1830 /* We have a match */
1831 if (folio)
1832 nfs_inode_remove_request(req);
1833 dprintk(" OK\n");
1834 goto next;
1835 }
1836 /* We have a mismatch. Write the page again */
1837 dprintk(" mismatch\n");
1838 nfs_mark_request_dirty(req);
1839 atomic_long_inc(&NFS_I(data->inode)->redirtied_pages);
1840 next:
1841 nfs_unlock_and_release_request(req);
1842 /* Latency breaker */
1843 cond_resched();
1844 }
1845
1846 nfs_init_cinfo(&cinfo, data->inode, data->dreq);
1847 nfs_commit_end(cinfo.mds);
1848 }
1849
nfs_commit_release(void * calldata)1850 static void nfs_commit_release(void *calldata)
1851 {
1852 struct nfs_commit_data *data = calldata;
1853
1854 data->completion_ops->completion(data);
1855 nfs_commitdata_release(calldata);
1856 }
1857
1858 static const struct rpc_call_ops nfs_commit_ops = {
1859 .rpc_call_prepare = nfs_commit_prepare,
1860 .rpc_call_done = nfs_commit_done,
1861 .rpc_release = nfs_commit_release,
1862 };
1863
1864 static const struct nfs_commit_completion_ops nfs_commit_completion_ops = {
1865 .completion = nfs_commit_release_pages,
1866 .resched_write = nfs_commit_resched_write,
1867 };
1868
nfs_generic_commit_list(struct inode * inode,struct list_head * head,int how,struct nfs_commit_info * cinfo)1869 int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
1870 int how, struct nfs_commit_info *cinfo)
1871 {
1872 int status;
1873
1874 status = pnfs_commit_list(inode, head, how, cinfo);
1875 if (status == PNFS_NOT_ATTEMPTED)
1876 status = nfs_commit_list(inode, head, how, cinfo);
1877 return status;
1878 }
1879
__nfs_commit_inode(struct inode * inode,int how,struct writeback_control * wbc)1880 static int __nfs_commit_inode(struct inode *inode, int how,
1881 struct writeback_control *wbc)
1882 {
1883 LIST_HEAD(head);
1884 struct nfs_commit_info cinfo;
1885 int may_wait = how & FLUSH_SYNC;
1886 int ret, nscan;
1887
1888 how &= ~FLUSH_SYNC;
1889 nfs_init_cinfo_from_inode(&cinfo, inode);
1890 nfs_commit_begin(cinfo.mds);
1891 for (;;) {
1892 ret = nscan = nfs_scan_commit(inode, &head, &cinfo);
1893 if (ret <= 0)
1894 break;
1895 ret = nfs_generic_commit_list(inode, &head, how, &cinfo);
1896 if (ret < 0)
1897 break;
1898 ret = 0;
1899 if (wbc && wbc->sync_mode == WB_SYNC_NONE) {
1900 if (nscan < wbc->nr_to_write)
1901 wbc->nr_to_write -= nscan;
1902 else
1903 wbc->nr_to_write = 0;
1904 }
1905 if (nscan < INT_MAX)
1906 break;
1907 cond_resched();
1908 }
1909 nfs_commit_end(cinfo.mds);
1910 if (ret || !may_wait)
1911 return ret;
1912 return wait_on_commit(cinfo.mds);
1913 }
1914
nfs_commit_inode(struct inode * inode,int how)1915 int nfs_commit_inode(struct inode *inode, int how)
1916 {
1917 return __nfs_commit_inode(inode, how, NULL);
1918 }
1919 EXPORT_SYMBOL_GPL(nfs_commit_inode);
1920
nfs_write_inode(struct inode * inode,struct writeback_control * wbc)1921 int nfs_write_inode(struct inode *inode, struct writeback_control *wbc)
1922 {
1923 struct nfs_inode *nfsi = NFS_I(inode);
1924 int flags = FLUSH_SYNC;
1925 int ret = 0;
1926
1927 if (wbc->sync_mode == WB_SYNC_NONE) {
1928 /* no commits means nothing needs to be done */
1929 if (!atomic_long_read(&nfsi->commit_info.ncommit))
1930 goto check_requests_outstanding;
1931
1932 /* Don't commit yet if this is a non-blocking flush and there
1933 * are a lot of outstanding writes for this mapping.
1934 */
1935 if (mapping_tagged(inode->i_mapping, PAGECACHE_TAG_WRITEBACK))
1936 goto out_mark_dirty;
1937
1938 /* don't wait for the COMMIT response */
1939 flags = 0;
1940 }
1941
1942 ret = __nfs_commit_inode(inode, flags, wbc);
1943 if (!ret) {
1944 if (flags & FLUSH_SYNC)
1945 return 0;
1946 } else if (atomic_long_read(&nfsi->commit_info.ncommit))
1947 goto out_mark_dirty;
1948
1949 check_requests_outstanding:
1950 if (!atomic_read(&nfsi->commit_info.rpcs_out))
1951 return ret;
1952 out_mark_dirty:
1953 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
1954 return ret;
1955 }
1956 EXPORT_SYMBOL_GPL(nfs_write_inode);
1957
1958 /*
1959 * Wrapper for filemap_write_and_wait_range()
1960 *
1961 * Needed for pNFS in order to ensure data becomes visible to the
1962 * client.
1963 */
nfs_filemap_write_and_wait_range(struct address_space * mapping,loff_t lstart,loff_t lend)1964 int nfs_filemap_write_and_wait_range(struct address_space *mapping,
1965 loff_t lstart, loff_t lend)
1966 {
1967 int ret;
1968
1969 ret = filemap_write_and_wait_range(mapping, lstart, lend);
1970 if (ret == 0)
1971 ret = pnfs_sync_inode(mapping->host, true);
1972 return ret;
1973 }
1974 EXPORT_SYMBOL_GPL(nfs_filemap_write_and_wait_range);
1975
1976 /*
1977 * flush the inode to disk.
1978 */
nfs_wb_all(struct inode * inode)1979 int nfs_wb_all(struct inode *inode)
1980 {
1981 int ret;
1982
1983 trace_nfs_writeback_inode_enter(inode);
1984
1985 ret = filemap_write_and_wait(inode->i_mapping);
1986 if (ret)
1987 goto out;
1988 ret = nfs_commit_inode(inode, FLUSH_SYNC);
1989 if (ret < 0)
1990 goto out;
1991 pnfs_sync_inode(inode, true);
1992 ret = 0;
1993
1994 out:
1995 trace_nfs_writeback_inode_exit(inode, ret);
1996 return ret;
1997 }
1998 EXPORT_SYMBOL_GPL(nfs_wb_all);
1999
nfs_wb_folio_cancel(struct inode * inode,struct folio * folio)2000 int nfs_wb_folio_cancel(struct inode *inode, struct folio *folio)
2001 {
2002 struct nfs_page *req;
2003 int ret = 0;
2004
2005 folio_wait_writeback(folio);
2006
2007 /* blocking call to cancel all requests and join to a single (head)
2008 * request */
2009 req = nfs_lock_and_join_requests(folio);
2010
2011 if (IS_ERR(req)) {
2012 ret = PTR_ERR(req);
2013 } else if (req) {
2014 /* all requests from this folio have been cancelled by
2015 * nfs_lock_and_join_requests, so just remove the head
2016 * request from the inode / page_private pointer and
2017 * release it */
2018 nfs_inode_remove_request(req);
2019 nfs_unlock_and_release_request(req);
2020 folio_cancel_dirty(folio);
2021 }
2022
2023 return ret;
2024 }
2025
2026 /**
2027 * nfs_wb_folio - Write back all requests on one page
2028 * @inode: pointer to page
2029 * @folio: pointer to folio
2030 *
2031 * Assumes that the folio has been locked by the caller, and will
2032 * not unlock it.
2033 */
nfs_wb_folio(struct inode * inode,struct folio * folio)2034 int nfs_wb_folio(struct inode *inode, struct folio *folio)
2035 {
2036 loff_t range_start = folio_pos(folio);
2037 size_t len = folio_size(folio);
2038 struct writeback_control wbc = {
2039 .sync_mode = WB_SYNC_ALL,
2040 .nr_to_write = 0,
2041 .range_start = range_start,
2042 .range_end = range_start + len - 1,
2043 };
2044 int ret;
2045
2046 trace_nfs_writeback_folio(inode, range_start, len);
2047
2048 for (;;) {
2049 folio_wait_writeback(folio);
2050 if (folio_clear_dirty_for_io(folio)) {
2051 ret = nfs_writepage_locked(folio, &wbc);
2052 if (ret < 0)
2053 goto out_error;
2054 continue;
2055 }
2056 ret = 0;
2057 if (!folio_test_private(folio))
2058 break;
2059 ret = nfs_commit_inode(inode, FLUSH_SYNC);
2060 if (ret < 0)
2061 goto out_error;
2062 }
2063 out_error:
2064 trace_nfs_writeback_folio_done(inode, range_start, len, ret);
2065 return ret;
2066 }
2067
2068 #ifdef CONFIG_MIGRATION
nfs_migrate_folio(struct address_space * mapping,struct folio * dst,struct folio * src,enum migrate_mode mode)2069 int nfs_migrate_folio(struct address_space *mapping, struct folio *dst,
2070 struct folio *src, enum migrate_mode mode)
2071 {
2072 /*
2073 * If the private flag is set, the folio is currently associated with
2074 * an in-progress read or write request. Don't try to migrate it.
2075 *
2076 * FIXME: we could do this in principle, but we'll need a way to ensure
2077 * that we can safely release the inode reference while holding
2078 * the folio lock.
2079 */
2080 if (folio_test_private(src)) {
2081 if (mode == MIGRATE_SYNC)
2082 nfs_wb_folio(src->mapping->host, src);
2083 if (folio_test_private(src))
2084 return -EBUSY;
2085 }
2086
2087 if (folio_test_private_2(src)) { /* [DEPRECATED] */
2088 if (mode == MIGRATE_ASYNC)
2089 return -EBUSY;
2090 folio_wait_private_2(src);
2091 }
2092
2093 return migrate_folio(mapping, dst, src, mode);
2094 }
2095 #endif
2096
nfs_init_writepagecache(void)2097 int __init nfs_init_writepagecache(void)
2098 {
2099 nfs_wdata_cachep = kmem_cache_create("nfs_write_data",
2100 sizeof(struct nfs_pgio_header),
2101 0, SLAB_HWCACHE_ALIGN,
2102 NULL);
2103 if (nfs_wdata_cachep == NULL)
2104 return -ENOMEM;
2105
2106 nfs_wdata_mempool = mempool_create_slab_pool(MIN_POOL_WRITE,
2107 nfs_wdata_cachep);
2108 if (nfs_wdata_mempool == NULL)
2109 goto out_destroy_write_cache;
2110
2111 nfs_cdata_cachep = kmem_cache_create("nfs_commit_data",
2112 sizeof(struct nfs_commit_data),
2113 0, SLAB_HWCACHE_ALIGN,
2114 NULL);
2115 if (nfs_cdata_cachep == NULL)
2116 goto out_destroy_write_mempool;
2117
2118 nfs_commit_mempool = mempool_create_slab_pool(MIN_POOL_COMMIT,
2119 nfs_cdata_cachep);
2120 if (nfs_commit_mempool == NULL)
2121 goto out_destroy_commit_cache;
2122
2123 /*
2124 * NFS congestion size, scale with available memory.
2125 *
2126 * 64MB: 8192k
2127 * 128MB: 11585k
2128 * 256MB: 16384k
2129 * 512MB: 23170k
2130 * 1GB: 32768k
2131 * 2GB: 46340k
2132 * 4GB: 65536k
2133 * 8GB: 92681k
2134 * 16GB: 131072k
2135 *
2136 * This allows larger machines to have larger/more transfers.
2137 * Limit the default to 256M
2138 */
2139 nfs_congestion_kb = (16*int_sqrt(totalram_pages())) << (PAGE_SHIFT-10);
2140 if (nfs_congestion_kb > 256*1024)
2141 nfs_congestion_kb = 256*1024;
2142
2143 return 0;
2144
2145 out_destroy_commit_cache:
2146 kmem_cache_destroy(nfs_cdata_cachep);
2147 out_destroy_write_mempool:
2148 mempool_destroy(nfs_wdata_mempool);
2149 out_destroy_write_cache:
2150 kmem_cache_destroy(nfs_wdata_cachep);
2151 return -ENOMEM;
2152 }
2153
nfs_destroy_writepagecache(void)2154 void nfs_destroy_writepagecache(void)
2155 {
2156 mempool_destroy(nfs_commit_mempool);
2157 kmem_cache_destroy(nfs_cdata_cachep);
2158 mempool_destroy(nfs_wdata_mempool);
2159 kmem_cache_destroy(nfs_wdata_cachep);
2160 }
2161
2162 static const struct nfs_rw_ops nfs_rw_write_ops = {
2163 .rw_alloc_header = nfs_writehdr_alloc,
2164 .rw_free_header = nfs_writehdr_free,
2165 .rw_done = nfs_writeback_done,
2166 .rw_result = nfs_writeback_result,
2167 .rw_initiate = nfs_initiate_write,
2168 };
2169