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1/*
2 * linux/fs/nfs/write.c
3 *
4 * Write file data over NFS.
5 *
6 * Copyright (C) 1996, 1997, Olaf Kirch <okir@monad.swb.de>
7 */
8
9#include <linux/types.h>
10#include <linux/slab.h>
11#include <linux/mm.h>
12#include <linux/pagemap.h>
13#include <linux/file.h>
14#include <linux/writeback.h>
15#include <linux/swap.h>
16#include <linux/migrate.h>
17
18#include <linux/sunrpc/clnt.h>
19#include <linux/nfs_fs.h>
20#include <linux/nfs_mount.h>
21#include <linux/nfs_page.h>
22#include <linux/backing-dev.h>
23#include <linux/export.h>
24
25#include <asm/uaccess.h>
26
27#include "delegation.h"
28#include "internal.h"
29#include "iostat.h"
30#include "nfs4_fs.h"
31#include "fscache.h"
32#include "pnfs.h"
33
34#define NFSDBG_FACILITY NFSDBG_PAGECACHE
35
36#define MIN_POOL_WRITE (32)
37#define MIN_POOL_COMMIT (4)
38
39/*
40 * Local function declarations
41 */
42static void nfs_redirty_request(struct nfs_page *req);
43static const struct rpc_call_ops nfs_write_common_ops;
44static const struct rpc_call_ops nfs_commit_ops;
45static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops;
46static const struct nfs_commit_completion_ops nfs_commit_completion_ops;
47
48static struct kmem_cache *nfs_wdata_cachep;
49static mempool_t *nfs_wdata_mempool;
50static struct kmem_cache *nfs_cdata_cachep;
51static mempool_t *nfs_commit_mempool;
52
53struct nfs_commit_data *nfs_commitdata_alloc(void)
54{
55 struct nfs_commit_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOFS);
56
57 if (p) {
58 memset(p, 0, sizeof(*p));
59 INIT_LIST_HEAD(&p->pages);
60 }
61 return p;
62}
63EXPORT_SYMBOL_GPL(nfs_commitdata_alloc);
64
65void nfs_commit_free(struct nfs_commit_data *p)
66{
67 mempool_free(p, nfs_commit_mempool);
68}
69EXPORT_SYMBOL_GPL(nfs_commit_free);
70
71struct nfs_write_header *nfs_writehdr_alloc(void)
72{
73 struct nfs_write_header *p = mempool_alloc(nfs_wdata_mempool, GFP_NOFS);
74
75 if (p) {
76 struct nfs_pgio_header *hdr = &p->header;
77
78 memset(p, 0, sizeof(*p));
79 INIT_LIST_HEAD(&hdr->pages);
80 INIT_LIST_HEAD(&hdr->rpc_list);
81 spin_lock_init(&hdr->lock);
82 atomic_set(&hdr->refcnt, 0);
83 hdr->verf = &p->verf;
84 }
85 return p;
86}
87
88static struct nfs_write_data *nfs_writedata_alloc(struct nfs_pgio_header *hdr,
89 unsigned int pagecount)
90{
91 struct nfs_write_data *data, *prealloc;
92
93 prealloc = &container_of(hdr, struct nfs_write_header, header)->rpc_data;
94 if (prealloc->header == NULL)
95 data = prealloc;
96 else
97 data = kzalloc(sizeof(*data), GFP_KERNEL);
98 if (!data)
99 goto out;
100
101 if (nfs_pgarray_set(&data->pages, pagecount)) {
102 data->header = hdr;
103 atomic_inc(&hdr->refcnt);
104 } else {
105 if (data != prealloc)
106 kfree(data);
107 data = NULL;
108 }
109out:
110 return data;
111}
112
113void nfs_writehdr_free(struct nfs_pgio_header *hdr)
114{
115 struct nfs_write_header *whdr = container_of(hdr, struct nfs_write_header, header);
116 mempool_free(whdr, nfs_wdata_mempool);
117}
118
119void nfs_writedata_release(struct nfs_write_data *wdata)
120{
121 struct nfs_pgio_header *hdr = wdata->header;
122 struct nfs_write_header *write_header = container_of(hdr, struct nfs_write_header, header);
123
124 put_nfs_open_context(wdata->args.context);
125 if (wdata->pages.pagevec != wdata->pages.page_array)
126 kfree(wdata->pages.pagevec);
127 if (wdata != &write_header->rpc_data)
128 kfree(wdata);
129 else
130 wdata->header = NULL;
131 if (atomic_dec_and_test(&hdr->refcnt))
132 hdr->completion_ops->completion(hdr);
133}
134
135static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error)
136{
137 ctx->error = error;
138 smp_wmb();
139 set_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags);
140}
141
142static struct nfs_page *nfs_page_find_request_locked(struct page *page)
143{
144 struct nfs_page *req = NULL;
145
146 if (PagePrivate(page)) {
147 req = (struct nfs_page *)page_private(page);
148 if (req != NULL)
149 kref_get(&req->wb_kref);
150 }
151 return req;
152}
153
154static struct nfs_page *nfs_page_find_request(struct page *page)
155{
156 struct inode *inode = page->mapping->host;
157 struct nfs_page *req = NULL;
158
159 spin_lock(&inode->i_lock);
160 req = nfs_page_find_request_locked(page);
161 spin_unlock(&inode->i_lock);
162 return req;
163}
164
165/* Adjust the file length if we're writing beyond the end */
166static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count)
167{
168 struct inode *inode = page->mapping->host;
169 loff_t end, i_size;
170 pgoff_t end_index;
171
172 spin_lock(&inode->i_lock);
173 i_size = i_size_read(inode);
174 end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
175 if (i_size > 0 && page->index < end_index)
176 goto out;
177 end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + ((loff_t)offset+count);
178 if (i_size >= end)
179 goto out;
180 i_size_write(inode, end);
181 nfs_inc_stats(inode, NFSIOS_EXTENDWRITE);
182out:
183 spin_unlock(&inode->i_lock);
184}
185
186/* A writeback failed: mark the page as bad, and invalidate the page cache */
187static void nfs_set_pageerror(struct page *page)
188{
189 SetPageError(page);
190 nfs_zap_mapping(page->mapping->host, page->mapping);
191}
192
193/* We can set the PG_uptodate flag if we see that a write request
194 * covers the full page.
195 */
196static void nfs_mark_uptodate(struct page *page, unsigned int base, unsigned int count)
197{
198 if (PageUptodate(page))
199 return;
200 if (base != 0)
201 return;
202 if (count != nfs_page_length(page))
203 return;
204 SetPageUptodate(page);
205}
206
207static int wb_priority(struct writeback_control *wbc)
208{
209 if (wbc->for_reclaim)
210 return FLUSH_HIGHPRI | FLUSH_STABLE;
211 if (wbc->for_kupdate || wbc->for_background)
212 return FLUSH_LOWPRI | FLUSH_COND_STABLE;
213 return FLUSH_COND_STABLE;
214}
215
216/*
217 * NFS congestion control
218 */
219
220int nfs_congestion_kb;
221
222#define NFS_CONGESTION_ON_THRESH (nfs_congestion_kb >> (PAGE_SHIFT-10))
223#define NFS_CONGESTION_OFF_THRESH \
224 (NFS_CONGESTION_ON_THRESH - (NFS_CONGESTION_ON_THRESH >> 2))
225
226static int nfs_set_page_writeback(struct page *page)
227{
228 int ret = test_set_page_writeback(page);
229
230 if (!ret) {
231 struct inode *inode = page->mapping->host;
232 struct nfs_server *nfss = NFS_SERVER(inode);
233
234 if (atomic_long_inc_return(&nfss->writeback) >
235 NFS_CONGESTION_ON_THRESH) {
236 set_bdi_congested(&nfss->backing_dev_info,
237 BLK_RW_ASYNC);
238 }
239 }
240 return ret;
241}
242
243static void nfs_end_page_writeback(struct page *page)
244{
245 struct inode *inode = page->mapping->host;
246 struct nfs_server *nfss = NFS_SERVER(inode);
247
248 end_page_writeback(page);
249 if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH)
250 clear_bdi_congested(&nfss->backing_dev_info, BLK_RW_ASYNC);
251}
252
253static struct nfs_page *nfs_find_and_lock_request(struct page *page, bool nonblock)
254{
255 struct inode *inode = page->mapping->host;
256 struct nfs_page *req;
257 int ret;
258
259 spin_lock(&inode->i_lock);
260 for (;;) {
261 req = nfs_page_find_request_locked(page);
262 if (req == NULL)
263 break;
264 if (nfs_lock_request(req))
265 break;
266 /* Note: If we hold the page lock, as is the case in nfs_writepage,
267 * then the call to nfs_lock_request() will always
268 * succeed provided that someone hasn't already marked the
269 * request as dirty (in which case we don't care).
270 */
271 spin_unlock(&inode->i_lock);
272 if (!nonblock)
273 ret = nfs_wait_on_request(req);
274 else
275 ret = -EAGAIN;
276 nfs_release_request(req);
277 if (ret != 0)
278 return ERR_PTR(ret);
279 spin_lock(&inode->i_lock);
280 }
281 spin_unlock(&inode->i_lock);
282 return req;
283}
284
285/*
286 * Find an associated nfs write request, and prepare to flush it out
287 * May return an error if the user signalled nfs_wait_on_request().
288 */
289static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio,
290 struct page *page, bool nonblock)
291{
292 struct nfs_page *req;
293 int ret = 0;
294
295 req = nfs_find_and_lock_request(page, nonblock);
296 if (!req)
297 goto out;
298 ret = PTR_ERR(req);
299 if (IS_ERR(req))
300 goto out;
301
302 ret = nfs_set_page_writeback(page);
303 BUG_ON(ret != 0);
304 BUG_ON(test_bit(PG_CLEAN, &req->wb_flags));
305
306 if (!nfs_pageio_add_request(pgio, req)) {
307 nfs_redirty_request(req);
308 ret = pgio->pg_error;
309 }
310out:
311 return ret;
312}
313
314static int nfs_do_writepage(struct page *page, struct writeback_control *wbc, struct nfs_pageio_descriptor *pgio)
315{
316 struct inode *inode = page->mapping->host;
317 int ret;
318
319 nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE);
320 nfs_add_stats(inode, NFSIOS_WRITEPAGES, 1);
321
322 nfs_pageio_cond_complete(pgio, page->index);
323 ret = nfs_page_async_flush(pgio, page, wbc->sync_mode == WB_SYNC_NONE);
324 if (ret == -EAGAIN) {
325 redirty_page_for_writepage(wbc, page);
326 ret = 0;
327 }
328 return ret;
329}
330
331/*
332 * Write an mmapped page to the server.
333 */
334static int nfs_writepage_locked(struct page *page, struct writeback_control *wbc)
335{
336 struct nfs_pageio_descriptor pgio;
337 int err;
338
339 nfs_pageio_init_write(&pgio, page->mapping->host, wb_priority(wbc),
340 &nfs_async_write_completion_ops);
341 err = nfs_do_writepage(page, wbc, &pgio);
342 nfs_pageio_complete(&pgio);
343 if (err < 0)
344 return err;
345 if (pgio.pg_error < 0)
346 return pgio.pg_error;
347 return 0;
348}
349
350int nfs_writepage(struct page *page, struct writeback_control *wbc)
351{
352 int ret;
353
354 ret = nfs_writepage_locked(page, wbc);
355 unlock_page(page);
356 return ret;
357}
358
359static int nfs_writepages_callback(struct page *page, struct writeback_control *wbc, void *data)
360{
361 int ret;
362
363 ret = nfs_do_writepage(page, wbc, data);
364 unlock_page(page);
365 return ret;
366}
367
368int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
369{
370 struct inode *inode = mapping->host;
371 unsigned long *bitlock = &NFS_I(inode)->flags;
372 struct nfs_pageio_descriptor pgio;
373 int err;
374
375 /* Stop dirtying of new pages while we sync */
376 err = wait_on_bit_lock(bitlock, NFS_INO_FLUSHING,
377 nfs_wait_bit_killable, TASK_KILLABLE);
378 if (err)
379 goto out_err;
380
381 nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES);
382
383 nfs_pageio_init_write(&pgio, inode, wb_priority(wbc),
384 &nfs_async_write_completion_ops);
385 err = write_cache_pages(mapping, wbc, nfs_writepages_callback, &pgio);
386 nfs_pageio_complete(&pgio);
387
388 clear_bit_unlock(NFS_INO_FLUSHING, bitlock);
389 smp_mb__after_clear_bit();
390 wake_up_bit(bitlock, NFS_INO_FLUSHING);
391
392 if (err < 0)
393 goto out_err;
394 err = pgio.pg_error;
395 if (err < 0)
396 goto out_err;
397 return 0;
398out_err:
399 return err;
400}
401
402/*
403 * Insert a write request into an inode
404 */
405static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
406{
407 struct nfs_inode *nfsi = NFS_I(inode);
408
409 /* Lock the request! */
410 nfs_lock_request(req);
411
412 spin_lock(&inode->i_lock);
413 if (!nfsi->npages && nfs_have_delegation(inode, FMODE_WRITE))
414 inode->i_version++;
415 set_bit(PG_MAPPED, &req->wb_flags);
416 SetPagePrivate(req->wb_page);
417 set_page_private(req->wb_page, (unsigned long)req);
418 nfsi->npages++;
419 kref_get(&req->wb_kref);
420 spin_unlock(&inode->i_lock);
421}
422
423/*
424 * Remove a write request from an inode
425 */
426static void nfs_inode_remove_request(struct nfs_page *req)
427{
428 struct inode *inode = req->wb_context->dentry->d_inode;
429 struct nfs_inode *nfsi = NFS_I(inode);
430
431 BUG_ON (!NFS_WBACK_BUSY(req));
432
433 spin_lock(&inode->i_lock);
434 set_page_private(req->wb_page, 0);
435 ClearPagePrivate(req->wb_page);
436 clear_bit(PG_MAPPED, &req->wb_flags);
437 nfsi->npages--;
438 spin_unlock(&inode->i_lock);
439 nfs_release_request(req);
440}
441
442static void
443nfs_mark_request_dirty(struct nfs_page *req)
444{
445 __set_page_dirty_nobuffers(req->wb_page);
446}
447
448#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
449/**
450 * nfs_request_add_commit_list - add request to a commit list
451 * @req: pointer to a struct nfs_page
452 * @dst: commit list head
453 * @cinfo: holds list lock and accounting info
454 *
455 * This sets the PG_CLEAN bit, updates the cinfo count of
456 * number of outstanding requests requiring a commit as well as
457 * the MM page stats.
458 *
459 * The caller must _not_ hold the cinfo->lock, but must be
460 * holding the nfs_page lock.
461 */
462void
463nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst,
464 struct nfs_commit_info *cinfo)
465{
466 set_bit(PG_CLEAN, &(req)->wb_flags);
467 spin_lock(cinfo->lock);
468 nfs_list_add_request(req, dst);
469 cinfo->mds->ncommit++;
470 spin_unlock(cinfo->lock);
471 if (!cinfo->dreq) {
472 inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
473 inc_bdi_stat(req->wb_page->mapping->backing_dev_info,
474 BDI_RECLAIMABLE);
475 __mark_inode_dirty(req->wb_context->dentry->d_inode,
476 I_DIRTY_DATASYNC);
477 }
478}
479EXPORT_SYMBOL_GPL(nfs_request_add_commit_list);
480
481/**
482 * nfs_request_remove_commit_list - Remove request from a commit list
483 * @req: pointer to a nfs_page
484 * @cinfo: holds list lock and accounting info
485 *
486 * This clears the PG_CLEAN bit, and updates the cinfo's count of
487 * number of outstanding requests requiring a commit
488 * It does not update the MM page stats.
489 *
490 * The caller _must_ hold the cinfo->lock and the nfs_page lock.
491 */
492void
493nfs_request_remove_commit_list(struct nfs_page *req,
494 struct nfs_commit_info *cinfo)
495{
496 if (!test_and_clear_bit(PG_CLEAN, &(req)->wb_flags))
497 return;
498 nfs_list_remove_request(req);
499 cinfo->mds->ncommit--;
500}
501EXPORT_SYMBOL_GPL(nfs_request_remove_commit_list);
502
503static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo,
504 struct inode *inode)
505{
506 cinfo->lock = &inode->i_lock;
507 cinfo->mds = &NFS_I(inode)->commit_info;
508 cinfo->ds = pnfs_get_ds_info(inode);
509 cinfo->dreq = NULL;
510 cinfo->completion_ops = &nfs_commit_completion_ops;
511}
512
513void nfs_init_cinfo(struct nfs_commit_info *cinfo,
514 struct inode *inode,
515 struct nfs_direct_req *dreq)
516{
517 if (dreq)
518 nfs_init_cinfo_from_dreq(cinfo, dreq);
519 else
520 nfs_init_cinfo_from_inode(cinfo, inode);
521}
522EXPORT_SYMBOL_GPL(nfs_init_cinfo);
523
524/*
525 * Add a request to the inode's commit list.
526 */
527void
528nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg,
529 struct nfs_commit_info *cinfo)
530{
531 if (pnfs_mark_request_commit(req, lseg, cinfo))
532 return;
533 nfs_request_add_commit_list(req, &cinfo->mds->list, cinfo);
534}
535
536static void
537nfs_clear_page_commit(struct page *page)
538{
539 dec_zone_page_state(page, NR_UNSTABLE_NFS);
540 dec_bdi_stat(page->mapping->backing_dev_info, BDI_RECLAIMABLE);
541}
542
543static void
544nfs_clear_request_commit(struct nfs_page *req)
545{
546 if (test_bit(PG_CLEAN, &req->wb_flags)) {
547 struct inode *inode = req->wb_context->dentry->d_inode;
548 struct nfs_commit_info cinfo;
549
550 nfs_init_cinfo_from_inode(&cinfo, inode);
551 if (!pnfs_clear_request_commit(req, &cinfo)) {
552 spin_lock(cinfo.lock);
553 nfs_request_remove_commit_list(req, &cinfo);
554 spin_unlock(cinfo.lock);
555 }
556 nfs_clear_page_commit(req->wb_page);
557 }
558}
559
560static inline
561int nfs_write_need_commit(struct nfs_write_data *data)
562{
563 if (data->verf.committed == NFS_DATA_SYNC)
564 return data->header->lseg == NULL;
565 return data->verf.committed != NFS_FILE_SYNC;
566}
567
568#else
569static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo,
570 struct inode *inode)
571{
572}
573
574void nfs_init_cinfo(struct nfs_commit_info *cinfo,
575 struct inode *inode,
576 struct nfs_direct_req *dreq)
577{
578}
579
580void
581nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg,
582 struct nfs_commit_info *cinfo)
583{
584}
585
586static void
587nfs_clear_request_commit(struct nfs_page *req)
588{
589}
590
591static inline
592int nfs_write_need_commit(struct nfs_write_data *data)
593{
594 return 0;
595}
596
597#endif
598
599static void nfs_write_completion(struct nfs_pgio_header *hdr)
600{
601 struct nfs_commit_info cinfo;
602 unsigned long bytes = 0;
603
604 if (test_bit(NFS_IOHDR_REDO, &hdr->flags))
605 goto out;
606 nfs_init_cinfo_from_inode(&cinfo, hdr->inode);
607 while (!list_empty(&hdr->pages)) {
608 struct nfs_page *req = nfs_list_entry(hdr->pages.next);
609
610 bytes += req->wb_bytes;
611 nfs_list_remove_request(req);
612 if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) &&
613 (hdr->good_bytes < bytes)) {
614 nfs_set_pageerror(req->wb_page);
615 nfs_context_set_write_error(req->wb_context, hdr->error);
616 goto remove_req;
617 }
618 if (test_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags)) {
619 nfs_mark_request_dirty(req);
620 goto next;
621 }
622 if (test_bit(NFS_IOHDR_NEED_COMMIT, &hdr->flags)) {
623 memcpy(&req->wb_verf, hdr->verf, sizeof(req->wb_verf));
624 nfs_mark_request_commit(req, hdr->lseg, &cinfo);
625 goto next;
626 }
627remove_req:
628 nfs_inode_remove_request(req);
629next:
630 nfs_unlock_request(req);
631 nfs_end_page_writeback(req->wb_page);
632 nfs_release_request(req);
633 }
634out:
635 hdr->release(hdr);
636}
637
638#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
639static unsigned long
640nfs_reqs_to_commit(struct nfs_commit_info *cinfo)
641{
642 return cinfo->mds->ncommit;
643}
644
645/* cinfo->lock held by caller */
646int
647nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
648 struct nfs_commit_info *cinfo, int max)
649{
650 struct nfs_page *req, *tmp;
651 int ret = 0;
652
653 list_for_each_entry_safe(req, tmp, src, wb_list) {
654 if (!nfs_lock_request(req))
655 continue;
656 kref_get(&req->wb_kref);
657 if (cond_resched_lock(cinfo->lock))
658 list_safe_reset_next(req, tmp, wb_list);
659 nfs_request_remove_commit_list(req, cinfo);
660 nfs_list_add_request(req, dst);
661 ret++;
662 if ((ret == max) && !cinfo->dreq)
663 break;
664 }
665 return ret;
666}
667
668/*
669 * nfs_scan_commit - Scan an inode for commit requests
670 * @inode: NFS inode to scan
671 * @dst: mds destination list
672 * @cinfo: mds and ds lists of reqs ready to commit
673 *
674 * Moves requests from the inode's 'commit' request list.
675 * The requests are *not* checked to ensure that they form a contiguous set.
676 */
677int
678nfs_scan_commit(struct inode *inode, struct list_head *dst,
679 struct nfs_commit_info *cinfo)
680{
681 int ret = 0;
682
683 spin_lock(cinfo->lock);
684 if (cinfo->mds->ncommit > 0) {
685 const int max = INT_MAX;
686
687 ret = nfs_scan_commit_list(&cinfo->mds->list, dst,
688 cinfo, max);
689 ret += pnfs_scan_commit_lists(inode, cinfo, max - ret);
690 }
691 spin_unlock(cinfo->lock);
692 return ret;
693}
694
695#else
696static unsigned long nfs_reqs_to_commit(struct nfs_commit_info *cinfo)
697{
698 return 0;
699}
700
701int nfs_scan_commit(struct inode *inode, struct list_head *dst,
702 struct nfs_commit_info *cinfo)
703{
704 return 0;
705}
706#endif
707
708/*
709 * Search for an existing write request, and attempt to update
710 * it to reflect a new dirty region on a given page.
711 *
712 * If the attempt fails, then the existing request is flushed out
713 * to disk.
714 */
715static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
716 struct page *page,
717 unsigned int offset,
718 unsigned int bytes)
719{
720 struct nfs_page *req;
721 unsigned int rqend;
722 unsigned int end;
723 int error;
724
725 if (!PagePrivate(page))
726 return NULL;
727
728 end = offset + bytes;
729 spin_lock(&inode->i_lock);
730
731 for (;;) {
732 req = nfs_page_find_request_locked(page);
733 if (req == NULL)
734 goto out_unlock;
735
736 rqend = req->wb_offset + req->wb_bytes;
737 /*
738 * Tell the caller to flush out the request if
739 * the offsets are non-contiguous.
740 * Note: nfs_flush_incompatible() will already
741 * have flushed out requests having wrong owners.
742 */
743 if (offset > rqend
744 || end < req->wb_offset)
745 goto out_flushme;
746
747 if (nfs_lock_request(req))
748 break;
749
750 /* The request is locked, so wait and then retry */
751 spin_unlock(&inode->i_lock);
752 error = nfs_wait_on_request(req);
753 nfs_release_request(req);
754 if (error != 0)
755 goto out_err;
756 spin_lock(&inode->i_lock);
757 }
758
759 /* Okay, the request matches. Update the region */
760 if (offset < req->wb_offset) {
761 req->wb_offset = offset;
762 req->wb_pgbase = offset;
763 }
764 if (end > rqend)
765 req->wb_bytes = end - req->wb_offset;
766 else
767 req->wb_bytes = rqend - req->wb_offset;
768out_unlock:
769 spin_unlock(&inode->i_lock);
770 if (req)
771 nfs_clear_request_commit(req);
772 return req;
773out_flushme:
774 spin_unlock(&inode->i_lock);
775 nfs_release_request(req);
776 error = nfs_wb_page(inode, page);
777out_err:
778 return ERR_PTR(error);
779}
780
781/*
782 * Try to update an existing write request, or create one if there is none.
783 *
784 * Note: Should always be called with the Page Lock held to prevent races
785 * if we have to add a new request. Also assumes that the caller has
786 * already called nfs_flush_incompatible() if necessary.
787 */
788static struct nfs_page * nfs_setup_write_request(struct nfs_open_context* ctx,
789 struct page *page, unsigned int offset, unsigned int bytes)
790{
791 struct inode *inode = page->mapping->host;
792 struct nfs_page *req;
793
794 req = nfs_try_to_update_request(inode, page, offset, bytes);
795 if (req != NULL)
796 goto out;
797 req = nfs_create_request(ctx, inode, page, offset, bytes);
798 if (IS_ERR(req))
799 goto out;
800 nfs_inode_add_request(inode, req);
801out:
802 return req;
803}
804
805static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page,
806 unsigned int offset, unsigned int count)
807{
808 struct nfs_page *req;
809
810 req = nfs_setup_write_request(ctx, page, offset, count);
811 if (IS_ERR(req))
812 return PTR_ERR(req);
813 /* Update file length */
814 nfs_grow_file(page, offset, count);
815 nfs_mark_uptodate(page, req->wb_pgbase, req->wb_bytes);
816 nfs_mark_request_dirty(req);
817 nfs_unlock_and_release_request(req);
818 return 0;
819}
820
821int nfs_flush_incompatible(struct file *file, struct page *page)
822{
823 struct nfs_open_context *ctx = nfs_file_open_context(file);
824 struct nfs_page *req;
825 int do_flush, status;
826 /*
827 * Look for a request corresponding to this page. If there
828 * is one, and it belongs to another file, we flush it out
829 * before we try to copy anything into the page. Do this
830 * due to the lack of an ACCESS-type call in NFSv2.
831 * Also do the same if we find a request from an existing
832 * dropped page.
833 */
834 do {
835 req = nfs_page_find_request(page);
836 if (req == NULL)
837 return 0;
838 do_flush = req->wb_page != page || req->wb_context != ctx ||
839 req->wb_lock_context->lockowner != current->files ||
840 req->wb_lock_context->pid != current->tgid;
841 nfs_release_request(req);
842 if (!do_flush)
843 return 0;
844 status = nfs_wb_page(page->mapping->host, page);
845 } while (status == 0);
846 return status;
847}
848
849/*
850 * If the page cache is marked as unsafe or invalid, then we can't rely on
851 * the PageUptodate() flag. In this case, we will need to turn off
852 * write optimisations that depend on the page contents being correct.
853 */
854static bool nfs_write_pageuptodate(struct page *page, struct inode *inode)
855{
856 if (nfs_have_delegated_attributes(inode))
857 goto out;
858 if (NFS_I(inode)->cache_validity & NFS_INO_REVAL_PAGECACHE)
859 return false;
860out:
861 return PageUptodate(page) != 0;
862}
863
864/*
865 * Update and possibly write a cached page of an NFS file.
866 *
867 * XXX: Keep an eye on generic_file_read to make sure it doesn't do bad
868 * things with a page scheduled for an RPC call (e.g. invalidate it).
869 */
870int nfs_updatepage(struct file *file, struct page *page,
871 unsigned int offset, unsigned int count)
872{
873 struct nfs_open_context *ctx = nfs_file_open_context(file);
874 struct inode *inode = page->mapping->host;
875 int status = 0;
876
877 nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE);
878
879 dprintk("NFS: nfs_updatepage(%s/%s %d@%lld)\n",
880 file->f_path.dentry->d_parent->d_name.name,
881 file->f_path.dentry->d_name.name, count,
882 (long long)(page_offset(page) + offset));
883
884 /* If we're not using byte range locks, and we know the page
885 * is up to date, it may be more efficient to extend the write
886 * to cover the entire page in order to avoid fragmentation
887 * inefficiencies.
888 */
889 if (nfs_write_pageuptodate(page, inode) &&
890 inode->i_flock == NULL &&
891 !(file->f_flags & O_DSYNC)) {
892 count = max(count + offset, nfs_page_length(page));
893 offset = 0;
894 }
895
896 status = nfs_writepage_setup(ctx, page, offset, count);
897 if (status < 0)
898 nfs_set_pageerror(page);
899 else
900 __set_page_dirty_nobuffers(page);
901
902 dprintk("NFS: nfs_updatepage returns %d (isize %lld)\n",
903 status, (long long)i_size_read(inode));
904 return status;
905}
906
907static int flush_task_priority(int how)
908{
909 switch (how & (FLUSH_HIGHPRI|FLUSH_LOWPRI)) {
910 case FLUSH_HIGHPRI:
911 return RPC_PRIORITY_HIGH;
912 case FLUSH_LOWPRI:
913 return RPC_PRIORITY_LOW;
914 }
915 return RPC_PRIORITY_NORMAL;
916}
917
918int nfs_initiate_write(struct rpc_clnt *clnt,
919 struct nfs_write_data *data,
920 const struct rpc_call_ops *call_ops,
921 int how, int flags)
922{
923 struct inode *inode = data->header->inode;
924 int priority = flush_task_priority(how);
925 struct rpc_task *task;
926 struct rpc_message msg = {
927 .rpc_argp = &data->args,
928 .rpc_resp = &data->res,
929 .rpc_cred = data->header->cred,
930 };
931 struct rpc_task_setup task_setup_data = {
932 .rpc_client = clnt,
933 .task = &data->task,
934 .rpc_message = &msg,
935 .callback_ops = call_ops,
936 .callback_data = data,
937 .workqueue = nfsiod_workqueue,
938 .flags = RPC_TASK_ASYNC | flags,
939 .priority = priority,
940 };
941 int ret = 0;
942
943 /* Set up the initial task struct. */
944 NFS_PROTO(inode)->write_setup(data, &msg);
945
946 dprintk("NFS: %5u initiated write call "
947 "(req %s/%lld, %u bytes @ offset %llu)\n",
948 data->task.tk_pid,
949 inode->i_sb->s_id,
950 (long long)NFS_FILEID(inode),
951 data->args.count,
952 (unsigned long long)data->args.offset);
953
954 task = rpc_run_task(&task_setup_data);
955 if (IS_ERR(task)) {
956 ret = PTR_ERR(task);
957 goto out;
958 }
959 if (how & FLUSH_SYNC) {
960 ret = rpc_wait_for_completion_task(task);
961 if (ret == 0)
962 ret = task->tk_status;
963 }
964 rpc_put_task(task);
965out:
966 return ret;
967}
968EXPORT_SYMBOL_GPL(nfs_initiate_write);
969
970/*
971 * Set up the argument/result storage required for the RPC call.
972 */
973static void nfs_write_rpcsetup(struct nfs_write_data *data,
974 unsigned int count, unsigned int offset,
975 int how, struct nfs_commit_info *cinfo)
976{
977 struct nfs_page *req = data->header->req;
978
979 /* Set up the RPC argument and reply structs
980 * NB: take care not to mess about with data->commit et al. */
981
982 data->args.fh = NFS_FH(data->header->inode);
983 data->args.offset = req_offset(req) + offset;
984 /* pnfs_set_layoutcommit needs this */
985 data->mds_offset = data->args.offset;
986 data->args.pgbase = req->wb_pgbase + offset;
987 data->args.pages = data->pages.pagevec;
988 data->args.count = count;
989 data->args.context = get_nfs_open_context(req->wb_context);
990 data->args.lock_context = req->wb_lock_context;
991 data->args.stable = NFS_UNSTABLE;
992 switch (how & (FLUSH_STABLE | FLUSH_COND_STABLE)) {
993 case 0:
994 break;
995 case FLUSH_COND_STABLE:
996 if (nfs_reqs_to_commit(cinfo))
997 break;
998 default:
999 data->args.stable = NFS_FILE_SYNC;
1000 }
1001
1002 data->res.fattr = &data->fattr;
1003 data->res.count = count;
1004 data->res.verf = &data->verf;
1005 nfs_fattr_init(&data->fattr);
1006}
1007
1008static int nfs_do_write(struct nfs_write_data *data,
1009 const struct rpc_call_ops *call_ops,
1010 int how)
1011{
1012 struct inode *inode = data->header->inode;
1013
1014 return nfs_initiate_write(NFS_CLIENT(inode), data, call_ops, how, 0);
1015}
1016
1017static int nfs_do_multiple_writes(struct list_head *head,
1018 const struct rpc_call_ops *call_ops,
1019 int how)
1020{
1021 struct nfs_write_data *data;
1022 int ret = 0;
1023
1024 while (!list_empty(head)) {
1025 int ret2;
1026
1027 data = list_first_entry(head, struct nfs_write_data, list);
1028 list_del_init(&data->list);
1029
1030 ret2 = nfs_do_write(data, call_ops, how);
1031 if (ret == 0)
1032 ret = ret2;
1033 }
1034 return ret;
1035}
1036
1037/* If a nfs_flush_* function fails, it should remove reqs from @head and
1038 * call this on each, which will prepare them to be retried on next
1039 * writeback using standard nfs.
1040 */
1041static void nfs_redirty_request(struct nfs_page *req)
1042{
1043 nfs_mark_request_dirty(req);
1044 nfs_unlock_request(req);
1045 nfs_end_page_writeback(req->wb_page);
1046 nfs_release_request(req);
1047}
1048
1049static void nfs_async_write_error(struct list_head *head)
1050{
1051 struct nfs_page *req;
1052
1053 while (!list_empty(head)) {
1054 req = nfs_list_entry(head->next);
1055 nfs_list_remove_request(req);
1056 nfs_redirty_request(req);
1057 }
1058}
1059
1060static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops = {
1061 .error_cleanup = nfs_async_write_error,
1062 .completion = nfs_write_completion,
1063};
1064
1065static void nfs_flush_error(struct nfs_pageio_descriptor *desc,
1066 struct nfs_pgio_header *hdr)
1067{
1068 set_bit(NFS_IOHDR_REDO, &hdr->flags);
1069 while (!list_empty(&hdr->rpc_list)) {
1070 struct nfs_write_data *data = list_first_entry(&hdr->rpc_list,
1071 struct nfs_write_data, list);
1072 list_del(&data->list);
1073 nfs_writedata_release(data);
1074 }
1075 desc->pg_completion_ops->error_cleanup(&desc->pg_list);
1076}
1077
1078/*
1079 * Generate multiple small requests to write out a single
1080 * contiguous dirty area on one page.
1081 */
1082static int nfs_flush_multi(struct nfs_pageio_descriptor *desc,
1083 struct nfs_pgio_header *hdr)
1084{
1085 struct nfs_page *req = hdr->req;
1086 struct page *page = req->wb_page;
1087 struct nfs_write_data *data;
1088 size_t wsize = desc->pg_bsize, nbytes;
1089 unsigned int offset;
1090 int requests = 0;
1091 struct nfs_commit_info cinfo;
1092
1093 nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq);
1094
1095 if ((desc->pg_ioflags & FLUSH_COND_STABLE) &&
1096 (desc->pg_moreio || nfs_reqs_to_commit(&cinfo) ||
1097 desc->pg_count > wsize))
1098 desc->pg_ioflags &= ~FLUSH_COND_STABLE;
1099
1100
1101 offset = 0;
1102 nbytes = desc->pg_count;
1103 do {
1104 size_t len = min(nbytes, wsize);
1105
1106 data = nfs_writedata_alloc(hdr, 1);
1107 if (!data) {
1108 nfs_flush_error(desc, hdr);
1109 return -ENOMEM;
1110 }
1111 data->pages.pagevec[0] = page;
1112 nfs_write_rpcsetup(data, len, offset, desc->pg_ioflags, &cinfo);
1113 list_add(&data->list, &hdr->rpc_list);
1114 requests++;
1115 nbytes -= len;
1116 offset += len;
1117 } while (nbytes != 0);
1118 nfs_list_remove_request(req);
1119 nfs_list_add_request(req, &hdr->pages);
1120 desc->pg_rpc_callops = &nfs_write_common_ops;
1121 return 0;
1122}
1123
1124/*
1125 * Create an RPC task for the given write request and kick it.
1126 * The page must have been locked by the caller.
1127 *
1128 * It may happen that the page we're passed is not marked dirty.
1129 * This is the case if nfs_updatepage detects a conflicting request
1130 * that has been written but not committed.
1131 */
1132static int nfs_flush_one(struct nfs_pageio_descriptor *desc,
1133 struct nfs_pgio_header *hdr)
1134{
1135 struct nfs_page *req;
1136 struct page **pages;
1137 struct nfs_write_data *data;
1138 struct list_head *head = &desc->pg_list;
1139 struct nfs_commit_info cinfo;
1140
1141 data = nfs_writedata_alloc(hdr, nfs_page_array_len(desc->pg_base,
1142 desc->pg_count));
1143 if (!data) {
1144 nfs_flush_error(desc, hdr);
1145 return -ENOMEM;
1146 }
1147
1148 nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq);
1149 pages = data->pages.pagevec;
1150 while (!list_empty(head)) {
1151 req = nfs_list_entry(head->next);
1152 nfs_list_remove_request(req);
1153 nfs_list_add_request(req, &hdr->pages);
1154 *pages++ = req->wb_page;
1155 }
1156
1157 if ((desc->pg_ioflags & FLUSH_COND_STABLE) &&
1158 (desc->pg_moreio || nfs_reqs_to_commit(&cinfo)))
1159 desc->pg_ioflags &= ~FLUSH_COND_STABLE;
1160
1161 /* Set up the argument struct */
1162 nfs_write_rpcsetup(data, desc->pg_count, 0, desc->pg_ioflags, &cinfo);
1163 list_add(&data->list, &hdr->rpc_list);
1164 desc->pg_rpc_callops = &nfs_write_common_ops;
1165 return 0;
1166}
1167
1168int nfs_generic_flush(struct nfs_pageio_descriptor *desc,
1169 struct nfs_pgio_header *hdr)
1170{
1171 if (desc->pg_bsize < PAGE_CACHE_SIZE)
1172 return nfs_flush_multi(desc, hdr);
1173 return nfs_flush_one(desc, hdr);
1174}
1175
1176static int nfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
1177{
1178 struct nfs_write_header *whdr;
1179 struct nfs_pgio_header *hdr;
1180 int ret;
1181
1182 whdr = nfs_writehdr_alloc();
1183 if (!whdr) {
1184 desc->pg_completion_ops->error_cleanup(&desc->pg_list);
1185 return -ENOMEM;
1186 }
1187 hdr = &whdr->header;
1188 nfs_pgheader_init(desc, hdr, nfs_writehdr_free);
1189 atomic_inc(&hdr->refcnt);
1190 ret = nfs_generic_flush(desc, hdr);
1191 if (ret == 0)
1192 ret = nfs_do_multiple_writes(&hdr->rpc_list,
1193 desc->pg_rpc_callops,
1194 desc->pg_ioflags);
1195 if (atomic_dec_and_test(&hdr->refcnt))
1196 hdr->completion_ops->completion(hdr);
1197 return ret;
1198}
1199
1200static const struct nfs_pageio_ops nfs_pageio_write_ops = {
1201 .pg_test = nfs_generic_pg_test,
1202 .pg_doio = nfs_generic_pg_writepages,
1203};
1204
1205void nfs_pageio_init_write_mds(struct nfs_pageio_descriptor *pgio,
1206 struct inode *inode, int ioflags,
1207 const struct nfs_pgio_completion_ops *compl_ops)
1208{
1209 nfs_pageio_init(pgio, inode, &nfs_pageio_write_ops, compl_ops,
1210 NFS_SERVER(inode)->wsize, ioflags);
1211}
1212
1213void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio)
1214{
1215 pgio->pg_ops = &nfs_pageio_write_ops;
1216 pgio->pg_bsize = NFS_SERVER(pgio->pg_inode)->wsize;
1217}
1218EXPORT_SYMBOL_GPL(nfs_pageio_reset_write_mds);
1219
1220void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
1221 struct inode *inode, int ioflags,
1222 const struct nfs_pgio_completion_ops *compl_ops)
1223{
1224 if (!pnfs_pageio_init_write(pgio, inode, ioflags, compl_ops))
1225 nfs_pageio_init_write_mds(pgio, inode, ioflags, compl_ops);
1226}
1227
1228void nfs_write_prepare(struct rpc_task *task, void *calldata)
1229{
1230 struct nfs_write_data *data = calldata;
1231 NFS_PROTO(data->header->inode)->write_rpc_prepare(task, data);
1232}
1233
1234void nfs_commit_prepare(struct rpc_task *task, void *calldata)
1235{
1236 struct nfs_commit_data *data = calldata;
1237
1238 NFS_PROTO(data->inode)->commit_rpc_prepare(task, data);
1239}
1240
1241/*
1242 * Handle a write reply that flushes a whole page.
1243 *
1244 * FIXME: There is an inherent race with invalidate_inode_pages and
1245 * writebacks since the page->count is kept > 1 for as long
1246 * as the page has a write request pending.
1247 */
1248static void nfs_writeback_done_common(struct rpc_task *task, void *calldata)
1249{
1250 struct nfs_write_data *data = calldata;
1251
1252 nfs_writeback_done(task, data);
1253}
1254
1255static void nfs_writeback_release_common(void *calldata)
1256{
1257 struct nfs_write_data *data = calldata;
1258 struct nfs_pgio_header *hdr = data->header;
1259 int status = data->task.tk_status;
1260
1261 if ((status >= 0) && nfs_write_need_commit(data)) {
1262 spin_lock(&hdr->lock);
1263 if (test_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags))
1264 ; /* Do nothing */
1265 else if (!test_and_set_bit(NFS_IOHDR_NEED_COMMIT, &hdr->flags))
1266 memcpy(hdr->verf, &data->verf, sizeof(*hdr->verf));
1267 else if (memcmp(hdr->verf, &data->verf, sizeof(*hdr->verf)))
1268 set_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags);
1269 spin_unlock(&hdr->lock);
1270 }
1271 nfs_writedata_release(data);
1272}
1273
1274static const struct rpc_call_ops nfs_write_common_ops = {
1275 .rpc_call_prepare = nfs_write_prepare,
1276 .rpc_call_done = nfs_writeback_done_common,
1277 .rpc_release = nfs_writeback_release_common,
1278};
1279
1280
1281/*
1282 * This function is called when the WRITE call is complete.
1283 */
1284void nfs_writeback_done(struct rpc_task *task, struct nfs_write_data *data)
1285{
1286 struct nfs_writeargs *argp = &data->args;
1287 struct nfs_writeres *resp = &data->res;
1288 struct inode *inode = data->header->inode;
1289 int status;
1290
1291 dprintk("NFS: %5u nfs_writeback_done (status %d)\n",
1292 task->tk_pid, task->tk_status);
1293
1294 /*
1295 * ->write_done will attempt to use post-op attributes to detect
1296 * conflicting writes by other clients. A strict interpretation
1297 * of close-to-open would allow us to continue caching even if
1298 * another writer had changed the file, but some applications
1299 * depend on tighter cache coherency when writing.
1300 */
1301 status = NFS_PROTO(inode)->write_done(task, data);
1302 if (status != 0)
1303 return;
1304 nfs_add_stats(inode, NFSIOS_SERVERWRITTENBYTES, resp->count);
1305
1306#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
1307 if (resp->verf->committed < argp->stable && task->tk_status >= 0) {
1308 /* We tried a write call, but the server did not
1309 * commit data to stable storage even though we
1310 * requested it.
1311 * Note: There is a known bug in Tru64 < 5.0 in which
1312 * the server reports NFS_DATA_SYNC, but performs
1313 * NFS_FILE_SYNC. We therefore implement this checking
1314 * as a dprintk() in order to avoid filling syslog.
1315 */
1316 static unsigned long complain;
1317
1318 /* Note this will print the MDS for a DS write */
1319 if (time_before(complain, jiffies)) {
1320 dprintk("NFS: faulty NFS server %s:"
1321 " (committed = %d) != (stable = %d)\n",
1322 NFS_SERVER(inode)->nfs_client->cl_hostname,
1323 resp->verf->committed, argp->stable);
1324 complain = jiffies + 300 * HZ;
1325 }
1326 }
1327#endif
1328 if (task->tk_status < 0)
1329 nfs_set_pgio_error(data->header, task->tk_status, argp->offset);
1330 else if (resp->count < argp->count) {
1331 static unsigned long complain;
1332
1333 /* This a short write! */
1334 nfs_inc_stats(inode, NFSIOS_SHORTWRITE);
1335
1336 /* Has the server at least made some progress? */
1337 if (resp->count == 0) {
1338 if (time_before(complain, jiffies)) {
1339 printk(KERN_WARNING
1340 "NFS: Server wrote zero bytes, expected %u.\n",
1341 argp->count);
1342 complain = jiffies + 300 * HZ;
1343 }
1344 nfs_set_pgio_error(data->header, -EIO, argp->offset);
1345 task->tk_status = -EIO;
1346 return;
1347 }
1348 /* Was this an NFSv2 write or an NFSv3 stable write? */
1349 if (resp->verf->committed != NFS_UNSTABLE) {
1350 /* Resend from where the server left off */
1351 data->mds_offset += resp->count;
1352 argp->offset += resp->count;
1353 argp->pgbase += resp->count;
1354 argp->count -= resp->count;
1355 } else {
1356 /* Resend as a stable write in order to avoid
1357 * headaches in the case of a server crash.
1358 */
1359 argp->stable = NFS_FILE_SYNC;
1360 }
1361 rpc_restart_call_prepare(task);
1362 }
1363}
1364
1365
1366#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
1367static int nfs_commit_set_lock(struct nfs_inode *nfsi, int may_wait)
1368{
1369 int ret;
1370
1371 if (!test_and_set_bit(NFS_INO_COMMIT, &nfsi->flags))
1372 return 1;
1373 if (!may_wait)
1374 return 0;
1375 ret = out_of_line_wait_on_bit_lock(&nfsi->flags,
1376 NFS_INO_COMMIT,
1377 nfs_wait_bit_killable,
1378 TASK_KILLABLE);
1379 return (ret < 0) ? ret : 1;
1380}
1381
1382static void nfs_commit_clear_lock(struct nfs_inode *nfsi)
1383{
1384 clear_bit(NFS_INO_COMMIT, &nfsi->flags);
1385 smp_mb__after_clear_bit();
1386 wake_up_bit(&nfsi->flags, NFS_INO_COMMIT);
1387}
1388
1389void nfs_commitdata_release(struct nfs_commit_data *data)
1390{
1391 put_nfs_open_context(data->context);
1392 nfs_commit_free(data);
1393}
1394EXPORT_SYMBOL_GPL(nfs_commitdata_release);
1395
1396int nfs_initiate_commit(struct rpc_clnt *clnt, struct nfs_commit_data *data,
1397 const struct rpc_call_ops *call_ops,
1398 int how, int flags)
1399{
1400 struct rpc_task *task;
1401 int priority = flush_task_priority(how);
1402 struct rpc_message msg = {
1403 .rpc_argp = &data->args,
1404 .rpc_resp = &data->res,
1405 .rpc_cred = data->cred,
1406 };
1407 struct rpc_task_setup task_setup_data = {
1408 .task = &data->task,
1409 .rpc_client = clnt,
1410 .rpc_message = &msg,
1411 .callback_ops = call_ops,
1412 .callback_data = data,
1413 .workqueue = nfsiod_workqueue,
1414 .flags = RPC_TASK_ASYNC | flags,
1415 .priority = priority,
1416 };
1417 /* Set up the initial task struct. */
1418 NFS_PROTO(data->inode)->commit_setup(data, &msg);
1419
1420 dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid);
1421
1422 task = rpc_run_task(&task_setup_data);
1423 if (IS_ERR(task))
1424 return PTR_ERR(task);
1425 if (how & FLUSH_SYNC)
1426 rpc_wait_for_completion_task(task);
1427 rpc_put_task(task);
1428 return 0;
1429}
1430EXPORT_SYMBOL_GPL(nfs_initiate_commit);
1431
1432/*
1433 * Set up the argument/result storage required for the RPC call.
1434 */
1435void nfs_init_commit(struct nfs_commit_data *data,
1436 struct list_head *head,
1437 struct pnfs_layout_segment *lseg,
1438 struct nfs_commit_info *cinfo)
1439{
1440 struct nfs_page *first = nfs_list_entry(head->next);
1441 struct inode *inode = first->wb_context->dentry->d_inode;
1442
1443 /* Set up the RPC argument and reply structs
1444 * NB: take care not to mess about with data->commit et al. */
1445
1446 list_splice_init(head, &data->pages);
1447
1448 data->inode = inode;
1449 data->cred = first->wb_context->cred;
1450 data->lseg = lseg; /* reference transferred */
1451 data->mds_ops = &nfs_commit_ops;
1452 data->completion_ops = cinfo->completion_ops;
1453 data->dreq = cinfo->dreq;
1454
1455 data->args.fh = NFS_FH(data->inode);
1456 /* Note: we always request a commit of the entire inode */
1457 data->args.offset = 0;
1458 data->args.count = 0;
1459 data->context = get_nfs_open_context(first->wb_context);
1460 data->res.fattr = &data->fattr;
1461 data->res.verf = &data->verf;
1462 nfs_fattr_init(&data->fattr);
1463}
1464EXPORT_SYMBOL_GPL(nfs_init_commit);
1465
1466void nfs_retry_commit(struct list_head *page_list,
1467 struct pnfs_layout_segment *lseg,
1468 struct nfs_commit_info *cinfo)
1469{
1470 struct nfs_page *req;
1471
1472 while (!list_empty(page_list)) {
1473 req = nfs_list_entry(page_list->next);
1474 nfs_list_remove_request(req);
1475 nfs_mark_request_commit(req, lseg, cinfo);
1476 if (!cinfo->dreq) {
1477 dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
1478 dec_bdi_stat(req->wb_page->mapping->backing_dev_info,
1479 BDI_RECLAIMABLE);
1480 }
1481 nfs_unlock_and_release_request(req);
1482 }
1483}
1484EXPORT_SYMBOL_GPL(nfs_retry_commit);
1485
1486/*
1487 * Commit dirty pages
1488 */
1489static int
1490nfs_commit_list(struct inode *inode, struct list_head *head, int how,
1491 struct nfs_commit_info *cinfo)
1492{
1493 struct nfs_commit_data *data;
1494
1495 data = nfs_commitdata_alloc();
1496
1497 if (!data)
1498 goto out_bad;
1499
1500 /* Set up the argument struct */
1501 nfs_init_commit(data, head, NULL, cinfo);
1502 atomic_inc(&cinfo->mds->rpcs_out);
1503 return nfs_initiate_commit(NFS_CLIENT(inode), data, data->mds_ops,
1504 how, 0);
1505 out_bad:
1506 nfs_retry_commit(head, NULL, cinfo);
1507 cinfo->completion_ops->error_cleanup(NFS_I(inode));
1508 return -ENOMEM;
1509}
1510
1511/*
1512 * COMMIT call returned
1513 */
1514static void nfs_commit_done(struct rpc_task *task, void *calldata)
1515{
1516 struct nfs_commit_data *data = calldata;
1517
1518 dprintk("NFS: %5u nfs_commit_done (status %d)\n",
1519 task->tk_pid, task->tk_status);
1520
1521 /* Call the NFS version-specific code */
1522 NFS_PROTO(data->inode)->commit_done(task, data);
1523}
1524
1525static void nfs_commit_release_pages(struct nfs_commit_data *data)
1526{
1527 struct nfs_page *req;
1528 int status = data->task.tk_status;
1529 struct nfs_commit_info cinfo;
1530
1531 while (!list_empty(&data->pages)) {
1532 req = nfs_list_entry(data->pages.next);
1533 nfs_list_remove_request(req);
1534 nfs_clear_page_commit(req->wb_page);
1535
1536 dprintk("NFS: commit (%s/%lld %d@%lld)",
1537 req->wb_context->dentry->d_sb->s_id,
1538 (long long)NFS_FILEID(req->wb_context->dentry->d_inode),
1539 req->wb_bytes,
1540 (long long)req_offset(req));
1541 if (status < 0) {
1542 nfs_context_set_write_error(req->wb_context, status);
1543 nfs_inode_remove_request(req);
1544 dprintk(", error = %d\n", status);
1545 goto next;
1546 }
1547
1548 /* Okay, COMMIT succeeded, apparently. Check the verifier
1549 * returned by the server against all stored verfs. */
1550 if (!memcmp(req->wb_verf.verifier, data->verf.verifier, sizeof(data->verf.verifier))) {
1551 /* We have a match */
1552 nfs_inode_remove_request(req);
1553 dprintk(" OK\n");
1554 goto next;
1555 }
1556 /* We have a mismatch. Write the page again */
1557 dprintk(" mismatch\n");
1558 nfs_mark_request_dirty(req);
1559 next:
1560 nfs_unlock_and_release_request(req);
1561 }
1562 nfs_init_cinfo(&cinfo, data->inode, data->dreq);
1563 if (atomic_dec_and_test(&cinfo.mds->rpcs_out))
1564 nfs_commit_clear_lock(NFS_I(data->inode));
1565}
1566
1567static void nfs_commit_release(void *calldata)
1568{
1569 struct nfs_commit_data *data = calldata;
1570
1571 data->completion_ops->completion(data);
1572 nfs_commitdata_release(calldata);
1573}
1574
1575static const struct rpc_call_ops nfs_commit_ops = {
1576 .rpc_call_prepare = nfs_commit_prepare,
1577 .rpc_call_done = nfs_commit_done,
1578 .rpc_release = nfs_commit_release,
1579};
1580
1581static const struct nfs_commit_completion_ops nfs_commit_completion_ops = {
1582 .completion = nfs_commit_release_pages,
1583 .error_cleanup = nfs_commit_clear_lock,
1584};
1585
1586int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
1587 int how, struct nfs_commit_info *cinfo)
1588{
1589 int status;
1590
1591 status = pnfs_commit_list(inode, head, how, cinfo);
1592 if (status == PNFS_NOT_ATTEMPTED)
1593 status = nfs_commit_list(inode, head, how, cinfo);
1594 return status;
1595}
1596
1597int nfs_commit_inode(struct inode *inode, int how)
1598{
1599 LIST_HEAD(head);
1600 struct nfs_commit_info cinfo;
1601 int may_wait = how & FLUSH_SYNC;
1602 int res;
1603
1604 res = nfs_commit_set_lock(NFS_I(inode), may_wait);
1605 if (res <= 0)
1606 goto out_mark_dirty;
1607 nfs_init_cinfo_from_inode(&cinfo, inode);
1608 res = nfs_scan_commit(inode, &head, &cinfo);
1609 if (res) {
1610 int error;
1611
1612 error = nfs_generic_commit_list(inode, &head, how, &cinfo);
1613 if (error < 0)
1614 return error;
1615 if (!may_wait)
1616 goto out_mark_dirty;
1617 error = wait_on_bit(&NFS_I(inode)->flags,
1618 NFS_INO_COMMIT,
1619 nfs_wait_bit_killable,
1620 TASK_KILLABLE);
1621 if (error < 0)
1622 return error;
1623 } else
1624 nfs_commit_clear_lock(NFS_I(inode));
1625 return res;
1626 /* Note: If we exit without ensuring that the commit is complete,
1627 * we must mark the inode as dirty. Otherwise, future calls to
1628 * sync_inode() with the WB_SYNC_ALL flag set will fail to ensure
1629 * that the data is on the disk.
1630 */
1631out_mark_dirty:
1632 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
1633 return res;
1634}
1635
1636static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_control *wbc)
1637{
1638 struct nfs_inode *nfsi = NFS_I(inode);
1639 int flags = FLUSH_SYNC;
1640 int ret = 0;
1641
1642 /* no commits means nothing needs to be done */
1643 if (!nfsi->commit_info.ncommit)
1644 return ret;
1645
1646 if (wbc->sync_mode == WB_SYNC_NONE) {
1647 /* Don't commit yet if this is a non-blocking flush and there
1648 * are a lot of outstanding writes for this mapping.
1649 */
1650 if (nfsi->commit_info.ncommit <= (nfsi->npages >> 1))
1651 goto out_mark_dirty;
1652
1653 /* don't wait for the COMMIT response */
1654 flags = 0;
1655 }
1656
1657 ret = nfs_commit_inode(inode, flags);
1658 if (ret >= 0) {
1659 if (wbc->sync_mode == WB_SYNC_NONE) {
1660 if (ret < wbc->nr_to_write)
1661 wbc->nr_to_write -= ret;
1662 else
1663 wbc->nr_to_write = 0;
1664 }
1665 return 0;
1666 }
1667out_mark_dirty:
1668 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
1669 return ret;
1670}
1671#else
1672static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_control *wbc)
1673{
1674 return 0;
1675}
1676#endif
1677
1678int nfs_write_inode(struct inode *inode, struct writeback_control *wbc)
1679{
1680 int ret;
1681
1682 ret = nfs_commit_unstable_pages(inode, wbc);
1683 if (ret >= 0 && test_bit(NFS_INO_LAYOUTCOMMIT, &NFS_I(inode)->flags)) {
1684 int status;
1685 bool sync = true;
1686
1687 if (wbc->sync_mode == WB_SYNC_NONE)
1688 sync = false;
1689
1690 status = pnfs_layoutcommit_inode(inode, sync);
1691 if (status < 0)
1692 return status;
1693 }
1694 return ret;
1695}
1696
1697/*
1698 * flush the inode to disk.
1699 */
1700int nfs_wb_all(struct inode *inode)
1701{
1702 struct writeback_control wbc = {
1703 .sync_mode = WB_SYNC_ALL,
1704 .nr_to_write = LONG_MAX,
1705 .range_start = 0,
1706 .range_end = LLONG_MAX,
1707 };
1708
1709 return sync_inode(inode, &wbc);
1710}
1711
1712int nfs_wb_page_cancel(struct inode *inode, struct page *page)
1713{
1714 struct nfs_page *req;
1715 int ret = 0;
1716
1717 BUG_ON(!PageLocked(page));
1718 for (;;) {
1719 wait_on_page_writeback(page);
1720 req = nfs_page_find_request(page);
1721 if (req == NULL)
1722 break;
1723 if (nfs_lock_request(req)) {
1724 nfs_clear_request_commit(req);
1725 nfs_inode_remove_request(req);
1726 /*
1727 * In case nfs_inode_remove_request has marked the
1728 * page as being dirty
1729 */
1730 cancel_dirty_page(page, PAGE_CACHE_SIZE);
1731 nfs_unlock_and_release_request(req);
1732 break;
1733 }
1734 ret = nfs_wait_on_request(req);
1735 nfs_release_request(req);
1736 if (ret < 0)
1737 break;
1738 }
1739 return ret;
1740}
1741
1742/*
1743 * Write back all requests on one page - we do this before reading it.
1744 */
1745int nfs_wb_page(struct inode *inode, struct page *page)
1746{
1747 loff_t range_start = page_offset(page);
1748 loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
1749 struct writeback_control wbc = {
1750 .sync_mode = WB_SYNC_ALL,
1751 .nr_to_write = 0,
1752 .range_start = range_start,
1753 .range_end = range_end,
1754 };
1755 int ret;
1756
1757 for (;;) {
1758 wait_on_page_writeback(page);
1759 if (clear_page_dirty_for_io(page)) {
1760 ret = nfs_writepage_locked(page, &wbc);
1761 if (ret < 0)
1762 goto out_error;
1763 continue;
1764 }
1765 if (!PagePrivate(page))
1766 break;
1767 ret = nfs_commit_inode(inode, FLUSH_SYNC);
1768 if (ret < 0)
1769 goto out_error;
1770 }
1771 return 0;
1772out_error:
1773 return ret;
1774}
1775
1776#ifdef CONFIG_MIGRATION
1777int nfs_migrate_page(struct address_space *mapping, struct page *newpage,
1778 struct page *page, enum migrate_mode mode)
1779{
1780 /*
1781 * If PagePrivate is set, then the page is currently associated with
1782 * an in-progress read or write request. Don't try to migrate it.
1783 *
1784 * FIXME: we could do this in principle, but we'll need a way to ensure
1785 * that we can safely release the inode reference while holding
1786 * the page lock.
1787 */
1788 if (PagePrivate(page))
1789 return -EBUSY;
1790
1791 nfs_fscache_release_page(page, GFP_KERNEL);
1792
1793 return migrate_page(mapping, newpage, page, mode);
1794}
1795#endif
1796
1797int __init nfs_init_writepagecache(void)
1798{
1799 nfs_wdata_cachep = kmem_cache_create("nfs_write_data",
1800 sizeof(struct nfs_write_header),
1801 0, SLAB_HWCACHE_ALIGN,
1802 NULL);
1803 if (nfs_wdata_cachep == NULL)
1804 return -ENOMEM;
1805
1806 nfs_wdata_mempool = mempool_create_slab_pool(MIN_POOL_WRITE,
1807 nfs_wdata_cachep);
1808 if (nfs_wdata_mempool == NULL)
1809 goto out_destroy_write_cache;
1810
1811 nfs_cdata_cachep = kmem_cache_create("nfs_commit_data",
1812 sizeof(struct nfs_commit_data),
1813 0, SLAB_HWCACHE_ALIGN,
1814 NULL);
1815 if (nfs_cdata_cachep == NULL)
1816 goto out_destroy_write_mempool;
1817
1818 nfs_commit_mempool = mempool_create_slab_pool(MIN_POOL_COMMIT,
1819 nfs_wdata_cachep);
1820 if (nfs_commit_mempool == NULL)
1821 goto out_destroy_commit_cache;
1822
1823 /*
1824 * NFS congestion size, scale with available memory.
1825 *
1826 * 64MB: 8192k
1827 * 128MB: 11585k
1828 * 256MB: 16384k
1829 * 512MB: 23170k
1830 * 1GB: 32768k
1831 * 2GB: 46340k
1832 * 4GB: 65536k
1833 * 8GB: 92681k
1834 * 16GB: 131072k
1835 *
1836 * This allows larger machines to have larger/more transfers.
1837 * Limit the default to 256M
1838 */
1839 nfs_congestion_kb = (16*int_sqrt(totalram_pages)) << (PAGE_SHIFT-10);
1840 if (nfs_congestion_kb > 256*1024)
1841 nfs_congestion_kb = 256*1024;
1842
1843 return 0;
1844
1845out_destroy_commit_cache:
1846 kmem_cache_destroy(nfs_cdata_cachep);
1847out_destroy_write_mempool:
1848 mempool_destroy(nfs_wdata_mempool);
1849out_destroy_write_cache:
1850 kmem_cache_destroy(nfs_wdata_cachep);
1851 return -ENOMEM;
1852}
1853
1854void nfs_destroy_writepagecache(void)
1855{
1856 mempool_destroy(nfs_commit_mempool);
1857 kmem_cache_destroy(nfs_cdata_cachep);
1858 mempool_destroy(nfs_wdata_mempool);
1859 kmem_cache_destroy(nfs_wdata_cachep);
1860}
1861
1/*
2 * linux/fs/nfs/write.c
3 *
4 * Write file data over NFS.
5 *
6 * Copyright (C) 1996, 1997, Olaf Kirch <okir@monad.swb.de>
7 */
8
9#include <linux/types.h>
10#include <linux/slab.h>
11#include <linux/mm.h>
12#include <linux/pagemap.h>
13#include <linux/file.h>
14#include <linux/writeback.h>
15#include <linux/swap.h>
16#include <linux/migrate.h>
17
18#include <linux/sunrpc/clnt.h>
19#include <linux/nfs_fs.h>
20#include <linux/nfs_mount.h>
21#include <linux/nfs_page.h>
22#include <linux/backing-dev.h>
23#include <linux/export.h>
24
25#include <asm/uaccess.h>
26
27#include "delegation.h"
28#include "internal.h"
29#include "iostat.h"
30#include "nfs4_fs.h"
31#include "fscache.h"
32#include "pnfs.h"
33
34#include "nfstrace.h"
35
36#define NFSDBG_FACILITY NFSDBG_PAGECACHE
37
38#define MIN_POOL_WRITE (32)
39#define MIN_POOL_COMMIT (4)
40
41/*
42 * Local function declarations
43 */
44static void nfs_redirty_request(struct nfs_page *req);
45static const struct rpc_call_ops nfs_write_common_ops;
46static const struct rpc_call_ops nfs_commit_ops;
47static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops;
48static const struct nfs_commit_completion_ops nfs_commit_completion_ops;
49
50static struct kmem_cache *nfs_wdata_cachep;
51static mempool_t *nfs_wdata_mempool;
52static struct kmem_cache *nfs_cdata_cachep;
53static mempool_t *nfs_commit_mempool;
54
55struct nfs_commit_data *nfs_commitdata_alloc(void)
56{
57 struct nfs_commit_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOIO);
58
59 if (p) {
60 memset(p, 0, sizeof(*p));
61 INIT_LIST_HEAD(&p->pages);
62 }
63 return p;
64}
65EXPORT_SYMBOL_GPL(nfs_commitdata_alloc);
66
67void nfs_commit_free(struct nfs_commit_data *p)
68{
69 mempool_free(p, nfs_commit_mempool);
70}
71EXPORT_SYMBOL_GPL(nfs_commit_free);
72
73struct nfs_write_header *nfs_writehdr_alloc(void)
74{
75 struct nfs_write_header *p = mempool_alloc(nfs_wdata_mempool, GFP_NOIO);
76
77 if (p) {
78 struct nfs_pgio_header *hdr = &p->header;
79
80 memset(p, 0, sizeof(*p));
81 INIT_LIST_HEAD(&hdr->pages);
82 INIT_LIST_HEAD(&hdr->rpc_list);
83 spin_lock_init(&hdr->lock);
84 atomic_set(&hdr->refcnt, 0);
85 hdr->verf = &p->verf;
86 }
87 return p;
88}
89EXPORT_SYMBOL_GPL(nfs_writehdr_alloc);
90
91static struct nfs_write_data *nfs_writedata_alloc(struct nfs_pgio_header *hdr,
92 unsigned int pagecount)
93{
94 struct nfs_write_data *data, *prealloc;
95
96 prealloc = &container_of(hdr, struct nfs_write_header, header)->rpc_data;
97 if (prealloc->header == NULL)
98 data = prealloc;
99 else
100 data = kzalloc(sizeof(*data), GFP_KERNEL);
101 if (!data)
102 goto out;
103
104 if (nfs_pgarray_set(&data->pages, pagecount)) {
105 data->header = hdr;
106 atomic_inc(&hdr->refcnt);
107 } else {
108 if (data != prealloc)
109 kfree(data);
110 data = NULL;
111 }
112out:
113 return data;
114}
115
116void nfs_writehdr_free(struct nfs_pgio_header *hdr)
117{
118 struct nfs_write_header *whdr = container_of(hdr, struct nfs_write_header, header);
119 mempool_free(whdr, nfs_wdata_mempool);
120}
121EXPORT_SYMBOL_GPL(nfs_writehdr_free);
122
123void nfs_writedata_release(struct nfs_write_data *wdata)
124{
125 struct nfs_pgio_header *hdr = wdata->header;
126 struct nfs_write_header *write_header = container_of(hdr, struct nfs_write_header, header);
127
128 put_nfs_open_context(wdata->args.context);
129 if (wdata->pages.pagevec != wdata->pages.page_array)
130 kfree(wdata->pages.pagevec);
131 if (wdata == &write_header->rpc_data) {
132 wdata->header = NULL;
133 wdata = NULL;
134 }
135 if (atomic_dec_and_test(&hdr->refcnt))
136 hdr->completion_ops->completion(hdr);
137 /* Note: we only free the rpc_task after callbacks are done.
138 * See the comment in rpc_free_task() for why
139 */
140 kfree(wdata);
141}
142EXPORT_SYMBOL_GPL(nfs_writedata_release);
143
144static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error)
145{
146 ctx->error = error;
147 smp_wmb();
148 set_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags);
149}
150
151static struct nfs_page *
152nfs_page_find_request_locked(struct nfs_inode *nfsi, struct page *page)
153{
154 struct nfs_page *req = NULL;
155
156 if (PagePrivate(page))
157 req = (struct nfs_page *)page_private(page);
158 else if (unlikely(PageSwapCache(page))) {
159 struct nfs_page *freq, *t;
160
161 /* Linearly search the commit list for the correct req */
162 list_for_each_entry_safe(freq, t, &nfsi->commit_info.list, wb_list) {
163 if (freq->wb_page == page) {
164 req = freq;
165 break;
166 }
167 }
168 }
169
170 if (req)
171 kref_get(&req->wb_kref);
172
173 return req;
174}
175
176static struct nfs_page *nfs_page_find_request(struct page *page)
177{
178 struct inode *inode = page_file_mapping(page)->host;
179 struct nfs_page *req = NULL;
180
181 spin_lock(&inode->i_lock);
182 req = nfs_page_find_request_locked(NFS_I(inode), page);
183 spin_unlock(&inode->i_lock);
184 return req;
185}
186
187/* Adjust the file length if we're writing beyond the end */
188static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count)
189{
190 struct inode *inode = page_file_mapping(page)->host;
191 loff_t end, i_size;
192 pgoff_t end_index;
193
194 spin_lock(&inode->i_lock);
195 i_size = i_size_read(inode);
196 end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
197 if (i_size > 0 && page_file_index(page) < end_index)
198 goto out;
199 end = page_file_offset(page) + ((loff_t)offset+count);
200 if (i_size >= end)
201 goto out;
202 i_size_write(inode, end);
203 nfs_inc_stats(inode, NFSIOS_EXTENDWRITE);
204out:
205 spin_unlock(&inode->i_lock);
206}
207
208/* A writeback failed: mark the page as bad, and invalidate the page cache */
209static void nfs_set_pageerror(struct page *page)
210{
211 nfs_zap_mapping(page_file_mapping(page)->host, page_file_mapping(page));
212}
213
214/* We can set the PG_uptodate flag if we see that a write request
215 * covers the full page.
216 */
217static void nfs_mark_uptodate(struct page *page, unsigned int base, unsigned int count)
218{
219 if (PageUptodate(page))
220 return;
221 if (base != 0)
222 return;
223 if (count != nfs_page_length(page))
224 return;
225 SetPageUptodate(page);
226}
227
228static int wb_priority(struct writeback_control *wbc)
229{
230 if (wbc->for_reclaim)
231 return FLUSH_HIGHPRI | FLUSH_STABLE;
232 if (wbc->for_kupdate || wbc->for_background)
233 return FLUSH_LOWPRI | FLUSH_COND_STABLE;
234 return FLUSH_COND_STABLE;
235}
236
237/*
238 * NFS congestion control
239 */
240
241int nfs_congestion_kb;
242
243#define NFS_CONGESTION_ON_THRESH (nfs_congestion_kb >> (PAGE_SHIFT-10))
244#define NFS_CONGESTION_OFF_THRESH \
245 (NFS_CONGESTION_ON_THRESH - (NFS_CONGESTION_ON_THRESH >> 2))
246
247static void nfs_set_page_writeback(struct page *page)
248{
249 struct nfs_server *nfss = NFS_SERVER(page_file_mapping(page)->host);
250 int ret = test_set_page_writeback(page);
251
252 WARN_ON_ONCE(ret != 0);
253
254 if (atomic_long_inc_return(&nfss->writeback) >
255 NFS_CONGESTION_ON_THRESH) {
256 set_bdi_congested(&nfss->backing_dev_info,
257 BLK_RW_ASYNC);
258 }
259}
260
261static void nfs_end_page_writeback(struct page *page)
262{
263 struct inode *inode = page_file_mapping(page)->host;
264 struct nfs_server *nfss = NFS_SERVER(inode);
265
266 end_page_writeback(page);
267 if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH)
268 clear_bdi_congested(&nfss->backing_dev_info, BLK_RW_ASYNC);
269}
270
271static struct nfs_page *nfs_find_and_lock_request(struct page *page, bool nonblock)
272{
273 struct inode *inode = page_file_mapping(page)->host;
274 struct nfs_page *req;
275 int ret;
276
277 spin_lock(&inode->i_lock);
278 for (;;) {
279 req = nfs_page_find_request_locked(NFS_I(inode), page);
280 if (req == NULL)
281 break;
282 if (nfs_lock_request(req))
283 break;
284 /* Note: If we hold the page lock, as is the case in nfs_writepage,
285 * then the call to nfs_lock_request() will always
286 * succeed provided that someone hasn't already marked the
287 * request as dirty (in which case we don't care).
288 */
289 spin_unlock(&inode->i_lock);
290 if (!nonblock)
291 ret = nfs_wait_on_request(req);
292 else
293 ret = -EAGAIN;
294 nfs_release_request(req);
295 if (ret != 0)
296 return ERR_PTR(ret);
297 spin_lock(&inode->i_lock);
298 }
299 spin_unlock(&inode->i_lock);
300 return req;
301}
302
303/*
304 * Find an associated nfs write request, and prepare to flush it out
305 * May return an error if the user signalled nfs_wait_on_request().
306 */
307static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio,
308 struct page *page, bool nonblock)
309{
310 struct nfs_page *req;
311 int ret = 0;
312
313 req = nfs_find_and_lock_request(page, nonblock);
314 if (!req)
315 goto out;
316 ret = PTR_ERR(req);
317 if (IS_ERR(req))
318 goto out;
319
320 nfs_set_page_writeback(page);
321 WARN_ON_ONCE(test_bit(PG_CLEAN, &req->wb_flags));
322
323 ret = 0;
324 if (!nfs_pageio_add_request(pgio, req)) {
325 nfs_redirty_request(req);
326 ret = pgio->pg_error;
327 }
328out:
329 return ret;
330}
331
332static int nfs_do_writepage(struct page *page, struct writeback_control *wbc, struct nfs_pageio_descriptor *pgio)
333{
334 struct inode *inode = page_file_mapping(page)->host;
335 int ret;
336
337 nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE);
338 nfs_add_stats(inode, NFSIOS_WRITEPAGES, 1);
339
340 nfs_pageio_cond_complete(pgio, page_file_index(page));
341 ret = nfs_page_async_flush(pgio, page, wbc->sync_mode == WB_SYNC_NONE);
342 if (ret == -EAGAIN) {
343 redirty_page_for_writepage(wbc, page);
344 ret = 0;
345 }
346 return ret;
347}
348
349/*
350 * Write an mmapped page to the server.
351 */
352static int nfs_writepage_locked(struct page *page, struct writeback_control *wbc)
353{
354 struct nfs_pageio_descriptor pgio;
355 int err;
356
357 NFS_PROTO(page_file_mapping(page)->host)->write_pageio_init(&pgio,
358 page->mapping->host,
359 wb_priority(wbc),
360 &nfs_async_write_completion_ops);
361 err = nfs_do_writepage(page, wbc, &pgio);
362 nfs_pageio_complete(&pgio);
363 if (err < 0)
364 return err;
365 if (pgio.pg_error < 0)
366 return pgio.pg_error;
367 return 0;
368}
369
370int nfs_writepage(struct page *page, struct writeback_control *wbc)
371{
372 int ret;
373
374 ret = nfs_writepage_locked(page, wbc);
375 unlock_page(page);
376 return ret;
377}
378
379static int nfs_writepages_callback(struct page *page, struct writeback_control *wbc, void *data)
380{
381 int ret;
382
383 ret = nfs_do_writepage(page, wbc, data);
384 unlock_page(page);
385 return ret;
386}
387
388int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
389{
390 struct inode *inode = mapping->host;
391 unsigned long *bitlock = &NFS_I(inode)->flags;
392 struct nfs_pageio_descriptor pgio;
393 int err;
394
395 /* Stop dirtying of new pages while we sync */
396 err = wait_on_bit_lock(bitlock, NFS_INO_FLUSHING,
397 nfs_wait_bit_killable, TASK_KILLABLE);
398 if (err)
399 goto out_err;
400
401 nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES);
402
403 NFS_PROTO(inode)->write_pageio_init(&pgio, inode, wb_priority(wbc), &nfs_async_write_completion_ops);
404 err = write_cache_pages(mapping, wbc, nfs_writepages_callback, &pgio);
405 nfs_pageio_complete(&pgio);
406
407 clear_bit_unlock(NFS_INO_FLUSHING, bitlock);
408 smp_mb__after_clear_bit();
409 wake_up_bit(bitlock, NFS_INO_FLUSHING);
410
411 if (err < 0)
412 goto out_err;
413 err = pgio.pg_error;
414 if (err < 0)
415 goto out_err;
416 return 0;
417out_err:
418 return err;
419}
420
421/*
422 * Insert a write request into an inode
423 */
424static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
425{
426 struct nfs_inode *nfsi = NFS_I(inode);
427
428 /* Lock the request! */
429 nfs_lock_request(req);
430
431 spin_lock(&inode->i_lock);
432 if (!nfsi->npages && NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE))
433 inode->i_version++;
434 /*
435 * Swap-space should not get truncated. Hence no need to plug the race
436 * with invalidate/truncate.
437 */
438 if (likely(!PageSwapCache(req->wb_page))) {
439 set_bit(PG_MAPPED, &req->wb_flags);
440 SetPagePrivate(req->wb_page);
441 set_page_private(req->wb_page, (unsigned long)req);
442 }
443 nfsi->npages++;
444 kref_get(&req->wb_kref);
445 spin_unlock(&inode->i_lock);
446}
447
448/*
449 * Remove a write request from an inode
450 */
451static void nfs_inode_remove_request(struct nfs_page *req)
452{
453 struct inode *inode = req->wb_context->dentry->d_inode;
454 struct nfs_inode *nfsi = NFS_I(inode);
455
456 spin_lock(&inode->i_lock);
457 if (likely(!PageSwapCache(req->wb_page))) {
458 set_page_private(req->wb_page, 0);
459 ClearPagePrivate(req->wb_page);
460 clear_bit(PG_MAPPED, &req->wb_flags);
461 }
462 nfsi->npages--;
463 spin_unlock(&inode->i_lock);
464 nfs_release_request(req);
465}
466
467static void
468nfs_mark_request_dirty(struct nfs_page *req)
469{
470 __set_page_dirty_nobuffers(req->wb_page);
471}
472
473#if IS_ENABLED(CONFIG_NFS_V3) || IS_ENABLED(CONFIG_NFS_V4)
474/**
475 * nfs_request_add_commit_list - add request to a commit list
476 * @req: pointer to a struct nfs_page
477 * @dst: commit list head
478 * @cinfo: holds list lock and accounting info
479 *
480 * This sets the PG_CLEAN bit, updates the cinfo count of
481 * number of outstanding requests requiring a commit as well as
482 * the MM page stats.
483 *
484 * The caller must _not_ hold the cinfo->lock, but must be
485 * holding the nfs_page lock.
486 */
487void
488nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst,
489 struct nfs_commit_info *cinfo)
490{
491 set_bit(PG_CLEAN, &(req)->wb_flags);
492 spin_lock(cinfo->lock);
493 nfs_list_add_request(req, dst);
494 cinfo->mds->ncommit++;
495 spin_unlock(cinfo->lock);
496 if (!cinfo->dreq) {
497 inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
498 inc_bdi_stat(page_file_mapping(req->wb_page)->backing_dev_info,
499 BDI_RECLAIMABLE);
500 __mark_inode_dirty(req->wb_context->dentry->d_inode,
501 I_DIRTY_DATASYNC);
502 }
503}
504EXPORT_SYMBOL_GPL(nfs_request_add_commit_list);
505
506/**
507 * nfs_request_remove_commit_list - Remove request from a commit list
508 * @req: pointer to a nfs_page
509 * @cinfo: holds list lock and accounting info
510 *
511 * This clears the PG_CLEAN bit, and updates the cinfo's count of
512 * number of outstanding requests requiring a commit
513 * It does not update the MM page stats.
514 *
515 * The caller _must_ hold the cinfo->lock and the nfs_page lock.
516 */
517void
518nfs_request_remove_commit_list(struct nfs_page *req,
519 struct nfs_commit_info *cinfo)
520{
521 if (!test_and_clear_bit(PG_CLEAN, &(req)->wb_flags))
522 return;
523 nfs_list_remove_request(req);
524 cinfo->mds->ncommit--;
525}
526EXPORT_SYMBOL_GPL(nfs_request_remove_commit_list);
527
528static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo,
529 struct inode *inode)
530{
531 cinfo->lock = &inode->i_lock;
532 cinfo->mds = &NFS_I(inode)->commit_info;
533 cinfo->ds = pnfs_get_ds_info(inode);
534 cinfo->dreq = NULL;
535 cinfo->completion_ops = &nfs_commit_completion_ops;
536}
537
538void nfs_init_cinfo(struct nfs_commit_info *cinfo,
539 struct inode *inode,
540 struct nfs_direct_req *dreq)
541{
542 if (dreq)
543 nfs_init_cinfo_from_dreq(cinfo, dreq);
544 else
545 nfs_init_cinfo_from_inode(cinfo, inode);
546}
547EXPORT_SYMBOL_GPL(nfs_init_cinfo);
548
549/*
550 * Add a request to the inode's commit list.
551 */
552void
553nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg,
554 struct nfs_commit_info *cinfo)
555{
556 if (pnfs_mark_request_commit(req, lseg, cinfo))
557 return;
558 nfs_request_add_commit_list(req, &cinfo->mds->list, cinfo);
559}
560
561static void
562nfs_clear_page_commit(struct page *page)
563{
564 dec_zone_page_state(page, NR_UNSTABLE_NFS);
565 dec_bdi_stat(page_file_mapping(page)->backing_dev_info, BDI_RECLAIMABLE);
566}
567
568static void
569nfs_clear_request_commit(struct nfs_page *req)
570{
571 if (test_bit(PG_CLEAN, &req->wb_flags)) {
572 struct inode *inode = req->wb_context->dentry->d_inode;
573 struct nfs_commit_info cinfo;
574
575 nfs_init_cinfo_from_inode(&cinfo, inode);
576 if (!pnfs_clear_request_commit(req, &cinfo)) {
577 spin_lock(cinfo.lock);
578 nfs_request_remove_commit_list(req, &cinfo);
579 spin_unlock(cinfo.lock);
580 }
581 nfs_clear_page_commit(req->wb_page);
582 }
583}
584
585static inline
586int nfs_write_need_commit(struct nfs_write_data *data)
587{
588 if (data->verf.committed == NFS_DATA_SYNC)
589 return data->header->lseg == NULL;
590 return data->verf.committed != NFS_FILE_SYNC;
591}
592
593#else
594static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo,
595 struct inode *inode)
596{
597}
598
599void nfs_init_cinfo(struct nfs_commit_info *cinfo,
600 struct inode *inode,
601 struct nfs_direct_req *dreq)
602{
603}
604
605void
606nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg,
607 struct nfs_commit_info *cinfo)
608{
609}
610
611static void
612nfs_clear_request_commit(struct nfs_page *req)
613{
614}
615
616static inline
617int nfs_write_need_commit(struct nfs_write_data *data)
618{
619 return 0;
620}
621
622#endif
623
624static void nfs_write_completion(struct nfs_pgio_header *hdr)
625{
626 struct nfs_commit_info cinfo;
627 unsigned long bytes = 0;
628
629 if (test_bit(NFS_IOHDR_REDO, &hdr->flags))
630 goto out;
631 nfs_init_cinfo_from_inode(&cinfo, hdr->inode);
632 while (!list_empty(&hdr->pages)) {
633 struct nfs_page *req = nfs_list_entry(hdr->pages.next);
634
635 bytes += req->wb_bytes;
636 nfs_list_remove_request(req);
637 if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) &&
638 (hdr->good_bytes < bytes)) {
639 nfs_set_pageerror(req->wb_page);
640 nfs_context_set_write_error(req->wb_context, hdr->error);
641 goto remove_req;
642 }
643 if (test_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags)) {
644 nfs_mark_request_dirty(req);
645 goto next;
646 }
647 if (test_bit(NFS_IOHDR_NEED_COMMIT, &hdr->flags)) {
648 memcpy(&req->wb_verf, &hdr->verf->verifier, sizeof(req->wb_verf));
649 nfs_mark_request_commit(req, hdr->lseg, &cinfo);
650 goto next;
651 }
652remove_req:
653 nfs_inode_remove_request(req);
654next:
655 nfs_unlock_request(req);
656 nfs_end_page_writeback(req->wb_page);
657 nfs_release_request(req);
658 }
659out:
660 hdr->release(hdr);
661}
662
663#if IS_ENABLED(CONFIG_NFS_V3) || IS_ENABLED(CONFIG_NFS_V4)
664static unsigned long
665nfs_reqs_to_commit(struct nfs_commit_info *cinfo)
666{
667 return cinfo->mds->ncommit;
668}
669
670/* cinfo->lock held by caller */
671int
672nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
673 struct nfs_commit_info *cinfo, int max)
674{
675 struct nfs_page *req, *tmp;
676 int ret = 0;
677
678 list_for_each_entry_safe(req, tmp, src, wb_list) {
679 if (!nfs_lock_request(req))
680 continue;
681 kref_get(&req->wb_kref);
682 if (cond_resched_lock(cinfo->lock))
683 list_safe_reset_next(req, tmp, wb_list);
684 nfs_request_remove_commit_list(req, cinfo);
685 nfs_list_add_request(req, dst);
686 ret++;
687 if ((ret == max) && !cinfo->dreq)
688 break;
689 }
690 return ret;
691}
692
693/*
694 * nfs_scan_commit - Scan an inode for commit requests
695 * @inode: NFS inode to scan
696 * @dst: mds destination list
697 * @cinfo: mds and ds lists of reqs ready to commit
698 *
699 * Moves requests from the inode's 'commit' request list.
700 * The requests are *not* checked to ensure that they form a contiguous set.
701 */
702int
703nfs_scan_commit(struct inode *inode, struct list_head *dst,
704 struct nfs_commit_info *cinfo)
705{
706 int ret = 0;
707
708 spin_lock(cinfo->lock);
709 if (cinfo->mds->ncommit > 0) {
710 const int max = INT_MAX;
711
712 ret = nfs_scan_commit_list(&cinfo->mds->list, dst,
713 cinfo, max);
714 ret += pnfs_scan_commit_lists(inode, cinfo, max - ret);
715 }
716 spin_unlock(cinfo->lock);
717 return ret;
718}
719
720#else
721static unsigned long nfs_reqs_to_commit(struct nfs_commit_info *cinfo)
722{
723 return 0;
724}
725
726int nfs_scan_commit(struct inode *inode, struct list_head *dst,
727 struct nfs_commit_info *cinfo)
728{
729 return 0;
730}
731#endif
732
733/*
734 * Search for an existing write request, and attempt to update
735 * it to reflect a new dirty region on a given page.
736 *
737 * If the attempt fails, then the existing request is flushed out
738 * to disk.
739 */
740static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
741 struct page *page,
742 unsigned int offset,
743 unsigned int bytes)
744{
745 struct nfs_page *req;
746 unsigned int rqend;
747 unsigned int end;
748 int error;
749
750 if (!PagePrivate(page))
751 return NULL;
752
753 end = offset + bytes;
754 spin_lock(&inode->i_lock);
755
756 for (;;) {
757 req = nfs_page_find_request_locked(NFS_I(inode), page);
758 if (req == NULL)
759 goto out_unlock;
760
761 rqend = req->wb_offset + req->wb_bytes;
762 /*
763 * Tell the caller to flush out the request if
764 * the offsets are non-contiguous.
765 * Note: nfs_flush_incompatible() will already
766 * have flushed out requests having wrong owners.
767 */
768 if (offset > rqend
769 || end < req->wb_offset)
770 goto out_flushme;
771
772 if (nfs_lock_request(req))
773 break;
774
775 /* The request is locked, so wait and then retry */
776 spin_unlock(&inode->i_lock);
777 error = nfs_wait_on_request(req);
778 nfs_release_request(req);
779 if (error != 0)
780 goto out_err;
781 spin_lock(&inode->i_lock);
782 }
783
784 /* Okay, the request matches. Update the region */
785 if (offset < req->wb_offset) {
786 req->wb_offset = offset;
787 req->wb_pgbase = offset;
788 }
789 if (end > rqend)
790 req->wb_bytes = end - req->wb_offset;
791 else
792 req->wb_bytes = rqend - req->wb_offset;
793out_unlock:
794 spin_unlock(&inode->i_lock);
795 if (req)
796 nfs_clear_request_commit(req);
797 return req;
798out_flushme:
799 spin_unlock(&inode->i_lock);
800 nfs_release_request(req);
801 error = nfs_wb_page(inode, page);
802out_err:
803 return ERR_PTR(error);
804}
805
806/*
807 * Try to update an existing write request, or create one if there is none.
808 *
809 * Note: Should always be called with the Page Lock held to prevent races
810 * if we have to add a new request. Also assumes that the caller has
811 * already called nfs_flush_incompatible() if necessary.
812 */
813static struct nfs_page * nfs_setup_write_request(struct nfs_open_context* ctx,
814 struct page *page, unsigned int offset, unsigned int bytes)
815{
816 struct inode *inode = page_file_mapping(page)->host;
817 struct nfs_page *req;
818
819 req = nfs_try_to_update_request(inode, page, offset, bytes);
820 if (req != NULL)
821 goto out;
822 req = nfs_create_request(ctx, inode, page, offset, bytes);
823 if (IS_ERR(req))
824 goto out;
825 nfs_inode_add_request(inode, req);
826out:
827 return req;
828}
829
830static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page,
831 unsigned int offset, unsigned int count)
832{
833 struct nfs_page *req;
834
835 req = nfs_setup_write_request(ctx, page, offset, count);
836 if (IS_ERR(req))
837 return PTR_ERR(req);
838 /* Update file length */
839 nfs_grow_file(page, offset, count);
840 nfs_mark_uptodate(page, req->wb_pgbase, req->wb_bytes);
841 nfs_mark_request_dirty(req);
842 nfs_unlock_and_release_request(req);
843 return 0;
844}
845
846int nfs_flush_incompatible(struct file *file, struct page *page)
847{
848 struct nfs_open_context *ctx = nfs_file_open_context(file);
849 struct nfs_lock_context *l_ctx;
850 struct nfs_page *req;
851 int do_flush, status;
852 /*
853 * Look for a request corresponding to this page. If there
854 * is one, and it belongs to another file, we flush it out
855 * before we try to copy anything into the page. Do this
856 * due to the lack of an ACCESS-type call in NFSv2.
857 * Also do the same if we find a request from an existing
858 * dropped page.
859 */
860 do {
861 req = nfs_page_find_request(page);
862 if (req == NULL)
863 return 0;
864 l_ctx = req->wb_lock_context;
865 do_flush = req->wb_page != page || req->wb_context != ctx;
866 if (l_ctx && ctx->dentry->d_inode->i_flock != NULL) {
867 do_flush |= l_ctx->lockowner.l_owner != current->files
868 || l_ctx->lockowner.l_pid != current->tgid;
869 }
870 nfs_release_request(req);
871 if (!do_flush)
872 return 0;
873 status = nfs_wb_page(page_file_mapping(page)->host, page);
874 } while (status == 0);
875 return status;
876}
877
878/*
879 * Avoid buffered writes when a open context credential's key would
880 * expire soon.
881 *
882 * Returns -EACCES if the key will expire within RPC_KEY_EXPIRE_FAIL.
883 *
884 * Return 0 and set a credential flag which triggers the inode to flush
885 * and performs NFS_FILE_SYNC writes if the key will expired within
886 * RPC_KEY_EXPIRE_TIMEO.
887 */
888int
889nfs_key_timeout_notify(struct file *filp, struct inode *inode)
890{
891 struct nfs_open_context *ctx = nfs_file_open_context(filp);
892 struct rpc_auth *auth = NFS_SERVER(inode)->client->cl_auth;
893
894 return rpcauth_key_timeout_notify(auth, ctx->cred);
895}
896
897/*
898 * Test if the open context credential key is marked to expire soon.
899 */
900bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx)
901{
902 return rpcauth_cred_key_to_expire(ctx->cred);
903}
904
905/*
906 * If the page cache is marked as unsafe or invalid, then we can't rely on
907 * the PageUptodate() flag. In this case, we will need to turn off
908 * write optimisations that depend on the page contents being correct.
909 */
910static bool nfs_write_pageuptodate(struct page *page, struct inode *inode)
911{
912 struct nfs_inode *nfsi = NFS_I(inode);
913
914 if (nfs_have_delegated_attributes(inode))
915 goto out;
916 if (nfsi->cache_validity & (NFS_INO_INVALID_DATA|NFS_INO_REVAL_PAGECACHE))
917 return false;
918 smp_rmb();
919 if (test_bit(NFS_INO_INVALIDATING, &nfsi->flags))
920 return false;
921out:
922 return PageUptodate(page) != 0;
923}
924
925/* If we know the page is up to date, and we're not using byte range locks (or
926 * if we have the whole file locked for writing), it may be more efficient to
927 * extend the write to cover the entire page in order to avoid fragmentation
928 * inefficiencies.
929 *
930 * If the file is opened for synchronous writes then we can just skip the rest
931 * of the checks.
932 */
933static int nfs_can_extend_write(struct file *file, struct page *page, struct inode *inode)
934{
935 if (file->f_flags & O_DSYNC)
936 return 0;
937 if (!nfs_write_pageuptodate(page, inode))
938 return 0;
939 if (NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE))
940 return 1;
941 if (inode->i_flock == NULL || (inode->i_flock->fl_start == 0 &&
942 inode->i_flock->fl_end == OFFSET_MAX &&
943 inode->i_flock->fl_type != F_RDLCK))
944 return 1;
945 return 0;
946}
947
948/*
949 * Update and possibly write a cached page of an NFS file.
950 *
951 * XXX: Keep an eye on generic_file_read to make sure it doesn't do bad
952 * things with a page scheduled for an RPC call (e.g. invalidate it).
953 */
954int nfs_updatepage(struct file *file, struct page *page,
955 unsigned int offset, unsigned int count)
956{
957 struct nfs_open_context *ctx = nfs_file_open_context(file);
958 struct inode *inode = page_file_mapping(page)->host;
959 int status = 0;
960
961 nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE);
962
963 dprintk("NFS: nfs_updatepage(%pD2 %d@%lld)\n",
964 file, count, (long long)(page_file_offset(page) + offset));
965
966 if (nfs_can_extend_write(file, page, inode)) {
967 count = max(count + offset, nfs_page_length(page));
968 offset = 0;
969 }
970
971 status = nfs_writepage_setup(ctx, page, offset, count);
972 if (status < 0)
973 nfs_set_pageerror(page);
974 else
975 __set_page_dirty_nobuffers(page);
976
977 dprintk("NFS: nfs_updatepage returns %d (isize %lld)\n",
978 status, (long long)i_size_read(inode));
979 return status;
980}
981
982static int flush_task_priority(int how)
983{
984 switch (how & (FLUSH_HIGHPRI|FLUSH_LOWPRI)) {
985 case FLUSH_HIGHPRI:
986 return RPC_PRIORITY_HIGH;
987 case FLUSH_LOWPRI:
988 return RPC_PRIORITY_LOW;
989 }
990 return RPC_PRIORITY_NORMAL;
991}
992
993int nfs_initiate_write(struct rpc_clnt *clnt,
994 struct nfs_write_data *data,
995 const struct rpc_call_ops *call_ops,
996 int how, int flags)
997{
998 struct inode *inode = data->header->inode;
999 int priority = flush_task_priority(how);
1000 struct rpc_task *task;
1001 struct rpc_message msg = {
1002 .rpc_argp = &data->args,
1003 .rpc_resp = &data->res,
1004 .rpc_cred = data->header->cred,
1005 };
1006 struct rpc_task_setup task_setup_data = {
1007 .rpc_client = clnt,
1008 .task = &data->task,
1009 .rpc_message = &msg,
1010 .callback_ops = call_ops,
1011 .callback_data = data,
1012 .workqueue = nfsiod_workqueue,
1013 .flags = RPC_TASK_ASYNC | flags,
1014 .priority = priority,
1015 };
1016 int ret = 0;
1017
1018 /* Set up the initial task struct. */
1019 NFS_PROTO(inode)->write_setup(data, &msg);
1020
1021 dprintk("NFS: %5u initiated write call "
1022 "(req %s/%llu, %u bytes @ offset %llu)\n",
1023 data->task.tk_pid,
1024 inode->i_sb->s_id,
1025 (unsigned long long)NFS_FILEID(inode),
1026 data->args.count,
1027 (unsigned long long)data->args.offset);
1028
1029 nfs4_state_protect_write(NFS_SERVER(inode)->nfs_client,
1030 &task_setup_data.rpc_client, &msg, data);
1031
1032 task = rpc_run_task(&task_setup_data);
1033 if (IS_ERR(task)) {
1034 ret = PTR_ERR(task);
1035 goto out;
1036 }
1037 if (how & FLUSH_SYNC) {
1038 ret = rpc_wait_for_completion_task(task);
1039 if (ret == 0)
1040 ret = task->tk_status;
1041 }
1042 rpc_put_task(task);
1043out:
1044 return ret;
1045}
1046EXPORT_SYMBOL_GPL(nfs_initiate_write);
1047
1048/*
1049 * Set up the argument/result storage required for the RPC call.
1050 */
1051static void nfs_write_rpcsetup(struct nfs_write_data *data,
1052 unsigned int count, unsigned int offset,
1053 int how, struct nfs_commit_info *cinfo)
1054{
1055 struct nfs_page *req = data->header->req;
1056
1057 /* Set up the RPC argument and reply structs
1058 * NB: take care not to mess about with data->commit et al. */
1059
1060 data->args.fh = NFS_FH(data->header->inode);
1061 data->args.offset = req_offset(req) + offset;
1062 /* pnfs_set_layoutcommit needs this */
1063 data->mds_offset = data->args.offset;
1064 data->args.pgbase = req->wb_pgbase + offset;
1065 data->args.pages = data->pages.pagevec;
1066 data->args.count = count;
1067 data->args.context = get_nfs_open_context(req->wb_context);
1068 data->args.lock_context = req->wb_lock_context;
1069 data->args.stable = NFS_UNSTABLE;
1070 switch (how & (FLUSH_STABLE | FLUSH_COND_STABLE)) {
1071 case 0:
1072 break;
1073 case FLUSH_COND_STABLE:
1074 if (nfs_reqs_to_commit(cinfo))
1075 break;
1076 default:
1077 data->args.stable = NFS_FILE_SYNC;
1078 }
1079
1080 data->res.fattr = &data->fattr;
1081 data->res.count = count;
1082 data->res.verf = &data->verf;
1083 nfs_fattr_init(&data->fattr);
1084}
1085
1086static int nfs_do_write(struct nfs_write_data *data,
1087 const struct rpc_call_ops *call_ops,
1088 int how)
1089{
1090 struct inode *inode = data->header->inode;
1091
1092 return nfs_initiate_write(NFS_CLIENT(inode), data, call_ops, how, 0);
1093}
1094
1095static int nfs_do_multiple_writes(struct list_head *head,
1096 const struct rpc_call_ops *call_ops,
1097 int how)
1098{
1099 struct nfs_write_data *data;
1100 int ret = 0;
1101
1102 while (!list_empty(head)) {
1103 int ret2;
1104
1105 data = list_first_entry(head, struct nfs_write_data, list);
1106 list_del_init(&data->list);
1107
1108 ret2 = nfs_do_write(data, call_ops, how);
1109 if (ret == 0)
1110 ret = ret2;
1111 }
1112 return ret;
1113}
1114
1115/* If a nfs_flush_* function fails, it should remove reqs from @head and
1116 * call this on each, which will prepare them to be retried on next
1117 * writeback using standard nfs.
1118 */
1119static void nfs_redirty_request(struct nfs_page *req)
1120{
1121 nfs_mark_request_dirty(req);
1122 nfs_unlock_request(req);
1123 nfs_end_page_writeback(req->wb_page);
1124 nfs_release_request(req);
1125}
1126
1127static void nfs_async_write_error(struct list_head *head)
1128{
1129 struct nfs_page *req;
1130
1131 while (!list_empty(head)) {
1132 req = nfs_list_entry(head->next);
1133 nfs_list_remove_request(req);
1134 nfs_redirty_request(req);
1135 }
1136}
1137
1138static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops = {
1139 .error_cleanup = nfs_async_write_error,
1140 .completion = nfs_write_completion,
1141};
1142
1143static void nfs_flush_error(struct nfs_pageio_descriptor *desc,
1144 struct nfs_pgio_header *hdr)
1145{
1146 set_bit(NFS_IOHDR_REDO, &hdr->flags);
1147 while (!list_empty(&hdr->rpc_list)) {
1148 struct nfs_write_data *data = list_first_entry(&hdr->rpc_list,
1149 struct nfs_write_data, list);
1150 list_del(&data->list);
1151 nfs_writedata_release(data);
1152 }
1153 desc->pg_completion_ops->error_cleanup(&desc->pg_list);
1154}
1155
1156/*
1157 * Generate multiple small requests to write out a single
1158 * contiguous dirty area on one page.
1159 */
1160static int nfs_flush_multi(struct nfs_pageio_descriptor *desc,
1161 struct nfs_pgio_header *hdr)
1162{
1163 struct nfs_page *req = hdr->req;
1164 struct page *page = req->wb_page;
1165 struct nfs_write_data *data;
1166 size_t wsize = desc->pg_bsize, nbytes;
1167 unsigned int offset;
1168 int requests = 0;
1169 struct nfs_commit_info cinfo;
1170
1171 nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq);
1172
1173 if ((desc->pg_ioflags & FLUSH_COND_STABLE) &&
1174 (desc->pg_moreio || nfs_reqs_to_commit(&cinfo) ||
1175 desc->pg_count > wsize))
1176 desc->pg_ioflags &= ~FLUSH_COND_STABLE;
1177
1178
1179 offset = 0;
1180 nbytes = desc->pg_count;
1181 do {
1182 size_t len = min(nbytes, wsize);
1183
1184 data = nfs_writedata_alloc(hdr, 1);
1185 if (!data) {
1186 nfs_flush_error(desc, hdr);
1187 return -ENOMEM;
1188 }
1189 data->pages.pagevec[0] = page;
1190 nfs_write_rpcsetup(data, len, offset, desc->pg_ioflags, &cinfo);
1191 list_add(&data->list, &hdr->rpc_list);
1192 requests++;
1193 nbytes -= len;
1194 offset += len;
1195 } while (nbytes != 0);
1196 nfs_list_remove_request(req);
1197 nfs_list_add_request(req, &hdr->pages);
1198 desc->pg_rpc_callops = &nfs_write_common_ops;
1199 return 0;
1200}
1201
1202/*
1203 * Create an RPC task for the given write request and kick it.
1204 * The page must have been locked by the caller.
1205 *
1206 * It may happen that the page we're passed is not marked dirty.
1207 * This is the case if nfs_updatepage detects a conflicting request
1208 * that has been written but not committed.
1209 */
1210static int nfs_flush_one(struct nfs_pageio_descriptor *desc,
1211 struct nfs_pgio_header *hdr)
1212{
1213 struct nfs_page *req;
1214 struct page **pages;
1215 struct nfs_write_data *data;
1216 struct list_head *head = &desc->pg_list;
1217 struct nfs_commit_info cinfo;
1218
1219 data = nfs_writedata_alloc(hdr, nfs_page_array_len(desc->pg_base,
1220 desc->pg_count));
1221 if (!data) {
1222 nfs_flush_error(desc, hdr);
1223 return -ENOMEM;
1224 }
1225
1226 nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq);
1227 pages = data->pages.pagevec;
1228 while (!list_empty(head)) {
1229 req = nfs_list_entry(head->next);
1230 nfs_list_remove_request(req);
1231 nfs_list_add_request(req, &hdr->pages);
1232 *pages++ = req->wb_page;
1233 }
1234
1235 if ((desc->pg_ioflags & FLUSH_COND_STABLE) &&
1236 (desc->pg_moreio || nfs_reqs_to_commit(&cinfo)))
1237 desc->pg_ioflags &= ~FLUSH_COND_STABLE;
1238
1239 /* Set up the argument struct */
1240 nfs_write_rpcsetup(data, desc->pg_count, 0, desc->pg_ioflags, &cinfo);
1241 list_add(&data->list, &hdr->rpc_list);
1242 desc->pg_rpc_callops = &nfs_write_common_ops;
1243 return 0;
1244}
1245
1246int nfs_generic_flush(struct nfs_pageio_descriptor *desc,
1247 struct nfs_pgio_header *hdr)
1248{
1249 if (desc->pg_bsize < PAGE_CACHE_SIZE)
1250 return nfs_flush_multi(desc, hdr);
1251 return nfs_flush_one(desc, hdr);
1252}
1253EXPORT_SYMBOL_GPL(nfs_generic_flush);
1254
1255static int nfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
1256{
1257 struct nfs_write_header *whdr;
1258 struct nfs_pgio_header *hdr;
1259 int ret;
1260
1261 whdr = nfs_writehdr_alloc();
1262 if (!whdr) {
1263 desc->pg_completion_ops->error_cleanup(&desc->pg_list);
1264 return -ENOMEM;
1265 }
1266 hdr = &whdr->header;
1267 nfs_pgheader_init(desc, hdr, nfs_writehdr_free);
1268 atomic_inc(&hdr->refcnt);
1269 ret = nfs_generic_flush(desc, hdr);
1270 if (ret == 0)
1271 ret = nfs_do_multiple_writes(&hdr->rpc_list,
1272 desc->pg_rpc_callops,
1273 desc->pg_ioflags);
1274 if (atomic_dec_and_test(&hdr->refcnt))
1275 hdr->completion_ops->completion(hdr);
1276 return ret;
1277}
1278
1279static const struct nfs_pageio_ops nfs_pageio_write_ops = {
1280 .pg_test = nfs_generic_pg_test,
1281 .pg_doio = nfs_generic_pg_writepages,
1282};
1283
1284void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
1285 struct inode *inode, int ioflags,
1286 const struct nfs_pgio_completion_ops *compl_ops)
1287{
1288 nfs_pageio_init(pgio, inode, &nfs_pageio_write_ops, compl_ops,
1289 NFS_SERVER(inode)->wsize, ioflags);
1290}
1291EXPORT_SYMBOL_GPL(nfs_pageio_init_write);
1292
1293void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio)
1294{
1295 pgio->pg_ops = &nfs_pageio_write_ops;
1296 pgio->pg_bsize = NFS_SERVER(pgio->pg_inode)->wsize;
1297}
1298EXPORT_SYMBOL_GPL(nfs_pageio_reset_write_mds);
1299
1300
1301void nfs_write_prepare(struct rpc_task *task, void *calldata)
1302{
1303 struct nfs_write_data *data = calldata;
1304 int err;
1305 err = NFS_PROTO(data->header->inode)->write_rpc_prepare(task, data);
1306 if (err)
1307 rpc_exit(task, err);
1308}
1309
1310void nfs_commit_prepare(struct rpc_task *task, void *calldata)
1311{
1312 struct nfs_commit_data *data = calldata;
1313
1314 NFS_PROTO(data->inode)->commit_rpc_prepare(task, data);
1315}
1316
1317/*
1318 * Handle a write reply that flushes a whole page.
1319 *
1320 * FIXME: There is an inherent race with invalidate_inode_pages and
1321 * writebacks since the page->count is kept > 1 for as long
1322 * as the page has a write request pending.
1323 */
1324static void nfs_writeback_done_common(struct rpc_task *task, void *calldata)
1325{
1326 struct nfs_write_data *data = calldata;
1327
1328 nfs_writeback_done(task, data);
1329}
1330
1331static void nfs_writeback_release_common(void *calldata)
1332{
1333 struct nfs_write_data *data = calldata;
1334 struct nfs_pgio_header *hdr = data->header;
1335 int status = data->task.tk_status;
1336
1337 if ((status >= 0) && nfs_write_need_commit(data)) {
1338 spin_lock(&hdr->lock);
1339 if (test_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags))
1340 ; /* Do nothing */
1341 else if (!test_and_set_bit(NFS_IOHDR_NEED_COMMIT, &hdr->flags))
1342 memcpy(hdr->verf, &data->verf, sizeof(*hdr->verf));
1343 else if (memcmp(hdr->verf, &data->verf, sizeof(*hdr->verf)))
1344 set_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags);
1345 spin_unlock(&hdr->lock);
1346 }
1347 nfs_writedata_release(data);
1348}
1349
1350static const struct rpc_call_ops nfs_write_common_ops = {
1351 .rpc_call_prepare = nfs_write_prepare,
1352 .rpc_call_done = nfs_writeback_done_common,
1353 .rpc_release = nfs_writeback_release_common,
1354};
1355
1356
1357/*
1358 * This function is called when the WRITE call is complete.
1359 */
1360void nfs_writeback_done(struct rpc_task *task, struct nfs_write_data *data)
1361{
1362 struct nfs_writeargs *argp = &data->args;
1363 struct nfs_writeres *resp = &data->res;
1364 struct inode *inode = data->header->inode;
1365 int status;
1366
1367 dprintk("NFS: %5u nfs_writeback_done (status %d)\n",
1368 task->tk_pid, task->tk_status);
1369
1370 /*
1371 * ->write_done will attempt to use post-op attributes to detect
1372 * conflicting writes by other clients. A strict interpretation
1373 * of close-to-open would allow us to continue caching even if
1374 * another writer had changed the file, but some applications
1375 * depend on tighter cache coherency when writing.
1376 */
1377 status = NFS_PROTO(inode)->write_done(task, data);
1378 if (status != 0)
1379 return;
1380 nfs_add_stats(inode, NFSIOS_SERVERWRITTENBYTES, resp->count);
1381
1382#if IS_ENABLED(CONFIG_NFS_V3) || IS_ENABLED(CONFIG_NFS_V4)
1383 if (resp->verf->committed < argp->stable && task->tk_status >= 0) {
1384 /* We tried a write call, but the server did not
1385 * commit data to stable storage even though we
1386 * requested it.
1387 * Note: There is a known bug in Tru64 < 5.0 in which
1388 * the server reports NFS_DATA_SYNC, but performs
1389 * NFS_FILE_SYNC. We therefore implement this checking
1390 * as a dprintk() in order to avoid filling syslog.
1391 */
1392 static unsigned long complain;
1393
1394 /* Note this will print the MDS for a DS write */
1395 if (time_before(complain, jiffies)) {
1396 dprintk("NFS: faulty NFS server %s:"
1397 " (committed = %d) != (stable = %d)\n",
1398 NFS_SERVER(inode)->nfs_client->cl_hostname,
1399 resp->verf->committed, argp->stable);
1400 complain = jiffies + 300 * HZ;
1401 }
1402 }
1403#endif
1404 if (task->tk_status < 0)
1405 nfs_set_pgio_error(data->header, task->tk_status, argp->offset);
1406 else if (resp->count < argp->count) {
1407 static unsigned long complain;
1408
1409 /* This a short write! */
1410 nfs_inc_stats(inode, NFSIOS_SHORTWRITE);
1411
1412 /* Has the server at least made some progress? */
1413 if (resp->count == 0) {
1414 if (time_before(complain, jiffies)) {
1415 printk(KERN_WARNING
1416 "NFS: Server wrote zero bytes, expected %u.\n",
1417 argp->count);
1418 complain = jiffies + 300 * HZ;
1419 }
1420 nfs_set_pgio_error(data->header, -EIO, argp->offset);
1421 task->tk_status = -EIO;
1422 return;
1423 }
1424 /* Was this an NFSv2 write or an NFSv3 stable write? */
1425 if (resp->verf->committed != NFS_UNSTABLE) {
1426 /* Resend from where the server left off */
1427 data->mds_offset += resp->count;
1428 argp->offset += resp->count;
1429 argp->pgbase += resp->count;
1430 argp->count -= resp->count;
1431 } else {
1432 /* Resend as a stable write in order to avoid
1433 * headaches in the case of a server crash.
1434 */
1435 argp->stable = NFS_FILE_SYNC;
1436 }
1437 rpc_restart_call_prepare(task);
1438 }
1439}
1440
1441
1442#if IS_ENABLED(CONFIG_NFS_V3) || IS_ENABLED(CONFIG_NFS_V4)
1443static int nfs_commit_set_lock(struct nfs_inode *nfsi, int may_wait)
1444{
1445 int ret;
1446
1447 if (!test_and_set_bit(NFS_INO_COMMIT, &nfsi->flags))
1448 return 1;
1449 if (!may_wait)
1450 return 0;
1451 ret = out_of_line_wait_on_bit_lock(&nfsi->flags,
1452 NFS_INO_COMMIT,
1453 nfs_wait_bit_killable,
1454 TASK_KILLABLE);
1455 return (ret < 0) ? ret : 1;
1456}
1457
1458static void nfs_commit_clear_lock(struct nfs_inode *nfsi)
1459{
1460 clear_bit(NFS_INO_COMMIT, &nfsi->flags);
1461 smp_mb__after_clear_bit();
1462 wake_up_bit(&nfsi->flags, NFS_INO_COMMIT);
1463}
1464
1465void nfs_commitdata_release(struct nfs_commit_data *data)
1466{
1467 put_nfs_open_context(data->context);
1468 nfs_commit_free(data);
1469}
1470EXPORT_SYMBOL_GPL(nfs_commitdata_release);
1471
1472int nfs_initiate_commit(struct rpc_clnt *clnt, struct nfs_commit_data *data,
1473 const struct rpc_call_ops *call_ops,
1474 int how, int flags)
1475{
1476 struct rpc_task *task;
1477 int priority = flush_task_priority(how);
1478 struct rpc_message msg = {
1479 .rpc_argp = &data->args,
1480 .rpc_resp = &data->res,
1481 .rpc_cred = data->cred,
1482 };
1483 struct rpc_task_setup task_setup_data = {
1484 .task = &data->task,
1485 .rpc_client = clnt,
1486 .rpc_message = &msg,
1487 .callback_ops = call_ops,
1488 .callback_data = data,
1489 .workqueue = nfsiod_workqueue,
1490 .flags = RPC_TASK_ASYNC | flags,
1491 .priority = priority,
1492 };
1493 /* Set up the initial task struct. */
1494 NFS_PROTO(data->inode)->commit_setup(data, &msg);
1495
1496 dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid);
1497
1498 nfs4_state_protect(NFS_SERVER(data->inode)->nfs_client,
1499 NFS_SP4_MACH_CRED_COMMIT, &task_setup_data.rpc_client, &msg);
1500
1501 task = rpc_run_task(&task_setup_data);
1502 if (IS_ERR(task))
1503 return PTR_ERR(task);
1504 if (how & FLUSH_SYNC)
1505 rpc_wait_for_completion_task(task);
1506 rpc_put_task(task);
1507 return 0;
1508}
1509EXPORT_SYMBOL_GPL(nfs_initiate_commit);
1510
1511/*
1512 * Set up the argument/result storage required for the RPC call.
1513 */
1514void nfs_init_commit(struct nfs_commit_data *data,
1515 struct list_head *head,
1516 struct pnfs_layout_segment *lseg,
1517 struct nfs_commit_info *cinfo)
1518{
1519 struct nfs_page *first = nfs_list_entry(head->next);
1520 struct inode *inode = first->wb_context->dentry->d_inode;
1521
1522 /* Set up the RPC argument and reply structs
1523 * NB: take care not to mess about with data->commit et al. */
1524
1525 list_splice_init(head, &data->pages);
1526
1527 data->inode = inode;
1528 data->cred = first->wb_context->cred;
1529 data->lseg = lseg; /* reference transferred */
1530 data->mds_ops = &nfs_commit_ops;
1531 data->completion_ops = cinfo->completion_ops;
1532 data->dreq = cinfo->dreq;
1533
1534 data->args.fh = NFS_FH(data->inode);
1535 /* Note: we always request a commit of the entire inode */
1536 data->args.offset = 0;
1537 data->args.count = 0;
1538 data->context = get_nfs_open_context(first->wb_context);
1539 data->res.fattr = &data->fattr;
1540 data->res.verf = &data->verf;
1541 nfs_fattr_init(&data->fattr);
1542}
1543EXPORT_SYMBOL_GPL(nfs_init_commit);
1544
1545void nfs_retry_commit(struct list_head *page_list,
1546 struct pnfs_layout_segment *lseg,
1547 struct nfs_commit_info *cinfo)
1548{
1549 struct nfs_page *req;
1550
1551 while (!list_empty(page_list)) {
1552 req = nfs_list_entry(page_list->next);
1553 nfs_list_remove_request(req);
1554 nfs_mark_request_commit(req, lseg, cinfo);
1555 if (!cinfo->dreq) {
1556 dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
1557 dec_bdi_stat(page_file_mapping(req->wb_page)->backing_dev_info,
1558 BDI_RECLAIMABLE);
1559 }
1560 nfs_unlock_and_release_request(req);
1561 }
1562}
1563EXPORT_SYMBOL_GPL(nfs_retry_commit);
1564
1565/*
1566 * Commit dirty pages
1567 */
1568static int
1569nfs_commit_list(struct inode *inode, struct list_head *head, int how,
1570 struct nfs_commit_info *cinfo)
1571{
1572 struct nfs_commit_data *data;
1573
1574 data = nfs_commitdata_alloc();
1575
1576 if (!data)
1577 goto out_bad;
1578
1579 /* Set up the argument struct */
1580 nfs_init_commit(data, head, NULL, cinfo);
1581 atomic_inc(&cinfo->mds->rpcs_out);
1582 return nfs_initiate_commit(NFS_CLIENT(inode), data, data->mds_ops,
1583 how, 0);
1584 out_bad:
1585 nfs_retry_commit(head, NULL, cinfo);
1586 cinfo->completion_ops->error_cleanup(NFS_I(inode));
1587 return -ENOMEM;
1588}
1589
1590/*
1591 * COMMIT call returned
1592 */
1593static void nfs_commit_done(struct rpc_task *task, void *calldata)
1594{
1595 struct nfs_commit_data *data = calldata;
1596
1597 dprintk("NFS: %5u nfs_commit_done (status %d)\n",
1598 task->tk_pid, task->tk_status);
1599
1600 /* Call the NFS version-specific code */
1601 NFS_PROTO(data->inode)->commit_done(task, data);
1602}
1603
1604static void nfs_commit_release_pages(struct nfs_commit_data *data)
1605{
1606 struct nfs_page *req;
1607 int status = data->task.tk_status;
1608 struct nfs_commit_info cinfo;
1609
1610 while (!list_empty(&data->pages)) {
1611 req = nfs_list_entry(data->pages.next);
1612 nfs_list_remove_request(req);
1613 nfs_clear_page_commit(req->wb_page);
1614
1615 dprintk("NFS: commit (%s/%llu %d@%lld)",
1616 req->wb_context->dentry->d_sb->s_id,
1617 (unsigned long long)NFS_FILEID(req->wb_context->dentry->d_inode),
1618 req->wb_bytes,
1619 (long long)req_offset(req));
1620 if (status < 0) {
1621 nfs_context_set_write_error(req->wb_context, status);
1622 nfs_inode_remove_request(req);
1623 dprintk(", error = %d\n", status);
1624 goto next;
1625 }
1626
1627 /* Okay, COMMIT succeeded, apparently. Check the verifier
1628 * returned by the server against all stored verfs. */
1629 if (!memcmp(&req->wb_verf, &data->verf.verifier, sizeof(req->wb_verf))) {
1630 /* We have a match */
1631 nfs_inode_remove_request(req);
1632 dprintk(" OK\n");
1633 goto next;
1634 }
1635 /* We have a mismatch. Write the page again */
1636 dprintk(" mismatch\n");
1637 nfs_mark_request_dirty(req);
1638 set_bit(NFS_CONTEXT_RESEND_WRITES, &req->wb_context->flags);
1639 next:
1640 nfs_unlock_and_release_request(req);
1641 }
1642 nfs_init_cinfo(&cinfo, data->inode, data->dreq);
1643 if (atomic_dec_and_test(&cinfo.mds->rpcs_out))
1644 nfs_commit_clear_lock(NFS_I(data->inode));
1645}
1646
1647static void nfs_commit_release(void *calldata)
1648{
1649 struct nfs_commit_data *data = calldata;
1650
1651 data->completion_ops->completion(data);
1652 nfs_commitdata_release(calldata);
1653}
1654
1655static const struct rpc_call_ops nfs_commit_ops = {
1656 .rpc_call_prepare = nfs_commit_prepare,
1657 .rpc_call_done = nfs_commit_done,
1658 .rpc_release = nfs_commit_release,
1659};
1660
1661static const struct nfs_commit_completion_ops nfs_commit_completion_ops = {
1662 .completion = nfs_commit_release_pages,
1663 .error_cleanup = nfs_commit_clear_lock,
1664};
1665
1666int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
1667 int how, struct nfs_commit_info *cinfo)
1668{
1669 int status;
1670
1671 status = pnfs_commit_list(inode, head, how, cinfo);
1672 if (status == PNFS_NOT_ATTEMPTED)
1673 status = nfs_commit_list(inode, head, how, cinfo);
1674 return status;
1675}
1676
1677int nfs_commit_inode(struct inode *inode, int how)
1678{
1679 LIST_HEAD(head);
1680 struct nfs_commit_info cinfo;
1681 int may_wait = how & FLUSH_SYNC;
1682 int res;
1683
1684 res = nfs_commit_set_lock(NFS_I(inode), may_wait);
1685 if (res <= 0)
1686 goto out_mark_dirty;
1687 nfs_init_cinfo_from_inode(&cinfo, inode);
1688 res = nfs_scan_commit(inode, &head, &cinfo);
1689 if (res) {
1690 int error;
1691
1692 error = nfs_generic_commit_list(inode, &head, how, &cinfo);
1693 if (error < 0)
1694 return error;
1695 if (!may_wait)
1696 goto out_mark_dirty;
1697 error = wait_on_bit(&NFS_I(inode)->flags,
1698 NFS_INO_COMMIT,
1699 nfs_wait_bit_killable,
1700 TASK_KILLABLE);
1701 if (error < 0)
1702 return error;
1703 } else
1704 nfs_commit_clear_lock(NFS_I(inode));
1705 return res;
1706 /* Note: If we exit without ensuring that the commit is complete,
1707 * we must mark the inode as dirty. Otherwise, future calls to
1708 * sync_inode() with the WB_SYNC_ALL flag set will fail to ensure
1709 * that the data is on the disk.
1710 */
1711out_mark_dirty:
1712 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
1713 return res;
1714}
1715
1716static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_control *wbc)
1717{
1718 struct nfs_inode *nfsi = NFS_I(inode);
1719 int flags = FLUSH_SYNC;
1720 int ret = 0;
1721
1722 /* no commits means nothing needs to be done */
1723 if (!nfsi->commit_info.ncommit)
1724 return ret;
1725
1726 if (wbc->sync_mode == WB_SYNC_NONE) {
1727 /* Don't commit yet if this is a non-blocking flush and there
1728 * are a lot of outstanding writes for this mapping.
1729 */
1730 if (nfsi->commit_info.ncommit <= (nfsi->npages >> 1))
1731 goto out_mark_dirty;
1732
1733 /* don't wait for the COMMIT response */
1734 flags = 0;
1735 }
1736
1737 ret = nfs_commit_inode(inode, flags);
1738 if (ret >= 0) {
1739 if (wbc->sync_mode == WB_SYNC_NONE) {
1740 if (ret < wbc->nr_to_write)
1741 wbc->nr_to_write -= ret;
1742 else
1743 wbc->nr_to_write = 0;
1744 }
1745 return 0;
1746 }
1747out_mark_dirty:
1748 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
1749 return ret;
1750}
1751#else
1752static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_control *wbc)
1753{
1754 return 0;
1755}
1756#endif
1757
1758int nfs_write_inode(struct inode *inode, struct writeback_control *wbc)
1759{
1760 return nfs_commit_unstable_pages(inode, wbc);
1761}
1762EXPORT_SYMBOL_GPL(nfs_write_inode);
1763
1764/*
1765 * flush the inode to disk.
1766 */
1767int nfs_wb_all(struct inode *inode)
1768{
1769 struct writeback_control wbc = {
1770 .sync_mode = WB_SYNC_ALL,
1771 .nr_to_write = LONG_MAX,
1772 .range_start = 0,
1773 .range_end = LLONG_MAX,
1774 };
1775 int ret;
1776
1777 trace_nfs_writeback_inode_enter(inode);
1778
1779 ret = sync_inode(inode, &wbc);
1780
1781 trace_nfs_writeback_inode_exit(inode, ret);
1782 return ret;
1783}
1784EXPORT_SYMBOL_GPL(nfs_wb_all);
1785
1786int nfs_wb_page_cancel(struct inode *inode, struct page *page)
1787{
1788 struct nfs_page *req;
1789 int ret = 0;
1790
1791 for (;;) {
1792 wait_on_page_writeback(page);
1793 req = nfs_page_find_request(page);
1794 if (req == NULL)
1795 break;
1796 if (nfs_lock_request(req)) {
1797 nfs_clear_request_commit(req);
1798 nfs_inode_remove_request(req);
1799 /*
1800 * In case nfs_inode_remove_request has marked the
1801 * page as being dirty
1802 */
1803 cancel_dirty_page(page, PAGE_CACHE_SIZE);
1804 nfs_unlock_and_release_request(req);
1805 break;
1806 }
1807 ret = nfs_wait_on_request(req);
1808 nfs_release_request(req);
1809 if (ret < 0)
1810 break;
1811 }
1812 return ret;
1813}
1814
1815/*
1816 * Write back all requests on one page - we do this before reading it.
1817 */
1818int nfs_wb_page(struct inode *inode, struct page *page)
1819{
1820 loff_t range_start = page_file_offset(page);
1821 loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
1822 struct writeback_control wbc = {
1823 .sync_mode = WB_SYNC_ALL,
1824 .nr_to_write = 0,
1825 .range_start = range_start,
1826 .range_end = range_end,
1827 };
1828 int ret;
1829
1830 trace_nfs_writeback_page_enter(inode);
1831
1832 for (;;) {
1833 wait_on_page_writeback(page);
1834 if (clear_page_dirty_for_io(page)) {
1835 ret = nfs_writepage_locked(page, &wbc);
1836 if (ret < 0)
1837 goto out_error;
1838 continue;
1839 }
1840 ret = 0;
1841 if (!PagePrivate(page))
1842 break;
1843 ret = nfs_commit_inode(inode, FLUSH_SYNC);
1844 if (ret < 0)
1845 goto out_error;
1846 }
1847out_error:
1848 trace_nfs_writeback_page_exit(inode, ret);
1849 return ret;
1850}
1851
1852#ifdef CONFIG_MIGRATION
1853int nfs_migrate_page(struct address_space *mapping, struct page *newpage,
1854 struct page *page, enum migrate_mode mode)
1855{
1856 /*
1857 * If PagePrivate is set, then the page is currently associated with
1858 * an in-progress read or write request. Don't try to migrate it.
1859 *
1860 * FIXME: we could do this in principle, but we'll need a way to ensure
1861 * that we can safely release the inode reference while holding
1862 * the page lock.
1863 */
1864 if (PagePrivate(page))
1865 return -EBUSY;
1866
1867 if (!nfs_fscache_release_page(page, GFP_KERNEL))
1868 return -EBUSY;
1869
1870 return migrate_page(mapping, newpage, page, mode);
1871}
1872#endif
1873
1874int __init nfs_init_writepagecache(void)
1875{
1876 nfs_wdata_cachep = kmem_cache_create("nfs_write_data",
1877 sizeof(struct nfs_write_header),
1878 0, SLAB_HWCACHE_ALIGN,
1879 NULL);
1880 if (nfs_wdata_cachep == NULL)
1881 return -ENOMEM;
1882
1883 nfs_wdata_mempool = mempool_create_slab_pool(MIN_POOL_WRITE,
1884 nfs_wdata_cachep);
1885 if (nfs_wdata_mempool == NULL)
1886 goto out_destroy_write_cache;
1887
1888 nfs_cdata_cachep = kmem_cache_create("nfs_commit_data",
1889 sizeof(struct nfs_commit_data),
1890 0, SLAB_HWCACHE_ALIGN,
1891 NULL);
1892 if (nfs_cdata_cachep == NULL)
1893 goto out_destroy_write_mempool;
1894
1895 nfs_commit_mempool = mempool_create_slab_pool(MIN_POOL_COMMIT,
1896 nfs_cdata_cachep);
1897 if (nfs_commit_mempool == NULL)
1898 goto out_destroy_commit_cache;
1899
1900 /*
1901 * NFS congestion size, scale with available memory.
1902 *
1903 * 64MB: 8192k
1904 * 128MB: 11585k
1905 * 256MB: 16384k
1906 * 512MB: 23170k
1907 * 1GB: 32768k
1908 * 2GB: 46340k
1909 * 4GB: 65536k
1910 * 8GB: 92681k
1911 * 16GB: 131072k
1912 *
1913 * This allows larger machines to have larger/more transfers.
1914 * Limit the default to 256M
1915 */
1916 nfs_congestion_kb = (16*int_sqrt(totalram_pages)) << (PAGE_SHIFT-10);
1917 if (nfs_congestion_kb > 256*1024)
1918 nfs_congestion_kb = 256*1024;
1919
1920 return 0;
1921
1922out_destroy_commit_cache:
1923 kmem_cache_destroy(nfs_cdata_cachep);
1924out_destroy_write_mempool:
1925 mempool_destroy(nfs_wdata_mempool);
1926out_destroy_write_cache:
1927 kmem_cache_destroy(nfs_wdata_cachep);
1928 return -ENOMEM;
1929}
1930
1931void nfs_destroy_writepagecache(void)
1932{
1933 mempool_destroy(nfs_commit_mempool);
1934 kmem_cache_destroy(nfs_cdata_cachep);
1935 mempool_destroy(nfs_wdata_mempool);
1936 kmem_cache_destroy(nfs_wdata_cachep);
1937}
1938