4 * Write file data over NFS.
6 * Copyright (C) 1996, 1997, Olaf Kirch <okir@monad.swb.de>
9 #include <linux/types.h>
10 #include <linux/slab.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>
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>
25 #include <asm/uaccess.h>
27 #include "delegation.h"
36 #define NFSDBG_FACILITY NFSDBG_PAGECACHE
38 #define MIN_POOL_WRITE (32)
39 #define MIN_POOL_COMMIT (4)
42 * Local function declarations
44 static void nfs_redirty_request(struct nfs_page *req);
45 static const struct rpc_call_ops nfs_commit_ops;
46 static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops;
47 static const struct nfs_commit_completion_ops nfs_commit_completion_ops;
48 static const struct nfs_rw_ops nfs_rw_write_ops;
50 static struct kmem_cache *nfs_wdata_cachep;
51 static mempool_t *nfs_wdata_mempool;
52 static struct kmem_cache *nfs_cdata_cachep;
53 static mempool_t *nfs_commit_mempool;
55 struct nfs_commit_data *nfs_commitdata_alloc(void)
57 struct nfs_commit_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOIO);
60 memset(p, 0, sizeof(*p));
61 INIT_LIST_HEAD(&p->pages);
65 EXPORT_SYMBOL_GPL(nfs_commitdata_alloc);
67 void nfs_commit_free(struct nfs_commit_data *p)
69 mempool_free(p, nfs_commit_mempool);
71 EXPORT_SYMBOL_GPL(nfs_commit_free);
73 static struct nfs_rw_header *nfs_writehdr_alloc(void)
75 struct nfs_rw_header *p = mempool_alloc(nfs_wdata_mempool, GFP_NOIO);
78 memset(p, 0, sizeof(*p));
82 static void nfs_writehdr_free(struct nfs_rw_header *whdr)
84 mempool_free(whdr, nfs_wdata_mempool);
87 static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error)
91 set_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags);
94 static struct nfs_page *
95 nfs_page_find_request_locked(struct nfs_inode *nfsi, struct page *page)
97 struct nfs_page *req = NULL;
99 if (PagePrivate(page))
100 req = (struct nfs_page *)page_private(page);
101 else if (unlikely(PageSwapCache(page))) {
102 struct nfs_page *freq, *t;
104 /* Linearly search the commit list for the correct req */
105 list_for_each_entry_safe(freq, t, &nfsi->commit_info.list, wb_list) {
106 if (freq->wb_page == page) {
114 kref_get(&req->wb_kref);
119 static struct nfs_page *nfs_page_find_request(struct page *page)
121 struct inode *inode = page_file_mapping(page)->host;
122 struct nfs_page *req = NULL;
124 spin_lock(&inode->i_lock);
125 req = nfs_page_find_request_locked(NFS_I(inode), page);
126 spin_unlock(&inode->i_lock);
130 /* Adjust the file length if we're writing beyond the end */
131 static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count)
133 struct inode *inode = page_file_mapping(page)->host;
137 spin_lock(&inode->i_lock);
138 i_size = i_size_read(inode);
139 end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
140 if (i_size > 0 && page_file_index(page) < end_index)
142 end = page_file_offset(page) + ((loff_t)offset+count);
145 i_size_write(inode, end);
146 nfs_inc_stats(inode, NFSIOS_EXTENDWRITE);
148 spin_unlock(&inode->i_lock);
151 /* A writeback failed: mark the page as bad, and invalidate the page cache */
152 static void nfs_set_pageerror(struct page *page)
154 nfs_zap_mapping(page_file_mapping(page)->host, page_file_mapping(page));
158 * nfs_page_group_search_locked
159 * @head - head request of page group
160 * @page_offset - offset into page
162 * Search page group with head @head to find a request that contains the
163 * page offset @page_offset.
165 * Returns a pointer to the first matching nfs request, or NULL if no
168 * Must be called with the page group lock held
170 static struct nfs_page *
171 nfs_page_group_search_locked(struct nfs_page *head, unsigned int page_offset)
173 struct nfs_page *req;
175 WARN_ON_ONCE(head != head->wb_head);
176 WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &head->wb_head->wb_flags));
180 if (page_offset >= req->wb_pgbase &&
181 page_offset < (req->wb_pgbase + req->wb_bytes))
184 req = req->wb_this_page;
185 } while (req != head);
191 * nfs_page_group_covers_page
192 * @head - head request of page group
194 * Return true if the page group with head @head covers the whole page,
195 * returns false otherwise
197 static bool nfs_page_group_covers_page(struct nfs_page *req)
199 struct nfs_page *tmp;
200 unsigned int pos = 0;
201 unsigned int len = nfs_page_length(req->wb_page);
203 nfs_page_group_lock(req);
206 tmp = nfs_page_group_search_locked(req->wb_head, pos);
208 /* no way this should happen */
209 WARN_ON_ONCE(tmp->wb_pgbase != pos);
210 pos += tmp->wb_bytes - (pos - tmp->wb_pgbase);
212 } while (tmp && pos < len);
214 nfs_page_group_unlock(req);
215 WARN_ON_ONCE(pos > len);
219 /* We can set the PG_uptodate flag if we see that a write request
220 * covers the full page.
222 static void nfs_mark_uptodate(struct nfs_page *req)
224 if (PageUptodate(req->wb_page))
226 if (!nfs_page_group_covers_page(req))
228 SetPageUptodate(req->wb_page);
231 static int wb_priority(struct writeback_control *wbc)
233 if (wbc->for_reclaim)
234 return FLUSH_HIGHPRI | FLUSH_STABLE;
235 if (wbc->for_kupdate || wbc->for_background)
236 return FLUSH_LOWPRI | FLUSH_COND_STABLE;
237 return FLUSH_COND_STABLE;
241 * NFS congestion control
244 int nfs_congestion_kb;
246 #define NFS_CONGESTION_ON_THRESH (nfs_congestion_kb >> (PAGE_SHIFT-10))
247 #define NFS_CONGESTION_OFF_THRESH \
248 (NFS_CONGESTION_ON_THRESH - (NFS_CONGESTION_ON_THRESH >> 2))
250 static void nfs_set_page_writeback(struct page *page)
252 struct nfs_server *nfss = NFS_SERVER(page_file_mapping(page)->host);
253 int ret = test_set_page_writeback(page);
255 WARN_ON_ONCE(ret != 0);
257 if (atomic_long_inc_return(&nfss->writeback) >
258 NFS_CONGESTION_ON_THRESH) {
259 set_bdi_congested(&nfss->backing_dev_info,
264 static void nfs_end_page_writeback(struct nfs_page *req)
266 struct inode *inode = page_file_mapping(req->wb_page)->host;
267 struct nfs_server *nfss = NFS_SERVER(inode);
269 if (!nfs_page_group_sync_on_bit(req, PG_WB_END))
272 end_page_writeback(req->wb_page);
273 if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH)
274 clear_bdi_congested(&nfss->backing_dev_info, BLK_RW_ASYNC);
277 static struct nfs_page *nfs_find_and_lock_request(struct page *page, bool nonblock)
279 struct inode *inode = page_file_mapping(page)->host;
280 struct nfs_page *req;
283 spin_lock(&inode->i_lock);
285 req = nfs_page_find_request_locked(NFS_I(inode), page);
288 if (nfs_lock_request(req))
290 /* Note: If we hold the page lock, as is the case in nfs_writepage,
291 * then the call to nfs_lock_request() will always
292 * succeed provided that someone hasn't already marked the
293 * request as dirty (in which case we don't care).
295 spin_unlock(&inode->i_lock);
297 ret = nfs_wait_on_request(req);
300 nfs_release_request(req);
303 spin_lock(&inode->i_lock);
305 spin_unlock(&inode->i_lock);
310 * Find an associated nfs write request, and prepare to flush it out
311 * May return an error if the user signalled nfs_wait_on_request().
313 static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio,
314 struct page *page, bool nonblock)
316 struct nfs_page *req;
319 req = nfs_find_and_lock_request(page, nonblock);
326 nfs_set_page_writeback(page);
327 WARN_ON_ONCE(test_bit(PG_CLEAN, &req->wb_flags));
330 if (!nfs_pageio_add_request(pgio, req)) {
331 nfs_redirty_request(req);
332 ret = pgio->pg_error;
338 static int nfs_do_writepage(struct page *page, struct writeback_control *wbc, struct nfs_pageio_descriptor *pgio)
340 struct inode *inode = page_file_mapping(page)->host;
343 nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE);
344 nfs_add_stats(inode, NFSIOS_WRITEPAGES, 1);
346 nfs_pageio_cond_complete(pgio, page_file_index(page));
347 ret = nfs_page_async_flush(pgio, page, wbc->sync_mode == WB_SYNC_NONE);
348 if (ret == -EAGAIN) {
349 redirty_page_for_writepage(wbc, page);
356 * Write an mmapped page to the server.
358 static int nfs_writepage_locked(struct page *page, struct writeback_control *wbc)
360 struct nfs_pageio_descriptor pgio;
363 nfs_pageio_init_write(&pgio, page->mapping->host, wb_priority(wbc),
364 false, &nfs_async_write_completion_ops);
365 err = nfs_do_writepage(page, wbc, &pgio);
366 nfs_pageio_complete(&pgio);
369 if (pgio.pg_error < 0)
370 return pgio.pg_error;
374 int nfs_writepage(struct page *page, struct writeback_control *wbc)
378 ret = nfs_writepage_locked(page, wbc);
383 static int nfs_writepages_callback(struct page *page, struct writeback_control *wbc, void *data)
387 ret = nfs_do_writepage(page, wbc, data);
392 int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
394 struct inode *inode = mapping->host;
395 unsigned long *bitlock = &NFS_I(inode)->flags;
396 struct nfs_pageio_descriptor pgio;
399 /* Stop dirtying of new pages while we sync */
400 err = wait_on_bit_lock(bitlock, NFS_INO_FLUSHING,
401 nfs_wait_bit_killable, TASK_KILLABLE);
405 nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES);
407 nfs_pageio_init_write(&pgio, inode, wb_priority(wbc), false,
408 &nfs_async_write_completion_ops);
409 err = write_cache_pages(mapping, wbc, nfs_writepages_callback, &pgio);
410 nfs_pageio_complete(&pgio);
412 clear_bit_unlock(NFS_INO_FLUSHING, bitlock);
413 smp_mb__after_atomic();
414 wake_up_bit(bitlock, NFS_INO_FLUSHING);
427 * Insert a write request into an inode
429 static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
431 struct nfs_inode *nfsi = NFS_I(inode);
433 WARN_ON_ONCE(req->wb_this_page != req);
435 /* Lock the request! */
436 nfs_lock_request(req);
438 spin_lock(&inode->i_lock);
439 if (!nfsi->npages && NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE))
442 * Swap-space should not get truncated. Hence no need to plug the race
443 * with invalidate/truncate.
445 if (likely(!PageSwapCache(req->wb_page))) {
446 set_bit(PG_MAPPED, &req->wb_flags);
447 SetPagePrivate(req->wb_page);
448 set_page_private(req->wb_page, (unsigned long)req);
451 set_bit(PG_INODE_REF, &req->wb_flags);
452 kref_get(&req->wb_kref);
453 spin_unlock(&inode->i_lock);
457 * Remove a write request from an inode
459 static void nfs_inode_remove_request(struct nfs_page *req)
461 struct inode *inode = req->wb_context->dentry->d_inode;
462 struct nfs_inode *nfsi = NFS_I(inode);
463 struct nfs_page *head;
465 if (nfs_page_group_sync_on_bit(req, PG_REMOVE)) {
468 spin_lock(&inode->i_lock);
469 if (likely(!PageSwapCache(head->wb_page))) {
470 set_page_private(head->wb_page, 0);
471 ClearPagePrivate(head->wb_page);
472 clear_bit(PG_MAPPED, &head->wb_flags);
475 spin_unlock(&inode->i_lock);
477 nfs_release_request(req);
481 nfs_mark_request_dirty(struct nfs_page *req)
483 __set_page_dirty_nobuffers(req->wb_page);
486 #if IS_ENABLED(CONFIG_NFS_V3) || IS_ENABLED(CONFIG_NFS_V4)
488 * nfs_request_add_commit_list - add request to a commit list
489 * @req: pointer to a struct nfs_page
490 * @dst: commit list head
491 * @cinfo: holds list lock and accounting info
493 * This sets the PG_CLEAN bit, updates the cinfo count of
494 * number of outstanding requests requiring a commit as well as
497 * The caller must _not_ hold the cinfo->lock, but must be
498 * holding the nfs_page lock.
501 nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst,
502 struct nfs_commit_info *cinfo)
504 set_bit(PG_CLEAN, &(req)->wb_flags);
505 spin_lock(cinfo->lock);
506 nfs_list_add_request(req, dst);
507 cinfo->mds->ncommit++;
508 spin_unlock(cinfo->lock);
510 inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
511 inc_bdi_stat(page_file_mapping(req->wb_page)->backing_dev_info,
513 __mark_inode_dirty(req->wb_context->dentry->d_inode,
517 EXPORT_SYMBOL_GPL(nfs_request_add_commit_list);
520 * nfs_request_remove_commit_list - Remove request from a commit list
521 * @req: pointer to a nfs_page
522 * @cinfo: holds list lock and accounting info
524 * This clears the PG_CLEAN bit, and updates the cinfo's count of
525 * number of outstanding requests requiring a commit
526 * It does not update the MM page stats.
528 * The caller _must_ hold the cinfo->lock and the nfs_page lock.
531 nfs_request_remove_commit_list(struct nfs_page *req,
532 struct nfs_commit_info *cinfo)
534 if (!test_and_clear_bit(PG_CLEAN, &(req)->wb_flags))
536 nfs_list_remove_request(req);
537 cinfo->mds->ncommit--;
539 EXPORT_SYMBOL_GPL(nfs_request_remove_commit_list);
541 static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo,
544 cinfo->lock = &inode->i_lock;
545 cinfo->mds = &NFS_I(inode)->commit_info;
546 cinfo->ds = pnfs_get_ds_info(inode);
548 cinfo->completion_ops = &nfs_commit_completion_ops;
551 void nfs_init_cinfo(struct nfs_commit_info *cinfo,
553 struct nfs_direct_req *dreq)
556 nfs_init_cinfo_from_dreq(cinfo, dreq);
558 nfs_init_cinfo_from_inode(cinfo, inode);
560 EXPORT_SYMBOL_GPL(nfs_init_cinfo);
563 * Add a request to the inode's commit list.
566 nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg,
567 struct nfs_commit_info *cinfo)
569 if (pnfs_mark_request_commit(req, lseg, cinfo))
571 nfs_request_add_commit_list(req, &cinfo->mds->list, cinfo);
575 nfs_clear_page_commit(struct page *page)
577 dec_zone_page_state(page, NR_UNSTABLE_NFS);
578 dec_bdi_stat(page_file_mapping(page)->backing_dev_info, BDI_RECLAIMABLE);
582 nfs_clear_request_commit(struct nfs_page *req)
584 if (test_bit(PG_CLEAN, &req->wb_flags)) {
585 struct inode *inode = req->wb_context->dentry->d_inode;
586 struct nfs_commit_info cinfo;
588 nfs_init_cinfo_from_inode(&cinfo, inode);
589 if (!pnfs_clear_request_commit(req, &cinfo)) {
590 spin_lock(cinfo.lock);
591 nfs_request_remove_commit_list(req, &cinfo);
592 spin_unlock(cinfo.lock);
594 nfs_clear_page_commit(req->wb_page);
599 int nfs_write_need_commit(struct nfs_pgio_data *data)
601 if (data->verf.committed == NFS_DATA_SYNC)
602 return data->header->lseg == NULL;
603 return data->verf.committed != NFS_FILE_SYNC;
607 static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo,
612 void nfs_init_cinfo(struct nfs_commit_info *cinfo,
614 struct nfs_direct_req *dreq)
619 nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg,
620 struct nfs_commit_info *cinfo)
625 nfs_clear_request_commit(struct nfs_page *req)
630 int nfs_write_need_commit(struct nfs_pgio_data *data)
637 static void nfs_write_completion(struct nfs_pgio_header *hdr)
639 struct nfs_commit_info cinfo;
640 unsigned long bytes = 0;
643 if (test_bit(NFS_IOHDR_REDO, &hdr->flags))
645 nfs_init_cinfo_from_inode(&cinfo, hdr->inode);
646 while (!list_empty(&hdr->pages)) {
647 struct nfs_page *req = nfs_list_entry(hdr->pages.next);
649 bytes += req->wb_bytes;
650 nfs_list_remove_request(req);
651 if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) &&
652 (hdr->good_bytes < bytes)) {
653 nfs_set_pageerror(req->wb_page);
654 nfs_context_set_write_error(req->wb_context, hdr->error);
657 if (test_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags)) {
658 nfs_mark_request_dirty(req);
661 if (test_bit(NFS_IOHDR_NEED_COMMIT, &hdr->flags)) {
662 memcpy(&req->wb_verf, &hdr->verf.verifier, sizeof(req->wb_verf));
663 nfs_mark_request_commit(req, hdr->lseg, &cinfo);
667 nfs_inode_remove_request(req);
669 nfs_unlock_request(req);
670 nfs_end_page_writeback(req);
671 do_destroy = !test_bit(NFS_IOHDR_NEED_COMMIT, &hdr->flags);
672 nfs_release_request(req);
678 #if IS_ENABLED(CONFIG_NFS_V3) || IS_ENABLED(CONFIG_NFS_V4)
680 nfs_reqs_to_commit(struct nfs_commit_info *cinfo)
682 return cinfo->mds->ncommit;
685 /* cinfo->lock held by caller */
687 nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
688 struct nfs_commit_info *cinfo, int max)
690 struct nfs_page *req, *tmp;
693 list_for_each_entry_safe(req, tmp, src, wb_list) {
694 if (!nfs_lock_request(req))
696 kref_get(&req->wb_kref);
697 if (cond_resched_lock(cinfo->lock))
698 list_safe_reset_next(req, tmp, wb_list);
699 nfs_request_remove_commit_list(req, cinfo);
700 nfs_list_add_request(req, dst);
702 if ((ret == max) && !cinfo->dreq)
709 * nfs_scan_commit - Scan an inode for commit requests
710 * @inode: NFS inode to scan
711 * @dst: mds destination list
712 * @cinfo: mds and ds lists of reqs ready to commit
714 * Moves requests from the inode's 'commit' request list.
715 * The requests are *not* checked to ensure that they form a contiguous set.
718 nfs_scan_commit(struct inode *inode, struct list_head *dst,
719 struct nfs_commit_info *cinfo)
723 spin_lock(cinfo->lock);
724 if (cinfo->mds->ncommit > 0) {
725 const int max = INT_MAX;
727 ret = nfs_scan_commit_list(&cinfo->mds->list, dst,
729 ret += pnfs_scan_commit_lists(inode, cinfo, max - ret);
731 spin_unlock(cinfo->lock);
736 unsigned long nfs_reqs_to_commit(struct nfs_commit_info *cinfo)
741 int nfs_scan_commit(struct inode *inode, struct list_head *dst,
742 struct nfs_commit_info *cinfo)
749 * Search for an existing write request, and attempt to update
750 * it to reflect a new dirty region on a given page.
752 * If the attempt fails, then the existing request is flushed out
755 static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
760 struct nfs_page *req;
765 if (!PagePrivate(page))
768 end = offset + bytes;
769 spin_lock(&inode->i_lock);
772 req = nfs_page_find_request_locked(NFS_I(inode), page);
776 /* should be handled by nfs_flush_incompatible */
777 WARN_ON_ONCE(req->wb_head != req);
778 WARN_ON_ONCE(req->wb_this_page != req);
780 rqend = req->wb_offset + req->wb_bytes;
782 * Tell the caller to flush out the request if
783 * the offsets are non-contiguous.
784 * Note: nfs_flush_incompatible() will already
785 * have flushed out requests having wrong owners.
788 || end < req->wb_offset)
791 if (nfs_lock_request(req))
794 /* The request is locked, so wait and then retry */
795 spin_unlock(&inode->i_lock);
796 error = nfs_wait_on_request(req);
797 nfs_release_request(req);
800 spin_lock(&inode->i_lock);
803 /* Okay, the request matches. Update the region */
804 if (offset < req->wb_offset) {
805 req->wb_offset = offset;
806 req->wb_pgbase = offset;
809 req->wb_bytes = end - req->wb_offset;
811 req->wb_bytes = rqend - req->wb_offset;
813 spin_unlock(&inode->i_lock);
815 nfs_clear_request_commit(req);
818 spin_unlock(&inode->i_lock);
819 nfs_release_request(req);
820 error = nfs_wb_page(inode, page);
822 return ERR_PTR(error);
826 * Try to update an existing write request, or create one if there is none.
828 * Note: Should always be called with the Page Lock held to prevent races
829 * if we have to add a new request. Also assumes that the caller has
830 * already called nfs_flush_incompatible() if necessary.
832 static struct nfs_page * nfs_setup_write_request(struct nfs_open_context* ctx,
833 struct page *page, unsigned int offset, unsigned int bytes)
835 struct inode *inode = page_file_mapping(page)->host;
836 struct nfs_page *req;
838 req = nfs_try_to_update_request(inode, page, offset, bytes);
841 req = nfs_create_request(ctx, page, NULL, offset, bytes);
844 nfs_inode_add_request(inode, req);
849 static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page,
850 unsigned int offset, unsigned int count)
852 struct nfs_page *req;
854 req = nfs_setup_write_request(ctx, page, offset, count);
857 /* Update file length */
858 nfs_grow_file(page, offset, count);
859 nfs_mark_uptodate(req);
860 nfs_mark_request_dirty(req);
861 nfs_unlock_and_release_request(req);
865 int nfs_flush_incompatible(struct file *file, struct page *page)
867 struct nfs_open_context *ctx = nfs_file_open_context(file);
868 struct nfs_lock_context *l_ctx;
869 struct nfs_page *req;
870 int do_flush, status;
872 * Look for a request corresponding to this page. If there
873 * is one, and it belongs to another file, we flush it out
874 * before we try to copy anything into the page. Do this
875 * due to the lack of an ACCESS-type call in NFSv2.
876 * Also do the same if we find a request from an existing
880 req = nfs_page_find_request(page);
883 l_ctx = req->wb_lock_context;
884 do_flush = req->wb_page != page || req->wb_context != ctx;
885 /* for now, flush if more than 1 request in page_group */
886 do_flush |= req->wb_this_page != req;
887 if (l_ctx && ctx->dentry->d_inode->i_flock != NULL) {
888 do_flush |= l_ctx->lockowner.l_owner != current->files
889 || l_ctx->lockowner.l_pid != current->tgid;
891 nfs_release_request(req);
894 status = nfs_wb_page(page_file_mapping(page)->host, page);
895 } while (status == 0);
900 * Avoid buffered writes when a open context credential's key would
903 * Returns -EACCES if the key will expire within RPC_KEY_EXPIRE_FAIL.
905 * Return 0 and set a credential flag which triggers the inode to flush
906 * and performs NFS_FILE_SYNC writes if the key will expired within
907 * RPC_KEY_EXPIRE_TIMEO.
910 nfs_key_timeout_notify(struct file *filp, struct inode *inode)
912 struct nfs_open_context *ctx = nfs_file_open_context(filp);
913 struct rpc_auth *auth = NFS_SERVER(inode)->client->cl_auth;
915 return rpcauth_key_timeout_notify(auth, ctx->cred);
919 * Test if the open context credential key is marked to expire soon.
921 bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx)
923 return rpcauth_cred_key_to_expire(ctx->cred);
927 * If the page cache is marked as unsafe or invalid, then we can't rely on
928 * the PageUptodate() flag. In this case, we will need to turn off
929 * write optimisations that depend on the page contents being correct.
931 static bool nfs_write_pageuptodate(struct page *page, struct inode *inode)
933 struct nfs_inode *nfsi = NFS_I(inode);
935 if (nfs_have_delegated_attributes(inode))
937 if (nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE)
940 if (test_bit(NFS_INO_INVALIDATING, &nfsi->flags))
943 if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
945 return PageUptodate(page) != 0;
948 /* If we know the page is up to date, and we're not using byte range locks (or
949 * if we have the whole file locked for writing), it may be more efficient to
950 * extend the write to cover the entire page in order to avoid fragmentation
953 * If the file is opened for synchronous writes then we can just skip the rest
956 static int nfs_can_extend_write(struct file *file, struct page *page, struct inode *inode)
958 if (file->f_flags & O_DSYNC)
960 if (!nfs_write_pageuptodate(page, inode))
962 if (NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE))
964 if (inode->i_flock == NULL || (inode->i_flock->fl_start == 0 &&
965 inode->i_flock->fl_end == OFFSET_MAX &&
966 inode->i_flock->fl_type != F_RDLCK))
972 * Update and possibly write a cached page of an NFS file.
974 * XXX: Keep an eye on generic_file_read to make sure it doesn't do bad
975 * things with a page scheduled for an RPC call (e.g. invalidate it).
977 int nfs_updatepage(struct file *file, struct page *page,
978 unsigned int offset, unsigned int count)
980 struct nfs_open_context *ctx = nfs_file_open_context(file);
981 struct inode *inode = page_file_mapping(page)->host;
984 nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE);
986 dprintk("NFS: nfs_updatepage(%pD2 %d@%lld)\n",
987 file, count, (long long)(page_file_offset(page) + offset));
989 if (nfs_can_extend_write(file, page, inode)) {
990 count = max(count + offset, nfs_page_length(page));
994 status = nfs_writepage_setup(ctx, page, offset, count);
996 nfs_set_pageerror(page);
998 __set_page_dirty_nobuffers(page);
1000 dprintk("NFS: nfs_updatepage returns %d (isize %lld)\n",
1001 status, (long long)i_size_read(inode));
1005 static int flush_task_priority(int how)
1007 switch (how & (FLUSH_HIGHPRI|FLUSH_LOWPRI)) {
1009 return RPC_PRIORITY_HIGH;
1011 return RPC_PRIORITY_LOW;
1013 return RPC_PRIORITY_NORMAL;
1016 static void nfs_initiate_write(struct nfs_pgio_data *data, struct rpc_message *msg,
1017 struct rpc_task_setup *task_setup_data, int how)
1019 struct inode *inode = data->header->inode;
1020 int priority = flush_task_priority(how);
1022 task_setup_data->priority = priority;
1023 NFS_PROTO(inode)->write_setup(data, msg);
1025 nfs4_state_protect_write(NFS_SERVER(inode)->nfs_client,
1026 &task_setup_data->rpc_client, msg, data);
1029 /* If a nfs_flush_* function fails, it should remove reqs from @head and
1030 * call this on each, which will prepare them to be retried on next
1031 * writeback using standard nfs.
1033 static void nfs_redirty_request(struct nfs_page *req)
1035 nfs_mark_request_dirty(req);
1036 nfs_unlock_request(req);
1037 nfs_end_page_writeback(req);
1038 nfs_release_request(req);
1041 static void nfs_async_write_error(struct list_head *head)
1043 struct nfs_page *req;
1045 while (!list_empty(head)) {
1046 req = nfs_list_entry(head->next);
1047 nfs_list_remove_request(req);
1048 nfs_redirty_request(req);
1052 static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops = {
1053 .error_cleanup = nfs_async_write_error,
1054 .completion = nfs_write_completion,
1057 void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
1058 struct inode *inode, int ioflags, bool force_mds,
1059 const struct nfs_pgio_completion_ops *compl_ops)
1061 struct nfs_server *server = NFS_SERVER(inode);
1062 const struct nfs_pageio_ops *pg_ops = &nfs_pgio_rw_ops;
1064 #ifdef CONFIG_NFS_V4_1
1065 if (server->pnfs_curr_ld && !force_mds)
1066 pg_ops = server->pnfs_curr_ld->pg_write_ops;
1068 nfs_pageio_init(pgio, inode, pg_ops, compl_ops, &nfs_rw_write_ops,
1069 server->wsize, ioflags);
1071 EXPORT_SYMBOL_GPL(nfs_pageio_init_write);
1073 void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio)
1075 pgio->pg_ops = &nfs_pgio_rw_ops;
1076 pgio->pg_bsize = NFS_SERVER(pgio->pg_inode)->wsize;
1078 EXPORT_SYMBOL_GPL(nfs_pageio_reset_write_mds);
1081 void nfs_commit_prepare(struct rpc_task *task, void *calldata)
1083 struct nfs_commit_data *data = calldata;
1085 NFS_PROTO(data->inode)->commit_rpc_prepare(task, data);
1088 static void nfs_writeback_release_common(struct nfs_pgio_data *data)
1090 struct nfs_pgio_header *hdr = data->header;
1091 int status = data->task.tk_status;
1093 if ((status >= 0) && nfs_write_need_commit(data)) {
1094 spin_lock(&hdr->lock);
1095 if (test_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags))
1097 else if (!test_and_set_bit(NFS_IOHDR_NEED_COMMIT, &hdr->flags))
1098 memcpy(&hdr->verf, &data->verf, sizeof(hdr->verf));
1099 else if (memcmp(&hdr->verf, &data->verf, sizeof(hdr->verf)))
1100 set_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags);
1101 spin_unlock(&hdr->lock);
1106 * Special version of should_remove_suid() that ignores capabilities.
1108 static int nfs_should_remove_suid(const struct inode *inode)
1110 umode_t mode = inode->i_mode;
1113 /* suid always must be killed */
1114 if (unlikely(mode & S_ISUID))
1115 kill = ATTR_KILL_SUID;
1118 * sgid without any exec bits is just a mandatory locking mark; leave
1119 * it alone. If some exec bits are set, it's a real sgid; kill it.
1121 if (unlikely((mode & S_ISGID) && (mode & S_IXGRP)))
1122 kill |= ATTR_KILL_SGID;
1124 if (unlikely(kill && S_ISREG(mode)))
1131 * This function is called when the WRITE call is complete.
1133 static int nfs_writeback_done(struct rpc_task *task, struct nfs_pgio_data *data,
1134 struct inode *inode)
1139 * ->write_done will attempt to use post-op attributes to detect
1140 * conflicting writes by other clients. A strict interpretation
1141 * of close-to-open would allow us to continue caching even if
1142 * another writer had changed the file, but some applications
1143 * depend on tighter cache coherency when writing.
1145 status = NFS_PROTO(inode)->write_done(task, data);
1148 nfs_add_stats(inode, NFSIOS_SERVERWRITTENBYTES, data->res.count);
1150 #if IS_ENABLED(CONFIG_NFS_V3) || IS_ENABLED(CONFIG_NFS_V4)
1151 if (data->res.verf->committed < data->args.stable && task->tk_status >= 0) {
1152 /* We tried a write call, but the server did not
1153 * commit data to stable storage even though we
1155 * Note: There is a known bug in Tru64 < 5.0 in which
1156 * the server reports NFS_DATA_SYNC, but performs
1157 * NFS_FILE_SYNC. We therefore implement this checking
1158 * as a dprintk() in order to avoid filling syslog.
1160 static unsigned long complain;
1162 /* Note this will print the MDS for a DS write */
1163 if (time_before(complain, jiffies)) {
1164 dprintk("NFS: faulty NFS server %s:"
1165 " (committed = %d) != (stable = %d)\n",
1166 NFS_SERVER(inode)->nfs_client->cl_hostname,
1167 data->res.verf->committed, data->args.stable);
1168 complain = jiffies + 300 * HZ;
1173 /* Deal with the suid/sgid bit corner case */
1174 if (nfs_should_remove_suid(inode))
1175 nfs_mark_for_revalidate(inode);
1180 * This function is called when the WRITE call is complete.
1182 static void nfs_writeback_result(struct rpc_task *task, struct nfs_pgio_data *data)
1184 struct nfs_pgio_args *argp = &data->args;
1185 struct nfs_pgio_res *resp = &data->res;
1187 if (resp->count < argp->count) {
1188 static unsigned long complain;
1190 /* This a short write! */
1191 nfs_inc_stats(data->header->inode, NFSIOS_SHORTWRITE);
1193 /* Has the server at least made some progress? */
1194 if (resp->count == 0) {
1195 if (time_before(complain, jiffies)) {
1197 "NFS: Server wrote zero bytes, expected %u.\n",
1199 complain = jiffies + 300 * HZ;
1201 nfs_set_pgio_error(data->header, -EIO, argp->offset);
1202 task->tk_status = -EIO;
1205 /* Was this an NFSv2 write or an NFSv3 stable write? */
1206 if (resp->verf->committed != NFS_UNSTABLE) {
1207 /* Resend from where the server left off */
1208 data->mds_offset += resp->count;
1209 argp->offset += resp->count;
1210 argp->pgbase += resp->count;
1211 argp->count -= resp->count;
1213 /* Resend as a stable write in order to avoid
1214 * headaches in the case of a server crash.
1216 argp->stable = NFS_FILE_SYNC;
1218 rpc_restart_call_prepare(task);
1223 #if IS_ENABLED(CONFIG_NFS_V3) || IS_ENABLED(CONFIG_NFS_V4)
1224 static int nfs_commit_set_lock(struct nfs_inode *nfsi, int may_wait)
1228 if (!test_and_set_bit(NFS_INO_COMMIT, &nfsi->flags))
1232 ret = out_of_line_wait_on_bit_lock(&nfsi->flags,
1234 nfs_wait_bit_killable,
1236 return (ret < 0) ? ret : 1;
1239 static void nfs_commit_clear_lock(struct nfs_inode *nfsi)
1241 clear_bit(NFS_INO_COMMIT, &nfsi->flags);
1242 smp_mb__after_atomic();
1243 wake_up_bit(&nfsi->flags, NFS_INO_COMMIT);
1246 void nfs_commitdata_release(struct nfs_commit_data *data)
1248 put_nfs_open_context(data->context);
1249 nfs_commit_free(data);
1251 EXPORT_SYMBOL_GPL(nfs_commitdata_release);
1253 int nfs_initiate_commit(struct rpc_clnt *clnt, struct nfs_commit_data *data,
1254 const struct rpc_call_ops *call_ops,
1257 struct rpc_task *task;
1258 int priority = flush_task_priority(how);
1259 struct rpc_message msg = {
1260 .rpc_argp = &data->args,
1261 .rpc_resp = &data->res,
1262 .rpc_cred = data->cred,
1264 struct rpc_task_setup task_setup_data = {
1265 .task = &data->task,
1267 .rpc_message = &msg,
1268 .callback_ops = call_ops,
1269 .callback_data = data,
1270 .workqueue = nfsiod_workqueue,
1271 .flags = RPC_TASK_ASYNC | flags,
1272 .priority = priority,
1274 /* Set up the initial task struct. */
1275 NFS_PROTO(data->inode)->commit_setup(data, &msg);
1277 dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid);
1279 nfs4_state_protect(NFS_SERVER(data->inode)->nfs_client,
1280 NFS_SP4_MACH_CRED_COMMIT, &task_setup_data.rpc_client, &msg);
1282 task = rpc_run_task(&task_setup_data);
1284 return PTR_ERR(task);
1285 if (how & FLUSH_SYNC)
1286 rpc_wait_for_completion_task(task);
1290 EXPORT_SYMBOL_GPL(nfs_initiate_commit);
1293 * Set up the argument/result storage required for the RPC call.
1295 void nfs_init_commit(struct nfs_commit_data *data,
1296 struct list_head *head,
1297 struct pnfs_layout_segment *lseg,
1298 struct nfs_commit_info *cinfo)
1300 struct nfs_page *first = nfs_list_entry(head->next);
1301 struct inode *inode = first->wb_context->dentry->d_inode;
1303 /* Set up the RPC argument and reply structs
1304 * NB: take care not to mess about with data->commit et al. */
1306 list_splice_init(head, &data->pages);
1308 data->inode = inode;
1309 data->cred = first->wb_context->cred;
1310 data->lseg = lseg; /* reference transferred */
1311 data->mds_ops = &nfs_commit_ops;
1312 data->completion_ops = cinfo->completion_ops;
1313 data->dreq = cinfo->dreq;
1315 data->args.fh = NFS_FH(data->inode);
1316 /* Note: we always request a commit of the entire inode */
1317 data->args.offset = 0;
1318 data->args.count = 0;
1319 data->context = get_nfs_open_context(first->wb_context);
1320 data->res.fattr = &data->fattr;
1321 data->res.verf = &data->verf;
1322 nfs_fattr_init(&data->fattr);
1324 EXPORT_SYMBOL_GPL(nfs_init_commit);
1326 void nfs_retry_commit(struct list_head *page_list,
1327 struct pnfs_layout_segment *lseg,
1328 struct nfs_commit_info *cinfo)
1330 struct nfs_page *req;
1332 while (!list_empty(page_list)) {
1333 req = nfs_list_entry(page_list->next);
1334 nfs_list_remove_request(req);
1335 nfs_mark_request_commit(req, lseg, cinfo);
1337 dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
1338 dec_bdi_stat(page_file_mapping(req->wb_page)->backing_dev_info,
1341 nfs_unlock_and_release_request(req);
1344 EXPORT_SYMBOL_GPL(nfs_retry_commit);
1347 * Commit dirty pages
1350 nfs_commit_list(struct inode *inode, struct list_head *head, int how,
1351 struct nfs_commit_info *cinfo)
1353 struct nfs_commit_data *data;
1355 data = nfs_commitdata_alloc();
1360 /* Set up the argument struct */
1361 nfs_init_commit(data, head, NULL, cinfo);
1362 atomic_inc(&cinfo->mds->rpcs_out);
1363 return nfs_initiate_commit(NFS_CLIENT(inode), data, data->mds_ops,
1366 nfs_retry_commit(head, NULL, cinfo);
1367 cinfo->completion_ops->error_cleanup(NFS_I(inode));
1372 * COMMIT call returned
1374 static void nfs_commit_done(struct rpc_task *task, void *calldata)
1376 struct nfs_commit_data *data = calldata;
1378 dprintk("NFS: %5u nfs_commit_done (status %d)\n",
1379 task->tk_pid, task->tk_status);
1381 /* Call the NFS version-specific code */
1382 NFS_PROTO(data->inode)->commit_done(task, data);
1385 static void nfs_commit_release_pages(struct nfs_commit_data *data)
1387 struct nfs_page *req;
1388 int status = data->task.tk_status;
1389 struct nfs_commit_info cinfo;
1391 while (!list_empty(&data->pages)) {
1392 req = nfs_list_entry(data->pages.next);
1393 nfs_list_remove_request(req);
1394 nfs_clear_page_commit(req->wb_page);
1396 dprintk("NFS: commit (%s/%llu %d@%lld)",
1397 req->wb_context->dentry->d_sb->s_id,
1398 (unsigned long long)NFS_FILEID(req->wb_context->dentry->d_inode),
1400 (long long)req_offset(req));
1402 nfs_context_set_write_error(req->wb_context, status);
1403 nfs_inode_remove_request(req);
1404 dprintk(", error = %d\n", status);
1408 /* Okay, COMMIT succeeded, apparently. Check the verifier
1409 * returned by the server against all stored verfs. */
1410 if (!memcmp(&req->wb_verf, &data->verf.verifier, sizeof(req->wb_verf))) {
1411 /* We have a match */
1412 nfs_inode_remove_request(req);
1416 /* We have a mismatch. Write the page again */
1417 dprintk(" mismatch\n");
1418 nfs_mark_request_dirty(req);
1419 set_bit(NFS_CONTEXT_RESEND_WRITES, &req->wb_context->flags);
1421 nfs_unlock_and_release_request(req);
1423 nfs_init_cinfo(&cinfo, data->inode, data->dreq);
1424 if (atomic_dec_and_test(&cinfo.mds->rpcs_out))
1425 nfs_commit_clear_lock(NFS_I(data->inode));
1428 static void nfs_commit_release(void *calldata)
1430 struct nfs_commit_data *data = calldata;
1432 data->completion_ops->completion(data);
1433 nfs_commitdata_release(calldata);
1436 static const struct rpc_call_ops nfs_commit_ops = {
1437 .rpc_call_prepare = nfs_commit_prepare,
1438 .rpc_call_done = nfs_commit_done,
1439 .rpc_release = nfs_commit_release,
1442 static const struct nfs_commit_completion_ops nfs_commit_completion_ops = {
1443 .completion = nfs_commit_release_pages,
1444 .error_cleanup = nfs_commit_clear_lock,
1447 int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
1448 int how, struct nfs_commit_info *cinfo)
1452 status = pnfs_commit_list(inode, head, how, cinfo);
1453 if (status == PNFS_NOT_ATTEMPTED)
1454 status = nfs_commit_list(inode, head, how, cinfo);
1458 int nfs_commit_inode(struct inode *inode, int how)
1461 struct nfs_commit_info cinfo;
1462 int may_wait = how & FLUSH_SYNC;
1465 res = nfs_commit_set_lock(NFS_I(inode), may_wait);
1467 goto out_mark_dirty;
1468 nfs_init_cinfo_from_inode(&cinfo, inode);
1469 res = nfs_scan_commit(inode, &head, &cinfo);
1473 error = nfs_generic_commit_list(inode, &head, how, &cinfo);
1477 goto out_mark_dirty;
1478 error = wait_on_bit(&NFS_I(inode)->flags,
1480 nfs_wait_bit_killable,
1485 nfs_commit_clear_lock(NFS_I(inode));
1487 /* Note: If we exit without ensuring that the commit is complete,
1488 * we must mark the inode as dirty. Otherwise, future calls to
1489 * sync_inode() with the WB_SYNC_ALL flag set will fail to ensure
1490 * that the data is on the disk.
1493 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
1497 static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_control *wbc)
1499 struct nfs_inode *nfsi = NFS_I(inode);
1500 int flags = FLUSH_SYNC;
1503 /* no commits means nothing needs to be done */
1504 if (!nfsi->commit_info.ncommit)
1507 if (wbc->sync_mode == WB_SYNC_NONE) {
1508 /* Don't commit yet if this is a non-blocking flush and there
1509 * are a lot of outstanding writes for this mapping.
1511 if (nfsi->commit_info.ncommit <= (nfsi->npages >> 1))
1512 goto out_mark_dirty;
1514 /* don't wait for the COMMIT response */
1518 ret = nfs_commit_inode(inode, flags);
1520 if (wbc->sync_mode == WB_SYNC_NONE) {
1521 if (ret < wbc->nr_to_write)
1522 wbc->nr_to_write -= ret;
1524 wbc->nr_to_write = 0;
1529 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
1533 static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_control *wbc)
1539 int nfs_write_inode(struct inode *inode, struct writeback_control *wbc)
1541 return nfs_commit_unstable_pages(inode, wbc);
1543 EXPORT_SYMBOL_GPL(nfs_write_inode);
1546 * flush the inode to disk.
1548 int nfs_wb_all(struct inode *inode)
1550 struct writeback_control wbc = {
1551 .sync_mode = WB_SYNC_ALL,
1552 .nr_to_write = LONG_MAX,
1554 .range_end = LLONG_MAX,
1558 trace_nfs_writeback_inode_enter(inode);
1560 ret = sync_inode(inode, &wbc);
1562 trace_nfs_writeback_inode_exit(inode, ret);
1565 EXPORT_SYMBOL_GPL(nfs_wb_all);
1567 int nfs_wb_page_cancel(struct inode *inode, struct page *page)
1569 struct nfs_page *req;
1573 wait_on_page_writeback(page);
1574 req = nfs_page_find_request(page);
1577 if (nfs_lock_request(req)) {
1578 nfs_clear_request_commit(req);
1579 nfs_inode_remove_request(req);
1581 * In case nfs_inode_remove_request has marked the
1582 * page as being dirty
1584 cancel_dirty_page(page, PAGE_CACHE_SIZE);
1585 nfs_unlock_and_release_request(req);
1588 ret = nfs_wait_on_request(req);
1589 nfs_release_request(req);
1597 * Write back all requests on one page - we do this before reading it.
1599 int nfs_wb_page(struct inode *inode, struct page *page)
1601 loff_t range_start = page_file_offset(page);
1602 loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
1603 struct writeback_control wbc = {
1604 .sync_mode = WB_SYNC_ALL,
1606 .range_start = range_start,
1607 .range_end = range_end,
1611 trace_nfs_writeback_page_enter(inode);
1614 wait_on_page_writeback(page);
1615 if (clear_page_dirty_for_io(page)) {
1616 ret = nfs_writepage_locked(page, &wbc);
1622 if (!PagePrivate(page))
1624 ret = nfs_commit_inode(inode, FLUSH_SYNC);
1629 trace_nfs_writeback_page_exit(inode, ret);
1633 #ifdef CONFIG_MIGRATION
1634 int nfs_migrate_page(struct address_space *mapping, struct page *newpage,
1635 struct page *page, enum migrate_mode mode)
1638 * If PagePrivate is set, then the page is currently associated with
1639 * an in-progress read or write request. Don't try to migrate it.
1641 * FIXME: we could do this in principle, but we'll need a way to ensure
1642 * that we can safely release the inode reference while holding
1645 if (PagePrivate(page))
1648 if (!nfs_fscache_release_page(page, GFP_KERNEL))
1651 return migrate_page(mapping, newpage, page, mode);
1655 int __init nfs_init_writepagecache(void)
1657 nfs_wdata_cachep = kmem_cache_create("nfs_write_data",
1658 sizeof(struct nfs_rw_header),
1659 0, SLAB_HWCACHE_ALIGN,
1661 if (nfs_wdata_cachep == NULL)
1664 nfs_wdata_mempool = mempool_create_slab_pool(MIN_POOL_WRITE,
1666 if (nfs_wdata_mempool == NULL)
1667 goto out_destroy_write_cache;
1669 nfs_cdata_cachep = kmem_cache_create("nfs_commit_data",
1670 sizeof(struct nfs_commit_data),
1671 0, SLAB_HWCACHE_ALIGN,
1673 if (nfs_cdata_cachep == NULL)
1674 goto out_destroy_write_mempool;
1676 nfs_commit_mempool = mempool_create_slab_pool(MIN_POOL_COMMIT,
1678 if (nfs_commit_mempool == NULL)
1679 goto out_destroy_commit_cache;
1682 * NFS congestion size, scale with available memory.
1694 * This allows larger machines to have larger/more transfers.
1695 * Limit the default to 256M
1697 nfs_congestion_kb = (16*int_sqrt(totalram_pages)) << (PAGE_SHIFT-10);
1698 if (nfs_congestion_kb > 256*1024)
1699 nfs_congestion_kb = 256*1024;
1703 out_destroy_commit_cache:
1704 kmem_cache_destroy(nfs_cdata_cachep);
1705 out_destroy_write_mempool:
1706 mempool_destroy(nfs_wdata_mempool);
1707 out_destroy_write_cache:
1708 kmem_cache_destroy(nfs_wdata_cachep);
1712 void nfs_destroy_writepagecache(void)
1714 mempool_destroy(nfs_commit_mempool);
1715 kmem_cache_destroy(nfs_cdata_cachep);
1716 mempool_destroy(nfs_wdata_mempool);
1717 kmem_cache_destroy(nfs_wdata_cachep);
1720 static const struct nfs_rw_ops nfs_rw_write_ops = {
1721 .rw_mode = FMODE_WRITE,
1722 .rw_alloc_header = nfs_writehdr_alloc,
1723 .rw_free_header = nfs_writehdr_free,
1724 .rw_release = nfs_writeback_release_common,
1725 .rw_done = nfs_writeback_done,
1726 .rw_result = nfs_writeback_result,
1727 .rw_initiate = nfs_initiate_write,