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"
34 #define NFSDBG_FACILITY NFSDBG_PAGECACHE
36 #define MIN_POOL_WRITE (32)
37 #define MIN_POOL_COMMIT (4)
40 * Local function declarations
42 static void nfs_pageio_init_write(struct nfs_pageio_descriptor *desc,
43 struct inode *inode, int ioflags);
44 static void nfs_redirty_request(struct nfs_page *req);
45 static const struct rpc_call_ops nfs_write_partial_ops;
46 static const struct rpc_call_ops nfs_write_full_ops;
47 static const struct rpc_call_ops nfs_commit_ops;
49 static struct kmem_cache *nfs_wdata_cachep;
50 static mempool_t *nfs_wdata_mempool;
51 static mempool_t *nfs_commit_mempool;
53 struct nfs_write_data *nfs_commitdata_alloc(void)
55 struct nfs_write_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOFS);
58 memset(p, 0, sizeof(*p));
59 INIT_LIST_HEAD(&p->pages);
63 EXPORT_SYMBOL_GPL(nfs_commitdata_alloc);
65 void nfs_commit_free(struct nfs_write_data *p)
67 if (p && (p->pagevec != &p->page_array[0]))
69 mempool_free(p, nfs_commit_mempool);
71 EXPORT_SYMBOL_GPL(nfs_commit_free);
73 struct nfs_write_data *nfs_writedata_alloc(unsigned int pagecount)
75 struct nfs_write_data *p = mempool_alloc(nfs_wdata_mempool, GFP_NOFS);
78 memset(p, 0, sizeof(*p));
79 INIT_LIST_HEAD(&p->pages);
80 p->npages = pagecount;
81 if (pagecount <= ARRAY_SIZE(p->page_array))
82 p->pagevec = p->page_array;
84 p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_NOFS);
86 mempool_free(p, nfs_wdata_mempool);
94 void nfs_writedata_free(struct nfs_write_data *p)
96 if (p && (p->pagevec != &p->page_array[0]))
98 mempool_free(p, nfs_wdata_mempool);
101 void nfs_writedata_release(struct nfs_write_data *wdata)
103 put_nfs_open_context(wdata->args.context);
104 nfs_writedata_free(wdata);
107 static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error)
111 set_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags);
114 static struct nfs_page *nfs_page_find_request_locked(struct page *page)
116 struct nfs_page *req = NULL;
118 if (PagePrivate(page)) {
119 req = (struct nfs_page *)page_private(page);
121 kref_get(&req->wb_kref);
126 static struct nfs_page *nfs_page_find_request(struct page *page)
128 struct inode *inode = page->mapping->host;
129 struct nfs_page *req = NULL;
131 spin_lock(&inode->i_lock);
132 req = nfs_page_find_request_locked(page);
133 spin_unlock(&inode->i_lock);
137 /* Adjust the file length if we're writing beyond the end */
138 static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count)
140 struct inode *inode = page->mapping->host;
144 spin_lock(&inode->i_lock);
145 i_size = i_size_read(inode);
146 end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
147 if (i_size > 0 && page->index < end_index)
149 end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + ((loff_t)offset+count);
152 i_size_write(inode, end);
153 nfs_inc_stats(inode, NFSIOS_EXTENDWRITE);
155 spin_unlock(&inode->i_lock);
158 /* A writeback failed: mark the page as bad, and invalidate the page cache */
159 static void nfs_set_pageerror(struct page *page)
162 nfs_zap_mapping(page->mapping->host, page->mapping);
165 /* We can set the PG_uptodate flag if we see that a write request
166 * covers the full page.
168 static void nfs_mark_uptodate(struct page *page, unsigned int base, unsigned int count)
170 if (PageUptodate(page))
174 if (count != nfs_page_length(page))
176 SetPageUptodate(page);
179 static int wb_priority(struct writeback_control *wbc)
181 if (wbc->for_reclaim)
182 return FLUSH_HIGHPRI | FLUSH_STABLE;
183 if (wbc->for_kupdate || wbc->for_background)
184 return FLUSH_LOWPRI | FLUSH_COND_STABLE;
185 return FLUSH_COND_STABLE;
189 * NFS congestion control
192 int nfs_congestion_kb;
194 #define NFS_CONGESTION_ON_THRESH (nfs_congestion_kb >> (PAGE_SHIFT-10))
195 #define NFS_CONGESTION_OFF_THRESH \
196 (NFS_CONGESTION_ON_THRESH - (NFS_CONGESTION_ON_THRESH >> 2))
198 static int nfs_set_page_writeback(struct page *page)
200 int ret = test_set_page_writeback(page);
203 struct inode *inode = page->mapping->host;
204 struct nfs_server *nfss = NFS_SERVER(inode);
206 page_cache_get(page);
207 if (atomic_long_inc_return(&nfss->writeback) >
208 NFS_CONGESTION_ON_THRESH) {
209 set_bdi_congested(&nfss->backing_dev_info,
216 static void nfs_end_page_writeback(struct page *page)
218 struct inode *inode = page->mapping->host;
219 struct nfs_server *nfss = NFS_SERVER(inode);
221 end_page_writeback(page);
222 page_cache_release(page);
223 if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH)
224 clear_bdi_congested(&nfss->backing_dev_info, BLK_RW_ASYNC);
227 static struct nfs_page *nfs_find_and_lock_request(struct page *page, bool nonblock)
229 struct inode *inode = page->mapping->host;
230 struct nfs_page *req;
233 spin_lock(&inode->i_lock);
235 req = nfs_page_find_request_locked(page);
238 if (nfs_lock_request_dontget(req))
240 /* Note: If we hold the page lock, as is the case in nfs_writepage,
241 * then the call to nfs_lock_request_dontget() will always
242 * succeed provided that someone hasn't already marked the
243 * request as dirty (in which case we don't care).
245 spin_unlock(&inode->i_lock);
247 ret = nfs_wait_on_request(req);
250 nfs_release_request(req);
253 spin_lock(&inode->i_lock);
255 spin_unlock(&inode->i_lock);
260 * Find an associated nfs write request, and prepare to flush it out
261 * May return an error if the user signalled nfs_wait_on_request().
263 static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio,
264 struct page *page, bool nonblock)
266 struct nfs_page *req;
269 req = nfs_find_and_lock_request(page, nonblock);
276 ret = nfs_set_page_writeback(page);
278 BUG_ON(test_bit(PG_CLEAN, &req->wb_flags));
280 if (!nfs_pageio_add_request(pgio, req)) {
281 nfs_redirty_request(req);
282 ret = pgio->pg_error;
288 static int nfs_do_writepage(struct page *page, struct writeback_control *wbc, struct nfs_pageio_descriptor *pgio)
290 struct inode *inode = page->mapping->host;
293 nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE);
294 nfs_add_stats(inode, NFSIOS_WRITEPAGES, 1);
296 nfs_pageio_cond_complete(pgio, page->index);
297 ret = nfs_page_async_flush(pgio, page, wbc->sync_mode == WB_SYNC_NONE);
298 if (ret == -EAGAIN) {
299 redirty_page_for_writepage(wbc, page);
306 * Write an mmapped page to the server.
308 static int nfs_writepage_locked(struct page *page, struct writeback_control *wbc)
310 struct nfs_pageio_descriptor pgio;
313 nfs_pageio_init_write(&pgio, page->mapping->host, wb_priority(wbc));
314 err = nfs_do_writepage(page, wbc, &pgio);
315 nfs_pageio_complete(&pgio);
318 if (pgio.pg_error < 0)
319 return pgio.pg_error;
323 int nfs_writepage(struct page *page, struct writeback_control *wbc)
327 ret = nfs_writepage_locked(page, wbc);
332 static int nfs_writepages_callback(struct page *page, struct writeback_control *wbc, void *data)
336 ret = nfs_do_writepage(page, wbc, data);
341 int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
343 struct inode *inode = mapping->host;
344 unsigned long *bitlock = &NFS_I(inode)->flags;
345 struct nfs_pageio_descriptor pgio;
348 /* Stop dirtying of new pages while we sync */
349 err = wait_on_bit_lock(bitlock, NFS_INO_FLUSHING,
350 nfs_wait_bit_killable, TASK_KILLABLE);
354 nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES);
356 nfs_pageio_init_write(&pgio, inode, wb_priority(wbc));
357 err = write_cache_pages(mapping, wbc, nfs_writepages_callback, &pgio);
358 nfs_pageio_complete(&pgio);
360 clear_bit_unlock(NFS_INO_FLUSHING, bitlock);
361 smp_mb__after_clear_bit();
362 wake_up_bit(bitlock, NFS_INO_FLUSHING);
375 * Insert a write request into an inode
377 static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
379 struct nfs_inode *nfsi = NFS_I(inode);
381 /* Lock the request! */
382 nfs_lock_request_dontget(req);
384 spin_lock(&inode->i_lock);
385 if (!nfsi->npages && nfs_have_delegation(inode, FMODE_WRITE))
387 set_bit(PG_MAPPED, &req->wb_flags);
388 SetPagePrivate(req->wb_page);
389 set_page_private(req->wb_page, (unsigned long)req);
391 kref_get(&req->wb_kref);
392 spin_unlock(&inode->i_lock);
396 * Remove a write request from an inode
398 static void nfs_inode_remove_request(struct nfs_page *req)
400 struct inode *inode = req->wb_context->dentry->d_inode;
401 struct nfs_inode *nfsi = NFS_I(inode);
403 BUG_ON (!NFS_WBACK_BUSY(req));
405 spin_lock(&inode->i_lock);
406 set_page_private(req->wb_page, 0);
407 ClearPagePrivate(req->wb_page);
408 clear_bit(PG_MAPPED, &req->wb_flags);
410 spin_unlock(&inode->i_lock);
411 nfs_release_request(req);
415 nfs_mark_request_dirty(struct nfs_page *req)
417 __set_page_dirty_nobuffers(req->wb_page);
420 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
422 * nfs_request_add_commit_list - add request to a commit list
423 * @req: pointer to a struct nfs_page
424 * @head: commit list head
426 * This sets the PG_CLEAN bit, updates the inode global count of
427 * number of outstanding requests requiring a commit as well as
430 * The caller must _not_ hold the inode->i_lock, but must be
431 * holding the nfs_page lock.
434 nfs_request_add_commit_list(struct nfs_page *req, struct list_head *head)
436 struct inode *inode = req->wb_context->dentry->d_inode;
438 set_bit(PG_CLEAN, &(req)->wb_flags);
439 spin_lock(&inode->i_lock);
440 nfs_list_add_request(req, head);
441 NFS_I(inode)->ncommit++;
442 spin_unlock(&inode->i_lock);
443 inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
444 inc_bdi_stat(req->wb_page->mapping->backing_dev_info, BDI_RECLAIMABLE);
445 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
447 EXPORT_SYMBOL_GPL(nfs_request_add_commit_list);
450 * nfs_request_remove_commit_list - Remove request from a commit list
451 * @req: pointer to a nfs_page
453 * This clears the PG_CLEAN bit, and updates the inode global count of
454 * number of outstanding requests requiring a commit
455 * It does not update the MM page stats.
457 * The caller _must_ hold the inode->i_lock and the nfs_page lock.
460 nfs_request_remove_commit_list(struct nfs_page *req)
462 struct inode *inode = req->wb_context->dentry->d_inode;
464 if (!test_and_clear_bit(PG_CLEAN, &(req)->wb_flags))
466 nfs_list_remove_request(req);
467 NFS_I(inode)->ncommit--;
469 EXPORT_SYMBOL_GPL(nfs_request_remove_commit_list);
473 * Add a request to the inode's commit list.
476 nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg)
478 struct inode *inode = req->wb_context->dentry->d_inode;
480 if (pnfs_mark_request_commit(req, lseg))
482 nfs_request_add_commit_list(req, &NFS_I(inode)->commit_list);
486 nfs_clear_page_commit(struct page *page)
488 dec_zone_page_state(page, NR_UNSTABLE_NFS);
489 dec_bdi_stat(page->mapping->backing_dev_info, BDI_RECLAIMABLE);
493 nfs_clear_request_commit(struct nfs_page *req)
495 if (test_bit(PG_CLEAN, &req->wb_flags)) {
496 struct inode *inode = req->wb_context->dentry->d_inode;
498 if (!pnfs_clear_request_commit(req)) {
499 spin_lock(&inode->i_lock);
500 nfs_request_remove_commit_list(req);
501 spin_unlock(&inode->i_lock);
503 nfs_clear_page_commit(req->wb_page);
508 int nfs_write_need_commit(struct nfs_write_data *data)
510 if (data->verf.committed == NFS_DATA_SYNC)
511 return data->lseg == NULL;
513 return data->verf.committed != NFS_FILE_SYNC;
517 int nfs_reschedule_unstable_write(struct nfs_page *req,
518 struct nfs_write_data *data)
520 if (test_and_clear_bit(PG_NEED_COMMIT, &req->wb_flags)) {
521 nfs_mark_request_commit(req, data->lseg);
524 if (test_and_clear_bit(PG_NEED_RESCHED, &req->wb_flags)) {
525 nfs_mark_request_dirty(req);
532 nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg)
537 nfs_clear_request_commit(struct nfs_page *req)
542 int nfs_write_need_commit(struct nfs_write_data *data)
548 int nfs_reschedule_unstable_write(struct nfs_page *req,
549 struct nfs_write_data *data)
555 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
557 nfs_need_commit(struct nfs_inode *nfsi)
559 return nfsi->ncommit > 0;
562 /* i_lock held by caller */
564 nfs_scan_commit_list(struct list_head *src, struct list_head *dst, int max,
567 struct nfs_page *req, *tmp;
570 list_for_each_entry_safe(req, tmp, src, wb_list) {
571 if (!nfs_lock_request(req))
573 if (cond_resched_lock(lock))
574 list_safe_reset_next(req, tmp, wb_list);
575 nfs_request_remove_commit_list(req);
576 nfs_list_add_request(req, dst);
585 * nfs_scan_commit - Scan an inode for commit requests
586 * @inode: NFS inode to scan
587 * @dst: destination list
589 * Moves requests from the inode's 'commit' request list.
590 * The requests are *not* checked to ensure that they form a contiguous set.
593 nfs_scan_commit(struct inode *inode, struct list_head *dst)
595 struct nfs_inode *nfsi = NFS_I(inode);
598 spin_lock(&inode->i_lock);
599 if (nfsi->ncommit > 0) {
600 const int max = INT_MAX;
602 ret = nfs_scan_commit_list(&nfsi->commit_list, dst, max,
604 ret += pnfs_scan_commit_lists(inode, max - ret,
607 spin_unlock(&inode->i_lock);
612 static inline int nfs_need_commit(struct nfs_inode *nfsi)
617 static inline int nfs_scan_commit(struct inode *inode, struct list_head *dst)
624 * Search for an existing write request, and attempt to update
625 * it to reflect a new dirty region on a given page.
627 * If the attempt fails, then the existing request is flushed out
630 static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
635 struct nfs_page *req;
640 if (!PagePrivate(page))
643 end = offset + bytes;
644 spin_lock(&inode->i_lock);
647 req = nfs_page_find_request_locked(page);
651 rqend = req->wb_offset + req->wb_bytes;
653 * Tell the caller to flush out the request if
654 * the offsets are non-contiguous.
655 * Note: nfs_flush_incompatible() will already
656 * have flushed out requests having wrong owners.
659 || end < req->wb_offset)
662 if (nfs_lock_request_dontget(req))
665 /* The request is locked, so wait and then retry */
666 spin_unlock(&inode->i_lock);
667 error = nfs_wait_on_request(req);
668 nfs_release_request(req);
671 spin_lock(&inode->i_lock);
674 /* Okay, the request matches. Update the region */
675 if (offset < req->wb_offset) {
676 req->wb_offset = offset;
677 req->wb_pgbase = offset;
680 req->wb_bytes = end - req->wb_offset;
682 req->wb_bytes = rqend - req->wb_offset;
684 spin_unlock(&inode->i_lock);
686 nfs_clear_request_commit(req);
689 spin_unlock(&inode->i_lock);
690 nfs_release_request(req);
691 error = nfs_wb_page(inode, page);
693 return ERR_PTR(error);
697 * Try to update an existing write request, or create one if there is none.
699 * Note: Should always be called with the Page Lock held to prevent races
700 * if we have to add a new request. Also assumes that the caller has
701 * already called nfs_flush_incompatible() if necessary.
703 static struct nfs_page * nfs_setup_write_request(struct nfs_open_context* ctx,
704 struct page *page, unsigned int offset, unsigned int bytes)
706 struct inode *inode = page->mapping->host;
707 struct nfs_page *req;
709 req = nfs_try_to_update_request(inode, page, offset, bytes);
712 req = nfs_create_request(ctx, inode, page, offset, bytes);
715 nfs_inode_add_request(inode, req);
720 static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page,
721 unsigned int offset, unsigned int count)
723 struct nfs_page *req;
725 req = nfs_setup_write_request(ctx, page, offset, count);
728 /* Update file length */
729 nfs_grow_file(page, offset, count);
730 nfs_mark_uptodate(page, req->wb_pgbase, req->wb_bytes);
731 nfs_mark_request_dirty(req);
732 nfs_unlock_request(req);
736 int nfs_flush_incompatible(struct file *file, struct page *page)
738 struct nfs_open_context *ctx = nfs_file_open_context(file);
739 struct nfs_page *req;
740 int do_flush, status;
742 * Look for a request corresponding to this page. If there
743 * is one, and it belongs to another file, we flush it out
744 * before we try to copy anything into the page. Do this
745 * due to the lack of an ACCESS-type call in NFSv2.
746 * Also do the same if we find a request from an existing
750 req = nfs_page_find_request(page);
753 do_flush = req->wb_page != page || req->wb_context != ctx ||
754 req->wb_lock_context->lockowner != current->files ||
755 req->wb_lock_context->pid != current->tgid;
756 nfs_release_request(req);
759 status = nfs_wb_page(page->mapping->host, page);
760 } while (status == 0);
765 * If the page cache is marked as unsafe or invalid, then we can't rely on
766 * the PageUptodate() flag. In this case, we will need to turn off
767 * write optimisations that depend on the page contents being correct.
769 static int nfs_write_pageuptodate(struct page *page, struct inode *inode)
771 return PageUptodate(page) &&
772 !(NFS_I(inode)->cache_validity & (NFS_INO_REVAL_PAGECACHE|NFS_INO_INVALID_DATA));
776 * Update and possibly write a cached page of an NFS file.
778 * XXX: Keep an eye on generic_file_read to make sure it doesn't do bad
779 * things with a page scheduled for an RPC call (e.g. invalidate it).
781 int nfs_updatepage(struct file *file, struct page *page,
782 unsigned int offset, unsigned int count)
784 struct nfs_open_context *ctx = nfs_file_open_context(file);
785 struct inode *inode = page->mapping->host;
788 nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE);
790 dprintk("NFS: nfs_updatepage(%s/%s %d@%lld)\n",
791 file->f_path.dentry->d_parent->d_name.name,
792 file->f_path.dentry->d_name.name, count,
793 (long long)(page_offset(page) + offset));
795 /* If we're not using byte range locks, and we know the page
796 * is up to date, it may be more efficient to extend the write
797 * to cover the entire page in order to avoid fragmentation
800 if (nfs_write_pageuptodate(page, inode) &&
801 inode->i_flock == NULL &&
802 !(file->f_flags & O_DSYNC)) {
803 count = max(count + offset, nfs_page_length(page));
807 status = nfs_writepage_setup(ctx, page, offset, count);
809 nfs_set_pageerror(page);
811 __set_page_dirty_nobuffers(page);
813 dprintk("NFS: nfs_updatepage returns %d (isize %lld)\n",
814 status, (long long)i_size_read(inode));
818 static void nfs_writepage_release(struct nfs_page *req,
819 struct nfs_write_data *data)
821 struct page *page = req->wb_page;
823 if (PageError(req->wb_page) || !nfs_reschedule_unstable_write(req, data))
824 nfs_inode_remove_request(req);
825 nfs_unlock_request(req);
826 nfs_end_page_writeback(page);
829 static int flush_task_priority(int how)
831 switch (how & (FLUSH_HIGHPRI|FLUSH_LOWPRI)) {
833 return RPC_PRIORITY_HIGH;
835 return RPC_PRIORITY_LOW;
837 return RPC_PRIORITY_NORMAL;
840 int nfs_initiate_write(struct nfs_write_data *data,
841 struct rpc_clnt *clnt,
842 const struct rpc_call_ops *call_ops,
845 struct inode *inode = data->inode;
846 int priority = flush_task_priority(how);
847 struct rpc_task *task;
848 struct rpc_message msg = {
849 .rpc_argp = &data->args,
850 .rpc_resp = &data->res,
851 .rpc_cred = data->cred,
853 struct rpc_task_setup task_setup_data = {
857 .callback_ops = call_ops,
858 .callback_data = data,
859 .workqueue = nfsiod_workqueue,
860 .flags = RPC_TASK_ASYNC,
861 .priority = priority,
865 /* Set up the initial task struct. */
866 NFS_PROTO(inode)->write_setup(data, &msg);
868 dprintk("NFS: %5u initiated write call "
869 "(req %s/%lld, %u bytes @ offset %llu)\n",
872 (long long)NFS_FILEID(inode),
874 (unsigned long long)data->args.offset);
876 task = rpc_run_task(&task_setup_data);
881 if (how & FLUSH_SYNC) {
882 ret = rpc_wait_for_completion_task(task);
884 ret = task->tk_status;
890 EXPORT_SYMBOL_GPL(nfs_initiate_write);
893 * Set up the argument/result storage required for the RPC call.
895 static void nfs_write_rpcsetup(struct nfs_page *req,
896 struct nfs_write_data *data,
897 unsigned int count, unsigned int offset,
900 struct inode *inode = req->wb_context->dentry->d_inode;
902 /* Set up the RPC argument and reply structs
903 * NB: take care not to mess about with data->commit et al. */
906 data->inode = inode = req->wb_context->dentry->d_inode;
907 data->cred = req->wb_context->cred;
909 data->args.fh = NFS_FH(inode);
910 data->args.offset = req_offset(req) + offset;
911 /* pnfs_set_layoutcommit needs this */
912 data->mds_offset = data->args.offset;
913 data->args.pgbase = req->wb_pgbase + offset;
914 data->args.pages = data->pagevec;
915 data->args.count = count;
916 data->args.context = get_nfs_open_context(req->wb_context);
917 data->args.lock_context = req->wb_lock_context;
918 data->args.stable = NFS_UNSTABLE;
919 switch (how & (FLUSH_STABLE | FLUSH_COND_STABLE)) {
922 case FLUSH_COND_STABLE:
923 if (nfs_need_commit(NFS_I(inode)))
926 data->args.stable = NFS_FILE_SYNC;
929 data->res.fattr = &data->fattr;
930 data->res.count = count;
931 data->res.verf = &data->verf;
932 nfs_fattr_init(&data->fattr);
935 static int nfs_do_write(struct nfs_write_data *data,
936 const struct rpc_call_ops *call_ops,
939 struct inode *inode = data->args.context->dentry->d_inode;
941 return nfs_initiate_write(data, NFS_CLIENT(inode), call_ops, how);
944 static int nfs_do_multiple_writes(struct list_head *head,
945 const struct rpc_call_ops *call_ops,
948 struct nfs_write_data *data;
951 while (!list_empty(head)) {
954 data = list_entry(head->next, struct nfs_write_data, list);
955 list_del_init(&data->list);
957 ret2 = nfs_do_write(data, call_ops, how);
964 /* If a nfs_flush_* function fails, it should remove reqs from @head and
965 * call this on each, which will prepare them to be retried on next
966 * writeback using standard nfs.
968 static void nfs_redirty_request(struct nfs_page *req)
970 struct page *page = req->wb_page;
972 nfs_mark_request_dirty(req);
973 nfs_unlock_request(req);
974 nfs_end_page_writeback(page);
978 * Generate multiple small requests to write out a single
979 * contiguous dirty area on one page.
981 static int nfs_flush_multi(struct nfs_pageio_descriptor *desc, struct list_head *res)
983 struct nfs_page *req = nfs_list_entry(desc->pg_list.next);
984 struct page *page = req->wb_page;
985 struct nfs_write_data *data;
986 size_t wsize = desc->pg_bsize, nbytes;
991 nfs_list_remove_request(req);
993 if ((desc->pg_ioflags & FLUSH_COND_STABLE) &&
994 (desc->pg_moreio || NFS_I(desc->pg_inode)->ncommit ||
995 desc->pg_count > wsize))
996 desc->pg_ioflags &= ~FLUSH_COND_STABLE;
1000 nbytes = desc->pg_count;
1002 size_t len = min(nbytes, wsize);
1004 data = nfs_writedata_alloc(1);
1007 data->pagevec[0] = page;
1008 nfs_write_rpcsetup(req, data, len, offset, desc->pg_ioflags);
1009 list_add(&data->list, res);
1013 } while (nbytes != 0);
1014 atomic_set(&req->wb_complete, requests);
1015 desc->pg_rpc_callops = &nfs_write_partial_ops;
1019 while (!list_empty(res)) {
1020 data = list_entry(res->next, struct nfs_write_data, list);
1021 list_del(&data->list);
1022 nfs_writedata_release(data);
1024 nfs_redirty_request(req);
1029 * Create an RPC task for the given write request and kick it.
1030 * The page must have been locked by the caller.
1032 * It may happen that the page we're passed is not marked dirty.
1033 * This is the case if nfs_updatepage detects a conflicting request
1034 * that has been written but not committed.
1036 static int nfs_flush_one(struct nfs_pageio_descriptor *desc, struct list_head *res)
1038 struct nfs_page *req;
1039 struct page **pages;
1040 struct nfs_write_data *data;
1041 struct list_head *head = &desc->pg_list;
1044 data = nfs_writedata_alloc(nfs_page_array_len(desc->pg_base,
1047 while (!list_empty(head)) {
1048 req = nfs_list_entry(head->next);
1049 nfs_list_remove_request(req);
1050 nfs_redirty_request(req);
1055 pages = data->pagevec;
1056 while (!list_empty(head)) {
1057 req = nfs_list_entry(head->next);
1058 nfs_list_remove_request(req);
1059 nfs_list_add_request(req, &data->pages);
1060 *pages++ = req->wb_page;
1062 req = nfs_list_entry(data->pages.next);
1064 if ((desc->pg_ioflags & FLUSH_COND_STABLE) &&
1065 (desc->pg_moreio || NFS_I(desc->pg_inode)->ncommit))
1066 desc->pg_ioflags &= ~FLUSH_COND_STABLE;
1068 /* Set up the argument struct */
1069 nfs_write_rpcsetup(req, data, desc->pg_count, 0, desc->pg_ioflags);
1070 list_add(&data->list, res);
1071 desc->pg_rpc_callops = &nfs_write_full_ops;
1076 int nfs_generic_flush(struct nfs_pageio_descriptor *desc, struct list_head *head)
1078 if (desc->pg_bsize < PAGE_CACHE_SIZE)
1079 return nfs_flush_multi(desc, head);
1080 return nfs_flush_one(desc, head);
1083 static int nfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
1088 ret = nfs_generic_flush(desc, &head);
1090 ret = nfs_do_multiple_writes(&head, desc->pg_rpc_callops,
1095 static const struct nfs_pageio_ops nfs_pageio_write_ops = {
1096 .pg_test = nfs_generic_pg_test,
1097 .pg_doio = nfs_generic_pg_writepages,
1100 void nfs_pageio_init_write_mds(struct nfs_pageio_descriptor *pgio,
1101 struct inode *inode, int ioflags)
1103 nfs_pageio_init(pgio, inode, &nfs_pageio_write_ops,
1104 NFS_SERVER(inode)->wsize, ioflags);
1107 void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio)
1109 pgio->pg_ops = &nfs_pageio_write_ops;
1110 pgio->pg_bsize = NFS_SERVER(pgio->pg_inode)->wsize;
1112 EXPORT_SYMBOL_GPL(nfs_pageio_reset_write_mds);
1114 static void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
1115 struct inode *inode, int ioflags)
1117 if (!pnfs_pageio_init_write(pgio, inode, ioflags))
1118 nfs_pageio_init_write_mds(pgio, inode, ioflags);
1122 * Handle a write reply that flushed part of a page.
1124 static void nfs_writeback_done_partial(struct rpc_task *task, void *calldata)
1126 struct nfs_write_data *data = calldata;
1128 dprintk("NFS: %5u write(%s/%lld %d@%lld)",
1130 data->req->wb_context->dentry->d_inode->i_sb->s_id,
1132 NFS_FILEID(data->req->wb_context->dentry->d_inode),
1133 data->req->wb_bytes, (long long)req_offset(data->req));
1135 nfs_writeback_done(task, data);
1138 static void nfs_writeback_release_partial(void *calldata)
1140 struct nfs_write_data *data = calldata;
1141 struct nfs_page *req = data->req;
1142 struct page *page = req->wb_page;
1143 int status = data->task.tk_status;
1146 nfs_set_pageerror(page);
1147 nfs_context_set_write_error(req->wb_context, status);
1148 dprintk(", error = %d\n", status);
1152 if (nfs_write_need_commit(data)) {
1153 struct inode *inode = page->mapping->host;
1155 spin_lock(&inode->i_lock);
1156 if (test_bit(PG_NEED_RESCHED, &req->wb_flags)) {
1157 /* Do nothing we need to resend the writes */
1158 } else if (!test_and_set_bit(PG_NEED_COMMIT, &req->wb_flags)) {
1159 memcpy(&req->wb_verf, &data->verf, sizeof(req->wb_verf));
1160 dprintk(" defer commit\n");
1161 } else if (memcmp(&req->wb_verf, &data->verf, sizeof(req->wb_verf))) {
1162 set_bit(PG_NEED_RESCHED, &req->wb_flags);
1163 clear_bit(PG_NEED_COMMIT, &req->wb_flags);
1164 dprintk(" server reboot detected\n");
1166 spin_unlock(&inode->i_lock);
1171 if (atomic_dec_and_test(&req->wb_complete))
1172 nfs_writepage_release(req, data);
1173 nfs_writedata_release(calldata);
1176 void nfs_write_prepare(struct rpc_task *task, void *calldata)
1178 struct nfs_write_data *data = calldata;
1179 NFS_PROTO(data->inode)->write_rpc_prepare(task, data);
1182 static const struct rpc_call_ops nfs_write_partial_ops = {
1183 .rpc_call_prepare = nfs_write_prepare,
1184 .rpc_call_done = nfs_writeback_done_partial,
1185 .rpc_release = nfs_writeback_release_partial,
1189 * Handle a write reply that flushes a whole page.
1191 * FIXME: There is an inherent race with invalidate_inode_pages and
1192 * writebacks since the page->count is kept > 1 for as long
1193 * as the page has a write request pending.
1195 static void nfs_writeback_done_full(struct rpc_task *task, void *calldata)
1197 struct nfs_write_data *data = calldata;
1199 nfs_writeback_done(task, data);
1202 static void nfs_writeback_release_full(void *calldata)
1204 struct nfs_write_data *data = calldata;
1205 int status = data->task.tk_status;
1207 /* Update attributes as result of writeback. */
1208 while (!list_empty(&data->pages)) {
1209 struct nfs_page *req = nfs_list_entry(data->pages.next);
1210 struct page *page = req->wb_page;
1212 nfs_list_remove_request(req);
1214 dprintk("NFS: %5u write (%s/%lld %d@%lld)",
1216 req->wb_context->dentry->d_inode->i_sb->s_id,
1217 (long long)NFS_FILEID(req->wb_context->dentry->d_inode),
1219 (long long)req_offset(req));
1222 nfs_set_pageerror(page);
1223 nfs_context_set_write_error(req->wb_context, status);
1224 dprintk(", error = %d\n", status);
1225 goto remove_request;
1228 if (nfs_write_need_commit(data)) {
1229 memcpy(&req->wb_verf, &data->verf, sizeof(req->wb_verf));
1230 nfs_mark_request_commit(req, data->lseg);
1231 dprintk(" marked for commit\n");
1236 nfs_inode_remove_request(req);
1238 nfs_unlock_request(req);
1239 nfs_end_page_writeback(page);
1241 nfs_writedata_release(calldata);
1244 static const struct rpc_call_ops nfs_write_full_ops = {
1245 .rpc_call_prepare = nfs_write_prepare,
1246 .rpc_call_done = nfs_writeback_done_full,
1247 .rpc_release = nfs_writeback_release_full,
1252 * This function is called when the WRITE call is complete.
1254 void nfs_writeback_done(struct rpc_task *task, struct nfs_write_data *data)
1256 struct nfs_writeargs *argp = &data->args;
1257 struct nfs_writeres *resp = &data->res;
1260 dprintk("NFS: %5u nfs_writeback_done (status %d)\n",
1261 task->tk_pid, task->tk_status);
1264 * ->write_done will attempt to use post-op attributes to detect
1265 * conflicting writes by other clients. A strict interpretation
1266 * of close-to-open would allow us to continue caching even if
1267 * another writer had changed the file, but some applications
1268 * depend on tighter cache coherency when writing.
1270 status = NFS_PROTO(data->inode)->write_done(task, data);
1273 nfs_add_stats(data->inode, NFSIOS_SERVERWRITTENBYTES, resp->count);
1275 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
1276 if (resp->verf->committed < argp->stable && task->tk_status >= 0) {
1277 /* We tried a write call, but the server did not
1278 * commit data to stable storage even though we
1280 * Note: There is a known bug in Tru64 < 5.0 in which
1281 * the server reports NFS_DATA_SYNC, but performs
1282 * NFS_FILE_SYNC. We therefore implement this checking
1283 * as a dprintk() in order to avoid filling syslog.
1285 static unsigned long complain;
1287 /* Note this will print the MDS for a DS write */
1288 if (time_before(complain, jiffies)) {
1289 dprintk("NFS: faulty NFS server %s:"
1290 " (committed = %d) != (stable = %d)\n",
1291 NFS_SERVER(data->inode)->nfs_client->cl_hostname,
1292 resp->verf->committed, argp->stable);
1293 complain = jiffies + 300 * HZ;
1297 /* Is this a short write? */
1298 if (task->tk_status >= 0 && resp->count < argp->count) {
1299 static unsigned long complain;
1301 nfs_inc_stats(data->inode, NFSIOS_SHORTWRITE);
1303 /* Has the server at least made some progress? */
1304 if (resp->count != 0) {
1305 /* Was this an NFSv2 write or an NFSv3 stable write? */
1306 if (resp->verf->committed != NFS_UNSTABLE) {
1307 /* Resend from where the server left off */
1308 data->mds_offset += resp->count;
1309 argp->offset += resp->count;
1310 argp->pgbase += resp->count;
1311 argp->count -= resp->count;
1313 /* Resend as a stable write in order to avoid
1314 * headaches in the case of a server crash.
1316 argp->stable = NFS_FILE_SYNC;
1318 rpc_restart_call_prepare(task);
1321 if (time_before(complain, jiffies)) {
1323 "NFS: Server wrote zero bytes, expected %u.\n",
1325 complain = jiffies + 300 * HZ;
1327 /* Can't do anything about it except throw an error. */
1328 task->tk_status = -EIO;
1334 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
1335 static int nfs_commit_set_lock(struct nfs_inode *nfsi, int may_wait)
1339 if (!test_and_set_bit(NFS_INO_COMMIT, &nfsi->flags))
1343 ret = out_of_line_wait_on_bit_lock(&nfsi->flags,
1345 nfs_wait_bit_killable,
1347 return (ret < 0) ? ret : 1;
1350 void nfs_commit_clear_lock(struct nfs_inode *nfsi)
1352 clear_bit(NFS_INO_COMMIT, &nfsi->flags);
1353 smp_mb__after_clear_bit();
1354 wake_up_bit(&nfsi->flags, NFS_INO_COMMIT);
1356 EXPORT_SYMBOL_GPL(nfs_commit_clear_lock);
1358 void nfs_commitdata_release(void *data)
1360 struct nfs_write_data *wdata = data;
1362 put_nfs_open_context(wdata->args.context);
1363 nfs_commit_free(wdata);
1365 EXPORT_SYMBOL_GPL(nfs_commitdata_release);
1367 int nfs_initiate_commit(struct nfs_write_data *data, struct rpc_clnt *clnt,
1368 const struct rpc_call_ops *call_ops,
1371 struct rpc_task *task;
1372 int priority = flush_task_priority(how);
1373 struct rpc_message msg = {
1374 .rpc_argp = &data->args,
1375 .rpc_resp = &data->res,
1376 .rpc_cred = data->cred,
1378 struct rpc_task_setup task_setup_data = {
1379 .task = &data->task,
1381 .rpc_message = &msg,
1382 .callback_ops = call_ops,
1383 .callback_data = data,
1384 .workqueue = nfsiod_workqueue,
1385 .flags = RPC_TASK_ASYNC,
1386 .priority = priority,
1388 /* Set up the initial task struct. */
1389 NFS_PROTO(data->inode)->commit_setup(data, &msg);
1391 dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid);
1393 task = rpc_run_task(&task_setup_data);
1395 return PTR_ERR(task);
1396 if (how & FLUSH_SYNC)
1397 rpc_wait_for_completion_task(task);
1401 EXPORT_SYMBOL_GPL(nfs_initiate_commit);
1404 * Set up the argument/result storage required for the RPC call.
1406 void nfs_init_commit(struct nfs_write_data *data,
1407 struct list_head *head,
1408 struct pnfs_layout_segment *lseg)
1410 struct nfs_page *first = nfs_list_entry(head->next);
1411 struct inode *inode = first->wb_context->dentry->d_inode;
1413 /* Set up the RPC argument and reply structs
1414 * NB: take care not to mess about with data->commit et al. */
1416 list_splice_init(head, &data->pages);
1418 data->inode = inode;
1419 data->cred = first->wb_context->cred;
1420 data->lseg = lseg; /* reference transferred */
1421 data->mds_ops = &nfs_commit_ops;
1423 data->args.fh = NFS_FH(data->inode);
1424 /* Note: we always request a commit of the entire inode */
1425 data->args.offset = 0;
1426 data->args.count = 0;
1427 data->args.context = get_nfs_open_context(first->wb_context);
1428 data->res.count = 0;
1429 data->res.fattr = &data->fattr;
1430 data->res.verf = &data->verf;
1431 nfs_fattr_init(&data->fattr);
1433 EXPORT_SYMBOL_GPL(nfs_init_commit);
1435 void nfs_retry_commit(struct list_head *page_list,
1436 struct pnfs_layout_segment *lseg)
1438 struct nfs_page *req;
1440 while (!list_empty(page_list)) {
1441 req = nfs_list_entry(page_list->next);
1442 nfs_list_remove_request(req);
1443 nfs_mark_request_commit(req, lseg);
1444 dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
1445 dec_bdi_stat(req->wb_page->mapping->backing_dev_info,
1447 nfs_unlock_request(req);
1450 EXPORT_SYMBOL_GPL(nfs_retry_commit);
1453 * Commit dirty pages
1456 nfs_commit_list(struct inode *inode, struct list_head *head, int how)
1458 struct nfs_write_data *data;
1460 data = nfs_commitdata_alloc();
1465 /* Set up the argument struct */
1466 nfs_init_commit(data, head, NULL);
1467 return nfs_initiate_commit(data, NFS_CLIENT(inode), data->mds_ops, how);
1469 nfs_retry_commit(head, NULL);
1470 nfs_commit_clear_lock(NFS_I(inode));
1475 * COMMIT call returned
1477 static void nfs_commit_done(struct rpc_task *task, void *calldata)
1479 struct nfs_write_data *data = calldata;
1481 dprintk("NFS: %5u nfs_commit_done (status %d)\n",
1482 task->tk_pid, task->tk_status);
1484 /* Call the NFS version-specific code */
1485 NFS_PROTO(data->inode)->commit_done(task, data);
1488 void nfs_commit_release_pages(struct nfs_write_data *data)
1490 struct nfs_page *req;
1491 int status = data->task.tk_status;
1493 while (!list_empty(&data->pages)) {
1494 req = nfs_list_entry(data->pages.next);
1495 nfs_list_remove_request(req);
1496 nfs_clear_page_commit(req->wb_page);
1498 dprintk("NFS: commit (%s/%lld %d@%lld)",
1499 req->wb_context->dentry->d_sb->s_id,
1500 (long long)NFS_FILEID(req->wb_context->dentry->d_inode),
1502 (long long)req_offset(req));
1504 nfs_context_set_write_error(req->wb_context, status);
1505 nfs_inode_remove_request(req);
1506 dprintk(", error = %d\n", status);
1510 /* Okay, COMMIT succeeded, apparently. Check the verifier
1511 * returned by the server against all stored verfs. */
1512 if (!memcmp(req->wb_verf.verifier, data->verf.verifier, sizeof(data->verf.verifier))) {
1513 /* We have a match */
1514 nfs_inode_remove_request(req);
1518 /* We have a mismatch. Write the page again */
1519 dprintk(" mismatch\n");
1520 nfs_mark_request_dirty(req);
1522 nfs_unlock_request(req);
1525 EXPORT_SYMBOL_GPL(nfs_commit_release_pages);
1527 static void nfs_commit_release(void *calldata)
1529 struct nfs_write_data *data = calldata;
1531 nfs_commit_release_pages(data);
1532 nfs_commit_clear_lock(NFS_I(data->inode));
1533 nfs_commitdata_release(calldata);
1536 static const struct rpc_call_ops nfs_commit_ops = {
1537 .rpc_call_prepare = nfs_write_prepare,
1538 .rpc_call_done = nfs_commit_done,
1539 .rpc_release = nfs_commit_release,
1542 int nfs_commit_inode(struct inode *inode, int how)
1545 int may_wait = how & FLUSH_SYNC;
1548 res = nfs_commit_set_lock(NFS_I(inode), may_wait);
1550 goto out_mark_dirty;
1551 res = nfs_scan_commit(inode, &head);
1555 error = pnfs_commit_list(inode, &head, how);
1556 if (error == PNFS_NOT_ATTEMPTED)
1557 error = nfs_commit_list(inode, &head, how);
1561 goto out_mark_dirty;
1562 error = wait_on_bit(&NFS_I(inode)->flags,
1564 nfs_wait_bit_killable,
1569 nfs_commit_clear_lock(NFS_I(inode));
1571 /* Note: If we exit without ensuring that the commit is complete,
1572 * we must mark the inode as dirty. Otherwise, future calls to
1573 * sync_inode() with the WB_SYNC_ALL flag set will fail to ensure
1574 * that the data is on the disk.
1577 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
1581 static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_control *wbc)
1583 struct nfs_inode *nfsi = NFS_I(inode);
1584 int flags = FLUSH_SYNC;
1587 /* no commits means nothing needs to be done */
1591 if (wbc->sync_mode == WB_SYNC_NONE) {
1592 /* Don't commit yet if this is a non-blocking flush and there
1593 * are a lot of outstanding writes for this mapping.
1595 if (nfsi->ncommit <= (nfsi->npages >> 1))
1596 goto out_mark_dirty;
1598 /* don't wait for the COMMIT response */
1602 ret = nfs_commit_inode(inode, flags);
1604 if (wbc->sync_mode == WB_SYNC_NONE) {
1605 if (ret < wbc->nr_to_write)
1606 wbc->nr_to_write -= ret;
1608 wbc->nr_to_write = 0;
1613 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
1617 static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_control *wbc)
1623 int nfs_write_inode(struct inode *inode, struct writeback_control *wbc)
1627 ret = nfs_commit_unstable_pages(inode, wbc);
1628 if (ret >= 0 && test_bit(NFS_INO_LAYOUTCOMMIT, &NFS_I(inode)->flags)) {
1632 if (wbc->sync_mode == WB_SYNC_NONE)
1635 status = pnfs_layoutcommit_inode(inode, sync);
1643 * flush the inode to disk.
1645 int nfs_wb_all(struct inode *inode)
1647 struct writeback_control wbc = {
1648 .sync_mode = WB_SYNC_ALL,
1649 .nr_to_write = LONG_MAX,
1651 .range_end = LLONG_MAX,
1654 return sync_inode(inode, &wbc);
1657 int nfs_wb_page_cancel(struct inode *inode, struct page *page)
1659 struct nfs_page *req;
1662 BUG_ON(!PageLocked(page));
1664 wait_on_page_writeback(page);
1665 req = nfs_page_find_request(page);
1668 if (nfs_lock_request_dontget(req)) {
1669 nfs_clear_request_commit(req);
1670 nfs_inode_remove_request(req);
1672 * In case nfs_inode_remove_request has marked the
1673 * page as being dirty
1675 cancel_dirty_page(page, PAGE_CACHE_SIZE);
1676 nfs_unlock_request(req);
1679 ret = nfs_wait_on_request(req);
1680 nfs_release_request(req);
1688 * Write back all requests on one page - we do this before reading it.
1690 int nfs_wb_page(struct inode *inode, struct page *page)
1692 loff_t range_start = page_offset(page);
1693 loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
1694 struct writeback_control wbc = {
1695 .sync_mode = WB_SYNC_ALL,
1697 .range_start = range_start,
1698 .range_end = range_end,
1703 wait_on_page_writeback(page);
1704 if (clear_page_dirty_for_io(page)) {
1705 ret = nfs_writepage_locked(page, &wbc);
1710 if (!PagePrivate(page))
1712 ret = nfs_commit_inode(inode, FLUSH_SYNC);
1721 #ifdef CONFIG_MIGRATION
1722 int nfs_migrate_page(struct address_space *mapping, struct page *newpage,
1723 struct page *page, enum migrate_mode mode)
1726 * If PagePrivate is set, then the page is currently associated with
1727 * an in-progress read or write request. Don't try to migrate it.
1729 * FIXME: we could do this in principle, but we'll need a way to ensure
1730 * that we can safely release the inode reference while holding
1733 if (PagePrivate(page))
1736 nfs_fscache_release_page(page, GFP_KERNEL);
1738 return migrate_page(mapping, newpage, page, mode);
1742 int __init nfs_init_writepagecache(void)
1744 nfs_wdata_cachep = kmem_cache_create("nfs_write_data",
1745 sizeof(struct nfs_write_data),
1746 0, SLAB_HWCACHE_ALIGN,
1748 if (nfs_wdata_cachep == NULL)
1751 nfs_wdata_mempool = mempool_create_slab_pool(MIN_POOL_WRITE,
1753 if (nfs_wdata_mempool == NULL)
1756 nfs_commit_mempool = mempool_create_slab_pool(MIN_POOL_COMMIT,
1758 if (nfs_commit_mempool == NULL)
1762 * NFS congestion size, scale with available memory.
1774 * This allows larger machines to have larger/more transfers.
1775 * Limit the default to 256M
1777 nfs_congestion_kb = (16*int_sqrt(totalram_pages)) << (PAGE_SHIFT-10);
1778 if (nfs_congestion_kb > 256*1024)
1779 nfs_congestion_kb = 256*1024;
1784 void nfs_destroy_writepagecache(void)
1786 mempool_destroy(nfs_commit_mempool);
1787 mempool_destroy(nfs_wdata_mempool);
1788 kmem_cache_destroy(nfs_wdata_cachep);