NFS: Replace __nfs_write_mapping with sync_inode()
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / nfs / write.c
blob0b323091b481f3031a0d8f58f730c515dbfaa9d6
1 /*
2 * linux/fs/nfs/write.c
4 * Write file data over NFS.
6 * Copyright (C) 1996, 1997, Olaf Kirch <okir@monad.swb.de>
7 */
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>
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>
24 #include <asm/uaccess.h>
26 #include "delegation.h"
27 #include "internal.h"
28 #include "iostat.h"
29 #include "nfs4_fs.h"
30 #include "fscache.h"
32 #define NFSDBG_FACILITY NFSDBG_PAGECACHE
34 #define MIN_POOL_WRITE (32)
35 #define MIN_POOL_COMMIT (4)
38 * Local function declarations
40 static void nfs_pageio_init_write(struct nfs_pageio_descriptor *desc,
41 struct inode *inode, int ioflags);
42 static void nfs_redirty_request(struct nfs_page *req);
43 static const struct rpc_call_ops nfs_write_partial_ops;
44 static const struct rpc_call_ops nfs_write_full_ops;
45 static const struct rpc_call_ops nfs_commit_ops;
47 static struct kmem_cache *nfs_wdata_cachep;
48 static mempool_t *nfs_wdata_mempool;
49 static mempool_t *nfs_commit_mempool;
51 struct nfs_write_data *nfs_commitdata_alloc(void)
53 struct nfs_write_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOFS);
55 if (p) {
56 memset(p, 0, sizeof(*p));
57 INIT_LIST_HEAD(&p->pages);
58 p->res.seq_res.sr_slotid = NFS4_MAX_SLOT_TABLE;
60 return p;
63 void nfs_commit_free(struct nfs_write_data *p)
65 if (p && (p->pagevec != &p->page_array[0]))
66 kfree(p->pagevec);
67 mempool_free(p, nfs_commit_mempool);
70 struct nfs_write_data *nfs_writedata_alloc(unsigned int pagecount)
72 struct nfs_write_data *p = mempool_alloc(nfs_wdata_mempool, GFP_NOFS);
74 if (p) {
75 memset(p, 0, sizeof(*p));
76 INIT_LIST_HEAD(&p->pages);
77 p->npages = pagecount;
78 p->res.seq_res.sr_slotid = NFS4_MAX_SLOT_TABLE;
79 if (pagecount <= ARRAY_SIZE(p->page_array))
80 p->pagevec = p->page_array;
81 else {
82 p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_NOFS);
83 if (!p->pagevec) {
84 mempool_free(p, nfs_wdata_mempool);
85 p = NULL;
89 return p;
92 void nfs_writedata_free(struct nfs_write_data *p)
94 if (p && (p->pagevec != &p->page_array[0]))
95 kfree(p->pagevec);
96 mempool_free(p, nfs_wdata_mempool);
99 static void nfs_writedata_release(struct nfs_write_data *wdata)
101 put_nfs_open_context(wdata->args.context);
102 nfs_writedata_free(wdata);
105 static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error)
107 ctx->error = error;
108 smp_wmb();
109 set_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags);
112 static struct nfs_page *nfs_page_find_request_locked(struct page *page)
114 struct nfs_page *req = NULL;
116 if (PagePrivate(page)) {
117 req = (struct nfs_page *)page_private(page);
118 if (req != NULL)
119 kref_get(&req->wb_kref);
121 return req;
124 static struct nfs_page *nfs_page_find_request(struct page *page)
126 struct inode *inode = page->mapping->host;
127 struct nfs_page *req = NULL;
129 spin_lock(&inode->i_lock);
130 req = nfs_page_find_request_locked(page);
131 spin_unlock(&inode->i_lock);
132 return req;
135 /* Adjust the file length if we're writing beyond the end */
136 static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count)
138 struct inode *inode = page->mapping->host;
139 loff_t end, i_size;
140 pgoff_t end_index;
142 spin_lock(&inode->i_lock);
143 i_size = i_size_read(inode);
144 end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
145 if (i_size > 0 && page->index < end_index)
146 goto out;
147 end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + ((loff_t)offset+count);
148 if (i_size >= end)
149 goto out;
150 i_size_write(inode, end);
151 nfs_inc_stats(inode, NFSIOS_EXTENDWRITE);
152 out:
153 spin_unlock(&inode->i_lock);
156 /* A writeback failed: mark the page as bad, and invalidate the page cache */
157 static void nfs_set_pageerror(struct page *page)
159 SetPageError(page);
160 nfs_zap_mapping(page->mapping->host, page->mapping);
163 /* We can set the PG_uptodate flag if we see that a write request
164 * covers the full page.
166 static void nfs_mark_uptodate(struct page *page, unsigned int base, unsigned int count)
168 if (PageUptodate(page))
169 return;
170 if (base != 0)
171 return;
172 if (count != nfs_page_length(page))
173 return;
174 SetPageUptodate(page);
177 static int wb_priority(struct writeback_control *wbc)
179 if (wbc->for_reclaim)
180 return FLUSH_HIGHPRI | FLUSH_STABLE;
181 if (wbc->for_kupdate || wbc->for_background)
182 return FLUSH_LOWPRI;
183 return 0;
187 * NFS congestion control
190 int nfs_congestion_kb;
192 #define NFS_CONGESTION_ON_THRESH (nfs_congestion_kb >> (PAGE_SHIFT-10))
193 #define NFS_CONGESTION_OFF_THRESH \
194 (NFS_CONGESTION_ON_THRESH - (NFS_CONGESTION_ON_THRESH >> 2))
196 static int nfs_set_page_writeback(struct page *page)
198 int ret = test_set_page_writeback(page);
200 if (!ret) {
201 struct inode *inode = page->mapping->host;
202 struct nfs_server *nfss = NFS_SERVER(inode);
204 if (atomic_long_inc_return(&nfss->writeback) >
205 NFS_CONGESTION_ON_THRESH) {
206 set_bdi_congested(&nfss->backing_dev_info,
207 BLK_RW_ASYNC);
210 return ret;
213 static void nfs_end_page_writeback(struct page *page)
215 struct inode *inode = page->mapping->host;
216 struct nfs_server *nfss = NFS_SERVER(inode);
218 end_page_writeback(page);
219 if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH)
220 clear_bdi_congested(&nfss->backing_dev_info, BLK_RW_ASYNC);
223 static struct nfs_page *nfs_find_and_lock_request(struct page *page)
225 struct inode *inode = page->mapping->host;
226 struct nfs_page *req;
227 int ret;
229 spin_lock(&inode->i_lock);
230 for (;;) {
231 req = nfs_page_find_request_locked(page);
232 if (req == NULL)
233 break;
234 if (nfs_set_page_tag_locked(req))
235 break;
236 /* Note: If we hold the page lock, as is the case in nfs_writepage,
237 * then the call to nfs_set_page_tag_locked() will always
238 * succeed provided that someone hasn't already marked the
239 * request as dirty (in which case we don't care).
241 spin_unlock(&inode->i_lock);
242 ret = nfs_wait_on_request(req);
243 nfs_release_request(req);
244 if (ret != 0)
245 return ERR_PTR(ret);
246 spin_lock(&inode->i_lock);
248 spin_unlock(&inode->i_lock);
249 return req;
253 * Find an associated nfs write request, and prepare to flush it out
254 * May return an error if the user signalled nfs_wait_on_request().
256 static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio,
257 struct page *page)
259 struct nfs_page *req;
260 int ret = 0;
262 req = nfs_find_and_lock_request(page);
263 if (!req)
264 goto out;
265 ret = PTR_ERR(req);
266 if (IS_ERR(req))
267 goto out;
269 ret = nfs_set_page_writeback(page);
270 BUG_ON(ret != 0);
271 BUG_ON(test_bit(PG_CLEAN, &req->wb_flags));
273 if (!nfs_pageio_add_request(pgio, req)) {
274 nfs_redirty_request(req);
275 ret = pgio->pg_error;
277 out:
278 return ret;
281 static int nfs_do_writepage(struct page *page, struct writeback_control *wbc, struct nfs_pageio_descriptor *pgio)
283 struct inode *inode = page->mapping->host;
285 nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE);
286 nfs_add_stats(inode, NFSIOS_WRITEPAGES, 1);
288 nfs_pageio_cond_complete(pgio, page->index);
289 return nfs_page_async_flush(pgio, page);
293 * Write an mmapped page to the server.
295 static int nfs_writepage_locked(struct page *page, struct writeback_control *wbc)
297 struct nfs_pageio_descriptor pgio;
298 int err;
300 nfs_pageio_init_write(&pgio, page->mapping->host, wb_priority(wbc));
301 err = nfs_do_writepage(page, wbc, &pgio);
302 nfs_pageio_complete(&pgio);
303 if (err < 0)
304 return err;
305 if (pgio.pg_error < 0)
306 return pgio.pg_error;
307 return 0;
310 int nfs_writepage(struct page *page, struct writeback_control *wbc)
312 int ret;
314 ret = nfs_writepage_locked(page, wbc);
315 unlock_page(page);
316 return ret;
319 static int nfs_writepages_callback(struct page *page, struct writeback_control *wbc, void *data)
321 int ret;
323 ret = nfs_do_writepage(page, wbc, data);
324 unlock_page(page);
325 return ret;
328 int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
330 struct inode *inode = mapping->host;
331 unsigned long *bitlock = &NFS_I(inode)->flags;
332 struct nfs_pageio_descriptor pgio;
333 int err;
335 /* Stop dirtying of new pages while we sync */
336 err = wait_on_bit_lock(bitlock, NFS_INO_FLUSHING,
337 nfs_wait_bit_killable, TASK_KILLABLE);
338 if (err)
339 goto out_err;
341 nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES);
343 nfs_pageio_init_write(&pgio, inode, wb_priority(wbc));
344 err = write_cache_pages(mapping, wbc, nfs_writepages_callback, &pgio);
345 nfs_pageio_complete(&pgio);
347 clear_bit_unlock(NFS_INO_FLUSHING, bitlock);
348 smp_mb__after_clear_bit();
349 wake_up_bit(bitlock, NFS_INO_FLUSHING);
351 if (err < 0)
352 goto out_err;
353 err = pgio.pg_error;
354 if (err < 0)
355 goto out_err;
356 return 0;
357 out_err:
358 return err;
362 * Insert a write request into an inode
364 static int nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
366 struct nfs_inode *nfsi = NFS_I(inode);
367 int error;
369 error = radix_tree_preload(GFP_NOFS);
370 if (error != 0)
371 goto out;
373 /* Lock the request! */
374 nfs_lock_request_dontget(req);
376 spin_lock(&inode->i_lock);
377 error = radix_tree_insert(&nfsi->nfs_page_tree, req->wb_index, req);
378 BUG_ON(error);
379 if (!nfsi->npages) {
380 igrab(inode);
381 if (nfs_have_delegation(inode, FMODE_WRITE))
382 nfsi->change_attr++;
384 SetPagePrivate(req->wb_page);
385 set_page_private(req->wb_page, (unsigned long)req);
386 nfsi->npages++;
387 kref_get(&req->wb_kref);
388 radix_tree_tag_set(&nfsi->nfs_page_tree, req->wb_index,
389 NFS_PAGE_TAG_LOCKED);
390 spin_unlock(&inode->i_lock);
391 radix_tree_preload_end();
392 out:
393 return error;
397 * Remove a write request from an inode
399 static void nfs_inode_remove_request(struct nfs_page *req)
401 struct inode *inode = req->wb_context->path.dentry->d_inode;
402 struct nfs_inode *nfsi = NFS_I(inode);
404 BUG_ON (!NFS_WBACK_BUSY(req));
406 spin_lock(&inode->i_lock);
407 set_page_private(req->wb_page, 0);
408 ClearPagePrivate(req->wb_page);
409 radix_tree_delete(&nfsi->nfs_page_tree, req->wb_index);
410 nfsi->npages--;
411 if (!nfsi->npages) {
412 spin_unlock(&inode->i_lock);
413 iput(inode);
414 } else
415 spin_unlock(&inode->i_lock);
416 nfs_clear_request(req);
417 nfs_release_request(req);
420 static void
421 nfs_mark_request_dirty(struct nfs_page *req)
423 __set_page_dirty_nobuffers(req->wb_page);
426 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
428 * Add a request to the inode's commit list.
430 static void
431 nfs_mark_request_commit(struct nfs_page *req)
433 struct inode *inode = req->wb_context->path.dentry->d_inode;
434 struct nfs_inode *nfsi = NFS_I(inode);
436 spin_lock(&inode->i_lock);
437 set_bit(PG_CLEAN, &(req)->wb_flags);
438 radix_tree_tag_set(&nfsi->nfs_page_tree,
439 req->wb_index,
440 NFS_PAGE_TAG_COMMIT);
441 nfsi->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);
448 static int
449 nfs_clear_request_commit(struct nfs_page *req)
451 struct page *page = req->wb_page;
453 if (test_and_clear_bit(PG_CLEAN, &(req)->wb_flags)) {
454 dec_zone_page_state(page, NR_UNSTABLE_NFS);
455 dec_bdi_stat(page->mapping->backing_dev_info, BDI_RECLAIMABLE);
456 return 1;
458 return 0;
461 static inline
462 int nfs_write_need_commit(struct nfs_write_data *data)
464 return data->verf.committed != NFS_FILE_SYNC;
467 static inline
468 int nfs_reschedule_unstable_write(struct nfs_page *req)
470 if (test_and_clear_bit(PG_NEED_COMMIT, &req->wb_flags)) {
471 nfs_mark_request_commit(req);
472 return 1;
474 if (test_and_clear_bit(PG_NEED_RESCHED, &req->wb_flags)) {
475 nfs_mark_request_dirty(req);
476 return 1;
478 return 0;
480 #else
481 static inline void
482 nfs_mark_request_commit(struct nfs_page *req)
486 static inline int
487 nfs_clear_request_commit(struct nfs_page *req)
489 return 0;
492 static inline
493 int nfs_write_need_commit(struct nfs_write_data *data)
495 return 0;
498 static inline
499 int nfs_reschedule_unstable_write(struct nfs_page *req)
501 return 0;
503 #endif
506 * Wait for a request to complete.
508 * Interruptible by fatal signals only.
510 static int nfs_wait_on_requests_locked(struct inode *inode, pgoff_t idx_start, unsigned int npages)
512 struct nfs_inode *nfsi = NFS_I(inode);
513 struct nfs_page *req;
514 pgoff_t idx_end, next;
515 unsigned int res = 0;
516 int error;
518 if (npages == 0)
519 idx_end = ~0;
520 else
521 idx_end = idx_start + npages - 1;
523 next = idx_start;
524 while (radix_tree_gang_lookup_tag(&nfsi->nfs_page_tree, (void **)&req, next, 1, NFS_PAGE_TAG_LOCKED)) {
525 if (req->wb_index > idx_end)
526 break;
528 next = req->wb_index + 1;
529 BUG_ON(!NFS_WBACK_BUSY(req));
531 kref_get(&req->wb_kref);
532 spin_unlock(&inode->i_lock);
533 error = nfs_wait_on_request(req);
534 nfs_release_request(req);
535 spin_lock(&inode->i_lock);
536 if (error < 0)
537 return error;
538 res++;
540 return res;
543 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
544 static int
545 nfs_need_commit(struct nfs_inode *nfsi)
547 return radix_tree_tagged(&nfsi->nfs_page_tree, NFS_PAGE_TAG_COMMIT);
551 * nfs_scan_commit - Scan an inode for commit requests
552 * @inode: NFS inode to scan
553 * @dst: destination list
554 * @idx_start: lower bound of page->index to scan.
555 * @npages: idx_start + npages sets the upper bound to scan.
557 * Moves requests from the inode's 'commit' request list.
558 * The requests are *not* checked to ensure that they form a contiguous set.
560 static int
561 nfs_scan_commit(struct inode *inode, struct list_head *dst, pgoff_t idx_start, unsigned int npages)
563 struct nfs_inode *nfsi = NFS_I(inode);
564 int ret;
566 if (!nfs_need_commit(nfsi))
567 return 0;
569 ret = nfs_scan_list(nfsi, dst, idx_start, npages, NFS_PAGE_TAG_COMMIT);
570 if (ret > 0)
571 nfsi->ncommit -= ret;
572 if (nfs_need_commit(NFS_I(inode)))
573 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
574 return ret;
576 #else
577 static inline int nfs_need_commit(struct nfs_inode *nfsi)
579 return 0;
582 static inline int nfs_scan_commit(struct inode *inode, struct list_head *dst, pgoff_t idx_start, unsigned int npages)
584 return 0;
586 #endif
589 * Search for an existing write request, and attempt to update
590 * it to reflect a new dirty region on a given page.
592 * If the attempt fails, then the existing request is flushed out
593 * to disk.
595 static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
596 struct page *page,
597 unsigned int offset,
598 unsigned int bytes)
600 struct nfs_page *req;
601 unsigned int rqend;
602 unsigned int end;
603 int error;
605 if (!PagePrivate(page))
606 return NULL;
608 end = offset + bytes;
609 spin_lock(&inode->i_lock);
611 for (;;) {
612 req = nfs_page_find_request_locked(page);
613 if (req == NULL)
614 goto out_unlock;
616 rqend = req->wb_offset + req->wb_bytes;
618 * Tell the caller to flush out the request if
619 * the offsets are non-contiguous.
620 * Note: nfs_flush_incompatible() will already
621 * have flushed out requests having wrong owners.
623 if (offset > rqend
624 || end < req->wb_offset)
625 goto out_flushme;
627 if (nfs_set_page_tag_locked(req))
628 break;
630 /* The request is locked, so wait and then retry */
631 spin_unlock(&inode->i_lock);
632 error = nfs_wait_on_request(req);
633 nfs_release_request(req);
634 if (error != 0)
635 goto out_err;
636 spin_lock(&inode->i_lock);
639 if (nfs_clear_request_commit(req) &&
640 radix_tree_tag_clear(&NFS_I(inode)->nfs_page_tree,
641 req->wb_index, NFS_PAGE_TAG_COMMIT) != NULL)
642 NFS_I(inode)->ncommit--;
644 /* Okay, the request matches. Update the region */
645 if (offset < req->wb_offset) {
646 req->wb_offset = offset;
647 req->wb_pgbase = offset;
649 if (end > rqend)
650 req->wb_bytes = end - req->wb_offset;
651 else
652 req->wb_bytes = rqend - req->wb_offset;
653 out_unlock:
654 spin_unlock(&inode->i_lock);
655 return req;
656 out_flushme:
657 spin_unlock(&inode->i_lock);
658 nfs_release_request(req);
659 error = nfs_wb_page(inode, page);
660 out_err:
661 return ERR_PTR(error);
665 * Try to update an existing write request, or create one if there is none.
667 * Note: Should always be called with the Page Lock held to prevent races
668 * if we have to add a new request. Also assumes that the caller has
669 * already called nfs_flush_incompatible() if necessary.
671 static struct nfs_page * nfs_setup_write_request(struct nfs_open_context* ctx,
672 struct page *page, unsigned int offset, unsigned int bytes)
674 struct inode *inode = page->mapping->host;
675 struct nfs_page *req;
676 int error;
678 req = nfs_try_to_update_request(inode, page, offset, bytes);
679 if (req != NULL)
680 goto out;
681 req = nfs_create_request(ctx, inode, page, offset, bytes);
682 if (IS_ERR(req))
683 goto out;
684 error = nfs_inode_add_request(inode, req);
685 if (error != 0) {
686 nfs_release_request(req);
687 req = ERR_PTR(error);
689 out:
690 return req;
693 static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page,
694 unsigned int offset, unsigned int count)
696 struct nfs_page *req;
698 req = nfs_setup_write_request(ctx, page, offset, count);
699 if (IS_ERR(req))
700 return PTR_ERR(req);
701 /* Update file length */
702 nfs_grow_file(page, offset, count);
703 nfs_mark_uptodate(page, req->wb_pgbase, req->wb_bytes);
704 nfs_clear_page_tag_locked(req);
705 return 0;
708 int nfs_flush_incompatible(struct file *file, struct page *page)
710 struct nfs_open_context *ctx = nfs_file_open_context(file);
711 struct nfs_page *req;
712 int do_flush, status;
714 * Look for a request corresponding to this page. If there
715 * is one, and it belongs to another file, we flush it out
716 * before we try to copy anything into the page. Do this
717 * due to the lack of an ACCESS-type call in NFSv2.
718 * Also do the same if we find a request from an existing
719 * dropped page.
721 do {
722 req = nfs_page_find_request(page);
723 if (req == NULL)
724 return 0;
725 do_flush = req->wb_page != page || req->wb_context != ctx;
726 nfs_release_request(req);
727 if (!do_flush)
728 return 0;
729 status = nfs_wb_page(page->mapping->host, page);
730 } while (status == 0);
731 return status;
735 * If the page cache is marked as unsafe or invalid, then we can't rely on
736 * the PageUptodate() flag. In this case, we will need to turn off
737 * write optimisations that depend on the page contents being correct.
739 static int nfs_write_pageuptodate(struct page *page, struct inode *inode)
741 return PageUptodate(page) &&
742 !(NFS_I(inode)->cache_validity & (NFS_INO_REVAL_PAGECACHE|NFS_INO_INVALID_DATA));
746 * Update and possibly write a cached page of an NFS file.
748 * XXX: Keep an eye on generic_file_read to make sure it doesn't do bad
749 * things with a page scheduled for an RPC call (e.g. invalidate it).
751 int nfs_updatepage(struct file *file, struct page *page,
752 unsigned int offset, unsigned int count)
754 struct nfs_open_context *ctx = nfs_file_open_context(file);
755 struct inode *inode = page->mapping->host;
756 int status = 0;
758 nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE);
760 dprintk("NFS: nfs_updatepage(%s/%s %d@%lld)\n",
761 file->f_path.dentry->d_parent->d_name.name,
762 file->f_path.dentry->d_name.name, count,
763 (long long)(page_offset(page) + offset));
765 /* If we're not using byte range locks, and we know the page
766 * is up to date, it may be more efficient to extend the write
767 * to cover the entire page in order to avoid fragmentation
768 * inefficiencies.
770 if (nfs_write_pageuptodate(page, inode) &&
771 inode->i_flock == NULL &&
772 !(file->f_flags & O_DSYNC)) {
773 count = max(count + offset, nfs_page_length(page));
774 offset = 0;
777 status = nfs_writepage_setup(ctx, page, offset, count);
778 if (status < 0)
779 nfs_set_pageerror(page);
780 else
781 __set_page_dirty_nobuffers(page);
783 dprintk("NFS: nfs_updatepage returns %d (isize %lld)\n",
784 status, (long long)i_size_read(inode));
785 return status;
788 static void nfs_writepage_release(struct nfs_page *req)
791 if (PageError(req->wb_page) || !nfs_reschedule_unstable_write(req)) {
792 nfs_end_page_writeback(req->wb_page);
793 nfs_inode_remove_request(req);
794 } else
795 nfs_end_page_writeback(req->wb_page);
796 nfs_clear_page_tag_locked(req);
799 static int flush_task_priority(int how)
801 switch (how & (FLUSH_HIGHPRI|FLUSH_LOWPRI)) {
802 case FLUSH_HIGHPRI:
803 return RPC_PRIORITY_HIGH;
804 case FLUSH_LOWPRI:
805 return RPC_PRIORITY_LOW;
807 return RPC_PRIORITY_NORMAL;
811 * Set up the argument/result storage required for the RPC call.
813 static int nfs_write_rpcsetup(struct nfs_page *req,
814 struct nfs_write_data *data,
815 const struct rpc_call_ops *call_ops,
816 unsigned int count, unsigned int offset,
817 int how)
819 struct inode *inode = req->wb_context->path.dentry->d_inode;
820 int flags = (how & FLUSH_SYNC) ? 0 : RPC_TASK_ASYNC;
821 int priority = flush_task_priority(how);
822 struct rpc_task *task;
823 struct rpc_message msg = {
824 .rpc_argp = &data->args,
825 .rpc_resp = &data->res,
826 .rpc_cred = req->wb_context->cred,
828 struct rpc_task_setup task_setup_data = {
829 .rpc_client = NFS_CLIENT(inode),
830 .task = &data->task,
831 .rpc_message = &msg,
832 .callback_ops = call_ops,
833 .callback_data = data,
834 .workqueue = nfsiod_workqueue,
835 .flags = flags,
836 .priority = priority,
839 /* Set up the RPC argument and reply structs
840 * NB: take care not to mess about with data->commit et al. */
842 data->req = req;
843 data->inode = inode = req->wb_context->path.dentry->d_inode;
844 data->cred = msg.rpc_cred;
846 data->args.fh = NFS_FH(inode);
847 data->args.offset = req_offset(req) + offset;
848 data->args.pgbase = req->wb_pgbase + offset;
849 data->args.pages = data->pagevec;
850 data->args.count = count;
851 data->args.context = get_nfs_open_context(req->wb_context);
852 data->args.stable = NFS_UNSTABLE;
853 if (how & FLUSH_STABLE) {
854 data->args.stable = NFS_DATA_SYNC;
855 if (!nfs_need_commit(NFS_I(inode)))
856 data->args.stable = NFS_FILE_SYNC;
859 data->res.fattr = &data->fattr;
860 data->res.count = count;
861 data->res.verf = &data->verf;
862 nfs_fattr_init(&data->fattr);
864 /* Set up the initial task struct. */
865 NFS_PROTO(inode)->write_setup(data, &msg);
867 dprintk("NFS: %5u initiated write call "
868 "(req %s/%lld, %u bytes @ offset %llu)\n",
869 data->task.tk_pid,
870 inode->i_sb->s_id,
871 (long long)NFS_FILEID(inode),
872 count,
873 (unsigned long long)data->args.offset);
875 task = rpc_run_task(&task_setup_data);
876 if (IS_ERR(task))
877 return PTR_ERR(task);
878 rpc_put_task(task);
879 return 0;
882 /* If a nfs_flush_* function fails, it should remove reqs from @head and
883 * call this on each, which will prepare them to be retried on next
884 * writeback using standard nfs.
886 static void nfs_redirty_request(struct nfs_page *req)
888 nfs_mark_request_dirty(req);
889 nfs_end_page_writeback(req->wb_page);
890 nfs_clear_page_tag_locked(req);
894 * Generate multiple small requests to write out a single
895 * contiguous dirty area on one page.
897 static int nfs_flush_multi(struct inode *inode, struct list_head *head, unsigned int npages, size_t count, int how)
899 struct nfs_page *req = nfs_list_entry(head->next);
900 struct page *page = req->wb_page;
901 struct nfs_write_data *data;
902 size_t wsize = NFS_SERVER(inode)->wsize, nbytes;
903 unsigned int offset;
904 int requests = 0;
905 int ret = 0;
906 LIST_HEAD(list);
908 nfs_list_remove_request(req);
910 nbytes = count;
911 do {
912 size_t len = min(nbytes, wsize);
914 data = nfs_writedata_alloc(1);
915 if (!data)
916 goto out_bad;
917 list_add(&data->pages, &list);
918 requests++;
919 nbytes -= len;
920 } while (nbytes != 0);
921 atomic_set(&req->wb_complete, requests);
923 ClearPageError(page);
924 offset = 0;
925 nbytes = count;
926 do {
927 int ret2;
929 data = list_entry(list.next, struct nfs_write_data, pages);
930 list_del_init(&data->pages);
932 data->pagevec[0] = page;
934 if (nbytes < wsize)
935 wsize = nbytes;
936 ret2 = nfs_write_rpcsetup(req, data, &nfs_write_partial_ops,
937 wsize, offset, how);
938 if (ret == 0)
939 ret = ret2;
940 offset += wsize;
941 nbytes -= wsize;
942 } while (nbytes != 0);
944 return ret;
946 out_bad:
947 while (!list_empty(&list)) {
948 data = list_entry(list.next, struct nfs_write_data, pages);
949 list_del(&data->pages);
950 nfs_writedata_release(data);
952 nfs_redirty_request(req);
953 return -ENOMEM;
957 * Create an RPC task for the given write request and kick it.
958 * The page must have been locked by the caller.
960 * It may happen that the page we're passed is not marked dirty.
961 * This is the case if nfs_updatepage detects a conflicting request
962 * that has been written but not committed.
964 static int nfs_flush_one(struct inode *inode, struct list_head *head, unsigned int npages, size_t count, int how)
966 struct nfs_page *req;
967 struct page **pages;
968 struct nfs_write_data *data;
970 data = nfs_writedata_alloc(npages);
971 if (!data)
972 goto out_bad;
974 pages = data->pagevec;
975 while (!list_empty(head)) {
976 req = nfs_list_entry(head->next);
977 nfs_list_remove_request(req);
978 nfs_list_add_request(req, &data->pages);
979 ClearPageError(req->wb_page);
980 *pages++ = req->wb_page;
982 req = nfs_list_entry(data->pages.next);
984 /* Set up the argument struct */
985 return nfs_write_rpcsetup(req, data, &nfs_write_full_ops, count, 0, how);
986 out_bad:
987 while (!list_empty(head)) {
988 req = nfs_list_entry(head->next);
989 nfs_list_remove_request(req);
990 nfs_redirty_request(req);
992 return -ENOMEM;
995 static void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
996 struct inode *inode, int ioflags)
998 size_t wsize = NFS_SERVER(inode)->wsize;
1000 if (wsize < PAGE_CACHE_SIZE)
1001 nfs_pageio_init(pgio, inode, nfs_flush_multi, wsize, ioflags);
1002 else
1003 nfs_pageio_init(pgio, inode, nfs_flush_one, wsize, ioflags);
1007 * Handle a write reply that flushed part of a page.
1009 static void nfs_writeback_done_partial(struct rpc_task *task, void *calldata)
1011 struct nfs_write_data *data = calldata;
1013 dprintk("NFS: %5u write(%s/%lld %d@%lld)",
1014 task->tk_pid,
1015 data->req->wb_context->path.dentry->d_inode->i_sb->s_id,
1016 (long long)
1017 NFS_FILEID(data->req->wb_context->path.dentry->d_inode),
1018 data->req->wb_bytes, (long long)req_offset(data->req));
1020 nfs_writeback_done(task, data);
1023 static void nfs_writeback_release_partial(void *calldata)
1025 struct nfs_write_data *data = calldata;
1026 struct nfs_page *req = data->req;
1027 struct page *page = req->wb_page;
1028 int status = data->task.tk_status;
1030 if (status < 0) {
1031 nfs_set_pageerror(page);
1032 nfs_context_set_write_error(req->wb_context, status);
1033 dprintk(", error = %d\n", status);
1034 goto out;
1037 if (nfs_write_need_commit(data)) {
1038 struct inode *inode = page->mapping->host;
1040 spin_lock(&inode->i_lock);
1041 if (test_bit(PG_NEED_RESCHED, &req->wb_flags)) {
1042 /* Do nothing we need to resend the writes */
1043 } else if (!test_and_set_bit(PG_NEED_COMMIT, &req->wb_flags)) {
1044 memcpy(&req->wb_verf, &data->verf, sizeof(req->wb_verf));
1045 dprintk(" defer commit\n");
1046 } else if (memcmp(&req->wb_verf, &data->verf, sizeof(req->wb_verf))) {
1047 set_bit(PG_NEED_RESCHED, &req->wb_flags);
1048 clear_bit(PG_NEED_COMMIT, &req->wb_flags);
1049 dprintk(" server reboot detected\n");
1051 spin_unlock(&inode->i_lock);
1052 } else
1053 dprintk(" OK\n");
1055 out:
1056 if (atomic_dec_and_test(&req->wb_complete))
1057 nfs_writepage_release(req);
1058 nfs_writedata_release(calldata);
1061 #if defined(CONFIG_NFS_V4_1)
1062 void nfs_write_prepare(struct rpc_task *task, void *calldata)
1064 struct nfs_write_data *data = calldata;
1065 struct nfs_client *clp = (NFS_SERVER(data->inode))->nfs_client;
1067 if (nfs4_setup_sequence(clp, &data->args.seq_args,
1068 &data->res.seq_res, 1, task))
1069 return;
1070 rpc_call_start(task);
1072 #endif /* CONFIG_NFS_V4_1 */
1074 static const struct rpc_call_ops nfs_write_partial_ops = {
1075 #if defined(CONFIG_NFS_V4_1)
1076 .rpc_call_prepare = nfs_write_prepare,
1077 #endif /* CONFIG_NFS_V4_1 */
1078 .rpc_call_done = nfs_writeback_done_partial,
1079 .rpc_release = nfs_writeback_release_partial,
1083 * Handle a write reply that flushes a whole page.
1085 * FIXME: There is an inherent race with invalidate_inode_pages and
1086 * writebacks since the page->count is kept > 1 for as long
1087 * as the page has a write request pending.
1089 static void nfs_writeback_done_full(struct rpc_task *task, void *calldata)
1091 struct nfs_write_data *data = calldata;
1093 nfs_writeback_done(task, data);
1096 static void nfs_writeback_release_full(void *calldata)
1098 struct nfs_write_data *data = calldata;
1099 int status = data->task.tk_status;
1101 /* Update attributes as result of writeback. */
1102 while (!list_empty(&data->pages)) {
1103 struct nfs_page *req = nfs_list_entry(data->pages.next);
1104 struct page *page = req->wb_page;
1106 nfs_list_remove_request(req);
1108 dprintk("NFS: %5u write (%s/%lld %d@%lld)",
1109 data->task.tk_pid,
1110 req->wb_context->path.dentry->d_inode->i_sb->s_id,
1111 (long long)NFS_FILEID(req->wb_context->path.dentry->d_inode),
1112 req->wb_bytes,
1113 (long long)req_offset(req));
1115 if (status < 0) {
1116 nfs_set_pageerror(page);
1117 nfs_context_set_write_error(req->wb_context, status);
1118 dprintk(", error = %d\n", status);
1119 goto remove_request;
1122 if (nfs_write_need_commit(data)) {
1123 memcpy(&req->wb_verf, &data->verf, sizeof(req->wb_verf));
1124 nfs_mark_request_commit(req);
1125 nfs_end_page_writeback(page);
1126 dprintk(" marked for commit\n");
1127 goto next;
1129 dprintk(" OK\n");
1130 remove_request:
1131 nfs_end_page_writeback(page);
1132 nfs_inode_remove_request(req);
1133 next:
1134 nfs_clear_page_tag_locked(req);
1136 nfs_writedata_release(calldata);
1139 static const struct rpc_call_ops nfs_write_full_ops = {
1140 #if defined(CONFIG_NFS_V4_1)
1141 .rpc_call_prepare = nfs_write_prepare,
1142 #endif /* CONFIG_NFS_V4_1 */
1143 .rpc_call_done = nfs_writeback_done_full,
1144 .rpc_release = nfs_writeback_release_full,
1149 * This function is called when the WRITE call is complete.
1151 int nfs_writeback_done(struct rpc_task *task, struct nfs_write_data *data)
1153 struct nfs_writeargs *argp = &data->args;
1154 struct nfs_writeres *resp = &data->res;
1155 struct nfs_server *server = NFS_SERVER(data->inode);
1156 int status;
1158 dprintk("NFS: %5u nfs_writeback_done (status %d)\n",
1159 task->tk_pid, task->tk_status);
1162 * ->write_done will attempt to use post-op attributes to detect
1163 * conflicting writes by other clients. A strict interpretation
1164 * of close-to-open would allow us to continue caching even if
1165 * another writer had changed the file, but some applications
1166 * depend on tighter cache coherency when writing.
1168 status = NFS_PROTO(data->inode)->write_done(task, data);
1169 if (status != 0)
1170 return status;
1171 nfs_add_stats(data->inode, NFSIOS_SERVERWRITTENBYTES, resp->count);
1173 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
1174 if (resp->verf->committed < argp->stable && task->tk_status >= 0) {
1175 /* We tried a write call, but the server did not
1176 * commit data to stable storage even though we
1177 * requested it.
1178 * Note: There is a known bug in Tru64 < 5.0 in which
1179 * the server reports NFS_DATA_SYNC, but performs
1180 * NFS_FILE_SYNC. We therefore implement this checking
1181 * as a dprintk() in order to avoid filling syslog.
1183 static unsigned long complain;
1185 if (time_before(complain, jiffies)) {
1186 dprintk("NFS: faulty NFS server %s:"
1187 " (committed = %d) != (stable = %d)\n",
1188 server->nfs_client->cl_hostname,
1189 resp->verf->committed, argp->stable);
1190 complain = jiffies + 300 * HZ;
1193 #endif
1194 /* Is this a short write? */
1195 if (task->tk_status >= 0 && resp->count < argp->count) {
1196 static unsigned long complain;
1198 nfs_inc_stats(data->inode, NFSIOS_SHORTWRITE);
1200 /* Has the server at least made some progress? */
1201 if (resp->count != 0) {
1202 /* Was this an NFSv2 write or an NFSv3 stable write? */
1203 if (resp->verf->committed != NFS_UNSTABLE) {
1204 /* Resend from where the server left off */
1205 argp->offset += resp->count;
1206 argp->pgbase += resp->count;
1207 argp->count -= resp->count;
1208 } else {
1209 /* Resend as a stable write in order to avoid
1210 * headaches in the case of a server crash.
1212 argp->stable = NFS_FILE_SYNC;
1214 nfs_restart_rpc(task, server->nfs_client);
1215 return -EAGAIN;
1217 if (time_before(complain, jiffies)) {
1218 printk(KERN_WARNING
1219 "NFS: Server wrote zero bytes, expected %u.\n",
1220 argp->count);
1221 complain = jiffies + 300 * HZ;
1223 /* Can't do anything about it except throw an error. */
1224 task->tk_status = -EIO;
1226 return 0;
1230 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
1231 static void nfs_commitdata_release(void *data)
1233 struct nfs_write_data *wdata = data;
1235 put_nfs_open_context(wdata->args.context);
1236 nfs_commit_free(wdata);
1240 * Set up the argument/result storage required for the RPC call.
1242 static int nfs_commit_rpcsetup(struct list_head *head,
1243 struct nfs_write_data *data,
1244 int how)
1246 struct nfs_page *first = nfs_list_entry(head->next);
1247 struct inode *inode = first->wb_context->path.dentry->d_inode;
1248 int flags = (how & FLUSH_SYNC) ? 0 : RPC_TASK_ASYNC;
1249 int priority = flush_task_priority(how);
1250 struct rpc_task *task;
1251 struct rpc_message msg = {
1252 .rpc_argp = &data->args,
1253 .rpc_resp = &data->res,
1254 .rpc_cred = first->wb_context->cred,
1256 struct rpc_task_setup task_setup_data = {
1257 .task = &data->task,
1258 .rpc_client = NFS_CLIENT(inode),
1259 .rpc_message = &msg,
1260 .callback_ops = &nfs_commit_ops,
1261 .callback_data = data,
1262 .workqueue = nfsiod_workqueue,
1263 .flags = flags,
1264 .priority = priority,
1267 /* Set up the RPC argument and reply structs
1268 * NB: take care not to mess about with data->commit et al. */
1270 list_splice_init(head, &data->pages);
1272 data->inode = inode;
1273 data->cred = msg.rpc_cred;
1275 data->args.fh = NFS_FH(data->inode);
1276 /* Note: we always request a commit of the entire inode */
1277 data->args.offset = 0;
1278 data->args.count = 0;
1279 data->args.context = get_nfs_open_context(first->wb_context);
1280 data->res.count = 0;
1281 data->res.fattr = &data->fattr;
1282 data->res.verf = &data->verf;
1283 nfs_fattr_init(&data->fattr);
1285 /* Set up the initial task struct. */
1286 NFS_PROTO(inode)->commit_setup(data, &msg);
1288 dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid);
1290 task = rpc_run_task(&task_setup_data);
1291 if (IS_ERR(task))
1292 return PTR_ERR(task);
1293 rpc_put_task(task);
1294 return 0;
1298 * Commit dirty pages
1300 static int
1301 nfs_commit_list(struct inode *inode, struct list_head *head, int how)
1303 struct nfs_write_data *data;
1304 struct nfs_page *req;
1306 data = nfs_commitdata_alloc();
1308 if (!data)
1309 goto out_bad;
1311 /* Set up the argument struct */
1312 return nfs_commit_rpcsetup(head, data, how);
1313 out_bad:
1314 while (!list_empty(head)) {
1315 req = nfs_list_entry(head->next);
1316 nfs_list_remove_request(req);
1317 nfs_mark_request_commit(req);
1318 dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
1319 dec_bdi_stat(req->wb_page->mapping->backing_dev_info,
1320 BDI_RECLAIMABLE);
1321 nfs_clear_page_tag_locked(req);
1323 return -ENOMEM;
1327 * COMMIT call returned
1329 static void nfs_commit_done(struct rpc_task *task, void *calldata)
1331 struct nfs_write_data *data = calldata;
1333 dprintk("NFS: %5u nfs_commit_done (status %d)\n",
1334 task->tk_pid, task->tk_status);
1336 /* Call the NFS version-specific code */
1337 if (NFS_PROTO(data->inode)->commit_done(task, data) != 0)
1338 return;
1341 static void nfs_commit_release(void *calldata)
1343 struct nfs_write_data *data = calldata;
1344 struct nfs_page *req;
1345 int status = data->task.tk_status;
1347 while (!list_empty(&data->pages)) {
1348 req = nfs_list_entry(data->pages.next);
1349 nfs_list_remove_request(req);
1350 nfs_clear_request_commit(req);
1352 dprintk("NFS: commit (%s/%lld %d@%lld)",
1353 req->wb_context->path.dentry->d_inode->i_sb->s_id,
1354 (long long)NFS_FILEID(req->wb_context->path.dentry->d_inode),
1355 req->wb_bytes,
1356 (long long)req_offset(req));
1357 if (status < 0) {
1358 nfs_context_set_write_error(req->wb_context, status);
1359 nfs_inode_remove_request(req);
1360 dprintk(", error = %d\n", status);
1361 goto next;
1364 /* Okay, COMMIT succeeded, apparently. Check the verifier
1365 * returned by the server against all stored verfs. */
1366 if (!memcmp(req->wb_verf.verifier, data->verf.verifier, sizeof(data->verf.verifier))) {
1367 /* We have a match */
1368 nfs_inode_remove_request(req);
1369 dprintk(" OK\n");
1370 goto next;
1372 /* We have a mismatch. Write the page again */
1373 dprintk(" mismatch\n");
1374 nfs_mark_request_dirty(req);
1375 next:
1376 nfs_clear_page_tag_locked(req);
1378 nfs_commitdata_release(calldata);
1381 static const struct rpc_call_ops nfs_commit_ops = {
1382 #if defined(CONFIG_NFS_V4_1)
1383 .rpc_call_prepare = nfs_write_prepare,
1384 #endif /* CONFIG_NFS_V4_1 */
1385 .rpc_call_done = nfs_commit_done,
1386 .rpc_release = nfs_commit_release,
1389 static int nfs_commit_inode(struct inode *inode, int how)
1391 LIST_HEAD(head);
1392 int res;
1394 spin_lock(&inode->i_lock);
1395 res = nfs_scan_commit(inode, &head, 0, 0);
1396 spin_unlock(&inode->i_lock);
1397 if (res) {
1398 int error = nfs_commit_list(inode, &head, how);
1399 if (error < 0)
1400 return error;
1402 return res;
1405 static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_control *wbc)
1407 struct nfs_inode *nfsi = NFS_I(inode);
1408 int flags = FLUSH_SYNC;
1409 int ret = 0;
1411 /* Don't commit yet if this is a non-blocking flush and there are
1412 * lots of outstanding writes for this mapping.
1414 if (wbc->sync_mode == WB_SYNC_NONE &&
1415 nfsi->ncommit <= (nfsi->npages >> 1))
1416 goto out_mark_dirty;
1418 if (wbc->nonblocking || wbc->for_background)
1419 flags = 0;
1420 ret = nfs_commit_inode(inode, flags);
1421 if (ret >= 0) {
1422 if (wbc->sync_mode == WB_SYNC_NONE) {
1423 if (ret < wbc->nr_to_write)
1424 wbc->nr_to_write -= ret;
1425 else
1426 wbc->nr_to_write = 0;
1428 return 0;
1430 out_mark_dirty:
1431 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
1432 return ret;
1434 #else
1435 static inline int nfs_commit_list(struct inode *inode, struct list_head *head, int how)
1437 return 0;
1440 static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_control *wbc)
1442 return 0;
1444 #endif
1446 int nfs_write_inode(struct inode *inode, struct writeback_control *wbc)
1448 return nfs_commit_unstable_pages(inode, wbc);
1451 long nfs_sync_mapping_wait(struct address_space *mapping, struct writeback_control *wbc, int how)
1453 struct inode *inode = mapping->host;
1454 pgoff_t idx_start, idx_end;
1455 unsigned int npages = 0;
1456 LIST_HEAD(head);
1457 long pages, ret;
1459 /* FIXME */
1460 if (wbc->range_cyclic)
1461 idx_start = 0;
1462 else {
1463 idx_start = wbc->range_start >> PAGE_CACHE_SHIFT;
1464 idx_end = wbc->range_end >> PAGE_CACHE_SHIFT;
1465 if (idx_end > idx_start) {
1466 pgoff_t l_npages = 1 + idx_end - idx_start;
1467 npages = l_npages;
1468 if (sizeof(npages) != sizeof(l_npages) &&
1469 (pgoff_t)npages != l_npages)
1470 npages = 0;
1473 spin_lock(&inode->i_lock);
1474 do {
1475 ret = nfs_wait_on_requests_locked(inode, idx_start, npages);
1476 if (ret != 0)
1477 continue;
1478 pages = nfs_scan_commit(inode, &head, idx_start, npages);
1479 if (pages == 0)
1480 break;
1481 pages += nfs_scan_commit(inode, &head, 0, 0);
1482 spin_unlock(&inode->i_lock);
1483 ret = nfs_commit_list(inode, &head, how);
1484 spin_lock(&inode->i_lock);
1486 } while (ret >= 0);
1487 spin_unlock(&inode->i_lock);
1488 return ret;
1492 * flush the inode to disk.
1494 int nfs_wb_all(struct inode *inode)
1496 struct writeback_control wbc = {
1497 .sync_mode = WB_SYNC_ALL,
1498 .nr_to_write = LONG_MAX,
1499 .range_start = 0,
1500 .range_end = LLONG_MAX,
1503 return sync_inode(inode, &wbc);
1506 int nfs_wb_page_cancel(struct inode *inode, struct page *page)
1508 struct nfs_page *req;
1509 int ret = 0;
1511 BUG_ON(!PageLocked(page));
1512 for (;;) {
1513 req = nfs_page_find_request(page);
1514 if (req == NULL)
1515 break;
1516 if (nfs_lock_request_dontget(req)) {
1517 nfs_inode_remove_request(req);
1519 * In case nfs_inode_remove_request has marked the
1520 * page as being dirty
1522 cancel_dirty_page(page, PAGE_CACHE_SIZE);
1523 nfs_unlock_request(req);
1524 break;
1526 ret = nfs_wait_on_request(req);
1527 nfs_release_request(req);
1528 if (ret < 0)
1529 break;
1531 return ret;
1534 static int nfs_wb_page_priority(struct inode *inode, struct page *page,
1535 int how)
1537 loff_t range_start = page_offset(page);
1538 loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
1539 struct writeback_control wbc = {
1540 .bdi = page->mapping->backing_dev_info,
1541 .sync_mode = WB_SYNC_ALL,
1542 .nr_to_write = LONG_MAX,
1543 .range_start = range_start,
1544 .range_end = range_end,
1546 int ret;
1548 do {
1549 if (clear_page_dirty_for_io(page)) {
1550 ret = nfs_writepage_locked(page, &wbc);
1551 if (ret < 0)
1552 goto out_error;
1553 } else if (!PagePrivate(page))
1554 break;
1555 ret = nfs_sync_mapping_wait(page->mapping, &wbc, how);
1556 if (ret < 0)
1557 goto out_error;
1558 } while (PagePrivate(page));
1559 return 0;
1560 out_error:
1561 __mark_inode_dirty(inode, I_DIRTY_PAGES);
1562 return ret;
1566 * Write back all requests on one page - we do this before reading it.
1568 int nfs_wb_page(struct inode *inode, struct page* page)
1570 return nfs_wb_page_priority(inode, page, FLUSH_STABLE);
1573 #ifdef CONFIG_MIGRATION
1574 int nfs_migrate_page(struct address_space *mapping, struct page *newpage,
1575 struct page *page)
1577 struct nfs_page *req;
1578 int ret;
1580 nfs_fscache_release_page(page, GFP_KERNEL);
1582 req = nfs_find_and_lock_request(page);
1583 ret = PTR_ERR(req);
1584 if (IS_ERR(req))
1585 goto out;
1587 ret = migrate_page(mapping, newpage, page);
1588 if (!req)
1589 goto out;
1590 if (ret)
1591 goto out_unlock;
1592 page_cache_get(newpage);
1593 spin_lock(&mapping->host->i_lock);
1594 req->wb_page = newpage;
1595 SetPagePrivate(newpage);
1596 set_page_private(newpage, (unsigned long)req);
1597 ClearPagePrivate(page);
1598 set_page_private(page, 0);
1599 spin_unlock(&mapping->host->i_lock);
1600 page_cache_release(page);
1601 out_unlock:
1602 nfs_clear_page_tag_locked(req);
1603 out:
1604 return ret;
1606 #endif
1608 int __init nfs_init_writepagecache(void)
1610 nfs_wdata_cachep = kmem_cache_create("nfs_write_data",
1611 sizeof(struct nfs_write_data),
1612 0, SLAB_HWCACHE_ALIGN,
1613 NULL);
1614 if (nfs_wdata_cachep == NULL)
1615 return -ENOMEM;
1617 nfs_wdata_mempool = mempool_create_slab_pool(MIN_POOL_WRITE,
1618 nfs_wdata_cachep);
1619 if (nfs_wdata_mempool == NULL)
1620 return -ENOMEM;
1622 nfs_commit_mempool = mempool_create_slab_pool(MIN_POOL_COMMIT,
1623 nfs_wdata_cachep);
1624 if (nfs_commit_mempool == NULL)
1625 return -ENOMEM;
1628 * NFS congestion size, scale with available memory.
1630 * 64MB: 8192k
1631 * 128MB: 11585k
1632 * 256MB: 16384k
1633 * 512MB: 23170k
1634 * 1GB: 32768k
1635 * 2GB: 46340k
1636 * 4GB: 65536k
1637 * 8GB: 92681k
1638 * 16GB: 131072k
1640 * This allows larger machines to have larger/more transfers.
1641 * Limit the default to 256M
1643 nfs_congestion_kb = (16*int_sqrt(totalram_pages)) << (PAGE_SHIFT-10);
1644 if (nfs_congestion_kb > 256*1024)
1645 nfs_congestion_kb = 256*1024;
1647 return 0;
1650 void nfs_destroy_writepagecache(void)
1652 mempool_destroy(nfs_commit_mempool);
1653 mempool_destroy(nfs_wdata_mempool);
1654 kmem_cache_destroy(nfs_wdata_cachep);