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>
24 #include <linux/freezer.h>
25 #include <linux/wait.h>
27 #include <asm/uaccess.h>
29 #include "delegation.h"
38 #define NFSDBG_FACILITY NFSDBG_PAGECACHE
40 #define MIN_POOL_WRITE (32)
41 #define MIN_POOL_COMMIT (4)
44 * Local function declarations
46 static void nfs_redirty_request(struct nfs_page *req);
47 static const struct rpc_call_ops nfs_commit_ops;
48 static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops;
49 static const struct nfs_commit_completion_ops nfs_commit_completion_ops;
50 static const struct nfs_rw_ops nfs_rw_write_ops;
51 static void nfs_clear_request_commit(struct nfs_page *req);
52 static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo,
54 static struct nfs_page *
55 nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi,
58 static struct kmem_cache *nfs_wdata_cachep;
59 static mempool_t *nfs_wdata_mempool;
60 static struct kmem_cache *nfs_cdata_cachep;
61 static mempool_t *nfs_commit_mempool;
63 struct nfs_commit_data *nfs_commitdata_alloc(void)
65 struct nfs_commit_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOIO);
68 memset(p, 0, sizeof(*p));
69 INIT_LIST_HEAD(&p->pages);
73 EXPORT_SYMBOL_GPL(nfs_commitdata_alloc);
75 void nfs_commit_free(struct nfs_commit_data *p)
77 mempool_free(p, nfs_commit_mempool);
79 EXPORT_SYMBOL_GPL(nfs_commit_free);
81 static struct nfs_pgio_header *nfs_writehdr_alloc(void)
83 struct nfs_pgio_header *p = mempool_alloc(nfs_wdata_mempool, GFP_NOIO);
86 memset(p, 0, sizeof(*p));
90 static void nfs_writehdr_free(struct nfs_pgio_header *hdr)
92 mempool_free(hdr, nfs_wdata_mempool);
95 static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error)
99 set_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags);
103 * nfs_page_find_head_request_locked - find head request associated with @page
105 * must be called while holding the inode lock.
107 * returns matching head request with reference held, or NULL if not found.
109 static struct nfs_page *
110 nfs_page_find_head_request_locked(struct nfs_inode *nfsi, struct page *page)
112 struct nfs_page *req = NULL;
114 if (PagePrivate(page))
115 req = (struct nfs_page *)page_private(page);
116 else if (unlikely(PageSwapCache(page)))
117 req = nfs_page_search_commits_for_head_request_locked(nfsi,
121 WARN_ON_ONCE(req->wb_head != req);
122 kref_get(&req->wb_kref);
129 * nfs_page_find_head_request - find head request associated with @page
131 * returns matching head request with reference held, or NULL if not found.
133 static struct nfs_page *nfs_page_find_head_request(struct page *page)
135 struct inode *inode = page_file_mapping(page)->host;
136 struct nfs_page *req = NULL;
138 spin_lock(&inode->i_lock);
139 req = nfs_page_find_head_request_locked(NFS_I(inode), page);
140 spin_unlock(&inode->i_lock);
144 /* Adjust the file length if we're writing beyond the end */
145 static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count)
147 struct inode *inode = page_file_mapping(page)->host;
151 spin_lock(&inode->i_lock);
152 i_size = i_size_read(inode);
153 end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
154 if (i_size > 0 && page_file_index(page) < end_index)
156 end = page_file_offset(page) + ((loff_t)offset+count);
159 i_size_write(inode, end);
160 nfs_inc_stats(inode, NFSIOS_EXTENDWRITE);
162 spin_unlock(&inode->i_lock);
165 /* A writeback failed: mark the page as bad, and invalidate the page cache */
166 static void nfs_set_pageerror(struct page *page)
168 nfs_zap_mapping(page_file_mapping(page)->host, page_file_mapping(page));
172 * nfs_page_group_search_locked
173 * @head - head request of page group
174 * @page_offset - offset into page
176 * Search page group with head @head to find a request that contains the
177 * page offset @page_offset.
179 * Returns a pointer to the first matching nfs request, or NULL if no
182 * Must be called with the page group lock held
184 static struct nfs_page *
185 nfs_page_group_search_locked(struct nfs_page *head, unsigned int page_offset)
187 struct nfs_page *req;
189 WARN_ON_ONCE(head != head->wb_head);
190 WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &head->wb_head->wb_flags));
194 if (page_offset >= req->wb_pgbase &&
195 page_offset < (req->wb_pgbase + req->wb_bytes))
198 req = req->wb_this_page;
199 } while (req != head);
205 * nfs_page_group_covers_page
206 * @head - head request of page group
208 * Return true if the page group with head @head covers the whole page,
209 * returns false otherwise
211 static bool nfs_page_group_covers_page(struct nfs_page *req)
213 struct nfs_page *tmp;
214 unsigned int pos = 0;
215 unsigned int len = nfs_page_length(req->wb_page);
217 nfs_page_group_lock(req, false);
220 tmp = nfs_page_group_search_locked(req->wb_head, pos);
222 /* no way this should happen */
223 WARN_ON_ONCE(tmp->wb_pgbase != pos);
224 pos += tmp->wb_bytes - (pos - tmp->wb_pgbase);
226 } while (tmp && pos < len);
228 nfs_page_group_unlock(req);
229 WARN_ON_ONCE(pos > len);
233 /* We can set the PG_uptodate flag if we see that a write request
234 * covers the full page.
236 static void nfs_mark_uptodate(struct nfs_page *req)
238 if (PageUptodate(req->wb_page))
240 if (!nfs_page_group_covers_page(req))
242 SetPageUptodate(req->wb_page);
245 static int wb_priority(struct writeback_control *wbc)
248 if (wbc->for_reclaim)
249 return FLUSH_HIGHPRI | FLUSH_STABLE;
250 if (wbc->sync_mode == WB_SYNC_ALL)
251 ret = FLUSH_COND_STABLE;
252 if (wbc->for_kupdate || wbc->for_background)
258 * NFS congestion control
261 int nfs_congestion_kb;
263 #define NFS_CONGESTION_ON_THRESH (nfs_congestion_kb >> (PAGE_SHIFT-10))
264 #define NFS_CONGESTION_OFF_THRESH \
265 (NFS_CONGESTION_ON_THRESH - (NFS_CONGESTION_ON_THRESH >> 2))
267 static void nfs_set_page_writeback(struct page *page)
269 struct nfs_server *nfss = NFS_SERVER(page_file_mapping(page)->host);
270 int ret = test_set_page_writeback(page);
272 WARN_ON_ONCE(ret != 0);
274 if (atomic_long_inc_return(&nfss->writeback) >
275 NFS_CONGESTION_ON_THRESH) {
276 set_bdi_congested(&nfss->backing_dev_info,
281 static void nfs_end_page_writeback(struct nfs_page *req)
283 struct inode *inode = page_file_mapping(req->wb_page)->host;
284 struct nfs_server *nfss = NFS_SERVER(inode);
286 if (!nfs_page_group_sync_on_bit(req, PG_WB_END))
289 end_page_writeback(req->wb_page);
290 if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH)
291 clear_bdi_congested(&nfss->backing_dev_info, BLK_RW_ASYNC);
295 /* nfs_page_group_clear_bits
296 * @req - an nfs request
297 * clears all page group related bits from @req
300 nfs_page_group_clear_bits(struct nfs_page *req)
302 clear_bit(PG_TEARDOWN, &req->wb_flags);
303 clear_bit(PG_UNLOCKPAGE, &req->wb_flags);
304 clear_bit(PG_UPTODATE, &req->wb_flags);
305 clear_bit(PG_WB_END, &req->wb_flags);
306 clear_bit(PG_REMOVE, &req->wb_flags);
311 * nfs_unroll_locks_and_wait - unlock all newly locked reqs and wait on @req
313 * this is a helper function for nfs_lock_and_join_requests
315 * @inode - inode associated with request page group, must be holding inode lock
316 * @head - head request of page group, must be holding head lock
317 * @req - request that couldn't lock and needs to wait on the req bit lock
318 * @nonblock - if true, don't actually wait
320 * NOTE: this must be called holding page_group bit lock and inode spin lock
321 * and BOTH will be released before returning.
323 * returns 0 on success, < 0 on error.
326 nfs_unroll_locks_and_wait(struct inode *inode, struct nfs_page *head,
327 struct nfs_page *req, bool nonblock)
328 __releases(&inode->i_lock)
330 struct nfs_page *tmp;
333 /* relinquish all the locks successfully grabbed this run */
334 for (tmp = head ; tmp != req; tmp = tmp->wb_this_page)
335 nfs_unlock_request(tmp);
337 WARN_ON_ONCE(test_bit(PG_TEARDOWN, &req->wb_flags));
339 /* grab a ref on the request that will be waited on */
340 kref_get(&req->wb_kref);
342 nfs_page_group_unlock(head);
343 spin_unlock(&inode->i_lock);
345 /* release ref from nfs_page_find_head_request_locked */
346 nfs_release_request(head);
349 ret = nfs_wait_on_request(req);
352 nfs_release_request(req);
358 * nfs_destroy_unlinked_subrequests - destroy recently unlinked subrequests
360 * @destroy_list - request list (using wb_this_page) terminated by @old_head
361 * @old_head - the old head of the list
363 * All subrequests must be locked and removed from all lists, so at this point
364 * they are only "active" in this function, and possibly in nfs_wait_on_request
365 * with a reference held by some other context.
368 nfs_destroy_unlinked_subrequests(struct nfs_page *destroy_list,
369 struct nfs_page *old_head)
371 while (destroy_list) {
372 struct nfs_page *subreq = destroy_list;
374 destroy_list = (subreq->wb_this_page == old_head) ?
375 NULL : subreq->wb_this_page;
377 WARN_ON_ONCE(old_head != subreq->wb_head);
379 /* make sure old group is not used */
380 subreq->wb_head = subreq;
381 subreq->wb_this_page = subreq;
383 /* subreq is now totally disconnected from page group or any
384 * write / commit lists. last chance to wake any waiters */
385 nfs_unlock_request(subreq);
387 if (!test_bit(PG_TEARDOWN, &subreq->wb_flags)) {
388 /* release ref on old head request */
389 nfs_release_request(old_head);
391 nfs_page_group_clear_bits(subreq);
393 /* release the PG_INODE_REF reference */
394 if (test_and_clear_bit(PG_INODE_REF, &subreq->wb_flags))
395 nfs_release_request(subreq);
399 WARN_ON_ONCE(test_bit(PG_CLEAN, &subreq->wb_flags));
400 /* zombie requests have already released the last
401 * reference and were waiting on the rest of the
402 * group to complete. Since it's no longer part of a
403 * group, simply free the request */
404 nfs_page_group_clear_bits(subreq);
405 nfs_free_request(subreq);
411 * nfs_lock_and_join_requests - join all subreqs to the head req and return
412 * a locked reference, cancelling any pending
413 * operations for this page.
415 * @page - the page used to lookup the "page group" of nfs_page structures
416 * @nonblock - if true, don't block waiting for request locks
418 * This function joins all sub requests to the head request by first
419 * locking all requests in the group, cancelling any pending operations
420 * and finally updating the head request to cover the whole range covered by
421 * the (former) group. All subrequests are removed from any write or commit
422 * lists, unlinked from the group and destroyed.
424 * Returns a locked, referenced pointer to the head request - which after
425 * this call is guaranteed to be the only request associated with the page.
426 * Returns NULL if no requests are found for @page, or a ERR_PTR if an
427 * error was encountered.
429 static struct nfs_page *
430 nfs_lock_and_join_requests(struct page *page, bool nonblock)
432 struct inode *inode = page_file_mapping(page)->host;
433 struct nfs_page *head, *subreq;
434 struct nfs_page *destroy_list = NULL;
435 unsigned int total_bytes;
441 WARN_ON_ONCE(destroy_list);
443 spin_lock(&inode->i_lock);
446 * A reference is taken only on the head request which acts as a
447 * reference to the whole page group - the group will not be destroyed
448 * until the head reference is released.
450 head = nfs_page_find_head_request_locked(NFS_I(inode), page);
453 spin_unlock(&inode->i_lock);
457 /* holding inode lock, so always make a non-blocking call to try the
459 ret = nfs_page_group_lock(head, true);
461 spin_unlock(&inode->i_lock);
463 if (!nonblock && ret == -EAGAIN) {
464 nfs_page_group_lock_wait(head);
465 nfs_release_request(head);
469 nfs_release_request(head);
473 /* lock each request in the page group */
477 * Subrequests are always contiguous, non overlapping
478 * and in order - but may be repeated (mirrored writes).
480 if (subreq->wb_offset == (head->wb_offset + total_bytes)) {
481 /* keep track of how many bytes this group covers */
482 total_bytes += subreq->wb_bytes;
483 } else if (WARN_ON_ONCE(subreq->wb_offset < head->wb_offset ||
484 ((subreq->wb_offset + subreq->wb_bytes) >
485 (head->wb_offset + total_bytes)))) {
486 nfs_page_group_unlock(head);
487 spin_unlock(&inode->i_lock);
488 return ERR_PTR(-EIO);
491 if (!nfs_lock_request(subreq)) {
492 /* releases page group bit lock and
493 * inode spin lock and all references */
494 ret = nfs_unroll_locks_and_wait(inode, head,
503 subreq = subreq->wb_this_page;
504 } while (subreq != head);
506 /* Now that all requests are locked, make sure they aren't on any list.
507 * Commit list removal accounting is done after locks are dropped */
510 nfs_clear_request_commit(subreq);
511 subreq = subreq->wb_this_page;
512 } while (subreq != head);
514 /* unlink subrequests from head, destroy them later */
515 if (head->wb_this_page != head) {
516 /* destroy list will be terminated by head */
517 destroy_list = head->wb_this_page;
518 head->wb_this_page = head;
520 /* change head request to cover whole range that
521 * the former page group covered */
522 head->wb_bytes = total_bytes;
526 * prepare head request to be added to new pgio descriptor
528 nfs_page_group_clear_bits(head);
531 * some part of the group was still on the inode list - otherwise
532 * the group wouldn't be involved in async write.
533 * grab a reference for the head request, iff it needs one.
535 if (!test_and_set_bit(PG_INODE_REF, &head->wb_flags))
536 kref_get(&head->wb_kref);
538 nfs_page_group_unlock(head);
540 /* drop lock to clean uprequests on destroy list */
541 spin_unlock(&inode->i_lock);
543 nfs_destroy_unlinked_subrequests(destroy_list, head);
545 /* still holds ref on head from nfs_page_find_head_request_locked
546 * and still has lock on head from lock loop */
551 * Find an associated nfs write request, and prepare to flush it out
552 * May return an error if the user signalled nfs_wait_on_request().
554 static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio,
555 struct page *page, bool nonblock)
557 struct nfs_page *req;
560 req = nfs_lock_and_join_requests(page, nonblock);
567 nfs_set_page_writeback(page);
568 WARN_ON_ONCE(test_bit(PG_CLEAN, &req->wb_flags));
571 if (!nfs_pageio_add_request(pgio, req)) {
572 nfs_redirty_request(req);
573 ret = pgio->pg_error;
575 nfs_add_stats(page_file_mapping(page)->host,
576 NFSIOS_WRITEPAGES, 1);
581 static int nfs_do_writepage(struct page *page, struct writeback_control *wbc, struct nfs_pageio_descriptor *pgio)
585 nfs_pageio_cond_complete(pgio, page_file_index(page));
586 ret = nfs_page_async_flush(pgio, page, wbc->sync_mode == WB_SYNC_NONE);
587 if (ret == -EAGAIN) {
588 redirty_page_for_writepage(wbc, page);
595 * Write an mmapped page to the server.
597 static int nfs_writepage_locked(struct page *page, struct writeback_control *wbc)
599 struct nfs_pageio_descriptor pgio;
600 struct inode *inode = page_file_mapping(page)->host;
603 nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE);
604 nfs_pageio_init_write(&pgio, inode, wb_priority(wbc),
605 false, &nfs_async_write_completion_ops);
606 err = nfs_do_writepage(page, wbc, &pgio);
607 nfs_pageio_complete(&pgio);
610 if (pgio.pg_error < 0)
611 return pgio.pg_error;
615 int nfs_writepage(struct page *page, struct writeback_control *wbc)
619 ret = nfs_writepage_locked(page, wbc);
624 static int nfs_writepages_callback(struct page *page, struct writeback_control *wbc, void *data)
628 ret = nfs_do_writepage(page, wbc, data);
633 int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
635 struct inode *inode = mapping->host;
636 unsigned long *bitlock = &NFS_I(inode)->flags;
637 struct nfs_pageio_descriptor pgio;
640 /* Stop dirtying of new pages while we sync */
641 err = wait_on_bit_lock_action(bitlock, NFS_INO_FLUSHING,
642 nfs_wait_bit_killable, TASK_KILLABLE);
646 nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES);
648 nfs_pageio_init_write(&pgio, inode, wb_priority(wbc), false,
649 &nfs_async_write_completion_ops);
650 err = write_cache_pages(mapping, wbc, nfs_writepages_callback, &pgio);
651 nfs_pageio_complete(&pgio);
653 clear_bit_unlock(NFS_INO_FLUSHING, bitlock);
654 smp_mb__after_atomic();
655 wake_up_bit(bitlock, NFS_INO_FLUSHING);
668 * Insert a write request into an inode
670 static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
672 struct nfs_inode *nfsi = NFS_I(inode);
674 WARN_ON_ONCE(req->wb_this_page != req);
676 /* Lock the request! */
677 nfs_lock_request(req);
679 spin_lock(&inode->i_lock);
680 if (!nfsi->nrequests &&
681 NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE))
684 * Swap-space should not get truncated. Hence no need to plug the race
685 * with invalidate/truncate.
687 if (likely(!PageSwapCache(req->wb_page))) {
688 set_bit(PG_MAPPED, &req->wb_flags);
689 SetPagePrivate(req->wb_page);
690 set_page_private(req->wb_page, (unsigned long)req);
693 /* this a head request for a page group - mark it as having an
694 * extra reference so sub groups can follow suit.
695 * This flag also informs pgio layer when to bump nrequests when
696 * adding subrequests. */
697 WARN_ON(test_and_set_bit(PG_INODE_REF, &req->wb_flags));
698 kref_get(&req->wb_kref);
699 spin_unlock(&inode->i_lock);
703 * Remove a write request from an inode
705 static void nfs_inode_remove_request(struct nfs_page *req)
707 struct inode *inode = d_inode(req->wb_context->dentry);
708 struct nfs_inode *nfsi = NFS_I(inode);
709 struct nfs_page *head;
711 if (nfs_page_group_sync_on_bit(req, PG_REMOVE)) {
714 spin_lock(&inode->i_lock);
715 if (likely(!PageSwapCache(head->wb_page))) {
716 set_page_private(head->wb_page, 0);
717 ClearPagePrivate(head->wb_page);
718 smp_mb__after_atomic();
719 wake_up_page(head->wb_page, PG_private);
720 clear_bit(PG_MAPPED, &head->wb_flags);
723 spin_unlock(&inode->i_lock);
725 spin_lock(&inode->i_lock);
727 spin_unlock(&inode->i_lock);
730 if (test_and_clear_bit(PG_INODE_REF, &req->wb_flags))
731 nfs_release_request(req);
735 nfs_mark_request_dirty(struct nfs_page *req)
737 __set_page_dirty_nobuffers(req->wb_page);
741 * nfs_page_search_commits_for_head_request_locked
743 * Search through commit lists on @inode for the head request for @page.
744 * Must be called while holding the inode (which is cinfo) lock.
746 * Returns the head request if found, or NULL if not found.
748 static struct nfs_page *
749 nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi,
752 struct nfs_page *freq, *t;
753 struct nfs_commit_info cinfo;
754 struct inode *inode = &nfsi->vfs_inode;
756 nfs_init_cinfo_from_inode(&cinfo, inode);
758 /* search through pnfs commit lists */
759 freq = pnfs_search_commit_reqs(inode, &cinfo, page);
761 return freq->wb_head;
763 /* Linearly search the commit list for the correct request */
764 list_for_each_entry_safe(freq, t, &cinfo.mds->list, wb_list) {
765 if (freq->wb_page == page)
766 return freq->wb_head;
773 * nfs_request_add_commit_list_locked - add request to a commit list
774 * @req: pointer to a struct nfs_page
775 * @dst: commit list head
776 * @cinfo: holds list lock and accounting info
778 * This sets the PG_CLEAN bit, updates the cinfo count of
779 * number of outstanding requests requiring a commit as well as
782 * The caller must hold the cinfo->lock, and the nfs_page lock.
785 nfs_request_add_commit_list_locked(struct nfs_page *req, struct list_head *dst,
786 struct nfs_commit_info *cinfo)
788 set_bit(PG_CLEAN, &req->wb_flags);
789 nfs_list_add_request(req, dst);
790 cinfo->mds->ncommit++;
792 EXPORT_SYMBOL_GPL(nfs_request_add_commit_list_locked);
795 * nfs_request_add_commit_list - add request to a commit list
796 * @req: pointer to a struct nfs_page
797 * @dst: commit list head
798 * @cinfo: holds list lock and accounting info
800 * This sets the PG_CLEAN bit, updates the cinfo count of
801 * number of outstanding requests requiring a commit as well as
804 * The caller must _not_ hold the cinfo->lock, but must be
805 * holding the nfs_page lock.
808 nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst,
809 struct nfs_commit_info *cinfo)
811 spin_lock(cinfo->lock);
812 nfs_request_add_commit_list_locked(req, dst, cinfo);
813 spin_unlock(cinfo->lock);
814 nfs_mark_page_unstable(req->wb_page, cinfo);
816 EXPORT_SYMBOL_GPL(nfs_request_add_commit_list);
819 * nfs_request_remove_commit_list - Remove request from a commit list
820 * @req: pointer to a nfs_page
821 * @cinfo: holds list lock and accounting info
823 * This clears the PG_CLEAN bit, and updates the cinfo's count of
824 * number of outstanding requests requiring a commit
825 * It does not update the MM page stats.
827 * The caller _must_ hold the cinfo->lock and the nfs_page lock.
830 nfs_request_remove_commit_list(struct nfs_page *req,
831 struct nfs_commit_info *cinfo)
833 if (!test_and_clear_bit(PG_CLEAN, &(req)->wb_flags))
835 nfs_list_remove_request(req);
836 cinfo->mds->ncommit--;
838 EXPORT_SYMBOL_GPL(nfs_request_remove_commit_list);
840 static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo,
843 cinfo->lock = &inode->i_lock;
844 cinfo->mds = &NFS_I(inode)->commit_info;
845 cinfo->ds = pnfs_get_ds_info(inode);
847 cinfo->completion_ops = &nfs_commit_completion_ops;
850 void nfs_init_cinfo(struct nfs_commit_info *cinfo,
852 struct nfs_direct_req *dreq)
855 nfs_init_cinfo_from_dreq(cinfo, dreq);
857 nfs_init_cinfo_from_inode(cinfo, inode);
859 EXPORT_SYMBOL_GPL(nfs_init_cinfo);
862 * Add a request to the inode's commit list.
865 nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg,
866 struct nfs_commit_info *cinfo, u32 ds_commit_idx)
868 if (pnfs_mark_request_commit(req, lseg, cinfo, ds_commit_idx))
870 nfs_request_add_commit_list(req, &cinfo->mds->list, cinfo);
874 nfs_clear_page_commit(struct page *page)
876 dec_zone_page_state(page, NR_UNSTABLE_NFS);
877 dec_wb_stat(&inode_to_bdi(page_file_mapping(page)->host)->wb,
881 /* Called holding inode (/cinfo) lock */
883 nfs_clear_request_commit(struct nfs_page *req)
885 if (test_bit(PG_CLEAN, &req->wb_flags)) {
886 struct inode *inode = d_inode(req->wb_context->dentry);
887 struct nfs_commit_info cinfo;
889 nfs_init_cinfo_from_inode(&cinfo, inode);
890 if (!pnfs_clear_request_commit(req, &cinfo)) {
891 nfs_request_remove_commit_list(req, &cinfo);
893 nfs_clear_page_commit(req->wb_page);
897 int nfs_write_need_commit(struct nfs_pgio_header *hdr)
899 if (hdr->verf.committed == NFS_DATA_SYNC)
900 return hdr->lseg == NULL;
901 return hdr->verf.committed != NFS_FILE_SYNC;
904 static void nfs_write_completion(struct nfs_pgio_header *hdr)
906 struct nfs_commit_info cinfo;
907 unsigned long bytes = 0;
909 if (test_bit(NFS_IOHDR_REDO, &hdr->flags))
911 nfs_init_cinfo_from_inode(&cinfo, hdr->inode);
912 while (!list_empty(&hdr->pages)) {
913 struct nfs_page *req = nfs_list_entry(hdr->pages.next);
915 bytes += req->wb_bytes;
916 nfs_list_remove_request(req);
917 if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) &&
918 (hdr->good_bytes < bytes)) {
919 nfs_set_pageerror(req->wb_page);
920 nfs_context_set_write_error(req->wb_context, hdr->error);
923 if (nfs_write_need_commit(hdr)) {
924 memcpy(&req->wb_verf, &hdr->verf.verifier, sizeof(req->wb_verf));
925 nfs_mark_request_commit(req, hdr->lseg, &cinfo,
926 hdr->pgio_mirror_idx);
930 nfs_inode_remove_request(req);
932 nfs_unlock_request(req);
933 nfs_end_page_writeback(req);
934 nfs_release_request(req);
941 nfs_reqs_to_commit(struct nfs_commit_info *cinfo)
943 return cinfo->mds->ncommit;
946 /* cinfo->lock held by caller */
948 nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
949 struct nfs_commit_info *cinfo, int max)
951 struct nfs_page *req, *tmp;
954 list_for_each_entry_safe(req, tmp, src, wb_list) {
955 if (!nfs_lock_request(req))
957 kref_get(&req->wb_kref);
958 if (cond_resched_lock(cinfo->lock))
959 list_safe_reset_next(req, tmp, wb_list);
960 nfs_request_remove_commit_list(req, cinfo);
961 nfs_list_add_request(req, dst);
963 if ((ret == max) && !cinfo->dreq)
970 * nfs_scan_commit - Scan an inode for commit requests
971 * @inode: NFS inode to scan
972 * @dst: mds destination list
973 * @cinfo: mds and ds lists of reqs ready to commit
975 * Moves requests from the inode's 'commit' request list.
976 * The requests are *not* checked to ensure that they form a contiguous set.
979 nfs_scan_commit(struct inode *inode, struct list_head *dst,
980 struct nfs_commit_info *cinfo)
984 spin_lock(cinfo->lock);
985 if (cinfo->mds->ncommit > 0) {
986 const int max = INT_MAX;
988 ret = nfs_scan_commit_list(&cinfo->mds->list, dst,
990 ret += pnfs_scan_commit_lists(inode, cinfo, max - ret);
992 spin_unlock(cinfo->lock);
997 * Search for an existing write request, and attempt to update
998 * it to reflect a new dirty region on a given page.
1000 * If the attempt fails, then the existing request is flushed out
1003 static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
1005 unsigned int offset,
1008 struct nfs_page *req;
1013 if (!PagePrivate(page))
1016 end = offset + bytes;
1017 spin_lock(&inode->i_lock);
1020 req = nfs_page_find_head_request_locked(NFS_I(inode), page);
1024 /* should be handled by nfs_flush_incompatible */
1025 WARN_ON_ONCE(req->wb_head != req);
1026 WARN_ON_ONCE(req->wb_this_page != req);
1028 rqend = req->wb_offset + req->wb_bytes;
1030 * Tell the caller to flush out the request if
1031 * the offsets are non-contiguous.
1032 * Note: nfs_flush_incompatible() will already
1033 * have flushed out requests having wrong owners.
1036 || end < req->wb_offset)
1039 if (nfs_lock_request(req))
1042 /* The request is locked, so wait and then retry */
1043 spin_unlock(&inode->i_lock);
1044 error = nfs_wait_on_request(req);
1045 nfs_release_request(req);
1048 spin_lock(&inode->i_lock);
1051 /* Okay, the request matches. Update the region */
1052 if (offset < req->wb_offset) {
1053 req->wb_offset = offset;
1054 req->wb_pgbase = offset;
1057 req->wb_bytes = end - req->wb_offset;
1059 req->wb_bytes = rqend - req->wb_offset;
1062 nfs_clear_request_commit(req);
1063 spin_unlock(&inode->i_lock);
1066 spin_unlock(&inode->i_lock);
1067 nfs_release_request(req);
1068 error = nfs_wb_page(inode, page);
1070 return ERR_PTR(error);
1074 * Try to update an existing write request, or create one if there is none.
1076 * Note: Should always be called with the Page Lock held to prevent races
1077 * if we have to add a new request. Also assumes that the caller has
1078 * already called nfs_flush_incompatible() if necessary.
1080 static struct nfs_page * nfs_setup_write_request(struct nfs_open_context* ctx,
1081 struct page *page, unsigned int offset, unsigned int bytes)
1083 struct inode *inode = page_file_mapping(page)->host;
1084 struct nfs_page *req;
1086 req = nfs_try_to_update_request(inode, page, offset, bytes);
1089 req = nfs_create_request(ctx, page, NULL, offset, bytes);
1092 nfs_inode_add_request(inode, req);
1097 static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page,
1098 unsigned int offset, unsigned int count)
1100 struct nfs_page *req;
1102 req = nfs_setup_write_request(ctx, page, offset, count);
1104 return PTR_ERR(req);
1105 /* Update file length */
1106 nfs_grow_file(page, offset, count);
1107 nfs_mark_uptodate(req);
1108 nfs_mark_request_dirty(req);
1109 nfs_unlock_and_release_request(req);
1113 int nfs_flush_incompatible(struct file *file, struct page *page)
1115 struct nfs_open_context *ctx = nfs_file_open_context(file);
1116 struct nfs_lock_context *l_ctx;
1117 struct file_lock_context *flctx = file_inode(file)->i_flctx;
1118 struct nfs_page *req;
1119 int do_flush, status;
1121 * Look for a request corresponding to this page. If there
1122 * is one, and it belongs to another file, we flush it out
1123 * before we try to copy anything into the page. Do this
1124 * due to the lack of an ACCESS-type call in NFSv2.
1125 * Also do the same if we find a request from an existing
1129 req = nfs_page_find_head_request(page);
1132 l_ctx = req->wb_lock_context;
1133 do_flush = req->wb_page != page ||
1134 !nfs_match_open_context(req->wb_context, ctx);
1135 /* for now, flush if more than 1 request in page_group */
1136 do_flush |= req->wb_this_page != req;
1137 if (l_ctx && flctx &&
1138 !(list_empty_careful(&flctx->flc_posix) &&
1139 list_empty_careful(&flctx->flc_flock))) {
1140 do_flush |= l_ctx->lockowner.l_owner != current->files
1141 || l_ctx->lockowner.l_pid != current->tgid;
1143 nfs_release_request(req);
1146 status = nfs_wb_page(page_file_mapping(page)->host, page);
1147 } while (status == 0);
1152 * Avoid buffered writes when a open context credential's key would
1155 * Returns -EACCES if the key will expire within RPC_KEY_EXPIRE_FAIL.
1157 * Return 0 and set a credential flag which triggers the inode to flush
1158 * and performs NFS_FILE_SYNC writes if the key will expired within
1159 * RPC_KEY_EXPIRE_TIMEO.
1162 nfs_key_timeout_notify(struct file *filp, struct inode *inode)
1164 struct nfs_open_context *ctx = nfs_file_open_context(filp);
1165 struct rpc_auth *auth = NFS_SERVER(inode)->client->cl_auth;
1167 return rpcauth_key_timeout_notify(auth, ctx->cred);
1171 * Test if the open context credential key is marked to expire soon.
1173 bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx)
1175 return rpcauth_cred_key_to_expire(ctx->cred);
1179 * If the page cache is marked as unsafe or invalid, then we can't rely on
1180 * the PageUptodate() flag. In this case, we will need to turn off
1181 * write optimisations that depend on the page contents being correct.
1183 static bool nfs_write_pageuptodate(struct page *page, struct inode *inode)
1185 struct nfs_inode *nfsi = NFS_I(inode);
1187 if (nfs_have_delegated_attributes(inode))
1189 if (nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE)
1192 if (test_bit(NFS_INO_INVALIDATING, &nfsi->flags))
1195 if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
1197 return PageUptodate(page) != 0;
1201 is_whole_file_wrlock(struct file_lock *fl)
1203 return fl->fl_start == 0 && fl->fl_end == OFFSET_MAX &&
1204 fl->fl_type == F_WRLCK;
1207 /* If we know the page is up to date, and we're not using byte range locks (or
1208 * if we have the whole file locked for writing), it may be more efficient to
1209 * extend the write to cover the entire page in order to avoid fragmentation
1212 * If the file is opened for synchronous writes then we can just skip the rest
1215 static int nfs_can_extend_write(struct file *file, struct page *page, struct inode *inode)
1218 struct file_lock_context *flctx = inode->i_flctx;
1219 struct file_lock *fl;
1221 if (file->f_flags & O_DSYNC)
1223 if (!nfs_write_pageuptodate(page, inode))
1225 if (NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE))
1227 if (!flctx || (list_empty_careful(&flctx->flc_flock) &&
1228 list_empty_careful(&flctx->flc_posix)))
1231 /* Check to see if there are whole file write locks */
1233 spin_lock(&flctx->flc_lock);
1234 if (!list_empty(&flctx->flc_posix)) {
1235 fl = list_first_entry(&flctx->flc_posix, struct file_lock,
1237 if (is_whole_file_wrlock(fl))
1239 } else if (!list_empty(&flctx->flc_flock)) {
1240 fl = list_first_entry(&flctx->flc_flock, struct file_lock,
1242 if (fl->fl_type == F_WRLCK)
1245 spin_unlock(&flctx->flc_lock);
1250 * Update and possibly write a cached page of an NFS file.
1252 * XXX: Keep an eye on generic_file_read to make sure it doesn't do bad
1253 * things with a page scheduled for an RPC call (e.g. invalidate it).
1255 int nfs_updatepage(struct file *file, struct page *page,
1256 unsigned int offset, unsigned int count)
1258 struct nfs_open_context *ctx = nfs_file_open_context(file);
1259 struct inode *inode = page_file_mapping(page)->host;
1262 nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE);
1264 dprintk("NFS: nfs_updatepage(%pD2 %d@%lld)\n",
1265 file, count, (long long)(page_file_offset(page) + offset));
1267 if (nfs_can_extend_write(file, page, inode)) {
1268 count = max(count + offset, nfs_page_length(page));
1272 status = nfs_writepage_setup(ctx, page, offset, count);
1274 nfs_set_pageerror(page);
1276 __set_page_dirty_nobuffers(page);
1278 dprintk("NFS: nfs_updatepage returns %d (isize %lld)\n",
1279 status, (long long)i_size_read(inode));
1283 static int flush_task_priority(int how)
1285 switch (how & (FLUSH_HIGHPRI|FLUSH_LOWPRI)) {
1287 return RPC_PRIORITY_HIGH;
1289 return RPC_PRIORITY_LOW;
1291 return RPC_PRIORITY_NORMAL;
1294 static void nfs_initiate_write(struct nfs_pgio_header *hdr,
1295 struct rpc_message *msg,
1296 const struct nfs_rpc_ops *rpc_ops,
1297 struct rpc_task_setup *task_setup_data, int how)
1299 int priority = flush_task_priority(how);
1301 task_setup_data->priority = priority;
1302 rpc_ops->write_setup(hdr, msg);
1304 nfs4_state_protect_write(NFS_SERVER(hdr->inode)->nfs_client,
1305 &task_setup_data->rpc_client, msg, hdr);
1308 /* If a nfs_flush_* function fails, it should remove reqs from @head and
1309 * call this on each, which will prepare them to be retried on next
1310 * writeback using standard nfs.
1312 static void nfs_redirty_request(struct nfs_page *req)
1314 nfs_mark_request_dirty(req);
1315 set_bit(NFS_CONTEXT_RESEND_WRITES, &req->wb_context->flags);
1316 nfs_unlock_request(req);
1317 nfs_end_page_writeback(req);
1318 nfs_release_request(req);
1321 static void nfs_async_write_error(struct list_head *head)
1323 struct nfs_page *req;
1325 while (!list_empty(head)) {
1326 req = nfs_list_entry(head->next);
1327 nfs_list_remove_request(req);
1328 nfs_redirty_request(req);
1332 static void nfs_async_write_reschedule_io(struct nfs_pgio_header *hdr)
1334 nfs_async_write_error(&hdr->pages);
1337 static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops = {
1338 .error_cleanup = nfs_async_write_error,
1339 .completion = nfs_write_completion,
1340 .reschedule_io = nfs_async_write_reschedule_io,
1343 void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
1344 struct inode *inode, int ioflags, bool force_mds,
1345 const struct nfs_pgio_completion_ops *compl_ops)
1347 struct nfs_server *server = NFS_SERVER(inode);
1348 const struct nfs_pageio_ops *pg_ops = &nfs_pgio_rw_ops;
1350 #ifdef CONFIG_NFS_V4_1
1351 if (server->pnfs_curr_ld && !force_mds)
1352 pg_ops = server->pnfs_curr_ld->pg_write_ops;
1354 nfs_pageio_init(pgio, inode, pg_ops, compl_ops, &nfs_rw_write_ops,
1355 server->wsize, ioflags);
1357 EXPORT_SYMBOL_GPL(nfs_pageio_init_write);
1359 void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio)
1361 struct nfs_pgio_mirror *mirror;
1363 if (pgio->pg_ops && pgio->pg_ops->pg_cleanup)
1364 pgio->pg_ops->pg_cleanup(pgio);
1366 pgio->pg_ops = &nfs_pgio_rw_ops;
1368 nfs_pageio_stop_mirroring(pgio);
1370 mirror = &pgio->pg_mirrors[0];
1371 mirror->pg_bsize = NFS_SERVER(pgio->pg_inode)->wsize;
1373 EXPORT_SYMBOL_GPL(nfs_pageio_reset_write_mds);
1376 void nfs_commit_prepare(struct rpc_task *task, void *calldata)
1378 struct nfs_commit_data *data = calldata;
1380 NFS_PROTO(data->inode)->commit_rpc_prepare(task, data);
1384 * Special version of should_remove_suid() that ignores capabilities.
1386 static int nfs_should_remove_suid(const struct inode *inode)
1388 umode_t mode = inode->i_mode;
1391 /* suid always must be killed */
1392 if (unlikely(mode & S_ISUID))
1393 kill = ATTR_KILL_SUID;
1396 * sgid without any exec bits is just a mandatory locking mark; leave
1397 * it alone. If some exec bits are set, it's a real sgid; kill it.
1399 if (unlikely((mode & S_ISGID) && (mode & S_IXGRP)))
1400 kill |= ATTR_KILL_SGID;
1402 if (unlikely(kill && S_ISREG(mode)))
1408 static void nfs_writeback_check_extend(struct nfs_pgio_header *hdr,
1409 struct nfs_fattr *fattr)
1411 struct nfs_pgio_args *argp = &hdr->args;
1412 struct nfs_pgio_res *resp = &hdr->res;
1413 u64 size = argp->offset + resp->count;
1415 if (!(fattr->valid & NFS_ATTR_FATTR_SIZE))
1417 if (nfs_size_to_loff_t(fattr->size) < i_size_read(hdr->inode)) {
1418 fattr->valid &= ~NFS_ATTR_FATTR_SIZE;
1421 if (size != fattr->size)
1423 /* Set attribute barrier */
1424 nfs_fattr_set_barrier(fattr);
1425 /* ...and update size */
1426 fattr->valid |= NFS_ATTR_FATTR_SIZE;
1429 void nfs_writeback_update_inode(struct nfs_pgio_header *hdr)
1431 struct nfs_fattr *fattr = &hdr->fattr;
1432 struct inode *inode = hdr->inode;
1434 spin_lock(&inode->i_lock);
1435 nfs_writeback_check_extend(hdr, fattr);
1436 nfs_post_op_update_inode_force_wcc_locked(inode, fattr);
1437 spin_unlock(&inode->i_lock);
1439 EXPORT_SYMBOL_GPL(nfs_writeback_update_inode);
1442 * This function is called when the WRITE call is complete.
1444 static int nfs_writeback_done(struct rpc_task *task,
1445 struct nfs_pgio_header *hdr,
1446 struct inode *inode)
1451 * ->write_done will attempt to use post-op attributes to detect
1452 * conflicting writes by other clients. A strict interpretation
1453 * of close-to-open would allow us to continue caching even if
1454 * another writer had changed the file, but some applications
1455 * depend on tighter cache coherency when writing.
1457 status = NFS_PROTO(inode)->write_done(task, hdr);
1460 nfs_add_stats(inode, NFSIOS_SERVERWRITTENBYTES, hdr->res.count);
1462 if (hdr->res.verf->committed < hdr->args.stable &&
1463 task->tk_status >= 0) {
1464 /* We tried a write call, but the server did not
1465 * commit data to stable storage even though we
1467 * Note: There is a known bug in Tru64 < 5.0 in which
1468 * the server reports NFS_DATA_SYNC, but performs
1469 * NFS_FILE_SYNC. We therefore implement this checking
1470 * as a dprintk() in order to avoid filling syslog.
1472 static unsigned long complain;
1474 /* Note this will print the MDS for a DS write */
1475 if (time_before(complain, jiffies)) {
1476 dprintk("NFS: faulty NFS server %s:"
1477 " (committed = %d) != (stable = %d)\n",
1478 NFS_SERVER(inode)->nfs_client->cl_hostname,
1479 hdr->res.verf->committed, hdr->args.stable);
1480 complain = jiffies + 300 * HZ;
1484 /* Deal with the suid/sgid bit corner case */
1485 if (nfs_should_remove_suid(inode))
1486 nfs_mark_for_revalidate(inode);
1491 * This function is called when the WRITE call is complete.
1493 static void nfs_writeback_result(struct rpc_task *task,
1494 struct nfs_pgio_header *hdr)
1496 struct nfs_pgio_args *argp = &hdr->args;
1497 struct nfs_pgio_res *resp = &hdr->res;
1499 if (resp->count < argp->count) {
1500 static unsigned long complain;
1502 /* This a short write! */
1503 nfs_inc_stats(hdr->inode, NFSIOS_SHORTWRITE);
1505 /* Has the server at least made some progress? */
1506 if (resp->count == 0) {
1507 if (time_before(complain, jiffies)) {
1509 "NFS: Server wrote zero bytes, expected %u.\n",
1511 complain = jiffies + 300 * HZ;
1513 nfs_set_pgio_error(hdr, -EIO, argp->offset);
1514 task->tk_status = -EIO;
1518 /* For non rpc-based layout drivers, retry-through-MDS */
1519 if (!task->tk_ops) {
1520 hdr->pnfs_error = -EAGAIN;
1524 /* Was this an NFSv2 write or an NFSv3 stable write? */
1525 if (resp->verf->committed != NFS_UNSTABLE) {
1526 /* Resend from where the server left off */
1527 hdr->mds_offset += resp->count;
1528 argp->offset += resp->count;
1529 argp->pgbase += resp->count;
1530 argp->count -= resp->count;
1532 /* Resend as a stable write in order to avoid
1533 * headaches in the case of a server crash.
1535 argp->stable = NFS_FILE_SYNC;
1537 rpc_restart_call_prepare(task);
1541 static int nfs_wait_atomic_killable(atomic_t *key)
1543 if (fatal_signal_pending(current))
1544 return -ERESTARTSYS;
1545 freezable_schedule_unsafe();
1549 static int wait_on_commit(struct nfs_mds_commit_info *cinfo)
1551 return wait_on_atomic_t(&cinfo->rpcs_out,
1552 nfs_wait_atomic_killable, TASK_KILLABLE);
1555 static void nfs_commit_begin(struct nfs_mds_commit_info *cinfo)
1557 atomic_inc(&cinfo->rpcs_out);
1560 static void nfs_commit_end(struct nfs_mds_commit_info *cinfo)
1562 if (atomic_dec_and_test(&cinfo->rpcs_out))
1563 wake_up_atomic_t(&cinfo->rpcs_out);
1566 void nfs_commitdata_release(struct nfs_commit_data *data)
1568 put_nfs_open_context(data->context);
1569 nfs_commit_free(data);
1571 EXPORT_SYMBOL_GPL(nfs_commitdata_release);
1573 int nfs_initiate_commit(struct rpc_clnt *clnt, struct nfs_commit_data *data,
1574 const struct nfs_rpc_ops *nfs_ops,
1575 const struct rpc_call_ops *call_ops,
1578 struct rpc_task *task;
1579 int priority = flush_task_priority(how);
1580 struct rpc_message msg = {
1581 .rpc_argp = &data->args,
1582 .rpc_resp = &data->res,
1583 .rpc_cred = data->cred,
1585 struct rpc_task_setup task_setup_data = {
1586 .task = &data->task,
1588 .rpc_message = &msg,
1589 .callback_ops = call_ops,
1590 .callback_data = data,
1591 .workqueue = nfsiod_workqueue,
1592 .flags = RPC_TASK_ASYNC | flags,
1593 .priority = priority,
1595 /* Set up the initial task struct. */
1596 nfs_ops->commit_setup(data, &msg);
1598 dprintk("NFS: initiated commit call\n");
1600 nfs4_state_protect(NFS_SERVER(data->inode)->nfs_client,
1601 NFS_SP4_MACH_CRED_COMMIT, &task_setup_data.rpc_client, &msg);
1603 task = rpc_run_task(&task_setup_data);
1605 return PTR_ERR(task);
1606 if (how & FLUSH_SYNC)
1607 rpc_wait_for_completion_task(task);
1611 EXPORT_SYMBOL_GPL(nfs_initiate_commit);
1613 static loff_t nfs_get_lwb(struct list_head *head)
1616 struct nfs_page *req;
1618 list_for_each_entry(req, head, wb_list)
1619 if (lwb < (req_offset(req) + req->wb_bytes))
1620 lwb = req_offset(req) + req->wb_bytes;
1626 * Set up the argument/result storage required for the RPC call.
1628 void nfs_init_commit(struct nfs_commit_data *data,
1629 struct list_head *head,
1630 struct pnfs_layout_segment *lseg,
1631 struct nfs_commit_info *cinfo)
1633 struct nfs_page *first = nfs_list_entry(head->next);
1634 struct inode *inode = d_inode(first->wb_context->dentry);
1636 /* Set up the RPC argument and reply structs
1637 * NB: take care not to mess about with data->commit et al. */
1639 list_splice_init(head, &data->pages);
1641 data->inode = inode;
1642 data->cred = first->wb_context->cred;
1643 data->lseg = lseg; /* reference transferred */
1644 /* only set lwb for pnfs commit */
1646 data->lwb = nfs_get_lwb(&data->pages);
1647 data->mds_ops = &nfs_commit_ops;
1648 data->completion_ops = cinfo->completion_ops;
1649 data->dreq = cinfo->dreq;
1651 data->args.fh = NFS_FH(data->inode);
1652 /* Note: we always request a commit of the entire inode */
1653 data->args.offset = 0;
1654 data->args.count = 0;
1655 data->context = get_nfs_open_context(first->wb_context);
1656 data->res.fattr = &data->fattr;
1657 data->res.verf = &data->verf;
1658 nfs_fattr_init(&data->fattr);
1660 EXPORT_SYMBOL_GPL(nfs_init_commit);
1662 void nfs_retry_commit(struct list_head *page_list,
1663 struct pnfs_layout_segment *lseg,
1664 struct nfs_commit_info *cinfo,
1667 struct nfs_page *req;
1669 while (!list_empty(page_list)) {
1670 req = nfs_list_entry(page_list->next);
1671 nfs_list_remove_request(req);
1672 nfs_mark_request_commit(req, lseg, cinfo, ds_commit_idx);
1674 nfs_clear_page_commit(req->wb_page);
1675 nfs_unlock_and_release_request(req);
1678 EXPORT_SYMBOL_GPL(nfs_retry_commit);
1681 nfs_commit_resched_write(struct nfs_commit_info *cinfo,
1682 struct nfs_page *req)
1684 __set_page_dirty_nobuffers(req->wb_page);
1688 * Commit dirty pages
1691 nfs_commit_list(struct inode *inode, struct list_head *head, int how,
1692 struct nfs_commit_info *cinfo)
1694 struct nfs_commit_data *data;
1696 data = nfs_commitdata_alloc();
1701 /* Set up the argument struct */
1702 nfs_init_commit(data, head, NULL, cinfo);
1703 atomic_inc(&cinfo->mds->rpcs_out);
1704 return nfs_initiate_commit(NFS_CLIENT(inode), data, NFS_PROTO(inode),
1705 data->mds_ops, how, 0);
1707 nfs_retry_commit(head, NULL, cinfo, 0);
1712 * COMMIT call returned
1714 static void nfs_commit_done(struct rpc_task *task, void *calldata)
1716 struct nfs_commit_data *data = calldata;
1718 dprintk("NFS: %5u nfs_commit_done (status %d)\n",
1719 task->tk_pid, task->tk_status);
1721 /* Call the NFS version-specific code */
1722 NFS_PROTO(data->inode)->commit_done(task, data);
1725 static void nfs_commit_release_pages(struct nfs_commit_data *data)
1727 struct nfs_page *req;
1728 int status = data->task.tk_status;
1729 struct nfs_commit_info cinfo;
1730 struct nfs_server *nfss;
1732 while (!list_empty(&data->pages)) {
1733 req = nfs_list_entry(data->pages.next);
1734 nfs_list_remove_request(req);
1735 nfs_clear_page_commit(req->wb_page);
1737 dprintk("NFS: commit (%s/%llu %d@%lld)",
1738 req->wb_context->dentry->d_sb->s_id,
1739 (unsigned long long)NFS_FILEID(d_inode(req->wb_context->dentry)),
1741 (long long)req_offset(req));
1743 nfs_context_set_write_error(req->wb_context, status);
1744 nfs_inode_remove_request(req);
1745 dprintk(", error = %d\n", status);
1749 /* Okay, COMMIT succeeded, apparently. Check the verifier
1750 * returned by the server against all stored verfs. */
1751 if (!memcmp(&req->wb_verf, &data->verf.verifier, sizeof(req->wb_verf))) {
1752 /* We have a match */
1753 nfs_inode_remove_request(req);
1757 /* We have a mismatch. Write the page again */
1758 dprintk(" mismatch\n");
1759 nfs_mark_request_dirty(req);
1760 set_bit(NFS_CONTEXT_RESEND_WRITES, &req->wb_context->flags);
1762 nfs_unlock_and_release_request(req);
1764 nfss = NFS_SERVER(data->inode);
1765 if (atomic_long_read(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH)
1766 clear_bdi_congested(&nfss->backing_dev_info, BLK_RW_ASYNC);
1768 nfs_init_cinfo(&cinfo, data->inode, data->dreq);
1769 nfs_commit_end(cinfo.mds);
1772 static void nfs_commit_release(void *calldata)
1774 struct nfs_commit_data *data = calldata;
1776 data->completion_ops->completion(data);
1777 nfs_commitdata_release(calldata);
1780 static const struct rpc_call_ops nfs_commit_ops = {
1781 .rpc_call_prepare = nfs_commit_prepare,
1782 .rpc_call_done = nfs_commit_done,
1783 .rpc_release = nfs_commit_release,
1786 static const struct nfs_commit_completion_ops nfs_commit_completion_ops = {
1787 .completion = nfs_commit_release_pages,
1788 .resched_write = nfs_commit_resched_write,
1791 int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
1792 int how, struct nfs_commit_info *cinfo)
1796 status = pnfs_commit_list(inode, head, how, cinfo);
1797 if (status == PNFS_NOT_ATTEMPTED)
1798 status = nfs_commit_list(inode, head, how, cinfo);
1802 int nfs_commit_inode(struct inode *inode, int how)
1805 struct nfs_commit_info cinfo;
1806 int may_wait = how & FLUSH_SYNC;
1810 nfs_init_cinfo_from_inode(&cinfo, inode);
1811 nfs_commit_begin(cinfo.mds);
1812 res = nfs_scan_commit(inode, &head, &cinfo);
1814 error = nfs_generic_commit_list(inode, &head, how, &cinfo);
1815 nfs_commit_end(cinfo.mds);
1819 goto out_mark_dirty;
1820 error = wait_on_commit(cinfo.mds);
1826 /* Note: If we exit without ensuring that the commit is complete,
1827 * we must mark the inode as dirty. Otherwise, future calls to
1828 * sync_inode() with the WB_SYNC_ALL flag set will fail to ensure
1829 * that the data is on the disk.
1832 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
1835 EXPORT_SYMBOL_GPL(nfs_commit_inode);
1837 int nfs_write_inode(struct inode *inode, struct writeback_control *wbc)
1839 struct nfs_inode *nfsi = NFS_I(inode);
1840 int flags = FLUSH_SYNC;
1843 /* no commits means nothing needs to be done */
1844 if (!nfsi->commit_info.ncommit)
1847 if (wbc->sync_mode == WB_SYNC_NONE) {
1848 /* Don't commit yet if this is a non-blocking flush and there
1849 * are a lot of outstanding writes for this mapping.
1851 if (nfsi->commit_info.ncommit <= (nfsi->nrequests >> 1))
1852 goto out_mark_dirty;
1854 /* don't wait for the COMMIT response */
1858 ret = nfs_commit_inode(inode, flags);
1860 if (wbc->sync_mode == WB_SYNC_NONE) {
1861 if (ret < wbc->nr_to_write)
1862 wbc->nr_to_write -= ret;
1864 wbc->nr_to_write = 0;
1869 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
1872 EXPORT_SYMBOL_GPL(nfs_write_inode);
1875 * flush the inode to disk.
1877 int nfs_wb_all(struct inode *inode)
1881 trace_nfs_writeback_inode_enter(inode);
1883 ret = filemap_write_and_wait(inode->i_mapping);
1886 ret = nfs_commit_inode(inode, FLUSH_SYNC);
1889 pnfs_sync_inode(inode, true);
1893 trace_nfs_writeback_inode_exit(inode, ret);
1896 EXPORT_SYMBOL_GPL(nfs_wb_all);
1898 int nfs_wb_page_cancel(struct inode *inode, struct page *page)
1900 struct nfs_page *req;
1903 wait_on_page_writeback(page);
1905 /* blocking call to cancel all requests and join to a single (head)
1907 req = nfs_lock_and_join_requests(page, false);
1912 /* all requests from this page have been cancelled by
1913 * nfs_lock_and_join_requests, so just remove the head
1914 * request from the inode / page_private pointer and
1916 nfs_inode_remove_request(req);
1917 nfs_unlock_and_release_request(req);
1924 * Write back all requests on one page - we do this before reading it.
1926 int nfs_wb_page(struct inode *inode, struct page *page)
1928 loff_t range_start = page_file_offset(page);
1929 loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
1930 struct writeback_control wbc = {
1931 .sync_mode = WB_SYNC_ALL,
1933 .range_start = range_start,
1934 .range_end = range_end,
1938 trace_nfs_writeback_page_enter(inode);
1941 wait_on_page_writeback(page);
1942 if (clear_page_dirty_for_io(page)) {
1943 ret = nfs_writepage_locked(page, &wbc);
1949 if (!PagePrivate(page))
1951 ret = nfs_commit_inode(inode, FLUSH_SYNC);
1956 trace_nfs_writeback_page_exit(inode, ret);
1960 #ifdef CONFIG_MIGRATION
1961 int nfs_migrate_page(struct address_space *mapping, struct page *newpage,
1962 struct page *page, enum migrate_mode mode)
1965 * If PagePrivate is set, then the page is currently associated with
1966 * an in-progress read or write request. Don't try to migrate it.
1968 * FIXME: we could do this in principle, but we'll need a way to ensure
1969 * that we can safely release the inode reference while holding
1972 if (PagePrivate(page))
1975 if (!nfs_fscache_release_page(page, GFP_KERNEL))
1978 return migrate_page(mapping, newpage, page, mode);
1982 int __init nfs_init_writepagecache(void)
1984 nfs_wdata_cachep = kmem_cache_create("nfs_write_data",
1985 sizeof(struct nfs_pgio_header),
1986 0, SLAB_HWCACHE_ALIGN,
1988 if (nfs_wdata_cachep == NULL)
1991 nfs_wdata_mempool = mempool_create_slab_pool(MIN_POOL_WRITE,
1993 if (nfs_wdata_mempool == NULL)
1994 goto out_destroy_write_cache;
1996 nfs_cdata_cachep = kmem_cache_create("nfs_commit_data",
1997 sizeof(struct nfs_commit_data),
1998 0, SLAB_HWCACHE_ALIGN,
2000 if (nfs_cdata_cachep == NULL)
2001 goto out_destroy_write_mempool;
2003 nfs_commit_mempool = mempool_create_slab_pool(MIN_POOL_COMMIT,
2005 if (nfs_commit_mempool == NULL)
2006 goto out_destroy_commit_cache;
2009 * NFS congestion size, scale with available memory.
2021 * This allows larger machines to have larger/more transfers.
2022 * Limit the default to 256M
2024 nfs_congestion_kb = (16*int_sqrt(totalram_pages)) << (PAGE_SHIFT-10);
2025 if (nfs_congestion_kb > 256*1024)
2026 nfs_congestion_kb = 256*1024;
2030 out_destroy_commit_cache:
2031 kmem_cache_destroy(nfs_cdata_cachep);
2032 out_destroy_write_mempool:
2033 mempool_destroy(nfs_wdata_mempool);
2034 out_destroy_write_cache:
2035 kmem_cache_destroy(nfs_wdata_cachep);
2039 void nfs_destroy_writepagecache(void)
2041 mempool_destroy(nfs_commit_mempool);
2042 kmem_cache_destroy(nfs_cdata_cachep);
2043 mempool_destroy(nfs_wdata_mempool);
2044 kmem_cache_destroy(nfs_wdata_cachep);
2047 static const struct nfs_rw_ops nfs_rw_write_ops = {
2048 .rw_mode = FMODE_WRITE,
2049 .rw_alloc_header = nfs_writehdr_alloc,
2050 .rw_free_header = nfs_writehdr_free,
2051 .rw_done = nfs_writeback_done,
2052 .rw_result = nfs_writeback_result,
2053 .rw_initiate = nfs_initiate_write,