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>
24 #include <asm/uaccess.h>
26 #include "delegation.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
);
56 memset(p
, 0, sizeof(*p
));
57 INIT_LIST_HEAD(&p
->pages
);
62 void nfs_commit_free(struct nfs_write_data
*p
)
64 if (p
&& (p
->pagevec
!= &p
->page_array
[0]))
66 mempool_free(p
, nfs_commit_mempool
);
69 struct nfs_write_data
*nfs_writedata_alloc(unsigned int pagecount
)
71 struct nfs_write_data
*p
= mempool_alloc(nfs_wdata_mempool
, GFP_NOFS
);
74 memset(p
, 0, sizeof(*p
));
75 INIT_LIST_HEAD(&p
->pages
);
76 p
->npages
= pagecount
;
77 if (pagecount
<= ARRAY_SIZE(p
->page_array
))
78 p
->pagevec
= p
->page_array
;
80 p
->pagevec
= kcalloc(pagecount
, sizeof(struct page
*), GFP_NOFS
);
82 mempool_free(p
, nfs_wdata_mempool
);
90 void nfs_writedata_free(struct nfs_write_data
*p
)
92 if (p
&& (p
->pagevec
!= &p
->page_array
[0]))
94 mempool_free(p
, nfs_wdata_mempool
);
97 static void nfs_writedata_release(struct nfs_write_data
*wdata
)
99 put_nfs_open_context(wdata
->args
.context
);
100 nfs_writedata_free(wdata
);
103 static void nfs_context_set_write_error(struct nfs_open_context
*ctx
, int error
)
107 set_bit(NFS_CONTEXT_ERROR_WRITE
, &ctx
->flags
);
110 static struct nfs_page
*nfs_page_find_request_locked(struct page
*page
)
112 struct nfs_page
*req
= NULL
;
114 if (PagePrivate(page
)) {
115 req
= (struct nfs_page
*)page_private(page
);
117 kref_get(&req
->wb_kref
);
122 static struct nfs_page
*nfs_page_find_request(struct page
*page
)
124 struct inode
*inode
= page
->mapping
->host
;
125 struct nfs_page
*req
= NULL
;
127 spin_lock(&inode
->i_lock
);
128 req
= nfs_page_find_request_locked(page
);
129 spin_unlock(&inode
->i_lock
);
133 /* Adjust the file length if we're writing beyond the end */
134 static void nfs_grow_file(struct page
*page
, unsigned int offset
, unsigned int count
)
136 struct inode
*inode
= page
->mapping
->host
;
140 spin_lock(&inode
->i_lock
);
141 i_size
= i_size_read(inode
);
142 end_index
= (i_size
- 1) >> PAGE_CACHE_SHIFT
;
143 if (i_size
> 0 && page
->index
< end_index
)
145 end
= ((loff_t
)page
->index
<< PAGE_CACHE_SHIFT
) + ((loff_t
)offset
+count
);
148 i_size_write(inode
, end
);
149 nfs_inc_stats(inode
, NFSIOS_EXTENDWRITE
);
151 spin_unlock(&inode
->i_lock
);
154 /* A writeback failed: mark the page as bad, and invalidate the page cache */
155 static void nfs_set_pageerror(struct page
*page
)
158 nfs_zap_mapping(page
->mapping
->host
, page
->mapping
);
161 /* We can set the PG_uptodate flag if we see that a write request
162 * covers the full page.
164 static void nfs_mark_uptodate(struct page
*page
, unsigned int base
, unsigned int count
)
166 if (PageUptodate(page
))
170 if (count
!= nfs_page_length(page
))
172 SetPageUptodate(page
);
175 static int wb_priority(struct writeback_control
*wbc
)
177 if (wbc
->for_reclaim
)
178 return FLUSH_HIGHPRI
| FLUSH_STABLE
;
179 if (wbc
->for_kupdate
|| wbc
->for_background
)
185 * NFS congestion control
188 int nfs_congestion_kb
;
190 #define NFS_CONGESTION_ON_THRESH (nfs_congestion_kb >> (PAGE_SHIFT-10))
191 #define NFS_CONGESTION_OFF_THRESH \
192 (NFS_CONGESTION_ON_THRESH - (NFS_CONGESTION_ON_THRESH >> 2))
194 static int nfs_set_page_writeback(struct page
*page
)
196 int ret
= test_set_page_writeback(page
);
199 struct inode
*inode
= page
->mapping
->host
;
200 struct nfs_server
*nfss
= NFS_SERVER(inode
);
202 page_cache_get(page
);
203 if (atomic_long_inc_return(&nfss
->writeback
) >
204 NFS_CONGESTION_ON_THRESH
) {
205 set_bdi_congested(&nfss
->backing_dev_info
,
212 static void nfs_end_page_writeback(struct page
*page
)
214 struct inode
*inode
= page
->mapping
->host
;
215 struct nfs_server
*nfss
= NFS_SERVER(inode
);
217 end_page_writeback(page
);
218 page_cache_release(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
, bool nonblock
)
225 struct inode
*inode
= page
->mapping
->host
;
226 struct nfs_page
*req
;
229 spin_lock(&inode
->i_lock
);
231 req
= nfs_page_find_request_locked(page
);
234 if (nfs_set_page_tag_locked(req
))
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
);
243 ret
= nfs_wait_on_request(req
);
246 nfs_release_request(req
);
249 spin_lock(&inode
->i_lock
);
251 spin_unlock(&inode
->i_lock
);
256 * Find an associated nfs write request, and prepare to flush it out
257 * May return an error if the user signalled nfs_wait_on_request().
259 static int nfs_page_async_flush(struct nfs_pageio_descriptor
*pgio
,
260 struct page
*page
, bool nonblock
)
262 struct nfs_page
*req
;
265 req
= nfs_find_and_lock_request(page
, nonblock
);
272 ret
= nfs_set_page_writeback(page
);
274 BUG_ON(test_bit(PG_CLEAN
, &req
->wb_flags
));
276 if (!nfs_pageio_add_request(pgio
, req
)) {
277 nfs_redirty_request(req
);
278 ret
= pgio
->pg_error
;
284 static int nfs_do_writepage(struct page
*page
, struct writeback_control
*wbc
, struct nfs_pageio_descriptor
*pgio
)
286 struct inode
*inode
= page
->mapping
->host
;
289 nfs_inc_stats(inode
, NFSIOS_VFSWRITEPAGE
);
290 nfs_add_stats(inode
, NFSIOS_WRITEPAGES
, 1);
292 nfs_pageio_cond_complete(pgio
, page
->index
);
293 ret
= nfs_page_async_flush(pgio
, page
, wbc
->sync_mode
== WB_SYNC_NONE
);
294 if (ret
== -EAGAIN
) {
295 redirty_page_for_writepage(wbc
, page
);
302 * Write an mmapped page to the server.
304 static int nfs_writepage_locked(struct page
*page
, struct writeback_control
*wbc
)
306 struct nfs_pageio_descriptor pgio
;
309 nfs_pageio_init_write(&pgio
, page
->mapping
->host
, wb_priority(wbc
));
310 err
= nfs_do_writepage(page
, wbc
, &pgio
);
311 nfs_pageio_complete(&pgio
);
314 if (pgio
.pg_error
< 0)
315 return pgio
.pg_error
;
319 int nfs_writepage(struct page
*page
, struct writeback_control
*wbc
)
323 ret
= nfs_writepage_locked(page
, wbc
);
328 static int nfs_writepages_callback(struct page
*page
, struct writeback_control
*wbc
, void *data
)
332 ret
= nfs_do_writepage(page
, wbc
, data
);
337 int nfs_writepages(struct address_space
*mapping
, struct writeback_control
*wbc
)
339 struct inode
*inode
= mapping
->host
;
340 unsigned long *bitlock
= &NFS_I(inode
)->flags
;
341 struct nfs_pageio_descriptor pgio
;
344 /* Stop dirtying of new pages while we sync */
345 err
= wait_on_bit_lock(bitlock
, NFS_INO_FLUSHING
,
346 nfs_wait_bit_killable
, TASK_KILLABLE
);
350 nfs_inc_stats(inode
, NFSIOS_VFSWRITEPAGES
);
352 nfs_pageio_init_write(&pgio
, inode
, wb_priority(wbc
));
353 err
= write_cache_pages(mapping
, wbc
, nfs_writepages_callback
, &pgio
);
354 nfs_pageio_complete(&pgio
);
356 clear_bit_unlock(NFS_INO_FLUSHING
, bitlock
);
357 smp_mb__after_clear_bit();
358 wake_up_bit(bitlock
, NFS_INO_FLUSHING
);
371 * Insert a write request into an inode
373 static int nfs_inode_add_request(struct inode
*inode
, struct nfs_page
*req
)
375 struct nfs_inode
*nfsi
= NFS_I(inode
);
378 error
= radix_tree_preload(GFP_NOFS
);
382 /* Lock the request! */
383 nfs_lock_request_dontget(req
);
385 spin_lock(&inode
->i_lock
);
386 error
= radix_tree_insert(&nfsi
->nfs_page_tree
, req
->wb_index
, req
);
390 if (nfs_have_delegation(inode
, FMODE_WRITE
))
393 SetPagePrivate(req
->wb_page
);
394 set_page_private(req
->wb_page
, (unsigned long)req
);
396 kref_get(&req
->wb_kref
);
397 radix_tree_tag_set(&nfsi
->nfs_page_tree
, req
->wb_index
,
398 NFS_PAGE_TAG_LOCKED
);
399 spin_unlock(&inode
->i_lock
);
400 radix_tree_preload_end();
406 * Remove a write request from an inode
408 static void nfs_inode_remove_request(struct nfs_page
*req
)
410 struct inode
*inode
= req
->wb_context
->path
.dentry
->d_inode
;
411 struct nfs_inode
*nfsi
= NFS_I(inode
);
413 BUG_ON (!NFS_WBACK_BUSY(req
));
415 spin_lock(&inode
->i_lock
);
416 set_page_private(req
->wb_page
, 0);
417 ClearPagePrivate(req
->wb_page
);
418 radix_tree_delete(&nfsi
->nfs_page_tree
, req
->wb_index
);
421 spin_unlock(&inode
->i_lock
);
424 spin_unlock(&inode
->i_lock
);
425 nfs_clear_request(req
);
426 nfs_release_request(req
);
430 nfs_mark_request_dirty(struct nfs_page
*req
)
432 __set_page_dirty_nobuffers(req
->wb_page
);
433 __mark_inode_dirty(req
->wb_page
->mapping
->host
, I_DIRTY_DATASYNC
);
436 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
438 * Add a request to the inode's commit list.
441 nfs_mark_request_commit(struct nfs_page
*req
)
443 struct inode
*inode
= req
->wb_context
->path
.dentry
->d_inode
;
444 struct nfs_inode
*nfsi
= NFS_I(inode
);
446 spin_lock(&inode
->i_lock
);
447 set_bit(PG_CLEAN
, &(req
)->wb_flags
);
448 radix_tree_tag_set(&nfsi
->nfs_page_tree
,
450 NFS_PAGE_TAG_COMMIT
);
452 spin_unlock(&inode
->i_lock
);
453 inc_zone_page_state(req
->wb_page
, NR_UNSTABLE_NFS
);
454 inc_bdi_stat(req
->wb_page
->mapping
->backing_dev_info
, BDI_RECLAIMABLE
);
455 __mark_inode_dirty(inode
, I_DIRTY_DATASYNC
);
459 nfs_clear_request_commit(struct nfs_page
*req
)
461 struct page
*page
= req
->wb_page
;
463 if (test_and_clear_bit(PG_CLEAN
, &(req
)->wb_flags
)) {
464 dec_zone_page_state(page
, NR_UNSTABLE_NFS
);
465 dec_bdi_stat(page
->mapping
->backing_dev_info
, BDI_RECLAIMABLE
);
472 int nfs_write_need_commit(struct nfs_write_data
*data
)
474 return data
->verf
.committed
!= NFS_FILE_SYNC
;
478 int nfs_reschedule_unstable_write(struct nfs_page
*req
)
480 if (test_and_clear_bit(PG_NEED_COMMIT
, &req
->wb_flags
)) {
481 nfs_mark_request_commit(req
);
484 if (test_and_clear_bit(PG_NEED_RESCHED
, &req
->wb_flags
)) {
485 nfs_mark_request_dirty(req
);
492 nfs_mark_request_commit(struct nfs_page
*req
)
497 nfs_clear_request_commit(struct nfs_page
*req
)
503 int nfs_write_need_commit(struct nfs_write_data
*data
)
509 int nfs_reschedule_unstable_write(struct nfs_page
*req
)
515 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
517 nfs_need_commit(struct nfs_inode
*nfsi
)
519 return radix_tree_tagged(&nfsi
->nfs_page_tree
, NFS_PAGE_TAG_COMMIT
);
523 * nfs_scan_commit - Scan an inode for commit requests
524 * @inode: NFS inode to scan
525 * @dst: destination list
526 * @idx_start: lower bound of page->index to scan.
527 * @npages: idx_start + npages sets the upper bound to scan.
529 * Moves requests from the inode's 'commit' request list.
530 * The requests are *not* checked to ensure that they form a contiguous set.
533 nfs_scan_commit(struct inode
*inode
, struct list_head
*dst
, pgoff_t idx_start
, unsigned int npages
)
535 struct nfs_inode
*nfsi
= NFS_I(inode
);
538 if (!nfs_need_commit(nfsi
))
541 ret
= nfs_scan_list(nfsi
, dst
, idx_start
, npages
, NFS_PAGE_TAG_COMMIT
);
543 nfsi
->ncommit
-= ret
;
544 if (nfs_need_commit(NFS_I(inode
)))
545 __mark_inode_dirty(inode
, I_DIRTY_DATASYNC
);
549 static inline int nfs_need_commit(struct nfs_inode
*nfsi
)
554 static inline int nfs_scan_commit(struct inode
*inode
, struct list_head
*dst
, pgoff_t idx_start
, unsigned int npages
)
561 * Search for an existing write request, and attempt to update
562 * it to reflect a new dirty region on a given page.
564 * If the attempt fails, then the existing request is flushed out
567 static struct nfs_page
*nfs_try_to_update_request(struct inode
*inode
,
572 struct nfs_page
*req
;
577 if (!PagePrivate(page
))
580 end
= offset
+ bytes
;
581 spin_lock(&inode
->i_lock
);
584 req
= nfs_page_find_request_locked(page
);
588 rqend
= req
->wb_offset
+ req
->wb_bytes
;
590 * Tell the caller to flush out the request if
591 * the offsets are non-contiguous.
592 * Note: nfs_flush_incompatible() will already
593 * have flushed out requests having wrong owners.
596 || end
< req
->wb_offset
)
599 if (nfs_set_page_tag_locked(req
))
602 /* The request is locked, so wait and then retry */
603 spin_unlock(&inode
->i_lock
);
604 error
= nfs_wait_on_request(req
);
605 nfs_release_request(req
);
608 spin_lock(&inode
->i_lock
);
611 if (nfs_clear_request_commit(req
) &&
612 radix_tree_tag_clear(&NFS_I(inode
)->nfs_page_tree
,
613 req
->wb_index
, NFS_PAGE_TAG_COMMIT
) != NULL
)
614 NFS_I(inode
)->ncommit
--;
616 /* Okay, the request matches. Update the region */
617 if (offset
< req
->wb_offset
) {
618 req
->wb_offset
= offset
;
619 req
->wb_pgbase
= offset
;
622 req
->wb_bytes
= end
- req
->wb_offset
;
624 req
->wb_bytes
= rqend
- req
->wb_offset
;
626 spin_unlock(&inode
->i_lock
);
629 spin_unlock(&inode
->i_lock
);
630 nfs_release_request(req
);
631 error
= nfs_wb_page(inode
, page
);
633 return ERR_PTR(error
);
637 * Try to update an existing write request, or create one if there is none.
639 * Note: Should always be called with the Page Lock held to prevent races
640 * if we have to add a new request. Also assumes that the caller has
641 * already called nfs_flush_incompatible() if necessary.
643 static struct nfs_page
* nfs_setup_write_request(struct nfs_open_context
* ctx
,
644 struct page
*page
, unsigned int offset
, unsigned int bytes
)
646 struct inode
*inode
= page
->mapping
->host
;
647 struct nfs_page
*req
;
650 req
= nfs_try_to_update_request(inode
, page
, offset
, bytes
);
653 req
= nfs_create_request(ctx
, inode
, page
, offset
, bytes
);
656 error
= nfs_inode_add_request(inode
, req
);
658 nfs_release_request(req
);
659 req
= ERR_PTR(error
);
665 static int nfs_writepage_setup(struct nfs_open_context
*ctx
, struct page
*page
,
666 unsigned int offset
, unsigned int count
)
668 struct nfs_page
*req
;
670 req
= nfs_setup_write_request(ctx
, page
, offset
, count
);
673 nfs_mark_request_dirty(req
);
674 /* Update file length */
675 nfs_grow_file(page
, offset
, count
);
676 nfs_mark_uptodate(page
, req
->wb_pgbase
, req
->wb_bytes
);
677 nfs_mark_request_dirty(req
);
678 nfs_clear_page_tag_locked(req
);
682 int nfs_flush_incompatible(struct file
*file
, struct page
*page
)
684 struct nfs_open_context
*ctx
= nfs_file_open_context(file
);
685 struct nfs_page
*req
;
686 int do_flush
, status
;
688 * Look for a request corresponding to this page. If there
689 * is one, and it belongs to another file, we flush it out
690 * before we try to copy anything into the page. Do this
691 * due to the lack of an ACCESS-type call in NFSv2.
692 * Also do the same if we find a request from an existing
696 req
= nfs_page_find_request(page
);
699 do_flush
= req
->wb_page
!= page
|| req
->wb_context
!= ctx
||
700 req
->wb_lock_context
->lockowner
!= current
->files
||
701 req
->wb_lock_context
->pid
!= current
->tgid
;
702 nfs_release_request(req
);
705 status
= nfs_wb_page(page
->mapping
->host
, page
);
706 } while (status
== 0);
711 * If the page cache is marked as unsafe or invalid, then we can't rely on
712 * the PageUptodate() flag. In this case, we will need to turn off
713 * write optimisations that depend on the page contents being correct.
715 static int nfs_write_pageuptodate(struct page
*page
, struct inode
*inode
)
717 return PageUptodate(page
) &&
718 !(NFS_I(inode
)->cache_validity
& (NFS_INO_REVAL_PAGECACHE
|NFS_INO_INVALID_DATA
));
722 * Update and possibly write a cached page of an NFS file.
724 * XXX: Keep an eye on generic_file_read to make sure it doesn't do bad
725 * things with a page scheduled for an RPC call (e.g. invalidate it).
727 int nfs_updatepage(struct file
*file
, struct page
*page
,
728 unsigned int offset
, unsigned int count
)
730 struct nfs_open_context
*ctx
= nfs_file_open_context(file
);
731 struct inode
*inode
= page
->mapping
->host
;
734 nfs_inc_stats(inode
, NFSIOS_VFSUPDATEPAGE
);
736 dprintk("NFS: nfs_updatepage(%s/%s %d@%lld)\n",
737 file
->f_path
.dentry
->d_parent
->d_name
.name
,
738 file
->f_path
.dentry
->d_name
.name
, count
,
739 (long long)(page_offset(page
) + offset
));
741 /* If we're not using byte range locks, and we know the page
742 * is up to date, it may be more efficient to extend the write
743 * to cover the entire page in order to avoid fragmentation
746 if (nfs_write_pageuptodate(page
, inode
) &&
747 inode
->i_flock
== NULL
&&
748 !(file
->f_flags
& O_DSYNC
)) {
749 count
= max(count
+ offset
, nfs_page_length(page
));
753 status
= nfs_writepage_setup(ctx
, page
, offset
, count
);
755 nfs_set_pageerror(page
);
757 dprintk("NFS: nfs_updatepage returns %d (isize %lld)\n",
758 status
, (long long)i_size_read(inode
));
762 static void nfs_writepage_release(struct nfs_page
*req
)
764 struct page
*page
= req
->wb_page
;
766 if (PageError(req
->wb_page
) || !nfs_reschedule_unstable_write(req
))
767 nfs_inode_remove_request(req
);
768 nfs_clear_page_tag_locked(req
);
769 nfs_end_page_writeback(page
);
772 static int flush_task_priority(int how
)
774 switch (how
& (FLUSH_HIGHPRI
|FLUSH_LOWPRI
)) {
776 return RPC_PRIORITY_HIGH
;
778 return RPC_PRIORITY_LOW
;
780 return RPC_PRIORITY_NORMAL
;
784 * Set up the argument/result storage required for the RPC call.
786 static int nfs_write_rpcsetup(struct nfs_page
*req
,
787 struct nfs_write_data
*data
,
788 const struct rpc_call_ops
*call_ops
,
789 unsigned int count
, unsigned int offset
,
792 struct inode
*inode
= req
->wb_context
->path
.dentry
->d_inode
;
793 int priority
= flush_task_priority(how
);
794 struct rpc_task
*task
;
795 struct rpc_message msg
= {
796 .rpc_argp
= &data
->args
,
797 .rpc_resp
= &data
->res
,
798 .rpc_cred
= req
->wb_context
->cred
,
800 struct rpc_task_setup task_setup_data
= {
801 .rpc_client
= NFS_CLIENT(inode
),
804 .callback_ops
= call_ops
,
805 .callback_data
= data
,
806 .workqueue
= nfsiod_workqueue
,
807 .flags
= RPC_TASK_ASYNC
,
808 .priority
= priority
,
812 /* Set up the RPC argument and reply structs
813 * NB: take care not to mess about with data->commit et al. */
816 data
->inode
= inode
= req
->wb_context
->path
.dentry
->d_inode
;
817 data
->cred
= msg
.rpc_cred
;
819 data
->args
.fh
= NFS_FH(inode
);
820 data
->args
.offset
= req_offset(req
) + offset
;
821 data
->args
.pgbase
= req
->wb_pgbase
+ offset
;
822 data
->args
.pages
= data
->pagevec
;
823 data
->args
.count
= count
;
824 data
->args
.context
= get_nfs_open_context(req
->wb_context
);
825 data
->args
.lock_context
= req
->wb_lock_context
;
826 data
->args
.stable
= NFS_UNSTABLE
;
827 if (how
& FLUSH_STABLE
) {
828 data
->args
.stable
= NFS_DATA_SYNC
;
829 if (!nfs_need_commit(NFS_I(inode
)))
830 data
->args
.stable
= NFS_FILE_SYNC
;
833 data
->res
.fattr
= &data
->fattr
;
834 data
->res
.count
= count
;
835 data
->res
.verf
= &data
->verf
;
836 nfs_fattr_init(&data
->fattr
);
838 /* Set up the initial task struct. */
839 NFS_PROTO(inode
)->write_setup(data
, &msg
);
841 dprintk("NFS: %5u initiated write call "
842 "(req %s/%lld, %u bytes @ offset %llu)\n",
845 (long long)NFS_FILEID(inode
),
847 (unsigned long long)data
->args
.offset
);
849 task
= rpc_run_task(&task_setup_data
);
854 if (how
& FLUSH_SYNC
) {
855 ret
= rpc_wait_for_completion_task(task
);
857 ret
= task
->tk_status
;
864 /* If a nfs_flush_* function fails, it should remove reqs from @head and
865 * call this on each, which will prepare them to be retried on next
866 * writeback using standard nfs.
868 static void nfs_redirty_request(struct nfs_page
*req
)
870 struct page
*page
= req
->wb_page
;
872 nfs_mark_request_dirty(req
);
873 nfs_clear_page_tag_locked(req
);
874 nfs_end_page_writeback(page
);
878 * Generate multiple small requests to write out a single
879 * contiguous dirty area on one page.
881 static int nfs_flush_multi(struct inode
*inode
, struct list_head
*head
, unsigned int npages
, size_t count
, int how
)
883 struct nfs_page
*req
= nfs_list_entry(head
->next
);
884 struct page
*page
= req
->wb_page
;
885 struct nfs_write_data
*data
;
886 size_t wsize
= NFS_SERVER(inode
)->wsize
, nbytes
;
892 nfs_list_remove_request(req
);
896 size_t len
= min(nbytes
, wsize
);
898 data
= nfs_writedata_alloc(1);
901 list_add(&data
->pages
, &list
);
904 } while (nbytes
!= 0);
905 atomic_set(&req
->wb_complete
, requests
);
907 ClearPageError(page
);
913 data
= list_entry(list
.next
, struct nfs_write_data
, pages
);
914 list_del_init(&data
->pages
);
916 data
->pagevec
[0] = page
;
920 ret2
= nfs_write_rpcsetup(req
, data
, &nfs_write_partial_ops
,
926 } while (nbytes
!= 0);
931 while (!list_empty(&list
)) {
932 data
= list_entry(list
.next
, struct nfs_write_data
, pages
);
933 list_del(&data
->pages
);
934 nfs_writedata_release(data
);
936 nfs_redirty_request(req
);
941 * Create an RPC task for the given write request and kick it.
942 * The page must have been locked by the caller.
944 * It may happen that the page we're passed is not marked dirty.
945 * This is the case if nfs_updatepage detects a conflicting request
946 * that has been written but not committed.
948 static int nfs_flush_one(struct inode
*inode
, struct list_head
*head
, unsigned int npages
, size_t count
, int how
)
950 struct nfs_page
*req
;
952 struct nfs_write_data
*data
;
954 data
= nfs_writedata_alloc(npages
);
958 pages
= data
->pagevec
;
959 while (!list_empty(head
)) {
960 req
= nfs_list_entry(head
->next
);
961 nfs_list_remove_request(req
);
962 nfs_list_add_request(req
, &data
->pages
);
963 ClearPageError(req
->wb_page
);
964 *pages
++ = req
->wb_page
;
966 req
= nfs_list_entry(data
->pages
.next
);
968 /* Set up the argument struct */
969 return nfs_write_rpcsetup(req
, data
, &nfs_write_full_ops
, count
, 0, how
);
971 while (!list_empty(head
)) {
972 req
= nfs_list_entry(head
->next
);
973 nfs_list_remove_request(req
);
974 nfs_redirty_request(req
);
979 static void nfs_pageio_init_write(struct nfs_pageio_descriptor
*pgio
,
980 struct inode
*inode
, int ioflags
)
982 size_t wsize
= NFS_SERVER(inode
)->wsize
;
984 if (wsize
< PAGE_CACHE_SIZE
)
985 nfs_pageio_init(pgio
, inode
, nfs_flush_multi
, wsize
, ioflags
);
987 nfs_pageio_init(pgio
, inode
, nfs_flush_one
, wsize
, ioflags
);
991 * Handle a write reply that flushed part of a page.
993 static void nfs_writeback_done_partial(struct rpc_task
*task
, void *calldata
)
995 struct nfs_write_data
*data
= calldata
;
997 dprintk("NFS: %5u write(%s/%lld %d@%lld)",
999 data
->req
->wb_context
->path
.dentry
->d_inode
->i_sb
->s_id
,
1001 NFS_FILEID(data
->req
->wb_context
->path
.dentry
->d_inode
),
1002 data
->req
->wb_bytes
, (long long)req_offset(data
->req
));
1004 nfs_writeback_done(task
, data
);
1007 static void nfs_writeback_release_partial(void *calldata
)
1009 struct nfs_write_data
*data
= calldata
;
1010 struct nfs_page
*req
= data
->req
;
1011 struct page
*page
= req
->wb_page
;
1012 int status
= data
->task
.tk_status
;
1015 nfs_set_pageerror(page
);
1016 nfs_context_set_write_error(req
->wb_context
, status
);
1017 dprintk(", error = %d\n", status
);
1021 if (nfs_write_need_commit(data
)) {
1022 struct inode
*inode
= page
->mapping
->host
;
1024 spin_lock(&inode
->i_lock
);
1025 if (test_bit(PG_NEED_RESCHED
, &req
->wb_flags
)) {
1026 /* Do nothing we need to resend the writes */
1027 } else if (!test_and_set_bit(PG_NEED_COMMIT
, &req
->wb_flags
)) {
1028 memcpy(&req
->wb_verf
, &data
->verf
, sizeof(req
->wb_verf
));
1029 dprintk(" defer commit\n");
1030 } else if (memcmp(&req
->wb_verf
, &data
->verf
, sizeof(req
->wb_verf
))) {
1031 set_bit(PG_NEED_RESCHED
, &req
->wb_flags
);
1032 clear_bit(PG_NEED_COMMIT
, &req
->wb_flags
);
1033 dprintk(" server reboot detected\n");
1035 spin_unlock(&inode
->i_lock
);
1040 if (atomic_dec_and_test(&req
->wb_complete
))
1041 nfs_writepage_release(req
);
1042 nfs_writedata_release(calldata
);
1045 #if defined(CONFIG_NFS_V4_1)
1046 void nfs_write_prepare(struct rpc_task
*task
, void *calldata
)
1048 struct nfs_write_data
*data
= calldata
;
1050 if (nfs4_setup_sequence(NFS_SERVER(data
->inode
),
1051 &data
->args
.seq_args
,
1052 &data
->res
.seq_res
, 1, task
))
1054 rpc_call_start(task
);
1056 #endif /* CONFIG_NFS_V4_1 */
1058 static const struct rpc_call_ops nfs_write_partial_ops
= {
1059 #if defined(CONFIG_NFS_V4_1)
1060 .rpc_call_prepare
= nfs_write_prepare
,
1061 #endif /* CONFIG_NFS_V4_1 */
1062 .rpc_call_done
= nfs_writeback_done_partial
,
1063 .rpc_release
= nfs_writeback_release_partial
,
1067 * Handle a write reply that flushes a whole page.
1069 * FIXME: There is an inherent race with invalidate_inode_pages and
1070 * writebacks since the page->count is kept > 1 for as long
1071 * as the page has a write request pending.
1073 static void nfs_writeback_done_full(struct rpc_task
*task
, void *calldata
)
1075 struct nfs_write_data
*data
= calldata
;
1077 nfs_writeback_done(task
, data
);
1080 static void nfs_writeback_release_full(void *calldata
)
1082 struct nfs_write_data
*data
= calldata
;
1083 int status
= data
->task
.tk_status
;
1085 /* Update attributes as result of writeback. */
1086 while (!list_empty(&data
->pages
)) {
1087 struct nfs_page
*req
= nfs_list_entry(data
->pages
.next
);
1088 struct page
*page
= req
->wb_page
;
1090 nfs_list_remove_request(req
);
1092 dprintk("NFS: %5u write (%s/%lld %d@%lld)",
1094 req
->wb_context
->path
.dentry
->d_inode
->i_sb
->s_id
,
1095 (long long)NFS_FILEID(req
->wb_context
->path
.dentry
->d_inode
),
1097 (long long)req_offset(req
));
1100 nfs_set_pageerror(page
);
1101 nfs_context_set_write_error(req
->wb_context
, status
);
1102 dprintk(", error = %d\n", status
);
1103 goto remove_request
;
1106 if (nfs_write_need_commit(data
)) {
1107 memcpy(&req
->wb_verf
, &data
->verf
, sizeof(req
->wb_verf
));
1108 nfs_mark_request_commit(req
);
1109 dprintk(" marked for commit\n");
1114 nfs_inode_remove_request(req
);
1116 nfs_clear_page_tag_locked(req
);
1117 nfs_end_page_writeback(page
);
1119 nfs_writedata_release(calldata
);
1122 static const struct rpc_call_ops nfs_write_full_ops
= {
1123 #if defined(CONFIG_NFS_V4_1)
1124 .rpc_call_prepare
= nfs_write_prepare
,
1125 #endif /* CONFIG_NFS_V4_1 */
1126 .rpc_call_done
= nfs_writeback_done_full
,
1127 .rpc_release
= nfs_writeback_release_full
,
1132 * This function is called when the WRITE call is complete.
1134 int nfs_writeback_done(struct rpc_task
*task
, struct nfs_write_data
*data
)
1136 struct nfs_writeargs
*argp
= &data
->args
;
1137 struct nfs_writeres
*resp
= &data
->res
;
1138 struct nfs_server
*server
= NFS_SERVER(data
->inode
);
1141 dprintk("NFS: %5u nfs_writeback_done (status %d)\n",
1142 task
->tk_pid
, task
->tk_status
);
1145 * ->write_done will attempt to use post-op attributes to detect
1146 * conflicting writes by other clients. A strict interpretation
1147 * of close-to-open would allow us to continue caching even if
1148 * another writer had changed the file, but some applications
1149 * depend on tighter cache coherency when writing.
1151 status
= NFS_PROTO(data
->inode
)->write_done(task
, data
);
1154 nfs_add_stats(data
->inode
, NFSIOS_SERVERWRITTENBYTES
, resp
->count
);
1156 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
1157 if (resp
->verf
->committed
< argp
->stable
&& task
->tk_status
>= 0) {
1158 /* We tried a write call, but the server did not
1159 * commit data to stable storage even though we
1161 * Note: There is a known bug in Tru64 < 5.0 in which
1162 * the server reports NFS_DATA_SYNC, but performs
1163 * NFS_FILE_SYNC. We therefore implement this checking
1164 * as a dprintk() in order to avoid filling syslog.
1166 static unsigned long complain
;
1168 if (time_before(complain
, jiffies
)) {
1169 dprintk("NFS: faulty NFS server %s:"
1170 " (committed = %d) != (stable = %d)\n",
1171 server
->nfs_client
->cl_hostname
,
1172 resp
->verf
->committed
, argp
->stable
);
1173 complain
= jiffies
+ 300 * HZ
;
1177 /* Is this a short write? */
1178 if (task
->tk_status
>= 0 && resp
->count
< argp
->count
) {
1179 static unsigned long complain
;
1181 nfs_inc_stats(data
->inode
, NFSIOS_SHORTWRITE
);
1183 /* Has the server at least made some progress? */
1184 if (resp
->count
!= 0) {
1185 /* Was this an NFSv2 write or an NFSv3 stable write? */
1186 if (resp
->verf
->committed
!= NFS_UNSTABLE
) {
1187 /* Resend from where the server left off */
1188 argp
->offset
+= resp
->count
;
1189 argp
->pgbase
+= resp
->count
;
1190 argp
->count
-= resp
->count
;
1192 /* Resend as a stable write in order to avoid
1193 * headaches in the case of a server crash.
1195 argp
->stable
= NFS_FILE_SYNC
;
1197 nfs_restart_rpc(task
, server
->nfs_client
);
1200 if (time_before(complain
, jiffies
)) {
1202 "NFS: Server wrote zero bytes, expected %u.\n",
1204 complain
= jiffies
+ 300 * HZ
;
1206 /* Can't do anything about it except throw an error. */
1207 task
->tk_status
= -EIO
;
1213 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
1214 static int nfs_commit_set_lock(struct nfs_inode
*nfsi
, int may_wait
)
1216 if (!test_and_set_bit(NFS_INO_COMMIT
, &nfsi
->flags
))
1218 if (may_wait
&& !out_of_line_wait_on_bit_lock(&nfsi
->flags
,
1219 NFS_INO_COMMIT
, nfs_wait_bit_killable
,
1225 static void nfs_commit_clear_lock(struct nfs_inode
*nfsi
)
1227 clear_bit(NFS_INO_COMMIT
, &nfsi
->flags
);
1228 smp_mb__after_clear_bit();
1229 wake_up_bit(&nfsi
->flags
, NFS_INO_COMMIT
);
1233 static void nfs_commitdata_release(void *data
)
1235 struct nfs_write_data
*wdata
= data
;
1237 put_nfs_open_context(wdata
->args
.context
);
1238 nfs_commit_free(wdata
);
1242 * Set up the argument/result storage required for the RPC call.
1244 static int nfs_commit_rpcsetup(struct list_head
*head
,
1245 struct nfs_write_data
*data
,
1248 struct nfs_page
*first
= nfs_list_entry(head
->next
);
1249 struct inode
*inode
= first
->wb_context
->path
.dentry
->d_inode
;
1250 int priority
= flush_task_priority(how
);
1251 struct rpc_task
*task
;
1252 struct rpc_message msg
= {
1253 .rpc_argp
= &data
->args
,
1254 .rpc_resp
= &data
->res
,
1255 .rpc_cred
= first
->wb_context
->cred
,
1257 struct rpc_task_setup task_setup_data
= {
1258 .task
= &data
->task
,
1259 .rpc_client
= NFS_CLIENT(inode
),
1260 .rpc_message
= &msg
,
1261 .callback_ops
= &nfs_commit_ops
,
1262 .callback_data
= data
,
1263 .workqueue
= nfsiod_workqueue
,
1264 .flags
= RPC_TASK_ASYNC
,
1265 .priority
= priority
,
1268 /* Set up the RPC argument and reply structs
1269 * NB: take care not to mess about with data->commit et al. */
1271 list_splice_init(head
, &data
->pages
);
1273 data
->inode
= inode
;
1274 data
->cred
= msg
.rpc_cred
;
1276 data
->args
.fh
= NFS_FH(data
->inode
);
1277 /* Note: we always request a commit of the entire inode */
1278 data
->args
.offset
= 0;
1279 data
->args
.count
= 0;
1280 data
->args
.context
= get_nfs_open_context(first
->wb_context
);
1281 data
->res
.count
= 0;
1282 data
->res
.fattr
= &data
->fattr
;
1283 data
->res
.verf
= &data
->verf
;
1284 nfs_fattr_init(&data
->fattr
);
1286 /* Set up the initial task struct. */
1287 NFS_PROTO(inode
)->commit_setup(data
, &msg
);
1289 dprintk("NFS: %5u initiated commit call\n", data
->task
.tk_pid
);
1291 task
= rpc_run_task(&task_setup_data
);
1293 return PTR_ERR(task
);
1299 * Commit dirty pages
1302 nfs_commit_list(struct inode
*inode
, struct list_head
*head
, int how
)
1304 struct nfs_write_data
*data
;
1305 struct nfs_page
*req
;
1307 data
= nfs_commitdata_alloc();
1312 /* Set up the argument struct */
1313 return nfs_commit_rpcsetup(head
, data
, how
);
1315 while (!list_empty(head
)) {
1316 req
= nfs_list_entry(head
->next
);
1317 nfs_list_remove_request(req
);
1318 nfs_mark_request_commit(req
);
1319 dec_zone_page_state(req
->wb_page
, NR_UNSTABLE_NFS
);
1320 dec_bdi_stat(req
->wb_page
->mapping
->backing_dev_info
,
1322 nfs_clear_page_tag_locked(req
);
1324 nfs_commit_clear_lock(NFS_I(inode
));
1329 * COMMIT call returned
1331 static void nfs_commit_done(struct rpc_task
*task
, void *calldata
)
1333 struct nfs_write_data
*data
= calldata
;
1335 dprintk("NFS: %5u nfs_commit_done (status %d)\n",
1336 task
->tk_pid
, task
->tk_status
);
1338 /* Call the NFS version-specific code */
1339 if (NFS_PROTO(data
->inode
)->commit_done(task
, data
) != 0)
1343 static void nfs_commit_release(void *calldata
)
1345 struct nfs_write_data
*data
= calldata
;
1346 struct nfs_page
*req
;
1347 int status
= data
->task
.tk_status
;
1349 while (!list_empty(&data
->pages
)) {
1350 req
= nfs_list_entry(data
->pages
.next
);
1351 nfs_list_remove_request(req
);
1352 nfs_clear_request_commit(req
);
1354 dprintk("NFS: commit (%s/%lld %d@%lld)",
1355 req
->wb_context
->path
.dentry
->d_inode
->i_sb
->s_id
,
1356 (long long)NFS_FILEID(req
->wb_context
->path
.dentry
->d_inode
),
1358 (long long)req_offset(req
));
1360 nfs_context_set_write_error(req
->wb_context
, status
);
1361 nfs_inode_remove_request(req
);
1362 dprintk(", error = %d\n", status
);
1366 /* Okay, COMMIT succeeded, apparently. Check the verifier
1367 * returned by the server against all stored verfs. */
1368 if (!memcmp(req
->wb_verf
.verifier
, data
->verf
.verifier
, sizeof(data
->verf
.verifier
))) {
1369 /* We have a match */
1370 nfs_inode_remove_request(req
);
1374 /* We have a mismatch. Write the page again */
1375 dprintk(" mismatch\n");
1376 nfs_mark_request_dirty(req
);
1378 nfs_clear_page_tag_locked(req
);
1380 nfs_commit_clear_lock(NFS_I(data
->inode
));
1381 nfs_commitdata_release(calldata
);
1384 static const struct rpc_call_ops nfs_commit_ops
= {
1385 #if defined(CONFIG_NFS_V4_1)
1386 .rpc_call_prepare
= nfs_write_prepare
,
1387 #endif /* CONFIG_NFS_V4_1 */
1388 .rpc_call_done
= nfs_commit_done
,
1389 .rpc_release
= nfs_commit_release
,
1392 int nfs_commit_inode(struct inode
*inode
, int how
)
1395 int may_wait
= how
& FLUSH_SYNC
;
1398 if (!nfs_commit_set_lock(NFS_I(inode
), may_wait
))
1399 goto out_mark_dirty
;
1400 spin_lock(&inode
->i_lock
);
1401 res
= nfs_scan_commit(inode
, &head
, 0, 0);
1402 spin_unlock(&inode
->i_lock
);
1404 int error
= nfs_commit_list(inode
, &head
, how
);
1408 wait_on_bit(&NFS_I(inode
)->flags
, NFS_INO_COMMIT
,
1409 nfs_wait_bit_killable
,
1412 goto out_mark_dirty
;
1414 nfs_commit_clear_lock(NFS_I(inode
));
1416 /* Note: If we exit without ensuring that the commit is complete,
1417 * we must mark the inode as dirty. Otherwise, future calls to
1418 * sync_inode() with the WB_SYNC_ALL flag set will fail to ensure
1419 * that the data is on the disk.
1422 __mark_inode_dirty(inode
, I_DIRTY_DATASYNC
);
1426 static int nfs_commit_unstable_pages(struct inode
*inode
, struct writeback_control
*wbc
)
1428 struct nfs_inode
*nfsi
= NFS_I(inode
);
1429 int flags
= FLUSH_SYNC
;
1432 if (wbc
->sync_mode
== WB_SYNC_NONE
) {
1433 /* Don't commit yet if this is a non-blocking flush and there
1434 * are a lot of outstanding writes for this mapping.
1436 if (nfsi
->ncommit
<= (nfsi
->npages
>> 1))
1437 goto out_mark_dirty
;
1439 /* don't wait for the COMMIT response */
1443 ret
= nfs_commit_inode(inode
, flags
);
1445 if (wbc
->sync_mode
== WB_SYNC_NONE
) {
1446 if (ret
< wbc
->nr_to_write
)
1447 wbc
->nr_to_write
-= ret
;
1449 wbc
->nr_to_write
= 0;
1454 __mark_inode_dirty(inode
, I_DIRTY_DATASYNC
);
1458 static int nfs_commit_unstable_pages(struct inode
*inode
, struct writeback_control
*wbc
)
1464 int nfs_write_inode(struct inode
*inode
, struct writeback_control
*wbc
)
1466 return nfs_commit_unstable_pages(inode
, wbc
);
1470 * flush the inode to disk.
1472 int nfs_wb_all(struct inode
*inode
)
1474 struct writeback_control wbc
= {
1475 .sync_mode
= WB_SYNC_ALL
,
1476 .nr_to_write
= LONG_MAX
,
1478 .range_end
= LLONG_MAX
,
1481 return sync_inode(inode
, &wbc
);
1484 int nfs_wb_page_cancel(struct inode
*inode
, struct page
*page
)
1486 struct nfs_page
*req
;
1489 BUG_ON(!PageLocked(page
));
1491 wait_on_page_writeback(page
);
1492 req
= nfs_page_find_request(page
);
1495 if (nfs_lock_request_dontget(req
)) {
1496 nfs_inode_remove_request(req
);
1498 * In case nfs_inode_remove_request has marked the
1499 * page as being dirty
1501 cancel_dirty_page(page
, PAGE_CACHE_SIZE
);
1502 nfs_unlock_request(req
);
1505 ret
= nfs_wait_on_request(req
);
1506 nfs_release_request(req
);
1514 * Write back all requests on one page - we do this before reading it.
1516 int nfs_wb_page(struct inode
*inode
, struct page
*page
)
1518 loff_t range_start
= page_offset(page
);
1519 loff_t range_end
= range_start
+ (loff_t
)(PAGE_CACHE_SIZE
- 1);
1520 struct writeback_control wbc
= {
1521 .sync_mode
= WB_SYNC_ALL
,
1523 .range_start
= range_start
,
1524 .range_end
= range_end
,
1529 wait_on_page_writeback(page
);
1530 if (clear_page_dirty_for_io(page
)) {
1531 ret
= nfs_writepage_locked(page
, &wbc
);
1536 if (!PagePrivate(page
))
1538 ret
= nfs_commit_inode(inode
, FLUSH_SYNC
);
1547 #ifdef CONFIG_MIGRATION
1548 int nfs_migrate_page(struct address_space
*mapping
, struct page
*newpage
,
1551 struct nfs_page
*req
;
1554 nfs_fscache_release_page(page
, GFP_KERNEL
);
1556 req
= nfs_find_and_lock_request(page
, false);
1561 ret
= migrate_page(mapping
, newpage
, page
);
1566 page_cache_get(newpage
);
1567 spin_lock(&mapping
->host
->i_lock
);
1568 req
->wb_page
= newpage
;
1569 SetPagePrivate(newpage
);
1570 set_page_private(newpage
, (unsigned long)req
);
1571 ClearPagePrivate(page
);
1572 set_page_private(page
, 0);
1573 spin_unlock(&mapping
->host
->i_lock
);
1574 page_cache_release(page
);
1576 nfs_clear_page_tag_locked(req
);
1582 int __init
nfs_init_writepagecache(void)
1584 nfs_wdata_cachep
= kmem_cache_create("nfs_write_data",
1585 sizeof(struct nfs_write_data
),
1586 0, SLAB_HWCACHE_ALIGN
,
1588 if (nfs_wdata_cachep
== NULL
)
1591 nfs_wdata_mempool
= mempool_create_slab_pool(MIN_POOL_WRITE
,
1593 if (nfs_wdata_mempool
== NULL
)
1596 nfs_commit_mempool
= mempool_create_slab_pool(MIN_POOL_COMMIT
,
1598 if (nfs_commit_mempool
== NULL
)
1602 * NFS congestion size, scale with available memory.
1614 * This allows larger machines to have larger/more transfers.
1615 * Limit the default to 256M
1617 nfs_congestion_kb
= (16*int_sqrt(totalram_pages
)) << (PAGE_SHIFT
-10);
1618 if (nfs_congestion_kb
> 256*1024)
1619 nfs_congestion_kb
= 256*1024;
1624 void nfs_destroy_writepagecache(void)
1626 mempool_destroy(nfs_commit_mempool
);
1627 mempool_destroy(nfs_wdata_mempool
);
1628 kmem_cache_destroy(nfs_wdata_cachep
);