4 * Writing file data over NFS.
6 * We do it like this: When a (user) process wishes to write data to an
7 * NFS file, a write request is allocated that contains the RPC task data
8 * plus some info on the page to be written, and added to the inode's
9 * write chain. If the process writes past the end of the page, an async
10 * RPC call to write the page is scheduled immediately; otherwise, the call
11 * is delayed for a few seconds.
13 * Just like readahead, no async I/O is performed if wsize < PAGE_SIZE.
15 * Write requests are kept on the inode's writeback list. Each entry in
16 * that list references the page (portion) to be written. When the
17 * cache timeout has expired, the RPC task is woken up, and tries to
18 * lock the page. As soon as it manages to do so, the request is moved
19 * from the writeback list to the writelock list.
21 * Note: we must make sure never to confuse the inode passed in the
22 * write_page request with the one in page->inode. As far as I understand
23 * it, these are different when doing a swap-out.
25 * To understand everything that goes on here and in the NFS read code,
26 * one should be aware that a page is locked in exactly one of the following
29 * - A write request is in progress.
30 * - A user process is in generic_file_write/nfs_update_page
31 * - A user process is in generic_file_read
33 * Also note that because of the way pages are invalidated in
34 * nfs_revalidate_inode, the following assertions hold:
36 * - If a page is dirty, there will be no read requests (a page will
37 * not be re-read unless invalidated by nfs_revalidate_inode).
38 * - If the page is not uptodate, there will be no pending write
39 * requests, and no process will be in nfs_update_page.
41 * FIXME: Interaction with the vmscan routines is not optimal yet.
42 * Either vmscan must be made nfs-savvy, or we need a different page
43 * reclaim concept that supports something like FS-independent
44 * buffer_heads with a b_ops-> field.
46 * Copyright (C) 1996, 1997, Olaf Kirch <okir@monad.swb.de>
49 #include <linux/types.h>
50 #include <linux/slab.h>
52 #include <linux/pagemap.h>
53 #include <linux/file.h>
54 #include <linux/writeback.h>
56 #include <linux/sunrpc/clnt.h>
57 #include <linux/nfs_fs.h>
58 #include <linux/nfs_mount.h>
59 #include <linux/nfs_page.h>
60 #include <linux/backing-dev.h>
62 #include <asm/uaccess.h>
63 #include <linux/smp_lock.h>
65 #include "delegation.h"
68 #define NFSDBG_FACILITY NFSDBG_PAGECACHE
70 #define MIN_POOL_WRITE (32)
71 #define MIN_POOL_COMMIT (4)
74 * Local function declarations
76 static struct nfs_page
* nfs_update_request(struct nfs_open_context
*,
79 unsigned int, unsigned int);
80 static int nfs_wait_on_write_congestion(struct address_space
*, int);
81 static int nfs_wait_on_requests(struct inode
*, unsigned long, unsigned int);
82 static long nfs_flush_mapping(struct address_space
*mapping
, struct writeback_control
*wbc
, int how
);
83 static const struct rpc_call_ops nfs_write_partial_ops
;
84 static const struct rpc_call_ops nfs_write_full_ops
;
85 static const struct rpc_call_ops nfs_commit_ops
;
87 static kmem_cache_t
*nfs_wdata_cachep
;
88 static mempool_t
*nfs_wdata_mempool
;
89 static mempool_t
*nfs_commit_mempool
;
91 static DECLARE_WAIT_QUEUE_HEAD(nfs_write_congestion
);
93 struct nfs_write_data
*nfs_commit_alloc(void)
95 struct nfs_write_data
*p
= mempool_alloc(nfs_commit_mempool
, SLAB_NOFS
);
98 memset(p
, 0, sizeof(*p
));
99 INIT_LIST_HEAD(&p
->pages
);
104 void nfs_commit_rcu_free(struct rcu_head
*head
)
106 struct nfs_write_data
*p
= container_of(head
, struct nfs_write_data
, task
.u
.tk_rcu
);
107 if (p
&& (p
->pagevec
!= &p
->page_array
[0]))
109 mempool_free(p
, nfs_commit_mempool
);
112 void nfs_commit_free(struct nfs_write_data
*wdata
)
114 call_rcu_bh(&wdata
->task
.u
.tk_rcu
, nfs_commit_rcu_free
);
117 struct nfs_write_data
*nfs_writedata_alloc(size_t len
)
119 unsigned int pagecount
= (len
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
120 struct nfs_write_data
*p
= mempool_alloc(nfs_wdata_mempool
, SLAB_NOFS
);
123 memset(p
, 0, sizeof(*p
));
124 INIT_LIST_HEAD(&p
->pages
);
125 p
->npages
= pagecount
;
126 if (pagecount
<= ARRAY_SIZE(p
->page_array
))
127 p
->pagevec
= p
->page_array
;
129 p
->pagevec
= kcalloc(pagecount
, sizeof(struct page
*), GFP_NOFS
);
131 mempool_free(p
, nfs_wdata_mempool
);
139 static void nfs_writedata_rcu_free(struct rcu_head
*head
)
141 struct nfs_write_data
*p
= container_of(head
, struct nfs_write_data
, task
.u
.tk_rcu
);
142 if (p
&& (p
->pagevec
!= &p
->page_array
[0]))
144 mempool_free(p
, nfs_wdata_mempool
);
147 static void nfs_writedata_free(struct nfs_write_data
*wdata
)
149 call_rcu_bh(&wdata
->task
.u
.tk_rcu
, nfs_writedata_rcu_free
);
152 void nfs_writedata_release(void *wdata
)
154 nfs_writedata_free(wdata
);
157 /* Adjust the file length if we're writing beyond the end */
158 static void nfs_grow_file(struct page
*page
, unsigned int offset
, unsigned int count
)
160 struct inode
*inode
= page
->mapping
->host
;
161 loff_t end
, i_size
= i_size_read(inode
);
162 unsigned long end_index
= (i_size
- 1) >> PAGE_CACHE_SHIFT
;
164 if (i_size
> 0 && page
->index
< end_index
)
166 end
= ((loff_t
)page
->index
<< PAGE_CACHE_SHIFT
) + ((loff_t
)offset
+count
);
169 nfs_inc_stats(inode
, NFSIOS_EXTENDWRITE
);
170 i_size_write(inode
, end
);
173 /* We can set the PG_uptodate flag if we see that a write request
174 * covers the full page.
176 static void nfs_mark_uptodate(struct page
*page
, unsigned int base
, unsigned int count
)
180 if (PageUptodate(page
))
184 if (count
== PAGE_CACHE_SIZE
) {
185 SetPageUptodate(page
);
189 end_offs
= i_size_read(page
->mapping
->host
) - 1;
192 /* Is this the last page? */
193 if (page
->index
!= (unsigned long)(end_offs
>> PAGE_CACHE_SHIFT
))
195 /* This is the last page: set PG_uptodate if we cover the entire
196 * extent of the data, then zero the rest of the page.
198 if (count
== (unsigned int)(end_offs
& (PAGE_CACHE_SIZE
- 1)) + 1) {
199 memclear_highpage_flush(page
, count
, PAGE_CACHE_SIZE
- count
);
200 SetPageUptodate(page
);
205 * Write a page synchronously.
206 * Offset is the data offset within the page.
208 static int nfs_writepage_sync(struct nfs_open_context
*ctx
, struct inode
*inode
,
209 struct page
*page
, unsigned int offset
, unsigned int count
,
212 unsigned int wsize
= NFS_SERVER(inode
)->wsize
;
213 int result
, written
= 0;
214 struct nfs_write_data
*wdata
;
216 wdata
= nfs_writedata_alloc(wsize
);
221 wdata
->cred
= ctx
->cred
;
222 wdata
->inode
= inode
;
223 wdata
->args
.fh
= NFS_FH(inode
);
224 wdata
->args
.context
= ctx
;
225 wdata
->args
.pages
= &page
;
226 wdata
->args
.stable
= NFS_FILE_SYNC
;
227 wdata
->args
.pgbase
= offset
;
228 wdata
->args
.count
= wsize
;
229 wdata
->res
.fattr
= &wdata
->fattr
;
230 wdata
->res
.verf
= &wdata
->verf
;
232 dprintk("NFS: nfs_writepage_sync(%s/%Ld %d@%Ld)\n",
234 (long long)NFS_FILEID(inode
),
235 count
, (long long)(page_offset(page
) + offset
));
237 set_page_writeback(page
);
238 nfs_begin_data_update(inode
);
241 wdata
->args
.count
= count
;
242 wdata
->args
.offset
= page_offset(page
) + wdata
->args
.pgbase
;
244 result
= NFS_PROTO(inode
)->write(wdata
);
247 /* Must mark the page invalid after I/O error */
248 ClearPageUptodate(page
);
251 if (result
< wdata
->args
.count
)
252 printk(KERN_WARNING
"NFS: short write, count=%u, result=%d\n",
253 wdata
->args
.count
, result
);
255 wdata
->args
.offset
+= result
;
256 wdata
->args
.pgbase
+= result
;
259 nfs_add_stats(inode
, NFSIOS_SERVERWRITTENBYTES
, result
);
261 /* Update file length */
262 nfs_grow_file(page
, offset
, written
);
263 /* Set the PG_uptodate flag? */
264 nfs_mark_uptodate(page
, offset
, written
);
267 ClearPageError(page
);
270 nfs_end_data_update(inode
);
271 end_page_writeback(page
);
272 nfs_writedata_release(wdata
);
273 return written
? written
: result
;
276 static int nfs_writepage_async(struct nfs_open_context
*ctx
,
277 struct inode
*inode
, struct page
*page
,
278 unsigned int offset
, unsigned int count
)
280 struct nfs_page
*req
;
282 req
= nfs_update_request(ctx
, inode
, page
, offset
, count
);
285 /* Update file length */
286 nfs_grow_file(page
, offset
, count
);
287 /* Set the PG_uptodate flag? */
288 nfs_mark_uptodate(page
, offset
, count
);
289 nfs_unlock_request(req
);
293 static int wb_priority(struct writeback_control
*wbc
)
295 if (wbc
->for_reclaim
)
296 return FLUSH_HIGHPRI
;
297 if (wbc
->for_kupdate
)
303 * Write an mmapped page to the server.
305 int nfs_writepage(struct page
*page
, struct writeback_control
*wbc
)
307 struct nfs_open_context
*ctx
;
308 struct inode
*inode
= page
->mapping
->host
;
309 unsigned long end_index
;
310 unsigned offset
= PAGE_CACHE_SIZE
;
311 loff_t i_size
= i_size_read(inode
);
312 int inode_referenced
= 0;
313 int priority
= wb_priority(wbc
);
316 nfs_inc_stats(inode
, NFSIOS_VFSWRITEPAGE
);
317 nfs_add_stats(inode
, NFSIOS_WRITEPAGES
, 1);
320 * Note: We need to ensure that we have a reference to the inode
321 * if we are to do asynchronous writes. If not, waiting
322 * in nfs_wait_on_request() may deadlock with clear_inode().
324 * If igrab() fails here, then it is in any case safe to
325 * call nfs_wb_page(), since there will be no pending writes.
327 if (igrab(inode
) != 0)
328 inode_referenced
= 1;
329 end_index
= i_size
>> PAGE_CACHE_SHIFT
;
331 /* Ensure we've flushed out any previous writes */
332 nfs_wb_page_priority(inode
, page
, priority
);
335 if (page
->index
< end_index
)
337 /* things got complicated... */
338 offset
= i_size
& (PAGE_CACHE_SIZE
-1);
340 /* OK, are we completely out? */
341 err
= 0; /* potential race with truncate - ignore */
342 if (page
->index
>= end_index
+1 || !offset
)
345 ctx
= nfs_find_open_context(inode
, NULL
, FMODE_WRITE
);
351 if (!IS_SYNC(inode
) && inode_referenced
) {
352 err
= nfs_writepage_async(ctx
, inode
, page
, 0, offset
);
353 if (!wbc
->for_writepages
)
354 nfs_flush_mapping(page
->mapping
, wbc
, wb_priority(wbc
));
356 err
= nfs_writepage_sync(ctx
, inode
, page
, 0,
360 redirty_page_for_writepage(wbc
, page
);
365 put_nfs_open_context(ctx
);
368 if (inode_referenced
)
374 * Note: causes nfs_update_request() to block on the assumption
375 * that the writeback is generated due to memory pressure.
377 int nfs_writepages(struct address_space
*mapping
, struct writeback_control
*wbc
)
379 struct backing_dev_info
*bdi
= mapping
->backing_dev_info
;
380 struct inode
*inode
= mapping
->host
;
383 nfs_inc_stats(inode
, NFSIOS_VFSWRITEPAGES
);
385 err
= generic_writepages(mapping
, wbc
);
388 while (test_and_set_bit(BDI_write_congested
, &bdi
->state
) != 0) {
389 if (wbc
->nonblocking
)
391 nfs_wait_on_write_congestion(mapping
, 0);
393 err
= nfs_flush_mapping(mapping
, wbc
, wb_priority(wbc
));
396 nfs_add_stats(inode
, NFSIOS_WRITEPAGES
, err
);
397 if (!wbc
->nonblocking
&& wbc
->sync_mode
== WB_SYNC_ALL
) {
398 err
= nfs_wait_on_requests(inode
, 0, 0);
402 err
= nfs_commit_inode(inode
, wb_priority(wbc
));
406 clear_bit(BDI_write_congested
, &bdi
->state
);
407 wake_up_all(&nfs_write_congestion
);
408 congestion_end(WRITE
);
413 * Insert a write request into an inode
415 static int nfs_inode_add_request(struct inode
*inode
, struct nfs_page
*req
)
417 struct nfs_inode
*nfsi
= NFS_I(inode
);
420 error
= radix_tree_insert(&nfsi
->nfs_page_tree
, req
->wb_index
, req
);
421 BUG_ON(error
== -EEXIST
);
426 nfs_begin_data_update(inode
);
427 if (nfs_have_delegation(inode
, FMODE_WRITE
))
430 SetPagePrivate(req
->wb_page
);
432 atomic_inc(&req
->wb_count
);
437 * Insert a write request into an inode
439 static void nfs_inode_remove_request(struct nfs_page
*req
)
441 struct inode
*inode
= req
->wb_context
->dentry
->d_inode
;
442 struct nfs_inode
*nfsi
= NFS_I(inode
);
444 BUG_ON (!NFS_WBACK_BUSY(req
));
446 spin_lock(&nfsi
->req_lock
);
447 ClearPagePrivate(req
->wb_page
);
448 radix_tree_delete(&nfsi
->nfs_page_tree
, req
->wb_index
);
451 spin_unlock(&nfsi
->req_lock
);
452 nfs_end_data_update(inode
);
455 spin_unlock(&nfsi
->req_lock
);
456 nfs_clear_request(req
);
457 nfs_release_request(req
);
463 static inline struct nfs_page
*
464 _nfs_find_request(struct inode
*inode
, unsigned long index
)
466 struct nfs_inode
*nfsi
= NFS_I(inode
);
467 struct nfs_page
*req
;
469 req
= (struct nfs_page
*)radix_tree_lookup(&nfsi
->nfs_page_tree
, index
);
471 atomic_inc(&req
->wb_count
);
475 static struct nfs_page
*
476 nfs_find_request(struct inode
*inode
, unsigned long index
)
478 struct nfs_page
*req
;
479 struct nfs_inode
*nfsi
= NFS_I(inode
);
481 spin_lock(&nfsi
->req_lock
);
482 req
= _nfs_find_request(inode
, index
);
483 spin_unlock(&nfsi
->req_lock
);
488 * Add a request to the inode's dirty list.
491 nfs_mark_request_dirty(struct nfs_page
*req
)
493 struct inode
*inode
= req
->wb_context
->dentry
->d_inode
;
494 struct nfs_inode
*nfsi
= NFS_I(inode
);
496 spin_lock(&nfsi
->req_lock
);
497 radix_tree_tag_set(&nfsi
->nfs_page_tree
,
498 req
->wb_index
, NFS_PAGE_TAG_DIRTY
);
499 nfs_list_add_request(req
, &nfsi
->dirty
);
501 spin_unlock(&nfsi
->req_lock
);
502 inc_zone_page_state(req
->wb_page
, NR_FILE_DIRTY
);
503 mark_inode_dirty(inode
);
507 * Check if a request is dirty
510 nfs_dirty_request(struct nfs_page
*req
)
512 struct nfs_inode
*nfsi
= NFS_I(req
->wb_context
->dentry
->d_inode
);
513 return !list_empty(&req
->wb_list
) && req
->wb_list_head
== &nfsi
->dirty
;
516 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
518 * Add a request to the inode's commit list.
521 nfs_mark_request_commit(struct nfs_page
*req
)
523 struct inode
*inode
= req
->wb_context
->dentry
->d_inode
;
524 struct nfs_inode
*nfsi
= NFS_I(inode
);
526 spin_lock(&nfsi
->req_lock
);
527 nfs_list_add_request(req
, &nfsi
->commit
);
529 spin_unlock(&nfsi
->req_lock
);
530 inc_zone_page_state(req
->wb_page
, NR_UNSTABLE_NFS
);
531 mark_inode_dirty(inode
);
536 * Wait for a request to complete.
538 * Interruptible by signals only if mounted with intr flag.
540 static int nfs_wait_on_requests_locked(struct inode
*inode
, unsigned long idx_start
, unsigned int npages
)
542 struct nfs_inode
*nfsi
= NFS_I(inode
);
543 struct nfs_page
*req
;
544 unsigned long idx_end
, next
;
545 unsigned int res
= 0;
551 idx_end
= idx_start
+ npages
- 1;
554 while (radix_tree_gang_lookup_tag(&nfsi
->nfs_page_tree
, (void **)&req
, next
, 1, NFS_PAGE_TAG_WRITEBACK
)) {
555 if (req
->wb_index
> idx_end
)
558 next
= req
->wb_index
+ 1;
559 BUG_ON(!NFS_WBACK_BUSY(req
));
561 atomic_inc(&req
->wb_count
);
562 spin_unlock(&nfsi
->req_lock
);
563 error
= nfs_wait_on_request(req
);
564 nfs_release_request(req
);
565 spin_lock(&nfsi
->req_lock
);
573 static int nfs_wait_on_requests(struct inode
*inode
, unsigned long idx_start
, unsigned int npages
)
575 struct nfs_inode
*nfsi
= NFS_I(inode
);
578 spin_lock(&nfsi
->req_lock
);
579 ret
= nfs_wait_on_requests_locked(inode
, idx_start
, npages
);
580 spin_unlock(&nfsi
->req_lock
);
584 static void nfs_cancel_dirty_list(struct list_head
*head
)
586 struct nfs_page
*req
;
587 while(!list_empty(head
)) {
588 req
= nfs_list_entry(head
->next
);
589 nfs_list_remove_request(req
);
590 nfs_inode_remove_request(req
);
591 nfs_clear_page_writeback(req
);
595 static void nfs_cancel_commit_list(struct list_head
*head
)
597 struct nfs_page
*req
;
599 while(!list_empty(head
)) {
600 req
= nfs_list_entry(head
->next
);
601 dec_zone_page_state(req
->wb_page
, NR_UNSTABLE_NFS
);
602 nfs_list_remove_request(req
);
603 nfs_inode_remove_request(req
);
604 nfs_unlock_request(req
);
608 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
610 * nfs_scan_commit - Scan an inode for commit requests
611 * @inode: NFS inode to scan
612 * @dst: destination list
613 * @idx_start: lower bound of page->index to scan.
614 * @npages: idx_start + npages sets the upper bound to scan.
616 * Moves requests from the inode's 'commit' request list.
617 * The requests are *not* checked to ensure that they form a contiguous set.
620 nfs_scan_commit(struct inode
*inode
, struct list_head
*dst
, unsigned long idx_start
, unsigned int npages
)
622 struct nfs_inode
*nfsi
= NFS_I(inode
);
625 if (nfsi
->ncommit
!= 0) {
626 res
= nfs_scan_list(nfsi
, &nfsi
->commit
, dst
, idx_start
, npages
);
627 nfsi
->ncommit
-= res
;
628 if ((nfsi
->ncommit
== 0) != list_empty(&nfsi
->commit
))
629 printk(KERN_ERR
"NFS: desynchronized value of nfs_i.ncommit.\n");
634 static inline int nfs_scan_commit(struct inode
*inode
, struct list_head
*dst
, unsigned long idx_start
, unsigned int npages
)
640 static int nfs_wait_on_write_congestion(struct address_space
*mapping
, int intr
)
642 struct backing_dev_info
*bdi
= mapping
->backing_dev_info
;
648 if (!bdi_write_congested(bdi
))
651 nfs_inc_stats(mapping
->host
, NFSIOS_CONGESTIONWAIT
);
654 struct rpc_clnt
*clnt
= NFS_CLIENT(mapping
->host
);
657 rpc_clnt_sigmask(clnt
, &oldset
);
658 prepare_to_wait(&nfs_write_congestion
, &wait
, TASK_INTERRUPTIBLE
);
659 if (bdi_write_congested(bdi
)) {
665 rpc_clnt_sigunmask(clnt
, &oldset
);
667 prepare_to_wait(&nfs_write_congestion
, &wait
, TASK_UNINTERRUPTIBLE
);
668 if (bdi_write_congested(bdi
))
671 finish_wait(&nfs_write_congestion
, &wait
);
677 * Try to update any existing write request, or create one if there is none.
678 * In order to match, the request's credentials must match those of
679 * the calling process.
681 * Note: Should always be called with the Page Lock held!
683 static struct nfs_page
* nfs_update_request(struct nfs_open_context
* ctx
,
684 struct inode
*inode
, struct page
*page
,
685 unsigned int offset
, unsigned int bytes
)
687 struct nfs_server
*server
= NFS_SERVER(inode
);
688 struct nfs_inode
*nfsi
= NFS_I(inode
);
689 struct nfs_page
*req
, *new = NULL
;
690 unsigned long rqend
, end
;
692 end
= offset
+ bytes
;
694 if (nfs_wait_on_write_congestion(page
->mapping
, server
->flags
& NFS_MOUNT_INTR
))
695 return ERR_PTR(-ERESTARTSYS
);
697 /* Loop over all inode entries and see if we find
698 * A request for the page we wish to update
700 spin_lock(&nfsi
->req_lock
);
701 req
= _nfs_find_request(inode
, page
->index
);
703 if (!nfs_lock_request_dontget(req
)) {
705 spin_unlock(&nfsi
->req_lock
);
706 error
= nfs_wait_on_request(req
);
707 nfs_release_request(req
);
710 nfs_release_request(new);
711 return ERR_PTR(error
);
715 spin_unlock(&nfsi
->req_lock
);
717 nfs_release_request(new);
723 nfs_lock_request_dontget(new);
724 error
= nfs_inode_add_request(inode
, new);
726 spin_unlock(&nfsi
->req_lock
);
727 nfs_unlock_request(new);
728 return ERR_PTR(error
);
730 spin_unlock(&nfsi
->req_lock
);
731 nfs_mark_request_dirty(new);
734 spin_unlock(&nfsi
->req_lock
);
736 new = nfs_create_request(ctx
, inode
, page
, offset
, bytes
);
741 /* We have a request for our page.
742 * If the creds don't match, or the
743 * page addresses don't match,
744 * tell the caller to wait on the conflicting
747 rqend
= req
->wb_offset
+ req
->wb_bytes
;
748 if (req
->wb_context
!= ctx
749 || req
->wb_page
!= page
750 || !nfs_dirty_request(req
)
751 || offset
> rqend
|| end
< req
->wb_offset
) {
752 nfs_unlock_request(req
);
753 return ERR_PTR(-EBUSY
);
756 /* Okay, the request matches. Update the region */
757 if (offset
< req
->wb_offset
) {
758 req
->wb_offset
= offset
;
759 req
->wb_pgbase
= offset
;
760 req
->wb_bytes
= rqend
- req
->wb_offset
;
764 req
->wb_bytes
= end
- req
->wb_offset
;
769 int nfs_flush_incompatible(struct file
*file
, struct page
*page
)
771 struct nfs_open_context
*ctx
= (struct nfs_open_context
*)file
->private_data
;
772 struct inode
*inode
= page
->mapping
->host
;
773 struct nfs_page
*req
;
776 * Look for a request corresponding to this page. If there
777 * is one, and it belongs to another file, we flush it out
778 * before we try to copy anything into the page. Do this
779 * due to the lack of an ACCESS-type call in NFSv2.
780 * Also do the same if we find a request from an existing
783 req
= nfs_find_request(inode
, page
->index
);
785 if (req
->wb_page
!= page
|| ctx
!= req
->wb_context
)
786 status
= nfs_wb_page(inode
, page
);
787 nfs_release_request(req
);
789 return (status
< 0) ? status
: 0;
793 * Update and possibly write a cached page of an NFS file.
795 * XXX: Keep an eye on generic_file_read to make sure it doesn't do bad
796 * things with a page scheduled for an RPC call (e.g. invalidate it).
798 int nfs_updatepage(struct file
*file
, struct page
*page
,
799 unsigned int offset
, unsigned int count
)
801 struct nfs_open_context
*ctx
= (struct nfs_open_context
*)file
->private_data
;
802 struct inode
*inode
= page
->mapping
->host
;
803 struct nfs_page
*req
;
806 nfs_inc_stats(inode
, NFSIOS_VFSUPDATEPAGE
);
808 dprintk("NFS: nfs_updatepage(%s/%s %d@%Ld)\n",
809 file
->f_dentry
->d_parent
->d_name
.name
,
810 file
->f_dentry
->d_name
.name
, count
,
811 (long long)(page_offset(page
) +offset
));
813 if (IS_SYNC(inode
)) {
814 status
= nfs_writepage_sync(ctx
, inode
, page
, offset
, count
, 0);
816 if (offset
== 0 && status
== PAGE_CACHE_SIZE
)
817 SetPageUptodate(page
);
823 /* If we're not using byte range locks, and we know the page
824 * is entirely in cache, it may be more efficient to avoid
825 * fragmenting write requests.
827 if (PageUptodate(page
) && inode
->i_flock
== NULL
&& !(file
->f_mode
& O_SYNC
)) {
828 loff_t end_offs
= i_size_read(inode
) - 1;
829 unsigned long end_index
= end_offs
>> PAGE_CACHE_SHIFT
;
833 if (unlikely(end_offs
< 0)) {
835 } else if (page
->index
== end_index
) {
837 pglen
= (unsigned int)(end_offs
& (PAGE_CACHE_SIZE
-1)) + 1;
840 } else if (page
->index
< end_index
)
841 count
= PAGE_CACHE_SIZE
;
845 * Try to find an NFS request corresponding to this page
847 * If the existing request cannot be updated, we must flush
851 req
= nfs_update_request(ctx
, inode
, page
, offset
, count
);
852 status
= (IS_ERR(req
)) ? PTR_ERR(req
) : 0;
853 if (status
!= -EBUSY
)
855 /* Request could not be updated. Flush it out and try again */
856 status
= nfs_wb_page(inode
, page
);
857 } while (status
>= 0);
863 /* Update file length */
864 nfs_grow_file(page
, offset
, count
);
865 /* Set the PG_uptodate flag? */
866 nfs_mark_uptodate(page
, req
->wb_pgbase
, req
->wb_bytes
);
867 nfs_unlock_request(req
);
869 dprintk("NFS: nfs_updatepage returns %d (isize %Ld)\n",
870 status
, (long long)i_size_read(inode
));
872 ClearPageUptodate(page
);
876 static void nfs_writepage_release(struct nfs_page
*req
)
878 end_page_writeback(req
->wb_page
);
880 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
881 if (!PageError(req
->wb_page
)) {
882 if (NFS_NEED_RESCHED(req
)) {
883 nfs_mark_request_dirty(req
);
885 } else if (NFS_NEED_COMMIT(req
)) {
886 nfs_mark_request_commit(req
);
890 nfs_inode_remove_request(req
);
893 nfs_clear_commit(req
);
894 nfs_clear_reschedule(req
);
896 nfs_inode_remove_request(req
);
898 nfs_clear_page_writeback(req
);
901 static inline int flush_task_priority(int how
)
903 switch (how
& (FLUSH_HIGHPRI
|FLUSH_LOWPRI
)) {
905 return RPC_PRIORITY_HIGH
;
907 return RPC_PRIORITY_LOW
;
909 return RPC_PRIORITY_NORMAL
;
913 * Set up the argument/result storage required for the RPC call.
915 static void nfs_write_rpcsetup(struct nfs_page
*req
,
916 struct nfs_write_data
*data
,
917 const struct rpc_call_ops
*call_ops
,
918 unsigned int count
, unsigned int offset
,
924 /* Set up the RPC argument and reply structs
925 * NB: take care not to mess about with data->commit et al. */
928 data
->inode
= inode
= req
->wb_context
->dentry
->d_inode
;
929 data
->cred
= req
->wb_context
->cred
;
931 data
->args
.fh
= NFS_FH(inode
);
932 data
->args
.offset
= req_offset(req
) + offset
;
933 data
->args
.pgbase
= req
->wb_pgbase
+ offset
;
934 data
->args
.pages
= data
->pagevec
;
935 data
->args
.count
= count
;
936 data
->args
.context
= req
->wb_context
;
938 data
->res
.fattr
= &data
->fattr
;
939 data
->res
.count
= count
;
940 data
->res
.verf
= &data
->verf
;
941 nfs_fattr_init(&data
->fattr
);
943 /* Set up the initial task struct. */
944 flags
= (how
& FLUSH_SYNC
) ? 0 : RPC_TASK_ASYNC
;
945 rpc_init_task(&data
->task
, NFS_CLIENT(inode
), flags
, call_ops
, data
);
946 NFS_PROTO(inode
)->write_setup(data
, how
);
948 data
->task
.tk_priority
= flush_task_priority(how
);
949 data
->task
.tk_cookie
= (unsigned long)inode
;
951 dprintk("NFS: %4d initiated write call (req %s/%Ld, %u bytes @ offset %Lu)\n",
954 (long long)NFS_FILEID(inode
),
956 (unsigned long long)data
->args
.offset
);
959 static void nfs_execute_write(struct nfs_write_data
*data
)
961 struct rpc_clnt
*clnt
= NFS_CLIENT(data
->inode
);
964 rpc_clnt_sigmask(clnt
, &oldset
);
965 rpc_execute(&data
->task
);
966 rpc_clnt_sigunmask(clnt
, &oldset
);
970 * Generate multiple small requests to write out a single
971 * contiguous dirty area on one page.
973 static int nfs_flush_multi(struct inode
*inode
, struct list_head
*head
, int how
)
975 struct nfs_page
*req
= nfs_list_entry(head
->next
);
976 struct page
*page
= req
->wb_page
;
977 struct nfs_write_data
*data
;
978 size_t wsize
= NFS_SERVER(inode
)->wsize
, nbytes
;
983 nfs_list_remove_request(req
);
985 nbytes
= req
->wb_bytes
;
987 size_t len
= min(nbytes
, wsize
);
989 data
= nfs_writedata_alloc(len
);
992 list_add(&data
->pages
, &list
);
995 } while (nbytes
!= 0);
996 atomic_set(&req
->wb_complete
, requests
);
998 ClearPageError(page
);
999 set_page_writeback(page
);
1001 nbytes
= req
->wb_bytes
;
1003 data
= list_entry(list
.next
, struct nfs_write_data
, pages
);
1004 list_del_init(&data
->pages
);
1006 data
->pagevec
[0] = page
;
1008 if (nbytes
> wsize
) {
1009 nfs_write_rpcsetup(req
, data
, &nfs_write_partial_ops
,
1010 wsize
, offset
, how
);
1014 nfs_write_rpcsetup(req
, data
, &nfs_write_partial_ops
,
1015 nbytes
, offset
, how
);
1018 nfs_execute_write(data
);
1019 } while (nbytes
!= 0);
1024 while (!list_empty(&list
)) {
1025 data
= list_entry(list
.next
, struct nfs_write_data
, pages
);
1026 list_del(&data
->pages
);
1027 nfs_writedata_release(data
);
1029 nfs_mark_request_dirty(req
);
1030 nfs_clear_page_writeback(req
);
1035 * Create an RPC task for the given write request and kick it.
1036 * The page must have been locked by the caller.
1038 * It may happen that the page we're passed is not marked dirty.
1039 * This is the case if nfs_updatepage detects a conflicting request
1040 * that has been written but not committed.
1042 static int nfs_flush_one(struct inode
*inode
, struct list_head
*head
, int how
)
1044 struct nfs_page
*req
;
1045 struct page
**pages
;
1046 struct nfs_write_data
*data
;
1049 data
= nfs_writedata_alloc(NFS_SERVER(inode
)->wsize
);
1053 pages
= data
->pagevec
;
1055 while (!list_empty(head
)) {
1056 req
= nfs_list_entry(head
->next
);
1057 nfs_list_remove_request(req
);
1058 nfs_list_add_request(req
, &data
->pages
);
1059 ClearPageError(req
->wb_page
);
1060 set_page_writeback(req
->wb_page
);
1061 *pages
++ = req
->wb_page
;
1062 count
+= req
->wb_bytes
;
1064 req
= nfs_list_entry(data
->pages
.next
);
1066 /* Set up the argument struct */
1067 nfs_write_rpcsetup(req
, data
, &nfs_write_full_ops
, count
, 0, how
);
1069 nfs_execute_write(data
);
1072 while (!list_empty(head
)) {
1073 struct nfs_page
*req
= nfs_list_entry(head
->next
);
1074 nfs_list_remove_request(req
);
1075 nfs_mark_request_dirty(req
);
1076 nfs_clear_page_writeback(req
);
1081 static int nfs_flush_list(struct inode
*inode
, struct list_head
*head
, int npages
, int how
)
1083 LIST_HEAD(one_request
);
1084 int (*flush_one
)(struct inode
*, struct list_head
*, int);
1085 struct nfs_page
*req
;
1086 int wpages
= NFS_SERVER(inode
)->wpages
;
1087 int wsize
= NFS_SERVER(inode
)->wsize
;
1090 flush_one
= nfs_flush_one
;
1091 if (wsize
< PAGE_CACHE_SIZE
)
1092 flush_one
= nfs_flush_multi
;
1093 /* For single writes, FLUSH_STABLE is more efficient */
1094 if (npages
<= wpages
&& npages
== NFS_I(inode
)->npages
1095 && nfs_list_entry(head
->next
)->wb_bytes
<= wsize
)
1096 how
|= FLUSH_STABLE
;
1099 nfs_coalesce_requests(head
, &one_request
, wpages
);
1100 req
= nfs_list_entry(one_request
.next
);
1101 error
= flush_one(inode
, &one_request
, how
);
1104 } while (!list_empty(head
));
1107 while (!list_empty(head
)) {
1108 req
= nfs_list_entry(head
->next
);
1109 nfs_list_remove_request(req
);
1110 nfs_mark_request_dirty(req
);
1111 nfs_clear_page_writeback(req
);
1117 * Handle a write reply that flushed part of a page.
1119 static void nfs_writeback_done_partial(struct rpc_task
*task
, void *calldata
)
1121 struct nfs_write_data
*data
= calldata
;
1122 struct nfs_page
*req
= data
->req
;
1123 struct page
*page
= req
->wb_page
;
1125 dprintk("NFS: write (%s/%Ld %d@%Ld)",
1126 req
->wb_context
->dentry
->d_inode
->i_sb
->s_id
,
1127 (long long)NFS_FILEID(req
->wb_context
->dentry
->d_inode
),
1129 (long long)req_offset(req
));
1131 if (nfs_writeback_done(task
, data
) != 0)
1134 if (task
->tk_status
< 0) {
1135 ClearPageUptodate(page
);
1137 req
->wb_context
->error
= task
->tk_status
;
1138 dprintk(", error = %d\n", task
->tk_status
);
1140 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
1141 if (data
->verf
.committed
< NFS_FILE_SYNC
) {
1142 if (!NFS_NEED_COMMIT(req
)) {
1143 nfs_defer_commit(req
);
1144 memcpy(&req
->wb_verf
, &data
->verf
, sizeof(req
->wb_verf
));
1145 dprintk(" defer commit\n");
1146 } else if (memcmp(&req
->wb_verf
, &data
->verf
, sizeof(req
->wb_verf
))) {
1147 nfs_defer_reschedule(req
);
1148 dprintk(" server reboot detected\n");
1155 if (atomic_dec_and_test(&req
->wb_complete
))
1156 nfs_writepage_release(req
);
1159 static const struct rpc_call_ops nfs_write_partial_ops
= {
1160 .rpc_call_done
= nfs_writeback_done_partial
,
1161 .rpc_release
= nfs_writedata_release
,
1165 * Handle a write reply that flushes a whole page.
1167 * FIXME: There is an inherent race with invalidate_inode_pages and
1168 * writebacks since the page->count is kept > 1 for as long
1169 * as the page has a write request pending.
1171 static void nfs_writeback_done_full(struct rpc_task
*task
, void *calldata
)
1173 struct nfs_write_data
*data
= calldata
;
1174 struct nfs_page
*req
;
1177 if (nfs_writeback_done(task
, data
) != 0)
1180 /* Update attributes as result of writeback. */
1181 while (!list_empty(&data
->pages
)) {
1182 req
= nfs_list_entry(data
->pages
.next
);
1183 nfs_list_remove_request(req
);
1184 page
= req
->wb_page
;
1186 dprintk("NFS: write (%s/%Ld %d@%Ld)",
1187 req
->wb_context
->dentry
->d_inode
->i_sb
->s_id
,
1188 (long long)NFS_FILEID(req
->wb_context
->dentry
->d_inode
),
1190 (long long)req_offset(req
));
1192 if (task
->tk_status
< 0) {
1193 ClearPageUptodate(page
);
1195 req
->wb_context
->error
= task
->tk_status
;
1196 end_page_writeback(page
);
1197 nfs_inode_remove_request(req
);
1198 dprintk(", error = %d\n", task
->tk_status
);
1201 end_page_writeback(page
);
1203 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
1204 if (data
->args
.stable
!= NFS_UNSTABLE
|| data
->verf
.committed
== NFS_FILE_SYNC
) {
1205 nfs_inode_remove_request(req
);
1209 memcpy(&req
->wb_verf
, &data
->verf
, sizeof(req
->wb_verf
));
1210 nfs_mark_request_commit(req
);
1211 dprintk(" marked for commit\n");
1213 nfs_inode_remove_request(req
);
1216 nfs_clear_page_writeback(req
);
1220 static const struct rpc_call_ops nfs_write_full_ops
= {
1221 .rpc_call_done
= nfs_writeback_done_full
,
1222 .rpc_release
= nfs_writedata_release
,
1227 * This function is called when the WRITE call is complete.
1229 int nfs_writeback_done(struct rpc_task
*task
, struct nfs_write_data
*data
)
1231 struct nfs_writeargs
*argp
= &data
->args
;
1232 struct nfs_writeres
*resp
= &data
->res
;
1235 dprintk("NFS: %4d nfs_writeback_done (status %d)\n",
1236 task
->tk_pid
, task
->tk_status
);
1239 * ->write_done will attempt to use post-op attributes to detect
1240 * conflicting writes by other clients. A strict interpretation
1241 * of close-to-open would allow us to continue caching even if
1242 * another writer had changed the file, but some applications
1243 * depend on tighter cache coherency when writing.
1245 status
= NFS_PROTO(data
->inode
)->write_done(task
, data
);
1248 nfs_add_stats(data
->inode
, NFSIOS_SERVERWRITTENBYTES
, resp
->count
);
1250 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
1251 if (resp
->verf
->committed
< argp
->stable
&& task
->tk_status
>= 0) {
1252 /* We tried a write call, but the server did not
1253 * commit data to stable storage even though we
1255 * Note: There is a known bug in Tru64 < 5.0 in which
1256 * the server reports NFS_DATA_SYNC, but performs
1257 * NFS_FILE_SYNC. We therefore implement this checking
1258 * as a dprintk() in order to avoid filling syslog.
1260 static unsigned long complain
;
1262 if (time_before(complain
, jiffies
)) {
1263 dprintk("NFS: faulty NFS server %s:"
1264 " (committed = %d) != (stable = %d)\n",
1265 NFS_SERVER(data
->inode
)->nfs_client
->cl_hostname
,
1266 resp
->verf
->committed
, argp
->stable
);
1267 complain
= jiffies
+ 300 * HZ
;
1271 /* Is this a short write? */
1272 if (task
->tk_status
>= 0 && resp
->count
< argp
->count
) {
1273 static unsigned long complain
;
1275 nfs_inc_stats(data
->inode
, NFSIOS_SHORTWRITE
);
1277 /* Has the server at least made some progress? */
1278 if (resp
->count
!= 0) {
1279 /* Was this an NFSv2 write or an NFSv3 stable write? */
1280 if (resp
->verf
->committed
!= NFS_UNSTABLE
) {
1281 /* Resend from where the server left off */
1282 argp
->offset
+= resp
->count
;
1283 argp
->pgbase
+= resp
->count
;
1284 argp
->count
-= resp
->count
;
1286 /* Resend as a stable write in order to avoid
1287 * headaches in the case of a server crash.
1289 argp
->stable
= NFS_FILE_SYNC
;
1291 rpc_restart_call(task
);
1294 if (time_before(complain
, jiffies
)) {
1296 "NFS: Server wrote zero bytes, expected %u.\n",
1298 complain
= jiffies
+ 300 * HZ
;
1300 /* Can't do anything about it except throw an error. */
1301 task
->tk_status
= -EIO
;
1307 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
1308 void nfs_commit_release(void *wdata
)
1310 nfs_commit_free(wdata
);
1314 * Set up the argument/result storage required for the RPC call.
1316 static void nfs_commit_rpcsetup(struct list_head
*head
,
1317 struct nfs_write_data
*data
,
1320 struct nfs_page
*first
;
1321 struct inode
*inode
;
1324 /* Set up the RPC argument and reply structs
1325 * NB: take care not to mess about with data->commit et al. */
1327 list_splice_init(head
, &data
->pages
);
1328 first
= nfs_list_entry(data
->pages
.next
);
1329 inode
= first
->wb_context
->dentry
->d_inode
;
1331 data
->inode
= inode
;
1332 data
->cred
= first
->wb_context
->cred
;
1334 data
->args
.fh
= NFS_FH(data
->inode
);
1335 /* Note: we always request a commit of the entire inode */
1336 data
->args
.offset
= 0;
1337 data
->args
.count
= 0;
1338 data
->res
.count
= 0;
1339 data
->res
.fattr
= &data
->fattr
;
1340 data
->res
.verf
= &data
->verf
;
1341 nfs_fattr_init(&data
->fattr
);
1343 /* Set up the initial task struct. */
1344 flags
= (how
& FLUSH_SYNC
) ? 0 : RPC_TASK_ASYNC
;
1345 rpc_init_task(&data
->task
, NFS_CLIENT(inode
), flags
, &nfs_commit_ops
, data
);
1346 NFS_PROTO(inode
)->commit_setup(data
, how
);
1348 data
->task
.tk_priority
= flush_task_priority(how
);
1349 data
->task
.tk_cookie
= (unsigned long)inode
;
1351 dprintk("NFS: %4d initiated commit call\n", data
->task
.tk_pid
);
1355 * Commit dirty pages
1358 nfs_commit_list(struct inode
*inode
, struct list_head
*head
, int how
)
1360 struct nfs_write_data
*data
;
1361 struct nfs_page
*req
;
1363 data
= nfs_commit_alloc();
1368 /* Set up the argument struct */
1369 nfs_commit_rpcsetup(head
, data
, how
);
1371 nfs_execute_write(data
);
1374 while (!list_empty(head
)) {
1375 req
= nfs_list_entry(head
->next
);
1376 nfs_list_remove_request(req
);
1377 nfs_mark_request_commit(req
);
1378 dec_zone_page_state(req
->wb_page
, NR_UNSTABLE_NFS
);
1379 nfs_clear_page_writeback(req
);
1385 * COMMIT call returned
1387 static void nfs_commit_done(struct rpc_task
*task
, void *calldata
)
1389 struct nfs_write_data
*data
= calldata
;
1390 struct nfs_page
*req
;
1392 dprintk("NFS: %4d nfs_commit_done (status %d)\n",
1393 task
->tk_pid
, task
->tk_status
);
1395 /* Call the NFS version-specific code */
1396 if (NFS_PROTO(data
->inode
)->commit_done(task
, data
) != 0)
1399 while (!list_empty(&data
->pages
)) {
1400 req
= nfs_list_entry(data
->pages
.next
);
1401 nfs_list_remove_request(req
);
1402 dec_zone_page_state(req
->wb_page
, NR_UNSTABLE_NFS
);
1404 dprintk("NFS: commit (%s/%Ld %d@%Ld)",
1405 req
->wb_context
->dentry
->d_inode
->i_sb
->s_id
,
1406 (long long)NFS_FILEID(req
->wb_context
->dentry
->d_inode
),
1408 (long long)req_offset(req
));
1409 if (task
->tk_status
< 0) {
1410 req
->wb_context
->error
= task
->tk_status
;
1411 nfs_inode_remove_request(req
);
1412 dprintk(", error = %d\n", task
->tk_status
);
1416 /* Okay, COMMIT succeeded, apparently. Check the verifier
1417 * returned by the server against all stored verfs. */
1418 if (!memcmp(req
->wb_verf
.verifier
, data
->verf
.verifier
, sizeof(data
->verf
.verifier
))) {
1419 /* We have a match */
1420 nfs_inode_remove_request(req
);
1424 /* We have a mismatch. Write the page again */
1425 dprintk(" mismatch\n");
1426 nfs_mark_request_dirty(req
);
1428 nfs_clear_page_writeback(req
);
1432 static const struct rpc_call_ops nfs_commit_ops
= {
1433 .rpc_call_done
= nfs_commit_done
,
1434 .rpc_release
= nfs_commit_release
,
1437 static inline int nfs_commit_list(struct inode
*inode
, struct list_head
*head
, int how
)
1443 static long nfs_flush_mapping(struct address_space
*mapping
, struct writeback_control
*wbc
, int how
)
1445 struct nfs_inode
*nfsi
= NFS_I(mapping
->host
);
1449 spin_lock(&nfsi
->req_lock
);
1450 res
= nfs_scan_dirty(mapping
, wbc
, &head
);
1451 spin_unlock(&nfsi
->req_lock
);
1453 int error
= nfs_flush_list(mapping
->host
, &head
, res
, how
);
1460 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
1461 int nfs_commit_inode(struct inode
*inode
, int how
)
1463 struct nfs_inode
*nfsi
= NFS_I(inode
);
1467 spin_lock(&nfsi
->req_lock
);
1468 res
= nfs_scan_commit(inode
, &head
, 0, 0);
1469 spin_unlock(&nfsi
->req_lock
);
1471 int error
= nfs_commit_list(inode
, &head
, how
);
1479 long nfs_sync_inode_wait(struct inode
*inode
, unsigned long idx_start
,
1480 unsigned int npages
, int how
)
1482 struct nfs_inode
*nfsi
= NFS_I(inode
);
1483 struct address_space
*mapping
= inode
->i_mapping
;
1484 struct writeback_control wbc
= {
1485 .bdi
= mapping
->backing_dev_info
,
1486 .sync_mode
= WB_SYNC_ALL
,
1487 .nr_to_write
= LONG_MAX
,
1488 .range_start
= ((loff_t
)idx_start
) << PAGE_CACHE_SHIFT
,
1489 .range_end
= ((loff_t
)(idx_start
+ npages
- 1)) << PAGE_CACHE_SHIFT
,
1492 int nocommit
= how
& FLUSH_NOCOMMIT
;
1495 how
&= ~FLUSH_NOCOMMIT
;
1496 spin_lock(&nfsi
->req_lock
);
1498 ret
= nfs_wait_on_requests_locked(inode
, idx_start
, npages
);
1501 pages
= nfs_scan_dirty(mapping
, &wbc
, &head
);
1503 spin_unlock(&nfsi
->req_lock
);
1504 if (how
& FLUSH_INVALIDATE
) {
1505 nfs_cancel_dirty_list(&head
);
1508 ret
= nfs_flush_list(inode
, &head
, pages
, how
);
1509 spin_lock(&nfsi
->req_lock
);
1514 pages
= nfs_scan_commit(inode
, &head
, idx_start
, npages
);
1517 if (how
& FLUSH_INVALIDATE
) {
1518 spin_unlock(&nfsi
->req_lock
);
1519 nfs_cancel_commit_list(&head
);
1521 spin_lock(&nfsi
->req_lock
);
1524 pages
+= nfs_scan_commit(inode
, &head
, 0, 0);
1525 spin_unlock(&nfsi
->req_lock
);
1526 ret
= nfs_commit_list(inode
, &head
, how
);
1527 spin_lock(&nfsi
->req_lock
);
1529 spin_unlock(&nfsi
->req_lock
);
1533 int __init
nfs_init_writepagecache(void)
1535 nfs_wdata_cachep
= kmem_cache_create("nfs_write_data",
1536 sizeof(struct nfs_write_data
),
1537 0, SLAB_HWCACHE_ALIGN
,
1539 if (nfs_wdata_cachep
== NULL
)
1542 nfs_wdata_mempool
= mempool_create_slab_pool(MIN_POOL_WRITE
,
1544 if (nfs_wdata_mempool
== NULL
)
1547 nfs_commit_mempool
= mempool_create_slab_pool(MIN_POOL_COMMIT
,
1549 if (nfs_commit_mempool
== NULL
)
1555 void nfs_destroy_writepagecache(void)
1557 mempool_destroy(nfs_commit_mempool
);
1558 mempool_destroy(nfs_wdata_mempool
);
1559 kmem_cache_destroy(nfs_wdata_cachep
);