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NFS: Fix up writeback_control->nr_to_write accounting
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CommitLineData
1da177e4
LT
1/*
2 * linux/fs/nfs/write.c
3 *
4 * Writing file data over NFS.
5 *
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.
12 *
13 * Just like readahead, no async I/O is performed if wsize < PAGE_SIZE.
14 *
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.
20 *
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.
24 *
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
27 * cases:
28 *
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
32 *
33 * Also note that because of the way pages are invalidated in
34 * nfs_revalidate_inode, the following assertions hold:
35 *
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.
40 *
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.
45 *
46 * Copyright (C) 1996, 1997, Olaf Kirch <okir@monad.swb.de>
47 */
48
1da177e4
LT
49#include <linux/types.h>
50#include <linux/slab.h>
51#include <linux/mm.h>
52#include <linux/pagemap.h>
53#include <linux/file.h>
1da177e4
LT
54#include <linux/writeback.h>
55
56#include <linux/sunrpc/clnt.h>
57#include <linux/nfs_fs.h>
58#include <linux/nfs_mount.h>
59#include <linux/nfs_page.h>
3fcfab16
AM
60#include <linux/backing-dev.h>
61
1da177e4
LT
62#include <asm/uaccess.h>
63#include <linux/smp_lock.h>
64
65#include "delegation.h"
49a70f27 66#include "internal.h"
91d5b470 67#include "iostat.h"
1da177e4
LT
68
69#define NFSDBG_FACILITY NFSDBG_PAGECACHE
70
71#define MIN_POOL_WRITE (32)
72#define MIN_POOL_COMMIT (4)
73
74/*
75 * Local function declarations
76 */
77static struct nfs_page * nfs_update_request(struct nfs_open_context*,
1da177e4
LT
78 struct page *,
79 unsigned int, unsigned int);
e261f51f 80static void nfs_mark_request_dirty(struct nfs_page *req);
1da177e4
LT
81static int nfs_wait_on_write_congestion(struct address_space *, int);
82static int nfs_wait_on_requests(struct inode *, unsigned long, unsigned int);
3f442547 83static long nfs_flush_mapping(struct address_space *mapping, struct writeback_control *wbc, int how);
788e7a89
TM
84static const struct rpc_call_ops nfs_write_partial_ops;
85static const struct rpc_call_ops nfs_write_full_ops;
86static const struct rpc_call_ops nfs_commit_ops;
1da177e4
LT
87
88static kmem_cache_t *nfs_wdata_cachep;
3feb2d49 89static mempool_t *nfs_wdata_mempool;
1da177e4
LT
90static mempool_t *nfs_commit_mempool;
91
92static DECLARE_WAIT_QUEUE_HEAD(nfs_write_congestion);
93
e9f7bee1 94struct nfs_write_data *nfs_commit_alloc(void)
1da177e4
LT
95{
96 struct nfs_write_data *p = mempool_alloc(nfs_commit_mempool, SLAB_NOFS);
40859d7e 97
1da177e4
LT
98 if (p) {
99 memset(p, 0, sizeof(*p));
100 INIT_LIST_HEAD(&p->pages);
101 }
102 return p;
103}
104
8aca67f0 105void nfs_commit_rcu_free(struct rcu_head *head)
1da177e4 106{
8aca67f0 107 struct nfs_write_data *p = container_of(head, struct nfs_write_data, task.u.tk_rcu);
40859d7e
CL
108 if (p && (p->pagevec != &p->page_array[0]))
109 kfree(p->pagevec);
1da177e4
LT
110 mempool_free(p, nfs_commit_mempool);
111}
112
8aca67f0
TM
113void nfs_commit_free(struct nfs_write_data *wdata)
114{
115 call_rcu_bh(&wdata->task.u.tk_rcu, nfs_commit_rcu_free);
116}
117
e9f7bee1 118struct nfs_write_data *nfs_writedata_alloc(size_t len)
3feb2d49 119{
e9f7bee1 120 unsigned int pagecount = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
3feb2d49
TM
121 struct nfs_write_data *p = mempool_alloc(nfs_wdata_mempool, SLAB_NOFS);
122
123 if (p) {
124 memset(p, 0, sizeof(*p));
125 INIT_LIST_HEAD(&p->pages);
e9f7bee1 126 p->npages = pagecount;
0d0b5cb3
CL
127 if (pagecount <= ARRAY_SIZE(p->page_array))
128 p->pagevec = p->page_array;
3feb2d49 129 else {
0d0b5cb3
CL
130 p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_NOFS);
131 if (!p->pagevec) {
3feb2d49
TM
132 mempool_free(p, nfs_wdata_mempool);
133 p = NULL;
134 }
135 }
136 }
137 return p;
138}
139
8aca67f0 140static void nfs_writedata_rcu_free(struct rcu_head *head)
3feb2d49 141{
8aca67f0 142 struct nfs_write_data *p = container_of(head, struct nfs_write_data, task.u.tk_rcu);
3feb2d49
TM
143 if (p && (p->pagevec != &p->page_array[0]))
144 kfree(p->pagevec);
145 mempool_free(p, nfs_wdata_mempool);
146}
147
8aca67f0
TM
148static void nfs_writedata_free(struct nfs_write_data *wdata)
149{
150 call_rcu_bh(&wdata->task.u.tk_rcu, nfs_writedata_rcu_free);
151}
152
963d8fe5 153void nfs_writedata_release(void *wdata)
1da177e4 154{
1da177e4
LT
155 nfs_writedata_free(wdata);
156}
157
277459d2
TM
158static struct nfs_page *nfs_page_find_request_locked(struct page *page)
159{
160 struct nfs_page *req = NULL;
161
162 if (PagePrivate(page)) {
163 req = (struct nfs_page *)page_private(page);
164 if (req != NULL)
165 atomic_inc(&req->wb_count);
166 }
167 return req;
168}
169
170static struct nfs_page *nfs_page_find_request(struct page *page)
171{
172 struct nfs_page *req = NULL;
173 spinlock_t *req_lock = &NFS_I(page->mapping->host)->req_lock;
174
175 spin_lock(req_lock);
176 req = nfs_page_find_request_locked(page);
177 spin_unlock(req_lock);
178 return req;
179}
180
1da177e4
LT
181/* Adjust the file length if we're writing beyond the end */
182static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count)
183{
184 struct inode *inode = page->mapping->host;
185 loff_t end, i_size = i_size_read(inode);
186 unsigned long end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
187
188 if (i_size > 0 && page->index < end_index)
189 return;
190 end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + ((loff_t)offset+count);
191 if (i_size >= end)
192 return;
91d5b470 193 nfs_inc_stats(inode, NFSIOS_EXTENDWRITE);
1da177e4
LT
194 i_size_write(inode, end);
195}
196
197/* We can set the PG_uptodate flag if we see that a write request
198 * covers the full page.
199 */
200static void nfs_mark_uptodate(struct page *page, unsigned int base, unsigned int count)
201{
1da177e4
LT
202 if (PageUptodate(page))
203 return;
204 if (base != 0)
205 return;
49a70f27 206 if (count != nfs_page_length(page))
1da177e4 207 return;
49a70f27 208 if (count != PAGE_CACHE_SIZE)
1da177e4 209 memclear_highpage_flush(page, count, PAGE_CACHE_SIZE - count);
49a70f27 210 SetPageUptodate(page);
1da177e4
LT
211}
212
e21195a7 213static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page,
1da177e4
LT
214 unsigned int offset, unsigned int count)
215{
216 struct nfs_page *req;
e21195a7 217 int ret;
1da177e4 218
e21195a7
TM
219 for (;;) {
220 req = nfs_update_request(ctx, page, offset, count);
221 if (!IS_ERR(req))
222 break;
223 ret = PTR_ERR(req);
224 if (ret != -EBUSY)
225 return ret;
226 ret = nfs_wb_page(page->mapping->host, page);
227 if (ret != 0)
228 return ret;
229 }
1da177e4
LT
230 /* Update file length */
231 nfs_grow_file(page, offset, count);
232 /* Set the PG_uptodate flag? */
233 nfs_mark_uptodate(page, offset, count);
234 nfs_unlock_request(req);
abd3e641 235 return 0;
1da177e4
LT
236}
237
238static int wb_priority(struct writeback_control *wbc)
239{
240 if (wbc->for_reclaim)
241 return FLUSH_HIGHPRI;
242 if (wbc->for_kupdate)
243 return FLUSH_LOWPRI;
244 return 0;
245}
246
e261f51f
TM
247/*
248 * Find an associated nfs write request, and prepare to flush it out
249 * Returns 1 if there was no write request, or if the request was
250 * already tagged by nfs_set_page_dirty.Returns 0 if the request
251 * was not tagged.
252 * May also return an error if the user signalled nfs_wait_on_request().
253 */
254static int nfs_page_mark_flush(struct page *page)
255{
256 struct nfs_page *req;
257 spinlock_t *req_lock = &NFS_I(page->mapping->host)->req_lock;
258 int ret;
259
260 spin_lock(req_lock);
261 for(;;) {
262 req = nfs_page_find_request_locked(page);
263 if (req == NULL) {
264 spin_unlock(req_lock);
265 return 1;
266 }
267 if (nfs_lock_request_dontget(req))
268 break;
269 /* Note: If we hold the page lock, as is the case in nfs_writepage,
270 * then the call to nfs_lock_request_dontget() will always
271 * succeed provided that someone hasn't already marked the
272 * request as dirty (in which case we don't care).
273 */
274 spin_unlock(req_lock);
275 ret = nfs_wait_on_request(req);
276 nfs_release_request(req);
277 if (ret != 0)
278 return ret;
279 spin_lock(req_lock);
280 }
281 spin_unlock(req_lock);
61822ab5 282 if (test_and_set_bit(PG_FLUSHING, &req->wb_flags) == 0) {
e261f51f 283 nfs_mark_request_dirty(req);
61822ab5
TM
284 set_page_writeback(page);
285 }
e261f51f
TM
286 ret = test_bit(PG_NEED_FLUSH, &req->wb_flags);
287 nfs_unlock_request(req);
288 return ret;
289}
290
1da177e4
LT
291/*
292 * Write an mmapped page to the server.
293 */
4d770ccf 294static int nfs_writepage_locked(struct page *page, struct writeback_control *wbc)
1da177e4
LT
295{
296 struct nfs_open_context *ctx;
297 struct inode *inode = page->mapping->host;
49a70f27 298 unsigned offset;
e261f51f 299 int err;
1da177e4 300
91d5b470
CL
301 nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE);
302 nfs_add_stats(inode, NFSIOS_WRITEPAGES, 1);
303
e261f51f
TM
304 err = nfs_page_mark_flush(page);
305 if (err <= 0)
306 goto out;
307 err = 0;
49a70f27
TM
308 offset = nfs_page_length(page);
309 if (!offset)
1da177e4 310 goto out;
49a70f27 311
d530838b 312 ctx = nfs_find_open_context(inode, NULL, FMODE_WRITE);
1da177e4
LT
313 if (ctx == NULL) {
314 err = -EBADF;
315 goto out;
316 }
200baa21 317 err = nfs_writepage_setup(ctx, page, 0, offset);
1da177e4 318 put_nfs_open_context(ctx);
e261f51f
TM
319 if (err != 0)
320 goto out;
321 err = nfs_page_mark_flush(page);
322 if (err > 0)
323 err = 0;
1da177e4 324out:
200baa21
TM
325 if (!wbc->for_writepages)
326 nfs_flush_mapping(page->mapping, wbc, wb_priority(wbc));
4d770ccf
TM
327 return err;
328}
329
330int nfs_writepage(struct page *page, struct writeback_control *wbc)
331{
332 int err;
333
334 err = nfs_writepage_locked(page, wbc);
1da177e4 335 unlock_page(page);
1da177e4
LT
336 return err;
337}
338
339/*
340 * Note: causes nfs_update_request() to block on the assumption
341 * that the writeback is generated due to memory pressure.
342 */
343int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
344{
345 struct backing_dev_info *bdi = mapping->backing_dev_info;
346 struct inode *inode = mapping->host;
347 int err;
348
91d5b470
CL
349 nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES);
350
1da177e4
LT
351 err = generic_writepages(mapping, wbc);
352 if (err)
353 return err;
354 while (test_and_set_bit(BDI_write_congested, &bdi->state) != 0) {
355 if (wbc->nonblocking)
356 return 0;
357 nfs_wait_on_write_congestion(mapping, 0);
358 }
28c6925f 359 err = nfs_flush_mapping(mapping, wbc, wb_priority(wbc));
1da177e4
LT
360 if (err < 0)
361 goto out;
91d5b470 362 nfs_add_stats(inode, NFSIOS_WRITEPAGES, err);
1da177e4
LT
363 if (!wbc->nonblocking && wbc->sync_mode == WB_SYNC_ALL) {
364 err = nfs_wait_on_requests(inode, 0, 0);
365 if (err < 0)
366 goto out;
367 }
3da28eb1 368 err = nfs_commit_inode(inode, wb_priority(wbc));
3f442547 369 if (err > 0)
1da177e4 370 err = 0;
1da177e4
LT
371out:
372 clear_bit(BDI_write_congested, &bdi->state);
373 wake_up_all(&nfs_write_congestion);
3fcfab16 374 congestion_end(WRITE);
1da177e4
LT
375 return err;
376}
377
378/*
379 * Insert a write request into an inode
380 */
381static int nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
382{
383 struct nfs_inode *nfsi = NFS_I(inode);
384 int error;
385
386 error = radix_tree_insert(&nfsi->nfs_page_tree, req->wb_index, req);
387 BUG_ON(error == -EEXIST);
388 if (error)
389 return error;
390 if (!nfsi->npages) {
391 igrab(inode);
392 nfs_begin_data_update(inode);
393 if (nfs_have_delegation(inode, FMODE_WRITE))
394 nfsi->change_attr++;
395 }
deb7d638 396 SetPagePrivate(req->wb_page);
277459d2 397 set_page_private(req->wb_page, (unsigned long)req);
1da177e4
LT
398 nfsi->npages++;
399 atomic_inc(&req->wb_count);
400 return 0;
401}
402
403/*
404 * Insert a write request into an inode
405 */
406static void nfs_inode_remove_request(struct nfs_page *req)
407{
408 struct inode *inode = req->wb_context->dentry->d_inode;
409 struct nfs_inode *nfsi = NFS_I(inode);
410
411 BUG_ON (!NFS_WBACK_BUSY(req));
412
413 spin_lock(&nfsi->req_lock);
277459d2 414 set_page_private(req->wb_page, 0);
deb7d638 415 ClearPagePrivate(req->wb_page);
1da177e4
LT
416 radix_tree_delete(&nfsi->nfs_page_tree, req->wb_index);
417 nfsi->npages--;
418 if (!nfsi->npages) {
419 spin_unlock(&nfsi->req_lock);
951a143b 420 nfs_end_data_update(inode);
1da177e4
LT
421 iput(inode);
422 } else
423 spin_unlock(&nfsi->req_lock);
424 nfs_clear_request(req);
425 nfs_release_request(req);
426}
427
1da177e4
LT
428/*
429 * Add a request to the inode's dirty list.
430 */
431static void
432nfs_mark_request_dirty(struct nfs_page *req)
433{
434 struct inode *inode = req->wb_context->dentry->d_inode;
435 struct nfs_inode *nfsi = NFS_I(inode);
436
437 spin_lock(&nfsi->req_lock);
3da28eb1
TM
438 radix_tree_tag_set(&nfsi->nfs_page_tree,
439 req->wb_index, NFS_PAGE_TAG_DIRTY);
1da177e4
LT
440 nfs_list_add_request(req, &nfsi->dirty);
441 nfsi->ndirty++;
442 spin_unlock(&nfsi->req_lock);
1da177e4
LT
443 mark_inode_dirty(inode);
444}
445
61822ab5
TM
446static void
447nfs_redirty_request(struct nfs_page *req)
448{
449 clear_bit(PG_FLUSHING, &req->wb_flags);
450 __set_page_dirty_nobuffers(req->wb_page);
451}
452
1da177e4
LT
453/*
454 * Check if a request is dirty
455 */
456static inline int
457nfs_dirty_request(struct nfs_page *req)
458{
e261f51f 459 return test_bit(PG_FLUSHING, &req->wb_flags) == 0;
1da177e4
LT
460}
461
462#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
463/*
464 * Add a request to the inode's commit list.
465 */
466static void
467nfs_mark_request_commit(struct nfs_page *req)
468{
469 struct inode *inode = req->wb_context->dentry->d_inode;
470 struct nfs_inode *nfsi = NFS_I(inode);
471
472 spin_lock(&nfsi->req_lock);
473 nfs_list_add_request(req, &nfsi->commit);
474 nfsi->ncommit++;
475 spin_unlock(&nfsi->req_lock);
fd39fc85 476 inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
1da177e4
LT
477 mark_inode_dirty(inode);
478}
479#endif
480
481/*
482 * Wait for a request to complete.
483 *
484 * Interruptible by signals only if mounted with intr flag.
485 */
c42de9dd 486static int nfs_wait_on_requests_locked(struct inode *inode, unsigned long idx_start, unsigned int npages)
1da177e4
LT
487{
488 struct nfs_inode *nfsi = NFS_I(inode);
489 struct nfs_page *req;
490 unsigned long idx_end, next;
491 unsigned int res = 0;
492 int error;
493
494 if (npages == 0)
495 idx_end = ~0;
496 else
497 idx_end = idx_start + npages - 1;
498
1da177e4 499 next = idx_start;
c6a556b8 500 while (radix_tree_gang_lookup_tag(&nfsi->nfs_page_tree, (void **)&req, next, 1, NFS_PAGE_TAG_WRITEBACK)) {
1da177e4
LT
501 if (req->wb_index > idx_end)
502 break;
503
504 next = req->wb_index + 1;
c6a556b8 505 BUG_ON(!NFS_WBACK_BUSY(req));
1da177e4
LT
506
507 atomic_inc(&req->wb_count);
508 spin_unlock(&nfsi->req_lock);
509 error = nfs_wait_on_request(req);
510 nfs_release_request(req);
c42de9dd 511 spin_lock(&nfsi->req_lock);
1da177e4
LT
512 if (error < 0)
513 return error;
1da177e4
LT
514 res++;
515 }
1da177e4
LT
516 return res;
517}
518
c42de9dd
TM
519static int nfs_wait_on_requests(struct inode *inode, unsigned long idx_start, unsigned int npages)
520{
521 struct nfs_inode *nfsi = NFS_I(inode);
522 int ret;
523
524 spin_lock(&nfsi->req_lock);
525 ret = nfs_wait_on_requests_locked(inode, idx_start, npages);
526 spin_unlock(&nfsi->req_lock);
527 return ret;
528}
529
83715ad5 530static void nfs_cancel_dirty_list(struct list_head *head)
d2ccddf0
TM
531{
532 struct nfs_page *req;
533 while(!list_empty(head)) {
534 req = nfs_list_entry(head->next);
535 nfs_list_remove_request(req);
536 nfs_inode_remove_request(req);
537 nfs_clear_page_writeback(req);
538 }
539}
540
83715ad5
TM
541static void nfs_cancel_commit_list(struct list_head *head)
542{
543 struct nfs_page *req;
544
545 while(!list_empty(head)) {
546 req = nfs_list_entry(head->next);
b6dff26a 547 dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
83715ad5
TM
548 nfs_list_remove_request(req);
549 nfs_inode_remove_request(req);
b6dff26a 550 nfs_unlock_request(req);
83715ad5
TM
551 }
552}
553
1da177e4
LT
554#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
555/*
556 * nfs_scan_commit - Scan an inode for commit requests
557 * @inode: NFS inode to scan
558 * @dst: destination list
559 * @idx_start: lower bound of page->index to scan.
560 * @npages: idx_start + npages sets the upper bound to scan.
561 *
562 * Moves requests from the inode's 'commit' request list.
563 * The requests are *not* checked to ensure that they form a contiguous set.
564 */
565static int
566nfs_scan_commit(struct inode *inode, struct list_head *dst, unsigned long idx_start, unsigned int npages)
567{
568 struct nfs_inode *nfsi = NFS_I(inode);
3da28eb1
TM
569 int res = 0;
570
571 if (nfsi->ncommit != 0) {
d2ccddf0 572 res = nfs_scan_list(nfsi, &nfsi->commit, dst, idx_start, npages);
3da28eb1
TM
573 nfsi->ncommit -= res;
574 if ((nfsi->ncommit == 0) != list_empty(&nfsi->commit))
575 printk(KERN_ERR "NFS: desynchronized value of nfs_i.ncommit.\n");
576 }
1da177e4
LT
577 return res;
578}
c42de9dd
TM
579#else
580static inline int nfs_scan_commit(struct inode *inode, struct list_head *dst, unsigned long idx_start, unsigned int npages)
581{
582 return 0;
583}
1da177e4
LT
584#endif
585
586static int nfs_wait_on_write_congestion(struct address_space *mapping, int intr)
587{
588 struct backing_dev_info *bdi = mapping->backing_dev_info;
589 DEFINE_WAIT(wait);
590 int ret = 0;
591
592 might_sleep();
593
594 if (!bdi_write_congested(bdi))
595 return 0;
91d5b470
CL
596
597 nfs_inc_stats(mapping->host, NFSIOS_CONGESTIONWAIT);
598
1da177e4
LT
599 if (intr) {
600 struct rpc_clnt *clnt = NFS_CLIENT(mapping->host);
601 sigset_t oldset;
602
603 rpc_clnt_sigmask(clnt, &oldset);
604 prepare_to_wait(&nfs_write_congestion, &wait, TASK_INTERRUPTIBLE);
605 if (bdi_write_congested(bdi)) {
606 if (signalled())
607 ret = -ERESTARTSYS;
608 else
609 schedule();
610 }
611 rpc_clnt_sigunmask(clnt, &oldset);
612 } else {
613 prepare_to_wait(&nfs_write_congestion, &wait, TASK_UNINTERRUPTIBLE);
614 if (bdi_write_congested(bdi))
615 schedule();
616 }
617 finish_wait(&nfs_write_congestion, &wait);
618 return ret;
619}
620
621
622/*
623 * Try to update any existing write request, or create one if there is none.
624 * In order to match, the request's credentials must match those of
625 * the calling process.
626 *
627 * Note: Should always be called with the Page Lock held!
628 */
629static struct nfs_page * nfs_update_request(struct nfs_open_context* ctx,
e21195a7 630 struct page *page, unsigned int offset, unsigned int bytes)
1da177e4 631{
e21195a7 632 struct inode *inode = page->mapping->host;
1da177e4
LT
633 struct nfs_inode *nfsi = NFS_I(inode);
634 struct nfs_page *req, *new = NULL;
635 unsigned long rqend, end;
636
637 end = offset + bytes;
638
e21195a7 639 if (nfs_wait_on_write_congestion(page->mapping, NFS_SERVER(inode)->flags & NFS_MOUNT_INTR))
1da177e4
LT
640 return ERR_PTR(-ERESTARTSYS);
641 for (;;) {
642 /* Loop over all inode entries and see if we find
643 * A request for the page we wish to update
644 */
645 spin_lock(&nfsi->req_lock);
277459d2 646 req = nfs_page_find_request_locked(page);
1da177e4
LT
647 if (req) {
648 if (!nfs_lock_request_dontget(req)) {
649 int error;
277459d2 650
1da177e4
LT
651 spin_unlock(&nfsi->req_lock);
652 error = nfs_wait_on_request(req);
653 nfs_release_request(req);
1dd594b2
NB
654 if (error < 0) {
655 if (new)
656 nfs_release_request(new);
1da177e4 657 return ERR_PTR(error);
1dd594b2 658 }
1da177e4
LT
659 continue;
660 }
661 spin_unlock(&nfsi->req_lock);
662 if (new)
663 nfs_release_request(new);
664 break;
665 }
666
667 if (new) {
668 int error;
669 nfs_lock_request_dontget(new);
670 error = nfs_inode_add_request(inode, new);
671 if (error) {
672 spin_unlock(&nfsi->req_lock);
673 nfs_unlock_request(new);
674 return ERR_PTR(error);
675 }
676 spin_unlock(&nfsi->req_lock);
1da177e4
LT
677 return new;
678 }
679 spin_unlock(&nfsi->req_lock);
680
681 new = nfs_create_request(ctx, inode, page, offset, bytes);
682 if (IS_ERR(new))
683 return new;
684 }
685
686 /* We have a request for our page.
687 * If the creds don't match, or the
688 * page addresses don't match,
689 * tell the caller to wait on the conflicting
690 * request.
691 */
692 rqend = req->wb_offset + req->wb_bytes;
693 if (req->wb_context != ctx
694 || req->wb_page != page
695 || !nfs_dirty_request(req)
696 || offset > rqend || end < req->wb_offset) {
697 nfs_unlock_request(req);
698 return ERR_PTR(-EBUSY);
699 }
700
701 /* Okay, the request matches. Update the region */
702 if (offset < req->wb_offset) {
703 req->wb_offset = offset;
704 req->wb_pgbase = offset;
705 req->wb_bytes = rqend - req->wb_offset;
706 }
707
708 if (end > rqend)
709 req->wb_bytes = end - req->wb_offset;
710
711 return req;
712}
713
714int nfs_flush_incompatible(struct file *file, struct page *page)
715{
716 struct nfs_open_context *ctx = (struct nfs_open_context *)file->private_data;
1da177e4 717 struct nfs_page *req;
1a54533e 718 int do_flush, status;
1da177e4
LT
719 /*
720 * Look for a request corresponding to this page. If there
721 * is one, and it belongs to another file, we flush it out
722 * before we try to copy anything into the page. Do this
723 * due to the lack of an ACCESS-type call in NFSv2.
724 * Also do the same if we find a request from an existing
725 * dropped page.
726 */
1a54533e
TM
727 do {
728 req = nfs_page_find_request(page);
729 if (req == NULL)
730 return 0;
731 do_flush = req->wb_page != page || req->wb_context != ctx
e261f51f 732 || !nfs_dirty_request(req);
1da177e4 733 nfs_release_request(req);
1a54533e
TM
734 if (!do_flush)
735 return 0;
736 status = nfs_wb_page(page->mapping->host, page);
737 } while (status == 0);
738 return status;
1da177e4
LT
739}
740
741/*
742 * Update and possibly write a cached page of an NFS file.
743 *
744 * XXX: Keep an eye on generic_file_read to make sure it doesn't do bad
745 * things with a page scheduled for an RPC call (e.g. invalidate it).
746 */
747int nfs_updatepage(struct file *file, struct page *page,
748 unsigned int offset, unsigned int count)
749{
750 struct nfs_open_context *ctx = (struct nfs_open_context *)file->private_data;
1da177e4 751 struct inode *inode = page->mapping->host;
1da177e4
LT
752 int status = 0;
753
91d5b470
CL
754 nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE);
755
1da177e4 756 dprintk("NFS: nfs_updatepage(%s/%s %d@%Ld)\n",
0bbacc40
CL
757 file->f_dentry->d_parent->d_name.name,
758 file->f_dentry->d_name.name, count,
759 (long long)(page_offset(page) +offset));
1da177e4 760
1da177e4
LT
761 /* If we're not using byte range locks, and we know the page
762 * is entirely in cache, it may be more efficient to avoid
763 * fragmenting write requests.
764 */
ab0a3dbe 765 if (PageUptodate(page) && inode->i_flock == NULL && !(file->f_mode & O_SYNC)) {
49a70f27 766 count = max(count + offset, nfs_page_length(page));
1da177e4 767 offset = 0;
1da177e4
LT
768 }
769
e21195a7 770 status = nfs_writepage_setup(ctx, page, offset, count);
e261f51f 771 __set_page_dirty_nobuffers(page);
1da177e4 772
1da177e4
LT
773 dprintk("NFS: nfs_updatepage returns %d (isize %Ld)\n",
774 status, (long long)i_size_read(inode));
775 if (status < 0)
776 ClearPageUptodate(page);
777 return status;
778}
779
780static void nfs_writepage_release(struct nfs_page *req)
781{
782 end_page_writeback(req->wb_page);
783
784#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
785 if (!PageError(req->wb_page)) {
786 if (NFS_NEED_RESCHED(req)) {
61822ab5 787 nfs_redirty_request(req);
1da177e4
LT
788 goto out;
789 } else if (NFS_NEED_COMMIT(req)) {
790 nfs_mark_request_commit(req);
791 goto out;
792 }
793 }
794 nfs_inode_remove_request(req);
795
796out:
797 nfs_clear_commit(req);
798 nfs_clear_reschedule(req);
799#else
800 nfs_inode_remove_request(req);
801#endif
c6a556b8 802 nfs_clear_page_writeback(req);
1da177e4
LT
803}
804
805static inline int flush_task_priority(int how)
806{
807 switch (how & (FLUSH_HIGHPRI|FLUSH_LOWPRI)) {
808 case FLUSH_HIGHPRI:
809 return RPC_PRIORITY_HIGH;
810 case FLUSH_LOWPRI:
811 return RPC_PRIORITY_LOW;
812 }
813 return RPC_PRIORITY_NORMAL;
814}
815
816/*
817 * Set up the argument/result storage required for the RPC call.
818 */
819static void nfs_write_rpcsetup(struct nfs_page *req,
820 struct nfs_write_data *data,
788e7a89 821 const struct rpc_call_ops *call_ops,
1da177e4
LT
822 unsigned int count, unsigned int offset,
823 int how)
824{
1da177e4 825 struct inode *inode;
788e7a89 826 int flags;
1da177e4
LT
827
828 /* Set up the RPC argument and reply structs
829 * NB: take care not to mess about with data->commit et al. */
830
831 data->req = req;
832 data->inode = inode = req->wb_context->dentry->d_inode;
833 data->cred = req->wb_context->cred;
834
835 data->args.fh = NFS_FH(inode);
836 data->args.offset = req_offset(req) + offset;
837 data->args.pgbase = req->wb_pgbase + offset;
838 data->args.pages = data->pagevec;
839 data->args.count = count;
840 data->args.context = req->wb_context;
841
842 data->res.fattr = &data->fattr;
843 data->res.count = count;
844 data->res.verf = &data->verf;
0e574af1 845 nfs_fattr_init(&data->fattr);
1da177e4 846
788e7a89
TM
847 /* Set up the initial task struct. */
848 flags = (how & FLUSH_SYNC) ? 0 : RPC_TASK_ASYNC;
849 rpc_init_task(&data->task, NFS_CLIENT(inode), flags, call_ops, data);
1da177e4
LT
850 NFS_PROTO(inode)->write_setup(data, how);
851
852 data->task.tk_priority = flush_task_priority(how);
853 data->task.tk_cookie = (unsigned long)inode;
1da177e4
LT
854
855 dprintk("NFS: %4d initiated write call (req %s/%Ld, %u bytes @ offset %Lu)\n",
0bbacc40 856 data->task.tk_pid,
1da177e4
LT
857 inode->i_sb->s_id,
858 (long long)NFS_FILEID(inode),
859 count,
860 (unsigned long long)data->args.offset);
861}
862
863static void nfs_execute_write(struct nfs_write_data *data)
864{
865 struct rpc_clnt *clnt = NFS_CLIENT(data->inode);
866 sigset_t oldset;
867
868 rpc_clnt_sigmask(clnt, &oldset);
1da177e4 869 rpc_execute(&data->task);
1da177e4
LT
870 rpc_clnt_sigunmask(clnt, &oldset);
871}
872
873/*
874 * Generate multiple small requests to write out a single
875 * contiguous dirty area on one page.
876 */
7d46a49f 877static int nfs_flush_multi(struct inode *inode, struct list_head *head, int how)
1da177e4
LT
878{
879 struct nfs_page *req = nfs_list_entry(head->next);
880 struct page *page = req->wb_page;
881 struct nfs_write_data *data;
e9f7bee1
TM
882 size_t wsize = NFS_SERVER(inode)->wsize, nbytes;
883 unsigned int offset;
1da177e4
LT
884 int requests = 0;
885 LIST_HEAD(list);
886
887 nfs_list_remove_request(req);
888
889 nbytes = req->wb_bytes;
e9f7bee1
TM
890 do {
891 size_t len = min(nbytes, wsize);
892
893 data = nfs_writedata_alloc(len);
1da177e4
LT
894 if (!data)
895 goto out_bad;
896 list_add(&data->pages, &list);
897 requests++;
e9f7bee1
TM
898 nbytes -= len;
899 } while (nbytes != 0);
1da177e4
LT
900 atomic_set(&req->wb_complete, requests);
901
902 ClearPageError(page);
1da177e4
LT
903 offset = 0;
904 nbytes = req->wb_bytes;
905 do {
906 data = list_entry(list.next, struct nfs_write_data, pages);
907 list_del_init(&data->pages);
908
909 data->pagevec[0] = page;
1da177e4
LT
910
911 if (nbytes > wsize) {
788e7a89
TM
912 nfs_write_rpcsetup(req, data, &nfs_write_partial_ops,
913 wsize, offset, how);
1da177e4
LT
914 offset += wsize;
915 nbytes -= wsize;
916 } else {
788e7a89
TM
917 nfs_write_rpcsetup(req, data, &nfs_write_partial_ops,
918 nbytes, offset, how);
1da177e4
LT
919 nbytes = 0;
920 }
921 nfs_execute_write(data);
922 } while (nbytes != 0);
923
924 return 0;
925
926out_bad:
927 while (!list_empty(&list)) {
928 data = list_entry(list.next, struct nfs_write_data, pages);
929 list_del(&data->pages);
8aca67f0 930 nfs_writedata_release(data);
1da177e4 931 }
61822ab5 932 nfs_redirty_request(req);
c6a556b8 933 nfs_clear_page_writeback(req);
1da177e4
LT
934 return -ENOMEM;
935}
936
937/*
938 * Create an RPC task for the given write request and kick it.
939 * The page must have been locked by the caller.
940 *
941 * It may happen that the page we're passed is not marked dirty.
942 * This is the case if nfs_updatepage detects a conflicting request
943 * that has been written but not committed.
944 */
7d46a49f 945static int nfs_flush_one(struct inode *inode, struct list_head *head, int how)
1da177e4
LT
946{
947 struct nfs_page *req;
948 struct page **pages;
949 struct nfs_write_data *data;
950 unsigned int count;
951
e9f7bee1 952 data = nfs_writedata_alloc(NFS_SERVER(inode)->wsize);
1da177e4
LT
953 if (!data)
954 goto out_bad;
955
956 pages = data->pagevec;
957 count = 0;
958 while (!list_empty(head)) {
959 req = nfs_list_entry(head->next);
960 nfs_list_remove_request(req);
961 nfs_list_add_request(req, &data->pages);
962 ClearPageError(req->wb_page);
1da177e4
LT
963 *pages++ = req->wb_page;
964 count += req->wb_bytes;
965 }
966 req = nfs_list_entry(data->pages.next);
967
1da177e4 968 /* Set up the argument struct */
788e7a89 969 nfs_write_rpcsetup(req, data, &nfs_write_full_ops, count, 0, how);
1da177e4
LT
970
971 nfs_execute_write(data);
972 return 0;
973 out_bad:
974 while (!list_empty(head)) {
975 struct nfs_page *req = nfs_list_entry(head->next);
976 nfs_list_remove_request(req);
61822ab5 977 nfs_redirty_request(req);
c6a556b8 978 nfs_clear_page_writeback(req);
1da177e4
LT
979 }
980 return -ENOMEM;
981}
982
7d46a49f 983static int nfs_flush_list(struct inode *inode, struct list_head *head, int npages, int how)
1da177e4
LT
984{
985 LIST_HEAD(one_request);
7d46a49f
TM
986 int (*flush_one)(struct inode *, struct list_head *, int);
987 struct nfs_page *req;
988 int wpages = NFS_SERVER(inode)->wpages;
989 int wsize = NFS_SERVER(inode)->wsize;
990 int error;
1da177e4 991
7d46a49f
TM
992 flush_one = nfs_flush_one;
993 if (wsize < PAGE_CACHE_SIZE)
994 flush_one = nfs_flush_multi;
995 /* For single writes, FLUSH_STABLE is more efficient */
996 if (npages <= wpages && npages == NFS_I(inode)->npages
997 && nfs_list_entry(head->next)->wb_bytes <= wsize)
998 how |= FLUSH_STABLE;
999
1000 do {
1001 nfs_coalesce_requests(head, &one_request, wpages);
1da177e4 1002 req = nfs_list_entry(one_request.next);
7d46a49f 1003 error = flush_one(inode, &one_request, how);
1da177e4 1004 if (error < 0)
7d46a49f
TM
1005 goto out_err;
1006 } while (!list_empty(head));
1007 return 0;
1008out_err:
1da177e4
LT
1009 while (!list_empty(head)) {
1010 req = nfs_list_entry(head->next);
1011 nfs_list_remove_request(req);
61822ab5 1012 nfs_redirty_request(req);
c6a556b8 1013 nfs_clear_page_writeback(req);
1da177e4
LT
1014 }
1015 return error;
1016}
1017
1018/*
1019 * Handle a write reply that flushed part of a page.
1020 */
788e7a89 1021static void nfs_writeback_done_partial(struct rpc_task *task, void *calldata)
1da177e4 1022{
788e7a89 1023 struct nfs_write_data *data = calldata;
1da177e4
LT
1024 struct nfs_page *req = data->req;
1025 struct page *page = req->wb_page;
1026
1027 dprintk("NFS: write (%s/%Ld %d@%Ld)",
1028 req->wb_context->dentry->d_inode->i_sb->s_id,
1029 (long long)NFS_FILEID(req->wb_context->dentry->d_inode),
1030 req->wb_bytes,
1031 (long long)req_offset(req));
1032
788e7a89
TM
1033 if (nfs_writeback_done(task, data) != 0)
1034 return;
1035
1036 if (task->tk_status < 0) {
1da177e4
LT
1037 ClearPageUptodate(page);
1038 SetPageError(page);
788e7a89
TM
1039 req->wb_context->error = task->tk_status;
1040 dprintk(", error = %d\n", task->tk_status);
1da177e4
LT
1041 } else {
1042#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
1043 if (data->verf.committed < NFS_FILE_SYNC) {
1044 if (!NFS_NEED_COMMIT(req)) {
1045 nfs_defer_commit(req);
1046 memcpy(&req->wb_verf, &data->verf, sizeof(req->wb_verf));
1047 dprintk(" defer commit\n");
1048 } else if (memcmp(&req->wb_verf, &data->verf, sizeof(req->wb_verf))) {
1049 nfs_defer_reschedule(req);
1050 dprintk(" server reboot detected\n");
1051 }
1052 } else
1053#endif
1054 dprintk(" OK\n");
1055 }
1056
1057 if (atomic_dec_and_test(&req->wb_complete))
1058 nfs_writepage_release(req);
1059}
1060
788e7a89
TM
1061static const struct rpc_call_ops nfs_write_partial_ops = {
1062 .rpc_call_done = nfs_writeback_done_partial,
1063 .rpc_release = nfs_writedata_release,
1064};
1065
1da177e4
LT
1066/*
1067 * Handle a write reply that flushes a whole page.
1068 *
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.
1072 */
788e7a89 1073static void nfs_writeback_done_full(struct rpc_task *task, void *calldata)
1da177e4 1074{
788e7a89 1075 struct nfs_write_data *data = calldata;
1da177e4
LT
1076 struct nfs_page *req;
1077 struct page *page;
1078
788e7a89
TM
1079 if (nfs_writeback_done(task, data) != 0)
1080 return;
1081
1da177e4
LT
1082 /* Update attributes as result of writeback. */
1083 while (!list_empty(&data->pages)) {
1084 req = nfs_list_entry(data->pages.next);
1085 nfs_list_remove_request(req);
1086 page = req->wb_page;
1087
1088 dprintk("NFS: write (%s/%Ld %d@%Ld)",
1089 req->wb_context->dentry->d_inode->i_sb->s_id,
1090 (long long)NFS_FILEID(req->wb_context->dentry->d_inode),
1091 req->wb_bytes,
1092 (long long)req_offset(req));
1093
788e7a89 1094 if (task->tk_status < 0) {
1da177e4
LT
1095 ClearPageUptodate(page);
1096 SetPageError(page);
788e7a89 1097 req->wb_context->error = task->tk_status;
1da177e4
LT
1098 end_page_writeback(page);
1099 nfs_inode_remove_request(req);
788e7a89 1100 dprintk(", error = %d\n", task->tk_status);
1da177e4
LT
1101 goto next;
1102 }
1103 end_page_writeback(page);
1104
1105#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
1106 if (data->args.stable != NFS_UNSTABLE || data->verf.committed == NFS_FILE_SYNC) {
1107 nfs_inode_remove_request(req);
1108 dprintk(" OK\n");
1109 goto next;
1110 }
1111 memcpy(&req->wb_verf, &data->verf, sizeof(req->wb_verf));
1112 nfs_mark_request_commit(req);
1113 dprintk(" marked for commit\n");
1114#else
1115 nfs_inode_remove_request(req);
1116#endif
1117 next:
c6a556b8 1118 nfs_clear_page_writeback(req);
1da177e4
LT
1119 }
1120}
1121
788e7a89
TM
1122static const struct rpc_call_ops nfs_write_full_ops = {
1123 .rpc_call_done = nfs_writeback_done_full,
1124 .rpc_release = nfs_writedata_release,
1125};
1126
1127
1da177e4
LT
1128/*
1129 * This function is called when the WRITE call is complete.
1130 */
462d5b32 1131int nfs_writeback_done(struct rpc_task *task, struct nfs_write_data *data)
1da177e4 1132{
1da177e4
LT
1133 struct nfs_writeargs *argp = &data->args;
1134 struct nfs_writeres *resp = &data->res;
788e7a89 1135 int status;
1da177e4
LT
1136
1137 dprintk("NFS: %4d nfs_writeback_done (status %d)\n",
1138 task->tk_pid, task->tk_status);
1139
f551e44f
CL
1140 /*
1141 * ->write_done will attempt to use post-op attributes to detect
1142 * conflicting writes by other clients. A strict interpretation
1143 * of close-to-open would allow us to continue caching even if
1144 * another writer had changed the file, but some applications
1145 * depend on tighter cache coherency when writing.
1146 */
788e7a89
TM
1147 status = NFS_PROTO(data->inode)->write_done(task, data);
1148 if (status != 0)
1149 return status;
91d5b470
CL
1150 nfs_add_stats(data->inode, NFSIOS_SERVERWRITTENBYTES, resp->count);
1151
1da177e4
LT
1152#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
1153 if (resp->verf->committed < argp->stable && task->tk_status >= 0) {
1154 /* We tried a write call, but the server did not
1155 * commit data to stable storage even though we
1156 * requested it.
1157 * Note: There is a known bug in Tru64 < 5.0 in which
1158 * the server reports NFS_DATA_SYNC, but performs
1159 * NFS_FILE_SYNC. We therefore implement this checking
1160 * as a dprintk() in order to avoid filling syslog.
1161 */
1162 static unsigned long complain;
1163
1164 if (time_before(complain, jiffies)) {
1165 dprintk("NFS: faulty NFS server %s:"
1166 " (committed = %d) != (stable = %d)\n",
54ceac45 1167 NFS_SERVER(data->inode)->nfs_client->cl_hostname,
1da177e4
LT
1168 resp->verf->committed, argp->stable);
1169 complain = jiffies + 300 * HZ;
1170 }
1171 }
1172#endif
1173 /* Is this a short write? */
1174 if (task->tk_status >= 0 && resp->count < argp->count) {
1175 static unsigned long complain;
1176
91d5b470
CL
1177 nfs_inc_stats(data->inode, NFSIOS_SHORTWRITE);
1178
1da177e4
LT
1179 /* Has the server at least made some progress? */
1180 if (resp->count != 0) {
1181 /* Was this an NFSv2 write or an NFSv3 stable write? */
1182 if (resp->verf->committed != NFS_UNSTABLE) {
1183 /* Resend from where the server left off */
1184 argp->offset += resp->count;
1185 argp->pgbase += resp->count;
1186 argp->count -= resp->count;
1187 } else {
1188 /* Resend as a stable write in order to avoid
1189 * headaches in the case of a server crash.
1190 */
1191 argp->stable = NFS_FILE_SYNC;
1192 }
1193 rpc_restart_call(task);
788e7a89 1194 return -EAGAIN;
1da177e4
LT
1195 }
1196 if (time_before(complain, jiffies)) {
1197 printk(KERN_WARNING
1198 "NFS: Server wrote zero bytes, expected %u.\n",
1199 argp->count);
1200 complain = jiffies + 300 * HZ;
1201 }
1202 /* Can't do anything about it except throw an error. */
1203 task->tk_status = -EIO;
1204 }
788e7a89 1205 return 0;
1da177e4
LT
1206}
1207
1208
1209#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
963d8fe5 1210void nfs_commit_release(void *wdata)
1da177e4 1211{
1da177e4
LT
1212 nfs_commit_free(wdata);
1213}
1214
1215/*
1216 * Set up the argument/result storage required for the RPC call.
1217 */
1218static void nfs_commit_rpcsetup(struct list_head *head,
788e7a89
TM
1219 struct nfs_write_data *data,
1220 int how)
1da177e4 1221{
3da28eb1 1222 struct nfs_page *first;
1da177e4 1223 struct inode *inode;
788e7a89 1224 int flags;
1da177e4
LT
1225
1226 /* Set up the RPC argument and reply structs
1227 * NB: take care not to mess about with data->commit et al. */
1228
1229 list_splice_init(head, &data->pages);
1230 first = nfs_list_entry(data->pages.next);
1da177e4
LT
1231 inode = first->wb_context->dentry->d_inode;
1232
1da177e4
LT
1233 data->inode = inode;
1234 data->cred = first->wb_context->cred;
1235
1236 data->args.fh = NFS_FH(data->inode);
3da28eb1
TM
1237 /* Note: we always request a commit of the entire inode */
1238 data->args.offset = 0;
1239 data->args.count = 0;
1240 data->res.count = 0;
1da177e4
LT
1241 data->res.fattr = &data->fattr;
1242 data->res.verf = &data->verf;
0e574af1 1243 nfs_fattr_init(&data->fattr);
788e7a89
TM
1244
1245 /* Set up the initial task struct. */
1246 flags = (how & FLUSH_SYNC) ? 0 : RPC_TASK_ASYNC;
1247 rpc_init_task(&data->task, NFS_CLIENT(inode), flags, &nfs_commit_ops, data);
1da177e4
LT
1248 NFS_PROTO(inode)->commit_setup(data, how);
1249
1250 data->task.tk_priority = flush_task_priority(how);
1251 data->task.tk_cookie = (unsigned long)inode;
1da177e4 1252
0bbacc40 1253 dprintk("NFS: %4d initiated commit call\n", data->task.tk_pid);
1da177e4
LT
1254}
1255
1256/*
1257 * Commit dirty pages
1258 */
1259static int
40859d7e 1260nfs_commit_list(struct inode *inode, struct list_head *head, int how)
1da177e4
LT
1261{
1262 struct nfs_write_data *data;
1263 struct nfs_page *req;
1264
e9f7bee1 1265 data = nfs_commit_alloc();
1da177e4
LT
1266
1267 if (!data)
1268 goto out_bad;
1269
1270 /* Set up the argument struct */
1271 nfs_commit_rpcsetup(head, data, how);
1272
1273 nfs_execute_write(data);
1274 return 0;
1275 out_bad:
1276 while (!list_empty(head)) {
1277 req = nfs_list_entry(head->next);
1278 nfs_list_remove_request(req);
1279 nfs_mark_request_commit(req);
83715ad5 1280 dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
5c2d97cb 1281 nfs_clear_page_writeback(req);
1da177e4
LT
1282 }
1283 return -ENOMEM;
1284}
1285
1286/*
1287 * COMMIT call returned
1288 */
788e7a89 1289static void nfs_commit_done(struct rpc_task *task, void *calldata)
1da177e4 1290{
963d8fe5 1291 struct nfs_write_data *data = calldata;
1da177e4 1292 struct nfs_page *req;
1da177e4
LT
1293
1294 dprintk("NFS: %4d nfs_commit_done (status %d)\n",
1295 task->tk_pid, task->tk_status);
1296
788e7a89
TM
1297 /* Call the NFS version-specific code */
1298 if (NFS_PROTO(data->inode)->commit_done(task, data) != 0)
1299 return;
1300
1da177e4
LT
1301 while (!list_empty(&data->pages)) {
1302 req = nfs_list_entry(data->pages.next);
1303 nfs_list_remove_request(req);
fd39fc85 1304 dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
1da177e4
LT
1305
1306 dprintk("NFS: commit (%s/%Ld %d@%Ld)",
1307 req->wb_context->dentry->d_inode->i_sb->s_id,
1308 (long long)NFS_FILEID(req->wb_context->dentry->d_inode),
1309 req->wb_bytes,
1310 (long long)req_offset(req));
1311 if (task->tk_status < 0) {
1312 req->wb_context->error = task->tk_status;
1313 nfs_inode_remove_request(req);
1314 dprintk(", error = %d\n", task->tk_status);
1315 goto next;
1316 }
1317
1318 /* Okay, COMMIT succeeded, apparently. Check the verifier
1319 * returned by the server against all stored verfs. */
1320 if (!memcmp(req->wb_verf.verifier, data->verf.verifier, sizeof(data->verf.verifier))) {
1321 /* We have a match */
1322 nfs_inode_remove_request(req);
1323 dprintk(" OK\n");
1324 goto next;
1325 }
1326 /* We have a mismatch. Write the page again */
1327 dprintk(" mismatch\n");
61822ab5 1328 nfs_redirty_request(req);
1da177e4 1329 next:
c6a556b8 1330 nfs_clear_page_writeback(req);
1da177e4 1331 }
1da177e4 1332}
788e7a89
TM
1333
1334static const struct rpc_call_ops nfs_commit_ops = {
1335 .rpc_call_done = nfs_commit_done,
1336 .rpc_release = nfs_commit_release,
1337};
c42de9dd
TM
1338#else
1339static inline int nfs_commit_list(struct inode *inode, struct list_head *head, int how)
1340{
1341 return 0;
1342}
1da177e4
LT
1343#endif
1344
3f442547 1345static long nfs_flush_mapping(struct address_space *mapping, struct writeback_control *wbc, int how)
1da177e4 1346{
28c6925f 1347 struct nfs_inode *nfsi = NFS_I(mapping->host);
1da177e4 1348 LIST_HEAD(head);
3f442547 1349 long res;
1da177e4
LT
1350
1351 spin_lock(&nfsi->req_lock);
3f442547 1352 res = nfs_scan_dirty(mapping, wbc, &head);
1da177e4 1353 spin_unlock(&nfsi->req_lock);
ab0a3dbe 1354 if (res) {
28c6925f 1355 int error = nfs_flush_list(mapping->host, &head, res, how);
7d46a49f
TM
1356 if (error < 0)
1357 return error;
ab0a3dbe 1358 }
1da177e4
LT
1359 return res;
1360}
1361
1362#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
3da28eb1 1363int nfs_commit_inode(struct inode *inode, int how)
1da177e4
LT
1364{
1365 struct nfs_inode *nfsi = NFS_I(inode);
1366 LIST_HEAD(head);
7d46a49f 1367 int res;
1da177e4
LT
1368
1369 spin_lock(&nfsi->req_lock);
3da28eb1
TM
1370 res = nfs_scan_commit(inode, &head, 0, 0);
1371 spin_unlock(&nfsi->req_lock);
1da177e4 1372 if (res) {
7d46a49f 1373 int error = nfs_commit_list(inode, &head, how);
3da28eb1
TM
1374 if (error < 0)
1375 return error;
1376 }
1da177e4
LT
1377 return res;
1378}
1379#endif
1380
1c75950b 1381long nfs_sync_mapping_wait(struct address_space *mapping, struct writeback_control *wbc, int how)
1da177e4 1382{
1c75950b 1383 struct inode *inode = mapping->host;
c42de9dd 1384 struct nfs_inode *nfsi = NFS_I(inode);
1c75950b
TM
1385 unsigned long idx_start, idx_end;
1386 unsigned int npages = 0;
c42de9dd 1387 LIST_HEAD(head);
70b9ecbd 1388 int nocommit = how & FLUSH_NOCOMMIT;
3f442547 1389 long pages, ret;
1da177e4 1390
1c75950b
TM
1391 /* FIXME */
1392 if (wbc->range_cyclic)
1393 idx_start = 0;
1394 else {
1395 idx_start = wbc->range_start >> PAGE_CACHE_SHIFT;
1396 idx_end = wbc->range_end >> PAGE_CACHE_SHIFT;
1397 if (idx_end > idx_start) {
1398 unsigned long l_npages = 1 + idx_end - idx_start;
1399 npages = l_npages;
1400 if (sizeof(npages) != sizeof(l_npages) &&
1401 (unsigned long)npages != l_npages)
1402 npages = 0;
1403 }
1404 }
c42de9dd
TM
1405 how &= ~FLUSH_NOCOMMIT;
1406 spin_lock(&nfsi->req_lock);
1da177e4 1407 do {
1c75950b 1408 wbc->pages_skipped = 0;
c42de9dd
TM
1409 ret = nfs_wait_on_requests_locked(inode, idx_start, npages);
1410 if (ret != 0)
70b9ecbd 1411 continue;
1c75950b 1412 pages = nfs_scan_dirty(mapping, wbc, &head);
c42de9dd
TM
1413 if (pages != 0) {
1414 spin_unlock(&nfsi->req_lock);
e8e058e8 1415 if (how & FLUSH_INVALIDATE) {
83715ad5 1416 nfs_cancel_dirty_list(&head);
e8e058e8
TM
1417 ret = pages;
1418 } else
d2ccddf0 1419 ret = nfs_flush_list(inode, &head, pages, how);
c42de9dd
TM
1420 spin_lock(&nfsi->req_lock);
1421 continue;
1422 }
1c75950b
TM
1423 if (wbc->pages_skipped != 0)
1424 continue;
c42de9dd
TM
1425 if (nocommit)
1426 break;
d2ccddf0 1427 pages = nfs_scan_commit(inode, &head, idx_start, npages);
1c75950b
TM
1428 if (pages == 0) {
1429 if (wbc->pages_skipped != 0)
1430 continue;
c42de9dd 1431 break;
1c75950b 1432 }
d2ccddf0
TM
1433 if (how & FLUSH_INVALIDATE) {
1434 spin_unlock(&nfsi->req_lock);
83715ad5 1435 nfs_cancel_commit_list(&head);
e8e058e8 1436 ret = pages;
d2ccddf0
TM
1437 spin_lock(&nfsi->req_lock);
1438 continue;
1439 }
1440 pages += nfs_scan_commit(inode, &head, 0, 0);
c42de9dd
TM
1441 spin_unlock(&nfsi->req_lock);
1442 ret = nfs_commit_list(inode, &head, how);
1443 spin_lock(&nfsi->req_lock);
1444 } while (ret >= 0);
1445 spin_unlock(&nfsi->req_lock);
1446 return ret;
1da177e4
LT
1447}
1448
1c75950b
TM
1449/*
1450 * flush the inode to disk.
1451 */
1452int nfs_wb_all(struct inode *inode)
1453{
1454 struct address_space *mapping = inode->i_mapping;
1455 struct writeback_control wbc = {
1456 .bdi = mapping->backing_dev_info,
1457 .sync_mode = WB_SYNC_ALL,
1458 .nr_to_write = LONG_MAX,
61822ab5 1459 .for_writepages = 1,
1c75950b
TM
1460 .range_cyclic = 1,
1461 };
1462 int ret;
1463
61822ab5
TM
1464 ret = generic_writepages(mapping, &wbc);
1465 if (ret < 0)
1466 goto out;
1c75950b
TM
1467 ret = nfs_sync_mapping_wait(mapping, &wbc, 0);
1468 if (ret >= 0)
1469 return 0;
61822ab5 1470out:
e507d9eb 1471 __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
1c75950b
TM
1472 return ret;
1473}
1474
1475int nfs_sync_mapping_range(struct address_space *mapping, loff_t range_start, loff_t range_end, int how)
1476{
1477 struct writeback_control wbc = {
1478 .bdi = mapping->backing_dev_info,
1479 .sync_mode = WB_SYNC_ALL,
1480 .nr_to_write = LONG_MAX,
1481 .range_start = range_start,
1482 .range_end = range_end,
61822ab5 1483 .for_writepages = 1,
1c75950b
TM
1484 };
1485 int ret;
1486
61822ab5
TM
1487 if (!(how & FLUSH_NOWRITEPAGE)) {
1488 ret = generic_writepages(mapping, &wbc);
1489 if (ret < 0)
1490 goto out;
1491 }
1c75950b
TM
1492 ret = nfs_sync_mapping_wait(mapping, &wbc, how);
1493 if (ret >= 0)
1494 return 0;
61822ab5 1495out:
e507d9eb 1496 __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
1c75950b
TM
1497 return ret;
1498}
1499
61822ab5 1500int nfs_wb_page_priority(struct inode *inode, struct page *page, int how)
1c75950b
TM
1501{
1502 loff_t range_start = page_offset(page);
1503 loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
4d770ccf
TM
1504 struct writeback_control wbc = {
1505 .bdi = page->mapping->backing_dev_info,
1506 .sync_mode = WB_SYNC_ALL,
1507 .nr_to_write = LONG_MAX,
1508 .range_start = range_start,
1509 .range_end = range_end,
1510 };
1511 int ret;
1c75950b 1512
4d770ccf
TM
1513 BUG_ON(!PageLocked(page));
1514 if (!(how & FLUSH_NOWRITEPAGE) && clear_page_dirty_for_io(page)) {
1515 ret = nfs_writepage_locked(page, &wbc);
1516 if (ret < 0)
1517 goto out;
1518 }
1519 ret = nfs_sync_mapping_wait(page->mapping, &wbc, how);
1520 if (ret >= 0)
1521 return 0;
1522out:
e507d9eb 1523 __mark_inode_dirty(inode, I_DIRTY_PAGES);
4d770ccf 1524 return ret;
1c75950b
TM
1525}
1526
1527/*
1528 * Write back all requests on one page - we do this before reading it.
1529 */
1530int nfs_wb_page(struct inode *inode, struct page* page)
1531{
4d770ccf 1532 return nfs_wb_page_priority(inode, page, FLUSH_STABLE);
1c75950b
TM
1533}
1534
1a54533e
TM
1535int nfs_set_page_dirty(struct page *page)
1536{
1537 struct nfs_page *req;
1538
1539 req = nfs_page_find_request(page);
1540 if (req != NULL) {
1541 /* Mark any existing write requests for flushing */
1542 set_bit(PG_NEED_FLUSH, &req->wb_flags);
1543 nfs_release_request(req);
1544 }
1545 return __set_page_dirty_nobuffers(page);
1546}
1547
1c75950b 1548
f7b422b1 1549int __init nfs_init_writepagecache(void)
1da177e4
LT
1550{
1551 nfs_wdata_cachep = kmem_cache_create("nfs_write_data",
1552 sizeof(struct nfs_write_data),
1553 0, SLAB_HWCACHE_ALIGN,
1554 NULL, NULL);
1555 if (nfs_wdata_cachep == NULL)
1556 return -ENOMEM;
1557
93d2341c
MD
1558 nfs_wdata_mempool = mempool_create_slab_pool(MIN_POOL_WRITE,
1559 nfs_wdata_cachep);
1da177e4
LT
1560 if (nfs_wdata_mempool == NULL)
1561 return -ENOMEM;
1562
93d2341c
MD
1563 nfs_commit_mempool = mempool_create_slab_pool(MIN_POOL_COMMIT,
1564 nfs_wdata_cachep);
1da177e4
LT
1565 if (nfs_commit_mempool == NULL)
1566 return -ENOMEM;
1567
1568 return 0;
1569}
1570
266bee88 1571void nfs_destroy_writepagecache(void)
1da177e4
LT
1572{
1573 mempool_destroy(nfs_commit_mempool);
1574 mempool_destroy(nfs_wdata_mempool);
1a1d92c1 1575 kmem_cache_destroy(nfs_wdata_cachep);
1da177e4
LT
1576}
1577