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10#include <linux/time.h>
11#include <linux/kernel.h>
12#include <linux/errno.h>
13#include <linux/fcntl.h>
14#include <linux/stat.h>
15#include <linux/mm.h>
16#include <linux/slab.h>
17#include <linux/pagemap.h>
18#include <linux/sunrpc/clnt.h>
19#include <linux/nfs_fs.h>
20#include <linux/nfs_page.h>
21
22#include <asm/system.h>
23
24#include "nfs4_fs.h"
25#include "internal.h"
26#include "iostat.h"
27#include "fscache.h"
28
29#define NFSDBG_FACILITY NFSDBG_PAGECACHE
30
31static int nfs_pagein_multi(struct inode *, struct list_head *, unsigned int, size_t, int);
32static int nfs_pagein_one(struct inode *, struct list_head *, unsigned int, size_t, int);
33static const struct rpc_call_ops nfs_read_partial_ops;
34static const struct rpc_call_ops nfs_read_full_ops;
35
36static struct kmem_cache *nfs_rdata_cachep;
37static mempool_t *nfs_rdata_mempool;
38
39#define MIN_POOL_READ (32)
40
41struct nfs_read_data *nfs_readdata_alloc(unsigned int pagecount)
42{
43 struct nfs_read_data *p = mempool_alloc(nfs_rdata_mempool, GFP_NOFS);
44
45 if (p) {
46 memset(p, 0, sizeof(*p));
47 INIT_LIST_HEAD(&p->pages);
48 p->npages = pagecount;
49 p->res.seq_res.sr_slotid = NFS4_MAX_SLOT_TABLE;
50 if (pagecount <= ARRAY_SIZE(p->page_array))
51 p->pagevec = p->page_array;
52 else {
53 p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_NOFS);
54 if (!p->pagevec) {
55 mempool_free(p, nfs_rdata_mempool);
56 p = NULL;
57 }
58 }
59 }
60 return p;
61}
62
63void nfs_readdata_free(struct nfs_read_data *p)
64{
65 if (p && (p->pagevec != &p->page_array[0]))
66 kfree(p->pagevec);
67 mempool_free(p, nfs_rdata_mempool);
68}
69
70static void nfs_readdata_release(struct nfs_read_data *rdata)
71{
72 put_nfs_open_context(rdata->args.context);
73 nfs_readdata_free(rdata);
74}
75
76static
77int nfs_return_empty_page(struct page *page)
78{
79 zero_user(page, 0, PAGE_CACHE_SIZE);
80 SetPageUptodate(page);
81 unlock_page(page);
82 return 0;
83}
84
85static void nfs_readpage_truncate_uninitialised_page(struct nfs_read_data *data)
86{
87 unsigned int remainder = data->args.count - data->res.count;
88 unsigned int base = data->args.pgbase + data->res.count;
89 unsigned int pglen;
90 struct page **pages;
91
92 if (data->res.eof == 0 || remainder == 0)
93 return;
94
95
96
97
98 pages = &data->args.pages[base >> PAGE_CACHE_SHIFT];
99 base &= ~PAGE_CACHE_MASK;
100 pglen = PAGE_CACHE_SIZE - base;
101 for (;;) {
102 if (remainder <= pglen) {
103 zero_user(*pages, base, remainder);
104 break;
105 }
106 zero_user(*pages, base, pglen);
107 pages++;
108 remainder -= pglen;
109 pglen = PAGE_CACHE_SIZE;
110 base = 0;
111 }
112}
113
114int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
115 struct page *page)
116{
117 LIST_HEAD(one_request);
118 struct nfs_page *new;
119 unsigned int len;
120
121 len = nfs_page_length(page);
122 if (len == 0)
123 return nfs_return_empty_page(page);
124 new = nfs_create_request(ctx, inode, page, 0, len);
125 if (IS_ERR(new)) {
126 unlock_page(page);
127 return PTR_ERR(new);
128 }
129 if (len < PAGE_CACHE_SIZE)
130 zero_user_segment(page, len, PAGE_CACHE_SIZE);
131
132 nfs_list_add_request(new, &one_request);
133 if (NFS_SERVER(inode)->rsize < PAGE_CACHE_SIZE)
134 nfs_pagein_multi(inode, &one_request, 1, len, 0);
135 else
136 nfs_pagein_one(inode, &one_request, 1, len, 0);
137 return 0;
138}
139
140static void nfs_readpage_release(struct nfs_page *req)
141{
142 struct inode *d_inode = req->wb_context->path.dentry->d_inode;
143
144 if (PageUptodate(req->wb_page))
145 nfs_readpage_to_fscache(d_inode, req->wb_page, 0);
146
147 unlock_page(req->wb_page);
148
149 dprintk("NFS: read done (%s/%Ld %d@%Ld)\n",
150 req->wb_context->path.dentry->d_inode->i_sb->s_id,
151 (long long)NFS_FILEID(req->wb_context->path.dentry->d_inode),
152 req->wb_bytes,
153 (long long)req_offset(req));
154 nfs_clear_request(req);
155 nfs_release_request(req);
156}
157
158
159
160
161static int nfs_read_rpcsetup(struct nfs_page *req, struct nfs_read_data *data,
162 const struct rpc_call_ops *call_ops,
163 unsigned int count, unsigned int offset)
164{
165 struct inode *inode = req->wb_context->path.dentry->d_inode;
166 int swap_flags = IS_SWAPFILE(inode) ? NFS_RPC_SWAPFLAGS : 0;
167 struct rpc_task *task;
168 struct rpc_message msg = {
169 .rpc_argp = &data->args,
170 .rpc_resp = &data->res,
171 .rpc_cred = req->wb_context->cred,
172 };
173 struct rpc_task_setup task_setup_data = {
174 .task = &data->task,
175 .rpc_client = NFS_CLIENT(inode),
176 .rpc_message = &msg,
177 .callback_ops = call_ops,
178 .callback_data = data,
179 .workqueue = nfsiod_workqueue,
180 .flags = RPC_TASK_ASYNC | swap_flags,
181 };
182
183 data->req = req;
184 data->inode = inode;
185 data->cred = msg.rpc_cred;
186
187 data->args.fh = NFS_FH(inode);
188 data->args.offset = req_offset(req) + offset;
189 data->args.pgbase = req->wb_pgbase + offset;
190 data->args.pages = data->pagevec;
191 data->args.count = count;
192 data->args.context = get_nfs_open_context(req->wb_context);
193
194 data->res.fattr = &data->fattr;
195 data->res.count = count;
196 data->res.eof = 0;
197 nfs_fattr_init(&data->fattr);
198
199
200 NFS_PROTO(inode)->read_setup(data, &msg);
201
202 dprintk("NFS: %5u initiated read call (req %s/%Ld, %u bytes @ offset %Lu)\n",
203 data->task.tk_pid,
204 inode->i_sb->s_id,
205 (long long)NFS_FILEID(inode),
206 count,
207 (unsigned long long)data->args.offset);
208
209 task = rpc_run_task(&task_setup_data);
210 if (IS_ERR(task))
211 return PTR_ERR(task);
212 rpc_put_task(task);
213 return 0;
214}
215
216static void
217nfs_async_read_error(struct list_head *head)
218{
219 struct nfs_page *req;
220
221 while (!list_empty(head)) {
222 req = nfs_list_entry(head->next);
223 nfs_list_remove_request(req);
224 SetPageError(req->wb_page);
225 nfs_readpage_release(req);
226 }
227}
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242static int nfs_pagein_multi(struct inode *inode, struct list_head *head, unsigned int npages, size_t count, int flags)
243{
244 struct nfs_page *req = nfs_list_entry(head->next);
245 struct page *page = req->wb_page;
246 struct nfs_read_data *data;
247 size_t rsize = NFS_SERVER(inode)->rsize, nbytes;
248 unsigned int offset;
249 int requests = 0;
250 int ret = 0;
251 LIST_HEAD(list);
252
253 nfs_list_remove_request(req);
254
255 nbytes = count;
256 do {
257 size_t len = min(nbytes,rsize);
258
259 data = nfs_readdata_alloc(1);
260 if (!data)
261 goto out_bad;
262 list_add(&data->pages, &list);
263 requests++;
264 nbytes -= len;
265 } while(nbytes != 0);
266 atomic_set(&req->wb_complete, requests);
267
268 ClearPageError(page);
269 offset = 0;
270 nbytes = count;
271 do {
272 int ret2;
273
274 data = list_entry(list.next, struct nfs_read_data, pages);
275 list_del_init(&data->pages);
276
277 data->pagevec[0] = page;
278
279 if (nbytes < rsize)
280 rsize = nbytes;
281 ret2 = nfs_read_rpcsetup(req, data, &nfs_read_partial_ops,
282 rsize, offset);
283 if (ret == 0)
284 ret = ret2;
285 offset += rsize;
286 nbytes -= rsize;
287 } while (nbytes != 0);
288
289 return ret;
290
291out_bad:
292 while (!list_empty(&list)) {
293 data = list_entry(list.next, struct nfs_read_data, pages);
294 list_del(&data->pages);
295 nfs_readdata_free(data);
296 }
297 SetPageError(page);
298 nfs_readpage_release(req);
299 return -ENOMEM;
300}
301
302static int nfs_pagein_one(struct inode *inode, struct list_head *head, unsigned int npages, size_t count, int flags)
303{
304 struct nfs_page *req;
305 struct page **pages;
306 struct nfs_read_data *data;
307 int ret = -ENOMEM;
308
309 data = nfs_readdata_alloc(npages);
310 if (!data)
311 goto out_bad;
312
313 pages = data->pagevec;
314 while (!list_empty(head)) {
315 req = nfs_list_entry(head->next);
316 nfs_list_remove_request(req);
317 nfs_list_add_request(req, &data->pages);
318 ClearPageError(req->wb_page);
319 *pages++ = req->wb_page;
320 }
321 req = nfs_list_entry(data->pages.next);
322
323 return nfs_read_rpcsetup(req, data, &nfs_read_full_ops, count, 0);
324out_bad:
325 nfs_async_read_error(head);
326 return ret;
327}
328
329
330
331
332
333int nfs_readpage_result(struct rpc_task *task, struct nfs_read_data *data)
334{
335 int status;
336
337 dprintk("NFS: %s: %5u, (status %d)\n", __func__, task->tk_pid,
338 task->tk_status);
339
340 status = NFS_PROTO(data->inode)->read_done(task, data);
341 if (status != 0)
342 return status;
343
344 nfs_add_stats(data->inode, NFSIOS_SERVERREADBYTES, data->res.count);
345
346 if (task->tk_status == -ESTALE) {
347 set_bit(NFS_INO_STALE, &NFS_I(data->inode)->flags);
348 nfs_mark_for_revalidate(data->inode);
349 }
350 return 0;
351}
352
353static void nfs_readpage_retry(struct rpc_task *task, struct nfs_read_data *data)
354{
355 struct nfs_readargs *argp = &data->args;
356 struct nfs_readres *resp = &data->res;
357
358 if (resp->eof || resp->count == argp->count)
359 goto out;
360
361
362 nfs_inc_stats(data->inode, NFSIOS_SHORTREAD);
363
364 if (resp->count == 0)
365 goto out;
366
367
368 argp->offset += resp->count;
369 argp->pgbase += resp->count;
370 argp->count -= resp->count;
371 nfs4_restart_rpc(task, NFS_SERVER(data->inode)->nfs_client);
372 return;
373out:
374 nfs4_sequence_free_slot(NFS_SERVER(data->inode)->nfs_client,
375 &data->res.seq_res);
376 return;
377
378}
379
380
381
382
383static void nfs_readpage_result_partial(struct rpc_task *task, void *calldata)
384{
385 struct nfs_read_data *data = calldata;
386
387 if (nfs_readpage_result(task, data) != 0)
388 return;
389 if (task->tk_status < 0)
390 return;
391
392 nfs_readpage_truncate_uninitialised_page(data);
393 nfs_readpage_retry(task, data);
394}
395
396static void nfs_readpage_release_partial(void *calldata)
397{
398 struct nfs_read_data *data = calldata;
399 struct nfs_page *req = data->req;
400 struct page *page = req->wb_page;
401 int status = data->task.tk_status;
402
403 if (status < 0)
404 SetPageError(page);
405
406 if (atomic_dec_and_test(&req->wb_complete)) {
407 if (!PageError(page))
408 SetPageUptodate(page);
409 nfs_readpage_release(req);
410 }
411 nfs_readdata_release(calldata);
412}
413
414#if defined(CONFIG_NFS_V4_1)
415void nfs_read_prepare(struct rpc_task *task, void *calldata)
416{
417 struct nfs_read_data *data = calldata;
418
419 if (nfs4_setup_sequence(NFS_SERVER(data->inode)->nfs_client,
420 &data->args.seq_args, &data->res.seq_res,
421 0, task))
422 return;
423 rpc_call_start(task);
424}
425#endif
426
427static const struct rpc_call_ops nfs_read_partial_ops = {
428#if defined(CONFIG_NFS_V4_1)
429 .rpc_call_prepare = nfs_read_prepare,
430#endif
431 .rpc_call_done = nfs_readpage_result_partial,
432 .rpc_release = nfs_readpage_release_partial,
433};
434
435static void nfs_readpage_set_pages_uptodate(struct nfs_read_data *data)
436{
437 unsigned int count = data->res.count;
438 unsigned int base = data->args.pgbase;
439 struct page **pages;
440
441 if (data->res.eof)
442 count = data->args.count;
443 if (unlikely(count == 0))
444 return;
445 pages = &data->args.pages[base >> PAGE_CACHE_SHIFT];
446 base &= ~PAGE_CACHE_MASK;
447 count += base;
448 for (;count >= PAGE_CACHE_SIZE; count -= PAGE_CACHE_SIZE, pages++)
449 SetPageUptodate(*pages);
450 if (count == 0)
451 return;
452
453 if (data->res.eof || data->res.count == data->args.count)
454 SetPageUptodate(*pages);
455}
456
457
458
459
460
461static void nfs_readpage_result_full(struct rpc_task *task, void *calldata)
462{
463 struct nfs_read_data *data = calldata;
464
465 if (nfs_readpage_result(task, data) != 0)
466 return;
467 if (task->tk_status < 0)
468 return;
469
470
471
472
473
474
475 nfs_readpage_truncate_uninitialised_page(data);
476 nfs_readpage_set_pages_uptodate(data);
477 nfs_readpage_retry(task, data);
478}
479
480static void nfs_readpage_release_full(void *calldata)
481{
482 struct nfs_read_data *data = calldata;
483
484 while (!list_empty(&data->pages)) {
485 struct nfs_page *req = nfs_list_entry(data->pages.next);
486
487 nfs_list_remove_request(req);
488 nfs_readpage_release(req);
489 }
490 nfs_readdata_release(calldata);
491}
492
493static const struct rpc_call_ops nfs_read_full_ops = {
494#if defined(CONFIG_NFS_V4_1)
495 .rpc_call_prepare = nfs_read_prepare,
496#endif
497 .rpc_call_done = nfs_readpage_result_full,
498 .rpc_release = nfs_readpage_release_full,
499};
500
501
502
503
504
505
506
507int nfs_readpage(struct file *file, struct page *page)
508{
509 struct nfs_open_context *ctx;
510 struct inode *inode = page->mapping->host;
511 int error;
512
513 dprintk("NFS: nfs_readpage (%p %ld@%lu)\n",
514 page, PAGE_CACHE_SIZE, page->index);
515 nfs_inc_stats(inode, NFSIOS_VFSREADPAGE);
516 nfs_add_stats(inode, NFSIOS_READPAGES, 1);
517
518
519
520
521
522
523
524
525 error = nfs_wb_page(inode, page);
526 if (error)
527 goto out_unlock;
528 if (PageUptodate(page))
529 goto out_unlock;
530
531 error = -ESTALE;
532 if (NFS_STALE(inode))
533 goto out_unlock;
534
535 if (file == NULL) {
536 error = -EBADF;
537 ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
538 if (ctx == NULL)
539 goto out_unlock;
540 } else
541 ctx = get_nfs_open_context(nfs_file_open_context(file));
542
543 if (!IS_SYNC(inode)) {
544 error = nfs_readpage_from_fscache(ctx, inode, page);
545 if (error == 0)
546 goto out;
547 }
548
549 error = nfs_readpage_async(ctx, inode, page);
550
551out:
552 put_nfs_open_context(ctx);
553 return error;
554out_unlock:
555 unlock_page(page);
556 return error;
557}
558
559struct nfs_readdesc {
560 struct nfs_pageio_descriptor *pgio;
561 struct nfs_open_context *ctx;
562};
563
564static int
565readpage_async_filler(void *data, struct page *page)
566{
567 struct nfs_readdesc *desc = (struct nfs_readdesc *)data;
568 struct inode *inode = page->mapping->host;
569 struct nfs_page *new;
570 unsigned int len;
571 int error;
572
573 len = nfs_page_length(page);
574 if (len == 0)
575 return nfs_return_empty_page(page);
576
577 new = nfs_create_request(desc->ctx, inode, page, 0, len);
578 if (IS_ERR(new))
579 goto out_error;
580
581 if (len < PAGE_CACHE_SIZE)
582 zero_user_segment(page, len, PAGE_CACHE_SIZE);
583 if (!nfs_pageio_add_request(desc->pgio, new)) {
584 error = desc->pgio->pg_error;
585 goto out_unlock;
586 }
587 return 0;
588out_error:
589 error = PTR_ERR(new);
590 SetPageError(page);
591out_unlock:
592 unlock_page(page);
593 return error;
594}
595
596int nfs_readpages(struct file *filp, struct address_space *mapping,
597 struct list_head *pages, unsigned nr_pages)
598{
599 struct nfs_pageio_descriptor pgio;
600 struct nfs_readdesc desc = {
601 .pgio = &pgio,
602 };
603 struct inode *inode = mapping->host;
604 struct nfs_server *server = NFS_SERVER(inode);
605 size_t rsize = server->rsize;
606 unsigned long npages;
607 int ret = -ESTALE;
608
609 dprintk("NFS: nfs_readpages (%s/%Ld %d)\n",
610 inode->i_sb->s_id,
611 (long long)NFS_FILEID(inode),
612 nr_pages);
613 nfs_inc_stats(inode, NFSIOS_VFSREADPAGES);
614
615 if (NFS_STALE(inode))
616 goto out;
617
618 if (filp == NULL) {
619 desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
620 if (desc.ctx == NULL)
621 return -EBADF;
622 } else
623 desc.ctx = get_nfs_open_context(nfs_file_open_context(filp));
624
625
626
627
628 ret = nfs_readpages_from_fscache(desc.ctx, inode, mapping,
629 pages, &nr_pages);
630 if (ret == 0)
631 goto read_complete;
632
633 if (rsize < PAGE_CACHE_SIZE)
634 nfs_pageio_init(&pgio, inode, nfs_pagein_multi, rsize, 0);
635 else
636 nfs_pageio_init(&pgio, inode, nfs_pagein_one, rsize, 0);
637
638 ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
639
640 nfs_pageio_complete(&pgio);
641 npages = (pgio.pg_bytes_written + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
642 nfs_add_stats(inode, NFSIOS_READPAGES, npages);
643read_complete:
644 put_nfs_open_context(desc.ctx);
645out:
646 return ret;
647}
648
649int __init nfs_init_readpagecache(void)
650{
651 nfs_rdata_cachep = kmem_cache_create("nfs_read_data",
652 sizeof(struct nfs_read_data),
653 0, SLAB_HWCACHE_ALIGN,
654 NULL);
655 if (nfs_rdata_cachep == NULL)
656 return -ENOMEM;
657
658 nfs_rdata_mempool = mempool_create_slab_pool(MIN_POOL_READ,
659 nfs_rdata_cachep);
660 if (nfs_rdata_mempool == NULL)
661 return -ENOMEM;
662
663 return 0;
664}
665
666void nfs_destroy_readpagecache(void)
667{
668 mempool_destroy(nfs_rdata_mempool);
669 kmem_cache_destroy(nfs_rdata_cachep);
670}
671