blob: 4affb536ada398efd20a07d8ffefd2f631f53749 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/nfs/read.c
3 *
4 * Block I/O for NFS
5 *
6 * Partial copy of Linus' read cache modifications to fs/nfs/file.c
7 * modified for async RPC by okir@monad.swb.de
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 */
9
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#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#include <linux/smp_lock.h>
22
23#include <asm/system.h>
24
Trond Myklebust49a70f22006-12-05 00:35:38 -050025#include "internal.h"
Chuck Lever91d5b472006-03-20 13:44:14 -050026#include "iostat.h"
27
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#define NFSDBG_FACILITY NFSDBG_PAGECACHE
29
30static int nfs_pagein_one(struct list_head *, struct inode *);
Trond Myklebustec06c092006-03-20 13:44:27 -050031static const struct rpc_call_ops nfs_read_partial_ops;
32static const struct rpc_call_ops nfs_read_full_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
Christoph Lametere18b8902006-12-06 20:33:20 -080034static struct kmem_cache *nfs_rdata_cachep;
Trond Myklebust3feb2d42006-03-20 13:44:37 -050035static mempool_t *nfs_rdata_mempool;
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
37#define MIN_POOL_READ (32)
38
Trond Myklebuste9f7bee2006-09-08 09:48:54 -070039struct nfs_read_data *nfs_readdata_alloc(size_t len)
Trond Myklebust3feb2d42006-03-20 13:44:37 -050040{
Trond Myklebuste9f7bee2006-09-08 09:48:54 -070041 unsigned int pagecount = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
Christoph Lametere6b4f8d2006-12-06 20:33:14 -080042 struct nfs_read_data *p = mempool_alloc(nfs_rdata_mempool, GFP_NOFS);
Trond Myklebust3feb2d42006-03-20 13:44:37 -050043
44 if (p) {
45 memset(p, 0, sizeof(*p));
46 INIT_LIST_HEAD(&p->pages);
Trond Myklebuste9f7bee2006-09-08 09:48:54 -070047 p->npages = pagecount;
Chuck Lever0d0b5cb2006-05-25 01:40:53 -040048 if (pagecount <= ARRAY_SIZE(p->page_array))
49 p->pagevec = p->page_array;
Trond Myklebust3feb2d42006-03-20 13:44:37 -050050 else {
Chuck Lever0d0b5cb2006-05-25 01:40:53 -040051 p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_NOFS);
52 if (!p->pagevec) {
Trond Myklebust3feb2d42006-03-20 13:44:37 -050053 mempool_free(p, nfs_rdata_mempool);
54 p = NULL;
55 }
56 }
57 }
58 return p;
59}
60
Trond Myklebust8aca67f2006-11-13 16:23:44 -050061static void nfs_readdata_rcu_free(struct rcu_head *head)
Trond Myklebust3feb2d42006-03-20 13:44:37 -050062{
Trond Myklebust8aca67f2006-11-13 16:23:44 -050063 struct nfs_read_data *p = container_of(head, struct nfs_read_data, task.u.tk_rcu);
Trond Myklebust3feb2d42006-03-20 13:44:37 -050064 if (p && (p->pagevec != &p->page_array[0]))
65 kfree(p->pagevec);
66 mempool_free(p, nfs_rdata_mempool);
67}
68
Trond Myklebust8aca67f2006-11-13 16:23:44 -050069static void nfs_readdata_free(struct nfs_read_data *rdata)
70{
71 call_rcu_bh(&rdata->task.u.tk_rcu, nfs_readdata_rcu_free);
72}
73
Trond Myklebust963d8fe2006-01-03 09:55:04 +010074void nfs_readdata_release(void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -070075{
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 nfs_readdata_free(data);
77}
78
79static
Linus Torvalds1da177e2005-04-16 15:20:36 -070080int nfs_return_empty_page(struct page *page)
81{
82 memclear_highpage_flush(page, 0, PAGE_CACHE_SIZE);
83 SetPageUptodate(page);
84 unlock_page(page);
85 return 0;
86}
87
Trond Myklebust1de3fc12006-05-25 01:40:44 -040088static void nfs_readpage_truncate_uninitialised_page(struct nfs_read_data *data)
89{
90 unsigned int remainder = data->args.count - data->res.count;
91 unsigned int base = data->args.pgbase + data->res.count;
92 unsigned int pglen;
93 struct page **pages;
94
95 if (data->res.eof == 0 || remainder == 0)
96 return;
97 /*
98 * Note: "remainder" can never be negative, since we check for
99 * this in the XDR code.
100 */
101 pages = &data->args.pages[base >> PAGE_CACHE_SHIFT];
102 base &= ~PAGE_CACHE_MASK;
103 pglen = PAGE_CACHE_SIZE - base;
Trond Myklebust79558f32006-08-22 13:44:32 -0400104 for (;;) {
105 if (remainder <= pglen) {
106 memclear_highpage_flush(*pages, base, remainder);
107 break;
108 }
Trond Myklebust1de3fc12006-05-25 01:40:44 -0400109 memclear_highpage_flush(*pages, base, pglen);
Trond Myklebust79558f32006-08-22 13:44:32 -0400110 pages++;
111 remainder -= pglen;
112 pglen = PAGE_CACHE_SIZE;
113 base = 0;
114 }
Trond Myklebust1de3fc12006-05-25 01:40:44 -0400115}
116
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117static int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
118 struct page *page)
119{
120 LIST_HEAD(one_request);
121 struct nfs_page *new;
122 unsigned int len;
123
Trond Myklebust49a70f22006-12-05 00:35:38 -0500124 len = nfs_page_length(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 if (len == 0)
126 return nfs_return_empty_page(page);
127 new = nfs_create_request(ctx, inode, page, 0, len);
128 if (IS_ERR(new)) {
129 unlock_page(page);
130 return PTR_ERR(new);
131 }
132 if (len < PAGE_CACHE_SIZE)
133 memclear_highpage_flush(page, len, PAGE_CACHE_SIZE - len);
134
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 nfs_list_add_request(new, &one_request);
136 nfs_pagein_one(&one_request, inode);
137 return 0;
138}
139
140static void nfs_readpage_release(struct nfs_page *req)
141{
142 unlock_page(req->wb_page);
143
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 dprintk("NFS: read done (%s/%Ld %d@%Ld)\n",
145 req->wb_context->dentry->d_inode->i_sb->s_id,
146 (long long)NFS_FILEID(req->wb_context->dentry->d_inode),
147 req->wb_bytes,
148 (long long)req_offset(req));
Nick Wilson10d2c462005-09-22 21:44:28 -0700149 nfs_clear_request(req);
150 nfs_release_request(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151}
152
153/*
154 * Set up the NFS read request struct
155 */
156static void nfs_read_rpcsetup(struct nfs_page *req, struct nfs_read_data *data,
Trond Myklebustec06c092006-03-20 13:44:27 -0500157 const struct rpc_call_ops *call_ops,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 unsigned int count, unsigned int offset)
159{
160 struct inode *inode;
Trond Myklebustec06c092006-03-20 13:44:27 -0500161 int flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162
163 data->req = req;
164 data->inode = inode = req->wb_context->dentry->d_inode;
165 data->cred = req->wb_context->cred;
166
167 data->args.fh = NFS_FH(inode);
168 data->args.offset = req_offset(req) + offset;
169 data->args.pgbase = req->wb_pgbase + offset;
170 data->args.pages = data->pagevec;
171 data->args.count = count;
172 data->args.context = req->wb_context;
173
174 data->res.fattr = &data->fattr;
175 data->res.count = count;
176 data->res.eof = 0;
Trond Myklebust0e574af2005-10-27 22:12:38 -0400177 nfs_fattr_init(&data->fattr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178
Trond Myklebustec06c092006-03-20 13:44:27 -0500179 /* Set up the initial task struct. */
180 flags = RPC_TASK_ASYNC | (IS_SWAPFILE(inode)? NFS_RPC_SWAPFLAGS : 0);
181 rpc_init_task(&data->task, NFS_CLIENT(inode), flags, call_ops, data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 NFS_PROTO(inode)->read_setup(data);
183
184 data->task.tk_cookie = (unsigned long)inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185
186 dprintk("NFS: %4d initiated read call (req %s/%Ld, %u bytes @ offset %Lu)\n",
187 data->task.tk_pid,
188 inode->i_sb->s_id,
189 (long long)NFS_FILEID(inode),
190 count,
191 (unsigned long long)data->args.offset);
192}
193
194static void
195nfs_async_read_error(struct list_head *head)
196{
197 struct nfs_page *req;
198
199 while (!list_empty(head)) {
200 req = nfs_list_entry(head->next);
201 nfs_list_remove_request(req);
202 SetPageError(req->wb_page);
203 nfs_readpage_release(req);
204 }
205}
206
207/*
208 * Start an async read operation
209 */
210static void nfs_execute_read(struct nfs_read_data *data)
211{
212 struct rpc_clnt *clnt = NFS_CLIENT(data->inode);
213 sigset_t oldset;
214
215 rpc_clnt_sigmask(clnt, &oldset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 rpc_execute(&data->task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 rpc_clnt_sigunmask(clnt, &oldset);
218}
219
220/*
221 * Generate multiple requests to fill a single page.
222 *
223 * We optimize to reduce the number of read operations on the wire. If we
224 * detect that we're reading a page, or an area of a page, that is past the
225 * end of file, we do not generate NFS read operations but just clear the
226 * parts of the page that would have come back zero from the server anyway.
227 *
228 * We rely on the cached value of i_size to make this determination; another
229 * client can fill pages on the server past our cached end-of-file, but we
230 * won't see the new data until our attribute cache is updated. This is more
231 * or less conventional NFS client behavior.
232 */
233static int nfs_pagein_multi(struct list_head *head, struct inode *inode)
234{
235 struct nfs_page *req = nfs_list_entry(head->next);
236 struct page *page = req->wb_page;
237 struct nfs_read_data *data;
Trond Myklebuste9f7bee2006-09-08 09:48:54 -0700238 size_t rsize = NFS_SERVER(inode)->rsize, nbytes;
239 unsigned int offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 int requests = 0;
241 LIST_HEAD(list);
242
243 nfs_list_remove_request(req);
244
245 nbytes = req->wb_bytes;
Trond Myklebuste9f7bee2006-09-08 09:48:54 -0700246 do {
247 size_t len = min(nbytes,rsize);
248
249 data = nfs_readdata_alloc(len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 if (!data)
251 goto out_bad;
252 INIT_LIST_HEAD(&data->pages);
253 list_add(&data->pages, &list);
254 requests++;
Trond Myklebuste9f7bee2006-09-08 09:48:54 -0700255 nbytes -= len;
256 } while(nbytes != 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 atomic_set(&req->wb_complete, requests);
258
259 ClearPageError(page);
260 offset = 0;
261 nbytes = req->wb_bytes;
262 do {
263 data = list_entry(list.next, struct nfs_read_data, pages);
264 list_del_init(&data->pages);
265
266 data->pagevec[0] = page;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267
268 if (nbytes > rsize) {
Trond Myklebustec06c092006-03-20 13:44:27 -0500269 nfs_read_rpcsetup(req, data, &nfs_read_partial_ops,
270 rsize, offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271 offset += rsize;
272 nbytes -= rsize;
273 } else {
Trond Myklebustec06c092006-03-20 13:44:27 -0500274 nfs_read_rpcsetup(req, data, &nfs_read_partial_ops,
275 nbytes, offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 nbytes = 0;
277 }
278 nfs_execute_read(data);
279 } while (nbytes != 0);
280
281 return 0;
282
283out_bad:
284 while (!list_empty(&list)) {
285 data = list_entry(list.next, struct nfs_read_data, pages);
286 list_del(&data->pages);
287 nfs_readdata_free(data);
288 }
289 SetPageError(page);
290 nfs_readpage_release(req);
291 return -ENOMEM;
292}
293
294static int nfs_pagein_one(struct list_head *head, struct inode *inode)
295{
296 struct nfs_page *req;
297 struct page **pages;
298 struct nfs_read_data *data;
299 unsigned int count;
300
301 if (NFS_SERVER(inode)->rsize < PAGE_CACHE_SIZE)
302 return nfs_pagein_multi(head, inode);
303
Trond Myklebuste9f7bee2006-09-08 09:48:54 -0700304 data = nfs_readdata_alloc(NFS_SERVER(inode)->rsize);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 if (!data)
306 goto out_bad;
307
308 INIT_LIST_HEAD(&data->pages);
309 pages = data->pagevec;
310 count = 0;
311 while (!list_empty(head)) {
312 req = nfs_list_entry(head->next);
313 nfs_list_remove_request(req);
314 nfs_list_add_request(req, &data->pages);
315 ClearPageError(req->wb_page);
316 *pages++ = req->wb_page;
317 count += req->wb_bytes;
318 }
319 req = nfs_list_entry(data->pages.next);
320
Trond Myklebustec06c092006-03-20 13:44:27 -0500321 nfs_read_rpcsetup(req, data, &nfs_read_full_ops, count, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322
323 nfs_execute_read(data);
324 return 0;
325out_bad:
326 nfs_async_read_error(head);
327 return -ENOMEM;
328}
329
330static int
331nfs_pagein_list(struct list_head *head, int rpages)
332{
333 LIST_HEAD(one_request);
334 struct nfs_page *req;
335 int error = 0;
336 unsigned int pages = 0;
337
338 while (!list_empty(head)) {
339 pages += nfs_coalesce_requests(head, &one_request, rpages);
340 req = nfs_list_entry(one_request.next);
341 error = nfs_pagein_one(&one_request, req->wb_context->dentry->d_inode);
342 if (error < 0)
343 break;
344 }
345 if (error >= 0)
346 return pages;
347
348 nfs_async_read_error(head);
349 return error;
350}
351
352/*
Trond Myklebust0b671302006-11-14 16:12:23 -0500353 * This is the callback from RPC telling us whether a reply was
354 * received or some error occurred (timeout or socket shutdown).
355 */
356int nfs_readpage_result(struct rpc_task *task, struct nfs_read_data *data)
357{
358 int status;
359
360 dprintk("%s: %4d, (status %d)\n", __FUNCTION__, task->tk_pid,
361 task->tk_status);
362
363 status = NFS_PROTO(data->inode)->read_done(task, data);
364 if (status != 0)
365 return status;
366
367 nfs_add_stats(data->inode, NFSIOS_SERVERREADBYTES, data->res.count);
368
369 if (task->tk_status == -ESTALE) {
370 set_bit(NFS_INO_STALE, &NFS_FLAGS(data->inode));
371 nfs_mark_for_revalidate(data->inode);
372 }
373 spin_lock(&data->inode->i_lock);
374 NFS_I(data->inode)->cache_validity |= NFS_INO_INVALID_ATIME;
375 spin_unlock(&data->inode->i_lock);
376 return 0;
377}
378
379static int nfs_readpage_retry(struct rpc_task *task, struct nfs_read_data *data)
380{
381 struct nfs_readargs *argp = &data->args;
382 struct nfs_readres *resp = &data->res;
383
384 if (resp->eof || resp->count == argp->count)
385 return 0;
386
387 /* This is a short read! */
388 nfs_inc_stats(data->inode, NFSIOS_SHORTREAD);
389 /* Has the server at least made some progress? */
390 if (resp->count == 0)
391 return 0;
392
393 /* Yes, so retry the read at the end of the data */
394 argp->offset += resp->count;
395 argp->pgbase += resp->count;
396 argp->count -= resp->count;
397 rpc_restart_call(task);
398 return -EAGAIN;
399}
400
401/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 * Handle a read reply that fills part of a page.
403 */
Trond Myklebustec06c092006-03-20 13:44:27 -0500404static void nfs_readpage_result_partial(struct rpc_task *task, void *calldata)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405{
Trond Myklebustec06c092006-03-20 13:44:27 -0500406 struct nfs_read_data *data = calldata;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 struct nfs_page *req = data->req;
408 struct page *page = req->wb_page;
409
Trond Myklebustec06c092006-03-20 13:44:27 -0500410 if (nfs_readpage_result(task, data) != 0)
411 return;
Trond Myklebust0b671302006-11-14 16:12:23 -0500412
413 if (likely(task->tk_status >= 0)) {
414 nfs_readpage_truncate_uninitialised_page(data);
415 if (nfs_readpage_retry(task, data) != 0)
416 return;
417 }
418 if (unlikely(task->tk_status < 0))
419 SetPageError(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 if (atomic_dec_and_test(&req->wb_complete)) {
421 if (!PageError(page))
422 SetPageUptodate(page);
423 nfs_readpage_release(req);
424 }
425}
426
Trond Myklebustec06c092006-03-20 13:44:27 -0500427static const struct rpc_call_ops nfs_read_partial_ops = {
428 .rpc_call_done = nfs_readpage_result_partial,
429 .rpc_release = nfs_readdata_release,
430};
431
Trond Myklebust1de3fc12006-05-25 01:40:44 -0400432static void nfs_readpage_set_pages_uptodate(struct nfs_read_data *data)
433{
434 unsigned int count = data->res.count;
435 unsigned int base = data->args.pgbase;
436 struct page **pages;
437
Trond Myklebust79558f32006-08-22 13:44:32 -0400438 if (data->res.eof)
439 count = data->args.count;
Trond Myklebust1de3fc12006-05-25 01:40:44 -0400440 if (unlikely(count == 0))
441 return;
442 pages = &data->args.pages[base >> PAGE_CACHE_SHIFT];
443 base &= ~PAGE_CACHE_MASK;
444 count += base;
445 for (;count >= PAGE_CACHE_SIZE; count -= PAGE_CACHE_SIZE, pages++)
446 SetPageUptodate(*pages);
Trond Myklebust0b671302006-11-14 16:12:23 -0500447 if (count == 0)
448 return;
449 /* Was this a short read? */
450 if (data->res.eof || data->res.count == data->args.count)
Trond Myklebust1de3fc12006-05-25 01:40:44 -0400451 SetPageUptodate(*pages);
452}
453
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454/*
455 * This is the callback from RPC telling us whether a reply was
456 * received or some error occurred (timeout or socket shutdown).
457 */
Trond Myklebustec06c092006-03-20 13:44:27 -0500458static void nfs_readpage_result_full(struct rpc_task *task, void *calldata)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459{
Trond Myklebustec06c092006-03-20 13:44:27 -0500460 struct nfs_read_data *data = calldata;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461
Trond Myklebust0b671302006-11-14 16:12:23 -0500462 if (nfs_readpage_result(task, data) != 0)
463 return;
Trond Myklebust1de3fc12006-05-25 01:40:44 -0400464 /*
Trond Myklebust0b671302006-11-14 16:12:23 -0500465 * Note: nfs_readpage_retry may change the values of
Trond Myklebust1de3fc12006-05-25 01:40:44 -0400466 * data->args. In the multi-page case, we therefore need
Trond Myklebust0b671302006-11-14 16:12:23 -0500467 * to ensure that we call nfs_readpage_set_pages_uptodate()
468 * first.
Trond Myklebust1de3fc12006-05-25 01:40:44 -0400469 */
470 if (likely(task->tk_status >= 0)) {
471 nfs_readpage_truncate_uninitialised_page(data);
472 nfs_readpage_set_pages_uptodate(data);
Trond Myklebust0b671302006-11-14 16:12:23 -0500473 if (nfs_readpage_retry(task, data) != 0)
474 return;
475 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 while (!list_empty(&data->pages)) {
477 struct nfs_page *req = nfs_list_entry(data->pages.next);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478
Trond Myklebust1de3fc12006-05-25 01:40:44 -0400479 nfs_list_remove_request(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480 nfs_readpage_release(req);
481 }
482}
483
Trond Myklebustec06c092006-03-20 13:44:27 -0500484static const struct rpc_call_ops nfs_read_full_ops = {
485 .rpc_call_done = nfs_readpage_result_full,
486 .rpc_release = nfs_readdata_release,
487};
488
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 * Read a page over NFS.
491 * We read the page synchronously in the following case:
492 * - The error flag is set for this page. This happens only when a
493 * previous async read operation failed.
494 */
495int nfs_readpage(struct file *file, struct page *page)
496{
497 struct nfs_open_context *ctx;
498 struct inode *inode = page->mapping->host;
499 int error;
500
501 dprintk("NFS: nfs_readpage (%p %ld@%lu)\n",
502 page, PAGE_CACHE_SIZE, page->index);
Chuck Lever91d5b472006-03-20 13:44:14 -0500503 nfs_inc_stats(inode, NFSIOS_VFSREADPAGE);
504 nfs_add_stats(inode, NFSIOS_READPAGES, 1);
505
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 /*
507 * Try to flush any pending writes to the file..
508 *
509 * NOTE! Because we own the page lock, there cannot
510 * be any new pending writes generated at this point
511 * for this page (other pages can be written to).
512 */
513 error = nfs_wb_page(inode, page);
514 if (error)
515 goto out_error;
516
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400517 error = -ESTALE;
518 if (NFS_STALE(inode))
519 goto out_error;
520
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521 if (file == NULL) {
Trond Myklebustcf1308f2006-11-19 16:44:52 -0500522 error = -EBADF;
Trond Myklebustd5308382005-11-04 15:33:38 -0500523 ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524 if (ctx == NULL)
Trond Myklebustcf1308f2006-11-19 16:44:52 -0500525 goto out_error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526 } else
527 ctx = get_nfs_open_context((struct nfs_open_context *)
528 file->private_data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529
Trond Myklebust8e0969f2006-12-13 15:23:44 -0500530 error = nfs_readpage_async(ctx, inode, page);
531
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532 put_nfs_open_context(ctx);
533 return error;
534
535out_error:
536 unlock_page(page);
537 return error;
538}
539
540struct nfs_readdesc {
541 struct list_head *head;
542 struct nfs_open_context *ctx;
543};
544
545static int
546readpage_async_filler(void *data, struct page *page)
547{
548 struct nfs_readdesc *desc = (struct nfs_readdesc *)data;
549 struct inode *inode = page->mapping->host;
550 struct nfs_page *new;
551 unsigned int len;
552
553 nfs_wb_page(inode, page);
Trond Myklebust49a70f22006-12-05 00:35:38 -0500554 len = nfs_page_length(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 if (len == 0)
556 return nfs_return_empty_page(page);
557 new = nfs_create_request(desc->ctx, inode, page, 0, len);
558 if (IS_ERR(new)) {
559 SetPageError(page);
560 unlock_page(page);
561 return PTR_ERR(new);
562 }
563 if (len < PAGE_CACHE_SIZE)
564 memclear_highpage_flush(page, len, PAGE_CACHE_SIZE - len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 nfs_list_add_request(new, desc->head);
566 return 0;
567}
568
569int nfs_readpages(struct file *filp, struct address_space *mapping,
570 struct list_head *pages, unsigned nr_pages)
571{
572 LIST_HEAD(head);
573 struct nfs_readdesc desc = {
574 .head = &head,
575 };
576 struct inode *inode = mapping->host;
577 struct nfs_server *server = NFS_SERVER(inode);
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400578 int ret = -ESTALE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579
580 dprintk("NFS: nfs_readpages (%s/%Ld %d)\n",
581 inode->i_sb->s_id,
582 (long long)NFS_FILEID(inode),
583 nr_pages);
Chuck Lever91d5b472006-03-20 13:44:14 -0500584 nfs_inc_stats(inode, NFSIOS_VFSREADPAGES);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400586 if (NFS_STALE(inode))
587 goto out;
588
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589 if (filp == NULL) {
Trond Myklebustd5308382005-11-04 15:33:38 -0500590 desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591 if (desc.ctx == NULL)
592 return -EBADF;
593 } else
594 desc.ctx = get_nfs_open_context((struct nfs_open_context *)
595 filp->private_data);
596 ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
597 if (!list_empty(&head)) {
598 int err = nfs_pagein_list(&head, server->rpages);
599 if (!ret)
Chuck Lever91d5b472006-03-20 13:44:14 -0500600 nfs_add_stats(inode, NFSIOS_READPAGES, err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 ret = err;
602 }
603 put_nfs_open_context(desc.ctx);
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400604out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605 return ret;
606}
607
David Howellsf7b422b2006-06-09 09:34:33 -0400608int __init nfs_init_readpagecache(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609{
610 nfs_rdata_cachep = kmem_cache_create("nfs_read_data",
611 sizeof(struct nfs_read_data),
612 0, SLAB_HWCACHE_ALIGN,
613 NULL, NULL);
614 if (nfs_rdata_cachep == NULL)
615 return -ENOMEM;
616
Matthew Dobson93d23412006-03-26 01:37:50 -0800617 nfs_rdata_mempool = mempool_create_slab_pool(MIN_POOL_READ,
618 nfs_rdata_cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619 if (nfs_rdata_mempool == NULL)
620 return -ENOMEM;
621
622 return 0;
623}
624
David Brownell266bee82006-06-27 12:59:15 -0700625void nfs_destroy_readpagecache(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626{
627 mempool_destroy(nfs_rdata_mempool);
Alexey Dobriyan1a1d92c2006-09-27 01:49:40 -0700628 kmem_cache_destroy(nfs_rdata_cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629}