Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
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 | |
1da177e4 LT |
8 | */ |
9 | ||
1da177e4 LT |
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 | #include <linux/smp_lock.h> | |
22 | ||
23 | #include <asm/system.h> | |
24 | ||
49a70f27 | 25 | #include "internal.h" |
91d5b470 CL |
26 | #include "iostat.h" |
27 | ||
1da177e4 LT |
28 | #define NFSDBG_FACILITY NFSDBG_PAGECACHE |
29 | ||
30 | static int nfs_pagein_one(struct list_head *, struct inode *); | |
ec06c096 TM |
31 | static const struct rpc_call_ops nfs_read_partial_ops; |
32 | static const struct rpc_call_ops nfs_read_full_ops; | |
1da177e4 | 33 | |
e18b890b | 34 | static struct kmem_cache *nfs_rdata_cachep; |
3feb2d49 | 35 | static mempool_t *nfs_rdata_mempool; |
1da177e4 LT |
36 | |
37 | #define MIN_POOL_READ (32) | |
38 | ||
e9f7bee1 | 39 | struct nfs_read_data *nfs_readdata_alloc(size_t len) |
3feb2d49 | 40 | { |
e9f7bee1 | 41 | unsigned int pagecount = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
e6b4f8da | 42 | struct nfs_read_data *p = mempool_alloc(nfs_rdata_mempool, GFP_NOFS); |
3feb2d49 TM |
43 | |
44 | if (p) { | |
45 | memset(p, 0, sizeof(*p)); | |
46 | INIT_LIST_HEAD(&p->pages); | |
e9f7bee1 | 47 | p->npages = pagecount; |
0d0b5cb3 CL |
48 | if (pagecount <= ARRAY_SIZE(p->page_array)) |
49 | p->pagevec = p->page_array; | |
3feb2d49 | 50 | else { |
0d0b5cb3 CL |
51 | p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_NOFS); |
52 | if (!p->pagevec) { | |
3feb2d49 TM |
53 | mempool_free(p, nfs_rdata_mempool); |
54 | p = NULL; | |
55 | } | |
56 | } | |
57 | } | |
58 | return p; | |
59 | } | |
60 | ||
8aca67f0 | 61 | static void nfs_readdata_rcu_free(struct rcu_head *head) |
3feb2d49 | 62 | { |
8aca67f0 | 63 | struct nfs_read_data *p = container_of(head, struct nfs_read_data, task.u.tk_rcu); |
3feb2d49 TM |
64 | if (p && (p->pagevec != &p->page_array[0])) |
65 | kfree(p->pagevec); | |
66 | mempool_free(p, nfs_rdata_mempool); | |
67 | } | |
68 | ||
8aca67f0 TM |
69 | static 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 | ||
963d8fe5 | 74 | void nfs_readdata_release(void *data) |
1da177e4 | 75 | { |
1da177e4 LT |
76 | nfs_readdata_free(data); |
77 | } | |
78 | ||
1da177e4 LT |
79 | static |
80 | int 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 | ||
1de3fc12 TM |
88 | static 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; | |
79558f36 TM |
104 | for (;;) { |
105 | if (remainder <= pglen) { | |
106 | memclear_highpage_flush(*pages, base, remainder); | |
107 | break; | |
108 | } | |
1de3fc12 | 109 | memclear_highpage_flush(*pages, base, pglen); |
79558f36 TM |
110 | pages++; |
111 | remainder -= pglen; | |
112 | pglen = PAGE_CACHE_SIZE; | |
113 | base = 0; | |
114 | } | |
1de3fc12 TM |
115 | } |
116 | ||
1da177e4 LT |
117 | static 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 | ||
49a70f27 | 124 | len = nfs_page_length(page); |
1da177e4 LT |
125 | 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 | ||
1da177e4 LT |
135 | nfs_list_add_request(new, &one_request); |
136 | nfs_pagein_one(&one_request, inode); | |
137 | return 0; | |
138 | } | |
139 | ||
140 | static void nfs_readpage_release(struct nfs_page *req) | |
141 | { | |
142 | unlock_page(req->wb_page); | |
143 | ||
1da177e4 LT |
144 | 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)); | |
10d2c46f NW |
149 | nfs_clear_request(req); |
150 | nfs_release_request(req); | |
1da177e4 LT |
151 | } |
152 | ||
153 | /* | |
154 | * Set up the NFS read request struct | |
155 | */ | |
156 | static void nfs_read_rpcsetup(struct nfs_page *req, struct nfs_read_data *data, | |
ec06c096 | 157 | const struct rpc_call_ops *call_ops, |
1da177e4 LT |
158 | unsigned int count, unsigned int offset) |
159 | { | |
160 | struct inode *inode; | |
ec06c096 | 161 | int flags; |
1da177e4 LT |
162 | |
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; | |
0e574af1 | 177 | nfs_fattr_init(&data->fattr); |
1da177e4 | 178 | |
ec06c096 TM |
179 | /* 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); | |
1da177e4 LT |
182 | NFS_PROTO(inode)->read_setup(data); |
183 | ||
184 | data->task.tk_cookie = (unsigned long)inode; | |
1da177e4 | 185 | |
a3f565b1 | 186 | dprintk("NFS: %5u initiated read call (req %s/%Ld, %u bytes @ offset %Lu)\n", |
1da177e4 LT |
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 | ||
194 | static void | |
195 | nfs_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 | */ | |
210 | static 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); | |
1da177e4 | 216 | rpc_execute(&data->task); |
1da177e4 LT |
217 | 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 | */ | |
233 | static 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; | |
e9f7bee1 TM |
238 | size_t rsize = NFS_SERVER(inode)->rsize, nbytes; |
239 | unsigned int offset; | |
1da177e4 LT |
240 | int requests = 0; |
241 | LIST_HEAD(list); | |
242 | ||
243 | nfs_list_remove_request(req); | |
244 | ||
245 | nbytes = req->wb_bytes; | |
e9f7bee1 TM |
246 | do { |
247 | size_t len = min(nbytes,rsize); | |
248 | ||
249 | data = nfs_readdata_alloc(len); | |
1da177e4 LT |
250 | if (!data) |
251 | goto out_bad; | |
252 | INIT_LIST_HEAD(&data->pages); | |
253 | list_add(&data->pages, &list); | |
254 | requests++; | |
e9f7bee1 TM |
255 | nbytes -= len; |
256 | } while(nbytes != 0); | |
1da177e4 LT |
257 | 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; | |
1da177e4 LT |
267 | |
268 | if (nbytes > rsize) { | |
ec06c096 TM |
269 | nfs_read_rpcsetup(req, data, &nfs_read_partial_ops, |
270 | rsize, offset); | |
1da177e4 LT |
271 | offset += rsize; |
272 | nbytes -= rsize; | |
273 | } else { | |
ec06c096 TM |
274 | nfs_read_rpcsetup(req, data, &nfs_read_partial_ops, |
275 | nbytes, offset); | |
1da177e4 LT |
276 | nbytes = 0; |
277 | } | |
278 | nfs_execute_read(data); | |
279 | } while (nbytes != 0); | |
280 | ||
281 | return 0; | |
282 | ||
283 | out_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 | ||
294 | static 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 | ||
e9f7bee1 | 304 | data = nfs_readdata_alloc(NFS_SERVER(inode)->rsize); |
1da177e4 LT |
305 | 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 | ||
ec06c096 | 321 | nfs_read_rpcsetup(req, data, &nfs_read_full_ops, count, 0); |
1da177e4 LT |
322 | |
323 | nfs_execute_read(data); | |
324 | return 0; | |
325 | out_bad: | |
326 | nfs_async_read_error(head); | |
327 | return -ENOMEM; | |
328 | } | |
329 | ||
330 | static int | |
d8a5ad75 | 331 | nfs_pagein_list(struct list_head *head, unsigned int rsize) |
1da177e4 | 332 | { |
d8a5ad75 TM |
333 | struct nfs_pageio_descriptor desc; |
334 | struct nfs_page *req; | |
335 | unsigned int pages = 0; | |
336 | int error = 0; | |
1da177e4 LT |
337 | |
338 | while (!list_empty(head)) { | |
d8a5ad75 TM |
339 | nfs_pageio_init(&desc, rsize); |
340 | nfs_pageio_add_list(&desc, head); | |
341 | req = nfs_list_entry(desc.pg_list.next); | |
342 | error = nfs_pagein_one(&desc.pg_list, req->wb_context->dentry->d_inode); | |
1da177e4 LT |
343 | if (error < 0) |
344 | break; | |
d8a5ad75 | 345 | pages += (desc.pg_count + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
1da177e4 | 346 | } |
1da177e4 LT |
347 | |
348 | nfs_async_read_error(head); | |
d8a5ad75 TM |
349 | if (error >= 0) |
350 | return pages; | |
1da177e4 LT |
351 | return error; |
352 | } | |
353 | ||
0b671301 TM |
354 | /* |
355 | * This is the callback from RPC telling us whether a reply was | |
356 | * received or some error occurred (timeout or socket shutdown). | |
357 | */ | |
358 | int nfs_readpage_result(struct rpc_task *task, struct nfs_read_data *data) | |
359 | { | |
360 | int status; | |
361 | ||
a3f565b1 | 362 | dprintk("NFS: %s: %5u, (status %d)\n", __FUNCTION__, task->tk_pid, |
0b671301 TM |
363 | task->tk_status); |
364 | ||
365 | status = NFS_PROTO(data->inode)->read_done(task, data); | |
366 | if (status != 0) | |
367 | return status; | |
368 | ||
369 | nfs_add_stats(data->inode, NFSIOS_SERVERREADBYTES, data->res.count); | |
370 | ||
371 | if (task->tk_status == -ESTALE) { | |
372 | set_bit(NFS_INO_STALE, &NFS_FLAGS(data->inode)); | |
373 | nfs_mark_for_revalidate(data->inode); | |
374 | } | |
375 | spin_lock(&data->inode->i_lock); | |
376 | NFS_I(data->inode)->cache_validity |= NFS_INO_INVALID_ATIME; | |
377 | spin_unlock(&data->inode->i_lock); | |
378 | return 0; | |
379 | } | |
380 | ||
381 | static int nfs_readpage_retry(struct rpc_task *task, struct nfs_read_data *data) | |
382 | { | |
383 | struct nfs_readargs *argp = &data->args; | |
384 | struct nfs_readres *resp = &data->res; | |
385 | ||
386 | if (resp->eof || resp->count == argp->count) | |
387 | return 0; | |
388 | ||
389 | /* This is a short read! */ | |
390 | nfs_inc_stats(data->inode, NFSIOS_SHORTREAD); | |
391 | /* Has the server at least made some progress? */ | |
392 | if (resp->count == 0) | |
393 | return 0; | |
394 | ||
395 | /* Yes, so retry the read at the end of the data */ | |
396 | argp->offset += resp->count; | |
397 | argp->pgbase += resp->count; | |
398 | argp->count -= resp->count; | |
399 | rpc_restart_call(task); | |
400 | return -EAGAIN; | |
401 | } | |
402 | ||
1da177e4 LT |
403 | /* |
404 | * Handle a read reply that fills part of a page. | |
405 | */ | |
ec06c096 | 406 | static void nfs_readpage_result_partial(struct rpc_task *task, void *calldata) |
1da177e4 | 407 | { |
ec06c096 | 408 | struct nfs_read_data *data = calldata; |
1da177e4 LT |
409 | struct nfs_page *req = data->req; |
410 | struct page *page = req->wb_page; | |
411 | ||
ec06c096 TM |
412 | if (nfs_readpage_result(task, data) != 0) |
413 | return; | |
0b671301 TM |
414 | |
415 | if (likely(task->tk_status >= 0)) { | |
416 | nfs_readpage_truncate_uninitialised_page(data); | |
417 | if (nfs_readpage_retry(task, data) != 0) | |
418 | return; | |
419 | } | |
420 | if (unlikely(task->tk_status < 0)) | |
421 | SetPageError(page); | |
1da177e4 LT |
422 | if (atomic_dec_and_test(&req->wb_complete)) { |
423 | if (!PageError(page)) | |
424 | SetPageUptodate(page); | |
425 | nfs_readpage_release(req); | |
426 | } | |
427 | } | |
428 | ||
ec06c096 TM |
429 | static const struct rpc_call_ops nfs_read_partial_ops = { |
430 | .rpc_call_done = nfs_readpage_result_partial, | |
431 | .rpc_release = nfs_readdata_release, | |
432 | }; | |
433 | ||
1de3fc12 TM |
434 | static void nfs_readpage_set_pages_uptodate(struct nfs_read_data *data) |
435 | { | |
436 | unsigned int count = data->res.count; | |
437 | unsigned int base = data->args.pgbase; | |
438 | struct page **pages; | |
439 | ||
79558f36 TM |
440 | if (data->res.eof) |
441 | count = data->args.count; | |
1de3fc12 TM |
442 | if (unlikely(count == 0)) |
443 | return; | |
444 | pages = &data->args.pages[base >> PAGE_CACHE_SHIFT]; | |
445 | base &= ~PAGE_CACHE_MASK; | |
446 | count += base; | |
447 | for (;count >= PAGE_CACHE_SIZE; count -= PAGE_CACHE_SIZE, pages++) | |
448 | SetPageUptodate(*pages); | |
0b671301 TM |
449 | if (count == 0) |
450 | return; | |
451 | /* Was this a short read? */ | |
452 | if (data->res.eof || data->res.count == data->args.count) | |
1de3fc12 TM |
453 | SetPageUptodate(*pages); |
454 | } | |
455 | ||
1da177e4 LT |
456 | /* |
457 | * This is the callback from RPC telling us whether a reply was | |
458 | * received or some error occurred (timeout or socket shutdown). | |
459 | */ | |
ec06c096 | 460 | static void nfs_readpage_result_full(struct rpc_task *task, void *calldata) |
1da177e4 | 461 | { |
ec06c096 | 462 | struct nfs_read_data *data = calldata; |
1da177e4 | 463 | |
0b671301 TM |
464 | if (nfs_readpage_result(task, data) != 0) |
465 | return; | |
1de3fc12 | 466 | /* |
0b671301 | 467 | * Note: nfs_readpage_retry may change the values of |
1de3fc12 | 468 | * data->args. In the multi-page case, we therefore need |
0b671301 TM |
469 | * to ensure that we call nfs_readpage_set_pages_uptodate() |
470 | * first. | |
1de3fc12 TM |
471 | */ |
472 | if (likely(task->tk_status >= 0)) { | |
473 | nfs_readpage_truncate_uninitialised_page(data); | |
474 | nfs_readpage_set_pages_uptodate(data); | |
0b671301 TM |
475 | if (nfs_readpage_retry(task, data) != 0) |
476 | return; | |
477 | } | |
1da177e4 LT |
478 | while (!list_empty(&data->pages)) { |
479 | struct nfs_page *req = nfs_list_entry(data->pages.next); | |
1da177e4 | 480 | |
1de3fc12 | 481 | nfs_list_remove_request(req); |
1da177e4 LT |
482 | nfs_readpage_release(req); |
483 | } | |
484 | } | |
485 | ||
ec06c096 TM |
486 | static const struct rpc_call_ops nfs_read_full_ops = { |
487 | .rpc_call_done = nfs_readpage_result_full, | |
488 | .rpc_release = nfs_readdata_release, | |
489 | }; | |
490 | ||
1da177e4 LT |
491 | /* |
492 | * Read a page over NFS. | |
493 | * We read the page synchronously in the following case: | |
494 | * - The error flag is set for this page. This happens only when a | |
495 | * previous async read operation failed. | |
496 | */ | |
497 | int nfs_readpage(struct file *file, struct page *page) | |
498 | { | |
499 | struct nfs_open_context *ctx; | |
500 | struct inode *inode = page->mapping->host; | |
501 | int error; | |
502 | ||
503 | dprintk("NFS: nfs_readpage (%p %ld@%lu)\n", | |
504 | page, PAGE_CACHE_SIZE, page->index); | |
91d5b470 CL |
505 | nfs_inc_stats(inode, NFSIOS_VFSREADPAGE); |
506 | nfs_add_stats(inode, NFSIOS_READPAGES, 1); | |
507 | ||
1da177e4 LT |
508 | /* |
509 | * Try to flush any pending writes to the file.. | |
510 | * | |
511 | * NOTE! Because we own the page lock, there cannot | |
512 | * be any new pending writes generated at this point | |
513 | * for this page (other pages can be written to). | |
514 | */ | |
515 | error = nfs_wb_page(inode, page); | |
516 | if (error) | |
517 | goto out_error; | |
518 | ||
5f004cf2 TM |
519 | error = -ESTALE; |
520 | if (NFS_STALE(inode)) | |
521 | goto out_error; | |
522 | ||
1da177e4 | 523 | if (file == NULL) { |
cf1308ff | 524 | error = -EBADF; |
d530838b | 525 | ctx = nfs_find_open_context(inode, NULL, FMODE_READ); |
1da177e4 | 526 | if (ctx == NULL) |
cf1308ff | 527 | goto out_error; |
1da177e4 LT |
528 | } else |
529 | ctx = get_nfs_open_context((struct nfs_open_context *) | |
530 | file->private_data); | |
1da177e4 | 531 | |
8e0969f0 TM |
532 | error = nfs_readpage_async(ctx, inode, page); |
533 | ||
1da177e4 LT |
534 | put_nfs_open_context(ctx); |
535 | return error; | |
536 | ||
537 | out_error: | |
538 | unlock_page(page); | |
539 | return error; | |
540 | } | |
541 | ||
542 | struct nfs_readdesc { | |
543 | struct list_head *head; | |
544 | struct nfs_open_context *ctx; | |
545 | }; | |
546 | ||
547 | static int | |
548 | readpage_async_filler(void *data, struct page *page) | |
549 | { | |
550 | struct nfs_readdesc *desc = (struct nfs_readdesc *)data; | |
551 | struct inode *inode = page->mapping->host; | |
552 | struct nfs_page *new; | |
553 | unsigned int len; | |
554 | ||
555 | nfs_wb_page(inode, page); | |
49a70f27 | 556 | len = nfs_page_length(page); |
1da177e4 LT |
557 | if (len == 0) |
558 | return nfs_return_empty_page(page); | |
559 | new = nfs_create_request(desc->ctx, inode, page, 0, len); | |
560 | if (IS_ERR(new)) { | |
561 | SetPageError(page); | |
562 | unlock_page(page); | |
563 | return PTR_ERR(new); | |
564 | } | |
565 | if (len < PAGE_CACHE_SIZE) | |
566 | memclear_highpage_flush(page, len, PAGE_CACHE_SIZE - len); | |
1da177e4 LT |
567 | nfs_list_add_request(new, desc->head); |
568 | return 0; | |
569 | } | |
570 | ||
571 | int nfs_readpages(struct file *filp, struct address_space *mapping, | |
572 | struct list_head *pages, unsigned nr_pages) | |
573 | { | |
574 | LIST_HEAD(head); | |
575 | struct nfs_readdesc desc = { | |
576 | .head = &head, | |
577 | }; | |
578 | struct inode *inode = mapping->host; | |
579 | struct nfs_server *server = NFS_SERVER(inode); | |
5f004cf2 | 580 | int ret = -ESTALE; |
1da177e4 LT |
581 | |
582 | dprintk("NFS: nfs_readpages (%s/%Ld %d)\n", | |
583 | inode->i_sb->s_id, | |
584 | (long long)NFS_FILEID(inode), | |
585 | nr_pages); | |
91d5b470 | 586 | nfs_inc_stats(inode, NFSIOS_VFSREADPAGES); |
1da177e4 | 587 | |
5f004cf2 TM |
588 | if (NFS_STALE(inode)) |
589 | goto out; | |
590 | ||
1da177e4 | 591 | if (filp == NULL) { |
d530838b | 592 | desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ); |
1da177e4 LT |
593 | if (desc.ctx == NULL) |
594 | return -EBADF; | |
595 | } else | |
596 | desc.ctx = get_nfs_open_context((struct nfs_open_context *) | |
597 | filp->private_data); | |
598 | ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc); | |
599 | if (!list_empty(&head)) { | |
d8a5ad75 | 600 | int err = nfs_pagein_list(&head, server->rsize); |
1da177e4 | 601 | if (!ret) |
91d5b470 | 602 | nfs_add_stats(inode, NFSIOS_READPAGES, err); |
1da177e4 LT |
603 | ret = err; |
604 | } | |
605 | put_nfs_open_context(desc.ctx); | |
5f004cf2 | 606 | out: |
1da177e4 LT |
607 | return ret; |
608 | } | |
609 | ||
f7b422b1 | 610 | int __init nfs_init_readpagecache(void) |
1da177e4 LT |
611 | { |
612 | nfs_rdata_cachep = kmem_cache_create("nfs_read_data", | |
613 | sizeof(struct nfs_read_data), | |
614 | 0, SLAB_HWCACHE_ALIGN, | |
615 | NULL, NULL); | |
616 | if (nfs_rdata_cachep == NULL) | |
617 | return -ENOMEM; | |
618 | ||
93d2341c MD |
619 | nfs_rdata_mempool = mempool_create_slab_pool(MIN_POOL_READ, |
620 | nfs_rdata_cachep); | |
1da177e4 LT |
621 | if (nfs_rdata_mempool == NULL) |
622 | return -ENOMEM; | |
623 | ||
624 | return 0; | |
625 | } | |
626 | ||
266bee88 | 627 | void nfs_destroy_readpagecache(void) |
1da177e4 LT |
628 | { |
629 | mempool_destroy(nfs_rdata_mempool); | |
1a1d92c1 | 630 | kmem_cache_destroy(nfs_rdata_cachep); |
1da177e4 | 631 | } |