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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 | ||
8d5658c9 TM |
30 | static int nfs_pagein_multi(struct inode *, struct list_head *, unsigned int, size_t, int); |
31 | static int nfs_pagein_one(struct inode *, struct list_head *, unsigned int, size_t, int); | |
ec06c096 TM |
32 | static const struct rpc_call_ops nfs_read_partial_ops; |
33 | static const struct rpc_call_ops nfs_read_full_ops; | |
1da177e4 | 34 | |
e18b890b | 35 | static struct kmem_cache *nfs_rdata_cachep; |
3feb2d49 | 36 | static mempool_t *nfs_rdata_mempool; |
1da177e4 LT |
37 | |
38 | #define MIN_POOL_READ (32) | |
39 | ||
8d5658c9 | 40 | struct nfs_read_data *nfs_readdata_alloc(unsigned int pagecount) |
3feb2d49 | 41 | { |
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 | { | |
60945cb7 | 82 | zero_user_page(page, 0, PAGE_CACHE_SIZE, KM_USER0); |
1da177e4 LT |
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) { | |
60945cb7 | 106 | zero_user_page(*pages, base, remainder, KM_USER0); |
79558f36 TM |
107 | break; |
108 | } | |
60945cb7 | 109 | zero_user_page(*pages, base, pglen, KM_USER0); |
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) | |
60945cb7 | 133 | zero_user_page(page, len, PAGE_CACHE_SIZE - len, KM_USER0); |
1da177e4 | 134 | |
1da177e4 | 135 | nfs_list_add_request(new, &one_request); |
bcb71bba | 136 | if (NFS_SERVER(inode)->rsize < PAGE_CACHE_SIZE) |
8d5658c9 | 137 | nfs_pagein_multi(inode, &one_request, 1, len, 0); |
bcb71bba | 138 | else |
8d5658c9 | 139 | nfs_pagein_one(inode, &one_request, 1, len, 0); |
1da177e4 LT |
140 | return 0; |
141 | } | |
142 | ||
143 | static void nfs_readpage_release(struct nfs_page *req) | |
144 | { | |
145 | unlock_page(req->wb_page); | |
146 | ||
1da177e4 | 147 | dprintk("NFS: read done (%s/%Ld %d@%Ld)\n", |
88be9f99 TM |
148 | req->wb_context->path.dentry->d_inode->i_sb->s_id, |
149 | (long long)NFS_FILEID(req->wb_context->path.dentry->d_inode), | |
1da177e4 LT |
150 | req->wb_bytes, |
151 | (long long)req_offset(req)); | |
10d2c46f NW |
152 | nfs_clear_request(req); |
153 | nfs_release_request(req); | |
1da177e4 LT |
154 | } |
155 | ||
156 | /* | |
157 | * Set up the NFS read request struct | |
158 | */ | |
159 | static void nfs_read_rpcsetup(struct nfs_page *req, struct nfs_read_data *data, | |
ec06c096 | 160 | const struct rpc_call_ops *call_ops, |
1da177e4 LT |
161 | unsigned int count, unsigned int offset) |
162 | { | |
84115e1c TM |
163 | struct inode *inode = req->wb_context->path.dentry->d_inode; |
164 | int swap_flags = IS_SWAPFILE(inode) ? NFS_RPC_SWAPFLAGS : 0; | |
165 | struct rpc_task_setup task_setup_data = { | |
166 | .rpc_client = NFS_CLIENT(inode), | |
167 | .callback_ops = call_ops, | |
168 | .callback_data = data, | |
169 | .flags = RPC_TASK_ASYNC | swap_flags, | |
170 | }; | |
1da177e4 LT |
171 | |
172 | data->req = req; | |
84115e1c | 173 | data->inode = inode; |
1da177e4 LT |
174 | data->cred = req->wb_context->cred; |
175 | ||
176 | data->args.fh = NFS_FH(inode); | |
177 | data->args.offset = req_offset(req) + offset; | |
178 | data->args.pgbase = req->wb_pgbase + offset; | |
179 | data->args.pages = data->pagevec; | |
180 | data->args.count = count; | |
181 | data->args.context = req->wb_context; | |
182 | ||
183 | data->res.fattr = &data->fattr; | |
184 | data->res.count = count; | |
185 | data->res.eof = 0; | |
0e574af1 | 186 | nfs_fattr_init(&data->fattr); |
1da177e4 | 187 | |
ec06c096 | 188 | /* Set up the initial task struct. */ |
84115e1c | 189 | rpc_init_task(&data->task, &task_setup_data); |
1da177e4 LT |
190 | NFS_PROTO(inode)->read_setup(data); |
191 | ||
a3f565b1 | 192 | dprintk("NFS: %5u initiated read call (req %s/%Ld, %u bytes @ offset %Lu)\n", |
1da177e4 LT |
193 | data->task.tk_pid, |
194 | inode->i_sb->s_id, | |
195 | (long long)NFS_FILEID(inode), | |
196 | count, | |
197 | (unsigned long long)data->args.offset); | |
198 | } | |
199 | ||
200 | static void | |
201 | nfs_async_read_error(struct list_head *head) | |
202 | { | |
203 | struct nfs_page *req; | |
204 | ||
205 | while (!list_empty(head)) { | |
206 | req = nfs_list_entry(head->next); | |
207 | nfs_list_remove_request(req); | |
208 | SetPageError(req->wb_page); | |
209 | nfs_readpage_release(req); | |
210 | } | |
211 | } | |
212 | ||
213 | /* | |
214 | * Start an async read operation | |
215 | */ | |
216 | static void nfs_execute_read(struct nfs_read_data *data) | |
217 | { | |
218 | struct rpc_clnt *clnt = NFS_CLIENT(data->inode); | |
219 | sigset_t oldset; | |
220 | ||
221 | rpc_clnt_sigmask(clnt, &oldset); | |
1da177e4 | 222 | rpc_execute(&data->task); |
1da177e4 LT |
223 | rpc_clnt_sigunmask(clnt, &oldset); |
224 | } | |
225 | ||
226 | /* | |
227 | * Generate multiple requests to fill a single page. | |
228 | * | |
229 | * We optimize to reduce the number of read operations on the wire. If we | |
230 | * detect that we're reading a page, or an area of a page, that is past the | |
231 | * end of file, we do not generate NFS read operations but just clear the | |
232 | * parts of the page that would have come back zero from the server anyway. | |
233 | * | |
234 | * We rely on the cached value of i_size to make this determination; another | |
235 | * client can fill pages on the server past our cached end-of-file, but we | |
236 | * won't see the new data until our attribute cache is updated. This is more | |
237 | * or less conventional NFS client behavior. | |
238 | */ | |
8d5658c9 | 239 | static int nfs_pagein_multi(struct inode *inode, struct list_head *head, unsigned int npages, size_t count, int flags) |
1da177e4 LT |
240 | { |
241 | struct nfs_page *req = nfs_list_entry(head->next); | |
242 | struct page *page = req->wb_page; | |
243 | struct nfs_read_data *data; | |
e9f7bee1 TM |
244 | size_t rsize = NFS_SERVER(inode)->rsize, nbytes; |
245 | unsigned int offset; | |
1da177e4 LT |
246 | int requests = 0; |
247 | LIST_HEAD(list); | |
248 | ||
249 | nfs_list_remove_request(req); | |
250 | ||
bcb71bba | 251 | nbytes = count; |
e9f7bee1 TM |
252 | do { |
253 | size_t len = min(nbytes,rsize); | |
254 | ||
8d5658c9 | 255 | data = nfs_readdata_alloc(1); |
1da177e4 LT |
256 | if (!data) |
257 | goto out_bad; | |
258 | INIT_LIST_HEAD(&data->pages); | |
259 | list_add(&data->pages, &list); | |
260 | requests++; | |
e9f7bee1 TM |
261 | nbytes -= len; |
262 | } while(nbytes != 0); | |
1da177e4 LT |
263 | atomic_set(&req->wb_complete, requests); |
264 | ||
265 | ClearPageError(page); | |
266 | offset = 0; | |
bcb71bba | 267 | nbytes = count; |
1da177e4 LT |
268 | do { |
269 | data = list_entry(list.next, struct nfs_read_data, pages); | |
270 | list_del_init(&data->pages); | |
271 | ||
272 | data->pagevec[0] = page; | |
1da177e4 | 273 | |
bcb71bba TM |
274 | if (nbytes < rsize) |
275 | rsize = nbytes; | |
276 | nfs_read_rpcsetup(req, data, &nfs_read_partial_ops, | |
277 | rsize, offset); | |
278 | offset += rsize; | |
279 | nbytes -= rsize; | |
1da177e4 LT |
280 | nfs_execute_read(data); |
281 | } while (nbytes != 0); | |
282 | ||
283 | return 0; | |
284 | ||
285 | out_bad: | |
286 | while (!list_empty(&list)) { | |
287 | data = list_entry(list.next, struct nfs_read_data, pages); | |
288 | list_del(&data->pages); | |
289 | nfs_readdata_free(data); | |
290 | } | |
291 | SetPageError(page); | |
292 | nfs_readpage_release(req); | |
293 | return -ENOMEM; | |
294 | } | |
295 | ||
8d5658c9 | 296 | static int nfs_pagein_one(struct inode *inode, struct list_head *head, unsigned int npages, size_t count, int flags) |
1da177e4 LT |
297 | { |
298 | struct nfs_page *req; | |
299 | struct page **pages; | |
300 | struct nfs_read_data *data; | |
1da177e4 | 301 | |
8d5658c9 | 302 | data = nfs_readdata_alloc(npages); |
1da177e4 LT |
303 | if (!data) |
304 | goto out_bad; | |
305 | ||
306 | INIT_LIST_HEAD(&data->pages); | |
307 | pages = data->pagevec; | |
1da177e4 LT |
308 | while (!list_empty(head)) { |
309 | req = nfs_list_entry(head->next); | |
310 | nfs_list_remove_request(req); | |
311 | nfs_list_add_request(req, &data->pages); | |
312 | ClearPageError(req->wb_page); | |
313 | *pages++ = req->wb_page; | |
1da177e4 LT |
314 | } |
315 | req = nfs_list_entry(data->pages.next); | |
316 | ||
ec06c096 | 317 | nfs_read_rpcsetup(req, data, &nfs_read_full_ops, count, 0); |
1da177e4 LT |
318 | |
319 | nfs_execute_read(data); | |
320 | return 0; | |
321 | out_bad: | |
322 | nfs_async_read_error(head); | |
323 | return -ENOMEM; | |
324 | } | |
325 | ||
0b671301 TM |
326 | /* |
327 | * This is the callback from RPC telling us whether a reply was | |
328 | * received or some error occurred (timeout or socket shutdown). | |
329 | */ | |
330 | int nfs_readpage_result(struct rpc_task *task, struct nfs_read_data *data) | |
331 | { | |
332 | int status; | |
333 | ||
a3f565b1 | 334 | dprintk("NFS: %s: %5u, (status %d)\n", __FUNCTION__, task->tk_pid, |
0b671301 TM |
335 | task->tk_status); |
336 | ||
337 | status = NFS_PROTO(data->inode)->read_done(task, data); | |
338 | if (status != 0) | |
339 | return status; | |
340 | ||
341 | nfs_add_stats(data->inode, NFSIOS_SERVERREADBYTES, data->res.count); | |
342 | ||
343 | if (task->tk_status == -ESTALE) { | |
344 | set_bit(NFS_INO_STALE, &NFS_FLAGS(data->inode)); | |
345 | nfs_mark_for_revalidate(data->inode); | |
346 | } | |
0b671301 TM |
347 | return 0; |
348 | } | |
349 | ||
350 | static int nfs_readpage_retry(struct rpc_task *task, struct nfs_read_data *data) | |
351 | { | |
352 | struct nfs_readargs *argp = &data->args; | |
353 | struct nfs_readres *resp = &data->res; | |
354 | ||
355 | if (resp->eof || resp->count == argp->count) | |
356 | return 0; | |
357 | ||
358 | /* This is a short read! */ | |
359 | nfs_inc_stats(data->inode, NFSIOS_SHORTREAD); | |
360 | /* Has the server at least made some progress? */ | |
361 | if (resp->count == 0) | |
362 | return 0; | |
363 | ||
364 | /* Yes, so retry the read at the end of the data */ | |
365 | argp->offset += resp->count; | |
366 | argp->pgbase += resp->count; | |
367 | argp->count -= resp->count; | |
368 | rpc_restart_call(task); | |
369 | return -EAGAIN; | |
370 | } | |
371 | ||
1da177e4 LT |
372 | /* |
373 | * Handle a read reply that fills part of a page. | |
374 | */ | |
ec06c096 | 375 | static void nfs_readpage_result_partial(struct rpc_task *task, void *calldata) |
1da177e4 | 376 | { |
ec06c096 | 377 | struct nfs_read_data *data = calldata; |
1da177e4 LT |
378 | struct nfs_page *req = data->req; |
379 | struct page *page = req->wb_page; | |
380 | ||
ec06c096 TM |
381 | if (nfs_readpage_result(task, data) != 0) |
382 | return; | |
0b671301 TM |
383 | |
384 | if (likely(task->tk_status >= 0)) { | |
385 | nfs_readpage_truncate_uninitialised_page(data); | |
386 | if (nfs_readpage_retry(task, data) != 0) | |
387 | return; | |
388 | } | |
389 | if (unlikely(task->tk_status < 0)) | |
390 | SetPageError(page); | |
1da177e4 LT |
391 | if (atomic_dec_and_test(&req->wb_complete)) { |
392 | if (!PageError(page)) | |
393 | SetPageUptodate(page); | |
394 | nfs_readpage_release(req); | |
395 | } | |
396 | } | |
397 | ||
ec06c096 TM |
398 | static const struct rpc_call_ops nfs_read_partial_ops = { |
399 | .rpc_call_done = nfs_readpage_result_partial, | |
400 | .rpc_release = nfs_readdata_release, | |
401 | }; | |
402 | ||
1de3fc12 TM |
403 | static void nfs_readpage_set_pages_uptodate(struct nfs_read_data *data) |
404 | { | |
405 | unsigned int count = data->res.count; | |
406 | unsigned int base = data->args.pgbase; | |
407 | struct page **pages; | |
408 | ||
79558f36 TM |
409 | if (data->res.eof) |
410 | count = data->args.count; | |
1de3fc12 TM |
411 | if (unlikely(count == 0)) |
412 | return; | |
413 | pages = &data->args.pages[base >> PAGE_CACHE_SHIFT]; | |
414 | base &= ~PAGE_CACHE_MASK; | |
415 | count += base; | |
416 | for (;count >= PAGE_CACHE_SIZE; count -= PAGE_CACHE_SIZE, pages++) | |
417 | SetPageUptodate(*pages); | |
0b671301 TM |
418 | if (count == 0) |
419 | return; | |
420 | /* Was this a short read? */ | |
421 | if (data->res.eof || data->res.count == data->args.count) | |
1de3fc12 TM |
422 | SetPageUptodate(*pages); |
423 | } | |
424 | ||
1da177e4 LT |
425 | /* |
426 | * This is the callback from RPC telling us whether a reply was | |
427 | * received or some error occurred (timeout or socket shutdown). | |
428 | */ | |
ec06c096 | 429 | static void nfs_readpage_result_full(struct rpc_task *task, void *calldata) |
1da177e4 | 430 | { |
ec06c096 | 431 | struct nfs_read_data *data = calldata; |
1da177e4 | 432 | |
0b671301 TM |
433 | if (nfs_readpage_result(task, data) != 0) |
434 | return; | |
1de3fc12 | 435 | /* |
0b671301 | 436 | * Note: nfs_readpage_retry may change the values of |
1de3fc12 | 437 | * data->args. In the multi-page case, we therefore need |
0b671301 TM |
438 | * to ensure that we call nfs_readpage_set_pages_uptodate() |
439 | * first. | |
1de3fc12 TM |
440 | */ |
441 | if (likely(task->tk_status >= 0)) { | |
442 | nfs_readpage_truncate_uninitialised_page(data); | |
443 | nfs_readpage_set_pages_uptodate(data); | |
0b671301 TM |
444 | if (nfs_readpage_retry(task, data) != 0) |
445 | return; | |
446 | } | |
1da177e4 LT |
447 | while (!list_empty(&data->pages)) { |
448 | struct nfs_page *req = nfs_list_entry(data->pages.next); | |
1da177e4 | 449 | |
1de3fc12 | 450 | nfs_list_remove_request(req); |
1da177e4 LT |
451 | nfs_readpage_release(req); |
452 | } | |
453 | } | |
454 | ||
ec06c096 TM |
455 | static const struct rpc_call_ops nfs_read_full_ops = { |
456 | .rpc_call_done = nfs_readpage_result_full, | |
457 | .rpc_release = nfs_readdata_release, | |
458 | }; | |
459 | ||
1da177e4 LT |
460 | /* |
461 | * Read a page over NFS. | |
462 | * We read the page synchronously in the following case: | |
463 | * - The error flag is set for this page. This happens only when a | |
464 | * previous async read operation failed. | |
465 | */ | |
466 | int nfs_readpage(struct file *file, struct page *page) | |
467 | { | |
468 | struct nfs_open_context *ctx; | |
469 | struct inode *inode = page->mapping->host; | |
470 | int error; | |
471 | ||
472 | dprintk("NFS: nfs_readpage (%p %ld@%lu)\n", | |
473 | page, PAGE_CACHE_SIZE, page->index); | |
91d5b470 CL |
474 | nfs_inc_stats(inode, NFSIOS_VFSREADPAGE); |
475 | nfs_add_stats(inode, NFSIOS_READPAGES, 1); | |
476 | ||
1da177e4 LT |
477 | /* |
478 | * Try to flush any pending writes to the file.. | |
479 | * | |
480 | * NOTE! Because we own the page lock, there cannot | |
481 | * be any new pending writes generated at this point | |
482 | * for this page (other pages can be written to). | |
483 | */ | |
484 | error = nfs_wb_page(inode, page); | |
485 | if (error) | |
de05a0cc TM |
486 | goto out_unlock; |
487 | if (PageUptodate(page)) | |
488 | goto out_unlock; | |
1da177e4 | 489 | |
5f004cf2 TM |
490 | error = -ESTALE; |
491 | if (NFS_STALE(inode)) | |
de05a0cc | 492 | goto out_unlock; |
5f004cf2 | 493 | |
1da177e4 | 494 | if (file == NULL) { |
cf1308ff | 495 | error = -EBADF; |
d530838b | 496 | ctx = nfs_find_open_context(inode, NULL, FMODE_READ); |
1da177e4 | 497 | if (ctx == NULL) |
de05a0cc | 498 | goto out_unlock; |
1da177e4 | 499 | } else |
cd3758e3 | 500 | ctx = get_nfs_open_context(nfs_file_open_context(file)); |
1da177e4 | 501 | |
8e0969f0 TM |
502 | error = nfs_readpage_async(ctx, inode, page); |
503 | ||
1da177e4 LT |
504 | put_nfs_open_context(ctx); |
505 | return error; | |
de05a0cc | 506 | out_unlock: |
1da177e4 LT |
507 | unlock_page(page); |
508 | return error; | |
509 | } | |
510 | ||
511 | struct nfs_readdesc { | |
8b09bee3 | 512 | struct nfs_pageio_descriptor *pgio; |
1da177e4 LT |
513 | struct nfs_open_context *ctx; |
514 | }; | |
515 | ||
516 | static int | |
517 | readpage_async_filler(void *data, struct page *page) | |
518 | { | |
519 | struct nfs_readdesc *desc = (struct nfs_readdesc *)data; | |
520 | struct inode *inode = page->mapping->host; | |
521 | struct nfs_page *new; | |
522 | unsigned int len; | |
de05a0cc TM |
523 | int error; |
524 | ||
525 | error = nfs_wb_page(inode, page); | |
526 | if (error) | |
527 | goto out_unlock; | |
528 | if (PageUptodate(page)) | |
529 | goto out_unlock; | |
1da177e4 | 530 | |
49a70f27 | 531 | len = nfs_page_length(page); |
1da177e4 LT |
532 | if (len == 0) |
533 | return nfs_return_empty_page(page); | |
de05a0cc | 534 | |
1da177e4 | 535 | new = nfs_create_request(desc->ctx, inode, page, 0, len); |
de05a0cc TM |
536 | if (IS_ERR(new)) |
537 | goto out_error; | |
538 | ||
1da177e4 | 539 | if (len < PAGE_CACHE_SIZE) |
60945cb7 | 540 | zero_user_page(page, len, PAGE_CACHE_SIZE - len, KM_USER0); |
8b09bee3 | 541 | nfs_pageio_add_request(desc->pgio, new); |
1da177e4 | 542 | return 0; |
de05a0cc TM |
543 | out_error: |
544 | error = PTR_ERR(new); | |
545 | SetPageError(page); | |
546 | out_unlock: | |
547 | unlock_page(page); | |
548 | return error; | |
1da177e4 LT |
549 | } |
550 | ||
551 | int nfs_readpages(struct file *filp, struct address_space *mapping, | |
552 | struct list_head *pages, unsigned nr_pages) | |
553 | { | |
8b09bee3 | 554 | struct nfs_pageio_descriptor pgio; |
1da177e4 | 555 | struct nfs_readdesc desc = { |
8b09bee3 | 556 | .pgio = &pgio, |
1da177e4 LT |
557 | }; |
558 | struct inode *inode = mapping->host; | |
559 | struct nfs_server *server = NFS_SERVER(inode); | |
8b09bee3 TM |
560 | size_t rsize = server->rsize; |
561 | unsigned long npages; | |
5f004cf2 | 562 | int ret = -ESTALE; |
1da177e4 LT |
563 | |
564 | dprintk("NFS: nfs_readpages (%s/%Ld %d)\n", | |
565 | inode->i_sb->s_id, | |
566 | (long long)NFS_FILEID(inode), | |
567 | nr_pages); | |
91d5b470 | 568 | nfs_inc_stats(inode, NFSIOS_VFSREADPAGES); |
1da177e4 | 569 | |
5f004cf2 TM |
570 | if (NFS_STALE(inode)) |
571 | goto out; | |
572 | ||
1da177e4 | 573 | if (filp == NULL) { |
d530838b | 574 | desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ); |
1da177e4 LT |
575 | if (desc.ctx == NULL) |
576 | return -EBADF; | |
577 | } else | |
cd3758e3 | 578 | desc.ctx = get_nfs_open_context(nfs_file_open_context(filp)); |
8b09bee3 TM |
579 | if (rsize < PAGE_CACHE_SIZE) |
580 | nfs_pageio_init(&pgio, inode, nfs_pagein_multi, rsize, 0); | |
581 | else | |
582 | nfs_pageio_init(&pgio, inode, nfs_pagein_one, rsize, 0); | |
583 | ||
1da177e4 | 584 | ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc); |
8b09bee3 TM |
585 | |
586 | nfs_pageio_complete(&pgio); | |
587 | npages = (pgio.pg_bytes_written + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; | |
588 | nfs_add_stats(inode, NFSIOS_READPAGES, npages); | |
1da177e4 | 589 | put_nfs_open_context(desc.ctx); |
5f004cf2 | 590 | out: |
1da177e4 LT |
591 | return ret; |
592 | } | |
593 | ||
f7b422b1 | 594 | int __init nfs_init_readpagecache(void) |
1da177e4 LT |
595 | { |
596 | nfs_rdata_cachep = kmem_cache_create("nfs_read_data", | |
597 | sizeof(struct nfs_read_data), | |
598 | 0, SLAB_HWCACHE_ALIGN, | |
20c2df83 | 599 | NULL); |
1da177e4 LT |
600 | if (nfs_rdata_cachep == NULL) |
601 | return -ENOMEM; | |
602 | ||
93d2341c MD |
603 | nfs_rdata_mempool = mempool_create_slab_pool(MIN_POOL_READ, |
604 | nfs_rdata_cachep); | |
1da177e4 LT |
605 | if (nfs_rdata_mempool == NULL) |
606 | return -ENOMEM; | |
607 | ||
608 | return 0; | |
609 | } | |
610 | ||
266bee88 | 611 | void nfs_destroy_readpagecache(void) |
1da177e4 LT |
612 | { |
613 | mempool_destroy(nfs_rdata_mempool); | |
1a1d92c1 | 614 | kmem_cache_destroy(nfs_rdata_cachep); |
1da177e4 | 615 | } |