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 | |
8 | * | |
9 | * We do an ugly hack here in order to return proper error codes to the | |
10 | * user program when a read request failed: since generic_file_read | |
11 | * only checks the return value of inode->i_op->readpage() which is always 0 | |
12 | * for async RPC, we set the error bit of the page to 1 when an error occurs, | |
13 | * and make nfs_readpage transmit requests synchronously when encountering this. | |
14 | * This is only a small problem, though, since we now retry all operations | |
15 | * within the RPC code when root squashing is suspected. | |
16 | */ | |
17 | ||
18 | #include <linux/config.h> | |
19 | #include <linux/time.h> | |
20 | #include <linux/kernel.h> | |
21 | #include <linux/errno.h> | |
22 | #include <linux/fcntl.h> | |
23 | #include <linux/stat.h> | |
24 | #include <linux/mm.h> | |
25 | #include <linux/slab.h> | |
26 | #include <linux/pagemap.h> | |
27 | #include <linux/sunrpc/clnt.h> | |
28 | #include <linux/nfs_fs.h> | |
29 | #include <linux/nfs_page.h> | |
30 | #include <linux/smp_lock.h> | |
31 | ||
32 | #include <asm/system.h> | |
33 | ||
34 | #define NFSDBG_FACILITY NFSDBG_PAGECACHE | |
35 | ||
36 | static int nfs_pagein_one(struct list_head *, struct inode *); | |
37 | static void nfs_readpage_result_partial(struct nfs_read_data *, int); | |
38 | static void nfs_readpage_result_full(struct nfs_read_data *, int); | |
39 | ||
40 | static kmem_cache_t *nfs_rdata_cachep; | |
41 | mempool_t *nfs_rdata_mempool; | |
42 | ||
43 | #define MIN_POOL_READ (32) | |
44 | ||
45 | void nfs_readdata_release(struct rpc_task *task) | |
46 | { | |
47 | struct nfs_read_data *data = (struct nfs_read_data *)task->tk_calldata; | |
48 | nfs_readdata_free(data); | |
49 | } | |
50 | ||
51 | static | |
52 | unsigned int nfs_page_length(struct inode *inode, struct page *page) | |
53 | { | |
54 | loff_t i_size = i_size_read(inode); | |
55 | unsigned long idx; | |
56 | ||
57 | if (i_size <= 0) | |
58 | return 0; | |
59 | idx = (i_size - 1) >> PAGE_CACHE_SHIFT; | |
60 | if (page->index > idx) | |
61 | return 0; | |
62 | if (page->index != idx) | |
63 | return PAGE_CACHE_SIZE; | |
64 | return 1 + ((i_size - 1) & (PAGE_CACHE_SIZE - 1)); | |
65 | } | |
66 | ||
67 | static | |
68 | int nfs_return_empty_page(struct page *page) | |
69 | { | |
70 | memclear_highpage_flush(page, 0, PAGE_CACHE_SIZE); | |
71 | SetPageUptodate(page); | |
72 | unlock_page(page); | |
73 | return 0; | |
74 | } | |
75 | ||
76 | /* | |
77 | * Read a page synchronously. | |
78 | */ | |
79 | static int nfs_readpage_sync(struct nfs_open_context *ctx, struct inode *inode, | |
80 | struct page *page) | |
81 | { | |
82 | unsigned int rsize = NFS_SERVER(inode)->rsize; | |
83 | unsigned int count = PAGE_CACHE_SIZE; | |
84 | int result; | |
85 | struct nfs_read_data *rdata; | |
86 | ||
87 | rdata = nfs_readdata_alloc(); | |
88 | if (!rdata) | |
89 | return -ENOMEM; | |
90 | ||
91 | memset(rdata, 0, sizeof(*rdata)); | |
92 | rdata->flags = (IS_SWAPFILE(inode)? NFS_RPC_SWAPFLAGS : 0); | |
93 | rdata->cred = ctx->cred; | |
94 | rdata->inode = inode; | |
95 | INIT_LIST_HEAD(&rdata->pages); | |
96 | rdata->args.fh = NFS_FH(inode); | |
97 | rdata->args.context = ctx; | |
98 | rdata->args.pages = &page; | |
99 | rdata->args.pgbase = 0UL; | |
100 | rdata->args.count = rsize; | |
101 | rdata->res.fattr = &rdata->fattr; | |
102 | ||
103 | dprintk("NFS: nfs_readpage_sync(%p)\n", page); | |
104 | ||
105 | /* | |
106 | * This works now because the socket layer never tries to DMA | |
107 | * into this buffer directly. | |
108 | */ | |
109 | do { | |
110 | if (count < rsize) | |
111 | rdata->args.count = count; | |
112 | rdata->res.count = rdata->args.count; | |
113 | rdata->args.offset = page_offset(page) + rdata->args.pgbase; | |
114 | ||
115 | dprintk("NFS: nfs_proc_read(%s, (%s/%Ld), %Lu, %u)\n", | |
116 | NFS_SERVER(inode)->hostname, | |
117 | inode->i_sb->s_id, | |
118 | (long long)NFS_FILEID(inode), | |
119 | (unsigned long long)rdata->args.pgbase, | |
120 | rdata->args.count); | |
121 | ||
122 | lock_kernel(); | |
123 | result = NFS_PROTO(inode)->read(rdata); | |
124 | unlock_kernel(); | |
125 | ||
126 | /* | |
127 | * Even if we had a partial success we can't mark the page | |
128 | * cache valid. | |
129 | */ | |
130 | if (result < 0) { | |
131 | if (result == -EISDIR) | |
132 | result = -EINVAL; | |
133 | goto io_error; | |
134 | } | |
135 | count -= result; | |
136 | rdata->args.pgbase += result; | |
137 | /* Note: result == 0 should only happen if we're caching | |
138 | * a write that extends the file and punches a hole. | |
139 | */ | |
140 | if (rdata->res.eof != 0 || result == 0) | |
141 | break; | |
142 | } while (count); | |
dc59250c | 143 | spin_lock(&inode->i_lock); |
55296809 | 144 | NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATIME; |
dc59250c | 145 | spin_unlock(&inode->i_lock); |
1da177e4 LT |
146 | |
147 | if (count) | |
148 | memclear_highpage_flush(page, rdata->args.pgbase, count); | |
149 | SetPageUptodate(page); | |
150 | if (PageError(page)) | |
151 | ClearPageError(page); | |
152 | result = 0; | |
153 | ||
154 | io_error: | |
155 | unlock_page(page); | |
156 | nfs_readdata_free(rdata); | |
157 | return result; | |
158 | } | |
159 | ||
160 | static int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode, | |
161 | struct page *page) | |
162 | { | |
163 | LIST_HEAD(one_request); | |
164 | struct nfs_page *new; | |
165 | unsigned int len; | |
166 | ||
167 | len = nfs_page_length(inode, page); | |
168 | if (len == 0) | |
169 | return nfs_return_empty_page(page); | |
170 | new = nfs_create_request(ctx, inode, page, 0, len); | |
171 | if (IS_ERR(new)) { | |
172 | unlock_page(page); | |
173 | return PTR_ERR(new); | |
174 | } | |
175 | if (len < PAGE_CACHE_SIZE) | |
176 | memclear_highpage_flush(page, len, PAGE_CACHE_SIZE - len); | |
177 | ||
1da177e4 LT |
178 | nfs_list_add_request(new, &one_request); |
179 | nfs_pagein_one(&one_request, inode); | |
180 | return 0; | |
181 | } | |
182 | ||
183 | static void nfs_readpage_release(struct nfs_page *req) | |
184 | { | |
185 | unlock_page(req->wb_page); | |
186 | ||
1da177e4 LT |
187 | dprintk("NFS: read done (%s/%Ld %d@%Ld)\n", |
188 | req->wb_context->dentry->d_inode->i_sb->s_id, | |
189 | (long long)NFS_FILEID(req->wb_context->dentry->d_inode), | |
190 | req->wb_bytes, | |
191 | (long long)req_offset(req)); | |
10d2c46f NW |
192 | nfs_clear_request(req); |
193 | nfs_release_request(req); | |
1da177e4 LT |
194 | } |
195 | ||
196 | /* | |
197 | * Set up the NFS read request struct | |
198 | */ | |
199 | static void nfs_read_rpcsetup(struct nfs_page *req, struct nfs_read_data *data, | |
200 | unsigned int count, unsigned int offset) | |
201 | { | |
202 | struct inode *inode; | |
203 | ||
204 | data->req = req; | |
205 | data->inode = inode = req->wb_context->dentry->d_inode; | |
206 | data->cred = req->wb_context->cred; | |
207 | ||
208 | data->args.fh = NFS_FH(inode); | |
209 | data->args.offset = req_offset(req) + offset; | |
210 | data->args.pgbase = req->wb_pgbase + offset; | |
211 | data->args.pages = data->pagevec; | |
212 | data->args.count = count; | |
213 | data->args.context = req->wb_context; | |
214 | ||
215 | data->res.fattr = &data->fattr; | |
216 | data->res.count = count; | |
217 | data->res.eof = 0; | |
0e574af1 | 218 | nfs_fattr_init(&data->fattr); |
1da177e4 LT |
219 | |
220 | NFS_PROTO(inode)->read_setup(data); | |
221 | ||
222 | data->task.tk_cookie = (unsigned long)inode; | |
223 | data->task.tk_calldata = data; | |
224 | /* Release requests */ | |
225 | data->task.tk_release = nfs_readdata_release; | |
226 | ||
227 | dprintk("NFS: %4d initiated read call (req %s/%Ld, %u bytes @ offset %Lu)\n", | |
228 | data->task.tk_pid, | |
229 | inode->i_sb->s_id, | |
230 | (long long)NFS_FILEID(inode), | |
231 | count, | |
232 | (unsigned long long)data->args.offset); | |
233 | } | |
234 | ||
235 | static void | |
236 | nfs_async_read_error(struct list_head *head) | |
237 | { | |
238 | struct nfs_page *req; | |
239 | ||
240 | while (!list_empty(head)) { | |
241 | req = nfs_list_entry(head->next); | |
242 | nfs_list_remove_request(req); | |
243 | SetPageError(req->wb_page); | |
244 | nfs_readpage_release(req); | |
245 | } | |
246 | } | |
247 | ||
248 | /* | |
249 | * Start an async read operation | |
250 | */ | |
251 | static void nfs_execute_read(struct nfs_read_data *data) | |
252 | { | |
253 | struct rpc_clnt *clnt = NFS_CLIENT(data->inode); | |
254 | sigset_t oldset; | |
255 | ||
256 | rpc_clnt_sigmask(clnt, &oldset); | |
257 | lock_kernel(); | |
258 | rpc_execute(&data->task); | |
259 | unlock_kernel(); | |
260 | rpc_clnt_sigunmask(clnt, &oldset); | |
261 | } | |
262 | ||
263 | /* | |
264 | * Generate multiple requests to fill a single page. | |
265 | * | |
266 | * We optimize to reduce the number of read operations on the wire. If we | |
267 | * detect that we're reading a page, or an area of a page, that is past the | |
268 | * end of file, we do not generate NFS read operations but just clear the | |
269 | * parts of the page that would have come back zero from the server anyway. | |
270 | * | |
271 | * We rely on the cached value of i_size to make this determination; another | |
272 | * client can fill pages on the server past our cached end-of-file, but we | |
273 | * won't see the new data until our attribute cache is updated. This is more | |
274 | * or less conventional NFS client behavior. | |
275 | */ | |
276 | static int nfs_pagein_multi(struct list_head *head, struct inode *inode) | |
277 | { | |
278 | struct nfs_page *req = nfs_list_entry(head->next); | |
279 | struct page *page = req->wb_page; | |
280 | struct nfs_read_data *data; | |
281 | unsigned int rsize = NFS_SERVER(inode)->rsize; | |
282 | unsigned int nbytes, offset; | |
283 | int requests = 0; | |
284 | LIST_HEAD(list); | |
285 | ||
286 | nfs_list_remove_request(req); | |
287 | ||
288 | nbytes = req->wb_bytes; | |
289 | for(;;) { | |
290 | data = nfs_readdata_alloc(); | |
291 | if (!data) | |
292 | goto out_bad; | |
293 | INIT_LIST_HEAD(&data->pages); | |
294 | list_add(&data->pages, &list); | |
295 | requests++; | |
296 | if (nbytes <= rsize) | |
297 | break; | |
298 | nbytes -= rsize; | |
299 | } | |
300 | atomic_set(&req->wb_complete, requests); | |
301 | ||
302 | ClearPageError(page); | |
303 | offset = 0; | |
304 | nbytes = req->wb_bytes; | |
305 | do { | |
306 | data = list_entry(list.next, struct nfs_read_data, pages); | |
307 | list_del_init(&data->pages); | |
308 | ||
309 | data->pagevec[0] = page; | |
310 | data->complete = nfs_readpage_result_partial; | |
311 | ||
312 | if (nbytes > rsize) { | |
313 | nfs_read_rpcsetup(req, data, rsize, offset); | |
314 | offset += rsize; | |
315 | nbytes -= rsize; | |
316 | } else { | |
317 | nfs_read_rpcsetup(req, data, nbytes, offset); | |
318 | nbytes = 0; | |
319 | } | |
320 | nfs_execute_read(data); | |
321 | } while (nbytes != 0); | |
322 | ||
323 | return 0; | |
324 | ||
325 | out_bad: | |
326 | while (!list_empty(&list)) { | |
327 | data = list_entry(list.next, struct nfs_read_data, pages); | |
328 | list_del(&data->pages); | |
329 | nfs_readdata_free(data); | |
330 | } | |
331 | SetPageError(page); | |
332 | nfs_readpage_release(req); | |
333 | return -ENOMEM; | |
334 | } | |
335 | ||
336 | static int nfs_pagein_one(struct list_head *head, struct inode *inode) | |
337 | { | |
338 | struct nfs_page *req; | |
339 | struct page **pages; | |
340 | struct nfs_read_data *data; | |
341 | unsigned int count; | |
342 | ||
343 | if (NFS_SERVER(inode)->rsize < PAGE_CACHE_SIZE) | |
344 | return nfs_pagein_multi(head, inode); | |
345 | ||
346 | data = nfs_readdata_alloc(); | |
347 | if (!data) | |
348 | goto out_bad; | |
349 | ||
350 | INIT_LIST_HEAD(&data->pages); | |
351 | pages = data->pagevec; | |
352 | count = 0; | |
353 | while (!list_empty(head)) { | |
354 | req = nfs_list_entry(head->next); | |
355 | nfs_list_remove_request(req); | |
356 | nfs_list_add_request(req, &data->pages); | |
357 | ClearPageError(req->wb_page); | |
358 | *pages++ = req->wb_page; | |
359 | count += req->wb_bytes; | |
360 | } | |
361 | req = nfs_list_entry(data->pages.next); | |
362 | ||
363 | data->complete = nfs_readpage_result_full; | |
364 | nfs_read_rpcsetup(req, data, count, 0); | |
365 | ||
366 | nfs_execute_read(data); | |
367 | return 0; | |
368 | out_bad: | |
369 | nfs_async_read_error(head); | |
370 | return -ENOMEM; | |
371 | } | |
372 | ||
373 | static int | |
374 | nfs_pagein_list(struct list_head *head, int rpages) | |
375 | { | |
376 | LIST_HEAD(one_request); | |
377 | struct nfs_page *req; | |
378 | int error = 0; | |
379 | unsigned int pages = 0; | |
380 | ||
381 | while (!list_empty(head)) { | |
382 | pages += nfs_coalesce_requests(head, &one_request, rpages); | |
383 | req = nfs_list_entry(one_request.next); | |
384 | error = nfs_pagein_one(&one_request, req->wb_context->dentry->d_inode); | |
385 | if (error < 0) | |
386 | break; | |
387 | } | |
388 | if (error >= 0) | |
389 | return pages; | |
390 | ||
391 | nfs_async_read_error(head); | |
392 | return error; | |
393 | } | |
394 | ||
395 | /* | |
396 | * Handle a read reply that fills part of a page. | |
397 | */ | |
398 | static void nfs_readpage_result_partial(struct nfs_read_data *data, int status) | |
399 | { | |
400 | struct nfs_page *req = data->req; | |
401 | struct page *page = req->wb_page; | |
402 | ||
403 | if (status >= 0) { | |
404 | unsigned int request = data->args.count; | |
405 | unsigned int result = data->res.count; | |
406 | ||
407 | if (result < request) { | |
408 | memclear_highpage_flush(page, | |
409 | data->args.pgbase + result, | |
410 | request - result); | |
411 | } | |
412 | } else | |
413 | SetPageError(page); | |
414 | ||
415 | if (atomic_dec_and_test(&req->wb_complete)) { | |
416 | if (!PageError(page)) | |
417 | SetPageUptodate(page); | |
418 | nfs_readpage_release(req); | |
419 | } | |
420 | } | |
421 | ||
422 | /* | |
423 | * This is the callback from RPC telling us whether a reply was | |
424 | * received or some error occurred (timeout or socket shutdown). | |
425 | */ | |
426 | static void nfs_readpage_result_full(struct nfs_read_data *data, int status) | |
427 | { | |
428 | unsigned int count = data->res.count; | |
429 | ||
430 | while (!list_empty(&data->pages)) { | |
431 | struct nfs_page *req = nfs_list_entry(data->pages.next); | |
432 | struct page *page = req->wb_page; | |
433 | nfs_list_remove_request(req); | |
434 | ||
435 | if (status >= 0) { | |
436 | if (count < PAGE_CACHE_SIZE) { | |
437 | if (count < req->wb_bytes) | |
438 | memclear_highpage_flush(page, | |
439 | req->wb_pgbase + count, | |
440 | req->wb_bytes - count); | |
441 | count = 0; | |
442 | } else | |
443 | count -= PAGE_CACHE_SIZE; | |
444 | SetPageUptodate(page); | |
445 | } else | |
446 | SetPageError(page); | |
447 | nfs_readpage_release(req); | |
448 | } | |
449 | } | |
450 | ||
451 | /* | |
452 | * This is the callback from RPC telling us whether a reply was | |
453 | * received or some error occurred (timeout or socket shutdown). | |
454 | */ | |
455 | void nfs_readpage_result(struct rpc_task *task) | |
456 | { | |
457 | struct nfs_read_data *data = (struct nfs_read_data *)task->tk_calldata; | |
458 | struct nfs_readargs *argp = &data->args; | |
459 | struct nfs_readres *resp = &data->res; | |
460 | int status = task->tk_status; | |
461 | ||
462 | dprintk("NFS: %4d nfs_readpage_result, (status %d)\n", | |
463 | task->tk_pid, status); | |
464 | ||
465 | /* Is this a short read? */ | |
466 | if (task->tk_status >= 0 && resp->count < argp->count && !resp->eof) { | |
467 | /* Has the server at least made some progress? */ | |
468 | if (resp->count != 0) { | |
469 | /* Yes, so retry the read at the end of the data */ | |
470 | argp->offset += resp->count; | |
471 | argp->pgbase += resp->count; | |
472 | argp->count -= resp->count; | |
473 | rpc_restart_call(task); | |
474 | return; | |
475 | } | |
476 | task->tk_status = -EIO; | |
477 | } | |
dc59250c | 478 | spin_lock(&data->inode->i_lock); |
55296809 | 479 | NFS_I(data->inode)->cache_validity |= NFS_INO_INVALID_ATIME; |
dc59250c | 480 | spin_unlock(&data->inode->i_lock); |
1da177e4 LT |
481 | data->complete(data, status); |
482 | } | |
483 | ||
484 | /* | |
485 | * Read a page over NFS. | |
486 | * We read the page synchronously in the following case: | |
487 | * - The error flag is set for this page. This happens only when a | |
488 | * previous async read operation failed. | |
489 | */ | |
490 | int nfs_readpage(struct file *file, struct page *page) | |
491 | { | |
492 | struct nfs_open_context *ctx; | |
493 | struct inode *inode = page->mapping->host; | |
494 | int error; | |
495 | ||
496 | dprintk("NFS: nfs_readpage (%p %ld@%lu)\n", | |
497 | page, PAGE_CACHE_SIZE, page->index); | |
498 | /* | |
499 | * Try to flush any pending writes to the file.. | |
500 | * | |
501 | * NOTE! Because we own the page lock, there cannot | |
502 | * be any new pending writes generated at this point | |
503 | * for this page (other pages can be written to). | |
504 | */ | |
505 | error = nfs_wb_page(inode, page); | |
506 | if (error) | |
507 | goto out_error; | |
508 | ||
509 | if (file == NULL) { | |
d530838b | 510 | ctx = nfs_find_open_context(inode, NULL, FMODE_READ); |
1da177e4 LT |
511 | if (ctx == NULL) |
512 | return -EBADF; | |
513 | } else | |
514 | ctx = get_nfs_open_context((struct nfs_open_context *) | |
515 | file->private_data); | |
516 | if (!IS_SYNC(inode)) { | |
517 | error = nfs_readpage_async(ctx, inode, page); | |
518 | goto out; | |
519 | } | |
520 | ||
521 | error = nfs_readpage_sync(ctx, inode, page); | |
522 | if (error < 0 && IS_SWAPFILE(inode)) | |
523 | printk("Aiee.. nfs swap-in of page failed!\n"); | |
524 | out: | |
525 | put_nfs_open_context(ctx); | |
526 | return error; | |
527 | ||
528 | out_error: | |
529 | unlock_page(page); | |
530 | return error; | |
531 | } | |
532 | ||
533 | struct nfs_readdesc { | |
534 | struct list_head *head; | |
535 | struct nfs_open_context *ctx; | |
536 | }; | |
537 | ||
538 | static int | |
539 | readpage_async_filler(void *data, struct page *page) | |
540 | { | |
541 | struct nfs_readdesc *desc = (struct nfs_readdesc *)data; | |
542 | struct inode *inode = page->mapping->host; | |
543 | struct nfs_page *new; | |
544 | unsigned int len; | |
545 | ||
546 | nfs_wb_page(inode, page); | |
547 | len = nfs_page_length(inode, page); | |
548 | if (len == 0) | |
549 | return nfs_return_empty_page(page); | |
550 | new = nfs_create_request(desc->ctx, inode, page, 0, len); | |
551 | if (IS_ERR(new)) { | |
552 | SetPageError(page); | |
553 | unlock_page(page); | |
554 | return PTR_ERR(new); | |
555 | } | |
556 | if (len < PAGE_CACHE_SIZE) | |
557 | memclear_highpage_flush(page, len, PAGE_CACHE_SIZE - len); | |
1da177e4 LT |
558 | nfs_list_add_request(new, desc->head); |
559 | return 0; | |
560 | } | |
561 | ||
562 | int nfs_readpages(struct file *filp, struct address_space *mapping, | |
563 | struct list_head *pages, unsigned nr_pages) | |
564 | { | |
565 | LIST_HEAD(head); | |
566 | struct nfs_readdesc desc = { | |
567 | .head = &head, | |
568 | }; | |
569 | struct inode *inode = mapping->host; | |
570 | struct nfs_server *server = NFS_SERVER(inode); | |
571 | int ret; | |
572 | ||
573 | dprintk("NFS: nfs_readpages (%s/%Ld %d)\n", | |
574 | inode->i_sb->s_id, | |
575 | (long long)NFS_FILEID(inode), | |
576 | nr_pages); | |
577 | ||
578 | if (filp == NULL) { | |
d530838b | 579 | desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ); |
1da177e4 LT |
580 | if (desc.ctx == NULL) |
581 | return -EBADF; | |
582 | } else | |
583 | desc.ctx = get_nfs_open_context((struct nfs_open_context *) | |
584 | filp->private_data); | |
585 | ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc); | |
586 | if (!list_empty(&head)) { | |
587 | int err = nfs_pagein_list(&head, server->rpages); | |
588 | if (!ret) | |
589 | ret = err; | |
590 | } | |
591 | put_nfs_open_context(desc.ctx); | |
592 | return ret; | |
593 | } | |
594 | ||
595 | int nfs_init_readpagecache(void) | |
596 | { | |
597 | nfs_rdata_cachep = kmem_cache_create("nfs_read_data", | |
598 | sizeof(struct nfs_read_data), | |
599 | 0, SLAB_HWCACHE_ALIGN, | |
600 | NULL, NULL); | |
601 | if (nfs_rdata_cachep == NULL) | |
602 | return -ENOMEM; | |
603 | ||
604 | nfs_rdata_mempool = mempool_create(MIN_POOL_READ, | |
605 | mempool_alloc_slab, | |
606 | mempool_free_slab, | |
607 | nfs_rdata_cachep); | |
608 | if (nfs_rdata_mempool == NULL) | |
609 | return -ENOMEM; | |
610 | ||
611 | return 0; | |
612 | } | |
613 | ||
614 | void nfs_destroy_readpagecache(void) | |
615 | { | |
616 | mempool_destroy(nfs_rdata_mempool); | |
617 | if (kmem_cache_destroy(nfs_rdata_cachep)) | |
618 | printk(KERN_INFO "nfs_read_data: not all structures were freed\n"); | |
619 | } |