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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 | { | |
eebd2aa3 | 82 | zero_user(page, 0, PAGE_CACHE_SIZE); |
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) { | |
eebd2aa3 | 106 | zero_user(*pages, base, remainder); |
79558f36 TM |
107 | break; |
108 | } | |
eebd2aa3 | 109 | zero_user(*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) | |
eebd2aa3 | 133 | zero_user_segment(page, len, PAGE_CACHE_SIZE); |
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; | |
07737691 | 165 | struct rpc_task *task; |
bdc7f021 TM |
166 | struct rpc_message msg = { |
167 | .rpc_argp = &data->args, | |
168 | .rpc_resp = &data->res, | |
169 | .rpc_cred = req->wb_context->cred, | |
170 | }; | |
84115e1c | 171 | struct rpc_task_setup task_setup_data = { |
07737691 | 172 | .task = &data->task, |
84115e1c | 173 | .rpc_client = NFS_CLIENT(inode), |
bdc7f021 | 174 | .rpc_message = &msg, |
84115e1c TM |
175 | .callback_ops = call_ops, |
176 | .callback_data = data, | |
177 | .flags = RPC_TASK_ASYNC | swap_flags, | |
178 | }; | |
1da177e4 LT |
179 | |
180 | data->req = req; | |
84115e1c | 181 | data->inode = inode; |
bdc7f021 | 182 | data->cred = msg.rpc_cred; |
1da177e4 LT |
183 | |
184 | data->args.fh = NFS_FH(inode); | |
185 | data->args.offset = req_offset(req) + offset; | |
186 | data->args.pgbase = req->wb_pgbase + offset; | |
187 | data->args.pages = data->pagevec; | |
188 | data->args.count = count; | |
189 | data->args.context = req->wb_context; | |
190 | ||
191 | data->res.fattr = &data->fattr; | |
192 | data->res.count = count; | |
193 | data->res.eof = 0; | |
0e574af1 | 194 | nfs_fattr_init(&data->fattr); |
1da177e4 | 195 | |
ec06c096 | 196 | /* Set up the initial task struct. */ |
bdc7f021 | 197 | NFS_PROTO(inode)->read_setup(data, &msg); |
1da177e4 | 198 | |
a3f565b1 | 199 | dprintk("NFS: %5u initiated read call (req %s/%Ld, %u bytes @ offset %Lu)\n", |
1da177e4 LT |
200 | data->task.tk_pid, |
201 | inode->i_sb->s_id, | |
202 | (long long)NFS_FILEID(inode), | |
203 | count, | |
204 | (unsigned long long)data->args.offset); | |
bdc7f021 | 205 | |
07737691 TM |
206 | task = rpc_run_task(&task_setup_data); |
207 | if (!IS_ERR(task)) | |
208 | rpc_put_task(task); | |
1da177e4 LT |
209 | } |
210 | ||
211 | static void | |
212 | nfs_async_read_error(struct list_head *head) | |
213 | { | |
214 | struct nfs_page *req; | |
215 | ||
216 | while (!list_empty(head)) { | |
217 | req = nfs_list_entry(head->next); | |
218 | nfs_list_remove_request(req); | |
219 | SetPageError(req->wb_page); | |
220 | nfs_readpage_release(req); | |
221 | } | |
222 | } | |
223 | ||
1da177e4 LT |
224 | /* |
225 | * Generate multiple requests to fill a single page. | |
226 | * | |
227 | * We optimize to reduce the number of read operations on the wire. If we | |
228 | * detect that we're reading a page, or an area of a page, that is past the | |
229 | * end of file, we do not generate NFS read operations but just clear the | |
230 | * parts of the page that would have come back zero from the server anyway. | |
231 | * | |
232 | * We rely on the cached value of i_size to make this determination; another | |
233 | * client can fill pages on the server past our cached end-of-file, but we | |
234 | * won't see the new data until our attribute cache is updated. This is more | |
235 | * or less conventional NFS client behavior. | |
236 | */ | |
8d5658c9 | 237 | static int nfs_pagein_multi(struct inode *inode, struct list_head *head, unsigned int npages, size_t count, int flags) |
1da177e4 LT |
238 | { |
239 | struct nfs_page *req = nfs_list_entry(head->next); | |
240 | struct page *page = req->wb_page; | |
241 | struct nfs_read_data *data; | |
e9f7bee1 TM |
242 | size_t rsize = NFS_SERVER(inode)->rsize, nbytes; |
243 | unsigned int offset; | |
1da177e4 LT |
244 | int requests = 0; |
245 | LIST_HEAD(list); | |
246 | ||
247 | nfs_list_remove_request(req); | |
248 | ||
bcb71bba | 249 | nbytes = count; |
e9f7bee1 TM |
250 | do { |
251 | size_t len = min(nbytes,rsize); | |
252 | ||
8d5658c9 | 253 | data = nfs_readdata_alloc(1); |
1da177e4 LT |
254 | if (!data) |
255 | goto out_bad; | |
256 | INIT_LIST_HEAD(&data->pages); | |
257 | list_add(&data->pages, &list); | |
258 | requests++; | |
e9f7bee1 TM |
259 | nbytes -= len; |
260 | } while(nbytes != 0); | |
1da177e4 LT |
261 | atomic_set(&req->wb_complete, requests); |
262 | ||
263 | ClearPageError(page); | |
264 | offset = 0; | |
bcb71bba | 265 | nbytes = count; |
1da177e4 LT |
266 | do { |
267 | data = list_entry(list.next, struct nfs_read_data, pages); | |
268 | list_del_init(&data->pages); | |
269 | ||
270 | data->pagevec[0] = page; | |
1da177e4 | 271 | |
bcb71bba TM |
272 | if (nbytes < rsize) |
273 | rsize = nbytes; | |
274 | nfs_read_rpcsetup(req, data, &nfs_read_partial_ops, | |
275 | rsize, offset); | |
276 | offset += rsize; | |
277 | nbytes -= rsize; | |
1da177e4 LT |
278 | } while (nbytes != 0); |
279 | ||
280 | return 0; | |
281 | ||
282 | out_bad: | |
283 | while (!list_empty(&list)) { | |
284 | data = list_entry(list.next, struct nfs_read_data, pages); | |
285 | list_del(&data->pages); | |
286 | nfs_readdata_free(data); | |
287 | } | |
288 | SetPageError(page); | |
289 | nfs_readpage_release(req); | |
290 | return -ENOMEM; | |
291 | } | |
292 | ||
8d5658c9 | 293 | static int nfs_pagein_one(struct inode *inode, struct list_head *head, unsigned int npages, size_t count, int flags) |
1da177e4 LT |
294 | { |
295 | struct nfs_page *req; | |
296 | struct page **pages; | |
297 | struct nfs_read_data *data; | |
1da177e4 | 298 | |
8d5658c9 | 299 | data = nfs_readdata_alloc(npages); |
1da177e4 LT |
300 | if (!data) |
301 | goto out_bad; | |
302 | ||
303 | INIT_LIST_HEAD(&data->pages); | |
304 | pages = data->pagevec; | |
1da177e4 LT |
305 | while (!list_empty(head)) { |
306 | req = nfs_list_entry(head->next); | |
307 | nfs_list_remove_request(req); | |
308 | nfs_list_add_request(req, &data->pages); | |
309 | ClearPageError(req->wb_page); | |
310 | *pages++ = req->wb_page; | |
1da177e4 LT |
311 | } |
312 | req = nfs_list_entry(data->pages.next); | |
313 | ||
ec06c096 | 314 | nfs_read_rpcsetup(req, data, &nfs_read_full_ops, count, 0); |
1da177e4 LT |
315 | return 0; |
316 | out_bad: | |
317 | nfs_async_read_error(head); | |
318 | return -ENOMEM; | |
319 | } | |
320 | ||
0b671301 TM |
321 | /* |
322 | * This is the callback from RPC telling us whether a reply was | |
323 | * received or some error occurred (timeout or socket shutdown). | |
324 | */ | |
325 | int nfs_readpage_result(struct rpc_task *task, struct nfs_read_data *data) | |
326 | { | |
327 | int status; | |
328 | ||
a3f565b1 | 329 | dprintk("NFS: %s: %5u, (status %d)\n", __FUNCTION__, task->tk_pid, |
0b671301 TM |
330 | task->tk_status); |
331 | ||
332 | status = NFS_PROTO(data->inode)->read_done(task, data); | |
333 | if (status != 0) | |
334 | return status; | |
335 | ||
336 | nfs_add_stats(data->inode, NFSIOS_SERVERREADBYTES, data->res.count); | |
337 | ||
338 | if (task->tk_status == -ESTALE) { | |
3a10c30a | 339 | set_bit(NFS_INO_STALE, &NFS_I(data->inode)->flags); |
0b671301 TM |
340 | nfs_mark_for_revalidate(data->inode); |
341 | } | |
0b671301 TM |
342 | return 0; |
343 | } | |
344 | ||
345 | static int nfs_readpage_retry(struct rpc_task *task, struct nfs_read_data *data) | |
346 | { | |
347 | struct nfs_readargs *argp = &data->args; | |
348 | struct nfs_readres *resp = &data->res; | |
349 | ||
350 | if (resp->eof || resp->count == argp->count) | |
351 | return 0; | |
352 | ||
353 | /* This is a short read! */ | |
354 | nfs_inc_stats(data->inode, NFSIOS_SHORTREAD); | |
355 | /* Has the server at least made some progress? */ | |
356 | if (resp->count == 0) | |
357 | return 0; | |
358 | ||
359 | /* Yes, so retry the read at the end of the data */ | |
360 | argp->offset += resp->count; | |
361 | argp->pgbase += resp->count; | |
362 | argp->count -= resp->count; | |
363 | rpc_restart_call(task); | |
364 | return -EAGAIN; | |
365 | } | |
366 | ||
1da177e4 LT |
367 | /* |
368 | * Handle a read reply that fills part of a page. | |
369 | */ | |
ec06c096 | 370 | static void nfs_readpage_result_partial(struct rpc_task *task, void *calldata) |
1da177e4 | 371 | { |
ec06c096 | 372 | struct nfs_read_data *data = calldata; |
1da177e4 LT |
373 | struct nfs_page *req = data->req; |
374 | struct page *page = req->wb_page; | |
375 | ||
ec06c096 TM |
376 | if (nfs_readpage_result(task, data) != 0) |
377 | return; | |
0b671301 TM |
378 | |
379 | if (likely(task->tk_status >= 0)) { | |
380 | nfs_readpage_truncate_uninitialised_page(data); | |
381 | if (nfs_readpage_retry(task, data) != 0) | |
382 | return; | |
383 | } | |
384 | if (unlikely(task->tk_status < 0)) | |
385 | SetPageError(page); | |
1da177e4 LT |
386 | if (atomic_dec_and_test(&req->wb_complete)) { |
387 | if (!PageError(page)) | |
388 | SetPageUptodate(page); | |
389 | nfs_readpage_release(req); | |
390 | } | |
391 | } | |
392 | ||
ec06c096 TM |
393 | static const struct rpc_call_ops nfs_read_partial_ops = { |
394 | .rpc_call_done = nfs_readpage_result_partial, | |
395 | .rpc_release = nfs_readdata_release, | |
396 | }; | |
397 | ||
1de3fc12 TM |
398 | static void nfs_readpage_set_pages_uptodate(struct nfs_read_data *data) |
399 | { | |
400 | unsigned int count = data->res.count; | |
401 | unsigned int base = data->args.pgbase; | |
402 | struct page **pages; | |
403 | ||
79558f36 TM |
404 | if (data->res.eof) |
405 | count = data->args.count; | |
1de3fc12 TM |
406 | if (unlikely(count == 0)) |
407 | return; | |
408 | pages = &data->args.pages[base >> PAGE_CACHE_SHIFT]; | |
409 | base &= ~PAGE_CACHE_MASK; | |
410 | count += base; | |
411 | for (;count >= PAGE_CACHE_SIZE; count -= PAGE_CACHE_SIZE, pages++) | |
412 | SetPageUptodate(*pages); | |
0b671301 TM |
413 | if (count == 0) |
414 | return; | |
415 | /* Was this a short read? */ | |
416 | if (data->res.eof || data->res.count == data->args.count) | |
1de3fc12 TM |
417 | SetPageUptodate(*pages); |
418 | } | |
419 | ||
1da177e4 LT |
420 | /* |
421 | * This is the callback from RPC telling us whether a reply was | |
422 | * received or some error occurred (timeout or socket shutdown). | |
423 | */ | |
ec06c096 | 424 | static void nfs_readpage_result_full(struct rpc_task *task, void *calldata) |
1da177e4 | 425 | { |
ec06c096 | 426 | struct nfs_read_data *data = calldata; |
1da177e4 | 427 | |
0b671301 TM |
428 | if (nfs_readpage_result(task, data) != 0) |
429 | return; | |
1de3fc12 | 430 | /* |
0b671301 | 431 | * Note: nfs_readpage_retry may change the values of |
1de3fc12 | 432 | * data->args. In the multi-page case, we therefore need |
0b671301 TM |
433 | * to ensure that we call nfs_readpage_set_pages_uptodate() |
434 | * first. | |
1de3fc12 TM |
435 | */ |
436 | if (likely(task->tk_status >= 0)) { | |
437 | nfs_readpage_truncate_uninitialised_page(data); | |
438 | nfs_readpage_set_pages_uptodate(data); | |
0b671301 TM |
439 | if (nfs_readpage_retry(task, data) != 0) |
440 | return; | |
441 | } | |
1da177e4 LT |
442 | while (!list_empty(&data->pages)) { |
443 | struct nfs_page *req = nfs_list_entry(data->pages.next); | |
1da177e4 | 444 | |
1de3fc12 | 445 | nfs_list_remove_request(req); |
1da177e4 LT |
446 | nfs_readpage_release(req); |
447 | } | |
448 | } | |
449 | ||
ec06c096 TM |
450 | static const struct rpc_call_ops nfs_read_full_ops = { |
451 | .rpc_call_done = nfs_readpage_result_full, | |
452 | .rpc_release = nfs_readdata_release, | |
453 | }; | |
454 | ||
1da177e4 LT |
455 | /* |
456 | * Read a page over NFS. | |
457 | * We read the page synchronously in the following case: | |
458 | * - The error flag is set for this page. This happens only when a | |
459 | * previous async read operation failed. | |
460 | */ | |
461 | int nfs_readpage(struct file *file, struct page *page) | |
462 | { | |
463 | struct nfs_open_context *ctx; | |
464 | struct inode *inode = page->mapping->host; | |
465 | int error; | |
466 | ||
467 | dprintk("NFS: nfs_readpage (%p %ld@%lu)\n", | |
468 | page, PAGE_CACHE_SIZE, page->index); | |
91d5b470 CL |
469 | nfs_inc_stats(inode, NFSIOS_VFSREADPAGE); |
470 | nfs_add_stats(inode, NFSIOS_READPAGES, 1); | |
471 | ||
1da177e4 LT |
472 | /* |
473 | * Try to flush any pending writes to the file.. | |
474 | * | |
475 | * NOTE! Because we own the page lock, there cannot | |
476 | * be any new pending writes generated at this point | |
477 | * for this page (other pages can be written to). | |
478 | */ | |
479 | error = nfs_wb_page(inode, page); | |
480 | if (error) | |
de05a0cc TM |
481 | goto out_unlock; |
482 | if (PageUptodate(page)) | |
483 | goto out_unlock; | |
1da177e4 | 484 | |
5f004cf2 TM |
485 | error = -ESTALE; |
486 | if (NFS_STALE(inode)) | |
de05a0cc | 487 | goto out_unlock; |
5f004cf2 | 488 | |
1da177e4 | 489 | if (file == NULL) { |
cf1308ff | 490 | error = -EBADF; |
d530838b | 491 | ctx = nfs_find_open_context(inode, NULL, FMODE_READ); |
1da177e4 | 492 | if (ctx == NULL) |
de05a0cc | 493 | goto out_unlock; |
1da177e4 | 494 | } else |
cd3758e3 | 495 | ctx = get_nfs_open_context(nfs_file_open_context(file)); |
1da177e4 | 496 | |
8e0969f0 TM |
497 | error = nfs_readpage_async(ctx, inode, page); |
498 | ||
1da177e4 LT |
499 | put_nfs_open_context(ctx); |
500 | return error; | |
de05a0cc | 501 | out_unlock: |
1da177e4 LT |
502 | unlock_page(page); |
503 | return error; | |
504 | } | |
505 | ||
506 | struct nfs_readdesc { | |
8b09bee3 | 507 | struct nfs_pageio_descriptor *pgio; |
1da177e4 LT |
508 | struct nfs_open_context *ctx; |
509 | }; | |
510 | ||
511 | static int | |
512 | readpage_async_filler(void *data, struct page *page) | |
513 | { | |
514 | struct nfs_readdesc *desc = (struct nfs_readdesc *)data; | |
515 | struct inode *inode = page->mapping->host; | |
516 | struct nfs_page *new; | |
517 | unsigned int len; | |
de05a0cc TM |
518 | int error; |
519 | ||
520 | error = nfs_wb_page(inode, page); | |
521 | if (error) | |
522 | goto out_unlock; | |
523 | if (PageUptodate(page)) | |
524 | goto out_unlock; | |
1da177e4 | 525 | |
49a70f27 | 526 | len = nfs_page_length(page); |
1da177e4 LT |
527 | if (len == 0) |
528 | return nfs_return_empty_page(page); | |
de05a0cc | 529 | |
1da177e4 | 530 | new = nfs_create_request(desc->ctx, inode, page, 0, len); |
de05a0cc TM |
531 | if (IS_ERR(new)) |
532 | goto out_error; | |
533 | ||
1da177e4 | 534 | if (len < PAGE_CACHE_SIZE) |
eebd2aa3 | 535 | zero_user_segment(page, len, PAGE_CACHE_SIZE); |
8b09bee3 | 536 | nfs_pageio_add_request(desc->pgio, new); |
1da177e4 | 537 | return 0; |
de05a0cc TM |
538 | out_error: |
539 | error = PTR_ERR(new); | |
540 | SetPageError(page); | |
541 | out_unlock: | |
542 | unlock_page(page); | |
543 | return error; | |
1da177e4 LT |
544 | } |
545 | ||
546 | int nfs_readpages(struct file *filp, struct address_space *mapping, | |
547 | struct list_head *pages, unsigned nr_pages) | |
548 | { | |
8b09bee3 | 549 | struct nfs_pageio_descriptor pgio; |
1da177e4 | 550 | struct nfs_readdesc desc = { |
8b09bee3 | 551 | .pgio = &pgio, |
1da177e4 LT |
552 | }; |
553 | struct inode *inode = mapping->host; | |
554 | struct nfs_server *server = NFS_SERVER(inode); | |
8b09bee3 TM |
555 | size_t rsize = server->rsize; |
556 | unsigned long npages; | |
5f004cf2 | 557 | int ret = -ESTALE; |
1da177e4 LT |
558 | |
559 | dprintk("NFS: nfs_readpages (%s/%Ld %d)\n", | |
560 | inode->i_sb->s_id, | |
561 | (long long)NFS_FILEID(inode), | |
562 | nr_pages); | |
91d5b470 | 563 | nfs_inc_stats(inode, NFSIOS_VFSREADPAGES); |
1da177e4 | 564 | |
5f004cf2 TM |
565 | if (NFS_STALE(inode)) |
566 | goto out; | |
567 | ||
1da177e4 | 568 | if (filp == NULL) { |
d530838b | 569 | desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ); |
1da177e4 LT |
570 | if (desc.ctx == NULL) |
571 | return -EBADF; | |
572 | } else | |
cd3758e3 | 573 | desc.ctx = get_nfs_open_context(nfs_file_open_context(filp)); |
8b09bee3 TM |
574 | if (rsize < PAGE_CACHE_SIZE) |
575 | nfs_pageio_init(&pgio, inode, nfs_pagein_multi, rsize, 0); | |
576 | else | |
577 | nfs_pageio_init(&pgio, inode, nfs_pagein_one, rsize, 0); | |
578 | ||
1da177e4 | 579 | ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc); |
8b09bee3 TM |
580 | |
581 | nfs_pageio_complete(&pgio); | |
582 | npages = (pgio.pg_bytes_written + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; | |
583 | nfs_add_stats(inode, NFSIOS_READPAGES, npages); | |
1da177e4 | 584 | put_nfs_open_context(desc.ctx); |
5f004cf2 | 585 | out: |
1da177e4 LT |
586 | return ret; |
587 | } | |
588 | ||
f7b422b1 | 589 | int __init nfs_init_readpagecache(void) |
1da177e4 LT |
590 | { |
591 | nfs_rdata_cachep = kmem_cache_create("nfs_read_data", | |
592 | sizeof(struct nfs_read_data), | |
593 | 0, SLAB_HWCACHE_ALIGN, | |
20c2df83 | 594 | NULL); |
1da177e4 LT |
595 | if (nfs_rdata_cachep == NULL) |
596 | return -ENOMEM; | |
597 | ||
93d2341c MD |
598 | nfs_rdata_mempool = mempool_create_slab_pool(MIN_POOL_READ, |
599 | nfs_rdata_cachep); | |
1da177e4 LT |
600 | if (nfs_rdata_mempool == NULL) |
601 | return -ENOMEM; | |
602 | ||
603 | return 0; | |
604 | } | |
605 | ||
266bee88 | 606 | void nfs_destroy_readpagecache(void) |
1da177e4 LT |
607 | { |
608 | mempool_destroy(nfs_rdata_mempool); | |
1a1d92c1 | 609 | kmem_cache_destroy(nfs_rdata_cachep); |
1da177e4 | 610 | } |