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Commit | Line | Data |
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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 | 26 | #include "iostat.h" |
9a9fc1c0 | 27 | #include "fscache.h" |
91d5b470 | 28 | |
1da177e4 LT |
29 | #define NFSDBG_FACILITY NFSDBG_PAGECACHE |
30 | ||
8d5658c9 TM |
31 | static int nfs_pagein_multi(struct inode *, struct list_head *, unsigned int, size_t, int); |
32 | static int nfs_pagein_one(struct inode *, struct list_head *, unsigned int, size_t, int); | |
ec06c096 TM |
33 | static const struct rpc_call_ops nfs_read_partial_ops; |
34 | static const struct rpc_call_ops nfs_read_full_ops; | |
1da177e4 | 35 | |
e18b890b | 36 | static struct kmem_cache *nfs_rdata_cachep; |
3feb2d49 | 37 | static mempool_t *nfs_rdata_mempool; |
1da177e4 LT |
38 | |
39 | #define MIN_POOL_READ (32) | |
40 | ||
8d5658c9 | 41 | struct nfs_read_data *nfs_readdata_alloc(unsigned int pagecount) |
3feb2d49 | 42 | { |
e6b4f8da | 43 | struct nfs_read_data *p = mempool_alloc(nfs_rdata_mempool, GFP_NOFS); |
3feb2d49 TM |
44 | |
45 | if (p) { | |
46 | memset(p, 0, sizeof(*p)); | |
47 | INIT_LIST_HEAD(&p->pages); | |
e9f7bee1 | 48 | p->npages = pagecount; |
0d0b5cb3 CL |
49 | if (pagecount <= ARRAY_SIZE(p->page_array)) |
50 | p->pagevec = p->page_array; | |
3feb2d49 | 51 | else { |
0d0b5cb3 CL |
52 | p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_NOFS); |
53 | if (!p->pagevec) { | |
3feb2d49 TM |
54 | mempool_free(p, nfs_rdata_mempool); |
55 | p = NULL; | |
56 | } | |
57 | } | |
58 | } | |
59 | return p; | |
60 | } | |
61 | ||
5e4424af | 62 | static void nfs_readdata_free(struct nfs_read_data *p) |
3feb2d49 TM |
63 | { |
64 | if (p && (p->pagevec != &p->page_array[0])) | |
65 | kfree(p->pagevec); | |
66 | mempool_free(p, nfs_rdata_mempool); | |
67 | } | |
68 | ||
963d8fe5 | 69 | void nfs_readdata_release(void *data) |
1da177e4 | 70 | { |
383ba719 TM |
71 | struct nfs_read_data *rdata = data; |
72 | ||
73 | put_nfs_open_context(rdata->args.context); | |
74 | nfs_readdata_free(rdata); | |
1da177e4 LT |
75 | } |
76 | ||
1da177e4 LT |
77 | static |
78 | int nfs_return_empty_page(struct page *page) | |
79 | { | |
eebd2aa3 | 80 | zero_user(page, 0, PAGE_CACHE_SIZE); |
1da177e4 LT |
81 | SetPageUptodate(page); |
82 | unlock_page(page); | |
83 | return 0; | |
84 | } | |
85 | ||
1de3fc12 TM |
86 | static void nfs_readpage_truncate_uninitialised_page(struct nfs_read_data *data) |
87 | { | |
88 | unsigned int remainder = data->args.count - data->res.count; | |
89 | unsigned int base = data->args.pgbase + data->res.count; | |
90 | unsigned int pglen; | |
91 | struct page **pages; | |
92 | ||
93 | if (data->res.eof == 0 || remainder == 0) | |
94 | return; | |
95 | /* | |
96 | * Note: "remainder" can never be negative, since we check for | |
97 | * this in the XDR code. | |
98 | */ | |
99 | pages = &data->args.pages[base >> PAGE_CACHE_SHIFT]; | |
100 | base &= ~PAGE_CACHE_MASK; | |
101 | pglen = PAGE_CACHE_SIZE - base; | |
79558f36 TM |
102 | for (;;) { |
103 | if (remainder <= pglen) { | |
eebd2aa3 | 104 | zero_user(*pages, base, remainder); |
79558f36 TM |
105 | break; |
106 | } | |
eebd2aa3 | 107 | zero_user(*pages, base, pglen); |
79558f36 TM |
108 | pages++; |
109 | remainder -= pglen; | |
110 | pglen = PAGE_CACHE_SIZE; | |
111 | base = 0; | |
112 | } | |
1de3fc12 TM |
113 | } |
114 | ||
f42b293d DH |
115 | int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode, |
116 | struct page *page) | |
1da177e4 LT |
117 | { |
118 | LIST_HEAD(one_request); | |
119 | struct nfs_page *new; | |
120 | unsigned int len; | |
121 | ||
49a70f27 | 122 | len = nfs_page_length(page); |
1da177e4 LT |
123 | if (len == 0) |
124 | return nfs_return_empty_page(page); | |
125 | new = nfs_create_request(ctx, inode, page, 0, len); | |
126 | if (IS_ERR(new)) { | |
127 | unlock_page(page); | |
128 | return PTR_ERR(new); | |
129 | } | |
130 | if (len < PAGE_CACHE_SIZE) | |
eebd2aa3 | 131 | zero_user_segment(page, len, PAGE_CACHE_SIZE); |
1da177e4 | 132 | |
1da177e4 | 133 | nfs_list_add_request(new, &one_request); |
bcb71bba | 134 | if (NFS_SERVER(inode)->rsize < PAGE_CACHE_SIZE) |
8d5658c9 | 135 | nfs_pagein_multi(inode, &one_request, 1, len, 0); |
bcb71bba | 136 | else |
8d5658c9 | 137 | nfs_pagein_one(inode, &one_request, 1, len, 0); |
1da177e4 LT |
138 | return 0; |
139 | } | |
140 | ||
141 | static void nfs_readpage_release(struct nfs_page *req) | |
142 | { | |
143 | unlock_page(req->wb_page); | |
144 | ||
1da177e4 | 145 | dprintk("NFS: read done (%s/%Ld %d@%Ld)\n", |
88be9f99 TM |
146 | req->wb_context->path.dentry->d_inode->i_sb->s_id, |
147 | (long long)NFS_FILEID(req->wb_context->path.dentry->d_inode), | |
1da177e4 LT |
148 | req->wb_bytes, |
149 | (long long)req_offset(req)); | |
10d2c46f NW |
150 | nfs_clear_request(req); |
151 | nfs_release_request(req); | |
1da177e4 LT |
152 | } |
153 | ||
154 | /* | |
155 | * Set up the NFS read request struct | |
156 | */ | |
dbae4c73 | 157 | static int nfs_read_rpcsetup(struct nfs_page *req, struct nfs_read_data *data, |
ec06c096 | 158 | const struct rpc_call_ops *call_ops, |
1da177e4 LT |
159 | unsigned int count, unsigned int offset) |
160 | { | |
84115e1c TM |
161 | struct inode *inode = req->wb_context->path.dentry->d_inode; |
162 | int swap_flags = IS_SWAPFILE(inode) ? NFS_RPC_SWAPFLAGS : 0; | |
07737691 | 163 | struct rpc_task *task; |
bdc7f021 TM |
164 | struct rpc_message msg = { |
165 | .rpc_argp = &data->args, | |
166 | .rpc_resp = &data->res, | |
167 | .rpc_cred = req->wb_context->cred, | |
168 | }; | |
84115e1c | 169 | struct rpc_task_setup task_setup_data = { |
07737691 | 170 | .task = &data->task, |
84115e1c | 171 | .rpc_client = NFS_CLIENT(inode), |
bdc7f021 | 172 | .rpc_message = &msg, |
84115e1c TM |
173 | .callback_ops = call_ops, |
174 | .callback_data = data, | |
101070ca | 175 | .workqueue = nfsiod_workqueue, |
84115e1c TM |
176 | .flags = RPC_TASK_ASYNC | swap_flags, |
177 | }; | |
1da177e4 LT |
178 | |
179 | data->req = req; | |
84115e1c | 180 | data->inode = inode; |
bdc7f021 | 181 | data->cred = msg.rpc_cred; |
1da177e4 LT |
182 | |
183 | data->args.fh = NFS_FH(inode); | |
184 | data->args.offset = req_offset(req) + offset; | |
185 | data->args.pgbase = req->wb_pgbase + offset; | |
186 | data->args.pages = data->pagevec; | |
187 | data->args.count = count; | |
383ba719 | 188 | data->args.context = get_nfs_open_context(req->wb_context); |
1da177e4 LT |
189 | |
190 | data->res.fattr = &data->fattr; | |
191 | data->res.count = count; | |
192 | data->res.eof = 0; | |
0e574af1 | 193 | nfs_fattr_init(&data->fattr); |
1da177e4 | 194 | |
ec06c096 | 195 | /* Set up the initial task struct. */ |
bdc7f021 | 196 | NFS_PROTO(inode)->read_setup(data, &msg); |
1da177e4 | 197 | |
a3f565b1 | 198 | dprintk("NFS: %5u initiated read call (req %s/%Ld, %u bytes @ offset %Lu)\n", |
1da177e4 LT |
199 | data->task.tk_pid, |
200 | inode->i_sb->s_id, | |
201 | (long long)NFS_FILEID(inode), | |
202 | count, | |
203 | (unsigned long long)data->args.offset); | |
bdc7f021 | 204 | |
07737691 | 205 | task = rpc_run_task(&task_setup_data); |
dbae4c73 TM |
206 | if (IS_ERR(task)) |
207 | return PTR_ERR(task); | |
208 | rpc_put_task(task); | |
209 | return 0; | |
1da177e4 LT |
210 | } |
211 | ||
212 | static void | |
213 | nfs_async_read_error(struct list_head *head) | |
214 | { | |
215 | struct nfs_page *req; | |
216 | ||
217 | while (!list_empty(head)) { | |
218 | req = nfs_list_entry(head->next); | |
219 | nfs_list_remove_request(req); | |
220 | SetPageError(req->wb_page); | |
221 | nfs_readpage_release(req); | |
222 | } | |
223 | } | |
224 | ||
1da177e4 LT |
225 | /* |
226 | * Generate multiple requests to fill a single page. | |
227 | * | |
228 | * We optimize to reduce the number of read operations on the wire. If we | |
229 | * detect that we're reading a page, or an area of a page, that is past the | |
230 | * end of file, we do not generate NFS read operations but just clear the | |
231 | * parts of the page that would have come back zero from the server anyway. | |
232 | * | |
233 | * We rely on the cached value of i_size to make this determination; another | |
234 | * client can fill pages on the server past our cached end-of-file, but we | |
235 | * won't see the new data until our attribute cache is updated. This is more | |
236 | * or less conventional NFS client behavior. | |
237 | */ | |
8d5658c9 | 238 | static int nfs_pagein_multi(struct inode *inode, struct list_head *head, unsigned int npages, size_t count, int flags) |
1da177e4 LT |
239 | { |
240 | struct nfs_page *req = nfs_list_entry(head->next); | |
241 | struct page *page = req->wb_page; | |
242 | struct nfs_read_data *data; | |
e9f7bee1 TM |
243 | size_t rsize = NFS_SERVER(inode)->rsize, nbytes; |
244 | unsigned int offset; | |
1da177e4 | 245 | int requests = 0; |
dbae4c73 | 246 | int ret = 0; |
1da177e4 LT |
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; | |
1da177e4 LT |
258 | list_add(&data->pages, &list); |
259 | requests++; | |
e9f7bee1 TM |
260 | nbytes -= len; |
261 | } while(nbytes != 0); | |
1da177e4 LT |
262 | atomic_set(&req->wb_complete, requests); |
263 | ||
264 | ClearPageError(page); | |
265 | offset = 0; | |
bcb71bba | 266 | nbytes = count; |
1da177e4 | 267 | do { |
dbae4c73 TM |
268 | int ret2; |
269 | ||
1da177e4 LT |
270 | data = list_entry(list.next, struct nfs_read_data, pages); |
271 | list_del_init(&data->pages); | |
272 | ||
273 | data->pagevec[0] = page; | |
1da177e4 | 274 | |
bcb71bba TM |
275 | if (nbytes < rsize) |
276 | rsize = nbytes; | |
dbae4c73 | 277 | ret2 = nfs_read_rpcsetup(req, data, &nfs_read_partial_ops, |
bcb71bba | 278 | rsize, offset); |
dbae4c73 TM |
279 | if (ret == 0) |
280 | ret = ret2; | |
bcb71bba TM |
281 | offset += rsize; |
282 | nbytes -= rsize; | |
1da177e4 LT |
283 | } while (nbytes != 0); |
284 | ||
dbae4c73 | 285 | return ret; |
1da177e4 LT |
286 | |
287 | out_bad: | |
288 | while (!list_empty(&list)) { | |
289 | data = list_entry(list.next, struct nfs_read_data, pages); | |
290 | list_del(&data->pages); | |
291 | nfs_readdata_free(data); | |
292 | } | |
293 | SetPageError(page); | |
294 | nfs_readpage_release(req); | |
295 | return -ENOMEM; | |
296 | } | |
297 | ||
8d5658c9 | 298 | static int nfs_pagein_one(struct inode *inode, struct list_head *head, unsigned int npages, size_t count, int flags) |
1da177e4 LT |
299 | { |
300 | struct nfs_page *req; | |
301 | struct page **pages; | |
302 | struct nfs_read_data *data; | |
dbae4c73 | 303 | int ret = -ENOMEM; |
1da177e4 | 304 | |
8d5658c9 | 305 | data = nfs_readdata_alloc(npages); |
1da177e4 LT |
306 | if (!data) |
307 | goto out_bad; | |
308 | ||
1da177e4 | 309 | pages = data->pagevec; |
1da177e4 LT |
310 | while (!list_empty(head)) { |
311 | req = nfs_list_entry(head->next); | |
312 | nfs_list_remove_request(req); | |
313 | nfs_list_add_request(req, &data->pages); | |
314 | ClearPageError(req->wb_page); | |
315 | *pages++ = req->wb_page; | |
1da177e4 LT |
316 | } |
317 | req = nfs_list_entry(data->pages.next); | |
318 | ||
dbae4c73 | 319 | return nfs_read_rpcsetup(req, data, &nfs_read_full_ops, count, 0); |
1da177e4 LT |
320 | out_bad: |
321 | nfs_async_read_error(head); | |
dbae4c73 | 322 | return ret; |
1da177e4 LT |
323 | } |
324 | ||
0b671301 TM |
325 | /* |
326 | * This is the callback from RPC telling us whether a reply was | |
327 | * received or some error occurred (timeout or socket shutdown). | |
328 | */ | |
329 | int nfs_readpage_result(struct rpc_task *task, struct nfs_read_data *data) | |
330 | { | |
331 | int status; | |
332 | ||
3110ff80 | 333 | dprintk("NFS: %s: %5u, (status %d)\n", __func__, task->tk_pid, |
0b671301 TM |
334 | task->tk_status); |
335 | ||
336 | status = NFS_PROTO(data->inode)->read_done(task, data); | |
337 | if (status != 0) | |
338 | return status; | |
339 | ||
340 | nfs_add_stats(data->inode, NFSIOS_SERVERREADBYTES, data->res.count); | |
341 | ||
342 | if (task->tk_status == -ESTALE) { | |
3a10c30a | 343 | set_bit(NFS_INO_STALE, &NFS_I(data->inode)->flags); |
0b671301 TM |
344 | nfs_mark_for_revalidate(data->inode); |
345 | } | |
0b671301 TM |
346 | return 0; |
347 | } | |
348 | ||
fdd1e74c | 349 | static void nfs_readpage_retry(struct rpc_task *task, struct nfs_read_data *data) |
0b671301 TM |
350 | { |
351 | struct nfs_readargs *argp = &data->args; | |
352 | struct nfs_readres *resp = &data->res; | |
353 | ||
354 | if (resp->eof || resp->count == argp->count) | |
fdd1e74c | 355 | return; |
0b671301 TM |
356 | |
357 | /* This is a short read! */ | |
358 | nfs_inc_stats(data->inode, NFSIOS_SHORTREAD); | |
359 | /* Has the server at least made some progress? */ | |
360 | if (resp->count == 0) | |
fdd1e74c | 361 | return; |
0b671301 TM |
362 | |
363 | /* Yes, so retry the read at the end of the data */ | |
364 | argp->offset += resp->count; | |
365 | argp->pgbase += resp->count; | |
366 | argp->count -= resp->count; | |
367 | rpc_restart_call(task); | |
0b671301 TM |
368 | } |
369 | ||
1da177e4 LT |
370 | /* |
371 | * Handle a read reply that fills part of a page. | |
372 | */ | |
ec06c096 | 373 | static void nfs_readpage_result_partial(struct rpc_task *task, void *calldata) |
1da177e4 | 374 | { |
ec06c096 | 375 | struct nfs_read_data *data = calldata; |
1da177e4 | 376 | |
ec06c096 TM |
377 | if (nfs_readpage_result(task, data) != 0) |
378 | return; | |
fdd1e74c TM |
379 | if (task->tk_status < 0) |
380 | return; | |
0b671301 | 381 | |
fdd1e74c TM |
382 | nfs_readpage_truncate_uninitialised_page(data); |
383 | nfs_readpage_retry(task, data); | |
384 | } | |
385 | ||
386 | static void nfs_readpage_release_partial(void *calldata) | |
387 | { | |
388 | struct nfs_read_data *data = calldata; | |
389 | struct nfs_page *req = data->req; | |
390 | struct page *page = req->wb_page; | |
391 | int status = data->task.tk_status; | |
392 | ||
393 | if (status < 0) | |
0b671301 | 394 | SetPageError(page); |
fdd1e74c | 395 | |
1da177e4 LT |
396 | if (atomic_dec_and_test(&req->wb_complete)) { |
397 | if (!PageError(page)) | |
398 | SetPageUptodate(page); | |
399 | nfs_readpage_release(req); | |
400 | } | |
fdd1e74c | 401 | nfs_readdata_release(calldata); |
1da177e4 LT |
402 | } |
403 | ||
ec06c096 TM |
404 | static const struct rpc_call_ops nfs_read_partial_ops = { |
405 | .rpc_call_done = nfs_readpage_result_partial, | |
fdd1e74c | 406 | .rpc_release = nfs_readpage_release_partial, |
ec06c096 TM |
407 | }; |
408 | ||
1de3fc12 TM |
409 | static void nfs_readpage_set_pages_uptodate(struct nfs_read_data *data) |
410 | { | |
411 | unsigned int count = data->res.count; | |
412 | unsigned int base = data->args.pgbase; | |
413 | struct page **pages; | |
414 | ||
79558f36 TM |
415 | if (data->res.eof) |
416 | count = data->args.count; | |
1de3fc12 TM |
417 | if (unlikely(count == 0)) |
418 | return; | |
419 | pages = &data->args.pages[base >> PAGE_CACHE_SHIFT]; | |
420 | base &= ~PAGE_CACHE_MASK; | |
421 | count += base; | |
422 | for (;count >= PAGE_CACHE_SIZE; count -= PAGE_CACHE_SIZE, pages++) | |
423 | SetPageUptodate(*pages); | |
0b671301 TM |
424 | if (count == 0) |
425 | return; | |
426 | /* Was this a short read? */ | |
427 | if (data->res.eof || data->res.count == data->args.count) | |
1de3fc12 TM |
428 | SetPageUptodate(*pages); |
429 | } | |
430 | ||
1da177e4 LT |
431 | /* |
432 | * This is the callback from RPC telling us whether a reply was | |
433 | * received or some error occurred (timeout or socket shutdown). | |
434 | */ | |
ec06c096 | 435 | static void nfs_readpage_result_full(struct rpc_task *task, void *calldata) |
1da177e4 | 436 | { |
ec06c096 | 437 | struct nfs_read_data *data = calldata; |
1da177e4 | 438 | |
0b671301 TM |
439 | if (nfs_readpage_result(task, data) != 0) |
440 | return; | |
fdd1e74c TM |
441 | if (task->tk_status < 0) |
442 | return; | |
1de3fc12 | 443 | /* |
0b671301 | 444 | * Note: nfs_readpage_retry may change the values of |
1de3fc12 | 445 | * data->args. In the multi-page case, we therefore need |
0b671301 TM |
446 | * to ensure that we call nfs_readpage_set_pages_uptodate() |
447 | * first. | |
1de3fc12 | 448 | */ |
fdd1e74c TM |
449 | nfs_readpage_truncate_uninitialised_page(data); |
450 | nfs_readpage_set_pages_uptodate(data); | |
451 | nfs_readpage_retry(task, data); | |
452 | } | |
453 | ||
454 | static void nfs_readpage_release_full(void *calldata) | |
455 | { | |
456 | struct nfs_read_data *data = calldata; | |
457 | ||
1da177e4 LT |
458 | while (!list_empty(&data->pages)) { |
459 | struct nfs_page *req = nfs_list_entry(data->pages.next); | |
1da177e4 | 460 | |
1de3fc12 | 461 | nfs_list_remove_request(req); |
1da177e4 LT |
462 | nfs_readpage_release(req); |
463 | } | |
fdd1e74c | 464 | nfs_readdata_release(calldata); |
1da177e4 LT |
465 | } |
466 | ||
ec06c096 TM |
467 | static const struct rpc_call_ops nfs_read_full_ops = { |
468 | .rpc_call_done = nfs_readpage_result_full, | |
fdd1e74c | 469 | .rpc_release = nfs_readpage_release_full, |
ec06c096 TM |
470 | }; |
471 | ||
1da177e4 LT |
472 | /* |
473 | * Read a page over NFS. | |
474 | * We read the page synchronously in the following case: | |
475 | * - The error flag is set for this page. This happens only when a | |
476 | * previous async read operation failed. | |
477 | */ | |
478 | int nfs_readpage(struct file *file, struct page *page) | |
479 | { | |
480 | struct nfs_open_context *ctx; | |
481 | struct inode *inode = page->mapping->host; | |
482 | int error; | |
483 | ||
484 | dprintk("NFS: nfs_readpage (%p %ld@%lu)\n", | |
485 | page, PAGE_CACHE_SIZE, page->index); | |
91d5b470 CL |
486 | nfs_inc_stats(inode, NFSIOS_VFSREADPAGE); |
487 | nfs_add_stats(inode, NFSIOS_READPAGES, 1); | |
488 | ||
1da177e4 LT |
489 | /* |
490 | * Try to flush any pending writes to the file.. | |
491 | * | |
492 | * NOTE! Because we own the page lock, there cannot | |
493 | * be any new pending writes generated at this point | |
494 | * for this page (other pages can be written to). | |
495 | */ | |
496 | error = nfs_wb_page(inode, page); | |
497 | if (error) | |
de05a0cc TM |
498 | goto out_unlock; |
499 | if (PageUptodate(page)) | |
500 | goto out_unlock; | |
1da177e4 | 501 | |
5f004cf2 TM |
502 | error = -ESTALE; |
503 | if (NFS_STALE(inode)) | |
de05a0cc | 504 | goto out_unlock; |
5f004cf2 | 505 | |
1da177e4 | 506 | if (file == NULL) { |
cf1308ff | 507 | error = -EBADF; |
d530838b | 508 | ctx = nfs_find_open_context(inode, NULL, FMODE_READ); |
1da177e4 | 509 | if (ctx == NULL) |
de05a0cc | 510 | goto out_unlock; |
1da177e4 | 511 | } else |
cd3758e3 | 512 | ctx = get_nfs_open_context(nfs_file_open_context(file)); |
1da177e4 | 513 | |
9a9fc1c0 DH |
514 | if (!IS_SYNC(inode)) { |
515 | error = nfs_readpage_from_fscache(ctx, inode, page); | |
516 | if (error == 0) | |
517 | goto out; | |
518 | } | |
519 | ||
8e0969f0 TM |
520 | error = nfs_readpage_async(ctx, inode, page); |
521 | ||
9a9fc1c0 | 522 | out: |
1da177e4 LT |
523 | put_nfs_open_context(ctx); |
524 | return error; | |
de05a0cc | 525 | out_unlock: |
1da177e4 LT |
526 | unlock_page(page); |
527 | return error; | |
528 | } | |
529 | ||
530 | struct nfs_readdesc { | |
8b09bee3 | 531 | struct nfs_pageio_descriptor *pgio; |
1da177e4 LT |
532 | struct nfs_open_context *ctx; |
533 | }; | |
534 | ||
535 | static int | |
536 | readpage_async_filler(void *data, struct page *page) | |
537 | { | |
538 | struct nfs_readdesc *desc = (struct nfs_readdesc *)data; | |
539 | struct inode *inode = page->mapping->host; | |
540 | struct nfs_page *new; | |
541 | unsigned int len; | |
de05a0cc TM |
542 | int error; |
543 | ||
49a70f27 | 544 | len = nfs_page_length(page); |
1da177e4 LT |
545 | if (len == 0) |
546 | return nfs_return_empty_page(page); | |
de05a0cc | 547 | |
1da177e4 | 548 | new = nfs_create_request(desc->ctx, inode, page, 0, len); |
de05a0cc TM |
549 | if (IS_ERR(new)) |
550 | goto out_error; | |
551 | ||
1da177e4 | 552 | if (len < PAGE_CACHE_SIZE) |
eebd2aa3 | 553 | zero_user_segment(page, len, PAGE_CACHE_SIZE); |
f8512ad0 FI |
554 | if (!nfs_pageio_add_request(desc->pgio, new)) { |
555 | error = desc->pgio->pg_error; | |
556 | goto out_unlock; | |
557 | } | |
1da177e4 | 558 | return 0; |
de05a0cc TM |
559 | out_error: |
560 | error = PTR_ERR(new); | |
561 | SetPageError(page); | |
562 | out_unlock: | |
563 | unlock_page(page); | |
564 | return error; | |
1da177e4 LT |
565 | } |
566 | ||
567 | int nfs_readpages(struct file *filp, struct address_space *mapping, | |
568 | struct list_head *pages, unsigned nr_pages) | |
569 | { | |
8b09bee3 | 570 | struct nfs_pageio_descriptor pgio; |
1da177e4 | 571 | struct nfs_readdesc desc = { |
8b09bee3 | 572 | .pgio = &pgio, |
1da177e4 LT |
573 | }; |
574 | struct inode *inode = mapping->host; | |
575 | struct nfs_server *server = NFS_SERVER(inode); | |
8b09bee3 TM |
576 | size_t rsize = server->rsize; |
577 | unsigned long npages; | |
5f004cf2 | 578 | int ret = -ESTALE; |
1da177e4 LT |
579 | |
580 | dprintk("NFS: nfs_readpages (%s/%Ld %d)\n", | |
581 | inode->i_sb->s_id, | |
582 | (long long)NFS_FILEID(inode), | |
583 | nr_pages); | |
91d5b470 | 584 | nfs_inc_stats(inode, NFSIOS_VFSREADPAGES); |
1da177e4 | 585 | |
5f004cf2 TM |
586 | if (NFS_STALE(inode)) |
587 | goto out; | |
588 | ||
1da177e4 | 589 | if (filp == NULL) { |
d530838b | 590 | desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ); |
1da177e4 LT |
591 | if (desc.ctx == NULL) |
592 | return -EBADF; | |
593 | } else | |
cd3758e3 | 594 | desc.ctx = get_nfs_open_context(nfs_file_open_context(filp)); |
9a9fc1c0 DH |
595 | |
596 | /* attempt to read as many of the pages as possible from the cache | |
597 | * - this returns -ENOBUFS immediately if the cookie is negative | |
598 | */ | |
599 | ret = nfs_readpages_from_fscache(desc.ctx, inode, mapping, | |
600 | pages, &nr_pages); | |
601 | if (ret == 0) | |
602 | goto read_complete; /* all pages were read */ | |
603 | ||
8b09bee3 TM |
604 | if (rsize < PAGE_CACHE_SIZE) |
605 | nfs_pageio_init(&pgio, inode, nfs_pagein_multi, rsize, 0); | |
606 | else | |
607 | nfs_pageio_init(&pgio, inode, nfs_pagein_one, rsize, 0); | |
608 | ||
1da177e4 | 609 | ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc); |
8b09bee3 TM |
610 | |
611 | nfs_pageio_complete(&pgio); | |
612 | npages = (pgio.pg_bytes_written + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; | |
613 | nfs_add_stats(inode, NFSIOS_READPAGES, npages); | |
9a9fc1c0 | 614 | read_complete: |
1da177e4 | 615 | put_nfs_open_context(desc.ctx); |
5f004cf2 | 616 | out: |
1da177e4 LT |
617 | return ret; |
618 | } | |
619 | ||
f7b422b1 | 620 | int __init nfs_init_readpagecache(void) |
1da177e4 LT |
621 | { |
622 | nfs_rdata_cachep = kmem_cache_create("nfs_read_data", | |
623 | sizeof(struct nfs_read_data), | |
624 | 0, SLAB_HWCACHE_ALIGN, | |
20c2df83 | 625 | NULL); |
1da177e4 LT |
626 | if (nfs_rdata_cachep == NULL) |
627 | return -ENOMEM; | |
628 | ||
93d2341c MD |
629 | nfs_rdata_mempool = mempool_create_slab_pool(MIN_POOL_READ, |
630 | nfs_rdata_cachep); | |
1da177e4 LT |
631 | if (nfs_rdata_mempool == NULL) |
632 | return -ENOMEM; | |
633 | ||
634 | return 0; | |
635 | } | |
636 | ||
266bee88 | 637 | void nfs_destroy_readpagecache(void) |
1da177e4 LT |
638 | { |
639 | mempool_destroy(nfs_rdata_mempool); | |
1a1d92c1 | 640 | kmem_cache_destroy(nfs_rdata_cachep); |
1da177e4 | 641 | } |