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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> | |
64419a9b | 21 | #include <linux/module.h> |
1da177e4 | 22 | |
bae724ef | 23 | #include "pnfs.h" |
1da177e4 | 24 | |
f11c88af | 25 | #include "nfs4_fs.h" |
49a70f27 | 26 | #include "internal.h" |
91d5b470 | 27 | #include "iostat.h" |
9a9fc1c0 | 28 | #include "fscache.h" |
91d5b470 | 29 | |
1da177e4 LT |
30 | #define NFSDBG_FACILITY NFSDBG_PAGECACHE |
31 | ||
1751c363 | 32 | static const struct nfs_pageio_ops nfs_pageio_read_ops; |
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; |
1da177e4 | 37 | |
cd841605 | 38 | struct nfs_read_header *nfs_readhdr_alloc(unsigned int pagecount) |
3feb2d49 | 39 | { |
cd841605 | 40 | struct nfs_read_header *p; |
3feb2d49 | 41 | |
b6ee8cd2 | 42 | p = kmem_cache_zalloc(nfs_rdata_cachep, GFP_KERNEL); |
3feb2d49 | 43 | if (p) { |
cd841605 FI |
44 | struct nfs_pgio_header *hdr = &p->header; |
45 | struct nfs_read_data *data = &p->rpc_data; | |
46 | ||
47 | INIT_LIST_HEAD(&hdr->pages); | |
48 | INIT_LIST_HEAD(&data->list); | |
49 | data->npages = pagecount; | |
50 | data->header = hdr; | |
51 | if (pagecount <= ARRAY_SIZE(data->page_array)) | |
52 | data->pagevec = data->page_array; | |
3feb2d49 | 53 | else { |
cd841605 FI |
54 | data->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_KERNEL); |
55 | if (!data->pagevec) { | |
b6ee8cd2 | 56 | kmem_cache_free(nfs_rdata_cachep, p); |
3feb2d49 TM |
57 | p = NULL; |
58 | } | |
59 | } | |
60 | } | |
61 | return p; | |
62 | } | |
63 | ||
cd841605 | 64 | void nfs_readhdr_free(struct nfs_pgio_header *hdr) |
3feb2d49 | 65 | { |
cd841605 FI |
66 | struct nfs_read_header *rhdr = container_of(hdr, struct nfs_read_header, header); |
67 | ||
68 | kmem_cache_free(nfs_rdata_cachep, rhdr); | |
3feb2d49 TM |
69 | } |
70 | ||
493292dd | 71 | void nfs_readdata_release(struct nfs_read_data *rdata) |
1da177e4 | 72 | { |
383ba719 | 73 | put_nfs_open_context(rdata->args.context); |
cd841605 FI |
74 | if (rdata->pagevec != rdata->page_array) |
75 | kfree(rdata->pagevec); | |
76 | nfs_readhdr_free(rdata->header); | |
1da177e4 LT |
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 | ||
62e4a769 | 117 | void nfs_pageio_init_read_mds(struct nfs_pageio_descriptor *pgio, |
1751c363 TM |
118 | struct inode *inode) |
119 | { | |
120 | nfs_pageio_init(pgio, inode, &nfs_pageio_read_ops, | |
121 | NFS_SERVER(inode)->rsize, 0); | |
122 | } | |
123 | ||
493292dd TM |
124 | void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio) |
125 | { | |
126 | pgio->pg_ops = &nfs_pageio_read_ops; | |
127 | pgio->pg_bsize = NFS_SERVER(pgio->pg_inode)->rsize; | |
128 | } | |
1f945357 | 129 | EXPORT_SYMBOL_GPL(nfs_pageio_reset_read_mds); |
493292dd | 130 | |
1751c363 TM |
131 | static void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio, |
132 | struct inode *inode) | |
133 | { | |
134 | if (!pnfs_pageio_init_read(pgio, inode)) | |
135 | nfs_pageio_init_read_mds(pgio, inode); | |
136 | } | |
137 | ||
f42b293d DH |
138 | int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode, |
139 | struct page *page) | |
1da177e4 | 140 | { |
1da177e4 LT |
141 | struct nfs_page *new; |
142 | unsigned int len; | |
c76069bd | 143 | struct nfs_pageio_descriptor pgio; |
1da177e4 | 144 | |
49a70f27 | 145 | len = nfs_page_length(page); |
1da177e4 LT |
146 | if (len == 0) |
147 | return nfs_return_empty_page(page); | |
148 | new = nfs_create_request(ctx, inode, page, 0, len); | |
149 | if (IS_ERR(new)) { | |
150 | unlock_page(page); | |
151 | return PTR_ERR(new); | |
152 | } | |
153 | if (len < PAGE_CACHE_SIZE) | |
eebd2aa3 | 154 | zero_user_segment(page, len, PAGE_CACHE_SIZE); |
1da177e4 | 155 | |
1751c363 | 156 | nfs_pageio_init_read(&pgio, inode); |
d8007d4d | 157 | nfs_pageio_add_request(&pgio, new); |
1751c363 | 158 | nfs_pageio_complete(&pgio); |
1da177e4 LT |
159 | return 0; |
160 | } | |
161 | ||
162 | static void nfs_readpage_release(struct nfs_page *req) | |
163 | { | |
3d4ff43d | 164 | struct inode *d_inode = req->wb_context->dentry->d_inode; |
7f8e05f6 DH |
165 | |
166 | if (PageUptodate(req->wb_page)) | |
167 | nfs_readpage_to_fscache(d_inode, req->wb_page, 0); | |
168 | ||
1da177e4 LT |
169 | unlock_page(req->wb_page); |
170 | ||
1da177e4 | 171 | dprintk("NFS: read done (%s/%Ld %d@%Ld)\n", |
3d4ff43d AV |
172 | req->wb_context->dentry->d_inode->i_sb->s_id, |
173 | (long long)NFS_FILEID(req->wb_context->dentry->d_inode), | |
1da177e4 LT |
174 | req->wb_bytes, |
175 | (long long)req_offset(req)); | |
10d2c46f | 176 | nfs_release_request(req); |
1da177e4 LT |
177 | } |
178 | ||
c5996c4e FI |
179 | int nfs_initiate_read(struct rpc_clnt *clnt, |
180 | struct nfs_read_data *data, | |
64419a9b | 181 | const struct rpc_call_ops *call_ops) |
1da177e4 | 182 | { |
cd841605 | 183 | struct inode *inode = data->header->inode; |
84115e1c | 184 | int swap_flags = IS_SWAPFILE(inode) ? NFS_RPC_SWAPFLAGS : 0; |
07737691 | 185 | struct rpc_task *task; |
bdc7f021 TM |
186 | struct rpc_message msg = { |
187 | .rpc_argp = &data->args, | |
188 | .rpc_resp = &data->res, | |
cd841605 | 189 | .rpc_cred = data->header->cred, |
bdc7f021 | 190 | }; |
84115e1c | 191 | struct rpc_task_setup task_setup_data = { |
07737691 | 192 | .task = &data->task, |
64419a9b | 193 | .rpc_client = clnt, |
bdc7f021 | 194 | .rpc_message = &msg, |
84115e1c TM |
195 | .callback_ops = call_ops, |
196 | .callback_data = data, | |
101070ca | 197 | .workqueue = nfsiod_workqueue, |
84115e1c TM |
198 | .flags = RPC_TASK_ASYNC | swap_flags, |
199 | }; | |
1da177e4 | 200 | |
64419a9b AA |
201 | /* Set up the initial task struct. */ |
202 | NFS_PROTO(inode)->read_setup(data, &msg); | |
203 | ||
204 | dprintk("NFS: %5u initiated read call (req %s/%lld, %u bytes @ " | |
205 | "offset %llu)\n", | |
206 | data->task.tk_pid, | |
207 | inode->i_sb->s_id, | |
208 | (long long)NFS_FILEID(inode), | |
209 | data->args.count, | |
210 | (unsigned long long)data->args.offset); | |
211 | ||
212 | task = rpc_run_task(&task_setup_data); | |
213 | if (IS_ERR(task)) | |
214 | return PTR_ERR(task); | |
215 | rpc_put_task(task); | |
216 | return 0; | |
217 | } | |
dc70d7b3 | 218 | EXPORT_SYMBOL_GPL(nfs_initiate_read); |
64419a9b AA |
219 | |
220 | /* | |
221 | * Set up the NFS read request struct | |
222 | */ | |
6e4efd56 TM |
223 | static void nfs_read_rpcsetup(struct nfs_page *req, struct nfs_read_data *data, |
224 | unsigned int count, unsigned int offset) | |
64419a9b | 225 | { |
cd841605 | 226 | struct inode *inode = data->header->inode; |
64419a9b | 227 | |
cd841605 FI |
228 | data->header->req = req; |
229 | data->header->inode = inode; | |
230 | data->header->cred = req->wb_context->cred; | |
1da177e4 LT |
231 | |
232 | data->args.fh = NFS_FH(inode); | |
233 | data->args.offset = req_offset(req) + offset; | |
234 | data->args.pgbase = req->wb_pgbase + offset; | |
235 | data->args.pages = data->pagevec; | |
236 | data->args.count = count; | |
383ba719 | 237 | data->args.context = get_nfs_open_context(req->wb_context); |
f11ac8db | 238 | data->args.lock_context = req->wb_lock_context; |
1da177e4 LT |
239 | |
240 | data->res.fattr = &data->fattr; | |
241 | data->res.count = count; | |
242 | data->res.eof = 0; | |
0e574af1 | 243 | nfs_fattr_init(&data->fattr); |
6e4efd56 | 244 | } |
1da177e4 | 245 | |
6e4efd56 | 246 | static int nfs_do_read(struct nfs_read_data *data, |
493292dd | 247 | const struct rpc_call_ops *call_ops) |
6e4efd56 | 248 | { |
cd841605 | 249 | struct inode *inode = data->header->inode; |
6e4efd56 | 250 | |
c5996c4e | 251 | return nfs_initiate_read(NFS_CLIENT(inode), data, call_ops); |
1da177e4 LT |
252 | } |
253 | ||
275acaaf TM |
254 | static int |
255 | nfs_do_multiple_reads(struct list_head *head, | |
493292dd | 256 | const struct rpc_call_ops *call_ops) |
275acaaf TM |
257 | { |
258 | struct nfs_read_data *data; | |
259 | int ret = 0; | |
260 | ||
261 | while (!list_empty(head)) { | |
262 | int ret2; | |
263 | ||
264 | data = list_entry(head->next, struct nfs_read_data, list); | |
265 | list_del_init(&data->list); | |
266 | ||
493292dd | 267 | ret2 = nfs_do_read(data, call_ops); |
275acaaf TM |
268 | if (ret == 0) |
269 | ret = ret2; | |
270 | } | |
271 | return ret; | |
272 | } | |
273 | ||
1da177e4 LT |
274 | static void |
275 | nfs_async_read_error(struct list_head *head) | |
276 | { | |
277 | struct nfs_page *req; | |
278 | ||
279 | while (!list_empty(head)) { | |
280 | req = nfs_list_entry(head->next); | |
281 | nfs_list_remove_request(req); | |
1da177e4 LT |
282 | nfs_readpage_release(req); |
283 | } | |
284 | } | |
285 | ||
1da177e4 LT |
286 | /* |
287 | * Generate multiple requests to fill a single page. | |
288 | * | |
289 | * We optimize to reduce the number of read operations on the wire. If we | |
290 | * detect that we're reading a page, or an area of a page, that is past the | |
291 | * end of file, we do not generate NFS read operations but just clear the | |
292 | * parts of the page that would have come back zero from the server anyway. | |
293 | * | |
294 | * We rely on the cached value of i_size to make this determination; another | |
295 | * client can fill pages on the server past our cached end-of-file, but we | |
296 | * won't see the new data until our attribute cache is updated. This is more | |
297 | * or less conventional NFS client behavior. | |
298 | */ | |
275acaaf | 299 | static int nfs_pagein_multi(struct nfs_pageio_descriptor *desc, struct list_head *res) |
1da177e4 | 300 | { |
c76069bd | 301 | struct nfs_page *req = nfs_list_entry(desc->pg_list.next); |
1da177e4 | 302 | struct page *page = req->wb_page; |
cd841605 | 303 | struct nfs_read_header *rhdr; |
1da177e4 | 304 | struct nfs_read_data *data; |
d097971d | 305 | size_t rsize = desc->pg_bsize, nbytes; |
e9f7bee1 | 306 | unsigned int offset; |
1da177e4 | 307 | int requests = 0; |
dbae4c73 | 308 | int ret = 0; |
1da177e4 LT |
309 | |
310 | nfs_list_remove_request(req); | |
311 | ||
275acaaf | 312 | offset = 0; |
c76069bd | 313 | nbytes = desc->pg_count; |
e9f7bee1 TM |
314 | do { |
315 | size_t len = min(nbytes,rsize); | |
316 | ||
cd841605 FI |
317 | rhdr = nfs_readhdr_alloc(1); |
318 | if (!rhdr) | |
1da177e4 | 319 | goto out_bad; |
cd841605 | 320 | data = &rhdr->rpc_data; |
275acaaf TM |
321 | data->pagevec[0] = page; |
322 | nfs_read_rpcsetup(req, data, len, offset); | |
323 | list_add(&data->list, res); | |
1da177e4 | 324 | requests++; |
e9f7bee1 | 325 | nbytes -= len; |
275acaaf | 326 | offset += len; |
e9f7bee1 | 327 | } while(nbytes != 0); |
1da177e4 | 328 | atomic_set(&req->wb_complete, requests); |
50828d7e | 329 | desc->pg_rpc_callops = &nfs_read_partial_ops; |
dbae4c73 | 330 | return ret; |
1da177e4 | 331 | out_bad: |
275acaaf TM |
332 | while (!list_empty(res)) { |
333 | data = list_entry(res->next, struct nfs_read_data, list); | |
6e4efd56 | 334 | list_del(&data->list); |
73fb7bc7 | 335 | nfs_readdata_release(data); |
1da177e4 | 336 | } |
1da177e4 LT |
337 | nfs_readpage_release(req); |
338 | return -ENOMEM; | |
339 | } | |
340 | ||
275acaaf | 341 | static int nfs_pagein_one(struct nfs_pageio_descriptor *desc, struct list_head *res) |
1da177e4 LT |
342 | { |
343 | struct nfs_page *req; | |
344 | struct page **pages; | |
cd841605 | 345 | struct nfs_read_header *rhdr; |
1da177e4 | 346 | struct nfs_read_data *data; |
c76069bd | 347 | struct list_head *head = &desc->pg_list; |
3b609184 | 348 | int ret = 0; |
1da177e4 | 349 | |
cd841605 FI |
350 | rhdr = nfs_readhdr_alloc(nfs_page_array_len(desc->pg_base, |
351 | desc->pg_count)); | |
352 | if (!rhdr) { | |
bae724ef | 353 | nfs_async_read_error(head); |
3b609184 | 354 | ret = -ENOMEM; |
bae724ef FI |
355 | goto out; |
356 | } | |
1da177e4 | 357 | |
cd841605 | 358 | data = &rhdr->rpc_data; |
1da177e4 | 359 | pages = data->pagevec; |
1da177e4 LT |
360 | while (!list_empty(head)) { |
361 | req = nfs_list_entry(head->next); | |
362 | nfs_list_remove_request(req); | |
cd841605 | 363 | nfs_list_add_request(req, &rhdr->header.pages); |
1da177e4 | 364 | *pages++ = req->wb_page; |
1da177e4 | 365 | } |
cd841605 | 366 | req = nfs_list_entry(rhdr->header.pages.next); |
1da177e4 | 367 | |
6e4efd56 | 368 | nfs_read_rpcsetup(req, data, desc->pg_count, 0); |
275acaaf | 369 | list_add(&data->list, res); |
50828d7e | 370 | desc->pg_rpc_callops = &nfs_read_full_ops; |
bae724ef | 371 | out: |
dbae4c73 | 372 | return ret; |
1da177e4 LT |
373 | } |
374 | ||
493292dd TM |
375 | int nfs_generic_pagein(struct nfs_pageio_descriptor *desc, struct list_head *head) |
376 | { | |
377 | if (desc->pg_bsize < PAGE_CACHE_SIZE) | |
378 | return nfs_pagein_multi(desc, head); | |
379 | return nfs_pagein_one(desc, head); | |
380 | } | |
381 | ||
382 | static int nfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc) | |
1751c363 | 383 | { |
275acaaf TM |
384 | LIST_HEAD(head); |
385 | int ret; | |
386 | ||
493292dd | 387 | ret = nfs_generic_pagein(desc, &head); |
50828d7e | 388 | if (ret == 0) |
493292dd | 389 | ret = nfs_do_multiple_reads(&head, desc->pg_rpc_callops); |
275acaaf | 390 | return ret; |
1751c363 | 391 | } |
1751c363 TM |
392 | |
393 | static const struct nfs_pageio_ops nfs_pageio_read_ops = { | |
394 | .pg_test = nfs_generic_pg_test, | |
395 | .pg_doio = nfs_generic_pg_readpages, | |
396 | }; | |
397 | ||
0b671301 TM |
398 | /* |
399 | * This is the callback from RPC telling us whether a reply was | |
400 | * received or some error occurred (timeout or socket shutdown). | |
401 | */ | |
402 | int nfs_readpage_result(struct rpc_task *task, struct nfs_read_data *data) | |
403 | { | |
cd841605 | 404 | struct inode *inode = data->header->inode; |
0b671301 TM |
405 | int status; |
406 | ||
3110ff80 | 407 | dprintk("NFS: %s: %5u, (status %d)\n", __func__, task->tk_pid, |
0b671301 TM |
408 | task->tk_status); |
409 | ||
cd841605 | 410 | status = NFS_PROTO(inode)->read_done(task, data); |
0b671301 TM |
411 | if (status != 0) |
412 | return status; | |
413 | ||
cd841605 | 414 | nfs_add_stats(inode, NFSIOS_SERVERREADBYTES, data->res.count); |
0b671301 TM |
415 | |
416 | if (task->tk_status == -ESTALE) { | |
cd841605 FI |
417 | set_bit(NFS_INO_STALE, &NFS_I(inode)->flags); |
418 | nfs_mark_for_revalidate(inode); | |
0b671301 | 419 | } |
0b671301 TM |
420 | return 0; |
421 | } | |
422 | ||
fdd1e74c | 423 | static void nfs_readpage_retry(struct rpc_task *task, struct nfs_read_data *data) |
0b671301 TM |
424 | { |
425 | struct nfs_readargs *argp = &data->args; | |
426 | struct nfs_readres *resp = &data->res; | |
427 | ||
428 | if (resp->eof || resp->count == argp->count) | |
d61e612a | 429 | return; |
0b671301 TM |
430 | |
431 | /* This is a short read! */ | |
cd841605 | 432 | nfs_inc_stats(data->header->inode, NFSIOS_SHORTREAD); |
0b671301 TM |
433 | /* Has the server at least made some progress? */ |
434 | if (resp->count == 0) | |
d61e612a | 435 | return; |
0b671301 TM |
436 | |
437 | /* Yes, so retry the read at the end of the data */ | |
cbdabc7f | 438 | data->mds_offset += resp->count; |
0b671301 TM |
439 | argp->offset += resp->count; |
440 | argp->pgbase += resp->count; | |
441 | argp->count -= resp->count; | |
d00c5d43 | 442 | rpc_restart_call_prepare(task); |
0b671301 TM |
443 | } |
444 | ||
1da177e4 LT |
445 | /* |
446 | * Handle a read reply that fills part of a page. | |
447 | */ | |
ec06c096 | 448 | static void nfs_readpage_result_partial(struct rpc_task *task, void *calldata) |
1da177e4 | 449 | { |
ec06c096 | 450 | struct nfs_read_data *data = calldata; |
1da177e4 | 451 | |
ec06c096 TM |
452 | if (nfs_readpage_result(task, data) != 0) |
453 | return; | |
fdd1e74c TM |
454 | if (task->tk_status < 0) |
455 | return; | |
0b671301 | 456 | |
fdd1e74c TM |
457 | nfs_readpage_truncate_uninitialised_page(data); |
458 | nfs_readpage_retry(task, data); | |
459 | } | |
460 | ||
461 | static void nfs_readpage_release_partial(void *calldata) | |
462 | { | |
463 | struct nfs_read_data *data = calldata; | |
cd841605 | 464 | struct nfs_page *req = data->header->req; |
fdd1e74c TM |
465 | struct page *page = req->wb_page; |
466 | int status = data->task.tk_status; | |
467 | ||
468 | if (status < 0) | |
fba73005 | 469 | set_bit(PG_PARTIAL_READ_FAILED, &req->wb_flags); |
fdd1e74c | 470 | |
1da177e4 | 471 | if (atomic_dec_and_test(&req->wb_complete)) { |
fba73005 | 472 | if (!test_bit(PG_PARTIAL_READ_FAILED, &req->wb_flags)) |
1da177e4 LT |
473 | SetPageUptodate(page); |
474 | nfs_readpage_release(req); | |
475 | } | |
cd841605 | 476 | nfs_readdata_release(data); |
1da177e4 LT |
477 | } |
478 | ||
f11c88af AA |
479 | void nfs_read_prepare(struct rpc_task *task, void *calldata) |
480 | { | |
481 | struct nfs_read_data *data = calldata; | |
cd841605 | 482 | NFS_PROTO(data->header->inode)->read_rpc_prepare(task, data); |
f11c88af | 483 | } |
f11c88af | 484 | |
ec06c096 | 485 | static const struct rpc_call_ops nfs_read_partial_ops = { |
f11c88af | 486 | .rpc_call_prepare = nfs_read_prepare, |
ec06c096 | 487 | .rpc_call_done = nfs_readpage_result_partial, |
fdd1e74c | 488 | .rpc_release = nfs_readpage_release_partial, |
ec06c096 TM |
489 | }; |
490 | ||
1de3fc12 TM |
491 | static void nfs_readpage_set_pages_uptodate(struct nfs_read_data *data) |
492 | { | |
493 | unsigned int count = data->res.count; | |
494 | unsigned int base = data->args.pgbase; | |
495 | struct page **pages; | |
496 | ||
79558f36 TM |
497 | if (data->res.eof) |
498 | count = data->args.count; | |
1de3fc12 TM |
499 | if (unlikely(count == 0)) |
500 | return; | |
501 | pages = &data->args.pages[base >> PAGE_CACHE_SHIFT]; | |
502 | base &= ~PAGE_CACHE_MASK; | |
503 | count += base; | |
504 | for (;count >= PAGE_CACHE_SIZE; count -= PAGE_CACHE_SIZE, pages++) | |
505 | SetPageUptodate(*pages); | |
0b671301 TM |
506 | if (count == 0) |
507 | return; | |
508 | /* Was this a short read? */ | |
509 | if (data->res.eof || data->res.count == data->args.count) | |
1de3fc12 TM |
510 | SetPageUptodate(*pages); |
511 | } | |
512 | ||
1da177e4 LT |
513 | /* |
514 | * This is the callback from RPC telling us whether a reply was | |
515 | * received or some error occurred (timeout or socket shutdown). | |
516 | */ | |
ec06c096 | 517 | static void nfs_readpage_result_full(struct rpc_task *task, void *calldata) |
1da177e4 | 518 | { |
ec06c096 | 519 | struct nfs_read_data *data = calldata; |
1da177e4 | 520 | |
0b671301 TM |
521 | if (nfs_readpage_result(task, data) != 0) |
522 | return; | |
fdd1e74c TM |
523 | if (task->tk_status < 0) |
524 | return; | |
1de3fc12 | 525 | /* |
0b671301 | 526 | * Note: nfs_readpage_retry may change the values of |
1de3fc12 | 527 | * data->args. In the multi-page case, we therefore need |
0b671301 TM |
528 | * to ensure that we call nfs_readpage_set_pages_uptodate() |
529 | * first. | |
1de3fc12 | 530 | */ |
fdd1e74c TM |
531 | nfs_readpage_truncate_uninitialised_page(data); |
532 | nfs_readpage_set_pages_uptodate(data); | |
533 | nfs_readpage_retry(task, data); | |
534 | } | |
535 | ||
536 | static void nfs_readpage_release_full(void *calldata) | |
537 | { | |
538 | struct nfs_read_data *data = calldata; | |
cd841605 | 539 | struct nfs_pgio_header *hdr = data->header; |
fdd1e74c | 540 | |
cd841605 FI |
541 | while (!list_empty(&hdr->pages)) { |
542 | struct nfs_page *req = nfs_list_entry(hdr->pages.next); | |
1da177e4 | 543 | |
1de3fc12 | 544 | nfs_list_remove_request(req); |
62e4a769 | 545 | nfs_readpage_release(req); |
1da177e4 | 546 | } |
fdd1e74c | 547 | nfs_readdata_release(calldata); |
1da177e4 LT |
548 | } |
549 | ||
ec06c096 | 550 | static const struct rpc_call_ops nfs_read_full_ops = { |
f11c88af | 551 | .rpc_call_prepare = nfs_read_prepare, |
ec06c096 | 552 | .rpc_call_done = nfs_readpage_result_full, |
fdd1e74c | 553 | .rpc_release = nfs_readpage_release_full, |
ec06c096 TM |
554 | }; |
555 | ||
1da177e4 LT |
556 | /* |
557 | * Read a page over NFS. | |
558 | * We read the page synchronously in the following case: | |
559 | * - The error flag is set for this page. This happens only when a | |
560 | * previous async read operation failed. | |
561 | */ | |
562 | int nfs_readpage(struct file *file, struct page *page) | |
563 | { | |
564 | struct nfs_open_context *ctx; | |
565 | struct inode *inode = page->mapping->host; | |
566 | int error; | |
567 | ||
568 | dprintk("NFS: nfs_readpage (%p %ld@%lu)\n", | |
569 | page, PAGE_CACHE_SIZE, page->index); | |
91d5b470 CL |
570 | nfs_inc_stats(inode, NFSIOS_VFSREADPAGE); |
571 | nfs_add_stats(inode, NFSIOS_READPAGES, 1); | |
572 | ||
1da177e4 LT |
573 | /* |
574 | * Try to flush any pending writes to the file.. | |
575 | * | |
576 | * NOTE! Because we own the page lock, there cannot | |
577 | * be any new pending writes generated at this point | |
578 | * for this page (other pages can be written to). | |
579 | */ | |
580 | error = nfs_wb_page(inode, page); | |
581 | if (error) | |
de05a0cc TM |
582 | goto out_unlock; |
583 | if (PageUptodate(page)) | |
584 | goto out_unlock; | |
1da177e4 | 585 | |
5f004cf2 TM |
586 | error = -ESTALE; |
587 | if (NFS_STALE(inode)) | |
de05a0cc | 588 | goto out_unlock; |
5f004cf2 | 589 | |
1da177e4 | 590 | if (file == NULL) { |
cf1308ff | 591 | error = -EBADF; |
d530838b | 592 | ctx = nfs_find_open_context(inode, NULL, FMODE_READ); |
1da177e4 | 593 | if (ctx == NULL) |
de05a0cc | 594 | goto out_unlock; |
1da177e4 | 595 | } else |
cd3758e3 | 596 | ctx = get_nfs_open_context(nfs_file_open_context(file)); |
1da177e4 | 597 | |
9a9fc1c0 DH |
598 | if (!IS_SYNC(inode)) { |
599 | error = nfs_readpage_from_fscache(ctx, inode, page); | |
600 | if (error == 0) | |
601 | goto out; | |
602 | } | |
603 | ||
8e0969f0 TM |
604 | error = nfs_readpage_async(ctx, inode, page); |
605 | ||
9a9fc1c0 | 606 | out: |
1da177e4 LT |
607 | put_nfs_open_context(ctx); |
608 | return error; | |
de05a0cc | 609 | out_unlock: |
1da177e4 LT |
610 | unlock_page(page); |
611 | return error; | |
612 | } | |
613 | ||
614 | struct nfs_readdesc { | |
8b09bee3 | 615 | struct nfs_pageio_descriptor *pgio; |
1da177e4 LT |
616 | struct nfs_open_context *ctx; |
617 | }; | |
618 | ||
619 | static int | |
620 | readpage_async_filler(void *data, struct page *page) | |
621 | { | |
622 | struct nfs_readdesc *desc = (struct nfs_readdesc *)data; | |
623 | struct inode *inode = page->mapping->host; | |
624 | struct nfs_page *new; | |
625 | unsigned int len; | |
de05a0cc TM |
626 | int error; |
627 | ||
49a70f27 | 628 | len = nfs_page_length(page); |
1da177e4 LT |
629 | if (len == 0) |
630 | return nfs_return_empty_page(page); | |
de05a0cc | 631 | |
1da177e4 | 632 | new = nfs_create_request(desc->ctx, inode, page, 0, len); |
de05a0cc TM |
633 | if (IS_ERR(new)) |
634 | goto out_error; | |
635 | ||
1da177e4 | 636 | if (len < PAGE_CACHE_SIZE) |
eebd2aa3 | 637 | zero_user_segment(page, len, PAGE_CACHE_SIZE); |
f8512ad0 FI |
638 | if (!nfs_pageio_add_request(desc->pgio, new)) { |
639 | error = desc->pgio->pg_error; | |
640 | goto out_unlock; | |
641 | } | |
1da177e4 | 642 | return 0; |
de05a0cc TM |
643 | out_error: |
644 | error = PTR_ERR(new); | |
de05a0cc TM |
645 | out_unlock: |
646 | unlock_page(page); | |
647 | return error; | |
1da177e4 LT |
648 | } |
649 | ||
650 | int nfs_readpages(struct file *filp, struct address_space *mapping, | |
651 | struct list_head *pages, unsigned nr_pages) | |
652 | { | |
8b09bee3 | 653 | struct nfs_pageio_descriptor pgio; |
1da177e4 | 654 | struct nfs_readdesc desc = { |
8b09bee3 | 655 | .pgio = &pgio, |
1da177e4 LT |
656 | }; |
657 | struct inode *inode = mapping->host; | |
8b09bee3 | 658 | unsigned long npages; |
5f004cf2 | 659 | int ret = -ESTALE; |
1da177e4 LT |
660 | |
661 | dprintk("NFS: nfs_readpages (%s/%Ld %d)\n", | |
662 | inode->i_sb->s_id, | |
663 | (long long)NFS_FILEID(inode), | |
664 | nr_pages); | |
91d5b470 | 665 | nfs_inc_stats(inode, NFSIOS_VFSREADPAGES); |
1da177e4 | 666 | |
5f004cf2 TM |
667 | if (NFS_STALE(inode)) |
668 | goto out; | |
669 | ||
1da177e4 | 670 | if (filp == NULL) { |
d530838b | 671 | desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ); |
1da177e4 LT |
672 | if (desc.ctx == NULL) |
673 | return -EBADF; | |
674 | } else | |
cd3758e3 | 675 | desc.ctx = get_nfs_open_context(nfs_file_open_context(filp)); |
9a9fc1c0 DH |
676 | |
677 | /* attempt to read as many of the pages as possible from the cache | |
678 | * - this returns -ENOBUFS immediately if the cookie is negative | |
679 | */ | |
680 | ret = nfs_readpages_from_fscache(desc.ctx, inode, mapping, | |
681 | pages, &nr_pages); | |
682 | if (ret == 0) | |
683 | goto read_complete; /* all pages were read */ | |
684 | ||
1751c363 | 685 | nfs_pageio_init_read(&pgio, inode); |
8b09bee3 | 686 | |
1da177e4 | 687 | ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc); |
8b09bee3 TM |
688 | |
689 | nfs_pageio_complete(&pgio); | |
690 | npages = (pgio.pg_bytes_written + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; | |
691 | nfs_add_stats(inode, NFSIOS_READPAGES, npages); | |
9a9fc1c0 | 692 | read_complete: |
1da177e4 | 693 | put_nfs_open_context(desc.ctx); |
5f004cf2 | 694 | out: |
1da177e4 LT |
695 | return ret; |
696 | } | |
697 | ||
f7b422b1 | 698 | int __init nfs_init_readpagecache(void) |
1da177e4 LT |
699 | { |
700 | nfs_rdata_cachep = kmem_cache_create("nfs_read_data", | |
cd841605 | 701 | sizeof(struct nfs_read_header), |
1da177e4 | 702 | 0, SLAB_HWCACHE_ALIGN, |
20c2df83 | 703 | NULL); |
1da177e4 LT |
704 | if (nfs_rdata_cachep == NULL) |
705 | return -ENOMEM; | |
706 | ||
1da177e4 LT |
707 | return 0; |
708 | } | |
709 | ||
266bee88 | 710 | void nfs_destroy_readpagecache(void) |
1da177e4 | 711 | { |
1a1d92c1 | 712 | kmem_cache_destroy(nfs_rdata_cachep); |
1da177e4 | 713 | } |