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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; |
4db6e0b7 | 33 | static const struct rpc_call_ops nfs_read_common_ops; |
1da177e4 | 34 | |
e18b890b | 35 | static struct kmem_cache *nfs_rdata_cachep; |
1da177e4 | 36 | |
4db6e0b7 | 37 | struct nfs_read_header *nfs_readhdr_alloc() |
3feb2d49 | 38 | { |
4db6e0b7 | 39 | struct nfs_read_header *rhdr; |
3feb2d49 | 40 | |
4db6e0b7 FI |
41 | rhdr = kmem_cache_zalloc(nfs_rdata_cachep, GFP_KERNEL); |
42 | if (rhdr) { | |
43 | struct nfs_pgio_header *hdr = &rhdr->header; | |
cd841605 FI |
44 | |
45 | INIT_LIST_HEAD(&hdr->pages); | |
4db6e0b7 FI |
46 | INIT_LIST_HEAD(&hdr->rpc_list); |
47 | spin_lock_init(&hdr->lock); | |
48 | atomic_set(&hdr->refcnt, 0); | |
49 | } | |
50 | return rhdr; | |
51 | } | |
52 | ||
53 | struct nfs_read_data *nfs_readdata_alloc(struct nfs_pgio_header *hdr, | |
54 | unsigned int pagecount) | |
55 | { | |
56 | struct nfs_read_data *data, *prealloc; | |
57 | ||
58 | prealloc = &container_of(hdr, struct nfs_read_header, header)->rpc_data; | |
59 | if (prealloc->header == NULL) | |
60 | data = prealloc; | |
61 | else | |
62 | data = kzalloc(sizeof(*data), GFP_KERNEL); | |
63 | if (!data) | |
64 | goto out; | |
65 | ||
66 | if (nfs_pgarray_set(&data->pages, pagecount)) { | |
cd841605 | 67 | data->header = hdr; |
4db6e0b7 FI |
68 | atomic_inc(&hdr->refcnt); |
69 | } else { | |
70 | if (data != prealloc) | |
71 | kfree(data); | |
72 | data = NULL; | |
3feb2d49 | 73 | } |
4db6e0b7 FI |
74 | out: |
75 | return data; | |
3feb2d49 TM |
76 | } |
77 | ||
cd841605 | 78 | void nfs_readhdr_free(struct nfs_pgio_header *hdr) |
3feb2d49 | 79 | { |
cd841605 FI |
80 | struct nfs_read_header *rhdr = container_of(hdr, struct nfs_read_header, header); |
81 | ||
82 | kmem_cache_free(nfs_rdata_cachep, rhdr); | |
3feb2d49 TM |
83 | } |
84 | ||
493292dd | 85 | void nfs_readdata_release(struct nfs_read_data *rdata) |
1da177e4 | 86 | { |
4db6e0b7 FI |
87 | struct nfs_pgio_header *hdr = rdata->header; |
88 | struct nfs_read_header *read_header = container_of(hdr, struct nfs_read_header, header); | |
89 | ||
383ba719 | 90 | put_nfs_open_context(rdata->args.context); |
30dd374f FI |
91 | if (rdata->pages.pagevec != rdata->pages.page_array) |
92 | kfree(rdata->pages.pagevec); | |
4db6e0b7 FI |
93 | if (rdata != &read_header->rpc_data) |
94 | kfree(rdata); | |
95 | else | |
96 | rdata->header = NULL; | |
97 | if (atomic_dec_and_test(&hdr->refcnt)) | |
98 | nfs_read_completion(hdr); | |
1da177e4 LT |
99 | } |
100 | ||
1da177e4 LT |
101 | static |
102 | int nfs_return_empty_page(struct page *page) | |
103 | { | |
eebd2aa3 | 104 | zero_user(page, 0, PAGE_CACHE_SIZE); |
1da177e4 LT |
105 | SetPageUptodate(page); |
106 | unlock_page(page); | |
107 | return 0; | |
108 | } | |
109 | ||
62e4a769 | 110 | void nfs_pageio_init_read_mds(struct nfs_pageio_descriptor *pgio, |
1751c363 TM |
111 | struct inode *inode) |
112 | { | |
113 | nfs_pageio_init(pgio, inode, &nfs_pageio_read_ops, | |
114 | NFS_SERVER(inode)->rsize, 0); | |
115 | } | |
116 | ||
493292dd TM |
117 | void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio) |
118 | { | |
119 | pgio->pg_ops = &nfs_pageio_read_ops; | |
120 | pgio->pg_bsize = NFS_SERVER(pgio->pg_inode)->rsize; | |
121 | } | |
1f945357 | 122 | EXPORT_SYMBOL_GPL(nfs_pageio_reset_read_mds); |
493292dd | 123 | |
1751c363 TM |
124 | static void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio, |
125 | struct inode *inode) | |
126 | { | |
127 | if (!pnfs_pageio_init_read(pgio, inode)) | |
128 | nfs_pageio_init_read_mds(pgio, inode); | |
129 | } | |
130 | ||
f42b293d DH |
131 | int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode, |
132 | struct page *page) | |
1da177e4 | 133 | { |
1da177e4 LT |
134 | struct nfs_page *new; |
135 | unsigned int len; | |
c76069bd | 136 | struct nfs_pageio_descriptor pgio; |
1da177e4 | 137 | |
49a70f27 | 138 | len = nfs_page_length(page); |
1da177e4 LT |
139 | if (len == 0) |
140 | return nfs_return_empty_page(page); | |
141 | new = nfs_create_request(ctx, inode, page, 0, len); | |
142 | if (IS_ERR(new)) { | |
143 | unlock_page(page); | |
144 | return PTR_ERR(new); | |
145 | } | |
146 | if (len < PAGE_CACHE_SIZE) | |
eebd2aa3 | 147 | zero_user_segment(page, len, PAGE_CACHE_SIZE); |
1da177e4 | 148 | |
1751c363 | 149 | nfs_pageio_init_read(&pgio, inode); |
d8007d4d | 150 | nfs_pageio_add_request(&pgio, new); |
1751c363 | 151 | nfs_pageio_complete(&pgio); |
1da177e4 LT |
152 | return 0; |
153 | } | |
154 | ||
155 | static void nfs_readpage_release(struct nfs_page *req) | |
156 | { | |
3d4ff43d | 157 | struct inode *d_inode = req->wb_context->dentry->d_inode; |
7f8e05f6 DH |
158 | |
159 | if (PageUptodate(req->wb_page)) | |
160 | nfs_readpage_to_fscache(d_inode, req->wb_page, 0); | |
161 | ||
1da177e4 LT |
162 | unlock_page(req->wb_page); |
163 | ||
1da177e4 | 164 | dprintk("NFS: read done (%s/%Ld %d@%Ld)\n", |
3d4ff43d AV |
165 | req->wb_context->dentry->d_inode->i_sb->s_id, |
166 | (long long)NFS_FILEID(req->wb_context->dentry->d_inode), | |
1da177e4 LT |
167 | req->wb_bytes, |
168 | (long long)req_offset(req)); | |
10d2c46f | 169 | nfs_release_request(req); |
1da177e4 LT |
170 | } |
171 | ||
4db6e0b7 FI |
172 | /* Note io was page aligned */ |
173 | void nfs_read_completion(struct nfs_pgio_header *hdr) | |
174 | { | |
175 | unsigned long bytes = 0; | |
176 | ||
177 | if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) | |
178 | goto out; | |
179 | if (!test_bit(NFS_IOHDR_ERROR, &hdr->flags)) { | |
180 | while (!list_empty(&hdr->pages)) { | |
181 | struct nfs_page *req = nfs_list_entry(hdr->pages.next); | |
182 | struct page *page = req->wb_page; | |
183 | ||
184 | if (test_bit(NFS_IOHDR_EOF, &hdr->flags)) { | |
185 | if (bytes > hdr->good_bytes) | |
186 | zero_user(page, 0, PAGE_SIZE); | |
187 | else if (hdr->good_bytes - bytes < PAGE_SIZE) | |
188 | zero_user_segment(page, | |
189 | hdr->good_bytes & ~PAGE_MASK, | |
190 | PAGE_SIZE); | |
191 | } | |
192 | SetPageUptodate(page); | |
193 | nfs_list_remove_request(req); | |
194 | nfs_readpage_release(req); | |
195 | bytes += PAGE_SIZE; | |
196 | } | |
197 | } else { | |
198 | while (!list_empty(&hdr->pages)) { | |
199 | struct nfs_page *req = nfs_list_entry(hdr->pages.next); | |
200 | ||
201 | bytes += req->wb_bytes; | |
202 | if (bytes <= hdr->good_bytes) | |
203 | SetPageUptodate(req->wb_page); | |
204 | nfs_list_remove_request(req); | |
205 | nfs_readpage_release(req); | |
206 | } | |
207 | } | |
208 | out: | |
209 | hdr->release(hdr); | |
210 | } | |
211 | ||
c5996c4e FI |
212 | int nfs_initiate_read(struct rpc_clnt *clnt, |
213 | struct nfs_read_data *data, | |
64419a9b | 214 | const struct rpc_call_ops *call_ops) |
1da177e4 | 215 | { |
cd841605 | 216 | struct inode *inode = data->header->inode; |
84115e1c | 217 | int swap_flags = IS_SWAPFILE(inode) ? NFS_RPC_SWAPFLAGS : 0; |
07737691 | 218 | struct rpc_task *task; |
bdc7f021 TM |
219 | struct rpc_message msg = { |
220 | .rpc_argp = &data->args, | |
221 | .rpc_resp = &data->res, | |
cd841605 | 222 | .rpc_cred = data->header->cred, |
bdc7f021 | 223 | }; |
84115e1c | 224 | struct rpc_task_setup task_setup_data = { |
07737691 | 225 | .task = &data->task, |
64419a9b | 226 | .rpc_client = clnt, |
bdc7f021 | 227 | .rpc_message = &msg, |
84115e1c TM |
228 | .callback_ops = call_ops, |
229 | .callback_data = data, | |
101070ca | 230 | .workqueue = nfsiod_workqueue, |
84115e1c TM |
231 | .flags = RPC_TASK_ASYNC | swap_flags, |
232 | }; | |
1da177e4 | 233 | |
64419a9b AA |
234 | /* Set up the initial task struct. */ |
235 | NFS_PROTO(inode)->read_setup(data, &msg); | |
236 | ||
237 | dprintk("NFS: %5u initiated read call (req %s/%lld, %u bytes @ " | |
238 | "offset %llu)\n", | |
239 | data->task.tk_pid, | |
240 | inode->i_sb->s_id, | |
241 | (long long)NFS_FILEID(inode), | |
242 | data->args.count, | |
243 | (unsigned long long)data->args.offset); | |
244 | ||
245 | task = rpc_run_task(&task_setup_data); | |
246 | if (IS_ERR(task)) | |
247 | return PTR_ERR(task); | |
248 | rpc_put_task(task); | |
249 | return 0; | |
250 | } | |
dc70d7b3 | 251 | EXPORT_SYMBOL_GPL(nfs_initiate_read); |
64419a9b AA |
252 | |
253 | /* | |
254 | * Set up the NFS read request struct | |
255 | */ | |
4db6e0b7 | 256 | static void nfs_read_rpcsetup(struct nfs_read_data *data, |
6e4efd56 | 257 | unsigned int count, unsigned int offset) |
64419a9b | 258 | { |
4db6e0b7 | 259 | struct nfs_page *req = data->header->req; |
1da177e4 | 260 | |
4db6e0b7 | 261 | data->args.fh = NFS_FH(data->header->inode); |
1da177e4 LT |
262 | data->args.offset = req_offset(req) + offset; |
263 | data->args.pgbase = req->wb_pgbase + offset; | |
30dd374f | 264 | data->args.pages = data->pages.pagevec; |
1da177e4 | 265 | data->args.count = count; |
383ba719 | 266 | data->args.context = get_nfs_open_context(req->wb_context); |
f11ac8db | 267 | data->args.lock_context = req->wb_lock_context; |
1da177e4 LT |
268 | |
269 | data->res.fattr = &data->fattr; | |
270 | data->res.count = count; | |
271 | data->res.eof = 0; | |
0e574af1 | 272 | nfs_fattr_init(&data->fattr); |
6e4efd56 | 273 | } |
1da177e4 | 274 | |
6e4efd56 | 275 | static int nfs_do_read(struct nfs_read_data *data, |
493292dd | 276 | const struct rpc_call_ops *call_ops) |
6e4efd56 | 277 | { |
cd841605 | 278 | struct inode *inode = data->header->inode; |
6e4efd56 | 279 | |
c5996c4e | 280 | return nfs_initiate_read(NFS_CLIENT(inode), data, call_ops); |
1da177e4 LT |
281 | } |
282 | ||
275acaaf TM |
283 | static int |
284 | nfs_do_multiple_reads(struct list_head *head, | |
493292dd | 285 | const struct rpc_call_ops *call_ops) |
275acaaf TM |
286 | { |
287 | struct nfs_read_data *data; | |
288 | int ret = 0; | |
289 | ||
290 | while (!list_empty(head)) { | |
291 | int ret2; | |
292 | ||
4db6e0b7 | 293 | data = list_first_entry(head, struct nfs_read_data, list); |
275acaaf TM |
294 | list_del_init(&data->list); |
295 | ||
493292dd | 296 | ret2 = nfs_do_read(data, call_ops); |
275acaaf TM |
297 | if (ret == 0) |
298 | ret = ret2; | |
299 | } | |
300 | return ret; | |
301 | } | |
302 | ||
4db6e0b7 | 303 | void |
1da177e4 LT |
304 | nfs_async_read_error(struct list_head *head) |
305 | { | |
306 | struct nfs_page *req; | |
307 | ||
308 | while (!list_empty(head)) { | |
309 | req = nfs_list_entry(head->next); | |
310 | nfs_list_remove_request(req); | |
1da177e4 LT |
311 | nfs_readpage_release(req); |
312 | } | |
313 | } | |
314 | ||
1da177e4 LT |
315 | /* |
316 | * Generate multiple requests to fill a single page. | |
317 | * | |
318 | * We optimize to reduce the number of read operations on the wire. If we | |
319 | * detect that we're reading a page, or an area of a page, that is past the | |
320 | * end of file, we do not generate NFS read operations but just clear the | |
321 | * parts of the page that would have come back zero from the server anyway. | |
322 | * | |
323 | * We rely on the cached value of i_size to make this determination; another | |
324 | * client can fill pages on the server past our cached end-of-file, but we | |
325 | * won't see the new data until our attribute cache is updated. This is more | |
326 | * or less conventional NFS client behavior. | |
327 | */ | |
4db6e0b7 FI |
328 | static int nfs_pagein_multi(struct nfs_pageio_descriptor *desc, |
329 | struct nfs_pgio_header *hdr) | |
1da177e4 | 330 | { |
4db6e0b7 | 331 | struct nfs_page *req = hdr->req; |
1da177e4 LT |
332 | struct page *page = req->wb_page; |
333 | struct nfs_read_data *data; | |
d097971d | 334 | size_t rsize = desc->pg_bsize, nbytes; |
e9f7bee1 | 335 | unsigned int offset; |
1da177e4 | 336 | int requests = 0; |
dbae4c73 | 337 | int ret = 0; |
1da177e4 LT |
338 | |
339 | nfs_list_remove_request(req); | |
4db6e0b7 | 340 | nfs_list_add_request(req, &hdr->pages); |
1da177e4 | 341 | |
275acaaf | 342 | offset = 0; |
c76069bd | 343 | nbytes = desc->pg_count; |
e9f7bee1 TM |
344 | do { |
345 | size_t len = min(nbytes,rsize); | |
346 | ||
4db6e0b7 FI |
347 | data = nfs_readdata_alloc(hdr, 1); |
348 | if (!data) | |
1da177e4 | 349 | goto out_bad; |
30dd374f | 350 | data->pages.pagevec[0] = page; |
4db6e0b7 FI |
351 | nfs_read_rpcsetup(data, len, offset); |
352 | list_add(&data->list, &hdr->rpc_list); | |
1da177e4 | 353 | requests++; |
e9f7bee1 | 354 | nbytes -= len; |
275acaaf | 355 | offset += len; |
e9f7bee1 | 356 | } while(nbytes != 0); |
4db6e0b7 | 357 | desc->pg_rpc_callops = &nfs_read_common_ops; |
dbae4c73 | 358 | return ret; |
1da177e4 | 359 | out_bad: |
4db6e0b7 FI |
360 | while (!list_empty(&hdr->rpc_list)) { |
361 | data = list_first_entry(&hdr->rpc_list, struct nfs_read_data, list); | |
6e4efd56 | 362 | list_del(&data->list); |
73fb7bc7 | 363 | nfs_readdata_release(data); |
1da177e4 | 364 | } |
4db6e0b7 | 365 | nfs_async_read_error(&hdr->pages); |
1da177e4 LT |
366 | return -ENOMEM; |
367 | } | |
368 | ||
4db6e0b7 FI |
369 | static int nfs_pagein_one(struct nfs_pageio_descriptor *desc, |
370 | struct nfs_pgio_header *hdr) | |
1da177e4 LT |
371 | { |
372 | struct nfs_page *req; | |
373 | struct page **pages; | |
4db6e0b7 | 374 | struct nfs_read_data *data; |
c76069bd | 375 | struct list_head *head = &desc->pg_list; |
3b609184 | 376 | int ret = 0; |
1da177e4 | 377 | |
4db6e0b7 FI |
378 | data = nfs_readdata_alloc(hdr, nfs_page_array_len(desc->pg_base, |
379 | desc->pg_count)); | |
380 | if (!data) { | |
bae724ef | 381 | nfs_async_read_error(head); |
3b609184 | 382 | ret = -ENOMEM; |
bae724ef FI |
383 | goto out; |
384 | } | |
1da177e4 | 385 | |
30dd374f | 386 | pages = data->pages.pagevec; |
1da177e4 LT |
387 | while (!list_empty(head)) { |
388 | req = nfs_list_entry(head->next); | |
389 | nfs_list_remove_request(req); | |
4db6e0b7 | 390 | nfs_list_add_request(req, &hdr->pages); |
1da177e4 | 391 | *pages++ = req->wb_page; |
1da177e4 | 392 | } |
1da177e4 | 393 | |
4db6e0b7 FI |
394 | nfs_read_rpcsetup(data, desc->pg_count, 0); |
395 | list_add(&data->list, &hdr->rpc_list); | |
396 | desc->pg_rpc_callops = &nfs_read_common_ops; | |
bae724ef | 397 | out: |
dbae4c73 | 398 | return ret; |
1da177e4 LT |
399 | } |
400 | ||
4db6e0b7 FI |
401 | int nfs_generic_pagein(struct nfs_pageio_descriptor *desc, |
402 | struct nfs_pgio_header *hdr) | |
493292dd TM |
403 | { |
404 | if (desc->pg_bsize < PAGE_CACHE_SIZE) | |
4db6e0b7 FI |
405 | return nfs_pagein_multi(desc, hdr); |
406 | return nfs_pagein_one(desc, hdr); | |
493292dd TM |
407 | } |
408 | ||
409 | static int nfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc) | |
1751c363 | 410 | { |
4db6e0b7 FI |
411 | struct nfs_read_header *rhdr; |
412 | struct nfs_pgio_header *hdr; | |
275acaaf TM |
413 | int ret; |
414 | ||
4db6e0b7 FI |
415 | rhdr = nfs_readhdr_alloc(); |
416 | if (!rhdr) { | |
417 | nfs_async_read_error(&desc->pg_list); | |
418 | return -ENOMEM; | |
419 | } | |
420 | hdr = &rhdr->header; | |
421 | nfs_pgheader_init(desc, hdr, nfs_readhdr_free); | |
422 | atomic_inc(&hdr->refcnt); | |
423 | ret = nfs_generic_pagein(desc, hdr); | |
50828d7e | 424 | if (ret == 0) |
4db6e0b7 FI |
425 | ret = nfs_do_multiple_reads(&hdr->rpc_list, |
426 | desc->pg_rpc_callops); | |
427 | else | |
428 | set_bit(NFS_IOHDR_REDO, &hdr->flags); | |
429 | if (atomic_dec_and_test(&hdr->refcnt)) | |
430 | nfs_read_completion(hdr); | |
275acaaf | 431 | return ret; |
1751c363 | 432 | } |
1751c363 TM |
433 | |
434 | static const struct nfs_pageio_ops nfs_pageio_read_ops = { | |
435 | .pg_test = nfs_generic_pg_test, | |
436 | .pg_doio = nfs_generic_pg_readpages, | |
437 | }; | |
438 | ||
0b671301 TM |
439 | /* |
440 | * This is the callback from RPC telling us whether a reply was | |
441 | * received or some error occurred (timeout or socket shutdown). | |
442 | */ | |
443 | int nfs_readpage_result(struct rpc_task *task, struct nfs_read_data *data) | |
444 | { | |
cd841605 | 445 | struct inode *inode = data->header->inode; |
0b671301 TM |
446 | int status; |
447 | ||
3110ff80 | 448 | dprintk("NFS: %s: %5u, (status %d)\n", __func__, task->tk_pid, |
0b671301 TM |
449 | task->tk_status); |
450 | ||
cd841605 | 451 | status = NFS_PROTO(inode)->read_done(task, data); |
0b671301 TM |
452 | if (status != 0) |
453 | return status; | |
454 | ||
cd841605 | 455 | nfs_add_stats(inode, NFSIOS_SERVERREADBYTES, data->res.count); |
0b671301 TM |
456 | |
457 | if (task->tk_status == -ESTALE) { | |
cd841605 FI |
458 | set_bit(NFS_INO_STALE, &NFS_I(inode)->flags); |
459 | nfs_mark_for_revalidate(inode); | |
0b671301 | 460 | } |
0b671301 TM |
461 | return 0; |
462 | } | |
463 | ||
fdd1e74c | 464 | static void nfs_readpage_retry(struct rpc_task *task, struct nfs_read_data *data) |
0b671301 TM |
465 | { |
466 | struct nfs_readargs *argp = &data->args; | |
467 | struct nfs_readres *resp = &data->res; | |
468 | ||
0b671301 | 469 | /* This is a short read! */ |
cd841605 | 470 | nfs_inc_stats(data->header->inode, NFSIOS_SHORTREAD); |
0b671301 | 471 | /* Has the server at least made some progress? */ |
4db6e0b7 FI |
472 | if (resp->count == 0) { |
473 | nfs_set_pgio_error(data->header, -EIO, argp->offset); | |
d61e612a | 474 | return; |
4db6e0b7 | 475 | } |
0b671301 | 476 | /* Yes, so retry the read at the end of the data */ |
cbdabc7f | 477 | data->mds_offset += resp->count; |
0b671301 TM |
478 | argp->offset += resp->count; |
479 | argp->pgbase += resp->count; | |
480 | argp->count -= resp->count; | |
d00c5d43 | 481 | rpc_restart_call_prepare(task); |
0b671301 TM |
482 | } |
483 | ||
4db6e0b7 | 484 | static void nfs_readpage_result_common(struct rpc_task *task, void *calldata) |
1da177e4 | 485 | { |
ec06c096 | 486 | struct nfs_read_data *data = calldata; |
4db6e0b7 FI |
487 | struct nfs_pgio_header *hdr = data->header; |
488 | ||
489 | /* Note the only returns of nfs_readpage_result are 0 and -EAGAIN */ | |
ec06c096 TM |
490 | if (nfs_readpage_result(task, data) != 0) |
491 | return; | |
fdd1e74c | 492 | if (task->tk_status < 0) |
4db6e0b7 FI |
493 | nfs_set_pgio_error(hdr, task->tk_status, data->args.offset); |
494 | else if (data->res.eof) { | |
495 | loff_t bound; | |
496 | ||
497 | bound = data->args.offset + data->res.count; | |
498 | spin_lock(&hdr->lock); | |
499 | if (bound < hdr->io_start + hdr->good_bytes) { | |
500 | set_bit(NFS_IOHDR_EOF, &hdr->flags); | |
501 | clear_bit(NFS_IOHDR_ERROR, &hdr->flags); | |
502 | hdr->good_bytes = bound - hdr->io_start; | |
503 | } | |
504 | spin_unlock(&hdr->lock); | |
505 | } else if (data->res.count != data->args.count) | |
506 | nfs_readpage_retry(task, data); | |
fdd1e74c TM |
507 | } |
508 | ||
4db6e0b7 | 509 | static void nfs_readpage_release_common(void *calldata) |
fdd1e74c | 510 | { |
4db6e0b7 | 511 | nfs_readdata_release(calldata); |
1da177e4 LT |
512 | } |
513 | ||
f11c88af AA |
514 | void nfs_read_prepare(struct rpc_task *task, void *calldata) |
515 | { | |
516 | struct nfs_read_data *data = calldata; | |
cd841605 | 517 | NFS_PROTO(data->header->inode)->read_rpc_prepare(task, data); |
f11c88af | 518 | } |
f11c88af | 519 | |
4db6e0b7 | 520 | static const struct rpc_call_ops nfs_read_common_ops = { |
f11c88af | 521 | .rpc_call_prepare = nfs_read_prepare, |
4db6e0b7 FI |
522 | .rpc_call_done = nfs_readpage_result_common, |
523 | .rpc_release = nfs_readpage_release_common, | |
ec06c096 TM |
524 | }; |
525 | ||
1da177e4 LT |
526 | /* |
527 | * Read a page over NFS. | |
528 | * We read the page synchronously in the following case: | |
529 | * - The error flag is set for this page. This happens only when a | |
530 | * previous async read operation failed. | |
531 | */ | |
532 | int nfs_readpage(struct file *file, struct page *page) | |
533 | { | |
534 | struct nfs_open_context *ctx; | |
535 | struct inode *inode = page->mapping->host; | |
536 | int error; | |
537 | ||
538 | dprintk("NFS: nfs_readpage (%p %ld@%lu)\n", | |
539 | page, PAGE_CACHE_SIZE, page->index); | |
91d5b470 CL |
540 | nfs_inc_stats(inode, NFSIOS_VFSREADPAGE); |
541 | nfs_add_stats(inode, NFSIOS_READPAGES, 1); | |
542 | ||
1da177e4 LT |
543 | /* |
544 | * Try to flush any pending writes to the file.. | |
545 | * | |
546 | * NOTE! Because we own the page lock, there cannot | |
547 | * be any new pending writes generated at this point | |
548 | * for this page (other pages can be written to). | |
549 | */ | |
550 | error = nfs_wb_page(inode, page); | |
551 | if (error) | |
de05a0cc TM |
552 | goto out_unlock; |
553 | if (PageUptodate(page)) | |
554 | goto out_unlock; | |
1da177e4 | 555 | |
5f004cf2 TM |
556 | error = -ESTALE; |
557 | if (NFS_STALE(inode)) | |
de05a0cc | 558 | goto out_unlock; |
5f004cf2 | 559 | |
1da177e4 | 560 | if (file == NULL) { |
cf1308ff | 561 | error = -EBADF; |
d530838b | 562 | ctx = nfs_find_open_context(inode, NULL, FMODE_READ); |
1da177e4 | 563 | if (ctx == NULL) |
de05a0cc | 564 | goto out_unlock; |
1da177e4 | 565 | } else |
cd3758e3 | 566 | ctx = get_nfs_open_context(nfs_file_open_context(file)); |
1da177e4 | 567 | |
9a9fc1c0 DH |
568 | if (!IS_SYNC(inode)) { |
569 | error = nfs_readpage_from_fscache(ctx, inode, page); | |
570 | if (error == 0) | |
571 | goto out; | |
572 | } | |
573 | ||
8e0969f0 TM |
574 | error = nfs_readpage_async(ctx, inode, page); |
575 | ||
9a9fc1c0 | 576 | out: |
1da177e4 LT |
577 | put_nfs_open_context(ctx); |
578 | return error; | |
de05a0cc | 579 | out_unlock: |
1da177e4 LT |
580 | unlock_page(page); |
581 | return error; | |
582 | } | |
583 | ||
584 | struct nfs_readdesc { | |
8b09bee3 | 585 | struct nfs_pageio_descriptor *pgio; |
1da177e4 LT |
586 | struct nfs_open_context *ctx; |
587 | }; | |
588 | ||
589 | static int | |
590 | readpage_async_filler(void *data, struct page *page) | |
591 | { | |
592 | struct nfs_readdesc *desc = (struct nfs_readdesc *)data; | |
593 | struct inode *inode = page->mapping->host; | |
594 | struct nfs_page *new; | |
595 | unsigned int len; | |
de05a0cc TM |
596 | int error; |
597 | ||
49a70f27 | 598 | len = nfs_page_length(page); |
1da177e4 LT |
599 | if (len == 0) |
600 | return nfs_return_empty_page(page); | |
de05a0cc | 601 | |
1da177e4 | 602 | new = nfs_create_request(desc->ctx, inode, page, 0, len); |
de05a0cc TM |
603 | if (IS_ERR(new)) |
604 | goto out_error; | |
605 | ||
1da177e4 | 606 | if (len < PAGE_CACHE_SIZE) |
eebd2aa3 | 607 | zero_user_segment(page, len, PAGE_CACHE_SIZE); |
f8512ad0 FI |
608 | if (!nfs_pageio_add_request(desc->pgio, new)) { |
609 | error = desc->pgio->pg_error; | |
610 | goto out_unlock; | |
611 | } | |
1da177e4 | 612 | return 0; |
de05a0cc TM |
613 | out_error: |
614 | error = PTR_ERR(new); | |
de05a0cc TM |
615 | out_unlock: |
616 | unlock_page(page); | |
617 | return error; | |
1da177e4 LT |
618 | } |
619 | ||
620 | int nfs_readpages(struct file *filp, struct address_space *mapping, | |
621 | struct list_head *pages, unsigned nr_pages) | |
622 | { | |
8b09bee3 | 623 | struct nfs_pageio_descriptor pgio; |
1da177e4 | 624 | struct nfs_readdesc desc = { |
8b09bee3 | 625 | .pgio = &pgio, |
1da177e4 LT |
626 | }; |
627 | struct inode *inode = mapping->host; | |
8b09bee3 | 628 | unsigned long npages; |
5f004cf2 | 629 | int ret = -ESTALE; |
1da177e4 LT |
630 | |
631 | dprintk("NFS: nfs_readpages (%s/%Ld %d)\n", | |
632 | inode->i_sb->s_id, | |
633 | (long long)NFS_FILEID(inode), | |
634 | nr_pages); | |
91d5b470 | 635 | nfs_inc_stats(inode, NFSIOS_VFSREADPAGES); |
1da177e4 | 636 | |
5f004cf2 TM |
637 | if (NFS_STALE(inode)) |
638 | goto out; | |
639 | ||
1da177e4 | 640 | if (filp == NULL) { |
d530838b | 641 | desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ); |
1da177e4 LT |
642 | if (desc.ctx == NULL) |
643 | return -EBADF; | |
644 | } else | |
cd3758e3 | 645 | desc.ctx = get_nfs_open_context(nfs_file_open_context(filp)); |
9a9fc1c0 DH |
646 | |
647 | /* attempt to read as many of the pages as possible from the cache | |
648 | * - this returns -ENOBUFS immediately if the cookie is negative | |
649 | */ | |
650 | ret = nfs_readpages_from_fscache(desc.ctx, inode, mapping, | |
651 | pages, &nr_pages); | |
652 | if (ret == 0) | |
653 | goto read_complete; /* all pages were read */ | |
654 | ||
1751c363 | 655 | nfs_pageio_init_read(&pgio, inode); |
8b09bee3 | 656 | |
1da177e4 | 657 | ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc); |
8b09bee3 TM |
658 | |
659 | nfs_pageio_complete(&pgio); | |
660 | npages = (pgio.pg_bytes_written + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; | |
661 | nfs_add_stats(inode, NFSIOS_READPAGES, npages); | |
9a9fc1c0 | 662 | read_complete: |
1da177e4 | 663 | put_nfs_open_context(desc.ctx); |
5f004cf2 | 664 | out: |
1da177e4 LT |
665 | return ret; |
666 | } | |
667 | ||
f7b422b1 | 668 | int __init nfs_init_readpagecache(void) |
1da177e4 LT |
669 | { |
670 | nfs_rdata_cachep = kmem_cache_create("nfs_read_data", | |
cd841605 | 671 | sizeof(struct nfs_read_header), |
1da177e4 | 672 | 0, SLAB_HWCACHE_ALIGN, |
20c2df83 | 673 | NULL); |
1da177e4 LT |
674 | if (nfs_rdata_cachep == NULL) |
675 | return -ENOMEM; | |
676 | ||
1da177e4 LT |
677 | return 0; |
678 | } | |
679 | ||
266bee88 | 680 | void nfs_destroy_readpagecache(void) |
1da177e4 | 681 | { |
1a1d92c1 | 682 | kmem_cache_destroy(nfs_rdata_cachep); |
1da177e4 | 683 | } |