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> | |
64419a9b | 21 | #include <linux/module.h> |
1da177e4 | 22 | |
f11c88af | 23 | #include "nfs4_fs.h" |
49a70f27 | 24 | #include "internal.h" |
91d5b470 | 25 | #include "iostat.h" |
9a9fc1c0 | 26 | #include "fscache.h" |
91d5b470 | 27 | |
1da177e4 LT |
28 | #define NFSDBG_FACILITY NFSDBG_PAGECACHE |
29 | ||
1751c363 | 30 | static const struct nfs_pageio_ops nfs_pageio_read_ops; |
4db6e0b7 | 31 | static const struct rpc_call_ops nfs_read_common_ops; |
061ae2ed | 32 | static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops; |
1da177e4 | 33 | |
e18b890b | 34 | static struct kmem_cache *nfs_rdata_cachep; |
1da177e4 | 35 | |
1385b811 | 36 | struct nfs_read_header *nfs_readhdr_alloc(void) |
3feb2d49 | 37 | { |
4db6e0b7 | 38 | struct nfs_read_header *rhdr; |
3feb2d49 | 39 | |
4db6e0b7 FI |
40 | rhdr = kmem_cache_zalloc(nfs_rdata_cachep, GFP_KERNEL); |
41 | if (rhdr) { | |
42 | struct nfs_pgio_header *hdr = &rhdr->header; | |
cd841605 FI |
43 | |
44 | INIT_LIST_HEAD(&hdr->pages); | |
4db6e0b7 FI |
45 | INIT_LIST_HEAD(&hdr->rpc_list); |
46 | spin_lock_init(&hdr->lock); | |
47 | atomic_set(&hdr->refcnt, 0); | |
48 | } | |
49 | return rhdr; | |
50 | } | |
89d77c8f | 51 | EXPORT_SYMBOL_GPL(nfs_readhdr_alloc); |
4db6e0b7 | 52 | |
584aa810 FI |
53 | static struct nfs_read_data *nfs_readdata_alloc(struct nfs_pgio_header *hdr, |
54 | unsigned int pagecount) | |
4db6e0b7 FI |
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 | 83 | } |
89d77c8f | 84 | EXPORT_SYMBOL_GPL(nfs_readhdr_free); |
3feb2d49 | 85 | |
493292dd | 86 | void nfs_readdata_release(struct nfs_read_data *rdata) |
1da177e4 | 87 | { |
4db6e0b7 FI |
88 | struct nfs_pgio_header *hdr = rdata->header; |
89 | struct nfs_read_header *read_header = container_of(hdr, struct nfs_read_header, header); | |
90 | ||
383ba719 | 91 | put_nfs_open_context(rdata->args.context); |
30dd374f FI |
92 | if (rdata->pages.pagevec != rdata->pages.page_array) |
93 | kfree(rdata->pages.pagevec); | |
6db6dd7d | 94 | if (rdata == &read_header->rpc_data) { |
4db6e0b7 | 95 | rdata->header = NULL; |
6db6dd7d TM |
96 | rdata = NULL; |
97 | } | |
4db6e0b7 | 98 | if (atomic_dec_and_test(&hdr->refcnt)) |
061ae2ed | 99 | hdr->completion_ops->completion(hdr); |
6db6dd7d TM |
100 | /* Note: we only free the rpc_task after callbacks are done. |
101 | * See the comment in rpc_free_task() for why | |
102 | */ | |
103 | kfree(rdata); | |
1da177e4 | 104 | } |
89d77c8f | 105 | EXPORT_SYMBOL_GPL(nfs_readdata_release); |
1da177e4 | 106 | |
1da177e4 LT |
107 | static |
108 | int nfs_return_empty_page(struct page *page) | |
109 | { | |
eebd2aa3 | 110 | zero_user(page, 0, PAGE_CACHE_SIZE); |
1da177e4 LT |
111 | SetPageUptodate(page); |
112 | unlock_page(page); | |
113 | return 0; | |
114 | } | |
115 | ||
1abb5088 | 116 | void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio, |
061ae2ed FI |
117 | struct inode *inode, |
118 | const struct nfs_pgio_completion_ops *compl_ops) | |
1751c363 | 119 | { |
061ae2ed | 120 | nfs_pageio_init(pgio, inode, &nfs_pageio_read_ops, compl_ops, |
1751c363 TM |
121 | NFS_SERVER(inode)->rsize, 0); |
122 | } | |
ddda8e0a | 123 | EXPORT_SYMBOL_GPL(nfs_pageio_init_read); |
1751c363 | 124 | |
493292dd TM |
125 | void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio) |
126 | { | |
127 | pgio->pg_ops = &nfs_pageio_read_ops; | |
128 | pgio->pg_bsize = NFS_SERVER(pgio->pg_inode)->rsize; | |
129 | } | |
1f945357 | 130 | EXPORT_SYMBOL_GPL(nfs_pageio_reset_read_mds); |
493292dd | 131 | |
f42b293d DH |
132 | int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode, |
133 | struct page *page) | |
1da177e4 | 134 | { |
1da177e4 LT |
135 | struct nfs_page *new; |
136 | unsigned int len; | |
c76069bd | 137 | struct nfs_pageio_descriptor pgio; |
1da177e4 | 138 | |
49a70f27 | 139 | len = nfs_page_length(page); |
1da177e4 LT |
140 | if (len == 0) |
141 | return nfs_return_empty_page(page); | |
142 | new = nfs_create_request(ctx, inode, page, 0, len); | |
143 | if (IS_ERR(new)) { | |
144 | unlock_page(page); | |
145 | return PTR_ERR(new); | |
146 | } | |
147 | if (len < PAGE_CACHE_SIZE) | |
eebd2aa3 | 148 | zero_user_segment(page, len, PAGE_CACHE_SIZE); |
1da177e4 | 149 | |
1abb5088 | 150 | NFS_PROTO(inode)->read_pageio_init(&pgio, inode, &nfs_async_read_completion_ops); |
d8007d4d | 151 | nfs_pageio_add_request(&pgio, new); |
1751c363 | 152 | nfs_pageio_complete(&pgio); |
2701d086 | 153 | NFS_I(inode)->read_io += pgio.pg_bytes_written; |
1da177e4 LT |
154 | return 0; |
155 | } | |
156 | ||
157 | static void nfs_readpage_release(struct nfs_page *req) | |
158 | { | |
3d4ff43d | 159 | struct inode *d_inode = req->wb_context->dentry->d_inode; |
7f8e05f6 DH |
160 | |
161 | if (PageUptodate(req->wb_page)) | |
162 | nfs_readpage_to_fscache(d_inode, req->wb_page, 0); | |
163 | ||
1da177e4 LT |
164 | unlock_page(req->wb_page); |
165 | ||
1e8968c5 | 166 | dprintk("NFS: read done (%s/%Lu %d@%Ld)\n", |
3d4ff43d | 167 | req->wb_context->dentry->d_inode->i_sb->s_id, |
1e8968c5 | 168 | (unsigned long long)NFS_FILEID(req->wb_context->dentry->d_inode), |
1da177e4 LT |
169 | req->wb_bytes, |
170 | (long long)req_offset(req)); | |
10d2c46f | 171 | nfs_release_request(req); |
1da177e4 LT |
172 | } |
173 | ||
4db6e0b7 | 174 | /* Note io was page aligned */ |
061ae2ed | 175 | static void nfs_read_completion(struct nfs_pgio_header *hdr) |
4db6e0b7 FI |
176 | { |
177 | unsigned long bytes = 0; | |
178 | ||
179 | if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) | |
180 | goto out; | |
4bd8b010 TM |
181 | while (!list_empty(&hdr->pages)) { |
182 | struct nfs_page *req = nfs_list_entry(hdr->pages.next); | |
183 | struct page *page = req->wb_page; | |
184 | ||
185 | if (test_bit(NFS_IOHDR_EOF, &hdr->flags)) { | |
186 | if (bytes > hdr->good_bytes) | |
187 | zero_user(page, 0, PAGE_SIZE); | |
188 | else if (hdr->good_bytes - bytes < PAGE_SIZE) | |
189 | zero_user_segment(page, | |
190 | hdr->good_bytes & ~PAGE_MASK, | |
191 | PAGE_SIZE); | |
4db6e0b7 | 192 | } |
4bd8b010 TM |
193 | bytes += req->wb_bytes; |
194 | if (test_bit(NFS_IOHDR_ERROR, &hdr->flags)) { | |
4db6e0b7 | 195 | if (bytes <= hdr->good_bytes) |
4bd8b010 TM |
196 | SetPageUptodate(page); |
197 | } else | |
198 | SetPageUptodate(page); | |
199 | nfs_list_remove_request(req); | |
200 | nfs_readpage_release(req); | |
4db6e0b7 FI |
201 | } |
202 | out: | |
203 | hdr->release(hdr); | |
204 | } | |
205 | ||
c5996c4e FI |
206 | int nfs_initiate_read(struct rpc_clnt *clnt, |
207 | struct nfs_read_data *data, | |
9f0ec176 | 208 | const struct rpc_call_ops *call_ops, int flags) |
1da177e4 | 209 | { |
cd841605 | 210 | struct inode *inode = data->header->inode; |
84115e1c | 211 | int swap_flags = IS_SWAPFILE(inode) ? NFS_RPC_SWAPFLAGS : 0; |
07737691 | 212 | struct rpc_task *task; |
bdc7f021 TM |
213 | struct rpc_message msg = { |
214 | .rpc_argp = &data->args, | |
215 | .rpc_resp = &data->res, | |
cd841605 | 216 | .rpc_cred = data->header->cred, |
bdc7f021 | 217 | }; |
84115e1c | 218 | struct rpc_task_setup task_setup_data = { |
07737691 | 219 | .task = &data->task, |
64419a9b | 220 | .rpc_client = clnt, |
bdc7f021 | 221 | .rpc_message = &msg, |
84115e1c TM |
222 | .callback_ops = call_ops, |
223 | .callback_data = data, | |
101070ca | 224 | .workqueue = nfsiod_workqueue, |
9f0ec176 | 225 | .flags = RPC_TASK_ASYNC | swap_flags | flags, |
84115e1c | 226 | }; |
1da177e4 | 227 | |
64419a9b AA |
228 | /* Set up the initial task struct. */ |
229 | NFS_PROTO(inode)->read_setup(data, &msg); | |
230 | ||
1e8968c5 | 231 | dprintk("NFS: %5u initiated read call (req %s/%llu, %u bytes @ " |
64419a9b AA |
232 | "offset %llu)\n", |
233 | data->task.tk_pid, | |
234 | inode->i_sb->s_id, | |
1e8968c5 | 235 | (unsigned long long)NFS_FILEID(inode), |
64419a9b AA |
236 | data->args.count, |
237 | (unsigned long long)data->args.offset); | |
238 | ||
239 | task = rpc_run_task(&task_setup_data); | |
240 | if (IS_ERR(task)) | |
241 | return PTR_ERR(task); | |
242 | rpc_put_task(task); | |
243 | return 0; | |
244 | } | |
dc70d7b3 | 245 | EXPORT_SYMBOL_GPL(nfs_initiate_read); |
64419a9b AA |
246 | |
247 | /* | |
248 | * Set up the NFS read request struct | |
249 | */ | |
4db6e0b7 | 250 | static void nfs_read_rpcsetup(struct nfs_read_data *data, |
6e4efd56 | 251 | unsigned int count, unsigned int offset) |
64419a9b | 252 | { |
4db6e0b7 | 253 | struct nfs_page *req = data->header->req; |
1da177e4 | 254 | |
4db6e0b7 | 255 | data->args.fh = NFS_FH(data->header->inode); |
1da177e4 LT |
256 | data->args.offset = req_offset(req) + offset; |
257 | data->args.pgbase = req->wb_pgbase + offset; | |
30dd374f | 258 | data->args.pages = data->pages.pagevec; |
1da177e4 | 259 | data->args.count = count; |
383ba719 | 260 | data->args.context = get_nfs_open_context(req->wb_context); |
f11ac8db | 261 | data->args.lock_context = req->wb_lock_context; |
1da177e4 LT |
262 | |
263 | data->res.fattr = &data->fattr; | |
264 | data->res.count = count; | |
265 | data->res.eof = 0; | |
0e574af1 | 266 | nfs_fattr_init(&data->fattr); |
6e4efd56 | 267 | } |
1da177e4 | 268 | |
6e4efd56 | 269 | static int nfs_do_read(struct nfs_read_data *data, |
493292dd | 270 | const struct rpc_call_ops *call_ops) |
6e4efd56 | 271 | { |
cd841605 | 272 | struct inode *inode = data->header->inode; |
6e4efd56 | 273 | |
9f0ec176 | 274 | return nfs_initiate_read(NFS_CLIENT(inode), data, call_ops, 0); |
1da177e4 LT |
275 | } |
276 | ||
275acaaf TM |
277 | static int |
278 | nfs_do_multiple_reads(struct list_head *head, | |
493292dd | 279 | const struct rpc_call_ops *call_ops) |
275acaaf TM |
280 | { |
281 | struct nfs_read_data *data; | |
282 | int ret = 0; | |
283 | ||
284 | while (!list_empty(head)) { | |
285 | int ret2; | |
286 | ||
4db6e0b7 | 287 | data = list_first_entry(head, struct nfs_read_data, list); |
275acaaf TM |
288 | list_del_init(&data->list); |
289 | ||
493292dd | 290 | ret2 = nfs_do_read(data, call_ops); |
275acaaf TM |
291 | if (ret == 0) |
292 | ret = ret2; | |
293 | } | |
294 | return ret; | |
295 | } | |
296 | ||
061ae2ed | 297 | static void |
1da177e4 LT |
298 | nfs_async_read_error(struct list_head *head) |
299 | { | |
300 | struct nfs_page *req; | |
301 | ||
302 | while (!list_empty(head)) { | |
303 | req = nfs_list_entry(head->next); | |
304 | nfs_list_remove_request(req); | |
1da177e4 LT |
305 | nfs_readpage_release(req); |
306 | } | |
307 | } | |
308 | ||
061ae2ed FI |
309 | static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops = { |
310 | .error_cleanup = nfs_async_read_error, | |
311 | .completion = nfs_read_completion, | |
312 | }; | |
313 | ||
25b11dcd TM |
314 | static void nfs_pagein_error(struct nfs_pageio_descriptor *desc, |
315 | struct nfs_pgio_header *hdr) | |
316 | { | |
317 | set_bit(NFS_IOHDR_REDO, &hdr->flags); | |
318 | while (!list_empty(&hdr->rpc_list)) { | |
319 | struct nfs_read_data *data = list_first_entry(&hdr->rpc_list, | |
320 | struct nfs_read_data, list); | |
321 | list_del(&data->list); | |
322 | nfs_readdata_release(data); | |
323 | } | |
324 | desc->pg_completion_ops->error_cleanup(&desc->pg_list); | |
325 | } | |
326 | ||
1da177e4 LT |
327 | /* |
328 | * Generate multiple requests to fill a single page. | |
329 | * | |
330 | * We optimize to reduce the number of read operations on the wire. If we | |
331 | * detect that we're reading a page, or an area of a page, that is past the | |
332 | * end of file, we do not generate NFS read operations but just clear the | |
333 | * parts of the page that would have come back zero from the server anyway. | |
334 | * | |
335 | * We rely on the cached value of i_size to make this determination; another | |
336 | * client can fill pages on the server past our cached end-of-file, but we | |
337 | * won't see the new data until our attribute cache is updated. This is more | |
338 | * or less conventional NFS client behavior. | |
339 | */ | |
4db6e0b7 FI |
340 | static int nfs_pagein_multi(struct nfs_pageio_descriptor *desc, |
341 | struct nfs_pgio_header *hdr) | |
1da177e4 | 342 | { |
4db6e0b7 | 343 | struct nfs_page *req = hdr->req; |
1da177e4 LT |
344 | struct page *page = req->wb_page; |
345 | struct nfs_read_data *data; | |
d097971d | 346 | size_t rsize = desc->pg_bsize, nbytes; |
e9f7bee1 | 347 | unsigned int offset; |
1da177e4 | 348 | |
275acaaf | 349 | offset = 0; |
c76069bd | 350 | nbytes = desc->pg_count; |
e9f7bee1 TM |
351 | do { |
352 | size_t len = min(nbytes,rsize); | |
353 | ||
4db6e0b7 | 354 | data = nfs_readdata_alloc(hdr, 1); |
25b11dcd TM |
355 | if (!data) { |
356 | nfs_pagein_error(desc, hdr); | |
357 | return -ENOMEM; | |
358 | } | |
30dd374f | 359 | data->pages.pagevec[0] = page; |
4db6e0b7 FI |
360 | nfs_read_rpcsetup(data, len, offset); |
361 | list_add(&data->list, &hdr->rpc_list); | |
e9f7bee1 | 362 | nbytes -= len; |
275acaaf | 363 | offset += len; |
9146ab50 | 364 | } while (nbytes != 0); |
25b11dcd TM |
365 | |
366 | nfs_list_remove_request(req); | |
367 | nfs_list_add_request(req, &hdr->pages); | |
4db6e0b7 | 368 | desc->pg_rpc_callops = &nfs_read_common_ops; |
9146ab50 | 369 | return 0; |
1da177e4 LT |
370 | } |
371 | ||
4db6e0b7 FI |
372 | static int nfs_pagein_one(struct nfs_pageio_descriptor *desc, |
373 | struct nfs_pgio_header *hdr) | |
1da177e4 LT |
374 | { |
375 | struct nfs_page *req; | |
376 | struct page **pages; | |
4db6e0b7 | 377 | struct nfs_read_data *data; |
c76069bd | 378 | struct list_head *head = &desc->pg_list; |
1da177e4 | 379 | |
4db6e0b7 FI |
380 | data = nfs_readdata_alloc(hdr, nfs_page_array_len(desc->pg_base, |
381 | desc->pg_count)); | |
382 | if (!data) { | |
25b11dcd | 383 | nfs_pagein_error(desc, hdr); |
9146ab50 | 384 | return -ENOMEM; |
bae724ef | 385 | } |
1da177e4 | 386 | |
30dd374f | 387 | pages = data->pages.pagevec; |
1da177e4 LT |
388 | while (!list_empty(head)) { |
389 | req = nfs_list_entry(head->next); | |
390 | nfs_list_remove_request(req); | |
4db6e0b7 | 391 | nfs_list_add_request(req, &hdr->pages); |
1da177e4 | 392 | *pages++ = req->wb_page; |
1da177e4 | 393 | } |
1da177e4 | 394 | |
4db6e0b7 FI |
395 | nfs_read_rpcsetup(data, desc->pg_count, 0); |
396 | list_add(&data->list, &hdr->rpc_list); | |
397 | desc->pg_rpc_callops = &nfs_read_common_ops; | |
9146ab50 | 398 | return 0; |
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 | 407 | } |
89d77c8f | 408 | EXPORT_SYMBOL_GPL(nfs_generic_pagein); |
493292dd TM |
409 | |
410 | static int nfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc) | |
1751c363 | 411 | { |
4db6e0b7 FI |
412 | struct nfs_read_header *rhdr; |
413 | struct nfs_pgio_header *hdr; | |
275acaaf TM |
414 | int ret; |
415 | ||
4db6e0b7 FI |
416 | rhdr = nfs_readhdr_alloc(); |
417 | if (!rhdr) { | |
061ae2ed | 418 | desc->pg_completion_ops->error_cleanup(&desc->pg_list); |
4db6e0b7 FI |
419 | return -ENOMEM; |
420 | } | |
421 | hdr = &rhdr->header; | |
422 | nfs_pgheader_init(desc, hdr, nfs_readhdr_free); | |
423 | atomic_inc(&hdr->refcnt); | |
424 | ret = nfs_generic_pagein(desc, hdr); | |
50828d7e | 425 | if (ret == 0) |
4db6e0b7 FI |
426 | ret = nfs_do_multiple_reads(&hdr->rpc_list, |
427 | desc->pg_rpc_callops); | |
4db6e0b7 | 428 | if (atomic_dec_and_test(&hdr->refcnt)) |
061ae2ed | 429 | hdr->completion_ops->completion(hdr); |
275acaaf | 430 | return ret; |
1751c363 | 431 | } |
1751c363 TM |
432 | |
433 | static const struct nfs_pageio_ops nfs_pageio_read_ops = { | |
434 | .pg_test = nfs_generic_pg_test, | |
435 | .pg_doio = nfs_generic_pg_readpages, | |
436 | }; | |
437 | ||
0b671301 TM |
438 | /* |
439 | * This is the callback from RPC telling us whether a reply was | |
440 | * received or some error occurred (timeout or socket shutdown). | |
441 | */ | |
442 | int nfs_readpage_result(struct rpc_task *task, struct nfs_read_data *data) | |
443 | { | |
cd841605 | 444 | struct inode *inode = data->header->inode; |
0b671301 TM |
445 | int status; |
446 | ||
3110ff80 | 447 | dprintk("NFS: %s: %5u, (status %d)\n", __func__, task->tk_pid, |
0b671301 TM |
448 | task->tk_status); |
449 | ||
cd841605 | 450 | status = NFS_PROTO(inode)->read_done(task, data); |
0b671301 TM |
451 | if (status != 0) |
452 | return status; | |
453 | ||
cd841605 | 454 | nfs_add_stats(inode, NFSIOS_SERVERREADBYTES, data->res.count); |
0b671301 TM |
455 | |
456 | if (task->tk_status == -ESTALE) { | |
cd841605 FI |
457 | set_bit(NFS_INO_STALE, &NFS_I(inode)->flags); |
458 | nfs_mark_for_revalidate(inode); | |
0b671301 | 459 | } |
0b671301 TM |
460 | return 0; |
461 | } | |
462 | ||
fdd1e74c | 463 | static void nfs_readpage_retry(struct rpc_task *task, struct nfs_read_data *data) |
0b671301 TM |
464 | { |
465 | struct nfs_readargs *argp = &data->args; | |
466 | struct nfs_readres *resp = &data->res; | |
467 | ||
0b671301 | 468 | /* This is a short read! */ |
cd841605 | 469 | nfs_inc_stats(data->header->inode, NFSIOS_SHORTREAD); |
0b671301 | 470 | /* Has the server at least made some progress? */ |
4db6e0b7 FI |
471 | if (resp->count == 0) { |
472 | nfs_set_pgio_error(data->header, -EIO, argp->offset); | |
d61e612a | 473 | return; |
4db6e0b7 | 474 | } |
0b671301 | 475 | /* Yes, so retry the read at the end of the data */ |
cbdabc7f | 476 | data->mds_offset += resp->count; |
0b671301 TM |
477 | argp->offset += resp->count; |
478 | argp->pgbase += resp->count; | |
479 | argp->count -= resp->count; | |
d00c5d43 | 480 | rpc_restart_call_prepare(task); |
0b671301 TM |
481 | } |
482 | ||
4db6e0b7 | 483 | static void nfs_readpage_result_common(struct rpc_task *task, void *calldata) |
1da177e4 | 484 | { |
ec06c096 | 485 | struct nfs_read_data *data = calldata; |
4db6e0b7 FI |
486 | struct nfs_pgio_header *hdr = data->header; |
487 | ||
488 | /* Note the only returns of nfs_readpage_result are 0 and -EAGAIN */ | |
ec06c096 TM |
489 | if (nfs_readpage_result(task, data) != 0) |
490 | return; | |
fdd1e74c | 491 | if (task->tk_status < 0) |
4db6e0b7 FI |
492 | nfs_set_pgio_error(hdr, task->tk_status, data->args.offset); |
493 | else if (data->res.eof) { | |
494 | loff_t bound; | |
495 | ||
496 | bound = data->args.offset + data->res.count; | |
497 | spin_lock(&hdr->lock); | |
498 | if (bound < hdr->io_start + hdr->good_bytes) { | |
499 | set_bit(NFS_IOHDR_EOF, &hdr->flags); | |
500 | clear_bit(NFS_IOHDR_ERROR, &hdr->flags); | |
501 | hdr->good_bytes = bound - hdr->io_start; | |
502 | } | |
503 | spin_unlock(&hdr->lock); | |
504 | } else if (data->res.count != data->args.count) | |
505 | nfs_readpage_retry(task, data); | |
fdd1e74c TM |
506 | } |
507 | ||
4db6e0b7 | 508 | static void nfs_readpage_release_common(void *calldata) |
fdd1e74c | 509 | { |
4db6e0b7 | 510 | nfs_readdata_release(calldata); |
1da177e4 LT |
511 | } |
512 | ||
f11c88af AA |
513 | void nfs_read_prepare(struct rpc_task *task, void *calldata) |
514 | { | |
515 | struct nfs_read_data *data = calldata; | |
ef1820f9 N |
516 | int err; |
517 | err = NFS_PROTO(data->header->inode)->read_rpc_prepare(task, data); | |
518 | if (err) | |
519 | rpc_exit(task, err); | |
f11c88af | 520 | } |
f11c88af | 521 | |
4db6e0b7 | 522 | static const struct rpc_call_ops nfs_read_common_ops = { |
f11c88af | 523 | .rpc_call_prepare = nfs_read_prepare, |
4db6e0b7 FI |
524 | .rpc_call_done = nfs_readpage_result_common, |
525 | .rpc_release = nfs_readpage_release_common, | |
ec06c096 TM |
526 | }; |
527 | ||
1da177e4 LT |
528 | /* |
529 | * Read a page over NFS. | |
530 | * We read the page synchronously in the following case: | |
531 | * - The error flag is set for this page. This happens only when a | |
532 | * previous async read operation failed. | |
533 | */ | |
534 | int nfs_readpage(struct file *file, struct page *page) | |
535 | { | |
536 | struct nfs_open_context *ctx; | |
d56b4ddf | 537 | struct inode *inode = page_file_mapping(page)->host; |
1da177e4 LT |
538 | int error; |
539 | ||
540 | dprintk("NFS: nfs_readpage (%p %ld@%lu)\n", | |
d56b4ddf | 541 | page, PAGE_CACHE_SIZE, page_file_index(page)); |
91d5b470 CL |
542 | nfs_inc_stats(inode, NFSIOS_VFSREADPAGE); |
543 | nfs_add_stats(inode, NFSIOS_READPAGES, 1); | |
544 | ||
1da177e4 LT |
545 | /* |
546 | * Try to flush any pending writes to the file.. | |
547 | * | |
548 | * NOTE! Because we own the page lock, there cannot | |
549 | * be any new pending writes generated at this point | |
550 | * for this page (other pages can be written to). | |
551 | */ | |
552 | error = nfs_wb_page(inode, page); | |
553 | if (error) | |
de05a0cc TM |
554 | goto out_unlock; |
555 | if (PageUptodate(page)) | |
556 | goto out_unlock; | |
1da177e4 | 557 | |
5f004cf2 TM |
558 | error = -ESTALE; |
559 | if (NFS_STALE(inode)) | |
de05a0cc | 560 | goto out_unlock; |
5f004cf2 | 561 | |
1da177e4 | 562 | if (file == NULL) { |
cf1308ff | 563 | error = -EBADF; |
d530838b | 564 | ctx = nfs_find_open_context(inode, NULL, FMODE_READ); |
1da177e4 | 565 | if (ctx == NULL) |
de05a0cc | 566 | goto out_unlock; |
1da177e4 | 567 | } else |
cd3758e3 | 568 | ctx = get_nfs_open_context(nfs_file_open_context(file)); |
1da177e4 | 569 | |
9a9fc1c0 DH |
570 | if (!IS_SYNC(inode)) { |
571 | error = nfs_readpage_from_fscache(ctx, inode, page); | |
572 | if (error == 0) | |
573 | goto out; | |
574 | } | |
575 | ||
8e0969f0 TM |
576 | error = nfs_readpage_async(ctx, inode, page); |
577 | ||
9a9fc1c0 | 578 | out: |
1da177e4 LT |
579 | put_nfs_open_context(ctx); |
580 | return error; | |
de05a0cc | 581 | out_unlock: |
1da177e4 LT |
582 | unlock_page(page); |
583 | return error; | |
584 | } | |
585 | ||
586 | struct nfs_readdesc { | |
8b09bee3 | 587 | struct nfs_pageio_descriptor *pgio; |
1da177e4 LT |
588 | struct nfs_open_context *ctx; |
589 | }; | |
590 | ||
591 | static int | |
592 | readpage_async_filler(void *data, struct page *page) | |
593 | { | |
594 | struct nfs_readdesc *desc = (struct nfs_readdesc *)data; | |
d56b4ddf | 595 | struct inode *inode = page_file_mapping(page)->host; |
1da177e4 LT |
596 | struct nfs_page *new; |
597 | unsigned int len; | |
de05a0cc TM |
598 | int error; |
599 | ||
49a70f27 | 600 | len = nfs_page_length(page); |
1da177e4 LT |
601 | if (len == 0) |
602 | return nfs_return_empty_page(page); | |
de05a0cc | 603 | |
1da177e4 | 604 | new = nfs_create_request(desc->ctx, inode, page, 0, len); |
de05a0cc TM |
605 | if (IS_ERR(new)) |
606 | goto out_error; | |
607 | ||
1da177e4 | 608 | if (len < PAGE_CACHE_SIZE) |
eebd2aa3 | 609 | zero_user_segment(page, len, PAGE_CACHE_SIZE); |
f8512ad0 FI |
610 | if (!nfs_pageio_add_request(desc->pgio, new)) { |
611 | error = desc->pgio->pg_error; | |
612 | goto out_unlock; | |
613 | } | |
1da177e4 | 614 | return 0; |
de05a0cc TM |
615 | out_error: |
616 | error = PTR_ERR(new); | |
de05a0cc TM |
617 | out_unlock: |
618 | unlock_page(page); | |
619 | return error; | |
1da177e4 LT |
620 | } |
621 | ||
622 | int nfs_readpages(struct file *filp, struct address_space *mapping, | |
623 | struct list_head *pages, unsigned nr_pages) | |
624 | { | |
8b09bee3 | 625 | struct nfs_pageio_descriptor pgio; |
1da177e4 | 626 | struct nfs_readdesc desc = { |
8b09bee3 | 627 | .pgio = &pgio, |
1da177e4 LT |
628 | }; |
629 | struct inode *inode = mapping->host; | |
8b09bee3 | 630 | unsigned long npages; |
5f004cf2 | 631 | int ret = -ESTALE; |
1da177e4 | 632 | |
1e8968c5 | 633 | dprintk("NFS: nfs_readpages (%s/%Lu %d)\n", |
1da177e4 | 634 | inode->i_sb->s_id, |
1e8968c5 | 635 | (unsigned long long)NFS_FILEID(inode), |
1da177e4 | 636 | nr_pages); |
91d5b470 | 637 | nfs_inc_stats(inode, NFSIOS_VFSREADPAGES); |
1da177e4 | 638 | |
5f004cf2 TM |
639 | if (NFS_STALE(inode)) |
640 | goto out; | |
641 | ||
1da177e4 | 642 | if (filp == NULL) { |
d530838b | 643 | desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ); |
1da177e4 LT |
644 | if (desc.ctx == NULL) |
645 | return -EBADF; | |
646 | } else | |
cd3758e3 | 647 | desc.ctx = get_nfs_open_context(nfs_file_open_context(filp)); |
9a9fc1c0 DH |
648 | |
649 | /* attempt to read as many of the pages as possible from the cache | |
650 | * - this returns -ENOBUFS immediately if the cookie is negative | |
651 | */ | |
652 | ret = nfs_readpages_from_fscache(desc.ctx, inode, mapping, | |
653 | pages, &nr_pages); | |
654 | if (ret == 0) | |
655 | goto read_complete; /* all pages were read */ | |
656 | ||
1abb5088 | 657 | NFS_PROTO(inode)->read_pageio_init(&pgio, inode, &nfs_async_read_completion_ops); |
8b09bee3 | 658 | |
1da177e4 | 659 | ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc); |
8b09bee3 TM |
660 | |
661 | nfs_pageio_complete(&pgio); | |
2701d086 | 662 | NFS_I(inode)->read_io += pgio.pg_bytes_written; |
8b09bee3 TM |
663 | npages = (pgio.pg_bytes_written + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
664 | nfs_add_stats(inode, NFSIOS_READPAGES, npages); | |
9a9fc1c0 | 665 | read_complete: |
1da177e4 | 666 | put_nfs_open_context(desc.ctx); |
5f004cf2 | 667 | out: |
1da177e4 LT |
668 | return ret; |
669 | } | |
670 | ||
f7b422b1 | 671 | int __init nfs_init_readpagecache(void) |
1da177e4 LT |
672 | { |
673 | nfs_rdata_cachep = kmem_cache_create("nfs_read_data", | |
cd841605 | 674 | sizeof(struct nfs_read_header), |
1da177e4 | 675 | 0, SLAB_HWCACHE_ALIGN, |
20c2df83 | 676 | NULL); |
1da177e4 LT |
677 | if (nfs_rdata_cachep == NULL) |
678 | return -ENOMEM; | |
679 | ||
1da177e4 LT |
680 | return 0; |
681 | } | |
682 | ||
266bee88 | 683 | void nfs_destroy_readpagecache(void) |
1da177e4 | 684 | { |
1a1d92c1 | 685 | kmem_cache_destroy(nfs_rdata_cachep); |
1da177e4 | 686 | } |