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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> | |
1da177e4 LT |
21 | |
22 | #include <asm/system.h> | |
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 | ||
bae724ef FI |
32 | static int nfs_pagein_multi(struct inode *, struct list_head *, unsigned int, size_t, int, struct pnfs_layout_segment *); |
33 | static int nfs_pagein_one(struct inode *, struct list_head *, unsigned int, size_t, int, struct pnfs_layout_segment *); | |
ec06c096 TM |
34 | static const struct rpc_call_ops nfs_read_partial_ops; |
35 | static const struct rpc_call_ops nfs_read_full_ops; | |
1da177e4 | 36 | |
e18b890b | 37 | static struct kmem_cache *nfs_rdata_cachep; |
3feb2d49 | 38 | static mempool_t *nfs_rdata_mempool; |
1da177e4 LT |
39 | |
40 | #define MIN_POOL_READ (32) | |
41 | ||
8d5658c9 | 42 | struct nfs_read_data *nfs_readdata_alloc(unsigned int pagecount) |
3feb2d49 | 43 | { |
93870d76 | 44 | struct nfs_read_data *p = mempool_alloc(nfs_rdata_mempool, GFP_KERNEL); |
3feb2d49 TM |
45 | |
46 | if (p) { | |
47 | memset(p, 0, sizeof(*p)); | |
48 | INIT_LIST_HEAD(&p->pages); | |
e9f7bee1 | 49 | p->npages = pagecount; |
0d0b5cb3 CL |
50 | if (pagecount <= ARRAY_SIZE(p->page_array)) |
51 | p->pagevec = p->page_array; | |
3feb2d49 | 52 | else { |
93870d76 | 53 | p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_KERNEL); |
0d0b5cb3 | 54 | if (!p->pagevec) { |
3feb2d49 TM |
55 | mempool_free(p, nfs_rdata_mempool); |
56 | p = NULL; | |
57 | } | |
58 | } | |
59 | } | |
60 | return p; | |
61 | } | |
62 | ||
1ae88b2e | 63 | void nfs_readdata_free(struct nfs_read_data *p) |
3feb2d49 TM |
64 | { |
65 | if (p && (p->pagevec != &p->page_array[0])) | |
66 | kfree(p->pagevec); | |
67 | mempool_free(p, nfs_rdata_mempool); | |
68 | } | |
69 | ||
1ae88b2e | 70 | static void nfs_readdata_release(struct nfs_read_data *rdata) |
1da177e4 | 71 | { |
bae724ef | 72 | put_lseg(rdata->lseg); |
383ba719 TM |
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) |
bae724ef | 135 | nfs_pagein_multi(inode, &one_request, 1, len, 0, NULL); |
bcb71bba | 136 | else |
bae724ef | 137 | nfs_pagein_one(inode, &one_request, 1, len, 0, NULL); |
1da177e4 LT |
138 | return 0; |
139 | } | |
140 | ||
141 | static void nfs_readpage_release(struct nfs_page *req) | |
142 | { | |
7f8e05f6 DH |
143 | struct inode *d_inode = req->wb_context->path.dentry->d_inode; |
144 | ||
145 | if (PageUptodate(req->wb_page)) | |
146 | nfs_readpage_to_fscache(d_inode, req->wb_page, 0); | |
147 | ||
1da177e4 LT |
148 | unlock_page(req->wb_page); |
149 | ||
1da177e4 | 150 | dprintk("NFS: read done (%s/%Ld %d@%Ld)\n", |
88be9f99 TM |
151 | req->wb_context->path.dentry->d_inode->i_sb->s_id, |
152 | (long long)NFS_FILEID(req->wb_context->path.dentry->d_inode), | |
1da177e4 LT |
153 | req->wb_bytes, |
154 | (long long)req_offset(req)); | |
10d2c46f | 155 | nfs_release_request(req); |
1da177e4 LT |
156 | } |
157 | ||
158 | /* | |
159 | * Set up the NFS read request struct | |
160 | */ | |
dbae4c73 | 161 | static int nfs_read_rpcsetup(struct nfs_page *req, struct nfs_read_data *data, |
ec06c096 | 162 | const struct rpc_call_ops *call_ops, |
bae724ef FI |
163 | unsigned int count, unsigned int offset, |
164 | struct pnfs_layout_segment *lseg) | |
1da177e4 | 165 | { |
84115e1c TM |
166 | struct inode *inode = req->wb_context->path.dentry->d_inode; |
167 | int swap_flags = IS_SWAPFILE(inode) ? NFS_RPC_SWAPFLAGS : 0; | |
07737691 | 168 | struct rpc_task *task; |
bdc7f021 TM |
169 | struct rpc_message msg = { |
170 | .rpc_argp = &data->args, | |
171 | .rpc_resp = &data->res, | |
172 | .rpc_cred = req->wb_context->cred, | |
173 | }; | |
84115e1c | 174 | struct rpc_task_setup task_setup_data = { |
07737691 | 175 | .task = &data->task, |
84115e1c | 176 | .rpc_client = NFS_CLIENT(inode), |
bdc7f021 | 177 | .rpc_message = &msg, |
84115e1c TM |
178 | .callback_ops = call_ops, |
179 | .callback_data = data, | |
101070ca | 180 | .workqueue = nfsiod_workqueue, |
84115e1c TM |
181 | .flags = RPC_TASK_ASYNC | swap_flags, |
182 | }; | |
1da177e4 LT |
183 | |
184 | data->req = req; | |
84115e1c | 185 | data->inode = inode; |
bdc7f021 | 186 | data->cred = msg.rpc_cred; |
bae724ef | 187 | data->lseg = get_lseg(lseg); |
1da177e4 LT |
188 | |
189 | data->args.fh = NFS_FH(inode); | |
190 | data->args.offset = req_offset(req) + offset; | |
191 | data->args.pgbase = req->wb_pgbase + offset; | |
192 | data->args.pages = data->pagevec; | |
193 | data->args.count = count; | |
383ba719 | 194 | data->args.context = get_nfs_open_context(req->wb_context); |
f11ac8db | 195 | data->args.lock_context = req->wb_lock_context; |
1da177e4 LT |
196 | |
197 | data->res.fattr = &data->fattr; | |
198 | data->res.count = count; | |
199 | data->res.eof = 0; | |
0e574af1 | 200 | nfs_fattr_init(&data->fattr); |
1da177e4 | 201 | |
ec06c096 | 202 | /* Set up the initial task struct. */ |
bdc7f021 | 203 | NFS_PROTO(inode)->read_setup(data, &msg); |
1da177e4 | 204 | |
a3f565b1 | 205 | dprintk("NFS: %5u initiated read call (req %s/%Ld, %u bytes @ offset %Lu)\n", |
1da177e4 LT |
206 | data->task.tk_pid, |
207 | inode->i_sb->s_id, | |
208 | (long long)NFS_FILEID(inode), | |
209 | count, | |
210 | (unsigned long long)data->args.offset); | |
bdc7f021 | 211 | |
07737691 | 212 | task = rpc_run_task(&task_setup_data); |
dbae4c73 TM |
213 | if (IS_ERR(task)) |
214 | return PTR_ERR(task); | |
215 | rpc_put_task(task); | |
216 | return 0; | |
1da177e4 LT |
217 | } |
218 | ||
219 | static void | |
220 | nfs_async_read_error(struct list_head *head) | |
221 | { | |
222 | struct nfs_page *req; | |
223 | ||
224 | while (!list_empty(head)) { | |
225 | req = nfs_list_entry(head->next); | |
226 | nfs_list_remove_request(req); | |
227 | SetPageError(req->wb_page); | |
228 | nfs_readpage_release(req); | |
229 | } | |
230 | } | |
231 | ||
1da177e4 LT |
232 | /* |
233 | * Generate multiple requests to fill a single page. | |
234 | * | |
235 | * We optimize to reduce the number of read operations on the wire. If we | |
236 | * detect that we're reading a page, or an area of a page, that is past the | |
237 | * end of file, we do not generate NFS read operations but just clear the | |
238 | * parts of the page that would have come back zero from the server anyway. | |
239 | * | |
240 | * We rely on the cached value of i_size to make this determination; another | |
241 | * client can fill pages on the server past our cached end-of-file, but we | |
242 | * won't see the new data until our attribute cache is updated. This is more | |
243 | * or less conventional NFS client behavior. | |
244 | */ | |
bae724ef | 245 | static int nfs_pagein_multi(struct inode *inode, struct list_head *head, unsigned int npages, size_t count, int flags, struct pnfs_layout_segment *lseg) |
1da177e4 LT |
246 | { |
247 | struct nfs_page *req = nfs_list_entry(head->next); | |
248 | struct page *page = req->wb_page; | |
249 | struct nfs_read_data *data; | |
e9f7bee1 TM |
250 | size_t rsize = NFS_SERVER(inode)->rsize, nbytes; |
251 | unsigned int offset; | |
1da177e4 | 252 | int requests = 0; |
dbae4c73 | 253 | int ret = 0; |
1da177e4 LT |
254 | LIST_HEAD(list); |
255 | ||
256 | nfs_list_remove_request(req); | |
257 | ||
bcb71bba | 258 | nbytes = count; |
e9f7bee1 TM |
259 | do { |
260 | size_t len = min(nbytes,rsize); | |
261 | ||
8d5658c9 | 262 | data = nfs_readdata_alloc(1); |
1da177e4 LT |
263 | if (!data) |
264 | goto out_bad; | |
1da177e4 LT |
265 | list_add(&data->pages, &list); |
266 | requests++; | |
e9f7bee1 TM |
267 | nbytes -= len; |
268 | } while(nbytes != 0); | |
1da177e4 LT |
269 | atomic_set(&req->wb_complete, requests); |
270 | ||
bae724ef FI |
271 | /* We know lseg==NULL */ |
272 | lseg = pnfs_update_layout(inode, req->wb_context, IOMODE_READ); | |
1da177e4 LT |
273 | ClearPageError(page); |
274 | offset = 0; | |
bcb71bba | 275 | nbytes = count; |
1da177e4 | 276 | do { |
dbae4c73 TM |
277 | int ret2; |
278 | ||
1da177e4 LT |
279 | data = list_entry(list.next, struct nfs_read_data, pages); |
280 | list_del_init(&data->pages); | |
281 | ||
282 | data->pagevec[0] = page; | |
1da177e4 | 283 | |
bcb71bba TM |
284 | if (nbytes < rsize) |
285 | rsize = nbytes; | |
dbae4c73 | 286 | ret2 = nfs_read_rpcsetup(req, data, &nfs_read_partial_ops, |
bae724ef | 287 | rsize, offset, lseg); |
dbae4c73 TM |
288 | if (ret == 0) |
289 | ret = ret2; | |
bcb71bba TM |
290 | offset += rsize; |
291 | nbytes -= rsize; | |
1da177e4 | 292 | } while (nbytes != 0); |
bae724ef | 293 | put_lseg(lseg); |
1da177e4 | 294 | |
dbae4c73 | 295 | return ret; |
1da177e4 LT |
296 | |
297 | out_bad: | |
298 | while (!list_empty(&list)) { | |
299 | data = list_entry(list.next, struct nfs_read_data, pages); | |
300 | list_del(&data->pages); | |
301 | nfs_readdata_free(data); | |
302 | } | |
303 | SetPageError(page); | |
304 | nfs_readpage_release(req); | |
305 | return -ENOMEM; | |
306 | } | |
307 | ||
bae724ef | 308 | static int nfs_pagein_one(struct inode *inode, struct list_head *head, unsigned int npages, size_t count, int flags, struct pnfs_layout_segment *lseg) |
1da177e4 LT |
309 | { |
310 | struct nfs_page *req; | |
311 | struct page **pages; | |
312 | struct nfs_read_data *data; | |
dbae4c73 | 313 | int ret = -ENOMEM; |
1da177e4 | 314 | |
8d5658c9 | 315 | data = nfs_readdata_alloc(npages); |
bae724ef FI |
316 | if (!data) { |
317 | nfs_async_read_error(head); | |
318 | goto out; | |
319 | } | |
1da177e4 | 320 | |
1da177e4 | 321 | pages = data->pagevec; |
1da177e4 LT |
322 | while (!list_empty(head)) { |
323 | req = nfs_list_entry(head->next); | |
324 | nfs_list_remove_request(req); | |
325 | nfs_list_add_request(req, &data->pages); | |
326 | ClearPageError(req->wb_page); | |
327 | *pages++ = req->wb_page; | |
1da177e4 LT |
328 | } |
329 | req = nfs_list_entry(data->pages.next); | |
bae724ef FI |
330 | if ((!lseg) && list_is_singular(&data->pages)) |
331 | lseg = pnfs_update_layout(inode, req->wb_context, IOMODE_READ); | |
1da177e4 | 332 | |
bae724ef FI |
333 | ret = nfs_read_rpcsetup(req, data, &nfs_read_full_ops, count, 0, lseg); |
334 | out: | |
335 | put_lseg(lseg); | |
dbae4c73 | 336 | return ret; |
1da177e4 LT |
337 | } |
338 | ||
0b671301 TM |
339 | /* |
340 | * This is the callback from RPC telling us whether a reply was | |
341 | * received or some error occurred (timeout or socket shutdown). | |
342 | */ | |
343 | int nfs_readpage_result(struct rpc_task *task, struct nfs_read_data *data) | |
344 | { | |
345 | int status; | |
346 | ||
3110ff80 | 347 | dprintk("NFS: %s: %5u, (status %d)\n", __func__, task->tk_pid, |
0b671301 TM |
348 | task->tk_status); |
349 | ||
350 | status = NFS_PROTO(data->inode)->read_done(task, data); | |
351 | if (status != 0) | |
352 | return status; | |
353 | ||
354 | nfs_add_stats(data->inode, NFSIOS_SERVERREADBYTES, data->res.count); | |
355 | ||
356 | if (task->tk_status == -ESTALE) { | |
3a10c30a | 357 | set_bit(NFS_INO_STALE, &NFS_I(data->inode)->flags); |
0b671301 TM |
358 | nfs_mark_for_revalidate(data->inode); |
359 | } | |
0b671301 TM |
360 | return 0; |
361 | } | |
362 | ||
fdd1e74c | 363 | static void nfs_readpage_retry(struct rpc_task *task, struct nfs_read_data *data) |
0b671301 TM |
364 | { |
365 | struct nfs_readargs *argp = &data->args; | |
366 | struct nfs_readres *resp = &data->res; | |
367 | ||
368 | if (resp->eof || resp->count == argp->count) | |
d61e612a | 369 | return; |
0b671301 TM |
370 | |
371 | /* This is a short read! */ | |
372 | nfs_inc_stats(data->inode, NFSIOS_SHORTREAD); | |
373 | /* Has the server at least made some progress? */ | |
374 | if (resp->count == 0) | |
d61e612a | 375 | return; |
0b671301 TM |
376 | |
377 | /* Yes, so retry the read at the end of the data */ | |
378 | argp->offset += resp->count; | |
379 | argp->pgbase += resp->count; | |
380 | argp->count -= resp->count; | |
0110ee15 | 381 | nfs_restart_rpc(task, NFS_SERVER(data->inode)->nfs_client); |
0b671301 TM |
382 | } |
383 | ||
1da177e4 LT |
384 | /* |
385 | * Handle a read reply that fills part of a page. | |
386 | */ | |
ec06c096 | 387 | static void nfs_readpage_result_partial(struct rpc_task *task, void *calldata) |
1da177e4 | 388 | { |
ec06c096 | 389 | struct nfs_read_data *data = calldata; |
1da177e4 | 390 | |
ec06c096 TM |
391 | if (nfs_readpage_result(task, data) != 0) |
392 | return; | |
fdd1e74c TM |
393 | if (task->tk_status < 0) |
394 | return; | |
0b671301 | 395 | |
fdd1e74c TM |
396 | nfs_readpage_truncate_uninitialised_page(data); |
397 | nfs_readpage_retry(task, data); | |
398 | } | |
399 | ||
400 | static void nfs_readpage_release_partial(void *calldata) | |
401 | { | |
402 | struct nfs_read_data *data = calldata; | |
403 | struct nfs_page *req = data->req; | |
404 | struct page *page = req->wb_page; | |
405 | int status = data->task.tk_status; | |
406 | ||
407 | if (status < 0) | |
0b671301 | 408 | SetPageError(page); |
fdd1e74c | 409 | |
1da177e4 LT |
410 | if (atomic_dec_and_test(&req->wb_complete)) { |
411 | if (!PageError(page)) | |
412 | SetPageUptodate(page); | |
413 | nfs_readpage_release(req); | |
414 | } | |
fdd1e74c | 415 | nfs_readdata_release(calldata); |
1da177e4 LT |
416 | } |
417 | ||
f11c88af AA |
418 | #if defined(CONFIG_NFS_V4_1) |
419 | void nfs_read_prepare(struct rpc_task *task, void *calldata) | |
420 | { | |
421 | struct nfs_read_data *data = calldata; | |
422 | ||
035168ab | 423 | if (nfs4_setup_sequence(NFS_SERVER(data->inode), |
f11c88af AA |
424 | &data->args.seq_args, &data->res.seq_res, |
425 | 0, task)) | |
426 | return; | |
427 | rpc_call_start(task); | |
428 | } | |
429 | #endif /* CONFIG_NFS_V4_1 */ | |
430 | ||
ec06c096 | 431 | static const struct rpc_call_ops nfs_read_partial_ops = { |
f11c88af AA |
432 | #if defined(CONFIG_NFS_V4_1) |
433 | .rpc_call_prepare = nfs_read_prepare, | |
434 | #endif /* CONFIG_NFS_V4_1 */ | |
ec06c096 | 435 | .rpc_call_done = nfs_readpage_result_partial, |
fdd1e74c | 436 | .rpc_release = nfs_readpage_release_partial, |
ec06c096 TM |
437 | }; |
438 | ||
1de3fc12 TM |
439 | static void nfs_readpage_set_pages_uptodate(struct nfs_read_data *data) |
440 | { | |
441 | unsigned int count = data->res.count; | |
442 | unsigned int base = data->args.pgbase; | |
443 | struct page **pages; | |
444 | ||
79558f36 TM |
445 | if (data->res.eof) |
446 | count = data->args.count; | |
1de3fc12 TM |
447 | if (unlikely(count == 0)) |
448 | return; | |
449 | pages = &data->args.pages[base >> PAGE_CACHE_SHIFT]; | |
450 | base &= ~PAGE_CACHE_MASK; | |
451 | count += base; | |
452 | for (;count >= PAGE_CACHE_SIZE; count -= PAGE_CACHE_SIZE, pages++) | |
453 | SetPageUptodate(*pages); | |
0b671301 TM |
454 | if (count == 0) |
455 | return; | |
456 | /* Was this a short read? */ | |
457 | if (data->res.eof || data->res.count == data->args.count) | |
1de3fc12 TM |
458 | SetPageUptodate(*pages); |
459 | } | |
460 | ||
1da177e4 LT |
461 | /* |
462 | * This is the callback from RPC telling us whether a reply was | |
463 | * received or some error occurred (timeout or socket shutdown). | |
464 | */ | |
ec06c096 | 465 | static void nfs_readpage_result_full(struct rpc_task *task, void *calldata) |
1da177e4 | 466 | { |
ec06c096 | 467 | struct nfs_read_data *data = calldata; |
1da177e4 | 468 | |
0b671301 TM |
469 | if (nfs_readpage_result(task, data) != 0) |
470 | return; | |
fdd1e74c TM |
471 | if (task->tk_status < 0) |
472 | return; | |
1de3fc12 | 473 | /* |
0b671301 | 474 | * Note: nfs_readpage_retry may change the values of |
1de3fc12 | 475 | * data->args. In the multi-page case, we therefore need |
0b671301 TM |
476 | * to ensure that we call nfs_readpage_set_pages_uptodate() |
477 | * first. | |
1de3fc12 | 478 | */ |
fdd1e74c TM |
479 | nfs_readpage_truncate_uninitialised_page(data); |
480 | nfs_readpage_set_pages_uptodate(data); | |
481 | nfs_readpage_retry(task, data); | |
482 | } | |
483 | ||
484 | static void nfs_readpage_release_full(void *calldata) | |
485 | { | |
486 | struct nfs_read_data *data = calldata; | |
487 | ||
1da177e4 LT |
488 | while (!list_empty(&data->pages)) { |
489 | struct nfs_page *req = nfs_list_entry(data->pages.next); | |
1da177e4 | 490 | |
1de3fc12 | 491 | nfs_list_remove_request(req); |
1da177e4 LT |
492 | nfs_readpage_release(req); |
493 | } | |
fdd1e74c | 494 | nfs_readdata_release(calldata); |
1da177e4 LT |
495 | } |
496 | ||
ec06c096 | 497 | static const struct rpc_call_ops nfs_read_full_ops = { |
f11c88af AA |
498 | #if defined(CONFIG_NFS_V4_1) |
499 | .rpc_call_prepare = nfs_read_prepare, | |
500 | #endif /* CONFIG_NFS_V4_1 */ | |
ec06c096 | 501 | .rpc_call_done = nfs_readpage_result_full, |
fdd1e74c | 502 | .rpc_release = nfs_readpage_release_full, |
ec06c096 TM |
503 | }; |
504 | ||
1da177e4 LT |
505 | /* |
506 | * Read a page over NFS. | |
507 | * We read the page synchronously in the following case: | |
508 | * - The error flag is set for this page. This happens only when a | |
509 | * previous async read operation failed. | |
510 | */ | |
511 | int nfs_readpage(struct file *file, struct page *page) | |
512 | { | |
513 | struct nfs_open_context *ctx; | |
514 | struct inode *inode = page->mapping->host; | |
515 | int error; | |
516 | ||
517 | dprintk("NFS: nfs_readpage (%p %ld@%lu)\n", | |
518 | page, PAGE_CACHE_SIZE, page->index); | |
91d5b470 CL |
519 | nfs_inc_stats(inode, NFSIOS_VFSREADPAGE); |
520 | nfs_add_stats(inode, NFSIOS_READPAGES, 1); | |
521 | ||
1da177e4 LT |
522 | /* |
523 | * Try to flush any pending writes to the file.. | |
524 | * | |
525 | * NOTE! Because we own the page lock, there cannot | |
526 | * be any new pending writes generated at this point | |
527 | * for this page (other pages can be written to). | |
528 | */ | |
529 | error = nfs_wb_page(inode, page); | |
530 | if (error) | |
de05a0cc TM |
531 | goto out_unlock; |
532 | if (PageUptodate(page)) | |
533 | goto out_unlock; | |
1da177e4 | 534 | |
5f004cf2 TM |
535 | error = -ESTALE; |
536 | if (NFS_STALE(inode)) | |
de05a0cc | 537 | goto out_unlock; |
5f004cf2 | 538 | |
1da177e4 | 539 | if (file == NULL) { |
cf1308ff | 540 | error = -EBADF; |
d530838b | 541 | ctx = nfs_find_open_context(inode, NULL, FMODE_READ); |
1da177e4 | 542 | if (ctx == NULL) |
de05a0cc | 543 | goto out_unlock; |
1da177e4 | 544 | } else |
cd3758e3 | 545 | ctx = get_nfs_open_context(nfs_file_open_context(file)); |
1da177e4 | 546 | |
9a9fc1c0 DH |
547 | if (!IS_SYNC(inode)) { |
548 | error = nfs_readpage_from_fscache(ctx, inode, page); | |
549 | if (error == 0) | |
550 | goto out; | |
551 | } | |
552 | ||
8e0969f0 TM |
553 | error = nfs_readpage_async(ctx, inode, page); |
554 | ||
9a9fc1c0 | 555 | out: |
1da177e4 LT |
556 | put_nfs_open_context(ctx); |
557 | return error; | |
de05a0cc | 558 | out_unlock: |
1da177e4 LT |
559 | unlock_page(page); |
560 | return error; | |
561 | } | |
562 | ||
563 | struct nfs_readdesc { | |
8b09bee3 | 564 | struct nfs_pageio_descriptor *pgio; |
1da177e4 LT |
565 | struct nfs_open_context *ctx; |
566 | }; | |
567 | ||
568 | static int | |
569 | readpage_async_filler(void *data, struct page *page) | |
570 | { | |
571 | struct nfs_readdesc *desc = (struct nfs_readdesc *)data; | |
572 | struct inode *inode = page->mapping->host; | |
573 | struct nfs_page *new; | |
574 | unsigned int len; | |
de05a0cc TM |
575 | int error; |
576 | ||
49a70f27 | 577 | len = nfs_page_length(page); |
1da177e4 LT |
578 | if (len == 0) |
579 | return nfs_return_empty_page(page); | |
de05a0cc | 580 | |
1da177e4 | 581 | new = nfs_create_request(desc->ctx, inode, page, 0, len); |
de05a0cc TM |
582 | if (IS_ERR(new)) |
583 | goto out_error; | |
584 | ||
1da177e4 | 585 | if (len < PAGE_CACHE_SIZE) |
eebd2aa3 | 586 | zero_user_segment(page, len, PAGE_CACHE_SIZE); |
f8512ad0 FI |
587 | if (!nfs_pageio_add_request(desc->pgio, new)) { |
588 | error = desc->pgio->pg_error; | |
589 | goto out_unlock; | |
590 | } | |
1da177e4 | 591 | return 0; |
de05a0cc TM |
592 | out_error: |
593 | error = PTR_ERR(new); | |
594 | SetPageError(page); | |
595 | out_unlock: | |
596 | unlock_page(page); | |
597 | return error; | |
1da177e4 LT |
598 | } |
599 | ||
600 | int nfs_readpages(struct file *filp, struct address_space *mapping, | |
601 | struct list_head *pages, unsigned nr_pages) | |
602 | { | |
8b09bee3 | 603 | struct nfs_pageio_descriptor pgio; |
1da177e4 | 604 | struct nfs_readdesc desc = { |
8b09bee3 | 605 | .pgio = &pgio, |
1da177e4 LT |
606 | }; |
607 | struct inode *inode = mapping->host; | |
608 | struct nfs_server *server = NFS_SERVER(inode); | |
8b09bee3 TM |
609 | size_t rsize = server->rsize; |
610 | unsigned long npages; | |
5f004cf2 | 611 | int ret = -ESTALE; |
1da177e4 LT |
612 | |
613 | dprintk("NFS: nfs_readpages (%s/%Ld %d)\n", | |
614 | inode->i_sb->s_id, | |
615 | (long long)NFS_FILEID(inode), | |
616 | nr_pages); | |
91d5b470 | 617 | nfs_inc_stats(inode, NFSIOS_VFSREADPAGES); |
1da177e4 | 618 | |
5f004cf2 TM |
619 | if (NFS_STALE(inode)) |
620 | goto out; | |
621 | ||
1da177e4 | 622 | if (filp == NULL) { |
d530838b | 623 | desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ); |
1da177e4 LT |
624 | if (desc.ctx == NULL) |
625 | return -EBADF; | |
626 | } else | |
cd3758e3 | 627 | desc.ctx = get_nfs_open_context(nfs_file_open_context(filp)); |
9a9fc1c0 DH |
628 | |
629 | /* attempt to read as many of the pages as possible from the cache | |
630 | * - this returns -ENOBUFS immediately if the cookie is negative | |
631 | */ | |
632 | ret = nfs_readpages_from_fscache(desc.ctx, inode, mapping, | |
633 | pages, &nr_pages); | |
634 | if (ret == 0) | |
635 | goto read_complete; /* all pages were read */ | |
636 | ||
94ad1c80 | 637 | pnfs_pageio_init_read(&pgio, inode); |
8b09bee3 TM |
638 | if (rsize < PAGE_CACHE_SIZE) |
639 | nfs_pageio_init(&pgio, inode, nfs_pagein_multi, rsize, 0); | |
640 | else | |
641 | nfs_pageio_init(&pgio, inode, nfs_pagein_one, rsize, 0); | |
642 | ||
1da177e4 | 643 | ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc); |
8b09bee3 TM |
644 | |
645 | nfs_pageio_complete(&pgio); | |
646 | npages = (pgio.pg_bytes_written + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; | |
647 | nfs_add_stats(inode, NFSIOS_READPAGES, npages); | |
9a9fc1c0 | 648 | read_complete: |
1da177e4 | 649 | put_nfs_open_context(desc.ctx); |
5f004cf2 | 650 | out: |
1da177e4 LT |
651 | return ret; |
652 | } | |
653 | ||
f7b422b1 | 654 | int __init nfs_init_readpagecache(void) |
1da177e4 LT |
655 | { |
656 | nfs_rdata_cachep = kmem_cache_create("nfs_read_data", | |
657 | sizeof(struct nfs_read_data), | |
658 | 0, SLAB_HWCACHE_ALIGN, | |
20c2df83 | 659 | NULL); |
1da177e4 LT |
660 | if (nfs_rdata_cachep == NULL) |
661 | return -ENOMEM; | |
662 | ||
93d2341c MD |
663 | nfs_rdata_mempool = mempool_create_slab_pool(MIN_POOL_READ, |
664 | nfs_rdata_cachep); | |
1da177e4 LT |
665 | if (nfs_rdata_mempool == NULL) |
666 | return -ENOMEM; | |
667 | ||
668 | return 0; | |
669 | } | |
670 | ||
266bee88 | 671 | void nfs_destroy_readpagecache(void) |
1da177e4 LT |
672 | { |
673 | mempool_destroy(nfs_rdata_mempool); | |
1a1d92c1 | 674 | kmem_cache_destroy(nfs_rdata_cachep); |
1da177e4 | 675 | } |