Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/nfs/pagelist.c | |
3 | * | |
4 | * A set of helper functions for managing NFS read and write requests. | |
5 | * The main purpose of these routines is to provide support for the | |
6 | * coalescing of several requests into a single RPC call. | |
7 | * | |
8 | * Copyright 2000, 2001 (c) Trond Myklebust <trond.myklebust@fys.uio.no> | |
9 | * | |
10 | */ | |
11 | ||
1da177e4 LT |
12 | #include <linux/slab.h> |
13 | #include <linux/file.h> | |
e8edc6e0 | 14 | #include <linux/sched.h> |
1da177e4 | 15 | #include <linux/sunrpc/clnt.h> |
1313e603 | 16 | #include <linux/nfs.h> |
1da177e4 LT |
17 | #include <linux/nfs3.h> |
18 | #include <linux/nfs4.h> | |
19 | #include <linux/nfs_page.h> | |
20 | #include <linux/nfs_fs.h> | |
21 | #include <linux/nfs_mount.h> | |
afeacc8c | 22 | #include <linux/export.h> |
1da177e4 | 23 | |
8d5658c9 | 24 | #include "internal.h" |
bae724ef | 25 | #include "pnfs.h" |
8d5658c9 | 26 | |
0eecb214 AS |
27 | #define NFSDBG_FACILITY NFSDBG_PAGECACHE |
28 | ||
e18b890b | 29 | static struct kmem_cache *nfs_page_cachep; |
ef2c488c | 30 | static const struct rpc_call_ops nfs_pgio_common_ops; |
1da177e4 | 31 | |
2bfc6e56 | 32 | static void nfs_free_request(struct nfs_page *); |
1da177e4 | 33 | |
00bfa30a | 34 | static bool nfs_pgarray_set(struct nfs_page_array *p, unsigned int pagecount) |
30dd374f FI |
35 | { |
36 | p->npages = pagecount; | |
37 | if (pagecount <= ARRAY_SIZE(p->page_array)) | |
38 | p->pagevec = p->page_array; | |
39 | else { | |
40 | p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_KERNEL); | |
41 | if (!p->pagevec) | |
42 | p->npages = 0; | |
43 | } | |
44 | return p->pagevec != NULL; | |
45 | } | |
46 | ||
4db6e0b7 FI |
47 | void nfs_pgheader_init(struct nfs_pageio_descriptor *desc, |
48 | struct nfs_pgio_header *hdr, | |
49 | void (*release)(struct nfs_pgio_header *hdr)) | |
50 | { | |
51 | hdr->req = nfs_list_entry(desc->pg_list.next); | |
52 | hdr->inode = desc->pg_inode; | |
53 | hdr->cred = hdr->req->wb_context->cred; | |
54 | hdr->io_start = req_offset(hdr->req); | |
55 | hdr->good_bytes = desc->pg_count; | |
584aa810 | 56 | hdr->dreq = desc->pg_dreq; |
f6166384 | 57 | hdr->layout_private = desc->pg_layout_private; |
4db6e0b7 | 58 | hdr->release = release; |
061ae2ed | 59 | hdr->completion_ops = desc->pg_completion_ops; |
584aa810 FI |
60 | if (hdr->completion_ops->init_hdr) |
61 | hdr->completion_ops->init_hdr(hdr); | |
4db6e0b7 | 62 | } |
89d77c8f | 63 | EXPORT_SYMBOL_GPL(nfs_pgheader_init); |
4db6e0b7 FI |
64 | |
65 | void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos) | |
66 | { | |
67 | spin_lock(&hdr->lock); | |
68 | if (pos < hdr->io_start + hdr->good_bytes) { | |
69 | set_bit(NFS_IOHDR_ERROR, &hdr->flags); | |
70 | clear_bit(NFS_IOHDR_EOF, &hdr->flags); | |
71 | hdr->good_bytes = pos - hdr->io_start; | |
72 | hdr->error = error; | |
73 | } | |
74 | spin_unlock(&hdr->lock); | |
75 | } | |
76 | ||
1da177e4 LT |
77 | static inline struct nfs_page * |
78 | nfs_page_alloc(void) | |
79 | { | |
192e501b | 80 | struct nfs_page *p = kmem_cache_zalloc(nfs_page_cachep, GFP_NOIO); |
72895b1a | 81 | if (p) |
1da177e4 | 82 | INIT_LIST_HEAD(&p->wb_list); |
1da177e4 LT |
83 | return p; |
84 | } | |
85 | ||
86 | static inline void | |
87 | nfs_page_free(struct nfs_page *p) | |
88 | { | |
89 | kmem_cache_free(nfs_page_cachep, p); | |
90 | } | |
91 | ||
577b4232 TM |
92 | static void |
93 | nfs_iocounter_inc(struct nfs_io_counter *c) | |
94 | { | |
95 | atomic_inc(&c->io_count); | |
96 | } | |
97 | ||
98 | static void | |
99 | nfs_iocounter_dec(struct nfs_io_counter *c) | |
100 | { | |
101 | if (atomic_dec_and_test(&c->io_count)) { | |
102 | clear_bit(NFS_IO_INPROGRESS, &c->flags); | |
4e857c58 | 103 | smp_mb__after_atomic(); |
577b4232 TM |
104 | wake_up_bit(&c->flags, NFS_IO_INPROGRESS); |
105 | } | |
106 | } | |
107 | ||
108 | static int | |
109 | __nfs_iocounter_wait(struct nfs_io_counter *c) | |
110 | { | |
111 | wait_queue_head_t *wq = bit_waitqueue(&c->flags, NFS_IO_INPROGRESS); | |
112 | DEFINE_WAIT_BIT(q, &c->flags, NFS_IO_INPROGRESS); | |
113 | int ret = 0; | |
114 | ||
115 | do { | |
116 | prepare_to_wait(wq, &q.wait, TASK_KILLABLE); | |
117 | set_bit(NFS_IO_INPROGRESS, &c->flags); | |
118 | if (atomic_read(&c->io_count) == 0) | |
119 | break; | |
120 | ret = nfs_wait_bit_killable(&c->flags); | |
121 | } while (atomic_read(&c->io_count) != 0); | |
122 | finish_wait(wq, &q.wait); | |
123 | return ret; | |
124 | } | |
125 | ||
126 | /** | |
127 | * nfs_iocounter_wait - wait for i/o to complete | |
128 | * @c: nfs_io_counter to use | |
129 | * | |
130 | * returns -ERESTARTSYS if interrupted by a fatal signal. | |
131 | * Otherwise returns 0 once the io_count hits 0. | |
132 | */ | |
133 | int | |
134 | nfs_iocounter_wait(struct nfs_io_counter *c) | |
135 | { | |
136 | if (atomic_read(&c->io_count) == 0) | |
137 | return 0; | |
138 | return __nfs_iocounter_wait(c); | |
139 | } | |
140 | ||
f868089b TM |
141 | static int nfs_wait_bit_uninterruptible(void *word) |
142 | { | |
143 | io_schedule(); | |
144 | return 0; | |
145 | } | |
146 | ||
2bfc6e56 WAA |
147 | /* |
148 | * nfs_page_group_lock - lock the head of the page group | |
149 | * @req - request in group that is to be locked | |
150 | * | |
151 | * this lock must be held if modifying the page group list | |
152 | */ | |
153 | void | |
154 | nfs_page_group_lock(struct nfs_page *req) | |
155 | { | |
156 | struct nfs_page *head = req->wb_head; | |
2bfc6e56 WAA |
157 | |
158 | WARN_ON_ONCE(head != head->wb_head); | |
159 | ||
f868089b TM |
160 | wait_on_bit_lock(&head->wb_flags, PG_HEADLOCK, |
161 | nfs_wait_bit_uninterruptible, | |
162 | TASK_UNINTERRUPTIBLE); | |
2bfc6e56 WAA |
163 | } |
164 | ||
165 | /* | |
166 | * nfs_page_group_unlock - unlock the head of the page group | |
167 | * @req - request in group that is to be unlocked | |
168 | */ | |
169 | void | |
170 | nfs_page_group_unlock(struct nfs_page *req) | |
171 | { | |
172 | struct nfs_page *head = req->wb_head; | |
173 | ||
174 | WARN_ON_ONCE(head != head->wb_head); | |
175 | ||
d1e1cda8 | 176 | smp_mb__before_atomic(); |
2bfc6e56 | 177 | clear_bit(PG_HEADLOCK, &head->wb_flags); |
d1e1cda8 | 178 | smp_mb__after_atomic(); |
2bfc6e56 WAA |
179 | wake_up_bit(&head->wb_flags, PG_HEADLOCK); |
180 | } | |
181 | ||
182 | /* | |
183 | * nfs_page_group_sync_on_bit_locked | |
184 | * | |
185 | * must be called with page group lock held | |
186 | */ | |
187 | static bool | |
188 | nfs_page_group_sync_on_bit_locked(struct nfs_page *req, unsigned int bit) | |
189 | { | |
190 | struct nfs_page *head = req->wb_head; | |
191 | struct nfs_page *tmp; | |
192 | ||
193 | WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &head->wb_flags)); | |
194 | WARN_ON_ONCE(test_and_set_bit(bit, &req->wb_flags)); | |
195 | ||
196 | tmp = req->wb_this_page; | |
197 | while (tmp != req) { | |
198 | if (!test_bit(bit, &tmp->wb_flags)) | |
199 | return false; | |
200 | tmp = tmp->wb_this_page; | |
201 | } | |
202 | ||
203 | /* true! reset all bits */ | |
204 | tmp = req; | |
205 | do { | |
206 | clear_bit(bit, &tmp->wb_flags); | |
207 | tmp = tmp->wb_this_page; | |
208 | } while (tmp != req); | |
209 | ||
210 | return true; | |
211 | } | |
212 | ||
213 | /* | |
214 | * nfs_page_group_sync_on_bit - set bit on current request, but only | |
215 | * return true if the bit is set for all requests in page group | |
216 | * @req - request in page group | |
217 | * @bit - PG_* bit that is used to sync page group | |
218 | */ | |
219 | bool nfs_page_group_sync_on_bit(struct nfs_page *req, unsigned int bit) | |
220 | { | |
221 | bool ret; | |
222 | ||
223 | nfs_page_group_lock(req); | |
224 | ret = nfs_page_group_sync_on_bit_locked(req, bit); | |
225 | nfs_page_group_unlock(req); | |
226 | ||
227 | return ret; | |
228 | } | |
229 | ||
230 | /* | |
231 | * nfs_page_group_init - Initialize the page group linkage for @req | |
232 | * @req - a new nfs request | |
233 | * @prev - the previous request in page group, or NULL if @req is the first | |
234 | * or only request in the group (the head). | |
235 | */ | |
236 | static inline void | |
237 | nfs_page_group_init(struct nfs_page *req, struct nfs_page *prev) | |
238 | { | |
239 | WARN_ON_ONCE(prev == req); | |
240 | ||
241 | if (!prev) { | |
242 | req->wb_head = req; | |
243 | req->wb_this_page = req; | |
244 | } else { | |
245 | WARN_ON_ONCE(prev->wb_this_page != prev->wb_head); | |
246 | WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &prev->wb_head->wb_flags)); | |
247 | req->wb_head = prev->wb_head; | |
248 | req->wb_this_page = prev->wb_this_page; | |
249 | prev->wb_this_page = req; | |
250 | ||
251 | /* grab extra ref if head request has extra ref from | |
252 | * the write/commit path to handle handoff between write | |
253 | * and commit lists */ | |
254 | if (test_bit(PG_INODE_REF, &prev->wb_head->wb_flags)) | |
255 | kref_get(&req->wb_kref); | |
256 | } | |
257 | } | |
258 | ||
259 | /* | |
260 | * nfs_page_group_destroy - sync the destruction of page groups | |
261 | * @req - request that no longer needs the page group | |
262 | * | |
263 | * releases the page group reference from each member once all | |
264 | * members have called this function. | |
265 | */ | |
266 | static void | |
267 | nfs_page_group_destroy(struct kref *kref) | |
268 | { | |
269 | struct nfs_page *req = container_of(kref, struct nfs_page, wb_kref); | |
270 | struct nfs_page *tmp, *next; | |
271 | ||
272 | if (!nfs_page_group_sync_on_bit(req, PG_TEARDOWN)) | |
273 | return; | |
274 | ||
275 | tmp = req; | |
276 | do { | |
277 | next = tmp->wb_this_page; | |
278 | /* unlink and free */ | |
279 | tmp->wb_this_page = tmp; | |
280 | tmp->wb_head = tmp; | |
281 | nfs_free_request(tmp); | |
282 | tmp = next; | |
283 | } while (tmp != req); | |
284 | } | |
285 | ||
1da177e4 LT |
286 | /** |
287 | * nfs_create_request - Create an NFS read/write request. | |
c02f557d | 288 | * @ctx: open context to use |
1da177e4 | 289 | * @page: page to write |
2bfc6e56 | 290 | * @last: last nfs request created for this page group or NULL if head |
1da177e4 LT |
291 | * @offset: starting offset within the page for the write |
292 | * @count: number of bytes to read/write | |
293 | * | |
294 | * The page must be locked by the caller. This makes sure we never | |
a19b89ca | 295 | * create two different requests for the same page. |
1da177e4 LT |
296 | * User should ensure it is safe to sleep in this function. |
297 | */ | |
298 | struct nfs_page * | |
8c8f1ac1 | 299 | nfs_create_request(struct nfs_open_context *ctx, struct page *page, |
2bfc6e56 WAA |
300 | struct nfs_page *last, unsigned int offset, |
301 | unsigned int count) | |
1da177e4 | 302 | { |
1da177e4 | 303 | struct nfs_page *req; |
b3c54de6 | 304 | struct nfs_lock_context *l_ctx; |
1da177e4 | 305 | |
c58c8441 TM |
306 | if (test_bit(NFS_CONTEXT_BAD, &ctx->flags)) |
307 | return ERR_PTR(-EBADF); | |
18eb8842 TM |
308 | /* try to allocate the request struct */ |
309 | req = nfs_page_alloc(); | |
310 | if (req == NULL) | |
311 | return ERR_PTR(-ENOMEM); | |
1da177e4 | 312 | |
015f0212 | 313 | /* get lock context early so we can deal with alloc failures */ |
b3c54de6 TM |
314 | l_ctx = nfs_get_lock_context(ctx); |
315 | if (IS_ERR(l_ctx)) { | |
015f0212 | 316 | nfs_page_free(req); |
b3c54de6 | 317 | return ERR_CAST(l_ctx); |
015f0212 | 318 | } |
b3c54de6 | 319 | req->wb_lock_context = l_ctx; |
577b4232 | 320 | nfs_iocounter_inc(&l_ctx->io_count); |
015f0212 | 321 | |
1da177e4 LT |
322 | /* Initialize the request struct. Initially, we assume a |
323 | * long write-back delay. This will be adjusted in | |
324 | * update_nfs_request below if the region is not locked. */ | |
325 | req->wb_page = page; | |
d56b4ddf | 326 | req->wb_index = page_file_index(page); |
1da177e4 LT |
327 | page_cache_get(page); |
328 | req->wb_offset = offset; | |
329 | req->wb_pgbase = offset; | |
330 | req->wb_bytes = count; | |
1da177e4 | 331 | req->wb_context = get_nfs_open_context(ctx); |
c03b4024 | 332 | kref_init(&req->wb_kref); |
2bfc6e56 | 333 | nfs_page_group_init(req, last); |
1da177e4 LT |
334 | return req; |
335 | } | |
336 | ||
337 | /** | |
1d1afcbc | 338 | * nfs_unlock_request - Unlock request and wake up sleepers. |
1da177e4 LT |
339 | * @req: |
340 | */ | |
1d1afcbc | 341 | void nfs_unlock_request(struct nfs_page *req) |
1da177e4 LT |
342 | { |
343 | if (!NFS_WBACK_BUSY(req)) { | |
344 | printk(KERN_ERR "NFS: Invalid unlock attempted\n"); | |
345 | BUG(); | |
346 | } | |
4e857c58 | 347 | smp_mb__before_atomic(); |
1da177e4 | 348 | clear_bit(PG_BUSY, &req->wb_flags); |
4e857c58 | 349 | smp_mb__after_atomic(); |
464a98bd | 350 | wake_up_bit(&req->wb_flags, PG_BUSY); |
3aff4ebb TM |
351 | } |
352 | ||
353 | /** | |
1d1afcbc TM |
354 | * nfs_unlock_and_release_request - Unlock request and release the nfs_page |
355 | * @req: | |
3aff4ebb | 356 | */ |
1d1afcbc | 357 | void nfs_unlock_and_release_request(struct nfs_page *req) |
3aff4ebb | 358 | { |
1d1afcbc | 359 | nfs_unlock_request(req); |
1da177e4 LT |
360 | nfs_release_request(req); |
361 | } | |
362 | ||
4d65c520 | 363 | /* |
1da177e4 LT |
364 | * nfs_clear_request - Free up all resources allocated to the request |
365 | * @req: | |
366 | * | |
bb6fbc45 TM |
367 | * Release page and open context resources associated with a read/write |
368 | * request after it has completed. | |
1da177e4 | 369 | */ |
4d65c520 | 370 | static void nfs_clear_request(struct nfs_page *req) |
1da177e4 | 371 | { |
cd52ed35 | 372 | struct page *page = req->wb_page; |
bb6fbc45 | 373 | struct nfs_open_context *ctx = req->wb_context; |
f11ac8db | 374 | struct nfs_lock_context *l_ctx = req->wb_lock_context; |
bb6fbc45 | 375 | |
cd52ed35 | 376 | if (page != NULL) { |
cd52ed35 | 377 | page_cache_release(page); |
1da177e4 LT |
378 | req->wb_page = NULL; |
379 | } | |
f11ac8db | 380 | if (l_ctx != NULL) { |
577b4232 | 381 | nfs_iocounter_dec(&l_ctx->io_count); |
f11ac8db TM |
382 | nfs_put_lock_context(l_ctx); |
383 | req->wb_lock_context = NULL; | |
384 | } | |
bb6fbc45 TM |
385 | if (ctx != NULL) { |
386 | put_nfs_open_context(ctx); | |
387 | req->wb_context = NULL; | |
388 | } | |
1da177e4 LT |
389 | } |
390 | ||
1da177e4 LT |
391 | /** |
392 | * nfs_release_request - Release the count on an NFS read/write request | |
393 | * @req: request to release | |
394 | * | |
395 | * Note: Should never be called with the spinlock held! | |
396 | */ | |
2bfc6e56 | 397 | static void nfs_free_request(struct nfs_page *req) |
1da177e4 | 398 | { |
2bfc6e56 WAA |
399 | WARN_ON_ONCE(req->wb_this_page != req); |
400 | ||
401 | /* extra debug: make sure no sync bits are still set */ | |
402 | WARN_ON_ONCE(test_bit(PG_TEARDOWN, &req->wb_flags)); | |
67d0338e WAA |
403 | WARN_ON_ONCE(test_bit(PG_UNLOCKPAGE, &req->wb_flags)); |
404 | WARN_ON_ONCE(test_bit(PG_UPTODATE, &req->wb_flags)); | |
20633f04 WAA |
405 | WARN_ON_ONCE(test_bit(PG_WB_END, &req->wb_flags)); |
406 | WARN_ON_ONCE(test_bit(PG_REMOVE, &req->wb_flags)); | |
1da177e4 | 407 | |
bb6fbc45 | 408 | /* Release struct file and open context */ |
1da177e4 | 409 | nfs_clear_request(req); |
1da177e4 LT |
410 | nfs_page_free(req); |
411 | } | |
412 | ||
c03b4024 TM |
413 | void nfs_release_request(struct nfs_page *req) |
414 | { | |
2bfc6e56 | 415 | kref_put(&req->wb_kref, nfs_page_group_destroy); |
9f557cd8 TM |
416 | } |
417 | ||
1da177e4 LT |
418 | /** |
419 | * nfs_wait_on_request - Wait for a request to complete. | |
420 | * @req: request to wait upon. | |
421 | * | |
150030b7 | 422 | * Interruptible by fatal signals only. |
1da177e4 LT |
423 | * The user is responsible for holding a count on the request. |
424 | */ | |
425 | int | |
426 | nfs_wait_on_request(struct nfs_page *req) | |
427 | { | |
9f557cd8 TM |
428 | return wait_on_bit(&req->wb_flags, PG_BUSY, |
429 | nfs_wait_bit_uninterruptible, | |
430 | TASK_UNINTERRUPTIBLE); | |
1da177e4 LT |
431 | } |
432 | ||
b4fdac1a WAA |
433 | /* |
434 | * nfs_generic_pg_test - determine if requests can be coalesced | |
435 | * @desc: pointer to descriptor | |
436 | * @prev: previous request in desc, or NULL | |
437 | * @req: this request | |
438 | * | |
439 | * Returns zero if @req can be coalesced into @desc, otherwise it returns | |
440 | * the size of the request. | |
441 | */ | |
442 | size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, | |
443 | struct nfs_page *prev, struct nfs_page *req) | |
5b36c7dc | 444 | { |
f0cb9ab8 WAA |
445 | if (desc->pg_count > desc->pg_bsize) { |
446 | /* should never happen */ | |
447 | WARN_ON_ONCE(1); | |
5b36c7dc | 448 | return 0; |
f0cb9ab8 | 449 | } |
5b36c7dc | 450 | |
f0cb9ab8 | 451 | return min(desc->pg_bsize - desc->pg_count, (size_t)req->wb_bytes); |
5b36c7dc | 452 | } |
19345cb2 | 453 | EXPORT_SYMBOL_GPL(nfs_generic_pg_test); |
5b36c7dc | 454 | |
1e7f3a48 | 455 | struct nfs_pgio_header *nfs_pgio_header_alloc(const struct nfs_rw_ops *ops) |
00bfa30a | 456 | { |
1e7f3a48 | 457 | struct nfs_pgio_header *hdr = ops->rw_alloc_header(); |
4a0de55c | 458 | |
1e7f3a48 | 459 | if (hdr) { |
4a0de55c | 460 | INIT_LIST_HEAD(&hdr->pages); |
4a0de55c AS |
461 | spin_lock_init(&hdr->lock); |
462 | atomic_set(&hdr->refcnt, 0); | |
463 | hdr->rw_ops = ops; | |
464 | } | |
1e7f3a48 | 465 | return hdr; |
4a0de55c | 466 | } |
1e7f3a48 | 467 | EXPORT_SYMBOL_GPL(nfs_pgio_header_alloc); |
4a0de55c AS |
468 | |
469 | /* | |
1e7f3a48 | 470 | * nfs_pgio_header_free - Free a read or write header |
4a0de55c AS |
471 | * @hdr: The header to free |
472 | */ | |
1e7f3a48 | 473 | void nfs_pgio_header_free(struct nfs_pgio_header *hdr) |
4a0de55c | 474 | { |
1e7f3a48 | 475 | hdr->rw_ops->rw_free_header(hdr); |
4a0de55c | 476 | } |
1e7f3a48 | 477 | EXPORT_SYMBOL_GPL(nfs_pgio_header_free); |
4a0de55c | 478 | |
00bfa30a AS |
479 | /** |
480 | * nfs_pgio_data_alloc - Allocate pageio data | |
481 | * @hdr: The header making a request | |
482 | * @pagecount: Number of pages to create | |
483 | */ | |
1e7f3a48 WAA |
484 | static bool nfs_pgio_data_init(struct nfs_pgio_header *hdr, |
485 | unsigned int pagecount) | |
00bfa30a | 486 | { |
d45f60c6 | 487 | if (nfs_pgarray_set(&hdr->page_array, pagecount)) { |
00bfa30a | 488 | atomic_inc(&hdr->refcnt); |
1e7f3a48 | 489 | return true; |
00bfa30a | 490 | } |
1e7f3a48 | 491 | return false; |
00bfa30a AS |
492 | } |
493 | ||
494 | /** | |
d45f60c6 WAA |
495 | * nfs_pgio_data_destroy - Properly release pageio data |
496 | * @hdr: The header with data to destroy | |
00bfa30a | 497 | */ |
d45f60c6 | 498 | void nfs_pgio_data_destroy(struct nfs_pgio_header *hdr) |
00bfa30a | 499 | { |
d45f60c6 WAA |
500 | put_nfs_open_context(hdr->args.context); |
501 | if (hdr->page_array.pagevec != hdr->page_array.page_array) | |
502 | kfree(hdr->page_array.pagevec); | |
00bfa30a AS |
503 | if (atomic_dec_and_test(&hdr->refcnt)) |
504 | hdr->completion_ops->completion(hdr); | |
00bfa30a | 505 | } |
1e7f3a48 | 506 | EXPORT_SYMBOL_GPL(nfs_pgio_data_destroy); |
00bfa30a | 507 | |
ce59515c AS |
508 | /** |
509 | * nfs_pgio_rpcsetup - Set up arguments for a pageio call | |
d45f60c6 | 510 | * @hdr: The pageio hdr |
ce59515c AS |
511 | * @count: Number of bytes to read |
512 | * @offset: Initial offset | |
513 | * @how: How to commit data (writes only) | |
514 | * @cinfo: Commit information for the call (writes only) | |
515 | */ | |
d45f60c6 | 516 | static void nfs_pgio_rpcsetup(struct nfs_pgio_header *hdr, |
ce59515c AS |
517 | unsigned int count, unsigned int offset, |
518 | int how, struct nfs_commit_info *cinfo) | |
519 | { | |
d45f60c6 | 520 | struct nfs_page *req = hdr->req; |
ce59515c AS |
521 | |
522 | /* Set up the RPC argument and reply structs | |
d45f60c6 | 523 | * NB: take care not to mess about with hdr->commit et al. */ |
ce59515c | 524 | |
d45f60c6 WAA |
525 | hdr->args.fh = NFS_FH(hdr->inode); |
526 | hdr->args.offset = req_offset(req) + offset; | |
ce59515c | 527 | /* pnfs_set_layoutcommit needs this */ |
d45f60c6 WAA |
528 | hdr->mds_offset = hdr->args.offset; |
529 | hdr->args.pgbase = req->wb_pgbase + offset; | |
530 | hdr->args.pages = hdr->page_array.pagevec; | |
531 | hdr->args.count = count; | |
532 | hdr->args.context = get_nfs_open_context(req->wb_context); | |
533 | hdr->args.lock_context = req->wb_lock_context; | |
534 | hdr->args.stable = NFS_UNSTABLE; | |
ce59515c AS |
535 | switch (how & (FLUSH_STABLE | FLUSH_COND_STABLE)) { |
536 | case 0: | |
537 | break; | |
538 | case FLUSH_COND_STABLE: | |
539 | if (nfs_reqs_to_commit(cinfo)) | |
540 | break; | |
541 | default: | |
d45f60c6 | 542 | hdr->args.stable = NFS_FILE_SYNC; |
ce59515c AS |
543 | } |
544 | ||
d45f60c6 WAA |
545 | hdr->res.fattr = &hdr->fattr; |
546 | hdr->res.count = count; | |
547 | hdr->res.eof = 0; | |
548 | hdr->res.verf = &hdr->writeverf; | |
549 | nfs_fattr_init(&hdr->fattr); | |
ce59515c AS |
550 | } |
551 | ||
a4cdda59 | 552 | /** |
d45f60c6 | 553 | * nfs_pgio_prepare - Prepare pageio hdr to go over the wire |
a4cdda59 | 554 | * @task: The current task |
d45f60c6 | 555 | * @calldata: pageio header to prepare |
a4cdda59 | 556 | */ |
6f92fa45 | 557 | static void nfs_pgio_prepare(struct rpc_task *task, void *calldata) |
a4cdda59 | 558 | { |
d45f60c6 | 559 | struct nfs_pgio_header *hdr = calldata; |
a4cdda59 | 560 | int err; |
d45f60c6 | 561 | err = NFS_PROTO(hdr->inode)->pgio_rpc_prepare(task, hdr); |
a4cdda59 AS |
562 | if (err) |
563 | rpc_exit(task, err); | |
564 | } | |
565 | ||
d45f60c6 | 566 | int nfs_initiate_pgio(struct rpc_clnt *clnt, struct nfs_pgio_header *hdr, |
1ed26f33 AS |
567 | const struct rpc_call_ops *call_ops, int how, int flags) |
568 | { | |
d45f60c6 | 569 | struct inode *inode = hdr->inode; |
1ed26f33 AS |
570 | struct rpc_task *task; |
571 | struct rpc_message msg = { | |
d45f60c6 WAA |
572 | .rpc_argp = &hdr->args, |
573 | .rpc_resp = &hdr->res, | |
574 | .rpc_cred = hdr->cred, | |
1ed26f33 AS |
575 | }; |
576 | struct rpc_task_setup task_setup_data = { | |
577 | .rpc_client = clnt, | |
d45f60c6 | 578 | .task = &hdr->task, |
1ed26f33 AS |
579 | .rpc_message = &msg, |
580 | .callback_ops = call_ops, | |
d45f60c6 | 581 | .callback_data = hdr, |
1ed26f33 AS |
582 | .workqueue = nfsiod_workqueue, |
583 | .flags = RPC_TASK_ASYNC | flags, | |
584 | }; | |
585 | int ret = 0; | |
586 | ||
d45f60c6 | 587 | hdr->rw_ops->rw_initiate(hdr, &msg, &task_setup_data, how); |
1ed26f33 AS |
588 | |
589 | dprintk("NFS: %5u initiated pgio call " | |
590 | "(req %s/%llu, %u bytes @ offset %llu)\n", | |
d45f60c6 WAA |
591 | hdr->task.tk_pid, |
592 | inode->i_sb->s_id, | |
593 | (unsigned long long)NFS_FILEID(inode), | |
594 | hdr->args.count, | |
595 | (unsigned long long)hdr->args.offset); | |
1ed26f33 AS |
596 | |
597 | task = rpc_run_task(&task_setup_data); | |
598 | if (IS_ERR(task)) { | |
599 | ret = PTR_ERR(task); | |
600 | goto out; | |
601 | } | |
602 | if (how & FLUSH_SYNC) { | |
603 | ret = rpc_wait_for_completion_task(task); | |
604 | if (ret == 0) | |
605 | ret = task->tk_status; | |
606 | } | |
607 | rpc_put_task(task); | |
608 | out: | |
609 | return ret; | |
610 | } | |
611 | EXPORT_SYMBOL_GPL(nfs_initiate_pgio); | |
612 | ||
844c9e69 AS |
613 | /** |
614 | * nfs_pgio_error - Clean up from a pageio error | |
615 | * @desc: IO descriptor | |
616 | * @hdr: pageio header | |
617 | */ | |
ef2c488c | 618 | static int nfs_pgio_error(struct nfs_pageio_descriptor *desc, |
844c9e69 AS |
619 | struct nfs_pgio_header *hdr) |
620 | { | |
844c9e69 | 621 | set_bit(NFS_IOHDR_REDO, &hdr->flags); |
d45f60c6 | 622 | nfs_pgio_data_destroy(hdr); |
844c9e69 AS |
623 | desc->pg_completion_ops->error_cleanup(&desc->pg_list); |
624 | return -ENOMEM; | |
625 | } | |
626 | ||
a4cdda59 AS |
627 | /** |
628 | * nfs_pgio_release - Release pageio data | |
d45f60c6 | 629 | * @calldata: The pageio header to release |
a4cdda59 | 630 | */ |
6f92fa45 | 631 | static void nfs_pgio_release(void *calldata) |
a4cdda59 | 632 | { |
d45f60c6 WAA |
633 | struct nfs_pgio_header *hdr = calldata; |
634 | if (hdr->rw_ops->rw_release) | |
635 | hdr->rw_ops->rw_release(hdr); | |
636 | nfs_pgio_data_destroy(hdr); | |
a4cdda59 AS |
637 | } |
638 | ||
1da177e4 | 639 | /** |
d8a5ad75 TM |
640 | * nfs_pageio_init - initialise a page io descriptor |
641 | * @desc: pointer to descriptor | |
bcb71bba TM |
642 | * @inode: pointer to inode |
643 | * @doio: pointer to io function | |
644 | * @bsize: io block size | |
645 | * @io_flags: extra parameters for the io function | |
d8a5ad75 | 646 | */ |
bcb71bba TM |
647 | void nfs_pageio_init(struct nfs_pageio_descriptor *desc, |
648 | struct inode *inode, | |
1751c363 | 649 | const struct nfs_pageio_ops *pg_ops, |
061ae2ed | 650 | const struct nfs_pgio_completion_ops *compl_ops, |
4a0de55c | 651 | const struct nfs_rw_ops *rw_ops, |
84dde76c | 652 | size_t bsize, |
bcb71bba | 653 | int io_flags) |
d8a5ad75 TM |
654 | { |
655 | INIT_LIST_HEAD(&desc->pg_list); | |
bcb71bba | 656 | desc->pg_bytes_written = 0; |
d8a5ad75 TM |
657 | desc->pg_count = 0; |
658 | desc->pg_bsize = bsize; | |
659 | desc->pg_base = 0; | |
b31268ac | 660 | desc->pg_moreio = 0; |
d9156f9f | 661 | desc->pg_recoalesce = 0; |
bcb71bba | 662 | desc->pg_inode = inode; |
1751c363 | 663 | desc->pg_ops = pg_ops; |
061ae2ed | 664 | desc->pg_completion_ops = compl_ops; |
4a0de55c | 665 | desc->pg_rw_ops = rw_ops; |
bcb71bba TM |
666 | desc->pg_ioflags = io_flags; |
667 | desc->pg_error = 0; | |
94ad1c80 | 668 | desc->pg_lseg = NULL; |
584aa810 | 669 | desc->pg_dreq = NULL; |
f6166384 | 670 | desc->pg_layout_private = NULL; |
d8a5ad75 | 671 | } |
89d77c8f | 672 | EXPORT_SYMBOL_GPL(nfs_pageio_init); |
d8a5ad75 | 673 | |
0eecb214 AS |
674 | /** |
675 | * nfs_pgio_result - Basic pageio error handling | |
676 | * @task: The task that ran | |
d45f60c6 | 677 | * @calldata: Pageio header to check |
0eecb214 | 678 | */ |
6f92fa45 | 679 | static void nfs_pgio_result(struct rpc_task *task, void *calldata) |
0eecb214 | 680 | { |
d45f60c6 WAA |
681 | struct nfs_pgio_header *hdr = calldata; |
682 | struct inode *inode = hdr->inode; | |
0eecb214 AS |
683 | |
684 | dprintk("NFS: %s: %5u, (status %d)\n", __func__, | |
685 | task->tk_pid, task->tk_status); | |
686 | ||
d45f60c6 | 687 | if (hdr->rw_ops->rw_done(task, hdr, inode) != 0) |
0eecb214 AS |
688 | return; |
689 | if (task->tk_status < 0) | |
d45f60c6 | 690 | nfs_set_pgio_error(hdr, task->tk_status, hdr->args.offset); |
0eecb214 | 691 | else |
d45f60c6 | 692 | hdr->rw_ops->rw_result(task, hdr); |
0eecb214 AS |
693 | } |
694 | ||
ef2c488c AS |
695 | /* |
696 | * Create an RPC task for the given read or write request and kick it. | |
697 | * The page must have been locked by the caller. | |
698 | * | |
699 | * It may happen that the page we're passed is not marked dirty. | |
700 | * This is the case if nfs_updatepage detects a conflicting request | |
701 | * that has been written but not committed. | |
702 | */ | |
f0cb9ab8 WAA |
703 | int nfs_generic_pgio(struct nfs_pageio_descriptor *desc, |
704 | struct nfs_pgio_header *hdr) | |
ef2c488c AS |
705 | { |
706 | struct nfs_page *req; | |
707 | struct page **pages; | |
ef2c488c AS |
708 | struct list_head *head = &desc->pg_list; |
709 | struct nfs_commit_info cinfo; | |
710 | ||
1e7f3a48 WAA |
711 | if (!nfs_pgio_data_init(hdr, nfs_page_array_len(desc->pg_base, |
712 | desc->pg_count))) | |
ef2c488c AS |
713 | return nfs_pgio_error(desc, hdr); |
714 | ||
715 | nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq); | |
d45f60c6 | 716 | pages = hdr->page_array.pagevec; |
ef2c488c AS |
717 | while (!list_empty(head)) { |
718 | req = nfs_list_entry(head->next); | |
719 | nfs_list_remove_request(req); | |
720 | nfs_list_add_request(req, &hdr->pages); | |
721 | *pages++ = req->wb_page; | |
722 | } | |
723 | ||
724 | if ((desc->pg_ioflags & FLUSH_COND_STABLE) && | |
725 | (desc->pg_moreio || nfs_reqs_to_commit(&cinfo))) | |
726 | desc->pg_ioflags &= ~FLUSH_COND_STABLE; | |
727 | ||
728 | /* Set up the argument struct */ | |
d45f60c6 | 729 | nfs_pgio_rpcsetup(hdr, desc->pg_count, 0, desc->pg_ioflags, &cinfo); |
ef2c488c AS |
730 | desc->pg_rpc_callops = &nfs_pgio_common_ops; |
731 | return 0; | |
732 | } | |
f0cb9ab8 | 733 | EXPORT_SYMBOL_GPL(nfs_generic_pgio); |
ef2c488c | 734 | |
41d8d5b7 | 735 | static int nfs_generic_pg_pgios(struct nfs_pageio_descriptor *desc) |
cf485fcd | 736 | { |
cf485fcd AS |
737 | struct nfs_pgio_header *hdr; |
738 | int ret; | |
739 | ||
1e7f3a48 WAA |
740 | hdr = nfs_pgio_header_alloc(desc->pg_rw_ops); |
741 | if (!hdr) { | |
cf485fcd AS |
742 | desc->pg_completion_ops->error_cleanup(&desc->pg_list); |
743 | return -ENOMEM; | |
744 | } | |
1e7f3a48 | 745 | nfs_pgheader_init(desc, hdr, nfs_pgio_header_free); |
cf485fcd AS |
746 | atomic_inc(&hdr->refcnt); |
747 | ret = nfs_generic_pgio(desc, hdr); | |
748 | if (ret == 0) | |
7f714720 | 749 | ret = nfs_initiate_pgio(NFS_CLIENT(hdr->inode), |
d45f60c6 | 750 | hdr, desc->pg_rpc_callops, |
7f714720 | 751 | desc->pg_ioflags, 0); |
cf485fcd AS |
752 | if (atomic_dec_and_test(&hdr->refcnt)) |
753 | hdr->completion_ops->completion(hdr); | |
754 | return ret; | |
755 | } | |
756 | ||
4109bb74 TM |
757 | static bool nfs_match_open_context(const struct nfs_open_context *ctx1, |
758 | const struct nfs_open_context *ctx2) | |
759 | { | |
760 | return ctx1->cred == ctx2->cred && ctx1->state == ctx2->state; | |
761 | } | |
762 | ||
763 | static bool nfs_match_lock_context(const struct nfs_lock_context *l1, | |
764 | const struct nfs_lock_context *l2) | |
765 | { | |
766 | return l1->lockowner.l_owner == l2->lockowner.l_owner | |
767 | && l1->lockowner.l_pid == l2->lockowner.l_pid; | |
768 | } | |
769 | ||
d8a5ad75 TM |
770 | /** |
771 | * nfs_can_coalesce_requests - test two requests for compatibility | |
772 | * @prev: pointer to nfs_page | |
773 | * @req: pointer to nfs_page | |
774 | * | |
775 | * The nfs_page structures 'prev' and 'req' are compared to ensure that the | |
776 | * page data area they describe is contiguous, and that their RPC | |
777 | * credentials, NFSv4 open state, and lockowners are the same. | |
778 | * | |
779 | * Return 'true' if this is the case, else return 'false'. | |
780 | */ | |
18ad0a9f BH |
781 | static bool nfs_can_coalesce_requests(struct nfs_page *prev, |
782 | struct nfs_page *req, | |
783 | struct nfs_pageio_descriptor *pgio) | |
d8a5ad75 | 784 | { |
b4fdac1a WAA |
785 | size_t size; |
786 | ||
ab75e417 WAA |
787 | if (prev) { |
788 | if (!nfs_match_open_context(req->wb_context, prev->wb_context)) | |
789 | return false; | |
790 | if (req->wb_context->dentry->d_inode->i_flock != NULL && | |
791 | !nfs_match_lock_context(req->wb_lock_context, | |
792 | prev->wb_lock_context)) | |
793 | return false; | |
ab75e417 WAA |
794 | if (req_offset(req) != req_offset(prev) + prev->wb_bytes) |
795 | return false; | |
796 | } | |
b4fdac1a | 797 | size = pgio->pg_ops->pg_test(pgio, prev, req); |
f0cb9ab8 WAA |
798 | WARN_ON_ONCE(size > req->wb_bytes); |
799 | if (size && size < req->wb_bytes) | |
800 | req->wb_bytes = size; | |
b4fdac1a | 801 | return size > 0; |
d8a5ad75 TM |
802 | } |
803 | ||
804 | /** | |
bcb71bba | 805 | * nfs_pageio_do_add_request - Attempt to coalesce a request into a page list. |
d8a5ad75 TM |
806 | * @desc: destination io descriptor |
807 | * @req: request | |
808 | * | |
809 | * Returns true if the request 'req' was successfully coalesced into the | |
810 | * existing list of pages 'desc'. | |
811 | */ | |
bcb71bba TM |
812 | static int nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc, |
813 | struct nfs_page *req) | |
d8a5ad75 | 814 | { |
ab75e417 | 815 | struct nfs_page *prev = NULL; |
d8a5ad75 | 816 | if (desc->pg_count != 0) { |
d8a5ad75 | 817 | prev = nfs_list_entry(desc->pg_list.prev); |
5b36c7dc | 818 | } else { |
d8007d4d TM |
819 | if (desc->pg_ops->pg_init) |
820 | desc->pg_ops->pg_init(desc, req); | |
d8a5ad75 | 821 | desc->pg_base = req->wb_pgbase; |
5b36c7dc | 822 | } |
ab75e417 WAA |
823 | if (!nfs_can_coalesce_requests(prev, req, desc)) |
824 | return 0; | |
d8a5ad75 TM |
825 | nfs_list_remove_request(req); |
826 | nfs_list_add_request(req, &desc->pg_list); | |
5b36c7dc | 827 | desc->pg_count += req->wb_bytes; |
d8a5ad75 TM |
828 | return 1; |
829 | } | |
830 | ||
bcb71bba TM |
831 | /* |
832 | * Helper for nfs_pageio_add_request and nfs_pageio_complete | |
833 | */ | |
834 | static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc) | |
835 | { | |
836 | if (!list_empty(&desc->pg_list)) { | |
1751c363 | 837 | int error = desc->pg_ops->pg_doio(desc); |
bcb71bba TM |
838 | if (error < 0) |
839 | desc->pg_error = error; | |
840 | else | |
841 | desc->pg_bytes_written += desc->pg_count; | |
842 | } | |
843 | if (list_empty(&desc->pg_list)) { | |
844 | desc->pg_count = 0; | |
845 | desc->pg_base = 0; | |
846 | } | |
847 | } | |
848 | ||
849 | /** | |
850 | * nfs_pageio_add_request - Attempt to coalesce a request into a page list. | |
851 | * @desc: destination io descriptor | |
852 | * @req: request | |
853 | * | |
2bfc6e56 WAA |
854 | * This may split a request into subrequests which are all part of the |
855 | * same page group. | |
856 | * | |
bcb71bba TM |
857 | * Returns true if the request 'req' was successfully coalesced into the |
858 | * existing list of pages 'desc'. | |
859 | */ | |
d9156f9f | 860 | static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, |
8b09bee3 | 861 | struct nfs_page *req) |
bcb71bba | 862 | { |
2bfc6e56 WAA |
863 | struct nfs_page *subreq; |
864 | unsigned int bytes_left = 0; | |
865 | unsigned int offset, pgbase; | |
866 | ||
867 | nfs_page_group_lock(req); | |
868 | ||
869 | subreq = req; | |
870 | bytes_left = subreq->wb_bytes; | |
871 | offset = subreq->wb_offset; | |
872 | pgbase = subreq->wb_pgbase; | |
873 | ||
874 | do { | |
875 | if (!nfs_pageio_do_add_request(desc, subreq)) { | |
876 | /* make sure pg_test call(s) did nothing */ | |
877 | WARN_ON_ONCE(subreq->wb_bytes != bytes_left); | |
878 | WARN_ON_ONCE(subreq->wb_offset != offset); | |
879 | WARN_ON_ONCE(subreq->wb_pgbase != pgbase); | |
880 | ||
881 | nfs_page_group_unlock(req); | |
882 | desc->pg_moreio = 1; | |
883 | nfs_pageio_doio(desc); | |
884 | if (desc->pg_error < 0) | |
885 | return 0; | |
886 | desc->pg_moreio = 0; | |
887 | if (desc->pg_recoalesce) | |
888 | return 0; | |
889 | /* retry add_request for this subreq */ | |
890 | nfs_page_group_lock(req); | |
891 | continue; | |
892 | } | |
893 | ||
894 | /* check for buggy pg_test call(s) */ | |
895 | WARN_ON_ONCE(subreq->wb_bytes + subreq->wb_pgbase > PAGE_SIZE); | |
896 | WARN_ON_ONCE(subreq->wb_bytes > bytes_left); | |
897 | WARN_ON_ONCE(subreq->wb_bytes == 0); | |
898 | ||
899 | bytes_left -= subreq->wb_bytes; | |
900 | offset += subreq->wb_bytes; | |
901 | pgbase += subreq->wb_bytes; | |
902 | ||
903 | if (bytes_left) { | |
904 | subreq = nfs_create_request(req->wb_context, | |
905 | req->wb_page, | |
906 | subreq, pgbase, bytes_left); | |
c1109558 TM |
907 | if (IS_ERR(subreq)) |
908 | goto err_ptr; | |
2bfc6e56 WAA |
909 | nfs_lock_request(subreq); |
910 | subreq->wb_offset = offset; | |
911 | subreq->wb_index = req->wb_index; | |
912 | } | |
913 | } while (bytes_left > 0); | |
914 | ||
915 | nfs_page_group_unlock(req); | |
bcb71bba | 916 | return 1; |
c1109558 TM |
917 | err_ptr: |
918 | desc->pg_error = PTR_ERR(subreq); | |
919 | nfs_page_group_unlock(req); | |
920 | return 0; | |
bcb71bba TM |
921 | } |
922 | ||
d9156f9f TM |
923 | static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc) |
924 | { | |
925 | LIST_HEAD(head); | |
926 | ||
927 | do { | |
928 | list_splice_init(&desc->pg_list, &head); | |
929 | desc->pg_bytes_written -= desc->pg_count; | |
930 | desc->pg_count = 0; | |
931 | desc->pg_base = 0; | |
932 | desc->pg_recoalesce = 0; | |
933 | ||
934 | while (!list_empty(&head)) { | |
935 | struct nfs_page *req; | |
936 | ||
937 | req = list_first_entry(&head, struct nfs_page, wb_list); | |
938 | nfs_list_remove_request(req); | |
939 | if (__nfs_pageio_add_request(desc, req)) | |
940 | continue; | |
941 | if (desc->pg_error < 0) | |
942 | return 0; | |
943 | break; | |
944 | } | |
945 | } while (desc->pg_recoalesce); | |
946 | return 1; | |
947 | } | |
948 | ||
949 | int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, | |
950 | struct nfs_page *req) | |
951 | { | |
952 | int ret; | |
953 | ||
954 | do { | |
955 | ret = __nfs_pageio_add_request(desc, req); | |
956 | if (ret) | |
957 | break; | |
958 | if (desc->pg_error < 0) | |
959 | break; | |
960 | ret = nfs_do_recoalesce(desc); | |
961 | } while (ret); | |
962 | return ret; | |
963 | } | |
89d77c8f | 964 | EXPORT_SYMBOL_GPL(nfs_pageio_add_request); |
d9156f9f | 965 | |
bcb71bba TM |
966 | /** |
967 | * nfs_pageio_complete - Complete I/O on an nfs_pageio_descriptor | |
968 | * @desc: pointer to io descriptor | |
969 | */ | |
970 | void nfs_pageio_complete(struct nfs_pageio_descriptor *desc) | |
971 | { | |
d9156f9f TM |
972 | for (;;) { |
973 | nfs_pageio_doio(desc); | |
974 | if (!desc->pg_recoalesce) | |
975 | break; | |
976 | if (!nfs_do_recoalesce(desc)) | |
977 | break; | |
978 | } | |
bcb71bba | 979 | } |
89d77c8f | 980 | EXPORT_SYMBOL_GPL(nfs_pageio_complete); |
bcb71bba | 981 | |
7fe7f848 TM |
982 | /** |
983 | * nfs_pageio_cond_complete - Conditional I/O completion | |
984 | * @desc: pointer to io descriptor | |
985 | * @index: page index | |
986 | * | |
987 | * It is important to ensure that processes don't try to take locks | |
988 | * on non-contiguous ranges of pages as that might deadlock. This | |
989 | * function should be called before attempting to wait on a locked | |
990 | * nfs_page. It will complete the I/O if the page index 'index' | |
991 | * is not contiguous with the existing list of pages in 'desc'. | |
992 | */ | |
993 | void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index) | |
994 | { | |
995 | if (!list_empty(&desc->pg_list)) { | |
996 | struct nfs_page *prev = nfs_list_entry(desc->pg_list.prev); | |
997 | if (index != prev->wb_index + 1) | |
d9156f9f | 998 | nfs_pageio_complete(desc); |
7fe7f848 TM |
999 | } |
1000 | } | |
1001 | ||
f7b422b1 | 1002 | int __init nfs_init_nfspagecache(void) |
1da177e4 LT |
1003 | { |
1004 | nfs_page_cachep = kmem_cache_create("nfs_page", | |
1005 | sizeof(struct nfs_page), | |
1006 | 0, SLAB_HWCACHE_ALIGN, | |
20c2df83 | 1007 | NULL); |
1da177e4 LT |
1008 | if (nfs_page_cachep == NULL) |
1009 | return -ENOMEM; | |
1010 | ||
1011 | return 0; | |
1012 | } | |
1013 | ||
266bee88 | 1014 | void nfs_destroy_nfspagecache(void) |
1da177e4 | 1015 | { |
1a1d92c1 | 1016 | kmem_cache_destroy(nfs_page_cachep); |
1da177e4 LT |
1017 | } |
1018 | ||
ef2c488c | 1019 | static const struct rpc_call_ops nfs_pgio_common_ops = { |
6f92fa45 AS |
1020 | .rpc_call_prepare = nfs_pgio_prepare, |
1021 | .rpc_call_done = nfs_pgio_result, | |
1022 | .rpc_release = nfs_pgio_release, | |
1023 | }; | |
41d8d5b7 AS |
1024 | |
1025 | const struct nfs_pageio_ops nfs_pgio_rw_ops = { | |
1026 | .pg_test = nfs_generic_pg_test, | |
1027 | .pg_doio = nfs_generic_pg_pgios, | |
1028 | }; |