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 | |
00bfa30a | 32 | static bool nfs_pgarray_set(struct nfs_page_array *p, unsigned int pagecount) |
30dd374f FI |
33 | { |
34 | p->npages = pagecount; | |
35 | if (pagecount <= ARRAY_SIZE(p->page_array)) | |
36 | p->pagevec = p->page_array; | |
37 | else { | |
38 | p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_KERNEL); | |
39 | if (!p->pagevec) | |
40 | p->npages = 0; | |
41 | } | |
42 | return p->pagevec != NULL; | |
43 | } | |
44 | ||
4db6e0b7 FI |
45 | void nfs_pgheader_init(struct nfs_pageio_descriptor *desc, |
46 | struct nfs_pgio_header *hdr, | |
47 | void (*release)(struct nfs_pgio_header *hdr)) | |
48 | { | |
49 | hdr->req = nfs_list_entry(desc->pg_list.next); | |
50 | hdr->inode = desc->pg_inode; | |
51 | hdr->cred = hdr->req->wb_context->cred; | |
52 | hdr->io_start = req_offset(hdr->req); | |
53 | hdr->good_bytes = desc->pg_count; | |
584aa810 | 54 | hdr->dreq = desc->pg_dreq; |
f6166384 | 55 | hdr->layout_private = desc->pg_layout_private; |
4db6e0b7 | 56 | hdr->release = release; |
061ae2ed | 57 | hdr->completion_ops = desc->pg_completion_ops; |
584aa810 FI |
58 | if (hdr->completion_ops->init_hdr) |
59 | hdr->completion_ops->init_hdr(hdr); | |
4db6e0b7 | 60 | } |
89d77c8f | 61 | EXPORT_SYMBOL_GPL(nfs_pgheader_init); |
4db6e0b7 FI |
62 | |
63 | void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos) | |
64 | { | |
65 | spin_lock(&hdr->lock); | |
66 | if (pos < hdr->io_start + hdr->good_bytes) { | |
67 | set_bit(NFS_IOHDR_ERROR, &hdr->flags); | |
68 | clear_bit(NFS_IOHDR_EOF, &hdr->flags); | |
69 | hdr->good_bytes = pos - hdr->io_start; | |
70 | hdr->error = error; | |
71 | } | |
72 | spin_unlock(&hdr->lock); | |
73 | } | |
74 | ||
1da177e4 LT |
75 | static inline struct nfs_page * |
76 | nfs_page_alloc(void) | |
77 | { | |
192e501b | 78 | struct nfs_page *p = kmem_cache_zalloc(nfs_page_cachep, GFP_NOIO); |
72895b1a | 79 | if (p) |
1da177e4 | 80 | INIT_LIST_HEAD(&p->wb_list); |
1da177e4 LT |
81 | return p; |
82 | } | |
83 | ||
84 | static inline void | |
85 | nfs_page_free(struct nfs_page *p) | |
86 | { | |
87 | kmem_cache_free(nfs_page_cachep, p); | |
88 | } | |
89 | ||
577b4232 TM |
90 | static void |
91 | nfs_iocounter_inc(struct nfs_io_counter *c) | |
92 | { | |
93 | atomic_inc(&c->io_count); | |
94 | } | |
95 | ||
96 | static void | |
97 | nfs_iocounter_dec(struct nfs_io_counter *c) | |
98 | { | |
99 | if (atomic_dec_and_test(&c->io_count)) { | |
100 | clear_bit(NFS_IO_INPROGRESS, &c->flags); | |
4e857c58 | 101 | smp_mb__after_atomic(); |
577b4232 TM |
102 | wake_up_bit(&c->flags, NFS_IO_INPROGRESS); |
103 | } | |
104 | } | |
105 | ||
106 | static int | |
107 | __nfs_iocounter_wait(struct nfs_io_counter *c) | |
108 | { | |
109 | wait_queue_head_t *wq = bit_waitqueue(&c->flags, NFS_IO_INPROGRESS); | |
110 | DEFINE_WAIT_BIT(q, &c->flags, NFS_IO_INPROGRESS); | |
111 | int ret = 0; | |
112 | ||
113 | do { | |
114 | prepare_to_wait(wq, &q.wait, TASK_KILLABLE); | |
115 | set_bit(NFS_IO_INPROGRESS, &c->flags); | |
116 | if (atomic_read(&c->io_count) == 0) | |
117 | break; | |
c1221321 | 118 | ret = nfs_wait_bit_killable(&q.key); |
577b4232 TM |
119 | } while (atomic_read(&c->io_count) != 0); |
120 | finish_wait(wq, &q.wait); | |
121 | return ret; | |
122 | } | |
123 | ||
124 | /** | |
125 | * nfs_iocounter_wait - wait for i/o to complete | |
126 | * @c: nfs_io_counter to use | |
127 | * | |
128 | * returns -ERESTARTSYS if interrupted by a fatal signal. | |
129 | * Otherwise returns 0 once the io_count hits 0. | |
130 | */ | |
131 | int | |
132 | nfs_iocounter_wait(struct nfs_io_counter *c) | |
133 | { | |
134 | if (atomic_read(&c->io_count) == 0) | |
135 | return 0; | |
136 | return __nfs_iocounter_wait(c); | |
137 | } | |
138 | ||
2bfc6e56 WAA |
139 | /* |
140 | * nfs_page_group_lock - lock the head of the page group | |
141 | * @req - request in group that is to be locked | |
fd2f3a06 | 142 | * @nonblock - if true don't block waiting for lock |
2bfc6e56 WAA |
143 | * |
144 | * this lock must be held if modifying the page group list | |
e7029206 | 145 | * |
bc8a309e WAA |
146 | * return 0 on success, < 0 on error: -EDELAY if nonblocking or the |
147 | * result from wait_on_bit_lock | |
148 | * | |
149 | * NOTE: calling with nonblock=false should always have set the | |
150 | * lock bit (see fs/buffer.c and other uses of wait_on_bit_lock | |
151 | * with TASK_UNINTERRUPTIBLE), so there is no need to check the result. | |
2bfc6e56 | 152 | */ |
e7029206 | 153 | int |
fd2f3a06 | 154 | nfs_page_group_lock(struct nfs_page *req, bool nonblock) |
2bfc6e56 WAA |
155 | { |
156 | struct nfs_page *head = req->wb_head; | |
2bfc6e56 WAA |
157 | |
158 | WARN_ON_ONCE(head != head->wb_head); | |
159 | ||
bc8a309e WAA |
160 | if (!test_and_set_bit(PG_HEADLOCK, &head->wb_flags)) |
161 | return 0; | |
e7029206 | 162 | |
bc8a309e WAA |
163 | if (!nonblock) |
164 | return wait_on_bit_lock(&head->wb_flags, PG_HEADLOCK, | |
165 | TASK_UNINTERRUPTIBLE); | |
166 | ||
167 | return -EAGAIN; | |
2bfc6e56 WAA |
168 | } |
169 | ||
170 | /* | |
171 | * nfs_page_group_unlock - unlock the head of the page group | |
172 | * @req - request in group that is to be unlocked | |
173 | */ | |
174 | void | |
175 | nfs_page_group_unlock(struct nfs_page *req) | |
176 | { | |
177 | struct nfs_page *head = req->wb_head; | |
178 | ||
179 | WARN_ON_ONCE(head != head->wb_head); | |
180 | ||
d1e1cda8 | 181 | smp_mb__before_atomic(); |
2bfc6e56 | 182 | clear_bit(PG_HEADLOCK, &head->wb_flags); |
d1e1cda8 | 183 | smp_mb__after_atomic(); |
2bfc6e56 WAA |
184 | wake_up_bit(&head->wb_flags, PG_HEADLOCK); |
185 | } | |
186 | ||
187 | /* | |
188 | * nfs_page_group_sync_on_bit_locked | |
189 | * | |
190 | * must be called with page group lock held | |
191 | */ | |
192 | static bool | |
193 | nfs_page_group_sync_on_bit_locked(struct nfs_page *req, unsigned int bit) | |
194 | { | |
195 | struct nfs_page *head = req->wb_head; | |
196 | struct nfs_page *tmp; | |
197 | ||
198 | WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &head->wb_flags)); | |
199 | WARN_ON_ONCE(test_and_set_bit(bit, &req->wb_flags)); | |
200 | ||
201 | tmp = req->wb_this_page; | |
202 | while (tmp != req) { | |
203 | if (!test_bit(bit, &tmp->wb_flags)) | |
204 | return false; | |
205 | tmp = tmp->wb_this_page; | |
206 | } | |
207 | ||
208 | /* true! reset all bits */ | |
209 | tmp = req; | |
210 | do { | |
211 | clear_bit(bit, &tmp->wb_flags); | |
212 | tmp = tmp->wb_this_page; | |
213 | } while (tmp != req); | |
214 | ||
215 | return true; | |
216 | } | |
217 | ||
218 | /* | |
219 | * nfs_page_group_sync_on_bit - set bit on current request, but only | |
220 | * return true if the bit is set for all requests in page group | |
221 | * @req - request in page group | |
222 | * @bit - PG_* bit that is used to sync page group | |
223 | */ | |
224 | bool nfs_page_group_sync_on_bit(struct nfs_page *req, unsigned int bit) | |
225 | { | |
226 | bool ret; | |
227 | ||
fd2f3a06 | 228 | nfs_page_group_lock(req, false); |
2bfc6e56 WAA |
229 | ret = nfs_page_group_sync_on_bit_locked(req, bit); |
230 | nfs_page_group_unlock(req); | |
231 | ||
232 | return ret; | |
233 | } | |
234 | ||
235 | /* | |
236 | * nfs_page_group_init - Initialize the page group linkage for @req | |
237 | * @req - a new nfs request | |
238 | * @prev - the previous request in page group, or NULL if @req is the first | |
239 | * or only request in the group (the head). | |
240 | */ | |
241 | static inline void | |
242 | nfs_page_group_init(struct nfs_page *req, struct nfs_page *prev) | |
243 | { | |
244 | WARN_ON_ONCE(prev == req); | |
245 | ||
246 | if (!prev) { | |
85710a83 | 247 | /* a head request */ |
2bfc6e56 WAA |
248 | req->wb_head = req; |
249 | req->wb_this_page = req; | |
250 | } else { | |
85710a83 | 251 | /* a subrequest */ |
2bfc6e56 WAA |
252 | WARN_ON_ONCE(prev->wb_this_page != prev->wb_head); |
253 | WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &prev->wb_head->wb_flags)); | |
254 | req->wb_head = prev->wb_head; | |
255 | req->wb_this_page = prev->wb_this_page; | |
256 | prev->wb_this_page = req; | |
257 | ||
85710a83 WAA |
258 | /* All subrequests take a ref on the head request until |
259 | * nfs_page_group_destroy is called */ | |
260 | kref_get(&req->wb_head->wb_kref); | |
261 | ||
2bfc6e56 WAA |
262 | /* grab extra ref if head request has extra ref from |
263 | * the write/commit path to handle handoff between write | |
264 | * and commit lists */ | |
17089a29 WAA |
265 | if (test_bit(PG_INODE_REF, &prev->wb_head->wb_flags)) { |
266 | set_bit(PG_INODE_REF, &req->wb_flags); | |
2bfc6e56 | 267 | kref_get(&req->wb_kref); |
17089a29 | 268 | } |
2bfc6e56 WAA |
269 | } |
270 | } | |
271 | ||
272 | /* | |
273 | * nfs_page_group_destroy - sync the destruction of page groups | |
274 | * @req - request that no longer needs the page group | |
275 | * | |
276 | * releases the page group reference from each member once all | |
277 | * members have called this function. | |
278 | */ | |
279 | static void | |
280 | nfs_page_group_destroy(struct kref *kref) | |
281 | { | |
282 | struct nfs_page *req = container_of(kref, struct nfs_page, wb_kref); | |
283 | struct nfs_page *tmp, *next; | |
284 | ||
85710a83 WAA |
285 | /* subrequests must release the ref on the head request */ |
286 | if (req->wb_head != req) | |
287 | nfs_release_request(req->wb_head); | |
288 | ||
2bfc6e56 WAA |
289 | if (!nfs_page_group_sync_on_bit(req, PG_TEARDOWN)) |
290 | return; | |
291 | ||
292 | tmp = req; | |
293 | do { | |
294 | next = tmp->wb_this_page; | |
295 | /* unlink and free */ | |
296 | tmp->wb_this_page = tmp; | |
297 | tmp->wb_head = tmp; | |
298 | nfs_free_request(tmp); | |
299 | tmp = next; | |
300 | } while (tmp != req); | |
301 | } | |
302 | ||
1da177e4 LT |
303 | /** |
304 | * nfs_create_request - Create an NFS read/write request. | |
c02f557d | 305 | * @ctx: open context to use |
1da177e4 | 306 | * @page: page to write |
2bfc6e56 | 307 | * @last: last nfs request created for this page group or NULL if head |
1da177e4 LT |
308 | * @offset: starting offset within the page for the write |
309 | * @count: number of bytes to read/write | |
310 | * | |
311 | * The page must be locked by the caller. This makes sure we never | |
a19b89ca | 312 | * create two different requests for the same page. |
1da177e4 LT |
313 | * User should ensure it is safe to sleep in this function. |
314 | */ | |
315 | struct nfs_page * | |
8c8f1ac1 | 316 | nfs_create_request(struct nfs_open_context *ctx, struct page *page, |
2bfc6e56 WAA |
317 | struct nfs_page *last, unsigned int offset, |
318 | unsigned int count) | |
1da177e4 | 319 | { |
1da177e4 | 320 | struct nfs_page *req; |
b3c54de6 | 321 | struct nfs_lock_context *l_ctx; |
1da177e4 | 322 | |
c58c8441 TM |
323 | if (test_bit(NFS_CONTEXT_BAD, &ctx->flags)) |
324 | return ERR_PTR(-EBADF); | |
18eb8842 TM |
325 | /* try to allocate the request struct */ |
326 | req = nfs_page_alloc(); | |
327 | if (req == NULL) | |
328 | return ERR_PTR(-ENOMEM); | |
1da177e4 | 329 | |
015f0212 | 330 | /* get lock context early so we can deal with alloc failures */ |
b3c54de6 TM |
331 | l_ctx = nfs_get_lock_context(ctx); |
332 | if (IS_ERR(l_ctx)) { | |
015f0212 | 333 | nfs_page_free(req); |
b3c54de6 | 334 | return ERR_CAST(l_ctx); |
015f0212 | 335 | } |
b3c54de6 | 336 | req->wb_lock_context = l_ctx; |
577b4232 | 337 | nfs_iocounter_inc(&l_ctx->io_count); |
015f0212 | 338 | |
1da177e4 LT |
339 | /* Initialize the request struct. Initially, we assume a |
340 | * long write-back delay. This will be adjusted in | |
341 | * update_nfs_request below if the region is not locked. */ | |
342 | req->wb_page = page; | |
d56b4ddf | 343 | req->wb_index = page_file_index(page); |
1da177e4 LT |
344 | page_cache_get(page); |
345 | req->wb_offset = offset; | |
346 | req->wb_pgbase = offset; | |
347 | req->wb_bytes = count; | |
1da177e4 | 348 | req->wb_context = get_nfs_open_context(ctx); |
c03b4024 | 349 | kref_init(&req->wb_kref); |
2bfc6e56 | 350 | nfs_page_group_init(req, last); |
1da177e4 LT |
351 | return req; |
352 | } | |
353 | ||
354 | /** | |
1d1afcbc | 355 | * nfs_unlock_request - Unlock request and wake up sleepers. |
1da177e4 LT |
356 | * @req: |
357 | */ | |
1d1afcbc | 358 | void nfs_unlock_request(struct nfs_page *req) |
1da177e4 LT |
359 | { |
360 | if (!NFS_WBACK_BUSY(req)) { | |
361 | printk(KERN_ERR "NFS: Invalid unlock attempted\n"); | |
362 | BUG(); | |
363 | } | |
4e857c58 | 364 | smp_mb__before_atomic(); |
1da177e4 | 365 | clear_bit(PG_BUSY, &req->wb_flags); |
4e857c58 | 366 | smp_mb__after_atomic(); |
464a98bd | 367 | wake_up_bit(&req->wb_flags, PG_BUSY); |
3aff4ebb TM |
368 | } |
369 | ||
370 | /** | |
1d1afcbc TM |
371 | * nfs_unlock_and_release_request - Unlock request and release the nfs_page |
372 | * @req: | |
3aff4ebb | 373 | */ |
1d1afcbc | 374 | void nfs_unlock_and_release_request(struct nfs_page *req) |
3aff4ebb | 375 | { |
1d1afcbc | 376 | nfs_unlock_request(req); |
1da177e4 LT |
377 | nfs_release_request(req); |
378 | } | |
379 | ||
4d65c520 | 380 | /* |
1da177e4 LT |
381 | * nfs_clear_request - Free up all resources allocated to the request |
382 | * @req: | |
383 | * | |
bb6fbc45 TM |
384 | * Release page and open context resources associated with a read/write |
385 | * request after it has completed. | |
1da177e4 | 386 | */ |
4d65c520 | 387 | static void nfs_clear_request(struct nfs_page *req) |
1da177e4 | 388 | { |
cd52ed35 | 389 | struct page *page = req->wb_page; |
bb6fbc45 | 390 | struct nfs_open_context *ctx = req->wb_context; |
f11ac8db | 391 | struct nfs_lock_context *l_ctx = req->wb_lock_context; |
bb6fbc45 | 392 | |
cd52ed35 | 393 | if (page != NULL) { |
cd52ed35 | 394 | page_cache_release(page); |
1da177e4 LT |
395 | req->wb_page = NULL; |
396 | } | |
f11ac8db | 397 | if (l_ctx != NULL) { |
577b4232 | 398 | nfs_iocounter_dec(&l_ctx->io_count); |
f11ac8db TM |
399 | nfs_put_lock_context(l_ctx); |
400 | req->wb_lock_context = NULL; | |
401 | } | |
bb6fbc45 TM |
402 | if (ctx != NULL) { |
403 | put_nfs_open_context(ctx); | |
404 | req->wb_context = NULL; | |
405 | } | |
1da177e4 LT |
406 | } |
407 | ||
1da177e4 LT |
408 | /** |
409 | * nfs_release_request - Release the count on an NFS read/write request | |
410 | * @req: request to release | |
411 | * | |
412 | * Note: Should never be called with the spinlock held! | |
413 | */ | |
d4581383 | 414 | void nfs_free_request(struct nfs_page *req) |
1da177e4 | 415 | { |
2bfc6e56 WAA |
416 | WARN_ON_ONCE(req->wb_this_page != req); |
417 | ||
418 | /* extra debug: make sure no sync bits are still set */ | |
419 | WARN_ON_ONCE(test_bit(PG_TEARDOWN, &req->wb_flags)); | |
67d0338e WAA |
420 | WARN_ON_ONCE(test_bit(PG_UNLOCKPAGE, &req->wb_flags)); |
421 | WARN_ON_ONCE(test_bit(PG_UPTODATE, &req->wb_flags)); | |
20633f04 WAA |
422 | WARN_ON_ONCE(test_bit(PG_WB_END, &req->wb_flags)); |
423 | WARN_ON_ONCE(test_bit(PG_REMOVE, &req->wb_flags)); | |
1da177e4 | 424 | |
bb6fbc45 | 425 | /* Release struct file and open context */ |
1da177e4 | 426 | nfs_clear_request(req); |
1da177e4 LT |
427 | nfs_page_free(req); |
428 | } | |
429 | ||
c03b4024 TM |
430 | void nfs_release_request(struct nfs_page *req) |
431 | { | |
2bfc6e56 | 432 | kref_put(&req->wb_kref, nfs_page_group_destroy); |
9f557cd8 TM |
433 | } |
434 | ||
1da177e4 LT |
435 | /** |
436 | * nfs_wait_on_request - Wait for a request to complete. | |
437 | * @req: request to wait upon. | |
438 | * | |
150030b7 | 439 | * Interruptible by fatal signals only. |
1da177e4 LT |
440 | * The user is responsible for holding a count on the request. |
441 | */ | |
442 | int | |
443 | nfs_wait_on_request(struct nfs_page *req) | |
444 | { | |
74316201 N |
445 | return wait_on_bit_io(&req->wb_flags, PG_BUSY, |
446 | TASK_UNINTERRUPTIBLE); | |
1da177e4 LT |
447 | } |
448 | ||
b4fdac1a WAA |
449 | /* |
450 | * nfs_generic_pg_test - determine if requests can be coalesced | |
451 | * @desc: pointer to descriptor | |
452 | * @prev: previous request in desc, or NULL | |
453 | * @req: this request | |
454 | * | |
455 | * Returns zero if @req can be coalesced into @desc, otherwise it returns | |
456 | * the size of the request. | |
457 | */ | |
458 | size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, | |
459 | struct nfs_page *prev, struct nfs_page *req) | |
5b36c7dc | 460 | { |
f0cb9ab8 WAA |
461 | if (desc->pg_count > desc->pg_bsize) { |
462 | /* should never happen */ | |
463 | WARN_ON_ONCE(1); | |
5b36c7dc | 464 | return 0; |
f0cb9ab8 | 465 | } |
5b36c7dc | 466 | |
f0cb9ab8 | 467 | return min(desc->pg_bsize - desc->pg_count, (size_t)req->wb_bytes); |
5b36c7dc | 468 | } |
19345cb2 | 469 | EXPORT_SYMBOL_GPL(nfs_generic_pg_test); |
5b36c7dc | 470 | |
1e7f3a48 | 471 | struct nfs_pgio_header *nfs_pgio_header_alloc(const struct nfs_rw_ops *ops) |
4a0de55c | 472 | { |
1e7f3a48 | 473 | struct nfs_pgio_header *hdr = ops->rw_alloc_header(); |
4a0de55c | 474 | |
1e7f3a48 | 475 | if (hdr) { |
4a0de55c | 476 | INIT_LIST_HEAD(&hdr->pages); |
4a0de55c | 477 | spin_lock_init(&hdr->lock); |
4a0de55c AS |
478 | hdr->rw_ops = ops; |
479 | } | |
1e7f3a48 | 480 | return hdr; |
4a0de55c | 481 | } |
1e7f3a48 | 482 | EXPORT_SYMBOL_GPL(nfs_pgio_header_alloc); |
4a0de55c AS |
483 | |
484 | /* | |
1e7f3a48 | 485 | * nfs_pgio_header_free - Free a read or write header |
4a0de55c AS |
486 | * @hdr: The header to free |
487 | */ | |
1e7f3a48 | 488 | void nfs_pgio_header_free(struct nfs_pgio_header *hdr) |
4a0de55c | 489 | { |
1e7f3a48 | 490 | hdr->rw_ops->rw_free_header(hdr); |
4a0de55c | 491 | } |
1e7f3a48 | 492 | EXPORT_SYMBOL_GPL(nfs_pgio_header_free); |
4a0de55c | 493 | |
00bfa30a | 494 | /** |
4714fb51 WAA |
495 | * nfs_pgio_data_destroy - make @hdr suitable for reuse |
496 | * | |
497 | * Frees memory and releases refs from nfs_generic_pgio, so that it may | |
498 | * be called again. | |
499 | * | |
500 | * @hdr: A header that has had nfs_generic_pgio called | |
00bfa30a | 501 | */ |
d45f60c6 | 502 | void nfs_pgio_data_destroy(struct nfs_pgio_header *hdr) |
00bfa30a | 503 | { |
d45f60c6 WAA |
504 | put_nfs_open_context(hdr->args.context); |
505 | if (hdr->page_array.pagevec != hdr->page_array.page_array) | |
506 | kfree(hdr->page_array.pagevec); | |
00bfa30a | 507 | } |
1e7f3a48 | 508 | EXPORT_SYMBOL_GPL(nfs_pgio_data_destroy); |
00bfa30a | 509 | |
ce59515c AS |
510 | /** |
511 | * nfs_pgio_rpcsetup - Set up arguments for a pageio call | |
d45f60c6 | 512 | * @hdr: The pageio hdr |
ce59515c AS |
513 | * @count: Number of bytes to read |
514 | * @offset: Initial offset | |
515 | * @how: How to commit data (writes only) | |
516 | * @cinfo: Commit information for the call (writes only) | |
517 | */ | |
d45f60c6 | 518 | static void nfs_pgio_rpcsetup(struct nfs_pgio_header *hdr, |
ce59515c AS |
519 | unsigned int count, unsigned int offset, |
520 | int how, struct nfs_commit_info *cinfo) | |
521 | { | |
d45f60c6 | 522 | struct nfs_page *req = hdr->req; |
ce59515c AS |
523 | |
524 | /* Set up the RPC argument and reply structs | |
d45f60c6 | 525 | * NB: take care not to mess about with hdr->commit et al. */ |
ce59515c | 526 | |
d45f60c6 WAA |
527 | hdr->args.fh = NFS_FH(hdr->inode); |
528 | hdr->args.offset = req_offset(req) + offset; | |
ce59515c | 529 | /* pnfs_set_layoutcommit needs this */ |
d45f60c6 WAA |
530 | hdr->mds_offset = hdr->args.offset; |
531 | hdr->args.pgbase = req->wb_pgbase + offset; | |
532 | hdr->args.pages = hdr->page_array.pagevec; | |
533 | hdr->args.count = count; | |
534 | hdr->args.context = get_nfs_open_context(req->wb_context); | |
535 | hdr->args.lock_context = req->wb_lock_context; | |
536 | hdr->args.stable = NFS_UNSTABLE; | |
ce59515c AS |
537 | switch (how & (FLUSH_STABLE | FLUSH_COND_STABLE)) { |
538 | case 0: | |
539 | break; | |
540 | case FLUSH_COND_STABLE: | |
541 | if (nfs_reqs_to_commit(cinfo)) | |
542 | break; | |
543 | default: | |
d45f60c6 | 544 | hdr->args.stable = NFS_FILE_SYNC; |
ce59515c AS |
545 | } |
546 | ||
d45f60c6 WAA |
547 | hdr->res.fattr = &hdr->fattr; |
548 | hdr->res.count = count; | |
549 | hdr->res.eof = 0; | |
c65e6254 | 550 | hdr->res.verf = &hdr->verf; |
d45f60c6 | 551 | nfs_fattr_init(&hdr->fattr); |
ce59515c AS |
552 | } |
553 | ||
a4cdda59 | 554 | /** |
d45f60c6 | 555 | * nfs_pgio_prepare - Prepare pageio hdr to go over the wire |
a4cdda59 | 556 | * @task: The current task |
d45f60c6 | 557 | * @calldata: pageio header to prepare |
a4cdda59 | 558 | */ |
6f92fa45 | 559 | static void nfs_pgio_prepare(struct rpc_task *task, void *calldata) |
a4cdda59 | 560 | { |
d45f60c6 | 561 | struct nfs_pgio_header *hdr = calldata; |
a4cdda59 | 562 | int err; |
d45f60c6 | 563 | err = NFS_PROTO(hdr->inode)->pgio_rpc_prepare(task, hdr); |
a4cdda59 AS |
564 | if (err) |
565 | rpc_exit(task, err); | |
566 | } | |
567 | ||
d45f60c6 | 568 | int nfs_initiate_pgio(struct rpc_clnt *clnt, struct nfs_pgio_header *hdr, |
1ed26f33 AS |
569 | const struct rpc_call_ops *call_ops, int how, int flags) |
570 | { | |
571 | struct rpc_task *task; | |
572 | struct rpc_message msg = { | |
d45f60c6 WAA |
573 | .rpc_argp = &hdr->args, |
574 | .rpc_resp = &hdr->res, | |
575 | .rpc_cred = hdr->cred, | |
1ed26f33 AS |
576 | }; |
577 | struct rpc_task_setup task_setup_data = { | |
578 | .rpc_client = clnt, | |
d45f60c6 | 579 | .task = &hdr->task, |
1ed26f33 AS |
580 | .rpc_message = &msg, |
581 | .callback_ops = call_ops, | |
d45f60c6 | 582 | .callback_data = hdr, |
1ed26f33 AS |
583 | .workqueue = nfsiod_workqueue, |
584 | .flags = RPC_TASK_ASYNC | flags, | |
585 | }; | |
586 | int ret = 0; | |
587 | ||
d45f60c6 | 588 | hdr->rw_ops->rw_initiate(hdr, &msg, &task_setup_data, how); |
1ed26f33 AS |
589 | |
590 | dprintk("NFS: %5u initiated pgio call " | |
591 | "(req %s/%llu, %u bytes @ offset %llu)\n", | |
d45f60c6 | 592 | hdr->task.tk_pid, |
343ae531 AS |
593 | hdr->inode->i_sb->s_id, |
594 | (unsigned long long)NFS_FILEID(hdr->inode), | |
d45f60c6 WAA |
595 | hdr->args.count, |
596 | (unsigned long long)hdr->args.offset); | |
1ed26f33 AS |
597 | |
598 | task = rpc_run_task(&task_setup_data); | |
599 | if (IS_ERR(task)) { | |
600 | ret = PTR_ERR(task); | |
601 | goto out; | |
602 | } | |
603 | if (how & FLUSH_SYNC) { | |
604 | ret = rpc_wait_for_completion_task(task); | |
605 | if (ret == 0) | |
606 | ret = task->tk_status; | |
607 | } | |
608 | rpc_put_task(task); | |
609 | out: | |
610 | return ret; | |
611 | } | |
612 | EXPORT_SYMBOL_GPL(nfs_initiate_pgio); | |
613 | ||
844c9e69 AS |
614 | /** |
615 | * nfs_pgio_error - Clean up from a pageio error | |
616 | * @desc: IO descriptor | |
617 | * @hdr: pageio header | |
618 | */ | |
ef2c488c | 619 | static int nfs_pgio_error(struct nfs_pageio_descriptor *desc, |
844c9e69 AS |
620 | struct nfs_pgio_header *hdr) |
621 | { | |
844c9e69 | 622 | set_bit(NFS_IOHDR_REDO, &hdr->flags); |
d45f60c6 | 623 | nfs_pgio_data_destroy(hdr); |
4714fb51 | 624 | hdr->completion_ops->completion(hdr); |
844c9e69 AS |
625 | desc->pg_completion_ops->error_cleanup(&desc->pg_list); |
626 | return -ENOMEM; | |
627 | } | |
628 | ||
a4cdda59 AS |
629 | /** |
630 | * nfs_pgio_release - Release pageio data | |
d45f60c6 | 631 | * @calldata: The pageio header to release |
a4cdda59 | 632 | */ |
6f92fa45 | 633 | static void nfs_pgio_release(void *calldata) |
a4cdda59 | 634 | { |
d45f60c6 WAA |
635 | struct nfs_pgio_header *hdr = calldata; |
636 | if (hdr->rw_ops->rw_release) | |
637 | hdr->rw_ops->rw_release(hdr); | |
638 | nfs_pgio_data_destroy(hdr); | |
4714fb51 | 639 | hdr->completion_ops->completion(hdr); |
a4cdda59 AS |
640 | } |
641 | ||
1da177e4 | 642 | /** |
d8a5ad75 TM |
643 | * nfs_pageio_init - initialise a page io descriptor |
644 | * @desc: pointer to descriptor | |
bcb71bba TM |
645 | * @inode: pointer to inode |
646 | * @doio: pointer to io function | |
647 | * @bsize: io block size | |
648 | * @io_flags: extra parameters for the io function | |
d8a5ad75 | 649 | */ |
bcb71bba TM |
650 | void nfs_pageio_init(struct nfs_pageio_descriptor *desc, |
651 | struct inode *inode, | |
1751c363 | 652 | const struct nfs_pageio_ops *pg_ops, |
061ae2ed | 653 | const struct nfs_pgio_completion_ops *compl_ops, |
4a0de55c | 654 | const struct nfs_rw_ops *rw_ops, |
84dde76c | 655 | size_t bsize, |
bcb71bba | 656 | int io_flags) |
d8a5ad75 TM |
657 | { |
658 | INIT_LIST_HEAD(&desc->pg_list); | |
bcb71bba | 659 | desc->pg_bytes_written = 0; |
d8a5ad75 TM |
660 | desc->pg_count = 0; |
661 | desc->pg_bsize = bsize; | |
662 | desc->pg_base = 0; | |
b31268ac | 663 | desc->pg_moreio = 0; |
d9156f9f | 664 | desc->pg_recoalesce = 0; |
bcb71bba | 665 | desc->pg_inode = inode; |
1751c363 | 666 | desc->pg_ops = pg_ops; |
061ae2ed | 667 | desc->pg_completion_ops = compl_ops; |
4a0de55c | 668 | desc->pg_rw_ops = rw_ops; |
bcb71bba TM |
669 | desc->pg_ioflags = io_flags; |
670 | desc->pg_error = 0; | |
94ad1c80 | 671 | desc->pg_lseg = NULL; |
584aa810 | 672 | desc->pg_dreq = NULL; |
f6166384 | 673 | desc->pg_layout_private = NULL; |
d8a5ad75 | 674 | } |
89d77c8f | 675 | EXPORT_SYMBOL_GPL(nfs_pageio_init); |
d8a5ad75 | 676 | |
0eecb214 AS |
677 | /** |
678 | * nfs_pgio_result - Basic pageio error handling | |
679 | * @task: The task that ran | |
d45f60c6 | 680 | * @calldata: Pageio header to check |
0eecb214 | 681 | */ |
6f92fa45 | 682 | static void nfs_pgio_result(struct rpc_task *task, void *calldata) |
0eecb214 | 683 | { |
d45f60c6 WAA |
684 | struct nfs_pgio_header *hdr = calldata; |
685 | struct inode *inode = hdr->inode; | |
0eecb214 AS |
686 | |
687 | dprintk("NFS: %s: %5u, (status %d)\n", __func__, | |
688 | task->tk_pid, task->tk_status); | |
689 | ||
d45f60c6 | 690 | if (hdr->rw_ops->rw_done(task, hdr, inode) != 0) |
0eecb214 AS |
691 | return; |
692 | if (task->tk_status < 0) | |
d45f60c6 | 693 | nfs_set_pgio_error(hdr, task->tk_status, hdr->args.offset); |
0eecb214 | 694 | else |
d45f60c6 | 695 | hdr->rw_ops->rw_result(task, hdr); |
0eecb214 AS |
696 | } |
697 | ||
ef2c488c AS |
698 | /* |
699 | * Create an RPC task for the given read or write request and kick it. | |
700 | * The page must have been locked by the caller. | |
701 | * | |
702 | * It may happen that the page we're passed is not marked dirty. | |
703 | * This is the case if nfs_updatepage detects a conflicting request | |
704 | * that has been written but not committed. | |
705 | */ | |
f0cb9ab8 WAA |
706 | int nfs_generic_pgio(struct nfs_pageio_descriptor *desc, |
707 | struct nfs_pgio_header *hdr) | |
ef2c488c AS |
708 | { |
709 | struct nfs_page *req; | |
710 | struct page **pages; | |
ef2c488c AS |
711 | struct list_head *head = &desc->pg_list; |
712 | struct nfs_commit_info cinfo; | |
4714fb51 | 713 | unsigned int pagecount; |
ef2c488c | 714 | |
4714fb51 WAA |
715 | pagecount = nfs_page_array_len(desc->pg_base, desc->pg_count); |
716 | if (!nfs_pgarray_set(&hdr->page_array, pagecount)) | |
ef2c488c AS |
717 | return nfs_pgio_error(desc, hdr); |
718 | ||
719 | nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq); | |
d45f60c6 | 720 | pages = hdr->page_array.pagevec; |
ef2c488c AS |
721 | while (!list_empty(head)) { |
722 | req = nfs_list_entry(head->next); | |
723 | nfs_list_remove_request(req); | |
724 | nfs_list_add_request(req, &hdr->pages); | |
725 | *pages++ = req->wb_page; | |
726 | } | |
727 | ||
728 | if ((desc->pg_ioflags & FLUSH_COND_STABLE) && | |
729 | (desc->pg_moreio || nfs_reqs_to_commit(&cinfo))) | |
730 | desc->pg_ioflags &= ~FLUSH_COND_STABLE; | |
731 | ||
732 | /* Set up the argument struct */ | |
d45f60c6 | 733 | nfs_pgio_rpcsetup(hdr, desc->pg_count, 0, desc->pg_ioflags, &cinfo); |
ef2c488c AS |
734 | desc->pg_rpc_callops = &nfs_pgio_common_ops; |
735 | return 0; | |
736 | } | |
f0cb9ab8 | 737 | EXPORT_SYMBOL_GPL(nfs_generic_pgio); |
ef2c488c | 738 | |
41d8d5b7 | 739 | static int nfs_generic_pg_pgios(struct nfs_pageio_descriptor *desc) |
cf485fcd | 740 | { |
cf485fcd AS |
741 | struct nfs_pgio_header *hdr; |
742 | int ret; | |
743 | ||
1e7f3a48 WAA |
744 | hdr = nfs_pgio_header_alloc(desc->pg_rw_ops); |
745 | if (!hdr) { | |
cf485fcd AS |
746 | desc->pg_completion_ops->error_cleanup(&desc->pg_list); |
747 | return -ENOMEM; | |
748 | } | |
1e7f3a48 | 749 | nfs_pgheader_init(desc, hdr, nfs_pgio_header_free); |
cf485fcd AS |
750 | ret = nfs_generic_pgio(desc, hdr); |
751 | if (ret == 0) | |
7f714720 | 752 | ret = nfs_initiate_pgio(NFS_CLIENT(hdr->inode), |
d45f60c6 | 753 | hdr, desc->pg_rpc_callops, |
7f714720 | 754 | desc->pg_ioflags, 0); |
cf485fcd AS |
755 | return ret; |
756 | } | |
757 | ||
4109bb74 TM |
758 | static bool nfs_match_open_context(const struct nfs_open_context *ctx1, |
759 | const struct nfs_open_context *ctx2) | |
760 | { | |
761 | return ctx1->cred == ctx2->cred && ctx1->state == ctx2->state; | |
762 | } | |
763 | ||
764 | static bool nfs_match_lock_context(const struct nfs_lock_context *l1, | |
765 | const struct nfs_lock_context *l2) | |
766 | { | |
767 | return l1->lockowner.l_owner == l2->lockowner.l_owner | |
768 | && l1->lockowner.l_pid == l2->lockowner.l_pid; | |
769 | } | |
770 | ||
d8a5ad75 TM |
771 | /** |
772 | * nfs_can_coalesce_requests - test two requests for compatibility | |
773 | * @prev: pointer to nfs_page | |
774 | * @req: pointer to nfs_page | |
775 | * | |
776 | * The nfs_page structures 'prev' and 'req' are compared to ensure that the | |
777 | * page data area they describe is contiguous, and that their RPC | |
778 | * credentials, NFSv4 open state, and lockowners are the same. | |
779 | * | |
780 | * Return 'true' if this is the case, else return 'false'. | |
781 | */ | |
18ad0a9f BH |
782 | static bool nfs_can_coalesce_requests(struct nfs_page *prev, |
783 | struct nfs_page *req, | |
784 | struct nfs_pageio_descriptor *pgio) | |
d8a5ad75 | 785 | { |
b4fdac1a WAA |
786 | size_t size; |
787 | ||
ab75e417 WAA |
788 | if (prev) { |
789 | if (!nfs_match_open_context(req->wb_context, prev->wb_context)) | |
790 | return false; | |
791 | if (req->wb_context->dentry->d_inode->i_flock != NULL && | |
792 | !nfs_match_lock_context(req->wb_lock_context, | |
793 | prev->wb_lock_context)) | |
794 | return false; | |
ab75e417 WAA |
795 | if (req_offset(req) != req_offset(prev) + prev->wb_bytes) |
796 | return false; | |
797 | } | |
b4fdac1a | 798 | size = pgio->pg_ops->pg_test(pgio, prev, req); |
f0cb9ab8 WAA |
799 | WARN_ON_ONCE(size > req->wb_bytes); |
800 | if (size && size < req->wb_bytes) | |
801 | req->wb_bytes = size; | |
b4fdac1a | 802 | return size > 0; |
d8a5ad75 TM |
803 | } |
804 | ||
805 | /** | |
bcb71bba | 806 | * nfs_pageio_do_add_request - Attempt to coalesce a request into a page list. |
d8a5ad75 TM |
807 | * @desc: destination io descriptor |
808 | * @req: request | |
809 | * | |
810 | * Returns true if the request 'req' was successfully coalesced into the | |
811 | * existing list of pages 'desc'. | |
812 | */ | |
bcb71bba TM |
813 | static int nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc, |
814 | struct nfs_page *req) | |
d8a5ad75 | 815 | { |
ab75e417 | 816 | struct nfs_page *prev = NULL; |
d8a5ad75 | 817 | if (desc->pg_count != 0) { |
d8a5ad75 | 818 | prev = nfs_list_entry(desc->pg_list.prev); |
5b36c7dc | 819 | } else { |
d8007d4d TM |
820 | if (desc->pg_ops->pg_init) |
821 | desc->pg_ops->pg_init(desc, req); | |
d8a5ad75 | 822 | desc->pg_base = req->wb_pgbase; |
5b36c7dc | 823 | } |
ab75e417 WAA |
824 | if (!nfs_can_coalesce_requests(prev, req, desc)) |
825 | return 0; | |
d8a5ad75 TM |
826 | nfs_list_remove_request(req); |
827 | nfs_list_add_request(req, &desc->pg_list); | |
5b36c7dc | 828 | desc->pg_count += req->wb_bytes; |
d8a5ad75 TM |
829 | return 1; |
830 | } | |
831 | ||
bcb71bba TM |
832 | /* |
833 | * Helper for nfs_pageio_add_request and nfs_pageio_complete | |
834 | */ | |
835 | static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc) | |
836 | { | |
837 | if (!list_empty(&desc->pg_list)) { | |
1751c363 | 838 | int error = desc->pg_ops->pg_doio(desc); |
bcb71bba TM |
839 | if (error < 0) |
840 | desc->pg_error = error; | |
841 | else | |
842 | desc->pg_bytes_written += desc->pg_count; | |
843 | } | |
844 | if (list_empty(&desc->pg_list)) { | |
845 | desc->pg_count = 0; | |
846 | desc->pg_base = 0; | |
847 | } | |
848 | } | |
849 | ||
850 | /** | |
851 | * nfs_pageio_add_request - Attempt to coalesce a request into a page list. | |
852 | * @desc: destination io descriptor | |
853 | * @req: request | |
854 | * | |
2bfc6e56 WAA |
855 | * This may split a request into subrequests which are all part of the |
856 | * same page group. | |
857 | * | |
bcb71bba TM |
858 | * Returns true if the request 'req' was successfully coalesced into the |
859 | * existing list of pages 'desc'. | |
860 | */ | |
d9156f9f | 861 | static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, |
8b09bee3 | 862 | struct nfs_page *req) |
bcb71bba | 863 | { |
2bfc6e56 WAA |
864 | struct nfs_page *subreq; |
865 | unsigned int bytes_left = 0; | |
866 | unsigned int offset, pgbase; | |
e7029206 | 867 | int ret; |
2bfc6e56 | 868 | |
fd2f3a06 | 869 | ret = nfs_page_group_lock(req, true); |
e7029206 WAA |
870 | if (ret < 0) { |
871 | desc->pg_error = ret; | |
872 | return 0; | |
873 | } | |
2bfc6e56 WAA |
874 | |
875 | subreq = req; | |
876 | bytes_left = subreq->wb_bytes; | |
877 | offset = subreq->wb_offset; | |
878 | pgbase = subreq->wb_pgbase; | |
879 | ||
880 | do { | |
881 | if (!nfs_pageio_do_add_request(desc, subreq)) { | |
882 | /* make sure pg_test call(s) did nothing */ | |
883 | WARN_ON_ONCE(subreq->wb_bytes != bytes_left); | |
884 | WARN_ON_ONCE(subreq->wb_offset != offset); | |
885 | WARN_ON_ONCE(subreq->wb_pgbase != pgbase); | |
886 | ||
887 | nfs_page_group_unlock(req); | |
888 | desc->pg_moreio = 1; | |
889 | nfs_pageio_doio(desc); | |
890 | if (desc->pg_error < 0) | |
891 | return 0; | |
2bfc6e56 WAA |
892 | if (desc->pg_recoalesce) |
893 | return 0; | |
894 | /* retry add_request for this subreq */ | |
fd2f3a06 | 895 | ret = nfs_page_group_lock(req, true); |
e7029206 WAA |
896 | if (ret < 0) { |
897 | desc->pg_error = ret; | |
898 | return 0; | |
899 | } | |
2bfc6e56 WAA |
900 | continue; |
901 | } | |
902 | ||
903 | /* check for buggy pg_test call(s) */ | |
904 | WARN_ON_ONCE(subreq->wb_bytes + subreq->wb_pgbase > PAGE_SIZE); | |
905 | WARN_ON_ONCE(subreq->wb_bytes > bytes_left); | |
906 | WARN_ON_ONCE(subreq->wb_bytes == 0); | |
907 | ||
908 | bytes_left -= subreq->wb_bytes; | |
909 | offset += subreq->wb_bytes; | |
910 | pgbase += subreq->wb_bytes; | |
911 | ||
912 | if (bytes_left) { | |
913 | subreq = nfs_create_request(req->wb_context, | |
914 | req->wb_page, | |
915 | subreq, pgbase, bytes_left); | |
c1109558 TM |
916 | if (IS_ERR(subreq)) |
917 | goto err_ptr; | |
2bfc6e56 WAA |
918 | nfs_lock_request(subreq); |
919 | subreq->wb_offset = offset; | |
920 | subreq->wb_index = req->wb_index; | |
921 | } | |
922 | } while (bytes_left > 0); | |
923 | ||
924 | nfs_page_group_unlock(req); | |
bcb71bba | 925 | return 1; |
c1109558 TM |
926 | err_ptr: |
927 | desc->pg_error = PTR_ERR(subreq); | |
928 | nfs_page_group_unlock(req); | |
929 | return 0; | |
bcb71bba TM |
930 | } |
931 | ||
d9156f9f TM |
932 | static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc) |
933 | { | |
934 | LIST_HEAD(head); | |
935 | ||
936 | do { | |
937 | list_splice_init(&desc->pg_list, &head); | |
938 | desc->pg_bytes_written -= desc->pg_count; | |
939 | desc->pg_count = 0; | |
940 | desc->pg_base = 0; | |
941 | desc->pg_recoalesce = 0; | |
f563b89b | 942 | desc->pg_moreio = 0; |
d9156f9f TM |
943 | |
944 | while (!list_empty(&head)) { | |
945 | struct nfs_page *req; | |
946 | ||
947 | req = list_first_entry(&head, struct nfs_page, wb_list); | |
948 | nfs_list_remove_request(req); | |
949 | if (__nfs_pageio_add_request(desc, req)) | |
950 | continue; | |
951 | if (desc->pg_error < 0) | |
952 | return 0; | |
953 | break; | |
954 | } | |
955 | } while (desc->pg_recoalesce); | |
956 | return 1; | |
957 | } | |
958 | ||
959 | int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, | |
960 | struct nfs_page *req) | |
961 | { | |
962 | int ret; | |
963 | ||
964 | do { | |
965 | ret = __nfs_pageio_add_request(desc, req); | |
966 | if (ret) | |
967 | break; | |
968 | if (desc->pg_error < 0) | |
969 | break; | |
970 | ret = nfs_do_recoalesce(desc); | |
971 | } while (ret); | |
972 | return ret; | |
973 | } | |
974 | ||
53113ad3 WAA |
975 | /* |
976 | * nfs_pageio_resend - Transfer requests to new descriptor and resend | |
977 | * @hdr - the pgio header to move request from | |
978 | * @desc - the pageio descriptor to add requests to | |
979 | * | |
980 | * Try to move each request (nfs_page) from @hdr to @desc then attempt | |
981 | * to send them. | |
982 | * | |
983 | * Returns 0 on success and < 0 on error. | |
984 | */ | |
985 | int nfs_pageio_resend(struct nfs_pageio_descriptor *desc, | |
986 | struct nfs_pgio_header *hdr) | |
987 | { | |
988 | LIST_HEAD(failed); | |
989 | ||
990 | desc->pg_dreq = hdr->dreq; | |
991 | while (!list_empty(&hdr->pages)) { | |
992 | struct nfs_page *req = nfs_list_entry(hdr->pages.next); | |
993 | ||
994 | nfs_list_remove_request(req); | |
995 | if (!nfs_pageio_add_request(desc, req)) | |
996 | nfs_list_add_request(req, &failed); | |
997 | } | |
998 | nfs_pageio_complete(desc); | |
999 | if (!list_empty(&failed)) { | |
1000 | list_move(&failed, &hdr->pages); | |
1001 | return -EIO; | |
1002 | } | |
1003 | return 0; | |
1004 | } | |
1005 | EXPORT_SYMBOL_GPL(nfs_pageio_resend); | |
d9156f9f | 1006 | |
bcb71bba TM |
1007 | /** |
1008 | * nfs_pageio_complete - Complete I/O on an nfs_pageio_descriptor | |
1009 | * @desc: pointer to io descriptor | |
1010 | */ | |
1011 | void nfs_pageio_complete(struct nfs_pageio_descriptor *desc) | |
1012 | { | |
d9156f9f TM |
1013 | for (;;) { |
1014 | nfs_pageio_doio(desc); | |
1015 | if (!desc->pg_recoalesce) | |
1016 | break; | |
1017 | if (!nfs_do_recoalesce(desc)) | |
1018 | break; | |
1019 | } | |
bcb71bba TM |
1020 | } |
1021 | ||
7fe7f848 TM |
1022 | /** |
1023 | * nfs_pageio_cond_complete - Conditional I/O completion | |
1024 | * @desc: pointer to io descriptor | |
1025 | * @index: page index | |
1026 | * | |
1027 | * It is important to ensure that processes don't try to take locks | |
1028 | * on non-contiguous ranges of pages as that might deadlock. This | |
1029 | * function should be called before attempting to wait on a locked | |
1030 | * nfs_page. It will complete the I/O if the page index 'index' | |
1031 | * is not contiguous with the existing list of pages in 'desc'. | |
1032 | */ | |
1033 | void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index) | |
1034 | { | |
1035 | if (!list_empty(&desc->pg_list)) { | |
1036 | struct nfs_page *prev = nfs_list_entry(desc->pg_list.prev); | |
1037 | if (index != prev->wb_index + 1) | |
d9156f9f | 1038 | nfs_pageio_complete(desc); |
7fe7f848 TM |
1039 | } |
1040 | } | |
1041 | ||
f7b422b1 | 1042 | int __init nfs_init_nfspagecache(void) |
1da177e4 LT |
1043 | { |
1044 | nfs_page_cachep = kmem_cache_create("nfs_page", | |
1045 | sizeof(struct nfs_page), | |
1046 | 0, SLAB_HWCACHE_ALIGN, | |
20c2df83 | 1047 | NULL); |
1da177e4 LT |
1048 | if (nfs_page_cachep == NULL) |
1049 | return -ENOMEM; | |
1050 | ||
1051 | return 0; | |
1052 | } | |
1053 | ||
266bee88 | 1054 | void nfs_destroy_nfspagecache(void) |
1da177e4 | 1055 | { |
1a1d92c1 | 1056 | kmem_cache_destroy(nfs_page_cachep); |
1da177e4 LT |
1057 | } |
1058 | ||
ef2c488c | 1059 | static const struct rpc_call_ops nfs_pgio_common_ops = { |
6f92fa45 AS |
1060 | .rpc_call_prepare = nfs_pgio_prepare, |
1061 | .rpc_call_done = nfs_pgio_result, | |
1062 | .rpc_release = nfs_pgio_release, | |
1063 | }; | |
41d8d5b7 AS |
1064 | |
1065 | const struct nfs_pageio_ops nfs_pgio_rw_ops = { | |
1066 | .pg_test = nfs_generic_pg_test, | |
1067 | .pg_doio = nfs_generic_pg_pgios, | |
1068 | }; |