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); |
92a56555 | 119 | } while (atomic_read(&c->io_count) != 0 && !ret); |
577b4232 TM |
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 | ||
7c3af975 WAA |
170 | /* |
171 | * nfs_page_group_lock_wait - wait for the lock to clear, but don't grab it | |
172 | * @req - a request in the group | |
173 | * | |
174 | * This is a blocking call to wait for the group lock to be cleared. | |
175 | */ | |
176 | void | |
177 | nfs_page_group_lock_wait(struct nfs_page *req) | |
178 | { | |
179 | struct nfs_page *head = req->wb_head; | |
180 | ||
181 | WARN_ON_ONCE(head != head->wb_head); | |
182 | ||
183 | wait_on_bit(&head->wb_flags, PG_HEADLOCK, | |
184 | TASK_UNINTERRUPTIBLE); | |
185 | } | |
186 | ||
2bfc6e56 WAA |
187 | /* |
188 | * nfs_page_group_unlock - unlock the head of the page group | |
189 | * @req - request in group that is to be unlocked | |
190 | */ | |
191 | void | |
192 | nfs_page_group_unlock(struct nfs_page *req) | |
193 | { | |
194 | struct nfs_page *head = req->wb_head; | |
195 | ||
196 | WARN_ON_ONCE(head != head->wb_head); | |
197 | ||
d1e1cda8 | 198 | smp_mb__before_atomic(); |
2bfc6e56 | 199 | clear_bit(PG_HEADLOCK, &head->wb_flags); |
d1e1cda8 | 200 | smp_mb__after_atomic(); |
2bfc6e56 WAA |
201 | wake_up_bit(&head->wb_flags, PG_HEADLOCK); |
202 | } | |
203 | ||
204 | /* | |
205 | * nfs_page_group_sync_on_bit_locked | |
206 | * | |
207 | * must be called with page group lock held | |
208 | */ | |
209 | static bool | |
210 | nfs_page_group_sync_on_bit_locked(struct nfs_page *req, unsigned int bit) | |
211 | { | |
212 | struct nfs_page *head = req->wb_head; | |
213 | struct nfs_page *tmp; | |
214 | ||
215 | WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &head->wb_flags)); | |
216 | WARN_ON_ONCE(test_and_set_bit(bit, &req->wb_flags)); | |
217 | ||
218 | tmp = req->wb_this_page; | |
219 | while (tmp != req) { | |
220 | if (!test_bit(bit, &tmp->wb_flags)) | |
221 | return false; | |
222 | tmp = tmp->wb_this_page; | |
223 | } | |
224 | ||
225 | /* true! reset all bits */ | |
226 | tmp = req; | |
227 | do { | |
228 | clear_bit(bit, &tmp->wb_flags); | |
229 | tmp = tmp->wb_this_page; | |
230 | } while (tmp != req); | |
231 | ||
232 | return true; | |
233 | } | |
234 | ||
235 | /* | |
236 | * nfs_page_group_sync_on_bit - set bit on current request, but only | |
237 | * return true if the bit is set for all requests in page group | |
238 | * @req - request in page group | |
239 | * @bit - PG_* bit that is used to sync page group | |
240 | */ | |
241 | bool nfs_page_group_sync_on_bit(struct nfs_page *req, unsigned int bit) | |
242 | { | |
243 | bool ret; | |
244 | ||
fd2f3a06 | 245 | nfs_page_group_lock(req, false); |
2bfc6e56 WAA |
246 | ret = nfs_page_group_sync_on_bit_locked(req, bit); |
247 | nfs_page_group_unlock(req); | |
248 | ||
249 | return ret; | |
250 | } | |
251 | ||
252 | /* | |
253 | * nfs_page_group_init - Initialize the page group linkage for @req | |
254 | * @req - a new nfs request | |
255 | * @prev - the previous request in page group, or NULL if @req is the first | |
256 | * or only request in the group (the head). | |
257 | */ | |
258 | static inline void | |
259 | nfs_page_group_init(struct nfs_page *req, struct nfs_page *prev) | |
260 | { | |
cb1410c7 | 261 | struct inode *inode; |
2bfc6e56 WAA |
262 | WARN_ON_ONCE(prev == req); |
263 | ||
264 | if (!prev) { | |
85710a83 | 265 | /* a head request */ |
2bfc6e56 WAA |
266 | req->wb_head = req; |
267 | req->wb_this_page = req; | |
268 | } else { | |
85710a83 | 269 | /* a subrequest */ |
2bfc6e56 WAA |
270 | WARN_ON_ONCE(prev->wb_this_page != prev->wb_head); |
271 | WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &prev->wb_head->wb_flags)); | |
272 | req->wb_head = prev->wb_head; | |
273 | req->wb_this_page = prev->wb_this_page; | |
274 | prev->wb_this_page = req; | |
275 | ||
85710a83 WAA |
276 | /* All subrequests take a ref on the head request until |
277 | * nfs_page_group_destroy is called */ | |
278 | kref_get(&req->wb_head->wb_kref); | |
279 | ||
cb1410c7 WAA |
280 | /* grab extra ref and bump the request count if head request |
281 | * has extra ref from the write/commit path to handle handoff | |
282 | * between write and commit lists. */ | |
17089a29 | 283 | if (test_bit(PG_INODE_REF, &prev->wb_head->wb_flags)) { |
cb1410c7 | 284 | inode = page_file_mapping(req->wb_page)->host; |
17089a29 | 285 | set_bit(PG_INODE_REF, &req->wb_flags); |
2bfc6e56 | 286 | kref_get(&req->wb_kref); |
cb1410c7 WAA |
287 | spin_lock(&inode->i_lock); |
288 | NFS_I(inode)->nrequests++; | |
289 | spin_unlock(&inode->i_lock); | |
17089a29 | 290 | } |
2bfc6e56 WAA |
291 | } |
292 | } | |
293 | ||
294 | /* | |
295 | * nfs_page_group_destroy - sync the destruction of page groups | |
296 | * @req - request that no longer needs the page group | |
297 | * | |
298 | * releases the page group reference from each member once all | |
299 | * members have called this function. | |
300 | */ | |
301 | static void | |
302 | nfs_page_group_destroy(struct kref *kref) | |
303 | { | |
304 | struct nfs_page *req = container_of(kref, struct nfs_page, wb_kref); | |
305 | struct nfs_page *tmp, *next; | |
306 | ||
85710a83 WAA |
307 | /* subrequests must release the ref on the head request */ |
308 | if (req->wb_head != req) | |
309 | nfs_release_request(req->wb_head); | |
310 | ||
2bfc6e56 WAA |
311 | if (!nfs_page_group_sync_on_bit(req, PG_TEARDOWN)) |
312 | return; | |
313 | ||
314 | tmp = req; | |
315 | do { | |
316 | next = tmp->wb_this_page; | |
317 | /* unlink and free */ | |
318 | tmp->wb_this_page = tmp; | |
319 | tmp->wb_head = tmp; | |
320 | nfs_free_request(tmp); | |
321 | tmp = next; | |
322 | } while (tmp != req); | |
323 | } | |
324 | ||
1da177e4 LT |
325 | /** |
326 | * nfs_create_request - Create an NFS read/write request. | |
c02f557d | 327 | * @ctx: open context to use |
1da177e4 | 328 | * @page: page to write |
2bfc6e56 | 329 | * @last: last nfs request created for this page group or NULL if head |
1da177e4 LT |
330 | * @offset: starting offset within the page for the write |
331 | * @count: number of bytes to read/write | |
332 | * | |
333 | * The page must be locked by the caller. This makes sure we never | |
a19b89ca | 334 | * create two different requests for the same page. |
1da177e4 LT |
335 | * User should ensure it is safe to sleep in this function. |
336 | */ | |
337 | struct nfs_page * | |
8c8f1ac1 | 338 | nfs_create_request(struct nfs_open_context *ctx, struct page *page, |
2bfc6e56 WAA |
339 | struct nfs_page *last, unsigned int offset, |
340 | unsigned int count) | |
1da177e4 | 341 | { |
1da177e4 | 342 | struct nfs_page *req; |
b3c54de6 | 343 | struct nfs_lock_context *l_ctx; |
1da177e4 | 344 | |
c58c8441 TM |
345 | if (test_bit(NFS_CONTEXT_BAD, &ctx->flags)) |
346 | return ERR_PTR(-EBADF); | |
18eb8842 TM |
347 | /* try to allocate the request struct */ |
348 | req = nfs_page_alloc(); | |
349 | if (req == NULL) | |
350 | return ERR_PTR(-ENOMEM); | |
1da177e4 | 351 | |
015f0212 | 352 | /* get lock context early so we can deal with alloc failures */ |
b3c54de6 TM |
353 | l_ctx = nfs_get_lock_context(ctx); |
354 | if (IS_ERR(l_ctx)) { | |
015f0212 | 355 | nfs_page_free(req); |
b3c54de6 | 356 | return ERR_CAST(l_ctx); |
015f0212 | 357 | } |
b3c54de6 | 358 | req->wb_lock_context = l_ctx; |
577b4232 | 359 | nfs_iocounter_inc(&l_ctx->io_count); |
015f0212 | 360 | |
1da177e4 LT |
361 | /* Initialize the request struct. Initially, we assume a |
362 | * long write-back delay. This will be adjusted in | |
363 | * update_nfs_request below if the region is not locked. */ | |
364 | req->wb_page = page; | |
d56b4ddf | 365 | req->wb_index = page_file_index(page); |
1da177e4 LT |
366 | page_cache_get(page); |
367 | req->wb_offset = offset; | |
368 | req->wb_pgbase = offset; | |
369 | req->wb_bytes = count; | |
1da177e4 | 370 | req->wb_context = get_nfs_open_context(ctx); |
c03b4024 | 371 | kref_init(&req->wb_kref); |
2bfc6e56 | 372 | nfs_page_group_init(req, last); |
1da177e4 LT |
373 | return req; |
374 | } | |
375 | ||
376 | /** | |
1d1afcbc | 377 | * nfs_unlock_request - Unlock request and wake up sleepers. |
1da177e4 LT |
378 | * @req: |
379 | */ | |
1d1afcbc | 380 | void nfs_unlock_request(struct nfs_page *req) |
1da177e4 LT |
381 | { |
382 | if (!NFS_WBACK_BUSY(req)) { | |
383 | printk(KERN_ERR "NFS: Invalid unlock attempted\n"); | |
384 | BUG(); | |
385 | } | |
4e857c58 | 386 | smp_mb__before_atomic(); |
1da177e4 | 387 | clear_bit(PG_BUSY, &req->wb_flags); |
4e857c58 | 388 | smp_mb__after_atomic(); |
464a98bd | 389 | wake_up_bit(&req->wb_flags, PG_BUSY); |
3aff4ebb TM |
390 | } |
391 | ||
392 | /** | |
1d1afcbc TM |
393 | * nfs_unlock_and_release_request - Unlock request and release the nfs_page |
394 | * @req: | |
3aff4ebb | 395 | */ |
1d1afcbc | 396 | void nfs_unlock_and_release_request(struct nfs_page *req) |
3aff4ebb | 397 | { |
1d1afcbc | 398 | nfs_unlock_request(req); |
1da177e4 LT |
399 | nfs_release_request(req); |
400 | } | |
401 | ||
4d65c520 | 402 | /* |
1da177e4 LT |
403 | * nfs_clear_request - Free up all resources allocated to the request |
404 | * @req: | |
405 | * | |
bb6fbc45 TM |
406 | * Release page and open context resources associated with a read/write |
407 | * request after it has completed. | |
1da177e4 | 408 | */ |
4d65c520 | 409 | static void nfs_clear_request(struct nfs_page *req) |
1da177e4 | 410 | { |
cd52ed35 | 411 | struct page *page = req->wb_page; |
bb6fbc45 | 412 | struct nfs_open_context *ctx = req->wb_context; |
f11ac8db | 413 | struct nfs_lock_context *l_ctx = req->wb_lock_context; |
bb6fbc45 | 414 | |
cd52ed35 | 415 | if (page != NULL) { |
cd52ed35 | 416 | page_cache_release(page); |
1da177e4 LT |
417 | req->wb_page = NULL; |
418 | } | |
f11ac8db | 419 | if (l_ctx != NULL) { |
577b4232 | 420 | nfs_iocounter_dec(&l_ctx->io_count); |
f11ac8db TM |
421 | nfs_put_lock_context(l_ctx); |
422 | req->wb_lock_context = NULL; | |
423 | } | |
bb6fbc45 TM |
424 | if (ctx != NULL) { |
425 | put_nfs_open_context(ctx); | |
426 | req->wb_context = NULL; | |
427 | } | |
1da177e4 LT |
428 | } |
429 | ||
1da177e4 LT |
430 | /** |
431 | * nfs_release_request - Release the count on an NFS read/write request | |
432 | * @req: request to release | |
433 | * | |
434 | * Note: Should never be called with the spinlock held! | |
435 | */ | |
d4581383 | 436 | void nfs_free_request(struct nfs_page *req) |
1da177e4 | 437 | { |
2bfc6e56 WAA |
438 | WARN_ON_ONCE(req->wb_this_page != req); |
439 | ||
440 | /* extra debug: make sure no sync bits are still set */ | |
441 | WARN_ON_ONCE(test_bit(PG_TEARDOWN, &req->wb_flags)); | |
67d0338e WAA |
442 | WARN_ON_ONCE(test_bit(PG_UNLOCKPAGE, &req->wb_flags)); |
443 | WARN_ON_ONCE(test_bit(PG_UPTODATE, &req->wb_flags)); | |
20633f04 WAA |
444 | WARN_ON_ONCE(test_bit(PG_WB_END, &req->wb_flags)); |
445 | WARN_ON_ONCE(test_bit(PG_REMOVE, &req->wb_flags)); | |
1da177e4 | 446 | |
bb6fbc45 | 447 | /* Release struct file and open context */ |
1da177e4 | 448 | nfs_clear_request(req); |
1da177e4 LT |
449 | nfs_page_free(req); |
450 | } | |
451 | ||
c03b4024 TM |
452 | void nfs_release_request(struct nfs_page *req) |
453 | { | |
2bfc6e56 | 454 | kref_put(&req->wb_kref, nfs_page_group_destroy); |
9f557cd8 TM |
455 | } |
456 | ||
1da177e4 LT |
457 | /** |
458 | * nfs_wait_on_request - Wait for a request to complete. | |
459 | * @req: request to wait upon. | |
460 | * | |
150030b7 | 461 | * Interruptible by fatal signals only. |
1da177e4 LT |
462 | * The user is responsible for holding a count on the request. |
463 | */ | |
464 | int | |
465 | nfs_wait_on_request(struct nfs_page *req) | |
466 | { | |
74316201 N |
467 | return wait_on_bit_io(&req->wb_flags, PG_BUSY, |
468 | TASK_UNINTERRUPTIBLE); | |
1da177e4 LT |
469 | } |
470 | ||
b4fdac1a WAA |
471 | /* |
472 | * nfs_generic_pg_test - determine if requests can be coalesced | |
473 | * @desc: pointer to descriptor | |
474 | * @prev: previous request in desc, or NULL | |
475 | * @req: this request | |
476 | * | |
477 | * Returns zero if @req can be coalesced into @desc, otherwise it returns | |
478 | * the size of the request. | |
479 | */ | |
480 | size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, | |
481 | struct nfs_page *prev, struct nfs_page *req) | |
5b36c7dc | 482 | { |
f0cb9ab8 WAA |
483 | if (desc->pg_count > desc->pg_bsize) { |
484 | /* should never happen */ | |
485 | WARN_ON_ONCE(1); | |
5b36c7dc | 486 | return 0; |
f0cb9ab8 | 487 | } |
5b36c7dc | 488 | |
2e11f829 CH |
489 | /* |
490 | * Limit the request size so that we can still allocate a page array | |
491 | * for it without upsetting the slab allocator. | |
492 | */ | |
493 | if (((desc->pg_count + req->wb_bytes) >> PAGE_SHIFT) * | |
494 | sizeof(struct page) > PAGE_SIZE) | |
495 | return 0; | |
496 | ||
f0cb9ab8 | 497 | return min(desc->pg_bsize - desc->pg_count, (size_t)req->wb_bytes); |
5b36c7dc | 498 | } |
19345cb2 | 499 | EXPORT_SYMBOL_GPL(nfs_generic_pg_test); |
5b36c7dc | 500 | |
1e7f3a48 | 501 | struct nfs_pgio_header *nfs_pgio_header_alloc(const struct nfs_rw_ops *ops) |
4a0de55c | 502 | { |
1e7f3a48 | 503 | struct nfs_pgio_header *hdr = ops->rw_alloc_header(); |
4a0de55c | 504 | |
1e7f3a48 | 505 | if (hdr) { |
4a0de55c | 506 | INIT_LIST_HEAD(&hdr->pages); |
4a0de55c | 507 | spin_lock_init(&hdr->lock); |
4a0de55c AS |
508 | hdr->rw_ops = ops; |
509 | } | |
1e7f3a48 | 510 | return hdr; |
4a0de55c | 511 | } |
1e7f3a48 | 512 | EXPORT_SYMBOL_GPL(nfs_pgio_header_alloc); |
4a0de55c AS |
513 | |
514 | /* | |
1e7f3a48 | 515 | * nfs_pgio_header_free - Free a read or write header |
4a0de55c AS |
516 | * @hdr: The header to free |
517 | */ | |
1e7f3a48 | 518 | void nfs_pgio_header_free(struct nfs_pgio_header *hdr) |
4a0de55c | 519 | { |
1e7f3a48 | 520 | hdr->rw_ops->rw_free_header(hdr); |
4a0de55c | 521 | } |
1e7f3a48 | 522 | EXPORT_SYMBOL_GPL(nfs_pgio_header_free); |
4a0de55c | 523 | |
00bfa30a | 524 | /** |
4714fb51 WAA |
525 | * nfs_pgio_data_destroy - make @hdr suitable for reuse |
526 | * | |
527 | * Frees memory and releases refs from nfs_generic_pgio, so that it may | |
528 | * be called again. | |
529 | * | |
530 | * @hdr: A header that has had nfs_generic_pgio called | |
00bfa30a | 531 | */ |
d45f60c6 | 532 | void nfs_pgio_data_destroy(struct nfs_pgio_header *hdr) |
00bfa30a | 533 | { |
3caa0c6e TM |
534 | if (hdr->args.context) |
535 | put_nfs_open_context(hdr->args.context); | |
d45f60c6 WAA |
536 | if (hdr->page_array.pagevec != hdr->page_array.page_array) |
537 | kfree(hdr->page_array.pagevec); | |
00bfa30a | 538 | } |
1e7f3a48 | 539 | EXPORT_SYMBOL_GPL(nfs_pgio_data_destroy); |
00bfa30a | 540 | |
ce59515c AS |
541 | /** |
542 | * nfs_pgio_rpcsetup - Set up arguments for a pageio call | |
d45f60c6 | 543 | * @hdr: The pageio hdr |
ce59515c AS |
544 | * @count: Number of bytes to read |
545 | * @offset: Initial offset | |
546 | * @how: How to commit data (writes only) | |
547 | * @cinfo: Commit information for the call (writes only) | |
548 | */ | |
d45f60c6 | 549 | static void nfs_pgio_rpcsetup(struct nfs_pgio_header *hdr, |
ce59515c AS |
550 | unsigned int count, unsigned int offset, |
551 | int how, struct nfs_commit_info *cinfo) | |
552 | { | |
d45f60c6 | 553 | struct nfs_page *req = hdr->req; |
ce59515c AS |
554 | |
555 | /* Set up the RPC argument and reply structs | |
d45f60c6 | 556 | * NB: take care not to mess about with hdr->commit et al. */ |
ce59515c | 557 | |
d45f60c6 WAA |
558 | hdr->args.fh = NFS_FH(hdr->inode); |
559 | hdr->args.offset = req_offset(req) + offset; | |
ce59515c | 560 | /* pnfs_set_layoutcommit needs this */ |
d45f60c6 WAA |
561 | hdr->mds_offset = hdr->args.offset; |
562 | hdr->args.pgbase = req->wb_pgbase + offset; | |
563 | hdr->args.pages = hdr->page_array.pagevec; | |
564 | hdr->args.count = count; | |
565 | hdr->args.context = get_nfs_open_context(req->wb_context); | |
566 | hdr->args.lock_context = req->wb_lock_context; | |
567 | hdr->args.stable = NFS_UNSTABLE; | |
ce59515c AS |
568 | switch (how & (FLUSH_STABLE | FLUSH_COND_STABLE)) { |
569 | case 0: | |
570 | break; | |
571 | case FLUSH_COND_STABLE: | |
572 | if (nfs_reqs_to_commit(cinfo)) | |
573 | break; | |
574 | default: | |
d45f60c6 | 575 | hdr->args.stable = NFS_FILE_SYNC; |
ce59515c AS |
576 | } |
577 | ||
d45f60c6 WAA |
578 | hdr->res.fattr = &hdr->fattr; |
579 | hdr->res.count = count; | |
580 | hdr->res.eof = 0; | |
c65e6254 | 581 | hdr->res.verf = &hdr->verf; |
d45f60c6 | 582 | nfs_fattr_init(&hdr->fattr); |
ce59515c AS |
583 | } |
584 | ||
a4cdda59 | 585 | /** |
d45f60c6 | 586 | * nfs_pgio_prepare - Prepare pageio hdr to go over the wire |
a4cdda59 | 587 | * @task: The current task |
d45f60c6 | 588 | * @calldata: pageio header to prepare |
a4cdda59 | 589 | */ |
6f92fa45 | 590 | static void nfs_pgio_prepare(struct rpc_task *task, void *calldata) |
a4cdda59 | 591 | { |
d45f60c6 | 592 | struct nfs_pgio_header *hdr = calldata; |
a4cdda59 | 593 | int err; |
d45f60c6 | 594 | err = NFS_PROTO(hdr->inode)->pgio_rpc_prepare(task, hdr); |
a4cdda59 AS |
595 | if (err) |
596 | rpc_exit(task, err); | |
597 | } | |
598 | ||
d45f60c6 | 599 | int nfs_initiate_pgio(struct rpc_clnt *clnt, struct nfs_pgio_header *hdr, |
1ed26f33 AS |
600 | const struct rpc_call_ops *call_ops, int how, int flags) |
601 | { | |
602 | struct rpc_task *task; | |
603 | struct rpc_message msg = { | |
d45f60c6 WAA |
604 | .rpc_argp = &hdr->args, |
605 | .rpc_resp = &hdr->res, | |
606 | .rpc_cred = hdr->cred, | |
1ed26f33 AS |
607 | }; |
608 | struct rpc_task_setup task_setup_data = { | |
609 | .rpc_client = clnt, | |
d45f60c6 | 610 | .task = &hdr->task, |
1ed26f33 AS |
611 | .rpc_message = &msg, |
612 | .callback_ops = call_ops, | |
d45f60c6 | 613 | .callback_data = hdr, |
1ed26f33 AS |
614 | .workqueue = nfsiod_workqueue, |
615 | .flags = RPC_TASK_ASYNC | flags, | |
616 | }; | |
617 | int ret = 0; | |
618 | ||
d45f60c6 | 619 | hdr->rw_ops->rw_initiate(hdr, &msg, &task_setup_data, how); |
1ed26f33 AS |
620 | |
621 | dprintk("NFS: %5u initiated pgio call " | |
622 | "(req %s/%llu, %u bytes @ offset %llu)\n", | |
d45f60c6 | 623 | hdr->task.tk_pid, |
343ae531 AS |
624 | hdr->inode->i_sb->s_id, |
625 | (unsigned long long)NFS_FILEID(hdr->inode), | |
d45f60c6 WAA |
626 | hdr->args.count, |
627 | (unsigned long long)hdr->args.offset); | |
1ed26f33 AS |
628 | |
629 | task = rpc_run_task(&task_setup_data); | |
630 | if (IS_ERR(task)) { | |
631 | ret = PTR_ERR(task); | |
632 | goto out; | |
633 | } | |
634 | if (how & FLUSH_SYNC) { | |
635 | ret = rpc_wait_for_completion_task(task); | |
636 | if (ret == 0) | |
637 | ret = task->tk_status; | |
638 | } | |
639 | rpc_put_task(task); | |
640 | out: | |
641 | return ret; | |
642 | } | |
643 | EXPORT_SYMBOL_GPL(nfs_initiate_pgio); | |
644 | ||
844c9e69 AS |
645 | /** |
646 | * nfs_pgio_error - Clean up from a pageio error | |
647 | * @desc: IO descriptor | |
648 | * @hdr: pageio header | |
649 | */ | |
ef2c488c | 650 | static int nfs_pgio_error(struct nfs_pageio_descriptor *desc, |
844c9e69 AS |
651 | struct nfs_pgio_header *hdr) |
652 | { | |
844c9e69 | 653 | set_bit(NFS_IOHDR_REDO, &hdr->flags); |
d45f60c6 | 654 | nfs_pgio_data_destroy(hdr); |
4714fb51 | 655 | hdr->completion_ops->completion(hdr); |
844c9e69 AS |
656 | desc->pg_completion_ops->error_cleanup(&desc->pg_list); |
657 | return -ENOMEM; | |
658 | } | |
659 | ||
a4cdda59 AS |
660 | /** |
661 | * nfs_pgio_release - Release pageio data | |
d45f60c6 | 662 | * @calldata: The pageio header to release |
a4cdda59 | 663 | */ |
6f92fa45 | 664 | static void nfs_pgio_release(void *calldata) |
a4cdda59 | 665 | { |
d45f60c6 WAA |
666 | struct nfs_pgio_header *hdr = calldata; |
667 | if (hdr->rw_ops->rw_release) | |
668 | hdr->rw_ops->rw_release(hdr); | |
669 | nfs_pgio_data_destroy(hdr); | |
4714fb51 | 670 | hdr->completion_ops->completion(hdr); |
a4cdda59 AS |
671 | } |
672 | ||
1da177e4 | 673 | /** |
d8a5ad75 TM |
674 | * nfs_pageio_init - initialise a page io descriptor |
675 | * @desc: pointer to descriptor | |
bcb71bba TM |
676 | * @inode: pointer to inode |
677 | * @doio: pointer to io function | |
678 | * @bsize: io block size | |
679 | * @io_flags: extra parameters for the io function | |
d8a5ad75 | 680 | */ |
bcb71bba TM |
681 | void nfs_pageio_init(struct nfs_pageio_descriptor *desc, |
682 | struct inode *inode, | |
1751c363 | 683 | const struct nfs_pageio_ops *pg_ops, |
061ae2ed | 684 | const struct nfs_pgio_completion_ops *compl_ops, |
4a0de55c | 685 | const struct nfs_rw_ops *rw_ops, |
84dde76c | 686 | size_t bsize, |
bcb71bba | 687 | int io_flags) |
d8a5ad75 TM |
688 | { |
689 | INIT_LIST_HEAD(&desc->pg_list); | |
bcb71bba | 690 | desc->pg_bytes_written = 0; |
d8a5ad75 TM |
691 | desc->pg_count = 0; |
692 | desc->pg_bsize = bsize; | |
693 | desc->pg_base = 0; | |
b31268ac | 694 | desc->pg_moreio = 0; |
d9156f9f | 695 | desc->pg_recoalesce = 0; |
bcb71bba | 696 | desc->pg_inode = inode; |
1751c363 | 697 | desc->pg_ops = pg_ops; |
061ae2ed | 698 | desc->pg_completion_ops = compl_ops; |
4a0de55c | 699 | desc->pg_rw_ops = rw_ops; |
bcb71bba TM |
700 | desc->pg_ioflags = io_flags; |
701 | desc->pg_error = 0; | |
94ad1c80 | 702 | desc->pg_lseg = NULL; |
584aa810 | 703 | desc->pg_dreq = NULL; |
f6166384 | 704 | desc->pg_layout_private = NULL; |
d8a5ad75 | 705 | } |
89d77c8f | 706 | EXPORT_SYMBOL_GPL(nfs_pageio_init); |
d8a5ad75 | 707 | |
0eecb214 AS |
708 | /** |
709 | * nfs_pgio_result - Basic pageio error handling | |
710 | * @task: The task that ran | |
d45f60c6 | 711 | * @calldata: Pageio header to check |
0eecb214 | 712 | */ |
6f92fa45 | 713 | static void nfs_pgio_result(struct rpc_task *task, void *calldata) |
0eecb214 | 714 | { |
d45f60c6 WAA |
715 | struct nfs_pgio_header *hdr = calldata; |
716 | struct inode *inode = hdr->inode; | |
0eecb214 AS |
717 | |
718 | dprintk("NFS: %s: %5u, (status %d)\n", __func__, | |
719 | task->tk_pid, task->tk_status); | |
720 | ||
d45f60c6 | 721 | if (hdr->rw_ops->rw_done(task, hdr, inode) != 0) |
0eecb214 AS |
722 | return; |
723 | if (task->tk_status < 0) | |
d45f60c6 | 724 | nfs_set_pgio_error(hdr, task->tk_status, hdr->args.offset); |
0eecb214 | 725 | else |
d45f60c6 | 726 | hdr->rw_ops->rw_result(task, hdr); |
0eecb214 AS |
727 | } |
728 | ||
ef2c488c AS |
729 | /* |
730 | * Create an RPC task for the given read or write request and kick it. | |
731 | * The page must have been locked by the caller. | |
732 | * | |
733 | * It may happen that the page we're passed is not marked dirty. | |
734 | * This is the case if nfs_updatepage detects a conflicting request | |
735 | * that has been written but not committed. | |
736 | */ | |
f0cb9ab8 WAA |
737 | int nfs_generic_pgio(struct nfs_pageio_descriptor *desc, |
738 | struct nfs_pgio_header *hdr) | |
ef2c488c AS |
739 | { |
740 | struct nfs_page *req; | |
bba5c188 WAA |
741 | struct page **pages, |
742 | *last_page; | |
ef2c488c AS |
743 | struct list_head *head = &desc->pg_list; |
744 | struct nfs_commit_info cinfo; | |
bba5c188 | 745 | unsigned int pagecount, pageused; |
ef2c488c | 746 | |
4714fb51 WAA |
747 | pagecount = nfs_page_array_len(desc->pg_base, desc->pg_count); |
748 | if (!nfs_pgarray_set(&hdr->page_array, pagecount)) | |
ef2c488c AS |
749 | return nfs_pgio_error(desc, hdr); |
750 | ||
751 | nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq); | |
d45f60c6 | 752 | pages = hdr->page_array.pagevec; |
bba5c188 WAA |
753 | last_page = NULL; |
754 | pageused = 0; | |
ef2c488c AS |
755 | while (!list_empty(head)) { |
756 | req = nfs_list_entry(head->next); | |
757 | nfs_list_remove_request(req); | |
758 | nfs_list_add_request(req, &hdr->pages); | |
bba5c188 | 759 | |
bba5c188 | 760 | if (!last_page || last_page != req->wb_page) { |
bba5c188 | 761 | pageused++; |
b8fb9c30 TM |
762 | if (pageused > pagecount) |
763 | break; | |
764 | *pages++ = last_page = req->wb_page; | |
bba5c188 | 765 | } |
ef2c488c | 766 | } |
bba5c188 WAA |
767 | if (WARN_ON_ONCE(pageused != pagecount)) |
768 | return nfs_pgio_error(desc, hdr); | |
ef2c488c AS |
769 | |
770 | if ((desc->pg_ioflags & FLUSH_COND_STABLE) && | |
771 | (desc->pg_moreio || nfs_reqs_to_commit(&cinfo))) | |
772 | desc->pg_ioflags &= ~FLUSH_COND_STABLE; | |
773 | ||
774 | /* Set up the argument struct */ | |
d45f60c6 | 775 | nfs_pgio_rpcsetup(hdr, desc->pg_count, 0, desc->pg_ioflags, &cinfo); |
ef2c488c AS |
776 | desc->pg_rpc_callops = &nfs_pgio_common_ops; |
777 | return 0; | |
778 | } | |
f0cb9ab8 | 779 | EXPORT_SYMBOL_GPL(nfs_generic_pgio); |
ef2c488c | 780 | |
41d8d5b7 | 781 | static int nfs_generic_pg_pgios(struct nfs_pageio_descriptor *desc) |
cf485fcd | 782 | { |
cf485fcd AS |
783 | struct nfs_pgio_header *hdr; |
784 | int ret; | |
785 | ||
1e7f3a48 WAA |
786 | hdr = nfs_pgio_header_alloc(desc->pg_rw_ops); |
787 | if (!hdr) { | |
cf485fcd AS |
788 | desc->pg_completion_ops->error_cleanup(&desc->pg_list); |
789 | return -ENOMEM; | |
790 | } | |
1e7f3a48 | 791 | nfs_pgheader_init(desc, hdr, nfs_pgio_header_free); |
cf485fcd AS |
792 | ret = nfs_generic_pgio(desc, hdr); |
793 | if (ret == 0) | |
7f714720 | 794 | ret = nfs_initiate_pgio(NFS_CLIENT(hdr->inode), |
d45f60c6 | 795 | hdr, desc->pg_rpc_callops, |
7f714720 | 796 | desc->pg_ioflags, 0); |
cf485fcd AS |
797 | return ret; |
798 | } | |
799 | ||
4109bb74 TM |
800 | static bool nfs_match_open_context(const struct nfs_open_context *ctx1, |
801 | const struct nfs_open_context *ctx2) | |
802 | { | |
803 | return ctx1->cred == ctx2->cred && ctx1->state == ctx2->state; | |
804 | } | |
805 | ||
806 | static bool nfs_match_lock_context(const struct nfs_lock_context *l1, | |
807 | const struct nfs_lock_context *l2) | |
808 | { | |
809 | return l1->lockowner.l_owner == l2->lockowner.l_owner | |
810 | && l1->lockowner.l_pid == l2->lockowner.l_pid; | |
811 | } | |
812 | ||
d8a5ad75 TM |
813 | /** |
814 | * nfs_can_coalesce_requests - test two requests for compatibility | |
815 | * @prev: pointer to nfs_page | |
816 | * @req: pointer to nfs_page | |
817 | * | |
818 | * The nfs_page structures 'prev' and 'req' are compared to ensure that the | |
819 | * page data area they describe is contiguous, and that their RPC | |
820 | * credentials, NFSv4 open state, and lockowners are the same. | |
821 | * | |
822 | * Return 'true' if this is the case, else return 'false'. | |
823 | */ | |
18ad0a9f BH |
824 | static bool nfs_can_coalesce_requests(struct nfs_page *prev, |
825 | struct nfs_page *req, | |
826 | struct nfs_pageio_descriptor *pgio) | |
d8a5ad75 | 827 | { |
b4fdac1a WAA |
828 | size_t size; |
829 | ||
ab75e417 WAA |
830 | if (prev) { |
831 | if (!nfs_match_open_context(req->wb_context, prev->wb_context)) | |
832 | return false; | |
833 | if (req->wb_context->dentry->d_inode->i_flock != NULL && | |
834 | !nfs_match_lock_context(req->wb_lock_context, | |
835 | prev->wb_lock_context)) | |
836 | return false; | |
ab75e417 WAA |
837 | if (req_offset(req) != req_offset(prev) + prev->wb_bytes) |
838 | return false; | |
78270e8f WAA |
839 | if (req->wb_page == prev->wb_page) { |
840 | if (req->wb_pgbase != prev->wb_pgbase + prev->wb_bytes) | |
841 | return false; | |
842 | } else { | |
843 | if (req->wb_pgbase != 0 || | |
844 | prev->wb_pgbase + prev->wb_bytes != PAGE_CACHE_SIZE) | |
845 | return false; | |
846 | } | |
ab75e417 | 847 | } |
b4fdac1a | 848 | size = pgio->pg_ops->pg_test(pgio, prev, req); |
f0cb9ab8 WAA |
849 | WARN_ON_ONCE(size > req->wb_bytes); |
850 | if (size && size < req->wb_bytes) | |
851 | req->wb_bytes = size; | |
b4fdac1a | 852 | return size > 0; |
d8a5ad75 TM |
853 | } |
854 | ||
855 | /** | |
bcb71bba | 856 | * nfs_pageio_do_add_request - Attempt to coalesce a request into a page list. |
d8a5ad75 TM |
857 | * @desc: destination io descriptor |
858 | * @req: request | |
859 | * | |
860 | * Returns true if the request 'req' was successfully coalesced into the | |
861 | * existing list of pages 'desc'. | |
862 | */ | |
bcb71bba TM |
863 | static int nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc, |
864 | struct nfs_page *req) | |
d8a5ad75 | 865 | { |
ab75e417 | 866 | struct nfs_page *prev = NULL; |
d8a5ad75 | 867 | if (desc->pg_count != 0) { |
d8a5ad75 | 868 | prev = nfs_list_entry(desc->pg_list.prev); |
5b36c7dc | 869 | } else { |
d8007d4d TM |
870 | if (desc->pg_ops->pg_init) |
871 | desc->pg_ops->pg_init(desc, req); | |
d8a5ad75 | 872 | desc->pg_base = req->wb_pgbase; |
5b36c7dc | 873 | } |
ab75e417 WAA |
874 | if (!nfs_can_coalesce_requests(prev, req, desc)) |
875 | return 0; | |
d8a5ad75 TM |
876 | nfs_list_remove_request(req); |
877 | nfs_list_add_request(req, &desc->pg_list); | |
5b36c7dc | 878 | desc->pg_count += req->wb_bytes; |
d8a5ad75 TM |
879 | return 1; |
880 | } | |
881 | ||
bcb71bba TM |
882 | /* |
883 | * Helper for nfs_pageio_add_request and nfs_pageio_complete | |
884 | */ | |
885 | static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc) | |
886 | { | |
887 | if (!list_empty(&desc->pg_list)) { | |
1751c363 | 888 | int error = desc->pg_ops->pg_doio(desc); |
bcb71bba TM |
889 | if (error < 0) |
890 | desc->pg_error = error; | |
891 | else | |
892 | desc->pg_bytes_written += desc->pg_count; | |
893 | } | |
894 | if (list_empty(&desc->pg_list)) { | |
895 | desc->pg_count = 0; | |
896 | desc->pg_base = 0; | |
897 | } | |
898 | } | |
899 | ||
900 | /** | |
901 | * nfs_pageio_add_request - Attempt to coalesce a request into a page list. | |
902 | * @desc: destination io descriptor | |
903 | * @req: request | |
904 | * | |
2bfc6e56 WAA |
905 | * This may split a request into subrequests which are all part of the |
906 | * same page group. | |
907 | * | |
bcb71bba TM |
908 | * Returns true if the request 'req' was successfully coalesced into the |
909 | * existing list of pages 'desc'. | |
910 | */ | |
d9156f9f | 911 | static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, |
8b09bee3 | 912 | struct nfs_page *req) |
bcb71bba | 913 | { |
2bfc6e56 WAA |
914 | struct nfs_page *subreq; |
915 | unsigned int bytes_left = 0; | |
916 | unsigned int offset, pgbase; | |
917 | ||
bfd484a5 | 918 | nfs_page_group_lock(req, false); |
2bfc6e56 WAA |
919 | |
920 | subreq = req; | |
921 | bytes_left = subreq->wb_bytes; | |
922 | offset = subreq->wb_offset; | |
923 | pgbase = subreq->wb_pgbase; | |
924 | ||
925 | do { | |
926 | if (!nfs_pageio_do_add_request(desc, subreq)) { | |
927 | /* make sure pg_test call(s) did nothing */ | |
928 | WARN_ON_ONCE(subreq->wb_bytes != bytes_left); | |
929 | WARN_ON_ONCE(subreq->wb_offset != offset); | |
930 | WARN_ON_ONCE(subreq->wb_pgbase != pgbase); | |
931 | ||
932 | nfs_page_group_unlock(req); | |
933 | desc->pg_moreio = 1; | |
934 | nfs_pageio_doio(desc); | |
935 | if (desc->pg_error < 0) | |
936 | return 0; | |
2bfc6e56 WAA |
937 | if (desc->pg_recoalesce) |
938 | return 0; | |
939 | /* retry add_request for this subreq */ | |
bfd484a5 | 940 | nfs_page_group_lock(req, false); |
2bfc6e56 WAA |
941 | continue; |
942 | } | |
943 | ||
944 | /* check for buggy pg_test call(s) */ | |
945 | WARN_ON_ONCE(subreq->wb_bytes + subreq->wb_pgbase > PAGE_SIZE); | |
946 | WARN_ON_ONCE(subreq->wb_bytes > bytes_left); | |
947 | WARN_ON_ONCE(subreq->wb_bytes == 0); | |
948 | ||
949 | bytes_left -= subreq->wb_bytes; | |
950 | offset += subreq->wb_bytes; | |
951 | pgbase += subreq->wb_bytes; | |
952 | ||
953 | if (bytes_left) { | |
954 | subreq = nfs_create_request(req->wb_context, | |
955 | req->wb_page, | |
956 | subreq, pgbase, bytes_left); | |
c1109558 TM |
957 | if (IS_ERR(subreq)) |
958 | goto err_ptr; | |
2bfc6e56 WAA |
959 | nfs_lock_request(subreq); |
960 | subreq->wb_offset = offset; | |
961 | subreq->wb_index = req->wb_index; | |
962 | } | |
963 | } while (bytes_left > 0); | |
964 | ||
965 | nfs_page_group_unlock(req); | |
bcb71bba | 966 | return 1; |
c1109558 TM |
967 | err_ptr: |
968 | desc->pg_error = PTR_ERR(subreq); | |
969 | nfs_page_group_unlock(req); | |
970 | return 0; | |
bcb71bba TM |
971 | } |
972 | ||
d9156f9f TM |
973 | static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc) |
974 | { | |
975 | LIST_HEAD(head); | |
976 | ||
977 | do { | |
978 | list_splice_init(&desc->pg_list, &head); | |
979 | desc->pg_bytes_written -= desc->pg_count; | |
980 | desc->pg_count = 0; | |
981 | desc->pg_base = 0; | |
982 | desc->pg_recoalesce = 0; | |
f563b89b | 983 | desc->pg_moreio = 0; |
d9156f9f TM |
984 | |
985 | while (!list_empty(&head)) { | |
986 | struct nfs_page *req; | |
987 | ||
988 | req = list_first_entry(&head, struct nfs_page, wb_list); | |
989 | nfs_list_remove_request(req); | |
990 | if (__nfs_pageio_add_request(desc, req)) | |
991 | continue; | |
992 | if (desc->pg_error < 0) | |
993 | return 0; | |
994 | break; | |
995 | } | |
996 | } while (desc->pg_recoalesce); | |
997 | return 1; | |
998 | } | |
999 | ||
1000 | int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, | |
1001 | struct nfs_page *req) | |
1002 | { | |
1003 | int ret; | |
1004 | ||
1005 | do { | |
1006 | ret = __nfs_pageio_add_request(desc, req); | |
1007 | if (ret) | |
1008 | break; | |
1009 | if (desc->pg_error < 0) | |
1010 | break; | |
1011 | ret = nfs_do_recoalesce(desc); | |
1012 | } while (ret); | |
1013 | return ret; | |
1014 | } | |
1015 | ||
53113ad3 WAA |
1016 | /* |
1017 | * nfs_pageio_resend - Transfer requests to new descriptor and resend | |
1018 | * @hdr - the pgio header to move request from | |
1019 | * @desc - the pageio descriptor to add requests to | |
1020 | * | |
1021 | * Try to move each request (nfs_page) from @hdr to @desc then attempt | |
1022 | * to send them. | |
1023 | * | |
1024 | * Returns 0 on success and < 0 on error. | |
1025 | */ | |
1026 | int nfs_pageio_resend(struct nfs_pageio_descriptor *desc, | |
1027 | struct nfs_pgio_header *hdr) | |
1028 | { | |
1029 | LIST_HEAD(failed); | |
1030 | ||
1031 | desc->pg_dreq = hdr->dreq; | |
1032 | while (!list_empty(&hdr->pages)) { | |
1033 | struct nfs_page *req = nfs_list_entry(hdr->pages.next); | |
1034 | ||
1035 | nfs_list_remove_request(req); | |
1036 | if (!nfs_pageio_add_request(desc, req)) | |
1037 | nfs_list_add_request(req, &failed); | |
1038 | } | |
1039 | nfs_pageio_complete(desc); | |
1040 | if (!list_empty(&failed)) { | |
1041 | list_move(&failed, &hdr->pages); | |
1042 | return -EIO; | |
1043 | } | |
1044 | return 0; | |
1045 | } | |
1046 | EXPORT_SYMBOL_GPL(nfs_pageio_resend); | |
d9156f9f | 1047 | |
bcb71bba TM |
1048 | /** |
1049 | * nfs_pageio_complete - Complete I/O on an nfs_pageio_descriptor | |
1050 | * @desc: pointer to io descriptor | |
1051 | */ | |
1052 | void nfs_pageio_complete(struct nfs_pageio_descriptor *desc) | |
1053 | { | |
d9156f9f TM |
1054 | for (;;) { |
1055 | nfs_pageio_doio(desc); | |
1056 | if (!desc->pg_recoalesce) | |
1057 | break; | |
1058 | if (!nfs_do_recoalesce(desc)) | |
1059 | break; | |
1060 | } | |
bcb71bba TM |
1061 | } |
1062 | ||
7fe7f848 TM |
1063 | /** |
1064 | * nfs_pageio_cond_complete - Conditional I/O completion | |
1065 | * @desc: pointer to io descriptor | |
1066 | * @index: page index | |
1067 | * | |
1068 | * It is important to ensure that processes don't try to take locks | |
1069 | * on non-contiguous ranges of pages as that might deadlock. This | |
1070 | * function should be called before attempting to wait on a locked | |
1071 | * nfs_page. It will complete the I/O if the page index 'index' | |
1072 | * is not contiguous with the existing list of pages in 'desc'. | |
1073 | */ | |
1074 | void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index) | |
1075 | { | |
1076 | if (!list_empty(&desc->pg_list)) { | |
1077 | struct nfs_page *prev = nfs_list_entry(desc->pg_list.prev); | |
1078 | if (index != prev->wb_index + 1) | |
d9156f9f | 1079 | nfs_pageio_complete(desc); |
7fe7f848 TM |
1080 | } |
1081 | } | |
1082 | ||
f7b422b1 | 1083 | int __init nfs_init_nfspagecache(void) |
1da177e4 LT |
1084 | { |
1085 | nfs_page_cachep = kmem_cache_create("nfs_page", | |
1086 | sizeof(struct nfs_page), | |
1087 | 0, SLAB_HWCACHE_ALIGN, | |
20c2df83 | 1088 | NULL); |
1da177e4 LT |
1089 | if (nfs_page_cachep == NULL) |
1090 | return -ENOMEM; | |
1091 | ||
1092 | return 0; | |
1093 | } | |
1094 | ||
266bee88 | 1095 | void nfs_destroy_nfspagecache(void) |
1da177e4 | 1096 | { |
1a1d92c1 | 1097 | kmem_cache_destroy(nfs_page_cachep); |
1da177e4 LT |
1098 | } |
1099 | ||
ef2c488c | 1100 | static const struct rpc_call_ops nfs_pgio_common_ops = { |
6f92fa45 AS |
1101 | .rpc_call_prepare = nfs_pgio_prepare, |
1102 | .rpc_call_done = nfs_pgio_result, | |
1103 | .rpc_release = nfs_pgio_release, | |
1104 | }; | |
41d8d5b7 AS |
1105 | |
1106 | const struct nfs_pageio_ops nfs_pgio_rw_ops = { | |
1107 | .pg_test = nfs_generic_pg_test, | |
1108 | .pg_doio = nfs_generic_pg_pgios, | |
1109 | }; |