1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/fs/nfs/pagelist.c 4 * 5 * A set of helper functions for managing NFS read and write requests. 6 * The main purpose of these routines is to provide support for the 7 * coalescing of several requests into a single RPC call. 8 * 9 * Copyright 2000, 2001 (c) Trond Myklebust <trond.myklebust@fys.uio.no> 10 * 11 */ 12 13 #include <linux/slab.h> 14 #include <linux/file.h> 15 #include <linux/sched.h> 16 #include <linux/sunrpc/clnt.h> 17 #include <linux/nfs.h> 18 #include <linux/nfs3.h> 19 #include <linux/nfs4.h> 20 #include <linux/nfs_fs.h> 21 #include <linux/nfs_page.h> 22 #include <linux/nfs_mount.h> 23 #include <linux/export.h> 24 25 #include "internal.h" 26 #include "pnfs.h" 27 #include "nfstrace.h" 28 29 #define NFSDBG_FACILITY NFSDBG_PAGECACHE 30 31 static struct kmem_cache *nfs_page_cachep; 32 static const struct rpc_call_ops nfs_pgio_common_ops; 33 34 static struct nfs_pgio_mirror * 35 nfs_pgio_get_mirror(struct nfs_pageio_descriptor *desc, u32 idx) 36 { 37 if (desc->pg_ops->pg_get_mirror) 38 return desc->pg_ops->pg_get_mirror(desc, idx); 39 return &desc->pg_mirrors[0]; 40 } 41 42 struct nfs_pgio_mirror * 43 nfs_pgio_current_mirror(struct nfs_pageio_descriptor *desc) 44 { 45 return nfs_pgio_get_mirror(desc, desc->pg_mirror_idx); 46 } 47 EXPORT_SYMBOL_GPL(nfs_pgio_current_mirror); 48 49 static u32 50 nfs_pgio_set_current_mirror(struct nfs_pageio_descriptor *desc, u32 idx) 51 { 52 if (desc->pg_ops->pg_set_mirror) 53 return desc->pg_ops->pg_set_mirror(desc, idx); 54 return desc->pg_mirror_idx; 55 } 56 57 void nfs_pgheader_init(struct nfs_pageio_descriptor *desc, 58 struct nfs_pgio_header *hdr, 59 void (*release)(struct nfs_pgio_header *hdr)) 60 { 61 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc); 62 63 64 hdr->req = nfs_list_entry(mirror->pg_list.next); 65 hdr->inode = desc->pg_inode; 66 hdr->cred = nfs_req_openctx(hdr->req)->cred; 67 hdr->io_start = req_offset(hdr->req); 68 hdr->good_bytes = mirror->pg_count; 69 hdr->io_completion = desc->pg_io_completion; 70 hdr->dreq = desc->pg_dreq; 71 hdr->release = release; 72 hdr->completion_ops = desc->pg_completion_ops; 73 if (hdr->completion_ops->init_hdr) 74 hdr->completion_ops->init_hdr(hdr); 75 76 hdr->pgio_mirror_idx = desc->pg_mirror_idx; 77 } 78 EXPORT_SYMBOL_GPL(nfs_pgheader_init); 79 80 void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos) 81 { 82 unsigned int new = pos - hdr->io_start; 83 84 trace_nfs_pgio_error(hdr, error, pos); 85 if (hdr->good_bytes > new) { 86 hdr->good_bytes = new; 87 clear_bit(NFS_IOHDR_EOF, &hdr->flags); 88 if (!test_and_set_bit(NFS_IOHDR_ERROR, &hdr->flags)) 89 hdr->error = error; 90 } 91 } 92 93 static inline struct nfs_page * 94 nfs_page_alloc(void) 95 { 96 struct nfs_page *p = kmem_cache_zalloc(nfs_page_cachep, GFP_KERNEL); 97 if (p) 98 INIT_LIST_HEAD(&p->wb_list); 99 return p; 100 } 101 102 static inline void 103 nfs_page_free(struct nfs_page *p) 104 { 105 kmem_cache_free(nfs_page_cachep, p); 106 } 107 108 /** 109 * nfs_iocounter_wait - wait for i/o to complete 110 * @l_ctx: nfs_lock_context with io_counter to use 111 * 112 * returns -ERESTARTSYS if interrupted by a fatal signal. 113 * Otherwise returns 0 once the io_count hits 0. 114 */ 115 int 116 nfs_iocounter_wait(struct nfs_lock_context *l_ctx) 117 { 118 return wait_var_event_killable(&l_ctx->io_count, 119 !atomic_read(&l_ctx->io_count)); 120 } 121 122 /** 123 * nfs_async_iocounter_wait - wait on a rpc_waitqueue for I/O 124 * to complete 125 * @task: the rpc_task that should wait 126 * @l_ctx: nfs_lock_context with io_counter to check 127 * 128 * Returns true if there is outstanding I/O to wait on and the 129 * task has been put to sleep. 130 */ 131 bool 132 nfs_async_iocounter_wait(struct rpc_task *task, struct nfs_lock_context *l_ctx) 133 { 134 struct inode *inode = d_inode(l_ctx->open_context->dentry); 135 bool ret = false; 136 137 if (atomic_read(&l_ctx->io_count) > 0) { 138 rpc_sleep_on(&NFS_SERVER(inode)->uoc_rpcwaitq, task, NULL); 139 ret = true; 140 } 141 142 if (atomic_read(&l_ctx->io_count) == 0) { 143 rpc_wake_up_queued_task(&NFS_SERVER(inode)->uoc_rpcwaitq, task); 144 ret = false; 145 } 146 147 return ret; 148 } 149 EXPORT_SYMBOL_GPL(nfs_async_iocounter_wait); 150 151 /* 152 * nfs_page_lock_head_request - page lock the head of the page group 153 * @req: any member of the page group 154 */ 155 struct nfs_page * 156 nfs_page_group_lock_head(struct nfs_page *req) 157 { 158 struct nfs_page *head = req->wb_head; 159 160 while (!nfs_lock_request(head)) { 161 int ret = nfs_wait_on_request(head); 162 if (ret < 0) 163 return ERR_PTR(ret); 164 } 165 if (head != req) 166 kref_get(&head->wb_kref); 167 return head; 168 } 169 170 /* 171 * nfs_unroll_locks - unlock all newly locked reqs and wait on @req 172 * @head: head request of page group, must be holding head lock 173 * @req: request that couldn't lock and needs to wait on the req bit lock 174 * 175 * This is a helper function for nfs_lock_and_join_requests 176 * returns 0 on success, < 0 on error. 177 */ 178 static void 179 nfs_unroll_locks(struct nfs_page *head, struct nfs_page *req) 180 { 181 struct nfs_page *tmp; 182 183 /* relinquish all the locks successfully grabbed this run */ 184 for (tmp = head->wb_this_page ; tmp != req; tmp = tmp->wb_this_page) { 185 if (!kref_read(&tmp->wb_kref)) 186 continue; 187 nfs_unlock_and_release_request(tmp); 188 } 189 } 190 191 /* 192 * nfs_page_group_lock_subreq - try to lock a subrequest 193 * @head: head request of page group 194 * @subreq: request to lock 195 * 196 * This is a helper function for nfs_lock_and_join_requests which 197 * must be called with the head request and page group both locked. 198 * On error, it returns with the page group unlocked. 199 */ 200 static int 201 nfs_page_group_lock_subreq(struct nfs_page *head, struct nfs_page *subreq) 202 { 203 int ret; 204 205 if (!kref_get_unless_zero(&subreq->wb_kref)) 206 return 0; 207 while (!nfs_lock_request(subreq)) { 208 nfs_page_group_unlock(head); 209 ret = nfs_wait_on_request(subreq); 210 if (!ret) 211 ret = nfs_page_group_lock(head); 212 if (ret < 0) { 213 nfs_unroll_locks(head, subreq); 214 nfs_release_request(subreq); 215 return ret; 216 } 217 } 218 return 0; 219 } 220 221 /* 222 * nfs_page_group_lock_subrequests - try to lock the subrequests 223 * @head: head request of page group 224 * 225 * This is a helper function for nfs_lock_and_join_requests which 226 * must be called with the head request locked. 227 */ 228 int nfs_page_group_lock_subrequests(struct nfs_page *head) 229 { 230 struct nfs_page *subreq; 231 int ret; 232 233 ret = nfs_page_group_lock(head); 234 if (ret < 0) 235 return ret; 236 /* lock each request in the page group */ 237 for (subreq = head->wb_this_page; subreq != head; 238 subreq = subreq->wb_this_page) { 239 ret = nfs_page_group_lock_subreq(head, subreq); 240 if (ret < 0) 241 return ret; 242 } 243 nfs_page_group_unlock(head); 244 return 0; 245 } 246 247 /* 248 * nfs_page_set_headlock - set the request PG_HEADLOCK 249 * @req: request that is to be locked 250 * 251 * this lock must be held when modifying req->wb_head 252 * 253 * return 0 on success, < 0 on error 254 */ 255 int 256 nfs_page_set_headlock(struct nfs_page *req) 257 { 258 if (!test_and_set_bit(PG_HEADLOCK, &req->wb_flags)) 259 return 0; 260 261 set_bit(PG_CONTENDED1, &req->wb_flags); 262 smp_mb__after_atomic(); 263 return wait_on_bit_lock(&req->wb_flags, PG_HEADLOCK, 264 TASK_UNINTERRUPTIBLE); 265 } 266 267 /* 268 * nfs_page_clear_headlock - clear the request PG_HEADLOCK 269 * @req: request that is to be locked 270 */ 271 void 272 nfs_page_clear_headlock(struct nfs_page *req) 273 { 274 smp_mb__before_atomic(); 275 clear_bit(PG_HEADLOCK, &req->wb_flags); 276 smp_mb__after_atomic(); 277 if (!test_bit(PG_CONTENDED1, &req->wb_flags)) 278 return; 279 wake_up_bit(&req->wb_flags, PG_HEADLOCK); 280 } 281 282 /* 283 * nfs_page_group_lock - lock the head of the page group 284 * @req: request in group that is to be locked 285 * 286 * this lock must be held when traversing or modifying the page 287 * group list 288 * 289 * return 0 on success, < 0 on error 290 */ 291 int 292 nfs_page_group_lock(struct nfs_page *req) 293 { 294 int ret; 295 296 ret = nfs_page_set_headlock(req); 297 if (ret || req->wb_head == req) 298 return ret; 299 return nfs_page_set_headlock(req->wb_head); 300 } 301 302 /* 303 * nfs_page_group_unlock - unlock the head of the page group 304 * @req: request in group that is to be unlocked 305 */ 306 void 307 nfs_page_group_unlock(struct nfs_page *req) 308 { 309 if (req != req->wb_head) 310 nfs_page_clear_headlock(req->wb_head); 311 nfs_page_clear_headlock(req); 312 } 313 314 /* 315 * nfs_page_group_sync_on_bit_locked 316 * 317 * must be called with page group lock held 318 */ 319 static bool 320 nfs_page_group_sync_on_bit_locked(struct nfs_page *req, unsigned int bit) 321 { 322 struct nfs_page *head = req->wb_head; 323 struct nfs_page *tmp; 324 325 WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &head->wb_flags)); 326 WARN_ON_ONCE(test_and_set_bit(bit, &req->wb_flags)); 327 328 tmp = req->wb_this_page; 329 while (tmp != req) { 330 if (!test_bit(bit, &tmp->wb_flags)) 331 return false; 332 tmp = tmp->wb_this_page; 333 } 334 335 /* true! reset all bits */ 336 tmp = req; 337 do { 338 clear_bit(bit, &tmp->wb_flags); 339 tmp = tmp->wb_this_page; 340 } while (tmp != req); 341 342 return true; 343 } 344 345 /* 346 * nfs_page_group_sync_on_bit - set bit on current request, but only 347 * return true if the bit is set for all requests in page group 348 * @req - request in page group 349 * @bit - PG_* bit that is used to sync page group 350 */ 351 bool nfs_page_group_sync_on_bit(struct nfs_page *req, unsigned int bit) 352 { 353 bool ret; 354 355 nfs_page_group_lock(req); 356 ret = nfs_page_group_sync_on_bit_locked(req, bit); 357 nfs_page_group_unlock(req); 358 359 return ret; 360 } 361 362 /* 363 * nfs_page_group_init - Initialize the page group linkage for @req 364 * @req - a new nfs request 365 * @prev - the previous request in page group, or NULL if @req is the first 366 * or only request in the group (the head). 367 */ 368 static inline void 369 nfs_page_group_init(struct nfs_page *req, struct nfs_page *prev) 370 { 371 struct inode *inode; 372 WARN_ON_ONCE(prev == req); 373 374 if (!prev) { 375 /* a head request */ 376 req->wb_head = req; 377 req->wb_this_page = req; 378 } else { 379 /* a subrequest */ 380 WARN_ON_ONCE(prev->wb_this_page != prev->wb_head); 381 WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &prev->wb_head->wb_flags)); 382 req->wb_head = prev->wb_head; 383 req->wb_this_page = prev->wb_this_page; 384 prev->wb_this_page = req; 385 386 /* All subrequests take a ref on the head request until 387 * nfs_page_group_destroy is called */ 388 kref_get(&req->wb_head->wb_kref); 389 390 /* grab extra ref and bump the request count if head request 391 * has extra ref from the write/commit path to handle handoff 392 * between write and commit lists. */ 393 if (test_bit(PG_INODE_REF, &prev->wb_head->wb_flags)) { 394 inode = page_file_mapping(req->wb_page)->host; 395 set_bit(PG_INODE_REF, &req->wb_flags); 396 kref_get(&req->wb_kref); 397 atomic_long_inc(&NFS_I(inode)->nrequests); 398 } 399 } 400 } 401 402 /* 403 * nfs_page_group_destroy - sync the destruction of page groups 404 * @req - request that no longer needs the page group 405 * 406 * releases the page group reference from each member once all 407 * members have called this function. 408 */ 409 static void 410 nfs_page_group_destroy(struct kref *kref) 411 { 412 struct nfs_page *req = container_of(kref, struct nfs_page, wb_kref); 413 struct nfs_page *head = req->wb_head; 414 struct nfs_page *tmp, *next; 415 416 if (!nfs_page_group_sync_on_bit(req, PG_TEARDOWN)) 417 goto out; 418 419 tmp = req; 420 do { 421 next = tmp->wb_this_page; 422 /* unlink and free */ 423 tmp->wb_this_page = tmp; 424 tmp->wb_head = tmp; 425 nfs_free_request(tmp); 426 tmp = next; 427 } while (tmp != req); 428 out: 429 /* subrequests must release the ref on the head request */ 430 if (head != req) 431 nfs_release_request(head); 432 } 433 434 static struct nfs_page * 435 __nfs_create_request(struct nfs_lock_context *l_ctx, struct page *page, 436 unsigned int pgbase, unsigned int offset, 437 unsigned int count) 438 { 439 struct nfs_page *req; 440 struct nfs_open_context *ctx = l_ctx->open_context; 441 442 if (test_bit(NFS_CONTEXT_BAD, &ctx->flags)) 443 return ERR_PTR(-EBADF); 444 /* try to allocate the request struct */ 445 req = nfs_page_alloc(); 446 if (req == NULL) 447 return ERR_PTR(-ENOMEM); 448 449 req->wb_lock_context = l_ctx; 450 refcount_inc(&l_ctx->count); 451 atomic_inc(&l_ctx->io_count); 452 453 /* Initialize the request struct. Initially, we assume a 454 * long write-back delay. This will be adjusted in 455 * update_nfs_request below if the region is not locked. */ 456 req->wb_page = page; 457 if (page) { 458 req->wb_index = page_index(page); 459 get_page(page); 460 } 461 req->wb_offset = offset; 462 req->wb_pgbase = pgbase; 463 req->wb_bytes = count; 464 kref_init(&req->wb_kref); 465 req->wb_nio = 0; 466 return req; 467 } 468 469 /** 470 * nfs_create_request - Create an NFS read/write request. 471 * @ctx: open context to use 472 * @page: page to write 473 * @offset: starting offset within the page for the write 474 * @count: number of bytes to read/write 475 * 476 * The page must be locked by the caller. This makes sure we never 477 * create two different requests for the same page. 478 * User should ensure it is safe to sleep in this function. 479 */ 480 struct nfs_page * 481 nfs_create_request(struct nfs_open_context *ctx, struct page *page, 482 unsigned int offset, unsigned int count) 483 { 484 struct nfs_lock_context *l_ctx = nfs_get_lock_context(ctx); 485 struct nfs_page *ret; 486 487 if (IS_ERR(l_ctx)) 488 return ERR_CAST(l_ctx); 489 ret = __nfs_create_request(l_ctx, page, offset, offset, count); 490 if (!IS_ERR(ret)) 491 nfs_page_group_init(ret, NULL); 492 nfs_put_lock_context(l_ctx); 493 return ret; 494 } 495 496 static struct nfs_page * 497 nfs_create_subreq(struct nfs_page *req, 498 unsigned int pgbase, 499 unsigned int offset, 500 unsigned int count) 501 { 502 struct nfs_page *last; 503 struct nfs_page *ret; 504 505 ret = __nfs_create_request(req->wb_lock_context, req->wb_page, 506 pgbase, offset, count); 507 if (!IS_ERR(ret)) { 508 /* find the last request */ 509 for (last = req->wb_head; 510 last->wb_this_page != req->wb_head; 511 last = last->wb_this_page) 512 ; 513 514 nfs_lock_request(ret); 515 ret->wb_index = req->wb_index; 516 nfs_page_group_init(ret, last); 517 ret->wb_nio = req->wb_nio; 518 } 519 return ret; 520 } 521 522 /** 523 * nfs_unlock_request - Unlock request and wake up sleepers. 524 * @req: pointer to request 525 */ 526 void nfs_unlock_request(struct nfs_page *req) 527 { 528 if (!NFS_WBACK_BUSY(req)) { 529 printk(KERN_ERR "NFS: Invalid unlock attempted\n"); 530 BUG(); 531 } 532 smp_mb__before_atomic(); 533 clear_bit(PG_BUSY, &req->wb_flags); 534 smp_mb__after_atomic(); 535 if (!test_bit(PG_CONTENDED2, &req->wb_flags)) 536 return; 537 wake_up_bit(&req->wb_flags, PG_BUSY); 538 } 539 540 /** 541 * nfs_unlock_and_release_request - Unlock request and release the nfs_page 542 * @req: pointer to request 543 */ 544 void nfs_unlock_and_release_request(struct nfs_page *req) 545 { 546 nfs_unlock_request(req); 547 nfs_release_request(req); 548 } 549 550 /* 551 * nfs_clear_request - Free up all resources allocated to the request 552 * @req: 553 * 554 * Release page and open context resources associated with a read/write 555 * request after it has completed. 556 */ 557 static void nfs_clear_request(struct nfs_page *req) 558 { 559 struct page *page = req->wb_page; 560 struct nfs_lock_context *l_ctx = req->wb_lock_context; 561 struct nfs_open_context *ctx; 562 563 if (page != NULL) { 564 put_page(page); 565 req->wb_page = NULL; 566 } 567 if (l_ctx != NULL) { 568 if (atomic_dec_and_test(&l_ctx->io_count)) { 569 wake_up_var(&l_ctx->io_count); 570 ctx = l_ctx->open_context; 571 if (test_bit(NFS_CONTEXT_UNLOCK, &ctx->flags)) 572 rpc_wake_up(&NFS_SERVER(d_inode(ctx->dentry))->uoc_rpcwaitq); 573 } 574 nfs_put_lock_context(l_ctx); 575 req->wb_lock_context = NULL; 576 } 577 } 578 579 /** 580 * nfs_free_request - Release the count on an NFS read/write request 581 * @req: request to release 582 * 583 * Note: Should never be called with the spinlock held! 584 */ 585 void nfs_free_request(struct nfs_page *req) 586 { 587 WARN_ON_ONCE(req->wb_this_page != req); 588 589 /* extra debug: make sure no sync bits are still set */ 590 WARN_ON_ONCE(test_bit(PG_TEARDOWN, &req->wb_flags)); 591 WARN_ON_ONCE(test_bit(PG_UNLOCKPAGE, &req->wb_flags)); 592 WARN_ON_ONCE(test_bit(PG_UPTODATE, &req->wb_flags)); 593 WARN_ON_ONCE(test_bit(PG_WB_END, &req->wb_flags)); 594 WARN_ON_ONCE(test_bit(PG_REMOVE, &req->wb_flags)); 595 596 /* Release struct file and open context */ 597 nfs_clear_request(req); 598 nfs_page_free(req); 599 } 600 601 void nfs_release_request(struct nfs_page *req) 602 { 603 kref_put(&req->wb_kref, nfs_page_group_destroy); 604 } 605 EXPORT_SYMBOL_GPL(nfs_release_request); 606 607 /** 608 * nfs_wait_on_request - Wait for a request to complete. 609 * @req: request to wait upon. 610 * 611 * Interruptible by fatal signals only. 612 * The user is responsible for holding a count on the request. 613 */ 614 int 615 nfs_wait_on_request(struct nfs_page *req) 616 { 617 if (!test_bit(PG_BUSY, &req->wb_flags)) 618 return 0; 619 set_bit(PG_CONTENDED2, &req->wb_flags); 620 smp_mb__after_atomic(); 621 return wait_on_bit_io(&req->wb_flags, PG_BUSY, 622 TASK_UNINTERRUPTIBLE); 623 } 624 EXPORT_SYMBOL_GPL(nfs_wait_on_request); 625 626 /* 627 * nfs_generic_pg_test - determine if requests can be coalesced 628 * @desc: pointer to descriptor 629 * @prev: previous request in desc, or NULL 630 * @req: this request 631 * 632 * Returns zero if @req cannot be coalesced into @desc, otherwise it returns 633 * the size of the request. 634 */ 635 size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, 636 struct nfs_page *prev, struct nfs_page *req) 637 { 638 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc); 639 640 641 if (mirror->pg_count > mirror->pg_bsize) { 642 /* should never happen */ 643 WARN_ON_ONCE(1); 644 return 0; 645 } 646 647 /* 648 * Limit the request size so that we can still allocate a page array 649 * for it without upsetting the slab allocator. 650 */ 651 if (((mirror->pg_count + req->wb_bytes) >> PAGE_SHIFT) * 652 sizeof(struct page *) > PAGE_SIZE) 653 return 0; 654 655 return min(mirror->pg_bsize - mirror->pg_count, (size_t)req->wb_bytes); 656 } 657 EXPORT_SYMBOL_GPL(nfs_generic_pg_test); 658 659 struct nfs_pgio_header *nfs_pgio_header_alloc(const struct nfs_rw_ops *ops) 660 { 661 struct nfs_pgio_header *hdr = ops->rw_alloc_header(); 662 663 if (hdr) { 664 INIT_LIST_HEAD(&hdr->pages); 665 hdr->rw_ops = ops; 666 } 667 return hdr; 668 } 669 EXPORT_SYMBOL_GPL(nfs_pgio_header_alloc); 670 671 /** 672 * nfs_pgio_data_destroy - make @hdr suitable for reuse 673 * 674 * Frees memory and releases refs from nfs_generic_pgio, so that it may 675 * be called again. 676 * 677 * @hdr: A header that has had nfs_generic_pgio called 678 */ 679 static void nfs_pgio_data_destroy(struct nfs_pgio_header *hdr) 680 { 681 if (hdr->args.context) 682 put_nfs_open_context(hdr->args.context); 683 if (hdr->page_array.pagevec != hdr->page_array.page_array) 684 kfree(hdr->page_array.pagevec); 685 } 686 687 /* 688 * nfs_pgio_header_free - Free a read or write header 689 * @hdr: The header to free 690 */ 691 void nfs_pgio_header_free(struct nfs_pgio_header *hdr) 692 { 693 nfs_pgio_data_destroy(hdr); 694 hdr->rw_ops->rw_free_header(hdr); 695 } 696 EXPORT_SYMBOL_GPL(nfs_pgio_header_free); 697 698 /** 699 * nfs_pgio_rpcsetup - Set up arguments for a pageio call 700 * @hdr: The pageio hdr 701 * @count: Number of bytes to read 702 * @how: How to commit data (writes only) 703 * @cinfo: Commit information for the call (writes only) 704 */ 705 static void nfs_pgio_rpcsetup(struct nfs_pgio_header *hdr, 706 unsigned int count, 707 int how, struct nfs_commit_info *cinfo) 708 { 709 struct nfs_page *req = hdr->req; 710 711 /* Set up the RPC argument and reply structs 712 * NB: take care not to mess about with hdr->commit et al. */ 713 714 hdr->args.fh = NFS_FH(hdr->inode); 715 hdr->args.offset = req_offset(req); 716 /* pnfs_set_layoutcommit needs this */ 717 hdr->mds_offset = hdr->args.offset; 718 hdr->args.pgbase = req->wb_pgbase; 719 hdr->args.pages = hdr->page_array.pagevec; 720 hdr->args.count = count; 721 hdr->args.context = get_nfs_open_context(nfs_req_openctx(req)); 722 hdr->args.lock_context = req->wb_lock_context; 723 hdr->args.stable = NFS_UNSTABLE; 724 switch (how & (FLUSH_STABLE | FLUSH_COND_STABLE)) { 725 case 0: 726 break; 727 case FLUSH_COND_STABLE: 728 if (nfs_reqs_to_commit(cinfo)) 729 break; 730 fallthrough; 731 default: 732 hdr->args.stable = NFS_FILE_SYNC; 733 } 734 735 hdr->res.fattr = &hdr->fattr; 736 hdr->res.count = 0; 737 hdr->res.eof = 0; 738 hdr->res.verf = &hdr->verf; 739 nfs_fattr_init(&hdr->fattr); 740 } 741 742 /** 743 * nfs_pgio_prepare - Prepare pageio hdr to go over the wire 744 * @task: The current task 745 * @calldata: pageio header to prepare 746 */ 747 static void nfs_pgio_prepare(struct rpc_task *task, void *calldata) 748 { 749 struct nfs_pgio_header *hdr = calldata; 750 int err; 751 err = NFS_PROTO(hdr->inode)->pgio_rpc_prepare(task, hdr); 752 if (err) 753 rpc_exit(task, err); 754 } 755 756 int nfs_initiate_pgio(struct rpc_clnt *clnt, struct nfs_pgio_header *hdr, 757 const struct cred *cred, const struct nfs_rpc_ops *rpc_ops, 758 const struct rpc_call_ops *call_ops, int how, int flags) 759 { 760 struct rpc_task *task; 761 struct rpc_message msg = { 762 .rpc_argp = &hdr->args, 763 .rpc_resp = &hdr->res, 764 .rpc_cred = cred, 765 }; 766 struct rpc_task_setup task_setup_data = { 767 .rpc_client = clnt, 768 .task = &hdr->task, 769 .rpc_message = &msg, 770 .callback_ops = call_ops, 771 .callback_data = hdr, 772 .workqueue = nfsiod_workqueue, 773 .flags = RPC_TASK_ASYNC | flags, 774 }; 775 776 hdr->rw_ops->rw_initiate(hdr, &msg, rpc_ops, &task_setup_data, how); 777 778 dprintk("NFS: initiated pgio call " 779 "(req %s/%llu, %u bytes @ offset %llu)\n", 780 hdr->inode->i_sb->s_id, 781 (unsigned long long)NFS_FILEID(hdr->inode), 782 hdr->args.count, 783 (unsigned long long)hdr->args.offset); 784 785 task = rpc_run_task(&task_setup_data); 786 if (IS_ERR(task)) 787 return PTR_ERR(task); 788 rpc_put_task(task); 789 return 0; 790 } 791 EXPORT_SYMBOL_GPL(nfs_initiate_pgio); 792 793 /** 794 * nfs_pgio_error - Clean up from a pageio error 795 * @hdr: pageio header 796 */ 797 static void nfs_pgio_error(struct nfs_pgio_header *hdr) 798 { 799 set_bit(NFS_IOHDR_REDO, &hdr->flags); 800 hdr->completion_ops->completion(hdr); 801 } 802 803 /** 804 * nfs_pgio_release - Release pageio data 805 * @calldata: The pageio header to release 806 */ 807 static void nfs_pgio_release(void *calldata) 808 { 809 struct nfs_pgio_header *hdr = calldata; 810 hdr->completion_ops->completion(hdr); 811 } 812 813 static void nfs_pageio_mirror_init(struct nfs_pgio_mirror *mirror, 814 unsigned int bsize) 815 { 816 INIT_LIST_HEAD(&mirror->pg_list); 817 mirror->pg_bytes_written = 0; 818 mirror->pg_count = 0; 819 mirror->pg_bsize = bsize; 820 mirror->pg_base = 0; 821 mirror->pg_recoalesce = 0; 822 } 823 824 /** 825 * nfs_pageio_init - initialise a page io descriptor 826 * @desc: pointer to descriptor 827 * @inode: pointer to inode 828 * @pg_ops: pointer to pageio operations 829 * @compl_ops: pointer to pageio completion operations 830 * @rw_ops: pointer to nfs read/write operations 831 * @bsize: io block size 832 * @io_flags: extra parameters for the io function 833 */ 834 void nfs_pageio_init(struct nfs_pageio_descriptor *desc, 835 struct inode *inode, 836 const struct nfs_pageio_ops *pg_ops, 837 const struct nfs_pgio_completion_ops *compl_ops, 838 const struct nfs_rw_ops *rw_ops, 839 size_t bsize, 840 int io_flags) 841 { 842 desc->pg_moreio = 0; 843 desc->pg_inode = inode; 844 desc->pg_ops = pg_ops; 845 desc->pg_completion_ops = compl_ops; 846 desc->pg_rw_ops = rw_ops; 847 desc->pg_ioflags = io_flags; 848 desc->pg_error = 0; 849 desc->pg_lseg = NULL; 850 desc->pg_io_completion = NULL; 851 desc->pg_dreq = NULL; 852 desc->pg_bsize = bsize; 853 854 desc->pg_mirror_count = 1; 855 desc->pg_mirror_idx = 0; 856 857 desc->pg_mirrors_dynamic = NULL; 858 desc->pg_mirrors = desc->pg_mirrors_static; 859 nfs_pageio_mirror_init(&desc->pg_mirrors[0], bsize); 860 desc->pg_maxretrans = 0; 861 } 862 863 /** 864 * nfs_pgio_result - Basic pageio error handling 865 * @task: The task that ran 866 * @calldata: Pageio header to check 867 */ 868 static void nfs_pgio_result(struct rpc_task *task, void *calldata) 869 { 870 struct nfs_pgio_header *hdr = calldata; 871 struct inode *inode = hdr->inode; 872 873 dprintk("NFS: %s: %5u, (status %d)\n", __func__, 874 task->tk_pid, task->tk_status); 875 876 if (hdr->rw_ops->rw_done(task, hdr, inode) != 0) 877 return; 878 if (task->tk_status < 0) 879 nfs_set_pgio_error(hdr, task->tk_status, hdr->args.offset); 880 else 881 hdr->rw_ops->rw_result(task, hdr); 882 } 883 884 /* 885 * Create an RPC task for the given read or write request and kick it. 886 * The page must have been locked by the caller. 887 * 888 * It may happen that the page we're passed is not marked dirty. 889 * This is the case if nfs_updatepage detects a conflicting request 890 * that has been written but not committed. 891 */ 892 int nfs_generic_pgio(struct nfs_pageio_descriptor *desc, 893 struct nfs_pgio_header *hdr) 894 { 895 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc); 896 897 struct nfs_page *req; 898 struct page **pages, 899 *last_page; 900 struct list_head *head = &mirror->pg_list; 901 struct nfs_commit_info cinfo; 902 struct nfs_page_array *pg_array = &hdr->page_array; 903 unsigned int pagecount, pageused; 904 gfp_t gfp_flags = GFP_KERNEL; 905 906 pagecount = nfs_page_array_len(mirror->pg_base, mirror->pg_count); 907 pg_array->npages = pagecount; 908 909 if (pagecount <= ARRAY_SIZE(pg_array->page_array)) 910 pg_array->pagevec = pg_array->page_array; 911 else { 912 pg_array->pagevec = kcalloc(pagecount, sizeof(struct page *), gfp_flags); 913 if (!pg_array->pagevec) { 914 pg_array->npages = 0; 915 nfs_pgio_error(hdr); 916 desc->pg_error = -ENOMEM; 917 return desc->pg_error; 918 } 919 } 920 921 nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq); 922 pages = hdr->page_array.pagevec; 923 last_page = NULL; 924 pageused = 0; 925 while (!list_empty(head)) { 926 req = nfs_list_entry(head->next); 927 nfs_list_move_request(req, &hdr->pages); 928 929 if (!last_page || last_page != req->wb_page) { 930 pageused++; 931 if (pageused > pagecount) 932 break; 933 *pages++ = last_page = req->wb_page; 934 } 935 } 936 if (WARN_ON_ONCE(pageused != pagecount)) { 937 nfs_pgio_error(hdr); 938 desc->pg_error = -EINVAL; 939 return desc->pg_error; 940 } 941 942 if ((desc->pg_ioflags & FLUSH_COND_STABLE) && 943 (desc->pg_moreio || nfs_reqs_to_commit(&cinfo))) 944 desc->pg_ioflags &= ~FLUSH_COND_STABLE; 945 946 /* Set up the argument struct */ 947 nfs_pgio_rpcsetup(hdr, mirror->pg_count, desc->pg_ioflags, &cinfo); 948 desc->pg_rpc_callops = &nfs_pgio_common_ops; 949 return 0; 950 } 951 EXPORT_SYMBOL_GPL(nfs_generic_pgio); 952 953 static int nfs_generic_pg_pgios(struct nfs_pageio_descriptor *desc) 954 { 955 struct nfs_pgio_header *hdr; 956 int ret; 957 958 hdr = nfs_pgio_header_alloc(desc->pg_rw_ops); 959 if (!hdr) { 960 desc->pg_error = -ENOMEM; 961 return desc->pg_error; 962 } 963 nfs_pgheader_init(desc, hdr, nfs_pgio_header_free); 964 ret = nfs_generic_pgio(desc, hdr); 965 if (ret == 0) 966 ret = nfs_initiate_pgio(NFS_CLIENT(hdr->inode), 967 hdr, 968 hdr->cred, 969 NFS_PROTO(hdr->inode), 970 desc->pg_rpc_callops, 971 desc->pg_ioflags, 972 RPC_TASK_CRED_NOREF); 973 return ret; 974 } 975 976 static struct nfs_pgio_mirror * 977 nfs_pageio_alloc_mirrors(struct nfs_pageio_descriptor *desc, 978 unsigned int mirror_count) 979 { 980 struct nfs_pgio_mirror *ret; 981 unsigned int i; 982 983 kfree(desc->pg_mirrors_dynamic); 984 desc->pg_mirrors_dynamic = NULL; 985 if (mirror_count == 1) 986 return desc->pg_mirrors_static; 987 ret = kmalloc_array(mirror_count, sizeof(*ret), GFP_KERNEL); 988 if (ret != NULL) { 989 for (i = 0; i < mirror_count; i++) 990 nfs_pageio_mirror_init(&ret[i], desc->pg_bsize); 991 desc->pg_mirrors_dynamic = ret; 992 } 993 return ret; 994 } 995 996 /* 997 * nfs_pageio_setup_mirroring - determine if mirroring is to be used 998 * by calling the pg_get_mirror_count op 999 */ 1000 static void nfs_pageio_setup_mirroring(struct nfs_pageio_descriptor *pgio, 1001 struct nfs_page *req) 1002 { 1003 unsigned int mirror_count = 1; 1004 1005 if (pgio->pg_ops->pg_get_mirror_count) 1006 mirror_count = pgio->pg_ops->pg_get_mirror_count(pgio, req); 1007 if (mirror_count == pgio->pg_mirror_count || pgio->pg_error < 0) 1008 return; 1009 1010 if (!mirror_count || mirror_count > NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX) { 1011 pgio->pg_error = -EINVAL; 1012 return; 1013 } 1014 1015 pgio->pg_mirrors = nfs_pageio_alloc_mirrors(pgio, mirror_count); 1016 if (pgio->pg_mirrors == NULL) { 1017 pgio->pg_error = -ENOMEM; 1018 pgio->pg_mirrors = pgio->pg_mirrors_static; 1019 mirror_count = 1; 1020 } 1021 pgio->pg_mirror_count = mirror_count; 1022 } 1023 1024 static void nfs_pageio_cleanup_mirroring(struct nfs_pageio_descriptor *pgio) 1025 { 1026 pgio->pg_mirror_count = 1; 1027 pgio->pg_mirror_idx = 0; 1028 pgio->pg_mirrors = pgio->pg_mirrors_static; 1029 kfree(pgio->pg_mirrors_dynamic); 1030 pgio->pg_mirrors_dynamic = NULL; 1031 } 1032 1033 static bool nfs_match_lock_context(const struct nfs_lock_context *l1, 1034 const struct nfs_lock_context *l2) 1035 { 1036 return l1->lockowner == l2->lockowner; 1037 } 1038 1039 /** 1040 * nfs_coalesce_size - test two requests for compatibility 1041 * @prev: pointer to nfs_page 1042 * @req: pointer to nfs_page 1043 * @pgio: pointer to nfs_pagio_descriptor 1044 * 1045 * The nfs_page structures 'prev' and 'req' are compared to ensure that the 1046 * page data area they describe is contiguous, and that their RPC 1047 * credentials, NFSv4 open state, and lockowners are the same. 1048 * 1049 * Returns size of the request that can be coalesced 1050 */ 1051 static unsigned int nfs_coalesce_size(struct nfs_page *prev, 1052 struct nfs_page *req, 1053 struct nfs_pageio_descriptor *pgio) 1054 { 1055 struct file_lock_context *flctx; 1056 1057 if (prev) { 1058 if (!nfs_match_open_context(nfs_req_openctx(req), nfs_req_openctx(prev))) 1059 return 0; 1060 flctx = d_inode(nfs_req_openctx(req)->dentry)->i_flctx; 1061 if (flctx != NULL && 1062 !(list_empty_careful(&flctx->flc_posix) && 1063 list_empty_careful(&flctx->flc_flock)) && 1064 !nfs_match_lock_context(req->wb_lock_context, 1065 prev->wb_lock_context)) 1066 return 0; 1067 if (req_offset(req) != req_offset(prev) + prev->wb_bytes) 1068 return 0; 1069 if (req->wb_page == prev->wb_page) { 1070 if (req->wb_pgbase != prev->wb_pgbase + prev->wb_bytes) 1071 return 0; 1072 } else { 1073 if (req->wb_pgbase != 0 || 1074 prev->wb_pgbase + prev->wb_bytes != PAGE_SIZE) 1075 return 0; 1076 } 1077 } 1078 return pgio->pg_ops->pg_test(pgio, prev, req); 1079 } 1080 1081 /** 1082 * nfs_pageio_do_add_request - Attempt to coalesce a request into a page list. 1083 * @desc: destination io descriptor 1084 * @req: request 1085 * 1086 * If the request 'req' was successfully coalesced into the existing list 1087 * of pages 'desc', it returns the size of req. 1088 */ 1089 static unsigned int 1090 nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc, 1091 struct nfs_page *req) 1092 { 1093 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc); 1094 struct nfs_page *prev = NULL; 1095 unsigned int size; 1096 1097 if (mirror->pg_count != 0) { 1098 prev = nfs_list_entry(mirror->pg_list.prev); 1099 } else { 1100 if (desc->pg_ops->pg_init) 1101 desc->pg_ops->pg_init(desc, req); 1102 if (desc->pg_error < 0) 1103 return 0; 1104 mirror->pg_base = req->wb_pgbase; 1105 } 1106 1107 if (desc->pg_maxretrans && req->wb_nio > desc->pg_maxretrans) { 1108 if (NFS_SERVER(desc->pg_inode)->flags & NFS_MOUNT_SOFTERR) 1109 desc->pg_error = -ETIMEDOUT; 1110 else 1111 desc->pg_error = -EIO; 1112 return 0; 1113 } 1114 1115 size = nfs_coalesce_size(prev, req, desc); 1116 if (size < req->wb_bytes) 1117 return size; 1118 nfs_list_move_request(req, &mirror->pg_list); 1119 mirror->pg_count += req->wb_bytes; 1120 return req->wb_bytes; 1121 } 1122 1123 /* 1124 * Helper for nfs_pageio_add_request and nfs_pageio_complete 1125 */ 1126 static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc) 1127 { 1128 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc); 1129 1130 1131 if (!list_empty(&mirror->pg_list)) { 1132 int error = desc->pg_ops->pg_doio(desc); 1133 if (error < 0) 1134 desc->pg_error = error; 1135 else 1136 mirror->pg_bytes_written += mirror->pg_count; 1137 } 1138 if (list_empty(&mirror->pg_list)) { 1139 mirror->pg_count = 0; 1140 mirror->pg_base = 0; 1141 } 1142 } 1143 1144 static void 1145 nfs_pageio_cleanup_request(struct nfs_pageio_descriptor *desc, 1146 struct nfs_page *req) 1147 { 1148 LIST_HEAD(head); 1149 1150 nfs_list_move_request(req, &head); 1151 desc->pg_completion_ops->error_cleanup(&head, desc->pg_error); 1152 } 1153 1154 /** 1155 * __nfs_pageio_add_request - Attempt to coalesce a request into a page list. 1156 * @desc: destination io descriptor 1157 * @req: request 1158 * 1159 * This may split a request into subrequests which are all part of the 1160 * same page group. If so, it will submit @req as the last one, to ensure 1161 * the pointer to @req is still valid in case of failure. 1162 * 1163 * Returns true if the request 'req' was successfully coalesced into the 1164 * existing list of pages 'desc'. 1165 */ 1166 static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, 1167 struct nfs_page *req) 1168 { 1169 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc); 1170 struct nfs_page *subreq; 1171 unsigned int size, subreq_size; 1172 1173 nfs_page_group_lock(req); 1174 1175 subreq = req; 1176 subreq_size = subreq->wb_bytes; 1177 for(;;) { 1178 size = nfs_pageio_do_add_request(desc, subreq); 1179 if (size == subreq_size) { 1180 /* We successfully submitted a request */ 1181 if (subreq == req) 1182 break; 1183 req->wb_pgbase += size; 1184 req->wb_bytes -= size; 1185 req->wb_offset += size; 1186 subreq_size = req->wb_bytes; 1187 subreq = req; 1188 continue; 1189 } 1190 if (WARN_ON_ONCE(subreq != req)) { 1191 nfs_page_group_unlock(req); 1192 nfs_pageio_cleanup_request(desc, subreq); 1193 subreq = req; 1194 subreq_size = req->wb_bytes; 1195 nfs_page_group_lock(req); 1196 } 1197 if (!size) { 1198 /* Can't coalesce any more, so do I/O */ 1199 nfs_page_group_unlock(req); 1200 desc->pg_moreio = 1; 1201 nfs_pageio_doio(desc); 1202 if (desc->pg_error < 0 || mirror->pg_recoalesce) 1203 return 0; 1204 /* retry add_request for this subreq */ 1205 nfs_page_group_lock(req); 1206 continue; 1207 } 1208 subreq = nfs_create_subreq(req, req->wb_pgbase, 1209 req->wb_offset, size); 1210 if (IS_ERR(subreq)) 1211 goto err_ptr; 1212 subreq_size = size; 1213 } 1214 1215 nfs_page_group_unlock(req); 1216 return 1; 1217 err_ptr: 1218 desc->pg_error = PTR_ERR(subreq); 1219 nfs_page_group_unlock(req); 1220 return 0; 1221 } 1222 1223 static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc) 1224 { 1225 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc); 1226 LIST_HEAD(head); 1227 1228 do { 1229 list_splice_init(&mirror->pg_list, &head); 1230 mirror->pg_bytes_written -= mirror->pg_count; 1231 mirror->pg_count = 0; 1232 mirror->pg_base = 0; 1233 mirror->pg_recoalesce = 0; 1234 1235 while (!list_empty(&head)) { 1236 struct nfs_page *req; 1237 1238 req = list_first_entry(&head, struct nfs_page, wb_list); 1239 if (__nfs_pageio_add_request(desc, req)) 1240 continue; 1241 if (desc->pg_error < 0) { 1242 list_splice_tail(&head, &mirror->pg_list); 1243 mirror->pg_recoalesce = 1; 1244 return 0; 1245 } 1246 break; 1247 } 1248 } while (mirror->pg_recoalesce); 1249 return 1; 1250 } 1251 1252 static int nfs_pageio_add_request_mirror(struct nfs_pageio_descriptor *desc, 1253 struct nfs_page *req) 1254 { 1255 int ret; 1256 1257 do { 1258 ret = __nfs_pageio_add_request(desc, req); 1259 if (ret) 1260 break; 1261 if (desc->pg_error < 0) 1262 break; 1263 ret = nfs_do_recoalesce(desc); 1264 } while (ret); 1265 1266 return ret; 1267 } 1268 1269 static void nfs_pageio_error_cleanup(struct nfs_pageio_descriptor *desc) 1270 { 1271 u32 midx; 1272 struct nfs_pgio_mirror *mirror; 1273 1274 if (!desc->pg_error) 1275 return; 1276 1277 for (midx = 0; midx < desc->pg_mirror_count; midx++) { 1278 mirror = nfs_pgio_get_mirror(desc, midx); 1279 desc->pg_completion_ops->error_cleanup(&mirror->pg_list, 1280 desc->pg_error); 1281 } 1282 } 1283 1284 int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, 1285 struct nfs_page *req) 1286 { 1287 u32 midx; 1288 unsigned int pgbase, offset, bytes; 1289 struct nfs_page *dupreq; 1290 1291 pgbase = req->wb_pgbase; 1292 offset = req->wb_offset; 1293 bytes = req->wb_bytes; 1294 1295 nfs_pageio_setup_mirroring(desc, req); 1296 if (desc->pg_error < 0) 1297 goto out_failed; 1298 1299 /* Create the mirror instances first, and fire them off */ 1300 for (midx = 1; midx < desc->pg_mirror_count; midx++) { 1301 nfs_page_group_lock(req); 1302 1303 dupreq = nfs_create_subreq(req, 1304 pgbase, offset, bytes); 1305 1306 nfs_page_group_unlock(req); 1307 if (IS_ERR(dupreq)) { 1308 desc->pg_error = PTR_ERR(dupreq); 1309 goto out_failed; 1310 } 1311 1312 nfs_pgio_set_current_mirror(desc, midx); 1313 if (!nfs_pageio_add_request_mirror(desc, dupreq)) 1314 goto out_cleanup_subreq; 1315 } 1316 1317 nfs_pgio_set_current_mirror(desc, 0); 1318 if (!nfs_pageio_add_request_mirror(desc, req)) 1319 goto out_failed; 1320 1321 return 1; 1322 1323 out_cleanup_subreq: 1324 nfs_pageio_cleanup_request(desc, dupreq); 1325 out_failed: 1326 nfs_pageio_error_cleanup(desc); 1327 return 0; 1328 } 1329 1330 /* 1331 * nfs_pageio_complete_mirror - Complete I/O on the current mirror of an 1332 * nfs_pageio_descriptor 1333 * @desc: pointer to io descriptor 1334 * @mirror_idx: pointer to mirror index 1335 */ 1336 static void nfs_pageio_complete_mirror(struct nfs_pageio_descriptor *desc, 1337 u32 mirror_idx) 1338 { 1339 struct nfs_pgio_mirror *mirror; 1340 u32 restore_idx; 1341 1342 restore_idx = nfs_pgio_set_current_mirror(desc, mirror_idx); 1343 mirror = nfs_pgio_current_mirror(desc); 1344 1345 for (;;) { 1346 nfs_pageio_doio(desc); 1347 if (desc->pg_error < 0 || !mirror->pg_recoalesce) 1348 break; 1349 if (!nfs_do_recoalesce(desc)) 1350 break; 1351 } 1352 nfs_pgio_set_current_mirror(desc, restore_idx); 1353 } 1354 1355 /* 1356 * nfs_pageio_resend - Transfer requests to new descriptor and resend 1357 * @hdr - the pgio header to move request from 1358 * @desc - the pageio descriptor to add requests to 1359 * 1360 * Try to move each request (nfs_page) from @hdr to @desc then attempt 1361 * to send them. 1362 * 1363 * Returns 0 on success and < 0 on error. 1364 */ 1365 int nfs_pageio_resend(struct nfs_pageio_descriptor *desc, 1366 struct nfs_pgio_header *hdr) 1367 { 1368 LIST_HEAD(pages); 1369 1370 desc->pg_io_completion = hdr->io_completion; 1371 desc->pg_dreq = hdr->dreq; 1372 list_splice_init(&hdr->pages, &pages); 1373 while (!list_empty(&pages)) { 1374 struct nfs_page *req = nfs_list_entry(pages.next); 1375 1376 if (!nfs_pageio_add_request(desc, req)) 1377 break; 1378 } 1379 nfs_pageio_complete(desc); 1380 if (!list_empty(&pages)) { 1381 int err = desc->pg_error < 0 ? desc->pg_error : -EIO; 1382 hdr->completion_ops->error_cleanup(&pages, err); 1383 nfs_set_pgio_error(hdr, err, hdr->io_start); 1384 return err; 1385 } 1386 return 0; 1387 } 1388 EXPORT_SYMBOL_GPL(nfs_pageio_resend); 1389 1390 /** 1391 * nfs_pageio_complete - Complete I/O then cleanup an nfs_pageio_descriptor 1392 * @desc: pointer to io descriptor 1393 */ 1394 void nfs_pageio_complete(struct nfs_pageio_descriptor *desc) 1395 { 1396 u32 midx; 1397 1398 for (midx = 0; midx < desc->pg_mirror_count; midx++) 1399 nfs_pageio_complete_mirror(desc, midx); 1400 1401 if (desc->pg_error < 0) 1402 nfs_pageio_error_cleanup(desc); 1403 if (desc->pg_ops->pg_cleanup) 1404 desc->pg_ops->pg_cleanup(desc); 1405 nfs_pageio_cleanup_mirroring(desc); 1406 } 1407 1408 /** 1409 * nfs_pageio_cond_complete - Conditional I/O completion 1410 * @desc: pointer to io descriptor 1411 * @index: page index 1412 * 1413 * It is important to ensure that processes don't try to take locks 1414 * on non-contiguous ranges of pages as that might deadlock. This 1415 * function should be called before attempting to wait on a locked 1416 * nfs_page. It will complete the I/O if the page index 'index' 1417 * is not contiguous with the existing list of pages in 'desc'. 1418 */ 1419 void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index) 1420 { 1421 struct nfs_pgio_mirror *mirror; 1422 struct nfs_page *prev; 1423 u32 midx; 1424 1425 for (midx = 0; midx < desc->pg_mirror_count; midx++) { 1426 mirror = nfs_pgio_get_mirror(desc, midx); 1427 if (!list_empty(&mirror->pg_list)) { 1428 prev = nfs_list_entry(mirror->pg_list.prev); 1429 if (index != prev->wb_index + 1) { 1430 nfs_pageio_complete(desc); 1431 break; 1432 } 1433 } 1434 } 1435 } 1436 1437 /* 1438 * nfs_pageio_stop_mirroring - stop using mirroring (set mirror count to 1) 1439 */ 1440 void nfs_pageio_stop_mirroring(struct nfs_pageio_descriptor *pgio) 1441 { 1442 nfs_pageio_complete(pgio); 1443 } 1444 1445 int __init nfs_init_nfspagecache(void) 1446 { 1447 nfs_page_cachep = kmem_cache_create("nfs_page", 1448 sizeof(struct nfs_page), 1449 0, SLAB_HWCACHE_ALIGN, 1450 NULL); 1451 if (nfs_page_cachep == NULL) 1452 return -ENOMEM; 1453 1454 return 0; 1455 } 1456 1457 void nfs_destroy_nfspagecache(void) 1458 { 1459 kmem_cache_destroy(nfs_page_cachep); 1460 } 1461 1462 static const struct rpc_call_ops nfs_pgio_common_ops = { 1463 .rpc_call_prepare = nfs_pgio_prepare, 1464 .rpc_call_done = nfs_pgio_result, 1465 .rpc_release = nfs_pgio_release, 1466 }; 1467 1468 const struct nfs_pageio_ops nfs_pgio_rw_ops = { 1469 .pg_test = nfs_generic_pg_test, 1470 .pg_doio = nfs_generic_pg_pgios, 1471 }; 1472