1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/fs/nfs/write.c 4 * 5 * Write file data over NFS. 6 * 7 * Copyright (C) 1996, 1997, Olaf Kirch <okir@monad.swb.de> 8 */ 9 10 #include <linux/types.h> 11 #include <linux/slab.h> 12 #include <linux/mm.h> 13 #include <linux/pagemap.h> 14 #include <linux/file.h> 15 #include <linux/writeback.h> 16 #include <linux/swap.h> 17 #include <linux/migrate.h> 18 19 #include <linux/sunrpc/clnt.h> 20 #include <linux/nfs_fs.h> 21 #include <linux/nfs_mount.h> 22 #include <linux/nfs_page.h> 23 #include <linux/backing-dev.h> 24 #include <linux/export.h> 25 #include <linux/freezer.h> 26 #include <linux/wait.h> 27 #include <linux/iversion.h> 28 29 #include <linux/uaccess.h> 30 #include <linux/sched/mm.h> 31 32 #include "delegation.h" 33 #include "internal.h" 34 #include "iostat.h" 35 #include "nfs4_fs.h" 36 #include "fscache.h" 37 #include "pnfs.h" 38 39 #include "nfstrace.h" 40 41 #define NFSDBG_FACILITY NFSDBG_PAGECACHE 42 43 #define MIN_POOL_WRITE (32) 44 #define MIN_POOL_COMMIT (4) 45 46 struct nfs_io_completion { 47 void (*complete)(void *data); 48 void *data; 49 struct kref refcount; 50 }; 51 52 /* 53 * Local function declarations 54 */ 55 static void nfs_redirty_request(struct nfs_page *req); 56 static const struct rpc_call_ops nfs_commit_ops; 57 static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops; 58 static const struct nfs_commit_completion_ops nfs_commit_completion_ops; 59 static const struct nfs_rw_ops nfs_rw_write_ops; 60 static void nfs_inode_remove_request(struct nfs_page *req); 61 static void nfs_clear_request_commit(struct nfs_page *req); 62 static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo, 63 struct inode *inode); 64 static struct nfs_page * 65 nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi, 66 struct page *page); 67 68 static struct kmem_cache *nfs_wdata_cachep; 69 static mempool_t *nfs_wdata_mempool; 70 static struct kmem_cache *nfs_cdata_cachep; 71 static mempool_t *nfs_commit_mempool; 72 73 struct nfs_commit_data *nfs_commitdata_alloc(void) 74 { 75 struct nfs_commit_data *p; 76 77 p = kmem_cache_zalloc(nfs_cdata_cachep, nfs_io_gfp_mask()); 78 if (!p) { 79 p = mempool_alloc(nfs_commit_mempool, GFP_NOWAIT); 80 if (!p) 81 return NULL; 82 memset(p, 0, sizeof(*p)); 83 } 84 INIT_LIST_HEAD(&p->pages); 85 return p; 86 } 87 EXPORT_SYMBOL_GPL(nfs_commitdata_alloc); 88 89 void nfs_commit_free(struct nfs_commit_data *p) 90 { 91 mempool_free(p, nfs_commit_mempool); 92 } 93 EXPORT_SYMBOL_GPL(nfs_commit_free); 94 95 static struct nfs_pgio_header *nfs_writehdr_alloc(void) 96 { 97 struct nfs_pgio_header *p; 98 99 p = kmem_cache_zalloc(nfs_wdata_cachep, nfs_io_gfp_mask()); 100 if (!p) { 101 p = mempool_alloc(nfs_wdata_mempool, GFP_NOWAIT); 102 if (!p) 103 return NULL; 104 memset(p, 0, sizeof(*p)); 105 } 106 p->rw_mode = FMODE_WRITE; 107 return p; 108 } 109 110 static void nfs_writehdr_free(struct nfs_pgio_header *hdr) 111 { 112 mempool_free(hdr, nfs_wdata_mempool); 113 } 114 115 static struct nfs_io_completion *nfs_io_completion_alloc(gfp_t gfp_flags) 116 { 117 return kmalloc(sizeof(struct nfs_io_completion), gfp_flags); 118 } 119 120 static void nfs_io_completion_init(struct nfs_io_completion *ioc, 121 void (*complete)(void *), void *data) 122 { 123 ioc->complete = complete; 124 ioc->data = data; 125 kref_init(&ioc->refcount); 126 } 127 128 static void nfs_io_completion_release(struct kref *kref) 129 { 130 struct nfs_io_completion *ioc = container_of(kref, 131 struct nfs_io_completion, refcount); 132 ioc->complete(ioc->data); 133 kfree(ioc); 134 } 135 136 static void nfs_io_completion_get(struct nfs_io_completion *ioc) 137 { 138 if (ioc != NULL) 139 kref_get(&ioc->refcount); 140 } 141 142 static void nfs_io_completion_put(struct nfs_io_completion *ioc) 143 { 144 if (ioc != NULL) 145 kref_put(&ioc->refcount, nfs_io_completion_release); 146 } 147 148 static void 149 nfs_page_set_inode_ref(struct nfs_page *req, struct inode *inode) 150 { 151 if (!test_and_set_bit(PG_INODE_REF, &req->wb_flags)) { 152 kref_get(&req->wb_kref); 153 atomic_long_inc(&NFS_I(inode)->nrequests); 154 } 155 } 156 157 static int 158 nfs_cancel_remove_inode(struct nfs_page *req, struct inode *inode) 159 { 160 int ret; 161 162 if (!test_bit(PG_REMOVE, &req->wb_flags)) 163 return 0; 164 ret = nfs_page_group_lock(req); 165 if (ret) 166 return ret; 167 if (test_and_clear_bit(PG_REMOVE, &req->wb_flags)) 168 nfs_page_set_inode_ref(req, inode); 169 nfs_page_group_unlock(req); 170 return 0; 171 } 172 173 static struct nfs_page * 174 nfs_page_private_request(struct page *page) 175 { 176 if (!PagePrivate(page)) 177 return NULL; 178 return (struct nfs_page *)page_private(page); 179 } 180 181 /* 182 * nfs_page_find_head_request_locked - find head request associated with @page 183 * 184 * must be called while holding the inode lock. 185 * 186 * returns matching head request with reference held, or NULL if not found. 187 */ 188 static struct nfs_page * 189 nfs_page_find_private_request(struct page *page) 190 { 191 struct address_space *mapping = page_file_mapping(page); 192 struct nfs_page *req; 193 194 if (!PagePrivate(page)) 195 return NULL; 196 spin_lock(&mapping->private_lock); 197 req = nfs_page_private_request(page); 198 if (req) { 199 WARN_ON_ONCE(req->wb_head != req); 200 kref_get(&req->wb_kref); 201 } 202 spin_unlock(&mapping->private_lock); 203 return req; 204 } 205 206 static struct nfs_page * 207 nfs_page_find_swap_request(struct page *page) 208 { 209 struct inode *inode = page_file_mapping(page)->host; 210 struct nfs_inode *nfsi = NFS_I(inode); 211 struct nfs_page *req = NULL; 212 if (!PageSwapCache(page)) 213 return NULL; 214 mutex_lock(&nfsi->commit_mutex); 215 if (PageSwapCache(page)) { 216 req = nfs_page_search_commits_for_head_request_locked(nfsi, 217 page); 218 if (req) { 219 WARN_ON_ONCE(req->wb_head != req); 220 kref_get(&req->wb_kref); 221 } 222 } 223 mutex_unlock(&nfsi->commit_mutex); 224 return req; 225 } 226 227 /* 228 * nfs_page_find_head_request - find head request associated with @page 229 * 230 * returns matching head request with reference held, or NULL if not found. 231 */ 232 static struct nfs_page *nfs_page_find_head_request(struct page *page) 233 { 234 struct nfs_page *req; 235 236 req = nfs_page_find_private_request(page); 237 if (!req) 238 req = nfs_page_find_swap_request(page); 239 return req; 240 } 241 242 static struct nfs_page *nfs_find_and_lock_page_request(struct page *page) 243 { 244 struct inode *inode = page_file_mapping(page)->host; 245 struct nfs_page *req, *head; 246 int ret; 247 248 for (;;) { 249 req = nfs_page_find_head_request(page); 250 if (!req) 251 return req; 252 head = nfs_page_group_lock_head(req); 253 if (head != req) 254 nfs_release_request(req); 255 if (IS_ERR(head)) 256 return head; 257 ret = nfs_cancel_remove_inode(head, inode); 258 if (ret < 0) { 259 nfs_unlock_and_release_request(head); 260 return ERR_PTR(ret); 261 } 262 /* Ensure that nobody removed the request before we locked it */ 263 if (head == nfs_page_private_request(page)) 264 break; 265 if (PageSwapCache(page)) 266 break; 267 nfs_unlock_and_release_request(head); 268 } 269 return head; 270 } 271 272 /* Adjust the file length if we're writing beyond the end */ 273 static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count) 274 { 275 struct inode *inode = page_file_mapping(page)->host; 276 loff_t end, i_size; 277 pgoff_t end_index; 278 279 spin_lock(&inode->i_lock); 280 i_size = i_size_read(inode); 281 end_index = (i_size - 1) >> PAGE_SHIFT; 282 if (i_size > 0 && page_index(page) < end_index) 283 goto out; 284 end = page_file_offset(page) + ((loff_t)offset+count); 285 if (i_size >= end) 286 goto out; 287 trace_nfs_size_grow(inode, end); 288 i_size_write(inode, end); 289 NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_SIZE; 290 nfs_inc_stats(inode, NFSIOS_EXTENDWRITE); 291 out: 292 spin_unlock(&inode->i_lock); 293 nfs_fscache_invalidate(inode, 0); 294 } 295 296 /* A writeback failed: mark the page as bad, and invalidate the page cache */ 297 static void nfs_set_pageerror(struct address_space *mapping) 298 { 299 struct inode *inode = mapping->host; 300 301 nfs_zap_mapping(mapping->host, mapping); 302 /* Force file size revalidation */ 303 spin_lock(&inode->i_lock); 304 nfs_set_cache_invalid(inode, NFS_INO_REVAL_FORCED | 305 NFS_INO_INVALID_CHANGE | 306 NFS_INO_INVALID_SIZE); 307 spin_unlock(&inode->i_lock); 308 } 309 310 static void nfs_mapping_set_error(struct page *page, int error) 311 { 312 struct address_space *mapping = page_file_mapping(page); 313 314 SetPageError(page); 315 filemap_set_wb_err(mapping, error); 316 if (mapping->host) 317 errseq_set(&mapping->host->i_sb->s_wb_err, 318 error == -ENOSPC ? -ENOSPC : -EIO); 319 nfs_set_pageerror(mapping); 320 } 321 322 /* 323 * nfs_page_group_search_locked 324 * @head - head request of page group 325 * @page_offset - offset into page 326 * 327 * Search page group with head @head to find a request that contains the 328 * page offset @page_offset. 329 * 330 * Returns a pointer to the first matching nfs request, or NULL if no 331 * match is found. 332 * 333 * Must be called with the page group lock held 334 */ 335 static struct nfs_page * 336 nfs_page_group_search_locked(struct nfs_page *head, unsigned int page_offset) 337 { 338 struct nfs_page *req; 339 340 req = head; 341 do { 342 if (page_offset >= req->wb_pgbase && 343 page_offset < (req->wb_pgbase + req->wb_bytes)) 344 return req; 345 346 req = req->wb_this_page; 347 } while (req != head); 348 349 return NULL; 350 } 351 352 /* 353 * nfs_page_group_covers_page 354 * @head - head request of page group 355 * 356 * Return true if the page group with head @head covers the whole page, 357 * returns false otherwise 358 */ 359 static bool nfs_page_group_covers_page(struct nfs_page *req) 360 { 361 struct nfs_page *tmp; 362 unsigned int pos = 0; 363 unsigned int len = nfs_page_length(req->wb_page); 364 365 nfs_page_group_lock(req); 366 367 for (;;) { 368 tmp = nfs_page_group_search_locked(req->wb_head, pos); 369 if (!tmp) 370 break; 371 pos = tmp->wb_pgbase + tmp->wb_bytes; 372 } 373 374 nfs_page_group_unlock(req); 375 return pos >= len; 376 } 377 378 /* We can set the PG_uptodate flag if we see that a write request 379 * covers the full page. 380 */ 381 static void nfs_mark_uptodate(struct nfs_page *req) 382 { 383 if (PageUptodate(req->wb_page)) 384 return; 385 if (!nfs_page_group_covers_page(req)) 386 return; 387 SetPageUptodate(req->wb_page); 388 } 389 390 static int wb_priority(struct writeback_control *wbc) 391 { 392 int ret = 0; 393 394 if (wbc->sync_mode == WB_SYNC_ALL) 395 ret = FLUSH_COND_STABLE; 396 return ret; 397 } 398 399 /* 400 * NFS congestion control 401 */ 402 403 int nfs_congestion_kb; 404 405 #define NFS_CONGESTION_ON_THRESH (nfs_congestion_kb >> (PAGE_SHIFT-10)) 406 #define NFS_CONGESTION_OFF_THRESH \ 407 (NFS_CONGESTION_ON_THRESH - (NFS_CONGESTION_ON_THRESH >> 2)) 408 409 static void nfs_set_page_writeback(struct page *page) 410 { 411 struct inode *inode = page_file_mapping(page)->host; 412 struct nfs_server *nfss = NFS_SERVER(inode); 413 int ret = test_set_page_writeback(page); 414 415 WARN_ON_ONCE(ret != 0); 416 417 if (atomic_long_inc_return(&nfss->writeback) > 418 NFS_CONGESTION_ON_THRESH) 419 nfss->write_congested = 1; 420 } 421 422 static void nfs_end_page_writeback(struct nfs_page *req) 423 { 424 struct inode *inode = page_file_mapping(req->wb_page)->host; 425 struct nfs_server *nfss = NFS_SERVER(inode); 426 bool is_done; 427 428 is_done = nfs_page_group_sync_on_bit(req, PG_WB_END); 429 nfs_unlock_request(req); 430 if (!is_done) 431 return; 432 433 end_page_writeback(req->wb_page); 434 if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH) 435 nfss->write_congested = 0; 436 } 437 438 /* 439 * nfs_destroy_unlinked_subrequests - destroy recently unlinked subrequests 440 * 441 * @destroy_list - request list (using wb_this_page) terminated by @old_head 442 * @old_head - the old head of the list 443 * 444 * All subrequests must be locked and removed from all lists, so at this point 445 * they are only "active" in this function, and possibly in nfs_wait_on_request 446 * with a reference held by some other context. 447 */ 448 static void 449 nfs_destroy_unlinked_subrequests(struct nfs_page *destroy_list, 450 struct nfs_page *old_head, 451 struct inode *inode) 452 { 453 while (destroy_list) { 454 struct nfs_page *subreq = destroy_list; 455 456 destroy_list = (subreq->wb_this_page == old_head) ? 457 NULL : subreq->wb_this_page; 458 459 /* Note: lock subreq in order to change subreq->wb_head */ 460 nfs_page_set_headlock(subreq); 461 WARN_ON_ONCE(old_head != subreq->wb_head); 462 463 /* make sure old group is not used */ 464 subreq->wb_this_page = subreq; 465 subreq->wb_head = subreq; 466 467 clear_bit(PG_REMOVE, &subreq->wb_flags); 468 469 /* Note: races with nfs_page_group_destroy() */ 470 if (!kref_read(&subreq->wb_kref)) { 471 /* Check if we raced with nfs_page_group_destroy() */ 472 if (test_and_clear_bit(PG_TEARDOWN, &subreq->wb_flags)) { 473 nfs_page_clear_headlock(subreq); 474 nfs_free_request(subreq); 475 } else 476 nfs_page_clear_headlock(subreq); 477 continue; 478 } 479 nfs_page_clear_headlock(subreq); 480 481 nfs_release_request(old_head); 482 483 if (test_and_clear_bit(PG_INODE_REF, &subreq->wb_flags)) { 484 nfs_release_request(subreq); 485 atomic_long_dec(&NFS_I(inode)->nrequests); 486 } 487 488 /* subreq is now totally disconnected from page group or any 489 * write / commit lists. last chance to wake any waiters */ 490 nfs_unlock_and_release_request(subreq); 491 } 492 } 493 494 /* 495 * nfs_join_page_group - destroy subrequests of the head req 496 * @head: the page used to lookup the "page group" of nfs_page structures 497 * @inode: Inode to which the request belongs. 498 * 499 * This function joins all sub requests to the head request by first 500 * locking all requests in the group, cancelling any pending operations 501 * and finally updating the head request to cover the whole range covered by 502 * the (former) group. All subrequests are removed from any write or commit 503 * lists, unlinked from the group and destroyed. 504 */ 505 void 506 nfs_join_page_group(struct nfs_page *head, struct inode *inode) 507 { 508 struct nfs_page *subreq; 509 struct nfs_page *destroy_list = NULL; 510 unsigned int pgbase, off, bytes; 511 512 pgbase = head->wb_pgbase; 513 bytes = head->wb_bytes; 514 off = head->wb_offset; 515 for (subreq = head->wb_this_page; subreq != head; 516 subreq = subreq->wb_this_page) { 517 /* Subrequests should always form a contiguous range */ 518 if (pgbase > subreq->wb_pgbase) { 519 off -= pgbase - subreq->wb_pgbase; 520 bytes += pgbase - subreq->wb_pgbase; 521 pgbase = subreq->wb_pgbase; 522 } 523 bytes = max(subreq->wb_pgbase + subreq->wb_bytes 524 - pgbase, bytes); 525 } 526 527 /* Set the head request's range to cover the former page group */ 528 head->wb_pgbase = pgbase; 529 head->wb_bytes = bytes; 530 head->wb_offset = off; 531 532 /* Now that all requests are locked, make sure they aren't on any list. 533 * Commit list removal accounting is done after locks are dropped */ 534 subreq = head; 535 do { 536 nfs_clear_request_commit(subreq); 537 subreq = subreq->wb_this_page; 538 } while (subreq != head); 539 540 /* unlink subrequests from head, destroy them later */ 541 if (head->wb_this_page != head) { 542 /* destroy list will be terminated by head */ 543 destroy_list = head->wb_this_page; 544 head->wb_this_page = head; 545 } 546 547 nfs_destroy_unlinked_subrequests(destroy_list, head, inode); 548 } 549 550 /* 551 * nfs_lock_and_join_requests - join all subreqs to the head req 552 * @page: the page used to lookup the "page group" of nfs_page structures 553 * 554 * This function joins all sub requests to the head request by first 555 * locking all requests in the group, cancelling any pending operations 556 * and finally updating the head request to cover the whole range covered by 557 * the (former) group. All subrequests are removed from any write or commit 558 * lists, unlinked from the group and destroyed. 559 * 560 * Returns a locked, referenced pointer to the head request - which after 561 * this call is guaranteed to be the only request associated with the page. 562 * Returns NULL if no requests are found for @page, or a ERR_PTR if an 563 * error was encountered. 564 */ 565 static struct nfs_page * 566 nfs_lock_and_join_requests(struct page *page) 567 { 568 struct inode *inode = page_file_mapping(page)->host; 569 struct nfs_page *head; 570 int ret; 571 572 /* 573 * A reference is taken only on the head request which acts as a 574 * reference to the whole page group - the group will not be destroyed 575 * until the head reference is released. 576 */ 577 head = nfs_find_and_lock_page_request(page); 578 if (IS_ERR_OR_NULL(head)) 579 return head; 580 581 /* lock each request in the page group */ 582 ret = nfs_page_group_lock_subrequests(head); 583 if (ret < 0) { 584 nfs_unlock_and_release_request(head); 585 return ERR_PTR(ret); 586 } 587 588 nfs_join_page_group(head, inode); 589 590 return head; 591 } 592 593 static void nfs_write_error(struct nfs_page *req, int error) 594 { 595 trace_nfs_write_error(req, error); 596 nfs_mapping_set_error(req->wb_page, error); 597 nfs_inode_remove_request(req); 598 nfs_end_page_writeback(req); 599 nfs_release_request(req); 600 } 601 602 /* 603 * Find an associated nfs write request, and prepare to flush it out 604 * May return an error if the user signalled nfs_wait_on_request(). 605 */ 606 static int nfs_page_async_flush(struct page *page, 607 struct writeback_control *wbc, 608 struct nfs_pageio_descriptor *pgio) 609 { 610 struct nfs_page *req; 611 int ret = 0; 612 613 req = nfs_lock_and_join_requests(page); 614 if (!req) 615 goto out; 616 ret = PTR_ERR(req); 617 if (IS_ERR(req)) 618 goto out; 619 620 nfs_set_page_writeback(page); 621 WARN_ON_ONCE(test_bit(PG_CLEAN, &req->wb_flags)); 622 623 /* If there is a fatal error that covers this write, just exit */ 624 ret = pgio->pg_error; 625 if (nfs_error_is_fatal_on_server(ret)) 626 goto out_launder; 627 628 ret = 0; 629 if (!nfs_pageio_add_request(pgio, req)) { 630 ret = pgio->pg_error; 631 /* 632 * Remove the problematic req upon fatal errors on the server 633 */ 634 if (nfs_error_is_fatal_on_server(ret)) 635 goto out_launder; 636 if (wbc->sync_mode == WB_SYNC_NONE) 637 ret = AOP_WRITEPAGE_ACTIVATE; 638 redirty_page_for_writepage(wbc, page); 639 nfs_redirty_request(req); 640 pgio->pg_error = 0; 641 } else 642 nfs_add_stats(page_file_mapping(page)->host, 643 NFSIOS_WRITEPAGES, 1); 644 out: 645 return ret; 646 out_launder: 647 nfs_write_error(req, ret); 648 return 0; 649 } 650 651 static int nfs_do_writepage(struct page *page, struct writeback_control *wbc, 652 struct nfs_pageio_descriptor *pgio) 653 { 654 nfs_pageio_cond_complete(pgio, page_index(page)); 655 return nfs_page_async_flush(page, wbc, pgio); 656 } 657 658 /* 659 * Write an mmapped page to the server. 660 */ 661 static int nfs_writepage_locked(struct page *page, 662 struct writeback_control *wbc) 663 { 664 struct nfs_pageio_descriptor pgio; 665 struct inode *inode = page_file_mapping(page)->host; 666 int err; 667 668 if (wbc->sync_mode == WB_SYNC_NONE && 669 NFS_SERVER(inode)->write_congested) 670 return AOP_WRITEPAGE_ACTIVATE; 671 672 nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE); 673 nfs_pageio_init_write(&pgio, inode, 0, 674 false, &nfs_async_write_completion_ops); 675 err = nfs_do_writepage(page, wbc, &pgio); 676 pgio.pg_error = 0; 677 nfs_pageio_complete(&pgio); 678 return err; 679 } 680 681 int nfs_writepage(struct page *page, struct writeback_control *wbc) 682 { 683 int ret; 684 685 ret = nfs_writepage_locked(page, wbc); 686 if (ret != AOP_WRITEPAGE_ACTIVATE) 687 unlock_page(page); 688 return ret; 689 } 690 691 static int nfs_writepages_callback(struct page *page, struct writeback_control *wbc, void *data) 692 { 693 int ret; 694 695 ret = nfs_do_writepage(page, wbc, data); 696 if (ret != AOP_WRITEPAGE_ACTIVATE) 697 unlock_page(page); 698 return ret; 699 } 700 701 static void nfs_io_completion_commit(void *inode) 702 { 703 nfs_commit_inode(inode, 0); 704 } 705 706 int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc) 707 { 708 struct inode *inode = mapping->host; 709 struct nfs_pageio_descriptor pgio; 710 struct nfs_io_completion *ioc = NULL; 711 unsigned int mntflags = NFS_SERVER(inode)->flags; 712 int priority = 0; 713 int err; 714 715 if (wbc->sync_mode == WB_SYNC_NONE && 716 NFS_SERVER(inode)->write_congested) 717 return 0; 718 719 nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES); 720 721 if (!(mntflags & NFS_MOUNT_WRITE_EAGER) || wbc->for_kupdate || 722 wbc->for_background || wbc->for_sync || wbc->for_reclaim) { 723 ioc = nfs_io_completion_alloc(GFP_KERNEL); 724 if (ioc) 725 nfs_io_completion_init(ioc, nfs_io_completion_commit, 726 inode); 727 priority = wb_priority(wbc); 728 } 729 730 do { 731 nfs_pageio_init_write(&pgio, inode, priority, false, 732 &nfs_async_write_completion_ops); 733 pgio.pg_io_completion = ioc; 734 err = write_cache_pages(mapping, wbc, nfs_writepages_callback, 735 &pgio); 736 pgio.pg_error = 0; 737 nfs_pageio_complete(&pgio); 738 } while (err < 0 && !nfs_error_is_fatal(err)); 739 nfs_io_completion_put(ioc); 740 741 if (err < 0) 742 goto out_err; 743 return 0; 744 out_err: 745 return err; 746 } 747 748 /* 749 * Insert a write request into an inode 750 */ 751 static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req) 752 { 753 struct address_space *mapping = page_file_mapping(req->wb_page); 754 struct nfs_inode *nfsi = NFS_I(inode); 755 756 WARN_ON_ONCE(req->wb_this_page != req); 757 758 /* Lock the request! */ 759 nfs_lock_request(req); 760 761 /* 762 * Swap-space should not get truncated. Hence no need to plug the race 763 * with invalidate/truncate. 764 */ 765 spin_lock(&mapping->private_lock); 766 if (likely(!PageSwapCache(req->wb_page))) { 767 set_bit(PG_MAPPED, &req->wb_flags); 768 SetPagePrivate(req->wb_page); 769 set_page_private(req->wb_page, (unsigned long)req); 770 } 771 spin_unlock(&mapping->private_lock); 772 atomic_long_inc(&nfsi->nrequests); 773 /* this a head request for a page group - mark it as having an 774 * extra reference so sub groups can follow suit. 775 * This flag also informs pgio layer when to bump nrequests when 776 * adding subrequests. */ 777 WARN_ON(test_and_set_bit(PG_INODE_REF, &req->wb_flags)); 778 kref_get(&req->wb_kref); 779 } 780 781 /* 782 * Remove a write request from an inode 783 */ 784 static void nfs_inode_remove_request(struct nfs_page *req) 785 { 786 struct address_space *mapping = page_file_mapping(req->wb_page); 787 struct inode *inode = mapping->host; 788 struct nfs_inode *nfsi = NFS_I(inode); 789 struct nfs_page *head; 790 791 if (nfs_page_group_sync_on_bit(req, PG_REMOVE)) { 792 head = req->wb_head; 793 794 spin_lock(&mapping->private_lock); 795 if (likely(head->wb_page && !PageSwapCache(head->wb_page))) { 796 set_page_private(head->wb_page, 0); 797 ClearPagePrivate(head->wb_page); 798 clear_bit(PG_MAPPED, &head->wb_flags); 799 } 800 spin_unlock(&mapping->private_lock); 801 } 802 803 if (test_and_clear_bit(PG_INODE_REF, &req->wb_flags)) { 804 nfs_release_request(req); 805 atomic_long_dec(&nfsi->nrequests); 806 } 807 } 808 809 static void 810 nfs_mark_request_dirty(struct nfs_page *req) 811 { 812 if (req->wb_page) 813 __set_page_dirty_nobuffers(req->wb_page); 814 } 815 816 /* 817 * nfs_page_search_commits_for_head_request_locked 818 * 819 * Search through commit lists on @inode for the head request for @page. 820 * Must be called while holding the inode (which is cinfo) lock. 821 * 822 * Returns the head request if found, or NULL if not found. 823 */ 824 static struct nfs_page * 825 nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi, 826 struct page *page) 827 { 828 struct nfs_page *freq, *t; 829 struct nfs_commit_info cinfo; 830 struct inode *inode = &nfsi->vfs_inode; 831 832 nfs_init_cinfo_from_inode(&cinfo, inode); 833 834 /* search through pnfs commit lists */ 835 freq = pnfs_search_commit_reqs(inode, &cinfo, page); 836 if (freq) 837 return freq->wb_head; 838 839 /* Linearly search the commit list for the correct request */ 840 list_for_each_entry_safe(freq, t, &cinfo.mds->list, wb_list) { 841 if (freq->wb_page == page) 842 return freq->wb_head; 843 } 844 845 return NULL; 846 } 847 848 /** 849 * nfs_request_add_commit_list_locked - add request to a commit list 850 * @req: pointer to a struct nfs_page 851 * @dst: commit list head 852 * @cinfo: holds list lock and accounting info 853 * 854 * This sets the PG_CLEAN bit, updates the cinfo count of 855 * number of outstanding requests requiring a commit as well as 856 * the MM page stats. 857 * 858 * The caller must hold NFS_I(cinfo->inode)->commit_mutex, and the 859 * nfs_page lock. 860 */ 861 void 862 nfs_request_add_commit_list_locked(struct nfs_page *req, struct list_head *dst, 863 struct nfs_commit_info *cinfo) 864 { 865 set_bit(PG_CLEAN, &req->wb_flags); 866 nfs_list_add_request(req, dst); 867 atomic_long_inc(&cinfo->mds->ncommit); 868 } 869 EXPORT_SYMBOL_GPL(nfs_request_add_commit_list_locked); 870 871 /** 872 * nfs_request_add_commit_list - add request to a commit list 873 * @req: pointer to a struct nfs_page 874 * @cinfo: holds list lock and accounting info 875 * 876 * This sets the PG_CLEAN bit, updates the cinfo count of 877 * number of outstanding requests requiring a commit as well as 878 * the MM page stats. 879 * 880 * The caller must _not_ hold the cinfo->lock, but must be 881 * holding the nfs_page lock. 882 */ 883 void 884 nfs_request_add_commit_list(struct nfs_page *req, struct nfs_commit_info *cinfo) 885 { 886 mutex_lock(&NFS_I(cinfo->inode)->commit_mutex); 887 nfs_request_add_commit_list_locked(req, &cinfo->mds->list, cinfo); 888 mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex); 889 if (req->wb_page) 890 nfs_mark_page_unstable(req->wb_page, cinfo); 891 } 892 EXPORT_SYMBOL_GPL(nfs_request_add_commit_list); 893 894 /** 895 * nfs_request_remove_commit_list - Remove request from a commit list 896 * @req: pointer to a nfs_page 897 * @cinfo: holds list lock and accounting info 898 * 899 * This clears the PG_CLEAN bit, and updates the cinfo's count of 900 * number of outstanding requests requiring a commit 901 * It does not update the MM page stats. 902 * 903 * The caller _must_ hold the cinfo->lock and the nfs_page lock. 904 */ 905 void 906 nfs_request_remove_commit_list(struct nfs_page *req, 907 struct nfs_commit_info *cinfo) 908 { 909 if (!test_and_clear_bit(PG_CLEAN, &(req)->wb_flags)) 910 return; 911 nfs_list_remove_request(req); 912 atomic_long_dec(&cinfo->mds->ncommit); 913 } 914 EXPORT_SYMBOL_GPL(nfs_request_remove_commit_list); 915 916 static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo, 917 struct inode *inode) 918 { 919 cinfo->inode = inode; 920 cinfo->mds = &NFS_I(inode)->commit_info; 921 cinfo->ds = pnfs_get_ds_info(inode); 922 cinfo->dreq = NULL; 923 cinfo->completion_ops = &nfs_commit_completion_ops; 924 } 925 926 void nfs_init_cinfo(struct nfs_commit_info *cinfo, 927 struct inode *inode, 928 struct nfs_direct_req *dreq) 929 { 930 if (dreq) 931 nfs_init_cinfo_from_dreq(cinfo, dreq); 932 else 933 nfs_init_cinfo_from_inode(cinfo, inode); 934 } 935 EXPORT_SYMBOL_GPL(nfs_init_cinfo); 936 937 /* 938 * Add a request to the inode's commit list. 939 */ 940 void 941 nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg, 942 struct nfs_commit_info *cinfo, u32 ds_commit_idx) 943 { 944 if (pnfs_mark_request_commit(req, lseg, cinfo, ds_commit_idx)) 945 return; 946 nfs_request_add_commit_list(req, cinfo); 947 } 948 949 static void 950 nfs_clear_page_commit(struct page *page) 951 { 952 dec_node_page_state(page, NR_WRITEBACK); 953 dec_wb_stat(&inode_to_bdi(page_file_mapping(page)->host)->wb, 954 WB_WRITEBACK); 955 } 956 957 /* Called holding the request lock on @req */ 958 static void 959 nfs_clear_request_commit(struct nfs_page *req) 960 { 961 if (test_bit(PG_CLEAN, &req->wb_flags)) { 962 struct nfs_open_context *ctx = nfs_req_openctx(req); 963 struct inode *inode = d_inode(ctx->dentry); 964 struct nfs_commit_info cinfo; 965 966 nfs_init_cinfo_from_inode(&cinfo, inode); 967 mutex_lock(&NFS_I(inode)->commit_mutex); 968 if (!pnfs_clear_request_commit(req, &cinfo)) { 969 nfs_request_remove_commit_list(req, &cinfo); 970 } 971 mutex_unlock(&NFS_I(inode)->commit_mutex); 972 nfs_clear_page_commit(req->wb_page); 973 } 974 } 975 976 int nfs_write_need_commit(struct nfs_pgio_header *hdr) 977 { 978 if (hdr->verf.committed == NFS_DATA_SYNC) 979 return hdr->lseg == NULL; 980 return hdr->verf.committed != NFS_FILE_SYNC; 981 } 982 983 static void nfs_async_write_init(struct nfs_pgio_header *hdr) 984 { 985 nfs_io_completion_get(hdr->io_completion); 986 } 987 988 static void nfs_write_completion(struct nfs_pgio_header *hdr) 989 { 990 struct nfs_commit_info cinfo; 991 unsigned long bytes = 0; 992 993 if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) 994 goto out; 995 nfs_init_cinfo_from_inode(&cinfo, hdr->inode); 996 while (!list_empty(&hdr->pages)) { 997 struct nfs_page *req = nfs_list_entry(hdr->pages.next); 998 999 bytes += req->wb_bytes; 1000 nfs_list_remove_request(req); 1001 if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) && 1002 (hdr->good_bytes < bytes)) { 1003 trace_nfs_comp_error(req, hdr->error); 1004 nfs_mapping_set_error(req->wb_page, hdr->error); 1005 goto remove_req; 1006 } 1007 if (nfs_write_need_commit(hdr)) { 1008 /* Reset wb_nio, since the write was successful. */ 1009 req->wb_nio = 0; 1010 memcpy(&req->wb_verf, &hdr->verf.verifier, sizeof(req->wb_verf)); 1011 nfs_mark_request_commit(req, hdr->lseg, &cinfo, 1012 hdr->pgio_mirror_idx); 1013 goto next; 1014 } 1015 remove_req: 1016 nfs_inode_remove_request(req); 1017 next: 1018 nfs_end_page_writeback(req); 1019 nfs_release_request(req); 1020 } 1021 out: 1022 nfs_io_completion_put(hdr->io_completion); 1023 hdr->release(hdr); 1024 } 1025 1026 unsigned long 1027 nfs_reqs_to_commit(struct nfs_commit_info *cinfo) 1028 { 1029 return atomic_long_read(&cinfo->mds->ncommit); 1030 } 1031 1032 /* NFS_I(cinfo->inode)->commit_mutex held by caller */ 1033 int 1034 nfs_scan_commit_list(struct list_head *src, struct list_head *dst, 1035 struct nfs_commit_info *cinfo, int max) 1036 { 1037 struct nfs_page *req, *tmp; 1038 int ret = 0; 1039 1040 list_for_each_entry_safe(req, tmp, src, wb_list) { 1041 kref_get(&req->wb_kref); 1042 if (!nfs_lock_request(req)) { 1043 nfs_release_request(req); 1044 continue; 1045 } 1046 nfs_request_remove_commit_list(req, cinfo); 1047 clear_bit(PG_COMMIT_TO_DS, &req->wb_flags); 1048 nfs_list_add_request(req, dst); 1049 ret++; 1050 if ((ret == max) && !cinfo->dreq) 1051 break; 1052 cond_resched(); 1053 } 1054 return ret; 1055 } 1056 EXPORT_SYMBOL_GPL(nfs_scan_commit_list); 1057 1058 /* 1059 * nfs_scan_commit - Scan an inode for commit requests 1060 * @inode: NFS inode to scan 1061 * @dst: mds destination list 1062 * @cinfo: mds and ds lists of reqs ready to commit 1063 * 1064 * Moves requests from the inode's 'commit' request list. 1065 * The requests are *not* checked to ensure that they form a contiguous set. 1066 */ 1067 int 1068 nfs_scan_commit(struct inode *inode, struct list_head *dst, 1069 struct nfs_commit_info *cinfo) 1070 { 1071 int ret = 0; 1072 1073 if (!atomic_long_read(&cinfo->mds->ncommit)) 1074 return 0; 1075 mutex_lock(&NFS_I(cinfo->inode)->commit_mutex); 1076 if (atomic_long_read(&cinfo->mds->ncommit) > 0) { 1077 const int max = INT_MAX; 1078 1079 ret = nfs_scan_commit_list(&cinfo->mds->list, dst, 1080 cinfo, max); 1081 ret += pnfs_scan_commit_lists(inode, cinfo, max - ret); 1082 } 1083 mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex); 1084 return ret; 1085 } 1086 1087 /* 1088 * Search for an existing write request, and attempt to update 1089 * it to reflect a new dirty region on a given page. 1090 * 1091 * If the attempt fails, then the existing request is flushed out 1092 * to disk. 1093 */ 1094 static struct nfs_page *nfs_try_to_update_request(struct inode *inode, 1095 struct page *page, 1096 unsigned int offset, 1097 unsigned int bytes) 1098 { 1099 struct nfs_page *req; 1100 unsigned int rqend; 1101 unsigned int end; 1102 int error; 1103 1104 end = offset + bytes; 1105 1106 req = nfs_lock_and_join_requests(page); 1107 if (IS_ERR_OR_NULL(req)) 1108 return req; 1109 1110 rqend = req->wb_offset + req->wb_bytes; 1111 /* 1112 * Tell the caller to flush out the request if 1113 * the offsets are non-contiguous. 1114 * Note: nfs_flush_incompatible() will already 1115 * have flushed out requests having wrong owners. 1116 */ 1117 if (offset > rqend || end < req->wb_offset) 1118 goto out_flushme; 1119 1120 /* Okay, the request matches. Update the region */ 1121 if (offset < req->wb_offset) { 1122 req->wb_offset = offset; 1123 req->wb_pgbase = offset; 1124 } 1125 if (end > rqend) 1126 req->wb_bytes = end - req->wb_offset; 1127 else 1128 req->wb_bytes = rqend - req->wb_offset; 1129 req->wb_nio = 0; 1130 return req; 1131 out_flushme: 1132 /* 1133 * Note: we mark the request dirty here because 1134 * nfs_lock_and_join_requests() cannot preserve 1135 * commit flags, so we have to replay the write. 1136 */ 1137 nfs_mark_request_dirty(req); 1138 nfs_unlock_and_release_request(req); 1139 error = nfs_wb_page(inode, page); 1140 return (error < 0) ? ERR_PTR(error) : NULL; 1141 } 1142 1143 /* 1144 * Try to update an existing write request, or create one if there is none. 1145 * 1146 * Note: Should always be called with the Page Lock held to prevent races 1147 * if we have to add a new request. Also assumes that the caller has 1148 * already called nfs_flush_incompatible() if necessary. 1149 */ 1150 static struct nfs_page * nfs_setup_write_request(struct nfs_open_context* ctx, 1151 struct page *page, unsigned int offset, unsigned int bytes) 1152 { 1153 struct inode *inode = page_file_mapping(page)->host; 1154 struct nfs_page *req; 1155 1156 req = nfs_try_to_update_request(inode, page, offset, bytes); 1157 if (req != NULL) 1158 goto out; 1159 req = nfs_create_request(ctx, page, offset, bytes); 1160 if (IS_ERR(req)) 1161 goto out; 1162 nfs_inode_add_request(inode, req); 1163 out: 1164 return req; 1165 } 1166 1167 static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page, 1168 unsigned int offset, unsigned int count) 1169 { 1170 struct nfs_page *req; 1171 1172 req = nfs_setup_write_request(ctx, page, offset, count); 1173 if (IS_ERR(req)) 1174 return PTR_ERR(req); 1175 /* Update file length */ 1176 nfs_grow_file(page, offset, count); 1177 nfs_mark_uptodate(req); 1178 nfs_mark_request_dirty(req); 1179 nfs_unlock_and_release_request(req); 1180 return 0; 1181 } 1182 1183 int nfs_flush_incompatible(struct file *file, struct page *page) 1184 { 1185 struct nfs_open_context *ctx = nfs_file_open_context(file); 1186 struct nfs_lock_context *l_ctx; 1187 struct file_lock_context *flctx = file_inode(file)->i_flctx; 1188 struct nfs_page *req; 1189 int do_flush, status; 1190 /* 1191 * Look for a request corresponding to this page. If there 1192 * is one, and it belongs to another file, we flush it out 1193 * before we try to copy anything into the page. Do this 1194 * due to the lack of an ACCESS-type call in NFSv2. 1195 * Also do the same if we find a request from an existing 1196 * dropped page. 1197 */ 1198 do { 1199 req = nfs_page_find_head_request(page); 1200 if (req == NULL) 1201 return 0; 1202 l_ctx = req->wb_lock_context; 1203 do_flush = req->wb_page != page || 1204 !nfs_match_open_context(nfs_req_openctx(req), ctx); 1205 if (l_ctx && flctx && 1206 !(list_empty_careful(&flctx->flc_posix) && 1207 list_empty_careful(&flctx->flc_flock))) { 1208 do_flush |= l_ctx->lockowner != current->files; 1209 } 1210 nfs_release_request(req); 1211 if (!do_flush) 1212 return 0; 1213 status = nfs_wb_page(page_file_mapping(page)->host, page); 1214 } while (status == 0); 1215 return status; 1216 } 1217 1218 /* 1219 * Avoid buffered writes when a open context credential's key would 1220 * expire soon. 1221 * 1222 * Returns -EACCES if the key will expire within RPC_KEY_EXPIRE_FAIL. 1223 * 1224 * Return 0 and set a credential flag which triggers the inode to flush 1225 * and performs NFS_FILE_SYNC writes if the key will expired within 1226 * RPC_KEY_EXPIRE_TIMEO. 1227 */ 1228 int 1229 nfs_key_timeout_notify(struct file *filp, struct inode *inode) 1230 { 1231 struct nfs_open_context *ctx = nfs_file_open_context(filp); 1232 1233 if (nfs_ctx_key_to_expire(ctx, inode) && 1234 !rcu_access_pointer(ctx->ll_cred)) 1235 /* Already expired! */ 1236 return -EACCES; 1237 return 0; 1238 } 1239 1240 /* 1241 * Test if the open context credential key is marked to expire soon. 1242 */ 1243 bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx, struct inode *inode) 1244 { 1245 struct rpc_auth *auth = NFS_SERVER(inode)->client->cl_auth; 1246 struct rpc_cred *cred, *new, *old = NULL; 1247 struct auth_cred acred = { 1248 .cred = ctx->cred, 1249 }; 1250 bool ret = false; 1251 1252 rcu_read_lock(); 1253 cred = rcu_dereference(ctx->ll_cred); 1254 if (cred && !(cred->cr_ops->crkey_timeout && 1255 cred->cr_ops->crkey_timeout(cred))) 1256 goto out; 1257 rcu_read_unlock(); 1258 1259 new = auth->au_ops->lookup_cred(auth, &acred, 0); 1260 if (new == cred) { 1261 put_rpccred(new); 1262 return true; 1263 } 1264 if (IS_ERR_OR_NULL(new)) { 1265 new = NULL; 1266 ret = true; 1267 } else if (new->cr_ops->crkey_timeout && 1268 new->cr_ops->crkey_timeout(new)) 1269 ret = true; 1270 1271 rcu_read_lock(); 1272 old = rcu_dereference_protected(xchg(&ctx->ll_cred, 1273 RCU_INITIALIZER(new)), 1); 1274 out: 1275 rcu_read_unlock(); 1276 put_rpccred(old); 1277 return ret; 1278 } 1279 1280 /* 1281 * If the page cache is marked as unsafe or invalid, then we can't rely on 1282 * the PageUptodate() flag. In this case, we will need to turn off 1283 * write optimisations that depend on the page contents being correct. 1284 */ 1285 static bool nfs_write_pageuptodate(struct page *page, struct inode *inode, 1286 unsigned int pagelen) 1287 { 1288 struct nfs_inode *nfsi = NFS_I(inode); 1289 1290 if (nfs_have_delegated_attributes(inode)) 1291 goto out; 1292 if (nfsi->cache_validity & 1293 (NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_SIZE)) 1294 return false; 1295 smp_rmb(); 1296 if (test_bit(NFS_INO_INVALIDATING, &nfsi->flags) && pagelen != 0) 1297 return false; 1298 out: 1299 if (nfsi->cache_validity & NFS_INO_INVALID_DATA && pagelen != 0) 1300 return false; 1301 return PageUptodate(page) != 0; 1302 } 1303 1304 static bool 1305 is_whole_file_wrlock(struct file_lock *fl) 1306 { 1307 return fl->fl_start == 0 && fl->fl_end == OFFSET_MAX && 1308 fl->fl_type == F_WRLCK; 1309 } 1310 1311 /* If we know the page is up to date, and we're not using byte range locks (or 1312 * if we have the whole file locked for writing), it may be more efficient to 1313 * extend the write to cover the entire page in order to avoid fragmentation 1314 * inefficiencies. 1315 * 1316 * If the file is opened for synchronous writes then we can just skip the rest 1317 * of the checks. 1318 */ 1319 static int nfs_can_extend_write(struct file *file, struct page *page, 1320 struct inode *inode, unsigned int pagelen) 1321 { 1322 int ret; 1323 struct file_lock_context *flctx = inode->i_flctx; 1324 struct file_lock *fl; 1325 1326 if (file->f_flags & O_DSYNC) 1327 return 0; 1328 if (!nfs_write_pageuptodate(page, inode, pagelen)) 1329 return 0; 1330 if (NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE)) 1331 return 1; 1332 if (!flctx || (list_empty_careful(&flctx->flc_flock) && 1333 list_empty_careful(&flctx->flc_posix))) 1334 return 1; 1335 1336 /* Check to see if there are whole file write locks */ 1337 ret = 0; 1338 spin_lock(&flctx->flc_lock); 1339 if (!list_empty(&flctx->flc_posix)) { 1340 fl = list_first_entry(&flctx->flc_posix, struct file_lock, 1341 fl_list); 1342 if (is_whole_file_wrlock(fl)) 1343 ret = 1; 1344 } else if (!list_empty(&flctx->flc_flock)) { 1345 fl = list_first_entry(&flctx->flc_flock, struct file_lock, 1346 fl_list); 1347 if (fl->fl_type == F_WRLCK) 1348 ret = 1; 1349 } 1350 spin_unlock(&flctx->flc_lock); 1351 return ret; 1352 } 1353 1354 /* 1355 * Update and possibly write a cached page of an NFS file. 1356 * 1357 * XXX: Keep an eye on generic_file_read to make sure it doesn't do bad 1358 * things with a page scheduled for an RPC call (e.g. invalidate it). 1359 */ 1360 int nfs_updatepage(struct file *file, struct page *page, 1361 unsigned int offset, unsigned int count) 1362 { 1363 struct nfs_open_context *ctx = nfs_file_open_context(file); 1364 struct address_space *mapping = page_file_mapping(page); 1365 struct inode *inode = mapping->host; 1366 unsigned int pagelen = nfs_page_length(page); 1367 int status = 0; 1368 1369 nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE); 1370 1371 dprintk("NFS: nfs_updatepage(%pD2 %d@%lld)\n", 1372 file, count, (long long)(page_file_offset(page) + offset)); 1373 1374 if (!count) 1375 goto out; 1376 1377 if (nfs_can_extend_write(file, page, inode, pagelen)) { 1378 count = max(count + offset, pagelen); 1379 offset = 0; 1380 } 1381 1382 status = nfs_writepage_setup(ctx, page, offset, count); 1383 if (status < 0) 1384 nfs_set_pageerror(mapping); 1385 out: 1386 dprintk("NFS: nfs_updatepage returns %d (isize %lld)\n", 1387 status, (long long)i_size_read(inode)); 1388 return status; 1389 } 1390 1391 static int flush_task_priority(int how) 1392 { 1393 switch (how & (FLUSH_HIGHPRI|FLUSH_LOWPRI)) { 1394 case FLUSH_HIGHPRI: 1395 return RPC_PRIORITY_HIGH; 1396 case FLUSH_LOWPRI: 1397 return RPC_PRIORITY_LOW; 1398 } 1399 return RPC_PRIORITY_NORMAL; 1400 } 1401 1402 static void nfs_initiate_write(struct nfs_pgio_header *hdr, 1403 struct rpc_message *msg, 1404 const struct nfs_rpc_ops *rpc_ops, 1405 struct rpc_task_setup *task_setup_data, int how) 1406 { 1407 int priority = flush_task_priority(how); 1408 1409 if (IS_SWAPFILE(hdr->inode)) 1410 task_setup_data->flags |= RPC_TASK_SWAPPER; 1411 task_setup_data->priority = priority; 1412 rpc_ops->write_setup(hdr, msg, &task_setup_data->rpc_client); 1413 trace_nfs_initiate_write(hdr); 1414 } 1415 1416 /* If a nfs_flush_* function fails, it should remove reqs from @head and 1417 * call this on each, which will prepare them to be retried on next 1418 * writeback using standard nfs. 1419 */ 1420 static void nfs_redirty_request(struct nfs_page *req) 1421 { 1422 /* Bump the transmission count */ 1423 req->wb_nio++; 1424 nfs_mark_request_dirty(req); 1425 set_bit(NFS_CONTEXT_RESEND_WRITES, &nfs_req_openctx(req)->flags); 1426 nfs_end_page_writeback(req); 1427 nfs_release_request(req); 1428 } 1429 1430 static void nfs_async_write_error(struct list_head *head, int error) 1431 { 1432 struct nfs_page *req; 1433 1434 while (!list_empty(head)) { 1435 req = nfs_list_entry(head->next); 1436 nfs_list_remove_request(req); 1437 if (nfs_error_is_fatal_on_server(error)) 1438 nfs_write_error(req, error); 1439 else 1440 nfs_redirty_request(req); 1441 } 1442 } 1443 1444 static void nfs_async_write_reschedule_io(struct nfs_pgio_header *hdr) 1445 { 1446 nfs_async_write_error(&hdr->pages, 0); 1447 filemap_fdatawrite_range(hdr->inode->i_mapping, hdr->args.offset, 1448 hdr->args.offset + hdr->args.count - 1); 1449 } 1450 1451 static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops = { 1452 .init_hdr = nfs_async_write_init, 1453 .error_cleanup = nfs_async_write_error, 1454 .completion = nfs_write_completion, 1455 .reschedule_io = nfs_async_write_reschedule_io, 1456 }; 1457 1458 void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio, 1459 struct inode *inode, int ioflags, bool force_mds, 1460 const struct nfs_pgio_completion_ops *compl_ops) 1461 { 1462 struct nfs_server *server = NFS_SERVER(inode); 1463 const struct nfs_pageio_ops *pg_ops = &nfs_pgio_rw_ops; 1464 1465 #ifdef CONFIG_NFS_V4_1 1466 if (server->pnfs_curr_ld && !force_mds) 1467 pg_ops = server->pnfs_curr_ld->pg_write_ops; 1468 #endif 1469 nfs_pageio_init(pgio, inode, pg_ops, compl_ops, &nfs_rw_write_ops, 1470 server->wsize, ioflags); 1471 } 1472 EXPORT_SYMBOL_GPL(nfs_pageio_init_write); 1473 1474 void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio) 1475 { 1476 struct nfs_pgio_mirror *mirror; 1477 1478 if (pgio->pg_ops && pgio->pg_ops->pg_cleanup) 1479 pgio->pg_ops->pg_cleanup(pgio); 1480 1481 pgio->pg_ops = &nfs_pgio_rw_ops; 1482 1483 nfs_pageio_stop_mirroring(pgio); 1484 1485 mirror = &pgio->pg_mirrors[0]; 1486 mirror->pg_bsize = NFS_SERVER(pgio->pg_inode)->wsize; 1487 } 1488 EXPORT_SYMBOL_GPL(nfs_pageio_reset_write_mds); 1489 1490 1491 void nfs_commit_prepare(struct rpc_task *task, void *calldata) 1492 { 1493 struct nfs_commit_data *data = calldata; 1494 1495 NFS_PROTO(data->inode)->commit_rpc_prepare(task, data); 1496 } 1497 1498 /* 1499 * Special version of should_remove_suid() that ignores capabilities. 1500 */ 1501 static int nfs_should_remove_suid(const struct inode *inode) 1502 { 1503 umode_t mode = inode->i_mode; 1504 int kill = 0; 1505 1506 /* suid always must be killed */ 1507 if (unlikely(mode & S_ISUID)) 1508 kill = ATTR_KILL_SUID; 1509 1510 /* 1511 * sgid without any exec bits is just a mandatory locking mark; leave 1512 * it alone. If some exec bits are set, it's a real sgid; kill it. 1513 */ 1514 if (unlikely((mode & S_ISGID) && (mode & S_IXGRP))) 1515 kill |= ATTR_KILL_SGID; 1516 1517 if (unlikely(kill && S_ISREG(mode))) 1518 return kill; 1519 1520 return 0; 1521 } 1522 1523 static void nfs_writeback_check_extend(struct nfs_pgio_header *hdr, 1524 struct nfs_fattr *fattr) 1525 { 1526 struct nfs_pgio_args *argp = &hdr->args; 1527 struct nfs_pgio_res *resp = &hdr->res; 1528 u64 size = argp->offset + resp->count; 1529 1530 if (!(fattr->valid & NFS_ATTR_FATTR_SIZE)) 1531 fattr->size = size; 1532 if (nfs_size_to_loff_t(fattr->size) < i_size_read(hdr->inode)) { 1533 fattr->valid &= ~NFS_ATTR_FATTR_SIZE; 1534 return; 1535 } 1536 if (size != fattr->size) 1537 return; 1538 /* Set attribute barrier */ 1539 nfs_fattr_set_barrier(fattr); 1540 /* ...and update size */ 1541 fattr->valid |= NFS_ATTR_FATTR_SIZE; 1542 } 1543 1544 void nfs_writeback_update_inode(struct nfs_pgio_header *hdr) 1545 { 1546 struct nfs_fattr *fattr = &hdr->fattr; 1547 struct inode *inode = hdr->inode; 1548 1549 spin_lock(&inode->i_lock); 1550 nfs_writeback_check_extend(hdr, fattr); 1551 nfs_post_op_update_inode_force_wcc_locked(inode, fattr); 1552 spin_unlock(&inode->i_lock); 1553 } 1554 EXPORT_SYMBOL_GPL(nfs_writeback_update_inode); 1555 1556 /* 1557 * This function is called when the WRITE call is complete. 1558 */ 1559 static int nfs_writeback_done(struct rpc_task *task, 1560 struct nfs_pgio_header *hdr, 1561 struct inode *inode) 1562 { 1563 int status; 1564 1565 /* 1566 * ->write_done will attempt to use post-op attributes to detect 1567 * conflicting writes by other clients. A strict interpretation 1568 * of close-to-open would allow us to continue caching even if 1569 * another writer had changed the file, but some applications 1570 * depend on tighter cache coherency when writing. 1571 */ 1572 status = NFS_PROTO(inode)->write_done(task, hdr); 1573 if (status != 0) 1574 return status; 1575 1576 nfs_add_stats(inode, NFSIOS_SERVERWRITTENBYTES, hdr->res.count); 1577 trace_nfs_writeback_done(task, hdr); 1578 1579 if (hdr->res.verf->committed < hdr->args.stable && 1580 task->tk_status >= 0) { 1581 /* We tried a write call, but the server did not 1582 * commit data to stable storage even though we 1583 * requested it. 1584 * Note: There is a known bug in Tru64 < 5.0 in which 1585 * the server reports NFS_DATA_SYNC, but performs 1586 * NFS_FILE_SYNC. We therefore implement this checking 1587 * as a dprintk() in order to avoid filling syslog. 1588 */ 1589 static unsigned long complain; 1590 1591 /* Note this will print the MDS for a DS write */ 1592 if (time_before(complain, jiffies)) { 1593 dprintk("NFS: faulty NFS server %s:" 1594 " (committed = %d) != (stable = %d)\n", 1595 NFS_SERVER(inode)->nfs_client->cl_hostname, 1596 hdr->res.verf->committed, hdr->args.stable); 1597 complain = jiffies + 300 * HZ; 1598 } 1599 } 1600 1601 /* Deal with the suid/sgid bit corner case */ 1602 if (nfs_should_remove_suid(inode)) { 1603 spin_lock(&inode->i_lock); 1604 nfs_set_cache_invalid(inode, NFS_INO_INVALID_MODE); 1605 spin_unlock(&inode->i_lock); 1606 } 1607 return 0; 1608 } 1609 1610 /* 1611 * This function is called when the WRITE call is complete. 1612 */ 1613 static void nfs_writeback_result(struct rpc_task *task, 1614 struct nfs_pgio_header *hdr) 1615 { 1616 struct nfs_pgio_args *argp = &hdr->args; 1617 struct nfs_pgio_res *resp = &hdr->res; 1618 1619 if (resp->count < argp->count) { 1620 static unsigned long complain; 1621 1622 /* This a short write! */ 1623 nfs_inc_stats(hdr->inode, NFSIOS_SHORTWRITE); 1624 1625 /* Has the server at least made some progress? */ 1626 if (resp->count == 0) { 1627 if (time_before(complain, jiffies)) { 1628 printk(KERN_WARNING 1629 "NFS: Server wrote zero bytes, expected %u.\n", 1630 argp->count); 1631 complain = jiffies + 300 * HZ; 1632 } 1633 nfs_set_pgio_error(hdr, -EIO, argp->offset); 1634 task->tk_status = -EIO; 1635 return; 1636 } 1637 1638 /* For non rpc-based layout drivers, retry-through-MDS */ 1639 if (!task->tk_ops) { 1640 hdr->pnfs_error = -EAGAIN; 1641 return; 1642 } 1643 1644 /* Was this an NFSv2 write or an NFSv3 stable write? */ 1645 if (resp->verf->committed != NFS_UNSTABLE) { 1646 /* Resend from where the server left off */ 1647 hdr->mds_offset += resp->count; 1648 argp->offset += resp->count; 1649 argp->pgbase += resp->count; 1650 argp->count -= resp->count; 1651 } else { 1652 /* Resend as a stable write in order to avoid 1653 * headaches in the case of a server crash. 1654 */ 1655 argp->stable = NFS_FILE_SYNC; 1656 } 1657 resp->count = 0; 1658 resp->verf->committed = 0; 1659 rpc_restart_call_prepare(task); 1660 } 1661 } 1662 1663 static int wait_on_commit(struct nfs_mds_commit_info *cinfo) 1664 { 1665 return wait_var_event_killable(&cinfo->rpcs_out, 1666 !atomic_read(&cinfo->rpcs_out)); 1667 } 1668 1669 static void nfs_commit_begin(struct nfs_mds_commit_info *cinfo) 1670 { 1671 atomic_inc(&cinfo->rpcs_out); 1672 } 1673 1674 bool nfs_commit_end(struct nfs_mds_commit_info *cinfo) 1675 { 1676 if (atomic_dec_and_test(&cinfo->rpcs_out)) { 1677 wake_up_var(&cinfo->rpcs_out); 1678 return true; 1679 } 1680 return false; 1681 } 1682 1683 void nfs_commitdata_release(struct nfs_commit_data *data) 1684 { 1685 put_nfs_open_context(data->context); 1686 nfs_commit_free(data); 1687 } 1688 EXPORT_SYMBOL_GPL(nfs_commitdata_release); 1689 1690 int nfs_initiate_commit(struct rpc_clnt *clnt, struct nfs_commit_data *data, 1691 const struct nfs_rpc_ops *nfs_ops, 1692 const struct rpc_call_ops *call_ops, 1693 int how, int flags) 1694 { 1695 struct rpc_task *task; 1696 int priority = flush_task_priority(how); 1697 struct rpc_message msg = { 1698 .rpc_argp = &data->args, 1699 .rpc_resp = &data->res, 1700 .rpc_cred = data->cred, 1701 }; 1702 struct rpc_task_setup task_setup_data = { 1703 .task = &data->task, 1704 .rpc_client = clnt, 1705 .rpc_message = &msg, 1706 .callback_ops = call_ops, 1707 .callback_data = data, 1708 .workqueue = nfsiod_workqueue, 1709 .flags = RPC_TASK_ASYNC | flags, 1710 .priority = priority, 1711 }; 1712 1713 if (nfs_server_capable(data->inode, NFS_CAP_MOVEABLE)) 1714 task_setup_data.flags |= RPC_TASK_MOVEABLE; 1715 1716 /* Set up the initial task struct. */ 1717 nfs_ops->commit_setup(data, &msg, &task_setup_data.rpc_client); 1718 trace_nfs_initiate_commit(data); 1719 1720 dprintk("NFS: initiated commit call\n"); 1721 1722 task = rpc_run_task(&task_setup_data); 1723 if (IS_ERR(task)) 1724 return PTR_ERR(task); 1725 if (how & FLUSH_SYNC) 1726 rpc_wait_for_completion_task(task); 1727 rpc_put_task(task); 1728 return 0; 1729 } 1730 EXPORT_SYMBOL_GPL(nfs_initiate_commit); 1731 1732 static loff_t nfs_get_lwb(struct list_head *head) 1733 { 1734 loff_t lwb = 0; 1735 struct nfs_page *req; 1736 1737 list_for_each_entry(req, head, wb_list) 1738 if (lwb < (req_offset(req) + req->wb_bytes)) 1739 lwb = req_offset(req) + req->wb_bytes; 1740 1741 return lwb; 1742 } 1743 1744 /* 1745 * Set up the argument/result storage required for the RPC call. 1746 */ 1747 void nfs_init_commit(struct nfs_commit_data *data, 1748 struct list_head *head, 1749 struct pnfs_layout_segment *lseg, 1750 struct nfs_commit_info *cinfo) 1751 { 1752 struct nfs_page *first; 1753 struct nfs_open_context *ctx; 1754 struct inode *inode; 1755 1756 /* Set up the RPC argument and reply structs 1757 * NB: take care not to mess about with data->commit et al. */ 1758 1759 if (head) 1760 list_splice_init(head, &data->pages); 1761 1762 first = nfs_list_entry(data->pages.next); 1763 ctx = nfs_req_openctx(first); 1764 inode = d_inode(ctx->dentry); 1765 1766 data->inode = inode; 1767 data->cred = ctx->cred; 1768 data->lseg = lseg; /* reference transferred */ 1769 /* only set lwb for pnfs commit */ 1770 if (lseg) 1771 data->lwb = nfs_get_lwb(&data->pages); 1772 data->mds_ops = &nfs_commit_ops; 1773 data->completion_ops = cinfo->completion_ops; 1774 data->dreq = cinfo->dreq; 1775 1776 data->args.fh = NFS_FH(data->inode); 1777 /* Note: we always request a commit of the entire inode */ 1778 data->args.offset = 0; 1779 data->args.count = 0; 1780 data->context = get_nfs_open_context(ctx); 1781 data->res.fattr = &data->fattr; 1782 data->res.verf = &data->verf; 1783 nfs_fattr_init(&data->fattr); 1784 nfs_commit_begin(cinfo->mds); 1785 } 1786 EXPORT_SYMBOL_GPL(nfs_init_commit); 1787 1788 void nfs_retry_commit(struct list_head *page_list, 1789 struct pnfs_layout_segment *lseg, 1790 struct nfs_commit_info *cinfo, 1791 u32 ds_commit_idx) 1792 { 1793 struct nfs_page *req; 1794 1795 while (!list_empty(page_list)) { 1796 req = nfs_list_entry(page_list->next); 1797 nfs_list_remove_request(req); 1798 nfs_mark_request_commit(req, lseg, cinfo, ds_commit_idx); 1799 if (!cinfo->dreq) 1800 nfs_clear_page_commit(req->wb_page); 1801 nfs_unlock_and_release_request(req); 1802 } 1803 } 1804 EXPORT_SYMBOL_GPL(nfs_retry_commit); 1805 1806 static void 1807 nfs_commit_resched_write(struct nfs_commit_info *cinfo, 1808 struct nfs_page *req) 1809 { 1810 __set_page_dirty_nobuffers(req->wb_page); 1811 } 1812 1813 /* 1814 * Commit dirty pages 1815 */ 1816 static int 1817 nfs_commit_list(struct inode *inode, struct list_head *head, int how, 1818 struct nfs_commit_info *cinfo) 1819 { 1820 struct nfs_commit_data *data; 1821 unsigned short task_flags = 0; 1822 1823 /* another commit raced with us */ 1824 if (list_empty(head)) 1825 return 0; 1826 1827 data = nfs_commitdata_alloc(); 1828 if (!data) { 1829 nfs_retry_commit(head, NULL, cinfo, -1); 1830 return -ENOMEM; 1831 } 1832 1833 /* Set up the argument struct */ 1834 nfs_init_commit(data, head, NULL, cinfo); 1835 if (NFS_SERVER(inode)->nfs_client->cl_minorversion) 1836 task_flags = RPC_TASK_MOVEABLE; 1837 return nfs_initiate_commit(NFS_CLIENT(inode), data, NFS_PROTO(inode), 1838 data->mds_ops, how, 1839 RPC_TASK_CRED_NOREF | task_flags); 1840 } 1841 1842 /* 1843 * COMMIT call returned 1844 */ 1845 static void nfs_commit_done(struct rpc_task *task, void *calldata) 1846 { 1847 struct nfs_commit_data *data = calldata; 1848 1849 /* Call the NFS version-specific code */ 1850 NFS_PROTO(data->inode)->commit_done(task, data); 1851 trace_nfs_commit_done(task, data); 1852 } 1853 1854 static void nfs_commit_release_pages(struct nfs_commit_data *data) 1855 { 1856 const struct nfs_writeverf *verf = data->res.verf; 1857 struct nfs_page *req; 1858 int status = data->task.tk_status; 1859 struct nfs_commit_info cinfo; 1860 struct nfs_server *nfss; 1861 1862 while (!list_empty(&data->pages)) { 1863 req = nfs_list_entry(data->pages.next); 1864 nfs_list_remove_request(req); 1865 if (req->wb_page) 1866 nfs_clear_page_commit(req->wb_page); 1867 1868 dprintk("NFS: commit (%s/%llu %d@%lld)", 1869 nfs_req_openctx(req)->dentry->d_sb->s_id, 1870 (unsigned long long)NFS_FILEID(d_inode(nfs_req_openctx(req)->dentry)), 1871 req->wb_bytes, 1872 (long long)req_offset(req)); 1873 if (status < 0) { 1874 if (req->wb_page) { 1875 trace_nfs_commit_error(req, status); 1876 nfs_mapping_set_error(req->wb_page, status); 1877 nfs_inode_remove_request(req); 1878 } 1879 dprintk_cont(", error = %d\n", status); 1880 goto next; 1881 } 1882 1883 /* Okay, COMMIT succeeded, apparently. Check the verifier 1884 * returned by the server against all stored verfs. */ 1885 if (nfs_write_match_verf(verf, req)) { 1886 /* We have a match */ 1887 if (req->wb_page) 1888 nfs_inode_remove_request(req); 1889 dprintk_cont(" OK\n"); 1890 goto next; 1891 } 1892 /* We have a mismatch. Write the page again */ 1893 dprintk_cont(" mismatch\n"); 1894 nfs_mark_request_dirty(req); 1895 set_bit(NFS_CONTEXT_RESEND_WRITES, &nfs_req_openctx(req)->flags); 1896 next: 1897 nfs_unlock_and_release_request(req); 1898 /* Latency breaker */ 1899 cond_resched(); 1900 } 1901 nfss = NFS_SERVER(data->inode); 1902 if (atomic_long_read(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH) 1903 nfss->write_congested = 0; 1904 1905 nfs_init_cinfo(&cinfo, data->inode, data->dreq); 1906 nfs_commit_end(cinfo.mds); 1907 } 1908 1909 static void nfs_commit_release(void *calldata) 1910 { 1911 struct nfs_commit_data *data = calldata; 1912 1913 data->completion_ops->completion(data); 1914 nfs_commitdata_release(calldata); 1915 } 1916 1917 static const struct rpc_call_ops nfs_commit_ops = { 1918 .rpc_call_prepare = nfs_commit_prepare, 1919 .rpc_call_done = nfs_commit_done, 1920 .rpc_release = nfs_commit_release, 1921 }; 1922 1923 static const struct nfs_commit_completion_ops nfs_commit_completion_ops = { 1924 .completion = nfs_commit_release_pages, 1925 .resched_write = nfs_commit_resched_write, 1926 }; 1927 1928 int nfs_generic_commit_list(struct inode *inode, struct list_head *head, 1929 int how, struct nfs_commit_info *cinfo) 1930 { 1931 int status; 1932 1933 status = pnfs_commit_list(inode, head, how, cinfo); 1934 if (status == PNFS_NOT_ATTEMPTED) 1935 status = nfs_commit_list(inode, head, how, cinfo); 1936 return status; 1937 } 1938 1939 static int __nfs_commit_inode(struct inode *inode, int how, 1940 struct writeback_control *wbc) 1941 { 1942 LIST_HEAD(head); 1943 struct nfs_commit_info cinfo; 1944 int may_wait = how & FLUSH_SYNC; 1945 int ret, nscan; 1946 1947 how &= ~FLUSH_SYNC; 1948 nfs_init_cinfo_from_inode(&cinfo, inode); 1949 nfs_commit_begin(cinfo.mds); 1950 for (;;) { 1951 ret = nscan = nfs_scan_commit(inode, &head, &cinfo); 1952 if (ret <= 0) 1953 break; 1954 ret = nfs_generic_commit_list(inode, &head, how, &cinfo); 1955 if (ret < 0) 1956 break; 1957 ret = 0; 1958 if (wbc && wbc->sync_mode == WB_SYNC_NONE) { 1959 if (nscan < wbc->nr_to_write) 1960 wbc->nr_to_write -= nscan; 1961 else 1962 wbc->nr_to_write = 0; 1963 } 1964 if (nscan < INT_MAX) 1965 break; 1966 cond_resched(); 1967 } 1968 nfs_commit_end(cinfo.mds); 1969 if (ret || !may_wait) 1970 return ret; 1971 return wait_on_commit(cinfo.mds); 1972 } 1973 1974 int nfs_commit_inode(struct inode *inode, int how) 1975 { 1976 return __nfs_commit_inode(inode, how, NULL); 1977 } 1978 EXPORT_SYMBOL_GPL(nfs_commit_inode); 1979 1980 int nfs_write_inode(struct inode *inode, struct writeback_control *wbc) 1981 { 1982 struct nfs_inode *nfsi = NFS_I(inode); 1983 int flags = FLUSH_SYNC; 1984 int ret = 0; 1985 1986 if (wbc->sync_mode == WB_SYNC_NONE) { 1987 /* no commits means nothing needs to be done */ 1988 if (!atomic_long_read(&nfsi->commit_info.ncommit)) 1989 goto check_requests_outstanding; 1990 1991 /* Don't commit yet if this is a non-blocking flush and there 1992 * are a lot of outstanding writes for this mapping. 1993 */ 1994 if (mapping_tagged(inode->i_mapping, PAGECACHE_TAG_WRITEBACK)) 1995 goto out_mark_dirty; 1996 1997 /* don't wait for the COMMIT response */ 1998 flags = 0; 1999 } 2000 2001 ret = __nfs_commit_inode(inode, flags, wbc); 2002 if (!ret) { 2003 if (flags & FLUSH_SYNC) 2004 return 0; 2005 } else if (atomic_long_read(&nfsi->commit_info.ncommit)) 2006 goto out_mark_dirty; 2007 2008 check_requests_outstanding: 2009 if (!atomic_read(&nfsi->commit_info.rpcs_out)) 2010 return ret; 2011 out_mark_dirty: 2012 __mark_inode_dirty(inode, I_DIRTY_DATASYNC); 2013 return ret; 2014 } 2015 EXPORT_SYMBOL_GPL(nfs_write_inode); 2016 2017 /* 2018 * Wrapper for filemap_write_and_wait_range() 2019 * 2020 * Needed for pNFS in order to ensure data becomes visible to the 2021 * client. 2022 */ 2023 int nfs_filemap_write_and_wait_range(struct address_space *mapping, 2024 loff_t lstart, loff_t lend) 2025 { 2026 int ret; 2027 2028 ret = filemap_write_and_wait_range(mapping, lstart, lend); 2029 if (ret == 0) 2030 ret = pnfs_sync_inode(mapping->host, true); 2031 return ret; 2032 } 2033 EXPORT_SYMBOL_GPL(nfs_filemap_write_and_wait_range); 2034 2035 /* 2036 * flush the inode to disk. 2037 */ 2038 int nfs_wb_all(struct inode *inode) 2039 { 2040 int ret; 2041 2042 trace_nfs_writeback_inode_enter(inode); 2043 2044 ret = filemap_write_and_wait(inode->i_mapping); 2045 if (ret) 2046 goto out; 2047 ret = nfs_commit_inode(inode, FLUSH_SYNC); 2048 if (ret < 0) 2049 goto out; 2050 pnfs_sync_inode(inode, true); 2051 ret = 0; 2052 2053 out: 2054 trace_nfs_writeback_inode_exit(inode, ret); 2055 return ret; 2056 } 2057 EXPORT_SYMBOL_GPL(nfs_wb_all); 2058 2059 int nfs_wb_folio_cancel(struct inode *inode, struct folio *folio) 2060 { 2061 struct nfs_page *req; 2062 int ret = 0; 2063 2064 folio_wait_writeback(folio); 2065 2066 /* blocking call to cancel all requests and join to a single (head) 2067 * request */ 2068 req = nfs_lock_and_join_requests(&folio->page); 2069 2070 if (IS_ERR(req)) { 2071 ret = PTR_ERR(req); 2072 } else if (req) { 2073 /* all requests from this folio have been cancelled by 2074 * nfs_lock_and_join_requests, so just remove the head 2075 * request from the inode / page_private pointer and 2076 * release it */ 2077 nfs_inode_remove_request(req); 2078 nfs_unlock_and_release_request(req); 2079 } 2080 2081 return ret; 2082 } 2083 2084 /* 2085 * Write back all requests on one page - we do this before reading it. 2086 */ 2087 int nfs_wb_page(struct inode *inode, struct page *page) 2088 { 2089 loff_t range_start = page_file_offset(page); 2090 loff_t range_end = range_start + (loff_t)(PAGE_SIZE - 1); 2091 struct writeback_control wbc = { 2092 .sync_mode = WB_SYNC_ALL, 2093 .nr_to_write = 0, 2094 .range_start = range_start, 2095 .range_end = range_end, 2096 }; 2097 int ret; 2098 2099 trace_nfs_writeback_page_enter(inode); 2100 2101 for (;;) { 2102 wait_on_page_writeback(page); 2103 if (clear_page_dirty_for_io(page)) { 2104 ret = nfs_writepage_locked(page, &wbc); 2105 if (ret < 0) 2106 goto out_error; 2107 continue; 2108 } 2109 ret = 0; 2110 if (!PagePrivate(page)) 2111 break; 2112 ret = nfs_commit_inode(inode, FLUSH_SYNC); 2113 if (ret < 0) 2114 goto out_error; 2115 } 2116 out_error: 2117 trace_nfs_writeback_page_exit(inode, ret); 2118 return ret; 2119 } 2120 2121 #ifdef CONFIG_MIGRATION 2122 int nfs_migrate_folio(struct address_space *mapping, struct folio *dst, 2123 struct folio *src, enum migrate_mode mode) 2124 { 2125 /* 2126 * If the private flag is set, the folio is currently associated with 2127 * an in-progress read or write request. Don't try to migrate it. 2128 * 2129 * FIXME: we could do this in principle, but we'll need a way to ensure 2130 * that we can safely release the inode reference while holding 2131 * the folio lock. 2132 */ 2133 if (folio_test_private(src)) 2134 return -EBUSY; 2135 2136 if (folio_test_fscache(src)) { 2137 if (mode == MIGRATE_ASYNC) 2138 return -EBUSY; 2139 folio_wait_fscache(src); 2140 } 2141 2142 return migrate_folio(mapping, dst, src, mode); 2143 } 2144 #endif 2145 2146 int __init nfs_init_writepagecache(void) 2147 { 2148 nfs_wdata_cachep = kmem_cache_create("nfs_write_data", 2149 sizeof(struct nfs_pgio_header), 2150 0, SLAB_HWCACHE_ALIGN, 2151 NULL); 2152 if (nfs_wdata_cachep == NULL) 2153 return -ENOMEM; 2154 2155 nfs_wdata_mempool = mempool_create_slab_pool(MIN_POOL_WRITE, 2156 nfs_wdata_cachep); 2157 if (nfs_wdata_mempool == NULL) 2158 goto out_destroy_write_cache; 2159 2160 nfs_cdata_cachep = kmem_cache_create("nfs_commit_data", 2161 sizeof(struct nfs_commit_data), 2162 0, SLAB_HWCACHE_ALIGN, 2163 NULL); 2164 if (nfs_cdata_cachep == NULL) 2165 goto out_destroy_write_mempool; 2166 2167 nfs_commit_mempool = mempool_create_slab_pool(MIN_POOL_COMMIT, 2168 nfs_cdata_cachep); 2169 if (nfs_commit_mempool == NULL) 2170 goto out_destroy_commit_cache; 2171 2172 /* 2173 * NFS congestion size, scale with available memory. 2174 * 2175 * 64MB: 8192k 2176 * 128MB: 11585k 2177 * 256MB: 16384k 2178 * 512MB: 23170k 2179 * 1GB: 32768k 2180 * 2GB: 46340k 2181 * 4GB: 65536k 2182 * 8GB: 92681k 2183 * 16GB: 131072k 2184 * 2185 * This allows larger machines to have larger/more transfers. 2186 * Limit the default to 256M 2187 */ 2188 nfs_congestion_kb = (16*int_sqrt(totalram_pages())) << (PAGE_SHIFT-10); 2189 if (nfs_congestion_kb > 256*1024) 2190 nfs_congestion_kb = 256*1024; 2191 2192 return 0; 2193 2194 out_destroy_commit_cache: 2195 kmem_cache_destroy(nfs_cdata_cachep); 2196 out_destroy_write_mempool: 2197 mempool_destroy(nfs_wdata_mempool); 2198 out_destroy_write_cache: 2199 kmem_cache_destroy(nfs_wdata_cachep); 2200 return -ENOMEM; 2201 } 2202 2203 void nfs_destroy_writepagecache(void) 2204 { 2205 mempool_destroy(nfs_commit_mempool); 2206 kmem_cache_destroy(nfs_cdata_cachep); 2207 mempool_destroy(nfs_wdata_mempool); 2208 kmem_cache_destroy(nfs_wdata_cachep); 2209 } 2210 2211 static const struct nfs_rw_ops nfs_rw_write_ops = { 2212 .rw_alloc_header = nfs_writehdr_alloc, 2213 .rw_free_header = nfs_writehdr_free, 2214 .rw_done = nfs_writeback_done, 2215 .rw_result = nfs_writeback_result, 2216 .rw_initiate = nfs_initiate_write, 2217 }; 2218