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