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 25 #include <asm/uaccess.h> 26 27 #include "delegation.h" 28 #include "internal.h" 29 #include "iostat.h" 30 #include "nfs4_fs.h" 31 #include "fscache.h" 32 #include "pnfs.h" 33 34 #include "nfstrace.h" 35 36 #define NFSDBG_FACILITY NFSDBG_PAGECACHE 37 38 #define MIN_POOL_WRITE (32) 39 #define MIN_POOL_COMMIT (4) 40 41 /* 42 * Local function declarations 43 */ 44 static void nfs_redirty_request(struct nfs_page *req); 45 static const struct rpc_call_ops nfs_commit_ops; 46 static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops; 47 static const struct nfs_commit_completion_ops nfs_commit_completion_ops; 48 static const struct nfs_rw_ops nfs_rw_write_ops; 49 50 static struct kmem_cache *nfs_wdata_cachep; 51 static mempool_t *nfs_wdata_mempool; 52 static struct kmem_cache *nfs_cdata_cachep; 53 static mempool_t *nfs_commit_mempool; 54 55 struct nfs_commit_data *nfs_commitdata_alloc(void) 56 { 57 struct nfs_commit_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOIO); 58 59 if (p) { 60 memset(p, 0, sizeof(*p)); 61 INIT_LIST_HEAD(&p->pages); 62 } 63 return p; 64 } 65 EXPORT_SYMBOL_GPL(nfs_commitdata_alloc); 66 67 void nfs_commit_free(struct nfs_commit_data *p) 68 { 69 mempool_free(p, nfs_commit_mempool); 70 } 71 EXPORT_SYMBOL_GPL(nfs_commit_free); 72 73 static struct nfs_rw_header *nfs_writehdr_alloc(void) 74 { 75 struct nfs_rw_header *p = mempool_alloc(nfs_wdata_mempool, GFP_NOIO); 76 77 if (p) 78 memset(p, 0, sizeof(*p)); 79 return p; 80 } 81 82 static void nfs_writehdr_free(struct nfs_rw_header *whdr) 83 { 84 mempool_free(whdr, nfs_wdata_mempool); 85 } 86 87 static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error) 88 { 89 ctx->error = error; 90 smp_wmb(); 91 set_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags); 92 } 93 94 static struct nfs_page * 95 nfs_page_find_request_locked(struct nfs_inode *nfsi, struct page *page) 96 { 97 struct nfs_page *req = NULL; 98 99 if (PagePrivate(page)) 100 req = (struct nfs_page *)page_private(page); 101 else if (unlikely(PageSwapCache(page))) { 102 struct nfs_page *freq, *t; 103 104 /* Linearly search the commit list for the correct req */ 105 list_for_each_entry_safe(freq, t, &nfsi->commit_info.list, wb_list) { 106 if (freq->wb_page == page) { 107 req = freq; 108 break; 109 } 110 } 111 } 112 113 if (req) 114 kref_get(&req->wb_kref); 115 116 return req; 117 } 118 119 static struct nfs_page *nfs_page_find_request(struct page *page) 120 { 121 struct inode *inode = page_file_mapping(page)->host; 122 struct nfs_page *req = NULL; 123 124 spin_lock(&inode->i_lock); 125 req = nfs_page_find_request_locked(NFS_I(inode), page); 126 spin_unlock(&inode->i_lock); 127 return req; 128 } 129 130 /* Adjust the file length if we're writing beyond the end */ 131 static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count) 132 { 133 struct inode *inode = page_file_mapping(page)->host; 134 loff_t end, i_size; 135 pgoff_t end_index; 136 137 spin_lock(&inode->i_lock); 138 i_size = i_size_read(inode); 139 end_index = (i_size - 1) >> PAGE_CACHE_SHIFT; 140 if (i_size > 0 && page_file_index(page) < end_index) 141 goto out; 142 end = page_file_offset(page) + ((loff_t)offset+count); 143 if (i_size >= end) 144 goto out; 145 i_size_write(inode, end); 146 nfs_inc_stats(inode, NFSIOS_EXTENDWRITE); 147 out: 148 spin_unlock(&inode->i_lock); 149 } 150 151 /* A writeback failed: mark the page as bad, and invalidate the page cache */ 152 static void nfs_set_pageerror(struct page *page) 153 { 154 nfs_zap_mapping(page_file_mapping(page)->host, page_file_mapping(page)); 155 } 156 157 /* We can set the PG_uptodate flag if we see that a write request 158 * covers the full page. 159 */ 160 static void nfs_mark_uptodate(struct page *page, unsigned int base, unsigned int count) 161 { 162 if (PageUptodate(page)) 163 return; 164 if (base != 0) 165 return; 166 if (count != nfs_page_length(page)) 167 return; 168 SetPageUptodate(page); 169 } 170 171 static int wb_priority(struct writeback_control *wbc) 172 { 173 if (wbc->for_reclaim) 174 return FLUSH_HIGHPRI | FLUSH_STABLE; 175 if (wbc->for_kupdate || wbc->for_background) 176 return FLUSH_LOWPRI | FLUSH_COND_STABLE; 177 return FLUSH_COND_STABLE; 178 } 179 180 /* 181 * NFS congestion control 182 */ 183 184 int nfs_congestion_kb; 185 186 #define NFS_CONGESTION_ON_THRESH (nfs_congestion_kb >> (PAGE_SHIFT-10)) 187 #define NFS_CONGESTION_OFF_THRESH \ 188 (NFS_CONGESTION_ON_THRESH - (NFS_CONGESTION_ON_THRESH >> 2)) 189 190 static void nfs_set_page_writeback(struct page *page) 191 { 192 struct nfs_server *nfss = NFS_SERVER(page_file_mapping(page)->host); 193 int ret = test_set_page_writeback(page); 194 195 WARN_ON_ONCE(ret != 0); 196 197 if (atomic_long_inc_return(&nfss->writeback) > 198 NFS_CONGESTION_ON_THRESH) { 199 set_bdi_congested(&nfss->backing_dev_info, 200 BLK_RW_ASYNC); 201 } 202 } 203 204 static void nfs_end_page_writeback(struct page *page) 205 { 206 struct inode *inode = page_file_mapping(page)->host; 207 struct nfs_server *nfss = NFS_SERVER(inode); 208 209 end_page_writeback(page); 210 if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH) 211 clear_bdi_congested(&nfss->backing_dev_info, BLK_RW_ASYNC); 212 } 213 214 static struct nfs_page *nfs_find_and_lock_request(struct page *page, bool nonblock) 215 { 216 struct inode *inode = page_file_mapping(page)->host; 217 struct nfs_page *req; 218 int ret; 219 220 spin_lock(&inode->i_lock); 221 for (;;) { 222 req = nfs_page_find_request_locked(NFS_I(inode), page); 223 if (req == NULL) 224 break; 225 if (nfs_lock_request(req)) 226 break; 227 /* Note: If we hold the page lock, as is the case in nfs_writepage, 228 * then the call to nfs_lock_request() will always 229 * succeed provided that someone hasn't already marked the 230 * request as dirty (in which case we don't care). 231 */ 232 spin_unlock(&inode->i_lock); 233 if (!nonblock) 234 ret = nfs_wait_on_request(req); 235 else 236 ret = -EAGAIN; 237 nfs_release_request(req); 238 if (ret != 0) 239 return ERR_PTR(ret); 240 spin_lock(&inode->i_lock); 241 } 242 spin_unlock(&inode->i_lock); 243 return req; 244 } 245 246 /* 247 * Find an associated nfs write request, and prepare to flush it out 248 * May return an error if the user signalled nfs_wait_on_request(). 249 */ 250 static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio, 251 struct page *page, bool nonblock) 252 { 253 struct nfs_page *req; 254 int ret = 0; 255 256 req = nfs_find_and_lock_request(page, nonblock); 257 if (!req) 258 goto out; 259 ret = PTR_ERR(req); 260 if (IS_ERR(req)) 261 goto out; 262 263 nfs_set_page_writeback(page); 264 WARN_ON_ONCE(test_bit(PG_CLEAN, &req->wb_flags)); 265 266 ret = 0; 267 if (!nfs_pageio_add_request(pgio, req)) { 268 nfs_redirty_request(req); 269 ret = pgio->pg_error; 270 } 271 out: 272 return ret; 273 } 274 275 static int nfs_do_writepage(struct page *page, struct writeback_control *wbc, struct nfs_pageio_descriptor *pgio) 276 { 277 struct inode *inode = page_file_mapping(page)->host; 278 int ret; 279 280 nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE); 281 nfs_add_stats(inode, NFSIOS_WRITEPAGES, 1); 282 283 nfs_pageio_cond_complete(pgio, page_file_index(page)); 284 ret = nfs_page_async_flush(pgio, page, wbc->sync_mode == WB_SYNC_NONE); 285 if (ret == -EAGAIN) { 286 redirty_page_for_writepage(wbc, page); 287 ret = 0; 288 } 289 return ret; 290 } 291 292 /* 293 * Write an mmapped page to the server. 294 */ 295 static int nfs_writepage_locked(struct page *page, struct writeback_control *wbc) 296 { 297 struct nfs_pageio_descriptor pgio; 298 int err; 299 300 nfs_pageio_init_write(&pgio, page->mapping->host, wb_priority(wbc), 301 false, &nfs_async_write_completion_ops); 302 err = nfs_do_writepage(page, wbc, &pgio); 303 nfs_pageio_complete(&pgio); 304 if (err < 0) 305 return err; 306 if (pgio.pg_error < 0) 307 return pgio.pg_error; 308 return 0; 309 } 310 311 int nfs_writepage(struct page *page, struct writeback_control *wbc) 312 { 313 int ret; 314 315 ret = nfs_writepage_locked(page, wbc); 316 unlock_page(page); 317 return ret; 318 } 319 320 static int nfs_writepages_callback(struct page *page, struct writeback_control *wbc, void *data) 321 { 322 int ret; 323 324 ret = nfs_do_writepage(page, wbc, data); 325 unlock_page(page); 326 return ret; 327 } 328 329 int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc) 330 { 331 struct inode *inode = mapping->host; 332 unsigned long *bitlock = &NFS_I(inode)->flags; 333 struct nfs_pageio_descriptor pgio; 334 int err; 335 336 /* Stop dirtying of new pages while we sync */ 337 err = wait_on_bit_lock(bitlock, NFS_INO_FLUSHING, 338 nfs_wait_bit_killable, TASK_KILLABLE); 339 if (err) 340 goto out_err; 341 342 nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES); 343 344 nfs_pageio_init_write(&pgio, inode, wb_priority(wbc), false, 345 &nfs_async_write_completion_ops); 346 err = write_cache_pages(mapping, wbc, nfs_writepages_callback, &pgio); 347 nfs_pageio_complete(&pgio); 348 349 clear_bit_unlock(NFS_INO_FLUSHING, bitlock); 350 smp_mb__after_clear_bit(); 351 wake_up_bit(bitlock, NFS_INO_FLUSHING); 352 353 if (err < 0) 354 goto out_err; 355 err = pgio.pg_error; 356 if (err < 0) 357 goto out_err; 358 return 0; 359 out_err: 360 return err; 361 } 362 363 /* 364 * Insert a write request into an inode 365 */ 366 static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req) 367 { 368 struct nfs_inode *nfsi = NFS_I(inode); 369 370 /* Lock the request! */ 371 nfs_lock_request(req); 372 373 spin_lock(&inode->i_lock); 374 if (!nfsi->npages && NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE)) 375 inode->i_version++; 376 /* 377 * Swap-space should not get truncated. Hence no need to plug the race 378 * with invalidate/truncate. 379 */ 380 if (likely(!PageSwapCache(req->wb_page))) { 381 set_bit(PG_MAPPED, &req->wb_flags); 382 SetPagePrivate(req->wb_page); 383 set_page_private(req->wb_page, (unsigned long)req); 384 } 385 nfsi->npages++; 386 kref_get(&req->wb_kref); 387 spin_unlock(&inode->i_lock); 388 } 389 390 /* 391 * Remove a write request from an inode 392 */ 393 static void nfs_inode_remove_request(struct nfs_page *req) 394 { 395 struct inode *inode = req->wb_context->dentry->d_inode; 396 struct nfs_inode *nfsi = NFS_I(inode); 397 398 spin_lock(&inode->i_lock); 399 if (likely(!PageSwapCache(req->wb_page))) { 400 set_page_private(req->wb_page, 0); 401 ClearPagePrivate(req->wb_page); 402 clear_bit(PG_MAPPED, &req->wb_flags); 403 } 404 nfsi->npages--; 405 spin_unlock(&inode->i_lock); 406 nfs_release_request(req); 407 } 408 409 static void 410 nfs_mark_request_dirty(struct nfs_page *req) 411 { 412 __set_page_dirty_nobuffers(req->wb_page); 413 } 414 415 #if IS_ENABLED(CONFIG_NFS_V3) || IS_ENABLED(CONFIG_NFS_V4) 416 /** 417 * nfs_request_add_commit_list - add request to a commit list 418 * @req: pointer to a struct nfs_page 419 * @dst: commit list head 420 * @cinfo: holds list lock and accounting info 421 * 422 * This sets the PG_CLEAN bit, updates the cinfo count of 423 * number of outstanding requests requiring a commit as well as 424 * the MM page stats. 425 * 426 * The caller must _not_ hold the cinfo->lock, but must be 427 * holding the nfs_page lock. 428 */ 429 void 430 nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst, 431 struct nfs_commit_info *cinfo) 432 { 433 set_bit(PG_CLEAN, &(req)->wb_flags); 434 spin_lock(cinfo->lock); 435 nfs_list_add_request(req, dst); 436 cinfo->mds->ncommit++; 437 spin_unlock(cinfo->lock); 438 if (!cinfo->dreq) { 439 inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS); 440 inc_bdi_stat(page_file_mapping(req->wb_page)->backing_dev_info, 441 BDI_RECLAIMABLE); 442 __mark_inode_dirty(req->wb_context->dentry->d_inode, 443 I_DIRTY_DATASYNC); 444 } 445 } 446 EXPORT_SYMBOL_GPL(nfs_request_add_commit_list); 447 448 /** 449 * nfs_request_remove_commit_list - Remove request from a commit list 450 * @req: pointer to a nfs_page 451 * @cinfo: holds list lock and accounting info 452 * 453 * This clears the PG_CLEAN bit, and updates the cinfo's count of 454 * number of outstanding requests requiring a commit 455 * It does not update the MM page stats. 456 * 457 * The caller _must_ hold the cinfo->lock and the nfs_page lock. 458 */ 459 void 460 nfs_request_remove_commit_list(struct nfs_page *req, 461 struct nfs_commit_info *cinfo) 462 { 463 if (!test_and_clear_bit(PG_CLEAN, &(req)->wb_flags)) 464 return; 465 nfs_list_remove_request(req); 466 cinfo->mds->ncommit--; 467 } 468 EXPORT_SYMBOL_GPL(nfs_request_remove_commit_list); 469 470 static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo, 471 struct inode *inode) 472 { 473 cinfo->lock = &inode->i_lock; 474 cinfo->mds = &NFS_I(inode)->commit_info; 475 cinfo->ds = pnfs_get_ds_info(inode); 476 cinfo->dreq = NULL; 477 cinfo->completion_ops = &nfs_commit_completion_ops; 478 } 479 480 void nfs_init_cinfo(struct nfs_commit_info *cinfo, 481 struct inode *inode, 482 struct nfs_direct_req *dreq) 483 { 484 if (dreq) 485 nfs_init_cinfo_from_dreq(cinfo, dreq); 486 else 487 nfs_init_cinfo_from_inode(cinfo, inode); 488 } 489 EXPORT_SYMBOL_GPL(nfs_init_cinfo); 490 491 /* 492 * Add a request to the inode's commit list. 493 */ 494 void 495 nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg, 496 struct nfs_commit_info *cinfo) 497 { 498 if (pnfs_mark_request_commit(req, lseg, cinfo)) 499 return; 500 nfs_request_add_commit_list(req, &cinfo->mds->list, cinfo); 501 } 502 503 static void 504 nfs_clear_page_commit(struct page *page) 505 { 506 dec_zone_page_state(page, NR_UNSTABLE_NFS); 507 dec_bdi_stat(page_file_mapping(page)->backing_dev_info, BDI_RECLAIMABLE); 508 } 509 510 static void 511 nfs_clear_request_commit(struct nfs_page *req) 512 { 513 if (test_bit(PG_CLEAN, &req->wb_flags)) { 514 struct inode *inode = req->wb_context->dentry->d_inode; 515 struct nfs_commit_info cinfo; 516 517 nfs_init_cinfo_from_inode(&cinfo, inode); 518 if (!pnfs_clear_request_commit(req, &cinfo)) { 519 spin_lock(cinfo.lock); 520 nfs_request_remove_commit_list(req, &cinfo); 521 spin_unlock(cinfo.lock); 522 } 523 nfs_clear_page_commit(req->wb_page); 524 } 525 } 526 527 static inline 528 int nfs_write_need_commit(struct nfs_pgio_data *data) 529 { 530 if (data->verf.committed == NFS_DATA_SYNC) 531 return data->header->lseg == NULL; 532 return data->verf.committed != NFS_FILE_SYNC; 533 } 534 535 #else 536 static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo, 537 struct inode *inode) 538 { 539 } 540 541 void nfs_init_cinfo(struct nfs_commit_info *cinfo, 542 struct inode *inode, 543 struct nfs_direct_req *dreq) 544 { 545 } 546 547 void 548 nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg, 549 struct nfs_commit_info *cinfo) 550 { 551 } 552 553 static void 554 nfs_clear_request_commit(struct nfs_page *req) 555 { 556 } 557 558 static inline 559 int nfs_write_need_commit(struct nfs_pgio_data *data) 560 { 561 return 0; 562 } 563 564 #endif 565 566 static void nfs_write_completion(struct nfs_pgio_header *hdr) 567 { 568 struct nfs_commit_info cinfo; 569 unsigned long bytes = 0; 570 571 if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) 572 goto out; 573 nfs_init_cinfo_from_inode(&cinfo, hdr->inode); 574 while (!list_empty(&hdr->pages)) { 575 struct nfs_page *req = nfs_list_entry(hdr->pages.next); 576 577 bytes += req->wb_bytes; 578 nfs_list_remove_request(req); 579 if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) && 580 (hdr->good_bytes < bytes)) { 581 nfs_set_pageerror(req->wb_page); 582 nfs_context_set_write_error(req->wb_context, hdr->error); 583 goto remove_req; 584 } 585 if (test_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags)) { 586 nfs_mark_request_dirty(req); 587 goto next; 588 } 589 if (test_bit(NFS_IOHDR_NEED_COMMIT, &hdr->flags)) { 590 memcpy(&req->wb_verf, &hdr->verf.verifier, sizeof(req->wb_verf)); 591 nfs_mark_request_commit(req, hdr->lseg, &cinfo); 592 goto next; 593 } 594 remove_req: 595 nfs_inode_remove_request(req); 596 next: 597 nfs_unlock_request(req); 598 nfs_end_page_writeback(req->wb_page); 599 nfs_release_request(req); 600 } 601 out: 602 hdr->release(hdr); 603 } 604 605 #if IS_ENABLED(CONFIG_NFS_V3) || IS_ENABLED(CONFIG_NFS_V4) 606 unsigned long 607 nfs_reqs_to_commit(struct nfs_commit_info *cinfo) 608 { 609 return cinfo->mds->ncommit; 610 } 611 612 /* cinfo->lock held by caller */ 613 int 614 nfs_scan_commit_list(struct list_head *src, struct list_head *dst, 615 struct nfs_commit_info *cinfo, int max) 616 { 617 struct nfs_page *req, *tmp; 618 int ret = 0; 619 620 list_for_each_entry_safe(req, tmp, src, wb_list) { 621 if (!nfs_lock_request(req)) 622 continue; 623 kref_get(&req->wb_kref); 624 if (cond_resched_lock(cinfo->lock)) 625 list_safe_reset_next(req, tmp, wb_list); 626 nfs_request_remove_commit_list(req, cinfo); 627 nfs_list_add_request(req, dst); 628 ret++; 629 if ((ret == max) && !cinfo->dreq) 630 break; 631 } 632 return ret; 633 } 634 635 /* 636 * nfs_scan_commit - Scan an inode for commit requests 637 * @inode: NFS inode to scan 638 * @dst: mds destination list 639 * @cinfo: mds and ds lists of reqs ready to commit 640 * 641 * Moves requests from the inode's 'commit' request list. 642 * The requests are *not* checked to ensure that they form a contiguous set. 643 */ 644 int 645 nfs_scan_commit(struct inode *inode, struct list_head *dst, 646 struct nfs_commit_info *cinfo) 647 { 648 int ret = 0; 649 650 spin_lock(cinfo->lock); 651 if (cinfo->mds->ncommit > 0) { 652 const int max = INT_MAX; 653 654 ret = nfs_scan_commit_list(&cinfo->mds->list, dst, 655 cinfo, max); 656 ret += pnfs_scan_commit_lists(inode, cinfo, max - ret); 657 } 658 spin_unlock(cinfo->lock); 659 return ret; 660 } 661 662 #else 663 unsigned long nfs_reqs_to_commit(struct nfs_commit_info *cinfo) 664 { 665 return 0; 666 } 667 668 int nfs_scan_commit(struct inode *inode, struct list_head *dst, 669 struct nfs_commit_info *cinfo) 670 { 671 return 0; 672 } 673 #endif 674 675 /* 676 * Search for an existing write request, and attempt to update 677 * it to reflect a new dirty region on a given page. 678 * 679 * If the attempt fails, then the existing request is flushed out 680 * to disk. 681 */ 682 static struct nfs_page *nfs_try_to_update_request(struct inode *inode, 683 struct page *page, 684 unsigned int offset, 685 unsigned int bytes) 686 { 687 struct nfs_page *req; 688 unsigned int rqend; 689 unsigned int end; 690 int error; 691 692 if (!PagePrivate(page)) 693 return NULL; 694 695 end = offset + bytes; 696 spin_lock(&inode->i_lock); 697 698 for (;;) { 699 req = nfs_page_find_request_locked(NFS_I(inode), page); 700 if (req == NULL) 701 goto out_unlock; 702 703 rqend = req->wb_offset + req->wb_bytes; 704 /* 705 * Tell the caller to flush out the request if 706 * the offsets are non-contiguous. 707 * Note: nfs_flush_incompatible() will already 708 * have flushed out requests having wrong owners. 709 */ 710 if (offset > rqend 711 || end < req->wb_offset) 712 goto out_flushme; 713 714 if (nfs_lock_request(req)) 715 break; 716 717 /* The request is locked, so wait and then retry */ 718 spin_unlock(&inode->i_lock); 719 error = nfs_wait_on_request(req); 720 nfs_release_request(req); 721 if (error != 0) 722 goto out_err; 723 spin_lock(&inode->i_lock); 724 } 725 726 /* Okay, the request matches. Update the region */ 727 if (offset < req->wb_offset) { 728 req->wb_offset = offset; 729 req->wb_pgbase = offset; 730 } 731 if (end > rqend) 732 req->wb_bytes = end - req->wb_offset; 733 else 734 req->wb_bytes = rqend - req->wb_offset; 735 out_unlock: 736 spin_unlock(&inode->i_lock); 737 if (req) 738 nfs_clear_request_commit(req); 739 return req; 740 out_flushme: 741 spin_unlock(&inode->i_lock); 742 nfs_release_request(req); 743 error = nfs_wb_page(inode, page); 744 out_err: 745 return ERR_PTR(error); 746 } 747 748 /* 749 * Try to update an existing write request, or create one if there is none. 750 * 751 * Note: Should always be called with the Page Lock held to prevent races 752 * if we have to add a new request. Also assumes that the caller has 753 * already called nfs_flush_incompatible() if necessary. 754 */ 755 static struct nfs_page * nfs_setup_write_request(struct nfs_open_context* ctx, 756 struct page *page, unsigned int offset, unsigned int bytes) 757 { 758 struct inode *inode = page_file_mapping(page)->host; 759 struct nfs_page *req; 760 761 req = nfs_try_to_update_request(inode, page, offset, bytes); 762 if (req != NULL) 763 goto out; 764 req = nfs_create_request(ctx, inode, page, offset, bytes); 765 if (IS_ERR(req)) 766 goto out; 767 nfs_inode_add_request(inode, req); 768 out: 769 return req; 770 } 771 772 static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page, 773 unsigned int offset, unsigned int count) 774 { 775 struct nfs_page *req; 776 777 req = nfs_setup_write_request(ctx, page, offset, count); 778 if (IS_ERR(req)) 779 return PTR_ERR(req); 780 /* Update file length */ 781 nfs_grow_file(page, offset, count); 782 nfs_mark_uptodate(page, req->wb_pgbase, req->wb_bytes); 783 nfs_mark_request_dirty(req); 784 nfs_unlock_and_release_request(req); 785 return 0; 786 } 787 788 int nfs_flush_incompatible(struct file *file, struct page *page) 789 { 790 struct nfs_open_context *ctx = nfs_file_open_context(file); 791 struct nfs_lock_context *l_ctx; 792 struct nfs_page *req; 793 int do_flush, status; 794 /* 795 * Look for a request corresponding to this page. If there 796 * is one, and it belongs to another file, we flush it out 797 * before we try to copy anything into the page. Do this 798 * due to the lack of an ACCESS-type call in NFSv2. 799 * Also do the same if we find a request from an existing 800 * dropped page. 801 */ 802 do { 803 req = nfs_page_find_request(page); 804 if (req == NULL) 805 return 0; 806 l_ctx = req->wb_lock_context; 807 do_flush = req->wb_page != page || req->wb_context != ctx; 808 if (l_ctx && ctx->dentry->d_inode->i_flock != NULL) { 809 do_flush |= l_ctx->lockowner.l_owner != current->files 810 || l_ctx->lockowner.l_pid != current->tgid; 811 } 812 nfs_release_request(req); 813 if (!do_flush) 814 return 0; 815 status = nfs_wb_page(page_file_mapping(page)->host, page); 816 } while (status == 0); 817 return status; 818 } 819 820 /* 821 * Avoid buffered writes when a open context credential's key would 822 * expire soon. 823 * 824 * Returns -EACCES if the key will expire within RPC_KEY_EXPIRE_FAIL. 825 * 826 * Return 0 and set a credential flag which triggers the inode to flush 827 * and performs NFS_FILE_SYNC writes if the key will expired within 828 * RPC_KEY_EXPIRE_TIMEO. 829 */ 830 int 831 nfs_key_timeout_notify(struct file *filp, struct inode *inode) 832 { 833 struct nfs_open_context *ctx = nfs_file_open_context(filp); 834 struct rpc_auth *auth = NFS_SERVER(inode)->client->cl_auth; 835 836 return rpcauth_key_timeout_notify(auth, ctx->cred); 837 } 838 839 /* 840 * Test if the open context credential key is marked to expire soon. 841 */ 842 bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx) 843 { 844 return rpcauth_cred_key_to_expire(ctx->cred); 845 } 846 847 /* 848 * If the page cache is marked as unsafe or invalid, then we can't rely on 849 * the PageUptodate() flag. In this case, we will need to turn off 850 * write optimisations that depend on the page contents being correct. 851 */ 852 static bool nfs_write_pageuptodate(struct page *page, struct inode *inode) 853 { 854 struct nfs_inode *nfsi = NFS_I(inode); 855 856 if (nfs_have_delegated_attributes(inode)) 857 goto out; 858 if (nfsi->cache_validity & (NFS_INO_INVALID_DATA|NFS_INO_REVAL_PAGECACHE)) 859 return false; 860 smp_rmb(); 861 if (test_bit(NFS_INO_INVALIDATING, &nfsi->flags)) 862 return false; 863 out: 864 return PageUptodate(page) != 0; 865 } 866 867 /* If we know the page is up to date, and we're not using byte range locks (or 868 * if we have the whole file locked for writing), it may be more efficient to 869 * extend the write to cover the entire page in order to avoid fragmentation 870 * inefficiencies. 871 * 872 * If the file is opened for synchronous writes then we can just skip the rest 873 * of the checks. 874 */ 875 static int nfs_can_extend_write(struct file *file, struct page *page, struct inode *inode) 876 { 877 if (file->f_flags & O_DSYNC) 878 return 0; 879 if (!nfs_write_pageuptodate(page, inode)) 880 return 0; 881 if (NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE)) 882 return 1; 883 if (inode->i_flock == NULL || (inode->i_flock->fl_start == 0 && 884 inode->i_flock->fl_end == OFFSET_MAX && 885 inode->i_flock->fl_type != F_RDLCK)) 886 return 1; 887 return 0; 888 } 889 890 /* 891 * Update and possibly write a cached page of an NFS file. 892 * 893 * XXX: Keep an eye on generic_file_read to make sure it doesn't do bad 894 * things with a page scheduled for an RPC call (e.g. invalidate it). 895 */ 896 int nfs_updatepage(struct file *file, struct page *page, 897 unsigned int offset, unsigned int count) 898 { 899 struct nfs_open_context *ctx = nfs_file_open_context(file); 900 struct inode *inode = page_file_mapping(page)->host; 901 int status = 0; 902 903 nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE); 904 905 dprintk("NFS: nfs_updatepage(%pD2 %d@%lld)\n", 906 file, count, (long long)(page_file_offset(page) + offset)); 907 908 if (nfs_can_extend_write(file, page, inode)) { 909 count = max(count + offset, nfs_page_length(page)); 910 offset = 0; 911 } 912 913 status = nfs_writepage_setup(ctx, page, offset, count); 914 if (status < 0) 915 nfs_set_pageerror(page); 916 else 917 __set_page_dirty_nobuffers(page); 918 919 dprintk("NFS: nfs_updatepage returns %d (isize %lld)\n", 920 status, (long long)i_size_read(inode)); 921 return status; 922 } 923 924 static int flush_task_priority(int how) 925 { 926 switch (how & (FLUSH_HIGHPRI|FLUSH_LOWPRI)) { 927 case FLUSH_HIGHPRI: 928 return RPC_PRIORITY_HIGH; 929 case FLUSH_LOWPRI: 930 return RPC_PRIORITY_LOW; 931 } 932 return RPC_PRIORITY_NORMAL; 933 } 934 935 static void nfs_initiate_write(struct nfs_pgio_data *data, struct rpc_message *msg, 936 struct rpc_task_setup *task_setup_data, int how) 937 { 938 struct inode *inode = data->header->inode; 939 int priority = flush_task_priority(how); 940 941 task_setup_data->priority = priority; 942 NFS_PROTO(inode)->write_setup(data, msg); 943 944 nfs4_state_protect_write(NFS_SERVER(inode)->nfs_client, 945 &task_setup_data->rpc_client, msg, data); 946 } 947 948 /* If a nfs_flush_* function fails, it should remove reqs from @head and 949 * call this on each, which will prepare them to be retried on next 950 * writeback using standard nfs. 951 */ 952 static void nfs_redirty_request(struct nfs_page *req) 953 { 954 nfs_mark_request_dirty(req); 955 nfs_unlock_request(req); 956 nfs_end_page_writeback(req->wb_page); 957 nfs_release_request(req); 958 } 959 960 static void nfs_async_write_error(struct list_head *head) 961 { 962 struct nfs_page *req; 963 964 while (!list_empty(head)) { 965 req = nfs_list_entry(head->next); 966 nfs_list_remove_request(req); 967 nfs_redirty_request(req); 968 } 969 } 970 971 static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops = { 972 .error_cleanup = nfs_async_write_error, 973 .completion = nfs_write_completion, 974 }; 975 976 void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio, 977 struct inode *inode, int ioflags, bool force_mds, 978 const struct nfs_pgio_completion_ops *compl_ops) 979 { 980 struct nfs_server *server = NFS_SERVER(inode); 981 const struct nfs_pageio_ops *pg_ops = &nfs_pgio_rw_ops; 982 983 #ifdef CONFIG_NFS_V4_1 984 if (server->pnfs_curr_ld && !force_mds) 985 pg_ops = server->pnfs_curr_ld->pg_write_ops; 986 #endif 987 nfs_pageio_init(pgio, inode, pg_ops, compl_ops, &nfs_rw_write_ops, 988 server->wsize, ioflags); 989 } 990 EXPORT_SYMBOL_GPL(nfs_pageio_init_write); 991 992 void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio) 993 { 994 pgio->pg_ops = &nfs_pgio_rw_ops; 995 pgio->pg_bsize = NFS_SERVER(pgio->pg_inode)->wsize; 996 } 997 EXPORT_SYMBOL_GPL(nfs_pageio_reset_write_mds); 998 999 1000 void nfs_commit_prepare(struct rpc_task *task, void *calldata) 1001 { 1002 struct nfs_commit_data *data = calldata; 1003 1004 NFS_PROTO(data->inode)->commit_rpc_prepare(task, data); 1005 } 1006 1007 static void nfs_writeback_release_common(struct nfs_pgio_data *data) 1008 { 1009 struct nfs_pgio_header *hdr = data->header; 1010 int status = data->task.tk_status; 1011 1012 if ((status >= 0) && nfs_write_need_commit(data)) { 1013 spin_lock(&hdr->lock); 1014 if (test_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags)) 1015 ; /* Do nothing */ 1016 else if (!test_and_set_bit(NFS_IOHDR_NEED_COMMIT, &hdr->flags)) 1017 memcpy(&hdr->verf, &data->verf, sizeof(hdr->verf)); 1018 else if (memcmp(&hdr->verf, &data->verf, sizeof(hdr->verf))) 1019 set_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags); 1020 spin_unlock(&hdr->lock); 1021 } 1022 } 1023 1024 /* 1025 * Special version of should_remove_suid() that ignores capabilities. 1026 */ 1027 static int nfs_should_remove_suid(const struct inode *inode) 1028 { 1029 umode_t mode = inode->i_mode; 1030 int kill = 0; 1031 1032 /* suid always must be killed */ 1033 if (unlikely(mode & S_ISUID)) 1034 kill = ATTR_KILL_SUID; 1035 1036 /* 1037 * sgid without any exec bits is just a mandatory locking mark; leave 1038 * it alone. If some exec bits are set, it's a real sgid; kill it. 1039 */ 1040 if (unlikely((mode & S_ISGID) && (mode & S_IXGRP))) 1041 kill |= ATTR_KILL_SGID; 1042 1043 if (unlikely(kill && S_ISREG(mode))) 1044 return kill; 1045 1046 return 0; 1047 } 1048 1049 /* 1050 * This function is called when the WRITE call is complete. 1051 */ 1052 static int nfs_writeback_done(struct rpc_task *task, struct nfs_pgio_data *data, 1053 struct inode *inode) 1054 { 1055 int status; 1056 1057 /* 1058 * ->write_done will attempt to use post-op attributes to detect 1059 * conflicting writes by other clients. A strict interpretation 1060 * of close-to-open would allow us to continue caching even if 1061 * another writer had changed the file, but some applications 1062 * depend on tighter cache coherency when writing. 1063 */ 1064 status = NFS_PROTO(inode)->write_done(task, data); 1065 if (status != 0) 1066 return status; 1067 nfs_add_stats(inode, NFSIOS_SERVERWRITTENBYTES, data->res.count); 1068 1069 #if IS_ENABLED(CONFIG_NFS_V3) || IS_ENABLED(CONFIG_NFS_V4) 1070 if (data->res.verf->committed < data->args.stable && task->tk_status >= 0) { 1071 /* We tried a write call, but the server did not 1072 * commit data to stable storage even though we 1073 * requested it. 1074 * Note: There is a known bug in Tru64 < 5.0 in which 1075 * the server reports NFS_DATA_SYNC, but performs 1076 * NFS_FILE_SYNC. We therefore implement this checking 1077 * as a dprintk() in order to avoid filling syslog. 1078 */ 1079 static unsigned long complain; 1080 1081 /* Note this will print the MDS for a DS write */ 1082 if (time_before(complain, jiffies)) { 1083 dprintk("NFS: faulty NFS server %s:" 1084 " (committed = %d) != (stable = %d)\n", 1085 NFS_SERVER(inode)->nfs_client->cl_hostname, 1086 data->res.verf->committed, data->args.stable); 1087 complain = jiffies + 300 * HZ; 1088 } 1089 } 1090 #endif 1091 1092 /* Deal with the suid/sgid bit corner case */ 1093 if (nfs_should_remove_suid(inode)) 1094 nfs_mark_for_revalidate(inode); 1095 return 0; 1096 } 1097 1098 /* 1099 * This function is called when the WRITE call is complete. 1100 */ 1101 static void nfs_writeback_result(struct rpc_task *task, struct nfs_pgio_data *data) 1102 { 1103 struct nfs_pgio_args *argp = &data->args; 1104 struct nfs_pgio_res *resp = &data->res; 1105 1106 if (resp->count < argp->count) { 1107 static unsigned long complain; 1108 1109 /* This a short write! */ 1110 nfs_inc_stats(data->header->inode, NFSIOS_SHORTWRITE); 1111 1112 /* Has the server at least made some progress? */ 1113 if (resp->count == 0) { 1114 if (time_before(complain, jiffies)) { 1115 printk(KERN_WARNING 1116 "NFS: Server wrote zero bytes, expected %u.\n", 1117 argp->count); 1118 complain = jiffies + 300 * HZ; 1119 } 1120 nfs_set_pgio_error(data->header, -EIO, argp->offset); 1121 task->tk_status = -EIO; 1122 return; 1123 } 1124 /* Was this an NFSv2 write or an NFSv3 stable write? */ 1125 if (resp->verf->committed != NFS_UNSTABLE) { 1126 /* Resend from where the server left off */ 1127 data->mds_offset += resp->count; 1128 argp->offset += resp->count; 1129 argp->pgbase += resp->count; 1130 argp->count -= resp->count; 1131 } else { 1132 /* Resend as a stable write in order to avoid 1133 * headaches in the case of a server crash. 1134 */ 1135 argp->stable = NFS_FILE_SYNC; 1136 } 1137 rpc_restart_call_prepare(task); 1138 } 1139 } 1140 1141 1142 #if IS_ENABLED(CONFIG_NFS_V3) || IS_ENABLED(CONFIG_NFS_V4) 1143 static int nfs_commit_set_lock(struct nfs_inode *nfsi, int may_wait) 1144 { 1145 int ret; 1146 1147 if (!test_and_set_bit(NFS_INO_COMMIT, &nfsi->flags)) 1148 return 1; 1149 if (!may_wait) 1150 return 0; 1151 ret = out_of_line_wait_on_bit_lock(&nfsi->flags, 1152 NFS_INO_COMMIT, 1153 nfs_wait_bit_killable, 1154 TASK_KILLABLE); 1155 return (ret < 0) ? ret : 1; 1156 } 1157 1158 static void nfs_commit_clear_lock(struct nfs_inode *nfsi) 1159 { 1160 clear_bit(NFS_INO_COMMIT, &nfsi->flags); 1161 smp_mb__after_clear_bit(); 1162 wake_up_bit(&nfsi->flags, NFS_INO_COMMIT); 1163 } 1164 1165 void nfs_commitdata_release(struct nfs_commit_data *data) 1166 { 1167 put_nfs_open_context(data->context); 1168 nfs_commit_free(data); 1169 } 1170 EXPORT_SYMBOL_GPL(nfs_commitdata_release); 1171 1172 int nfs_initiate_commit(struct rpc_clnt *clnt, struct nfs_commit_data *data, 1173 const struct rpc_call_ops *call_ops, 1174 int how, int flags) 1175 { 1176 struct rpc_task *task; 1177 int priority = flush_task_priority(how); 1178 struct rpc_message msg = { 1179 .rpc_argp = &data->args, 1180 .rpc_resp = &data->res, 1181 .rpc_cred = data->cred, 1182 }; 1183 struct rpc_task_setup task_setup_data = { 1184 .task = &data->task, 1185 .rpc_client = clnt, 1186 .rpc_message = &msg, 1187 .callback_ops = call_ops, 1188 .callback_data = data, 1189 .workqueue = nfsiod_workqueue, 1190 .flags = RPC_TASK_ASYNC | flags, 1191 .priority = priority, 1192 }; 1193 /* Set up the initial task struct. */ 1194 NFS_PROTO(data->inode)->commit_setup(data, &msg); 1195 1196 dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid); 1197 1198 nfs4_state_protect(NFS_SERVER(data->inode)->nfs_client, 1199 NFS_SP4_MACH_CRED_COMMIT, &task_setup_data.rpc_client, &msg); 1200 1201 task = rpc_run_task(&task_setup_data); 1202 if (IS_ERR(task)) 1203 return PTR_ERR(task); 1204 if (how & FLUSH_SYNC) 1205 rpc_wait_for_completion_task(task); 1206 rpc_put_task(task); 1207 return 0; 1208 } 1209 EXPORT_SYMBOL_GPL(nfs_initiate_commit); 1210 1211 /* 1212 * Set up the argument/result storage required for the RPC call. 1213 */ 1214 void nfs_init_commit(struct nfs_commit_data *data, 1215 struct list_head *head, 1216 struct pnfs_layout_segment *lseg, 1217 struct nfs_commit_info *cinfo) 1218 { 1219 struct nfs_page *first = nfs_list_entry(head->next); 1220 struct inode *inode = first->wb_context->dentry->d_inode; 1221 1222 /* Set up the RPC argument and reply structs 1223 * NB: take care not to mess about with data->commit et al. */ 1224 1225 list_splice_init(head, &data->pages); 1226 1227 data->inode = inode; 1228 data->cred = first->wb_context->cred; 1229 data->lseg = lseg; /* reference transferred */ 1230 data->mds_ops = &nfs_commit_ops; 1231 data->completion_ops = cinfo->completion_ops; 1232 data->dreq = cinfo->dreq; 1233 1234 data->args.fh = NFS_FH(data->inode); 1235 /* Note: we always request a commit of the entire inode */ 1236 data->args.offset = 0; 1237 data->args.count = 0; 1238 data->context = get_nfs_open_context(first->wb_context); 1239 data->res.fattr = &data->fattr; 1240 data->res.verf = &data->verf; 1241 nfs_fattr_init(&data->fattr); 1242 } 1243 EXPORT_SYMBOL_GPL(nfs_init_commit); 1244 1245 void nfs_retry_commit(struct list_head *page_list, 1246 struct pnfs_layout_segment *lseg, 1247 struct nfs_commit_info *cinfo) 1248 { 1249 struct nfs_page *req; 1250 1251 while (!list_empty(page_list)) { 1252 req = nfs_list_entry(page_list->next); 1253 nfs_list_remove_request(req); 1254 nfs_mark_request_commit(req, lseg, cinfo); 1255 if (!cinfo->dreq) { 1256 dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS); 1257 dec_bdi_stat(page_file_mapping(req->wb_page)->backing_dev_info, 1258 BDI_RECLAIMABLE); 1259 } 1260 nfs_unlock_and_release_request(req); 1261 } 1262 } 1263 EXPORT_SYMBOL_GPL(nfs_retry_commit); 1264 1265 /* 1266 * Commit dirty pages 1267 */ 1268 static int 1269 nfs_commit_list(struct inode *inode, struct list_head *head, int how, 1270 struct nfs_commit_info *cinfo) 1271 { 1272 struct nfs_commit_data *data; 1273 1274 data = nfs_commitdata_alloc(); 1275 1276 if (!data) 1277 goto out_bad; 1278 1279 /* Set up the argument struct */ 1280 nfs_init_commit(data, head, NULL, cinfo); 1281 atomic_inc(&cinfo->mds->rpcs_out); 1282 return nfs_initiate_commit(NFS_CLIENT(inode), data, data->mds_ops, 1283 how, 0); 1284 out_bad: 1285 nfs_retry_commit(head, NULL, cinfo); 1286 cinfo->completion_ops->error_cleanup(NFS_I(inode)); 1287 return -ENOMEM; 1288 } 1289 1290 /* 1291 * COMMIT call returned 1292 */ 1293 static void nfs_commit_done(struct rpc_task *task, void *calldata) 1294 { 1295 struct nfs_commit_data *data = calldata; 1296 1297 dprintk("NFS: %5u nfs_commit_done (status %d)\n", 1298 task->tk_pid, task->tk_status); 1299 1300 /* Call the NFS version-specific code */ 1301 NFS_PROTO(data->inode)->commit_done(task, data); 1302 } 1303 1304 static void nfs_commit_release_pages(struct nfs_commit_data *data) 1305 { 1306 struct nfs_page *req; 1307 int status = data->task.tk_status; 1308 struct nfs_commit_info cinfo; 1309 1310 while (!list_empty(&data->pages)) { 1311 req = nfs_list_entry(data->pages.next); 1312 nfs_list_remove_request(req); 1313 nfs_clear_page_commit(req->wb_page); 1314 1315 dprintk("NFS: commit (%s/%llu %d@%lld)", 1316 req->wb_context->dentry->d_sb->s_id, 1317 (unsigned long long)NFS_FILEID(req->wb_context->dentry->d_inode), 1318 req->wb_bytes, 1319 (long long)req_offset(req)); 1320 if (status < 0) { 1321 nfs_context_set_write_error(req->wb_context, status); 1322 nfs_inode_remove_request(req); 1323 dprintk(", error = %d\n", status); 1324 goto next; 1325 } 1326 1327 /* Okay, COMMIT succeeded, apparently. Check the verifier 1328 * returned by the server against all stored verfs. */ 1329 if (!memcmp(&req->wb_verf, &data->verf.verifier, sizeof(req->wb_verf))) { 1330 /* We have a match */ 1331 nfs_inode_remove_request(req); 1332 dprintk(" OK\n"); 1333 goto next; 1334 } 1335 /* We have a mismatch. Write the page again */ 1336 dprintk(" mismatch\n"); 1337 nfs_mark_request_dirty(req); 1338 set_bit(NFS_CONTEXT_RESEND_WRITES, &req->wb_context->flags); 1339 next: 1340 nfs_unlock_and_release_request(req); 1341 } 1342 nfs_init_cinfo(&cinfo, data->inode, data->dreq); 1343 if (atomic_dec_and_test(&cinfo.mds->rpcs_out)) 1344 nfs_commit_clear_lock(NFS_I(data->inode)); 1345 } 1346 1347 static void nfs_commit_release(void *calldata) 1348 { 1349 struct nfs_commit_data *data = calldata; 1350 1351 data->completion_ops->completion(data); 1352 nfs_commitdata_release(calldata); 1353 } 1354 1355 static const struct rpc_call_ops nfs_commit_ops = { 1356 .rpc_call_prepare = nfs_commit_prepare, 1357 .rpc_call_done = nfs_commit_done, 1358 .rpc_release = nfs_commit_release, 1359 }; 1360 1361 static const struct nfs_commit_completion_ops nfs_commit_completion_ops = { 1362 .completion = nfs_commit_release_pages, 1363 .error_cleanup = nfs_commit_clear_lock, 1364 }; 1365 1366 int nfs_generic_commit_list(struct inode *inode, struct list_head *head, 1367 int how, struct nfs_commit_info *cinfo) 1368 { 1369 int status; 1370 1371 status = pnfs_commit_list(inode, head, how, cinfo); 1372 if (status == PNFS_NOT_ATTEMPTED) 1373 status = nfs_commit_list(inode, head, how, cinfo); 1374 return status; 1375 } 1376 1377 int nfs_commit_inode(struct inode *inode, int how) 1378 { 1379 LIST_HEAD(head); 1380 struct nfs_commit_info cinfo; 1381 int may_wait = how & FLUSH_SYNC; 1382 int res; 1383 1384 res = nfs_commit_set_lock(NFS_I(inode), may_wait); 1385 if (res <= 0) 1386 goto out_mark_dirty; 1387 nfs_init_cinfo_from_inode(&cinfo, inode); 1388 res = nfs_scan_commit(inode, &head, &cinfo); 1389 if (res) { 1390 int error; 1391 1392 error = nfs_generic_commit_list(inode, &head, how, &cinfo); 1393 if (error < 0) 1394 return error; 1395 if (!may_wait) 1396 goto out_mark_dirty; 1397 error = wait_on_bit(&NFS_I(inode)->flags, 1398 NFS_INO_COMMIT, 1399 nfs_wait_bit_killable, 1400 TASK_KILLABLE); 1401 if (error < 0) 1402 return error; 1403 } else 1404 nfs_commit_clear_lock(NFS_I(inode)); 1405 return res; 1406 /* Note: If we exit without ensuring that the commit is complete, 1407 * we must mark the inode as dirty. Otherwise, future calls to 1408 * sync_inode() with the WB_SYNC_ALL flag set will fail to ensure 1409 * that the data is on the disk. 1410 */ 1411 out_mark_dirty: 1412 __mark_inode_dirty(inode, I_DIRTY_DATASYNC); 1413 return res; 1414 } 1415 1416 static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_control *wbc) 1417 { 1418 struct nfs_inode *nfsi = NFS_I(inode); 1419 int flags = FLUSH_SYNC; 1420 int ret = 0; 1421 1422 /* no commits means nothing needs to be done */ 1423 if (!nfsi->commit_info.ncommit) 1424 return ret; 1425 1426 if (wbc->sync_mode == WB_SYNC_NONE) { 1427 /* Don't commit yet if this is a non-blocking flush and there 1428 * are a lot of outstanding writes for this mapping. 1429 */ 1430 if (nfsi->commit_info.ncommit <= (nfsi->npages >> 1)) 1431 goto out_mark_dirty; 1432 1433 /* don't wait for the COMMIT response */ 1434 flags = 0; 1435 } 1436 1437 ret = nfs_commit_inode(inode, flags); 1438 if (ret >= 0) { 1439 if (wbc->sync_mode == WB_SYNC_NONE) { 1440 if (ret < wbc->nr_to_write) 1441 wbc->nr_to_write -= ret; 1442 else 1443 wbc->nr_to_write = 0; 1444 } 1445 return 0; 1446 } 1447 out_mark_dirty: 1448 __mark_inode_dirty(inode, I_DIRTY_DATASYNC); 1449 return ret; 1450 } 1451 #else 1452 static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_control *wbc) 1453 { 1454 return 0; 1455 } 1456 #endif 1457 1458 int nfs_write_inode(struct inode *inode, struct writeback_control *wbc) 1459 { 1460 return nfs_commit_unstable_pages(inode, wbc); 1461 } 1462 EXPORT_SYMBOL_GPL(nfs_write_inode); 1463 1464 /* 1465 * flush the inode to disk. 1466 */ 1467 int nfs_wb_all(struct inode *inode) 1468 { 1469 struct writeback_control wbc = { 1470 .sync_mode = WB_SYNC_ALL, 1471 .nr_to_write = LONG_MAX, 1472 .range_start = 0, 1473 .range_end = LLONG_MAX, 1474 }; 1475 int ret; 1476 1477 trace_nfs_writeback_inode_enter(inode); 1478 1479 ret = sync_inode(inode, &wbc); 1480 1481 trace_nfs_writeback_inode_exit(inode, ret); 1482 return ret; 1483 } 1484 EXPORT_SYMBOL_GPL(nfs_wb_all); 1485 1486 int nfs_wb_page_cancel(struct inode *inode, struct page *page) 1487 { 1488 struct nfs_page *req; 1489 int ret = 0; 1490 1491 for (;;) { 1492 wait_on_page_writeback(page); 1493 req = nfs_page_find_request(page); 1494 if (req == NULL) 1495 break; 1496 if (nfs_lock_request(req)) { 1497 nfs_clear_request_commit(req); 1498 nfs_inode_remove_request(req); 1499 /* 1500 * In case nfs_inode_remove_request has marked the 1501 * page as being dirty 1502 */ 1503 cancel_dirty_page(page, PAGE_CACHE_SIZE); 1504 nfs_unlock_and_release_request(req); 1505 break; 1506 } 1507 ret = nfs_wait_on_request(req); 1508 nfs_release_request(req); 1509 if (ret < 0) 1510 break; 1511 } 1512 return ret; 1513 } 1514 1515 /* 1516 * Write back all requests on one page - we do this before reading it. 1517 */ 1518 int nfs_wb_page(struct inode *inode, struct page *page) 1519 { 1520 loff_t range_start = page_file_offset(page); 1521 loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1); 1522 struct writeback_control wbc = { 1523 .sync_mode = WB_SYNC_ALL, 1524 .nr_to_write = 0, 1525 .range_start = range_start, 1526 .range_end = range_end, 1527 }; 1528 int ret; 1529 1530 trace_nfs_writeback_page_enter(inode); 1531 1532 for (;;) { 1533 wait_on_page_writeback(page); 1534 if (clear_page_dirty_for_io(page)) { 1535 ret = nfs_writepage_locked(page, &wbc); 1536 if (ret < 0) 1537 goto out_error; 1538 continue; 1539 } 1540 ret = 0; 1541 if (!PagePrivate(page)) 1542 break; 1543 ret = nfs_commit_inode(inode, FLUSH_SYNC); 1544 if (ret < 0) 1545 goto out_error; 1546 } 1547 out_error: 1548 trace_nfs_writeback_page_exit(inode, ret); 1549 return ret; 1550 } 1551 1552 #ifdef CONFIG_MIGRATION 1553 int nfs_migrate_page(struct address_space *mapping, struct page *newpage, 1554 struct page *page, enum migrate_mode mode) 1555 { 1556 /* 1557 * If PagePrivate is set, then the page is currently associated with 1558 * an in-progress read or write request. Don't try to migrate it. 1559 * 1560 * FIXME: we could do this in principle, but we'll need a way to ensure 1561 * that we can safely release the inode reference while holding 1562 * the page lock. 1563 */ 1564 if (PagePrivate(page)) 1565 return -EBUSY; 1566 1567 if (!nfs_fscache_release_page(page, GFP_KERNEL)) 1568 return -EBUSY; 1569 1570 return migrate_page(mapping, newpage, page, mode); 1571 } 1572 #endif 1573 1574 int __init nfs_init_writepagecache(void) 1575 { 1576 nfs_wdata_cachep = kmem_cache_create("nfs_write_data", 1577 sizeof(struct nfs_rw_header), 1578 0, SLAB_HWCACHE_ALIGN, 1579 NULL); 1580 if (nfs_wdata_cachep == NULL) 1581 return -ENOMEM; 1582 1583 nfs_wdata_mempool = mempool_create_slab_pool(MIN_POOL_WRITE, 1584 nfs_wdata_cachep); 1585 if (nfs_wdata_mempool == NULL) 1586 goto out_destroy_write_cache; 1587 1588 nfs_cdata_cachep = kmem_cache_create("nfs_commit_data", 1589 sizeof(struct nfs_commit_data), 1590 0, SLAB_HWCACHE_ALIGN, 1591 NULL); 1592 if (nfs_cdata_cachep == NULL) 1593 goto out_destroy_write_mempool; 1594 1595 nfs_commit_mempool = mempool_create_slab_pool(MIN_POOL_COMMIT, 1596 nfs_cdata_cachep); 1597 if (nfs_commit_mempool == NULL) 1598 goto out_destroy_commit_cache; 1599 1600 /* 1601 * NFS congestion size, scale with available memory. 1602 * 1603 * 64MB: 8192k 1604 * 128MB: 11585k 1605 * 256MB: 16384k 1606 * 512MB: 23170k 1607 * 1GB: 32768k 1608 * 2GB: 46340k 1609 * 4GB: 65536k 1610 * 8GB: 92681k 1611 * 16GB: 131072k 1612 * 1613 * This allows larger machines to have larger/more transfers. 1614 * Limit the default to 256M 1615 */ 1616 nfs_congestion_kb = (16*int_sqrt(totalram_pages)) << (PAGE_SHIFT-10); 1617 if (nfs_congestion_kb > 256*1024) 1618 nfs_congestion_kb = 256*1024; 1619 1620 return 0; 1621 1622 out_destroy_commit_cache: 1623 kmem_cache_destroy(nfs_cdata_cachep); 1624 out_destroy_write_mempool: 1625 mempool_destroy(nfs_wdata_mempool); 1626 out_destroy_write_cache: 1627 kmem_cache_destroy(nfs_wdata_cachep); 1628 return -ENOMEM; 1629 } 1630 1631 void nfs_destroy_writepagecache(void) 1632 { 1633 mempool_destroy(nfs_commit_mempool); 1634 kmem_cache_destroy(nfs_cdata_cachep); 1635 mempool_destroy(nfs_wdata_mempool); 1636 kmem_cache_destroy(nfs_wdata_cachep); 1637 } 1638 1639 static const struct nfs_rw_ops nfs_rw_write_ops = { 1640 .rw_mode = FMODE_WRITE, 1641 .rw_alloc_header = nfs_writehdr_alloc, 1642 .rw_free_header = nfs_writehdr_free, 1643 .rw_release = nfs_writeback_release_common, 1644 .rw_done = nfs_writeback_done, 1645 .rw_result = nfs_writeback_result, 1646 .rw_initiate = nfs_initiate_write, 1647 }; 1648