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 WARN_ON_ONCE(req->wb_this_page != req); 371 372 /* Lock the request! */ 373 nfs_lock_request(req); 374 375 spin_lock(&inode->i_lock); 376 if (!nfsi->npages && NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE)) 377 inode->i_version++; 378 /* 379 * Swap-space should not get truncated. Hence no need to plug the race 380 * with invalidate/truncate. 381 */ 382 if (likely(!PageSwapCache(req->wb_page))) { 383 set_bit(PG_MAPPED, &req->wb_flags); 384 SetPagePrivate(req->wb_page); 385 set_page_private(req->wb_page, (unsigned long)req); 386 } 387 nfsi->npages++; 388 set_bit(PG_INODE_REF, &req->wb_flags); 389 kref_get(&req->wb_kref); 390 spin_unlock(&inode->i_lock); 391 } 392 393 /* 394 * Remove a write request from an inode 395 */ 396 static void nfs_inode_remove_request(struct nfs_page *req) 397 { 398 struct inode *inode = req->wb_context->dentry->d_inode; 399 struct nfs_inode *nfsi = NFS_I(inode); 400 401 spin_lock(&inode->i_lock); 402 if (likely(!PageSwapCache(req->wb_page))) { 403 set_page_private(req->wb_page, 0); 404 ClearPagePrivate(req->wb_page); 405 clear_bit(PG_MAPPED, &req->wb_flags); 406 } 407 nfsi->npages--; 408 spin_unlock(&inode->i_lock); 409 nfs_release_request(req); 410 } 411 412 static void 413 nfs_mark_request_dirty(struct nfs_page *req) 414 { 415 __set_page_dirty_nobuffers(req->wb_page); 416 } 417 418 #if IS_ENABLED(CONFIG_NFS_V3) || IS_ENABLED(CONFIG_NFS_V4) 419 /** 420 * nfs_request_add_commit_list - add request to a commit list 421 * @req: pointer to a struct nfs_page 422 * @dst: commit list head 423 * @cinfo: holds list lock and accounting info 424 * 425 * This sets the PG_CLEAN bit, updates the cinfo count of 426 * number of outstanding requests requiring a commit as well as 427 * the MM page stats. 428 * 429 * The caller must _not_ hold the cinfo->lock, but must be 430 * holding the nfs_page lock. 431 */ 432 void 433 nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst, 434 struct nfs_commit_info *cinfo) 435 { 436 set_bit(PG_CLEAN, &(req)->wb_flags); 437 spin_lock(cinfo->lock); 438 nfs_list_add_request(req, dst); 439 cinfo->mds->ncommit++; 440 spin_unlock(cinfo->lock); 441 if (!cinfo->dreq) { 442 inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS); 443 inc_bdi_stat(page_file_mapping(req->wb_page)->backing_dev_info, 444 BDI_RECLAIMABLE); 445 __mark_inode_dirty(req->wb_context->dentry->d_inode, 446 I_DIRTY_DATASYNC); 447 } 448 } 449 EXPORT_SYMBOL_GPL(nfs_request_add_commit_list); 450 451 /** 452 * nfs_request_remove_commit_list - Remove request from a commit list 453 * @req: pointer to a nfs_page 454 * @cinfo: holds list lock and accounting info 455 * 456 * This clears the PG_CLEAN bit, and updates the cinfo's count of 457 * number of outstanding requests requiring a commit 458 * It does not update the MM page stats. 459 * 460 * The caller _must_ hold the cinfo->lock and the nfs_page lock. 461 */ 462 void 463 nfs_request_remove_commit_list(struct nfs_page *req, 464 struct nfs_commit_info *cinfo) 465 { 466 if (!test_and_clear_bit(PG_CLEAN, &(req)->wb_flags)) 467 return; 468 nfs_list_remove_request(req); 469 cinfo->mds->ncommit--; 470 } 471 EXPORT_SYMBOL_GPL(nfs_request_remove_commit_list); 472 473 static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo, 474 struct inode *inode) 475 { 476 cinfo->lock = &inode->i_lock; 477 cinfo->mds = &NFS_I(inode)->commit_info; 478 cinfo->ds = pnfs_get_ds_info(inode); 479 cinfo->dreq = NULL; 480 cinfo->completion_ops = &nfs_commit_completion_ops; 481 } 482 483 void nfs_init_cinfo(struct nfs_commit_info *cinfo, 484 struct inode *inode, 485 struct nfs_direct_req *dreq) 486 { 487 if (dreq) 488 nfs_init_cinfo_from_dreq(cinfo, dreq); 489 else 490 nfs_init_cinfo_from_inode(cinfo, inode); 491 } 492 EXPORT_SYMBOL_GPL(nfs_init_cinfo); 493 494 /* 495 * Add a request to the inode's commit list. 496 */ 497 void 498 nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg, 499 struct nfs_commit_info *cinfo) 500 { 501 if (pnfs_mark_request_commit(req, lseg, cinfo)) 502 return; 503 nfs_request_add_commit_list(req, &cinfo->mds->list, cinfo); 504 } 505 506 static void 507 nfs_clear_page_commit(struct page *page) 508 { 509 dec_zone_page_state(page, NR_UNSTABLE_NFS); 510 dec_bdi_stat(page_file_mapping(page)->backing_dev_info, BDI_RECLAIMABLE); 511 } 512 513 static void 514 nfs_clear_request_commit(struct nfs_page *req) 515 { 516 if (test_bit(PG_CLEAN, &req->wb_flags)) { 517 struct inode *inode = req->wb_context->dentry->d_inode; 518 struct nfs_commit_info cinfo; 519 520 nfs_init_cinfo_from_inode(&cinfo, inode); 521 if (!pnfs_clear_request_commit(req, &cinfo)) { 522 spin_lock(cinfo.lock); 523 nfs_request_remove_commit_list(req, &cinfo); 524 spin_unlock(cinfo.lock); 525 } 526 nfs_clear_page_commit(req->wb_page); 527 } 528 } 529 530 static inline 531 int nfs_write_need_commit(struct nfs_pgio_data *data) 532 { 533 if (data->verf.committed == NFS_DATA_SYNC) 534 return data->header->lseg == NULL; 535 return data->verf.committed != NFS_FILE_SYNC; 536 } 537 538 #else 539 static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo, 540 struct inode *inode) 541 { 542 } 543 544 void nfs_init_cinfo(struct nfs_commit_info *cinfo, 545 struct inode *inode, 546 struct nfs_direct_req *dreq) 547 { 548 } 549 550 void 551 nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg, 552 struct nfs_commit_info *cinfo) 553 { 554 } 555 556 static void 557 nfs_clear_request_commit(struct nfs_page *req) 558 { 559 } 560 561 static inline 562 int nfs_write_need_commit(struct nfs_pgio_data *data) 563 { 564 return 0; 565 } 566 567 #endif 568 569 static void nfs_write_completion(struct nfs_pgio_header *hdr) 570 { 571 struct nfs_commit_info cinfo; 572 unsigned long bytes = 0; 573 bool do_destroy; 574 575 if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) 576 goto out; 577 nfs_init_cinfo_from_inode(&cinfo, hdr->inode); 578 while (!list_empty(&hdr->pages)) { 579 struct nfs_page *req = nfs_list_entry(hdr->pages.next); 580 581 bytes += req->wb_bytes; 582 nfs_list_remove_request(req); 583 if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) && 584 (hdr->good_bytes < bytes)) { 585 nfs_set_pageerror(req->wb_page); 586 nfs_context_set_write_error(req->wb_context, hdr->error); 587 goto remove_req; 588 } 589 if (test_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags)) { 590 nfs_mark_request_dirty(req); 591 goto next; 592 } 593 if (test_bit(NFS_IOHDR_NEED_COMMIT, &hdr->flags)) { 594 memcpy(&req->wb_verf, &hdr->verf.verifier, sizeof(req->wb_verf)); 595 nfs_mark_request_commit(req, hdr->lseg, &cinfo); 596 goto next; 597 } 598 remove_req: 599 nfs_inode_remove_request(req); 600 next: 601 nfs_unlock_request(req); 602 nfs_end_page_writeback(req->wb_page); 603 do_destroy = !test_bit(NFS_IOHDR_NEED_COMMIT, &hdr->flags); 604 nfs_release_request(req); 605 } 606 out: 607 hdr->release(hdr); 608 } 609 610 #if IS_ENABLED(CONFIG_NFS_V3) || IS_ENABLED(CONFIG_NFS_V4) 611 unsigned long 612 nfs_reqs_to_commit(struct nfs_commit_info *cinfo) 613 { 614 return cinfo->mds->ncommit; 615 } 616 617 /* cinfo->lock held by caller */ 618 int 619 nfs_scan_commit_list(struct list_head *src, struct list_head *dst, 620 struct nfs_commit_info *cinfo, int max) 621 { 622 struct nfs_page *req, *tmp; 623 int ret = 0; 624 625 list_for_each_entry_safe(req, tmp, src, wb_list) { 626 if (!nfs_lock_request(req)) 627 continue; 628 kref_get(&req->wb_kref); 629 if (cond_resched_lock(cinfo->lock)) 630 list_safe_reset_next(req, tmp, wb_list); 631 nfs_request_remove_commit_list(req, cinfo); 632 nfs_list_add_request(req, dst); 633 ret++; 634 if ((ret == max) && !cinfo->dreq) 635 break; 636 } 637 return ret; 638 } 639 640 /* 641 * nfs_scan_commit - Scan an inode for commit requests 642 * @inode: NFS inode to scan 643 * @dst: mds destination list 644 * @cinfo: mds and ds lists of reqs ready to commit 645 * 646 * Moves requests from the inode's 'commit' request list. 647 * The requests are *not* checked to ensure that they form a contiguous set. 648 */ 649 int 650 nfs_scan_commit(struct inode *inode, struct list_head *dst, 651 struct nfs_commit_info *cinfo) 652 { 653 int ret = 0; 654 655 spin_lock(cinfo->lock); 656 if (cinfo->mds->ncommit > 0) { 657 const int max = INT_MAX; 658 659 ret = nfs_scan_commit_list(&cinfo->mds->list, dst, 660 cinfo, max); 661 ret += pnfs_scan_commit_lists(inode, cinfo, max - ret); 662 } 663 spin_unlock(cinfo->lock); 664 return ret; 665 } 666 667 #else 668 unsigned long nfs_reqs_to_commit(struct nfs_commit_info *cinfo) 669 { 670 return 0; 671 } 672 673 int nfs_scan_commit(struct inode *inode, struct list_head *dst, 674 struct nfs_commit_info *cinfo) 675 { 676 return 0; 677 } 678 #endif 679 680 /* 681 * Search for an existing write request, and attempt to update 682 * it to reflect a new dirty region on a given page. 683 * 684 * If the attempt fails, then the existing request is flushed out 685 * to disk. 686 */ 687 static struct nfs_page *nfs_try_to_update_request(struct inode *inode, 688 struct page *page, 689 unsigned int offset, 690 unsigned int bytes) 691 { 692 struct nfs_page *req; 693 unsigned int rqend; 694 unsigned int end; 695 int error; 696 697 if (!PagePrivate(page)) 698 return NULL; 699 700 end = offset + bytes; 701 spin_lock(&inode->i_lock); 702 703 for (;;) { 704 req = nfs_page_find_request_locked(NFS_I(inode), page); 705 if (req == NULL) 706 goto out_unlock; 707 708 /* should be handled by nfs_flush_incompatible */ 709 WARN_ON_ONCE(req->wb_head != req); 710 WARN_ON_ONCE(req->wb_this_page != req); 711 712 rqend = req->wb_offset + req->wb_bytes; 713 /* 714 * Tell the caller to flush out the request if 715 * the offsets are non-contiguous. 716 * Note: nfs_flush_incompatible() will already 717 * have flushed out requests having wrong owners. 718 */ 719 if (offset > rqend 720 || end < req->wb_offset) 721 goto out_flushme; 722 723 if (nfs_lock_request(req)) 724 break; 725 726 /* The request is locked, so wait and then retry */ 727 spin_unlock(&inode->i_lock); 728 error = nfs_wait_on_request(req); 729 nfs_release_request(req); 730 if (error != 0) 731 goto out_err; 732 spin_lock(&inode->i_lock); 733 } 734 735 /* Okay, the request matches. Update the region */ 736 if (offset < req->wb_offset) { 737 req->wb_offset = offset; 738 req->wb_pgbase = offset; 739 } 740 if (end > rqend) 741 req->wb_bytes = end - req->wb_offset; 742 else 743 req->wb_bytes = rqend - req->wb_offset; 744 out_unlock: 745 spin_unlock(&inode->i_lock); 746 if (req) 747 nfs_clear_request_commit(req); 748 return req; 749 out_flushme: 750 spin_unlock(&inode->i_lock); 751 nfs_release_request(req); 752 error = nfs_wb_page(inode, page); 753 out_err: 754 return ERR_PTR(error); 755 } 756 757 /* 758 * Try to update an existing write request, or create one if there is none. 759 * 760 * Note: Should always be called with the Page Lock held to prevent races 761 * if we have to add a new request. Also assumes that the caller has 762 * already called nfs_flush_incompatible() if necessary. 763 */ 764 static struct nfs_page * nfs_setup_write_request(struct nfs_open_context* ctx, 765 struct page *page, unsigned int offset, unsigned int bytes) 766 { 767 struct inode *inode = page_file_mapping(page)->host; 768 struct nfs_page *req; 769 770 req = nfs_try_to_update_request(inode, page, offset, bytes); 771 if (req != NULL) 772 goto out; 773 req = nfs_create_request(ctx, page, NULL, offset, bytes); 774 if (IS_ERR(req)) 775 goto out; 776 nfs_inode_add_request(inode, req); 777 out: 778 return req; 779 } 780 781 static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page, 782 unsigned int offset, unsigned int count) 783 { 784 struct nfs_page *req; 785 786 req = nfs_setup_write_request(ctx, page, offset, count); 787 if (IS_ERR(req)) 788 return PTR_ERR(req); 789 /* Update file length */ 790 nfs_grow_file(page, offset, count); 791 nfs_mark_uptodate(page, req->wb_pgbase, req->wb_bytes); 792 nfs_mark_request_dirty(req); 793 nfs_unlock_and_release_request(req); 794 return 0; 795 } 796 797 int nfs_flush_incompatible(struct file *file, struct page *page) 798 { 799 struct nfs_open_context *ctx = nfs_file_open_context(file); 800 struct nfs_lock_context *l_ctx; 801 struct nfs_page *req; 802 int do_flush, status; 803 /* 804 * Look for a request corresponding to this page. If there 805 * is one, and it belongs to another file, we flush it out 806 * before we try to copy anything into the page. Do this 807 * due to the lack of an ACCESS-type call in NFSv2. 808 * Also do the same if we find a request from an existing 809 * dropped page. 810 */ 811 do { 812 req = nfs_page_find_request(page); 813 if (req == NULL) 814 return 0; 815 l_ctx = req->wb_lock_context; 816 do_flush = req->wb_page != page || req->wb_context != ctx; 817 /* for now, flush if more than 1 request in page_group */ 818 do_flush |= req->wb_this_page != req; 819 if (l_ctx && ctx->dentry->d_inode->i_flock != NULL) { 820 do_flush |= l_ctx->lockowner.l_owner != current->files 821 || l_ctx->lockowner.l_pid != current->tgid; 822 } 823 nfs_release_request(req); 824 if (!do_flush) 825 return 0; 826 status = nfs_wb_page(page_file_mapping(page)->host, page); 827 } while (status == 0); 828 return status; 829 } 830 831 /* 832 * Avoid buffered writes when a open context credential's key would 833 * expire soon. 834 * 835 * Returns -EACCES if the key will expire within RPC_KEY_EXPIRE_FAIL. 836 * 837 * Return 0 and set a credential flag which triggers the inode to flush 838 * and performs NFS_FILE_SYNC writes if the key will expired within 839 * RPC_KEY_EXPIRE_TIMEO. 840 */ 841 int 842 nfs_key_timeout_notify(struct file *filp, struct inode *inode) 843 { 844 struct nfs_open_context *ctx = nfs_file_open_context(filp); 845 struct rpc_auth *auth = NFS_SERVER(inode)->client->cl_auth; 846 847 return rpcauth_key_timeout_notify(auth, ctx->cred); 848 } 849 850 /* 851 * Test if the open context credential key is marked to expire soon. 852 */ 853 bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx) 854 { 855 return rpcauth_cred_key_to_expire(ctx->cred); 856 } 857 858 /* 859 * If the page cache is marked as unsafe or invalid, then we can't rely on 860 * the PageUptodate() flag. In this case, we will need to turn off 861 * write optimisations that depend on the page contents being correct. 862 */ 863 static bool nfs_write_pageuptodate(struct page *page, struct inode *inode) 864 { 865 struct nfs_inode *nfsi = NFS_I(inode); 866 867 if (nfs_have_delegated_attributes(inode)) 868 goto out; 869 if (nfsi->cache_validity & (NFS_INO_INVALID_DATA|NFS_INO_REVAL_PAGECACHE)) 870 return false; 871 smp_rmb(); 872 if (test_bit(NFS_INO_INVALIDATING, &nfsi->flags)) 873 return false; 874 out: 875 return PageUptodate(page) != 0; 876 } 877 878 /* If we know the page is up to date, and we're not using byte range locks (or 879 * if we have the whole file locked for writing), it may be more efficient to 880 * extend the write to cover the entire page in order to avoid fragmentation 881 * inefficiencies. 882 * 883 * If the file is opened for synchronous writes then we can just skip the rest 884 * of the checks. 885 */ 886 static int nfs_can_extend_write(struct file *file, struct page *page, struct inode *inode) 887 { 888 if (file->f_flags & O_DSYNC) 889 return 0; 890 if (!nfs_write_pageuptodate(page, inode)) 891 return 0; 892 if (NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE)) 893 return 1; 894 if (inode->i_flock == NULL || (inode->i_flock->fl_start == 0 && 895 inode->i_flock->fl_end == OFFSET_MAX && 896 inode->i_flock->fl_type != F_RDLCK)) 897 return 1; 898 return 0; 899 } 900 901 /* 902 * Update and possibly write a cached page of an NFS file. 903 * 904 * XXX: Keep an eye on generic_file_read to make sure it doesn't do bad 905 * things with a page scheduled for an RPC call (e.g. invalidate it). 906 */ 907 int nfs_updatepage(struct file *file, struct page *page, 908 unsigned int offset, unsigned int count) 909 { 910 struct nfs_open_context *ctx = nfs_file_open_context(file); 911 struct inode *inode = page_file_mapping(page)->host; 912 int status = 0; 913 914 nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE); 915 916 dprintk("NFS: nfs_updatepage(%pD2 %d@%lld)\n", 917 file, count, (long long)(page_file_offset(page) + offset)); 918 919 if (nfs_can_extend_write(file, page, inode)) { 920 count = max(count + offset, nfs_page_length(page)); 921 offset = 0; 922 } 923 924 status = nfs_writepage_setup(ctx, page, offset, count); 925 if (status < 0) 926 nfs_set_pageerror(page); 927 else 928 __set_page_dirty_nobuffers(page); 929 930 dprintk("NFS: nfs_updatepage returns %d (isize %lld)\n", 931 status, (long long)i_size_read(inode)); 932 return status; 933 } 934 935 static int flush_task_priority(int how) 936 { 937 switch (how & (FLUSH_HIGHPRI|FLUSH_LOWPRI)) { 938 case FLUSH_HIGHPRI: 939 return RPC_PRIORITY_HIGH; 940 case FLUSH_LOWPRI: 941 return RPC_PRIORITY_LOW; 942 } 943 return RPC_PRIORITY_NORMAL; 944 } 945 946 static void nfs_initiate_write(struct nfs_pgio_data *data, struct rpc_message *msg, 947 struct rpc_task_setup *task_setup_data, int how) 948 { 949 struct inode *inode = data->header->inode; 950 int priority = flush_task_priority(how); 951 952 task_setup_data->priority = priority; 953 NFS_PROTO(inode)->write_setup(data, msg); 954 955 nfs4_state_protect_write(NFS_SERVER(inode)->nfs_client, 956 &task_setup_data->rpc_client, msg, data); 957 } 958 959 /* If a nfs_flush_* function fails, it should remove reqs from @head and 960 * call this on each, which will prepare them to be retried on next 961 * writeback using standard nfs. 962 */ 963 static void nfs_redirty_request(struct nfs_page *req) 964 { 965 nfs_mark_request_dirty(req); 966 nfs_unlock_request(req); 967 nfs_end_page_writeback(req->wb_page); 968 nfs_release_request(req); 969 } 970 971 static void nfs_async_write_error(struct list_head *head) 972 { 973 struct nfs_page *req; 974 975 while (!list_empty(head)) { 976 req = nfs_list_entry(head->next); 977 nfs_list_remove_request(req); 978 nfs_redirty_request(req); 979 } 980 } 981 982 static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops = { 983 .error_cleanup = nfs_async_write_error, 984 .completion = nfs_write_completion, 985 }; 986 987 void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio, 988 struct inode *inode, int ioflags, bool force_mds, 989 const struct nfs_pgio_completion_ops *compl_ops) 990 { 991 struct nfs_server *server = NFS_SERVER(inode); 992 const struct nfs_pageio_ops *pg_ops = &nfs_pgio_rw_ops; 993 994 #ifdef CONFIG_NFS_V4_1 995 if (server->pnfs_curr_ld && !force_mds) 996 pg_ops = server->pnfs_curr_ld->pg_write_ops; 997 #endif 998 nfs_pageio_init(pgio, inode, pg_ops, compl_ops, &nfs_rw_write_ops, 999 server->wsize, ioflags); 1000 } 1001 EXPORT_SYMBOL_GPL(nfs_pageio_init_write); 1002 1003 void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio) 1004 { 1005 pgio->pg_ops = &nfs_pgio_rw_ops; 1006 pgio->pg_bsize = NFS_SERVER(pgio->pg_inode)->wsize; 1007 } 1008 EXPORT_SYMBOL_GPL(nfs_pageio_reset_write_mds); 1009 1010 1011 void nfs_commit_prepare(struct rpc_task *task, void *calldata) 1012 { 1013 struct nfs_commit_data *data = calldata; 1014 1015 NFS_PROTO(data->inode)->commit_rpc_prepare(task, data); 1016 } 1017 1018 static void nfs_writeback_release_common(struct nfs_pgio_data *data) 1019 { 1020 struct nfs_pgio_header *hdr = data->header; 1021 int status = data->task.tk_status; 1022 1023 if ((status >= 0) && nfs_write_need_commit(data)) { 1024 spin_lock(&hdr->lock); 1025 if (test_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags)) 1026 ; /* Do nothing */ 1027 else if (!test_and_set_bit(NFS_IOHDR_NEED_COMMIT, &hdr->flags)) 1028 memcpy(&hdr->verf, &data->verf, sizeof(hdr->verf)); 1029 else if (memcmp(&hdr->verf, &data->verf, sizeof(hdr->verf))) 1030 set_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags); 1031 spin_unlock(&hdr->lock); 1032 } 1033 } 1034 1035 /* 1036 * Special version of should_remove_suid() that ignores capabilities. 1037 */ 1038 static int nfs_should_remove_suid(const struct inode *inode) 1039 { 1040 umode_t mode = inode->i_mode; 1041 int kill = 0; 1042 1043 /* suid always must be killed */ 1044 if (unlikely(mode & S_ISUID)) 1045 kill = ATTR_KILL_SUID; 1046 1047 /* 1048 * sgid without any exec bits is just a mandatory locking mark; leave 1049 * it alone. If some exec bits are set, it's a real sgid; kill it. 1050 */ 1051 if (unlikely((mode & S_ISGID) && (mode & S_IXGRP))) 1052 kill |= ATTR_KILL_SGID; 1053 1054 if (unlikely(kill && S_ISREG(mode))) 1055 return kill; 1056 1057 return 0; 1058 } 1059 1060 /* 1061 * This function is called when the WRITE call is complete. 1062 */ 1063 static int nfs_writeback_done(struct rpc_task *task, struct nfs_pgio_data *data, 1064 struct inode *inode) 1065 { 1066 int status; 1067 1068 /* 1069 * ->write_done will attempt to use post-op attributes to detect 1070 * conflicting writes by other clients. A strict interpretation 1071 * of close-to-open would allow us to continue caching even if 1072 * another writer had changed the file, but some applications 1073 * depend on tighter cache coherency when writing. 1074 */ 1075 status = NFS_PROTO(inode)->write_done(task, data); 1076 if (status != 0) 1077 return status; 1078 nfs_add_stats(inode, NFSIOS_SERVERWRITTENBYTES, data->res.count); 1079 1080 #if IS_ENABLED(CONFIG_NFS_V3) || IS_ENABLED(CONFIG_NFS_V4) 1081 if (data->res.verf->committed < data->args.stable && task->tk_status >= 0) { 1082 /* We tried a write call, but the server did not 1083 * commit data to stable storage even though we 1084 * requested it. 1085 * Note: There is a known bug in Tru64 < 5.0 in which 1086 * the server reports NFS_DATA_SYNC, but performs 1087 * NFS_FILE_SYNC. We therefore implement this checking 1088 * as a dprintk() in order to avoid filling syslog. 1089 */ 1090 static unsigned long complain; 1091 1092 /* Note this will print the MDS for a DS write */ 1093 if (time_before(complain, jiffies)) { 1094 dprintk("NFS: faulty NFS server %s:" 1095 " (committed = %d) != (stable = %d)\n", 1096 NFS_SERVER(inode)->nfs_client->cl_hostname, 1097 data->res.verf->committed, data->args.stable); 1098 complain = jiffies + 300 * HZ; 1099 } 1100 } 1101 #endif 1102 1103 /* Deal with the suid/sgid bit corner case */ 1104 if (nfs_should_remove_suid(inode)) 1105 nfs_mark_for_revalidate(inode); 1106 return 0; 1107 } 1108 1109 /* 1110 * This function is called when the WRITE call is complete. 1111 */ 1112 static void nfs_writeback_result(struct rpc_task *task, struct nfs_pgio_data *data) 1113 { 1114 struct nfs_pgio_args *argp = &data->args; 1115 struct nfs_pgio_res *resp = &data->res; 1116 1117 if (resp->count < argp->count) { 1118 static unsigned long complain; 1119 1120 /* This a short write! */ 1121 nfs_inc_stats(data->header->inode, NFSIOS_SHORTWRITE); 1122 1123 /* Has the server at least made some progress? */ 1124 if (resp->count == 0) { 1125 if (time_before(complain, jiffies)) { 1126 printk(KERN_WARNING 1127 "NFS: Server wrote zero bytes, expected %u.\n", 1128 argp->count); 1129 complain = jiffies + 300 * HZ; 1130 } 1131 nfs_set_pgio_error(data->header, -EIO, argp->offset); 1132 task->tk_status = -EIO; 1133 return; 1134 } 1135 /* Was this an NFSv2 write or an NFSv3 stable write? */ 1136 if (resp->verf->committed != NFS_UNSTABLE) { 1137 /* Resend from where the server left off */ 1138 data->mds_offset += resp->count; 1139 argp->offset += resp->count; 1140 argp->pgbase += resp->count; 1141 argp->count -= resp->count; 1142 } else { 1143 /* Resend as a stable write in order to avoid 1144 * headaches in the case of a server crash. 1145 */ 1146 argp->stable = NFS_FILE_SYNC; 1147 } 1148 rpc_restart_call_prepare(task); 1149 } 1150 } 1151 1152 1153 #if IS_ENABLED(CONFIG_NFS_V3) || IS_ENABLED(CONFIG_NFS_V4) 1154 static int nfs_commit_set_lock(struct nfs_inode *nfsi, int may_wait) 1155 { 1156 int ret; 1157 1158 if (!test_and_set_bit(NFS_INO_COMMIT, &nfsi->flags)) 1159 return 1; 1160 if (!may_wait) 1161 return 0; 1162 ret = out_of_line_wait_on_bit_lock(&nfsi->flags, 1163 NFS_INO_COMMIT, 1164 nfs_wait_bit_killable, 1165 TASK_KILLABLE); 1166 return (ret < 0) ? ret : 1; 1167 } 1168 1169 static void nfs_commit_clear_lock(struct nfs_inode *nfsi) 1170 { 1171 clear_bit(NFS_INO_COMMIT, &nfsi->flags); 1172 smp_mb__after_clear_bit(); 1173 wake_up_bit(&nfsi->flags, NFS_INO_COMMIT); 1174 } 1175 1176 void nfs_commitdata_release(struct nfs_commit_data *data) 1177 { 1178 put_nfs_open_context(data->context); 1179 nfs_commit_free(data); 1180 } 1181 EXPORT_SYMBOL_GPL(nfs_commitdata_release); 1182 1183 int nfs_initiate_commit(struct rpc_clnt *clnt, struct nfs_commit_data *data, 1184 const struct rpc_call_ops *call_ops, 1185 int how, int flags) 1186 { 1187 struct rpc_task *task; 1188 int priority = flush_task_priority(how); 1189 struct rpc_message msg = { 1190 .rpc_argp = &data->args, 1191 .rpc_resp = &data->res, 1192 .rpc_cred = data->cred, 1193 }; 1194 struct rpc_task_setup task_setup_data = { 1195 .task = &data->task, 1196 .rpc_client = clnt, 1197 .rpc_message = &msg, 1198 .callback_ops = call_ops, 1199 .callback_data = data, 1200 .workqueue = nfsiod_workqueue, 1201 .flags = RPC_TASK_ASYNC | flags, 1202 .priority = priority, 1203 }; 1204 /* Set up the initial task struct. */ 1205 NFS_PROTO(data->inode)->commit_setup(data, &msg); 1206 1207 dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid); 1208 1209 nfs4_state_protect(NFS_SERVER(data->inode)->nfs_client, 1210 NFS_SP4_MACH_CRED_COMMIT, &task_setup_data.rpc_client, &msg); 1211 1212 task = rpc_run_task(&task_setup_data); 1213 if (IS_ERR(task)) 1214 return PTR_ERR(task); 1215 if (how & FLUSH_SYNC) 1216 rpc_wait_for_completion_task(task); 1217 rpc_put_task(task); 1218 return 0; 1219 } 1220 EXPORT_SYMBOL_GPL(nfs_initiate_commit); 1221 1222 /* 1223 * Set up the argument/result storage required for the RPC call. 1224 */ 1225 void nfs_init_commit(struct nfs_commit_data *data, 1226 struct list_head *head, 1227 struct pnfs_layout_segment *lseg, 1228 struct nfs_commit_info *cinfo) 1229 { 1230 struct nfs_page *first = nfs_list_entry(head->next); 1231 struct inode *inode = first->wb_context->dentry->d_inode; 1232 1233 /* Set up the RPC argument and reply structs 1234 * NB: take care not to mess about with data->commit et al. */ 1235 1236 list_splice_init(head, &data->pages); 1237 1238 data->inode = inode; 1239 data->cred = first->wb_context->cred; 1240 data->lseg = lseg; /* reference transferred */ 1241 data->mds_ops = &nfs_commit_ops; 1242 data->completion_ops = cinfo->completion_ops; 1243 data->dreq = cinfo->dreq; 1244 1245 data->args.fh = NFS_FH(data->inode); 1246 /* Note: we always request a commit of the entire inode */ 1247 data->args.offset = 0; 1248 data->args.count = 0; 1249 data->context = get_nfs_open_context(first->wb_context); 1250 data->res.fattr = &data->fattr; 1251 data->res.verf = &data->verf; 1252 nfs_fattr_init(&data->fattr); 1253 } 1254 EXPORT_SYMBOL_GPL(nfs_init_commit); 1255 1256 void nfs_retry_commit(struct list_head *page_list, 1257 struct pnfs_layout_segment *lseg, 1258 struct nfs_commit_info *cinfo) 1259 { 1260 struct nfs_page *req; 1261 1262 while (!list_empty(page_list)) { 1263 req = nfs_list_entry(page_list->next); 1264 nfs_list_remove_request(req); 1265 nfs_mark_request_commit(req, lseg, cinfo); 1266 if (!cinfo->dreq) { 1267 dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS); 1268 dec_bdi_stat(page_file_mapping(req->wb_page)->backing_dev_info, 1269 BDI_RECLAIMABLE); 1270 } 1271 nfs_unlock_and_release_request(req); 1272 } 1273 } 1274 EXPORT_SYMBOL_GPL(nfs_retry_commit); 1275 1276 /* 1277 * Commit dirty pages 1278 */ 1279 static int 1280 nfs_commit_list(struct inode *inode, struct list_head *head, int how, 1281 struct nfs_commit_info *cinfo) 1282 { 1283 struct nfs_commit_data *data; 1284 1285 data = nfs_commitdata_alloc(); 1286 1287 if (!data) 1288 goto out_bad; 1289 1290 /* Set up the argument struct */ 1291 nfs_init_commit(data, head, NULL, cinfo); 1292 atomic_inc(&cinfo->mds->rpcs_out); 1293 return nfs_initiate_commit(NFS_CLIENT(inode), data, data->mds_ops, 1294 how, 0); 1295 out_bad: 1296 nfs_retry_commit(head, NULL, cinfo); 1297 cinfo->completion_ops->error_cleanup(NFS_I(inode)); 1298 return -ENOMEM; 1299 } 1300 1301 /* 1302 * COMMIT call returned 1303 */ 1304 static void nfs_commit_done(struct rpc_task *task, void *calldata) 1305 { 1306 struct nfs_commit_data *data = calldata; 1307 1308 dprintk("NFS: %5u nfs_commit_done (status %d)\n", 1309 task->tk_pid, task->tk_status); 1310 1311 /* Call the NFS version-specific code */ 1312 NFS_PROTO(data->inode)->commit_done(task, data); 1313 } 1314 1315 static void nfs_commit_release_pages(struct nfs_commit_data *data) 1316 { 1317 struct nfs_page *req; 1318 int status = data->task.tk_status; 1319 struct nfs_commit_info cinfo; 1320 1321 while (!list_empty(&data->pages)) { 1322 req = nfs_list_entry(data->pages.next); 1323 nfs_list_remove_request(req); 1324 nfs_clear_page_commit(req->wb_page); 1325 1326 dprintk("NFS: commit (%s/%llu %d@%lld)", 1327 req->wb_context->dentry->d_sb->s_id, 1328 (unsigned long long)NFS_FILEID(req->wb_context->dentry->d_inode), 1329 req->wb_bytes, 1330 (long long)req_offset(req)); 1331 if (status < 0) { 1332 nfs_context_set_write_error(req->wb_context, status); 1333 nfs_inode_remove_request(req); 1334 dprintk(", error = %d\n", status); 1335 goto next; 1336 } 1337 1338 /* Okay, COMMIT succeeded, apparently. Check the verifier 1339 * returned by the server against all stored verfs. */ 1340 if (!memcmp(&req->wb_verf, &data->verf.verifier, sizeof(req->wb_verf))) { 1341 /* We have a match */ 1342 nfs_inode_remove_request(req); 1343 dprintk(" OK\n"); 1344 goto next; 1345 } 1346 /* We have a mismatch. Write the page again */ 1347 dprintk(" mismatch\n"); 1348 nfs_mark_request_dirty(req); 1349 set_bit(NFS_CONTEXT_RESEND_WRITES, &req->wb_context->flags); 1350 next: 1351 nfs_unlock_and_release_request(req); 1352 } 1353 nfs_init_cinfo(&cinfo, data->inode, data->dreq); 1354 if (atomic_dec_and_test(&cinfo.mds->rpcs_out)) 1355 nfs_commit_clear_lock(NFS_I(data->inode)); 1356 } 1357 1358 static void nfs_commit_release(void *calldata) 1359 { 1360 struct nfs_commit_data *data = calldata; 1361 1362 data->completion_ops->completion(data); 1363 nfs_commitdata_release(calldata); 1364 } 1365 1366 static const struct rpc_call_ops nfs_commit_ops = { 1367 .rpc_call_prepare = nfs_commit_prepare, 1368 .rpc_call_done = nfs_commit_done, 1369 .rpc_release = nfs_commit_release, 1370 }; 1371 1372 static const struct nfs_commit_completion_ops nfs_commit_completion_ops = { 1373 .completion = nfs_commit_release_pages, 1374 .error_cleanup = nfs_commit_clear_lock, 1375 }; 1376 1377 int nfs_generic_commit_list(struct inode *inode, struct list_head *head, 1378 int how, struct nfs_commit_info *cinfo) 1379 { 1380 int status; 1381 1382 status = pnfs_commit_list(inode, head, how, cinfo); 1383 if (status == PNFS_NOT_ATTEMPTED) 1384 status = nfs_commit_list(inode, head, how, cinfo); 1385 return status; 1386 } 1387 1388 int nfs_commit_inode(struct inode *inode, int how) 1389 { 1390 LIST_HEAD(head); 1391 struct nfs_commit_info cinfo; 1392 int may_wait = how & FLUSH_SYNC; 1393 int res; 1394 1395 res = nfs_commit_set_lock(NFS_I(inode), may_wait); 1396 if (res <= 0) 1397 goto out_mark_dirty; 1398 nfs_init_cinfo_from_inode(&cinfo, inode); 1399 res = nfs_scan_commit(inode, &head, &cinfo); 1400 if (res) { 1401 int error; 1402 1403 error = nfs_generic_commit_list(inode, &head, how, &cinfo); 1404 if (error < 0) 1405 return error; 1406 if (!may_wait) 1407 goto out_mark_dirty; 1408 error = wait_on_bit(&NFS_I(inode)->flags, 1409 NFS_INO_COMMIT, 1410 nfs_wait_bit_killable, 1411 TASK_KILLABLE); 1412 if (error < 0) 1413 return error; 1414 } else 1415 nfs_commit_clear_lock(NFS_I(inode)); 1416 return res; 1417 /* Note: If we exit without ensuring that the commit is complete, 1418 * we must mark the inode as dirty. Otherwise, future calls to 1419 * sync_inode() with the WB_SYNC_ALL flag set will fail to ensure 1420 * that the data is on the disk. 1421 */ 1422 out_mark_dirty: 1423 __mark_inode_dirty(inode, I_DIRTY_DATASYNC); 1424 return res; 1425 } 1426 1427 static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_control *wbc) 1428 { 1429 struct nfs_inode *nfsi = NFS_I(inode); 1430 int flags = FLUSH_SYNC; 1431 int ret = 0; 1432 1433 /* no commits means nothing needs to be done */ 1434 if (!nfsi->commit_info.ncommit) 1435 return ret; 1436 1437 if (wbc->sync_mode == WB_SYNC_NONE) { 1438 /* Don't commit yet if this is a non-blocking flush and there 1439 * are a lot of outstanding writes for this mapping. 1440 */ 1441 if (nfsi->commit_info.ncommit <= (nfsi->npages >> 1)) 1442 goto out_mark_dirty; 1443 1444 /* don't wait for the COMMIT response */ 1445 flags = 0; 1446 } 1447 1448 ret = nfs_commit_inode(inode, flags); 1449 if (ret >= 0) { 1450 if (wbc->sync_mode == WB_SYNC_NONE) { 1451 if (ret < wbc->nr_to_write) 1452 wbc->nr_to_write -= ret; 1453 else 1454 wbc->nr_to_write = 0; 1455 } 1456 return 0; 1457 } 1458 out_mark_dirty: 1459 __mark_inode_dirty(inode, I_DIRTY_DATASYNC); 1460 return ret; 1461 } 1462 #else 1463 static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_control *wbc) 1464 { 1465 return 0; 1466 } 1467 #endif 1468 1469 int nfs_write_inode(struct inode *inode, struct writeback_control *wbc) 1470 { 1471 return nfs_commit_unstable_pages(inode, wbc); 1472 } 1473 EXPORT_SYMBOL_GPL(nfs_write_inode); 1474 1475 /* 1476 * flush the inode to disk. 1477 */ 1478 int nfs_wb_all(struct inode *inode) 1479 { 1480 struct writeback_control wbc = { 1481 .sync_mode = WB_SYNC_ALL, 1482 .nr_to_write = LONG_MAX, 1483 .range_start = 0, 1484 .range_end = LLONG_MAX, 1485 }; 1486 int ret; 1487 1488 trace_nfs_writeback_inode_enter(inode); 1489 1490 ret = sync_inode(inode, &wbc); 1491 1492 trace_nfs_writeback_inode_exit(inode, ret); 1493 return ret; 1494 } 1495 EXPORT_SYMBOL_GPL(nfs_wb_all); 1496 1497 int nfs_wb_page_cancel(struct inode *inode, struct page *page) 1498 { 1499 struct nfs_page *req; 1500 int ret = 0; 1501 1502 for (;;) { 1503 wait_on_page_writeback(page); 1504 req = nfs_page_find_request(page); 1505 if (req == NULL) 1506 break; 1507 if (nfs_lock_request(req)) { 1508 nfs_clear_request_commit(req); 1509 nfs_inode_remove_request(req); 1510 /* 1511 * In case nfs_inode_remove_request has marked the 1512 * page as being dirty 1513 */ 1514 cancel_dirty_page(page, PAGE_CACHE_SIZE); 1515 nfs_unlock_and_release_request(req); 1516 break; 1517 } 1518 ret = nfs_wait_on_request(req); 1519 nfs_release_request(req); 1520 if (ret < 0) 1521 break; 1522 } 1523 return ret; 1524 } 1525 1526 /* 1527 * Write back all requests on one page - we do this before reading it. 1528 */ 1529 int nfs_wb_page(struct inode *inode, struct page *page) 1530 { 1531 loff_t range_start = page_file_offset(page); 1532 loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1); 1533 struct writeback_control wbc = { 1534 .sync_mode = WB_SYNC_ALL, 1535 .nr_to_write = 0, 1536 .range_start = range_start, 1537 .range_end = range_end, 1538 }; 1539 int ret; 1540 1541 trace_nfs_writeback_page_enter(inode); 1542 1543 for (;;) { 1544 wait_on_page_writeback(page); 1545 if (clear_page_dirty_for_io(page)) { 1546 ret = nfs_writepage_locked(page, &wbc); 1547 if (ret < 0) 1548 goto out_error; 1549 continue; 1550 } 1551 ret = 0; 1552 if (!PagePrivate(page)) 1553 break; 1554 ret = nfs_commit_inode(inode, FLUSH_SYNC); 1555 if (ret < 0) 1556 goto out_error; 1557 } 1558 out_error: 1559 trace_nfs_writeback_page_exit(inode, ret); 1560 return ret; 1561 } 1562 1563 #ifdef CONFIG_MIGRATION 1564 int nfs_migrate_page(struct address_space *mapping, struct page *newpage, 1565 struct page *page, enum migrate_mode mode) 1566 { 1567 /* 1568 * If PagePrivate is set, then the page is currently associated with 1569 * an in-progress read or write request. Don't try to migrate it. 1570 * 1571 * FIXME: we could do this in principle, but we'll need a way to ensure 1572 * that we can safely release the inode reference while holding 1573 * the page lock. 1574 */ 1575 if (PagePrivate(page)) 1576 return -EBUSY; 1577 1578 if (!nfs_fscache_release_page(page, GFP_KERNEL)) 1579 return -EBUSY; 1580 1581 return migrate_page(mapping, newpage, page, mode); 1582 } 1583 #endif 1584 1585 int __init nfs_init_writepagecache(void) 1586 { 1587 nfs_wdata_cachep = kmem_cache_create("nfs_write_data", 1588 sizeof(struct nfs_rw_header), 1589 0, SLAB_HWCACHE_ALIGN, 1590 NULL); 1591 if (nfs_wdata_cachep == NULL) 1592 return -ENOMEM; 1593 1594 nfs_wdata_mempool = mempool_create_slab_pool(MIN_POOL_WRITE, 1595 nfs_wdata_cachep); 1596 if (nfs_wdata_mempool == NULL) 1597 goto out_destroy_write_cache; 1598 1599 nfs_cdata_cachep = kmem_cache_create("nfs_commit_data", 1600 sizeof(struct nfs_commit_data), 1601 0, SLAB_HWCACHE_ALIGN, 1602 NULL); 1603 if (nfs_cdata_cachep == NULL) 1604 goto out_destroy_write_mempool; 1605 1606 nfs_commit_mempool = mempool_create_slab_pool(MIN_POOL_COMMIT, 1607 nfs_cdata_cachep); 1608 if (nfs_commit_mempool == NULL) 1609 goto out_destroy_commit_cache; 1610 1611 /* 1612 * NFS congestion size, scale with available memory. 1613 * 1614 * 64MB: 8192k 1615 * 128MB: 11585k 1616 * 256MB: 16384k 1617 * 512MB: 23170k 1618 * 1GB: 32768k 1619 * 2GB: 46340k 1620 * 4GB: 65536k 1621 * 8GB: 92681k 1622 * 16GB: 131072k 1623 * 1624 * This allows larger machines to have larger/more transfers. 1625 * Limit the default to 256M 1626 */ 1627 nfs_congestion_kb = (16*int_sqrt(totalram_pages)) << (PAGE_SHIFT-10); 1628 if (nfs_congestion_kb > 256*1024) 1629 nfs_congestion_kb = 256*1024; 1630 1631 return 0; 1632 1633 out_destroy_commit_cache: 1634 kmem_cache_destroy(nfs_cdata_cachep); 1635 out_destroy_write_mempool: 1636 mempool_destroy(nfs_wdata_mempool); 1637 out_destroy_write_cache: 1638 kmem_cache_destroy(nfs_wdata_cachep); 1639 return -ENOMEM; 1640 } 1641 1642 void nfs_destroy_writepagecache(void) 1643 { 1644 mempool_destroy(nfs_commit_mempool); 1645 kmem_cache_destroy(nfs_cdata_cachep); 1646 mempool_destroy(nfs_wdata_mempool); 1647 kmem_cache_destroy(nfs_wdata_cachep); 1648 } 1649 1650 static const struct nfs_rw_ops nfs_rw_write_ops = { 1651 .rw_mode = FMODE_WRITE, 1652 .rw_alloc_header = nfs_writehdr_alloc, 1653 .rw_free_header = nfs_writehdr_free, 1654 .rw_release = nfs_writeback_release_common, 1655 .rw_done = nfs_writeback_done, 1656 .rw_result = nfs_writeback_result, 1657 .rw_initiate = nfs_initiate_write, 1658 }; 1659