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 #define NFSDBG_FACILITY NFSDBG_PAGECACHE 35 36 #define MIN_POOL_WRITE (32) 37 #define MIN_POOL_COMMIT (4) 38 39 /* 40 * Local function declarations 41 */ 42 static void nfs_redirty_request(struct nfs_page *req); 43 static const struct rpc_call_ops nfs_write_common_ops; 44 static const struct rpc_call_ops nfs_commit_ops; 45 static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops; 46 static const struct nfs_commit_completion_ops nfs_commit_completion_ops; 47 48 static struct kmem_cache *nfs_wdata_cachep; 49 static mempool_t *nfs_wdata_mempool; 50 static struct kmem_cache *nfs_cdata_cachep; 51 static mempool_t *nfs_commit_mempool; 52 53 struct nfs_commit_data *nfs_commitdata_alloc(void) 54 { 55 struct nfs_commit_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOFS); 56 57 if (p) { 58 memset(p, 0, sizeof(*p)); 59 INIT_LIST_HEAD(&p->pages); 60 } 61 return p; 62 } 63 EXPORT_SYMBOL_GPL(nfs_commitdata_alloc); 64 65 void nfs_commit_free(struct nfs_commit_data *p) 66 { 67 mempool_free(p, nfs_commit_mempool); 68 } 69 EXPORT_SYMBOL_GPL(nfs_commit_free); 70 71 struct nfs_write_header *nfs_writehdr_alloc(void) 72 { 73 struct nfs_write_header *p = mempool_alloc(nfs_wdata_mempool, GFP_NOFS); 74 75 if (p) { 76 struct nfs_pgio_header *hdr = &p->header; 77 78 memset(p, 0, sizeof(*p)); 79 INIT_LIST_HEAD(&hdr->pages); 80 INIT_LIST_HEAD(&hdr->rpc_list); 81 spin_lock_init(&hdr->lock); 82 atomic_set(&hdr->refcnt, 0); 83 hdr->verf = &p->verf; 84 } 85 return p; 86 } 87 88 static struct nfs_write_data *nfs_writedata_alloc(struct nfs_pgio_header *hdr, 89 unsigned int pagecount) 90 { 91 struct nfs_write_data *data, *prealloc; 92 93 prealloc = &container_of(hdr, struct nfs_write_header, header)->rpc_data; 94 if (prealloc->header == NULL) 95 data = prealloc; 96 else 97 data = kzalloc(sizeof(*data), GFP_KERNEL); 98 if (!data) 99 goto out; 100 101 if (nfs_pgarray_set(&data->pages, pagecount)) { 102 data->header = hdr; 103 atomic_inc(&hdr->refcnt); 104 } else { 105 if (data != prealloc) 106 kfree(data); 107 data = NULL; 108 } 109 out: 110 return data; 111 } 112 113 void nfs_writehdr_free(struct nfs_pgio_header *hdr) 114 { 115 struct nfs_write_header *whdr = container_of(hdr, struct nfs_write_header, header); 116 mempool_free(whdr, nfs_wdata_mempool); 117 } 118 119 void nfs_writedata_release(struct nfs_write_data *wdata) 120 { 121 struct nfs_pgio_header *hdr = wdata->header; 122 struct nfs_write_header *write_header = container_of(hdr, struct nfs_write_header, header); 123 124 put_nfs_open_context(wdata->args.context); 125 if (wdata->pages.pagevec != wdata->pages.page_array) 126 kfree(wdata->pages.pagevec); 127 if (wdata != &write_header->rpc_data) 128 kfree(wdata); 129 else 130 wdata->header = NULL; 131 if (atomic_dec_and_test(&hdr->refcnt)) 132 hdr->completion_ops->completion(hdr); 133 } 134 135 static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error) 136 { 137 ctx->error = error; 138 smp_wmb(); 139 set_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags); 140 } 141 142 static struct nfs_page *nfs_page_find_request_locked(struct page *page) 143 { 144 struct nfs_page *req = NULL; 145 146 if (PagePrivate(page)) { 147 req = (struct nfs_page *)page_private(page); 148 if (req != NULL) 149 kref_get(&req->wb_kref); 150 } 151 return req; 152 } 153 154 static struct nfs_page *nfs_page_find_request(struct page *page) 155 { 156 struct inode *inode = page->mapping->host; 157 struct nfs_page *req = NULL; 158 159 spin_lock(&inode->i_lock); 160 req = nfs_page_find_request_locked(page); 161 spin_unlock(&inode->i_lock); 162 return req; 163 } 164 165 /* Adjust the file length if we're writing beyond the end */ 166 static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count) 167 { 168 struct inode *inode = page->mapping->host; 169 loff_t end, i_size; 170 pgoff_t end_index; 171 172 spin_lock(&inode->i_lock); 173 i_size = i_size_read(inode); 174 end_index = (i_size - 1) >> PAGE_CACHE_SHIFT; 175 if (i_size > 0 && page->index < end_index) 176 goto out; 177 end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + ((loff_t)offset+count); 178 if (i_size >= end) 179 goto out; 180 i_size_write(inode, end); 181 nfs_inc_stats(inode, NFSIOS_EXTENDWRITE); 182 out: 183 spin_unlock(&inode->i_lock); 184 } 185 186 /* A writeback failed: mark the page as bad, and invalidate the page cache */ 187 static void nfs_set_pageerror(struct page *page) 188 { 189 SetPageError(page); 190 nfs_zap_mapping(page->mapping->host, page->mapping); 191 } 192 193 /* We can set the PG_uptodate flag if we see that a write request 194 * covers the full page. 195 */ 196 static void nfs_mark_uptodate(struct page *page, unsigned int base, unsigned int count) 197 { 198 if (PageUptodate(page)) 199 return; 200 if (base != 0) 201 return; 202 if (count != nfs_page_length(page)) 203 return; 204 SetPageUptodate(page); 205 } 206 207 static int wb_priority(struct writeback_control *wbc) 208 { 209 if (wbc->for_reclaim) 210 return FLUSH_HIGHPRI | FLUSH_STABLE; 211 if (wbc->for_kupdate || wbc->for_background) 212 return FLUSH_LOWPRI | FLUSH_COND_STABLE; 213 return FLUSH_COND_STABLE; 214 } 215 216 /* 217 * NFS congestion control 218 */ 219 220 int nfs_congestion_kb; 221 222 #define NFS_CONGESTION_ON_THRESH (nfs_congestion_kb >> (PAGE_SHIFT-10)) 223 #define NFS_CONGESTION_OFF_THRESH \ 224 (NFS_CONGESTION_ON_THRESH - (NFS_CONGESTION_ON_THRESH >> 2)) 225 226 static int nfs_set_page_writeback(struct page *page) 227 { 228 int ret = test_set_page_writeback(page); 229 230 if (!ret) { 231 struct inode *inode = page->mapping->host; 232 struct nfs_server *nfss = NFS_SERVER(inode); 233 234 if (atomic_long_inc_return(&nfss->writeback) > 235 NFS_CONGESTION_ON_THRESH) { 236 set_bdi_congested(&nfss->backing_dev_info, 237 BLK_RW_ASYNC); 238 } 239 } 240 return ret; 241 } 242 243 static void nfs_end_page_writeback(struct page *page) 244 { 245 struct inode *inode = page->mapping->host; 246 struct nfs_server *nfss = NFS_SERVER(inode); 247 248 end_page_writeback(page); 249 if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH) 250 clear_bdi_congested(&nfss->backing_dev_info, BLK_RW_ASYNC); 251 } 252 253 static struct nfs_page *nfs_find_and_lock_request(struct page *page, bool nonblock) 254 { 255 struct inode *inode = page->mapping->host; 256 struct nfs_page *req; 257 int ret; 258 259 spin_lock(&inode->i_lock); 260 for (;;) { 261 req = nfs_page_find_request_locked(page); 262 if (req == NULL) 263 break; 264 if (nfs_lock_request(req)) 265 break; 266 /* Note: If we hold the page lock, as is the case in nfs_writepage, 267 * then the call to nfs_lock_request() will always 268 * succeed provided that someone hasn't already marked the 269 * request as dirty (in which case we don't care). 270 */ 271 spin_unlock(&inode->i_lock); 272 if (!nonblock) 273 ret = nfs_wait_on_request(req); 274 else 275 ret = -EAGAIN; 276 nfs_release_request(req); 277 if (ret != 0) 278 return ERR_PTR(ret); 279 spin_lock(&inode->i_lock); 280 } 281 spin_unlock(&inode->i_lock); 282 return req; 283 } 284 285 /* 286 * Find an associated nfs write request, and prepare to flush it out 287 * May return an error if the user signalled nfs_wait_on_request(). 288 */ 289 static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio, 290 struct page *page, bool nonblock) 291 { 292 struct nfs_page *req; 293 int ret = 0; 294 295 req = nfs_find_and_lock_request(page, nonblock); 296 if (!req) 297 goto out; 298 ret = PTR_ERR(req); 299 if (IS_ERR(req)) 300 goto out; 301 302 ret = nfs_set_page_writeback(page); 303 BUG_ON(ret != 0); 304 BUG_ON(test_bit(PG_CLEAN, &req->wb_flags)); 305 306 if (!nfs_pageio_add_request(pgio, req)) { 307 nfs_redirty_request(req); 308 ret = pgio->pg_error; 309 } 310 out: 311 return ret; 312 } 313 314 static int nfs_do_writepage(struct page *page, struct writeback_control *wbc, struct nfs_pageio_descriptor *pgio) 315 { 316 struct inode *inode = page->mapping->host; 317 int ret; 318 319 nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE); 320 nfs_add_stats(inode, NFSIOS_WRITEPAGES, 1); 321 322 nfs_pageio_cond_complete(pgio, page->index); 323 ret = nfs_page_async_flush(pgio, page, wbc->sync_mode == WB_SYNC_NONE); 324 if (ret == -EAGAIN) { 325 redirty_page_for_writepage(wbc, page); 326 ret = 0; 327 } 328 return ret; 329 } 330 331 /* 332 * Write an mmapped page to the server. 333 */ 334 static int nfs_writepage_locked(struct page *page, struct writeback_control *wbc) 335 { 336 struct nfs_pageio_descriptor pgio; 337 int err; 338 339 nfs_pageio_init_write(&pgio, page->mapping->host, wb_priority(wbc), 340 &nfs_async_write_completion_ops); 341 err = nfs_do_writepage(page, wbc, &pgio); 342 nfs_pageio_complete(&pgio); 343 if (err < 0) 344 return err; 345 if (pgio.pg_error < 0) 346 return pgio.pg_error; 347 return 0; 348 } 349 350 int nfs_writepage(struct page *page, struct writeback_control *wbc) 351 { 352 int ret; 353 354 ret = nfs_writepage_locked(page, wbc); 355 unlock_page(page); 356 return ret; 357 } 358 359 static int nfs_writepages_callback(struct page *page, struct writeback_control *wbc, void *data) 360 { 361 int ret; 362 363 ret = nfs_do_writepage(page, wbc, data); 364 unlock_page(page); 365 return ret; 366 } 367 368 int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc) 369 { 370 struct inode *inode = mapping->host; 371 unsigned long *bitlock = &NFS_I(inode)->flags; 372 struct nfs_pageio_descriptor pgio; 373 int err; 374 375 /* Stop dirtying of new pages while we sync */ 376 err = wait_on_bit_lock(bitlock, NFS_INO_FLUSHING, 377 nfs_wait_bit_killable, TASK_KILLABLE); 378 if (err) 379 goto out_err; 380 381 nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES); 382 383 nfs_pageio_init_write(&pgio, inode, wb_priority(wbc), 384 &nfs_async_write_completion_ops); 385 err = write_cache_pages(mapping, wbc, nfs_writepages_callback, &pgio); 386 nfs_pageio_complete(&pgio); 387 388 clear_bit_unlock(NFS_INO_FLUSHING, bitlock); 389 smp_mb__after_clear_bit(); 390 wake_up_bit(bitlock, NFS_INO_FLUSHING); 391 392 if (err < 0) 393 goto out_err; 394 err = pgio.pg_error; 395 if (err < 0) 396 goto out_err; 397 return 0; 398 out_err: 399 return err; 400 } 401 402 /* 403 * Insert a write request into an inode 404 */ 405 static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req) 406 { 407 struct nfs_inode *nfsi = NFS_I(inode); 408 409 /* Lock the request! */ 410 nfs_lock_request(req); 411 412 spin_lock(&inode->i_lock); 413 if (!nfsi->npages && nfs_have_delegation(inode, FMODE_WRITE)) 414 inode->i_version++; 415 set_bit(PG_MAPPED, &req->wb_flags); 416 SetPagePrivate(req->wb_page); 417 set_page_private(req->wb_page, (unsigned long)req); 418 nfsi->npages++; 419 kref_get(&req->wb_kref); 420 spin_unlock(&inode->i_lock); 421 } 422 423 /* 424 * Remove a write request from an inode 425 */ 426 static void nfs_inode_remove_request(struct nfs_page *req) 427 { 428 struct inode *inode = req->wb_context->dentry->d_inode; 429 struct nfs_inode *nfsi = NFS_I(inode); 430 431 BUG_ON (!NFS_WBACK_BUSY(req)); 432 433 spin_lock(&inode->i_lock); 434 set_page_private(req->wb_page, 0); 435 ClearPagePrivate(req->wb_page); 436 clear_bit(PG_MAPPED, &req->wb_flags); 437 nfsi->npages--; 438 spin_unlock(&inode->i_lock); 439 nfs_release_request(req); 440 } 441 442 static void 443 nfs_mark_request_dirty(struct nfs_page *req) 444 { 445 __set_page_dirty_nobuffers(req->wb_page); 446 } 447 448 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) 449 /** 450 * nfs_request_add_commit_list - add request to a commit list 451 * @req: pointer to a struct nfs_page 452 * @dst: commit list head 453 * @cinfo: holds list lock and accounting info 454 * 455 * This sets the PG_CLEAN bit, updates the cinfo count of 456 * number of outstanding requests requiring a commit as well as 457 * the MM page stats. 458 * 459 * The caller must _not_ hold the cinfo->lock, but must be 460 * holding the nfs_page lock. 461 */ 462 void 463 nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst, 464 struct nfs_commit_info *cinfo) 465 { 466 set_bit(PG_CLEAN, &(req)->wb_flags); 467 spin_lock(cinfo->lock); 468 nfs_list_add_request(req, dst); 469 cinfo->mds->ncommit++; 470 spin_unlock(cinfo->lock); 471 if (!cinfo->dreq) { 472 inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS); 473 inc_bdi_stat(req->wb_page->mapping->backing_dev_info, 474 BDI_RECLAIMABLE); 475 __mark_inode_dirty(req->wb_context->dentry->d_inode, 476 I_DIRTY_DATASYNC); 477 } 478 } 479 EXPORT_SYMBOL_GPL(nfs_request_add_commit_list); 480 481 /** 482 * nfs_request_remove_commit_list - Remove request from a commit list 483 * @req: pointer to a nfs_page 484 * @cinfo: holds list lock and accounting info 485 * 486 * This clears the PG_CLEAN bit, and updates the cinfo's count of 487 * number of outstanding requests requiring a commit 488 * It does not update the MM page stats. 489 * 490 * The caller _must_ hold the cinfo->lock and the nfs_page lock. 491 */ 492 void 493 nfs_request_remove_commit_list(struct nfs_page *req, 494 struct nfs_commit_info *cinfo) 495 { 496 if (!test_and_clear_bit(PG_CLEAN, &(req)->wb_flags)) 497 return; 498 nfs_list_remove_request(req); 499 cinfo->mds->ncommit--; 500 } 501 EXPORT_SYMBOL_GPL(nfs_request_remove_commit_list); 502 503 static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo, 504 struct inode *inode) 505 { 506 cinfo->lock = &inode->i_lock; 507 cinfo->mds = &NFS_I(inode)->commit_info; 508 cinfo->ds = pnfs_get_ds_info(inode); 509 cinfo->dreq = NULL; 510 cinfo->completion_ops = &nfs_commit_completion_ops; 511 } 512 513 void nfs_init_cinfo(struct nfs_commit_info *cinfo, 514 struct inode *inode, 515 struct nfs_direct_req *dreq) 516 { 517 if (dreq) 518 nfs_init_cinfo_from_dreq(cinfo, dreq); 519 else 520 nfs_init_cinfo_from_inode(cinfo, inode); 521 } 522 EXPORT_SYMBOL_GPL(nfs_init_cinfo); 523 524 /* 525 * Add a request to the inode's commit list. 526 */ 527 void 528 nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg, 529 struct nfs_commit_info *cinfo) 530 { 531 if (pnfs_mark_request_commit(req, lseg, cinfo)) 532 return; 533 nfs_request_add_commit_list(req, &cinfo->mds->list, cinfo); 534 } 535 536 static void 537 nfs_clear_page_commit(struct page *page) 538 { 539 dec_zone_page_state(page, NR_UNSTABLE_NFS); 540 dec_bdi_stat(page->mapping->backing_dev_info, BDI_RECLAIMABLE); 541 } 542 543 static void 544 nfs_clear_request_commit(struct nfs_page *req) 545 { 546 if (test_bit(PG_CLEAN, &req->wb_flags)) { 547 struct inode *inode = req->wb_context->dentry->d_inode; 548 struct nfs_commit_info cinfo; 549 550 nfs_init_cinfo_from_inode(&cinfo, inode); 551 if (!pnfs_clear_request_commit(req, &cinfo)) { 552 spin_lock(cinfo.lock); 553 nfs_request_remove_commit_list(req, &cinfo); 554 spin_unlock(cinfo.lock); 555 } 556 nfs_clear_page_commit(req->wb_page); 557 } 558 } 559 560 static inline 561 int nfs_write_need_commit(struct nfs_write_data *data) 562 { 563 if (data->verf.committed == NFS_DATA_SYNC) 564 return data->header->lseg == NULL; 565 return data->verf.committed != NFS_FILE_SYNC; 566 } 567 568 #else 569 static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo, 570 struct inode *inode) 571 { 572 } 573 574 void nfs_init_cinfo(struct nfs_commit_info *cinfo, 575 struct inode *inode, 576 struct nfs_direct_req *dreq) 577 { 578 } 579 580 void 581 nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg, 582 struct nfs_commit_info *cinfo) 583 { 584 } 585 586 static void 587 nfs_clear_request_commit(struct nfs_page *req) 588 { 589 } 590 591 static inline 592 int nfs_write_need_commit(struct nfs_write_data *data) 593 { 594 return 0; 595 } 596 597 #endif 598 599 static void nfs_write_completion(struct nfs_pgio_header *hdr) 600 { 601 struct nfs_commit_info cinfo; 602 unsigned long bytes = 0; 603 604 if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) 605 goto out; 606 nfs_init_cinfo_from_inode(&cinfo, hdr->inode); 607 while (!list_empty(&hdr->pages)) { 608 struct nfs_page *req = nfs_list_entry(hdr->pages.next); 609 610 bytes += req->wb_bytes; 611 nfs_list_remove_request(req); 612 if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) && 613 (hdr->good_bytes < bytes)) { 614 nfs_set_pageerror(req->wb_page); 615 nfs_context_set_write_error(req->wb_context, hdr->error); 616 goto remove_req; 617 } 618 if (test_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags)) { 619 nfs_mark_request_dirty(req); 620 goto next; 621 } 622 if (test_bit(NFS_IOHDR_NEED_COMMIT, &hdr->flags)) { 623 memcpy(&req->wb_verf, hdr->verf, sizeof(req->wb_verf)); 624 nfs_mark_request_commit(req, hdr->lseg, &cinfo); 625 goto next; 626 } 627 remove_req: 628 nfs_inode_remove_request(req); 629 next: 630 nfs_unlock_request(req); 631 nfs_end_page_writeback(req->wb_page); 632 nfs_release_request(req); 633 } 634 out: 635 hdr->release(hdr); 636 } 637 638 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) 639 static unsigned long 640 nfs_reqs_to_commit(struct nfs_commit_info *cinfo) 641 { 642 return cinfo->mds->ncommit; 643 } 644 645 /* cinfo->lock held by caller */ 646 int 647 nfs_scan_commit_list(struct list_head *src, struct list_head *dst, 648 struct nfs_commit_info *cinfo, int max) 649 { 650 struct nfs_page *req, *tmp; 651 int ret = 0; 652 653 list_for_each_entry_safe(req, tmp, src, wb_list) { 654 if (!nfs_lock_request(req)) 655 continue; 656 kref_get(&req->wb_kref); 657 if (cond_resched_lock(cinfo->lock)) 658 list_safe_reset_next(req, tmp, wb_list); 659 nfs_request_remove_commit_list(req, cinfo); 660 nfs_list_add_request(req, dst); 661 ret++; 662 if ((ret == max) && !cinfo->dreq) 663 break; 664 } 665 return ret; 666 } 667 668 /* 669 * nfs_scan_commit - Scan an inode for commit requests 670 * @inode: NFS inode to scan 671 * @dst: mds destination list 672 * @cinfo: mds and ds lists of reqs ready to commit 673 * 674 * Moves requests from the inode's 'commit' request list. 675 * The requests are *not* checked to ensure that they form a contiguous set. 676 */ 677 int 678 nfs_scan_commit(struct inode *inode, struct list_head *dst, 679 struct nfs_commit_info *cinfo) 680 { 681 int ret = 0; 682 683 spin_lock(cinfo->lock); 684 if (cinfo->mds->ncommit > 0) { 685 const int max = INT_MAX; 686 687 ret = nfs_scan_commit_list(&cinfo->mds->list, dst, 688 cinfo, max); 689 ret += pnfs_scan_commit_lists(inode, cinfo, max - ret); 690 } 691 spin_unlock(cinfo->lock); 692 return ret; 693 } 694 695 #else 696 static unsigned long nfs_reqs_to_commit(struct nfs_commit_info *cinfo) 697 { 698 return 0; 699 } 700 701 int nfs_scan_commit(struct inode *inode, struct list_head *dst, 702 struct nfs_commit_info *cinfo) 703 { 704 return 0; 705 } 706 #endif 707 708 /* 709 * Search for an existing write request, and attempt to update 710 * it to reflect a new dirty region on a given page. 711 * 712 * If the attempt fails, then the existing request is flushed out 713 * to disk. 714 */ 715 static struct nfs_page *nfs_try_to_update_request(struct inode *inode, 716 struct page *page, 717 unsigned int offset, 718 unsigned int bytes) 719 { 720 struct nfs_page *req; 721 unsigned int rqend; 722 unsigned int end; 723 int error; 724 725 if (!PagePrivate(page)) 726 return NULL; 727 728 end = offset + bytes; 729 spin_lock(&inode->i_lock); 730 731 for (;;) { 732 req = nfs_page_find_request_locked(page); 733 if (req == NULL) 734 goto out_unlock; 735 736 rqend = req->wb_offset + req->wb_bytes; 737 /* 738 * Tell the caller to flush out the request if 739 * the offsets are non-contiguous. 740 * Note: nfs_flush_incompatible() will already 741 * have flushed out requests having wrong owners. 742 */ 743 if (offset > rqend 744 || end < req->wb_offset) 745 goto out_flushme; 746 747 if (nfs_lock_request(req)) 748 break; 749 750 /* The request is locked, so wait and then retry */ 751 spin_unlock(&inode->i_lock); 752 error = nfs_wait_on_request(req); 753 nfs_release_request(req); 754 if (error != 0) 755 goto out_err; 756 spin_lock(&inode->i_lock); 757 } 758 759 /* Okay, the request matches. Update the region */ 760 if (offset < req->wb_offset) { 761 req->wb_offset = offset; 762 req->wb_pgbase = offset; 763 } 764 if (end > rqend) 765 req->wb_bytes = end - req->wb_offset; 766 else 767 req->wb_bytes = rqend - req->wb_offset; 768 out_unlock: 769 spin_unlock(&inode->i_lock); 770 if (req) 771 nfs_clear_request_commit(req); 772 return req; 773 out_flushme: 774 spin_unlock(&inode->i_lock); 775 nfs_release_request(req); 776 error = nfs_wb_page(inode, page); 777 out_err: 778 return ERR_PTR(error); 779 } 780 781 /* 782 * Try to update an existing write request, or create one if there is none. 783 * 784 * Note: Should always be called with the Page Lock held to prevent races 785 * if we have to add a new request. Also assumes that the caller has 786 * already called nfs_flush_incompatible() if necessary. 787 */ 788 static struct nfs_page * nfs_setup_write_request(struct nfs_open_context* ctx, 789 struct page *page, unsigned int offset, unsigned int bytes) 790 { 791 struct inode *inode = page->mapping->host; 792 struct nfs_page *req; 793 794 req = nfs_try_to_update_request(inode, page, offset, bytes); 795 if (req != NULL) 796 goto out; 797 req = nfs_create_request(ctx, inode, page, offset, bytes); 798 if (IS_ERR(req)) 799 goto out; 800 nfs_inode_add_request(inode, req); 801 out: 802 return req; 803 } 804 805 static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page, 806 unsigned int offset, unsigned int count) 807 { 808 struct nfs_page *req; 809 810 req = nfs_setup_write_request(ctx, page, offset, count); 811 if (IS_ERR(req)) 812 return PTR_ERR(req); 813 /* Update file length */ 814 nfs_grow_file(page, offset, count); 815 nfs_mark_uptodate(page, req->wb_pgbase, req->wb_bytes); 816 nfs_mark_request_dirty(req); 817 nfs_unlock_and_release_request(req); 818 return 0; 819 } 820 821 int nfs_flush_incompatible(struct file *file, struct page *page) 822 { 823 struct nfs_open_context *ctx = nfs_file_open_context(file); 824 struct nfs_page *req; 825 int do_flush, status; 826 /* 827 * Look for a request corresponding to this page. If there 828 * is one, and it belongs to another file, we flush it out 829 * before we try to copy anything into the page. Do this 830 * due to the lack of an ACCESS-type call in NFSv2. 831 * Also do the same if we find a request from an existing 832 * dropped page. 833 */ 834 do { 835 req = nfs_page_find_request(page); 836 if (req == NULL) 837 return 0; 838 do_flush = req->wb_page != page || req->wb_context != ctx || 839 req->wb_lock_context->lockowner != current->files || 840 req->wb_lock_context->pid != current->tgid; 841 nfs_release_request(req); 842 if (!do_flush) 843 return 0; 844 status = nfs_wb_page(page->mapping->host, page); 845 } while (status == 0); 846 return status; 847 } 848 849 /* 850 * If the page cache is marked as unsafe or invalid, then we can't rely on 851 * the PageUptodate() flag. In this case, we will need to turn off 852 * write optimisations that depend on the page contents being correct. 853 */ 854 static bool nfs_write_pageuptodate(struct page *page, struct inode *inode) 855 { 856 if (nfs_have_delegated_attributes(inode)) 857 goto out; 858 if (NFS_I(inode)->cache_validity & NFS_INO_REVAL_PAGECACHE) 859 return false; 860 out: 861 return PageUptodate(page) != 0; 862 } 863 864 /* 865 * Update and possibly write a cached page of an NFS file. 866 * 867 * XXX: Keep an eye on generic_file_read to make sure it doesn't do bad 868 * things with a page scheduled for an RPC call (e.g. invalidate it). 869 */ 870 int nfs_updatepage(struct file *file, struct page *page, 871 unsigned int offset, unsigned int count) 872 { 873 struct nfs_open_context *ctx = nfs_file_open_context(file); 874 struct inode *inode = page->mapping->host; 875 int status = 0; 876 877 nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE); 878 879 dprintk("NFS: nfs_updatepage(%s/%s %d@%lld)\n", 880 file->f_path.dentry->d_parent->d_name.name, 881 file->f_path.dentry->d_name.name, count, 882 (long long)(page_offset(page) + offset)); 883 884 /* If we're not using byte range locks, and we know the page 885 * is up to date, it may be more efficient to extend the write 886 * to cover the entire page in order to avoid fragmentation 887 * inefficiencies. 888 */ 889 if (nfs_write_pageuptodate(page, inode) && 890 inode->i_flock == NULL && 891 !(file->f_flags & O_DSYNC)) { 892 count = max(count + offset, nfs_page_length(page)); 893 offset = 0; 894 } 895 896 status = nfs_writepage_setup(ctx, page, offset, count); 897 if (status < 0) 898 nfs_set_pageerror(page); 899 else 900 __set_page_dirty_nobuffers(page); 901 902 dprintk("NFS: nfs_updatepage returns %d (isize %lld)\n", 903 status, (long long)i_size_read(inode)); 904 return status; 905 } 906 907 static int flush_task_priority(int how) 908 { 909 switch (how & (FLUSH_HIGHPRI|FLUSH_LOWPRI)) { 910 case FLUSH_HIGHPRI: 911 return RPC_PRIORITY_HIGH; 912 case FLUSH_LOWPRI: 913 return RPC_PRIORITY_LOW; 914 } 915 return RPC_PRIORITY_NORMAL; 916 } 917 918 int nfs_initiate_write(struct rpc_clnt *clnt, 919 struct nfs_write_data *data, 920 const struct rpc_call_ops *call_ops, 921 int how, int flags) 922 { 923 struct inode *inode = data->header->inode; 924 int priority = flush_task_priority(how); 925 struct rpc_task *task; 926 struct rpc_message msg = { 927 .rpc_argp = &data->args, 928 .rpc_resp = &data->res, 929 .rpc_cred = data->header->cred, 930 }; 931 struct rpc_task_setup task_setup_data = { 932 .rpc_client = clnt, 933 .task = &data->task, 934 .rpc_message = &msg, 935 .callback_ops = call_ops, 936 .callback_data = data, 937 .workqueue = nfsiod_workqueue, 938 .flags = RPC_TASK_ASYNC | flags, 939 .priority = priority, 940 }; 941 int ret = 0; 942 943 /* Set up the initial task struct. */ 944 NFS_PROTO(inode)->write_setup(data, &msg); 945 946 dprintk("NFS: %5u initiated write call " 947 "(req %s/%lld, %u bytes @ offset %llu)\n", 948 data->task.tk_pid, 949 inode->i_sb->s_id, 950 (long long)NFS_FILEID(inode), 951 data->args.count, 952 (unsigned long long)data->args.offset); 953 954 task = rpc_run_task(&task_setup_data); 955 if (IS_ERR(task)) { 956 ret = PTR_ERR(task); 957 goto out; 958 } 959 if (how & FLUSH_SYNC) { 960 ret = rpc_wait_for_completion_task(task); 961 if (ret == 0) 962 ret = task->tk_status; 963 } 964 rpc_put_task(task); 965 out: 966 return ret; 967 } 968 EXPORT_SYMBOL_GPL(nfs_initiate_write); 969 970 /* 971 * Set up the argument/result storage required for the RPC call. 972 */ 973 static void nfs_write_rpcsetup(struct nfs_write_data *data, 974 unsigned int count, unsigned int offset, 975 int how, struct nfs_commit_info *cinfo) 976 { 977 struct nfs_page *req = data->header->req; 978 979 /* Set up the RPC argument and reply structs 980 * NB: take care not to mess about with data->commit et al. */ 981 982 data->args.fh = NFS_FH(data->header->inode); 983 data->args.offset = req_offset(req) + offset; 984 /* pnfs_set_layoutcommit needs this */ 985 data->mds_offset = data->args.offset; 986 data->args.pgbase = req->wb_pgbase + offset; 987 data->args.pages = data->pages.pagevec; 988 data->args.count = count; 989 data->args.context = get_nfs_open_context(req->wb_context); 990 data->args.lock_context = req->wb_lock_context; 991 data->args.stable = NFS_UNSTABLE; 992 switch (how & (FLUSH_STABLE | FLUSH_COND_STABLE)) { 993 case 0: 994 break; 995 case FLUSH_COND_STABLE: 996 if (nfs_reqs_to_commit(cinfo)) 997 break; 998 default: 999 data->args.stable = NFS_FILE_SYNC; 1000 } 1001 1002 data->res.fattr = &data->fattr; 1003 data->res.count = count; 1004 data->res.verf = &data->verf; 1005 nfs_fattr_init(&data->fattr); 1006 } 1007 1008 static int nfs_do_write(struct nfs_write_data *data, 1009 const struct rpc_call_ops *call_ops, 1010 int how) 1011 { 1012 struct inode *inode = data->header->inode; 1013 1014 return nfs_initiate_write(NFS_CLIENT(inode), data, call_ops, how, 0); 1015 } 1016 1017 static int nfs_do_multiple_writes(struct list_head *head, 1018 const struct rpc_call_ops *call_ops, 1019 int how) 1020 { 1021 struct nfs_write_data *data; 1022 int ret = 0; 1023 1024 while (!list_empty(head)) { 1025 int ret2; 1026 1027 data = list_first_entry(head, struct nfs_write_data, list); 1028 list_del_init(&data->list); 1029 1030 ret2 = nfs_do_write(data, call_ops, how); 1031 if (ret == 0) 1032 ret = ret2; 1033 } 1034 return ret; 1035 } 1036 1037 /* If a nfs_flush_* function fails, it should remove reqs from @head and 1038 * call this on each, which will prepare them to be retried on next 1039 * writeback using standard nfs. 1040 */ 1041 static void nfs_redirty_request(struct nfs_page *req) 1042 { 1043 nfs_mark_request_dirty(req); 1044 nfs_unlock_request(req); 1045 nfs_end_page_writeback(req->wb_page); 1046 nfs_release_request(req); 1047 } 1048 1049 static void nfs_async_write_error(struct list_head *head) 1050 { 1051 struct nfs_page *req; 1052 1053 while (!list_empty(head)) { 1054 req = nfs_list_entry(head->next); 1055 nfs_list_remove_request(req); 1056 nfs_redirty_request(req); 1057 } 1058 } 1059 1060 static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops = { 1061 .error_cleanup = nfs_async_write_error, 1062 .completion = nfs_write_completion, 1063 }; 1064 1065 static void nfs_flush_error(struct nfs_pageio_descriptor *desc, 1066 struct nfs_pgio_header *hdr) 1067 { 1068 set_bit(NFS_IOHDR_REDO, &hdr->flags); 1069 while (!list_empty(&hdr->rpc_list)) { 1070 struct nfs_write_data *data = list_first_entry(&hdr->rpc_list, 1071 struct nfs_write_data, list); 1072 list_del(&data->list); 1073 nfs_writedata_release(data); 1074 } 1075 desc->pg_completion_ops->error_cleanup(&desc->pg_list); 1076 } 1077 1078 /* 1079 * Generate multiple small requests to write out a single 1080 * contiguous dirty area on one page. 1081 */ 1082 static int nfs_flush_multi(struct nfs_pageio_descriptor *desc, 1083 struct nfs_pgio_header *hdr) 1084 { 1085 struct nfs_page *req = hdr->req; 1086 struct page *page = req->wb_page; 1087 struct nfs_write_data *data; 1088 size_t wsize = desc->pg_bsize, nbytes; 1089 unsigned int offset; 1090 int requests = 0; 1091 struct nfs_commit_info cinfo; 1092 1093 nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq); 1094 1095 if ((desc->pg_ioflags & FLUSH_COND_STABLE) && 1096 (desc->pg_moreio || nfs_reqs_to_commit(&cinfo) || 1097 desc->pg_count > wsize)) 1098 desc->pg_ioflags &= ~FLUSH_COND_STABLE; 1099 1100 1101 offset = 0; 1102 nbytes = desc->pg_count; 1103 do { 1104 size_t len = min(nbytes, wsize); 1105 1106 data = nfs_writedata_alloc(hdr, 1); 1107 if (!data) { 1108 nfs_flush_error(desc, hdr); 1109 return -ENOMEM; 1110 } 1111 data->pages.pagevec[0] = page; 1112 nfs_write_rpcsetup(data, len, offset, desc->pg_ioflags, &cinfo); 1113 list_add(&data->list, &hdr->rpc_list); 1114 requests++; 1115 nbytes -= len; 1116 offset += len; 1117 } while (nbytes != 0); 1118 nfs_list_remove_request(req); 1119 nfs_list_add_request(req, &hdr->pages); 1120 desc->pg_rpc_callops = &nfs_write_common_ops; 1121 return 0; 1122 } 1123 1124 /* 1125 * Create an RPC task for the given write request and kick it. 1126 * The page must have been locked by the caller. 1127 * 1128 * It may happen that the page we're passed is not marked dirty. 1129 * This is the case if nfs_updatepage detects a conflicting request 1130 * that has been written but not committed. 1131 */ 1132 static int nfs_flush_one(struct nfs_pageio_descriptor *desc, 1133 struct nfs_pgio_header *hdr) 1134 { 1135 struct nfs_page *req; 1136 struct page **pages; 1137 struct nfs_write_data *data; 1138 struct list_head *head = &desc->pg_list; 1139 struct nfs_commit_info cinfo; 1140 1141 data = nfs_writedata_alloc(hdr, nfs_page_array_len(desc->pg_base, 1142 desc->pg_count)); 1143 if (!data) { 1144 nfs_flush_error(desc, hdr); 1145 return -ENOMEM; 1146 } 1147 1148 nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq); 1149 pages = data->pages.pagevec; 1150 while (!list_empty(head)) { 1151 req = nfs_list_entry(head->next); 1152 nfs_list_remove_request(req); 1153 nfs_list_add_request(req, &hdr->pages); 1154 *pages++ = req->wb_page; 1155 } 1156 1157 if ((desc->pg_ioflags & FLUSH_COND_STABLE) && 1158 (desc->pg_moreio || nfs_reqs_to_commit(&cinfo))) 1159 desc->pg_ioflags &= ~FLUSH_COND_STABLE; 1160 1161 /* Set up the argument struct */ 1162 nfs_write_rpcsetup(data, desc->pg_count, 0, desc->pg_ioflags, &cinfo); 1163 list_add(&data->list, &hdr->rpc_list); 1164 desc->pg_rpc_callops = &nfs_write_common_ops; 1165 return 0; 1166 } 1167 1168 int nfs_generic_flush(struct nfs_pageio_descriptor *desc, 1169 struct nfs_pgio_header *hdr) 1170 { 1171 if (desc->pg_bsize < PAGE_CACHE_SIZE) 1172 return nfs_flush_multi(desc, hdr); 1173 return nfs_flush_one(desc, hdr); 1174 } 1175 1176 static int nfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc) 1177 { 1178 struct nfs_write_header *whdr; 1179 struct nfs_pgio_header *hdr; 1180 int ret; 1181 1182 whdr = nfs_writehdr_alloc(); 1183 if (!whdr) { 1184 desc->pg_completion_ops->error_cleanup(&desc->pg_list); 1185 return -ENOMEM; 1186 } 1187 hdr = &whdr->header; 1188 nfs_pgheader_init(desc, hdr, nfs_writehdr_free); 1189 atomic_inc(&hdr->refcnt); 1190 ret = nfs_generic_flush(desc, hdr); 1191 if (ret == 0) 1192 ret = nfs_do_multiple_writes(&hdr->rpc_list, 1193 desc->pg_rpc_callops, 1194 desc->pg_ioflags); 1195 if (atomic_dec_and_test(&hdr->refcnt)) 1196 hdr->completion_ops->completion(hdr); 1197 return ret; 1198 } 1199 1200 static const struct nfs_pageio_ops nfs_pageio_write_ops = { 1201 .pg_test = nfs_generic_pg_test, 1202 .pg_doio = nfs_generic_pg_writepages, 1203 }; 1204 1205 void nfs_pageio_init_write_mds(struct nfs_pageio_descriptor *pgio, 1206 struct inode *inode, int ioflags, 1207 const struct nfs_pgio_completion_ops *compl_ops) 1208 { 1209 nfs_pageio_init(pgio, inode, &nfs_pageio_write_ops, compl_ops, 1210 NFS_SERVER(inode)->wsize, ioflags); 1211 } 1212 1213 void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio) 1214 { 1215 pgio->pg_ops = &nfs_pageio_write_ops; 1216 pgio->pg_bsize = NFS_SERVER(pgio->pg_inode)->wsize; 1217 } 1218 EXPORT_SYMBOL_GPL(nfs_pageio_reset_write_mds); 1219 1220 void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio, 1221 struct inode *inode, int ioflags, 1222 const struct nfs_pgio_completion_ops *compl_ops) 1223 { 1224 if (!pnfs_pageio_init_write(pgio, inode, ioflags, compl_ops)) 1225 nfs_pageio_init_write_mds(pgio, inode, ioflags, compl_ops); 1226 } 1227 1228 void nfs_write_prepare(struct rpc_task *task, void *calldata) 1229 { 1230 struct nfs_write_data *data = calldata; 1231 NFS_PROTO(data->header->inode)->write_rpc_prepare(task, data); 1232 } 1233 1234 void nfs_commit_prepare(struct rpc_task *task, void *calldata) 1235 { 1236 struct nfs_commit_data *data = calldata; 1237 1238 NFS_PROTO(data->inode)->commit_rpc_prepare(task, data); 1239 } 1240 1241 /* 1242 * Handle a write reply that flushes a whole page. 1243 * 1244 * FIXME: There is an inherent race with invalidate_inode_pages and 1245 * writebacks since the page->count is kept > 1 for as long 1246 * as the page has a write request pending. 1247 */ 1248 static void nfs_writeback_done_common(struct rpc_task *task, void *calldata) 1249 { 1250 struct nfs_write_data *data = calldata; 1251 1252 nfs_writeback_done(task, data); 1253 } 1254 1255 static void nfs_writeback_release_common(void *calldata) 1256 { 1257 struct nfs_write_data *data = calldata; 1258 struct nfs_pgio_header *hdr = data->header; 1259 int status = data->task.tk_status; 1260 1261 if ((status >= 0) && nfs_write_need_commit(data)) { 1262 spin_lock(&hdr->lock); 1263 if (test_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags)) 1264 ; /* Do nothing */ 1265 else if (!test_and_set_bit(NFS_IOHDR_NEED_COMMIT, &hdr->flags)) 1266 memcpy(hdr->verf, &data->verf, sizeof(*hdr->verf)); 1267 else if (memcmp(hdr->verf, &data->verf, sizeof(*hdr->verf))) 1268 set_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags); 1269 spin_unlock(&hdr->lock); 1270 } 1271 nfs_writedata_release(data); 1272 } 1273 1274 static const struct rpc_call_ops nfs_write_common_ops = { 1275 .rpc_call_prepare = nfs_write_prepare, 1276 .rpc_call_done = nfs_writeback_done_common, 1277 .rpc_release = nfs_writeback_release_common, 1278 }; 1279 1280 1281 /* 1282 * This function is called when the WRITE call is complete. 1283 */ 1284 void nfs_writeback_done(struct rpc_task *task, struct nfs_write_data *data) 1285 { 1286 struct nfs_writeargs *argp = &data->args; 1287 struct nfs_writeres *resp = &data->res; 1288 struct inode *inode = data->header->inode; 1289 int status; 1290 1291 dprintk("NFS: %5u nfs_writeback_done (status %d)\n", 1292 task->tk_pid, task->tk_status); 1293 1294 /* 1295 * ->write_done will attempt to use post-op attributes to detect 1296 * conflicting writes by other clients. A strict interpretation 1297 * of close-to-open would allow us to continue caching even if 1298 * another writer had changed the file, but some applications 1299 * depend on tighter cache coherency when writing. 1300 */ 1301 status = NFS_PROTO(inode)->write_done(task, data); 1302 if (status != 0) 1303 return; 1304 nfs_add_stats(inode, NFSIOS_SERVERWRITTENBYTES, resp->count); 1305 1306 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) 1307 if (resp->verf->committed < argp->stable && task->tk_status >= 0) { 1308 /* We tried a write call, but the server did not 1309 * commit data to stable storage even though we 1310 * requested it. 1311 * Note: There is a known bug in Tru64 < 5.0 in which 1312 * the server reports NFS_DATA_SYNC, but performs 1313 * NFS_FILE_SYNC. We therefore implement this checking 1314 * as a dprintk() in order to avoid filling syslog. 1315 */ 1316 static unsigned long complain; 1317 1318 /* Note this will print the MDS for a DS write */ 1319 if (time_before(complain, jiffies)) { 1320 dprintk("NFS: faulty NFS server %s:" 1321 " (committed = %d) != (stable = %d)\n", 1322 NFS_SERVER(inode)->nfs_client->cl_hostname, 1323 resp->verf->committed, argp->stable); 1324 complain = jiffies + 300 * HZ; 1325 } 1326 } 1327 #endif 1328 if (task->tk_status < 0) 1329 nfs_set_pgio_error(data->header, task->tk_status, argp->offset); 1330 else if (resp->count < argp->count) { 1331 static unsigned long complain; 1332 1333 /* This a short write! */ 1334 nfs_inc_stats(inode, NFSIOS_SHORTWRITE); 1335 1336 /* Has the server at least made some progress? */ 1337 if (resp->count == 0) { 1338 if (time_before(complain, jiffies)) { 1339 printk(KERN_WARNING 1340 "NFS: Server wrote zero bytes, expected %u.\n", 1341 argp->count); 1342 complain = jiffies + 300 * HZ; 1343 } 1344 nfs_set_pgio_error(data->header, -EIO, argp->offset); 1345 task->tk_status = -EIO; 1346 return; 1347 } 1348 /* Was this an NFSv2 write or an NFSv3 stable write? */ 1349 if (resp->verf->committed != NFS_UNSTABLE) { 1350 /* Resend from where the server left off */ 1351 data->mds_offset += resp->count; 1352 argp->offset += resp->count; 1353 argp->pgbase += resp->count; 1354 argp->count -= resp->count; 1355 } else { 1356 /* Resend as a stable write in order to avoid 1357 * headaches in the case of a server crash. 1358 */ 1359 argp->stable = NFS_FILE_SYNC; 1360 } 1361 rpc_restart_call_prepare(task); 1362 } 1363 } 1364 1365 1366 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) 1367 static int nfs_commit_set_lock(struct nfs_inode *nfsi, int may_wait) 1368 { 1369 int ret; 1370 1371 if (!test_and_set_bit(NFS_INO_COMMIT, &nfsi->flags)) 1372 return 1; 1373 if (!may_wait) 1374 return 0; 1375 ret = out_of_line_wait_on_bit_lock(&nfsi->flags, 1376 NFS_INO_COMMIT, 1377 nfs_wait_bit_killable, 1378 TASK_KILLABLE); 1379 return (ret < 0) ? ret : 1; 1380 } 1381 1382 static void nfs_commit_clear_lock(struct nfs_inode *nfsi) 1383 { 1384 clear_bit(NFS_INO_COMMIT, &nfsi->flags); 1385 smp_mb__after_clear_bit(); 1386 wake_up_bit(&nfsi->flags, NFS_INO_COMMIT); 1387 } 1388 1389 void nfs_commitdata_release(struct nfs_commit_data *data) 1390 { 1391 put_nfs_open_context(data->context); 1392 nfs_commit_free(data); 1393 } 1394 EXPORT_SYMBOL_GPL(nfs_commitdata_release); 1395 1396 int nfs_initiate_commit(struct rpc_clnt *clnt, struct nfs_commit_data *data, 1397 const struct rpc_call_ops *call_ops, 1398 int how, int flags) 1399 { 1400 struct rpc_task *task; 1401 int priority = flush_task_priority(how); 1402 struct rpc_message msg = { 1403 .rpc_argp = &data->args, 1404 .rpc_resp = &data->res, 1405 .rpc_cred = data->cred, 1406 }; 1407 struct rpc_task_setup task_setup_data = { 1408 .task = &data->task, 1409 .rpc_client = clnt, 1410 .rpc_message = &msg, 1411 .callback_ops = call_ops, 1412 .callback_data = data, 1413 .workqueue = nfsiod_workqueue, 1414 .flags = RPC_TASK_ASYNC | flags, 1415 .priority = priority, 1416 }; 1417 /* Set up the initial task struct. */ 1418 NFS_PROTO(data->inode)->commit_setup(data, &msg); 1419 1420 dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid); 1421 1422 task = rpc_run_task(&task_setup_data); 1423 if (IS_ERR(task)) 1424 return PTR_ERR(task); 1425 if (how & FLUSH_SYNC) 1426 rpc_wait_for_completion_task(task); 1427 rpc_put_task(task); 1428 return 0; 1429 } 1430 EXPORT_SYMBOL_GPL(nfs_initiate_commit); 1431 1432 /* 1433 * Set up the argument/result storage required for the RPC call. 1434 */ 1435 void nfs_init_commit(struct nfs_commit_data *data, 1436 struct list_head *head, 1437 struct pnfs_layout_segment *lseg, 1438 struct nfs_commit_info *cinfo) 1439 { 1440 struct nfs_page *first = nfs_list_entry(head->next); 1441 struct inode *inode = first->wb_context->dentry->d_inode; 1442 1443 /* Set up the RPC argument and reply structs 1444 * NB: take care not to mess about with data->commit et al. */ 1445 1446 list_splice_init(head, &data->pages); 1447 1448 data->inode = inode; 1449 data->cred = first->wb_context->cred; 1450 data->lseg = lseg; /* reference transferred */ 1451 data->mds_ops = &nfs_commit_ops; 1452 data->completion_ops = cinfo->completion_ops; 1453 data->dreq = cinfo->dreq; 1454 1455 data->args.fh = NFS_FH(data->inode); 1456 /* Note: we always request a commit of the entire inode */ 1457 data->args.offset = 0; 1458 data->args.count = 0; 1459 data->context = get_nfs_open_context(first->wb_context); 1460 data->res.fattr = &data->fattr; 1461 data->res.verf = &data->verf; 1462 nfs_fattr_init(&data->fattr); 1463 } 1464 EXPORT_SYMBOL_GPL(nfs_init_commit); 1465 1466 void nfs_retry_commit(struct list_head *page_list, 1467 struct pnfs_layout_segment *lseg, 1468 struct nfs_commit_info *cinfo) 1469 { 1470 struct nfs_page *req; 1471 1472 while (!list_empty(page_list)) { 1473 req = nfs_list_entry(page_list->next); 1474 nfs_list_remove_request(req); 1475 nfs_mark_request_commit(req, lseg, cinfo); 1476 if (!cinfo->dreq) { 1477 dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS); 1478 dec_bdi_stat(req->wb_page->mapping->backing_dev_info, 1479 BDI_RECLAIMABLE); 1480 } 1481 nfs_unlock_and_release_request(req); 1482 } 1483 } 1484 EXPORT_SYMBOL_GPL(nfs_retry_commit); 1485 1486 /* 1487 * Commit dirty pages 1488 */ 1489 static int 1490 nfs_commit_list(struct inode *inode, struct list_head *head, int how, 1491 struct nfs_commit_info *cinfo) 1492 { 1493 struct nfs_commit_data *data; 1494 1495 data = nfs_commitdata_alloc(); 1496 1497 if (!data) 1498 goto out_bad; 1499 1500 /* Set up the argument struct */ 1501 nfs_init_commit(data, head, NULL, cinfo); 1502 atomic_inc(&cinfo->mds->rpcs_out); 1503 return nfs_initiate_commit(NFS_CLIENT(inode), data, data->mds_ops, 1504 how, 0); 1505 out_bad: 1506 nfs_retry_commit(head, NULL, cinfo); 1507 cinfo->completion_ops->error_cleanup(NFS_I(inode)); 1508 return -ENOMEM; 1509 } 1510 1511 /* 1512 * COMMIT call returned 1513 */ 1514 static void nfs_commit_done(struct rpc_task *task, void *calldata) 1515 { 1516 struct nfs_commit_data *data = calldata; 1517 1518 dprintk("NFS: %5u nfs_commit_done (status %d)\n", 1519 task->tk_pid, task->tk_status); 1520 1521 /* Call the NFS version-specific code */ 1522 NFS_PROTO(data->inode)->commit_done(task, data); 1523 } 1524 1525 static void nfs_commit_release_pages(struct nfs_commit_data *data) 1526 { 1527 struct nfs_page *req; 1528 int status = data->task.tk_status; 1529 struct nfs_commit_info cinfo; 1530 1531 while (!list_empty(&data->pages)) { 1532 req = nfs_list_entry(data->pages.next); 1533 nfs_list_remove_request(req); 1534 nfs_clear_page_commit(req->wb_page); 1535 1536 dprintk("NFS: commit (%s/%lld %d@%lld)", 1537 req->wb_context->dentry->d_sb->s_id, 1538 (long long)NFS_FILEID(req->wb_context->dentry->d_inode), 1539 req->wb_bytes, 1540 (long long)req_offset(req)); 1541 if (status < 0) { 1542 nfs_context_set_write_error(req->wb_context, status); 1543 nfs_inode_remove_request(req); 1544 dprintk(", error = %d\n", status); 1545 goto next; 1546 } 1547 1548 /* Okay, COMMIT succeeded, apparently. Check the verifier 1549 * returned by the server against all stored verfs. */ 1550 if (!memcmp(req->wb_verf.verifier, data->verf.verifier, sizeof(data->verf.verifier))) { 1551 /* We have a match */ 1552 nfs_inode_remove_request(req); 1553 dprintk(" OK\n"); 1554 goto next; 1555 } 1556 /* We have a mismatch. Write the page again */ 1557 dprintk(" mismatch\n"); 1558 nfs_mark_request_dirty(req); 1559 next: 1560 nfs_unlock_and_release_request(req); 1561 } 1562 nfs_init_cinfo(&cinfo, data->inode, data->dreq); 1563 if (atomic_dec_and_test(&cinfo.mds->rpcs_out)) 1564 nfs_commit_clear_lock(NFS_I(data->inode)); 1565 } 1566 1567 static void nfs_commit_release(void *calldata) 1568 { 1569 struct nfs_commit_data *data = calldata; 1570 1571 data->completion_ops->completion(data); 1572 nfs_commitdata_release(calldata); 1573 } 1574 1575 static const struct rpc_call_ops nfs_commit_ops = { 1576 .rpc_call_prepare = nfs_commit_prepare, 1577 .rpc_call_done = nfs_commit_done, 1578 .rpc_release = nfs_commit_release, 1579 }; 1580 1581 static const struct nfs_commit_completion_ops nfs_commit_completion_ops = { 1582 .completion = nfs_commit_release_pages, 1583 .error_cleanup = nfs_commit_clear_lock, 1584 }; 1585 1586 int nfs_generic_commit_list(struct inode *inode, struct list_head *head, 1587 int how, struct nfs_commit_info *cinfo) 1588 { 1589 int status; 1590 1591 status = pnfs_commit_list(inode, head, how, cinfo); 1592 if (status == PNFS_NOT_ATTEMPTED) 1593 status = nfs_commit_list(inode, head, how, cinfo); 1594 return status; 1595 } 1596 1597 int nfs_commit_inode(struct inode *inode, int how) 1598 { 1599 LIST_HEAD(head); 1600 struct nfs_commit_info cinfo; 1601 int may_wait = how & FLUSH_SYNC; 1602 int res; 1603 1604 res = nfs_commit_set_lock(NFS_I(inode), may_wait); 1605 if (res <= 0) 1606 goto out_mark_dirty; 1607 nfs_init_cinfo_from_inode(&cinfo, inode); 1608 res = nfs_scan_commit(inode, &head, &cinfo); 1609 if (res) { 1610 int error; 1611 1612 error = nfs_generic_commit_list(inode, &head, how, &cinfo); 1613 if (error < 0) 1614 return error; 1615 if (!may_wait) 1616 goto out_mark_dirty; 1617 error = wait_on_bit(&NFS_I(inode)->flags, 1618 NFS_INO_COMMIT, 1619 nfs_wait_bit_killable, 1620 TASK_KILLABLE); 1621 if (error < 0) 1622 return error; 1623 } else 1624 nfs_commit_clear_lock(NFS_I(inode)); 1625 return res; 1626 /* Note: If we exit without ensuring that the commit is complete, 1627 * we must mark the inode as dirty. Otherwise, future calls to 1628 * sync_inode() with the WB_SYNC_ALL flag set will fail to ensure 1629 * that the data is on the disk. 1630 */ 1631 out_mark_dirty: 1632 __mark_inode_dirty(inode, I_DIRTY_DATASYNC); 1633 return res; 1634 } 1635 1636 static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_control *wbc) 1637 { 1638 struct nfs_inode *nfsi = NFS_I(inode); 1639 int flags = FLUSH_SYNC; 1640 int ret = 0; 1641 1642 /* no commits means nothing needs to be done */ 1643 if (!nfsi->commit_info.ncommit) 1644 return ret; 1645 1646 if (wbc->sync_mode == WB_SYNC_NONE) { 1647 /* Don't commit yet if this is a non-blocking flush and there 1648 * are a lot of outstanding writes for this mapping. 1649 */ 1650 if (nfsi->commit_info.ncommit <= (nfsi->npages >> 1)) 1651 goto out_mark_dirty; 1652 1653 /* don't wait for the COMMIT response */ 1654 flags = 0; 1655 } 1656 1657 ret = nfs_commit_inode(inode, flags); 1658 if (ret >= 0) { 1659 if (wbc->sync_mode == WB_SYNC_NONE) { 1660 if (ret < wbc->nr_to_write) 1661 wbc->nr_to_write -= ret; 1662 else 1663 wbc->nr_to_write = 0; 1664 } 1665 return 0; 1666 } 1667 out_mark_dirty: 1668 __mark_inode_dirty(inode, I_DIRTY_DATASYNC); 1669 return ret; 1670 } 1671 #else 1672 static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_control *wbc) 1673 { 1674 return 0; 1675 } 1676 #endif 1677 1678 int nfs_write_inode(struct inode *inode, struct writeback_control *wbc) 1679 { 1680 int ret; 1681 1682 ret = nfs_commit_unstable_pages(inode, wbc); 1683 if (ret >= 0 && test_bit(NFS_INO_LAYOUTCOMMIT, &NFS_I(inode)->flags)) { 1684 int status; 1685 bool sync = true; 1686 1687 if (wbc->sync_mode == WB_SYNC_NONE) 1688 sync = false; 1689 1690 status = pnfs_layoutcommit_inode(inode, sync); 1691 if (status < 0) 1692 return status; 1693 } 1694 return ret; 1695 } 1696 1697 /* 1698 * flush the inode to disk. 1699 */ 1700 int nfs_wb_all(struct inode *inode) 1701 { 1702 struct writeback_control wbc = { 1703 .sync_mode = WB_SYNC_ALL, 1704 .nr_to_write = LONG_MAX, 1705 .range_start = 0, 1706 .range_end = LLONG_MAX, 1707 }; 1708 1709 return sync_inode(inode, &wbc); 1710 } 1711 1712 int nfs_wb_page_cancel(struct inode *inode, struct page *page) 1713 { 1714 struct nfs_page *req; 1715 int ret = 0; 1716 1717 BUG_ON(!PageLocked(page)); 1718 for (;;) { 1719 wait_on_page_writeback(page); 1720 req = nfs_page_find_request(page); 1721 if (req == NULL) 1722 break; 1723 if (nfs_lock_request(req)) { 1724 nfs_clear_request_commit(req); 1725 nfs_inode_remove_request(req); 1726 /* 1727 * In case nfs_inode_remove_request has marked the 1728 * page as being dirty 1729 */ 1730 cancel_dirty_page(page, PAGE_CACHE_SIZE); 1731 nfs_unlock_and_release_request(req); 1732 break; 1733 } 1734 ret = nfs_wait_on_request(req); 1735 nfs_release_request(req); 1736 if (ret < 0) 1737 break; 1738 } 1739 return ret; 1740 } 1741 1742 /* 1743 * Write back all requests on one page - we do this before reading it. 1744 */ 1745 int nfs_wb_page(struct inode *inode, struct page *page) 1746 { 1747 loff_t range_start = page_offset(page); 1748 loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1); 1749 struct writeback_control wbc = { 1750 .sync_mode = WB_SYNC_ALL, 1751 .nr_to_write = 0, 1752 .range_start = range_start, 1753 .range_end = range_end, 1754 }; 1755 int ret; 1756 1757 for (;;) { 1758 wait_on_page_writeback(page); 1759 if (clear_page_dirty_for_io(page)) { 1760 ret = nfs_writepage_locked(page, &wbc); 1761 if (ret < 0) 1762 goto out_error; 1763 continue; 1764 } 1765 if (!PagePrivate(page)) 1766 break; 1767 ret = nfs_commit_inode(inode, FLUSH_SYNC); 1768 if (ret < 0) 1769 goto out_error; 1770 } 1771 return 0; 1772 out_error: 1773 return ret; 1774 } 1775 1776 #ifdef CONFIG_MIGRATION 1777 int nfs_migrate_page(struct address_space *mapping, struct page *newpage, 1778 struct page *page, enum migrate_mode mode) 1779 { 1780 /* 1781 * If PagePrivate is set, then the page is currently associated with 1782 * an in-progress read or write request. Don't try to migrate it. 1783 * 1784 * FIXME: we could do this in principle, but we'll need a way to ensure 1785 * that we can safely release the inode reference while holding 1786 * the page lock. 1787 */ 1788 if (PagePrivate(page)) 1789 return -EBUSY; 1790 1791 nfs_fscache_release_page(page, GFP_KERNEL); 1792 1793 return migrate_page(mapping, newpage, page, mode); 1794 } 1795 #endif 1796 1797 int __init nfs_init_writepagecache(void) 1798 { 1799 nfs_wdata_cachep = kmem_cache_create("nfs_write_data", 1800 sizeof(struct nfs_write_header), 1801 0, SLAB_HWCACHE_ALIGN, 1802 NULL); 1803 if (nfs_wdata_cachep == NULL) 1804 return -ENOMEM; 1805 1806 nfs_wdata_mempool = mempool_create_slab_pool(MIN_POOL_WRITE, 1807 nfs_wdata_cachep); 1808 if (nfs_wdata_mempool == NULL) 1809 return -ENOMEM; 1810 1811 nfs_cdata_cachep = kmem_cache_create("nfs_commit_data", 1812 sizeof(struct nfs_commit_data), 1813 0, SLAB_HWCACHE_ALIGN, 1814 NULL); 1815 if (nfs_cdata_cachep == NULL) 1816 return -ENOMEM; 1817 1818 nfs_commit_mempool = mempool_create_slab_pool(MIN_POOL_COMMIT, 1819 nfs_wdata_cachep); 1820 if (nfs_commit_mempool == NULL) 1821 return -ENOMEM; 1822 1823 /* 1824 * NFS congestion size, scale with available memory. 1825 * 1826 * 64MB: 8192k 1827 * 128MB: 11585k 1828 * 256MB: 16384k 1829 * 512MB: 23170k 1830 * 1GB: 32768k 1831 * 2GB: 46340k 1832 * 4GB: 65536k 1833 * 8GB: 92681k 1834 * 16GB: 131072k 1835 * 1836 * This allows larger machines to have larger/more transfers. 1837 * Limit the default to 256M 1838 */ 1839 nfs_congestion_kb = (16*int_sqrt(totalram_pages)) << (PAGE_SHIFT-10); 1840 if (nfs_congestion_kb > 256*1024) 1841 nfs_congestion_kb = 256*1024; 1842 1843 return 0; 1844 } 1845 1846 void nfs_destroy_writepagecache(void) 1847 { 1848 mempool_destroy(nfs_commit_mempool); 1849 mempool_destroy(nfs_wdata_mempool); 1850 kmem_cache_destroy(nfs_wdata_cachep); 1851 } 1852 1853