1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * Copyright (C) International Business Machines Corp., 2000-2005 4 * Portions Copyright (C) Christoph Hellwig, 2001-2002 5 */ 6 7#include <linux/fs.h> 8#include <linux/mm.h> 9#include <linux/module.h> 10#include <linux/bio.h> 11#include <linux/slab.h> 12#include <linux/init.h> 13#include <linux/buffer_head.h> 14#include <linux/mempool.h> 15#include <linux/seq_file.h> 16#include <linux/writeback.h> 17#include "jfs_incore.h" 18#include "jfs_superblock.h" 19#include "jfs_filsys.h" 20#include "jfs_metapage.h" 21#include "jfs_txnmgr.h" 22#include "jfs_debug.h" 23 24#ifdef CONFIG_JFS_STATISTICS 25static struct { 26 uint pagealloc; /* # of page allocations */ 27 uint pagefree; /* # of page frees */ 28 uint lockwait; /* # of sleeping lock_metapage() calls */ 29} mpStat; 30#endif 31 32#define metapage_locked(mp) test_bit(META_locked, &(mp)->flag) 33#define trylock_metapage(mp) test_and_set_bit_lock(META_locked, &(mp)->flag) 34 35static inline void unlock_metapage(struct metapage *mp) 36{ 37 clear_bit_unlock(META_locked, &mp->flag); 38 wake_up(&mp->wait); 39} 40 41static inline void __lock_metapage(struct metapage *mp) 42{ 43 DECLARE_WAITQUEUE(wait, current); 44 INCREMENT(mpStat.lockwait); 45 add_wait_queue_exclusive(&mp->wait, &wait); 46 do { 47 set_current_state(TASK_UNINTERRUPTIBLE); 48 if (metapage_locked(mp)) { 49 unlock_page(mp->page); 50 io_schedule(); 51 lock_page(mp->page); 52 } 53 } while (trylock_metapage(mp)); 54 __set_current_state(TASK_RUNNING); 55 remove_wait_queue(&mp->wait, &wait); 56} 57 58/* 59 * Must have mp->page locked 60 */ 61static inline void lock_metapage(struct metapage *mp) 62{ 63 if (trylock_metapage(mp)) 64 __lock_metapage(mp); 65} 66 67#define METAPOOL_MIN_PAGES 32 68static struct kmem_cache *metapage_cache; 69static mempool_t *metapage_mempool; 70 71#define MPS_PER_PAGE (PAGE_SIZE >> L2PSIZE) 72 73#if MPS_PER_PAGE > 1 74 75struct meta_anchor { 76 int mp_count; 77 atomic_t io_count; 78 struct metapage *mp[MPS_PER_PAGE]; 79}; 80#define mp_anchor(page) ((struct meta_anchor *)page_private(page)) 81 82static inline struct metapage *page_to_mp(struct page *page, int offset) 83{ 84 if (!PagePrivate(page)) 85 return NULL; 86 return mp_anchor(page)->mp[offset >> L2PSIZE]; 87} 88 89static inline int insert_metapage(struct page *page, struct metapage *mp) 90{ 91 struct meta_anchor *a; 92 int index; 93 int l2mp_blocks; /* log2 blocks per metapage */ 94 95 if (PagePrivate(page)) 96 a = mp_anchor(page); 97 else { 98 a = kzalloc(sizeof(struct meta_anchor), GFP_NOFS); 99 if (!a) 100 return -ENOMEM; 101 set_page_private(page, (unsigned long)a); 102 SetPagePrivate(page); 103 kmap(page); 104 } 105 106 if (mp) { 107 l2mp_blocks = L2PSIZE - page->mapping->host->i_blkbits; 108 index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1); 109 a->mp_count++; 110 a->mp[index] = mp; 111 } 112 113 return 0; 114} 115 116static inline void remove_metapage(struct page *page, struct metapage *mp) 117{ 118 struct meta_anchor *a = mp_anchor(page); 119 int l2mp_blocks = L2PSIZE - page->mapping->host->i_blkbits; 120 int index; 121 122 index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1); 123 124 BUG_ON(a->mp[index] != mp); 125 126 a->mp[index] = NULL; 127 if (--a->mp_count == 0) { 128 kfree(a); 129 set_page_private(page, 0); 130 ClearPagePrivate(page); 131 kunmap(page); 132 } 133} 134 135static inline void inc_io(struct page *page) 136{ 137 atomic_inc(&mp_anchor(page)->io_count); 138} 139 140static inline void dec_io(struct page *page, void (*handler) (struct page *)) 141{ 142 if (atomic_dec_and_test(&mp_anchor(page)->io_count)) 143 handler(page); 144} 145 146#else 147static inline struct metapage *page_to_mp(struct page *page, int offset) 148{ 149 return PagePrivate(page) ? (struct metapage *)page_private(page) : NULL; 150} 151 152static inline int insert_metapage(struct page *page, struct metapage *mp) 153{ 154 if (mp) { 155 set_page_private(page, (unsigned long)mp); 156 SetPagePrivate(page); 157 kmap(page); 158 } 159 return 0; 160} 161 162static inline void remove_metapage(struct page *page, struct metapage *mp) 163{ 164 set_page_private(page, 0); 165 ClearPagePrivate(page); 166 kunmap(page); 167} 168 169#define inc_io(page) do {} while(0) 170#define dec_io(page, handler) handler(page) 171 172#endif 173 174static inline struct metapage *alloc_metapage(gfp_t gfp_mask) 175{ 176 struct metapage *mp = mempool_alloc(metapage_mempool, gfp_mask); 177 178 if (mp) { 179 mp->lid = 0; 180 mp->lsn = 0; 181 mp->data = NULL; 182 mp->clsn = 0; 183 mp->log = NULL; 184 init_waitqueue_head(&mp->wait); 185 } 186 return mp; 187} 188 189static inline void free_metapage(struct metapage *mp) 190{ 191 mempool_free(mp, metapage_mempool); 192} 193 194int __init metapage_init(void) 195{ 196 /* 197 * Allocate the metapage structures 198 */ 199 metapage_cache = kmem_cache_create("jfs_mp", sizeof(struct metapage), 200 0, 0, NULL); 201 if (metapage_cache == NULL) 202 return -ENOMEM; 203 204 metapage_mempool = mempool_create_slab_pool(METAPOOL_MIN_PAGES, 205 metapage_cache); 206 207 if (metapage_mempool == NULL) { 208 kmem_cache_destroy(metapage_cache); 209 return -ENOMEM; 210 } 211 212 return 0; 213} 214 215void metapage_exit(void) 216{ 217 mempool_destroy(metapage_mempool); 218 kmem_cache_destroy(metapage_cache); 219} 220 221static inline void drop_metapage(struct page *page, struct metapage *mp) 222{ 223 if (mp->count || mp->nohomeok || test_bit(META_dirty, &mp->flag) || 224 test_bit(META_io, &mp->flag)) 225 return; 226 remove_metapage(page, mp); 227 INCREMENT(mpStat.pagefree); 228 free_metapage(mp); 229} 230 231/* 232 * Metapage address space operations 233 */ 234 235static sector_t metapage_get_blocks(struct inode *inode, sector_t lblock, 236 int *len) 237{ 238 int rc = 0; 239 int xflag; 240 s64 xaddr; 241 sector_t file_blocks = (inode->i_size + inode->i_sb->s_blocksize - 1) >> 242 inode->i_blkbits; 243 244 if (lblock >= file_blocks) 245 return 0; 246 if (lblock + *len > file_blocks) 247 *len = file_blocks - lblock; 248 249 if (inode->i_ino) { 250 rc = xtLookup(inode, (s64)lblock, *len, &xflag, &xaddr, len, 0); 251 if ((rc == 0) && *len) 252 lblock = (sector_t)xaddr; 253 else 254 lblock = 0; 255 } /* else no mapping */ 256 257 return lblock; 258} 259 260static void last_read_complete(struct page *page) 261{ 262 if (!PageError(page)) 263 SetPageUptodate(page); 264 unlock_page(page); 265} 266 267static void metapage_read_end_io(struct bio *bio) 268{ 269 struct page *page = bio->bi_private; 270 271 if (bio->bi_status) { 272 printk(KERN_ERR "metapage_read_end_io: I/O error\n"); 273 SetPageError(page); 274 } 275 276 dec_io(page, last_read_complete); 277 bio_put(bio); 278} 279 280static void remove_from_logsync(struct metapage *mp) 281{ 282 struct jfs_log *log = mp->log; 283 unsigned long flags; 284/* 285 * This can race. Recheck that log hasn't been set to null, and after 286 * acquiring logsync lock, recheck lsn 287 */ 288 if (!log) 289 return; 290 291 LOGSYNC_LOCK(log, flags); 292 if (mp->lsn) { 293 mp->log = NULL; 294 mp->lsn = 0; 295 mp->clsn = 0; 296 log->count--; 297 list_del(&mp->synclist); 298 } 299 LOGSYNC_UNLOCK(log, flags); 300} 301 302static void last_write_complete(struct page *page) 303{ 304 struct metapage *mp; 305 unsigned int offset; 306 307 for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) { 308 mp = page_to_mp(page, offset); 309 if (mp && test_bit(META_io, &mp->flag)) { 310 if (mp->lsn) 311 remove_from_logsync(mp); 312 clear_bit(META_io, &mp->flag); 313 } 314 /* 315 * I'd like to call drop_metapage here, but I don't think it's 316 * safe unless I have the page locked 317 */ 318 } 319 end_page_writeback(page); 320} 321 322static void metapage_write_end_io(struct bio *bio) 323{ 324 struct page *page = bio->bi_private; 325 326 BUG_ON(!PagePrivate(page)); 327 328 if (bio->bi_status) { 329 printk(KERN_ERR "metapage_write_end_io: I/O error\n"); 330 SetPageError(page); 331 } 332 dec_io(page, last_write_complete); 333 bio_put(bio); 334} 335 336static int metapage_writepage(struct page *page, struct writeback_control *wbc) 337{ 338 struct bio *bio = NULL; 339 int block_offset; /* block offset of mp within page */ 340 struct inode *inode = page->mapping->host; 341 int blocks_per_mp = JFS_SBI(inode->i_sb)->nbperpage; 342 int len; 343 int xlen; 344 struct metapage *mp; 345 int redirty = 0; 346 sector_t lblock; 347 int nr_underway = 0; 348 sector_t pblock; 349 sector_t next_block = 0; 350 sector_t page_start; 351 unsigned long bio_bytes = 0; 352 unsigned long bio_offset = 0; 353 int offset; 354 int bad_blocks = 0; 355 356 page_start = (sector_t)page->index << 357 (PAGE_SHIFT - inode->i_blkbits); 358 BUG_ON(!PageLocked(page)); 359 BUG_ON(PageWriteback(page)); 360 set_page_writeback(page); 361 362 for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) { 363 mp = page_to_mp(page, offset); 364 365 if (!mp || !test_bit(META_dirty, &mp->flag)) 366 continue; 367 368 if (mp->nohomeok && !test_bit(META_forcewrite, &mp->flag)) { 369 redirty = 1; 370 /* 371 * Make sure this page isn't blocked indefinitely. 372 * If the journal isn't undergoing I/O, push it 373 */ 374 if (mp->log && !(mp->log->cflag & logGC_PAGEOUT)) 375 jfs_flush_journal(mp->log, 0); 376 continue; 377 } 378 379 clear_bit(META_dirty, &mp->flag); 380 set_bit(META_io, &mp->flag); 381 block_offset = offset >> inode->i_blkbits; 382 lblock = page_start + block_offset; 383 if (bio) { 384 if (xlen && lblock == next_block) { 385 /* Contiguous, in memory & on disk */ 386 len = min(xlen, blocks_per_mp); 387 xlen -= len; 388 bio_bytes += len << inode->i_blkbits; 389 continue; 390 } 391 /* Not contiguous */ 392 if (bio_add_page(bio, page, bio_bytes, bio_offset) < 393 bio_bytes) 394 goto add_failed; 395 /* 396 * Increment counter before submitting i/o to keep 397 * count from hitting zero before we're through 398 */ 399 inc_io(page); 400 if (!bio->bi_iter.bi_size) 401 goto dump_bio; 402 submit_bio(bio); 403 nr_underway++; 404 bio = NULL; 405 } else 406 inc_io(page); 407 xlen = (PAGE_SIZE - offset) >> inode->i_blkbits; 408 pblock = metapage_get_blocks(inode, lblock, &xlen); 409 if (!pblock) { 410 printk(KERN_ERR "JFS: metapage_get_blocks failed\n"); 411 /* 412 * We already called inc_io(), but can't cancel it 413 * with dec_io() until we're done with the page 414 */ 415 bad_blocks++; 416 continue; 417 } 418 len = min(xlen, (int)JFS_SBI(inode->i_sb)->nbperpage); 419 420 bio = bio_alloc(inode->i_sb->s_bdev, 1, REQ_OP_WRITE, GFP_NOFS); 421 bio->bi_iter.bi_sector = pblock << (inode->i_blkbits - 9); 422 bio->bi_end_io = metapage_write_end_io; 423 bio->bi_private = page; 424 425 /* Don't call bio_add_page yet, we may add to this vec */ 426 bio_offset = offset; 427 bio_bytes = len << inode->i_blkbits; 428 429 xlen -= len; 430 next_block = lblock + len; 431 } 432 if (bio) { 433 if (bio_add_page(bio, page, bio_bytes, bio_offset) < bio_bytes) 434 goto add_failed; 435 if (!bio->bi_iter.bi_size) 436 goto dump_bio; 437 438 submit_bio(bio); 439 nr_underway++; 440 } 441 if (redirty) 442 redirty_page_for_writepage(wbc, page); 443 444 unlock_page(page); 445 446 if (bad_blocks) 447 goto err_out; 448 449 if (nr_underway == 0) 450 end_page_writeback(page); 451 452 return 0; 453add_failed: 454 /* We should never reach here, since we're only adding one vec */ 455 printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n"); 456 goto skip; 457dump_bio: 458 print_hex_dump(KERN_ERR, "JFS: dump of bio: ", DUMP_PREFIX_ADDRESS, 16, 459 4, bio, sizeof(*bio), 0); 460skip: 461 bio_put(bio); 462 unlock_page(page); 463 dec_io(page, last_write_complete); 464err_out: 465 while (bad_blocks--) 466 dec_io(page, last_write_complete); 467 return -EIO; 468} 469 470static int metapage_read_folio(struct file *fp, struct folio *folio) 471{ 472 struct page *page = &folio->page; 473 struct inode *inode = page->mapping->host; 474 struct bio *bio = NULL; 475 int block_offset; 476 int blocks_per_page = i_blocks_per_page(inode, page); 477 sector_t page_start; /* address of page in fs blocks */ 478 sector_t pblock; 479 int xlen; 480 unsigned int len; 481 int offset; 482 483 BUG_ON(!PageLocked(page)); 484 page_start = (sector_t)page->index << 485 (PAGE_SHIFT - inode->i_blkbits); 486 487 block_offset = 0; 488 while (block_offset < blocks_per_page) { 489 xlen = blocks_per_page - block_offset; 490 pblock = metapage_get_blocks(inode, page_start + block_offset, 491 &xlen); 492 if (pblock) { 493 if (!PagePrivate(page)) 494 insert_metapage(page, NULL); 495 inc_io(page); 496 if (bio) 497 submit_bio(bio); 498 499 bio = bio_alloc(inode->i_sb->s_bdev, 1, REQ_OP_READ, 500 GFP_NOFS); 501 bio->bi_iter.bi_sector = 502 pblock << (inode->i_blkbits - 9); 503 bio->bi_end_io = metapage_read_end_io; 504 bio->bi_private = page; 505 len = xlen << inode->i_blkbits; 506 offset = block_offset << inode->i_blkbits; 507 if (bio_add_page(bio, page, len, offset) < len) 508 goto add_failed; 509 block_offset += xlen; 510 } else 511 block_offset++; 512 } 513 if (bio) 514 submit_bio(bio); 515 else 516 unlock_page(page); 517 518 return 0; 519 520add_failed: 521 printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n"); 522 bio_put(bio); 523 dec_io(page, last_read_complete); 524 return -EIO; 525} 526 527static bool metapage_release_folio(struct folio *folio, gfp_t gfp_mask) 528{ 529 struct metapage *mp; 530 bool ret = true; 531 int offset; 532 533 for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) { 534 mp = page_to_mp(&folio->page, offset); 535 536 if (!mp) 537 continue; 538 539 jfs_info("metapage_release_folio: mp = 0x%p", mp); 540 if (mp->count || mp->nohomeok || 541 test_bit(META_dirty, &mp->flag)) { 542 jfs_info("count = %ld, nohomeok = %d", mp->count, 543 mp->nohomeok); 544 ret = false; 545 continue; 546 } 547 if (mp->lsn) 548 remove_from_logsync(mp); 549 remove_metapage(&folio->page, mp); 550 INCREMENT(mpStat.pagefree); 551 free_metapage(mp); 552 } 553 return ret; 554} 555 556static void metapage_invalidate_folio(struct folio *folio, size_t offset, 557 size_t length) 558{ 559 BUG_ON(offset || length < folio_size(folio)); 560 561 BUG_ON(folio_test_writeback(folio)); 562 563 metapage_release_folio(folio, 0); 564} 565 566const struct address_space_operations jfs_metapage_aops = { 567 .read_folio = metapage_read_folio, 568 .writepage = metapage_writepage, 569 .release_folio = metapage_release_folio, 570 .invalidate_folio = metapage_invalidate_folio, 571 .dirty_folio = filemap_dirty_folio, 572}; 573 574struct metapage *__get_metapage(struct inode *inode, unsigned long lblock, 575 unsigned int size, int absolute, 576 unsigned long new) 577{ 578 int l2BlocksPerPage; 579 int l2bsize; 580 struct address_space *mapping; 581 struct metapage *mp = NULL; 582 struct page *page; 583 unsigned long page_index; 584 unsigned long page_offset; 585 586 jfs_info("__get_metapage: ino = %ld, lblock = 0x%lx, abs=%d", 587 inode->i_ino, lblock, absolute); 588 589 l2bsize = inode->i_blkbits; 590 l2BlocksPerPage = PAGE_SHIFT - l2bsize; 591 page_index = lblock >> l2BlocksPerPage; 592 page_offset = (lblock - (page_index << l2BlocksPerPage)) << l2bsize; 593 if ((page_offset + size) > PAGE_SIZE) { 594 jfs_err("MetaData crosses page boundary!!"); 595 jfs_err("lblock = %lx, size = %d", lblock, size); 596 dump_stack(); 597 return NULL; 598 } 599 if (absolute) 600 mapping = JFS_SBI(inode->i_sb)->direct_inode->i_mapping; 601 else { 602 /* 603 * If an nfs client tries to read an inode that is larger 604 * than any existing inodes, we may try to read past the 605 * end of the inode map 606 */ 607 if ((lblock << inode->i_blkbits) >= inode->i_size) 608 return NULL; 609 mapping = inode->i_mapping; 610 } 611 612 if (new && (PSIZE == PAGE_SIZE)) { 613 page = grab_cache_page(mapping, page_index); 614 if (!page) { 615 jfs_err("grab_cache_page failed!"); 616 return NULL; 617 } 618 SetPageUptodate(page); 619 } else { 620 page = read_mapping_page(mapping, page_index, NULL); 621 if (IS_ERR(page)) { 622 jfs_err("read_mapping_page failed!"); 623 return NULL; 624 } 625 lock_page(page); 626 } 627 628 mp = page_to_mp(page, page_offset); 629 if (mp) { 630 if (mp->logical_size != size) { 631 jfs_error(inode->i_sb, 632 "get_mp->logical_size != size\n"); 633 jfs_err("logical_size = %d, size = %d", 634 mp->logical_size, size); 635 dump_stack(); 636 goto unlock; 637 } 638 mp->count++; 639 lock_metapage(mp); 640 if (test_bit(META_discard, &mp->flag)) { 641 if (!new) { 642 jfs_error(inode->i_sb, 643 "using a discarded metapage\n"); 644 discard_metapage(mp); 645 goto unlock; 646 } 647 clear_bit(META_discard, &mp->flag); 648 } 649 } else { 650 INCREMENT(mpStat.pagealloc); 651 mp = alloc_metapage(GFP_NOFS); 652 if (!mp) 653 goto unlock; 654 mp->page = page; 655 mp->sb = inode->i_sb; 656 mp->flag = 0; 657 mp->xflag = COMMIT_PAGE; 658 mp->count = 1; 659 mp->nohomeok = 0; 660 mp->logical_size = size; 661 mp->data = page_address(page) + page_offset; 662 mp->index = lblock; 663 if (unlikely(insert_metapage(page, mp))) { 664 free_metapage(mp); 665 goto unlock; 666 } 667 lock_metapage(mp); 668 } 669 670 if (new) { 671 jfs_info("zeroing mp = 0x%p", mp); 672 memset(mp->data, 0, PSIZE); 673 } 674 675 unlock_page(page); 676 jfs_info("__get_metapage: returning = 0x%p data = 0x%p", mp, mp->data); 677 return mp; 678 679unlock: 680 unlock_page(page); 681 return NULL; 682} 683 684void grab_metapage(struct metapage * mp) 685{ 686 jfs_info("grab_metapage: mp = 0x%p", mp); 687 get_page(mp->page); 688 lock_page(mp->page); 689 mp->count++; 690 lock_metapage(mp); 691 unlock_page(mp->page); 692} 693 694static int metapage_write_one(struct page *page) 695{ 696 struct folio *folio = page_folio(page); 697 struct address_space *mapping = folio->mapping; 698 struct writeback_control wbc = { 699 .sync_mode = WB_SYNC_ALL, 700 .nr_to_write = folio_nr_pages(folio), 701 }; 702 int ret = 0; 703 704 BUG_ON(!folio_test_locked(folio)); 705 706 folio_wait_writeback(folio); 707 708 if (folio_clear_dirty_for_io(folio)) { 709 folio_get(folio); 710 ret = metapage_writepage(page, &wbc); 711 if (ret == 0) 712 folio_wait_writeback(folio); 713 folio_put(folio); 714 } else { 715 folio_unlock(folio); 716 } 717 718 if (!ret) 719 ret = filemap_check_errors(mapping); 720 return ret; 721} 722 723void force_metapage(struct metapage *mp) 724{ 725 struct page *page = mp->page; 726 jfs_info("force_metapage: mp = 0x%p", mp); 727 set_bit(META_forcewrite, &mp->flag); 728 clear_bit(META_sync, &mp->flag); 729 get_page(page); 730 lock_page(page); 731 set_page_dirty(page); 732 if (metapage_write_one(page)) 733 jfs_error(mp->sb, "metapage_write_one() failed\n"); 734 clear_bit(META_forcewrite, &mp->flag); 735 put_page(page); 736} 737 738void hold_metapage(struct metapage *mp) 739{ 740 lock_page(mp->page); 741} 742 743void put_metapage(struct metapage *mp) 744{ 745 if (mp->count || mp->nohomeok) { 746 /* Someone else will release this */ 747 unlock_page(mp->page); 748 return; 749 } 750 get_page(mp->page); 751 mp->count++; 752 lock_metapage(mp); 753 unlock_page(mp->page); 754 release_metapage(mp); 755} 756 757void release_metapage(struct metapage * mp) 758{ 759 struct page *page = mp->page; 760 jfs_info("release_metapage: mp = 0x%p, flag = 0x%lx", mp, mp->flag); 761 762 BUG_ON(!page); 763 764 lock_page(page); 765 unlock_metapage(mp); 766 767 assert(mp->count); 768 if (--mp->count || mp->nohomeok) { 769 unlock_page(page); 770 put_page(page); 771 return; 772 } 773 774 if (test_bit(META_dirty, &mp->flag)) { 775 set_page_dirty(page); 776 if (test_bit(META_sync, &mp->flag)) { 777 clear_bit(META_sync, &mp->flag); 778 if (metapage_write_one(page)) 779 jfs_error(mp->sb, "metapage_write_one() failed\n"); 780 lock_page(page); 781 } 782 } else if (mp->lsn) /* discard_metapage doesn't remove it */ 783 remove_from_logsync(mp); 784 785 /* Try to keep metapages from using up too much memory */ 786 drop_metapage(page, mp); 787 788 unlock_page(page); 789 put_page(page); 790} 791 792void __invalidate_metapages(struct inode *ip, s64 addr, int len) 793{ 794 sector_t lblock; 795 int l2BlocksPerPage = PAGE_SHIFT - ip->i_blkbits; 796 int BlocksPerPage = 1 << l2BlocksPerPage; 797 /* All callers are interested in block device's mapping */ 798 struct address_space *mapping = 799 JFS_SBI(ip->i_sb)->direct_inode->i_mapping; 800 struct metapage *mp; 801 struct page *page; 802 unsigned int offset; 803 804 /* 805 * Mark metapages to discard. They will eventually be 806 * released, but should not be written. 807 */ 808 for (lblock = addr & ~(BlocksPerPage - 1); lblock < addr + len; 809 lblock += BlocksPerPage) { 810 page = find_lock_page(mapping, lblock >> l2BlocksPerPage); 811 if (!page) 812 continue; 813 for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) { 814 mp = page_to_mp(page, offset); 815 if (!mp) 816 continue; 817 if (mp->index < addr) 818 continue; 819 if (mp->index >= addr + len) 820 break; 821 822 clear_bit(META_dirty, &mp->flag); 823 set_bit(META_discard, &mp->flag); 824 if (mp->lsn) 825 remove_from_logsync(mp); 826 } 827 unlock_page(page); 828 put_page(page); 829 } 830} 831 832#ifdef CONFIG_JFS_STATISTICS 833int jfs_mpstat_proc_show(struct seq_file *m, void *v) 834{ 835 seq_printf(m, 836 "JFS Metapage statistics\n" 837 "=======================\n" 838 "page allocations = %d\n" 839 "page frees = %d\n" 840 "lock waits = %d\n", 841 mpStat.pagealloc, 842 mpStat.pagefree, 843 mpStat.lockwait); 844 return 0; 845} 846#endif 847