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 25 static 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 35 static inline void unlock_metapage(struct metapage *mp) 36 { 37 clear_bit_unlock(META_locked, &mp->flag); 38 wake_up(&mp->wait); 39 } 40 41 static 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 */ 61 static 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 68 static struct kmem_cache *metapage_cache; 69 static mempool_t *metapage_mempool; 70 71 #define MPS_PER_PAGE (PAGE_SIZE >> L2PSIZE) 72 73 #if MPS_PER_PAGE > 1 74 75 struct 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 82 static 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 89 static 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 } 115 116 static 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 } 134 135 static inline void inc_io(struct page *page) 136 { 137 atomic_inc(&mp_anchor(page)->io_count); 138 } 139 140 static 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 147 static inline struct metapage *page_to_mp(struct page *page, int offset) 148 { 149 return PagePrivate(page) ? (struct metapage *)page_private(page) : NULL; 150 } 151 152 static 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 } 161 162 static 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 173 174 static 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 } 188 189 static inline void free_metapage(struct metapage *mp) 190 { 191 mempool_free(mp, metapage_mempool); 192 } 193 194 int __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 } 214 215 void metapage_exit(void) 216 { 217 mempool_destroy(metapage_mempool); 218 kmem_cache_destroy(metapage_cache); 219 } 220 221 static 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 */ 234 235 static 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 } 259 260 static void last_read_complete(struct page *page) 261 { 262 if (!PageError(page)) 263 SetPageUptodate(page); 264 unlock_page(page); 265 } 266 267 static 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 } 279 280 static 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 } 301 302 static 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 } 321 322 static 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 } 335 336 static 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(GFP_NOFS, 1); 421 bio_set_dev(bio, inode->i_sb->s_bdev); 422 bio->bi_iter.bi_sector = pblock << (inode->i_blkbits - 9); 423 bio->bi_end_io = metapage_write_end_io; 424 bio->bi_private = page; 425 bio_set_op_attrs(bio, REQ_OP_WRITE, 0); 426 427 /* Don't call bio_add_page yet, we may add to this vec */ 428 bio_offset = offset; 429 bio_bytes = len << inode->i_blkbits; 430 431 xlen -= len; 432 next_block = lblock + len; 433 } 434 if (bio) { 435 if (bio_add_page(bio, page, bio_bytes, bio_offset) < bio_bytes) 436 goto add_failed; 437 if (!bio->bi_iter.bi_size) 438 goto dump_bio; 439 440 submit_bio(bio); 441 nr_underway++; 442 } 443 if (redirty) 444 redirty_page_for_writepage(wbc, page); 445 446 unlock_page(page); 447 448 if (bad_blocks) 449 goto err_out; 450 451 if (nr_underway == 0) 452 end_page_writeback(page); 453 454 return 0; 455 add_failed: 456 /* We should never reach here, since we're only adding one vec */ 457 printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n"); 458 goto skip; 459 dump_bio: 460 print_hex_dump(KERN_ERR, "JFS: dump of bio: ", DUMP_PREFIX_ADDRESS, 16, 461 4, bio, sizeof(*bio), 0); 462 skip: 463 bio_put(bio); 464 unlock_page(page); 465 dec_io(page, last_write_complete); 466 err_out: 467 while (bad_blocks--) 468 dec_io(page, last_write_complete); 469 return -EIO; 470 } 471 472 static int metapage_readpage(struct file *fp, struct page *page) 473 { 474 struct inode *inode = page->mapping->host; 475 struct bio *bio = NULL; 476 int block_offset; 477 int blocks_per_page = i_blocks_per_page(inode, page); 478 sector_t page_start; /* address of page in fs blocks */ 479 sector_t pblock; 480 int xlen; 481 unsigned int len; 482 int offset; 483 484 BUG_ON(!PageLocked(page)); 485 page_start = (sector_t)page->index << 486 (PAGE_SHIFT - inode->i_blkbits); 487 488 block_offset = 0; 489 while (block_offset < blocks_per_page) { 490 xlen = blocks_per_page - block_offset; 491 pblock = metapage_get_blocks(inode, page_start + block_offset, 492 &xlen); 493 if (pblock) { 494 if (!PagePrivate(page)) 495 insert_metapage(page, NULL); 496 inc_io(page); 497 if (bio) 498 submit_bio(bio); 499 500 bio = bio_alloc(GFP_NOFS, 1); 501 bio_set_dev(bio, inode->i_sb->s_bdev); 502 bio->bi_iter.bi_sector = 503 pblock << (inode->i_blkbits - 9); 504 bio->bi_end_io = metapage_read_end_io; 505 bio->bi_private = page; 506 bio_set_op_attrs(bio, REQ_OP_READ, 0); 507 len = xlen << inode->i_blkbits; 508 offset = block_offset << inode->i_blkbits; 509 if (bio_add_page(bio, page, len, offset) < len) 510 goto add_failed; 511 block_offset += xlen; 512 } else 513 block_offset++; 514 } 515 if (bio) 516 submit_bio(bio); 517 else 518 unlock_page(page); 519 520 return 0; 521 522 add_failed: 523 printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n"); 524 bio_put(bio); 525 dec_io(page, last_read_complete); 526 return -EIO; 527 } 528 529 static int metapage_releasepage(struct page *page, gfp_t gfp_mask) 530 { 531 struct metapage *mp; 532 int ret = 1; 533 int offset; 534 535 for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) { 536 mp = page_to_mp(page, offset); 537 538 if (!mp) 539 continue; 540 541 jfs_info("metapage_releasepage: mp = 0x%p", mp); 542 if (mp->count || mp->nohomeok || 543 test_bit(META_dirty, &mp->flag)) { 544 jfs_info("count = %ld, nohomeok = %d", mp->count, 545 mp->nohomeok); 546 ret = 0; 547 continue; 548 } 549 if (mp->lsn) 550 remove_from_logsync(mp); 551 remove_metapage(page, mp); 552 INCREMENT(mpStat.pagefree); 553 free_metapage(mp); 554 } 555 return ret; 556 } 557 558 static void metapage_invalidatepage(struct page *page, unsigned int offset, 559 unsigned int length) 560 { 561 BUG_ON(offset || length < PAGE_SIZE); 562 563 BUG_ON(PageWriteback(page)); 564 565 metapage_releasepage(page, 0); 566 } 567 568 const struct address_space_operations jfs_metapage_aops = { 569 .readpage = metapage_readpage, 570 .writepage = metapage_writepage, 571 .releasepage = metapage_releasepage, 572 .invalidatepage = metapage_invalidatepage, 573 .set_page_dirty = __set_page_dirty_nobuffers, 574 }; 575 576 struct metapage *__get_metapage(struct inode *inode, unsigned long lblock, 577 unsigned int size, int absolute, 578 unsigned long new) 579 { 580 int l2BlocksPerPage; 581 int l2bsize; 582 struct address_space *mapping; 583 struct metapage *mp = NULL; 584 struct page *page; 585 unsigned long page_index; 586 unsigned long page_offset; 587 588 jfs_info("__get_metapage: ino = %ld, lblock = 0x%lx, abs=%d", 589 inode->i_ino, lblock, absolute); 590 591 l2bsize = inode->i_blkbits; 592 l2BlocksPerPage = PAGE_SHIFT - l2bsize; 593 page_index = lblock >> l2BlocksPerPage; 594 page_offset = (lblock - (page_index << l2BlocksPerPage)) << l2bsize; 595 if ((page_offset + size) > PAGE_SIZE) { 596 jfs_err("MetaData crosses page boundary!!"); 597 jfs_err("lblock = %lx, size = %d", lblock, size); 598 dump_stack(); 599 return NULL; 600 } 601 if (absolute) 602 mapping = JFS_SBI(inode->i_sb)->direct_inode->i_mapping; 603 else { 604 /* 605 * If an nfs client tries to read an inode that is larger 606 * than any existing inodes, we may try to read past the 607 * end of the inode map 608 */ 609 if ((lblock << inode->i_blkbits) >= inode->i_size) 610 return NULL; 611 mapping = inode->i_mapping; 612 } 613 614 if (new && (PSIZE == PAGE_SIZE)) { 615 page = grab_cache_page(mapping, page_index); 616 if (!page) { 617 jfs_err("grab_cache_page failed!"); 618 return NULL; 619 } 620 SetPageUptodate(page); 621 } else { 622 page = read_mapping_page(mapping, page_index, NULL); 623 if (IS_ERR(page) || !PageUptodate(page)) { 624 jfs_err("read_mapping_page failed!"); 625 return NULL; 626 } 627 lock_page(page); 628 } 629 630 mp = page_to_mp(page, page_offset); 631 if (mp) { 632 if (mp->logical_size != size) { 633 jfs_error(inode->i_sb, 634 "get_mp->logical_size != size\n"); 635 jfs_err("logical_size = %d, size = %d", 636 mp->logical_size, size); 637 dump_stack(); 638 goto unlock; 639 } 640 mp->count++; 641 lock_metapage(mp); 642 if (test_bit(META_discard, &mp->flag)) { 643 if (!new) { 644 jfs_error(inode->i_sb, 645 "using a discarded metapage\n"); 646 discard_metapage(mp); 647 goto unlock; 648 } 649 clear_bit(META_discard, &mp->flag); 650 } 651 } else { 652 INCREMENT(mpStat.pagealloc); 653 mp = alloc_metapage(GFP_NOFS); 654 if (!mp) 655 goto unlock; 656 mp->page = page; 657 mp->sb = inode->i_sb; 658 mp->flag = 0; 659 mp->xflag = COMMIT_PAGE; 660 mp->count = 1; 661 mp->nohomeok = 0; 662 mp->logical_size = size; 663 mp->data = page_address(page) + page_offset; 664 mp->index = lblock; 665 if (unlikely(insert_metapage(page, mp))) { 666 free_metapage(mp); 667 goto unlock; 668 } 669 lock_metapage(mp); 670 } 671 672 if (new) { 673 jfs_info("zeroing mp = 0x%p", mp); 674 memset(mp->data, 0, PSIZE); 675 } 676 677 unlock_page(page); 678 jfs_info("__get_metapage: returning = 0x%p data = 0x%p", mp, mp->data); 679 return mp; 680 681 unlock: 682 unlock_page(page); 683 return NULL; 684 } 685 686 void grab_metapage(struct metapage * mp) 687 { 688 jfs_info("grab_metapage: mp = 0x%p", mp); 689 get_page(mp->page); 690 lock_page(mp->page); 691 mp->count++; 692 lock_metapage(mp); 693 unlock_page(mp->page); 694 } 695 696 void force_metapage(struct metapage *mp) 697 { 698 struct page *page = mp->page; 699 jfs_info("force_metapage: mp = 0x%p", mp); 700 set_bit(META_forcewrite, &mp->flag); 701 clear_bit(META_sync, &mp->flag); 702 get_page(page); 703 lock_page(page); 704 set_page_dirty(page); 705 if (write_one_page(page)) 706 jfs_error(mp->sb, "write_one_page() failed\n"); 707 clear_bit(META_forcewrite, &mp->flag); 708 put_page(page); 709 } 710 711 void hold_metapage(struct metapage *mp) 712 { 713 lock_page(mp->page); 714 } 715 716 void put_metapage(struct metapage *mp) 717 { 718 if (mp->count || mp->nohomeok) { 719 /* Someone else will release this */ 720 unlock_page(mp->page); 721 return; 722 } 723 get_page(mp->page); 724 mp->count++; 725 lock_metapage(mp); 726 unlock_page(mp->page); 727 release_metapage(mp); 728 } 729 730 void release_metapage(struct metapage * mp) 731 { 732 struct page *page = mp->page; 733 jfs_info("release_metapage: mp = 0x%p, flag = 0x%lx", mp, mp->flag); 734 735 BUG_ON(!page); 736 737 lock_page(page); 738 unlock_metapage(mp); 739 740 assert(mp->count); 741 if (--mp->count || mp->nohomeok) { 742 unlock_page(page); 743 put_page(page); 744 return; 745 } 746 747 if (test_bit(META_dirty, &mp->flag)) { 748 set_page_dirty(page); 749 if (test_bit(META_sync, &mp->flag)) { 750 clear_bit(META_sync, &mp->flag); 751 if (write_one_page(page)) 752 jfs_error(mp->sb, "write_one_page() failed\n"); 753 lock_page(page); /* write_one_page unlocks the page */ 754 } 755 } else if (mp->lsn) /* discard_metapage doesn't remove it */ 756 remove_from_logsync(mp); 757 758 /* Try to keep metapages from using up too much memory */ 759 drop_metapage(page, mp); 760 761 unlock_page(page); 762 put_page(page); 763 } 764 765 void __invalidate_metapages(struct inode *ip, s64 addr, int len) 766 { 767 sector_t lblock; 768 int l2BlocksPerPage = PAGE_SHIFT - ip->i_blkbits; 769 int BlocksPerPage = 1 << l2BlocksPerPage; 770 /* All callers are interested in block device's mapping */ 771 struct address_space *mapping = 772 JFS_SBI(ip->i_sb)->direct_inode->i_mapping; 773 struct metapage *mp; 774 struct page *page; 775 unsigned int offset; 776 777 /* 778 * Mark metapages to discard. They will eventually be 779 * released, but should not be written. 780 */ 781 for (lblock = addr & ~(BlocksPerPage - 1); lblock < addr + len; 782 lblock += BlocksPerPage) { 783 page = find_lock_page(mapping, lblock >> l2BlocksPerPage); 784 if (!page) 785 continue; 786 for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) { 787 mp = page_to_mp(page, offset); 788 if (!mp) 789 continue; 790 if (mp->index < addr) 791 continue; 792 if (mp->index >= addr + len) 793 break; 794 795 clear_bit(META_dirty, &mp->flag); 796 set_bit(META_discard, &mp->flag); 797 if (mp->lsn) 798 remove_from_logsync(mp); 799 } 800 unlock_page(page); 801 put_page(page); 802 } 803 } 804 805 #ifdef CONFIG_JFS_STATISTICS 806 int jfs_mpstat_proc_show(struct seq_file *m, void *v) 807 { 808 seq_printf(m, 809 "JFS Metapage statistics\n" 810 "=======================\n" 811 "page allocations = %d\n" 812 "page frees = %d\n" 813 "lock waits = %d\n", 814 mpStat.pagealloc, 815 mpStat.pagefree, 816 mpStat.lockwait); 817 return 0; 818 } 819 #endif 820