1 /* 2 * Copyright (C) International Business Machines Corp., 2000-2005 3 * Portions Copyright (C) Christoph Hellwig, 2001-2002 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation; either version 2 of the License, or 8 * (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See 13 * the GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18 */ 19 20 #include <linux/fs.h> 21 #include <linux/mm.h> 22 #include <linux/module.h> 23 #include <linux/bio.h> 24 #include <linux/slab.h> 25 #include <linux/init.h> 26 #include <linux/buffer_head.h> 27 #include <linux/mempool.h> 28 #include <linux/seq_file.h> 29 #include "jfs_incore.h" 30 #include "jfs_superblock.h" 31 #include "jfs_filsys.h" 32 #include "jfs_metapage.h" 33 #include "jfs_txnmgr.h" 34 #include "jfs_debug.h" 35 36 #ifdef CONFIG_JFS_STATISTICS 37 static struct { 38 uint pagealloc; /* # of page allocations */ 39 uint pagefree; /* # of page frees */ 40 uint lockwait; /* # of sleeping lock_metapage() calls */ 41 } mpStat; 42 #endif 43 44 #define metapage_locked(mp) test_bit(META_locked, &(mp)->flag) 45 #define trylock_metapage(mp) test_and_set_bit_lock(META_locked, &(mp)->flag) 46 47 static inline void unlock_metapage(struct metapage *mp) 48 { 49 clear_bit_unlock(META_locked, &mp->flag); 50 wake_up(&mp->wait); 51 } 52 53 static inline void __lock_metapage(struct metapage *mp) 54 { 55 DECLARE_WAITQUEUE(wait, current); 56 INCREMENT(mpStat.lockwait); 57 add_wait_queue_exclusive(&mp->wait, &wait); 58 do { 59 set_current_state(TASK_UNINTERRUPTIBLE); 60 if (metapage_locked(mp)) { 61 unlock_page(mp->page); 62 io_schedule(); 63 lock_page(mp->page); 64 } 65 } while (trylock_metapage(mp)); 66 __set_current_state(TASK_RUNNING); 67 remove_wait_queue(&mp->wait, &wait); 68 } 69 70 /* 71 * Must have mp->page locked 72 */ 73 static inline void lock_metapage(struct metapage *mp) 74 { 75 if (trylock_metapage(mp)) 76 __lock_metapage(mp); 77 } 78 79 #define METAPOOL_MIN_PAGES 32 80 static struct kmem_cache *metapage_cache; 81 static mempool_t *metapage_mempool; 82 83 #define MPS_PER_PAGE (PAGE_SIZE >> L2PSIZE) 84 85 #if MPS_PER_PAGE > 1 86 87 struct meta_anchor { 88 int mp_count; 89 atomic_t io_count; 90 struct metapage *mp[MPS_PER_PAGE]; 91 }; 92 #define mp_anchor(page) ((struct meta_anchor *)page_private(page)) 93 94 static inline struct metapage *page_to_mp(struct page *page, int offset) 95 { 96 if (!PagePrivate(page)) 97 return NULL; 98 return mp_anchor(page)->mp[offset >> L2PSIZE]; 99 } 100 101 static inline int insert_metapage(struct page *page, struct metapage *mp) 102 { 103 struct meta_anchor *a; 104 int index; 105 int l2mp_blocks; /* log2 blocks per metapage */ 106 107 if (PagePrivate(page)) 108 a = mp_anchor(page); 109 else { 110 a = kzalloc(sizeof(struct meta_anchor), GFP_NOFS); 111 if (!a) 112 return -ENOMEM; 113 set_page_private(page, (unsigned long)a); 114 SetPagePrivate(page); 115 kmap(page); 116 } 117 118 if (mp) { 119 l2mp_blocks = L2PSIZE - page->mapping->host->i_blkbits; 120 index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1); 121 a->mp_count++; 122 a->mp[index] = mp; 123 } 124 125 return 0; 126 } 127 128 static inline void remove_metapage(struct page *page, struct metapage *mp) 129 { 130 struct meta_anchor *a = mp_anchor(page); 131 int l2mp_blocks = L2PSIZE - page->mapping->host->i_blkbits; 132 int index; 133 134 index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1); 135 136 BUG_ON(a->mp[index] != mp); 137 138 a->mp[index] = NULL; 139 if (--a->mp_count == 0) { 140 kfree(a); 141 set_page_private(page, 0); 142 ClearPagePrivate(page); 143 kunmap(page); 144 } 145 } 146 147 static inline void inc_io(struct page *page) 148 { 149 atomic_inc(&mp_anchor(page)->io_count); 150 } 151 152 static inline void dec_io(struct page *page, void (*handler) (struct page *)) 153 { 154 if (atomic_dec_and_test(&mp_anchor(page)->io_count)) 155 handler(page); 156 } 157 158 #else 159 static inline struct metapage *page_to_mp(struct page *page, int offset) 160 { 161 return PagePrivate(page) ? (struct metapage *)page_private(page) : NULL; 162 } 163 164 static inline int insert_metapage(struct page *page, struct metapage *mp) 165 { 166 if (mp) { 167 set_page_private(page, (unsigned long)mp); 168 SetPagePrivate(page); 169 kmap(page); 170 } 171 return 0; 172 } 173 174 static inline void remove_metapage(struct page *page, struct metapage *mp) 175 { 176 set_page_private(page, 0); 177 ClearPagePrivate(page); 178 kunmap(page); 179 } 180 181 #define inc_io(page) do {} while(0) 182 #define dec_io(page, handler) handler(page) 183 184 #endif 185 186 static inline struct metapage *alloc_metapage(gfp_t gfp_mask) 187 { 188 struct metapage *mp = mempool_alloc(metapage_mempool, gfp_mask); 189 190 if (mp) { 191 mp->lid = 0; 192 mp->lsn = 0; 193 mp->data = NULL; 194 mp->clsn = 0; 195 mp->log = NULL; 196 init_waitqueue_head(&mp->wait); 197 } 198 return mp; 199 } 200 201 static inline void free_metapage(struct metapage *mp) 202 { 203 mempool_free(mp, metapage_mempool); 204 } 205 206 int __init metapage_init(void) 207 { 208 /* 209 * Allocate the metapage structures 210 */ 211 metapage_cache = kmem_cache_create("jfs_mp", sizeof(struct metapage), 212 0, 0, NULL); 213 if (metapage_cache == NULL) 214 return -ENOMEM; 215 216 metapage_mempool = mempool_create_slab_pool(METAPOOL_MIN_PAGES, 217 metapage_cache); 218 219 if (metapage_mempool == NULL) { 220 kmem_cache_destroy(metapage_cache); 221 return -ENOMEM; 222 } 223 224 return 0; 225 } 226 227 void metapage_exit(void) 228 { 229 mempool_destroy(metapage_mempool); 230 kmem_cache_destroy(metapage_cache); 231 } 232 233 static inline void drop_metapage(struct page *page, struct metapage *mp) 234 { 235 if (mp->count || mp->nohomeok || test_bit(META_dirty, &mp->flag) || 236 test_bit(META_io, &mp->flag)) 237 return; 238 remove_metapage(page, mp); 239 INCREMENT(mpStat.pagefree); 240 free_metapage(mp); 241 } 242 243 /* 244 * Metapage address space operations 245 */ 246 247 static sector_t metapage_get_blocks(struct inode *inode, sector_t lblock, 248 int *len) 249 { 250 int rc = 0; 251 int xflag; 252 s64 xaddr; 253 sector_t file_blocks = (inode->i_size + inode->i_sb->s_blocksize - 1) >> 254 inode->i_blkbits; 255 256 if (lblock >= file_blocks) 257 return 0; 258 if (lblock + *len > file_blocks) 259 *len = file_blocks - lblock; 260 261 if (inode->i_ino) { 262 rc = xtLookup(inode, (s64)lblock, *len, &xflag, &xaddr, len, 0); 263 if ((rc == 0) && *len) 264 lblock = (sector_t)xaddr; 265 else 266 lblock = 0; 267 } /* else no mapping */ 268 269 return lblock; 270 } 271 272 static void last_read_complete(struct page *page) 273 { 274 if (!PageError(page)) 275 SetPageUptodate(page); 276 unlock_page(page); 277 } 278 279 static void metapage_read_end_io(struct bio *bio) 280 { 281 struct page *page = bio->bi_private; 282 283 if (bio->bi_status) { 284 printk(KERN_ERR "metapage_read_end_io: I/O error\n"); 285 SetPageError(page); 286 } 287 288 dec_io(page, last_read_complete); 289 bio_put(bio); 290 } 291 292 static void remove_from_logsync(struct metapage *mp) 293 { 294 struct jfs_log *log = mp->log; 295 unsigned long flags; 296 /* 297 * This can race. Recheck that log hasn't been set to null, and after 298 * acquiring logsync lock, recheck lsn 299 */ 300 if (!log) 301 return; 302 303 LOGSYNC_LOCK(log, flags); 304 if (mp->lsn) { 305 mp->log = NULL; 306 mp->lsn = 0; 307 mp->clsn = 0; 308 log->count--; 309 list_del(&mp->synclist); 310 } 311 LOGSYNC_UNLOCK(log, flags); 312 } 313 314 static void last_write_complete(struct page *page) 315 { 316 struct metapage *mp; 317 unsigned int offset; 318 319 for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) { 320 mp = page_to_mp(page, offset); 321 if (mp && test_bit(META_io, &mp->flag)) { 322 if (mp->lsn) 323 remove_from_logsync(mp); 324 clear_bit(META_io, &mp->flag); 325 } 326 /* 327 * I'd like to call drop_metapage here, but I don't think it's 328 * safe unless I have the page locked 329 */ 330 } 331 end_page_writeback(page); 332 } 333 334 static void metapage_write_end_io(struct bio *bio) 335 { 336 struct page *page = bio->bi_private; 337 338 BUG_ON(!PagePrivate(page)); 339 340 if (bio->bi_status) { 341 printk(KERN_ERR "metapage_write_end_io: I/O error\n"); 342 SetPageError(page); 343 } 344 dec_io(page, last_write_complete); 345 bio_put(bio); 346 } 347 348 static int metapage_writepage(struct page *page, struct writeback_control *wbc) 349 { 350 struct bio *bio = NULL; 351 int block_offset; /* block offset of mp within page */ 352 struct inode *inode = page->mapping->host; 353 int blocks_per_mp = JFS_SBI(inode->i_sb)->nbperpage; 354 int len; 355 int xlen; 356 struct metapage *mp; 357 int redirty = 0; 358 sector_t lblock; 359 int nr_underway = 0; 360 sector_t pblock; 361 sector_t next_block = 0; 362 sector_t page_start; 363 unsigned long bio_bytes = 0; 364 unsigned long bio_offset = 0; 365 int offset; 366 int bad_blocks = 0; 367 368 page_start = (sector_t)page->index << 369 (PAGE_SHIFT - inode->i_blkbits); 370 BUG_ON(!PageLocked(page)); 371 BUG_ON(PageWriteback(page)); 372 set_page_writeback(page); 373 374 for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) { 375 mp = page_to_mp(page, offset); 376 377 if (!mp || !test_bit(META_dirty, &mp->flag)) 378 continue; 379 380 if (mp->nohomeok && !test_bit(META_forcewrite, &mp->flag)) { 381 redirty = 1; 382 /* 383 * Make sure this page isn't blocked indefinitely. 384 * If the journal isn't undergoing I/O, push it 385 */ 386 if (mp->log && !(mp->log->cflag & logGC_PAGEOUT)) 387 jfs_flush_journal(mp->log, 0); 388 continue; 389 } 390 391 clear_bit(META_dirty, &mp->flag); 392 set_bit(META_io, &mp->flag); 393 block_offset = offset >> inode->i_blkbits; 394 lblock = page_start + block_offset; 395 if (bio) { 396 if (xlen && lblock == next_block) { 397 /* Contiguous, in memory & on disk */ 398 len = min(xlen, blocks_per_mp); 399 xlen -= len; 400 bio_bytes += len << inode->i_blkbits; 401 continue; 402 } 403 /* Not contiguous */ 404 if (bio_add_page(bio, page, bio_bytes, bio_offset) < 405 bio_bytes) 406 goto add_failed; 407 /* 408 * Increment counter before submitting i/o to keep 409 * count from hitting zero before we're through 410 */ 411 inc_io(page); 412 if (!bio->bi_iter.bi_size) 413 goto dump_bio; 414 submit_bio(bio); 415 nr_underway++; 416 bio = NULL; 417 } else 418 inc_io(page); 419 xlen = (PAGE_SIZE - offset) >> inode->i_blkbits; 420 pblock = metapage_get_blocks(inode, lblock, &xlen); 421 if (!pblock) { 422 printk(KERN_ERR "JFS: metapage_get_blocks failed\n"); 423 /* 424 * We already called inc_io(), but can't cancel it 425 * with dec_io() until we're done with the page 426 */ 427 bad_blocks++; 428 continue; 429 } 430 len = min(xlen, (int)JFS_SBI(inode->i_sb)->nbperpage); 431 432 bio = bio_alloc(GFP_NOFS, 1); 433 bio_set_dev(bio, inode->i_sb->s_bdev); 434 bio->bi_iter.bi_sector = pblock << (inode->i_blkbits - 9); 435 bio->bi_end_io = metapage_write_end_io; 436 bio->bi_private = page; 437 bio_set_op_attrs(bio, REQ_OP_WRITE, 0); 438 439 /* Don't call bio_add_page yet, we may add to this vec */ 440 bio_offset = offset; 441 bio_bytes = len << inode->i_blkbits; 442 443 xlen -= len; 444 next_block = lblock + len; 445 } 446 if (bio) { 447 if (bio_add_page(bio, page, bio_bytes, bio_offset) < bio_bytes) 448 goto add_failed; 449 if (!bio->bi_iter.bi_size) 450 goto dump_bio; 451 452 submit_bio(bio); 453 nr_underway++; 454 } 455 if (redirty) 456 redirty_page_for_writepage(wbc, page); 457 458 unlock_page(page); 459 460 if (bad_blocks) 461 goto err_out; 462 463 if (nr_underway == 0) 464 end_page_writeback(page); 465 466 return 0; 467 add_failed: 468 /* We should never reach here, since we're only adding one vec */ 469 printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n"); 470 goto skip; 471 dump_bio: 472 print_hex_dump(KERN_ERR, "JFS: dump of bio: ", DUMP_PREFIX_ADDRESS, 16, 473 4, bio, sizeof(*bio), 0); 474 skip: 475 bio_put(bio); 476 unlock_page(page); 477 dec_io(page, last_write_complete); 478 err_out: 479 while (bad_blocks--) 480 dec_io(page, last_write_complete); 481 return -EIO; 482 } 483 484 static int metapage_readpage(struct file *fp, struct page *page) 485 { 486 struct inode *inode = page->mapping->host; 487 struct bio *bio = NULL; 488 int block_offset; 489 int blocks_per_page = PAGE_SIZE >> inode->i_blkbits; 490 sector_t page_start; /* address of page in fs blocks */ 491 sector_t pblock; 492 int xlen; 493 unsigned int len; 494 int offset; 495 496 BUG_ON(!PageLocked(page)); 497 page_start = (sector_t)page->index << 498 (PAGE_SHIFT - inode->i_blkbits); 499 500 block_offset = 0; 501 while (block_offset < blocks_per_page) { 502 xlen = blocks_per_page - block_offset; 503 pblock = metapage_get_blocks(inode, page_start + block_offset, 504 &xlen); 505 if (pblock) { 506 if (!PagePrivate(page)) 507 insert_metapage(page, NULL); 508 inc_io(page); 509 if (bio) 510 submit_bio(bio); 511 512 bio = bio_alloc(GFP_NOFS, 1); 513 bio_set_dev(bio, inode->i_sb->s_bdev); 514 bio->bi_iter.bi_sector = 515 pblock << (inode->i_blkbits - 9); 516 bio->bi_end_io = metapage_read_end_io; 517 bio->bi_private = page; 518 bio_set_op_attrs(bio, REQ_OP_READ, 0); 519 len = xlen << inode->i_blkbits; 520 offset = block_offset << inode->i_blkbits; 521 if (bio_add_page(bio, page, len, offset) < len) 522 goto add_failed; 523 block_offset += xlen; 524 } else 525 block_offset++; 526 } 527 if (bio) 528 submit_bio(bio); 529 else 530 unlock_page(page); 531 532 return 0; 533 534 add_failed: 535 printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n"); 536 bio_put(bio); 537 dec_io(page, last_read_complete); 538 return -EIO; 539 } 540 541 static int metapage_releasepage(struct page *page, gfp_t gfp_mask) 542 { 543 struct metapage *mp; 544 int ret = 1; 545 int offset; 546 547 for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) { 548 mp = page_to_mp(page, offset); 549 550 if (!mp) 551 continue; 552 553 jfs_info("metapage_releasepage: mp = 0x%p", mp); 554 if (mp->count || mp->nohomeok || 555 test_bit(META_dirty, &mp->flag)) { 556 jfs_info("count = %ld, nohomeok = %d", mp->count, 557 mp->nohomeok); 558 ret = 0; 559 continue; 560 } 561 if (mp->lsn) 562 remove_from_logsync(mp); 563 remove_metapage(page, mp); 564 INCREMENT(mpStat.pagefree); 565 free_metapage(mp); 566 } 567 return ret; 568 } 569 570 static void metapage_invalidatepage(struct page *page, unsigned int offset, 571 unsigned int length) 572 { 573 BUG_ON(offset || length < PAGE_SIZE); 574 575 BUG_ON(PageWriteback(page)); 576 577 metapage_releasepage(page, 0); 578 } 579 580 const struct address_space_operations jfs_metapage_aops = { 581 .readpage = metapage_readpage, 582 .writepage = metapage_writepage, 583 .releasepage = metapage_releasepage, 584 .invalidatepage = metapage_invalidatepage, 585 .set_page_dirty = __set_page_dirty_nobuffers, 586 }; 587 588 struct metapage *__get_metapage(struct inode *inode, unsigned long lblock, 589 unsigned int size, int absolute, 590 unsigned long new) 591 { 592 int l2BlocksPerPage; 593 int l2bsize; 594 struct address_space *mapping; 595 struct metapage *mp = NULL; 596 struct page *page; 597 unsigned long page_index; 598 unsigned long page_offset; 599 600 jfs_info("__get_metapage: ino = %ld, lblock = 0x%lx, abs=%d", 601 inode->i_ino, lblock, absolute); 602 603 l2bsize = inode->i_blkbits; 604 l2BlocksPerPage = PAGE_SHIFT - l2bsize; 605 page_index = lblock >> l2BlocksPerPage; 606 page_offset = (lblock - (page_index << l2BlocksPerPage)) << l2bsize; 607 if ((page_offset + size) > PAGE_SIZE) { 608 jfs_err("MetaData crosses page boundary!!"); 609 jfs_err("lblock = %lx, size = %d", lblock, size); 610 dump_stack(); 611 return NULL; 612 } 613 if (absolute) 614 mapping = JFS_SBI(inode->i_sb)->direct_inode->i_mapping; 615 else { 616 /* 617 * If an nfs client tries to read an inode that is larger 618 * than any existing inodes, we may try to read past the 619 * end of the inode map 620 */ 621 if ((lblock << inode->i_blkbits) >= inode->i_size) 622 return NULL; 623 mapping = inode->i_mapping; 624 } 625 626 if (new && (PSIZE == PAGE_SIZE)) { 627 page = grab_cache_page(mapping, page_index); 628 if (!page) { 629 jfs_err("grab_cache_page failed!"); 630 return NULL; 631 } 632 SetPageUptodate(page); 633 } else { 634 page = read_mapping_page(mapping, page_index, NULL); 635 if (IS_ERR(page) || !PageUptodate(page)) { 636 jfs_err("read_mapping_page failed!"); 637 return NULL; 638 } 639 lock_page(page); 640 } 641 642 mp = page_to_mp(page, page_offset); 643 if (mp) { 644 if (mp->logical_size != size) { 645 jfs_error(inode->i_sb, 646 "get_mp->logical_size != size\n"); 647 jfs_err("logical_size = %d, size = %d", 648 mp->logical_size, size); 649 dump_stack(); 650 goto unlock; 651 } 652 mp->count++; 653 lock_metapage(mp); 654 if (test_bit(META_discard, &mp->flag)) { 655 if (!new) { 656 jfs_error(inode->i_sb, 657 "using a discarded metapage\n"); 658 discard_metapage(mp); 659 goto unlock; 660 } 661 clear_bit(META_discard, &mp->flag); 662 } 663 } else { 664 INCREMENT(mpStat.pagealloc); 665 mp = alloc_metapage(GFP_NOFS); 666 if (!mp) 667 goto unlock; 668 mp->page = page; 669 mp->sb = inode->i_sb; 670 mp->flag = 0; 671 mp->xflag = COMMIT_PAGE; 672 mp->count = 1; 673 mp->nohomeok = 0; 674 mp->logical_size = size; 675 mp->data = page_address(page) + page_offset; 676 mp->index = lblock; 677 if (unlikely(insert_metapage(page, mp))) { 678 free_metapage(mp); 679 goto unlock; 680 } 681 lock_metapage(mp); 682 } 683 684 if (new) { 685 jfs_info("zeroing mp = 0x%p", mp); 686 memset(mp->data, 0, PSIZE); 687 } 688 689 unlock_page(page); 690 jfs_info("__get_metapage: returning = 0x%p data = 0x%p", mp, mp->data); 691 return mp; 692 693 unlock: 694 unlock_page(page); 695 return NULL; 696 } 697 698 void grab_metapage(struct metapage * mp) 699 { 700 jfs_info("grab_metapage: mp = 0x%p", mp); 701 get_page(mp->page); 702 lock_page(mp->page); 703 mp->count++; 704 lock_metapage(mp); 705 unlock_page(mp->page); 706 } 707 708 void force_metapage(struct metapage *mp) 709 { 710 struct page *page = mp->page; 711 jfs_info("force_metapage: mp = 0x%p", mp); 712 set_bit(META_forcewrite, &mp->flag); 713 clear_bit(META_sync, &mp->flag); 714 get_page(page); 715 lock_page(page); 716 set_page_dirty(page); 717 if (write_one_page(page)) 718 jfs_error(mp->sb, "write_one_page() failed\n"); 719 clear_bit(META_forcewrite, &mp->flag); 720 put_page(page); 721 } 722 723 void hold_metapage(struct metapage *mp) 724 { 725 lock_page(mp->page); 726 } 727 728 void put_metapage(struct metapage *mp) 729 { 730 if (mp->count || mp->nohomeok) { 731 /* Someone else will release this */ 732 unlock_page(mp->page); 733 return; 734 } 735 get_page(mp->page); 736 mp->count++; 737 lock_metapage(mp); 738 unlock_page(mp->page); 739 release_metapage(mp); 740 } 741 742 void release_metapage(struct metapage * mp) 743 { 744 struct page *page = mp->page; 745 jfs_info("release_metapage: mp = 0x%p, flag = 0x%lx", mp, mp->flag); 746 747 BUG_ON(!page); 748 749 lock_page(page); 750 unlock_metapage(mp); 751 752 assert(mp->count); 753 if (--mp->count || mp->nohomeok) { 754 unlock_page(page); 755 put_page(page); 756 return; 757 } 758 759 if (test_bit(META_dirty, &mp->flag)) { 760 set_page_dirty(page); 761 if (test_bit(META_sync, &mp->flag)) { 762 clear_bit(META_sync, &mp->flag); 763 if (write_one_page(page)) 764 jfs_error(mp->sb, "write_one_page() failed\n"); 765 lock_page(page); /* write_one_page unlocks the page */ 766 } 767 } else if (mp->lsn) /* discard_metapage doesn't remove it */ 768 remove_from_logsync(mp); 769 770 /* Try to keep metapages from using up too much memory */ 771 drop_metapage(page, mp); 772 773 unlock_page(page); 774 put_page(page); 775 } 776 777 void __invalidate_metapages(struct inode *ip, s64 addr, int len) 778 { 779 sector_t lblock; 780 int l2BlocksPerPage = PAGE_SHIFT - ip->i_blkbits; 781 int BlocksPerPage = 1 << l2BlocksPerPage; 782 /* All callers are interested in block device's mapping */ 783 struct address_space *mapping = 784 JFS_SBI(ip->i_sb)->direct_inode->i_mapping; 785 struct metapage *mp; 786 struct page *page; 787 unsigned int offset; 788 789 /* 790 * Mark metapages to discard. They will eventually be 791 * released, but should not be written. 792 */ 793 for (lblock = addr & ~(BlocksPerPage - 1); lblock < addr + len; 794 lblock += BlocksPerPage) { 795 page = find_lock_page(mapping, lblock >> l2BlocksPerPage); 796 if (!page) 797 continue; 798 for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) { 799 mp = page_to_mp(page, offset); 800 if (!mp) 801 continue; 802 if (mp->index < addr) 803 continue; 804 if (mp->index >= addr + len) 805 break; 806 807 clear_bit(META_dirty, &mp->flag); 808 set_bit(META_discard, &mp->flag); 809 if (mp->lsn) 810 remove_from_logsync(mp); 811 } 812 unlock_page(page); 813 put_page(page); 814 } 815 } 816 817 #ifdef CONFIG_JFS_STATISTICS 818 static int jfs_mpstat_proc_show(struct seq_file *m, void *v) 819 { 820 seq_printf(m, 821 "JFS Metapage statistics\n" 822 "=======================\n" 823 "page allocations = %d\n" 824 "page frees = %d\n" 825 "lock waits = %d\n", 826 mpStat.pagealloc, 827 mpStat.pagefree, 828 mpStat.lockwait); 829 return 0; 830 } 831 832 static int jfs_mpstat_proc_open(struct inode *inode, struct file *file) 833 { 834 return single_open(file, jfs_mpstat_proc_show, NULL); 835 } 836 837 const struct file_operations jfs_mpstat_proc_fops = { 838 .open = jfs_mpstat_proc_open, 839 .read = seq_read, 840 .llseek = seq_lseek, 841 .release = single_release, 842 }; 843 #endif 844