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