page.c (bc030d6cb9532877c1c5a3f5e7123344fa24a285) page.c (622daaff0a8975fb5c5b95f24f3234550ba32e92)
1/*
2 * page.c - buffer/page management specific to NILFS
3 *
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or

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541 spin_unlock_irq(&mapping->tree_lock);
542 return clear_page_dirty_for_io(page);
543 }
544 spin_unlock_irq(&mapping->tree_lock);
545 return 0;
546 }
547 return TestClearPageDirty(page);
548}
1/*
2 * page.c - buffer/page management specific to NILFS
3 *
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or

--- 532 unchanged lines hidden (view full) ---

541 spin_unlock_irq(&mapping->tree_lock);
542 return clear_page_dirty_for_io(page);
543 }
544 spin_unlock_irq(&mapping->tree_lock);
545 return 0;
546 }
547 return TestClearPageDirty(page);
548}
549
550/**
551 * nilfs_find_uncommitted_extent - find extent of uncommitted data
552 * @inode: inode
553 * @start_blk: start block offset (in)
554 * @blkoff: start offset of the found extent (out)
555 *
556 * This function searches an extent of buffers marked "delayed" which
557 * starts from a block offset equal to or larger than @start_blk. If
558 * such an extent was found, this will store the start offset in
559 * @blkoff and return its length in blocks. Otherwise, zero is
560 * returned.
561 */
562unsigned long nilfs_find_uncommitted_extent(struct inode *inode,
563 sector_t start_blk,
564 sector_t *blkoff)
565{
566 unsigned int i;
567 pgoff_t index;
568 unsigned int nblocks_in_page;
569 unsigned long length = 0;
570 sector_t b;
571 struct pagevec pvec;
572 struct page *page;
573
574 if (inode->i_mapping->nrpages == 0)
575 return 0;
576
577 index = start_blk >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
578 nblocks_in_page = 1U << (PAGE_CACHE_SHIFT - inode->i_blkbits);
579
580 pagevec_init(&pvec, 0);
581
582repeat:
583 pvec.nr = find_get_pages_contig(inode->i_mapping, index, PAGEVEC_SIZE,
584 pvec.pages);
585 if (pvec.nr == 0)
586 return length;
587
588 if (length > 0 && pvec.pages[0]->index > index)
589 goto out;
590
591 b = pvec.pages[0]->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
592 i = 0;
593 do {
594 page = pvec.pages[i];
595
596 lock_page(page);
597 if (page_has_buffers(page)) {
598 struct buffer_head *bh, *head;
599
600 bh = head = page_buffers(page);
601 do {
602 if (b < start_blk)
603 continue;
604 if (buffer_delay(bh)) {
605 if (length == 0)
606 *blkoff = b;
607 length++;
608 } else if (length > 0) {
609 goto out_locked;
610 }
611 } while (++b, bh = bh->b_this_page, bh != head);
612 } else {
613 if (length > 0)
614 goto out_locked;
615
616 b += nblocks_in_page;
617 }
618 unlock_page(page);
619
620 } while (++i < pagevec_count(&pvec));
621
622 index = page->index + 1;
623 pagevec_release(&pvec);
624 cond_resched();
625 goto repeat;
626
627out_locked:
628 unlock_page(page);
629out:
630 pagevec_release(&pvec);
631 return length;
632}