aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorChristoph Hellwig <hch@lst.de>2018-06-01 12:05:15 -0400
committerDarrick J. Wong <darrick.wong@oracle.com>2018-06-01 21:37:33 -0400
commitafd9d6a1df75807684fa40dab77c52e104e5c74b (patch)
tree6411e69f4f2c8c64aceb79f17448c93368de4d68
parentbd56b3e14410b8cf6a4c13c94f7065341b179517 (diff)
fs: use ->is_partially_uptodate in page_cache_seek_hole_data
This way the implementation doesn't depend on buffer_head internals. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
-rw-r--r--fs/iomap.c83
1 files changed, 40 insertions, 43 deletions
diff --git a/fs/iomap.c b/fs/iomap.c
index 2a20d50f0c1d..206539d369a8 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -595,34 +595,53 @@ EXPORT_SYMBOL_GPL(iomap_fiemap);
595 595
596/* 596/*
597 * Seek for SEEK_DATA / SEEK_HOLE within @page, starting at @lastoff. 597 * Seek for SEEK_DATA / SEEK_HOLE within @page, starting at @lastoff.
598 * 598 * Returns true if found and updates @lastoff to the offset in file.
599 * Returns the offset within the file on success, and -ENOENT otherwise.
600 */ 599 */
601static loff_t 600static bool
602page_seek_hole_data(struct page *page, loff_t lastoff, int whence) 601page_seek_hole_data(struct inode *inode, struct page *page, loff_t *lastoff,
602 int whence)
603{ 603{
604 loff_t offset = page_offset(page); 604 const struct address_space_operations *ops = inode->i_mapping->a_ops;
605 struct buffer_head *bh, *head; 605 unsigned int bsize = i_blocksize(inode), off;
606 bool seek_data = whence == SEEK_DATA; 606 bool seek_data = whence == SEEK_DATA;
607 loff_t poff = page_offset(page);
607 608
608 if (lastoff < offset) 609 if (WARN_ON_ONCE(*lastoff >= poff + PAGE_SIZE))
609 lastoff = offset; 610 return false;
610
611 bh = head = page_buffers(page);
612 do {
613 offset += bh->b_size;
614 if (lastoff >= offset)
615 continue;
616 611
612 if (*lastoff < poff) {
617 /* 613 /*
618 * Any buffer with valid data in it should have BH_Uptodate set. 614 * Last offset smaller than the start of the page means we found
615 * a hole:
619 */ 616 */
620 if (buffer_uptodate(bh) == seek_data) 617 if (whence == SEEK_HOLE)
621 return lastoff; 618 return true;
619 *lastoff = poff;
620 }
622 621
623 lastoff = offset; 622 /*
624 } while ((bh = bh->b_this_page) != head); 623 * Just check the page unless we can and should check block ranges:
625 return -ENOENT; 624 */
625 if (bsize == PAGE_SIZE || !ops->is_partially_uptodate)
626 return PageUptodate(page) == seek_data;
627
628 lock_page(page);
629 if (unlikely(page->mapping != inode->i_mapping))
630 goto out_unlock_not_found;
631
632 for (off = 0; off < PAGE_SIZE; off += bsize) {
633 if ((*lastoff & ~PAGE_MASK) >= off + bsize)
634 continue;
635 if (ops->is_partially_uptodate(page, off, bsize) == seek_data) {
636 unlock_page(page);
637 return true;
638 }
639 *lastoff = poff + off + bsize;
640 }
641
642out_unlock_not_found:
643 unlock_page(page);
644 return false;
626} 645}
627 646
628/* 647/*
@@ -659,30 +678,8 @@ page_cache_seek_hole_data(struct inode *inode, loff_t offset, loff_t length,
659 for (i = 0; i < nr_pages; i++) { 678 for (i = 0; i < nr_pages; i++) {
660 struct page *page = pvec.pages[i]; 679 struct page *page = pvec.pages[i];
661 680
662 /* 681 if (page_seek_hole_data(inode, page, &lastoff, whence))
663 * At this point, the page may be truncated or
664 * invalidated (changing page->mapping to NULL), or
665 * even swizzled back from swapper_space to tmpfs file
666 * mapping. However, page->index will not change
667 * because we have a reference on the page.
668 *
669 * If current page offset is beyond where we've ended,
670 * we've found a hole.
671 */
672 if (whence == SEEK_HOLE &&
673 lastoff < page_offset(page))
674 goto check_range; 682 goto check_range;
675
676 lock_page(page);
677 if (likely(page->mapping == inode->i_mapping) &&
678 page_has_buffers(page)) {
679 lastoff = page_seek_hole_data(page, lastoff, whence);
680 if (lastoff >= 0) {
681 unlock_page(page);
682 goto check_range;
683 }
684 }
685 unlock_page(page);
686 lastoff = page_offset(page) + PAGE_SIZE; 683 lastoff = page_offset(page) + PAGE_SIZE;
687 } 684 }
688 pagevec_release(&pvec); 685 pagevec_release(&pvec);