Commit f3d315eb authored by Christoph Hellwig's avatar Christoph Hellwig Committed by David Sterba
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btrfs: don't check for uptodate pages in read_extent_buffer_pages 



The only place that reads in pages and thus marks them uptodate for
the btree inode is read_extent_buffer_pages.  Which means that either
pages are already uptodate from an old buffer when creating a new
one in alloc_extent_buffer, or they will be updated by ca call
to read_extent_buffer_pages.  This means the checks for uptodate
pages in read_extent_buffer_pages and read_extent_buffer_subpage are
superfluous and can be removed.

Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 011134f4

fs/btrfs/extent_io.c

+1 −20
Original line number Diff line number Diff line
@@ -4136,10 +4136,7 @@ static int read_extent_buffer_subpage(struct extent_buffer *eb, int wait, 
			return ret;

	}



	if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags) ||

	    PageUptodate(page) ||

	    btrfs_subpage_test_uptodate(fs_info, page, eb->start, eb->len)) {

		set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);

	if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags)) {

		unlock_extent(io_tree, eb->start, eb->start + eb->len - 1,

			      &cached_state);

		return 0;
@@ -4166,7 +4163,6 @@ int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num, 
	int i;

	struct page *page;

	int locked_pages = 0;

	int all_uptodate = 1;

	int num_pages;



	if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
@@ -4201,21 +4197,6 @@ int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num, 
		}

		locked_pages++;

	}

	/*

	 * We need to firstly lock all pages to make sure that

	 * the uptodate bit of our pages won't be affected by

	 * clear_extent_buffer_uptodate().

	 */

	for (i = 0; i < num_pages; i++) {

		page = eb->pages[i];

		if (!PageUptodate(page))

			all_uptodate = 0;

	}



	if (all_uptodate) {

		set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);

		goto unlock_exit;

	}



	__read_extent_buffer_pages(eb, mirror_num, check);