Commit 81a79b6a authored by Christoph Hellwig's avatar Christoph Hellwig Committed by David Sterba
Browse files

btrfs: move page locking from lock_extent_buffer_for_io to write_one_eb 



Locking the pages in lock_extent_buffer_for_io only for the non-subpage
case is very confusing.  Move it to write_one_eb to mirror the subpage
case and simplify the code. Now lock_extent_buffer_for_io does not leave
all the pages locked and each is individually locked/unlocked in
write_one_eb.

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 50b21d7a

fs/btrfs/extent_io.c

+1 −14
Original line number Diff line number Diff line
@@ -1636,7 +1636,6 @@ static noinline_for_stack bool lock_extent_buffer_for_io(struct extent_buffer *e 
{

	struct btrfs_fs_info *fs_info = eb->fs_info;

	bool ret = false;

	int i;



	btrfs_tree_lock(eb);

	while (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) {
@@ -1664,20 +1663,7 @@ static noinline_for_stack bool lock_extent_buffer_for_io(struct extent_buffer *e 
	} else {

		spin_unlock(&eb->refs_lock);

	}



	btrfs_tree_unlock(eb);



	/*

	 * Either we don't need to submit any tree block, or we're submitting

	 * subpage eb.

	 * Subpage metadata doesn't use page locking at all, so we can skip

	 * the page locking.

	 */

	if (!ret || fs_info->nodesize < PAGE_SIZE)

		return ret;



	for (i = 0; i < num_extent_pages(eb); i++)

		lock_page(eb->pages[i]);

	return ret;

}
@@ -1960,6 +1946,7 @@ static noinline_for_stack void write_one_eb(struct extent_buffer *eb, 
	for (i = 0; i < num_pages; i++) {

		struct page *p = eb->pages[i];



		lock_page(p);

		clear_page_dirty_for_io(p);

		set_page_writeback(p);

		submit_extent_page(&bio_ctrl, disk_bytenr, p, PAGE_SIZE, 0);