Commit e6698b34 authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: replace for_each_set_bit() with for_each_set_bitmap() 



Inside extent_io.c, there are several simple call sites doing things
like:

	for_each_set_bit(bit, bitmap, bitmap_size) {
		/* handle one fs block */
	}

The workload includes:

- set_bit()
  Inside extent_writepage_io().

  This can be replaced with a bitmap_set().

- btrfs_folio_set_lock()
- btrfs_mark_ordered_io_finished()
  Inside writepage_delalloc().

  Instead of calling it multiple times, we can pass a range into the
  function with one call.

Reviewed-by: default avatarBoris Burkov <boris@bur.io>
Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 44820d80

fs/btrfs/extent_io.c

+16 −10
Original line number Diff line number Diff line
@@ -1439,8 +1439,9 @@ static noinline_for_stack int writepage_delalloc(struct btrfs_inode *inode, 
	u64 delalloc_start = page_start;

	u64 delalloc_end = page_end;

	u64 delalloc_to_write = 0;

	unsigned int start_bit;

	unsigned int end_bit;

	int ret = 0;

	int bit;



	/* Save the dirty bitmap as our submission bitmap will be a subset of it. */

	if (btrfs_is_subpage(fs_info, folio)) {
@@ -1450,10 +1451,12 @@ static noinline_for_stack int writepage_delalloc(struct btrfs_inode *inode, 
		bio_ctrl->submit_bitmap = 1;

	}



	for_each_set_bit(bit, &bio_ctrl->submit_bitmap, blocks_per_folio) {

		u64 start = page_start + (bit << fs_info->sectorsize_bits);

	for_each_set_bitrange(start_bit, end_bit, &bio_ctrl->submit_bitmap,

			      blocks_per_folio) {

		u64 start = page_start + (start_bit << fs_info->sectorsize_bits);

		u32 len = (end_bit - start_bit) << fs_info->sectorsize_bits;



		btrfs_folio_set_lock(fs_info, folio, start, fs_info->sectorsize);

		btrfs_folio_set_lock(fs_info, folio, start, len);

	}



	/* Lock all (subpage) delalloc ranges inside the folio first. */
@@ -1570,10 +1573,13 @@ static noinline_for_stack int writepage_delalloc(struct btrfs_inode *inode, 
				fs_info->sectorsize_bits,

				blocks_per_folio);



		for_each_set_bit(bit, &bio_ctrl->submit_bitmap, bitmap_size)

			btrfs_mark_ordered_io_finished(inode, folio,

				page_start + (bit << fs_info->sectorsize_bits),

				fs_info->sectorsize, false);

		for_each_set_bitrange(start_bit, end_bit, &bio_ctrl->submit_bitmap,

				      bitmap_size) {

			u64 start = page_start + (start_bit << fs_info->sectorsize_bits);

			u32 len = (end_bit - start_bit) << fs_info->sectorsize_bits;



			btrfs_mark_ordered_io_finished(inode, folio, start, len, false);

		}

		return ret;

	}

out:
@@ -1741,8 +1747,8 @@ static noinline_for_stack int extent_writepage_io(struct btrfs_inode *inode, 
		return ret;

	}



	for (cur = start; cur < end; cur += fs_info->sectorsize)

		set_bit((cur - folio_start) >> fs_info->sectorsize_bits, &range_bitmap);

	bitmap_set(&range_bitmap, (start - folio_pos(folio)) >> fs_info->sectorsize_bits,

		   len >> fs_info->sectorsize_bits);

	bitmap_and(&bio_ctrl->submit_bitmap, &bio_ctrl->submit_bitmap, &range_bitmap,

		   blocks_per_folio);