Commit 2d4e0b84 authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: introduce submit_compressed_bio() for compression 



The new helper, submit_compressed_bio(), will aggregate the following
work:

- Increase compressed_bio::pending_bios
- Remap the endio function
- Map and submit the bio

This slightly reorders calls to btrfs_csum_one_bio or
btrfs_lookup_bio_sums but but none of them does anything regarding IO
submission so this is effectively no change. We mainly care about order
of

- atomic_inc
- btrfs_bio_wq_end_io
- btrfs_map_bio

Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 6853c64a

fs/btrfs/compression.c

+19 −26
Original line number Diff line number Diff line
@@ -419,6 +419,21 @@ static void end_compressed_bio_write(struct bio *bio) 
	bio_put(bio);

}



static blk_status_t submit_compressed_bio(struct btrfs_fs_info *fs_info,

					  struct compressed_bio *cb,

					  struct bio *bio, int mirror_num)

{

	blk_status_t ret;



	ASSERT(bio->bi_iter.bi_size);

	atomic_inc(&cb->pending_bios);

	ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA);

	if (ret)

		return ret;

	ret = btrfs_map_bio(fs_info, bio, mirror_num);

	return ret;

}



/*

 * worker function to build and submit bios for previously compressed pages.

 * The corresponding pages in the inode should be marked for writeback
@@ -514,19 +529,13 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start, 


		page->mapping = NULL;

		if (submit || len < PAGE_SIZE) {

			atomic_inc(&cb->pending_bios);

			ret = btrfs_bio_wq_end_io(fs_info, bio,

						  BTRFS_WQ_ENDIO_DATA);

			if (ret)

				goto finish_cb;



			if (!skip_sum) {

				ret = btrfs_csum_one_bio(inode, bio, start, 1);

				if (ret)

					goto finish_cb;

			}



			ret = btrfs_map_bio(fs_info, bio, 0);

			ret = submit_compressed_bio(fs_info, cb, bio, 0);

			if (ret)

				goto finish_cb;
@@ -553,18 +562,13 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start, 
		cond_resched();

	}



	atomic_inc(&cb->pending_bios);

	ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA);

	if (ret)

		goto last_bio;



	if (!skip_sum) {

		ret = btrfs_csum_one_bio(inode, bio, start, 1);

		if (ret)

			goto last_bio;

	}



	ret = btrfs_map_bio(fs_info, bio, 0);

	ret = submit_compressed_bio(fs_info, cb, bio, 0);

	if (ret)

		goto last_bio;
@@ -868,12 +872,6 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, 
		if (submit || bio_add_page(comp_bio, page, pg_len, 0) < pg_len) {

			unsigned int nr_sectors;



			atomic_inc(&cb->pending_bios);

			ret = btrfs_bio_wq_end_io(fs_info, comp_bio,

						  BTRFS_WQ_ENDIO_DATA);

			if (ret)

				goto finish_cb;



			ret = btrfs_lookup_bio_sums(inode, comp_bio, sums);

			if (ret)

				goto finish_cb;
@@ -882,7 +880,7 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, 
						  fs_info->sectorsize);

			sums += fs_info->csum_size * nr_sectors;



			ret = btrfs_map_bio(fs_info, comp_bio, mirror_num);

			ret = submit_compressed_bio(fs_info, cb, comp_bio, mirror_num);

			if (ret)

				goto finish_cb;
@@ -897,16 +895,11 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, 
		cur_disk_byte += pg_len;

	}



	atomic_inc(&cb->pending_bios);

	ret = btrfs_bio_wq_end_io(fs_info, comp_bio, BTRFS_WQ_ENDIO_DATA);

	if (ret)

		goto last_bio;



	ret = btrfs_lookup_bio_sums(inode, comp_bio, sums);

	if (ret)

		goto last_bio;



	ret = btrfs_map_bio(fs_info, comp_bio, mirror_num);

	ret = submit_compressed_bio(fs_info, cb, comp_bio, mirror_num);

	if (ret)

		goto last_bio;