Commit 10e924bc authored by Christoph Hellwig's avatar Christoph Hellwig Committed by David Sterba
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btrfs: factor out a btrfs_add_compressed_bio_pages helper 



Factor out a common helper to add the compressed_bio pages to the
bio that is shared by the compressed read and write path.

Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.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 d7294e4d

fs/btrfs/compression.c

+41 −63
Original line number Diff line number Diff line
@@ -280,6 +280,42 @@ static void end_compressed_bio_write(struct btrfs_bio *bbio) 
	queue_work(fs_info->compressed_write_workers, &cb->write_end_work);

}



static void btrfs_add_compressed_bio_pages(struct compressed_bio *cb,

					   u64 disk_bytenr)

{

	struct btrfs_fs_info *fs_info = cb->bbio.inode->root->fs_info;

	struct bio *bio = &cb->bbio.bio;

	u64 cur_disk_byte = disk_bytenr;



	bio->bi_iter.bi_sector = disk_bytenr >> SECTOR_SHIFT;

	while (cur_disk_byte < disk_bytenr + cb->compressed_len) {

		u64 offset = cur_disk_byte - disk_bytenr;

		unsigned int index = offset >> PAGE_SHIFT;

		unsigned int real_size;

		unsigned int added;

		struct page *page = cb->compressed_pages[index];



		/*

		 * We have various limit on the real read size:

		 * - page boundary

		 * - compressed length boundary

		 */

		real_size = min_t(u64, U32_MAX, PAGE_SIZE - offset_in_page(offset));

		real_size = min_t(u64, real_size, cb->compressed_len - offset);

		ASSERT(IS_ALIGNED(real_size, fs_info->sectorsize));



		added = bio_add_page(bio, page, real_size, offset_in_page(offset));

		/*

		 * Maximum compressed extent is smaller than bio size limit,

		 * thus bio_add_page() should always success.

		 */

		ASSERT(added == real_size);

		cur_disk_byte += added;

	}



	ASSERT(bio->bi_iter.bi_size);

}



/*

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

 * The corresponding pages in the inode should be marked for writeback
@@ -299,9 +335,7 @@ void btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start, 
				 bool writeback)

{

	struct btrfs_fs_info *fs_info = inode->root->fs_info;

	struct bio *bio;

	struct compressed_bio *cb;

	u64 cur_disk_bytenr = disk_start;



	ASSERT(IS_ALIGNED(start, fs_info->sectorsize) &&

	       IS_ALIGNED(len, fs_info->sectorsize));
@@ -322,37 +356,9 @@ void btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start, 
	INIT_WORK(&cb->write_end_work, btrfs_finish_compressed_write_work);

	cb->nr_pages = nr_pages;



	bio = &cb->bbio.bio;

	bio->bi_iter.bi_sector = disk_start >> SECTOR_SHIFT;



	while (cur_disk_bytenr < disk_start + compressed_len) {

		u64 offset = cur_disk_bytenr - disk_start;

		unsigned int index = offset >> PAGE_SHIFT;

		unsigned int real_size;

		unsigned int added;

		struct page *page = compressed_pages[index];



		/*

		 * We have various limits on the real read size:

		 * - page boundary

		 * - compressed length boundary

		 */

		real_size = min_t(u64, U32_MAX, PAGE_SIZE - offset_in_page(offset));

		real_size = min_t(u64, real_size, compressed_len - offset);

		ASSERT(IS_ALIGNED(real_size, fs_info->sectorsize));



		added = bio_add_page(bio, page, real_size, offset_in_page(offset));

		/*

		 * Maximum compressed extent is smaller than bio size limit,

		 * thus bio_add_page() should always success.

		 */

		ASSERT(added == real_size);

		cur_disk_bytenr += added;

	}

	btrfs_add_compressed_bio_pages(cb, disk_start);

	btrfs_submit_bio(&cb->bbio.bio, 0);



	/* Finished the range. */

	ASSERT(bio->bi_iter.bi_size);

	btrfs_submit_bio(bio, 0);

	if (blkcg_css)

		kthread_associate_blkcg(NULL);

}
@@ -523,9 +529,7 @@ void btrfs_submit_compressed_read(struct bio *bio, int mirror_num) 
	struct extent_map_tree *em_tree = &inode->extent_tree;

	struct compressed_bio *cb;

	unsigned int compressed_len;

	struct bio *comp_bio;

	const u64 disk_bytenr = bio->bi_iter.bi_sector << SECTOR_SHIFT;

	u64 cur_disk_byte = disk_bytenr;

	u64 file_offset = btrfs_bio(bio)->file_offset;

	u64 em_len;

	u64 em_start;
@@ -549,8 +553,6 @@ void btrfs_submit_compressed_read(struct bio *bio, int mirror_num) 


	cb = alloc_compressed_bio(inode, file_offset, REQ_OP_READ,

				  end_compressed_bio_read);

	comp_bio = &cb->bbio.bio;

	comp_bio->bi_iter.bi_sector = cur_disk_byte >> SECTOR_SHIFT;



	cb->start = em->orig_start;

	em_len = em->len;
@@ -582,42 +584,18 @@ void btrfs_submit_compressed_read(struct bio *bio, int mirror_num) 
	/* include any pages we added in add_ra-bio_pages */

	cb->len = bio->bi_iter.bi_size;



	while (cur_disk_byte < disk_bytenr + compressed_len) {

		u64 offset = cur_disk_byte - disk_bytenr;

		unsigned int index = offset >> PAGE_SHIFT;

		unsigned int real_size;

		unsigned int added;

		struct page *page = cb->compressed_pages[index];



		/*

		 * We have various limit on the real read size:

		 * - page boundary

		 * - compressed length boundary

		 */

		real_size = min_t(u64, U32_MAX, PAGE_SIZE - offset_in_page(offset));

		real_size = min_t(u64, real_size, compressed_len - offset);

		ASSERT(IS_ALIGNED(real_size, fs_info->sectorsize));



		added = bio_add_page(comp_bio, page, real_size, offset_in_page(offset));

		/*

		 * Maximum compressed extent is smaller than bio size limit,

		 * thus bio_add_page() should always success.

		 */

		ASSERT(added == real_size);

		cur_disk_byte += added;

	}

	btrfs_add_compressed_bio_pages(cb, disk_bytenr);



	if (memstall)

		psi_memstall_leave(&pflags);



	ASSERT(comp_bio->bi_iter.bi_size);

	btrfs_submit_bio(comp_bio, mirror_num);

	btrfs_submit_bio(&cb->bbio.bio, mirror_num);

	return;



out_free_compressed_pages:

	kfree(cb->compressed_pages);

out_free_bio:

	bio_put(comp_bio);

	bio_put(&cb->bbio.bio);

out:

	btrfs_bio_end_io(btrfs_bio(bio), ret);

}