Commit 97861cd1 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by David Sterba
Browse files

btrfs: refactor end_bio_extent_readpage code flow 



Untangle the goto and move the code it jumps to so it goes in the order
of the most likely states first.

Reviewed-by: default avatarNikolay Borisov <nborisov@suse.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent a5aa7ab6

fs/btrfs/extent_io.c

+40 −46
Original line number Diff line number Diff line
@@ -3017,7 +3017,6 @@ static void end_bio_extent_readpage(struct bio *bio) 
	 */

	u32 bio_offset = 0;

	int mirror;

	int ret;

	struct bvec_iter_all iter_all;



	ASSERT(!bio_flagged(bio, BIO_CLONED));
@@ -3028,6 +3027,7 @@ static void end_bio_extent_readpage(struct bio *bio) 
		struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);

		const u32 sectorsize = fs_info->sectorsize;

		unsigned int error_bitmap = (unsigned int)-1;

		bool repair = false;

		u64 start;

		u64 end;

		u32 len;
@@ -3065,55 +3065,23 @@ static void end_bio_extent_readpage(struct bio *bio) 
			if (is_data_inode(inode)) {

				error_bitmap = btrfs_verify_data_csum(bbio,

						bio_offset, page, start, end);

				ret = error_bitmap;

				if (error_bitmap)

					uptodate = false;

			} else {

				ret = btrfs_validate_metadata_buffer(bbio,

					page, start, end, mirror);

			}

			if (ret)

				if (btrfs_validate_metadata_buffer(bbio,

						page, start, end, mirror))

					uptodate = false;

			else

				clean_io_failure(BTRFS_I(inode)->root->fs_info,

						 failure_tree, tree, start,

						 page,

						 btrfs_ino(BTRFS_I(inode)), 0);

			}



		if (likely(uptodate))

			goto readpage_ok;



		if (is_data_inode(inode)) {

			/*

			 * If we failed to submit the IO at all we'll have a

			 * mirror_num == 0, in which case we need to just mark

			 * the page with an error and unlock it and carry on.

			 */

			if (mirror == 0)

				goto readpage_ok;



			/*

			 * submit_data_read_repair() will handle all the good

			 * and bad sectors, we just continue to the next bvec.

			 */

			submit_data_read_repair(inode, bio, bio_offset, bvec,

						mirror, error_bitmap);



			ASSERT(bio_offset + len > bio_offset);

			bio_offset += len;

			continue;

		} else {

			struct extent_buffer *eb;



			eb = find_extent_buffer_readpage(fs_info, page, start);

			set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);

			eb->read_mirror = mirror;

			atomic_dec(&eb->io_pages);

		}

readpage_ok:



		if (likely(uptodate)) {

			loff_t i_size = i_size_read(inode);

			pgoff_t end_index = i_size >> PAGE_SHIFT;



			clean_io_failure(BTRFS_I(inode)->root->fs_info,

					 failure_tree, tree, start, page,

					 btrfs_ino(BTRFS_I(inode)), 0);



			/*

			 * Zero out the remaining part if this range straddles

			 * i_size.
@@ -3130,15 +3098,41 @@ static void end_bio_extent_readpage(struct bio *bio) 
				zero_user_segment(page, zero_start,

						  offset_in_page(end) + 1);

			}

		} else if (is_data_inode(inode)) {

			/*

			 * Only try to repair bios that actually made it to a

			 * device.  If the bio failed to be submitted mirror

			 * is 0 and we need to fail it without retrying.

			 */

			if (mirror > 0)

				repair = true;

		} else {

			struct extent_buffer *eb;



			eb = find_extent_buffer_readpage(fs_info, page, start);

			set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);

			eb->read_mirror = mirror;

			atomic_dec(&eb->io_pages);

		}

		ASSERT(bio_offset + len > bio_offset);

		bio_offset += len;



		if (repair) {

			/*

			 * submit_data_read_repair() will handle all the good

			 * and bad sectors, we just continue to the next bvec.

			 */

			submit_data_read_repair(inode, bio, bio_offset, bvec,

						mirror, error_bitmap);

		} else {

			/* Update page status and unlock */

			end_page_read(page, uptodate, start, len);

			endio_readpage_release_extent(&processed, BTRFS_I(inode),

					start, end, PageUptodate(page));

		}



		ASSERT(bio_offset + len > bio_offset);

		bio_offset += len;



	}

	/* Release the last extent */

	endio_readpage_release_extent(&processed, NULL, 0, 0, false);

	btrfs_bio_free_csum(bbio);