Commit 8cad6fed authored by Christoph Hellwig's avatar Christoph Hellwig Committed by David Sterba
Browse files

btrfs: remove the alignment checks in end_bbio_data_read() 



end_bbio_data_read() checks that each iterated folio fragment is aligned
and justifies that with block drivers advancing the bio.  But block
driver only advance bi_iter, while end_bbio_data_read() uses
bio_for_each_folio_all() to iterate the immutable bi_io_vec array that
can't be changed by drivers at all.

Furthermore btrfs has already did the alignment check of the file
offset inside submit_one_sector(), and the size is fixed to fs block
size, there is no need to re-do the alignment check again inside the
endio function.

So just remove the unnecessary alignment check along with the incorrect
comment.

Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarQu Wenruo <wqu@suse.com>
Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent ecf5b757

fs/btrfs/extent_io.c

+3 −24
Original line number Diff line number Diff line
@@ -501,43 +501,22 @@ static void end_bbio_data_read(struct btrfs_bio *bbio) 
	struct btrfs_fs_info *fs_info = bbio->fs_info;

	struct bio *bio = &bbio->bio;

	struct folio_iter fi;

	const u32 sectorsize = fs_info->sectorsize;



	ASSERT(!bio_flagged(bio, BIO_CLONED));

	bio_for_each_folio_all(fi, &bbio->bio) {

		bool uptodate = !bio->bi_status;

		struct folio *folio = fi.folio;

		struct inode *inode = folio->mapping->host;

		u64 start;

		u64 end;

		u32 len;

		u64 start = folio_pos(folio) + fi.offset;



		btrfs_debug(fs_info,

			"%s: bi_sector=%llu, err=%d, mirror=%u",

			__func__, bio->bi_iter.bi_sector, bio->bi_status,

			bbio->mirror_num);



		/*

		 * We always issue full-sector reads, but if some block in a

		 * folio fails to read, blk_update_request() will advance

		 * bv_offset and adjust bv_len to compensate.  Print a warning

		 * for unaligned offsets, and an error if they don't add up to

		 * a full sector.

		 */

		if (!IS_ALIGNED(fi.offset, sectorsize))

			btrfs_err(fs_info,

		"partial page read in btrfs with offset %zu and length %zu",

				  fi.offset, fi.length);

		else if (!IS_ALIGNED(fi.offset + fi.length, sectorsize))

			btrfs_info(fs_info,

		"incomplete page read with offset %zu and length %zu",

				   fi.offset, fi.length);



		start = folio_pos(folio) + fi.offset;

		end = start + fi.length - 1;

		len = fi.length;



		if (likely(uptodate)) {

			u64 end = start + fi.length - 1;

			loff_t i_size = i_size_read(inode);



			/*
@@ -562,7 +541,7 @@ static void end_bbio_data_read(struct btrfs_bio *bbio) 
		}



		/* Update page status and unlock. */

		end_folio_read(folio, uptodate, start, len);

		end_folio_read(folio, uptodate, start, fi.length);

	}

	bio_put(bio);

}