diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index a389820d158b5b7ae64a2c6dfecabbb6ed3ed9bb..1c70cff4a9e1e7d5e48213c6d0e3be54f8b29cc9 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -4213,8 +4213,8 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 		return -ENOMEM;
 	path->leave_spinning = 1;
 
-	start = ALIGN(start, BTRFS_I(inode)->root->sectorsize);
-	len = ALIGN(len, BTRFS_I(inode)->root->sectorsize);
+	start = round_down(start, BTRFS_I(inode)->root->sectorsize);
+	len = round_up(max, BTRFS_I(inode)->root->sectorsize) - start;
 
 	/*
 	 * lookup the last file extent.  We're not using i_size here