diff --git a/fs/jfs/super.c b/fs/jfs/super.c
index 90ee0de..143bcd1 100644
--- a/fs/jfs/super.c
+++ b/fs/jfs/super.c
@@ -678,6 +678,7 @@
 				sb->s_blocksize - offset : towrite;
 
 		tmp_bh.b_state = 0;
+		tmp_bh.b_size = 1 << inode->i_blkbits;
 		err = jfs_get_block(inode, blk, &tmp_bh, 1);
 		if (err)
 			goto out;