From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f51.google.com ([209.85.220.51]:34799 "EHLO mail-pa0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932681AbcAZIqG (ORCPT ); Tue, 26 Jan 2016 03:46:06 -0500 Received: by mail-pa0-f51.google.com with SMTP id uo6so96749899pac.1 for ; Tue, 26 Jan 2016 00:46:05 -0800 (PST) References: <1453792397-4363-1-git-send-email-bhlee.kernel@gmail.com> <56A729F8.4010603@giantdisaster.de> From: Byongho Lee To: Stefan Behrens Cc: linux-btrfs@vger.kernel.org, dsterba@suse.cz Subject: Re: [PATCH] btrfs: simplify expression in btrfs_csum_bytes_to_leaves() In-reply-to: <56A729F8.4010603@giantdisaster.de> Date: Tue, 26 Jan 2016 17:46:00 +0900 Message-ID: <87r3h4lodz.fsf@gmail.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-btrfs-owner@vger.kernel.org List-ID: Hi Stefan, Stefan Behrens writes: > The result of the calculation is different, which doesn't look right. > The expression comes out this way. (root->nodesize + root->nodesize * (BTRFS_MAX_LEVEL - 1)) * 2 * num_items ->(root->nodesize * (1 + BTRFS_MAX_LEVEL - 1)) * 2 * num_items ->(root->nodesize * (BTRFS_MAX_LEVEL)) * 2 * num_items =>root->nodesize * BTRFS_MAX_LEVEL * 2 * num_items Am I missing? > > On Tue, 26 Jan 2016 16:13:17 +0900, Byongho Lee wrote: >> Simplify expression in btrfs_csum_bytes_to_leaves(). >> >> Signed-off-by: Byongho Lee >> --- >> fs/btrfs/ctree.h | 3 +-- >> 1 file changed, 1 insertion(+), 2 deletions(-) >> >> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h >> index a9496644f47d..3ab8026280a2 100644 >> --- a/fs/btrfs/ctree.h >> +++ b/fs/btrfs/ctree.h >> @@ -3448,8 +3448,7 @@ u64 btrfs_csum_bytes_to_leaves(struct btrfs_root *root, u64 csum_bytes); >> static inline u64 btrfs_calc_trans_metadata_size(struct btrfs_root *root, >> unsigned num_items) >> { >> - return (root->nodesize + root->nodesize * (BTRFS_MAX_LEVEL - 1)) * >> - 2 * num_items; >> + return root->nodesize * BTRFS_MAX_LEVEL * 2 * num_items; >> } >> >> /* >>