From mboxrd@z Thu Jan 1 00:00:00 1970 From: Theodore Ts'o Subject: [PATCH 2/9] ext4: avoid duplicate writes of the backup bg descriptor blocks Date: Thu, 13 Sep 2012 18:49:09 -0400 Message-ID: <1347576556-5725-3-git-send-email-tytso@mit.edu> References: <1347576556-5725-1-git-send-email-tytso@mit.edu> Cc: Yongqiang Yang , "Theodore Ts'o" , stable@vger.kernel.org To: Ext4 Developers List Return-path: Received: from li9-11.members.linode.com ([67.18.176.11]:50570 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751074Ab2IMWtT (ORCPT ); Thu, 13 Sep 2012 18:49:19 -0400 In-Reply-To: <1347576556-5725-1-git-send-email-tytso@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: From: Yongqiang Yang The resize code was needlessly writing the backup block group descriptor blocks multiple times (once per block group) during an online resize. Signed-off-by: Yongqiang Yang Signed-off-by: "Theodore Ts'o" Cc: stable@vger.kernel.org --- fs/ext4/resize.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index a0ee26c..365d800 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1358,13 +1358,15 @@ exit_journal: err = err2; if (!err) { - int i; + int gdb_num = group / EXT4_DESC_PER_BLOCK(sb); + int gdb_num_end = ((group + flex_gd->count - 1) / + EXT4_DESC_PER_BLOCK(sb)); + update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es, sizeof(struct ext4_super_block)); - for (i = 0; i < flex_gd->count; i++, group++) { + for (; gdb_num <= gdb_num_end; gdb_num++) { struct buffer_head *gdb_bh; - int gdb_num; - gdb_num = group / EXT4_BLOCKS_PER_GROUP(sb); + gdb_bh = sbi->s_group_desc[gdb_num]; update_backups(sb, gdb_bh->b_blocknr, gdb_bh->b_data, gdb_bh->b_size); -- 1.7.12.rc0.22.gcdd159b