From 0acdb8876fead922c9ffa6768c5675a37485c48c Mon Sep 17 00:00:00 2001 From: Tao Ma Date: Wed, 26 Sep 2012 00:08:57 -0400 Subject: [PATCH] ext4: don't call update_backups() multiple times for the same bg When performing an online resize, we add a bunch of groups at one time in ext4_flex_group_add, so in most cases a lot of group descriptors will be in the same group block. But in the end of this function, update_backups will be called for every group descriptor and the same block will be copied and journalled again and again. It is really a waste. Fix things so we only update a particular bg descriptor block once and skip subsequent updates of the same block. Signed-off-by: Tao Ma Signed-off-by: "Theodore Ts'o" --- fs/ext4/resize.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index f21fdbf5c75d..7a75e1086961 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1460,6 +1460,7 @@ exit_journal: EXT4_DESC_PER_BLOCK(sb)); int meta_bg = EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG); + sector_t old_gdb = 0; update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es, sizeof(struct ext4_super_block), 0); @@ -1467,8 +1468,11 @@ exit_journal: struct buffer_head *gdb_bh; gdb_bh = sbi->s_group_desc[gdb_num]; + if (old_gdb == gdb_bh->b_blocknr) + continue; update_backups(sb, gdb_bh->b_blocknr, gdb_bh->b_data, gdb_bh->b_size, meta_bg); + old_gdb = gdb_bh->b_blocknr; } } exit: -- 2.30.2