From 85c8f176a6111ecde9c158109989dbd445a0e59a Mon Sep 17 00:00:00 2001 From: Andrew Perepechko Date: Sun, 30 Apr 2017 00:46:35 -0400 Subject: [PATCH] ext4: preload block group descriptors With enabled meta_bg option block group descriptors reading IO is not sequential and requires optimization. Signed-off-by: Andrew Perepechko Signed-off-by: Theodore Ts'o --- fs/ext4/super.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 9ec8963ba6049..9a40e0c16dcc7 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3879,6 +3879,12 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) bgl_lock_init(sbi->s_blockgroup_lock); + /* Pre-read the descriptors into the buffer cache */ + for (i = 0; i < db_count; i++) { + block = descriptor_loc(sb, logical_sb_block, i); + sb_breadahead(sb, block); + } + for (i = 0; i < db_count; i++) { block = descriptor_loc(sb, logical_sb_block, i); sbi->s_group_desc[i] = sb_bread_unmovable(sb, block); -- 2.30.2