ext4: Disable dirty list tracking of dquots when journalling quotas (91389240) · Commits · 戴 / test

When journalling quotas, we writeback all dquots immediately after changing them as part of current transation. Thus there's no need to write anything in dquot_writeback_dquots() and so we can avoid updating list of dirty dquots to reduce dq_list_lock contention. This change reduces time to create 500000 files on ext4 on ramdisk by 50 different processes in separate directories by 15% when user quota is turned on. Signed-off-by:

Jan Kara <jack@suse.cz>

fs/ext4/super.c

+8 −1

Original line number	Diff line number	Diff line
		@@ -5404,6 +5404,13 @@ static int ext4_quota_on(struct super_block *sb, int type, int format_id,
		ext4_msg(sb, KERN_WARNING,
		"Quota file not on filesystem root. "
		"Journaled quota will not work");
		sb_dqopt(sb)->flags \|= DQUOT_NOLIST_DIRTY;
		} else {
		/*
		* Clear the flag just in case mount options changed since
		* last time.
		*/
		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
		}

		/*
		@@ -5500,7 +5507,7 @@ static int ext4_enable_quotas(struct super_block *sb)
		test_opt(sb, PRJQUOTA),
		};

		sb_dqopt(sb)->flags \|= DQUOT_QUOTA_SYS_FILE;
		sb_dqopt(sb)->flags \|= DQUOT_QUOTA_SYS_FILE \| DQUOT_NOLIST_DIRTY;
		for (type = 0; type < EXT4_MAXQUOTAS; type++) {
		if (qf_inums[type]) {
		err = ext4_quota_enable(sb, type, QFMT_VFS_V1,

Admin message