From: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Date: Mon, 4 Jul 2022 05:46:03 +0000 (+0530)
Subject: ext4: reflect mb_optimize_scan value in options file
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=3fa5d23e68a34dae9df2be168750dc5e03e0e40d;p=linux.git

ext4: reflect mb_optimize_scan value in options file

Add support to display the mb_optimize_scan value in
/proc/fs/ext4/<dev>/options file. The option is only
displayed when the value is non default.

Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20220704054603.21462-1-ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index a6d71a41a0c4d..9e84a5597f428 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3011,6 +3011,15 @@ static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
 	} else if (test_opt2(sb, DAX_INODE)) {
 		SEQ_OPTS_PUTS("dax=inode");
 	}
+
+	if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
+			!test_opt2(sb, MB_OPTIMIZE_SCAN)) {
+		SEQ_OPTS_PUTS("mb_optimize_scan=0");
+	} else if (sbi->s_groups_count < MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
+			test_opt2(sb, MB_OPTIMIZE_SCAN)) {
+		SEQ_OPTS_PUTS("mb_optimize_scan=1");
+	}
+
 	ext4_show_quota_options(seq, sb);
 	return 0;
 }