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>
---
 fs/ext4/super.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 845f2f8aee5f..e3fd50b0d6b7 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;
 }
-- 
2.27.0

On Mon, 4 Jul 2022 11:16:03 +0530, Ojaswin Mujoo wrote:
> 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.
> 
> 

Applied, thanks!

[1/1] ext4: Reflect mb_optimize_scan value in options file
      commit: 961edf078b5606ce480ae2ebdac64ca829ea3f75

Best regards,
-- 
Theodore Ts'o <tytso@mit.edu>