[PATCH] ext4: show the default enabled prefetch_block_bitmaps option

[libaokun]

From: Baokun Li <libaokun1@xxxxxxxxxx>

After commit 21175ca434c5 ("ext4: make prefetch_block_bitmaps default"),
we enable 'prefetch_block_bitmaps' by default, but this is not shown in
the '/proc/fs/ext4/sdx/options' procfs interface.

This makes it impossible to distinguish whether the feature is enabled by
default or not, so 'prefetch_block_bitmaps' is shown in the 'options'
procfs interface when prefetch_block_bitmaps is enabled by default.

This makes it easy to notice changes to the default mount options between
versions through the '/proc/fs/ext4/sdx/options' procfs interface.

Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx>
---
 fs/ext4/super.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index b77acba4a719..c88a47639e9c 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3030,6 +3030,9 @@ static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
 		SEQ_OPTS_PUTS("mb_optimize_scan=1");
 	}
 
+	if (!test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS))
+		SEQ_OPTS_PUTS("prefetch_block_bitmaps");
+
 	ext4_show_quota_options(seq, sb);
 	return 0;
 }
-- 
2.31.1