[RFC PATCH 1/9] ext4: add deprecation warning for inline_data feature

From: Yun Zhou

Date: Mon Jul 27 2026 - 06:59:37 EST


Emit a mount-time warning when the inline_data feature is enabled,
directing users to convert their filesystems with tune2fs.

Signed-off-by: Yun Zhou <yun.zhou@xxxxxxxxxxxxx>
---
fs/ext4/super.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 6c18b5adffca..9913e30b7040 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3145,6 +3145,12 @@ static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
ext4_msg(sb, KERN_WARNING,
"warning: checktime reached, "
"running e2fsck is recommended");
+ if (ext4_has_feature_inline_data(sb))
+ ext4_msg(sb, KERN_WARNING,
+ "warning: inline_data feature is deprecated and "
+ "will be removed in a future kernel release. "
+ "Use 'tune2fs -O ^inline_data' to convert.");
+
if (!sbi->s_journal)
es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
--
2.43.0