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From: michael.opdenacker@bootlin.com
To: jack@suse.com
Cc: linux-ext4@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Michael Opdenacker <michael.opdenacker@bootlin.com>
Subject: [PATCH] ext2: mark as deprecated
Date: Thu, 22 Feb 2024 10:50:01 +0100
Message-Id: <20240222095001.137660-1-michael.opdenacker@bootlin.com>
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From: Michael Opdenacker <michael.opdenacker@bootlin.com>

Add a DEPRECATED keyword to the kernel parameter description,
to warn users that this filesystem doesn't support dates beyond 2038.

Signed-off-by: Michael Opdenacker <michael.opdenacker@bootlin.com>
---
 fs/ext2/Kconfig | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/fs/ext2/Kconfig b/fs/ext2/Kconfig
index 74d98965902e..49e4660ae436 100644
--- a/fs/ext2/Kconfig
+++ b/fs/ext2/Kconfig
@@ -1,16 +1,30 @@
 # SPDX-License-Identifier: GPL-2.0-only
 config EXT2_FS
-	tristate "Second extended fs support"
+	tristate "Second extended fs support (DEPRECATED)"
 	select BUFFER_HEAD
 	select FS_IOMAP
 	select LEGACY_DIRECT_IO
 	help
 	  Ext2 is a standard Linux file system for hard disks.
 
-	  To compile this file system support as a module, choose M here: the
-	  module will be called ext2.
+	  It is deprecated because even if the filesystem is created with
+	  256 byte inodes (mkfs.ext2 -I 256), the filesystem driver will stick
+	  to 32 bit dates. Because of this, this filesystem does not support
+	  dates beyond 03:14:07 UTC on 19 January 2038.
 
-	  If unsure, say Y.
+	  Ext2 users are advised to migrate their partitions to ext4:
+
+	  $ tune2fs -O extents,uninit_bg,dir_index,has_journal /dev/sda1
+	  $ e2fsck -pf /dev/sda1
+
+	  Ext4 is also a working solution for very small partitions
+	  as it can be created without a journal:
+
+	  $ mkfs.ext4 -O ^has_journal /dev/sda1
+
+	  This code is kept as a simple reference for filesystem developers.
+
+	  If unsure, say N.
 
 config EXT2_FS_XATTR
 	bool "Ext2 extended attributes"
-- 
2.34.1