[PATCH] ext2: mark as deprecated

[PATCH] ext2: mark as deprecated

[michael.opdenacker]

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

Re: [PATCH] ext2: mark as deprecated

[Jan Kara]

On Thu 22-02-24 10:50:01, michael.opdenacker@bootlin.com wrote:
> 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>

Thanks! I've modified the help text to:

          Ext2 is a standard Linux file system for hard disks.

          This filesystem driver is deprecated because it does not properly
          support inode time stamps beyond 03:14:07 UTC on 19 January 2038.

          Ext2 users are advised to use ext4 driver to access their filesystem.
          The driver is fully compatible, supports filesystems without journal
          or extents, and also supports larger time stamps if the filesystem
          is created with at least 256 byte inodes.

          This code is kept as a simple reference for filesystem developers.

          If unsure, say N.

and added it to my tree.

								Honza

> ---
>  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
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR