[PATCH] reiserfs: Deprecate reiserfs

[Jan Kara <jack@suse.cz>]

Reiserfs is relatively old filesystem and its development has ceased
quite some years ago. Linux distributions moved away from it towards
other filesystems such as btrfs, xfs, or ext4. To reduce maintenance
burden on cross filesystem changes (such as new mount API, iomap, folios
...) let's add a deprecation notice when the filesystem is mounted and
schedule its removal to 2024.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/reiserfs/Kconfig | 10 +++++++---
 fs/reiserfs/super.c |  2 ++
 2 files changed, 9 insertions(+), 3 deletions(-)

Here's my suggestion for deprecating reiserfs. If nobody has reasons against
this, I'll send the patch to Linus during the next merge window.

diff --git a/fs/reiserfs/Kconfig b/fs/reiserfs/Kconfig
index 8fd54ed8f844..eafee53ddabc 100644
--- a/fs/reiserfs/Kconfig
+++ b/fs/reiserfs/Kconfig
@@ -1,10 +1,14 @@
 # SPDX-License-Identifier: GPL-2.0-only
 config REISERFS_FS
-	tristate "Reiserfs support"
+	tristate "Reiserfs support (deprecated)"
 	select CRC32
 	help
-	  Stores not just filenames but the files themselves in a balanced
-	  tree.  Uses journalling.
+	  Reiserfs is deprecated and scheduled to be removed from the kernel
+	  in 2024. If you are still using it, please migrate to another
+	  filesystem or tell us your usecase for reiserfs.
+
+	  Reiserfs stores not just filenames but the files themselves in a
+	  balanced tree.  Uses journalling.
 
 	  Balanced trees are more efficient than traditional file system
 	  architectural foundations.
diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c
index 82e09901462e..74c1cda3bc3e 100644
--- a/fs/reiserfs/super.c
+++ b/fs/reiserfs/super.c
@@ -1652,6 +1652,8 @@ static int read_super_block(struct super_block *s, int offset)
 		return 1;
 	}
 
+	reiserfs_warning(NULL, "", "reiserfs filesystem is deprecated and "
+		"scheduled to be removed from the kernel in 2024");
 	SB_BUFFER_WITH_SB(s) = bh;
 	SB_DISK_SUPER_BLOCK(s) = rs;
 
-- 
2.31.1