[PATCH 00/24] vfs: require filesystems to explicitly opt-in to lease support

[Jan Kara]

On Thu 08-01-26 12:12:55, Jeff Layton wrote:
> Yesterday, I sent patches to fix how directory delegation support is
> handled on filesystems where the should be disabled [1]. That set is
> appropriate for v6.19. For v7.0, I want to make lease support be more
> opt-in, rather than opt-out:
> 
> For historical reasons, when ->setlease() file_operation is set to NULL,
> the default is to use the kernel-internal lease implementation. This
> means that if you want to disable them, you need to explicitly set the
> ->setlease() file_operation to simple_nosetlease() or the equivalent.
> 
> This has caused a number of problems over the years as some filesystems
> have inadvertantly allowed leases to be acquired simply by having left
> it set to NULL. It would be better if filesystems had to opt-in to lease
> support, particularly with the advent of directory delegations.
> 
> This series has sets the ->setlease() operation in a pile of existing
> local filesystems to generic_setlease() and then changes
> kernel_setlease() to return -EINVAL when the setlease() operation is not
> set.
> 
> With this change, new filesystems will need to explicitly set the
> ->setlease() operations in order to provide lease and delegation
> support.
> 
> I mainly focused on filesystems that are NFS exportable, since NFS and
> SMB are the main users of file leases, and they tend to end up exporting
> the same filesystem types. Let me know if I've missed any.

So, what about kernfs and fuse? They seem to be exportable and don't have
.setlease set...

								Honza

> 
> [1]: https://lore.kernel.org/linux-fsdevel/20260107-setlease-6-19-v1-0-85f034abcc57@kernel.org/
> 
> Signed-off-by: Jeff Layton <jlayton at kernel.org>
> ---
> Jeff Layton (24):
>       fs: add setlease to generic_ro_fops and read-only filesystem directory operations
>       affs: add setlease file operation
>       btrfs: add setlease file operation
>       erofs: add setlease file operation
>       ext2: add setlease file operation
>       ext4: add setlease file operation
>       exfat: add setlease file operation
>       f2fs: add setlease file operation
>       fat: add setlease file operation
>       gfs2: add a setlease file operation
>       jffs2: add setlease file operation
>       jfs: add setlease file operation
>       nilfs2: add setlease file operation
>       ntfs3: add setlease file operation
>       ocfs2: add setlease file operation
>       orangefs: add setlease file operation
>       overlayfs: add setlease file operation
>       squashfs: add setlease file operation
>       tmpfs: add setlease file operation
>       udf: add setlease file operation
>       ufs: add setlease file operation
>       xfs: add setlease file operation
>       filelock: default to returning -EINVAL when ->setlease operation is NULL
>       fs: remove simple_nosetlease()
> 
>  Documentation/filesystems/porting.rst |  9 +++++++++
>  Documentation/filesystems/vfs.rst     |  9 ++++++---
>  fs/9p/vfs_dir.c                       |  2 --
>  fs/9p/vfs_file.c                      |  2 --
>  fs/affs/dir.c                         |  2 ++
>  fs/affs/file.c                        |  2 ++
>  fs/befs/linuxvfs.c                    |  2 ++
>  fs/btrfs/file.c                       |  2 ++
>  fs/btrfs/inode.c                      |  2 ++
>  fs/ceph/dir.c                         |  2 --
>  fs/ceph/file.c                        |  1 -
>  fs/cramfs/inode.c                     |  2 ++
>  fs/efs/dir.c                          |  2 ++
>  fs/erofs/data.c                       |  2 ++
>  fs/erofs/dir.c                        |  2 ++
>  fs/exfat/dir.c                        |  2 ++
>  fs/exfat/file.c                       |  2 ++
>  fs/ext2/dir.c                         |  2 ++
>  fs/ext2/file.c                        |  2 ++
>  fs/ext4/dir.c                         |  2 ++
>  fs/ext4/file.c                        |  2 ++
>  fs/f2fs/dir.c                         |  2 ++
>  fs/f2fs/file.c                        |  2 ++
>  fs/fat/dir.c                          |  2 ++
>  fs/fat/file.c                         |  2 ++
>  fs/freevxfs/vxfs_lookup.c             |  2 ++
>  fs/fuse/dir.c                         |  1 -
>  fs/gfs2/file.c                        |  3 +--
>  fs/isofs/dir.c                        |  2 ++
>  fs/jffs2/dir.c                        |  2 ++
>  fs/jffs2/file.c                       |  2 ++
>  fs/jfs/file.c                         |  2 ++
>  fs/jfs/namei.c                        |  2 ++
>  fs/libfs.c                            | 20 ++------------------
>  fs/locks.c                            |  3 +--
>  fs/nfs/dir.c                          |  1 -
>  fs/nfs/file.c                         |  1 -
>  fs/nilfs2/dir.c                       |  3 ++-
>  fs/nilfs2/file.c                      |  2 ++
>  fs/ntfs3/dir.c                        |  3 +++
>  fs/ntfs3/file.c                       |  3 +++
>  fs/ocfs2/file.c                       |  5 +++++
>  fs/orangefs/dir.c                     |  4 +++-
>  fs/orangefs/file.c                    |  1 +
>  fs/overlayfs/file.c                   |  2 ++
>  fs/overlayfs/readdir.c                |  2 ++
>  fs/qnx4/dir.c                         |  2 ++
>  fs/qnx6/dir.c                         |  2 ++
>  fs/read_write.c                       |  2 ++
>  fs/smb/client/cifsfs.c                |  1 -
>  fs/squashfs/dir.c                     |  2 ++
>  fs/squashfs/file.c                    |  4 +++-
>  fs/udf/dir.c                          |  2 ++
>  fs/udf/file.c                         |  2 ++
>  fs/ufs/dir.c                          |  2 ++
>  fs/ufs/file.c                         |  2 ++
>  fs/vboxsf/dir.c                       |  1 -
>  fs/vboxsf/file.c                      |  1 -
>  fs/xfs/xfs_file.c                     |  3 +++
>  include/linux/fs.h                    |  1 -
>  mm/shmem.c                            |  2 ++
>  61 files changed, 116 insertions(+), 42 deletions(-)
> ---
> base-commit: 731ce71a6c8adb8b8f873643beacaeedc1564500
> change-id: 20260107-setlease-6-20-299eb5695c5a
> 
> Best regards,
> -- 
> Jeff Layton <jlayton at kernel.org>
> 
-- 
Jan Kara <jack at suse.com>
SUSE Labs, CR