vfs: require filesystems to explicitly opt-in to lease support

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.

[1]: https://lore.kernel.org/linux-fsdevel/20260107-setlease-6...

Signed-off-by: Jeff Layton <jlayton@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@kernel.org>