Merge patch series "vfs: require filesystems to explicitly opt-in to lease support"

Jeff Layton <jlayton@kernel.org> says:

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-6-19-v1-0-85f034abcc57@kernel.org/

* patches from https://patch.msgid.link/20260108-setlease-6-20-v1-0-ea4dec9b67fa@kernel.org: (24 commits)
  fs: remove simple_nosetlease()
  filelock: default to returning -EINVAL when ->setlease operation is NULL
  xfs: add setlease file operation
  ufs: add setlease file operation
  udf: add setlease file operation
  tmpfs: add setlease file operation
  squashfs: add setlease file operation
  overlayfs: add setlease file operation
  orangefs: add setlease file operation
  ocfs2: add setlease file operation
  ntfs3: add setlease file operation
  nilfs2: add setlease file operation
  jfs: add setlease file operation
  jffs2: add setlease file operation
  gfs2: add a setlease file operation
  fat: add setlease file operation
  f2fs: add setlease file operation
  exfat: add setlease file operation
  ext4: add setlease file operation
  ext2: add setlease file operation
  ...

Link: https://patch.msgid.link/20260108-setlease-6-20-v1-0-ea4dec9b67fa@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

Author: brauner

Documentation/filesystems/porting.rst

@@ -1334,3 +1334,12 @@ end_creating() and the parent will be unlocked precisely when necessary.
 
 kill_litter_super() is gone; convert to DCACHE_PERSISTENT use (as all
 in-tree filesystems have done).
+
+---
+
+**mandatory**
+
+The ->setlease() file_operation must now be explicitly set in order to provide
+support for leases. When set to NULL, the kernel will now return -EINVAL to
+attempts to set a lease. Filesystems that wish to use the kernel-internal lease
+implementation should set it to generic_setlease().

Documentation/filesystems/vfs.rst

@@ -1180,9 +1180,12 @@ otherwise noted.
 	method is used by the splice(2) system call
 
 ``setlease``
-	called by the VFS to set or release a file lock lease.  setlease
-	implementations should call generic_setlease to record or remove
-	the lease in the inode after setting it.
+	called by the VFS to set or release a file lock lease.  Local
+	filesystems that wish to use the kernel-internal lease implementation
+	should set this to generic_setlease(). Other setlease implementations
+	should call generic_setlease() to record or remove the lease in the inode
+	after setting it. When set to NULL, attempts to set or remove a lease will
+	return -EINVAL.
 
 ``fallocate``
 	called by the VFS to preallocate blocks or punch a hole.

fs/9p/vfs_dir.c

@@ -242,7 +242,6 @@ const struct file_operations v9fs_dir_operations = {
 	.iterate_shared = v9fs_dir_readdir,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
-	.setlease = simple_nosetlease,
 };
 
 const struct file_operations v9fs_dir_operations_dotl = {
@@ -252,5 +251,4 @@ const struct file_operations v9fs_dir_operations_dotl = {
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
 	.fsync = v9fs_file_fsync_dotl,
-	.setlease = simple_nosetlease,
 };

fs/9p/vfs_file.c

@@ -517,7 +517,6 @@ const struct file_operations v9fs_file_operations = {
 	.splice_read = v9fs_file_splice_read,
 	.splice_write = iter_file_splice_write,
 	.fsync = v9fs_file_fsync,
-	.setlease = simple_nosetlease,
 };
 
 const struct file_operations v9fs_file_operations_dotl = {
@@ -532,5 +531,4 @@ const struct file_operations v9fs_file_operations_dotl = {
 	.splice_read = v9fs_file_splice_read,
 	.splice_write = iter_file_splice_write,
 	.fsync = v9fs_file_fsync_dotl,
-	.setlease = simple_nosetlease,
 };

fs/affs/dir.c

@@ -15,6 +15,7 @@
  */
 
 #include <linux/iversion.h>
+#include <linux/filelock.h>
 #include "affs.h"
 
 struct affs_dir_data {
@@ -55,6 +56,7 @@ const struct file_operations affs_dir_operations = {
 	.iterate_shared	= affs_readdir,
 	.fsync		= affs_file_fsync,
 	.release	= affs_dir_release,
+	.setlease	= generic_setlease,
 };
 
 /*

fs/affs/file.c

@@ -15,6 +15,7 @@
 
 #include <linux/uio.h>
 #include <linux/blkdev.h>
+#include <linux/filelock.h>
 #include <linux/mpage.h>
 #include "affs.h"
 
@@ -1008,6 +1009,7 @@ const struct file_operations affs_file_operations = {
 	.release	= affs_file_release,
 	.fsync		= affs_file_fsync,
 	.splice_read	= filemap_splice_read,
+	.setlease	= generic_setlease,
 };
 
 const struct inode_operations affs_file_inode_operations = {

fs/befs/linuxvfs.c

@@ -14,6 +14,7 @@
 #include <linux/fs_context.h>
 #include <linux/fs_parser.h>
 #include <linux/errno.h>
+#include <linux/filelock.h>
 #include <linux/stat.h>
 #include <linux/nls.h>
 #include <linux/buffer_head.h>
@@ -79,6 +80,7 @@ static const struct file_operations befs_dir_operations = {
 	.read		= generic_read_dir,
 	.iterate_shared	= befs_readdir,
 	.llseek		= generic_file_llseek,
+	.setlease	= generic_setlease,
 };
 
 static const struct inode_operations befs_dir_inode_operations = {

fs/btrfs/file.c

@@ -10,6 +10,7 @@
 #include <linux/string.h>
 #include <linux/backing-dev.h>
 #include <linux/falloc.h>
+#include <linux/filelock.h>
 #include <linux/writeback.h>
 #include <linux/compat.h>
 #include <linux/slab.h>
@@ -3867,6 +3868,7 @@ const struct file_operations btrfs_file_operations = {
 	.remap_file_range = btrfs_remap_file_range,
 	.uring_cmd	= btrfs_uring_cmd,
 	.fop_flags	= FOP_BUFFER_RASYNC | FOP_BUFFER_WASYNC,
+	.setlease	= generic_setlease,
 };
 
 int btrfs_fdatawrite_range(struct btrfs_inode *inode, loff_t start, loff_t end)

fs/btrfs/inode.c

@@ -8,6 +8,7 @@
 #include <linux/bio.h>
 #include <linux/blk-cgroup.h>
 #include <linux/file.h>
+#include <linux/filelock.h>
 #include <linux/fs.h>
 #include <linux/fs_struct.h>
 #include <linux/pagemap.h>
@@ -10596,6 +10597,7 @@ static const struct file_operations btrfs_dir_file_operations = {
 #endif
 	.release        = btrfs_release_file,
 	.fsync		= btrfs_sync_file,
+	.setlease	= generic_setlease,
 };
 
 /*

fs/ceph/dir.c

@@ -2214,15 +2214,13 @@ const struct file_operations ceph_dir_fops = {
 	.fsync = ceph_fsync,
 	.lock = ceph_lock,
 	.flock = ceph_flock,
-	.setlease = simple_nosetlease,
 };
 
 const struct file_operations ceph_snapdir_fops = {
 	.iterate_shared = shared_ceph_readdir,
 	.llseek = ceph_dir_llseek,
 	.open = ceph_open,
 	.release = ceph_release,
-	.setlease = simple_nosetlease,
 };
 
 const struct inode_operations ceph_dir_iops = {