Re: [PATCH 00/20] filelock: split struct file_lock into file_lock and file_lease structs

Chuck Lever
2024-01-17T15:15:22Z

On Tue, Jan 16, 2024 at 02:45:56PM -0500, Jeff Layton wrote:
> Long ago, file locks used to hang off of a singly-linked list in struct
> inode. Because of this, when leases were added, they were added to the
> same list and so they had to be tracked using the same sort of
> structure.
>
> Several years ago, we added struct file_lock_context, which allowed us
> to use separate lists to track different types of file locks. Given
> that, leases no longer need to be tracked using struct file_lock.
>
> That said, a lot of the underlying infrastructure _is_ the same between
> file leases and locks, so we can't completely separate everything.

Naive question: locks and leases are similar. Why do they need to be
split apart? The cover letter doesn't address that, and I'm new
enough at this that I don't have that context.

> This patchset first splits a group of fields used by both file locks and
> leases into a new struct file_lock_core, that is then embedded in struct
> file_lock. Coccinelle was then used to convert a lot of the callers to
> deal with the move, with the remaining 25% or so converted by hand.
>
> It then converts several internal functions in fs/locks.c to work
> with struct file_lock_core. Lastly, struct file_lock is split into
> struct file_lock and file_lease, and the lease-related APIs converted to
> take struct file_lease.
>
> After the first few patches (which I left split up for easier review),
> the set should be bisectable. I'll plan to squash the first few
> together to make sure the resulting set is bisectable before merge.
>
> Finally, I left the coccinelle scripts I used in tree. I had heard it
> was preferable to merge those along with the patches that they
> generate, but I wasn't sure where they go. I can either move those to a
> more appropriate location or we can just drop that commit if it's not
> needed.
>
> I'd like to have this considered for inclusion in v6.9. Christian, would
> you be amenable to shepherding this into mainline (assuming there are no
> major objections, of course)?
>
> Signed-off-by: Jeff Layton <jlayton@kernel.org>
> ---
> Jeff Layton (20):
> filelock: split common fields into struct file_lock_core
> filelock: add coccinelle scripts to move fields to struct file_lock_core
> filelock: the results of the coccinelle conversion
> filelock: fixups after the coccinelle changes
> filelock: convert some internal functions to use file_lock_core instead
> filelock: convert more internal functions to use file_lock_core
> filelock: make posix_same_owner take file_lock_core pointers
> filelock: convert posix_owner_key to take file_lock_core arg
> filelock: make locks_{insert,delete}_global_locks take file_lock_core arg
> filelock: convert locks_{insert,delete}_global_blocked
> filelock: convert the IS_* macros to take file_lock_core
> filelock: make __locks_delete_block and __locks_wake_up_blocks take file_lock_core
> filelock: convert __locks_insert_block, conflict and deadlock checks to use file_lock_core
> filelock: convert fl_blocker to file_lock_core
> filelock: clean up locks_delete_block internals
> filelock: reorganize locks_delete_block and __locks_insert_block
> filelock: make assign_type helper take a file_lock_core pointer
> filelock: convert locks_wake_up_blocks to take a file_lock_core pointer
> filelock: convert locks_insert_lock_ctx and locks_delete_lock_ctx
> filelock: split leases out of struct file_lock
>
> cocci/filelock.cocci | 81 +++++
> cocci/filelock2.cocci | 6 +
> cocci/nlm.cocci | 81 +++++
> fs/9p/vfs_file.c | 38 +-
> fs/afs/flock.c | 55 +--
> fs/ceph/locks.c | 74 ++--
> fs/dlm/plock.c | 44 +--
> fs/fuse/file.c | 14 +-
> fs/gfs2/file.c | 16 +-
> fs/libfs.c | 2 +-
> fs/lockd/clnt4xdr.c | 14 +-
> fs/lockd/clntlock.c | 2 +-
> fs/lockd/clntproc.c | 60 +--
> fs/lockd/clntxdr.c | 14 +-
> fs/lockd/svc4proc.c | 10 +-
> fs/lockd/svclock.c | 64 ++--
> fs/lockd/svcproc.c | 10 +-
> fs/lockd/svcsubs.c | 24 +-
> fs/lockd/xdr.c | 14 +-
> fs/lockd/xdr4.c | 14 +-
> fs/locks.c | 785 ++++++++++++++++++++++------------------
> fs/nfs/delegation.c | 4 +-
> fs/nfs/file.c | 22 +-
> fs/nfs/nfs3proc.c | 2 +-
> fs/nfs/nfs4_fs.h | 2 +-
> fs/nfs/nfs4file.c | 2 +-
> fs/nfs/nfs4proc.c | 39 +-
> fs/nfs/nfs4state.c | 6 +-
> fs/nfs/nfs4trace.h | 4 +-
> fs/nfs/nfs4xdr.c | 8 +-
> fs/nfs/write.c | 8 +-
> fs/nfsd/filecache.c | 4 +-
> fs/nfsd/nfs4callback.c | 2 +-
> fs/nfsd/nfs4layouts.c | 34 +-
> fs/nfsd/nfs4state.c | 98 ++---
> fs/ocfs2/locks.c | 12 +-
> fs/ocfs2/stack_user.c | 2 +-
> fs/smb/client/cifsfs.c | 2 +-
> fs/smb/client/cifssmb.c | 8 +-
> fs/smb/client/file.c | 74 ++--
> fs/smb/client/smb2file.c | 2 +-
> fs/smb/server/smb2pdu.c | 44 +--
> fs/smb/server/vfs.c | 14 +-
> include/linux/filelock.h | 58 ++-
> include/linux/fs.h | 5 +-
> include/linux/lockd/lockd.h | 8 +-
> include/trace/events/afs.h | 4 +-
> include/trace/events/filelock.h | 54 +--
> 48 files changed, 1119 insertions(+), 825 deletions(-)
> ---
> base-commit: 052d534373b7ed33712a63d5e17b2b6cdbce84fd
> change-id: 20240116-flsplit-bdb46824db68
>
> Best regards,
> --
> Jeff Layton <jlayton@kernel.org>
>

--
Chuck Lever