Re: [PATCH v2 00/41] filelock: split struct file_lock into file_lock and file_lease structs

[Jeff Layton <jlayton@kernel.org>]

On Thu, 2024-01-25 at 09:57 -0500, Chuck Lever wrote:
> On Thu, Jan 25, 2024 at 05:42:41AM -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.
> > 
> > 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.
> > 
> > Signed-off-by: Jeff Layton <jlayton@kernel.org>
> 
> v2 looks nicer.
> 
> I would add a few list handling primitives, as I see enough
> instances of list_for_each_entry, list_for_each_entry_safe,
> list_first_entry, and list_first_entry_or_null on fl_core.flc_list
> to make it worth having those.
> 
> Also, there doesn't seem to be benefit for API consumers to have to
> understand the internal structure of struct file_lock/lease to reach
> into fl_core. Having accessor functions for common fields like
> fl_type and fl_flags could be cleaner.
> 

That is a good suggestion. I had considered it before and figured "why
bother", but I think that would make things simpler.

I'll plan to do a v3 that has more helpers. Possibly we can just convert
some of the subsystems ahead of time and avoid some churn. Stay tuned...

> For the series:
> 
> Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
> 
> For the nfsd and lockd parts:
> 
> Acked-by: Chuck Lever <chuck.lever@oracle.com>
> 
> 
> > ---
> > Changes in v2:
> > - renamed file_lock_core fields to have "flc_" prefix
> > - used macros to more easily do the change piecemeal
> > - broke up patches into per-subsystem ones
> > - Link to v1: https://lore.kernel.org/r/20240116-flsplit-v1-0-c9d0f4370a5d@kernel.org
> > 
> > ---
> > Jeff Layton (41):
> >       filelock: rename some fields in tracepoints
> >       filelock: rename fl_pid variable in lock_get_status
> >       dlm: rename fl_flags variable in dlm_posix_unlock
> >       nfs: rename fl_flags variable in nfs4_proc_unlck
> >       nfsd: rename fl_type and fl_flags variables in nfsd4_lock
> >       lockd: rename fl_flags and fl_type variables in nlmclnt_lock
> >       9p: rename fl_type variable in v9fs_file_do_lock
> >       afs: rename fl_type variable in afs_next_locker
> >       filelock: drop the IS_* macros
> >       filelock: split common fields into struct file_lock_core
> >       filelock: add coccinelle scripts to move fields to struct file_lock_core
> >       filelock: have fs/locks.c deal with file_lock_core directly
> >       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: 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: convert locks_translate_pid to take file_lock_core
> >       filelock: convert seqfile handling to use file_lock_core
> >       9p: adapt to breakup of struct file_lock
> >       afs: adapt to breakup of struct file_lock
> >       ceph: adapt to breakup of struct file_lock
> >       dlm: adapt to breakup of struct file_lock
> >       gfs2: adapt to breakup of struct file_lock
> >       lockd: adapt to breakup of struct file_lock
> >       nfs: adapt to breakup of struct file_lock
> >       nfsd: adapt to breakup of struct file_lock
> >       ocfs2: adapt to breakup of struct file_lock
> >       smb/client: adapt to breakup of struct file_lock
> >       smb/server: adapt to breakup of struct file_lock
> >       filelock: remove temporary compatability macros
> >       filelock: split leases out of struct file_lock
> > 
> >  cocci/filelock.cocci            |  88 +++++
> >  cocci/nlm.cocci                 |  81 ++++
> >  fs/9p/vfs_file.c                |  40 +-
> >  fs/afs/flock.c                  |  59 +--
> >  fs/ceph/locks.c                 |  74 ++--
> >  fs/dlm/plock.c                  |  44 +--
> >  fs/gfs2/file.c                  |  16 +-
> >  fs/libfs.c                      |   2 +-
> >  fs/lockd/clnt4xdr.c             |  14 +-
> >  fs/lockd/clntlock.c             |   2 +-
> >  fs/lockd/clntproc.c             |  65 +--
> >  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                      | 848 ++++++++++++++++++++++------------------
> >  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              |  22 +-
> >  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             | 118 +++---
> >  fs/ocfs2/locks.c                |  12 +-
> >  fs/ocfs2/stack_user.c           |   2 +-
> >  fs/open.c                       |   2 +-
> >  fs/posix_acl.c                  |   4 +-
> >  fs/smb/client/cifsfs.c          |   2 +-
> >  fs/smb/client/cifssmb.c         |   8 +-
> >  fs/smb/client/file.c            |  76 ++--
> >  fs/smb/client/smb2file.c        |   2 +-
> >  fs/smb/server/smb2pdu.c         |  44 +--
> >  fs/smb/server/vfs.c             |  14 +-
> >  include/linux/filelock.h        |  80 ++--
> >  include/linux/fs.h              |   5 +-
> >  include/linux/lockd/lockd.h     |   8 +-
> >  include/linux/lockd/xdr.h       |   2 +-
> >  include/trace/events/afs.h      |   4 +-
> >  include/trace/events/filelock.h | 102 ++---
> >  49 files changed, 1198 insertions(+), 923 deletions(-)
> > ---
> > base-commit: 615d300648869c774bd1fe54b4627bb0c20faed4
> > change-id: 20240116-flsplit-bdb46824db68
> > 
> > Best regards,
> > -- 
> > Jeff Layton <jlayton@kernel.org>
> > 
> 

-- 
Jeff Layton <jlayton@kernel.org>