Re: [PATCH v3 00/28] vfs/nfsd: add support for CB_NOTIFY callbacks in directory delegations

Chuck Lever
2026-04-29T13:41:35Z

On Tue, Apr 28, 2026, at 3:09 AM, Jeff Layton wrote:
> Re-posting the set per Christian's request. The only difference in this
> version is a small error handling fix in alloc_init_dir_deleg(). The old
> version could crash since release_pages() can't handle an array with
> NULL pointers in it.
>
> ---------------------------------8<------------------------------------
>
> This patchset builds on the directory delegation work we did a few
> months ago, to add support for CB_NOTIFY callbacks for some events. In
> particular, creates, unlinks and renames. The server also sends updated
> directory attributes in the notifications. With this support, the client
> can register interest in a directory and get notifications about changes
> within it without losing its lease.
>
> The series starts with patches to allow the vfs to ignore certain types
> of events on directories. nfsd can then request these sorts of
> delegations on directories, and then set up inotify watches on the
> directory to trigger sending CB_NOTIFY events.
>
> This has mainly been tested with pynfs, with some new testcases that
> I'll be posting soon. They seem to work fine with those tests, but I
> don't think we'll want to merge these until we have a complete
> client-side implementation to test against.
>
> Signed-off-by: Jeff Layton <jlayton@kernel.org>
> ---
> Changes in v3:
> - Fix error handling in alloc_init_dir_deleg()
> - Link to v2:
> https://lore.kernel.org/r/20260416-dir-deleg-v2-0-851426a550f6@kernel.org
>
> Changes in v2:
> - Fix __break_lease handling with different lease types on flc_lease
> list
> - Add FSNOTIFY_EVENT_RENAME data type to properly handle
> cross-directory rename events
> - Display fsnotify mask symbolically in tracepoints
> - New tracepoint in fsnotify()
> - Recalc fsnotify mask after unlocking lease instead of before
> - Don't notify client that is making the changes
> - After sending CB_NOTIFY, requeue if new events came in while running
> - Document removal of NFS4_VERIFIER_SIZE/NFS4_FHSIZE from UAPI headers
> - Properly release nfsd_dir_fsnotify_group on server shutdown
> - Link to v1:
> https://lore.kernel.org/r/20260407-dir-deleg-v1-0-aaf68c478abd@kernel.org
>
> ---
> Jeff Layton (28):
> filelock: pass current blocking lease to
> trace_break_lease_block() rather than "new_fl"
> filelock: add support for ignoring deleg breaks for dir change
> events
> filelock: add a tracepoint to start of break_lease()
> filelock: add an inode_lease_ignore_mask helper
> fsnotify: new tracepoint in fsnotify()
> fsnotify: add fsnotify_modify_mark_mask()
> fsnotify: add FSNOTIFY_EVENT_RENAME data type
> nfsd: check fl_lmops in nfsd_breaker_owns_lease()
> nfsd: add protocol support for CB_NOTIFY
> nfs_common: add new NOTIFY4_* flags proposed in RFC8881bis
> nfsd: allow nfsd to get a dir lease with an ignore mask
> nfsd: update the fsnotify mark when setting or removing a dir
> delegation
> nfsd: make nfsd4_callback_ops->prepare operation bool return
> nfsd: add callback encoding and decoding linkages for CB_NOTIFY
> nfsd: use RCU to protect fi_deleg_file
> nfsd: add data structures for handling CB_NOTIFY
> nfsd: add notification handlers for dir events
> nfsd: add tracepoint to dir_event handler
> nfsd: apply the notify mask to the delegation when requested
> nfsd: add helper to marshal a fattr4 from completed args
> nfsd: allow nfsd4_encode_fattr4_change() to work with no export
> nfsd: send basic file attributes in CB_NOTIFY
> nfsd: allow encoding a filehandle into fattr4 without a svc_fh
> nfsd: add a fi_connectable flag to struct nfs4_file
> nfsd: add the filehandle to returned attributes in CB_NOTIFY
> nfsd: properly track requested child attributes
> nfsd: track requested dir attributes
> nfsd: add support to CB_NOTIFY for dir attribute changes
>
> Documentation/sunrpc/xdr/nfs4_1.x | 264 ++++++++++++++-
> fs/attr.c | 2 +-
> fs/locks.c | 118 +++++--
> fs/namei.c | 31 +-
> fs/nfsd/filecache.c | 70 +++-
> fs/nfsd/nfs4callback.c | 60 +++-
> fs/nfsd/nfs4layouts.c | 5 +-
> fs/nfsd/nfs4proc.c | 17 +
> fs/nfsd/nfs4state.c | 551 ++++++++++++++++++++++++++++----
> fs/nfsd/nfs4xdr.c | 323 +++++++++++++++++--
> fs/nfsd/nfs4xdr_gen.c | 601 ++++++++++++++++++++++++++++++++++-
> fs/nfsd/nfs4xdr_gen.h | 20 +-
> fs/nfsd/state.h | 72 ++++-
> fs/nfsd/trace.h | 23 ++
> fs/nfsd/xdr4.h | 5 +
> fs/nfsd/xdr4cb.h | 12 +
> fs/notify/fsnotify.c | 5 +
> fs/notify/mark.c | 29 ++
> fs/posix_acl.c | 4 +-
> fs/xattr.c | 4 +-
> include/linux/filelock.h | 54 +++-
> include/linux/fsnotify.h | 8 +-
> include/linux/fsnotify_backend.h | 21 ++
> include/linux/nfs4.h | 127 --------
> include/linux/sunrpc/xdrgen/nfs4_1.h | 291 ++++++++++++++++-
> include/trace/events/filelock.h | 38 ++-
> include/trace/events/fsnotify.h | 51 +++
> include/trace/misc/fsnotify.h | 35 ++
> include/uapi/linux/nfs4.h | 2 -
> 29 files changed, 2519 insertions(+), 324 deletions(-)
> ---
> base-commit: f4d71dd7fd9cec357c32431fa55c107b96008312
> change-id: 20260325-dir-deleg-339066dd1017
>
> Best regards,
> --
> Jeff Layton <jlayton@kernel.org>

For the series:

Acked-by: Chuck Lever <chuck.lever@oracle.com>

--
Chuck Lever