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

Jeff Layton
2026-04-28T07:10:18Z

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>