Re: [PATCH v3 27/38] nfsd: add notification handlers for dir events
From: Jeff Layton <jlayton@kernel.org>
Date: 2025-09-25 17:15:58
Also in:
linux-cifs, linux-doc, linux-fsdevel, linux-nfs, linux-unionfs, linux-xfs, lkml, netfs
On Wed, 2025-09-24 at 14:06 -0400, Jeff Layton wrote:
Add the necessary parts to accept a fsnotify callback for directory change event and create a CB_NOTIFY request for it. When a dir nfsd_file is created set a handle_event callback to handle the notification. Use that to allocate a nfsd_notify_event object and then hand off a reference to each delegation's CB_NOTIFY. If anything fails along the way, recall any affected delegations. Signed-off-by: Jeff Layton <jlayton@kernel.org> --- fs/nfsd/filecache.c | 51 ++++++++++---- fs/nfsd/nfs4callback.c | 19 +++-- fs/nfsd/nfs4state.c | 185 +++++++++++++++++++++++++++++++++++++++++++++++++ fs/nfsd/nfs4xdr.c | 95 +++++++++++++++++++++++++ fs/nfsd/state.h | 2 + fs/nfsd/xdr4.h | 2 + 6 files changed, 337 insertions(+), 17 deletions(-)
[...]
+
+int
+nfsd_handle_dir_event(u32 mask, const struct inode *dir, const void *data,
+ int data_type, const struct qstr *name)
+{
+ struct dentry *dentry = fsnotify_data_dentry(data, data_type);
+ struct file_lock_context *ctx;
+ struct file_lock_core *flc;
+ struct nfsd_notify_event *evt;
+
+ ctx = locks_inode_context(dir);
+ if (!ctx || list_empty(&ctx->flc_lease))
+ return 0;
+
+ evt = alloc_nfsd_notify_event(mask, name, dentry);
+ if (!evt) {
+ nfsd_recall_all_dir_delegs(dir);
+ return 0;
+ }
+
+ spin_lock(&ctx->flc_lock);
+ list_for_each_entry(flc, &ctx->flc_lease, flc_list) {
+ struct file_lease *fl = container_of(flc, struct file_lease, c);
+ struct nfs4_delegation *dp = flc->flc_owner;
+ struct nfsd4_cb_notify *ncn = &dp->dl_cb_notify;
+
+ if (!should_notify_deleg(mask, fl))
+ continue;
+
+ spin_lock(&ncn->ncn_lock);
+ if (ncn->ncn_evt_cnt >= NOTIFY4_EVENT_QUEUE_SIZE) {
+ /* We're generating notifications too fast. Recall. */
+ spin_unlock(&ncn->ncn_lock);
+ nfsd_break_deleg_cb(fl);
+ continue;
+ }
+ ncn->ncn_evt[ncn->ncn_evt_cnt++] = nfsd_notify_event_get(evt);The above nfsd_notify_event_get() causes a refcount leak. Fixed in tree. -- Jeff Layton [off-list ref]