[PATCH 24/24] nfsd: add support to CB_NOTIFY for dir attribute changes
From: Jeff Layton
Date: Tue Apr 07 2026 - 09:32:54 EST
If the client requested dir attribute change notifications, send those
alongside any set of add/remove/rename events. Note that the server will
still recall the delegation on a SETATTR, so these are only sent for
changes to child dirents.
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/nfsd/nfs4state.c | 25 ++++++++++++++++++++--
fs/nfsd/nfs4xdr.c | 61 +++++++++++++++++++++++++++++++++++++++++++++--------
fs/nfsd/xdr4.h | 2 ++
3 files changed, 77 insertions(+), 11 deletions(-)
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index c4b6f4d65a47..01a2fb11dc0e 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -3470,10 +3470,15 @@ nfsd4_cb_notify_prepare(struct nfsd4_callback *cb)
struct nfsd_notify_event *events[NOTIFY4_EVENT_QUEUE_SIZE];
struct xdr_buf xdr = { .buflen = PAGE_SIZE * NOTIFY4_PAGE_ARRAY_SIZE,
.pages = ncn->ncn_pages };
+ int limit = NOTIFY4_EVENT_QUEUE_SIZE;
struct xdr_stream stream;
struct nfsd_file *nf;
- int count, i;
bool error = false;
+ int count, i;
+
+ /* Save a slot for dir attr update if requested */
+ if (dp->dl_notify_mask & BIT(NOTIFY4_CHANGE_DIR_ATTRS))
+ --limit;
xdr_init_encode_pages(&stream, &xdr);
@@ -3487,7 +3492,7 @@ nfsd4_cb_notify_prepare(struct nfsd4_callback *cb)
}
/* we can't keep up! */
- if (count > NOTIFY4_EVENT_QUEUE_SIZE) {
+ if (count > limit) {
spin_unlock(&ncn->ncn_lock);
goto out_recall;
}
@@ -3534,6 +3539,22 @@ nfsd4_cb_notify_prepare(struct nfsd4_callback *cb)
nfsd_notify_event_put(nne);
}
if (!error) {
+ if (dp->dl_notify_mask & BIT(NOTIFY4_CHANGE_DIR_ATTRS)) {
+ u32 *maskp = (u32 *)xdr_reserve_space(&stream, sizeof(*maskp));
+
+ if (maskp) {
+ u8 *p = nfsd4_encode_dir_attr_change(&stream, dp, nf);
+
+ if (p) {
+ *maskp = BIT(NOTIFY4_CHANGE_DIR_ATTRS);
+ ncn->ncn_nf[count].notify_mask.count = 1;
+ ncn->ncn_nf[count].notify_mask.element = maskp;
+ ncn->ncn_nf[count].notify_vals.data = p;
+ ncn->ncn_nf[count].notify_vals.len = (u8 *)stream.p - p;
+ ++count;
+ }
+ }
+ }
ncn->ncn_nf_cnt = count;
nfsd_file_put(nf);
return true;
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 35646809becb..6e76502ca149 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -4152,11 +4152,11 @@ nfsd4_setup_notify_entry4(struct notify_entry4 *ne, struct xdr_stream *xdr,
struct nfsd_file *nf, char *name, u32 namelen)
{
struct nfs4_file *fi = dp->dl_stid.sc_file;
- struct path path = { .mnt = nf->nf_file->f_path.mnt,
- .dentry = dentry };
+ struct path path = nf->nf_file->f_path;
struct nfsd4_fattr_args args = { };
uint32_t *attrmask;
__be32 status;
+ bool parent;
int ret;
/* Reserve space for attrmask */
@@ -4168,6 +4168,9 @@ nfsd4_setup_notify_entry4(struct notify_entry4 *ne, struct xdr_stream *xdr,
ne->ne_file.len = namelen;
ne->ne_attrs.attrmask.element = attrmask;
+ parent = (dentry == path.dentry);
+ path.dentry = dentry;
+
/* FIXME: d_find_alias for inode ? */
if (!path.dentry || !d_inode(path.dentry))
goto noattrs;
@@ -4183,15 +4186,20 @@ nfsd4_setup_notify_entry4(struct notify_entry4 *ne, struct xdr_stream *xdr,
args.change_attr = nfsd4_change_attribute(&args.stat);
- attrmask[0] = dp->dl_child_attrs[0];
- attrmask[1] = dp->dl_child_attrs[1];
- attrmask[2] = 0;
+ if (parent) {
+ attrmask[0] = dp->dl_dir_attrs[0];
+ attrmask[1] = dp->dl_dir_attrs[1];
+ } else {
+ attrmask[0] = dp->dl_child_attrs[0];
+ attrmask[1] = dp->dl_child_attrs[1];
- if (!setup_notify_fhandle(dentry, fi, nf, &args))
- attrmask[0] &= ~FATTR4_WORD0_FILEHANDLE;
+ if (!setup_notify_fhandle(dentry, fi, nf, &args))
+ attrmask[0] &= ~FATTR4_WORD0_FILEHANDLE;
- if (!(args.stat.result_mask & STATX_BTIME))
- attrmask[1] &= ~FATTR4_WORD1_TIME_CREATE;
+ if (!(args.stat.result_mask & STATX_BTIME))
+ attrmask[1] &= ~FATTR4_WORD1_TIME_CREATE;
+ }
+ attrmask[2] = 0;
ne->ne_attrs.attrmask.count = 2;
ne->ne_attrs.attr_vals.data = (u8 *)xdr->p;
@@ -4283,6 +4291,41 @@ u8 *nfsd4_encode_notify_event(struct xdr_stream *xdr, struct nfsd_notify_event *
return NULL;
}
+/**
+ * nfsd4_encode_dir_attr_change
+ * @xdr: stream to which to encode the fattr4
+ * @dp: delegation where the event occurred
+ * @nf: nfsd_file opened on the directory
+ *
+ * Encode a dir attr change event.
+ */
+u8 *nfsd4_encode_dir_attr_change(struct xdr_stream *xdr, struct nfs4_delegation *dp,
+ struct nfsd_file *nf)
+{
+ struct dentry *dentry = nf->nf_file->f_path.dentry;
+ struct notify_attr4 na = { };
+ struct name_snapshot n;
+ bool ret;
+ u8 *p = NULL;
+
+ if (!(dp->dl_notify_mask & BIT(NOTIFY4_CHANGE_DIR_ATTRS)))
+ return NULL;
+
+ take_dentry_name_snapshot(&n, dentry);
+ ret = nfsd4_setup_notify_entry4(&na.na_changed_entry, xdr,
+ dentry, dp, nf, (char *)n.name.name,
+ n.name.len);
+
+ /* Don't bother with the event if we're not encoding attrs */
+ if (ret && na.na_changed_entry.ne_attrs.attr_vals.len) {
+ p = (u8 *)xdr->p;
+ if (!xdrgen_encode_notify_attr4(xdr, &na))
+ p = NULL;
+ }
+ release_dentry_name_snapshot(&n);
+ return p;
+}
+
static void svcxdr_init_encode_from_buffer(struct xdr_stream *xdr,
struct xdr_buf *buf, __be32 *p, int bytes)
{
diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
index d276840aca50..cf7f0df68d63 100644
--- a/fs/nfsd/xdr4.h
+++ b/fs/nfsd/xdr4.h
@@ -958,6 +958,8 @@ __be32 nfsd4_encode_fattr_to_buf(__be32 **p, int words,
u8 *nfsd4_encode_notify_event(struct xdr_stream *xdr, struct nfsd_notify_event *nne,
struct nfs4_delegation *dd, struct nfsd_file *nf,
u32 *notify_mask);
+u8 *nfsd4_encode_dir_attr_change(struct xdr_stream *xdr, struct nfs4_delegation *dp,
+ struct nfsd_file *nf);
extern __be32 nfsd4_setclientid(struct svc_rqst *rqstp,
struct nfsd4_compound_state *, union nfsd4_op_u *u);
extern __be32 nfsd4_setclientid_confirm(struct svc_rqst *rqstp,
--
2.53.0