[PATCH v7 18/20] nfsd: properly track requested child attributes

From: Jeff Layton

Date: Tue Jun 16 2026 - 08:13:24 EST


Track the union of requested and supported child attributes in the
delegation, and only encode the attributes in that union when sending
add/remove/rename updates.

Since the requested child attributes can now include word1 attributes,
gddr_child_attributes[1] may be non-zero and nfsd4_encode_bitmap4() can
emit a two-word bitmap. Bump the child-attribute bitmap budget in
nfsd4_get_dir_delegation_rsize() from one word to two accordingly, so the
reply-size check before this non-idempotent op accounts for the larger
encoding.

Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/nfsd/nfs4proc.c | 4 +++-
fs/nfsd/nfs4state.c | 18 ++++++++++++++++++
fs/nfsd/nfs4xdr.c | 15 ++++++---------
fs/nfsd/state.h | 1 +
4 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index be79b6063afe..576346578ee0 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -2608,6 +2608,8 @@ nfsd4_get_dir_delegation(struct svc_rqst *rqstp,

gdd->gddrnf_status = GDD4_OK;
memcpy(&gdd->gddr_stateid, &dd->dl_stid.sc_stateid, sizeof(gdd->gddr_stateid));
+ gdd->gddr_child_attributes[0] = dd->dl_child_attrs[0];
+ gdd->gddr_child_attributes[1] = dd->dl_child_attrs[1];
nfs4_put_stid(&dd->dl_stid);
return nfs_ok;
}
@@ -3574,7 +3576,7 @@ static u32 nfsd4_get_dir_delegation_rsize(const struct svc_rqst *rqstp,
op_encode_verifier_maxsz +
op_encode_stateid_maxsz +
2 /* gddr_notification */ +
- 2 /* gddr_child_attributes */ +
+ 3 /* gddr_child_attributes */ +
2 /* gddr_dir_attributes */) * sizeof(__be32);
}

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 682c00fbd2fb..c4dc0428f0a6 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -9959,6 +9959,21 @@ nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct dentry *dentry,
return status;
}

+#define GDD_WORD0_CHILD_ATTRS (FATTR4_WORD0_TYPE | \
+ FATTR4_WORD0_CHANGE | \
+ FATTR4_WORD0_SIZE | \
+ FATTR4_WORD0_FILEID | \
+ FATTR4_WORD0_FILEHANDLE)
+
+#define GDD_WORD1_CHILD_ATTRS (FATTR4_WORD1_MODE | \
+ FATTR4_WORD1_NUMLINKS | \
+ FATTR4_WORD1_RAWDEV | \
+ FATTR4_WORD1_SPACE_USED | \
+ FATTR4_WORD1_TIME_ACCESS | \
+ FATTR4_WORD1_TIME_METADATA | \
+ FATTR4_WORD1_TIME_MODIFY | \
+ FATTR4_WORD1_TIME_CREATE)
+
/**
* nfsd_get_dir_deleg - attempt to get a directory delegation
* @cstate: compound state
@@ -10027,6 +10042,9 @@ nfsd_get_dir_deleg(struct nfsd4_compound_state *cstate,
dp->dl_stid.sc_export =
exp_get(cstate->current_fh.fh_export);

+ dp->dl_child_attrs[0] = gdd->gdda_child_attributes[0] & GDD_WORD0_CHILD_ATTRS;
+ dp->dl_child_attrs[1] = gdd->gdda_child_attributes[1] & GDD_WORD1_CHILD_ATTRS;
+
/*
* NB: gddr_notification[0] represents the notifications that
* will be granted to the client
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index b3a4b134d309..0649bb4cf2e7 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -4284,18 +4284,15 @@ nfsd4_setup_notify_entry4(struct notify_entry4 *ne, struct xdr_stream *xdr,

args.change_attr = nfsd4_change_attribute(&args.stat);

- attrmask[0] = FATTR4_WORD0_TYPE | FATTR4_WORD0_CHANGE |
- FATTR4_WORD0_SIZE | FATTR4_WORD0_FILEID;
- attrmask[1] = FATTR4_WORD1_MODE | FATTR4_WORD1_NUMLINKS | FATTR4_WORD1_RAWDEV |
- FATTR4_WORD1_SPACE_USED | FATTR4_WORD1_TIME_ACCESS |
- FATTR4_WORD1_TIME_METADATA | FATTR4_WORD1_TIME_MODIFY;
+ attrmask[0] = dp->dl_child_attrs[0];
+ attrmask[1] = dp->dl_child_attrs[1];
attrmask[2] = 0;

- if (setup_notify_fhandle(dentry, dp, nf, &args))
- attrmask[0] |= FATTR4_WORD0_FILEHANDLE;
+ if (!setup_notify_fhandle(dentry, dp, 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;

ne->ne_attrs.attrmask.count = 2;
ne->ne_attrs.attr_vals.data = (u8 *)xdr->p;
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index 7a66048a130c..2bc54546deb3 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -300,6 +300,7 @@ struct nfs4_delegation {

/* For dir delegations */
u32 dl_notify_mask;
+ u32 dl_child_attrs[2];
};

static inline bool deleg_is_read(u32 dl_type)

--
2.54.0