[PATCH v3 33/38] nfsd: allow encoding a filehandle into fattr4 without a svc_fh

From: Jeff Layton
Date: Wed Sep 24 2025 - 14:18:08 EST


The current fattr4 encoder requires a svc_fh in order to encode the
filehandle. This is not available in a CB_NOTIFY callback. Add a a new
"fhandle" field to struct nfsd4_fattr_args and copy the filehandle into
there from the svc_fh. CB_NOTIFY will populate it via other means.

Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/nfsd/nfs4xdr.c | 35 ++++++++++++++++++++---------------
1 file changed, 20 insertions(+), 15 deletions(-)

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 1db2bd974bfa9d899f590f4b4e869115ab73aff6..822a9d47dd88df579e4f57f04dd6737653f71c94 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -2561,7 +2561,7 @@ nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
}

static __be32 nfsd4_encode_nfs_fh4(struct xdr_stream *xdr,
- struct knfsd_fh *fh_handle)
+ const struct knfsd_fh *fh_handle)
{
return nfsd4_encode_opaque(xdr, fh_handle->fh_raw, fh_handle->fh_size);
}
@@ -2924,6 +2924,7 @@ struct nfsd4_fattr_args {
struct svc_fh *fhp;
struct svc_export *exp;
struct dentry *dentry;
+ struct knfsd_fh fhandle;
struct kstat stat;
struct kstatfs statfs;
struct nfs4_acl *acl;
@@ -3129,7 +3130,7 @@ static __be32 nfsd4_encode_fattr4_acl(struct xdr_stream *xdr,
static __be32 nfsd4_encode_fattr4_filehandle(struct xdr_stream *xdr,
const struct nfsd4_fattr_args *args)
{
- return nfsd4_encode_nfs_fh4(xdr, &args->fhp->fh_handle);
+ return nfsd4_encode_nfs_fh4(xdr, &args->fhandle);
}

static __be32 nfsd4_encode_fattr4_fileid(struct xdr_stream *xdr,
@@ -3678,19 +3679,23 @@ nfsd4_encode_fattr4(struct svc_rqst *rqstp, struct xdr_stream *xdr,
if (err)
goto out_nfserr;
}
- if ((attrmask[0] & (FATTR4_WORD0_FILEHANDLE | FATTR4_WORD0_FSID)) &&
- !fhp) {
- tempfh = kmalloc(sizeof(struct svc_fh), GFP_KERNEL);
- status = nfserr_jukebox;
- if (!tempfh)
- goto out;
- fh_init(tempfh, NFS4_FHSIZE);
- status = fh_compose(tempfh, exp, dentry, NULL);
- if (status)
- goto out;
- args.fhp = tempfh;
- } else
- args.fhp = fhp;
+
+ args.fhp = fhp;
+ if ((attrmask[0] & (FATTR4_WORD0_FILEHANDLE | FATTR4_WORD0_FSID))) {
+ if (!args.fhp) {
+ tempfh = kmalloc(sizeof(struct svc_fh), GFP_KERNEL);
+ status = nfserr_jukebox;
+ if (!tempfh)
+ goto out;
+ fh_init(tempfh, NFS4_FHSIZE);
+ status = fh_compose(tempfh, exp, dentry, NULL);
+ if (status)
+ goto out;
+ args.fhp = tempfh;
+ }
+ if (args.fhp)
+ fh_copy_shallow(&args.fhandle, &args.fhp->fh_handle);
+ }

if (attrmask[0] & FATTR4_WORD0_ACL) {
err = nfsd4_get_nfs4_acl(rqstp, dentry, &args.acl);

--
2.51.0