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

[Jeff Layton <jlayton@kernel.org>]

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@kernel.org>
---
 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