From f8cba47344f794b54373189bec23195b51020faf Mon Sep 17 00:00:00 2001
From: Chuck Lever <chuck.lever@oracle.com>
Date: Wed, 18 Nov 2020 14:38:47 -0500
Subject: [PATCH] NFSD: Update the NFSv2 GETACL result encoder to use struct
 xdr_stream

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 fs/nfsd/nfs2acl.c | 42 ++++++++++++++++--------------------------
 fs/nfsd/nfsxdr.c  | 24 ++++++++++++++++++++++--
 fs/nfsd/xdr.h     |  3 +++
 3 files changed, 41 insertions(+), 28 deletions(-)

diff --git a/fs/nfsd/nfs2acl.c b/fs/nfsd/nfs2acl.c
index 855e17772eba4..4a15ae6fdbc26 100644
--- a/fs/nfsd/nfs2acl.c
+++ b/fs/nfsd/nfs2acl.c
@@ -242,51 +242,41 @@ static int nfsaclsvc_decode_accessargs(struct svc_rqst *rqstp, __be32 *p)
 /* GETACL */
 static int nfsaclsvc_encode_getaclres(struct svc_rqst *rqstp, __be32 *p)
 {
+	struct xdr_stream *xdr = &rqstp->rq_res_stream;
 	struct nfsd3_getaclres *resp = rqstp->rq_resp;
 	struct dentry *dentry = resp->fh.fh_dentry;
 	struct inode *inode;
-	struct kvec *head = rqstp->rq_res.head;
-	unsigned int base;
-	int n;
 	int w;
 
-	*p++ = resp->status;
-	if (resp->status != nfs_ok)
-		return xdr_ressize_check(rqstp, p);
+	if (!svcxdr_encode_stat(xdr, resp->status))
+		return 0;
 
-	/*
-	 * Since this is version 2, the check for nfserr in
-	 * nfsd_dispatch actually ensures the following cannot happen.
-	 * However, it seems fragile to depend on that.
-	 */
 	if (dentry == NULL || d_really_is_negative(dentry))
-		return 0;
+		return 1;
 	inode = d_inode(dentry);
 
-	p = nfs2svc_encode_fattr(rqstp, p, &resp->fh, &resp->stat);
-	*p++ = htonl(resp->mask);
-	if (!xdr_ressize_check(rqstp, p))
+	if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat))
+		return 0;
+	if (xdr_stream_encode_u32(xdr, resp->mask) < 0)
 		return 0;
-	base = (char *)p - (char *)head->iov_base;
 
 	rqstp->rq_res.page_len = w = nfsacl_size(
 		(resp->mask & NFS_ACL)   ? resp->acl_access  : NULL,
 		(resp->mask & NFS_DFACL) ? resp->acl_default : NULL);
 	while (w > 0) {
 		if (!*(rqstp->rq_next_page++))
-			return 0;
+			return 1;
 		w -= PAGE_SIZE;
 	}
 
-	n = nfsacl_encode(&rqstp->rq_res, base, inode,
-			  resp->acl_access,
-			  resp->mask & NFS_ACL, 0);
-	if (n > 0)
-		n = nfsacl_encode(&rqstp->rq_res, base + n, inode,
-				  resp->acl_default,
-				  resp->mask & NFS_DFACL,
-				  NFS_ACL_DEFAULT);
-	return (n > 0);
+	if (!nfs_stream_encode_acl(xdr, inode, resp->acl_access,
+				   resp->mask & NFS_ACL, 0))
+		return 0;
+	if (!nfs_stream_encode_acl(xdr, inode, resp->acl_default,
+				   resp->mask & NFS_DFACL, NFS_ACL_DEFAULT))
+		return 0;
+
+	return 1;
 }
 
 static int nfsaclsvc_encode_attrstatres(struct svc_rqst *rqstp, __be32 *p)
diff --git a/fs/nfsd/nfsxdr.c b/fs/nfsd/nfsxdr.c
index 5df6f00d76fd5..1fed3a8deb183 100644
--- a/fs/nfsd/nfsxdr.c
+++ b/fs/nfsd/nfsxdr.c
@@ -26,7 +26,16 @@ static const u32 nfs_ftypes[] = {
  * Basic NFSv2 data types (RFC 1094 Section 2.3)
  */
 
-static bool
+/**
+ * svcxdr_encode_stat - Encode an NFSv2 status code
+ * @xdr: XDR stream
+ * @status: status value to encode
+ *
+ * Return values:
+ *   %false: Send buffer space was exhausted
+ *   %true: Success
+ */
+bool
 svcxdr_encode_stat(struct xdr_stream *xdr, __be32 status)
 {
 	__be32 *p;
@@ -250,7 +259,18 @@ encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
 	return p;
 }
 
-static bool
+/**
+ * svcxdr_encode_fattr - Encode NFSv2 file attributes
+ * @rqstp: Context of a completed RPC transaction
+ * @xdr: XDR stream
+ * @fhp: File handle to encode
+ * @stat: Attributes to encode
+ *
+ * Return values:
+ *   %false: Send buffer space was exhausted
+ *   %true: Success
+ */
+bool
 svcxdr_encode_fattr(struct svc_rqst *rqstp, struct xdr_stream *xdr,
 		    const struct svc_fh *fhp, const struct kstat *stat)
 {
diff --git a/fs/nfsd/xdr.h b/fs/nfsd/xdr.h
index bfffcb70a5f8e..ad7f7eabf41a0 100644
--- a/fs/nfsd/xdr.h
+++ b/fs/nfsd/xdr.h
@@ -170,5 +170,8 @@ void nfssvc_release_readres(struct svc_rqst *rqstp);
 /* Helper functions for NFSv2 ACL code */
 __be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp, struct kstat *stat);
 bool svcxdr_decode_fhandle(struct xdr_stream *xdr, struct svc_fh *fhp);
+bool svcxdr_encode_stat(struct xdr_stream *xdr, __be32 status);
+bool svcxdr_encode_fattr(struct svc_rqst *rqstp, struct xdr_stream *xdr,
+			 const struct svc_fh *fhp, const struct kstat *stat);
 
 #endif /* LINUX_NFSD_H */