NFSD: Call NFSv2 encoders on error returns

Remove special dispatcher logic for NFSv2 error responses. These are
rare to the point of becoming extinct, but all NFS responses have to
pay the cost of the extra conditional branches.

With this change, the NFSv2 error cases now get proper
xdr_ressize_check() calls.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

fs/nfsd/nfs2acl.c

@@ -14,7 +14,6 @@
 #include "vfs.h"
 
 #define NFSDDBG_FACILITY		NFSDDBG_PROC
-#define RETURN_STATUS(st)	{ resp->status = (st); return (st); }
 
 /*
  * NULL call.
@@ -35,24 +34,25 @@ static __be32 nfsacld_proc_getacl(struct svc_rqst *rqstp)
 	struct posix_acl *acl;
 	struct inode *inode;
 	svc_fh *fh;
-	__be32 nfserr = 0;
 
 	dprintk("nfsd: GETACL(2acl)   %s\n", SVCFH_fmt(&argp->fh));
 
 	fh = fh_copy(&resp->fh, &argp->fh);
-	nfserr = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_NOP);
-	if (nfserr)
-		RETURN_STATUS(nfserr);
+	resp->status = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_NOP);
+	if (resp->status != nfs_ok)
+		goto out;
 
 	inode = d_inode(fh->fh_dentry);
 
-	if (argp->mask & ~NFS_ACL_MASK)
-		RETURN_STATUS(nfserr_inval);
+	if (argp->mask & ~NFS_ACL_MASK) {
+		resp->status = nfserr_inval;
+		goto out;
+	}
 	resp->mask = argp->mask;
 
-	nfserr = fh_getattr(fh, &resp->stat);
-	if (nfserr)
-		RETURN_STATUS(nfserr);
+	resp->status = fh_getattr(fh, &resp->stat);
+	if (resp->status != nfs_ok)
+		goto out;
 
 	if (resp->mask & (NFS_ACL|NFS_ACLCNT)) {
 		acl = get_acl(inode, ACL_TYPE_ACCESS);
@@ -61,7 +61,7 @@ static __be32 nfsacld_proc_getacl(struct svc_rqst *rqstp)
 			acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
 		}
 		if (IS_ERR(acl)) {
-			nfserr = nfserrno(PTR_ERR(acl));
+			resp->status = nfserrno(PTR_ERR(acl));
 			goto fail;
 		}
 		resp->acl_access = acl;
@@ -71,19 +71,20 @@ static __be32 nfsacld_proc_getacl(struct svc_rqst *rqstp)
 		   of a non-directory! */
 		acl = get_acl(inode, ACL_TYPE_DEFAULT);
 		if (IS_ERR(acl)) {
-			nfserr = nfserrno(PTR_ERR(acl));
+			resp->status = nfserrno(PTR_ERR(acl));
 			goto fail;
 		}
 		resp->acl_default = acl;
 	}
 
 	/* resp->acl_{access,default} are released in nfssvc_release_getacl. */
-	RETURN_STATUS(0);
+out:
+	return resp->status;
 
 fail:
 	posix_acl_release(resp->acl_access);
 	posix_acl_release(resp->acl_default);
-	RETURN_STATUS(nfserr);
+	goto out;
 }
 
 /*
@@ -95,14 +96,13 @@ static __be32 nfsacld_proc_setacl(struct svc_rqst *rqstp)
 	struct nfsd_attrstat *resp = rqstp->rq_resp;
 	struct inode *inode;
 	svc_fh *fh;
-	__be32 nfserr = 0;
 	int error;
 
 	dprintk("nfsd: SETACL(2acl)   %s\n", SVCFH_fmt(&argp->fh));
 
 	fh = fh_copy(&resp->fh, &argp->fh);
-	nfserr = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_SATTR);
-	if (nfserr)
+	resp->status = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_SATTR);
+	if (resp->status != nfs_ok)
 		goto out;
 
 	inode = d_inode(fh->fh_dentry);
@@ -124,19 +124,20 @@ static __be32 nfsacld_proc_setacl(struct svc_rqst *rqstp)
 
 	fh_drop_write(fh);
 
-	nfserr = fh_getattr(fh, &resp->stat);
+	resp->status = fh_getattr(fh, &resp->stat);
 
 out:
 	/* argp->acl_{access,default} may have been allocated in
 	   nfssvc_decode_setaclargs. */
 	posix_acl_release(argp->acl_access);
 	posix_acl_release(argp->acl_default);
-	return nfserr;
+	return resp->status;
+
 out_drop_lock:
 	fh_unlock(fh);
 	fh_drop_write(fh);
 out_errno:
-	nfserr = nfserrno(error);
+	resp->status = nfserrno(error);
 	goto out;
 }
 
@@ -147,15 +148,16 @@ static __be32 nfsacld_proc_getattr(struct svc_rqst *rqstp)
 {
 	struct nfsd_fhandle *argp = rqstp->rq_argp;
 	struct nfsd_attrstat *resp = rqstp->rq_resp;
-	__be32 nfserr;
+
 	dprintk("nfsd: GETATTR  %s\n", SVCFH_fmt(&argp->fh));
 
 	fh_copy(&resp->fh, &argp->fh);
-	nfserr = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_NOP);
-	if (nfserr)
-		return nfserr;
-	nfserr = fh_getattr(&resp->fh, &resp->stat);
-	return nfserr;
+	resp->status = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_NOP);
+	if (resp->status != nfs_ok)
+		goto out;
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	return resp->status;
 }
 
 /*
@@ -165,7 +167,6 @@ static __be32 nfsacld_proc_access(struct svc_rqst *rqstp)
 {
 	struct nfsd3_accessargs *argp = rqstp->rq_argp;
 	struct nfsd3_accessres *resp = rqstp->rq_resp;
-	__be32 nfserr;
 
 	dprintk("nfsd: ACCESS(2acl)   %s 0x%x\n",
 			SVCFH_fmt(&argp->fh),
@@ -173,11 +174,12 @@ static __be32 nfsacld_proc_access(struct svc_rqst *rqstp)
 
 	fh_copy(&resp->fh, &argp->fh);
 	resp->access = argp->access;
-	nfserr = nfsd_access(rqstp, &resp->fh, &resp->access, NULL);
-	if (nfserr)
-		return nfserr;
-	nfserr = fh_getattr(&resp->fh, &resp->stat);
-	return nfserr;
+	resp->status = nfsd_access(rqstp, &resp->fh, &resp->access, NULL);
+	if (resp->status != nfs_ok)
+		goto out;
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	return resp->status;
 }
 
 /*
@@ -273,6 +275,9 @@ static int nfsaclsvc_encode_getaclres(struct svc_rqst *rqstp, __be32 *p)
 	int n;
 	int w;
 
+	if (resp->status != nfs_ok)
+		return xdr_ressize_check(rqstp, p);
+
 	/*
 	 * Since this is version 2, the check for nfserr in
 	 * nfsd_dispatch actually ensures the following cannot happen.
@@ -312,6 +317,9 @@ static int nfsaclsvc_encode_attrstatres(struct svc_rqst *rqstp, __be32 *p)
 {
 	struct nfsd_attrstat *resp = rqstp->rq_resp;
 
+	if (resp->status != nfs_ok)
+		return xdr_ressize_check(rqstp, p);
+
 	p = nfs2svc_encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 	return xdr_ressize_check(rqstp, p);
 }
@@ -321,6 +329,9 @@ static int nfsaclsvc_encode_accessres(struct svc_rqst *rqstp, __be32 *p)
 {
 	struct nfsd3_accessres *resp = rqstp->rq_resp;
 
+	if (resp->status != nfs_ok)
+		return xdr_ressize_check(rqstp, p);
+
 	p = nfs2svc_encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 	*p++ = htonl(resp->access);
 	return xdr_ressize_check(rqstp, p);

fs/nfsd/nfssvc.c

@@ -1056,12 +1056,8 @@ int nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
 	if (rqstp->rq_proc != 0)
 		*nfserrp++ = nfserr;
 
-	/*
-	 * For NFSv2, additional info is never returned in case of an error.
-	 */
-	if (!(nfserr && rqstp->rq_vers == 2))
-		if (!proc->pc_encode(rqstp, nfserrp))
-			goto out_encode_err;
+	if (!proc->pc_encode(rqstp, nfserrp))
+		goto out_encode_err;
 
 	nfsd_cache_update(rqstp, rqstp->rq_cachetype, statp + 1);
 out_cached_reply:

fs/nfsd/nfsxdr.c

@@ -434,6 +434,9 @@ nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p)
 {
 	struct nfsd_attrstat *resp = rqstp->rq_resp;
 
+	if (resp->status != nfs_ok)
+		return xdr_ressize_check(rqstp, p);
+
 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 	return xdr_ressize_check(rqstp, p);
 }
@@ -443,6 +446,9 @@ nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p)
 {
 	struct nfsd_diropres *resp = rqstp->rq_resp;
 
+	if (resp->status != nfs_ok)
+		return xdr_ressize_check(rqstp, p);
+
 	p = encode_fh(p, &resp->fh);
 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 	return xdr_ressize_check(rqstp, p);
@@ -453,6 +459,9 @@ nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p)
 {
 	struct nfsd_readlinkres *resp = rqstp->rq_resp;
 
+	if (resp->status != nfs_ok)
+		return xdr_ressize_check(rqstp, p);
+
 	*p++ = htonl(resp->len);
 	xdr_ressize_check(rqstp, p);
 	rqstp->rq_res.page_len = resp->len;
@@ -470,6 +479,9 @@ nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p)
 {
 	struct nfsd_readres *resp = rqstp->rq_resp;
 
+	if (resp->status != nfs_ok)
+		return xdr_ressize_check(rqstp, p);
+
 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 	*p++ = htonl(resp->count);
 	xdr_ressize_check(rqstp, p);
@@ -490,6 +502,9 @@ nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p)
 {
 	struct nfsd_readdirres *resp = rqstp->rq_resp;
 
+	if (resp->status != nfs_ok)
+		return xdr_ressize_check(rqstp, p);
+
 	xdr_ressize_check(rqstp, p);
 	p = resp->buffer;
 	*p++ = 0;			/* no more entries */
@@ -505,6 +520,9 @@ nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p)
 	struct nfsd_statfsres *resp = rqstp->rq_resp;
 	struct kstatfs	*stat = &resp->stats;
 
+	if (resp->status != nfs_ok)
+		return xdr_ressize_check(rqstp, p);
+
 	*p++ = htonl(NFSSVC_MAXBLKSIZE_V2);	/* max transfer size */
 	*p++ = htonl(stat->f_bsize);
 	*p++ = htonl(stat->f_blocks);

fs/nfsd/xdr.h

@@ -83,26 +83,32 @@ struct nfsd_readdirargs {
 };
 
 struct nfsd_attrstat {
+	__be32			status;
 	struct svc_fh		fh;
 	struct kstat		stat;
 };
 
 struct nfsd_diropres  {
+	__be32			status;
 	struct svc_fh		fh;
 	struct kstat		stat;
 };
 
 struct nfsd_readlinkres {
+	__be32			status;
 	int			len;
 };
 
 struct nfsd_readres {
+	__be32			status;
 	struct svc_fh		fh;
 	unsigned long		count;
 	struct kstat		stat;
 };
 
 struct nfsd_readdirres {
+	__be32			status;
+
 	int			count;
 
 	struct readdir_cd	common;
@@ -112,6 +118,7 @@ struct nfsd_readdirres {
 };
 
 struct nfsd_statfsres {
+	__be32			status;
 	struct kstatfs		stats;
 };