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>

1 files changed, 101 insertions, 84 deletions

diff --git a/fs/nfsd/nfsproc.c b/fs/nfsd/nfsproc.c
index c349e1dac3ff..526170319ecf 100644
--- a/fs/nfsd/nfsproc.c
+++ b/fs/nfsd/nfsproc.c
@@ -13,25 +13,12 @@
 
 #define NFSDDBG_FACILITY		NFSDDBG_PROC
 
-
 static __be32
 nfsd_proc_null(struct svc_rqst *rqstp)
 {
 	return nfs_ok;
 }
 
-static __be32
-nfsd_return_attrs(__be32 err, struct nfsd_attrstat *resp)
-{
-	if (err) return err;
-	return fh_getattr(&resp->fh, &resp->stat);
-}
-static __be32
-nfsd_return_dirop(__be32 err, struct nfsd_diropres *resp)
-{
-	if (err) return err;
-	return fh_getattr(&resp->fh, &resp->stat);
-}
 /*
  * Get a file's attributes
  * N.B. After this call resp->fh needs an fh_put
@@ -41,13 +28,17 @@ nfsd_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 | NFSD_MAY_BYPASS_GSS_ON_ROOT);
-	return nfsd_return_attrs(nfserr, resp);
+	resp->status = fh_verify(rqstp, &resp->fh, 0,
+				 NFSD_MAY_NOP | NFSD_MAY_BYPASS_GSS_ON_ROOT);
+	if (resp->status != nfs_ok)
+		goto out;
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	return resp->status;
 }
 
 /*
@@ -61,7 +52,6 @@ nfsd_proc_setattr(struct svc_rqst *rqstp)
 	struct nfsd_attrstat *resp = rqstp->rq_resp;
 	struct iattr *iap = &argp->attrs;
 	struct svc_fh *fhp;
-	__be32 nfserr;
 
 	dprintk("nfsd: SETATTR  %s, valid=%x, size=%ld\n",
 		SVCFH_fmt(&argp->fh),
@@ -93,9 +83,9 @@ nfsd_proc_setattr(struct svc_rqst *rqstp)
 		 */
 		time64_t delta = iap->ia_atime.tv_sec - ktime_get_real_seconds();
 
-		nfserr = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
-		if (nfserr)
-			goto done;
+		resp->status = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
+		if (resp->status != nfs_ok)
+			return resp->status;
 
 		if (delta < 0)
 			delta = -delta;
@@ -110,9 +100,13 @@ nfsd_proc_setattr(struct svc_rqst *rqstp)
 		}
 	}
 
-	nfserr = nfsd_setattr(rqstp, fhp, iap, 0, (time64_t)0);
-done:
-	return nfsd_return_attrs(nfserr, resp);
+	resp->status = nfsd_setattr(rqstp, fhp, iap, 0, (time64_t)0);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	return resp->status;
 }
 
 /* Obsolete, replaced by MNTPROC_MNT. */
@@ -133,17 +127,20 @@ nfsd_proc_lookup(struct svc_rqst *rqstp)
 {
 	struct nfsd_diropargs *argp = rqstp->rq_argp;
 	struct nfsd_diropres *resp = rqstp->rq_resp;
-	__be32	nfserr;
 
 	dprintk("nfsd: LOOKUP   %s %.*s\n",
 		SVCFH_fmt(&argp->fh), argp->len, argp->name);
 
 	fh_init(&resp->fh, NFS_FHSIZE);
-	nfserr = nfsd_lookup(rqstp, &argp->fh, argp->name, argp->len,
-				 &resp->fh);
-
+	resp->status = nfsd_lookup(rqstp, &argp->fh, argp->name, argp->len,
+				   &resp->fh);
 	fh_put(&argp->fh);
-	return nfsd_return_dirop(nfserr, resp);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	return resp->status;
 }
 
 /*
@@ -154,16 +151,15 @@ nfsd_proc_readlink(struct svc_rqst *rqstp)
 {
 	struct nfsd_readlinkargs *argp = rqstp->rq_argp;
 	struct nfsd_readlinkres *resp = rqstp->rq_resp;
-	__be32	nfserr;
 
 	dprintk("nfsd: READLINK %s\n", SVCFH_fmt(&argp->fh));
 
 	/* Read the symlink. */
 	resp->len = NFS_MAXPATHLEN;
-	nfserr = nfsd_readlink(rqstp, &argp->fh, argp->buffer, &resp->len);
+	resp->status = nfsd_readlink(rqstp, &argp->fh, argp->buffer, &resp->len);
 
 	fh_put(&argp->fh);
-	return nfserr;
+	return resp->status;
 }
 
 /*
@@ -175,7 +171,6 @@ nfsd_proc_read(struct svc_rqst *rqstp)
 {
 	struct nfsd_readargs *argp = rqstp->rq_argp;
 	struct nfsd_readres *resp = rqstp->rq_resp;
-	__be32	nfserr;
 	u32 eof;
 
 	dprintk("nfsd: READ    %s %d bytes at %d\n",
@@ -197,14 +192,17 @@ nfsd_proc_read(struct svc_rqst *rqstp)
 	svc_reserve_auth(rqstp, (19<<2) + argp->count + 4);
 
 	resp->count = argp->count;
-	nfserr = nfsd_read(rqstp, fh_copy(&resp->fh, &argp->fh),
-				  argp->offset,
-			   	  rqstp->rq_vec, argp->vlen,
-				  &resp->count,
-				  &eof);
-
-	if (nfserr) return nfserr;
-	return fh_getattr(&resp->fh, &resp->stat);
+	resp->status = nfsd_read(rqstp, fh_copy(&resp->fh, &argp->fh),
+				 argp->offset,
+				 rqstp->rq_vec, argp->vlen,
+				 &resp->count,
+				 &eof);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	return resp->status;
 }
 
 /* Reserved */
@@ -223,7 +221,6 @@ nfsd_proc_write(struct svc_rqst *rqstp)
 {
 	struct nfsd_writeargs *argp = rqstp->rq_argp;
 	struct nfsd_attrstat *resp = rqstp->rq_resp;
-	__be32	nfserr;
 	unsigned long cnt = argp->len;
 	unsigned int nvecs;
 
@@ -233,12 +230,20 @@ nfsd_proc_write(struct svc_rqst *rqstp)
 
 	nvecs = svc_fill_write_vector(rqstp, rqstp->rq_arg.pages,
 				      &argp->first, cnt);
-	if (!nvecs)
-		return nfserr_io;
-	nfserr = nfsd_write(rqstp, fh_copy(&resp->fh, &argp->fh),
-			    argp->offset, rqstp->rq_vec, nvecs,
-			    &cnt, NFS_DATA_SYNC, NULL);
-	return nfsd_return_attrs(nfserr, resp);
+	if (!nvecs) {
+		resp->status = nfserr_io;
+		goto out;
+	}
+
+	resp->status = nfsd_write(rqstp, fh_copy(&resp->fh, &argp->fh),
+				  argp->offset, rqstp->rq_vec, nvecs,
+				  &cnt, NFS_DATA_SYNC, NULL);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	return resp->status;
 }
 
 /*
@@ -258,7 +263,6 @@ nfsd_proc_create(struct svc_rqst *rqstp)
 	struct inode	*inode;
 	struct dentry	*dchild;
 	int		type, mode;
-	__be32		nfserr;
 	int		hosterr;
 	dev_t		rdev = 0, wanted = new_decode_dev(attr->ia_size);
 
@@ -266,40 +270,40 @@ nfsd_proc_create(struct svc_rqst *rqstp)
 		SVCFH_fmt(dirfhp), argp->len, argp->name);
 
 	/* First verify the parent file handle */
-	nfserr = fh_verify(rqstp, dirfhp, S_IFDIR, NFSD_MAY_EXEC);
-	if (nfserr)
+	resp->status = fh_verify(rqstp, dirfhp, S_IFDIR, NFSD_MAY_EXEC);
+	if (resp->status != nfs_ok)
 		goto done; /* must fh_put dirfhp even on error */
 
 	/* Check for NFSD_MAY_WRITE in nfsd_create if necessary */
 
-	nfserr = nfserr_exist;
+	resp->status = nfserr_exist;
 	if (isdotent(argp->name, argp->len))
 		goto done;
 	hosterr = fh_want_write(dirfhp);
 	if (hosterr) {
-		nfserr = nfserrno(hosterr);
+		resp->status = nfserrno(hosterr);
 		goto done;
 	}
 
 	fh_lock_nested(dirfhp, I_MUTEX_PARENT);
 	dchild = lookup_one_len(argp->name, dirfhp->fh_dentry, argp->len);
 	if (IS_ERR(dchild)) {
-		nfserr = nfserrno(PTR_ERR(dchild));
+		resp->status = nfserrno(PTR_ERR(dchild));
 		goto out_unlock;
 	}
 	fh_init(newfhp, NFS_FHSIZE);
-	nfserr = fh_compose(newfhp, dirfhp->fh_export, dchild, dirfhp);
-	if (!nfserr && d_really_is_negative(dchild))
-		nfserr = nfserr_noent;
+	resp->status = fh_compose(newfhp, dirfhp->fh_export, dchild, dirfhp);
+	if (!resp->status && d_really_is_negative(dchild))
+		resp->status = nfserr_noent;
 	dput(dchild);
-	if (nfserr) {
-		if (nfserr != nfserr_noent)
+	if (resp->status) {
+		if (resp->status != nfserr_noent)
 			goto out_unlock;
 		/*
 		 * If the new file handle wasn't verified, we can't tell
 		 * whether the file exists or not. Time to bail ...
 		 */
-		nfserr = nfserr_acces;
+		resp->status = nfserr_acces;
 		if (!newfhp->fh_dentry) {
 			printk(KERN_WARNING 
 				"nfsd_proc_create: file handle not verified\n");
@@ -332,11 +336,11 @@ nfsd_proc_create(struct svc_rqst *rqstp)
 					 *   echo thing > device-special-file-or-pipe
 					 * by doing a CREATE with type==0
 					 */
-					nfserr = nfsd_permission(rqstp,
+					resp->status = nfsd_permission(rqstp,
 								 newfhp->fh_export,
 								 newfhp->fh_dentry,
 								 NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS);
-					if (nfserr && nfserr != nfserr_rofs)
+					if (resp->status && resp->status != nfserr_rofs)
 						goto out_unlock;
 				}
 			} else
@@ -372,16 +376,17 @@ nfsd_proc_create(struct svc_rqst *rqstp)
 		attr->ia_valid &= ~ATTR_SIZE;
 
 		/* Make sure the type and device matches */
-		nfserr = nfserr_exist;
+		resp->status = nfserr_exist;
 		if (inode && type != (inode->i_mode & S_IFMT))
 			goto out_unlock;
 	}
 
-	nfserr = 0;
+	resp->status = nfs_ok;
 	if (!inode) {
 		/* File doesn't exist. Create it and set attrs */
-		nfserr = nfsd_create_locked(rqstp, dirfhp, argp->name,
-					argp->len, attr, type, rdev, newfhp);
+		resp->status = nfsd_create_locked(rqstp, dirfhp, argp->name,
+						  argp->len, attr, type, rdev,
+						  newfhp);
 	} else if (type == S_IFREG) {
 		dprintk("nfsd:   existing %s, valid=%x, size=%ld\n",
 			argp->name, attr->ia_valid, (long) attr->ia_size);
@@ -391,7 +396,8 @@ nfsd_proc_create(struct svc_rqst *rqstp)
 		 */
 		attr->ia_valid &= ATTR_SIZE;
 		if (attr->ia_valid)
-			nfserr = nfsd_setattr(rqstp, newfhp, attr, 0, (time64_t)0);
+			resp->status = nfsd_setattr(rqstp, newfhp, attr, 0,
+						    (time64_t)0);
 	}
 
 out_unlock:
@@ -400,7 +406,11 @@ out_unlock:
 	fh_drop_write(dirfhp);
 done:
 	fh_put(dirfhp);
-	return nfsd_return_dirop(nfserr, resp);
+	if (resp->status != nfs_ok)
+		goto out;
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	return resp->status;
 }
 
 static __be32
@@ -463,14 +473,18 @@ nfsd_proc_symlink(struct svc_rqst *rqstp)
 	struct svc_fh	newfh;
 	__be32		nfserr;
 
-	if (argp->tlen > NFS_MAXPATHLEN)
-		return nfserr_nametoolong;
+	if (argp->tlen > NFS_MAXPATHLEN) {
+		nfserr = nfserr_nametoolong;
+		goto out;
+	}
 
 	argp->tname = svc_fill_symlink_pathname(rqstp, &argp->first,
 						page_address(rqstp->rq_arg.pages[0]),
 						argp->tlen);
-	if (IS_ERR(argp->tname))
-		return nfserrno(PTR_ERR(argp->tname));
+	if (IS_ERR(argp->tname)) {
+		nfserr = nfserrno(PTR_ERR(argp->tname));
+		goto out;
+	}
 
 	dprintk("nfsd: SYMLINK  %s %.*s -> %.*s\n",
 		SVCFH_fmt(&argp->ffh), argp->flen, argp->fname,
@@ -483,6 +497,7 @@ nfsd_proc_symlink(struct svc_rqst *rqstp)
 	kfree(argp->tname);
 	fh_put(&argp->ffh);
 	fh_put(&newfh);
+out:
 	return nfserr;
 }
 
@@ -495,7 +510,6 @@ nfsd_proc_mkdir(struct svc_rqst *rqstp)
 {
 	struct nfsd_createargs *argp = rqstp->rq_argp;
 	struct nfsd_diropres *resp = rqstp->rq_resp;
-	__be32	nfserr;
 
 	dprintk("nfsd: MKDIR    %s %.*s\n", SVCFH_fmt(&argp->fh), argp->len, argp->name);
 
@@ -506,10 +520,15 @@ nfsd_proc_mkdir(struct svc_rqst *rqstp)
 
 	argp->attrs.ia_valid &= ~ATTR_SIZE;
 	fh_init(&resp->fh, NFS_FHSIZE);
-	nfserr = nfsd_create(rqstp, &argp->fh, argp->name, argp->len,
-				    &argp->attrs, S_IFDIR, 0, &resp->fh);
+	resp->status = nfsd_create(rqstp, &argp->fh, argp->name, argp->len,
+				   &argp->attrs, S_IFDIR, 0, &resp->fh);
 	fh_put(&argp->fh);
-	return nfsd_return_dirop(nfserr, resp);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	return resp->status;
 }
 
 /*
@@ -537,7 +556,6 @@ nfsd_proc_readdir(struct svc_rqst *rqstp)
 	struct nfsd_readdirargs *argp = rqstp->rq_argp;
 	struct nfsd_readdirres *resp = rqstp->rq_resp;
 	int		count;
-	__be32		nfserr;
 	loff_t		offset;
 
 	dprintk("nfsd: READDIR  %s %d bytes at %d\n",
@@ -558,15 +576,15 @@ nfsd_proc_readdir(struct svc_rqst *rqstp)
 	resp->common.err = nfs_ok;
 	/* Read directory and encode entries on the fly */
 	offset = argp->cookie;
-	nfserr = nfsd_readdir(rqstp, &argp->fh, &offset, 
-			      &resp->common, nfssvc_encode_entry);
+	resp->status = nfsd_readdir(rqstp, &argp->fh, &offset,
+				    &resp->common, nfssvc_encode_entry);
 
 	resp->count = resp->buffer - argp->buffer;
 	if (resp->offset)
 		*resp->offset = htonl(offset);
 
 	fh_put(&argp->fh);
-	return nfserr;
+	return resp->status;
 }
 
 /*
@@ -577,14 +595,13 @@ nfsd_proc_statfs(struct svc_rqst *rqstp)
 {
 	struct nfsd_fhandle *argp = rqstp->rq_argp;
 	struct nfsd_statfsres *resp = rqstp->rq_resp;
-	__be32	nfserr;
 
 	dprintk("nfsd: STATFS   %s\n", SVCFH_fmt(&argp->fh));
 
-	nfserr = nfsd_statfs(rqstp, &argp->fh, &resp->stats,
-			NFSD_MAY_BYPASS_GSS_ON_ROOT);
+	resp->status = nfsd_statfs(rqstp, &argp->fh, &resp->stats,
+				   NFSD_MAY_BYPASS_GSS_ON_ROOT);
 	fh_put(&argp->fh);
-	return nfserr;
+	return resp->status;
 }
 
 /*