nfscl: Add support for a NFSv4 AppendWrite RPC

For IO_APPEND VOP_WRITE()s, the code first does a
Getattr RPC to acquire the file's size, before it
can do the Write RPC.

Although NFS does not have an append write operation,
an NFSv4 compound can use a Verify operation to check
that the client's notion of the file's size is
correct, followed by the Write operation.

This patch modifies nfscl_wcc_data() to optionally
acquire the file's size, for use with an AppendWrite.
Although the "stuff" arguments are always NULL
(these were used for the Mac OSX port and should be
cleared out someday), make the argument to
nfscl_wcc_data() explicitly NULL for clarity.

This patch does not cause any semantics change until
the AppendWrite is added in a future commit.

4 files changed, 26 insertions, 21 deletions

diff --git a/sys/fs/nfs/nfs_commonsubs.c b/sys/fs/nfs/nfs_commonsubs.c
index d3c329a3abc7..0a601553fa40 100644
--- a/sys/fs/nfs/nfs_commonsubs.c
+++ b/sys/fs/nfs/nfs_commonsubs.c
@@ -441,6 +441,10 @@ nfscl_reqstart(struct nfsrv_descript *nd, int procnum, struct nfsmount *nmp,
 					NFSGETATTR_ATTRBIT(&attrbits);
 				else {
 					NFSWCCATTR_ATTRBIT(&attrbits);
+					/* For AppendWrite, get the size. */
+					if (procnum == NFSPROC_APPENDWRITE)
+						NFSSETBIT_ATTRBIT(&attrbits,
+						    NFSATTRBIT_SIZE);
 					nd->nd_flag |= ND_V4WCCATTR;
 				}
 				(void) nfsrv_putattrbit(nd, &attrbits);
diff --git a/sys/fs/nfs/nfs_var.h b/sys/fs/nfs/nfs_var.h
index c0ddb8441a7c..0af1daa429cf 100644
--- a/sys/fs/nfs/nfs_var.h
+++ b/sys/fs/nfs/nfs_var.h
@@ -376,7 +376,7 @@ int nfscl_mtofh(struct nfsrv_descript *, struct nfsfh **,
 int nfscl_postop_attr(struct nfsrv_descript *, struct nfsvattr *, int *,
     void *);
 int nfscl_wcc_data(struct nfsrv_descript *, vnode_t,
-    struct nfsvattr *, int *, int *, void *);
+    struct nfsvattr *, int *, int *, uint64_t *);
 int nfsm_loadattr(struct nfsrv_descript *, struct nfsvattr *);
 int nfscl_request(struct nfsrv_descript *, vnode_t,
          NFSPROC_T *, struct ucred *, void *);
diff --git a/sys/fs/nfsclient/nfs_clport.c b/sys/fs/nfsclient/nfs_clport.c
index 5c79e3ac6960..e9deb7bb7f88 100644
--- a/sys/fs/nfsclient/nfs_clport.c
+++ b/sys/fs/nfsclient/nfs_clport.c
@@ -781,7 +781,7 @@ nfscl_start_renewthread(struct nfsclclient *clp)
  */
 int
 nfscl_wcc_data(struct nfsrv_descript *nd, struct vnode *vp,
-    struct nfsvattr *nap, int *flagp, int *wccflagp, void *stuff)
+    struct nfsvattr *nap, int *flagp, int *wccflagp, uint64_t *repsizep)
 {
 	u_int32_t *tl;
 	struct nfsnode *np = VTONFS(vp);
@@ -804,7 +804,7 @@ nfscl_wcc_data(struct nfsrv_descript *nd, struct vnode *vp,
 				NFSUNLOCKNODE(np);
 			}
 		}
-		error = nfscl_postop_attr(nd, nap, flagp, stuff);
+		error = nfscl_postop_attr(nd, nap, flagp, NULL);
 		if (wccflagp != NULL && *flagp == 0)
 			*wccflagp = 0;
 	} else if ((nd->nd_flag & (ND_NOMOREDATA | ND_NFSV4 | ND_V4WCCATTR))
@@ -820,6 +820,8 @@ nfscl_wcc_data(struct nfsrv_descript *nd, struct vnode *vp,
 		NFSM_DISSECT(tl, u_int32_t *, 2 * NFSX_UNSIGNED);
 		if (*++tl)
 			nd->nd_flag |= ND_NOMOREDATA;
+		if (repsizep != NULL)
+			*repsizep = nfsva.na_size;
 		if (wccflagp != NULL &&
 		    nfsva.na_vattr.va_mtime.tv_sec != 0) {
 			NFSLOCKNODE(np);
diff --git a/sys/fs/nfsclient/nfs_clrpcops.c b/sys/fs/nfsclient/nfs_clrpcops.c
index cc4899af1c90..3029875df986 100644
--- a/sys/fs/nfsclient/nfs_clrpcops.c
+++ b/sys/fs/nfsclient/nfs_clrpcops.c
@@ -1378,7 +1378,7 @@ nfsrpc_setattrrpc(vnode_t vp, struct vattr *vap,
 	if (error)
 		return (error);
 	if (nd->nd_flag & (ND_NFSV3 | ND_NFSV4))
-		error = nfscl_wcc_data(nd, vp, rnap, attrflagp, NULL, stuff);
+		error = nfscl_wcc_data(nd, vp, rnap, attrflagp, NULL, NULL);
 	if ((nd->nd_flag & (ND_NFSV4 | ND_NOMOREDATA)) == ND_NFSV4 && !error)
 		error = nfsrv_getattrbits(nd, &attrbits, NULL, NULL);
 	if (!(nd->nd_flag & ND_NFSV3) && !nd->nd_repstat && !error)
@@ -2035,7 +2035,7 @@ nfsrpc_writerpc(vnode_t vp, struct uio *uiop, int *iomode,
 		}
 		if (nd->nd_flag & (ND_NFSV3 | ND_NFSV4)) {
 			error = nfscl_wcc_data(nd, vp, nap, attrflagp,
-			    &wccflag, stuff);
+			    &wccflag, NULL);
 			if (error)
 				goto nfsmout;
 		}
@@ -2199,7 +2199,7 @@ nfsrpc_deallocaterpc(vnode_t vp, off_t offs, off_t len,
 	if (error != 0)
 		return (error);
 	wccflag = 0;
-	error = nfscl_wcc_data(nd, vp, nap, attrflagp, &wccflag, stuff);
+	error = nfscl_wcc_data(nd, vp, nap, attrflagp, &wccflag, NULL);
 	if (error != 0)
 		goto nfsmout;
 	if (nd->nd_repstat == 0) {
@@ -2276,7 +2276,7 @@ nfsrpc_mknod(vnode_t dvp, char *name, int namelen, struct vattr *vap,
 	if (error)
 		return (error);
 	if (nd->nd_flag & ND_NFSV4)
-		error = nfscl_wcc_data(nd, dvp, dnap, dattrflagp, NULL, dstuff);
+		error = nfscl_wcc_data(nd, dvp, dnap, dattrflagp, NULL, NULL);
 	if (!nd->nd_repstat) {
 		if (nd->nd_flag & ND_NFSV4) {
 			NFSM_DISSECT(tl, u_int32_t *, 5 * NFSX_UNSIGNED);
@@ -2289,7 +2289,7 @@ nfsrpc_mknod(vnode_t dvp, char *name, int namelen, struct vattr *vap,
 			goto nfsmout;
 	}
 	if (nd->nd_flag & ND_NFSV3)
-		error = nfscl_wcc_data(nd, dvp, dnap, dattrflagp, NULL, dstuff);
+		error = nfscl_wcc_data(nd, dvp, dnap, dattrflagp, NULL, NULL);
 	if (!error && nd->nd_repstat)
 		error = nd->nd_repstat;
 nfsmout:
@@ -2413,7 +2413,7 @@ nfsrpc_createv23(vnode_t dvp, char *name, int namelen, struct vattr *vap,
 			goto nfsmout;
 	}
 	if (nd->nd_flag & ND_NFSV3)
-		error = nfscl_wcc_data(nd, dvp, dnap, dattrflagp, NULL, dstuff);
+		error = nfscl_wcc_data(nd, dvp, dnap, dattrflagp, NULL, NULL);
 	if (nd->nd_repstat != 0 && error == 0)
 		error = nd->nd_repstat;
 nfsmout:
@@ -2736,7 +2736,7 @@ tryagain:
 				nd->nd_flag |= ND_NOMOREDATA;
 			}
 		}
-		error = nfscl_wcc_data(nd, dvp, dnap, dattrflagp, NULL, dstuff);
+		error = nfscl_wcc_data(nd, dvp, dnap, dattrflagp, NULL, NULL);
 	}
 	if (nd->nd_repstat && !error)
 		error = nd->nd_repstat;
@@ -2883,8 +2883,7 @@ tryagain:
 			if (*(tl + 1))
 				nd->nd_flag |= ND_NOMOREDATA;
 		}
-		error = nfscl_wcc_data(nd, fdvp, fnap, fattrflagp, NULL,
-		    fstuff);
+		error = nfscl_wcc_data(nd, fdvp, fnap, fattrflagp, NULL, NULL);
 		/* and the second wcc attribute reply. */
 		if ((nd->nd_flag & (ND_NFSV4 | ND_NOMOREDATA)) == ND_NFSV4 &&
 		    !error) {
@@ -2894,7 +2893,7 @@ tryagain:
 		}
 		if (!error)
 			error = nfscl_wcc_data(nd, tdvp, tnap, tattrflagp,
-			    NULL, tstuff);
+			    NULL, NULL);
 	}
 	if (nd->nd_repstat && !error)
 		error = nd->nd_repstat;
@@ -2944,7 +2943,7 @@ nfsrpc_link(vnode_t dvp, vnode_t vp, char *name, int namelen,
 		error = nfscl_postop_attr(nd, nap, attrflagp, dstuff);
 		if (!error)
 			error = nfscl_wcc_data(nd, dvp, dnap, dattrflagp,
-			    NULL, dstuff);
+			    NULL, NULL);
 	} else if ((nd->nd_flag & (ND_NFSV4 | ND_NOMOREDATA)) == ND_NFSV4) {
 		/*
 		 * First, parse out the PutFH and Getattr result.
@@ -2957,7 +2956,7 @@ nfsrpc_link(vnode_t dvp, vnode_t vp, char *name, int namelen,
 		/*
 		 * Get the pre-op attributes.
 		 */
-		error = nfscl_wcc_data(nd, dvp, dnap, dattrflagp, NULL, dstuff);
+		error = nfscl_wcc_data(nd, dvp, dnap, dattrflagp, NULL, NULL);
 	}
 	if (nd->nd_repstat && !error)
 		error = nd->nd_repstat;
@@ -3004,13 +3003,13 @@ nfsrpc_symlink(vnode_t dvp, char *name, int namelen, const char *target,
 	if (error)
 		return (error);
 	if (nd->nd_flag & ND_NFSV4)
-		error = nfscl_wcc_data(nd, dvp, dnap, dattrflagp, NULL, dstuff);
+		error = nfscl_wcc_data(nd, dvp, dnap, dattrflagp, NULL, NULL);
 	if ((nd->nd_flag & ND_NFSV3) && !error) {
 		if (!nd->nd_repstat)
 			error = nfscl_mtofh(nd, nfhpp, nnap, attrflagp);
 		if (!error)
 			error = nfscl_wcc_data(nd, dvp, dnap, dattrflagp,
-			    NULL, dstuff);
+			    NULL, NULL);
 	}
 	if (nd->nd_repstat && !error)
 		error = nd->nd_repstat;
@@ -3074,7 +3073,7 @@ nfsrpc_mkdir(vnode_t dvp, char *name, int namelen, struct vattr *vap,
 	if (error)
 		return (error);
 	if (nd->nd_flag & ND_NFSV4)
-		error = nfscl_wcc_data(nd, dvp, dnap, dattrflagp, NULL, dstuff);
+		error = nfscl_wcc_data(nd, dvp, dnap, dattrflagp, NULL, NULL);
 	if (!nd->nd_repstat && !error) {
 		if (nd->nd_flag & ND_NFSV4) {
 			NFSM_DISSECT(tl, u_int32_t *, 5 * NFSX_UNSIGNED);
@@ -3092,7 +3091,7 @@ nfsrpc_mkdir(vnode_t dvp, char *name, int namelen, struct vattr *vap,
 		}
 	}
 	if ((nd->nd_flag & ND_NFSV3) && !error)
-		error = nfscl_wcc_data(nd, dvp, dnap, dattrflagp, NULL, dstuff);
+		error = nfscl_wcc_data(nd, dvp, dnap, dattrflagp, NULL, NULL);
 	if (nd->nd_repstat && !error)
 		error = nd->nd_repstat;
 nfsmout:
@@ -3128,7 +3127,7 @@ nfsrpc_rmdir(vnode_t dvp, char *name, int namelen, struct ucred *cred,
 	if (error)
 		return (error);
 	if (nd->nd_flag & (ND_NFSV3 | ND_NFSV4))
-		error = nfscl_wcc_data(nd, dvp, dnap, dattrflagp, NULL, dstuff);
+		error = nfscl_wcc_data(nd, dvp, dnap, dattrflagp, NULL, NULL);
 	if (nd->nd_repstat && !error)
 		error = nd->nd_repstat;
 	m_freem(nd->nd_mrep);
@@ -4178,7 +4177,7 @@ nfsrpc_commit(vnode_t vp, u_quad_t offset, int cnt, struct ucred *cred,
 	error = nfscl_request(nd, vp, p, cred, stuff);
 	if (error)
 		return (error);
-	error = nfscl_wcc_data(nd, vp, nap, attrflagp, NULL, stuff);
+	error = nfscl_wcc_data(nd, vp, nap, attrflagp, NULL, NULL);
 	if (!error && !nd->nd_repstat) {
 		NFSM_DISSECT(tl, u_int32_t *, NFSX_VERF);
 		NFSLOCKMNT(nmp);