# HG changeset patch
# Parent  ce9001c93fecb58f58492e4023a71fec6466a37a
Adjust namei internals to be able to make an external call to parse
the pathname. (Basically, this means change the signature of
namei_getcomponent() to pass in the directory vnode and to allow
failures.)

diff -r ce9001c93fec sys/kern/vfs_lookup.c
--- a/sys/kern/vfs_lookup.c	Tue Apr 12 00:03:06 2016 -0400
+++ b/sys/kern/vfs_lookup.c	Sun Apr 17 01:11:16 2016 -0400
@@ -228,16 +228,19 @@
  * Find the end of the first path component in NAME and return its
  * length.
  */
-static size_t
-namei_getcomponent(const char *name)
+static int
+namei_getcomponent(struct vnode *dvp, const char *name, size_t *ret)
 {
 	size_t pos;
 
+	(void)dvp;
+
 	pos = 0;
 	while (name[pos] != '\0' && name[pos] != '/') {
 		pos++;
 	}
-	return pos;
+	*ret = pos;
+	return 0;
 }
 
 ////////////////////////////////////////////////////////////
@@ -816,9 +819,10 @@
  * Inspect the leading path component and update the state accordingly.
  */
 static int
-lookup_parsepath(struct namei_state *state)
+lookup_parsepath(struct namei_state *state, struct vnode *searchdir)
 {
 	const char *cp;			/* pointer into pathname argument */
+	int error;
 
 	struct componentname *cnp = state->cnp;
 	struct nameidata *ndp = state->ndp;
@@ -837,7 +841,11 @@
 	 * is held and locked.
 	 */
 	cnp->cn_consume = 0;
-	cnp->cn_namelen = namei_getcomponent(cnp->cn_nameptr);
+	error = namei_getcomponent(searchdir, cnp->cn_nameptr,
+				   &cnp->cn_namelen);
+	if (error) {
+		return error;
+	}
 	cp = cnp->cn_nameptr + cnp->cn_namelen;
 	if (cnp->cn_namelen > KERNEL_NAME_MAX) {
 		return ENAMETOOLONG;
@@ -1222,7 +1230,7 @@
 		/* and we shouldn't have looped around if we were done */
 		KASSERT(cnp->cn_nameptr[0] != '\0');
 
-		error = lookup_parsepath(state);
+		error = lookup_parsepath(state, searchdir);
 		if (error) {
 			vput(searchdir);
 			ndp->ni_dvp = NULL;
@@ -1618,7 +1626,7 @@
 static int
 do_lookup_for_nfsd_index(struct namei_state *state)
 {
-	int error = 0;
+	int error;
 
 	struct componentname *cnp = state->cnp;
 	struct nameidata *ndp = state->ndp;
@@ -1636,7 +1644,12 @@
 	ndp->ni_dvp = NULL;
 
 	cnp->cn_consume = 0;
-	cnp->cn_namelen = namei_getcomponent(cnp->cn_nameptr);
+	error = namei_getcomponent(startdir, cnp->cn_nameptr,
+				   &cnp->cn_namelen);
+	if (error) {
+		return error;
+	}
+
 	cp = cnp->cn_nameptr + cnp->cn_namelen;
 	KASSERT(cnp->cn_namelen <= KERNEL_NAME_MAX);
 	ndp->ni_pathlen -= cnp->cn_namelen;
@@ -1760,7 +1773,10 @@
 	if ((uint32_t)newhash != (uint32_t)cnp->cn_hash)
 		panic("relookup: bad hash");
 #endif
-	newlen = namei_getcomponent(cnp->cn_nameptr);
+	error = namei_getcomponent(dvp, cnp->cn_nameptr, &newlen);
+	if (error) {
+		panic("relookup: parsepath failed with error %d", error);
+	}
 	if (cnp->cn_namelen != newlen)
 		panic("relookup: bad len");
 	cp = cnp->cn_nameptr + cnp->cn_namelen;