From a995789e4783349efc714d4d961c9b9d8d7c04fb Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Thu, 18 Mar 1993 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1993-03-18

---
 port/devproc.c |  2 ++
 port/sysfile.c | 24 ++++++++++--------------
 2 files changed, 12 insertions(+), 14 deletions(-)

diff --git a/port/devproc.c b/port/devproc.c
index e723dce8a594da767b7a0833b01204da4c7a53c5..167116bad89033f5d9c35650b84a4fc0dc4ba86a 100644
--- a/port/devproc.c
+++ b/port/devproc.c
@@ -626,6 +626,8 @@ procctlreq(Proc *p, char *va, int n)
 	}
 	else if(strncmp(buf, "hang", 4) == 0)
 		p->hang = 1;
+	else if(strncmp(buf, "nohang", 6) == 0)
+		p->hang = 0;
 	else if(strncmp(buf, "waitstop", 8) == 0)
 		procstopwait(p, 0);
 	else if(strncmp(buf, "startstop", 9) == 0) {
diff --git a/port/sysfile.c b/port/sysfile.c
index 67a7337e921c908ea04edcb4307d7522af2d5ae2..2d9232ffea533bb385c36e77f5a9994d4072011f 100644
--- a/port/sysfile.c
+++ b/port/sysfile.c
@@ -232,26 +232,24 @@ unionread(Chan *c, void *va, long n)
 	Pgrp *pg;
 
 	pg = u->p->pgrp;
-	qlock(&pg->nsh);
+	rlock(&pg->ns);
 
 	for(;;) {
 		if(waserror()) {
-			qunlock(&pg->nsh);
+			runlock(&pg->ns);
 			nexterror();
 		}
-		nc = clone(c->mnt->cmnt, 0);
+		nc = clone(c->mnt->to, 0);
 		poperror();
 
 		if(c->mountid != c->mnt->mountid) {
-			pprint("unionread: changed underfoot\n");
-			qunlock(&pg->nsh);
+			pprint("unionread: changed underfoot?\n");
+			runlock(&pg->ns);
 			close(nc);
 			return 0;
 		}
 
-		/*
-		 * Error causes component of union to be skipped
-		 */
+		/* Error causes component of union to be skipped */
 		if(waserror()) {	
 			close(nc);
 			goto next;
@@ -260,26 +258,24 @@ unionread(Chan *c, void *va, long n)
 		nc = (*devtab[nc->type].open)(nc, OREAD);
 		nc->offset = c->offset;
 		nr = (*devtab[nc->type].read)(nc, va, n, nc->offset);
-		/*
-		 * devdirread e.g. changes it
-		 */
+		/* devdirread e.g. changes it */
 		c->offset = nc->offset;	
 		poperror();
 
 		close(nc);
 		if(nr > 0) {
-			qunlock(&pg->nsh);
+			runlock(&pg->ns);
 			return nr;
 		}
 		/* Advance to next element */
 	next:
-		c->mnt = c->mnt->mount;
+		c->mnt = c->mnt->next;
 		if(c->mnt == 0)
 			break;
 		c->mountid = c->mnt->mountid;
 		c->offset = 0;
 	}
-	qunlock(&pg->nsh);
+	runlock(&pg->ns);
 	return 0;
 }