/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ #include <u.h>#include <libc.h>#include <fcall.h>#include <thread.h>#include <9p.h>#include <auth.h> static void postproc(void*); void_postmountsrv(Srv *s, char *name, char *mtpt, int flag){	int fd[2]; 	if(!s->nopipe){		if(pipe(fd) < 0)			sysfatal("pipe: %r");		s->infd = s->outfd = fd[1];		s->srvfd = fd[0];	}	if(name)		if(postfd(name, s->srvfd) < 0)			sysfatal("postfd %s: %r", name); 	if(_forker == nil)		sysfatal("no forker");	_forker(postproc, s, RFNAMEG); 	/*	 * Normally the server is posting as the last thing it does	 * before exiting, so the correct thing to do is drop into	 * a different fd space and close the 9P server half of the	 * pipe before trying to mount the kernel half.  This way,	 * if the file server dies, we don't have a ref to the 9P server	 * half of the pipe.  Then killing the other procs will drop	 * all the refs on the 9P server half, and the mount will fail.	 * Otherwise the mount hangs forever.	 *	 * Libthread in general and acme win in particular make	 * it hard to make this fd bookkeeping work out properly,	 * so leaveinfdopen is a flag that win sets to opt out of this	 * safety net.	 */	if(!s->leavefdsopen){		rfork(RFFDG);		rendezvous(0, 0);		close(s->infd);		if(s->infd != s->outfd)			close(s->outfd);	} 	if(mtpt){		if(amount(s->srvfd, mtpt, flag, "") == -1)			sysfatal("mount %s: %r", mtpt);	}else		close(s->srvfd);} static voidpostproc(void *v){	Srv *s; 	s = v;	if(!s->leavefdsopen){		rfork(RFNOTEG);		rendezvous(0, 0);		close(s->srvfd);	}	srv(s);}