1 #include <u.h>
2 #include <libc.h>
3 #include <fcall.h>
4 #include <thread.h>
5 #include <9p.h>
6 #include "post.h"
7 
8 Postcrud*
9 _post1(Srv *s, char *name, char *mtpt, int flag)
10 {
11 	Postcrud *p;
12 
13 	p = emalloc9p(sizeof *p);
14 	if(!s->nopipe){
15 		if(pipe(p->fd) < 0)
16 			sysfatal("pipe: %r");
17 		s->infd = s->outfd = p->fd[1];
18 		s->srvfd = p->fd[0];
19 	}
20 	if(name)
21 		if(postfd(name, s->srvfd) < 0)
22 			sysfatal("postfd %s: %r", name);
23 	p->s = s;
24 	p->mtpt = mtpt;
25 	p->flag = flag;
26 	return p;
27 }
28 
29 void
30 _post2(void *v)
31 {
32 	Srv *s;
33 
34 	s = v;
35 	if(!s->leavefdsopen){
36 		rfork(RFNOTEG);
37 		rendezvous((ulong)s, 0);
38 		close(s->srvfd);
39 	}
40 	srv(s);
41 }
42 
43 void
44 _post3(Postcrud *p)
45 {
46 	/*
47 	 * Normally the server is posting as the last thing it does
48 	 * before exiting, so the correct thing to do is drop into
49 	 * a different fd space and close the 9P server half of the
50 	 * pipe before trying to mount the kernel half.  This way,
51 	 * if the file server dies, we don't have a ref to the 9P server
52 	 * half of the pipe.  Then killing the other procs will drop
53 	 * all the refs on the 9P server half, and the mount will fail.
54 	 * Otherwise the mount hangs forever.
55 	 *
56 	 * Libthread in general and acme win in particular make
57 	 * it hard to make this fd bookkeeping work out properly,
58 	 * so leaveinfdopen is a flag that win sets to opt out of this
59 	 * safety net.
60 	 */
61 	if(!p->s->leavefdsopen){
62 		rfork(RFFDG);
63 		rendezvous((ulong)p->s, 0);
64 		close(p->s->infd);
65 		if(p->s->infd != p->s->outfd)
66 			close(p->s->outfd);
67 	}
68 
69 #if 0
70 	if(p->mtpt){
71 		if(amount(p->s->srvfd, p->mtpt, p->flag, "") == -1)
72 			sysfatal("mount %s: %r", p->mtpt);
73 	}else
74 #endif
75 		close(p->s->srvfd);
76 	free(p);
77 }