1 #include <u.h>
2 #include <libc.h>
3 #include <fcall.h>
4 #include <thread.h>
5 #include <9p.h>
6 #include <auth.h>
7
8 static void postproc(void*);
9
10 void
_postmountsrv(Srv * s,char * name,char * mtpt,int flag)11 _postmountsrv(Srv *s, char *name, char *mtpt, int flag)
12 {
13 int fd[2];
14
15 if(!s->nopipe){
16 if(pipe(fd) < 0)
17 sysfatal("pipe: %r");
18 s->infd = s->outfd = fd[1];
19 s->srvfd = fd[0];
20 }
21 if(name)
22 if(postfd(name, s->srvfd) < 0)
23 sysfatal("postfd %s: %r", name);
24
25 if(_forker == nil)
26 sysfatal("no forker");
27 _forker(postproc, s, RFNAMEG);
28
29 /*
30 * Normally the server is posting as the last thing it does
31 * before exiting, so the correct thing to do is drop into
32 * a different fd space and close the 9P server half of the
33 * pipe before trying to mount the kernel half. This way,
34 * if the file server dies, we don't have a ref to the 9P server
35 * half of the pipe. Then killing the other procs will drop
36 * all the refs on the 9P server half, and the mount will fail.
37 * Otherwise the mount hangs forever.
38 *
39 * Libthread in general and acme win in particular make
40 * it hard to make this fd bookkeeping work out properly,
41 * so leaveinfdopen is a flag that win sets to opt out of this
42 * safety net.
43 */
44 if(!s->leavefdsopen){
45 rfork(RFFDG);
46 rendezvous(0, 0);
47 close(s->infd);
48 if(s->infd != s->outfd)
49 close(s->outfd);
50 }
51
52 if(mtpt){
53 if(amount(s->srvfd, mtpt, flag, "") == -1)
54 sysfatal("mount %s: %r", mtpt);
55 }else
56 close(s->srvfd);
57 }
58
59 static void
postproc(void * v)60 postproc(void *v)
61 {
62 Srv *s;
63
64 s = v;
65 if(!s->leavefdsopen){
66 rfork(RFNOTEG);
67 rendezvous(0, 0);
68 close(s->srvfd);
69 }
70 srv(s);
71 }
72