ref: 51f76ae999813bdbf33b06bb4e6c6c8b00f4aec8
dir: /sys/src/lib9p/post.c/
#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); } void _postsharesrv(Srv *s, char *name, char *mtpt, char *desc) { 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(sharefd(mtpt, desc, s->srvfd) < 0) sysfatal("sharefd %s: %r", mtpt); }else close(s->srvfd); } static void postproc(void *v) { Srv *s; s = v; if(!s->leavefdsopen){ rfork(RFNOTEG); rendezvous(0, 0); close(s->srvfd); } srv(s); }