| Message ID | 4D005006.9080307@cn.fujitsu.com |
|---|---|
| State | New |
| Headers | show |
At 2010-12-09 11:41, Wen Congyang Write: > When I use the command 'virsh save' to save the domain state, > I receive the following error message: > operation failed: Migration unexpectedly failed. > > I debug the qemu by adding some printf(), and find the function > pclose() returns -1. > > I use strace to trace qemu, the log is as the following: > ====== > close(17) = 0 > --- SIGCHLD (Child exited) @ 0 (0) --- > wait4(-1, NULL, WNOHANG, NULL) = 22016 > rt_sigreturn(0) = 0 > wait4(22016, 0x7fff7f1034fc, 0, NULL) = -1 ECHILD (No child processes) > ====== > > We wait the child twice: one is in signal SIGCHLD handling and the other > one is in pclose(). > > We should disable sigcld handling before calling pclose(). > > Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> > Ping :)
At 12/14/2010 05:23 PM, Wen Congyang Write: > At 2010-12-09 11:41, Wen Congyang Write: >> When I use the command 'virsh save' to save the domain state, >> I receive the following error message: >> operation failed: Migration unexpectedly failed. >> >> I debug the qemu by adding some printf(), and find the function >> pclose() returns -1. >> >> I use strace to trace qemu, the log is as the following: >> ====== >> close(17) = 0 >> --- SIGCHLD (Child exited) @ 0 (0) --- >> wait4(-1, NULL, WNOHANG, NULL) = 22016 >> rt_sigreturn(0) = 0 >> wait4(22016, 0x7fff7f1034fc, 0, NULL) = -1 ECHILD (No child processes) >> ====== >> >> We wait the child twice: one is in signal SIGCHLD handling and the other >> one is in pclose(). >> >> We should disable sigcld handling before calling pclose(). >> >> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> >> > Ping :) > > Ping Again... :)
Am 20.12.2010 um 02:25 schrieb Wen Congyang: > At 12/14/2010 05:23 PM, Wen Congyang Write: >> At 2010-12-09 11:41, Wen Congyang Write: >>> When I use the command 'virsh save' to save the domain state, >>> I receive the following error message: >>> operation failed: Migration unexpectedly failed. >>> >>> I debug the qemu by adding some printf(), and find the function >>> pclose() returns -1. >>> >>> I use strace to trace qemu, the log is as the following: >>> ====== >>> close(17) = 0 >>> --- SIGCHLD (Child exited) @ 0 (0) --- >>> wait4(-1, NULL, WNOHANG, NULL) = 22016 >>> rt_sigreturn(0) = 0 >>> wait4(22016, 0x7fff7f1034fc, 0, NULL) = -1 ECHILD (No child >>> processes) >>> ====== >>> >>> We wait the child twice: one is in signal SIGCHLD handling and the >>> other >>> one is in pclose(). >>> >>> We should disable sigcld handling before calling pclose(). >>> >>> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> >>> >> Ping :) >> >> > > Ping Again... :) os-posix.c part looks sane to me, but what about Win32? Wouldn't it need stub functions? Andreas
At 12/20/2010 02:33 PM, Andreas Färber Write: > Am 20.12.2010 um 02:25 schrieb Wen Congyang: > >> At 12/14/2010 05:23 PM, Wen Congyang Write: >>> At 2010-12-09 11:41, Wen Congyang Write: >>>> When I use the command 'virsh save' to save the domain state, >>>> I receive the following error message: >>>> operation failed: Migration unexpectedly failed. >>>> >>>> I debug the qemu by adding some printf(), and find the function >>>> pclose() returns -1. >>>> >>>> I use strace to trace qemu, the log is as the following: >>>> ====== >>>> close(17) = 0 >>>> --- SIGCHLD (Child exited) @ 0 (0) --- >>>> wait4(-1, NULL, WNOHANG, NULL) = 22016 >>>> rt_sigreturn(0) = 0 >>>> wait4(22016, 0x7fff7f1034fc, 0, NULL) = -1 ECHILD (No child >>>> processes) >>>> ====== >>>> >>>> We wait the child twice: one is in signal SIGCHLD handling and the >>>> other >>>> one is in pclose(). >>>> >>>> We should disable sigcld handling before calling pclose(). >>>> >>>> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> >>>> >>> Ping :) >>> >>> >> >> Ping Again... :) > > os-posix.c part looks sane to me, but what about Win32? Wouldn't it need > stub functions? I do not know whether there is same BUG on Windows. I will add stub functions for Win32. > > Andreas >
====== We wait the child twice: one is in signal SIGCHLD handling and the other one is in pclose(). We should disable sigcld handling before calling pclose(). Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> --- os-posix.c | 19 +++++++++++++++++++ qemu-os-posix.h | 2 ++ savevm.c | 2 ++ 3 files changed, 23 insertions(+), 0 deletions(-) diff --git a/os-posix.c b/os-posix.c index 38c29d1..b163995 100644 --- a/os-posix.c +++ b/os-posix.c @@ -86,6 +86,25 @@ void os_setup_signal_handling(void) sigaction(SIGCHLD, &act, NULL); } +void os_stop_sigchld_handling(void) +{ + struct sigaction act; + + memset(&act, 0, sizeof(act)); + act.sa_handler = SIG_DFL; + sigaction(SIGCHLD, &act, NULL); +} + +void os_resume_sigchld_handling(void) +{ + struct sigaction act; + + memset(&act, 0, sizeof(act)); + act.sa_handler = sigchld_handler; + act.sa_flags = SA_NOCLDSTOP; + sigaction(SIGCHLD, &act, NULL); +} + /* Find a likely location for support files using the location of the binary. For installed binaries this will be "$bindir/../share/qemu". When running from the build tree this will be "$bindir/../pc-bios". */ diff --git a/qemu-os-posix.h b/qemu-os-posix.h index 353f878..e819295 100644 --- a/qemu-os-posix.h +++ b/qemu-os-posix.h @@ -33,6 +33,8 @@ static inline void os_host_main_loop_wait(int *timeout) void os_set_line_buffering(void); void os_set_proc_name(const char *s); void os_setup_signal_handling(void); +void os_stop_sigchld_handling(void); +void os_resume_sigchld_handling(void); void os_daemonize(void); void os_setup_post(void); diff --git a/savevm.c b/savevm.c index d38f79e..08a5f88 100644 --- a/savevm.c +++ b/savevm.c @@ -234,7 +234,9 @@ static int stdio_pclose(void *opaque) { QEMUFileStdio *s = opaque; int ret; + os_stop_sigchld_handling(); ret = pclose(s->stdio_file); + os_resume_sigchld_handling(); qemu_free(s); return ret; }