qemu-nbd: trap SIGTERM

The client process right now uses SIGTERM to interrupt the server side.
This does not affect the exit status of "qemu-nbd -v -c" because the
server is a child process.  This will change when both sides will be
in the same process, and anyway cleaning up things nicely upon SIGTERM
is good practice.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Paolo Bonzini 2011-11-04 15:51:19 +01:00 committed by Kevin Wolf
parent 74624688b3
commit bb345110f0
1 changed files with 29 additions and 5 deletions

View File

@ -36,6 +36,7 @@
#define NBD_BUFFER_SIZE (1024*1024)
static int sigterm_wfd;
static int verbose;
static void usage(const char *name)
@ -163,6 +164,14 @@ static int find_partition(BlockDriverState *bs, int partition,
return -1;
}
static void termsig_handler(int signum)
{
static int sigterm_reported;
if (!sigterm_reported) {
sigterm_reported = (write(sigterm_wfd, "", 1) == 1);
}
}
static void show_parts(const char *device)
{
if (fork() == 0) {
@ -231,6 +240,18 @@ int main(int argc, char **argv)
int max_fd;
int persistent = 0;
/* Set up a SIGTERM handler so that we exit with a nice status code. */
struct sigaction sa_sigterm;
int sigterm_fd[2];
if (qemu_pipe(sigterm_fd) == -1) {
err(EXIT_FAILURE, "Error setting up communication pipe");
}
sigterm_wfd = sigterm_fd[1];
memset(&sa_sigterm, 0, sizeof(sa_sigterm));
sa_sigterm.sa_handler = termsig_handler;
sigaction(SIGTERM, &sa_sigterm, NULL);
while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
switch (ch) {
case 's':
@ -423,7 +444,6 @@ int main(int argc, char **argv)
close(fd);
out:
kill(pid, SIGTERM);
unlink(socket);
return ret;
}
@ -444,18 +464,22 @@ int main(int argc, char **argv)
nb_fds++;
data = qemu_blockalign(bs, NBD_BUFFER_SIZE);
if (data == NULL)
if (data == NULL) {
errx(EXIT_FAILURE, "Cannot allocate data buffer");
}
do {
FD_ZERO(&fds);
FD_SET(sigterm_fd[0], &fds);
for (i = 0; i < nb_fds; i++)
FD_SET(sharing_fds[i], &fds);
ret = select(max_fd + 1, &fds, NULL, NULL, NULL);
if (ret == -1)
do {
ret = select(max_fd + 1, &fds, NULL, NULL, NULL);
} while (ret == -1 && errno == EINTR);
if (ret == -1 || FD_ISSET(sigterm_fd[0], &fds)) {
break;
}
if (FD_ISSET(sharing_fds[0], &fds))
ret--;