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/* NBD client library in userspace
* Copyright Red Hat
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/* Deliberately shutdown while stranding commands, to check their status.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include <errno.h>
#include <signal.h>
#include <libnbd.h>
static bool write_retired;
static const char *progname;
static int
callback (void *ignored, int *error)
{
if (*error != ENOTCONN) {
fprintf (stderr, "%s: unexpected error in pwrite callback: %s\n",
progname, strerror (*error));
return 0;
}
write_retired = 1;
return 1;
}
static char buf[2 * 1024 * 1024];
int
main (int argc, char *argv[])
{
struct nbd_handle *nbd;
int err;
const char *msg;
int64_t cookie;
const char *cmd[] = { NBDKIT, "-s", "--exit-with-parent",
"memory", "size=2m", NULL };
progname = argv[0];
nbd = nbd_create ();
if (nbd == NULL) {
fprintf (stderr, "%s: %s\n", argv[0], nbd_get_error ());
exit (EXIT_FAILURE);
}
/* Connect to a server. */
if (nbd_connect_command (nbd, (char **)cmd) == -1) {
fprintf (stderr, "%s: %s\n", argv[0], nbd_get_error ());
exit (EXIT_FAILURE);
}
/* Pause the server from reading, so that our first request will
* exceed the buffer and force the second request to be stuck client
* side (without stopping the server, we would be racing on whether
* we hit a block on writes based on whether the server can read
* faster than we can fill the pipe).
*/
if (nbd_kill_subprocess (nbd, SIGSTOP) == -1) {
fprintf (stderr, "%s: test failed: nbd_kill_subprocess: %s\n", argv[0],
nbd_get_error ());
exit (EXIT_FAILURE);
}
/* Issue back-to-back write requests, both large enough to block. Set up
* the second to auto-retire via callback.
*/
if ((cookie = nbd_aio_pwrite (nbd, buf, sizeof buf, 0,
NBD_NULL_COMPLETION, 0)) == -1) {
fprintf (stderr, "%s: test failed: first nbd_aio_pwrite: %s\n", argv[0],
nbd_get_error ());
exit (EXIT_FAILURE);
}
if (nbd_aio_pwrite (nbd, buf, sizeof buf, 0,
(nbd_completion_callback) { .callback = callback },
0) == -1) {
fprintf (stderr, "%s: test failed: second nbd_aio_pwrite: %s\n", argv[0],
nbd_get_error ());
exit (EXIT_FAILURE);
}
/* Resume the server; but now our state machine remains blocked
* until we notify or otherwise poll it.
*/
if (nbd_kill_subprocess (nbd, SIGCONT) == -1) {
fprintf (stderr, "%s: test failed: nbd_kill_subprocess: %s\n", argv[0],
nbd_get_error ());
exit (EXIT_FAILURE);
}
if (nbd_aio_peek_command_completed (nbd) != 0) {
fprintf (stderr, "%s: test failed: nbd_aio_peek_command_completed\n",
argv[0]);
exit (EXIT_FAILURE);
}
if (nbd_aio_command_completed (nbd, cookie) != 0) {
fprintf (stderr, "%s: test failed: nbd_aio_command_completed\n", argv[0]);
exit (EXIT_FAILURE);
}
/* Send an immediate shutdown. This will abort the second write, as
* well as kick the state machine to finish the first.
*/
if (nbd_shutdown (nbd, LIBNBD_SHUTDOWN_ABANDON_PENDING) == -1) {
fprintf (stderr, "%s: test failed: nbd_shutdown\n", argv[0]);
exit (EXIT_FAILURE);
}
/* All in-flight commands should now be completed. But whether the
* first write succeeded or failed depends on the server, so we
* merely retire it without checking status.
*/
if (nbd_aio_in_flight (nbd) != 0) {
fprintf (stderr, "%s: test failed: nbd_aio_in_flight\n", argv[0]);
exit (EXIT_FAILURE);
}
if (nbd_aio_peek_command_completed (nbd) != cookie) {
fprintf (stderr, "%s: test failed: nbd_aio_peek_command_completed\n",
argv[0]);
exit (EXIT_FAILURE);
}
nbd_aio_command_completed (nbd, cookie);
/* With all commands retired, no further command should be pending */
if (!write_retired) {
fprintf (stderr, "%s: test failed: second nbd_aio_pwrite not retired\n",
argv[0]);
exit (EXIT_FAILURE);
}
if (nbd_aio_peek_command_completed (nbd) != -1) {
fprintf (stderr, "%s: test failed: nbd_aio_peek_command_completed\n",
argv[0]);
exit (EXIT_FAILURE);
}
msg = nbd_get_error ();
err = nbd_get_errno ();
printf ("error: \"%s\"\n", msg);
printf ("errno: %d (%s)\n", err, strerror (err));
if (err != EINVAL) {
fprintf (stderr, "%s: test failed: unexpected errno %d (%s)\n", argv[0],
err, strerror (err));
exit (EXIT_FAILURE);
}
nbd_close (nbd);
exit (EXIT_SUCCESS);
}
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