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/* nbdkit
* Copyright Red Hat
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name of Red Hat nor the names of its contributors may be
* used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <inttypes.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <libnbd.h>
#include "requires.h"
#define DISK_SIZE (100 * 1024 * 1024)
static char *loopdev; /* Name of the loop device. */
static void detach_loopdev (void);
int
main (int argc, char *argv[])
{
struct nbd_handle *nbd;
int r;
int fd;
char cmd[64], buf[64];
char disk[] = LARGE_TMPDIR "/diskXXXXXX"; /* Backing disk. */
FILE *pp;
size_t len;
int64_t size;
/* This test must be run as root (usually 'sudo make check-root'),
* otherwise skip.
*/
requires_root ();
/* /dev/loop-control must be accessible. */
r = access ("/dev/loop-control", W_OK);
if (r != 0) {
fprintf (stderr, "%s: /dev/loop-control is not writable.\n",
argv[0]);
exit (77);
}
/* losetup must be available. */
requires ("losetup --version");
/* Create the temporary backing disk. */
fd = mkstemp (disk);
if (fd == -1) {
perror ("mkstemp");
exit (EXIT_FAILURE);
}
if (ftruncate (fd, DISK_SIZE) == -1) {
perror ("ftruncate");
unlink (disk);
exit (EXIT_FAILURE);
}
/* Create the loopback device. */
snprintf (cmd, sizeof cmd, "losetup -f --show %s", disk);
pp = popen (cmd, "r");
if (pp == NULL) {
perror ("popen: losetup");
unlink (disk);
exit (EXIT_FAILURE);
}
if (fgets (buf, sizeof buf, pp) == NULL) {
fprintf (stderr, "%s: could not read loop device name from losetup\n",
argv[0]);
unlink (disk);
exit (EXIT_FAILURE);
}
len = strlen (buf);
if (len > 0 && buf[len-1] == '\n') {
buf[len-1] = '\0';
len--;
}
pclose (pp);
/* We can delete the backing disk. The loop device will hold it open. */
unlink (disk);
/* If we get to this point, set up an atexit handler to detach the
* loop device.
*/
loopdev = malloc (len+1);
if (loopdev == NULL) {
perror ("malloc");
exit (EXIT_FAILURE);
}
strcpy (loopdev, buf);
atexit (detach_loopdev);
/* Create the nbd handle. */
nbd = nbd_create ();
if (nbd == NULL) {
fprintf (stderr, "%s\n", nbd_get_error ());
exit (EXIT_FAILURE);
}
/* Start nbdkit. */
if (nbd_connect_command (nbd,
(char *[]) {
"nbdkit", "-s", "--exit-with-parent",
"file", loopdev,
NULL }) == -1) {
fprintf (stderr, "%s\n", nbd_get_error ());
exit (EXIT_FAILURE);
}
/* Check the disk size matches the loop device size. */
size = nbd_get_size (nbd);
if (size == -1) {
fprintf (stderr, "%s\n", nbd_get_error ());
exit (EXIT_FAILURE);
}
if (size != DISK_SIZE) {
fprintf (stderr, "%s: incorrect export size, "
"expected: %d actual: %" PRIi64 "\n",
argv[0], DISK_SIZE, size);
exit (EXIT_FAILURE);
}
/* Print (don't check) the block size preferences. */
printf ("minimum = %" PRIu64 "\n",
nbd_get_block_size (nbd, LIBNBD_SIZE_MINIMUM));
printf ("preferred = %" PRIu64 "\n",
nbd_get_block_size (nbd, LIBNBD_SIZE_PREFERRED));
printf ("maximum = %" PRIu64 "\n",
nbd_get_block_size (nbd, LIBNBD_SIZE_MAXIMUM));
nbd_close (nbd);
/* The atexit handler should detach the loop device and clean up
* the backing disk.
*/
exit (EXIT_SUCCESS);
}
/* atexit handler. */
static void
detach_loopdev (void)
{
char cmd[64];
if (loopdev == NULL)
return;
snprintf (cmd, sizeof cmd, "losetup -d %s", loopdev);
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-result"
system (cmd);
#pragma GCC diagnostic pop
free (loopdev);
loopdev = NULL;
}
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