/* Copyright (c) 2014 Red Hat, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of version 2 the GNU General Public License as
* published by the Free Software Foundation.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
***********************************************************************
* File: mountns03.c
*
* Tests a slave mount: slave mount is like a shared mount except that
* mount and umount events only propagate towards it.
*
* Description:
* 1. Creates directories "A", "B" and files "A/A", "B/B"
* 2. Unshares mount namespace and makes it private (so mounts/umounts
* have no effect on a real system)
* 3. Bind mounts directory "A" to itself
* 4. Makes directory "A" shared
* 5. Clones a new child process with CLONE_NEWNS flag and makes "A"
* a slave mount
* 6. There are two testcases (where X is parent namespace and Y child
* namespace):
* 1)
* X: bind mounts "B" to "A"
* Y: must see the file "A/B"
* X: umounts "A"
* 2)
* Y: bind mounts "B" to "A"
* X: must see only the "A/A" and must not see "A/B" (as slave
* mount does not forward propagation)
* Y: umounts "A"
***********************************************************************/
#define _GNU_SOURCE
#include <sys/wait.h>
#include <sys/mount.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include "mountns_helper.h"
#include "test.h"
#include "safe_macros.h"
char *TCID = "mountns03";
int TST_TOTAL = 2;
#if defined(MS_SHARED) && defined(MS_PRIVATE) \
&& defined(MS_REC) && defined(MS_SLAVE)
int child_func(void *arg LTP_ATTRIBUTE_UNUSED)
{
int ret = 0;
/* makes mount DIRA a slave of DIRA (all slave mounts have
* a master mount which is a shared mount) */
if (mount("none", DIRA, "none", MS_SLAVE, NULL) == -1) {
perror("mount");
return 1;
}
TST_SAFE_CHECKPOINT_WAKE_AND_WAIT(NULL, 0);
/* checks that shared mounts propagates to slave mount */
if (access(DIRA"/B", F_OK) == -1)
ret = 2;
TST_SAFE_CHECKPOINT_WAKE_AND_WAIT(NULL, 0);
/* bind mounts DIRB to DIRA making contents of DIRB visible
* in DIRA */
if (mount(DIRB, DIRA, "none", MS_BIND, NULL) == -1) {
perror("mount");
return 1;
}
TST_SAFE_CHECKPOINT_WAKE_AND_WAIT(NULL, 0);
umount(DIRA);
return ret;
}
static void test(void)
{
int status;
/* unshares the mount ns */
if (unshare(CLONE_NEWNS) == -1)
tst_brkm(TBROK | TERRNO, cleanup, "unshare failed");
/* makes sure parent mounts/umounts have no effect on a real system */
SAFE_MOUNT(cleanup, "none", "/", "none", MS_REC|MS_PRIVATE, NULL);
/* bind mounts DIRA to itself */
SAFE_MOUNT(cleanup, DIRA, DIRA, "none", MS_BIND, NULL);
/* makes mount DIRA shared */
SAFE_MOUNT(cleanup, "none", DIRA, "none", MS_SHARED, NULL);
if (do_clone_tests(CLONE_NEWNS, child_func, NULL, NULL, NULL) == -1)
tst_brkm(TBROK | TERRNO, cleanup, "clone failed");
/* waits for child to make a slave mount */
TST_SAFE_CHECKPOINT_WAIT(cleanup, 0);
/* bind mounts DIRB to DIRA making contents of DIRB visible
* in DIRA */
SAFE_MOUNT(cleanup, DIRB, DIRA, "none", MS_BIND, NULL);
TST_SAFE_CHECKPOINT_WAKE_AND_WAIT(cleanup, 0);
SAFE_UMOUNT(cleanup, DIRA);
TST_SAFE_CHECKPOINT_WAKE_AND_WAIT(cleanup, 0);
/* checks that slave mount doesn't propagate to shared mount */
if ((access(DIRA"/A", F_OK) == 0) && (access(DIRA"/B", F_OK) == -1))
tst_resm(TPASS, "propagation from slave mount passed");
else
tst_resm(TFAIL, "propagation form slave mount failed");
TST_SAFE_CHECKPOINT_WAKE(cleanup, 0);
SAFE_WAIT(cleanup, &status);
if (WIFEXITED(status)) {
if (WEXITSTATUS(status) == 0)
tst_resm(TPASS, "propagation to slave mount passed");
else
tst_resm(TFAIL, "propagation to slave mount failed");
}
if (WIFSIGNALED(status)) {
tst_resm(TBROK, "child was killed with signal %s",
tst_strsig(WTERMSIG(status)));
return;
}
SAFE_UMOUNT(cleanup, DIRA);
}
int main(int argc, char *argv[])
{
int lc;
tst_parse_opts(argc, argv, NULL, NULL);
setup();
for (lc = 0; TEST_LOOPING(lc); lc++)
test();
cleanup();
tst_exit();
}
#else
int main(void)
{
tst_brkm(TCONF, NULL, "needed mountflags are not defined");
}
#endif