| /* 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 "test.h" |
| #include "libclone.h" |
| #include "safe_macros.h" |
| #include "safe_file_ops.h" |
| #include "mountns_helper.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) |
| { |
| 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_CHECKPOINT_SIGNAL_PARENT(&checkpoint1); |
| TST_CHECKPOINT_CHILD_WAIT(&checkpoint2); |
| |
| /* checks that shared mounts propagates to slave mount */ |
| if (access(DIRA"/B", F_OK) == -1) |
| ret = 2; |
| |
| TST_CHECKPOINT_SIGNAL_PARENT(&checkpoint1); |
| TST_CHECKPOINT_CHILD_WAIT(&checkpoint2); |
| |
| /* 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_CHECKPOINT_SIGNAL_PARENT(&checkpoint1); |
| TST_CHECKPOINT_CHILD_WAIT(&checkpoint2); |
| |
| 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_CHECKPOINT_PARENT_WAIT(cleanup, &checkpoint1); |
| |
| /* bind mounts DIRB to DIRA making contents of DIRB visible |
| * in DIRA */ |
| SAFE_MOUNT(cleanup, DIRB, DIRA, "none", MS_BIND, NULL); |
| |
| TST_CHECKPOINT_SIGNAL_CHILD(cleanup, &checkpoint2); |
| TST_CHECKPOINT_PARENT_WAIT(cleanup, &checkpoint1); |
| |
| SAFE_UMOUNT(cleanup, DIRA); |
| |
| TST_CHECKPOINT_SIGNAL_CHILD(cleanup, &checkpoint2); |
| TST_CHECKPOINT_PARENT_WAIT(cleanup, &checkpoint1); |
| |
| /* 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_CHECKPOINT_SIGNAL_CHILD(cleanup, &checkpoint2); |
| |
| |
| 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[]) |
| { |
| const char *msg; |
| int lc; |
| |
| msg = parse_opts(argc, argv, NULL, NULL); |
| if (msg != NULL) |
| tst_brkm(TBROK, NULL, "OPTION PARSING ERROR - %s", msg); |
| |
| 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 |