Matus Marhefka | ce30a7b | 2014-10-02 14:28:47 +0200 | [diff] [blame^] | 1 | /* Copyright (c) 2014 Red Hat, Inc. |
| 2 | * |
| 3 | * This program is free software: you can redistribute it and/or modify |
| 4 | * it under the terms of version 2 the GNU General Public License as |
| 5 | * published by the Free Software Foundation. |
| 6 | * |
| 7 | * This program is distributed in the hope that it will be useful, |
| 8 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 9 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 10 | * GNU General Public License for more details. |
| 11 | * |
| 12 | * You should have received a copy of the GNU General Public License |
| 13 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 14 | *********************************************************************** |
| 15 | * File: mountns03.c |
| 16 | * |
| 17 | * Tests a slave mount: slave mount is like a shared mount except that |
| 18 | * mount and umount events only propagate towards it. |
| 19 | * |
| 20 | * Description: |
| 21 | * 1. Creates directories "A", "B" and files "A/A", "B/B" |
| 22 | * 2. Unshares mount namespace and makes it private (so mounts/umounts |
| 23 | * have no effect on a real system) |
| 24 | * 3. Bind mounts directory "A" to itself |
| 25 | * 4. Makes directory "A" shared |
| 26 | * 5. Clones a new child process with CLONE_NEWNS flag and makes "A" |
| 27 | * a slave mount |
| 28 | * 6. There are two testcases (where X is parent namespace and Y child |
| 29 | * namespace): |
| 30 | * 1) |
| 31 | * X: bind mounts "B" to "A" |
| 32 | * Y: must see the file "A/B" |
| 33 | * X: umounts "A" |
| 34 | * 2) |
| 35 | * Y: bind mounts "B" to "A" |
| 36 | * X: must see only the "A/A" and must not see "A/B" (as slave |
| 37 | * mount does not forward propagation) |
| 38 | * Y: umounts "A" |
| 39 | ***********************************************************************/ |
| 40 | |
| 41 | #define _GNU_SOURCE |
| 42 | #include <sys/wait.h> |
| 43 | #include <sys/mount.h> |
| 44 | #include <stdio.h> |
| 45 | #include <unistd.h> |
| 46 | #include <errno.h> |
| 47 | #include "test.h" |
| 48 | #include "usctest.h" |
| 49 | #include "libclone.h" |
| 50 | #include "safe_macros.h" |
| 51 | #include "safe_file_ops.h" |
| 52 | #include "mountns_helper.h" |
| 53 | |
| 54 | |
| 55 | char *TCID = "mountns03"; |
| 56 | int TST_TOTAL = 2; |
| 57 | |
| 58 | |
| 59 | #if defined(MS_SHARED) && defined(MS_PRIVATE) \ |
| 60 | && defined(MS_REC) && defined(MS_SLAVE) |
| 61 | |
| 62 | int child_func(void *arg) |
| 63 | { |
| 64 | int ret = 0; |
| 65 | |
| 66 | /* makes mount DIRA a slave of DIRA (all slave mounts have |
| 67 | * a master mount which is a shared mount) */ |
| 68 | if (mount("none", DIRA, "none", MS_SLAVE, NULL) == -1) { |
| 69 | perror("mount"); |
| 70 | return 1; |
| 71 | } |
| 72 | |
| 73 | TST_CHECKPOINT_SIGNAL_PARENT(&checkpoint1); |
| 74 | TST_CHECKPOINT_CHILD_WAIT(&checkpoint2); |
| 75 | |
| 76 | /* checks that shared mounts propagates to slave mount */ |
| 77 | if (access(DIRA"/B", F_OK) == -1) |
| 78 | ret = 2; |
| 79 | |
| 80 | TST_CHECKPOINT_SIGNAL_PARENT(&checkpoint1); |
| 81 | TST_CHECKPOINT_CHILD_WAIT(&checkpoint2); |
| 82 | |
| 83 | /* bind mounts DIRB to DIRA making contents of DIRB visible |
| 84 | * in DIRA */ |
| 85 | if (mount(DIRB, DIRA, "none", MS_BIND, NULL) == -1) { |
| 86 | perror("mount"); |
| 87 | return 1; |
| 88 | } |
| 89 | |
| 90 | TST_CHECKPOINT_SIGNAL_PARENT(&checkpoint1); |
| 91 | TST_CHECKPOINT_CHILD_WAIT(&checkpoint2); |
| 92 | |
| 93 | umount(DIRA); |
| 94 | return ret; |
| 95 | } |
| 96 | |
| 97 | static void test(void) |
| 98 | { |
| 99 | int status; |
| 100 | |
| 101 | /* unshares the mount ns */ |
| 102 | if (unshare(CLONE_NEWNS) == -1) |
| 103 | tst_brkm(TBROK | TERRNO, cleanup, "unshare failed"); |
| 104 | /* makes sure parent mounts/umounts have no effect on a real system */ |
| 105 | SAFE_MOUNT(cleanup, "none", "/", "none", MS_REC|MS_PRIVATE, NULL); |
| 106 | |
| 107 | /* bind mounts DIRA to itself */ |
| 108 | SAFE_MOUNT(cleanup, DIRA, DIRA, "none", MS_BIND, NULL); |
| 109 | |
| 110 | /* makes mount DIRA shared */ |
| 111 | SAFE_MOUNT(cleanup, "none", DIRA, "none", MS_SHARED, NULL); |
| 112 | |
| 113 | if (do_clone_tests(CLONE_NEWNS, child_func, NULL, NULL, NULL) == -1) |
| 114 | tst_brkm(TBROK | TERRNO, cleanup, "clone failed"); |
| 115 | |
| 116 | /* waits for child to make a slave mount */ |
| 117 | TST_CHECKPOINT_PARENT_WAIT(cleanup, &checkpoint1); |
| 118 | |
| 119 | /* bind mounts DIRB to DIRA making contents of DIRB visible |
| 120 | * in DIRA */ |
| 121 | SAFE_MOUNT(cleanup, DIRB, DIRA, "none", MS_BIND, NULL); |
| 122 | |
| 123 | TST_CHECKPOINT_SIGNAL_CHILD(cleanup, &checkpoint2); |
| 124 | TST_CHECKPOINT_PARENT_WAIT(cleanup, &checkpoint1); |
| 125 | |
| 126 | SAFE_UMOUNT(cleanup, DIRA); |
| 127 | |
| 128 | TST_CHECKPOINT_SIGNAL_CHILD(cleanup, &checkpoint2); |
| 129 | TST_CHECKPOINT_PARENT_WAIT(cleanup, &checkpoint1); |
| 130 | |
| 131 | /* checks that slave mount doesn't propagate to shared mount */ |
| 132 | if ((access(DIRA"/A", F_OK) == 0) && (access(DIRA"/B", F_OK) == -1)) |
| 133 | tst_resm(TPASS, "propagation from slave mount passed"); |
| 134 | else |
| 135 | tst_resm(TFAIL, "propagation form slave mount failed"); |
| 136 | |
| 137 | TST_CHECKPOINT_SIGNAL_CHILD(cleanup, &checkpoint2); |
| 138 | |
| 139 | |
| 140 | SAFE_WAIT(cleanup, &status); |
| 141 | if (WIFEXITED(status)) { |
| 142 | if (WEXITSTATUS(status) == 0) |
| 143 | tst_resm(TPASS, "propagation to slave mount passed"); |
| 144 | else |
| 145 | tst_resm(TFAIL, "propagation to slave mount failed"); |
| 146 | } |
| 147 | if (WIFSIGNALED(status)) { |
| 148 | tst_resm(TBROK, "child was killed with signal %s", |
| 149 | tst_strsig(WTERMSIG(status))); |
| 150 | return; |
| 151 | } |
| 152 | |
| 153 | SAFE_UMOUNT(cleanup, DIRA); |
| 154 | } |
| 155 | |
| 156 | int main(int argc, char *argv[]) |
| 157 | { |
| 158 | const char *msg; |
| 159 | int lc; |
| 160 | |
| 161 | msg = parse_opts(argc, argv, NULL, NULL); |
| 162 | if (msg != NULL) |
| 163 | tst_brkm(TBROK, NULL, "OPTION PARSING ERROR - %s", msg); |
| 164 | |
| 165 | setup(); |
| 166 | |
| 167 | for (lc = 0; TEST_LOOPING(lc); lc++) |
| 168 | test(); |
| 169 | |
| 170 | cleanup(); |
| 171 | tst_exit(); |
| 172 | } |
| 173 | |
| 174 | #else |
| 175 | int main(void) |
| 176 | { |
| 177 | tst_brkm(TCONF, NULL, "needed mountflags are not defined"); |
| 178 | } |
| 179 | #endif |