minix/tests/test58.c

   1 /* This tests the behavior of Minix when the current working dir (cwd) doesn't
   2  * actually exist and we either:
   3  *   - create a new file
   4  *   - make a new directory
   5  *   - make a special file (mknod)
   6  *   - create a hard link
   7  *   - create a symbolic link, or
   8  *   - rename a file
   9  * In each case, `a component of the path does not name an existing file', and
  10  * the operation should fail with ENOENT. These tests should actually be
  11  * distributed over the other tests that actually test the specific system
  12  * calls.
  13  */
  14
  15 #include <stdio.h>
  16 #include <errno.h>
  17 #include <fcntl.h>
  18 #include <unistd.h>
  19 #include <sys/socket.h>
  20 #include <sys/types.h>
  21 #include <sys/wait.h>
  22 #include <sys/stat.h>
  23 #include <sys/syslimits.h>
  24
  25 int subtest = -1;
  26 int max_error = 999;    /* Effectively no limit. This is necessary as this
  27                          * test tries to undo errors and should therefore not
  28                          * preemptively exit, as that would leave the FS
  29                          * in a corrupted state. */
  30
  31 #include "common.h"
  32
  33 #define TEST_PATH "a/b/c"
  34 #define INTEGR_MSG "You might want to check fs integrity\n"
  35
  36 void do_test(void);
  37
  38 void do_test(void)
  39 {
  40   int r, fd;
  41   int s[2];
  42   char buf[1], testroot[PATH_MAX+1], renamebuf[PATH_MAX+1];
  43
  44   subtest = 1;
  45   if (socketpair(PF_UNIX, SOCK_STREAM, 0, s) == -1) e(1);
  46   if (system("mkdir -p " TEST_PATH) == -1) e(2);
  47   if (realpath(".", testroot) == NULL) e(3);
  48
  49   r = fork();
  50   if (r == -1) e(4);
  51   else if (r == 0) { /* Child */
  52         /* Change child's cwd to TEST_PATH */
  53         if (chdir(TEST_PATH) == -1) e(5);
  54
  55         /* Signal parent we're ready for the test */
  56         buf[0] = 'a';
  57         if (write(s[0], buf, sizeof(buf)) != sizeof(buf)) e(6);
  58
  59         /* Wait for parent to remove my cwd */
  60         if (read(s[0], buf, sizeof(buf)) != sizeof(buf)) e(7);
  61
  62         /* Try to create a file */
  63         if ((fd = open("testfile", O_RDWR | O_CREAT)) != -1) {
  64                 e(8);
  65                 /* Uh oh. We created a file?! Try to remove it. */
  66                 (void) close(fd);
  67                 if (unlink("testfile") != 0) {
  68                         /* This is not good. We created a file, but we can
  69                          * never access it; we have a spurious inode.
  70                          */
  71                         e(9);
  72                         printf(INTEGR_MSG);
  73                         exit(errct);
  74                 }
  75         }
  76         if (errno != ENOENT) e(10);
  77
  78         /* Try to create a dir */
  79         errno = 0;
  80         if (mkdir("testdir", 0777) == 0) {
  81                 e(11);
  82                 /* Uh oh. This shouldn't have been possible. Try to undo. */
  83                 if (rmdir("testdir") != 0) {
  84                         /* Not good. */
  85                         e(12);
  86                         printf(INTEGR_MSG);
  87                         exit(errct);
  88                 }
  89         }
  90         if (errno != ENOENT) e(13);
  91
  92         /* Try to create a special file */
  93         errno = 0;
  94         if (mknod("testnode", 0777 | S_IFIFO, 0) == 0) {
  95                 e(14);
  96                 /* Impossible. Try to make it unhappen. */
  97                 if (unlink("testnode") != 0) {
  98                         /* Not good. */
  99                         e(15);
 100                         printf(INTEGR_MSG);
 101                         exit(errct);
 102                 }
 103         }
 104         if (errno != ENOENT) e(16);
 105
 106         /* Try to rename a file */
 107         errno = 0;
 108         /* First create a file in the test dir */
 109         snprintf(renamebuf, PATH_MAX, "%s/oldname", testroot);
 110         if ((fd = open(renamebuf, O_RDWR | O_CREAT)) == -1) e(17);
 111         if (close(fd) != 0) e(18);
 112
 113         /* Now try to rename that file to an entry in the current, non-existing
 114          * working directory.
 115          */
 116         if (rename(renamebuf, "testrename") == 0) {
 117                 e(19);
 118                 /* This shouldn't have been possible. Revert the name change.
 119                  */
 120                 if (rename("testrename", renamebuf) != 0) {
 121                         /* Failed */
 122                         e(20);
 123                         printf(INTEGR_MSG);
 124                         exit(errct);
 125                 }
 126         }
 127
 128         /* Try to create a hard link to that file */
 129         errno = 0;
 130         if (link(renamebuf, "testhlink") == 0) {
 131                 e(21);
 132                 /* Try to undo the hard link to prevent fs corruption. */
 133                 if (unlink("testhlink") != 0) {
 134                         /* Failed. */
 135                         e(22);
 136                         printf(INTEGR_MSG);
 137                         exit(errct);
 138                 }
 139         }
 140         if (errno != ENOENT) e(23);
 141
 142         /* Try to create a symlink */
 143         errno = 0;
 144         if (symlink(testroot, "testslink") == 0) {
 145                 e(24);
 146                 /* Try to remove the symlink to prevent fs corruption. */
 147                 if (unlink("testslink") != 0) {
 148                         /* Failed. */
 149                         e(25);
 150                         printf(INTEGR_MSG);
 151                         exit(errct);
 152                 }
 153         }
 154         if (errno != ENOENT) e(26);
 155
 156         exit(errct);
 157   } else { /* Parent */
 158         int status;
 159
 160         /* Wait for the child to enter the TEST_PATH dir */
 161         if (read(s[1], buf, sizeof(buf)) != sizeof(buf)) e(27);
 162
 163         /* Delete TEST_PATH */
 164         if (rmdir(TEST_PATH) != 0) e(28);
 165
 166         /* Tell child we removed its cwd */
 167         buf[0] = 'b';
 168         if (write(s[1], buf, sizeof(buf)) != sizeof(buf)) e(29);
 169
 170         wait(&status);
 171         errct += WEXITSTATUS(status);   /* Count errors */
 172   }
 173 }
 174
 175 int main(int argc, char* argv[])
 176 {
 177   start(58);
 178   do_test();
 179   quit();
 180   return(-1);   /* Unreachable */
 181 }
 182
 183