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      1 /*
      2  * Copyright (c) International Business Machines  Corp., 2003
      3  *
      4  * This program is free software;  you can redistribute it and/or modify
      5  * it under the terms of the GNU General Public License as published by
      6  * the Free Software Foundation; either version 2 of the License, or
      7  * (at your option) any later version.
      8  *
      9  * This program is distributed in the hope that it will be useful,
     10  * but WITHOUT ANY WARRANTY;  without even the implied warranty of
     11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
     12  * the GNU General Public License for more details.
     13  *
     14  * You should have received a copy of the GNU General Public License
     15  * along with this program;  if not, write to the Free Software
     16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
     17  */
     18 
     19 /*
     20  * Test Description:
     21  *  Verify that truncating a mmaped file works correctly.
     22  *
     23  * Expected Result:
     24  *  ftruncate should be allowed to increase, decrease, or zero the
     25  *  size of a file that has been mmaped
     26  *
     27  *  Test:
     28  *   Use ftruncate to shrink the file while it is mapped
     29  *   Use ftruncate to grow the file while it is mapped
     30  *   Use ftruncate to zero the size of the file while it is mapped
     31  *
     32  * HISTORY
     33  *	04/2003 Written by Paul Larson
     34  */
     35 #include <stdio.h>
     36 #include <unistd.h>
     37 #include <fcntl.h>
     38 #include <errno.h>
     39 #include <sys/mman.h>
     40 #include <sys/types.h>
     41 #include "test.h"
     42 
     43 #define mapsize (1 << 14)
     44 
     45 char *TCID = "mmap09";
     46 int TST_TOTAL = 3;
     47 
     48 static int fd;
     49 static char *maddr;
     50 
     51 static struct test_case_t {
     52 	off_t newsize;
     53 	char *desc;
     54 } TC[] = {
     55 	{mapsize - 8192, "ftruncate mmaped file to a smaller size"},
     56 	{mapsize + 1024, "ftruncate mmaped file to a larger size"},
     57 	{0, "ftruncate mmaped file to 0 size"},
     58 };
     59 
     60 static void setup(void);
     61 static void cleanup(void);
     62 
     63 int main(int argc, char **argv)
     64 {
     65 	int lc;
     66 	int i;
     67 
     68 	tst_parse_opts(argc, argv, NULL, NULL);
     69 
     70 	setup();
     71 
     72 	for (lc = 0; TEST_LOOPING(lc); lc++) {
     73 		tst_count = 0;
     74 		for (i = 0; i < TST_TOTAL; i++) {
     75 			TEST(ftruncate(fd, TC[i].newsize));
     76 
     77 			if (TEST_RETURN == -1) {
     78 				tst_resm(TFAIL | TTERRNO, "%s", TC[i].desc);
     79 			} else {
     80 				tst_resm(TPASS, "%s", TC[i].desc);
     81 			}
     82 		}
     83 
     84 	}
     85 
     86 	cleanup();
     87 	tst_exit();
     88 }
     89 
     90 static void setup(void)
     91 {
     92 	tst_sig(NOFORK, DEF_HANDLER, cleanup);
     93 
     94 	TEST_PAUSE;
     95 
     96 	tst_tmpdir();
     97 
     98 	if ((fd = open("mmaptest", O_RDWR | O_CREAT, 0666)) < 0)
     99 		tst_brkm(TFAIL | TERRNO, cleanup, "opening mmaptest failed");
    100 
    101 	/* ftruncate the file to 16k */
    102 	if (ftruncate(fd, mapsize) < 0)
    103 		tst_brkm(TFAIL | TERRNO, cleanup, "ftruncate file failed");
    104 
    105 	maddr = mmap(0, mapsize, PROT_READ | PROT_WRITE,
    106 		     MAP_FILE | MAP_SHARED, fd, 0);
    107 	if (maddr == MAP_FAILED)
    108 		tst_brkm(TFAIL | TERRNO, cleanup, "mmapping mmaptest failed");
    109 
    110 	/* fill up the file with A's */
    111 	memset(maddr, 'A', mapsize);
    112 }
    113 
    114 static void cleanup(void)
    115 {
    116 	munmap(maddr, mapsize);
    117 	close(fd);
    118 	tst_rmdir();
    119 }
    120