tests/unlink-under-feet.c

   1 /*
   2  * Copyright (c) 2001, 2006 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #ifdef HAVE_CONFIG_H
  35 #include <config.h>
  36 #endif
  37
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include <sys/types.h>
  41 #include <sys/stat.h>
  42 #include <fcntl.h>
  43 #include <unistd.h>
  44
  45 #include <roken.h>
  46 #include <err.h>
  47
  48 RCSID("$Id$");
  49
  50 #define BLOCK_SIZE      (256*1024)
  51 #define BUF_SIZE        1024
  52
  53 /*
  54  * unlink a dirty, open file. The resulting installattr used to make
  55  * nnpfs truncate the open file to zero.
  56  */
  57
  58 static void
  59 writeat(int fd, off_t offset, char *buf, size_t sz)
  60 {
  61     if (lseek(fd, offset, SEEK_SET) != offset)
  62         err(1, "lseek/w at %llu", (unsigned long long)offset);
  63
  64     if (write(fd, buf, sz) != sz)
  65         err(1, "write at %llu", (unsigned long long)offset);
  66 }
  67
  68 static void
  69 readat(int fd, off_t offset, char *buf, const char *data, size_t sz)
  70 {
  71     if (lseek(fd, offset, SEEK_SET) != offset)
  72         err(1, "lseek/r at %llu", (unsigned long long)offset);
  73
  74     if (read(fd, buf, sz) != sz)
  75         err(1, "read at %llu", (unsigned long long)offset);
  76
  77     if (memcmp(buf, data, sz)) {
  78         fprintf(stderr, "read %x, expected %x\n",
  79                 *(unsigned*)buf, *(unsigned*)data);
  80         errx(1, "memcmp at %llu", (unsigned long long)offset);
  81     }
  82 }
  83
  84 static void
  85 doit(const char *filename)
  86 {
  87     int fd;
  88
  89     char *databuf = malloc(BUF_SIZE);
  90     char *scratch = malloc(BUF_SIZE);
  91
  92     if (!databuf || !scratch)
  93         errx(1, "malloc failed");
  94
  95     memset(databuf, 0xe3, BUF_SIZE);
  96
  97     fd = open(filename, O_RDWR | O_TRUNC | O_CREAT, 0666);
  98     if (fd < 0)
  99         err(1, "open %s", filename);
 100
 101     writeat(fd, BLOCK_SIZE, databuf, BUF_SIZE);
 102
 103     if (unlink(filename) < 0)
 104         err(1, "unlink %s", filename);
 105
 106     readat(fd, BLOCK_SIZE, scratch, databuf, BUF_SIZE);
 107
 108     if (close(fd) < 0)
 109         err(1, "close %s", filename);
 110
 111     free(databuf);
 112     free(scratch);
 113 }
 114
 115 int
 116 main(int argc, char **argv)
 117 {
 118     setprogname(argv[0]);
 119
 120     if (argc == 1)
 121         doit("foo");
 122     else if (argc == 2)
 123         doit(argv[1]);
 124     else
 125         errx(1, "usage: %s [filename]", argv[0]);
 126     return 0;
 127 }