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/*
* This file and its contents are supplied under the terms of the
* Common Development and Distribution License ("CDDL"), version 1.0.
* You may only use this file in accordance with the terms of version
* 1.0 of the CDDL.
*
* A full copy of the text of the CDDL should have accompanied this
* source. A copy of the CDDL is also available via the Internet at
* http://www.illumos.org/license/CDDL.
*/
/*
* Copyright 2012 Jilin Xpd <jilinxpd@gmail.com>
* Copyright 2018 Nexenta Systems, Inc.
*/
/*
* Test if file read/write is coherent with mmap, perform 2 tests:
* modify file through mmap, and check the result through file read.
* modify file through file write, and check the result through mmap.
*/
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
void
usage(void)
{
fprintf(stderr,
"usage: rw_mmap -n <size>[b|k|m|g] -f <filename>\n");
exit(1);
}
int
main(int argc, char **argv)
{
char *suffix;
char *filename = NULL;
char *file_addr;
char *p;
size_t filesize;
ssize_t blksize;
size_t cnt = 1;
size_t mul = 1;
int c, fid;
char *buf;
/*
* parse arguments
*/
while ((c = getopt(argc, argv, "n:f:")) != -1) {
switch (c) {
case 'n':
cnt = (size_t)strtoul(optarg, &suffix, 0);
if (cnt == 0)
goto bad_n_arg;
switch (*suffix) {
case '\0':
case 'b':
mul = 1;
break;
case 'k':
mul = 1024;
break;
case 'm':
mul = (1024 * 1024);
break;
case 'g':
mul = (1024 * 1024 * 1024);
break;
default:
bad_n_arg:
fprintf(stderr, "-n %s: invalid size\n",
optarg);
return (1);
}
cnt = cnt * mul;
break;
case 'f': /* target file */
filename = optarg;
break;
case ':': /* missing optarg */
fprintf(stderr,
"Option -%c requires an arg\n", optopt);
usage();
break;
case '?':
fprintf(stderr,
"Unrecognized option: -%c\n", optopt);
usage();
break;
}
}
/* open test file */
fid = open(filename, O_RDWR | O_CREAT | O_TRUNC,
S_IRUSR | S_IWUSR | S_IROTH | S_IWOTH);
if (fid == -1) {
fprintf(stderr, "open %s error=%d\n", filename, errno);
return (1);
}
/* extend file */
filesize = cnt;
if (ftruncate(fid, filesize) == -1) {
fprintf(stderr, "ftrunc %s error=%d\n", filename, errno);
return (1);
}
/* map file */
file_addr = mmap(NULL, filesize,
PROT_READ | PROT_WRITE, MAP_SHARED, fid, 0);
if (file_addr == MAP_FAILED) {
fprintf(stderr, "mmap %s error=%d\n", filename, errno);
return (1);
}
blksize = 4096;
buf = malloc(blksize);
if (buf == NULL) {
fprintf(stderr, "malloc failed\n");
return (1);
}
/* verify fread and mmap see the same data */
p = file_addr + 2013; /* not aligned to 4KB, on purpose */
lseek(fid, 2013, SEEK_SET);
while (p < file_addr + filesize) {
blksize = read(fid, buf, blksize);
if (blksize < 0) {
perror(filename);
return (1);
}
if (blksize == 0)
break;
if (memcmp(buf, p, blksize) != 0) {
fprintf(stderr, "memcmp failed 1\n");
return (1);
}
p += blksize;
}
/* modify file through mmap, verify fread can see the change */
blksize = 4096;
p = file_addr + 2013; /* not aligned to 4KB */
lseek(fid, 2013, SEEK_SET);
c = 'a';
while (p < file_addr + filesize) {
if (p + blksize > file_addr + filesize)
blksize = file_addr + filesize - p;
memset(p, c++, blksize);
blksize = read(fid, buf, blksize);
if (blksize < 0) {
perror(filename);
return (1);
}
if (blksize == 0)
break;
if (memcmp(buf, p, blksize) != 0) {
fprintf(stderr, "memcmp failed 2\n");
return (1);
}
p += blksize;
}
/* modify file through fwrite, verify mmap can see the change */
blksize = 4096;
p = file_addr + 2013; /* not aligned to 4KB */
lseek(fid, 2013, SEEK_SET);
c = 'Z';
while (p < file_addr + filesize) {
if (p + blksize > file_addr + filesize)
blksize = file_addr + filesize - p;
memset(buf, c--, blksize);
blksize = write(fid, buf, blksize);
if (blksize < 0) {
perror(filename);
return (1);
}
if (blksize == 0)
break;
if (memcmp(buf, p, blksize) != 0) {
fprintf(stderr, "memcmp failed 3\n");
return (1);
}
p += blksize;
}
/* sync pages to file */
if (msync(file_addr, filesize, MS_SYNC) == -1) {
fprintf(stderr, "msync %s error=%d\n", filename, errno);
return (1);
}
/* unmap file */
if (munmap(file_addr, filesize) == -1) {
fprintf(stderr, "munmap %s error=%d\n", filename, errno);
return (1);
}
/* close file */
if (close(fid) == -1) {
fprintf(stderr, "close %s error=%d\n", filename, errno);
return (1);
}
return (0);
}
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