zfs/tests/zfs-tests/cmd/stride_dd.c

344 lines
7.2 KiB
C

/*
* 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 (c) 2018 by Delphix. All rights reserved.
*/
#include <sys/types.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
static int alignment = 0;
static int bsize = 0;
static int count = 0;
static char *ifile = NULL;
static char *ofile = NULL;
static off_t stride = 1;
static off_t seek = 0;
static int seekbytes = 0;
static int if_o_direct = 0;
static int of_o_direct = 0;
static int skip = 0;
static int skipbytes = 0;
static int entire_file = 0;
static const char *execname = "stride_dd";
static void usage(void);
static void parse_options(int argc, char *argv[]);
static void
usage(void)
{
(void) fprintf(stderr,
"usage: %s -i inputfile -o outputfile -b blocksize [-c count]\n"
" [-s stride] [-k seekblocks] [-K seekbytes]\n"
" [-a alignment] [-d if_o_direct] [-D of_o_direct]\n"
" [-p skipblocks] [-P skipbytes] [-e entire_file]\n"
"\n"
"Simplified version of dd that supports the stride option.\n"
"A stride of n means that for each block written, n - 1 blocks\n"
"are skipped in both the input and output file. A stride of 1\n"
"means that blocks are read and written consecutively.\n"
"All numeric parameters must be integers.\n"
"\n"
" inputfile: File to read from\n"
" outputfile: File to write to\n"
" blocksize: Size of each block to read/write\n"
" count: Number of blocks to read/write (Required"
" unless -e is used)\n"
" stride: Read/write a block then skip (stride - 1) blocks"
"\n"
" seekblocks: Number of blocks to skip at start of output\n"
" seekbytes: Treat seekblocks as byte count\n"
" alignment: Alignment passed to posix_memalign() (default"
" PAGE_SIZE)\n"
" if_o_direct: Use O_DIRECT with inputfile (default no O_DIRECT)"
"\n"
" of_o_direct: Use O_DIRECT with outputfile (default no "
" O_DIRECT)\n"
" skipblocks: Number of blocks to skip at start of input "
" (default 0)\n"
" skipbytes: Treat skipblocks as byte count\n"
" entire_file: When used the entire inputfile will be read and"
" count will be ignored\n",
execname);
(void) exit(1);
}
/*
* posix_memalign() only allows for alignments which are postive, powers of two
* and a multiple of sizeof (void *).
*/
static int
invalid_alignment(int alignment)
{
if ((alignment < 0) || (alignment & (alignment - 1)) ||
((alignment % sizeof (void *)))) {
(void) fprintf(stderr,
"Alignment must be a postive, power of two, and multiple "
"of sizeof (void *).\n");
return (1);
}
return (0);
}
static void
parse_options(int argc, char *argv[])
{
int c;
int errflag = 0;
execname = argv[0];
alignment = sysconf(_SC_PAGE_SIZE);
extern char *optarg;
extern int optind, optopt;
while ((c = getopt(argc, argv, "a:b:c:deDi:o:s:k:Kp:P")) != -1) {
switch (c) {
case 'a':
alignment = atoi(optarg);
break;
case 'b':
bsize = atoi(optarg);
break;
case 'c':
count = atoi(optarg);
break;
case 'd':
if_o_direct = 1;
break;
case 'e':
entire_file = 1;
break;
case 'D':
of_o_direct = 1;
break;
case 'i':
ifile = optarg;
break;
case 'o':
ofile = optarg;
break;
case 's':
stride = atoi(optarg);
break;
case 'k':
seek = atoi(optarg);
break;
case 'K':
seekbytes = 1;
break;
case 'p':
skip = atoi(optarg);
break;
case 'P':
skipbytes = 1;
break;
case ':':
(void) fprintf(stderr,
"Option -%c requires an operand\n", optopt);
errflag++;
break;
case '?':
default:
(void) fprintf(stderr,
"Unrecognized option: -%c\n", optopt);
errflag++;
break;
}
if (errflag) {
(void) usage();
}
}
if (bsize <= 0 || stride <= 0 || ifile == NULL || ofile == NULL ||
seek < 0 || invalid_alignment(alignment) || skip < 0) {
(void) fprintf(stderr,
"Required parameter(s) missing or invalid.\n");
(void) usage();
}
if (count <= 0 && entire_file == 0) {
(void) fprintf(stderr,
"Required parameter(s) missing or invalid.\n");
(void) usage();
}
}
static void
read_entire_file(int ifd, int ofd, void *buf)
{
int c;
do {
c = read(ifd, buf, bsize);
if (c < 0) {
perror("read");
exit(2);
} else if (c != 0) {
c = write(ofd, buf, bsize);
if (c < 0) {
perror("write");
exit(2);
}
}
if (stride > 1) {
if (lseek(ifd, (stride - 1) * bsize, SEEK_CUR) == -1) {
perror("input lseek");
exit(2);
}
if (lseek(ofd, (stride - 1) * bsize, SEEK_CUR) == -1) {
perror("output lseek");
exit(2);
}
}
} while (c != 0);
}
static void
read_on_count(int ifd, int ofd, void *buf)
{
int i;
int c;
for (i = 0; i < count; i++) {
c = read(ifd, buf, bsize);
if (c != bsize) {
if (c < 0) {
perror("read");
} else {
(void) fprintf(stderr,
"%s: unexpected short read, read %d "
"bytes, expected %d\n", execname,
c, bsize);
}
exit(2);
}
c = write(ofd, buf, bsize);
if (c != bsize) {
if (c < 0) {
perror("write");
} else {
(void) fprintf(stderr,
"%s: unexpected short write, wrote %d "
"bytes, expected %d\n", execname,
c, bsize);
}
exit(2);
}
if (stride > 1) {
if (lseek(ifd, (stride - 1) * bsize, SEEK_CUR) == -1) {
perror("input lseek");
exit(2);
}
if (lseek(ofd, (stride - 1) * bsize, SEEK_CUR) == -1) {
perror("output lseek");
exit(2);
}
}
}
}
int
main(int argc, char *argv[])
{
int ifd;
int ofd;
int ifd_flags = O_RDONLY;
int ofd_flags = O_WRONLY | O_CREAT;
void *buf;
parse_options(argc, argv);
if (if_o_direct)
ifd_flags |= O_DIRECT;
if (of_o_direct)
ofd_flags |= O_DIRECT;
ifd = open(ifile, ifd_flags);
if (ifd == -1) {
(void) fprintf(stderr, "%s: %s: ", execname, ifile);
perror("open");
exit(2);
}
ofd = open(ofile, ofd_flags, 0666);
if (ofd == -1) {
(void) fprintf(stderr, "%s: %s: ", execname, ofile);
perror("open");
exit(2);
}
/*
* We use valloc because some character block devices expect a
* page-aligned buffer.
*/
int err = posix_memalign(&buf, alignment, bsize);
if (err != 0) {
(void) fprintf(stderr,
"%s: %s\n", execname, strerror(err));
exit(2);
}
if (skip > 0) {
int skipamt = skipbytes == 1 ? skip : skip * bsize;
if (lseek(ifd, skipamt, SEEK_CUR) == -1) {
perror("input lseek");
exit(2);
}
}
if (seek > 0) {
int seekamt = seekbytes == 1 ? seek : seek * bsize;
if (lseek(ofd, seekamt, SEEK_CUR) == -1) {
perror("output lseek");
exit(2);
}
}
if (entire_file == 1)
read_entire_file(ifd, ofd, buf);
else
read_on_count(ifd, ofd, buf);
free(buf);
(void) close(ofd);
(void) close(ifd);
return (0);
}