qemu-io.c

/*
 * Command line utility to exercise the QEMU I/O path.
 *
 * Copyright (C) 2009 Red Hat, Inc.
 * Copyright (c) 2003-2005 Silicon Graphics, Inc.
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or later.
 * See the COPYING file in the top-level directory.
 */
#include <sys/types.h>
#include <stdarg.h>
#include <stdio.h>
#include <getopt.h>
#include "qemu-common.h"
#include "block_int.h"
#include "cmd.h"
#define VERSION	"0.0.1"
#define CMD_NOFILE_OK	0x01
char *progname;
static BlockDriverState *bs;
static int misalign;
/*
 * Memory allocation helpers.
 *
 * Make sure memory is aligned by default, or purposefully misaligned if
 * that is specified on the command line.
 */
#define MISALIGN_OFFSET		16
static void *qemu_io_alloc(size_t len, int pattern)
{
	void *buf;
	if (misalign)
		len += MISALIGN_OFFSET;
	buf = qemu_memalign(512, len);
	memset(buf, pattern, len);
	if (misalign)
		buf += MISALIGN_OFFSET;
	return buf;
}
static void qemu_io_free(void *p)
{
	if (misalign)
		p -= MISALIGN_OFFSET;
	qemu_vfree(p);
}
static void
dump_buffer(const void *buffer, int64_t offset, int len)
{
	int i, j;
	const uint8_t *p;
	for (i = 0, p = buffer; i < len; i += 16) {
		const uint8_t *s = p;
		printf("%08llx:  ", (unsigned long long)offset + i);
		for (j = 0; j < 16 && i + j < len; j++, p++)
			printf("%02x ", *p);
		printf(" ");
		for (j = 0; j < 16 && i + j < len; j++, s++) {
			if (isalnum(*s))
				printf("%c", *s);
			else
				printf(".");
		}
		printf("\n");
	}
}
static void
print_report(const char *op, struct timeval *t, int64_t offset,
		int count, int total, int cnt, int Cflag)
{
	char s1[64], s2[64], ts[64];
	timestr(t, ts, sizeof(ts), Cflag ? VERBOSE_FIXED_TIME : 0);
	if (!Cflag) {
		cvtstr((double)total, s1, sizeof(s1));
		cvtstr(tdiv((double)total, *t), s2, sizeof(s2));
		printf("%s %d/%d bytes at offset %lld\n",
			op, total, count, (long long)offset);
		printf("%s, %d ops; %s (%s/sec and %.4f ops/sec)\n",
			s1, cnt, ts, s2, tdiv((double)cnt, *t));
	} else {/* bytes,ops,time,bytes/sec,ops/sec */
		printf("%d,%d,%s,%.3f,%.3f\n",
			total, cnt, ts,
			tdiv((double)total, *t),
			tdiv((double)cnt, *t));
	}
}
/*
 * Parse multiple length statements for vectored I/O, and construct an I/O
 * vector matching it.
 */
static void *
create_iovec(QEMUIOVector *qiov, char **argv, int nr_iov, int pattern)
{
	size_t *sizes = calloc(nr_iov, sizeof(size_t));
	size_t count = 0;
	void *buf, *p;
	int i;
	for (i = 0; i < nr_iov; i++) {
		char *arg = argv[i];
		long long len;
		len = cvtnum(arg);
		if (len < 0) {
			printf("non-numeric length argument -- %s\n", arg);
			return NULL;
		}
		/* should be SIZE_T_MAX, but that doesn't exist */
		if (len > UINT_MAX) {
			printf("too large length argument -- %s\n", arg);
			return NULL;
		}
		if (len & 0x1ff) {
			printf("length argument %lld is not sector aligned\n",
				len);
			return NULL;
		}
		sizes[i] = len;
		count += len;
	}
	qemu_iovec_init(qiov, nr_iov);
	buf = p = qemu_io_alloc(count, pattern);
	for (i = 0; i < nr_iov; i++) {
		qemu_iovec_add(qiov, p, sizes[i]);
		p += sizes[i];
	}
	free(sizes);
	return buf;
}
static int do_read(char *buf, int64_t offset, int count, int *total)
{
	int ret;
	ret = bdrv_read(bs, offset >> 9, (uint8_t *)buf, count >> 9);
	if (ret < 0)
		return ret;
	*total = count;
	return 1;
}
static int do_write(char *buf, int64_t offset, int count, int *total)
{
	int ret;
	ret = bdrv_write(bs, offset >> 9, (uint8_t *)buf, count >> 9);
	if (ret < 0)
		return ret;
	*total = count;
	return 1;
}
static int do_pread(char *buf, int64_t offset, int count, int *total)
{
	*total = bdrv_pread(bs, offset, (uint8_t *)buf, count);
	if (*total < 0)
		return *total;
	return 1;
}
static int do_pwrite(char *buf, int64_t offset, int count, int *total)
{
	*total = bdrv_pwrite(bs, offset, (uint8_t *)buf, count);
	if (*total < 0)
		return *total;
	return 1;
}
#define NOT_DONE 0x7fffffff
static void aio_rw_done(void *opaque, int ret)
{
	*(int *)opaque = ret;
}
static int do_aio_readv(QEMUIOVector *qiov, int64_t offset, int *total)
{
	BlockDriverAIOCB *acb;
	int async_ret = NOT_DONE;
	acb = bdrv_aio_readv(bs, offset >> 9, qiov, qiov->size >> 9,
			     aio_rw_done, &async_ret);
	if (!acb)
		return -EIO;
	while (async_ret == NOT_DONE)
		qemu_aio_wait();
	*total = qiov->size;
	return async_ret < 0 ? async_ret : 1;
}
static int do_aio_writev(QEMUIOVector *qiov, int64_t offset, int *total)
{
	BlockDriverAIOCB *acb;
	int async_ret = NOT_DONE;
	acb = bdrv_aio_writev(bs, offset >> 9, qiov, qiov->size >> 9,
			      aio_rw_done, &async_ret);
	if (!acb)
		return -EIO;
	while (async_ret == NOT_DONE)
		qemu_aio_wait();
	*total = qiov->size;
	return async_ret < 0 ? async_ret : 1;
}
static const cmdinfo_t read_cmd;
static void
read_help(void)
{
	printf(
"\n"
" reads a range of bytes from the given offset\n"
"\n"
" Example:\n"
" 'read -v 512 1k' - dumps 1 kilobyte read from 512 bytes into the file\n"
"\n"
" Reads a segment of the currently open file, optionally dumping it to the\n"
" standard output stream (with -v option) for subsequent inspection.\n"
" -C, -- report statistics in a machine parsable format\n"
" -l, -- length for pattern verification (only with -P)\n"
" -p, -- use bdrv_pread to read the file\n"
" -P, -- use a pattern to verify read data\n"
" -q, -- quite mode, do not show I/O statistics\n"
" -s, -- start offset for pattern verification (only with -P)\n"
" -v, -- dump buffer to standard output\n"
"\n");
}
static int
read_f(int argc, char **argv)
{
	struct timeval t1, t2;
	int Cflag = 0, pflag = 0, qflag = 0, vflag = 0;
	int Pflag = 0, sflag = 0, lflag = 0;
	int c, cnt;
	char *buf;
	int64_t offset;
	int count;
        /* Some compilers get confused and warn if this is not initialized.  */
        int total = 0;
	int pattern = 0, pattern_offset = 0, pattern_count = 0;
	while ((c = getopt(argc, argv, "Cl:pP:qs:v")) != EOF) {
		switch (c) {
		case 'C':
			Cflag = 1;
			break;
		case 'l':
			lflag = 1;
			pattern_count = cvtnum(optarg);
			if (pattern_count < 0) {
				printf("non-numeric length argument -- %s\n", optarg);
				return 0;
			}
			break;
		case 'p':
			pflag = 1;
			break;
		case 'P':
			Pflag = 1;
			pattern = atoi(optarg);
			break;
		case 'q':
			qflag = 1;
			break;
		case 's':
			sflag = 1;
			pattern_offset = cvtnum(optarg);
			if (pattern_offset < 0) {
				printf("non-numeric length argument -- %s\n", optarg);
				return 0;
			}
			break;
		case 'v':
			vflag = 1;
			break;
		default:
			return command_usage(&read_cmd);
		}
	}
	if (optind != argc - 2)
		return command_usage(&read_cmd);
	offset = cvtnum(argv[optind]);
	if (offset < 0) {
		printf("non-numeric length argument -- %s\n", argv[optind]);
		return 0;
	}
	optind++;
	count = cvtnum(argv[optind]);
	if (count < 0) {
		printf("non-numeric length argument -- %s\n", argv[optind]);
		return 0;
	}
    if (!Pflag && (lflag || sflag)) {
        return command_usage(&read_cmd);
    }
    if (!lflag) {
        pattern_count = count - pattern_offset;
    }
    if ((pattern_count < 0) || (pattern_count + pattern_offset > count))  {
        printf("pattern verfication range exceeds end of read data\n");
        return 0;
    }
	if (!pflag)
		if (offset & 0x1ff) {
			printf("offset %lld is not sector aligned\n",
				(long long)offset);
			return 0;
		if (count & 0x1ff) {
			printf("count %d is not sector aligned\n",
				count);
			return 0;
		}
	}
	buf = qemu_io_alloc(count, 0xab);
	gettimeofday(&t1, NULL);
	if (pflag)
		cnt = do_pread(buf, offset, count, &total);
	else
		cnt = do_read(buf, offset, count, &total);
	gettimeofday(&t2, NULL);
	if (cnt < 0) {
		printf("read failed: %s\n", strerror(-cnt));
		goto out;
	}
	if (Pflag) {
		void* cmp_buf = malloc(pattern_count);
		memset(cmp_buf, pattern, pattern_count);
		if (memcmp(buf + pattern_offset, cmp_buf, pattern_count)) {
			printf("Pattern verification failed at offset %lld, "
				"%d bytes\n",
				(long long) offset + pattern_offset, pattern_count);
		}
		free(cmp_buf);
	}
	if (qflag)
		goto out;
        if (vflag)
		dump_buffer(buf, offset, count);
	/* Finally, report back -- -C gives a parsable format */
	t2 = tsub(t2, t1);
	print_report("read", &t2, offset, count, total, cnt, Cflag);
out:
	qemu_io_free(buf);
	return 0;
}
static const cmdinfo_t read_cmd = {
	.name		= "read",
	.altname	= "r",
	.cfunc		= read_f,
	.argmin		= 2,
	.argmax		= -1,
	.args		= "[-aCpqv] [-P pattern [-s off] [-l len]] off len",
	.oneline	= "reads a number of bytes at a specified offset",
	.help		= read_help,
};
static const cmdinfo_t readv_cmd;
static void
readv_help(void)
{
	printf(
"\n"
" reads a range of bytes from the given offset into multiple buffers\n"
"\n"
" Example:\n"
" 'readv -v 512 1k 1k ' - dumps 2 kilobytes read from 512 bytes into the file\n"
"\n"
" Reads a segment of the currently open file, optionally dumping it to the\n"
" standard output stream (with -v option) for subsequent inspection.\n"
" Uses multiple iovec buffers if more than one byte range is specified.\n"
" -C, -- report statistics in a machine parsable format\n"
" -P, -- use a pattern to verify read data\n"
" -v, -- dump buffer to standard output\n"
" -q, -- quite mode, do not show I/O statistics\n"
"\n");
}
static int
readv_f(int argc, char **argv)
{
	struct timeval t1, t2;
	int Cflag = 0, qflag = 0, vflag = 0;
	int c, cnt;
	char *buf;
	int64_t offset;
	int total;
	int nr_iov;
	QEMUIOVector qiov;
	int pattern = 0;
	int Pflag = 0;
	while ((c = getopt(argc, argv, "CP:qv")) != EOF) {
		switch (c) {
		case 'C':
			Cflag = 1;
			break;
		case 'P':
			Pflag = 1;
			pattern = atoi(optarg);
			break;
		case 'q':
			qflag = 1;
			break;
		case 'v':
			vflag = 1;
			break;
		default:
			return command_usage(&readv_cmd);
		}
	}
	if (optind > argc - 2)
		return command_usage(&readv_cmd);
	offset = cvtnum(argv[optind]);
	if (offset < 0) {
		printf("non-numeric length argument -- %s\n", argv[optind]);
		return 0;
	}
	optind++;
	if (offset & 0x1ff) {
		printf("offset %lld is not sector aligned\n",
			(long long)offset);
		return 0;
	}
	nr_iov = argc - optind;
	buf = create_iovec(&qiov, &argv[optind], nr_iov, 0xab);
	gettimeofday(&t1, NULL);
	cnt = do_aio_readv(&qiov, offset, &total);
	gettimeofday(&t2, NULL);
	if (cnt < 0) {
		printf("readv failed: %s\n", strerror(-cnt));
		goto out;
	}
	if (Pflag) {
		void* cmp_buf = malloc(qiov.size);
		memset(cmp_buf, pattern, qiov.size);
		if (memcmp(buf, cmp_buf, qiov.size)) {
			printf("Pattern verification failed at offset %lld, "
				"%zd bytes\n",
				(long long) offset, qiov.size);
		}
		free(cmp_buf);
	}
	if (qflag)
		goto out;
        if (vflag)
		dump_buffer(buf, offset, qiov.size);
	/* Finally, report back -- -C gives a parsable format */
	t2 = tsub(t2, t1);
	print_report("read", &t2, offset, qiov.size, total, cnt, Cflag);
out:
	qemu_io_free(buf);
	return 0;
}
static const cmdinfo_t readv_cmd = {
	.name		= "readv",
	.cfunc		= readv_f,
	.argmin		= 2,
	.argmax		= -1,
	.args		= "[-Cqv] [-P pattern ] off len [len..]",
	.oneline	= "reads a number of bytes at a specified offset",
	.help		= readv_help,
};
static const cmdinfo_t write_cmd;
static void
write_help(void)
{
	printf(
"\n"
" writes a range of bytes from the given offset\n"
"\n"
" Example:\n"
" 'write 512 1k' - writes 1 kilobyte at 512 bytes into the open file\n"
"\n"
" Writes into a segment of the currently open file, using a buffer\n"
" filled with a set pattern (0xcdcdcdcd).\n"
" -p, -- use bdrv_pwrite to write the file\n"
" -P, -- use different pattern to fill file\n"
" -C, -- report statistics in a machine parsable format\n"
" -q, -- quite mode, do not show I/O statistics\n"
"\n");
}
static int
write_f(int argc, char **argv)
{
	struct timeval t1, t2;
	int Cflag = 0, pflag = 0, qflag = 0;
	int c, cnt;
	char *buf;
	int64_t offset;
	int count;
        /* Some compilers get confused and warn if this is not initialized.  */
        int total = 0;
	int pattern = 0xcd;
	while ((c = getopt(argc, argv, "CpP:q")) != EOF) {
		switch (c) {
		case 'C':
			Cflag = 1;
			break;
		case 'p':
			pflag = 1;
			break;
		case 'P':
			pattern = atoi(optarg);
			break;
		case 'q':
			qflag = 1;
			break;
		default:
			return command_usage(&write_cmd);
		}
	}
	if (optind != argc - 2)
		return command_usage(&write_cmd);
	offset = cvtnum(argv[optind]);
	if (offset < 0) {
		printf("non-numeric length argument -- %s\n", argv[optind]);
		return 0;
	}
	optind++;
	count = cvtnum(argv[optind]);
	if (count < 0) {
		printf("non-numeric length argument -- %s\n", argv[optind]);
		return 0;
	}
	if (!pflag) {
		if (offset & 0x1ff) {
			printf("offset %lld is not sector aligned\n",
				(long long)offset);
			return 0;
		}
		if (count & 0x1ff) {
			printf("count %d is not sector aligned\n",
				count);
			return 0;
		}
	}
	buf = qemu_io_alloc(count, pattern);
	gettimeofday(&t1, NULL);
	if (pflag)
		cnt = do_pwrite(buf, offset, count, &total);
	else
		cnt = do_write(buf, offset, count, &total);
	gettimeofday(&t2, NULL);
	if (cnt < 0) {
		printf("write failed: %s\n", strerror(-cnt));
		goto out;
	}
	if (qflag)
		goto out;
	/* Finally, report back -- -C gives a parsable format */
	t2 = tsub(t2, t1);
	print_report("wrote", &t2, offset, count, total, cnt, Cflag);
out:
	qemu_io_free(buf);
	return 0;
}
static const cmdinfo_t write_cmd = {
	.name		= "write",
	.altname	= "w",
	.cfunc		= write_f,
	.argmin		= 2,
	.argmax		= -1,
	.args		= "[-aCpq] [-P pattern ] off len",
	.oneline	= "writes a number of bytes at a specified offset",
	.help		= write_help,
};
static const cmdinfo_t writev_cmd;
static void
writev_help(void)
{
	printf(
"\n"
" writes a range of bytes from the given offset source from multiple buffers\n"
"\n"
" Example:\n"
" 'write 512 1k 1k' - writes 2 kilobytes at 512 bytes into the open file\n"
"\n"
" Writes into a segment of the currently open file, using a buffer\n"
" filled with a set pattern (0xcdcdcdcd).\n"
" -P, -- use different pattern to fill file\n"
" -C, -- report statistics in a machine parsable format\n"
" -q, -- quite mode, do not show I/O statistics\n"
"\n");
}
static int
writev_f(int argc, char **argv)
{
	struct timeval t1, t2;
	int Cflag = 0, qflag = 0;
	int c, cnt;
	char *buf;
	int64_t offset;
	int total;
	int nr_iov;
	int pattern = 0xcd;
	QEMUIOVector qiov;
	while ((c = getopt(argc, argv, "CqP:")) != EOF) {
		switch (c) {
		case 'C':
			Cflag = 1;
			break;
		case 'q':
			qflag = 1;
			break;
		case 'P':
			pattern = atoi(optarg);
			break;
		default:
			return command_usage(&writev_cmd);
		}
	}
	if (optind > argc - 2)
		return command_usage(&writev_cmd);
	offset = cvtnum(argv[optind]);
	if (offset < 0) {
		printf("non-numeric length argument -- %s\n", argv[optind]);
		return 0;
	}
	optind++;
	if (offset & 0x1ff) {
		printf("offset %lld is not sector aligned\n",
			(long long)offset);
		return 0;
	}
	nr_iov = argc - optind;
	buf = create_iovec(&qiov, &argv[optind], nr_iov, pattern);
	gettimeofday(&t1, NULL);
	cnt = do_aio_writev(&qiov, offset, &total);
	gettimeofday(&t2, NULL);
	if (cnt < 0) {
		printf("writev failed: %s\n", strerror(-cnt));
		goto out;
	}
	if (qflag)
		goto out;
	/* Finally, report back -- -C gives a parsable format */
	t2 = tsub(t2, t1);
	print_report("wrote", &t2, offset, qiov.size, total, cnt, Cflag);
out:
	qemu_io_free(buf);
	return 0;
}
static const cmdinfo_t writev_cmd = {
	.name		= "writev",
	.cfunc		= writev_f,
	.argmin		= 2,
	.argmax		= -1,
	.args		= "[-Cq] [-P pattern ] off len [len..]",
	.oneline	= "writes a number of bytes at a specified offset",
	.help		= writev_help,
};
struct aio_ctx {
	QEMUIOVector qiov;
	int64_t offset;
	char *buf;
	int qflag;
	int vflag;
	int Cflag;
	int Pflag;
	int pattern;
	struct timeval t1;
};
static void
aio_write_done(void *opaque, int ret)
{
	struct aio_ctx *ctx = opaque;
	struct timeval t2;
	gettimeofday(&t2, NULL);
	if (ret < 0) {
		printf("aio_write failed: %s\n", strerror(-ret));
		goto out;
	}
	if (ctx->qflag) {
		goto out;
	}
	/* Finally, report back -- -C gives a parsable format */
	t2 = tsub(t2, ctx->t1);
	print_report("wrote", &t2, ctx->offset, ctx->qiov.size,
		     ctx->qiov.size, 1, ctx->Cflag);
out:
	qemu_io_free(ctx->buf);
	free(ctx);
}
static const cmdinfo_t aio_read_cmd;
static void
aio_read_done(void *opaque, int ret)
{
	struct aio_ctx *ctx = opaque;
	struct timeval t2;
	gettimeofday(&t2, NULL);
	if (ret < 0) {
		printf("readv failed: %s\n", strerror(-ret));
		goto out;
	}
	if (ctx->Pflag) {
		void *cmp_buf = malloc(ctx->qiov.size);
		memset(cmp_buf, ctx->pattern, ctx->qiov.size);
		if (memcmp(ctx->buf, cmp_buf, ctx->qiov.size)) {
			printf("Pattern verification failed at offset %lld, "
				"%zd bytes\n",
				(long long) ctx->offset, ctx->qiov.size);
		}
		free(cmp_buf);
	}
	if (ctx->qflag) {
		goto out;
	}
	if (ctx->vflag) {
		dump_buffer(ctx->buf, ctx->offset, ctx->qiov.size);
	}
	/* Finally, report back -- -C gives a parsable format */
	t2 = tsub(t2, ctx->t1);
	print_report("read", &t2, ctx->offset, ctx->qiov.size,
		     ctx->qiov.size, 1, ctx->Cflag);
out:
	qemu_io_free(ctx->buf);
	free(ctx);
}
static void
aio_read_help(void)
{
	printf(
"\n"
" asynchronously reads a range of bytes from the given offset\n"
"\n"
" Example:\n"
" 'aio_read -v 512 1k 1k ' - dumps 2 kilobytes read from 512 bytes into the file\n"
"\n"
" Reads a segment of the currently open file, optionally dumping it to the\n"
" standard output stream (with -v option) for subsequent inspection.\n"
" The read is performed asynchronously and should the aio_flush command \n"
" should be used to ensure all outstanding aio requests have been completed\n"
" -C, -- report statistics in a machine parsable format\n"
" -P, -- use a pattern to verify read data\n"
" -v, -- dump buffer to standard output\n"
" -q, -- quite mode, do not show I/O statistics\n"
"\n");
}
static int
aio_read_f(int argc, char **argv)
{
	int nr_iov, c;
	struct aio_ctx *ctx = calloc(1, sizeof(struct aio_ctx));
	BlockDriverAIOCB *acb;
	while ((c = getopt(argc, argv, "CP:qv")) != EOF) {
		switch (c) {
		case 'C':
			ctx->Cflag = 1;
			break;
		case 'P':
			ctx->Pflag = 1;
			ctx->pattern = atoi(optarg);
			break;
		case 'q':
			ctx->qflag = 1;
			break;
		case 'v':
			ctx->vflag = 1;
			break;
		default:
			free(ctx);
			return command_usage(&aio_read_cmd);
		}
	}
	if (optind > argc - 2) {
		free(ctx);
		return command_usage(&aio_read_cmd);
	}
	ctx->offset = cvtnum(argv[optind]);
	if (ctx->offset < 0) {
		printf("non-numeric length argument -- %s\n", argv[optind]);
		free(ctx);
		return 0;
	}
	optind++;
	if (ctx->offset & 0x1ff) {
		printf("offset %lld is not sector aligned\n",
			(long long)ctx->offset);
		free(ctx);
		return 0;
	}
	nr_iov = argc - optind;
	ctx->buf = create_iovec(&ctx->qiov, &argv[optind], nr_iov, 0xab);
	gettimeofday(&ctx->t1, NULL);
	acb = bdrv_aio_readv(bs, ctx->offset >> 9, &ctx->qiov,
			      ctx->qiov.size >> 9, aio_read_done, ctx);
	if (!acb) {
		free(ctx->buf);
		free(ctx);
		return -EIO;
	}
	return 0;
}
static const cmdinfo_t aio_read_cmd = {
	.name		= "aio_read",
	.cfunc		= aio_read_f,
	.argmin		= 2,
	.argmax		= -1,
	.args		= "[-Cqv] [-P pattern ] off len [len..]",
	.oneline	= "asynchronously reads a number of bytes",
	.help		= aio_read_help,
};
static const cmdinfo_t aio_write_cmd;
static void
aio_write_help(void)
{
	printf(
"\n"
" asynchronously writes a range of bytes from the given offset source \n"
" from multiple buffers\n"
"\n"
" Example:\n"
" 'aio_write 512 1k 1k' - writes 2 kilobytes at 512 bytes into the open file\n"
"\n"
" Writes into a segment of the currently open file, using a buffer\n"
" filled with a set pattern (0xcdcdcdcd).\n"
" The write is performed asynchronously and should the aio_flush command \n"
" should be used to ensure all outstanding aio requests have been completed\n"
" -P, -- use different pattern to fill file\n"
" -C, -- report statistics in a machine parsable format\n"
" -q, -- quite mode, do not show I/O statistics\n"
"\n");
}
static int
aio_write_f(int argc, char **argv)
{
	int nr_iov, c;
	int pattern = 0xcd;
	struct aio_ctx *ctx = calloc(1, sizeof(struct aio_ctx));
	BlockDriverAIOCB *acb;
	while ((c = getopt(argc, argv, "CqP:")) != EOF) {
		switch (c) {
		case 'C':
			ctx->Cflag = 1;
			break;
		case 'q':
			ctx->qflag = 1;
			break;
		case 'P':
			pattern = atoi(optarg);
			break;
		default:
			free(ctx);
			return command_usage(&aio_write_cmd);
		}
	}
	if (optind > argc - 2) {
		free(ctx);
		return command_usage(&aio_write_cmd);
	}
	ctx->offset = cvtnum(argv[optind]);
	if (ctx->offset < 0) {
		printf("non-numeric length argument -- %s\n", argv[optind]);
		free(ctx);
		return 0;
	}
	optind++;
	if (ctx->offset & 0x1ff) {
		printf("offset %lld is not sector aligned\n",
			(long long)ctx->offset);
		free(ctx);
		return 0;
	}
	nr_iov = argc - optind;
	ctx->buf = create_iovec(&ctx->qiov, &argv[optind], nr_iov, pattern);
	gettimeofday(&ctx->t1, NULL);
	acb = bdrv_aio_writev(bs, ctx->offset >> 9, &ctx->qiov,
			      ctx->qiov.size >> 9, aio_write_done, ctx);
	if (!acb) {
		free(ctx->buf);
		free(ctx);
		return -EIO;
	}
	return 0;
}
static const cmdinfo_t aio_write_cmd = {
	.name		= "aio_write",
	.cfunc		= aio_write_f,
	.argmin		= 2,
	.argmax		= -1,
	.args		= "[-Cq] [-P pattern ] off len [len..]",
	.oneline	= "asynchronously writes a number of bytes",
	.help		= aio_write_help,
};
static int
aio_flush_f(int argc, char **argv)
{
	qemu_aio_flush();
	return 0;
}
static const cmdinfo_t aio_flush_cmd = {
	.name		= "aio_flush",
	.cfunc		= aio_flush_f,
	.oneline	= "completes all outstanding aio requets"
};
static int
flush_f(int argc, char **argv)
{
	bdrv_flush(bs);
	return 0;
}
static const cmdinfo_t flush_cmd = {
	.name		= "flush",
	.altname	= "f",
	.cfunc		= flush_f,
	.oneline	= "flush all in-core file state to disk",
};
static int
truncate_f(int argc, char **argv)
{
	int64_t offset;
	int ret;
	offset = cvtnum(argv[1]);
	if (offset < 0) {
		printf("non-numeric truncate argument -- %s\n", argv[1]);
		return 0;
	}
	ret = bdrv_truncate(bs, offset);
	if (ret < 0) {
		printf("truncate: %s", strerror(ret));
		return 0;
	}
	return 0;
}
static const cmdinfo_t truncate_cmd = {
	.name		= "truncate",
	.altname	= "t",
	.cfunc		= truncate_f,
	.argmin		= 1,
	.argmax		= 1,
	.args		= "off",
	.oneline	= "truncates the current file at the given offset",
};
static int
length_f(int argc, char **argv)
{
        int64_t size;
	char s1[64];
	size = bdrv_getlength(bs);
	if (size < 0) {
		printf("getlength: %s", strerror(size));
		return 0;
	}
	cvtstr(size, s1, sizeof(s1));
	printf("%s\n", s1);
	return 0;
}
static const cmdinfo_t length_cmd = {
	.name		= "length",
	.altname	= "l",
	.cfunc		= length_f,
	.oneline	= "gets the length of the current file",
};
static int
info_f(int argc, char **argv)
{
	BlockDriverInfo bdi;
	char s1[64], s2[64];
	int ret;
	if (bs->drv && bs->drv->format_name)
		printf("format name: %s\n", bs->drv->format_name);
	if (bs->drv && bs->drv->protocol_name)
		printf("format name: %s\n", bs->drv->protocol_name);
	ret = bdrv_get_info(bs, &bdi);
	if (ret)
		return 0;
	cvtstr(bdi.cluster_size, s1, sizeof(s1));
	cvtstr(bdi.vm_state_offset, s2, sizeof(s2));
	printf("cluster size: %s\n", s1);
	printf("vm state offset: %s\n", s2);
	return 0;
}
static const cmdinfo_t info_cmd = {
	.name		= "info",
	.altname	= "i",
	.cfunc		= info_f,
	.oneline	= "prints information about the current file",
};
static int
alloc_f(int argc, char **argv)
{
	int64_t offset;
	int nb_sectors;
	char s1[64];
	int num;
	int ret;
	const char *retstr;
	offset = cvtnum(argv[1]);
	if (offset & 0x1ff) {
		printf("offset %lld is not sector aligned\n",
			(long long)offset);
		return 0;
	}
	if (argc == 3)
		nb_sectors = cvtnum(argv[2]);
	else
		nb_sectors = 1;
	ret = bdrv_is_allocated(bs, offset >> 9, nb_sectors, &num);
	cvtstr(offset, s1, sizeof(s1));
	retstr = ret ? "allocated" : "not allocated";
	if (nb_sectors == 1)
		printf("sector %s at offset %s\n", retstr, s1);
	else
		printf("%d/%d sectors %s at offset %s\n",
			num, nb_sectors, retstr, s1);
	return 0;
}
static const cmdinfo_t alloc_cmd = {
	.name		= "alloc",
	.altname	= "a",
	.argmin		= 1,
	.argmax		= 2,
	.cfunc		= alloc_f,
	.args		= "off [sectors]",
	.oneline	= "checks if a sector is present in the file",
};
static int
close_f(int argc, char **argv)
{
	bdrv_close(bs);
	bs = NULL;
	return 0;
}
static const cmdinfo_t close_cmd = {
	.name		= "close",
	.altname	= "c",
	.cfunc		= close_f,
	.oneline	= "close the current open file",
};
static int openfile(char *name, int flags, int growable)
{
	if (bs) {
		fprintf(stderr, "file open already, try 'help close'\n");
		return 1;
	}
	bs = bdrv_new("hda");
	if (!bs)
		return 1;
	if (bdrv_open(bs, name, flags) == -1) {
		fprintf(stderr, "%s: can't open device %s\n", progname, name);
		bs = NULL;
		return 1;
	}
	if (growable) {
		if (!bs->drv || !bs->drv->protocol_name) {
			fprintf(stderr,
				"%s: only protocols can be opened growable\n",
				progname);
			return 1;
		}
		bs->growable = 1;
	}
	return 0;
}
static void
open_help(void)
{
	printf(
"\n"
" opens a new file in the requested mode\n"
"\n"
" Example:\n"
" 'open -Cn /tmp/data' - creates/opens data file read-write and uncached\n"
"\n"
" Opens a file for subsequent use by all of the other qemu-io commands.\n"
" -C, -- create new file if it doesn't exist\n"
" -r, -- open file read-only\n"
" -s, -- use snapshot file\n"
" -n, -- disable host cache\n"
" -g, -- allow file to grow (only applies to protocols)"
"\n");
}
static const cmdinfo_t open_cmd;
static int
open_f(int argc, char **argv)
{
	int flags = 0;
	int readonly = 0;
	int growable = 0;
	int c;
	while ((c = getopt(argc, argv, "snCrg")) != EOF) {
		switch (c) {
		case 's':
			flags |= BDRV_O_SNAPSHOT;
			break;
		case 'n':
			flags |= BDRV_O_NOCACHE;
			break;
		case 'C':
			flags |= BDRV_O_CREAT;
			break;
		case 'r':
			readonly = 1;
			break;
		case 'g':
			growable = 1;
			break;
		default:
			return command_usage(&open_cmd);
		}
	}
	if (readonly)
		flags |= BDRV_O_RDONLY;
	else
		flags |= BDRV_O_RDWR;
	if (optind != argc - 1)
		return command_usage(&open_cmd);
	return openfile(argv[optind], flags, growable);
}
static const cmdinfo_t open_cmd = {
	.name		= "open",
	.altname	= "o",
	.cfunc		= open_f,
	.argmin		= 1,
	.argmax		= -1,
	.flags		= CMD_NOFILE_OK,
	.args		= "[-Crsn] [path]",
	.oneline	= "open the file specified by path",
	.help		= open_help,
};
static int
init_args_command(
        int     index)
{
	/* only one device allowed so far */
	if (index >= 1)
		return 0;
	return ++index;
}
static int
init_check_command(
	const cmdinfo_t *ct)
{
	if (ct->flags & CMD_FLAG_GLOBAL)
		return 1;
	if (!(ct->flags & CMD_NOFILE_OK) && !bs) {
		fprintf(stderr, "no file open, try 'help open'\n");
		return 0;
	}
	return 1;
}
static void usage(const char *name)
{
	printf(
"Usage: %s [-h] [-V] [-Crsnm] [-c cmd] ... [file]\n"
"QEMU Disk exerciser\n"
"\n"
"  -C, --create         create new file if it doesn't exist\n"
"  -c, --cmd            command to execute\n"
"  -r, --read-only      export read-only\n"
"  -s, --snapshot       use snapshot file\n"
"  -n, --nocache        disable host cache\n"
"  -m, --misalign       misalign allocations for O_DIRECT\n"
"  -h, --help           display this help and exit\n"
"  -V, --version        output version information and exit\n"
"\n",
	name);
}
int main(int argc, char **argv)
{
	int readonly = 0;
	int growable = 0;
	const char *sopt = "hVc:Crsnmg";
	struct option lopt[] = {
		{ "help", 0, 0, 'h' },
		{ "version", 0, 0, 'V' },
		{ "offset", 1, 0, 'o' },
		{ "cmd", 1, 0, 'c' },
		{ "create", 0, 0, 'C' },
		{ "read-only", 0, 0, 'r' },
		{ "snapshot", 0, 0, 's' },
		{ "nocache", 0, 0, 'n' },
		{ "misalign", 0, 0, 'm' },
		{ "growable", 0, 0, 'g' },
		{ NULL, 0, 0, 0 }
	};
	int c;
	int opt_index = 0;
	int flags = 0;
	progname = basename(argv[0]);
	while ((c = getopt_long(argc, argv, sopt, lopt, &opt_index)) != -1) {
		switch (c) {
		case 's':
			flags |= BDRV_O_SNAPSHOT;
			break;
		case 'n':
			flags |= BDRV_O_NOCACHE;
			break;
		case 'c':
			add_user_command(optarg);
			break;
		case 'C':
			flags |= BDRV_O_CREAT;
			break;
		case 'r':
			readonly = 1;
			break;
		case 'm':
			misalign = 1;
			break;
		case 'g':
			growable = 1;
			break;
		case 'V':
			printf("%s version %s\n", progname, VERSION);
			exit(0);
		case 'h':
			usage(progname);
			exit(0);
		default:
			usage(progname);
			exit(1);
		}
	}
	if ((argc - optind) > 1) {
		usage(progname);
		exit(1);
	}
	bdrv_init();
	/* initialize commands */
	quit_init();
	help_init();
	add_command(&open_cmd);
	add_command(&close_cmd);
	add_command(&read_cmd);
	add_command(&readv_cmd);
	add_command(&write_cmd);
	add_command(&writev_cmd);
	add_command(&aio_read_cmd);
	add_command(&aio_write_cmd);
	add_command(&aio_flush_cmd);
	add_command(&flush_cmd);
	add_command(&truncate_cmd);
	add_command(&length_cmd);
	add_command(&info_cmd);
	add_command(&alloc_cmd);
	add_args_command(init_args_command);
	add_check_command(init_check_command);
	/* open the device */
	if (readonly)
		flags |= BDRV_O_RDONLY;
	else
		flags |= BDRV_O_RDWR;
	if ((argc - optind) == 1)
		openfile(argv[optind], flags, growable);
	command_loop();
	/*
	 * Make sure all outstanding requests get flushed the program exits.
	 */
	qemu_aio_flush();
	if (bs)
		bdrv_close(bs);
	return 0;
}