Archipelago » qemu

/*

 * 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(char *buffer, int64_t offset, int len)

{

        int i, j;

        char *p;

        for (i = 0, p = buffer; i < len; i += 16) {

                char    *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((int)*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));

        }

}

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 >> 9;

        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"

" -p, -- use bdrv_pread to read the file\n"

" -C, -- report statistics in a machine parsable format\n"

" -v, -- dump buffer to standard output\n"

" -q, -- quite mode, do not show I/O statistics\n"

"\n");

}

static int

read_f(int argc, char **argv)

{

        struct timeval t1, t2;

        int Cflag = 0, pflag = 0, qflag = 0, vflag = 0;

        int c, cnt;

        char *buf;

        int64_t offset;

        int count, total;

        while ((c = getopt(argc, argv, "Cpqv")) != EOF) {

                switch (c) {

                case 'C':

                        Cflag = 1;

                        break;

                case 'p':

                        pflag = 1;

                        break;

                case 'q':

                        qflag = 1;

                        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)

                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));

                return 0;

        }

        if (qflag)

                return 0;

        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);

        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] 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"

" -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, *p;

        int64_t offset;

        int count = 0, total;

        int nr_iov, i;

        QEMUIOVector qiov;

        while ((c = getopt(argc, argv, "Cqv")) != EOF) {

                switch (c) {

                case 'C':

                        Cflag = 1;

                        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;

        }

        if (count & 0x1ff) {

                printf("count %d is not sector aligned\n",

                        count);

                return 0;

        }

        for (i = optind; i < argc; i++) {

                size_t len;

                len = cvtnum(argv[i]);

                if (len < 0) {

                        printf("non-numeric length argument -- %s\n", argv[i]);

                        return 0;

                }

                count += len;

        }

        nr_iov = argc - optind;

        qemu_iovec_init(&qiov, nr_iov);

        buf = p = qemu_io_alloc(count, 0xab);

        for (i = 0; i < nr_iov; i++) {

                size_t len;

                len = cvtnum(argv[optind]);

                if (len < 0) {

                        printf("non-numeric length argument -- %s\n",

                                argv[optind]);

                        return 0;

                }

                qemu_iovec_add(&qiov, p, len);

                p += len;

                optind++;

        }

        gettimeofday(&t1, NULL);

        cnt = do_aio_readv(&qiov, offset, &total);

        gettimeofday(&t2, NULL);

        if (cnt < 0) {

                printf("readv failed: %s\n", strerror(-cnt));

                return 0;

        }

        if (qflag)

                return 0;

        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);

        qemu_io_free(buf);

        return 0;

}

static const cmdinfo_t readv_cmd = {

        .name                = "readv",

        .cfunc                = readv_f,

        .argmin                = 2,

        .argmax                = -1,

        .args                = "[-Cqv] 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, total;

        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));

                return 0;

        }

        if (qflag)

                return 0;

        /* Finally, report back -- -C gives a parsable format */

        t2 = tsub(t2, t1);

        print_report("wrote", &t2, offset, count, total, cnt, Cflag);

        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, *p;

        int64_t offset;

        int count = 0, total;

        int nr_iov, i;

        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;

        }

        if (count & 0x1ff) {

                printf("count %d is not sector aligned\n",

                        count);

                return 0;

        }

        for (i = optind; i < argc; i++) {

                size_t len;

                len = cvtnum(argv[optind]);

                if (len < 0) {

                        printf("non-numeric length argument -- %s\n", argv[i]);

                        return 0;

                }

                count += len;

        }

        nr_iov = argc - optind;

        qemu_iovec_init(&qiov, nr_iov);

        buf = p = qemu_io_alloc(count, 0xab);

        for (i = 0; i < nr_iov; i++) {

                size_t len;

                len = cvtnum(argv[optind]);

                if (len < 0) {

                        printf("non-numeric length argument -- %s\n",

                                argv[optind]);

                        return 0;

                }

                qemu_iovec_add(&qiov, p, len);

                p += len;

                optind++;

        }

        gettimeofday(&t1, NULL);

        cnt = do_aio_writev(&qiov, offset, &total);

        gettimeofday(&t2, NULL);

        if (cnt < 0) {

                printf("writev failed: %s\n", strerror(-cnt));

                return 0;

        }

        if (qflag)

                return 0;

        /* Finally, report back -- -C gives a parsable format */

        t2 = tsub(t2, t1);

        print_report("wrote", &t2, offset, qiov.size, total, cnt, Cflag);

        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,

};

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;

        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);

        if (ret) {

                printf("is_allocated: %s", strerror(ret));

                return 0;

        }

        cvtstr(offset, s1, sizeof(s1));

        if (nb_sectors == 1)

                printf("sector allocated at offset %s\n", s1);

        else

                printf("%d/%d sectors allocated at offset %s\n",

                        num, nb_sectors, 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)

{

        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;

        }

        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"

"\n");

}

static const cmdinfo_t open_cmd;

static int

open_f(int argc, char **argv)

{

        int flags = 0;

        int readonly = 0;

        int c;

        while ((c = getopt(argc, argv, "snCr")) != 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;

                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);

}

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 excerciser\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;

        const char *sopt = "hVc:Crsnm";

        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' },

                { 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 '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(&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);

        command_loop();

        if (bs)

                bdrv_close(bs);

        return 0;

}