482 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			482 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			C
		
	
	
	
/*
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 *  Copyright (C) 2005  Anthony Liguori <anthony@codemonkey.ws>
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 *
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 *  Network Block Device
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 *
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 *  This program is free software; you can redistribute it and/or modify
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 *  it under the terms of the GNU General Public License as published by
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 *  the Free Software Foundation; under version 2 of the License.
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 *
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 *  This program is distributed in the hope that it will be useful,
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 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
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 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 *  GNU General Public License for more details.
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 *
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 *  You should have received a copy of the GNU General Public License
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 *  along with this program; if not, see <http://www.gnu.org/licenses/>.
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 */
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#include <qemu-common.h>
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#include "block_int.h"
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#include "nbd.h"
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#include <stdarg.h>
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#include <stdio.h>
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#include <getopt.h>
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#include <err.h>
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <netinet/tcp.h>
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#include <arpa/inet.h>
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#include <signal.h>
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#include <libgen.h>
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#define SOCKET_PATH    "/var/lock/qemu-nbd-%s"
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#define NBD_BUFFER_SIZE (1024*1024)
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static int verbose;
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static void usage(const char *name)
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{
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    printf(
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"Usage: %s [OPTIONS] FILE\n"
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"QEMU Disk Network Block Device Server\n"
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"\n"
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"  -p, --port=PORT      port to listen on (default `1024')\n"
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"  -o, --offset=OFFSET  offset into the image\n"
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"  -b, --bind=IFACE     interface to bind to (default `0.0.0.0')\n"
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"  -k, --socket=PATH    path to the unix socket\n"
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"                       (default '"SOCKET_PATH"')\n"
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"  -r, --read-only      export read-only\n"
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"  -P, --partition=NUM  only expose partition NUM\n"
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"  -s, --snapshot       use snapshot file\n"
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"  -n, --nocache        disable host cache\n"
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"  -c, --connect=DEV    connect FILE to the local NBD device DEV\n"
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"  -d, --disconnect     disconnect the specified device\n"
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"  -e, --shared=NUM     device can be shared by NUM clients (default '1')\n"
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"  -t, --persistent     don't exit on the last connection\n"
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"  -v, --verbose        display extra debugging information\n"
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"  -h, --help           display this help and exit\n"
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"  -V, --version        output version information and exit\n"
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"\n"
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"Report bugs to <anthony@codemonkey.ws>\n"
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    , name, "DEVICE");
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}
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static void version(const char *name)
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{
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    printf(
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"%s version 0.0.1\n"
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"Written by Anthony Liguori.\n"
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"\n"
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"Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n"
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"This is free software; see the source for copying conditions.  There is NO\n"
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"warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
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    , name);
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}
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struct partition_record
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{
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    uint8_t bootable;
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    uint8_t start_head;
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    uint32_t start_cylinder;
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    uint8_t start_sector;
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    uint8_t system;
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    uint8_t end_head;
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    uint8_t end_cylinder;
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    uint8_t end_sector;
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    uint32_t start_sector_abs;
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    uint32_t nb_sectors_abs;
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};
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static void read_partition(uint8_t *p, struct partition_record *r)
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{
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    r->bootable = p[0];
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    r->start_head = p[1];
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    r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300);
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    r->start_sector = p[2] & 0x3f;
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    r->system = p[4];
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    r->end_head = p[5];
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    r->end_cylinder = p[7] | ((p[6] << 2) & 0x300);
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    r->end_sector = p[6] & 0x3f;
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    r->start_sector_abs = p[8] | p[9] << 8 | p[10] << 16 | p[11] << 24;
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    r->nb_sectors_abs = p[12] | p[13] << 8 | p[14] << 16 | p[15] << 24;
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}
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static int find_partition(BlockDriverState *bs, int partition,
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                          off_t *offset, off_t *size)
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{
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    struct partition_record mbr[4];
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    uint8_t data[512];
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    int i;
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    int ext_partnum = 4;
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    if (bdrv_read(bs, 0, data, 1))
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        errx(EINVAL, "error while reading");
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    if (data[510] != 0x55 || data[511] != 0xaa) {
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        errno = -EINVAL;
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        return -1;
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    }
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    for (i = 0; i < 4; i++) {
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        read_partition(&data[446 + 16 * i], &mbr[i]);
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        if (!mbr[i].nb_sectors_abs)
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            continue;
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        if (mbr[i].system == 0xF || mbr[i].system == 0x5) {
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            struct partition_record ext[4];
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            uint8_t data1[512];
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            int j;
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            if (bdrv_read(bs, mbr[i].start_sector_abs, data1, 1))
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                errx(EINVAL, "error while reading");
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            for (j = 0; j < 4; j++) {
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                read_partition(&data1[446 + 16 * j], &ext[j]);
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                if (!ext[j].nb_sectors_abs)
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                    continue;
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                if ((ext_partnum + j + 1) == partition) {
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                    *offset = (uint64_t)ext[j].start_sector_abs << 9;
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                    *size = (uint64_t)ext[j].nb_sectors_abs << 9;
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                    return 0;
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                }
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            }
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            ext_partnum += 4;
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        } else if ((i + 1) == partition) {
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            *offset = (uint64_t)mbr[i].start_sector_abs << 9;
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            *size = (uint64_t)mbr[i].nb_sectors_abs << 9;
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            return 0;
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        }
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    }
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    errno = -ENOENT;
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    return -1;
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}
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static void show_parts(const char *device)
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{
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    if (fork() == 0) {
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        int nbd;
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        /* linux just needs an open() to trigger
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         * the partition table update
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         * but remember to load the module with max_part != 0 :
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         *     modprobe nbd max_part=63
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         */
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        nbd = open(device, O_RDWR);
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        if (nbd != -1)
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              close(nbd);
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        exit(0);
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    }
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}
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int main(int argc, char **argv)
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{
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    BlockDriverState *bs;
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    off_t dev_offset = 0;
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    off_t offset = 0;
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    bool readonly = false;
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    bool disconnect = false;
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    const char *bindto = "0.0.0.0";
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    int port = 1024;
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    struct sockaddr_in addr;
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    socklen_t addr_len = sizeof(addr);
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    off_t fd_size;
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    char *device = NULL;
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    char *socket = NULL;
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    char sockpath[128];
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    const char *sopt = "hVb:o:p:rsnP:c:dvk:e:t";
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    struct option lopt[] = {
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        { "help", 0, NULL, 'h' },
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        { "version", 0, NULL, 'V' },
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        { "bind", 1, NULL, 'b' },
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        { "port", 1, NULL, 'p' },
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        { "socket", 1, NULL, 'k' },
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        { "offset", 1, NULL, 'o' },
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        { "read-only", 0, NULL, 'r' },
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        { "partition", 1, NULL, 'P' },
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        { "connect", 1, NULL, 'c' },
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        { "disconnect", 0, NULL, 'd' },
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        { "snapshot", 0, NULL, 's' },
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        { "nocache", 0, NULL, 'n' },
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        { "shared", 1, NULL, 'e' },
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        { "persistent", 0, NULL, 't' },
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        { "verbose", 0, NULL, 'v' },
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        { NULL, 0, NULL, 0 }
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    };
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    int ch;
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    int opt_ind = 0;
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    int li;
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    char *end;
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    int flags = BDRV_O_RDWR;
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    int partition = -1;
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    int ret;
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    int shared = 1;
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    uint8_t *data;
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    fd_set fds;
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    int *sharing_fds;
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    int fd;
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    int i;
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    int nb_fds = 0;
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    int max_fd;
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    int persistent = 0;
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    while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
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        switch (ch) {
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        case 's':
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            flags |= BDRV_O_SNAPSHOT;
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            break;
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        case 'n':
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            flags |= BDRV_O_NOCACHE;
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            break;
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        case 'b':
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            bindto = optarg;
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            break;
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        case 'p':
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            li = strtol(optarg, &end, 0);
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            if (*end) {
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                errx(EINVAL, "Invalid port `%s'", optarg);
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            }
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            if (li < 1 || li > 65535) {
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                errx(EINVAL, "Port out of range `%s'", optarg);
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            }
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            port = (uint16_t)li;
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            break;
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        case 'o':
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                dev_offset = strtoll (optarg, &end, 0);
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            if (*end) {
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                errx(EINVAL, "Invalid offset `%s'", optarg);
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            }
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            if (dev_offset < 0) {
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                errx(EINVAL, "Offset must be positive `%s'", optarg);
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            }
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            break;
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        case 'r':
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            readonly = true;
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            break;
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        case 'P':
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            partition = strtol(optarg, &end, 0);
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            if (*end)
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                errx(EINVAL, "Invalid partition `%s'", optarg);
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            if (partition < 1 || partition > 8)
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                errx(EINVAL, "Invalid partition %d", partition);
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            break;
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        case 'k':
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            socket = optarg;
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            if (socket[0] != '/')
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                errx(EINVAL, "socket path must be absolute\n");
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            break;
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        case 'd':
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            disconnect = true;
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            break;
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        case 'c':
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            device = optarg;
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            break;
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        case 'e':
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            shared = strtol(optarg, &end, 0);
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            if (*end) {
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                errx(EINVAL, "Invalid shared device number '%s'", optarg);
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            }
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            if (shared < 1) {
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                errx(EINVAL, "Shared device number must be greater than 0\n");
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            }
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            break;
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	case 't':
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	    persistent = 1;
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	    break;
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        case 'v':
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            verbose = 1;
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            break;
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        case 'V':
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            version(argv[0]);
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            exit(0);
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            break;
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        case 'h':
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            usage(argv[0]);
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            exit(0);
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            break;
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        case '?':
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            errx(EINVAL, "Try `%s --help' for more information.",
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                 argv[0]);
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        }
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    }
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    if ((argc - optind) != 1) {
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        errx(EINVAL, "Invalid number of argument.\n"
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             "Try `%s --help' for more information.",
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             argv[0]);
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    }
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    if (disconnect) {
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        fd = open(argv[optind], O_RDWR);
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        if (fd == -1)
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            errx(errno, "Cannot open %s", argv[optind]);
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        nbd_disconnect(fd);
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        close(fd);
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        printf("%s disconnected\n", argv[optind]);
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	return 0;
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    }
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    bdrv_init();
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    bs = bdrv_new("hda");
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    if (bs == NULL)
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        return 1;
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    if (bdrv_open(bs, argv[optind], flags) == -1)
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        return 1;
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    fd_size = bs->total_sectors * 512;
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    if (partition != -1 &&
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        find_partition(bs, partition, &dev_offset, &fd_size))
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        errx(errno, "Could not find partition %d", partition);
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    if (device) {
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        pid_t pid;
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        int sock;
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        if (!verbose) {
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            /* detach client and server */
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            if (daemon(0, 0) == -1) {
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                errx(errno, "Failed to daemonize");
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            }
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        }
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        if (socket == NULL) {
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            snprintf(sockpath, sizeof(sockpath), SOCKET_PATH,
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                     basename(device));
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            socket = sockpath;
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        }
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        pid = fork();
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        if (pid < 0)
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            return 1;
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        if (pid != 0) {
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            off_t size;
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            size_t blocksize;
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            ret = 0;
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            bdrv_close(bs);
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            do {
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                sock = unix_socket_outgoing(socket);
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                if (sock == -1) {
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                    if (errno != ENOENT && errno != ECONNREFUSED)
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                        goto out;
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                    sleep(1);	/* wait children */
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                }
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            } while (sock == -1);
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            fd = open(device, O_RDWR);
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            if (fd == -1) {
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                ret = 1;
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                goto out;
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            }
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            ret = nbd_receive_negotiate(sock, &size, &blocksize);
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            if (ret == -1) {
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                ret = 1;
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                goto out;
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            }
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            ret = nbd_init(fd, sock, size, blocksize);
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            if (ret == -1) {
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                ret = 1;
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                goto out;
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            }
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            printf("NBD device %s is now connected to file %s\n",
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                    device, argv[optind]);
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	    /* update partition table */
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            show_parts(device);
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            nbd_client(fd, sock);
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            close(fd);
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 out:
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            kill(pid, SIGTERM);
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            unlink(socket);
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            return ret;
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        }
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        /* children */
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    }
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    sharing_fds = qemu_malloc((shared + 1) * sizeof(int));
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    if (socket) {
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        sharing_fds[0] = unix_socket_incoming(socket);
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    } else {
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        sharing_fds[0] = tcp_socket_incoming(bindto, port);
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    }
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    if (sharing_fds[0] == -1)
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        return 1;
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    max_fd = sharing_fds[0];
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    nb_fds++;
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    data = qemu_memalign(512, NBD_BUFFER_SIZE);
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    if (data == NULL)
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        errx(ENOMEM, "Cannot allocate data buffer");
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    do {
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        FD_ZERO(&fds);
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        for (i = 0; i < nb_fds; i++)
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            FD_SET(sharing_fds[i], &fds);
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        ret = select(max_fd + 1, &fds, NULL, NULL, NULL);
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        if (ret == -1)
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            break;
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        if (FD_ISSET(sharing_fds[0], &fds))
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            ret--;
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        for (i = 1; i < nb_fds && ret; i++) {
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            if (FD_ISSET(sharing_fds[i], &fds)) {
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                if (nbd_trip(bs, sharing_fds[i], fd_size, dev_offset,
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                    &offset, readonly, data, NBD_BUFFER_SIZE) != 0) {
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                    close(sharing_fds[i]);
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                    nb_fds--;
 | 
						|
                    sharing_fds[i] = sharing_fds[nb_fds];
 | 
						|
                    i--;
 | 
						|
                }
 | 
						|
                ret--;
 | 
						|
            }
 | 
						|
        }
 | 
						|
        /* new connection ? */
 | 
						|
        if (FD_ISSET(sharing_fds[0], &fds)) {
 | 
						|
            if (nb_fds < shared + 1) {
 | 
						|
                sharing_fds[nb_fds] = accept(sharing_fds[0],
 | 
						|
                                             (struct sockaddr *)&addr,
 | 
						|
                                             &addr_len);
 | 
						|
                if (sharing_fds[nb_fds] != -1 &&
 | 
						|
                    nbd_negotiate(sharing_fds[nb_fds], fd_size) != -1) {
 | 
						|
                        if (sharing_fds[nb_fds] > max_fd)
 | 
						|
                            max_fd = sharing_fds[nb_fds];
 | 
						|
                        nb_fds++;
 | 
						|
                }
 | 
						|
            }
 | 
						|
        }
 | 
						|
    } while (persistent || nb_fds > 1);
 | 
						|
    qemu_vfree(data);
 | 
						|
 | 
						|
    close(sharing_fds[0]);
 | 
						|
    bdrv_close(bs);
 | 
						|
    qemu_free(sharing_fds);
 | 
						|
    if (socket)
 | 
						|
        unlink(socket);
 | 
						|
 | 
						|
    return 0;
 | 
						|
}
 |