xref: /aosp_15_r20/external/sg3_utils/src/sg_write_same.c (revision 44704f698541f6367e81f991ef8bb54ccbf3fc18)

/*
 * Copyright (c) 2009-2022 Douglas Gilbert.
 * All rights reserved.
 * Use of this source code is governed by a BSD-style
 * license that can be found in the BSD_LICENSE file.
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <stdbool.h>
#include <string.h>
#include <errno.h>
#include <limits.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <getopt.h>
#define __STDC_FORMAT_MACROS 1
#include <inttypes.h>

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "sg_lib.h"
#include "sg_pt.h"
#include "sg_cmds_basic.h"
#include "sg_cmds_extra.h"
#include "sg_unaligned.h"
#include "sg_pr2serr.h"

static const char * version_str = "1.34 20220127";


#define ME "sg_write_same: "

#define WRITE_SAME10_OP 0x41
#define WRITE_SAME16_OP 0x93
#define VARIABLE_LEN_OP 0x7f
#define WRITE_SAME32_SA 0xd
#define WRITE_SAME32_ADD 0x18
#define WRITE_SAME10_LEN 10
#define WRITE_SAME16_LEN 16
#define WRITE_SAME32_LEN 32
#define RCAP10_RESP_LEN 8
#define RCAP16_RESP_LEN 32
#define SENSE_BUFF_LEN 64       /* Arbitrary, could be larger */
#define DEF_TIMEOUT_SECS 60
#define DEF_WS_CDB_SIZE WRITE_SAME10_LEN
#define DEF_WS_NUMBLOCKS 1
#define MAX_XFER_LEN (64 * 1024)
#define EBUFF_SZ 512

#ifndef UINT32_MAX
#define UINT32_MAX ((uint32_t)-1)
#endif

static struct option long_options[] = {
    {"10", no_argument, 0, 'R'},
    {"16", no_argument, 0, 'S'},
    {"32", no_argument, 0, 'T'},
    {"anchor", no_argument, 0, 'a'},
    {"ff", no_argument, 0, 'f'},
    {"grpnum", required_argument, 0, 'g'},
    {"help", no_argument, 0, 'h'},
    {"in", required_argument, 0, 'i'},
    {"lba", required_argument, 0, 'l'},
    {"lbdata", no_argument, 0, 'L'},
    {"ndob", no_argument, 0, 'N'},
    {"num", required_argument, 0, 'n'},
    {"pbdata", no_argument, 0, 'P'},
    {"timeout", required_argument, 0, 't'},
    {"unmap", no_argument, 0, 'U'},
    {"verbose", no_argument, 0, 'v'},
    {"version", no_argument, 0, 'V'},
    {"wrprotect", required_argument, 0, 'w'},
    {"xferlen", required_argument, 0, 'x'},
    {0, 0, 0, 0},
};

struct opts_t {
    bool anchor;
    bool ff;
    bool ndob;
    bool lbdata;
    bool pbdata;
    bool unmap;
    bool verbose_given;
    bool version_given;
    bool want_ws10;
    int grpnum;
    int numblocks;
    int timeout;
    int verbose;
    int wrprotect;
    int xfer_len;
    int pref_cdb_size;
    uint64_t lba;
    char ifilename[256];
};


static void
usage()
{
    pr2serr("Usage: sg_write_same [--10] [--16] [--32] [--anchor] "
            "[-ff] [--grpnum=GN]\n"
            "                     [--help] [--in=IF] [--lba=LBA] [--lbdata] "
            "[--ndob]\n"
            "                     [--num=NUM] [--pbdata] [--timeout=TO] "
            "[--unmap]\n"
            "                     [--verbose] [--version] [--wrprotect=WRP] "
            "[xferlen=LEN]\n"
            "                     DEVICE\n"
            "  where:\n"
            "    --10|-R              send WRITE SAME(10) (even if '--unmap' "
            "is given)\n"
            "    --16|-S              send WRITE SAME(16) (def: 10 unless "
            "'--unmap' given,\n"
            "                         LBA+NUM > 32 bits, or NUM > 65535; "
            "then def 16)\n"
            "    --32|-T              send WRITE SAME(32) (def: 10 or 16)\n"
            "    --anchor|-a          set ANCHOR field in cdb\n"
            "    --ff|-f              use buffer of 0xff bytes for fill "
            "(def: 0x0 bytes)\n"
            "    --grpnum=GN|-g GN    GN is group number field (def: 0)\n"
            "    --help|-h            print out usage message\n"
            "    --in=IF|-i IF        IF is file to fetch one block of data "
            "from (use LEN\n"
            "                         bytes or whole file). Block written to "
            "DEVICE\n"
            "    --lba=LBA|-l LBA     LBA is the logical block address to "
            "start (def: 0)\n"
            "    --lbdata|-L          set LBDATA bit (obsolete)\n"
            "    --ndob|-N            set NDOB (no data-out buffer) bit in "
            "cdb\n"
            "    --num=NUM|-n NUM     NUM is number of logical blocks to "
            "write (def: 1)\n"
            "                         [Beware NUM==0 may mean: 'rest of "
            "device']\n"
            "    --pbdata|-P          set PBDATA bit (obsolete)\n"
            "    --timeout=TO|-t TO    command timeout (unit: seconds) (def: "
            "60)\n"
            "    --unmap|-U           set UNMAP bit\n"
            "    --verbose|-v         increase verbosity\n"
            "    --version|-V         print version string then exit\n"
            "    --wrprotect=WPR|-w WPR    WPR is the WRPROTECT field value "
            "(def: 0)\n"
            "    --xferlen=LEN|-x LEN    LEN is number of bytes from IF to "
            "send to\n"
            "                            DEVICE (def: IF file length)\n\n"
            "Performs a SCSI WRITE SAME (10, 16 or 32) command. NDOB bit is "
            "only\nsupported by the 16 and 32 byte variants. When set the "
            "specified blocks\nwill be filled with zeros or the "
            "'provisioning initialization pattern'\nas indicated by the "
            "LBPRZ field. As a precaution one of the '--in=',\n'--lba=' or "
            "'--num=' options is required.\nAnother implementation of WRITE "
            "SAME is found in the sg_write_x utility.\n"
            );
}

static int
do_write_same(int sg_fd, const struct opts_t * op, const void * dataoutp,
              int * act_cdb_lenp)
{
    int ret, res, sense_cat, cdb_len;
    uint64_t llba;
    uint8_t ws_cdb[WRITE_SAME32_LEN] SG_C_CPP_ZERO_INIT;
    uint8_t sense_b[SENSE_BUFF_LEN] SG_C_CPP_ZERO_INIT;
    struct sg_pt_base * ptvp;

    cdb_len = op->pref_cdb_size;
    if (WRITE_SAME10_LEN == cdb_len) {
        llba = op->lba + op->numblocks;
        if ((op->numblocks > 0xffff) || (llba > UINT32_MAX) ||
            op->ndob || (op->unmap && (! op->want_ws10))) {
            cdb_len = WRITE_SAME16_LEN;
            if (op->verbose) {
                const char * cp = "use WRITE SAME(16) instead of 10 byte "
                                  "cdb";

                if (op->numblocks > 0xffff)
                    pr2serr("%s since blocks exceed 65535\n", cp);
                else if (llba > UINT32_MAX)
                    pr2serr("%s since LBA may exceed 32 bits\n", cp);
                else
                    pr2serr("%s due to ndob or unmap settings\n", cp);
            }
        }
    }
    if (act_cdb_lenp)
        *act_cdb_lenp = cdb_len;
    switch (cdb_len) {
    case WRITE_SAME10_LEN:
        ws_cdb[0] = WRITE_SAME10_OP;
        ws_cdb[1] = ((op->wrprotect & 0x7) << 5);
        /* ANCHOR + UNMAP not allowed for WRITE_SAME10 in sbc3r24+r25 but
         * a proposal has been made to allow it. Anticipate approval. */
        if (op->anchor)
            ws_cdb[1] |= 0x10;
        if (op->unmap)
            ws_cdb[1] |= 0x8;
        if (op->pbdata)
            ws_cdb[1] |= 0x4;
        if (op->lbdata)
            ws_cdb[1] |= 0x2;
        sg_put_unaligned_be32((uint32_t)op->lba, ws_cdb + 2);
        ws_cdb[6] = (op->grpnum & GRPNUM_MASK);
        sg_put_unaligned_be16((uint16_t)op->numblocks, ws_cdb + 7);
        break;
    case WRITE_SAME16_LEN:
        ws_cdb[0] = WRITE_SAME16_OP;
        ws_cdb[1] = ((op->wrprotect & 0x7) << 5);
        if (op->anchor)
            ws_cdb[1] |= 0x10;
        if (op->unmap)
            ws_cdb[1] |= 0x8;
        if (op->pbdata)
            ws_cdb[1] |= 0x4;
        if (op->lbdata)
            ws_cdb[1] |= 0x2;
        if (op->ndob)
            ws_cdb[1] |= 0x1;
        sg_put_unaligned_be64(op->lba, ws_cdb + 2);
        sg_put_unaligned_be32((uint32_t)op->numblocks, ws_cdb + 10);
        ws_cdb[14] = (op->grpnum & GRPNUM_MASK);
        break;
    case WRITE_SAME32_LEN:
        ws_cdb[0] = VARIABLE_LEN_OP;
        ws_cdb[6] = (op->grpnum & GRPNUM_MASK);
        ws_cdb[7] = WRITE_SAME32_ADD;
        sg_put_unaligned_be16((uint16_t)WRITE_SAME32_SA, ws_cdb + 8);
        ws_cdb[10] = ((op->wrprotect & 0x7) << 5);
        if (op->anchor)
            ws_cdb[10] |= 0x10;
        if (op->unmap)
            ws_cdb[10] |= 0x8;
        if (op->pbdata)
            ws_cdb[10] |= 0x4;
        if (op->lbdata)
            ws_cdb[10] |= 0x2;
        if (op->ndob)
            ws_cdb[10] |= 0x1;
        sg_put_unaligned_be64(op->lba, ws_cdb + 12);
        sg_put_unaligned_be32((uint32_t)op->numblocks, ws_cdb + 28);
        break;
    default:
        pr2serr("do_write_same: bad cdb length %d\n", cdb_len);
        return -1;
    }

    if (op->verbose > 1) {
        char b[128];

        pr2serr("    Write same(%d) cdb: %s\n", cdb_len,
                sg_get_command_str(ws_cdb, cdb_len, false, sizeof(b), b));
        pr2serr("    Data-out buffer length=%d\n", op->xfer_len);
    }
    if ((op->verbose > 3) && (op->xfer_len > 0)) {
        pr2serr("    Data-out buffer contents:\n");
        hex2stderr((const uint8_t *)dataoutp, op->xfer_len, 1);
    }
    ptvp = construct_scsi_pt_obj();
    if (NULL == ptvp) {
        pr2serr("Write same(%d): out of memory\n", cdb_len);
        return -1;
    }
    set_scsi_pt_cdb(ptvp, ws_cdb, cdb_len);
    set_scsi_pt_sense(ptvp, sense_b, sizeof(sense_b));
    set_scsi_pt_data_out(ptvp, (uint8_t *)dataoutp, op->xfer_len);
    res = do_scsi_pt(ptvp, sg_fd, op->timeout, op->verbose);
    ret = sg_cmds_process_resp(ptvp, "Write same", res, true /*noisy */,
                               op->verbose, &sense_cat);
    if (-1 == ret) {
        if (get_scsi_pt_transport_err(ptvp))
            ret = SG_LIB_TRANSPORT_ERROR;
        else
            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
    } else if (-2 == ret) {
        switch (sense_cat) {
        case SG_LIB_CAT_RECOVERED:
        case SG_LIB_CAT_NO_SENSE:
            ret = 0;
            break;
        case SG_LIB_CAT_MEDIUM_HARD:
            {
                bool valid;
                int slen;
                uint64_t ull = 0;

                slen = get_scsi_pt_sense_len(ptvp);
                valid = sg_get_sense_info_fld(sense_b, slen, &ull);
                if (valid)
                    pr2serr("Medium or hardware error starting at lba=%"
                            PRIu64 " [0x%" PRIx64 "]\n", ull, ull);
            }
            ret = sense_cat;
            break;
        case SG_LIB_CAT_ILLEGAL_REQ:
            if (op->verbose)
                sg_print_command_len(ws_cdb, cdb_len);
            /* FALL THROUGH */
        default:
            ret = sense_cat;
            break;
        }
    } else
        ret = 0;

    destruct_scsi_pt_obj(ptvp);
    return ret;
}


int
main(int argc, char * argv[])
{
    bool got_stdin = false;
    bool if_given = false;
    bool lba_given = false;
    bool num_given = false;
    bool prot_en;
    int res, c, infd, act_cdb_len, vb, err;
    int sg_fd = -1;
    int ret = -1;
    uint32_t block_size;
    int64_t ll;
    const char * device_name = NULL;
    struct opts_t * op;
    uint8_t * wBuff = NULL;
    uint8_t * free_wBuff = NULL;
    char ebuff[EBUFF_SZ];
    char b[80];
    uint8_t resp_buff[RCAP16_RESP_LEN];
    struct opts_t opts;
    struct stat a_stat;

    op = &opts;
    memset(op, 0, sizeof(opts));
    op->numblocks = DEF_WS_NUMBLOCKS;
    op->pref_cdb_size = DEF_WS_CDB_SIZE;
    op->timeout = DEF_TIMEOUT_SECS;
    while (1) {
        int option_index = 0;

        c = getopt_long(argc, argv, "afg:hi:l:Ln:NPRSt:TUvVw:x:",
                        long_options, &option_index);
        if (c == -1)
            break;

        switch (c) {
        case 'a':
            op->anchor = true;
            break;
        case 'f':
            op->ff = true;
            break;
        case 'g':
            op->grpnum = sg_get_num(optarg);
            if ((op->grpnum < 0) || (op->grpnum > 63))  {
                pr2serr("bad argument to '--grpnum'\n");
                return SG_LIB_SYNTAX_ERROR;
            }
            break;
        case 'h':
        case '?':
            usage();
            return 0;
        case 'i':
            strncpy(op->ifilename, optarg, sizeof(op->ifilename) - 1);
            op->ifilename[sizeof(op->ifilename) - 1] = '\0';
            if_given = true;
            break;
        case 'l':
            ll = sg_get_llnum(optarg);
            if (-1 == ll) {
                pr2serr("bad argument to '--lba'\n");
                return SG_LIB_SYNTAX_ERROR;
            }
            op->lba = (uint64_t)ll;
            lba_given = true;
            break;
        case 'L':
            op->lbdata = true;
            break;
        case 'n':
            op->numblocks = sg_get_num(optarg);
            if (op->numblocks < 0)  {
                pr2serr("bad argument to '--num'\n");
                return SG_LIB_SYNTAX_ERROR;
            }
            num_given = true;
            break;
        case 'N':
            op->ndob = true;
            break;
        case 'P':
            op->pbdata = true;
            break;
        case 'R':
            op->want_ws10 = true;
            break;
        case 'S':
            if (DEF_WS_CDB_SIZE != op->pref_cdb_size) {
                pr2serr("only one '--10', '--16' or '--32' please\n");
                return SG_LIB_CONTRADICT;
            }
            op->pref_cdb_size = 16;
            break;
        case 't':
            op->timeout = sg_get_num(optarg);
            if (op->timeout < 0)  {
                pr2serr("bad argument to '--timeout'\n");
                return SG_LIB_SYNTAX_ERROR;
            }
            break;
        case 'T':
            if (DEF_WS_CDB_SIZE != op->pref_cdb_size) {
                pr2serr("only one '--10', '--16' or '--32' please\n");
                return SG_LIB_CONTRADICT;
            }
            op->pref_cdb_size = 32;
            break;
        case 'U':
            op->unmap = true;
            break;
        case 'v':
            op->verbose_given = true;
            ++op->verbose;
            break;
        case 'V':
            op->version_given = true;
            break;
        case 'w':
            op->wrprotect = sg_get_num(optarg);
            if ((op->wrprotect < 0) || (op->wrprotect > 7))  {
                pr2serr("bad argument to '--wrprotect'\n");
                return SG_LIB_SYNTAX_ERROR;
            }
            break;
        case 'x':
            op->xfer_len = sg_get_num(optarg);
            if (op->xfer_len < 0) {
                pr2serr("bad argument to '--xferlen'\n");
                return SG_LIB_SYNTAX_ERROR;
            }
            break;
        default:
            pr2serr("unrecognised option code 0x%x ??\n", c);
            usage();
            return SG_LIB_SYNTAX_ERROR;
        }
    }
    if (optind < argc) {
        if (NULL == device_name) {
            device_name = argv[optind];
            ++optind;
        }
        if (optind < argc) {
            for (; optind < argc; ++optind)
                pr2serr("Unexpected extra argument: %s\n", argv[optind]);
            usage();
            return SG_LIB_SYNTAX_ERROR;
        }
    }
    if (op->want_ws10 && (DEF_WS_CDB_SIZE != op->pref_cdb_size)) {
        pr2serr("only one '--10', '--16' or '--32' please\n");
        return SG_LIB_CONTRADICT;
    }

#ifdef DEBUG
    pr2serr("In DEBUG mode, ");
    if (op->verbose_given && op->version_given) {
        pr2serr("but override: '-vV' given, zero verbose and continue\n");
        op->verbose_given = false;
        op->version_given = false;
        op->verbose = 0;
    } else if (! op->verbose_given) {
        pr2serr("set '-vv'\n");
        op->verbose = 2;
    } else
        pr2serr("keep verbose=%d\n", op->verbose);
#else
    if (op->verbose_given && op->version_given)
        pr2serr("Not in DEBUG mode, so '-vV' has no special action\n");
#endif
    if (op->version_given) {
        pr2serr(ME "version: %s\n", version_str);
        return 0;
    }

    if (NULL == device_name) {
        pr2serr("Missing device name!\n\n");
        usage();
        return SG_LIB_SYNTAX_ERROR;
    }
    vb = op->verbose;

    if ((! if_given) && (! lba_given) && (! num_given)) {
        pr2serr("As a precaution, one of '--in=', '--lba=' or '--num=' is "
                "required\n");
        return SG_LIB_CONTRADICT;
    }

    if (op->ndob) {
        if (if_given) {
            pr2serr("Can't have both --ndob and '--in='\n");
            return SG_LIB_CONTRADICT;
        }
        if (0 != op->xfer_len) {
            pr2serr("With --ndob only '--xferlen=0' (or not given) is "
                    "acceptable\n");
            return SG_LIB_CONTRADICT;
        }
    } else if (op->ifilename[0]) {
        got_stdin = (0 == strcmp(op->ifilename, "-"));
        if (! got_stdin) {
            memset(&a_stat, 0, sizeof(a_stat));
            if (stat(op->ifilename, &a_stat) < 0) {
                err = errno;
                if (vb)
                    pr2serr("unable to stat(%s): %s\n", op->ifilename,
                            safe_strerror(err));
                return sg_convert_errno(err);
            }
            if (op->xfer_len <= 0)
                op->xfer_len = (int)a_stat.st_size;
        }
    }

    sg_fd = sg_cmds_open_device(device_name, false /* rw */, vb);
    if (sg_fd < 0) {
        if (op->verbose)
            pr2serr(ME "open error: %s: %s\n", device_name,
                    safe_strerror(-sg_fd));
        ret = sg_convert_errno(-sg_fd);
        goto err_out;
    }

    if (! op->ndob) {
        prot_en = false;
        if (0 == op->xfer_len) {
            res = sg_ll_readcap_16(sg_fd, false /* pmi */, 0 /* llba */,
                                   resp_buff, RCAP16_RESP_LEN, true,
                                   (vb ? (vb - 1): 0));
            if (SG_LIB_CAT_UNIT_ATTENTION == res) {
                pr2serr("Read capacity(16) unit attention, try again\n");
                res = sg_ll_readcap_16(sg_fd, false, 0, resp_buff,
                                       RCAP16_RESP_LEN, true,
                                       (vb ? (vb - 1): 0));
            }
            if (0 == res) {
                if (vb > 3)
                    hex2stderr(resp_buff, RCAP16_RESP_LEN, 1);
                block_size = sg_get_unaligned_be32(resp_buff + 8);
                prot_en = !!(resp_buff[12] & 0x1);
                op->xfer_len = block_size;
                if (prot_en && (op->wrprotect > 0))
                    op->xfer_len += 8;
            } else if ((SG_LIB_CAT_INVALID_OP == res) ||
                       (SG_LIB_CAT_ILLEGAL_REQ == res)) {
                if (vb)
                    pr2serr("Read capacity(16) not supported, try Read "
                            "capacity(10)\n");
                res = sg_ll_readcap_10(sg_fd, false /* pmi */, 0 /* lba */,
                                       resp_buff, RCAP10_RESP_LEN, true,
                                       (vb ? (vb - 1): 0));
                if (0 == res) {
                    if (vb > 3)
                        hex2stderr(resp_buff, RCAP10_RESP_LEN, 1);
                    block_size = sg_get_unaligned_be32(resp_buff + 4);
                    op->xfer_len = block_size;
                } else {
                    sg_get_category_sense_str(res, sizeof(b), b, vb);
                    pr2serr("Read capacity(10): %s\n", b);
                    pr2serr("Unable to calculate block size\n");
                }
            } else if (vb) {
                sg_get_category_sense_str(res, sizeof(b), b, vb);
                pr2serr("Read capacity(16): %s\n", b);
                pr2serr("Unable to calculate block size\n");
            }
        }
        if (op->xfer_len < 1) {
            pr2serr("unable to deduce block size, please give '--xferlen=' "
                    "argument\n");
            ret = SG_LIB_SYNTAX_ERROR;
            goto err_out;
        }
        if (op->xfer_len > MAX_XFER_LEN) {
            pr2serr("'--xferlen=%d is out of range ( want <= %d)\n",
                    op->xfer_len, MAX_XFER_LEN);
            ret = SG_LIB_SYNTAX_ERROR;
            goto err_out;
        }
        wBuff = (uint8_t *)sg_memalign(op->xfer_len, 0, &free_wBuff, false);
        if (NULL == wBuff) {
            pr2serr("unable to allocate %d bytes of memory with "
                    "sg_memalign()\n", op->xfer_len);
            ret = sg_convert_errno(ENOMEM);
            goto err_out;
        }
        if (op->ff)
            memset(wBuff, 0xff, op->xfer_len);
        if (op->ifilename[0]) {
            if (got_stdin) {
                infd = STDIN_FILENO;
                if (sg_set_binary_mode(STDIN_FILENO) < 0)
                    perror("sg_set_binary_mode");
            } else {
                if ((infd = open(op->ifilename, O_RDONLY)) < 0) {
                    ret = sg_convert_errno(errno);
                    snprintf(ebuff, EBUFF_SZ, ME "could not open %.400s for "
                             "reading", op->ifilename);
                    perror(ebuff);
                    goto err_out;
                } else if (sg_set_binary_mode(infd) < 0)
                    perror("sg_set_binary_mode");
            }
            res = read(infd, wBuff, op->xfer_len);
            if (res < 0) {
                ret = sg_convert_errno(errno);
                snprintf(ebuff, EBUFF_SZ, ME "couldn't read from %.400s",
                         op->ifilename);
                perror(ebuff);
                if (! got_stdin)
                    close(infd);
                goto err_out;
            }
            if (res < op->xfer_len) {
                pr2serr("tried to read %d bytes from %s, got %d bytes\n",
                        op->xfer_len, op->ifilename, res);
                pr2serr("  so pad with 0x0 bytes and continue\n");
            }
            if (! got_stdin)
                close(infd);
        } else {
            if (vb)
                pr2serr("Default data-out buffer set to %d zeros\n",
                        op->xfer_len);
            if (prot_en && (op->wrprotect > 0)) {
               /* default for protection is 0xff, rest get 0x0 */
                memset(wBuff + op->xfer_len - 8, 0xff, 8);
                if (vb)
                    pr2serr(" ... apart from last 8 bytes which are set to "
                            "0xff\n");
            }
        }
    }

    ret = do_write_same(sg_fd, op, wBuff, &act_cdb_len);
    if (ret) {
        sg_get_category_sense_str(ret, sizeof(b), b, vb);
        pr2serr("Write same(%d): %s\n", act_cdb_len, b);
    }

err_out:
    if (free_wBuff)
        free(free_wBuff);
    if (sg_fd >= 0) {
        res = sg_cmds_close_device(sg_fd);
        if (res < 0) {
            pr2serr("close error: %s\n", safe_strerror(-res));
            if (0 == ret)
                ret = sg_convert_errno(-res);
        }
    }
    if (0 == op->verbose) {
        if (! sg_if_can2stderr("sg_write_same failed: ", ret))
            pr2serr("Some error occurred, try again with '-v' "
                    "or '-vv' for more information\n");
    }
    return (ret >= 0) ? ret : SG_LIB_CAT_OTHER;
}