]> git.ipfire.org Git - thirdparty/util-linux.git/blobdiff - sys-utils/losetup.c
script: add note about --log-in and passwords
[thirdparty/util-linux.git] / sys-utils / losetup.c
index 9201782ad64069e895d9e3cf73ce2385654ad9a2..379b95f174cf8b6c492968e8815424f1f3c3f5d3 100644 (file)
@@ -35,6 +35,8 @@ enum {
        A_SHOW_ONE,             /* print info about one device */
        A_FIND_FREE,            /* find first unused */
        A_SET_CAPACITY,         /* set device capacity */
+       A_SET_DIRECT_IO,        /* set accessing backing file by direct io */
+       A_SET_BLOCKSIZE,        /* set logical block size of the loop device */
 };
 
 enum {
@@ -48,30 +50,37 @@ enum {
        COL_PARTSCAN,
        COL_RO,
        COL_SIZELIMIT,
+       COL_DIO,
+       COL_LOGSEC,
 };
 
 /* basic output flags */
 static int no_headings;
 static int raw;
+static int json;
 
 struct colinfo {
        const char *name;
        double whint;
        int flags;
        const char *help;
+
+       int json_type;  /* default is string */
 };
 
 static struct colinfo infos[] = {
-       [COL_AUTOCLR]     = { "AUTOCLEAR",    1, SCOLS_FL_RIGHT, N_("autoclear flag set")},
+       [COL_AUTOCLR]     = { "AUTOCLEAR",    1, SCOLS_FL_RIGHT, N_("autoclear flag set"), SCOLS_JSON_BOOLEAN},
        [COL_BACK_FILE]   = { "BACK-FILE",  0.3, 0, N_("device backing file")},
-       [COL_BACK_INO]    = { "BACK-INO",     4, SCOLS_FL_RIGHT, N_("backing file inode number")},
+       [COL_BACK_INO]    = { "BACK-INO",     4, SCOLS_FL_RIGHT, N_("backing file inode number"), SCOLS_JSON_NUMBER},
        [COL_BACK_MAJMIN] = { "BACK-MAJ:MIN", 6, 0, N_("backing file major:minor device number")},
        [COL_NAME]        = { "NAME",      0.25, 0, N_("loop device name")},
-       [COL_OFFSET]      = { "OFFSET",       5, SCOLS_FL_RIGHT, N_("offset from the beginning")},
-       [COL_PARTSCAN]    = { "PARTSCAN",     1, SCOLS_FL_RIGHT, N_("partscan flag set")},
-       [COL_RO]          = { "RO",           1, SCOLS_FL_RIGHT, N_("read-only device")},
-       [COL_SIZELIMIT]   = { "SIZELIMIT",    5, SCOLS_FL_RIGHT, N_("size limit of the file in bytes")},
+       [COL_OFFSET]      = { "OFFSET",       5, SCOLS_FL_RIGHT, N_("offset from the beginning"), SCOLS_JSON_NUMBER},
+       [COL_PARTSCAN]    = { "PARTSCAN",     1, SCOLS_FL_RIGHT, N_("partscan flag set"), SCOLS_JSON_BOOLEAN},
+       [COL_RO]          = { "RO",           1, SCOLS_FL_RIGHT, N_("read-only device"), SCOLS_JSON_BOOLEAN},
+       [COL_SIZELIMIT]   = { "SIZELIMIT",    5, SCOLS_FL_RIGHT, N_("size limit of the file in bytes"), SCOLS_JSON_NUMBER},
        [COL_MAJMIN]      = { "MAJ:MIN",      3, 0, N_("loop device major:minor number")},
+       [COL_DIO]         = { "DIO",          1, SCOLS_FL_RIGHT, N_("access backing file with direct-io"), SCOLS_JSON_BOOLEAN},
+       [COL_LOGSEC]      = { "LOG-SEC",      4, SCOLS_FL_RIGHT, N_("logical sector size in bytes"), SCOLS_JSON_NUMBER},
 };
 
 static int columns[ARRAY_SIZE(infos) * 2] = {-1};
@@ -109,7 +118,7 @@ static int printf_loopdev(struct loopdev_cxt *lc)
        uint64_t x;
        dev_t dev = 0;
        ino_t ino = 0;
-       char *fname = NULL;
+       char *fname;
        uint32_t type;
 
        fname = loopcxt_get_backing_file(lc);
@@ -132,8 +141,7 @@ static int printf_loopdev(struct loopdev_cxt *lc)
 
                if (loopcxt_get_sizelimit(lc, &x) == 0 && x)
                                printf(_(", sizelimit %ju"), x);
-               printf("\n");
-               return 0;
+               goto done;
        }
 
        printf("%s: [%04d]:%" PRIu64 " (%s)",
@@ -153,6 +161,9 @@ static int printf_loopdev(struct loopdev_cxt *lc)
                if (e && *e)
                        printf(_(", encryption %s (type %u)"), e, type);
        }
+
+done:
+       free(fname);
        printf("\n");
        return 0;
 }
@@ -174,10 +185,10 @@ static int show_all_loops(struct loopdev_cxt *lc, const char *file,
                        int used;
                        const char *bf = cn_file ? cn_file : file;
 
-                       used = loopcxt_is_used(lc, st, bf, offset, flags);
+                       used = loopcxt_is_used(lc, st, bf, offset, 0, flags);
                        if (!used && !cn_file) {
                                bf = cn_file = canonicalize_path(file);
-                               used = loopcxt_is_used(lc, st, bf, offset, flags);
+                               used = loopcxt_is_used(lc, st, bf, offset, 0, flags);
                        }
                        if (!used)
                                continue;
@@ -221,6 +232,7 @@ static int set_scols_data(struct loopdev_cxt *lc, struct libscols_line *ln)
                const char *p = NULL;                   /* external data */
                char *np = NULL;                        /* allocated here */
                uint64_t x = 0;
+               int rc = 0;
 
                switch(get_column_id(i)) {
                case COL_NAME:
@@ -269,18 +281,28 @@ static int set_scols_data(struct loopdev_cxt *lc, struct libscols_line *ln)
                case COL_RO:
                        p = loopcxt_is_readonly(lc) ? "1" : "0";
                        break;
+               case COL_DIO:
+                       p = loopcxt_is_dio(lc) ? "1" : "0";
+                       break;
                case COL_PARTSCAN:
                        p = loopcxt_is_partscan(lc) ? "1" : "0";
                        break;
+               case COL_LOGSEC:
+                       if (loopcxt_get_blocksize(lc, &x) == 0)
+                               xasprintf(&np, "%jd", x);
+                       break;
                default:
                        return -EINVAL;
                }
 
 
                if (p)
-                       scols_line_set_data(ln, i, p);          /* calls strdup() */
+                       rc = scols_line_set_data(ln, i, p);     /* calls strdup() */
                else if (np)
-                       scols_line_refer_data(ln, i, np);       /* only refers */
+                       rc = scols_line_refer_data(ln, i, np);  /* only refers */
+
+               if (rc)
+                       err(EXIT_FAILURE, _("failed to add output data"));
        }
 
        return 0;
@@ -300,22 +322,30 @@ static int show_table(struct loopdev_cxt *lc,
        scols_init_debug(0);
 
        if (!(tb = scols_new_table()))
-               err(EXIT_FAILURE, _("failed to initialize output table"));
+               err(EXIT_FAILURE, _("failed to allocate output table"));
        scols_table_enable_raw(tb, raw);
+       scols_table_enable_json(tb, json);
        scols_table_enable_noheadings(tb, no_headings);
 
+       if (json)
+               scols_table_set_name(tb, "loopdevices");
+
        for (i = 0; i < ncolumns; i++) {
                struct colinfo *ci = get_column_info(i);
+               struct libscols_column *cl;
 
-               if (!scols_table_new_column(tb, ci->name, ci->whint, ci->flags))
-                       err(EXIT_FAILURE, _("failed to initialize output column"));
+               cl = scols_table_new_column(tb, ci->name, ci->whint, ci->flags);
+               if (!cl)
+                       err(EXIT_FAILURE, _("failed to allocate output column"));
+               if (json)
+                       scols_column_set_json_type(cl, ci->json_type);
        }
 
        /* only one loopdev requested (already assigned to loopdev_cxt) */
        if (loopcxt_get_device(lc)) {
                ln = scols_table_new_line(tb, NULL);
                if (!ln)
-                       err(EXIT_FAILURE, _("failed to initialize output line"));
+                       err(EXIT_FAILURE, _("failed to allocate output line"));
                rc = set_scols_data(lc, ln);
 
        /* list all loopdevs */
@@ -333,10 +363,10 @@ static int show_table(struct loopdev_cxt *lc,
                                int used;
                                const char *bf = cn_file ? cn_file : file;
 
-                               used = loopcxt_is_used(lc, st, bf, offset, flags);
+                               used = loopcxt_is_used(lc, st, bf, offset, 0, flags);
                                if (!used && !cn_file) {
                                        bf = cn_file = canonicalize_path(file);
-                                       used = loopcxt_is_used(lc, st, bf, offset, flags);
+                                       used = loopcxt_is_used(lc, st, bf, offset, 0, flags);
                                }
                                if (!used)
                                        continue;
@@ -344,7 +374,7 @@ static int show_table(struct loopdev_cxt *lc,
 
                        ln = scols_table_new_line(tb, NULL);
                        if (!ln)
-                               err(EXIT_FAILURE, _("failed to initialize output column"));
+                               err(EXIT_FAILURE, _("failed to allocate output line"));
                        rc = set_scols_data(lc, ln);
                        if (rc)
                                break;
@@ -360,8 +390,9 @@ done:
        return rc;
 }
 
-static void usage(FILE *out)
+static void __attribute__((__noreturn__)) usage(void)
 {
+       FILE *out = stdout;
        size_t i;
 
        fputs(USAGE_HEADER, out);
@@ -374,6 +405,7 @@ static void usage(FILE *out)
        fputs(USAGE_SEPARATOR, out);
        fputs(_("Set up and control loop devices.\n"), out);
 
+       /* commands */
        fputs(USAGE_OPTIONS, out);
        fputs(_(" -a, --all                     list all used devices\n"), out);
        fputs(_(" -d, --detach <loopdev>...     detach one or more devices\n"), out);
@@ -381,37 +413,41 @@ static void usage(FILE *out)
        fputs(_(" -f, --find                    find first unused device\n"), out);
        fputs(_(" -c, --set-capacity <loopdev>  resize the device\n"), out);
        fputs(_(" -j, --associated <file>       list all devices associated with <file>\n"), out);
+       fputs(_(" -L, --nooverlap               avoid possible conflict between devices\n"), out);
 
+       /* commands options */
        fputs(USAGE_SEPARATOR, out);
-
        fputs(_(" -o, --offset <num>            start at offset <num> into file\n"), out);
        fputs(_("     --sizelimit <num>         device is limited to <num> bytes of the file\n"), out);
+       fputs(_(" -b, --sector-size <num>       set the logical sector size to <num>\n"), out);
        fputs(_(" -P, --partscan                create a partitioned loop device\n"), out);
        fputs(_(" -r, --read-only               set up a read-only loop device\n"), out);
+       fputs(_("     --direct-io[=<on|off>]    open backing file with O_DIRECT\n"), out);
        fputs(_("     --show                    print device name after setup (with -f)\n"), out);
        fputs(_(" -v, --verbose                 verbose mode\n"), out);
 
+       /* output options */
        fputs(USAGE_SEPARATOR, out);
-
+       fputs(_(" -J, --json                    use JSON --list output format\n"), out);
        fputs(_(" -l, --list                    list info about all or specified (default)\n"), out);
-       fputs(_(" -O, --output <cols>           specify columns to output for --list\n"), out);
        fputs(_(" -n, --noheadings              don't print headings for --list output\n"), out);
+       fputs(_(" -O, --output <cols>           specify columns to output for --list\n"), out);
+       fputs(_("     --output-all              output all columns\n"), out);
        fputs(_("     --raw                     use raw --list output format\n"), out);
 
        fputs(USAGE_SEPARATOR, out);
-       fputs(USAGE_HELP, out);
-       fputs(USAGE_VERSION, out);
+       printf(USAGE_HELP_OPTIONS(31));
 
-       fputs(_("\nAvailable --list columns:\n"), out);
+       fputs(USAGE_COLUMNS, out);
        for (i = 0; i < ARRAY_SIZE(infos); i++)
                fprintf(out, " %12s  %s\n", infos[i].name, _(infos[i].help));
 
-       fprintf(out, USAGE_MAN_TAIL("losetup(8)"));
+       printf(USAGE_MAN_TAIL("losetup(8)"));
 
-       exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
+       exit(EXIT_SUCCESS);
 }
 
-static void warn_size(const char *filename, uint64_t size)
+static void warn_size(const char *filename, uint64_t size, uint64_t offset, int flags)
 {
        struct stat st;
 
@@ -419,6 +455,9 @@ static void warn_size(const char *filename, uint64_t size)
                if (stat(filename, &st) || S_ISBLK(st.st_mode))
                        return;
                size = st.st_size;
+
+               if (flags & LOOPDEV_FL_OFFSET)
+                       size -= offset;
        }
 
        if (size < 512)
@@ -431,47 +470,171 @@ static void warn_size(const char *filename, uint64_t size)
                        filename);
 }
 
+static int create_loop(struct loopdev_cxt *lc,
+                      int nooverlap, int lo_flags, int flags,
+                      const char *file, uint64_t offset, uint64_t sizelimit,
+                      uint64_t blocksize)
+{
+       int hasdev = loopcxt_has_device(lc);
+       int rc = 0;
+
+       /* losetup --find --noverlap file.img */
+       if (!hasdev && nooverlap) {
+               rc = loopcxt_find_overlap(lc, file, offset, sizelimit);
+               switch (rc) {
+               case 0: /* not found */
+                       break;
+
+               case 1: /* overlap */
+                       loopcxt_deinit(lc);
+                       errx(EXIT_FAILURE, _("%s: overlapping loop device exists"), file);
+
+               case 2: /* overlap -- full size and offset match (reuse) */
+               {
+                       uint32_t lc_encrypt_type;
+
+                       /* Once a loop is initialized RO, there is no
+                        * way to change its parameters. */
+                       if (loopcxt_is_readonly(lc)
+                           && !(lo_flags & LO_FLAGS_READ_ONLY)) {
+                               loopcxt_deinit(lc);
+                               errx(EXIT_FAILURE, _("%s: overlapping read-only loop device exists"), file);
+                       }
+
+                       /* This is no more supported, but check to be safe. */
+                       if (loopcxt_get_encrypt_type(lc, &lc_encrypt_type) == 0
+                           && lc_encrypt_type != LO_CRYPT_NONE) {
+                               loopcxt_deinit(lc);
+                               errx(EXIT_FAILURE, _("%s: overlapping encrypted loop device exists"), file);
+                       }
+
+                       lc->info.lo_flags &= ~LO_FLAGS_AUTOCLEAR;
+                       if (loopcxt_ioctl_status(lc)) {
+                               loopcxt_deinit(lc);
+                               errx(EXIT_FAILURE, _("%s: failed to re-use loop device"), file);
+                       }
+                       return 0;       /* success, re-use */
+               }
+               default: /* error */
+                       loopcxt_deinit(lc);
+                       errx(EXIT_FAILURE, _("failed to inspect loop devices"));
+                       return -errno;
+               }
+       }
+
+       if (hasdev && !is_loopdev(loopcxt_get_device(lc)))
+               loopcxt_add_device(lc);
+
+       /* losetup --noverlap /dev/loopN file.img */
+       if (hasdev && nooverlap) {
+               struct loopdev_cxt lc2;
+
+               if (loopcxt_init(&lc2, 0)) {
+                       loopcxt_deinit(lc);
+                       err(EXIT_FAILURE, _("failed to initialize loopcxt"));
+               }
+               rc = loopcxt_find_overlap(&lc2, file, offset, sizelimit);
+               loopcxt_deinit(&lc2);
+
+               if (rc) {
+                       loopcxt_deinit(lc);
+                       if (rc > 0)
+                               errx(EXIT_FAILURE, _("%s: overlapping loop device exists"), file);
+                       err(EXIT_FAILURE, _("%s: failed to check for conflicting loop devices"), file);
+               }
+       }
+
+       /* Create a new device */
+       do {
+               const char *errpre;
+
+               /* Note that loopcxt_{find_unused,set_device}() resets
+                * loopcxt struct.
+                */
+               if (!hasdev && (rc = loopcxt_find_unused(lc))) {
+                       warnx(_("cannot find an unused loop device"));
+                       break;
+               }
+               if (flags & LOOPDEV_FL_OFFSET)
+                       loopcxt_set_offset(lc, offset);
+               if (flags & LOOPDEV_FL_SIZELIMIT)
+                       loopcxt_set_sizelimit(lc, sizelimit);
+               if (lo_flags)
+                       loopcxt_set_flags(lc, lo_flags);
+               if (blocksize > 0)
+                       loopcxt_set_blocksize(lc, blocksize);
+
+               if ((rc = loopcxt_set_backing_file(lc, file))) {
+                       warn(_("%s: failed to use backing file"), file);
+                       break;
+               }
+               errno = 0;
+               rc = loopcxt_setup_device(lc);
+               if (rc == 0)
+                       break;                  /* success */
+               if (errno == EBUSY && !hasdev)
+                       continue;
+
+               /* errors */
+               errpre = hasdev && loopcxt_get_fd(lc) < 0 ?
+                                loopcxt_get_device(lc) : file;
+               warn(_("%s: failed to set up loop device"), errpre);
+               break;
+       } while (hasdev == 0);
+
+       return rc;
+}
+
 int main(int argc, char **argv)
 {
        struct loopdev_cxt lc;
-       int act = 0, flags = 0, c;
+       int act = 0, flags = 0, no_overlap = 0, c;
        char *file = NULL;
-       uint64_t offset = 0, sizelimit = 0;
+       uint64_t offset = 0, sizelimit = 0, blocksize = 0;
        int res = 0, showdev = 0, lo_flags = 0;
        char *outarg = NULL;
        int list = 0;
+       unsigned long use_dio = 0, set_dio = 0, set_blocksize = 0;
 
        enum {
                OPT_SIZELIMIT = CHAR_MAX + 1,
                OPT_SHOW,
-               OPT_RAW
+               OPT_RAW,
+               OPT_DIO,
+               OPT_OUTPUT_ALL
        };
        static const struct option longopts[] = {
-               { "all", 0, 0, 'a' },
-               { "set-capacity", 1, 0, 'c' },
-               { "detach", 1, 0, 'd' },
-               { "detach-all", 0, 0, 'D' },
-               { "find", 0, 0, 'f' },
-               { "help", 0, 0, 'h' },
-               { "associated", 1, 0, 'j' },
-               { "list", 0, 0, 'l' },
-               { "noheadings", 0, 0, 'n' },
-               { "offset", 1, 0, 'o' },
-               { "output", 1, 0, 'O' },
-               { "sizelimit", 1, 0, OPT_SIZELIMIT },
-               { "partscan", 0, 0, 'P' },
-               { "read-only", 0, 0, 'r' },
-               { "raw", 0, 0, OPT_RAW },
-               { "show", 0, 0, OPT_SHOW },
-               { "verbose", 0, 0, 'v' },
-               { "version", 0, 0, 'V' },
-               { NULL, 0, 0, 0 }
+               { "all",          no_argument,       NULL, 'a'           },
+               { "set-capacity", required_argument, NULL, 'c'           },
+               { "detach",       required_argument, NULL, 'd'           },
+               { "detach-all",   no_argument,       NULL, 'D'           },
+               { "find",         no_argument,       NULL, 'f'           },
+               { "nooverlap",    no_argument,       NULL, 'L'           },
+               { "help",         no_argument,       NULL, 'h'           },
+               { "associated",   required_argument, NULL, 'j'           },
+               { "json",         no_argument,       NULL, 'J'           },
+               { "list",         no_argument,       NULL, 'l'           },
+               { "sector-size",  required_argument, NULL, 'b'      },
+               { "noheadings",   no_argument,       NULL, 'n'           },
+               { "offset",       required_argument, NULL, 'o'           },
+               { "output",       required_argument, NULL, 'O'           },
+               { "output-all",   no_argument,       NULL, OPT_OUTPUT_ALL },
+               { "sizelimit",    required_argument, NULL, OPT_SIZELIMIT },
+               { "partscan",     no_argument,       NULL, 'P'           },
+               { "read-only",    no_argument,       NULL, 'r'           },
+               { "direct-io",    optional_argument, NULL, OPT_DIO       },
+               { "raw",          no_argument,       NULL, OPT_RAW       },
+               { "show",         no_argument,       NULL, OPT_SHOW      },
+               { "verbose",      no_argument,       NULL, 'v'           },
+               { "version",      no_argument,       NULL, 'V'           },
+               { NULL, 0, NULL, 0 }
        };
 
        static const ul_excl_t excl[] = {       /* rows and cols in ASCII order */
                { 'D','a','c','d','f','j' },
                { 'D','c','d','f','l' },
                { 'D','c','d','f','O' },
+               { 'J',OPT_RAW },
                { 0 }
        };
        int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT;
@@ -479,12 +642,12 @@ int main(int argc, char **argv)
        setlocale(LC_ALL, "");
        bindtextdomain(PACKAGE, LOCALEDIR);
        textdomain(PACKAGE);
-       atexit(close_stdout);
+       close_stdout_atexit();
 
        if (loopcxt_init(&lc, 0))
                err(EXIT_FAILURE, _("failed to initialize loopcxt"));
 
-       while ((c = getopt_long(argc, argv, "ac:d:Dfhj:lno:O:PrvV",
+       while ((c = getopt_long(argc, argv, "ab:c:d:Dfhj:JlLno:O:PrvV",
                                longopts, NULL)) != -1) {
 
                err_exclusive_options(c, longopts, excl, excl_st);
@@ -493,6 +656,10 @@ int main(int argc, char **argv)
                case 'a':
                        act = A_SHOW;
                        break;
+               case 'b':
+                       set_blocksize = 1;
+                       blocksize = strtosize_or_err(optarg, _("failed to parse logical block size"));
+                       break;
                case 'c':
                        act = A_SET_CAPACITY;
                        if (!is_loopdev(optarg) ||
@@ -516,8 +683,8 @@ int main(int argc, char **argv)
                case 'f':
                        act = A_FIND_FREE;
                        break;
-               case 'h':
-                       usage(stdout);
+               case 'J':
+                       json = 1;
                        break;
                case 'j':
                        act = A_SHOW;
@@ -526,6 +693,9 @@ int main(int argc, char **argv)
                case 'l':
                        list = 1;
                        break;
+               case 'L':
+                       no_overlap = 1;
+                       break;
                case 'n':
                        no_headings = 1;
                        break;
@@ -540,32 +710,51 @@ int main(int argc, char **argv)
                        outarg = optarg;
                        list = 1;
                        break;
+               case OPT_OUTPUT_ALL:
+                       for (ncolumns = 0; ncolumns < ARRAY_SIZE(infos); ncolumns++)
+                               columns[ncolumns] = ncolumns;
+                       break;
                case 'P':
                        lo_flags |= LO_FLAGS_PARTSCAN;
                        break;
                case OPT_SHOW:
                        showdev = 1;
                        break;
+               case OPT_DIO:
+                       use_dio = set_dio = 1;
+                       if (optarg)
+                               use_dio = parse_switch(optarg, _("argument error"), "on", "off", NULL);
+                       break;
                case 'v':
                        break;
-               case 'V':
-                       printf(UTIL_LINUX_VERSION);
-                       return EXIT_SUCCESS;
                case OPT_SIZELIMIT:                     /* --sizelimit */
                        sizelimit = strtosize_or_err(optarg, _("failed to parse size"));
                        flags |= LOOPDEV_FL_SIZELIMIT;
                         break;
+
+               case 'h':
+                       usage();
+               case 'V':
+                       print_version(EXIT_SUCCESS);
                default:
-                       usage(stderr);
+                       errtryhelp(EXIT_FAILURE);
                }
        }
 
+       ul_path_init_debug();
+       ul_sysfs_init_debug();
+
        /* default is --list --all */
        if (argc == 1) {
                act = A_SHOW;
                list = 1;
        }
 
+       if (!act && argc == 2 && (raw || json)) {
+               act = A_SHOW;
+               list = 1;
+       }
+
        /* default --list output columns */
        if (list && !ncolumns) {
                columns[ncolumns++] = COL_NAME;
@@ -574,6 +763,8 @@ int main(int argc, char **argv)
                columns[ncolumns++] = COL_AUTOCLR;
                columns[ncolumns++] = COL_RO;
                columns[ncolumns++] = COL_BACK_FILE;
+               columns[ncolumns++] = COL_DIO;
+               columns[ncolumns++] = COL_LOGSEC;
        }
 
        if (act == A_FIND_FREE && optind < argc) {
@@ -582,6 +773,9 @@ int main(int argc, char **argv)
                 */
                act = A_CREATE;
                file = argv[optind++];
+
+               if (optind < argc)
+                       errx(EXIT_FAILURE, _("unexpected arguments"));
        }
 
        if (list && !act && optind == argc)
@@ -593,8 +787,15 @@ int main(int argc, char **argv)
        if (!act && optind + 1 == argc) {
                /*
                 * losetup [--list] <device>
+                * OR
+                * losetup {--direct-io[=off]|--logical-blocksize=size}... <device>
                 */
-               act = A_SHOW_ONE;
+               if (!(set_dio || set_blocksize))
+                       act = A_SHOW_ONE;
+               if (set_dio)
+                       act = A_SET_DIRECT_IO;
+               if (set_blocksize)
+                       act = A_SET_BLOCKSIZE;
                if (!is_loopdev(argv[optind]) ||
                    loopcxt_set_device(&lc, argv[optind]))
                        err(EXIT_FAILURE, _("%s: failed to use device"),
@@ -624,7 +825,7 @@ int main(int argc, char **argv)
            (sizelimit || lo_flags || showdev))
                errx(EXIT_FAILURE,
                        _("the options %s are allowed during loop device setup only"),
-                       "--{sizelimit,read-only,show}");
+                       "--{sizelimit,partscan,read-only,show}");
 
        if ((flags & LOOPDEV_FL_OFFSET) &&
            act != A_CREATE && (act != A_SHOW || !file))
@@ -636,52 +837,16 @@ int main(int argc, char **argv)
 
        switch (act) {
        case A_CREATE:
-       {
-               int hasdev = loopcxt_has_device(&lc);
-
-               if (hasdev && !is_loopdev(loopcxt_get_device(&lc)))
-                       loopcxt_add_device(&lc);
-               do {
-                       const char *errpre;
-
-                       /* Note that loopcxt_{find_unused,set_device}() resets
-                        * loopcxt struct.
-                        */
-                       if (!hasdev && (res = loopcxt_find_unused(&lc))) {
-                               warnx(_("cannot find an unused loop device"));
-                               break;
-                       }
-                       if (flags & LOOPDEV_FL_OFFSET)
-                               loopcxt_set_offset(&lc, offset);
-                       if (flags & LOOPDEV_FL_SIZELIMIT)
-                               loopcxt_set_sizelimit(&lc, sizelimit);
-                       if (lo_flags)
-                               loopcxt_set_flags(&lc, lo_flags);
-                       if ((res = loopcxt_set_backing_file(&lc, file))) {
-                               warn(_("%s: failed to use backing file"), file);
-                               break;
-                       }
-                       errno = 0;
-                       res = loopcxt_setup_device(&lc);
-                       if (res == 0)
-                               break;                  /* success */
-                       if (errno == EBUSY && !hasdev)
-                               continue;
-
-                       /* errors */
-                       errpre = hasdev && loopcxt_get_fd(&lc) < 0 ?
-                                        loopcxt_get_device(&lc) : file;
-                       warn(_("%s: failed to set up loop device"), errpre);
-                       break;
-               } while (hasdev == 0);
-
+               res = create_loop(&lc, no_overlap, lo_flags, flags, file,
+                                 offset, sizelimit, blocksize);
                if (res == 0) {
                        if (showdev)
                                printf("%s\n", loopcxt_get_device(&lc));
-                       warn_size(file, sizelimit);
+                       warn_size(file, sizelimit, offset, flags);
+                       if (set_dio)
+                               goto lo_set_dio;
                }
                break;
-       }
        case A_DELETE:
                res = delete_loop(&lc);
                while (optind < argc) {
@@ -726,13 +891,27 @@ int main(int argc, char **argv)
                        warn("%s", loopcxt_get_device(&lc));
                break;
        case A_SET_CAPACITY:
-               res = loopcxt_set_capacity(&lc);
+               res = loopcxt_ioctl_capacity(&lc);
                if (res)
                        warn(_("%s: set capacity failed"),
                                loopcxt_get_device(&lc));
                break;
+       case A_SET_DIRECT_IO:
+lo_set_dio:
+               res = loopcxt_ioctl_dio(&lc, use_dio);
+               if (res)
+                       warn(_("%s: set direct io failed"),
+                               loopcxt_get_device(&lc));
+               break;
+       case A_SET_BLOCKSIZE:
+               res = loopcxt_ioctl_blocksize(&lc, blocksize);
+               if (res)
+                       warn(_("%s: set logical block size failed"),
+                               loopcxt_get_device(&lc));
+               break;
        default:
-               usage(stderr);
+               warnx(_("bad usage"));
+               errtryhelp(EXIT_FAILURE);
                break;
        }