/*
* Copyright (C) 2011 Karel Zak <kzak@redhat.com>
* Originally from Ted's losetup.c
*
* losetup.c - setup and control loop devices
*/
#include <assert.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <inttypes.h>
#include <getopt.h>
#include <libsmartcols.h>
#include "c.h"
#include "nls.h"
#include "strutils.h"
#include "loopdev.h"
#include "closestream.h"
#include "optutils.h"
#include "xalloc.h"
#include "canonicalize.h"
#include "pathnames.h"
enum {
A_CREATE = 1, /* setup a new device */
A_DELETE, /* delete given device(s) */
A_DELETE_ALL, /* delete all devices */
A_SHOW, /* list devices */
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 {
COL_NAME = 0,
COL_AUTOCLR,
COL_BACK_FILE,
COL_BACK_INO,
COL_BACK_MAJMIN,
COL_MAJMIN,
COL_OFFSET,
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"), 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"), 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"), 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};
static size_t ncolumns;
static int get_column_id(int num)
{
assert(num >= 0);
assert((size_t) num < ncolumns);
assert(columns[num] < (int) ARRAY_SIZE(infos));
return columns[num];
}
static struct colinfo *get_column_info(int num)
{
return &infos[ get_column_id(num) ];
}
static int column_name_to_id(const char *name, size_t namesz)
{
size_t i;
for (i = 0; i < ARRAY_SIZE(infos); i++) {
const char *cn = infos[i].name;
if (!strncasecmp(name, cn, namesz) && !*(cn + namesz))
return i;
}
warnx(_("unknown column: %s"), name);
return -1;
}
static int printf_loopdev(struct loopdev_cxt *lc)
{
uint64_t x;
dev_t dev = 0;
ino_t ino = 0;
char *fname;
uint32_t type;
fname = loopcxt_get_backing_file(lc);
if (!fname)
return -EINVAL;
if (loopcxt_get_backing_devno(lc, &dev) == 0)
loopcxt_get_backing_inode(lc, &ino);
if (!dev && !ino) {
/*
* Probably non-root user (no permissions to
* call LOOP_GET_STATUS ioctls).
*/
printf("%s: []: (%s)",
loopcxt_get_device(lc), fname);
if (loopcxt_get_offset(lc, &x) == 0 && x)
printf(_(", offset %ju"), x);
if (loopcxt_get_sizelimit(lc, &x) == 0 && x)
printf(_(", sizelimit %ju"), x);
goto done;
}
printf("%s: [%04d]:%" PRIu64 " (%s)",
loopcxt_get_device(lc), (int) dev, ino, fname);
if (loopcxt_get_offset(lc, &x) == 0 && x)
printf(_(", offset %ju"), x);
if (loopcxt_get_sizelimit(lc, &x) == 0 && x)
printf(_(", sizelimit %ju"), x);
if (loopcxt_get_encrypt_type(lc, &type) == 0) {
const char *e = loopcxt_get_crypt_name(lc);
if ((!e || !*e) && type == 1)
e = "XOR";
if (e && *e)
printf(_(", encryption %s (type %u)"), e, type);
}
done:
free(fname);
printf("\n");
return 0;
}
static int show_all_loops(struct loopdev_cxt *lc, const char *file,
uint64_t offset, int flags)
{
struct stat sbuf, *st = &sbuf;
char *cn_file = NULL;
if (loopcxt_init_iterator(lc, LOOPITER_FL_USED))
return -1;
if (!file || stat(file, st))
st = NULL;
while (loopcxt_next(lc) == 0) {
if (file) {
int used;
const char *bf = cn_file ? cn_file : file;
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, 0, flags);
}
if (!used)
continue;
}
printf_loopdev(lc);
}
loopcxt_deinit_iterator(lc);
free(cn_file);
return 0;
}
static int delete_loop(struct loopdev_cxt *lc)
{
if (loopcxt_delete_device(lc))
warn(_("%s: detach failed"), loopcxt_get_device(lc));
else
return 0;
return -1;
}
static int delete_all_loops(struct loopdev_cxt *lc)
{
int res = 0;
if (loopcxt_init_iterator(lc, LOOPITER_FL_USED))
return -1;
while (loopcxt_next(lc) == 0)
res += delete_loop(lc);
loopcxt_deinit_iterator(lc);
return res;
}
static int set_scols_data(struct loopdev_cxt *lc, struct libscols_line *ln)
{
size_t i;
for (i = 0; i < ncolumns; i++) {
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:
p = loopcxt_get_device(lc);
break;
case COL_BACK_FILE:
p = loopcxt_get_backing_file(lc);
break;
case COL_OFFSET:
if (loopcxt_get_offset(lc, &x) == 0)
xasprintf(&np, "%jd", x);
break;
case COL_SIZELIMIT:
if (loopcxt_get_sizelimit(lc, &x) == 0)
xasprintf(&np, "%jd", x);
break;
case COL_BACK_MAJMIN:
{
dev_t dev = 0;
if (loopcxt_get_backing_devno(lc, &dev) == 0 && dev)
xasprintf(&np, "%8u:%-3u", major(dev), minor(dev));
break;
}
case COL_MAJMIN:
{
struct stat st;
if (loopcxt_get_device(lc)
&& stat(loopcxt_get_device(lc), &st) == 0
&& S_ISBLK(st.st_mode)
&& major(st.st_rdev) == LOOPDEV_MAJOR)
xasprintf(&np, "%3u:%-3u", major(st.st_rdev),
minor(st.st_rdev));
break;
}
case COL_BACK_INO:
{
ino_t ino = 0;
if (loopcxt_get_backing_inode(lc, &ino) == 0 && ino)
xasprintf(&np, "%ju", ino);
break;
}
case COL_AUTOCLR:
p = loopcxt_is_autoclear(lc) ? "1" : "0";
break;
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)
rc = scols_line_set_data(ln, i, p); /* calls strdup() */
else if (np)
rc = scols_line_refer_data(ln, i, np); /* only refers */
if (rc)
err(EXIT_FAILURE, _("failed to add output data"));
}
return 0;
}
static int show_table(struct loopdev_cxt *lc,
const char *file,
uint64_t offset,
int flags)
{
struct stat sbuf, *st = &sbuf;
struct libscols_table *tb;
struct libscols_line *ln;
int rc = 0;
size_t i;
scols_init_debug(0);
if (!(tb = scols_new_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;
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 allocate output line"));
rc = set_scols_data(lc, ln);
/* list all loopdevs */
} else {
char *cn_file = NULL;
rc = loopcxt_init_iterator(lc, LOOPITER_FL_USED);
if (rc)
goto done;
if (!file || stat(file, st))
st = NULL;
while (loopcxt_next(lc) == 0) {
if (file) {
int used;
const char *bf = cn_file ? cn_file : file;
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, 0, flags);
}
if (!used)
continue;
}
ln = scols_table_new_line(tb, NULL);
if (!ln)
err(EXIT_FAILURE, _("failed to allocate output line"));
rc = set_scols_data(lc, ln);
if (rc)
break;
}
loopcxt_deinit_iterator(lc);
free(cn_file);
}
done:
if (rc == 0)
rc = scols_print_table(tb);
scols_unref_table(tb);
return rc;
}
static void __attribute__((__noreturn__)) usage(void)
{
FILE *out = stdout;
size_t i;
fputs(USAGE_HEADER, out);
fprintf(out,
_(" %1$s [options] [<loopdev>]\n"
" %1$s [options] -f | <loopdev> <file>\n"),
program_invocation_short_name);
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);
fputs(_(" -D, --detach-all detach all used devices\n"), 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(_(" -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);
printf(USAGE_HELP_OPTIONS(31));
fputs(USAGE_COLUMNS, out);
for (i = 0; i < ARRAY_SIZE(infos); i++)
fprintf(out, " %12s %s\n", infos[i].name, _(infos[i].help));
printf(USAGE_MAN_TAIL("losetup(8)"));
exit(EXIT_SUCCESS);
}
static void warn_size(const char *filename, uint64_t size, uint64_t offset, int flags)
{
struct stat st;
if (!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)
warnx(_("%s: Warning: file is smaller than 512 bytes; the loop device "
"may be useless or invisible for system tools."),
filename);
else if (size % 512)
warnx(_("%s: Warning: file does not fit into a 512-byte sector; "
"the end of the file will be ignored."),
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, no_overlap = 0, c;
char *file = NULL;
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_DIO,
OPT_OUTPUT_ALL
};
static const struct option longopts[] = {
{ "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;
setlocale(LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
close_stdout_atexit();
if (loopcxt_init(&lc, 0))
err(EXIT_FAILURE, _("failed to initialize loopcxt"));
while ((c = getopt_long(argc, argv, "ab:c:d:Dfhj:JlLno:O:PrvV",
longopts, NULL)) != -1) {
err_exclusive_options(c, longopts, excl, excl_st);
switch (c) {
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) ||
loopcxt_set_device(&lc, optarg))
err(EXIT_FAILURE, _("%s: failed to use device"),
optarg);
break;
case 'r':
lo_flags |= LO_FLAGS_READ_ONLY;
break;
case 'd':
act = A_DELETE;
if (!is_loopdev(optarg) ||
loopcxt_set_device(&lc, optarg))
err(EXIT_FAILURE, _("%s: failed to use device"),
optarg);
break;
case 'D':
act = A_DELETE_ALL;
break;
case 'f':
act = A_FIND_FREE;
break;
case 'J':
json = 1;
break;
case 'j':
act = A_SHOW;
file = optarg;
break;
case 'l':
list = 1;
break;
case 'L':
no_overlap = 1;
break;
case 'n':
no_headings = 1;
break;
case OPT_RAW:
raw = 1;
break;
case 'o':
offset = strtosize_or_err(optarg, _("failed to parse offset"));
flags |= LOOPDEV_FL_OFFSET;
break;
case 'O':
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 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:
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;
columns[ncolumns++] = COL_SIZELIMIT;
columns[ncolumns++] = COL_OFFSET;
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) {
/*
* losetup -f <backing_file>
*/
act = A_CREATE;
file = argv[optind++];
if (optind < argc)
errx(EXIT_FAILURE, _("unexpected arguments"));
}
if (list && !act && optind == argc)
/*
* losetup --list defaults to --all
*/
act = A_SHOW;
if (!act && optind + 1 == argc) {
/*
* losetup [--list] <device>
* OR
* losetup {--direct-io[=off]|--logical-blocksize=size}... <device>
*/
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"),
argv[optind]);
optind++;
}
if (!act) {
/*
* losetup <loopdev> <backing_file>
*/
act = A_CREATE;
if (optind >= argc)
errx(EXIT_FAILURE, _("no loop device specified"));
/* don't use is_loopdev() here, the device does not have exist yet */
if (loopcxt_set_device(&lc, argv[optind]))
err(EXIT_FAILURE, _("%s: failed to use device"),
argv[optind]);
optind++;
if (optind >= argc)
errx(EXIT_FAILURE, _("no file specified"));
file = argv[optind++];
}
if (act != A_CREATE &&
(sizelimit || lo_flags || showdev))
errx(EXIT_FAILURE,
_("the options %s are allowed during loop device setup only"),
"--{sizelimit,partscan,read-only,show}");
if ((flags & LOOPDEV_FL_OFFSET) &&
act != A_CREATE && (act != A_SHOW || !file))
errx(EXIT_FAILURE, _("the option --offset is not allowed in this context"));
if (outarg && string_add_to_idarray(outarg, columns, ARRAY_SIZE(columns),
&ncolumns, column_name_to_id) < 0)
return EXIT_FAILURE;
switch (act) {
case A_CREATE:
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, offset, flags);
if (set_dio)
goto lo_set_dio;
}
break;
case A_DELETE:
res = delete_loop(&lc);
while (optind < argc) {
if (!is_loopdev(argv[optind]) ||
loopcxt_set_device(&lc, argv[optind]))
warn(_("%s: failed to use device"),
argv[optind]);
optind++;
res += delete_loop(&lc);
}
break;
case A_DELETE_ALL:
res = delete_all_loops(&lc);
break;
case A_FIND_FREE:
res = loopcxt_find_unused(&lc);
if (res) {
int errsv = errno;
if (access(_PATH_DEV_LOOPCTL, F_OK) == 0 &&
access(_PATH_DEV_LOOPCTL, W_OK) != 0)
;
else
errno = errsv;
warn(_("cannot find an unused loop device"));
} else
printf("%s\n", loopcxt_get_device(&lc));
break;
case A_SHOW:
if (list)
res = show_table(&lc, file, offset, flags);
else
res = show_all_loops(&lc, file, offset, flags);
break;
case A_SHOW_ONE:
if (list)
res = show_table(&lc, NULL, 0, 0);
else
res = printf_loopdev(&lc);
if (res)
warn("%s", loopcxt_get_device(&lc));
break;
case A_SET_CAPACITY:
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:
warnx(_("bad usage"));
errtryhelp(EXIT_FAILURE);
break;
}
loopcxt_deinit(&lc);
return res ? EXIT_FAILURE : EXIT_SUCCESS;
}