int mnt_context_setup_loopdev(struct libmnt_context *cxt)
{
const char *backing_file, *optstr, *loopdev = NULL;
char *val = NULL, *loopval = NULL;
size_t len;
struct loopdev_cxt lc;
int rc = 0, lo_flags = 0;
uint64_t offset = 0, sizelimit = 0;
assert(cxt);
assert(cxt->fs);
assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
backing_file = mnt_fs_get_srcpath(cxt->fs);
if (!backing_file)
return -EINVAL;
DBG(LOOP, ul_debugobj(cxt, "trying to setup device for %s", backing_file));
if (cxt->mountflags & MS_RDONLY) {
DBG(LOOP, ul_debugobj(cxt, "enabling READ-ONLY flag"));
lo_flags |= LO_FLAGS_READ_ONLY;
}
optstr = mnt_fs_get_user_options(cxt->fs);
/*
* loop=
*/
if (rc == 0 && (cxt->user_mountflags & MNT_MS_LOOP) &&
mnt_optstr_get_option(optstr, "loop", &val, &len) == 0 && val) {
loopval = strndup(val, len);
rc = loopval ? 0 : -ENOMEM;
}
/*
* offset=
*/
if (rc == 0 && (cxt->user_mountflags & MNT_MS_OFFSET) &&
mnt_optstr_get_option(optstr, "offset", &val, &len) == 0) {
rc = mnt_parse_offset(val, len, &offset);
if (rc) {
DBG(LOOP, ul_debugobj(cxt, "failed to parse offset="));
rc = -MNT_ERR_MOUNTOPT;
}
}
/*
* sizelimit=
*/
if (rc == 0 && (cxt->user_mountflags & MNT_MS_SIZELIMIT) &&
mnt_optstr_get_option(optstr, "sizelimit", &val, &len) == 0) {
rc = mnt_parse_offset(val, len, &sizelimit);
if (rc) {
DBG(LOOP, ul_debugobj(cxt, "failed to parse sizelimit="));
rc = -MNT_ERR_MOUNTOPT;
}
}
/*
* encryption=
*/
if (rc == 0 && (cxt->user_mountflags & MNT_MS_ENCRYPTION) &&
mnt_optstr_get_option(optstr, "encryption", &val, &len) == 0) {
DBG(LOOP, ul_debugobj(cxt, "encryption no longer supported"));
rc = -MNT_ERR_MOUNTOPT;
}
if (rc == 0 && is_mounted_same_loopfile(cxt,
mnt_context_get_target(cxt),
backing_file, offset))
rc = -EBUSY;
if (rc)
goto done_no_deinit;
/* It is possible to mount the same file more times. If we set more
* than one loop device referring to the same file, kernel has no
* mechanism to detect it. To prevent data corruption, the same loop
* device has to be recycled.
*/
if (backing_file) {
rc = loopcxt_init(&lc, 0);
if (rc)
goto done_no_deinit;
rc = loopcxt_find_overlap(&lc, backing_file, offset, sizelimit);
switch (rc) {
case 0: /* not found */
DBG(LOOP, ul_debugobj(cxt, "not found overlaping loopdev"));
loopcxt_deinit(&lc);
break;
case 1: /* overlap */
DBG(LOOP, ul_debugobj(cxt, "overlaping %s detected",
loopcxt_get_device(&lc)));
rc = -MNT_ERR_LOOPOVERLAP;
goto done;
case 2: /* overlap -- full size and offset match (reuse) */
{
uint32_t lc_encrypt_type;
DBG(LOOP, ul_debugobj(cxt, "re-using existing loop device %s",
loopcxt_get_device(&lc)));
/* 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)) {
DBG(LOOP, ul_debugobj(cxt, "%s is read-only",
loopcxt_get_device(&lc)));
rc = -EROFS;
goto done;
}
/* 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) {
DBG(LOOP, ul_debugobj(cxt, "encryption no longer supported for device %s",
loopcxt_get_device(&lc)));
rc = -MNT_ERR_LOOPOVERLAP;
goto done;
}
rc = 0;
goto success;
}
default: /* error */
goto done;
}
}
DBG(LOOP, ul_debugobj(cxt, "not found; create a new loop device"));
rc = loopcxt_init(&lc, 0);
if (rc)
goto done_no_deinit;
if (loopval) {
rc = loopcxt_set_device(&lc, loopval);
if (rc == 0)
loopdev = loopcxt_get_device(&lc);
}
if (rc)
goto done;
/* since 2.6.37 we don't have to store backing filename to mtab
* because kernel provides the name in /sys.
*/
if (get_linux_version() >= KERNEL_VERSION(2, 6, 37) ||
!mnt_context_mtab_writable(cxt)) {
DBG(LOOP, ul_debugobj(cxt, "enabling AUTOCLEAR flag"));
lo_flags |= LO_FLAGS_AUTOCLEAR;
}
do {
/* found free device */
if (!loopdev) {
rc = loopcxt_find_unused(&lc);
if (rc)
goto done;
DBG(LOOP, ul_debugobj(cxt, "trying to use %s",
loopcxt_get_device(&lc)));
}
/* set device attributes
* -- note that loopcxt_find_unused() resets "lc"
*/
rc = loopcxt_set_backing_file(&lc, backing_file);
if (!rc && offset)
rc = loopcxt_set_offset(&lc, offset);
if (!rc && sizelimit)
rc = loopcxt_set_sizelimit(&lc, sizelimit);
if (!rc)
loopcxt_set_flags(&lc, lo_flags);
if (rc) {
DBG(LOOP, ul_debugobj(cxt, "failed to set loop attributes"));
goto done;
}
/* setup the device */
rc = loopcxt_setup_device(&lc);
if (!rc)
break; /* success */
if (loopdev || rc != -EBUSY) {
DBG(LOOP, ul_debugobj(cxt, "failed to setup device"));
rc = -MNT_ERR_LOOPDEV;
goto done;
}
DBG(LOOP, ul_debugobj(cxt, "device stolen...trying again"));
} while (1);
success:
if (!rc)
rc = mnt_fs_set_source(cxt->fs, loopcxt_get_device(&lc));
if (!rc) {
/* success */
cxt->flags |= MNT_FL_LOOPDEV_READY;
if ((cxt->user_mountflags & MNT_MS_LOOP) &&
loopcxt_is_autoclear(&lc)) {
/*
* autoclear flag accepted by the kernel, don't store
* the "loop=" option to mtab.
*/
DBG(LOOP, ul_debugobj(cxt, "removing unnecessary loop= from mtab"));
cxt->user_mountflags &= ~MNT_MS_LOOP;
mnt_optstr_remove_option(&cxt->fs->user_optstr, "loop");
}
if (!(cxt->mountflags & MS_RDONLY) &&
loopcxt_is_readonly(&lc))
/*
* mount planned read-write, but loopdev is read-only,
* let's fix mount options...
*/
mnt_context_set_mflags(cxt, cxt->mountflags | MS_RDONLY);
/* we have to keep the device open until mount(1),
* otherwise it will be auto-cleared by kernel
*/
cxt->loopdev_fd = loopcxt_get_fd(&lc);
if (cxt->loopdev_fd < 0) {
DBG(LOOP, ul_debugobj(cxt, "failed to get loopdev FD"));
rc = -errno;
} else
loopcxt_set_fd(&lc, -1, 0);
}
done:
loopcxt_deinit(&lc);
done_no_deinit:
free(loopval);
return rc;
}
int mnt_context_setup_loopdev(struct libmnt_context *cxt)
{
const char *backing_file, *optstr, *loopdev = NULL;
char *val = NULL;
size_t len;
struct loopdev_cxt lc;
int rc = 0, lo_flags = 0;
uint64_t offset = 0, sizelimit = 0;
assert(cxt->fs);
assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
if (!cxt)
return -EINVAL;
backing_file = mnt_fs_get_srcpath(cxt->fs);
if (!backing_file)
return -EINVAL;
DBG(CXT, ul_debugobj(cxt, "trying to setup loopdev for %s", backing_file));
if (cxt->mountflags & MS_RDONLY) {
DBG(CXT, ul_debugobj(cxt, "enabling READ-ONLY flag"));
lo_flags |= LO_FLAGS_READ_ONLY;
}
rc = loopcxt_init(&lc, 0);
if (rc)
return rc;
ON_DBG(CXT, loopcxt_enable_debug(&lc, 1));
optstr = mnt_fs_get_user_options(cxt->fs);
/*
* loop=
*/
if (rc == 0 && (cxt->user_mountflags & MNT_MS_LOOP) &&
mnt_optstr_get_option(optstr, "loop", &val, &len) == 0 && val) {
val = strndup(val, len);
rc = val ? loopcxt_set_device(&lc, val) : -ENOMEM;
free(val);
if (rc == 0)
loopdev = loopcxt_get_device(&lc);
}
/*
* offset=
*/
if (rc == 0 && (cxt->user_mountflags & MNT_MS_OFFSET) &&
mnt_optstr_get_option(optstr, "offset", &val, &len) == 0) {
rc = mnt_parse_offset(val, len, &offset);
if (rc) {
DBG(CXT, ul_debugobj(cxt, "failed to parse offset="));
rc = -MNT_ERR_MOUNTOPT;
}
}
/*
* sizelimit=
*/
if (rc == 0 && (cxt->user_mountflags & MNT_MS_SIZELIMIT) &&
mnt_optstr_get_option(optstr, "sizelimit", &val, &len) == 0) {
rc = mnt_parse_offset(val, len, &sizelimit);
if (rc) {
DBG(CXT, ul_debugobj(cxt, "failed to parse sizelimit="));
rc = -MNT_ERR_MOUNTOPT;
}
}
/*
* encryption=
*/
if (rc == 0 && (cxt->user_mountflags & MNT_MS_ENCRYPTION) &&
mnt_optstr_get_option(optstr, "encryption", &val, &len) == 0) {
DBG(CXT, ul_debugobj(cxt, "encryption no longer supported"));
rc = -MNT_ERR_MOUNTOPT;
}
if (rc == 0 && is_mounted_same_loopfile(cxt,
mnt_context_get_target(cxt),
backing_file, offset))
rc = -EBUSY;
if (rc)
goto done;
/* since 2.6.37 we don't have to store backing filename to mtab
* because kernel provides the name in /sys.
*/
if (get_linux_version() >= KERNEL_VERSION(2, 6, 37) ||
!mnt_context_mtab_writable(cxt)) {
DBG(CXT, ul_debugobj(cxt, "enabling AUTOCLEAR flag"));
lo_flags |= LO_FLAGS_AUTOCLEAR;
}
do {
/* found free device */
if (!loopdev) {
rc = loopcxt_find_unused(&lc);
if (rc)
goto done;
DBG(CXT, ul_debugobj(cxt, "trying to use %s",
loopcxt_get_device(&lc)));
}
/* set device attributes
* -- note that loopcxt_find_unused() resets "lc"
*/
rc = loopcxt_set_backing_file(&lc, backing_file);
if (!rc && offset)
rc = loopcxt_set_offset(&lc, offset);
if (!rc && sizelimit)
rc = loopcxt_set_sizelimit(&lc, sizelimit);
if (!rc)
loopcxt_set_flags(&lc, lo_flags);
if (rc) {
DBG(CXT, ul_debugobj(cxt, "failed to set loopdev attributes"));
goto done;
}
/* setup the device */
rc = loopcxt_setup_device(&lc);
if (!rc)
break; /* success */
if (loopdev || rc != -EBUSY) {
DBG(CXT, ul_debugobj(cxt, "failed to setup device"));
rc = -MNT_ERR_LOOPDEV;
goto done;
}
DBG(CXT, ul_debugobj(cxt, "loopdev stolen...trying again"));
} while (1);
if (!rc)
rc = mnt_fs_set_source(cxt->fs, loopcxt_get_device(&lc));
if (!rc) {
/* success */
cxt->flags |= MNT_FL_LOOPDEV_READY;
if ((cxt->user_mountflags & MNT_MS_LOOP) &&
loopcxt_is_autoclear(&lc)) {
/*
* autoclear flag accepted by the kernel, don't store
* the "loop=" option to mtab.
*/
cxt->user_mountflags &= ~MNT_MS_LOOP;
mnt_optstr_remove_option(&cxt->fs->user_optstr, "loop");
}
if (!(cxt->mountflags & MS_RDONLY) &&
loopcxt_is_readonly(&lc))
/*
* mount planned read-write, but loopdev is read-only,
* let's fix mount options...
*/
mnt_context_set_mflags(cxt, cxt->mountflags | MS_RDONLY);
/* we have to keep the device open until mount(1),
* otherwise it will be auto-cleared by kernel
*/
cxt->loopdev_fd = loopcxt_get_fd(&lc);
loopcxt_set_fd(&lc, -1, 0);
}
done:
loopcxt_deinit(&lc);
return rc;
}
int main(int argc, char **argv)
{
struct loopdev_cxt lc;
int act = 0, flags = 0, passfd = -1, c;
char *file = NULL, *encryption = NULL;
uint64_t offset = 0, sizelimit = 0;
int res = 0, showdev = 0, lo_flags = 0;
enum {
OPT_SIZELIMIT = CHAR_MAX + 1,
OPT_SHOW
};
static const struct option longopts[] = {
{ "all", 0, 0, 'a' },
{ "set-capacity", 1, 0, 'c' },
{ "detach", 1, 0, 'd' },
{ "detach-all", 0, 0, 'D' },
{ "encryption", 1, 0, 'e' },
{ "find", 0, 0, 'f' },
{ "help", 0, 0, 'h' },
{ "associated", 1, 0, 'j' },
{ "offset", 1, 0, 'o' },
{ "sizelimit", 1, 0, OPT_SIZELIMIT },
{ "pass-fd", 1, 0, 'p' },
{ "partscan", 0, 0, 'P' },
{ "read-only", 0, 0, 'r' },
{ "show", 0, 0, OPT_SHOW },
{ "verbose", 0, 0, 'v' },
{ "version", 0, 0, 'V' },
{ NULL, 0, 0, 0 }
};
setlocale(LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
atexit(close_stdout);
loopcxt_init(&lc, 0);
loopcxt_enable_debug(&lc, getenv("LOOPDEV_DEBUG") ? TRUE : FALSE);
while ((c = getopt_long(argc, argv, "ac:d:De:E:fhj:o:p:PrvV",
longopts, NULL)) != -1) {
if (act && strchr("acdDfj", c))
errx(EXIT_FAILURE,
_("the options %s are mutually exclusive"),
"--{all,associated,set-capacity,detach,detach-all,find}");
switch (c) {
case 'a':
act = A_SHOW;
break;
case 'c':
act = A_SET_CAPACITY;
loopcxt_set_device(&lc, optarg);
break;
case 'r':
lo_flags |= LO_FLAGS_READ_ONLY;
break;
case 'd':
act = A_DELETE;
loopcxt_set_device(&lc, optarg);
break;
case 'D':
act = A_DELETE_ALL;
break;
case 'E':
case 'e':
encryption = optarg;
break;
case 'f':
act = A_FIND_FREE;
break;
case 'h':
usage(stdout);
break;
case 'j':
act = A_SHOW;
file = optarg;
break;
case 'o':
offset = strtosize_or_err(optarg, _("failed to parse offset"));
flags |= LOOPDEV_FL_OFFSET;
break;
case 'p':
passfd = strtou32_or_err(optarg,
_("invalid passphrase file descriptor"));
break;
case 'P':
lo_flags |= LO_FLAGS_PARTSCAN;
break;
case OPT_SHOW:
showdev = 1;
break;
case 'v':
verbose = 1;
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;
default:
usage(stderr);
}
}
if (argc == 1)
usage(stderr);
if (act == A_FIND_FREE && optind < argc) {
/*
* losetup -f <backing_file>
*/
act = A_CREATE;
file = argv[optind++];
}
if (!act && optind + 1 == argc) {
/*
* losetup <device>
*/
act = A_SHOW_ONE;
loopcxt_set_device(&lc, argv[optind++]);
}
if (!act) {
/*
* losetup <loopdev> <backing_file>
*/
act = A_CREATE;
if (optind >= argc)
errx(EXIT_FAILURE, _("no loop device specified"));
loopcxt_set_device(&lc, argv[optind++]);
if (optind >= argc)
errx(EXIT_FAILURE, _("no file specified"));
file = argv[optind++];
}
if (act != A_CREATE &&
(encryption || sizelimit || passfd != -1 || lo_flags || showdev))
errx(EXIT_FAILURE,
_("the options %s are allowed to loop device setup only"),
"--{encryption,sizelimit,pass-fd,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."));
switch (act) {
case A_CREATE:
{
char *pass = NULL;
int hasdev = loopcxt_has_device(&lc);
if (encryption) {
#ifdef MCL_FUTURE
if(mlockall(MCL_CURRENT | MCL_FUTURE))
err(EXIT_FAILURE, _("couldn't lock into memory"));
#endif
pass = xgetpass(passfd, _("Password: "******"not found unused device"));
break;
}
if (encryption && pass)
loopcxt_set_encryption(&lc, encryption, pass);
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) {
warn(_("%s: failed to setup loop device"),
hasdev && loopcxt_get_fd(&lc) < 0 ?
loopcxt_get_device(&lc) : file);
break;
}
} while (hasdev == 0);
free(pass);
if (showdev && res == 0)
printf("%s\n", loopcxt_get_device(&lc));
break;
}
case A_DELETE:
res = delete_loop(&lc);
while (optind < argc) {
loopcxt_set_device(&lc, argv[optind++]);
res += delete_loop(&lc);
}
break;
case A_DELETE_ALL:
res = delete_all_loops(&lc);
break;
case A_FIND_FREE:
if (loopcxt_find_unused(&lc))
warn(_("find unused loop device failed"));
else
printf("%s\n", loopcxt_get_device(&lc));
break;
case A_SHOW:
res = show_all_loops(&lc, file, offset, flags);
break;
case A_SHOW_ONE:
res = printf_loopdev(&lc);
if (res)
warn(_("%s"), loopcxt_get_device(&lc));
break;
case A_SET_CAPACITY:
res = set_capacity(&lc);
break;
default:
usage(stderr);
break;
}
loopcxt_deinit(&lc);
return res ? EXIT_FAILURE : EXIT_SUCCESS;
}
int main(int argc, char **argv)
{
struct loopdev_cxt lc;
int act = 0, flags = 0, c;
char *file = NULL;
uint64_t offset = 0, sizelimit = 0;
int res = 0, showdev = 0, lo_flags = 0;
enum {
OPT_SIZELIMIT = CHAR_MAX + 1,
OPT_SHOW
};
static const struct option longopts[] = {
{ "all", 0, 0, 'a' },
{ "set-capacity", 1, 0, 'c' },
{ "detach", 1, 0, 'd' },
{ "detach-all", 0, 0, 'D' },
{ "encryption", 1, 0, 'e' },
{ "find", 0, 0, 'f' },
{ "help", 0, 0, 'h' },
{ "associated", 1, 0, 'j' },
{ "offset", 1, 0, 'o' },
{ "sizelimit", 1, 0, OPT_SIZELIMIT },
{ "pass-fd", 1, 0, 'p' },
{ "partscan", 0, 0, 'P' },
{ "read-only", 0, 0, 'r' },
{ "show", 0, 0, OPT_SHOW },
{ "verbose", 0, 0, 'v' },
{ "version", 0, 0, 'V' },
{ NULL, 0, 0, 0 }
};
static const ul_excl_t excl[] = { /* rows and cols in ASCII order */
{ 'D','a','c','d','f','j' },
{ 0 }
};
int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT;
setlocale(LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
atexit(close_stdout);
if (loopcxt_init(&lc, 0))
err(EXIT_FAILURE, _("failed to initialize loopcxt"));
while ((c = getopt_long(argc, argv, "ac:d:De:E:fhj:o:p:PrvV",
longopts, NULL)) != -1) {
err_exclusive_options(c, longopts, excl, excl_st);
switch (c) {
case 'a':
act = A_SHOW;
break;
case 'c':
act = A_SET_CAPACITY;
if (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 (loopcxt_set_device(&lc, optarg))
err(EXIT_FAILURE, _("%s: failed to use device"),
optarg);
break;
case 'D':
act = A_DELETE_ALL;
break;
case 'E':
case 'e':
errx(EXIT_FAILURE, _("encryption not supported, use cryptsetup(8) instead"));
break;
case 'f':
act = A_FIND_FREE;
break;
case 'h':
usage(stdout);
break;
case 'j':
act = A_SHOW;
file = optarg;
break;
case 'o':
offset = strtosize_or_err(optarg, _("failed to parse offset"));
flags |= LOOPDEV_FL_OFFSET;
break;
case 'p':
warn(_("--pass-fd is no longer supported"));
break;
case 'P':
lo_flags |= LO_FLAGS_PARTSCAN;
break;
case OPT_SHOW:
showdev = 1;
break;
case 'v':
verbose = 1;
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;
default:
usage(stderr);
}
}
if (argc == 1)
usage(stderr);
if (act == A_FIND_FREE && optind < argc) {
/*
* losetup -f <backing_file>
*/
act = A_CREATE;
file = argv[optind++];
}
if (!act && optind + 1 == argc) {
/*
* losetup <device>
*/
act = A_SHOW_ONE;
if (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"));
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 to loop device setup only"),
"--{sizelimit,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."));
switch (act) {
case A_CREATE:
{
int hasdev = loopcxt_has_device(&lc);
do {
/* Note that loopcxt_{find_unused,set_device}() resets
* loopcxt struct.
*/
if (!hasdev && (res = loopcxt_find_unused(&lc))) {
warnx(_("not found unused 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) {
warn(_("%s: failed to setup loop device"),
hasdev && loopcxt_get_fd(&lc) < 0 ?
loopcxt_get_device(&lc) : file);
break;
}
} while (hasdev == 0);
if (res == 0) {
if (showdev)
printf("%s\n", loopcxt_get_device(&lc));
warn_size(file, sizelimit);
}
break;
}
case A_DELETE:
res = delete_loop(&lc);
while (optind < argc) {
if (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:
if (loopcxt_find_unused(&lc))
warn(_("find unused loop device failed"));
else
printf("%s\n", loopcxt_get_device(&lc));
break;
case A_SHOW:
res = show_all_loops(&lc, file, offset, flags);
break;
case A_SHOW_ONE:
res = printf_loopdev(&lc);
if (res)
warn(_("%s"), loopcxt_get_device(&lc));
break;
case A_SET_CAPACITY:
res = set_capacity(&lc);
break;
default:
usage(stderr);
break;
}
loopcxt_deinit(&lc);
return res ? EXIT_FAILURE : EXIT_SUCCESS;
}