Adding upstream version 2.36.1.upstream/2.36.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 925 insertions, 0 deletions

diff --git a/sys-utils/losetup.c b/sys-utils/losetup.c
new file mode 100644
index 0000000..7aadc9f
--- /dev/null
+++ b/sys-utils/losetup.c
@@ -0,0 +1,925 @@
+/*
+ * 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, ntries = 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 && ntries < 64) {
+			xusleep(200000);
+			ntries++;
+			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;
+}
+