*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
+//config:config LOSETUP
+//config: bool "losetup (5.4 kb)"
+//config: default y
+//config: select PLATFORM_LINUX
+//config: help
+//config: losetup is used to associate or detach a loop device with a regular
+//config: file or block device, and to query the status of a loop device. This
+//config: version does not currently support enabling data encryption.
+
+//applet:IF_LOSETUP(APPLET_NOEXEC(losetup, losetup, BB_DIR_SBIN, BB_SUID_DROP, losetup))
+
+//kbuild:lib-$(CONFIG_LOSETUP) += losetup.o
//usage:#define losetup_trivial_usage
//usage: "[-r] [-o OFS] {-f|LOOPDEV} FILE - associate loop devices\n"
OPT_r = (1 << 4), /* must be last */
};
- opt_complementary = "?2:d--ofar:a--ofr";
- opt = getopt32(argv, "do:far", &opt_o);
+ opt = getopt32(argv, "^" "do:far" "\0" "?2:d--ofar:a--ofr", &opt_o);
argv += optind;
/* LOOPDEV */
d = *argv++;
if (argv[0]) {
- if (set_loop(&d, argv[0], offset, (opt & OPT_r)) < 0)
+ if (set_loop(&d, argv[0], offset, (opt & OPT_r) ? BB_LO_FLAGS_READ_ONLY : 0) < 0)
bb_simple_perror_msg_and_die(argv[0]);
return EXIT_SUCCESS;
}
}
+ /* TODO: util-linux 2.28 shows this when run w/o params:
+ * NAME SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE DIO
+ * /dev/loop0 0 0 1 0 /PATH/TO/FILE 0
+ *
+ * implemented by reading /sys:
+ *
+ * open("/sys/block", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 3
+ * newfstatat(3, "loop0/loop/backing_file", {st_mode=S_IFREG|0444, st_size=4096, ...}, 0) = 0
+ * stat("/dev/loop0", {st_mode=S_IFBLK|0660, st_rdev=makedev(7, 0), ...}) = 0
+ * open("/sys/dev/block/7:0/loop/offset", O_RDONLY|O_CLOEXEC) = 5
+ * read(5, "0\n", 4096) = 2
+ * open("/sys/dev/block/7:0/loop/sizelimit", O_RDONLY|O_CLOEXEC) = 5
+ * read(5, "0\n", 4096) = 2
+ * open("/sys/dev/block/7:0/loop/offset", O_RDONLY|O_CLOEXEC) = 5
+ * read(5, "0\n", 4096) = 2
+ * open("/sys/dev/block/7:0/loop/autoclear", O_RDONLY|O_CLOEXEC) = 5
+ * read(5, "1\n", 4096) = 2
+ * open("/sys/dev/block/7:0/ro", O_RDONLY|O_CLOEXEC) = 5
+ * read(5, "0\n", 4096) = 2
+ * open("/sys/dev/block/7:0/loop/backing_file", O_RDONLY|O_CLOEXEC) = 5
+ * read(5, "/PATH/TO/FILE", 4096) = 37
+ * open("/sys/dev/block/7:0/loop/dio", O_RDONLY|O_CLOEXEC) = 5
+ * read(5, "0\n", 4096) = 2
+ */
+
bb_show_usage(); /* does not return */
/*return EXIT_FAILURE;*/
}