2 files changed, 23 insertions, 18 deletions

diff --git a/include/libbb.h b/include/libbb.h
index b5d1156ae..65c6b9f39 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -1803,7 +1803,7 @@ extern const char bb_default_login_shell[] ALIGN1;
 # define VC_4 "/dev/vc/4"
 # define VC_5 "/dev/vc/5"
 # define VC_FORMAT "/dev/vc/%d"
-# define LOOP_FORMAT "/dev/loop/%d"
+# define LOOP_FORMAT "/dev/loop/%u"
 # define LOOP_NAMESIZE (sizeof("/dev/loop/") + sizeof(int)*3 + 1)
 # define LOOP_NAME "/dev/loop/"
 # define FB_0 "/dev/fb/0"
@@ -1816,7 +1816,7 @@ extern const char bb_default_login_shell[] ALIGN1;
 # define VC_4 "/dev/tty4"
 # define VC_5 "/dev/tty5"
 # define VC_FORMAT "/dev/tty%d"
-# define LOOP_FORMAT "/dev/loop%d"
+# define LOOP_FORMAT "/dev/loop%u"
 # define LOOP_NAMESIZE (sizeof("/dev/loop") + sizeof(int)*3 + 1)
 # define LOOP_NAME "/dev/loop"
 # define FB_0 "/dev/fb0"
diff --git a/util-linux/losetup.c b/util-linux/losetup.c
index c69763335..d450b5a78 100644
--- a/util-linux/losetup.c
+++ b/util-linux/losetup.c
@@ -10,12 +10,12 @@
 //usage:#define losetup_trivial_usage
 //usage:       "[-r] [-o OFS] {-f|LOOPDEV} FILE - associate loop devices\n"
 //usage:       "        losetup -d LOOPDEV - disassociate\n"
-//usage:       "        losetup -a - show status of  all\n"
-//usage:       "        losetup -f - show next available"
+//usage:       "        losetup -a - show status\n"
+//usage:       "        losetup -f - show next free loop device"
 //usage:#define losetup_full_usage "\n\n"
 //usage:       "        -o OFS  Start OFS bytes into FILE"
 //usage:     "\n        -r      Read-only"
-//usage:     "\n        -f      Show/find first free loop device"
+//usage:     "\n        -f      Show/use next free loop device"
 //usage:
 //usage:#define losetup_notes_usage
 //usage:       "One argument (losetup /dev/loop1) will display the current association\n"
@@ -27,6 +27,10 @@
 
 #include "libbb.h"
 
+/* 1048575 is a max possible minor number in Linux circa 2010 */
+/* for now use something less extreme */
+#define MAX_LOOP_NUM 1023
+
 int losetup_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int losetup_main(int argc UNUSED_PARAM, char **argv)
 {
@@ -59,7 +63,7 @@ int losetup_main(int argc UNUSED_PARAM, char **argv)
         }
 
         /* -d LOOPDEV */
-        if (opt == OPT_d) {
+        if (opt == OPT_d && argv[0]) {
                 if (del_loop(argv[0]))
                         bb_simple_perror_msg_and_die(argv[0]);
                 return EXIT_SUCCESS;
@@ -68,15 +72,14 @@ int losetup_main(int argc UNUSED_PARAM, char **argv)
         /* -a */
         if (opt == OPT_a) {
                 int n;
-                for (n = 0; n < 10; n++) {
+                for (n = 0; n < MAX_LOOP_NUM; n++) {
                         char *s;
 
                         sprintf(dev, LOOP_FORMAT, n);
                         s = query_loop(dev);
                         if (s) {
                                 printf("%s: %s\n", dev, s);
-                                if (ENABLE_FEATURE_CLEAN_UP)
-                                        free(s);
+                                free(s);
                         }
                 }
                 return EXIT_SUCCESS;
@@ -88,11 +91,13 @@ int losetup_main(int argc UNUSED_PARAM, char **argv)
                 int n = 0;
 
                 do {
-                        sprintf(dev, LOOP_FORMAT, n);
+                        if (n > MAX_LOOP_NUM)
+                                bb_error_msg_and_die("no free loop devices");
+                        sprintf(dev, LOOP_FORMAT, n++);
                         s = query_loop(dev);
-                        if (s && ENABLE_FEATURE_CLEAN_UP)
-                                free(s);
+                        free(s);
                 } while (s);
+                /* now: dev is next free "/dev/loopN" */
                 if ((opt == OPT_f) && !argv[0]) {
                         puts(dev);
                         return EXIT_SUCCESS;
@@ -104,18 +109,18 @@ int losetup_main(int argc UNUSED_PARAM, char **argv)
                 unsigned long long offset = 0;
                 char *d = dev;
 
-                if (opt == OPT_o)
+                if (opt & OPT_o)
                         offset = xatoull(opt_o);
-                if (opt != OPT_f)
-                        d = *(argv++);
+                if (!(opt & OPT_f))
+                        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)) < 0)
                                 bb_simple_perror_msg_and_die(argv[0]);
                         return EXIT_SUCCESS;
                 }
         }
 
-        bb_show_usage();
-        return EXIT_FAILURE;
+        bb_show_usage(); /* does not return */
+        /*return EXIT_FAILURE;*/
 }