Changeset 3621 in MondoRescue for branches/3.3/mindi-busybox/util-linux/losetup.c

Timestamp:

Dec 20, 2016, 4:07:32 PM (7 years ago)

Author:

Bruno Cornec

Message:

New 3?3 banch for incorporation of latest busybox 1.25. Changing minor version to handle potential incompatibilities.

Location:

branches/3.3

Files:

• . (copied) (copied from branches/3.2 )
• mindi-busybox/util-linux/losetup.c (modified) (3 diffs)

branches/3.3/mindi-busybox/util-linux/losetup.c

@@ -9 +9 @@
 
 //usage:#define losetup_trivial_usage
-//usage:       "[-r] [-o OFS] LOOPDEV FILE - associate loop devices\n"
+//usage:       "[-r] [-o OFS] {-f|LOOPDEV} FILE - associate loop devices\n"
 //usage:       "    losetup -d LOOPDEV - disassociate\n"
-//usage:       "    losetup [-f] - show"
+//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 first free loop device"
+//usage:     "\n    -f  Show/use next free loop device"
 //usage:
 //usage:#define losetup_notes_usage
-//usage:       "No arguments will display all current associations.\n"
 //usage:       "One argument (losetup /dev/loop1) will display the current association\n"
 //usage:       "(if any), or disassociate it (with -d). The display shows the offset\n"
@@ -28 +28 @@
 #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)
 {
     unsigned opt;
-    int n;
     char *opt_o;
-    unsigned long long offset = 0;
+    char dev[LOOP_NAMESIZE];
     enum {
         OPT_d = (1 << 0),
         OPT_o = (1 << 1),
         OPT_f = (1 << 2),
-        OPT_r = (1 << 3), /* must be last */
+        OPT_a = (1 << 3),
+        OPT_r = (1 << 4), /* must be last */
     };
 
-    /* max 2 args, -d,-o,-f opts are mutually exclusive */
-    opt_complementary = "?2:d--of:o--df:f--do";
-    opt = getopt32(argv, "do:fr", &opt_o);
+    opt_complementary = "?2:d--ofar:a--ofr";
+    opt = getopt32(argv, "do:far", &opt_o);
     argv += optind;
 
-    if (opt == OPT_o)
-        offset = xatoull(opt_o);
-
-    if (opt == OPT_d) {
-        /* -d BLOCKDEV */
-        if (!argv[0] || argv[1])
-            bb_show_usage();
-        if (del_loop(argv[0]))
-            bb_simple_perror_msg_and_die(argv[0]);
-        return EXIT_SUCCESS;
-    }
-
-    if (argv[0]) {
+    /* LOOPDEV */
+    if (!opt && argv[0] && !argv[1]) {
         char *s;
 
-        if (opt == OPT_f) /* -f should not have arguments */
-            bb_show_usage();
-
-        if (argv[1]) {
-            /* [-r] [-o OFS] BLOCKDEV FILE */
-            if (set_loop(&argv[0], argv[1], offset, (opt / OPT_r)) < 0)
-                bb_simple_perror_msg_and_die(argv[0]);
-            return EXIT_SUCCESS;
-        }
-        /* [-r] [-o OFS] BLOCKDEV */
         s = query_loop(argv[0]);
         if (!s)
@@ -81 +63 @@
     }
 
-    /* [-r] [-o OFS|-f] with no params */
-    n = 0;
-    while (1) {
+    /* -d LOOPDEV */
+    if (opt == OPT_d && argv[0]) {
+        if (del_loop(argv[0]))
+            bb_simple_perror_msg_and_die(argv[0]);
+        return EXIT_SUCCESS;
+    }
+
+    /* -a */
+    if (opt == OPT_a) {
+        int 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);
+                free(s);
+            }
+        }
+        return EXIT_SUCCESS;
+    }
+
+    /* contains -f */
+    if (opt & OPT_f) {
         char *s;
-        char dev[LOOP_NAMESIZE];
+        int n = 0;
 
-        sprintf(dev, LOOP_FORMAT, n);
-        s = query_loop(dev);
-        n++;
-        if (!s) {
-            if (n > 9 && errno && errno != ENXIO)
-                return EXIT_SUCCESS;
-            if (opt == OPT_f) {
-                puts(dev);
-                return EXIT_SUCCESS;
-            }
-        } else {
-            if (opt != OPT_f)
-                printf("%s: %s\n", dev, s);
-            if (ENABLE_FEATURE_CLEAN_UP)
-                free(s);
+        do {
+            if (n > MAX_LOOP_NUM)
+                bb_error_msg_and_die("no free loop devices");
+            sprintf(dev, LOOP_FORMAT, n++);
+            s = query_loop(dev);
+            free(s);
+        } while (s);
+        /* now: dev is next free "/dev/loopN" */
+        if ((opt == OPT_f) && !argv[0]) {
+            puts(dev);
+            return EXIT_SUCCESS;
         }
     }
-    return EXIT_SUCCESS;
+
+    /* [-r] [-o OFS] {-f|LOOPDEV} FILE */
+    if (argv[0] && ((opt & OPT_f) || argv[1])) {
+        unsigned long long offset = 0;
+        char *d = dev;
+
+        if (opt & OPT_o)
+            offset = xatoull(opt_o);
+        if (!(opt & OPT_f))
+            d = *argv++;
+
+        if (argv[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(); /* does not return */
+    /*return EXIT_FAILURE;*/
 }