Imported from util-linux-2.10s tarball.

[thirdparty/util-linux.git] / mount / lomount.c

diff --git a/mount/lomount.c b/mount/lomount.c
index 52157a14a8cb0f1697caf9ce08a80e3dd5edde58..cabc44461874e8404b51fe1c723eec456903c8d4 100644 (file)
--- a/mount/lomount.c
+++ b/mount/lomount.c
@@ -68,7 +68,7 @@ crypt_name (int id) {
        return "undefined";
 }
 
-static void 
+static int
 show_loop (char *device) {
        struct loop_info loopinfo;
        int fd;
@@ -77,36 +77,69 @@ show_loop (char *device) {
                int errsv = errno;
                fprintf(stderr, _("loop: can't open device %s: %s\n"),
                        device, strerror (errsv));
-               return;
+               return 2;
        }
        if (ioctl (fd, LOOP_GET_STATUS, &loopinfo) < 0) {
                int errsv = errno;
                fprintf(stderr, _("loop: can't get info on device %s: %s\n"),
                        device, strerror (errsv));
                close (fd);
-               return;
+               return 1;
        }
        printf (_("%s: [%04x]:%ld (%s) offset %d, %s encryption\n"),
                device, loopinfo.lo_device, loopinfo.lo_inode,
                loopinfo.lo_name, loopinfo.lo_offset,
                crypt_name (loopinfo.lo_encrypt_type));
        close (fd);
+
+       return 0;
 }
 #endif
 
+int
+is_loop_device (const char *device) {
+       struct stat statbuf;
+       int loopmajor;
+#if 1
+       loopmajor = 7;
+#else
+       FILE *procdev;
+       char line[100], *cp;
+
+       loopmajor = 0;
+       if ((procdev = fopen(PROC_DEVICES, "r")) != NULL) {
+               while (fgets (line, sizeof(line), procdev)) {
+                       if ((cp = strstr (line, " loop\n")) != NULL) {
+                               *cp='\0';
+                               loopmajor=atoi(line);
+                               break;
+                       }
+               }
+               fclose(procdev);
+       }
+#endif
+       return (loopmajor && stat(device, &statbuf) == 0 &&
+               S_ISBLK(statbuf.st_mode) &&
+               (statbuf.st_rdev>>8) == loopmajor);
+}
+
+#define SIZE(a) (sizeof(a)/sizeof(a[0]))
+
 char *
 find_unused_loop_device (void) {
        /* Just creating a device, say in /tmp, is probably a bad idea -
           people might have problems with backup or so.
           So, we just try /dev/loop[0-7]. */
        char dev[20];
-       int i, fd, somedev = 0, someloop = 0, loop_known = 0;
+       char *loop_formats[] = { "/dev/loop%d", "/dev/loop/%d" };
+       int i, j, fd, somedev = 0, someloop = 0, loop_known = 0;
        struct stat statbuf;
        struct loop_info loopinfo;
        FILE *procdev;
 
-       for(i = 0; i < 256; i++) {
-               sprintf(dev, "/dev/loop%d", i);
+       for (j = 0; j < SIZE(loop_formats); j++) {
+           for(i = 0; i < 256; i++) {
+               sprintf(dev, loop_formats[j], i);
                if (stat (dev, &statbuf) == 0 && S_ISBLK(statbuf.st_mode)) {
                        somedev++;
                        fd = open (dev, O_RDONLY);
@@ -121,8 +154,8 @@ find_unused_loop_device (void) {
                        }
                        continue;/* continue trying as long as devices exist */
                }
-               if (i >= 7)
-                       break;
+               break;
+           }
        }
 
        /* Nothing found. Why not? */
@@ -393,7 +426,7 @@ main(int argc, char **argv) {
                if (delete)
                        res = del_loop(argv[optind]);
                else
-                       show_loop(argv[optind]);
+                       res = show_loop(argv[optind]);
        } else {
                if (offset && sscanf(offset,"%d",&off) != 1)
                        usage();