+ info("probing at offset 0x%" PRIx64 ", size 0x%" PRIx64 "\n", off, size);
+
+ /*
+ * We probe for all known filesystems to find conflicting signatures. If
+ * we find multiple matching signatures and one of the detected filesystem
+ * types claims that it can not co-exist with any other filesystem type,
+ * we do not return a probing result.
+ *
+ * We can not afford to mount a volume with the wrong filesystem code and
+ * possibly corrupt it. Linux sytems have the problem of dozens of possible
+ * filesystem types, and volumes with left-over signatures from former
+ * filesystem types. Invalid signatures need to be removed from the volume
+ * to make the filesystem detection successful.
+ *
+ * We do not want to read that many bytes from probed floppies, skip volumes
+ * smaller than a usual floppy disk.
+ */
+ if (size > 1440 * 1024) {
+ int found = 0;
+ int force_unique_result = 0;
+ int first_match = -1;
+
+ volume_id_reset_result(id);
+ for (i = 0; i < ARRAY_SIZE(prober_filesystem); i++) {
+ int match;
+
+ match = (prober_filesystem[i].prober(id, off, size) == 0);
+ if (match) {
+ info("signature '%s' %i detected\n", id->type, i);
+ if (id->force_unique_result)
+ force_unique_result = 1;
+ if (found > 0 && force_unique_result) {
+ info("conflicting signatures found, skip results\n");
+ return -1;
+ }
+ found++;
+ if (first_match < 0)
+ first_match = i;
+ }
+ }
+ if (found < 1)
+ return -1;
+ if (found == 1)
+ goto found;
+ if (found > 1) {
+ volume_id_reset_result(id);
+ info("re-read first match metadata %i\n", first_match);
+ if (prober_filesystem[first_match].prober(id, off, size) == 0)
+ goto found;
+ return -1;
+ }
+ }