merge with mainline

kern/emu/getroot.c

@@ -80,6 +80,86 @@ xgetcwd (void)
   return path;
 }
 
+#ifdef __linux__
+
+/* Statting something on a btrfs filesystem always returns a virtual device
+   major/minor pair rather than the real underlying device, because btrfs
+   can span multiple underlying devices (and even if it's currently only
+   using a single device it can be dynamically extended onto another).  We
+   can't deal with the multiple-device case yet, but in the meantime, we can
+   at least cope with the single-device case by scanning
+   /proc/self/mountinfo.  */
+static char *
+find_root_device_from_mountinfo (const char *dir)
+{
+  FILE *fp;
+  char *buf = NULL;
+  size_t len = 0;
+  char *ret = NULL;
+
+  fp = fopen ("/proc/self/mountinfo", "r");
+  if (! fp)
+    return NULL; /* fall through to other methods */
+
+  while (getline (&buf, &len, fp) > 0)
+    {
+      int mnt_id, parent_mnt_id;
+      unsigned int major, minor;
+      char enc_root[PATH_MAX], enc_path[PATH_MAX];
+      int count;
+      size_t enc_path_len;
+      const char *sep;
+      char fstype[PATH_MAX], device[PATH_MAX];
+      struct stat st;
+
+      if (sscanf (buf, "%d %d %u:%u %s %s%n",
+		  &mnt_id, &parent_mnt_id, &major, &minor, enc_root, enc_path,
+		  &count) < 6)
+	continue;
+
+      if (strcmp (enc_root, "/") != 0)
+	continue; /* only a subtree is mounted */
+
+      enc_path_len = strlen (enc_path);
+      if (strncmp (dir, enc_path, enc_path_len) != 0 ||
+	  (dir[enc_path_len] && dir[enc_path_len] != '/'))
+	continue;
+
+      /* This is a parent of the requested directory.  /proc/self/mountinfo
+	 is in mount order, so it must be the closest parent we've
+	 encountered so far.  If it's virtual, return its device node;
+	 otherwise, carry on to try to find something closer.  */
+
+      free (ret);
+      ret = NULL;
+
+      if (major != 0)
+	continue; /* not a virtual device */
+
+      sep = strstr (buf + count, " - ");
+      if (!sep)
+	continue;
+
+      sep += sizeof (" - ") - 1;
+      if (sscanf (sep, "%s %s", fstype, device) != 2)
+	continue;
+
+      if (stat (device, &st) < 0)
+	continue;
+
+      if (!S_ISBLK (st.st_mode))
+	continue; /* not a block device */
+
+      ret = strdup (device);
+    }
+
+  free (buf);
+  fclose (fp);
+  return ret;
+}
+
+#endif /* __linux__ */
+
 #ifdef __MINGW32__
 
 static char *
@@ -366,6 +446,12 @@ grub_guess_root_device (const char *dir)
 #else /* !__GNU__ */
   struct stat st;
 
+#ifdef __linux__
+  os_dev = find_root_device_from_mountinfo (dir);
+  if (os_dev)
+    return os_dev;
+#endif /* __linux__ */
+
   if (stat (dir, &st) < 0)
     grub_util_error ("cannot stat `%s'", dir);
 

kern/emu/hostdisk.c

@@ -413,7 +413,11 @@ devmapper_fail:
   if (fd == -1)
     {
       grub_error (GRUB_ERR_BAD_DEVICE,
+# if !defined(__NetBSD__)
 		  "cannot open `%s' while attempting to get disk geometry", dev);
+# else /* defined(__NetBSD__) */
+		  "cannot open `%s' while attempting to get disk label", dev);
+# endif /* !defined(__NetBSD__) */
       return 0;
     }
 
@@ -425,7 +429,11 @@ devmapper_fail:
 # endif /* !defined(__NetBSD__) */
     {
       grub_error (GRUB_ERR_BAD_DEVICE,
+# if !defined(__NetBSD__)
 		  "cannot get disk geometry of `%s'", dev);
+# else /* defined(__NetBSD__) */
+		  "cannot get disk label of `%s'", dev);
+# endif /* !defined(__NetBSD__) */
       close (fd);
       return 0;
     }
@@ -1256,22 +1264,28 @@ devmapper_out:
   return path;
 
 #elif defined(__NetBSD__)
-  /* NetBSD uses "/dev/r[wsc]d[0-9]+[a-z]".  */
+  /* NetBSD uses "/dev/r[a-z]+[0-9][a-z]".  */
   char *path = xstrdup (os_dev);
-  if (strncmp ("/dev/rwd", path, 8) == 0 ||
-      strncmp ("/dev/rsd", path, 8) == 0 ||
-      strncmp ("/dev/rcd", path, 8) == 0)
+  if (strncmp ("/dev/r", path, sizeof("/dev/r") - 1) == 0 &&
+      (path[sizeof("/dev/r") - 1] >= 'a' && path[sizeof("/dev/r") - 1] <= 'z') &&
+      strncmp ("fd", path + sizeof("/dev/r") - 1, sizeof("fd") - 1) != 0)    /* not a floppy device name */
     {
-      char *q;
-      q = path + strlen(path) - 1;    /* last character */
-      if (grub_isalpha(*q) && grub_isdigit(*(q-1)))
-        {
-          int rawpart = -1;
+      char *p;
+      for (p = path + sizeof("/dev/r"); *p >= 'a' && *p <= 'z'; p++);
+      if (grub_isdigit(*p))
+	{
+	  p++;
+	  if ((*p >= 'a' && *p <= 'z') && (*(p+1) == '\0'))
+	    {
+	      /* path matches the required regular expression and
+		 p points to its last character.  */
+	      int rawpart = -1;
 # ifdef HAVE_GETRAWPARTITION
-          rawpart = getrawpartition();
+	      rawpart = getrawpartition();
 # endif /* HAVE_GETRAWPARTITION */
-          if (rawpart >= 0)
-            *q = 'a' + rawpart;
+	      if (rawpart >= 0)
+		*p = 'a' + rawpart;
+	    }
         }
     }
   return path;
@@ -1429,8 +1443,7 @@ grub_util_biosdisk_get_grub_dev (const char *os_dev)
       return name;
 # else /* defined(__NetBSD__) */
     /* Since os_dev and convert_system_partition_to_system_disk (os_dev) are
-     * different, we know that os_dev is of the form /dev/r[wsc]d[0-9]+[a-z]
-     * and in particular it cannot be a floppy device.  */
+     * different, we know that os_dev cannot be a floppy device.  */
 # endif /* !defined(__NetBSD__) */
 
     start = find_partition_start (os_dev);