Don't stat devices unless we have to.

	* grub-core/kern/emu/getroot.c (grub_find_device): Recognize
	dir == /dev/mapper.
	(grub_guess_root_device): Use already known os_dev if possible.
	* grub-core/kern/emu/hostdisk.c
	(convert_system_partition_to_system_disk): Scan only in /dev/mapper
	if device is known to be a dm one.

	Also-By: Colin Watson <cjwatson@ubuntu.com>

diff --git a/ChangeLog b/ChangeLog
index c94b7482defb566454bcf6269f1371f790c50506..a01d57576e33a82590c76a16237a8574b5088bec 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+2011-05-21  Colin Watson  <cjwatson@ubuntu.com>
+2011-05-21  Vladimir Serbinenko  <phcoder@gmail.com>
+
+       Don't stat devices unless we have to.
+
+       * grub-core/kern/emu/getroot.c (grub_find_device): Recognize
+       dir == /dev/mapper.
+       (grub_guess_root_device): Use already known os_dev if possible.
+       * grub-core/kern/emu/hostdisk.c
+       (convert_system_partition_to_system_disk): Scan only in /dev/mapper
+       if device is known to be a dm one.
+
 2011-05-20  Colin Watson  <cjwatson@ubuntu.com>
 
        * util/grub-mkconfig.in: Export GRUB_CMDLINE_LINUX_XEN_REPLACE and

diff --git a/grub-core/kern/emu/getroot.c b/grub-core/kern/emu/getroot.c
index b1b4f188c26f724bc0c092eb97659ef3b8230aba..6e49cc31b95af4e3cacadad2be7c84e1ea23d307 100644 (file)
--- a/grub-core/kern/emu/getroot.c
+++ b/grub-core/kern/emu/getroot.c
@@ -358,7 +358,7 @@ grub_find_device (const char *dir, dev_t dev)
 
       if (S_ISLNK (st.st_mode)) {
 #ifdef __linux__
-       if (strcmp (dir, "mapper") == 0) {
+       if (strcmp (dir, "mapper") == 0 || strcmp (dir, "/dev/mapper") == 0) {
          /* Follow symbolic links under /dev/mapper/; the canonical name
             may be something like /dev/dm-0, but the names under
             /dev/mapper/ are more human-readable and so we prefer them if
@@ -609,20 +609,27 @@ grub_guess_root_device (const char *dir)
 
   if (os_dev)
     {
-      if (stat (os_dev, &st) >= 0)
-       dev = st.st_rdev;
-      else
-       grub_util_error ("cannot stat `%s'", os_dev);
-      free (os_dev);
+      char *tmp = os_dev;
+      os_dev = canonicalize_file_name (os_dev);
+      free (tmp);
     }
-  else
+
+  if (os_dev)
     {
-      if (stat (dir, &st) >= 0)
-       dev = st.st_dev;
-      else
-       grub_util_error ("cannot stat `%s'", dir);
+      if (strncmp (os_dev, "/dev/dm-", sizeof ("/dev/dm-") - 1) != 0)
+       return os_dev;
+      if (stat (os_dev, &st) < 0)
+       grub_util_error ("cannot stat `%s'", os_dev);
+      free (os_dev);
+      dev = st.st_rdev;
+      return grub_find_device ("/dev/mapper", dev);
     }
 
+  if (stat (dir, &st) < 0)
+    grub_util_error ("cannot stat `%s'", dir);
+
+  dev = st.st_dev;
+  
 #ifdef __CYGWIN__
   /* Cygwin specific function.  */
   os_dev = grub_find_device (dir, dev);

diff --git a/grub-core/kern/emu/hostdisk.c b/grub-core/kern/emu/hostdisk.c
index d3db7e6be8630dcd5699fd758906da7d6b648fa5..d633059c38a9602e601fe6a7a54a27308e5c21f9 100644 (file)
--- a/grub-core/kern/emu/hostdisk.c
+++ b/grub-core/kern/emu/hostdisk.c
@@ -1408,7 +1408,8 @@ convert_system_partition_to_system_disk (const char *os_dev, struct stat *st)
                  if (tree)
                    dm_tree_free (tree);
                  free (path);
-                 char *ret = grub_find_device (NULL, (major << 8) | minor);
+                 char *ret = grub_find_device ("/dev/mapper",
+                                               (major << 8) | minor);
                  return ret;
                }