From: Colin Watson <cjwatson@ubuntu.com>

Subject: Improve devmapper support

Date: 2011-05-18 07:35:47 +0000

=== modified file 'grub-core/kern/emu/getroot.c'

--- a/grub-core/kern/emu/getroot.c	2011-04-21 09:26:29 +0000

+++ b/grub-core/kern/emu/getroot.c	2011-05-18 07:35:47 +0000

@@ -34,6 +34,10 @@

 #include <stdint.h>

 #include <grub/util/misc.h>

+#ifdef HAVE_DEVICE_MAPPER

+# include <libdevmapper.h>

+#endif

+

 #ifdef __GNU__

 #include <hurd.h>

 #include <hurd/lookup.h>

@@ -634,32 +638,65 @@

 }

 static int

-grub_util_is_dmraid (const char *os_dev)

+grub_util_is_lvm (const char *os_dev)

 {

-  if (! strncmp (os_dev, "/dev/mapper/nvidia_", 19))

-    return 1;

-  else if (! strncmp (os_dev, "/dev/mapper/isw_", 16))

-    return 1;

-  else if (! strncmp (os_dev, "/dev/mapper/hpt37x_", 19))

-    return 1;

-  else if (! strncmp (os_dev, "/dev/mapper/hpt45x_", 19))

-    return 1;

-  else if (! strncmp (os_dev, "/dev/mapper/via_", 16))

-    return 1;

-  else if (! strncmp (os_dev, "/dev/mapper/lsi_", 16))

-    return 1;

-  else if (! strncmp (os_dev, "/dev/mapper/pdc_", 16))

-    return 1;

-  else if (! strncmp (os_dev, "/dev/mapper/jmicron_", 20))

-    return 1;

-  else if (! strncmp (os_dev, "/dev/mapper/asr_", 16))

-    return 1;

-  else if (! strncmp (os_dev, "/dev/mapper/sil_", 16))

-    return 1;

-  else if (! strncmp (os_dev, "/dev/mapper/ddf1_", 17))

-    return 1;

-

-  return 0;

+  if ((strncmp ("/dev/mapper/", os_dev, 12) != 0))

+    return 0;

+  

+#ifdef HAVE_DEVICE_MAPPER

+  {

+    struct dm_tree *tree;

+    uint32_t maj, min;

+    struct dm_tree_node *node = NULL;

+    const char *node_uuid;

+    struct stat st;

+

+    if (stat (os_dev, &st) < 0)

+      return 0;

+

+    tree = dm_tree_create ();

+    if (! tree)

+      {

+	grub_printf ("Failed to create tree\n");

+	grub_dprintf ("hostdisk", "dm_tree_create failed\n");

+	return 0;

+      }

+

+    maj = major (st.st_rdev);

+    min = minor (st.st_rdev);

+

+    if (! dm_tree_add_dev (tree, maj, min))

+      {

+	grub_dprintf ("hostdisk", "dm_tree_add_dev failed\n");

+	dm_tree_free (tree);

+	return 0;

+      }

+

+    node = dm_tree_find_node (tree, maj, min);

+    if (! node)

+      {

+	grub_dprintf ("hostdisk", "dm_tree_find_node failed\n");

+	dm_tree_free (tree);

+	return 0;

+      }

+    node_uuid = dm_tree_node_get_uuid (node);

+    if (! node_uuid)

+      {

+	grub_dprintf ("hostdisk", "%s has no DM uuid\n", os_dev);

+	dm_tree_free (tree);

+	return 0;

+      }

+    if (strncmp (node_uuid, "LVM-", 4) != 0)

+      {

+	dm_tree_free (tree);

+	return 0;

+      }

+    dm_tree_free (tree);

+    return 1;

+  }

+#else

+  return 1;

+#endif /* HAVE_DEVICE_MAPPER */

 }

 int

@@ -671,13 +708,11 @@

     return GRUB_DEV_ABSTRACTION_NONE;

   /* Check for LVM.  */

-  if (!strncmp (os_dev, "/dev/mapper/", 12)

-      && ! grub_util_is_dmraid (os_dev)

-      && strncmp (os_dev, "/dev/mapper/mpath", 17) != 0)

+  if (grub_util_is_lvm (os_dev))

     return GRUB_DEV_ABSTRACTION_LVM;

   /* Check for RAID.  */

-  if (!strncmp (os_dev, "/dev/md", 7))

+  if (!strncmp (os_dev, "/dev/md", 7) && ! grub_util_device_is_mapped (os_dev))

     return GRUB_DEV_ABSTRACTION_RAID;

 #endif

=== modified file 'grub-core/kern/emu/hostdisk.c'

--- a/grub-core/kern/emu/hostdisk.c	2011-05-09 16:59:35 +0000

+++ b/grub-core/kern/emu/hostdisk.c	2011-05-18 07:35:47 +0000

@@ -24,6 +24,7 @@

 #include <grub/err.h>

 #include <grub/emu/misc.h>

 #include <grub/emu/hostdisk.h>

+#include <grub/emu/getroot.h>

 #include <grub/misc.h>

 #include <grub/i18n.h>

 #include <grub/list.h>

@@ -331,18 +332,23 @@

   return GRUB_ERR_NONE;

 }

+int

+grub_util_device_is_mapped (const char *dev)

+{

 #ifdef HAVE_DEVICE_MAPPER

-static int

-device_is_mapped (const char *dev)

-{

   struct stat st;

+  if (!grub_device_mapper_supported ())

+    return 0;

+

   if (stat (dev, &st) < 0)

     return 0;

   return dm_is_dm_major (major (st.st_rdev));

+#else

+  return 0;

+#endif /* HAVE_DEVICE_MAPPER */

 }

-#endif /* HAVE_DEVICE_MAPPER */

 #if defined (__FreeBSD__) || defined(__FreeBSD_kernel__)

 /* FIXME: geom actually gives us the whole container hierarchy.

@@ -418,7 +424,7 @@

 # endif /* !defined(HAVE_DIOCGDINFO) */

 # ifdef HAVE_DEVICE_MAPPER

-  if (grub_device_mapper_supported () && device_is_mapped (dev)) {

+  if (grub_util_device_is_mapped (dev)) {

     struct dm_task *task = NULL;

     grub_uint64_t start, length;

     char *target_type, *params, *space;

@@ -1149,6 +1155,54 @@

   return ret;

 }

+#ifdef HAVE_DEVICE_MAPPER

+static int

+grub_util_get_dm_node_linear_info (const char *dev,

+				   int *maj, int *min)

+{

+  struct dm_task *dmt;

+  void *next = NULL;

+  uint64_t length, start;

+  char *target, *params;

+  char *ptr;

+  int major, minor;

+

+  dmt = dm_task_create(DM_DEVICE_TABLE);

+  if (!dmt)

+    return 0;

+  

+  if (!dm_task_set_name(dmt, dev))

+    return 0;

+  dm_task_no_open_count(dmt);

+  if (!dm_task_run(dmt))

+    return 0;

+  next = dm_get_next_target(dmt, next, &start, &length,

+			    &target, &params);

+  if (grub_strcmp (target, "linear") != 0)

+    return 0;

+  major = grub_strtoul (params, &ptr, 10);

+  if (grub_errno)

+    {

+      grub_errno = GRUB_ERR_NONE;

+      return 0;

+    }

+  if (*ptr != ':')

+    return 0;

+  ptr++;

+  minor = grub_strtoul (ptr, 0, 10);

+  if (grub_errno)

+    {

+      grub_errno = GRUB_ERR_NONE;

+      return 0;

+    }

+  if (maj)

+    *maj = major;

+  if (min)

+    *min = minor;

+  return 1;

+}

+#endif

+

 static char *

 convert_system_partition_to_system_disk (const char *os_dev, struct stat *st)

 {

@@ -1325,9 +1379,39 @@

 	      node = NULL;

 	      goto devmapper_out;

 	    }

-	  else if (strncmp (node_uuid, "DMRAID-", 7) != 0)

-	    {

+	  if (strncmp (node_uuid, "LVM-", 4) == 0)

+	    {

+	      grub_dprintf ("hostdisk", "%s is an LVM\n", path);

+	      node = NULL;

+	      goto devmapper_out;

+	    }

+	  if (strncmp (node_uuid, "mpath-", 6) == 0)

+	    {

+	      /* Multipath partitions have partN-mpath-* UUIDs, and are

+		 linear mappings so are handled by

+		 grub_util_get_dm_node_linear_info.  Multipath disks are not

+		 linear mappings and must be handled specially.  */

+	      grub_dprintf ("hostdisk", "%s is a multipath disk\n", path);

+	      mapper_name = dm_tree_node_get_name (node);

+	      goto devmapper_out;

+	    }

+	  if (strncmp (node_uuid, "DMRAID-", 7) != 0)

+	    {

+	      int major, minor;

+	      const char *node_name;

 	      grub_dprintf ("hostdisk", "%s is not DM-RAID\n", path);

+

+	      if ((node_name = dm_tree_node_get_name (node))

+		  && grub_util_get_dm_node_linear_info (node_name,

+							&major, &minor))

+		{

+		  if (tree)

+		    dm_tree_free (tree);

+		  free (path);

+		  char *ret = grub_find_device (NULL, (major << 8) | minor);

+		  return ret;

+		}

+

 	      node = NULL;

 	      goto devmapper_out;

 	    }

=== modified file 'include/grub/emu/misc.h'

--- a/include/grub/emu/misc.h	2010-12-02 13:26:46 +0000

+++ b/include/grub/emu/misc.h	2011-05-18 07:35:47 +0000

@@ -54,6 +54,8 @@

 char *grub_make_system_path_relative_to_its_root (const char *path)

   __attribute__ ((warn_unused_result));

+int

+grub_util_device_is_mapped (const char *dev);

 void * EXPORT_FUNC(xmalloc) (grub_size_t size) __attribute__ ((warn_unused_result));

 void * EXPORT_FUNC(xrealloc) (void *ptr, grub_size_t size) __attribute__ ((warn_unused_result));