* include/grub/partition.h (grub_partition_map): Change prototype of

embed to take a maximum value for nsectors.
	* include/grub/emu/hostdisk.h (grub_util_ldm_embed): Likewise.
	* include/grub/fs.h (grub_fs): Likewise.
	* grub-core/partmap/msdos.c (embed_signatures): New array.
	(pc_partition_map_embed): Check for and avoid sectors matching any
	of the signatures in embed_signatures, up to max_nsectors.
	* grub-core/partmap/gpt.c (gpt_partition_map_embed): Restrict
	returned sector map to max_nsectors.
	* grub-core/disk/ldm.c (grub_util_ldm_embed): Likewise.
	* grub-core/fs/btrfs.c (grub_btrfs_embed): Likewise.
	* grub-core/fs/zfs/zfs.c (grub_zfs_embed): Likewise.
	* util/grub-setup.c (setup): Allow for the embedding area being
	split into multiple blocklists.  Tell dest_partmap->embed the
	maximum number of sectors we care about.

include/grub/emu/hostdisk.h

@@ -48,6 +48,7 @@ grub_util_is_ldm (grub_disk_t disk);
 #ifdef GRUB_UTIL
 grub_err_t
 grub_util_ldm_embed (struct grub_disk *disk, unsigned int *nsectors,
+		     unsigned int max_nsectors,
 		     grub_embed_type_t embed_type,
 		     grub_disk_addr_t **sectors);
 #endif

include/grub/fs.h

@@ -81,6 +81,7 @@ struct grub_fs
 #ifdef GRUB_UTIL
   /* Determine sectors available for embedding.  */
   grub_err_t (*embed) (grub_device_t device, unsigned int *nsectors,
+		       unsigned int max_nsectors,
 		       grub_embed_type_t embed_type,
 		       grub_disk_addr_t **sectors);
 

include/grub/partition.h

@@ -50,6 +50,7 @@ struct grub_partition_map
 #ifdef GRUB_UTIL
   /* Determine sectors available for embedding.  */
   grub_err_t (*embed) (struct grub_disk *disk, unsigned int *nsectors,
+		       unsigned int max_nsectors,
 		       grub_embed_type_t embed_type,
 		       grub_disk_addr_t **sectors);
 #endif