Merge pull request #16 from wesbarnett/master

Add GRUB_BTRFS_LIMIT 
add GRUB_BTRFS_SUBVOLUME_SORT

41_snapshots-btrfs

@@ -72,6 +72,14 @@ nkernel=("${GRUB_BTRFS_NKERNEL[@]}")
 ninit=("${GRUB_BTRFS_NINIT[@]}")
 ## Microcode(s) name(s)
 microcode=("${GRUB_BTRFS_INTEL_UCODE[@]}")
+## Limit to show in menu
+limit=("${GRUB_BTRFS_LIMIT[@]:-100}")
+## How to sort
+subvolsort=${GRUB_BTRFS_SUBVOLUME_SORT:-"descending"}
+case "${subvolsort}" in
+    ascending)          btrfssubvolsort=("--sort=+rootid");;
+    *)                  btrfssubvolsort=("--sort=-rootid")
+esac
 
 ########################
 ### variables script ###
@@ -156,7 +164,7 @@ snapshots_entry()
 ## List of snapshots on filesystem
 snapshot_list()
 {
-	for snap in $(btrfs subvolume list -sa /); do
+	for snap in $(btrfs subvolume list -sa "${btrfssubvolsort}" /); do
 		IFS=$oldIFS
 		snap=($snap)
 		local snap_path_name=${snap[@]:13:${#snap[@]}}
@@ -249,6 +257,7 @@ title_format()
 list_kernels_initramfs()
 {
 	IFS=$'\n'
+    c=0
 	for item in $(snapshot_list); do
 		IFS=$oldIFS
 		item=($item)
@@ -276,6 +285,10 @@ list_kernels_initramfs()
 		title_format
 		# echo "${title_menu[*]}"
 		snapshots_entry
+        c=$((1+$c))
+        if [[ $c -gt $limit ]]; then
+            break;
+        fi
 	done
 	IFS=$oldIFS
 }
@@ -292,4 +305,4 @@ if [ ${choise_of_method} = "1" ] ; then
 	umount $gbgmp
 	gettext_printf "###### - Grub-btrfs: Auto-detect - ######\n" >&2 ;
 fi
-### End choice of method ###
+### End choice of method ###

README.md

@@ -54,7 +54,15 @@ Add this lines to /etc/default/grub:
 
 	(Use only if you have custom intel-ucode or auto-detect failed.)
 
+* GRUB_BTRFS_LIMIT=("100")
 
+    (Limit the number of snapshots populated in the GRUB menu.)
+
+* GRUB_BTRFS_SUBVOLUME_SORT=("descending")
+
+    (Sort the found subvolumes by newest first ("descending") or oldest first
+("ascending"). If "ascending" is chosen then the $GRUB_BTRFS_LIMIT oldest
+subvolumes will populate the menu.)
 
 Generate grub.cfg (on Archlinux use grub-mkconfig -o /boot/grub/grub.cfg )