From 1703d6f8cfae4973ed5d84e60f3151b707303530 Mon Sep 17 00:00:00 2001
From: Silvio Rhatto <rhatto@riseup.net>
Date: Sun, 12 May 2019 12:16:28 -0300
Subject: Calculate partition alignment

---
 share/hydractl/provision | 59 +++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 53 insertions(+), 6 deletions(-)

diff --git a/share/hydractl/provision b/share/hydractl/provision
index 24fd614..ac78699 100755
--- a/share/hydractl/provision
+++ b/share/hydractl/provision
@@ -82,6 +82,20 @@ function hydra_provision_create_volume {
   fi
 }
 
+# Determine optimal partition start taking into account disk alignment
+# This function needs to know where the last partition ends
+function partition_sector_start {
+  local sector_start="$1"
+  local last_partition_end="$2"
+  local optimal_sector_size="$3"
+
+  while (( $sector_start <= $last_partition_end + 1)); do
+    sector_start="$(($sector_start + $optimal_sector_size))"
+  done
+
+  echo $sector_start
+}
+
 # Make sure there is provision config.
 function hydra_provision_config {
   local base_arch="`uname -m`"
@@ -186,21 +200,54 @@ if [ "$num_devices" != "1" ]; then
   boot_device="$device"
   syst_device="$device"
 else
+  # Partition alignment
+  megabyte="$((1024*1024))"
+  block="`echo $device | sed -e 's|^/dev/||'`"
+  optimal_size="`cat /sys/block/$block/queue/optimal_io_size`"
+  alignment_offset="`cat /sys/block/$block/alignment_offset`"
+  block_size="`cat /sys/block/$block/queue/physical_block_size`"
+  start="$((($optimal_size + $alignment_offset) / $block_size))"
+  optimal_sector_size="$(($optimal_size / $block_size))"
+
+  #start="`awk -v x=$(cat /sys/block/$block/queue/optimal_io_size) \
+  #            -v y=$(cat /sys/block/$block/alignment_offset)      \
+  #            -v z=$(cat /sys/block/$block/queue/physical_block_size) 'BEGIN { print ( x + y ) / z }'`"
+
+  # Sector size for a 1MB partition
+  bios_grub_size="$(($megabyte/$block_size))"
+  bios_grub_end="$(($start + $bios_grub_size - 1))"
+
   # Regular disk partitioning.
   hydra_sudo_run parted -s -- $device mklabel gpt
-  hydra_sudo_run parted -s -- $device unit    MB mkpart    non-fs 2  3
+  #hydra_sudo_run parted -s -- $device unit   MB mkpart    non-fs 2  3
+  hydra_sudo_run parted -s -- $device mkpart  non-fs ${start}s ${bios_grub_end}s
   hydra_sudo_run parted -s -- $device set     1  bios_grub on
 
   if [ "$encrypt" == "y" ]; then
-    hydra_sudo_run parted -s -- $device unit MB mkpart ext2 3 -1
-    hydra_sudo_run parted -s -- $device set  2  lvm    on
+    # Second partition must also be aligned by a multiple of $optimal_sector_size
+    # So we find the minimum optimal start sector which is after the grub partition
+    #lvm_start="$(($bios_grub_end + 1))"
+    lvm_start="`partition_sector_start $start $bios_grub_end $optimal_sector_size`"
+
+    #hydra_sudo_run parted -s -- $device unit MB mkpart ext2 3 -1
+    hydra_sudo_run parted -s -- $device mkpart ext2 ${lvm_start}s -1
+    hydra_sudo_run parted -s -- $device set    2    lvm on
 
     boot_device="$device"2
     syst_device="$device"2
   else
-    hydra_sudo_run parted -s -- $device unit MB mkpart ext2 3   200
-    hydra_sudo_run parted -s -- $device unit MB mkpart ext2 200 -1
-    hydra_sudo_run parted -s -- $device set  3  lvm    on
+    # Make a 200MB boot partition
+    #boot_start="$(($bios_grub_end + 1))"
+    boot_start="`partition_sector_start $start $bios_grub_end $optimal_sector_size`"
+    boot_size="$((200*megabyte/$block_size))"
+    boot_end="$(($boot_start + $boot_size -1))"
+    #lvm_start="$($boot_end + 1))"
+    lvm_start="`partition_sector_start $start $boot_end $optimal_sector_size`"
+
+    #hydra_sudo_run parted -s -- $device unit MB mkpart ext2 3   200
+    hydra_sudo_run parted -s -- $device mkpart ext2 ${boot_start}s ${boot_end}s
+    hydra_sudo_run parted -s -- $device mkpart ext2 ${lvm_start}s -1
+    hydra_sudo_run parted -s -- $device set    3    lvm on
 
     boot_device="$device"2
     syst_device="$device"3
-- 
cgit v1.2.3