board/common: speed up mounting and boot

Reduce /var image size to 128M (resized at first boot anyway) and tune
mke2fs options for faster mounting.  Set ext4 'uninit_bg' feature and
use '-m 0 -i 4096' extraargs in genimage to optimize filesystem creation
and reduce overhead.  The genimage tool has several tweaks enabled by
default already, the 'uninit_bg' feature speeds up the time to check
the file system.

Disable periodic fsck with tune2fs at boot while keeping safety checks
intact.  Adjust mount options in fstab to reduce journal syncs and
improve boot time.

Fix severe performance regression in find_partition_by_label() that was
calling sgdisk on every block device including virtual devices (ram, loop,
dm-mapper). This caused boot delays of up to 24 seconds on systems with
many block devices. Now skip virtual devices that don't have GPT tables,
reducing the delay to ~2 seconds.

Also clean up is_mmc() function to use cached result.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

board/aarch64/bananapi-bpi-r3/genimage.cfg.in

@@ -4,16 +4,23 @@ image cfg.ext4 {
         size = 128M
         ext4 {
                 label = "cfg"
+                use-mke2fs = true
+                features = "uninit_bg"
+                extraargs = "-m 0 -i 4096"
         }
 }
 
+# The /var partition will be expanded automatically at first boot
+# to use the full size of the SD-card or eMMC media.
 image var.ext4 {
         empty = true
         temporary = true
-        size = 1G
+        size = 128M
         ext4 {
                 label = "var"
                 use-mke2fs = true
+                features = "uninit_bg"
+                extraargs = "-m 0 -i 4096"
         }
 }
 

board/aarch64/friendlyarm-nanopi-r2s/genimage.cfg.in

@@ -5,17 +5,24 @@ image cfg.ext4 {
 
 	ext4 {
 		label = "cfg"
+                use-mke2fs = true
+                features = "uninit_bg"
+                extraargs = "-m 0 -i 4096"
 	}
 }
 
+# The /var partition will be expanded automatically at first boot
+# to use the full size of the SD-card or eMMC media.
 image var.ext4 {
 	empty = true
 	temporary = true
-	size = 512M
+	size = 128M
 
 	ext4 {
 		label = "var"
-		use-mke2fs = true
+                use-mke2fs = true
+                features = "uninit_bg"
+                extraargs = "-m 0 -i 4096"
 	}
 }
 

board/aarch64/raspberrypi-rpi64/genimage.cfg.in

@@ -15,17 +15,24 @@ image cfg.ext4 {
 
 	ext4 {
 		label = "cfg"
+                use-mke2fs = true
+                features = "uninit_bg"
+                extraargs = "-m 0 -i 4096"
 	}
 }
 
+# The /var partition will be expanded automatically at first boot
+# to use the full size of the SD-card or eMMC media.
 image var.ext4 {
 	empty = true
 	temporary = true
-	size = 512M
+	size = 128M
 
 	ext4 {
 		label = "var"
-		use-mke2fs = true
+                use-mke2fs = true
+                features = "uninit_bg"
+                extraargs = "-m 0 -i 4096"
 	}
 }
 

board/common/mkaux.sh

@@ -11,7 +11,8 @@ image aux.ext4 {
 	ext4 {
 		label = "aux"
 		use-mke2fs = true
-		features = "^metadata_csum,^metadata_csum_seed"
+		features = "^metadata_csum,^metadata_csum_seed,uninit_bg"
+                extraargs = "-m 0 -i 4096"
 	}
 }
 

board/common/rootfs/etc/fstab

@@ -15,9 +15,9 @@ cfgfs		/config		configfs	nofail,noauto		0	0
 # The chosen backing storage for the overlays placed on /cfg, /etc,
 # /home, /root, and /var, are determined dynamically by /usr/libexec/infix/mnt
 # depending on the available devices.
-mnttmp		/mnt/tmp	tmpfs		defaults			0	0
-LABEL=aux	/mnt/aux	auto		noatime,nodiratime,noauto	0	0
-LABEL=var	/mnt/var	auto		noatime,nodiratime,noauto	0	0
-LABEL=cfg	/mnt/cfg	auto		noatime,nodiratime,noauto	0	0
-hostfs		/mnt/host	9p		cache=none,msize=16384,noauto	0	0
-/usr/libexec/infix/mnt#	/cfg	helper		none				0	0
+mnttmp		/mnt/tmp	tmpfs	defaults				0	0
+LABEL=aux	/mnt/aux	auto	noatime,nodiratime,noauto,commit=30,errors=remount-ro	0 0
+LABEL=var	/mnt/var	auto	noatime,nodiratime,noauto,commit=30,errors=remount-ro	0 0
+LABEL=cfg	/mnt/cfg	auto	noatime,nodiratime,noauto,commit=30,errors=remount-ro	0 0
+hostfs		/mnt/host	9p	cache=none,msize=16384,noauto		0	0
+/usr/libexec/infix/mnt#	/cfg	helper	none					0	0

board/common/rootfs/usr/libexec/infix/mnt

@@ -19,6 +19,7 @@ set -e
 
 nm=$(basename "$0")
 err=0
+mmc=""
 opt="-k"
 
 # External button or bootloader changed kernel command line
@@ -53,17 +54,22 @@ factory_reset()
 
 is_mmc()
 {
+    [ -n "$mmc" ] && return $mmc
+
     # Check if primary or secondary partition (our rootfs) is on MMC
     for label in primary secondary; do
         devname=$(find_partition_by_label "$label" 2>/dev/null)
         if [ -n "$devname" ]; then
             case "$devname" in
                 mmcblk*)
+		    mmc=0
                     return 0
                     ;;
             esac
         fi
     done
+
+    mmc=1
     return 1
 }
 
@@ -89,8 +95,15 @@ find_partition_by_label()
 
     for diskpath in /sys/class/block/*; do
 	devname=$(basename "$diskpath")
+
+	# Skip partitions, only check whole disks
 	[ -f "$diskpath/partition" ] && continue
 
+	# Skip ram, loop, and other virtual devices
+	case "$devname" in
+	    ram*|loop*|nullb*|dm-*) continue ;;
+	esac
+
 	disk="/dev/$devname"
 	result=$(sgdisk -p "$disk" 2>/dev/null | awk -v label="$label" -v devname="$devname" '
 	    /^  *[0-9]/ {
@@ -275,6 +288,9 @@ mount_rw()
     fi
 
     # TODO: Also look for UBI partitions
+
+    # 
+    tune2fs -c 0 -i 0 LABEL="$1" 2>/dev/null 
     mount LABEL="$1" 2>/dev/null && return 0
 
     return 1