satrim

#!/bin/bash
#
# V1.0
#
# Standalone script to enable SSD trim
#
# Run the script with no arguments to enable SSD Trim on all SSD disks
# Specific disk can be enabled by: /usr/local/bin/te /dev/sda,/dev/sdb
#
# Notes
#   The script can be rerun on a disk that already has Trim enabled
#   If 2 disks on same adapter, both get unmap enabled, since it's done at the (USB device) adapter level
#    If the 2 disks have different discard_max_bytes settings, then it MUST be run on both disks to get udev set up correctly
#
# References
#   https://lemariva.com/blog/2020/08/raspberry-pi-4-ssd-booting-enabled-trim
#   https://www.jeffgeerling.com/blog/2020/enabling-trim-on-external-ssd-on-raspberry-pi
#   https://forums.raspberrypi.com/viewtopic.php?t=351443
#

# Enables code sharing with sdm
function logtoboth() {
    echo "$1"
}

function trimcfg() {
    disks="$1"
    # disks="" [all], "all", or a list of disks ("/dev/sda,/dev/sdb", etc)
    [ "$disks" == "" ] && disks="all"
    while read id diskname
    do
	if [ "$disks" == "all" ] || [[ "$disks" =~ "$diskname" ]]
	then
	    logtoboth "* Plugin $pfx: found disk $diskname"
	    id=${id#[}
	    id=${id%]}
	    rawdev=${diskname##/dev/}
	    pmfile=/sys/block/$rawdev/device/scsi_disk/$id/provisioning_mode 
	    [ ! -f  $pmfile ] && logtoboth "? Plugin $pfx: Cannot find $pmfile" && exit
	    lbacount=$(sg_vpd -p bl $diskname | grep "unmap LBA" | (read w1 w2 w3 w4 lbc rest; echo $lbc))
	    unmapsupp=$(sg_vpd -p lbpv $diskname | grep "Unmap command supported" | (read w1 w2 w3 w4 ws ; echo $ws))
	    if [ $lbacount -gt 0 -a $unmapsupp -eq 1 ]
	    then
		maxbytes=$((lbacount*512))
		read pmode < $pmfile
		if [ "$pmode" != "unmap" ]
		then
		    logtoboth "* Plugin $pfx: Set provisioning mode 'unmap' on $diskname"
		    csts=$(set -o | grep noclobber | (read vn vs ; echo $vs))
		    [ "$csts" == "on" ] && set +o noclobber
		    echo "unmap" > $pmfile
		    [ "$csts" == "on" ] && set -o noclobber
		    logtoboth "* Plugin $pfx: Set discard_max_bytes to $maxbytes"
		    echo "$maxbytes" > /sys/block/$rawdev/queue/discard_max_bytes
		else
		    logtoboth "* Plugin $pfx: Device $diskname provisioning mode already set to unmap"
		fi
		#
		# Create udev rule for this disk
		#
		udevrule="/etc/udev/rules.d/10-$rawdev-trim.rules"
		oldudevrule="/etc/udev/rules.d/.10-$rawdev-trim-pre-$(date +'%Y-%m-%d-%H-%M-%S').rules"
		if [ -f $udevrule ]
		then
		    logtoboth "* Plugin $pfx: Renaming existing udev rule $udevrule to $oldudevrule"
		    mv $udevrule $oldudevrule
		fi
		idp=""
		idv=""
		while read usbdir
		do
		    dskdir="$(find $usbdir/ -name $rawdev -print)"
		    if [ "$dskdir" != "" ]
		    then
			#  strip everything after "host" in $dskdir
			devpath=${dskdir%%/host*}
			[ ! -L $devpath/port ] && devpath="${devpath%/*}"
			if [ -L $devpath/port ]
			then
			    idp=$(cat $devpath/idProduct)
			    idv=$(cat $devpath/idVendor)
			else
			    logtoboth "* Plugin $pfx: ? Could not find USB path for $rawdev"
			    logtoboth "               Please sudo /usr/local/bin/debug-trim-enable to gather output for maintainer"
			    rm -f /usr/local/bin/debug-trim-enable
			    trimlog="/root/trim-enable.log"
			    cat > /usr/local/bin/debug-trim-enable <<EOF
#!/bin/bash
sudo printf "Debug information for device $diskname\n" > $trimlog
sudo printf "\n** lsusb\n" >> $trimlog
sudo lsusb >> $trimlog
sudo printf "\n** ls -l /etc/udev/rules.d\n" >> $trimlog
sudo ls -l /etc/udev/rules.d >> $trimlog
sudo printf "\n** cat /etc/udev/rules.d/10*trim.rules\n" >> $trimlog
sudo cat /etc/udev/rules.d/10-*-*trim.rules >> $trimlog
sudo printf "\n** sg_vpd -p bl $diskname\n" >> $trimlog
sudo sg_vpd -p bl $diskname  >> $trimlog
sudo printf "\n** sg_vpd -p lbpv $diskname\n" >> $trimlog
sudo sg_vpd -p lbpv $diskname >> $trimlog
echo "Please get the file '$trimlog' to the maintainer"
EOF
			    chmod 755 /usr/local/bin/debug-trim-enable
			fi
		    fi
		done < <(find /sys/bus/usb/devices -maxdepth 1 -type l  -regextype egrep -regex '.*usb[0-9]' -print)
		if [ "$idv" != "" -a "$idp" != "" ]
		then
		    echo "ACTION==\"add|change\", ATTRS{idVendor}==\"$idv\", ATTRS{idProduct}==\"$idp\", SUBSYSTEM==\"scsi_disk\", ATTR{provisioning_mode}=\"unmap\"" > $udevrule
		    echo "ACTION==\"add|change\", KERNEL==\"$rawdev\", SUBSYSTEM==\"block\", RUN+=\"/bin/sh -c 'echo $maxbytes > /sys/block/$rawdev/queue/discard_max_bytes'\"" >> $udevrule
		    logtoboth "* Plugin $pfx: Write udev rule $udevrule"
		    logtoboth "* Plugin $pfx:  with contents: $(cat $udevrule)"
		else
		    logtoboth "? Plugin $pfx: Did not find idProduct and idVendor for $diskname"
		fi
	    else
		logtoboth "% Plugin $pfx: Device $diskname does not support trim"
	    fi
	fi
    done < <(lsscsi --brief)
}

[[ ! $EUID -eq 0 ]] && echo "? Please run as root: sudo $0 $*" && exit
for p in lsscsi sg_vpd
do
    [ "$(type -p $p)" == "" ] && echo "? $p missing; Do sudo apt --yes install sg3-utils lsscsi" && exit
done
pfx="trim-enable"
trimcfg "$1"
exit