Prebaked scripts for zpool status/iostat -c

This patch updates the "zpool status/iostat -c" commands to only run
"pre-baked" scripts from the /etc/zfs/zpool.d directory (or wherever
you install to).  The scripts can only be run from -c as an unprivileged
user (unless the ZPOOL_SCRIPTS_AS_ROOT environment var is
set by root).  This was done to encourage scripts to be written is such
a way that normal users can use them, and to be cautious.  If your
script needs to run a privileged command, consider adding the
appropriate line in /etc/sudoers.  See zpool(8) for an example of how
to do this.

The patch also allows the scripts to output custom column names.  If
the script outputs a line like:

name=value

then "name" is used for the column name, and "value" is its value.
Multiple columns can be specified by outputting multiple lines.  Column
names and values can have spaces.  If the value is empty, a dash (-) is
printed instead.

After all the "name=value" lines are read (if any), zpool will take the
next the next line of output (if any) and print it without a column
header.  After that, no more lines will be processed. This can be
useful for printing errors.

Lastly, this patch also disables the -c option with the latency and
request size histograms, since it produced awkward output and made the
code harder to maintain.

Reviewed-by: Brian Behlendorf <[email protected]>
Reviewed-by: Giuseppe Di Natale <[email protected]>
Signed-off-by: Tony Hutter <[email protected]>
Closes #5852

Makefile.am

@@ -57,7 +57,8 @@ shellcheck:
 			scripts/zfs-tests.sh \
 			scripts/zfs.sh \
 			scripts/commitcheck.sh \
-			$$(find cmd/zed/zed.d/*.sh -type f); \
+			$$(find cmd/zed/zed.d/*.sh -type f) \
+			$$(find cmd/zpool/zpool.d/* -executable); \
 	fi
 
 lint: cppcheck paxcheck

cmd/zpool/Makefile.am

@@ -20,3 +20,54 @@ zpool_LDADD = \
 	$(top_builddir)/lib/libzfs/libzfs.la \
 	$(top_builddir)/lib/libzfs_core/libzfs_core.la \
 	-lm $(LIBBLKID)
+
+zpoolconfdir = $(sysconfdir)/zfs/zpool.d
+zpoolexecdir = $(libexecdir)/zfs/zpool.d
+
+EXTRA_DIST = zpool.d/README
+
+dist_zpoolexec_SCRIPTS = \
+	zpool.d/enc \
+	zpool.d/encdev \
+	zpool.d/fault_led \
+	zpool.d/iostat \
+	zpool.d/iostat-1s \
+	zpool.d/iostat-10s \
+	zpool.d/label \
+	zpool.d/locate_led \
+	zpool.d/lsblk \
+	zpool.d/model \
+	zpool.d/serial \
+	zpool.d/ses \
+	zpool.d/size \
+	zpool.d/slaves \
+	zpool.d/slot \
+	zpool.d/upath \
+	zpool.d/vendor
+
+zpoolconfdefaults = \
+	enc \
+	encdev \
+	fault_led \
+	iostat \
+	iostat-1s \
+	iostat-10s \
+	label \
+	locate_led \
+	lsblk \
+	model \
+	serial \
+	ses \
+	size \
+	slaves \
+	slot \
+	upath \
+	vendor
+
+install-data-hook:
+	$(MKDIR_P) "$(DESTDIR)$(zpoolconfdir)"
+	for f in $(zpoolconfdefaults); do \
+	  test -f "$(DESTDIR)$(zpoolconfdir)/$${f}" -o \
+	       -L "$(DESTDIR)$(zpoolconfdir)/$${f}" || \
+	    ln -s "$(zpoolexecdir)/$${f}" "$(DESTDIR)$(zpoolconfdir)"; \
+	done

cmd/zpool/zpool.d/README

@@ -0,0 +1,9 @@
+This directory contains scripts that can be run the zpool status/iostat
+-c option:
+
+	zpool status -c script1,script2, ...
+
+	zpool iostat -vc script1,script2, ...
+
+Some scripts output different values depending on the symlink name that is
+used to run them.  See the zpool(8) man page for more details.

cmd/zpool/zpool.d/enc

@@ -0,0 +1 @@
+ses

cmd/zpool/zpool.d/encdev

@@ -0,0 +1 @@
+ses

cmd/zpool/zpool.d/fault_led

@@ -0,0 +1 @@
+ses

cmd/zpool/zpool.d/iostat

@@ -0,0 +1,65 @@
+#!/bin/sh
+#
+# Display most relevant iostat bandwidth/latency numbers.  The output is
+# dependent on the name of the script/symlink used to call it.
+#
+
+helpstr="
+iostat:		Show iostat values since boot (summary page).
+iostat-1s:	Do a single 1-second iostat sample and show values.
+iostat-10s:	Do a single 10-second iostat sample and show values."
+
+script=$(basename "$0")
+if [ "$1" = "-h" ] ; then
+	echo "$helpstr" | grep "$script:" | tr -s '\t' | cut -f 2-
+	exit
+fi
+
+if [ "$script" = "iostat-1s" ] ; then
+	# Do a single one-second sample
+	extra="1 1"
+	# Don't show summary stats
+	y="-y"
+elif [ "$script" = "iostat-10s" ] ; then
+	# Do a single ten-second sample
+	extra="10 1"
+	# Don't show summary stats
+	y="-y"
+fi
+
+if [ -f "$VDEV_UPATH" ] ; then
+	# We're a file-based vdev, iostat doesn't work on us.  Do nothing.
+	exit
+fi
+
+out=$(eval "iostat $y -k -x $VDEV_UPATH $extra")
+
+# Sample output (we want the last two lines):
+#
+# Linux 2.6.32-642.13.1.el6.x86_64 (centos68) 	03/09/2017 	_x86_64_	(6 CPU)
+#
+# avg-cpu:  %user   %nice %system %iowait  %steal   %idle
+#           0.00    0.00    0.00    0.00    0.00  100.00
+#
+# Device:         rrqm/s   wrqm/s     r/s     w/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await r_await w_await  svctm  %util
+# sdb               0.00     0.00    0.00    0.00     0.00     0.00     0.00     0.00    0.00    0.00    0.00   0.00   0.00
+#
+
+# Get the column names
+cols=$(echo "$out" | grep Device)
+
+# Get the values and tab separate them to make them cut-able.
+vals="$(echo "$out" | grep -A1 Device | tail -n 1 | sed -r 's/[[:blank:]]+/\t/g')"
+
+i=0
+for col in $cols ; do
+	i=$((i+1))
+	# Skip the first column since it's just the device name
+	if [ "$col" = "Device:" ] ; then
+		continue
+	fi
+
+	# Get i'th value
+	val=$(echo "$vals" | cut -f "$i")
+	echo "$col=$val"
+done

cmd/zpool/zpool.d/iostat-10s

@@ -0,0 +1 @@
+iostat

cmd/zpool/zpool.d/iostat-1s

@@ -0,0 +1 @@
+iostat

cmd/zpool/zpool.d/label

@@ -0,0 +1 @@
+lsblk

cmd/zpool/zpool.d/locate_led

@@ -0,0 +1 @@
+ses

cmd/zpool/zpool.d/lsblk

@@ -0,0 +1,84 @@
+#!/bin/sh
+#
+# Print some common lsblk values
+#
+# Any (lowercased) name symlinked to the lsblk script will be passed to lsblk
+# as one of its --output names.  Here's a partial list of --output names
+# from the lsblk binary:
+#
+# Available columns (for --output):
+#        NAME  device name
+#       KNAME  internal kernel device name
+#     MAJ:MIN  major:minor device number
+#      FSTYPE  filesystem type
+#  MOUNTPOINT  where the device is mounted
+#       LABEL  filesystem LABEL
+#        UUID  filesystem UUID
+#          RA  read-ahead of the device
+#          RO  read-only device
+#          RM  removable device
+#       MODEL  device identifier
+#        SIZE  size of the device
+#       STATE  state of the device
+#       OWNER  user name
+#       GROUP  group name
+#        MODE  device node permissions
+#   ALIGNMENT  alignment offset
+#      MIN-IO  minimum I/O size
+#      OPT-IO  optimal I/O size
+#     PHY-SEC  physical sector size
+#     LOG-SEC  logical sector size
+#        ROTA  rotational device
+#       SCHED  I/O scheduler name
+#     RQ-SIZE  request queue size
+#        TYPE  device type
+#    DISC-ALN  discard alignment offset
+#   DISC-GRAN  discard granularity
+#    DISC-MAX  discard max bytes
+#   DISC-ZERO  discard zeroes data
+#
+# If the script is run as just 'lsblk' then print out disk size, vendor,
+# model number and serial number.
+
+
+helpstr="
+label:	Show filesystem label.
+model:	Show disk model number.
+serial:	Show disk serial number.
+size:	Show the disk capacity.
+vendor:	Show the disk vendor.
+lsblk:	Show the disk size, vendor, model number, and serial number."
+
+script=$(basename "$0")
+
+if [ "$1" = "-h" ] ; then
+        echo "$helpstr" | grep "$script:" | tr -s '\t' | cut -f 2-
+        exit
+fi
+
+if [ "$script" = "lsblk" ] ; then
+	list="size vendor model serial"
+else
+	list=$(echo "$script" | tr '[:upper:]' '[:lower:]')
+fi
+
+# Older versions of lsblk don't support all these values (like SERIAL).
+for i in $list ; do
+
+	# Special case: Looking up the size of a file-based vdev can't
+	# be done with lsblk.
+	if [ "$i" = "size" ] && [ -f "$VDEV_UPATH" ] ; then
+		size="$(du -h --apparent-size $VDEV_UPATH | cut -f 1)"
+		echo "size=$size"
+		continue
+	fi
+
+
+	val=""
+	if val=$(eval "lsblk -dl -n -o $i $VDEV_UPATH 2>/dev/null") ; then
+		# Remove leading/trailing whitespace from value
+		val=$(echo "$val" | sed -e 's/^[[:space:]]*//' \
+		     -e 's/[[:space:]]*$//')
+	fi
+	echo "$i=$val"
+done

cmd/zpool/zpool.d/model

@@ -0,0 +1 @@
+lsblk

cmd/zpool/zpool.d/serial

@@ -0,0 +1 @@
+lsblk

cmd/zpool/zpool.d/ses

@@ -0,0 +1,52 @@
+#!/bin/sh
+#
+# Print SCSI Enclosure Services (SES) info. The output is dependent on the name
+# of the script/symlink used to call it.
+#
+helpstr="
+enc:		Show disk enclosure w:x:y:z value.
+slot:		Show disk slot number as reported by the enclosure.
+encdev:		Show the /dev/sg* device for the enclosure associated with the disk slot.
+fault_led:	Show the value of the disk enclosure slot fault LED.
+locate_led:	Show the value of the disk enclosure slot locate LED.
+ses:		Show disk's enclosure, enclosure dev, slot number, and fault/locate LED values."
+
+script=$(basename "$0")
+if [ "$1" = "-h" ] ; then
+	echo "$helpstr" | grep "$script:" | tr -s '\t' | cut -f 2-
+	exit
+fi
+
+if [ "$script" = "ses" ] ; then
+	scripts='enc encdev slot fault_led locate_led'
+else
+	scripts="$script"
+fi
+
+for i in $scripts ; do
+	if [ -z "$VDEV_ENC_SYSFS_PATH" ] ; then
+		echo "$i="
+		continue
+	fi
+
+	val=""
+	case $i in
+	enc)
+		val=$(ls "$VDEV_ENC_SYSFS_PATH/../../" 2>/dev/null)
+		;;
+	slot)
+		val=$(cat "$VDEV_ENC_SYSFS_PATH/slot" 2>/dev/null)
+		;;
+	encdev)
+		val=$(ls "$VDEV_ENC_SYSFS_PATH/../device/scsi_generic" 2>/dev/null)
+		;;
+	fault_led)
+		val=$(cat "$VDEV_ENC_SYSFS_PATH/fault" 2>/dev/null)
+		;;
+	locate_led)
+		val=$(cat "$VDEV_ENC_SYSFS_PATH/locate" 2>/dev/null)
+		;;
+	esac
+	echo "$i=$val"
+done
+

cmd/zpool/zpool.d/size

@@ -0,0 +1 @@
+lsblk

cmd/zpool/zpool.d/slaves

@@ -0,0 +1,32 @@
+#!/bin/sh
+#
+# Show device mapper slave devices.  This is useful for looking up the
+# /dev/sd* devices associated with a dm or multipath device.  For example:
+#
+# $ ls /sys/block/dm-113/slaves/
+# sddt  sdjw
+#
+
+if [ "$1" = "-h" ] ; then
+	echo "Show device mapper slave devices."
+	exit
+fi
+
+dev="$VDEV_PATH"
+
+# If the VDEV path is a symlink, resolve it to a real device
+if [ -L "$dev" ] ; then
+	dev=$(readlink "$dev")
+fi
+
+dev=$(basename "$dev")
+val=""
+if [ -d "/sys/class/block/$dev/slaves" ] ; then
+	# ls -C: output in columns, no newlines
+	val=$(ls -C "/sys/class/block/$dev/slaves")
+
+	# ls -C will print two spaces between files; change to one space.
+	val=$(echo "$val" | sed -r 's/[[:blank:]]+/ /g')
+fi
+
+echo "slaves=$val"

cmd/zpool/zpool.d/slot

@@ -0,0 +1 @@
+ses

cmd/zpool/zpool.d/upath

@@ -0,0 +1,7 @@
+#!/bin/sh
+if [ "$1" = "-h" ] ; then
+	echo "Show the underlying path for a device."
+	exit
+fi
+
+echo upath="$VDEV_UPATH"

cmd/zpool/zpool.d/vendor

@@ -0,0 +1 @@
+lsblk