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 

1 files changed, 84 insertions, 0 deletions

diff --git a/cmd/zpool/zpool.d/lsblk b/cmd/zpool/zpool.d/lsblk
new file mode 100755
index 000000000..e38a71941
--- /dev/null
+++ b/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