Merge ~rodsmith/plainbox-provider-checkbox:disk-stress-ng-support-lvm into plainbox-provider-checkbox:master

[Rod Smith]

Adds support for LVM to the disk-stress-ng test. When the test detects that the biggest partition is an LVM, it scans the LVM for logical volumes and, if one of them is the biggest device, tests on it rather than on a small partition (or nothing at all).

[Jeff Lane  (bladernr)]

Tested, and a bit cleaner than my attempt.

review: Approve

diff --git a/bin/disk_stress_ng b/bin/disk_stress_ng
index 8445488..802d116 100755
--- a/bin/disk_stress_ng
+++ b/bin/disk_stress_ng
@@ -63,11 +63,40 @@ get_params() {
 } # get_params()
 
 
-# Find the largest partition that holds a supported filesystem on $disk_device.
+# Find the largest logical volume in an LVM partition.
 # Output:
 #   $largest_part -- Device filename of largest qualifying partition
 #   $largest_size -- Size of largest qualifying partition
 #   $largest_fs -- Filesystem (ext4, etc.) used on largest qualifying partition
+# Note: Above variables are initialized in find_largest_partition(), which
+# calls this function.
+# Caveat: If LVM is used, there can be no guarantee that a specific disk
+# device is actually being tested. Thus, an LVM configuration should span
+# just one disk device. LVM may be used on one disk, but subsequent disks
+# should use "raw" partitions.
+find_largest_lv() {
+    local partonly=$(echo $partition | cut -f 3 -d "/")
+    for syslv in $(ls -d /sys/block/dm-*/slaves/$partonly) ; do
+        lv=$(echo "$syslv" | cut -f 4 -d "/")
+        size=$(cat /sys/block/$lv/size)
+        sector_size=$(cat /sys/block/$lv/queue/hw_sector_size)
+        let size=$size*$sector_size
+        local blkid_info=$(blkid -s TYPE /dev/$lv | grep -E ext2\|ext3\|ext4\|xfs\|jfs\|btrfs)
+        if [ "$size" -gt "$largest_size" ] && [ -n "$blkid_info" ] ; then
+            local blkid_info=$(blkid -s TYPE /dev/$lv)
+            largest_size=$size
+            largest_part="/dev/$lv"
+            largest_fs=$(blkid -s TYPE "/dev/$lv" | cut -d "=" -f 2)
+        fi
+    done
+} # find_largest_lv()
+
+
+# Find the largest partition that holds a supported filesystem on $disk_device.
+# Output:
+#   $largest_part -- Device filename of largest qualifying partition or logical volume
+#   $largest_size -- Size of largest qualifying partition or logical volume
+#   $largest_fs -- Filesystem (ext4, etc.) used on largest qualifying partition or logicl volume
 #   $unsupported_fs -- Empty or contains name of unsupported filesystem found on disk
 find_largest_partition() {
     largest_part=""
@@ -76,11 +105,15 @@ find_largest_partition() {
     unsupported_fs=""
     for partition in $(echo "$partitions" | cut -d " " -f 1) ; do
         part_size=$(echo "$partitions" | grep "$partition " | cut -d " " -f 2)
-        local blkid_info=$(blkid -s TYPE /dev/$partition | grep -E ext2\|ext3\|ext4\|xfs\|jfs\|btrfs)
+        local blkid_info=$(blkid -s TYPE /dev/$partition | grep -E ext2\|ext3\|ext4\|xfs\|jfs\|btrfs\|LVM2_member)
         if [ "$part_size" -gt "$largest_size" ] && [ -n "$blkid_info" ]  ; then
-            largest_size=$part_size
-            largest_part="/dev/$partition"
-            largest_fs=$(blkid -s TYPE "/dev/$partition" | cut -d "=" -f 2)
+            if [[ "$blkid_info" =~ .*LVM2_member.* ]] ; then
+                find_largest_lv
+            else
+                largest_size=$part_size
+                largest_part="/dev/$partition"
+                largest_fs=$(blkid -s TYPE "/dev/$partition" | cut -d "=" -f 2)
+            fi
         fi
         local blkid_info=$(blkid -s TYPE /dev/$partition | grep -E ntfs\|vfat\|hfs)
         if [ -n "$blkid_info" ]  ; then