From 5a34ff0a99a3c5e7ba4f7982d5de3d0dcc9e3045 Mon Sep 17 00:00:00 2001
From: Craig Small <csmall@enc.com.au>
Date: Wed, 29 Jan 2014 22:22:11 +1100
Subject: [PATCH] Check for presence of disks in vmstat
vmstat -d or vmstat -p would crash mysteriously under different
circumstances. The problem was eventually tracked down to /sys not
being mounted which meant is_disk() always returned false.
The partition would then be attempted to be linked to a non-existent
disk causing a segfault.
vmstat will now not link to a disk if none exists.
The change in testing will skip those tests when /sys/block doesn't
exist.
Many thanks to Daniel Schepler for his analysis and suggestions.
Bug-Debian: http://bugs.debian.org/736628
---
proc/sysinfo.c | 7 +++++--
testsuite/vmstat.test/vmstat.exp | 22 +++++++++++++++-------
2 files changed, 20 insertions(+), 9 deletions(-)
diff --git a/proc/sysinfo.c b/proc/sysinfo.c
index f318376c..1680cc4a 100644
--- a/proc/sysinfo.c
+++ b/proc/sysinfo.c
@@ -938,8 +938,11 @@ unsigned int getdiskstat(struct disk_stat **disks, struct partition_stat **parti
&(*partitions)[cPartition].writes,
&(*partitions)[cPartition].requested_writes
);
- (*partitions)[cPartition++].parent_disk = cDisk-1;
- (*disks)[cDisk-1].partitions++;
+
+ if (cDisk > 0) {
+ (*partitions)[cPartition++].parent_disk = cDisk-1;
+ (*disks)[cDisk-1].partitions++;
+ }
}
}
diff --git a/testsuite/vmstat.test/vmstat.exp b/testsuite/vmstat.test/vmstat.exp
index fb5de149..f470afc3 100644
--- a/testsuite/vmstat.test/vmstat.exp
+++ b/testsuite/vmstat.test/vmstat.exp
@@ -26,15 +26,23 @@ expect_pass "$test" "^Cache\\s+Num\\s+Total\\s+Size\\s+Pages\\s+\(\[\(\)A-Za-z0-
}
set test "vmstat disk information (-d option)"
-spawn $vmstat -d
-expect_pass "$test" "^disk\[ -\]+reads\[ -\]+writes\[ -\]+IO\[ -\]+\\s+total\\s+merged\\s+sectors\\s+ms\\s+total\\s+merged\\s+sectors\\s+ms\\s+cur\\s+sec\\s+"
+if { [ file readable "/sys/block" ] == 0 } {
+ unsupported "$test /sys/block not readable"
+} else {
+ spawn $vmstat -d
+ expect_pass "$test" "^disk\[ -\]+reads\[ -\]+writes\[ -\]+IO\[ -\]+\\s+total\\s+merged\\s+sectors\\s+ms\\s+total\\s+merged\\s+sectors\\s+ms\\s+cur\\s+sec\\s+"
+}
# Need a partition
set diskstats [ exec cat /proc/diskstats ]
-if [ regexp "\\s+\\d+\\s+\\d+\\s+\(\[a-z\]+\\d+\)\\s+\[0-9\]\[0-9\]+" $diskstats line partition == 1 ] {
- set test "vmstat partition (using $partition)"
- spawn $vmstat -p $partition
- expect_pass "$test" "^${partition}\\s+reads"
+if { [ file readable "/sys/block" ] == 0 } {
+ unsupported "vmstat partition /sys/block not readable"
} else {
- unsupported "vmstat partition (cannot find partition)"
+ if [ regexp "\\s+\\d+\\s+\\d+\\s+\(\[a-z\]+\\d+\)\\s+\[0-9\]\[0-9\]+" $diskstats line partition == 1 ] {
+ set test "vmstat partition (using $partition)"
+ spawn $vmstat -p $partition
+ expect_pass "$test" "^${partition}\\s+reads"
+ } else {
+ unsupported "vmstat partition (cannot find partition)"
+ }
}
--
2.40.0