Re: [PATCH blktests] Add use of logger so that syslog files show when each test starts

[Omar Sandoval <osandov@osandov.com>]

On Mon, Nov 26, 2018 at 01:32:11PM -0500, Theodore Y. Ts'o wrote:
> On Mon, Nov 26, 2018 at 09:50:57AM -0800, Omar Sandoval wrote:
> > 
> > Hey, Ted, sorry, I meant to ask you about this in person at LPC but
> > forgot to. Forgive my ignorance about syslog, but does syslog not pick
> > up the line we write to dmesg?
> 
> Unfortunately, it does not.
> 
> root@xfstests-ltm:~# echo foo testing >> /dev/kmsg 
> root@xfstests-ltm:~# dmesg | tail
> [    7.103899] random: crng init done
> [    7.104759] random: 7 urandom warning(s) missed due to ratelimiting
> [    7.154525] EDAC MC: Ver: 3.0.0
> [    7.221973] EDAC sbridge: Seeking for: PCI ID 8086:2fa0
> [    7.221977] EDAC sbridge:  Ver: 1.1.1 
> [    7.259154] device-mapper: uevent: version 1.0.3
> [    7.267252] device-mapper: ioctl: 4.35.0-ioctl (2016-06-23) initialised: dm-devel@redhat.com
> [    7.762306] EXT4-fs (sda1): resizing filesystem from 2620928 to 13106683 blocks
> [    8.541258] EXT4-fs (sda1): resized filesystem to 13106683
> [840160.646340] foo testing
> root@xfstests-ltm:~# tail /var/log/kern.log
> root@xfstests-ltm:~# grep kern.log /etc/rsyslog.conf 
> kern.*				-/var/log/kern.log
> 
> So as you can see nothing written to kern.log, even though we wrote to
> /dev/kmsg.
> 
> To prove that kern.log will get kernel messages:
> 
> root@xfstests-ltm:~# mke2fs -t ext4 -Fq /tmp/foo.img 8M
> root@xfstests-ltm:~# mount -t ext4 /tmp/foo.img /mnt
> root@xfstests-ltm:~# echo testing > /sys/fs/ext4/loop0/trigger_fs_error 
> root@xfstests-ltm:~# tail /var/log/kern.log
> Nov 26 13:30:22 xfstests-ltm kernel: [840286.728296] loop: module loaded
> Nov 26 13:30:22 xfstests-ltm kernel: [840286.752181] EXT4-fs (loop0): mounted filesystem with ordered data mode. Opts: (null)
> Nov 26 13:30:41 xfstests-ltm kernel: [840305.773418] EXT4-fs error (device loop0): trigger_test_error:123: comm bash: testing
> root@xfstests-ltm:~# 

Hm, what if we output it as KERN_INFO?

diff --git a/check b/check
index f6c3537..9b4765f 100755
--- a/check
+++ b/check
@@ -314,7 +314,7 @@ _call_test() {
 
 	if [[ -w /dev/kmsg ]]; then
 		local dmesg_marker="run blktests $TEST_NAME at ${TEST_RUN["date"]}"
-		echo "$dmesg_marker" >> /dev/kmsg
+		echo "<6>$dmesg_marker" >> /dev/kmsg
 	else
 		local dmesg_marker=""
 		CHECK_DMESG=0