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@xxxxxxxxxx
> [ 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
