Commit Graph

24 Commits

Author SHA1 Message Date
Kairui Song
61e016939c User get_mount_info to replace findmnt calls
Use get_mount_info so that fstab is used as a failback when look for
mount info.

Signed-off-by: Kairui Song <kasong@redhat.com>
Acked-by: Pingfan Liu <piliu@redhat.com>
2020-05-22 16:14:02 +08:00
Kairui Song
0624148414 Add a is_mounted helper
Use is_mounted helper instaed of calling findmnt directly or checking if
"mount" value is empty.

If findmnt looks for fstab as well, some non mounted entry will also
return value. Required to support non-mounted target.

Signed-off-by: Kairui Song <kasong@redhat.com>
Acked-by: Pingfan Liu <piliu@redhat.com>
2020-05-22 16:13:24 +08:00
Kairui Song
33e79681d9 Fix the problem that kdump prints redundant /
In second kernel, kdump always prints redundant '/':

kdump: saving to /sysroot//var/crash/127.0.0.1-2020-03-12-21:32:54/

Just trim it.

Signed-off-by: Kairui Song <kasong@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2020-05-11 14:22:22 +08:00
Kazuhito Hagio
74081a2b64 Don't unmount the dump target just after saving vmcore
Since commit 6dee286467 ("Don't mount the dump target unless needed"),
dump_fs function unmounts the dump target just after saving vmcore.

This broke the condition that it's mounted when executing "kdump_post",
which had been stable since RHEL5, and a certain tool which uses the
kdump_post hook to save information of 2nd kernel to the dump target
started to fail.

As unmounting it is done by systemd-shutdown before reboot without
the umount command as below, so let's don't unmount it in dump_fs.

  systemd-shutdown[1]: Unmounting file systems.
  [547]: Remounting '/sysroot' read-only in with options '(null)'.
  EXT4-fs (dm-0): re-mounted. Opts: (null)
  [548]: Unmounting '/sysroot'.

Signed-off-by: Kazuhito Hagio <k-hagio-ab@nec.com>
Acked-by: Kairui Song <kasong@redhat.com>
2020-04-27 16:30:59 +08:00
Hari Bathini
e3f2f926dd powerpc: enable the scripts to capture dump on POWERNV platform
With FADump support added on POWERNV paltform, enable the scripts to
capture /proc/vmcore. Also, if CONFIG_OPAL_CORE is enabled, OPAL core
is preserved and exported on POWERNV platform. So, offload OPAL core,
if it is available.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Acked-by: Kairui Song <kasong@redhat.com>
2020-02-06 22:13:06 +08:00
Kairui Song
cee618593c Add a hook to wait for kdump target in initqueue
The dracut initqueue may quit immediately and won't trigger any hook if
there is no "finished" hook still pending (finished hook will be deleted
once it return 0).

This issue start to appear with latest dracut, latest dracut use
network-manager to configure the network,
network-manager module only install "settled" hook, and we didn't
install any other hook. So NFS/SSH dump will fail. iSCSI dump works
because dracut iscsi module will install a "finished" hook to detect if
the iscsi target is up.

So for NFS/SSH we keep initqueue running until the host successfully get
a valid IP address, which means the network is ready.

Signed-off-by: Kairui Song <kasong@redhat.com>
Acked-by: Pingfan Liu <piliu@redhat.com>
2020-01-29 08:12:45 +08:00
Kairui Song
39352d0cfc Don't execute final_action if failure_action terminates the system
If failure_action is shutdown/reboot/halt, final_action is pointless as
the system will be already stopping. And if final_action is different
from failure_action, it will trigger a systemd race problem and cause
unexpected behavior to occur.

So let the error handler stop and exit after performing failure_action
successfully if failure_action is one of shutdown/reboot/halt.
This way, final_action will not be executed.

Signed-off-by: Kairui Song <kasong@redhat.com>
Acked-by: Pingfan Liu <piliu@redhat.com>
2019-11-01 11:21:58 +08:00
Kairui Song
6dee286467 Don't mount the dump target unless needed
For fadump, this helps to reduce the risk of boot failure, and
may also help speed up the boot by a bit.

For normal kdump, this will delay the dump target mounting, and no
longer depend on systemd to do the mounting job.

And currently there is a failure that caused by some mount handling
bug with kernel and systemd that is failing the system booting:

[FAILED] Failed to mount /kdumproot/home.
See 'systemctl status kdumproot-home.mount' for details.
[DEPEND] Dependency failed for Local File Systems.
[  OK  ] Reached target Remote File Systems (Pre).
[  OK  ] Reached target Remote File Systems.
         Starting udev Coldplug all Devices...
         Starting Create Volatile Files and Directories...
         Starting Kdump Emergency...

This patch can bypass it. The fix of root cause is still WIP, but this
patch itself is a nice to have optimization so it's reasonable to do so.

Signed-off-by: Kairui Song <kasong@redhat.com>
Acked-by: Pingfan Liu <piliu@redhat.com>
2019-09-29 17:12:54 +08:00
Kairui Song
75d9132417 Get rid of duplicated strip_comments when reading config
When reading kdump configs, a single parsing should be enough and this
saves a lot of duplicated striping call which speed up the total load
speed.

Speed up about 2 second when building and 0.1 second for reload in my
tests.

Signed-off-by: Kairui Song <kasong@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2019-05-20 16:56:28 +08:00
Kazuhito Hagio
242da37c58 Add final_action option to kdump.conf
If a crash occurs repeatedly after enabling kdump, the system goes
into a crash loop and the dump target may get filled up by vmcores.
This is likely especially with early kdump.

This patch introduces 'final_action' option to kdump.conf, in order
for users to be able to power off the system even after capturing
a vmcore successfully.

Signed-off-by: Kazuhito Hagio <k-hagio@ab.jp.nec.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Lianbo Jiang <lijiang@redhat.com>
Cc: Bhupesh Sharma <bhsharma@redhat.com>
Acked-by: Bhupesh Sharma <bhsharma@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Kairui Song <kasong@redhat.com>
2019-01-22 17:58:24 +08:00
Kazuhito Hagio
cc95f0a744 Add failure_action as alias of default and make default obsolete
In preparation for adding 'final_action' option, since it's confusing
to have the 'final_action' and 'default' options at the same time,
this patch introduces 'failure_action' as an alias of the 'default'
option to /etc/kdump.conf, and makes 'default' obsolete to be removed
in the future.

Also, the "default action" term is renamed to "failure action".

Signed-off-by: Kazuhito Hagio <k-hagio@ab.jp.nec.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Lianbo Jiang <lijiang@redhat.com>
Cc: Bhupesh Sharma <bhsharma@redhat.com>
Acked-by: Bhupesh Sharma <bhsharma@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Kairui Song <kasong@redhat.com>
2019-01-22 17:57:53 +08:00
Pingfan Liu
89565289c6 kdump-lib-initramfs.sh: using -force option when poweroff
If default action is poweroff, we can observe that the machine is
rebooted, instead of poweroff. That is due to the following two race
processes:
    systemctl poweroff
    systemctl reboot -f
which is launched by kdump-error-handle.sh.

Unfortunately, although both of them are executed in systemd block
mode, but due to poweroff will tear down some internal things in
systemd, there is no guarantee for the block mode. As we can see
the msg "Failed to execute operation: Connection reset by peer",
which is thrown by "systemctl reboot -f".

poweroff and reboot share most of code, if one fails, then the other
should also fails, so it is meaningless to use reboot as the backup of
poweroff. Using "systemctl poweroff -f", the sdbus will teared down
immediately, which prevent the following "systemctl reboot -f" from
executing. Meanwhile, as man systemctl says:
    -f, --force
        When used with enable, overwrite any existing conflicting symlinks.

        When used with halt, poweroff, reboot or kexec, execute the selected
        operation without shutting down all units. However, all processes will
        be killed forcibly and all file systems are unmounted or remounted read-only.

Hence, replacing the 'poweroff' with 'systemctl poweroff -f'

Signed-off-by: Pingfan Liu <piliu@redhat.com>
Acked-by: Kairui Song <kasong@redhat.com>
2018-12-10 14:37:57 +08:00
Kenneth Dsouza
ac55095191 kdump-lib-initramfs.sh: Add check to remount to rw mode only if dump target is ro.
Currently the script does not check if the dump target is read-only and would
always mount to read-write mode. This caused an issue with nfs mount as the
fstab options would be reconsidered while remounting to read-write mode.
The remount would fail with the below error as all options cannot be changed
runtime.

mount.nfs: mount(2): Invalid argument
mount.nfs: an incorrect mount option was specified

Which in result would not save the vmcore on the dump target.

This patch addresses this issue by checking the dump target status for read-only.
If yes, remount to read-write mode without reconsidering the fstab options.

Signed-off-by: Kenneth D'souza <kdsouza@redhat.com>
Acked-by: Kairui Song <kasong@redhat.com>
2018-10-15 10:46:44 +08:00
Pingfan Liu
0165cfa332 kdump-lib-initramfs.sh: ignore the failure of echo
The kdump-capture.service will fail, if the following conds are meet up.
-1. boot up a VM with the following cmd:
qemu-kvm   -name 'avocado-vt-vm1'  -sandbox off    -machine pc   -nodefaults  -vga cirrus \
    -drive id=drive_image1,if=none,snapshot=off,aio=native,cache=none,format=qcow2,file=$guest_img \
    -device virtio-blk-pci,id=image1,drive=drive_image1,bootindex=0,bus=pci.0,addr=04 \
    -device virtio-net-pci,mac=9a:4d:4e:4f:50:51,id=id3DveCw,vectors=4,netdev=idgW5YRp,bus=pci.0,addr=05 \
    -netdev tap,id=idgW5YRp \
    -m 2048  \
    -smp 4,maxcpus=4,cores=2,threads=1,sockets=2  \
    -cpu 'SandyBridge',+kvm_pv_unhalt \
    -vnc :0  \
    -rtc base=utc,clock=host,driftfix=slew  \
    -boot order=cdn,once=c,menu=off,strict=off \
    -enable-kvm \
    -monitor stdio \
    -qmp tcp:localhost:4444,server,nowait
-2. in kernel cmdline with the following options: console=tty0 console=ttyS0,

Because the  "-nodefaults" option in qemu cmd excludes the emulation of serial port, the ttyS0 will
have no real backend device. We can observe such issue in 1st kernel by:
	echo teststring > /dev/console or
	echo teststring > /dev/ttyS0,
It gets the error "-bash: echo: write error: Input/output error".
Such conds cause small issue in 1st kernel, but it is a big problem for kdump-capture and emergency
service.

This patch aims to work aroundthe issue in kdump-capture service:
dump_fs() return value will affect the following code in dracut-kdump.sh
	DUMP_RETVAL=$?    <---
	do_kdump_post $DUMP_RETVAL
	if [ $? -ne 0 ]; then
	    echo "kdump: kdump_post script exited with non-zero status!"
	fi

Although kdump-capture saves the vmcore successfully, but it exit 1 and
fall on emergency service.

Signed-off-by: Pingfan Liu <piliu@redhat.com>
Reviewed-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-04-27 13:59:49 +08:00
Dave Young
b253434819 use "systemctl reboot -f" for reboot action
In latest rawhide kdump kernel reboot hangs because systemd reports a
conflict when kdump calls reboot during booting. Need further investigation
about the new systemd behavior.

Here is the error message copied from kdump session:
[snip]
kdump: saving vmcore complete
Failed to start reboot.target: Transaction contains conflicting jobs 'stop' and 'start' for shutdown.target. Probably contradicting requirement dependencies configured.
Failed to talk to init daemon.
[FAILED] Failed to start Kdump Vmcore Save Service.
[snip]

We previouly use "reboot -f" but later we changed to reboot because we want
systemd to take care of the shutdown path, mainly for umount filesystems.

Change back to "reboot -f" works but we still need umount by ourselves.
During my tests with "reboot -f" I get below dirty ext2 filesystem:

[root@localhost ~]# fsck /dev/vdb
fsck from util-linux 2.27
e2fsck 1.42.13 (17-May-2015)
/dev/vdb was not cleanly unmounted, check forced.

Actually "reboot -f" equals to "systemctl reboot -f -f"

systemctl manpage says "-f" and "-f -f" means different behavior:
When use -f with reboot, will execute reboot without shutting down all units.
However all processes will be killed forcibly and all file systems are
unmounted or remounted read-only. If -f is specified twice, will reboot
immediately without terminating any processes or unmounting any file systems.

Thus change to use "systemctl reboot -f" for our reboot actions. It can fix
the problem and at the same time it can ensure filesystems are umounted before
rebooting.

OTOH, a systemd changes cause the breakage, it may be a system service new
design, Later I can dig into systemd changes see which commit cause the
breakage.

Signed-off-by: Dave Young <dyoung@redhat.com
Signed-off-by: Dangyi Liu <dliu@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
2015-12-11 15:20:54 +08:00
Baoquan He
6f4940f198 Revert "execute kdump_post after do_default_action"
This reverts commit f4c45236bf.
Since that commit will change the behaviour of kdump_post. That is not
good.

Signed-off-by: Baoquan He <bhe@redhat.com>
2015-04-08 15:50:16 +08:00
WANG Chao
84f94be90b make kdump saving directory name consistent with RHEL6
Now we use the pattern:
  <machine/ipaddr>-YYYY.MM.DD-HH:MM:SS

while rhel6 uses the following:
  <machine/ipaddr>-YYYY-MM-DD-HH:MM:SS

This change may break someone's script and we should change it back to
keep consistent between releases.

Signed-off-by: WANG Chao <chaowang@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Minfei Huang <mhuang@redhat.com>
2015-02-25 16:52:05 +08:00
Baoquan He
f4c45236bf execute kdump_post after do_default_action
User complains that kdump_post script doesn't execute after mount
failed. This happened since mount failure will trigger
kdump-error-handler.service, and then start kdump-error-handler.sh.
However in kdump-error-handler.sh it doesn't execute kdump_post.
Hence add it in this patch.

Surely the function do_kdump_post need be moved into kdump-lib-initramfs.sh
to be a common function.

v1->v2:
    Add a return value to do_kdump_post when invoked in kdump_error-handler.sh.
    And call do_kdump_post earlier than do_default_action, otherwise
    it may not execute if reboot/poweroff/halt.

Signed-off-by: Baoquan He <bhe@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Acked-by: Meifei Huang <mhuang@redhat.com>
2015-02-11 17:11:02 +08:00
WANG Chao
1742affe2c kdump-initramfs-lib: Fix core_collector issue
In ssh or raw dump case, if user do not specify "core_collector" in
kdump.conf, kdump will fail. Because global DEFAULT_CORE_COLLECTOR
variable isn't applied to CORE_COLLECTOR. Now fix it and clean up the
duplicate code in kdump.sh.

Signed-off-by: WANG Chao <chaowang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
2014-12-05 11:02:31 +08:00
WANG Chao
5a77531f8a Let systemd handle unmount
Since we've use systemd to control the shutdown path, there's not need
for us to unmount the filesystem, systemd will do that for us just like
it does in a normal boot.

Signed-off-by: WANG Chao <chaowang@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
2014-08-06 12:02:59 +08:00
WANG Chao
1719a8aa92 do not force shutdown
It's more safe to use systemd (init) to control the shutdown path for us
in either reboot or power off or halt action.

Signed-off-by: WANG Chao <chaowang@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
2014-08-06 12:02:59 +08:00
WANG Chao
002337c671 Introduce kdump error handling service
Now upon failure kdump script might not be called at all and it might
not be able to execute default action. It results in a hang.

Because we disable emergency shell and rely on kdump.sh being invoked
through dracut-pre-pivot hook. But it might happen that we never call
into dracut-pre-pivot hook because certain systemd targets could not
reach due to failure in their dependencies. In those cases error
handling code does not run and system hangs. For example:

sysroot-var-crash.mount --> initrd-root-fs.target --> initrd.target \
  --> dracut-pre-pivot.service --> kdump.sh

If /sysroot/var/crash mount fails, initrd-root-fs.target will not be
reached. And then initrd.target will not be reached,
dracut-pre-pivot.service wouldn't run. Finally kdump.sh wouldn't run.

To solve this problem, we need to separate the error handling code from
dracut-pre-pivot hook, and every time when a failure shows up, the
separated code can be called by the emergency service.

By default systemd provides an emergency service which will drop us into
shell every time upon a critical failure. It's very convenient for us to
re-use the framework of systemd emergency, because we don't have to
touch the other parts of systemd. We can use our own script instead of
the default one.

This new scheme will overwrite emergency shell and replace with kdump
error handling code. And this code will do the error handling as needed.
Now, we will not rely on dracut-pre-pivot hook running always. Instead
whenever error happens and it is serious enough that emergency shell
needed to run, now kdump error handler will run.

dracut-emergency is also replaced by kdump error handler and it's
enabled again all the way down. So all the failure (including systemd
and dracut) in 2nd kernel could be captured, and trigger kdump error
handler.

dracut-initqueue is a special case, which calls "systemctl start
emergency" directly, not via "OnFailure=emergency". In case of failure,
emergency is started, but not in a isolation mode, which means
dracut-initqueue is still running. On the other hand, emergency will
call dracut-initqueue again when default action is dump_to_rootfs.
systemd would block on the last dracut-initqueue, waiting for the first
instance to exit, which leaves us hang. It looks like the following:

dracut-initqueue (running)
  --> call dracut-emergency:
    --> dracut-emergency (running)
      --> kdump-error-handler.sh (running)
        --> call dracut-initqueue:
          --> blocking and waiting for the original instance to exit.

To fix this, I'd like to introduce a wrapper emergency service. This
emegency service will replace both the systemd and dracut emergency. And
this service does nothing but to isolate to real kdump error handler
service:

dracut-initqueue (running)
  --> call dracut-emergency:
    --> dracut-emergency isolate to kdump-error-handler.service
      --> dracut-emergency and dracut-initqueue will both be stopped
          and kdump-error-handler.service will run kdump-error-handler.sh.

In a normal failure case, this still works:
foo.service fails
  --> trigger emergency.service
    --> emergency.service isolates to kdump-error-handler.service
      --> kdump-error-handler.service will run kdump-error-handler.sh

Signed-off-by: WANG Chao <chaowang@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2014-08-05 13:13:32 +08:00
WANG Chao
0787accc4e cleanup: mount dump target under /sysroot in 2nd kernel
This patch does the following change in 2nd kernel:
 - dump target is mounted under /sysroot

With this change,  we don't need to track what we've mounted in 2nd
kernel. We can just umount recursively every mount in /sysroot by
command:

  umount -R /sysroot

It's very convenient to do so, because it's hard to track what we've
mounted when we're in error handling path (later patches). So mount
everything under /sysroot is reasonable and practical for us.

Also clean up a bit along with this patch.

Signed-off-by: WANG Chao <chaowang@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2014-08-05 13:13:30 +08:00
WANG Chao
3b27570bea cleanup: extract functions from kdump.sh to kdump-lib-initramfs.sh
Extract functions from kdump.sh, and construct kdump-lib-initramfs.sh as
kdump common functions/varaibles library.

kdump-lib-initramfs.sh will include kdump-lib.sh, because it will use
the functions from there. IOW, kdump-lib-initramfs.sh will be a superset
of kdump-lib.sh

So after this cleanup:

- scripts running in 1st kernel only have to include kdump-lib.sh
- scripts running in 2nd kernel only have to include kdump-lib-initramfs.sh

Signed-off-by: WANG Chao <chaowang@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2014-08-05 13:13:11 +08:00