Commit Graph

111 Commits

Author SHA1 Message Date
Kenneth Dsouza
d92b9364ae kdumpctl: Error out if path is set more than once.
Currently the kdumpctl script doesn't check if the path option is
set more than once due to which a vmcore is not captured.

This patch addresses this issue by ensuring that only one path
is specified in /etc/kdump.conf file.

Signed-off-by: Kenneth D'souza <kdsouza@redhat.com>
Acked-by: Kairui Song <kasong@redhat.com>
2018-08-22 15:23:32 +08:00
Kairui Song
6b479b6572 kdumpctl: Rebuild initramfs if loaded kernel modules changed
Currently, we only rebuilt kdump initramfs on config file change,
fs change, or watchdog related change. This will not cover the case
that hardware changed but fs layout and other configurations still
stays the same, and kdump may fail.

To cover such case, we can detect and compare loaded kernel modules,
if a hardware change requires the image to be rebuilt, loaded kernel
modules must have changed.

Starting from commit 7047294 dracut will record loaded kernel modules
when the image is built if hostonly mode is enabled.  With this patch,
kdumpctl will compare the recorded value with currently loaded kernel
modules, and rebuild the image on change.

"kdumpctl start" will be a bit slower, as we have to call lsinitrd one
more time to get the loaded kernel modules list. I measure the time
consumption and we have an overall 0.2s increased loading time.

Time consumption of command "kdumpctl restart":

Before:
real    0m0.587s
user    0m0.481s
sys     0m0.102s

After:
real    0m0.731s
user    0m0.591s
sys     0m0.133s

Time comsumption of command "kdumpctl restart" with image rebuild:

Before (force rebuild):
real    0m10.972s
user    0m8.966s
sys     0m1.318s

After (inserted ~100 new modules):
real    0m11.220s
user    0m9.387s
sys     0m1.337s

Signed-off-by: Kairui Song <kasong@redhat.com>
2018-07-26 19:25:09 +08:00
Lianbo Jiang
b1fbeebd08 move some common functions from kdumpctl to kdump-lib.sh
we move some common functions from kdumpctl to kdump-lib.sh, the
functions could be used in other modules, such as early kdump.
It has no bad effect.

Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Reviewed-by: Kazuhito Hagio <khagio@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2018-05-29 10:18:40 +08:00
Dave Young
3578c54ff2 Fix kdumpctl showmem
showmem function mistakenly added some noise character before the
real code, it could be some copy-paste error.

Fixes: 1a6cb43a19
2018-05-24 13:27:02 +08:00
Bhupesh Sharma
5221d4b90c kdumpctl: Remove 'netroot' and 'iscsi initiator' entries from kdump cmdline
In a iSCSI multipath environment (which uses iSCSI software initiator
and target environment) when the vmcore file is saved on the target,
kdump always fails to establish a iSCSI session and also fails to
collect dump due to duplicate entries for 'netroot' and
'iscsi initiator' in the kdump bootargs:

   # echo c > /proc/sysrq-trigger

   [83471.842707] SysRq : Trigger a crash
   [83471.843233] BUG: unable to handle kernel NULL pointer dereference at           (null)
   [83471.844155] IP: [<ffffffffac82ed16>] sysrq_handle_crash+0x16/0x20
   [83471.844931] PGD 800000023f710067 PUD 229fd6067 PMD 0
   [83471.845655] Oops: 0002 [#1] SMP

   <snip..>

   [83471.861889] Call Trace:
   [83471.862162]  [<ffffffffac82f53d>] __handle_sysrq+0x10d/0x170
   [83471.862771]  [<ffffffffac82f9af>] write_sysrq_trigger+0x2f/0x40
   [83471.863405]  [<ffffffffac690630>] proc_reg_write+0x40/0x80
   [83471.863984]  [<ffffffffac61acd0>] vfs_write+0xc0/0x1f0
   [83471.864536]  [<ffffffffac61baff>] SyS_write+0x7f/0xf0
   [83471.865075]  [<ffffffffacb1f7d5>] system_call_fastpath+0x1c/0x21
   [83471.865714] Code: eb 9b 45 01 f4 45 39 65 34 75 e5 4c 89 ef e8 e2 f7 ff ff eb db 0f 1f 44 00 00 55 48 89 e5 c7 05 41 47 81 00 01 00 00 00 0f ae f8 <c6> 04 25 00 00 00 00 01 5d c3 0f 1f 44 00 00 55 31 c0 c7 05 be
   [83471.868888] RIP  [<ffffffffac82ed16>] sysrq_handle_crash+0x16/0x20
   [83471.869700]  RSP <ffff9e7fe77b7e58>
   [83471.870074] CR2: 0000000000000000

   <snip..>

            Starting Login iSCSI Target iqn.2014-08.com.example:t1...
   [  OK  ] Stopped Login iSCSI Target iqn.2014-08.com.example:t1.
            Starting Login iSCSI Target iqn.2014-08.com.example:t1...
   [    6.607051] scsi host2: iSCSI Initiator over TCP/IP
   [FAILED] Failed to start Login iSCSI Target iqn.2014-08.com.example:t1.
   See 'systemctl status "iscsistart_\\x40...com.example:t1.service"' for details.
   [  126.572911] dracut-initqueue[243]: Warning: dracut-initqueue timeout - starting timeout scripts
            Stopping Open-iSCSI...
   [  OK  ] Stopped Open-iSCSI.
            Starting Open-iSCSI...
   [  OK  ] Started Open-iSCSI.
            Starting Login iSCSI Target iqn.2014-08.com.example:t1...
   [  OK  ] Stopped Login iSCSI Target iqn.2014-08.com.example:t1.
            Starting Login iSCSI Target iqn.2014-08.com.example:t1...
   [  131.095897] scsi host3: iSCSI Initiator over TCP/IP
   [FAILED] Failed to start Login iSCSI Target iqn.2014-08.com.example:t1.
   See 'systemctl status "iscsistart_\\x40...com.example:t1.service"' for details.
   [  251.085029] dracut-initqueue[243]: Warning: dracut-initqueue timeout - starting timeout scripts
   [  251.594554] dracut-initqueue[243]: Warning: dracut-initqueue timeout - starting timeout scripts

   <snip..>

This patch fixes the same by removing the 'netroot',
'rd.iscsi.initiator' and 'iscsi_initiator' entries from the kdump boot
cmdline.

One reason why this is safe is our kdump target setup does not
depend on 1st kernel inherited cmdline params now since the work
we dropped root dependency.

Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2018-05-21 14:09:17 +08:00
Pingfan Liu
1a6cb43a19 kdumpctl: add showmem cmd
port from rhel, original patch is contributed by Minfei Huang:

Using /sys to determines crashkernel actual size is confusing since
there is no unit of measure.

Add a new command "kdumpctl showmem" to show the reserved memory kindly.

Signed-off-by: Pingfan Liu <piliu@redhat.com>
Signed-off-by: Minfei Huang <mhuang@redhat.com>
Acked-by: Bhupesh Sharma <bhsharma@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2018-05-21 14:06:30 +08:00
Lianbo Jiang
dbe8214586 kdumpctl: Check the modification time of core_collector
When core_collector is changed, the kdump initramfs needs to
be rebuilt before it is loaded.

Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2018-03-22 16:10:58 +08:00
Pingfan Liu
cde5944f93 kdumpctl: skip selinux-relabel for dracut_args --mount dump target
When using "dracut_args --mount" to specify dump target, e.g. nfs like:
    path /
    core_collector makedumpfile -d 31
    dracut_args --mount "host:/path /var/crash nfs defaults"
kdump service should neither guarantees the correctness, nor relabels it.

For current code, since dracut_args dump targets are likely not mounted
so kdump service mistakenly relabel the rootfs, which is meanless and
takes very long time.

Signed-off-by: Pingfan Liu <piliu@redhat.com>
2017-12-04 12:51:15 +08:00
Baoquan He
85156bfc66 Revert "kdumpctl: sanity check of nr_cpus for x86_64 in case running out of vectors"
This reverts commit 2040103bd7.

Reason is it's based on the environment of 1st kernel where all
present devices could be active and initialized during bootup.
Then all pci devices will request irqs. While kdump only brings
up those devices which are necessary for vmcore dumping. So this
commit is not meaningful and helpless to very large extent. And
it will print out 'Warning' when calculated result is larger than
1 cpu, actually it's a false positive report most of the time.

So revert the commit, and can check the git history for later
reference.

[dyoung]: on some machine this warning message shows up but
later we found the irq numbers with and without nr_cpus=1 is
quite different so this need more investigation since
the formula is not accurate.

Signed-off-by: Baoquan He <bhe@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-12-04 12:50:50 +08:00
Bhupesh Sharma
cb3d1c1c3f kdumpctl: Error out in case there are white spaces before an option name
Resolves: BZ1484945
https://bugzilla.redhat.com/show_bug.cgi?id=1484945

Currently the kdumpctl script doesn't handle
whitespaces (including TABs) which might be there before
an option name in the kdump.conf

This patch addresses this issue, by ensuring that the
kdumpctl errors out in case it finds any stray space(s)
or tab(s) before a option name.

Reported-by: Kenneth D'souza <kdsouza@redhat.com>
Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com>
Acked-by: Pratyush Anand <panand@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-10-11 09:57:31 +08:00
Hari Bathini
601766a3d9 fadump: rebuild default initrd with dump capture capability
As default initrd is used for booting fadump capture kernel, it must be
rebuilt with dump capture capability when dump mode is fadump. Check if
default initrd is already fadump capable and rebuild, if necessary.

Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Reviewed-by: Xunlei Pang <xlpang@redhat.com>
2017-09-06 15:42:13 +08:00
Xunlei Pang
2c9a863fd3 kdumpctl: remove some cmdline inheritage from 1st kernel
Now with the help of "--hostonly-cmdline", dracut will generate
the needed cmdlines for the dump target, so we can avoid the
corresponding duplicate or unnecessary inheritage.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-09-06 15:40:15 +08:00
Xunlei Pang
31dc60ad20 Change dump_to_rootfs to use "--mount" instead of "root=X"
Currently, we kept "root=X" for the dump_to_rootfs case, this
patch consolidates to use "--mount" for all the kdump mounts.

One advantage of this way is that dracut can correctly mark root
(in case of dump_to_rootfs is specified) as the host device when
"--no-hostonly-default-device" is added in the following patch.

Changed the code style in passing, as shellcheck tool reported:
Use $(..) instead of deprecated `..`

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-09-06 15:39:41 +08:00
Xunlei Pang
d5fe9022d0 kdumpctl: move is_fadump_capable() to kdump-lib.sh
Make is_fadump_capable() a library function, as we will need
it in mkdumprd.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-09-06 15:39:23 +08:00
Xunlei Pang
1bd757bc96 Revert "kdumpctl: use generated rd.lvm.lv=X"
This reverts commit cb38b32dfc.

We are going to add "--hostonly-cmdline" dracut argument in
the following patch.

With the help of "--hostonly-cmdline", dracut will generate
"rd.lvm.lv=X" for us, no need to implement here again.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-09-06 15:38:39 +08:00
Xunlei Pang
8250f23c10 Revert "mkdumprd: omit crypt when there is no crypt kdump target"
This reverts commit 54a5bcc4ee.

We are going to add "--no-hostonly-default-device" dracut argument
in the following patch.

With the help of "--no-hostonly-default-device", dracut only
adds the dump target as host devices, which naturally guarantees
only required dracut modules being selected.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-09-06 15:38:09 +08:00
Xunlei Pang
9df0cbbeed kdumpctl: use "apicid" other than "initial apicid"
We met a problem on AMD machines, when using "nr_cpus=4" for
kdump, and crash happens on cpus other than cpu0, kdump kernel
will fail to boot and eventually reset.

After some debugging, we found that it stuck at the kernel path
do_boot_cpu()-> ... ->wakeup_secondary_cpu_via_init():
 apic_icr_write(APIC_INT_LEVELTRIG|APIC_INT_ASSERT|APIC_DM_INIT,
            phys_apicid);
that is, it stuck at sending INIT from AP to BP and reset, which
is actually what "disable_cpu_apicid=X" tries to solve. Printing
the value of @phys_apicid showed that it was the value of "apicid"
other that of "initial apicid" showed by /proc/cpuinfo.

As described in x86 specification:
"In MP systems, the local APIC ID is also used as a processor ID by the
BIOS and the operating system. Some processors permit software to modify
the APIC ID. However, the ability of software to modify the APIC ID is
processor model specific. Because of this, operating system software
should avoid writing to the local APIC ID register. The value returned by
bits 31-24 of the EBX register (when the CPUID instruction is executed with a
source operand value of 1 in the EAX register) is always the Initial APIC ID
(determined by the platform initialization). This is true even if software
has changed the value in the Local APIC ID register."

From kernel commit 151e0c7de("x86, apic, kexec: Add disable_cpu_apicid
kernel parameter"), we can see in generic_processor_info(), it uses
a)read_apic_id() and b)@apicid to compare with @disabled_cpu_apicid.

a)@apicid which is actually @phys_apicid above-mentioned is from the
  following calltrace(on the problematic AMD machine):
    generic_processor_info+0x37/0x300
    acpi_register_lapic+0x30/0x90
    acpi_parse_lapic+0x40/0x50
    acpi_table_parse_entries_array+0x171/0x1de
    acpi_boot_init+0xed/0x50f
  The value of @apicid(from acpi MADT) is equal to the value of "apicid"
  showed by /proc/cpuinfo as proved by our debug printk.
b)read_apic_id() gets the value from LAPIC ID register which is "apicid"
  as well.

While the value of "initial apicid" is from cpuid instruction.

One example of "apicid" and "initial apicid" of cpu0 from /proc/cpuinfo
on AMD machine:
  apicid          : 32
  initial apicid  : 0

Therefore, we should assign /proc/cpuifo "apicid" to "disable_cpu_apicid=X".

We've never met such issue before, because we usually tested "nr_cpus=1",
and mostly on Intel machines, and "apicid" and "initial apicid" have the
same value in most cases on Intel machines.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-07-19 09:50:04 +08:00
Xunlei Pang
54a5bcc4ee mkdumprd: omit crypt when there is no crypt kdump target
Resolves: bz1451717
https://bugzilla.redhat.com/1451717

When there is no crypt related kdump target, we can safely
omit "crypt" dracut module, this can avoid the pop asking
disk password during kdump boot in some cases.

This patch introduces omit_dracut_modules() before calling
dracut, we can omit more modules to reduce initrd size in
the future.

We don't want to omit any module for fadump, thus we move
is_fadump_capable() into kdump-lib.sh as a helper to use.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-07-14 14:54:31 +08:00
Xunlei Pang
cb38b32dfc kdumpctl: use generated rd.lvm.lv=X
Resolves: bz1451717
https://bugzilla.redhat.com/1451717

When there is any "rd.lvm.lv=X", "lvm" dracut module will
try to recognize all the lvm volumes which is unnecessary
and probably cause trouble for us.

See https://bugzilla.redhat.com/show_bug.cgi?id=1451717#c2

Remove all the rd.lvm.lv=X inherited from the kernel cmdline,
and generate the corresponding cmdline as needed for kdump.
Because prepare_cmdline() is only used by kdump, we don't need
to add any fadump judgement(also remove the existing judgement
in passing).

Currently, we don't handle "rd.lvm.vg=X", we can add it in
when there is some bug reported in the future.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-07-14 14:54:23 +08:00
Xunlei Pang
3ee00cd384 kdump-lib.sh: introduce get_kdump_targets()
Resolves: bz1451717
https://bugzilla.redhat.com/1451717

We need to know all the kdump targets including the dump
target and root in case of "dump_to_rootfs".

This is useful for us to do some extra work related to the
type of different targets.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-07-14 14:54:06 +08:00
Xunlei Pang
1bc78e025f kdump-lib.sh: fix improper get_block_dump_target()
Resolves: bz1451717
https://bugzilla.redhat.com/1451717

This patch improves get_block_dump_target as follows:
-Consider block device in the special "--dracut-args --mount ..."
 in get_user_configured_dump_disk().
-Consider save path instead of root fs in get_block_dump_target(),
 and move it into kdump-lib.sh because we will have another user
 in the following patch.
-For nfs/ssh dumping, there is no need to check the root device.
-Move get_save_path into kdump-lib.sh.

After this patch, get_block_dump_target() can always return the
correct block dump target specified.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-07-14 14:53:43 +08:00
Ziyue Yang
0933f89f65 kdumpctl: fix infinite loop caused by running under bash
Description of problem
(https://bugzilla.redhat.com/show_bug.cgi?id=1465735):
Run `kdumpctl status` as normal user, get below error messages:

Another app is currently holding the kdump lock; waiting for it to exit...
flock: 9: Bad file descriptor
Another app is currently holding the kdump lock; waiting for it to exit...
flock: 9: Bad file descriptor
...

The bug is caused by behavior difference between bash
and sh (bash in posix).

In the function single_instance_lock in kdumpctl script,
there is

exec 9>/var/lock/kdump

which will fail in user mode. However, this fail will cause
script exiting under bash but not exiting under sh, causing
infinite loop because the flock will always fail.

According to the 16th item in
ftp://ftp.gnu.org/old-gnu/Manuals/bash-2.02/html_node/bashref_66.html

If a POSIX.2 special builtin returns an error status, a non-
interactive shell exits.

And according to
https://www.gnu.org/software/bash/manual/html_node/Special-Builtins.html

exec is one of the POSIX.2 special builtin's.

This patch fixes the bug by checking exec return value.

Fixes: 9fb2996d05 ("kdumpctl: change the shebang header to use /bin/bash")
Signed-off-by: Ziyue Yang <ziyang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Reviewed-by: Xunlei Pang <xlpang@redhat.com>
2017-07-14 14:47:37 +08:00
Pingfan Liu
1ca4c9f009 kdumpctl: for fence_kdump, the ipaddr of this node should be excluded from list
kdump should not send fence_kdump notifications to local host, because
the role of the falied node (i.e local host) is to send fence_kdump
notifications to other nodes to tell them I'm kdumping, tell to itself is
nonsense. And we have excluded hostname of local host but when one use ip
address we also need exclude it.

Signed-off-by: Pingfan Liu <piliu@redhat.com>
Reviewed-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-05-18 16:44:42 +08:00
Xunlei Pang
9fb2996d05 kdumpctl: change the shebang header to use /bin/bash
We met one issue that when changing softlink of "/usr/bin/sh"
to point to "ksh" instead of the default "bash", kdumpctl will
not work and go wrong.

kdumpctl is expected to run under bash like dracut, we should
change its shebang header from "#!/bin/sh" to "#!/bin/bash".

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-05-12 09:58:51 +08:00
Xunlei Pang
2b4b7a6374 kdumpctl: call strip_comments only when necessary to speedup
The "time kdumpctl start" command shows that strip_comments()
consumes lots of cpu time. By only calling it when necessary,
it saves us nearly half second.

Tested on my Fedora kvm machine.
Before this patch:
$ time kdumpctl start
kexec: loaded kdump kernel
Starting kdump: [OK]

real	0m1.849s
user	0m1.497s
sys	0m0.462s

After this patch:
$ time kdumpctl start
kexec: loaded kdump kernel
Starting kdump: [OK]

real	0m1.344s
user	0m1.195s
sys	0m0.195s

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-05-12 09:57:29 +08:00
Xunlei Pang
7f725ef13a Revert "kdumpctl: improve "while read" time for /etc/kdump.conf"
Resolves: bz1449801

"cat $KDUMP_CONFIG_FILE|grep -v "^#"|while read ..." use pipes
to invoke subshells, as a result we met "the dreaded inaccessible
variables within a subshell problem" as described in the book
"Advanced Bash-Scripting Guide".

It cause regressions, so revert it.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-05-12 09:57:29 +08:00
Xunlei Pang
38c0b4aa3a kdumpctl: improve "while read" time for /etc/kdump.conf
I found using "cat $KDUMP_CONFIG_FILE|grep -v "^#"|while read ..."
instead of "while read ... do ...; done < $KDUMP_CONFIG_FILE" will
make the script run faster, it saves us nearly half second.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Pratyush Anand <panand@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-05-05 16:14:33 +08:00
Xunlei Pang
88a3385e96 kdumpctl: update check_dump_fs_modified() to use "lsinitrd -f"
We use faster "lsinitrd XXX -f usr/lib/dracut/build-parameter.txt"
instead of "lsinitrd XXX | grep "^Arguments:" | head -1", this can
save us around one second.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Pratyush Anand <panand@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-05-05 16:14:33 +08:00
Xunlei Pang
2a5f362521 kdumpctl: improve check_wdt_modified()
Use the logic of dracut 04watchdog/module-setup.sh to check,
then we only need to compare the content of 00-watchdog.conf,
so we can save one operation of lsinitrd.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Pratyush Anand <panand@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-05-05 16:14:33 +08:00
Xunlei Pang
c63c0a1084 kdumpctl: remove is_mode_switched()
handle_mode_switch() can ensure the correct logic, so remove
the needless is_mode_switched(). This helps to save one slow
lsinitrd operation for each boot.

Improved backup_default_initrd() to judge DEFAULT_INITRD.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Pratyush Anand <panand@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-05-05 16:14:33 +08:00
Xunlei Pang
071ea2a277 kdumpctl: bail out earlier in case of no reserved memory
Some cloud people complained that VM boot speed is slower than
Ubuntu and other distributions, after some debugging, we found
that one of the causes is kdump service starts too slow(7seconds
according to the test result on the test VM), actually there is
no "crashkernel=X" specified. Although kdump service is parallel,
it affects the speed more or less especially on VMs with few cpus,
which is unacceptable. It is even worse when kdump initramfs is
built out in case of no reserved memory at first boot.

Commit afa4a35d3 ("kdumpctrl: kdump feasibility should fail if no
crash memory") can actually solve this issue.

This patch is a supplement of above-mentioned commit, we bail out
start() even earlier in case of no reserved memory.

Also made some cosmatic changes for check_crash_mem_reserved().

1) Before this patch
$ time kdumpctl start
No memory reserved for crash kernel.
Starting kdump: [FAILED]

real    0m0.282s
user    0m0.184s
sys     0m0.146s

2) After this patch
$ time kdumpctl start
No memory reserved for crash kernel
Starting kdump: [FAILED]

real    0m0.010s
user    0m0.008s
sys     0m0.001s

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Pratyush Anand <panand@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-05-02 17:23:57 +08:00
Bhupesh Sharma
a284fa9005 kdump: Introduce 'force_no_rebuild' option
This patch introduces the 'force_no_rebuild' option
inside the 'kdump.conf' and its handling inside the 'kdumpctl'
script.

There might be several use cases, where a system admin
decides that he doesn't need to rebuild the kdump initrd
and wants to use an existing version of the same. In such cases,
he can set the 'force_no_rebuild' option inside 'kdump.conf'
to 1, to force the 'kdumpctl' script not to rebuild the kdump
initrd.

Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com>
Acked-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-04-27 13:59:49 +08:00
Xunlei Pang
3b311653f2 Revert "kdumpctl: filter 'root' kernel parameter when running in live images"
This reverts commit 892bea7aa

We already eliminated the root filesystem by removing "root=X"
in case of non-root dumping, and for livecd it must be non-root
dumping according to "live-image-kdump-howto.txt".

So it's time to revert this commit.

Also update "live-image-kdump-howto.txt", make sure users do not
configure "default dump_to_rootfs".

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Pratyush Anand <panand@redhat.com>
Acked-by:Dave Young <dyoung@redhat.com>
2017-04-11 16:03:12 +08:00
Xunlei Pang
b40c1f96cf kdumpctl: remove "root=X" for kdump boot
Since the current dracut of Fedora already supports not always
mounting root device, we can remove "root=X" from the command
line directly, and always get the dump target specified in
"/etc/kdump.conf" and mount it. If the dump target is located
at root filesystem, we will add the root mount info explicitly
from kdump side instead of from dracut side.

For example, in case of nfs/ssh/usb/raw/etc(non-root) dumping,
kdump will not mount the unnecessary root fs after this change.

This patch removes "root=X" via the "KDUMP_COMMANDLINE_REMOVE"
(if "default dump_to_rootfs" is specified, don't remove "root=X"),
and mounts non-root target under "/kdumproot", the root target
still under "/sysroot"(to be align with systemd sysroot.mount).

After removing "root=X", we now add root fs mount information
explicitly from the kdump side.

Changed check_dump_fs_modified() a little to avoid rebuild when
dump target is root, since we add root fs mount explicitly now.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Pratyush Anand <panand@redhat.com>
Acked-by:Dave Young <dyoung@redhat.com>
2017-04-11 16:02:12 +08:00
Xunlei Pang
bf5b3da107 kdumpctl: fix a bug in remove_cmdline_param()
For the following scripts:
  cmdline="root=/dev/mapper/fedora-root rd.lvm.lv=fedora/root rw"
  remove_cmdline_param $cmdline "root"

  cmdline="root=nfs4:192.168.122.9:/ ip=ens3:dhcp rw"
  remove_cmdline_param $cmdline "root"

The current implementation will get the wrong results:
  "rd.lvm.lv=fedora/ rw"
  ":/ ip=ens3:dhcp rw"

After this patch we can get the correct results:
  "rd.lvm.lv=fedora/root rw"
  "ip=ens3:dhcp rw"

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Pratyush Anand <panand@redhat.com>
Acked-by:Dave Young <dyoung@redhat.com>
2017-04-11 16:01:50 +08:00
Pratyush Anand
21dcf7e3b1 kdumpctl: fix status check when CONFIG_CRASH_DUMP is not enabled in kernel
When kexec_crash_loaded does not exist, means kdump was not enabled in
kernel we get

$ kdumpctl status
cat: /sys/kernel/kexec_crash_loaded: No such file or directory
/usr/bin/kdumpctl: line 879: [: ==: unary operator expected
Kdump is not operational

After this patch:
$ kdumpctl status
Perhaps CONFIG_CRASH_DUMP is not enabled in kernel
Kdump is not operational

Signed-off-by: Pratyush Anand <panand@redhat.com>
Reviewed-by: Bhupesh Sharma <bhsharma@redhat.com>
Reviewed-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-04-11 16:01:25 +08:00
Xunlei Pang
2040103bd7 kdumpctl: sanity check of nr_cpus for x86_64 in case running out of vectors
Check the number of cpus for x86_64 kdump kernel to boot with.
We met an issue on x86_64: kdump runs out of vectors with the
default "nr_cpus=1", when requesting tons of irqs.

This patch detects such situation and warns users about the risk.

The total number of vectors percpu is 256 defined by x86 architecture.
The available vectors can be allocated to io devices percpu starts
from FIRST_EXTERNAL_VECTOR(see kernel code), and some high-numbered
ones are consumed by some system interrupts. As a result, the vectors
for io device are within [FIRST_EXTERNAL_VECTOR, FIRST_SYSTEM_VECTOR),
with one known exception, 0x80 within the range is reserved specially
as the syscall vector.

FIRST_EXTERNAL_VECTOR is invariably 32, while FIRST_SYSTEM_VECTOR can
vary between different kernel versions. E.g. FIRST_SYSTEM_VECTOR gets
0xef(with CONFIG_X86_LOCAL_APIC on)for linux-4.10, that is 17 vectors
reserved, considering it may increase in the future and the special
vectors, we use a flexible variance and assume there are 32 reserved
from FIRST_EXTERNAL_VECTOR. Then the max vectors for device interrupts
percpu is: (256-32)-32=192, we acquire the number N of device interrupts
from /proc/irq/, then the number of minimal cpus required is calculated:
(N + 192 - 1) / 192

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Pratyush Anand <panand@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-01-23 15:52:24 +08:00
Xunlei Pang
211b36b8f9 kdumpctl: change prepare_cmdline() to operate KDUMP_COMMANDLINE directly
Since KDUMP_COMMANDLINE is a global variable, prepare_cmdline can
modify it directly instead of echoing back the result. This change
enables it to output messages.

Changed some coding styles.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Acked-by: Pratyush Anand <panand@redhat.com>
2017-01-23 15:51:28 +08:00
Dave Young
631d979eb3 drop dracut duplicate functions
We maintained several kdump specific functions which are duplicate with the
similar versions in dracut,  Dracut upstream splitted dracut init stuff from
dracut-functions.sh so that we can source it now.

Notes about kdump_get_presistent_dev:
Dracut now has a persistent_policy feature, for kdump when we dump to
raw disks we do not care the filesystem uuid and labels so we prefer to
search disk id instead. For raw disk set the persistent_policy before calling
get_persistent_dev ensure kdump logic still work.

Tested filesystem and raw dump in kvm guests.

[Xunlei: drop other functions other than get_persistent_dev.]

Signed-off-by: Dave Young <dyoung@redhat.com>
Reviewed-by: Xunlei Pang <xlpang@redhat.com>
2016-11-28 10:41:22 +08:00
Tong Li
ac1eb7edce Correct two typos in kdumpctl and kdump.conf
Signed-off-by: Tong Li <tonli@redhat.com>
Reviewed-by: Xunlei Pang <xlpang@redhat.com>
2016-11-28 10:41:05 +08:00
Hari Bathini
6a5e908d85 fadump: restore default initrd when fadump mode is disabled
When fadump mode is enabled, the default initrd is rebuilt with kdump
dracut module. As the default initrd is altered, the original default
initrd is backed up. But we are not restoring it when fadump mode is
disabled. This patch tries to restore the backed up default initrd on
disabling fadump mode.

Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
2016-11-11 11:01:13 +08:00
Tong Li
892bea7aae kdumpctl: filter 'root' kernel parameter when running in live images
Kernels of live images are booted with a kernel parameter which looks
like "root=live:CDLABEL=Fedora-WS-Live-25_A-2". This argument can't be
recognized by dracut during kdump process and will cause failure
of kdump if users didn't set KUDMP_COMMANDLINE in /etc/sysconfig/kdump.
So we should filter out 'root' when we find such a parameter in
/proc/cmdline to make kdump work correctly in live images.

Signed-off-by: Tong Li <tonli@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2016-11-11 10:56:35 +08:00
Pratyush Anand
4db9e59e89 kdumpctl: fix target identification for systems without initrd
We get following error on the systems that have everything built-in and no
initrd is used.

	Kernel dev name of /dev/root is not found.
	Dump target /dev/root is probably not mounted.

It happens because `df $path` gets /dev/root from /proc/self/mountinfo.

Fix this by identifying real target device when `df $path` returns
Filesystem as /dev/root.

Reported-and-tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Pratyush Anand <panand@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2016-09-16 15:40:48 +08:00
Pratyush Anand
1edfff7809 kdumpctl: remove duplicate statement
Since we also check for mount point of $_target after if/else loop, so
there is no need to do the same thing specifically in else loop as well.

Remove those duplicate statement from else loop.

Signed-off-by: Pratyush Anand <panand@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2016-09-16 15:40:48 +08:00
Pratyush Anand
1bb23e7536 kdumpctl: check /etc/fstab modification only when it exists
On a diskless client /etc/fstab does not exist. Therefore check
modification time of this file for rebuild only if it exists.

Also use --fstab option with findmnt only when /etc/fstab exists.

Signed-off-by: Pratyush Anand <panand@redhat.com>
Reviewed-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2016-09-16 15:40:48 +08:00
Pratyush Anand
9b95184251 kdumpctl: Kill duplicate code related to file modication check
commit "28e8c4b5ac89 kdumpctl: Move file modification check logic in
check_system_modified()" copied file modification check logic instead of
moving.
Kill the duplicate logic from original calling function check_rebuild().

Signed-off-by: Pratyush Anand <panand@redhat.com>
Reviewed-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2016-09-16 15:40:48 +08:00
Xunlei Pang
74c6f46429 Support special mount information via "dracut_args"
There are some complaints about nfs kdump that users must mount
nfs beforehand, which may cause some overhead to nfs server.
For example, there're thounsands of diskless clients deployed with
nfs dumping, each time the client is boot up, it will trigger
kdump rebuilding so will mount nfs, thus resulting in thousands
of nfs request concurrently imposed on the same nfs server.

We introduce a new way of specifying mount information via the
already-existent "dracut_args" directive(so avoid adding extra
directives in /etc/kdump.conf), we will skip all the filesystem
mounting and checking stuff for it. So it can be used in the
above-mentioned nfs scenario to avoid severe nfs server overhead.

Specifically, if there is any "--mount" information specified via
"dracut_args" in /etc/kdump.conf, always use it as the final mount
without any validation(mounting or checking like mount options,
fs size, etc), so users are expected to ensure its correctness.

NOTE:
-Only one mount target is allowed using "dracut_args" globally.
-Dracut will create <mountpoint> if it doesn't exist in kdump kernel,
 <mountpoint> must be specified as an absolute path.
-Users should do a test first and ensure it works because kdump does
 not prepare the mount or check all the validity.

Reviewed-by: Pratyush Anand <panand@redhat.com>
Suggested-by: Dave Young <dyoung@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
2016-08-26 14:03:48 +08:00
Pratyush Anand
6a2b39b96e kdumpctl: force rebuild in case of watchdog state change
If state of a watchdog device is changed by an user after kdumpctl restart
then initramfs must be rebuilt on the basis of new watchdog status.

Testing:
-------------------------------------------------------
Initramfs	wdt state
		Prev	Current		Result
-------------------------------------------------------
Not Exist	NA	X		Rebuild
Exist		Inact	Inact		No Rebuild
Exist		Inact	Act		Force Rebuild
Exist		Act	Inact		Force Rebuild
Exist		Act	Act(Same wdt)	No Rebuild
Exist		Act	Act(Diff wdt)	Force Rebuild
Exist		Act	Module Removed	Force Rebuild

Signed-off-by: Pratyush Anand <panand@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2016-07-21 13:56:20 +08:00
Pratyush Anand
81f2c9ea6f get_persistent_dev(): fix name contention with dracut's similar function
Resolves: BZ1348898

dracut-functions.sh defines a get_persistent_dev(). Earlier, we had another
local get_persistent_dev() in mkdumprd, however that was moved to
kdump-lib.sh, so that it can be reused in kdumpctl.

Since, dracut-module-setup.sh (which is dracut's
99kdumpbase/module-setup.sh) sources kdump-lib.sh. Therefore, once dracut
will execute 99kdumpbase module, it's own get_persistent_dev() function is
overwritten by kdump's version. If any other dracut module calls
get_persistent_dev() thereafter then, kdump's version is executed, which was
not expected.

Therefore rename kdump's get_persistent_dev() as kdump_get_persistent_dev()
to avoid any name contention.

Signed-off-by: Pratyush Anand <panand@redhat.com>
Acked-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2016-06-28 03:28:47 +08:00
Pratyush Anand
afa4a35d3d kdumpctrl: kdump feasibility should fail if no crash memory
Currently initramfs is rebuilt even when crash kernel memory is not
available and then latter on kdump service is failed.

Its better to fail during feasibility itself when crash memory is not
reserved.

Signed-off-by: Pratyush Anand <panand@redhat.com>
Acked-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2016-05-16 10:15:24 +08:00