On Mon, Oct 8, 2018 at 3:10 PM, Kairui Song <kasong(a)redhat.com> wrote:
Hi Kenneth,
Can you provide more info like what argument do you have in your
fstab entry?
What's the mount status before and after the remount? What's you kdump config?
kdump is already dropping arguments like "ro", "nofail" which are
causing problems,
and remount as rw shouldn't cause such problem.
nfs-server-ip: y.y.y.y
nfs-client-ip: x.x.x.x
# kdump-config --show
default shell
nfs y.y.y.y:/home
# findmnt --fstab /mnt
TARGET SOURCE FSTYPE OPTIONS
/mnt y.y.y.y:/home nfs rsize=3072,wsize=3072
# findmnt /mnt
TARGET SOURCE FSTYPE OPTIONS
/mnt yy.y.y:/home nfs4
rw,relatime,vers=4.1,rsize=2048,wsize=2048,namlen=255,hard,proto=tcp,port=0,timeo=600,retrans=2,sec=sys,clientaddr=x.x.x.x,local_lock=none,addr=192.168.122.1
# mount -o,remount /mnt -vv
mount.nfs: mount(2): Invalid argument
mount.nfs: an incorrect mount option was specified
Issue: When the remount is invoked with only the mount point, the
fstab options for the dump target will be reconsidered and options
like rsize,wsize or nolock cannot be changed on a mounted share. As
the rsize and wsize values might not always be the one specified in
/etc/fstab but will depend on the nfs-server and nfs-client
negotiation.
Refer man nfs for rsize,wsize and remount for explanation.
Possible solutions:
1> Eliminate the remount to rw as the dump target will always be mounted to rw.
2> Add check for read-only status for dump target and mount to rw only
if found ro ignoring fstab options. I have sent a patch for this but I
prefer solution number 3.
3> Change the remount line not to check fstab again as we are just
concerned with rw option. (mount -o remount,rw <device> <mount-point>)
Let me know which solution you would like me to send in a V2 or keep this patch.
> On Mon, Oct 8, 2018 at 1:46 PM Kenneth Dsouza <kdsouza(a)redhat.com> wrote:
>>
>> From: Kenneth D'souza <kdsouza(a)redhat.com>
>>
>> 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: 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(a)redhat.com>
>> ---
>> kdump-lib-initramfs.sh | 8 +++++++-
>> 1 file changed, 7 insertions(+), 1 deletion(-)
>>
>> diff --git a/kdump-lib-initramfs.sh b/kdump-lib-initramfs.sh
>> index 2c18c87..8adcba2 100755
>> --- a/kdump-lib-initramfs.sh
>> +++ b/kdump-lib-initramfs.sh
>> @@ -100,7 +100,13 @@ dump_fs()
>>
>> echo "kdump: saving to $_mp/$KDUMP_PATH/$HOST_IP-$DATEDIR/"
>>
>> - mount -o remount,rw $_mp || return 1
>> + # Only remount to read-write mode if the dump target is mounted read-only.
>> + check_status=$(grep "\srw[\s,]" /proc/mounts | grep -i $_mp)
>> + if [ -z "$check_status" ]; then
>> + echo "kdump: Mounting Dump target $_dev in rw mode."
>> + mount -o remount,rw $_dev $_mp || return 1
>> + fi
>> +
>> mkdir -p $_mp/$KDUMP_PATH/$HOST_IP-$DATEDIR || return 1
>>
>> save_vmcore_dmesg_fs ${DMESG_COLLECTOR}
"$_mp/$KDUMP_PATH/$HOST_IP-$DATEDIR/"
>> --
>> 2.14.3
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>
>
>
> --
> Best Regards,
> Kairui Song