On Mon, Oct 8, 2018 at 3:10 PM, Kairui Song <kasong(a)redhat.com&gt; wrote: 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&gt; wrote: >> >> From: Kenneth D'souza <kdsouza(a)redhat.com&gt; >> >> 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&gt; >> --- >> 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 >> _______________________________________________ >> kexec mailing list -- kexec(a)lists.fedoraproject.org >> To unsubscribe send an email to kexec-leave(a)lists.fedoraproject.org >> Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html >> List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines >> List Archives: https://lists.fedoraproject.org/archives/list/kexec@lists.fedoraproject.org > > > > -- > Best Regards, > Kairui Song

Thanks for the inputs. I will send a V2 with the suggested changes. On Wed, Oct 10, 2018 at 9:07 AM, Kairui Song <kasong(a)redhat.com&gt; wrote: > Thanks for the declaration, now I understand how that happens and your > fix looks good. > > Only one thing, I would suggest using findmnt to find the mount > options and prefix local > variable with "local", align to _dev and _mp, this make the code > cleaner and more robust. > eg. something like "local _op=$(findmnt -k -f -n -r -o OPTIONS $1)" > > > > On Mon, Oct 8, 2018 at 10:49 PM Kenneth Dsouza <kdsouza(a)redhat.com&gt; wrote: >> >> On Mon, Oct 8, 2018 at 3:10 PM, Kairui Song <kasong(a)redhat.com&gt; 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&gt; wrote: >> >> >> >> From: Kenneth D'souza <kdsouza(a)redhat.com&gt; >> >> >> >> 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&gt; >> >> --- >> >> 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 >> >> _______________________________________________ >> >> kexec mailing list -- kexec(a)lists.fedoraproject.org >> >> To unsubscribe send an email to kexec-leave(a)lists.fedoraproject.org >> >> Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html >> >> List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines >> >> List Archives: https://lists.fedoraproject.org/archives/list/kexec@lists.fedoraproject.org >> > >> > >> > >> > -- >> > Best Regards, >> > Kairui Song > > > > -- > Best Regards, > Kairui Song