Ceph » CephFS

Will add one mount option "suspend=<on|off>" to suspend the specified mount point.

Currently the remount is not working, need to fix this first.

From Jeff's idea and comments of the first version to fulfill the "halt" mount option, which will try to close all the monc/osdc/mdsc connections without doing any cleanup beforehand, but the socket close routine will send one FIN to the peer, so this couldn't be 100% simulate pulling cable or hard reset the node case.

Dig into the iptable/netfilter code, we can fulfill the iptable DROP rules in kceph directly if there is no any potential problems for this, but it will by pass the userspace iptable app.

This is for ceph-fuse: https://github.com/ceph/ceph/pull/33576

This will use a separating network namespace to isolate the fuse client from the os, then we can just shutdown
the veth inferace of the network namespace container, with this it will just DROP all the socket packets from the cluster without any response.

This is just for fuse client in userspace, next will try this in kclient.

For now both kernel and fuse are working the https://github.com/ceph/ceph/pull/33576.

# ./unshare_ns_mount.sh 

This will help to isolate the network namespace from OS for the mount client!

usage: unshare_ns_mount.sh [OPTIONS [paramters]] [--brxip <ip_address/mask>]
OPTIONS:
  --fuse    <ceph-fuse options>
    The ceph-fuse command options
    $ unshare_ns_mount.sh --fuse -m 192.168.0.1:6789 /mnt/cephfs -o nonempty

  --kernel  <mount options>
    The mount command options
    $ unshare_ns_mount.sh --kernel -t ceph 192.168.0.1:6789:/ /mnt/cephfs -o fs=a

  --suspend <mountpoint>
    Down the veth interface in the network namespace
    $ unshare_ns_mount.sh --suspend /mnt/cephfs

  --resume  <mountpoint>
    Up the veth interface in the network namespace
    $ unshare_ns_mount.sh --resume /mnt/cephfs

  --umount  <mountpoint>
    Umount and delete the network namespace
    $ unshare_ns_mount.sh --umount /mnt/cephfs

  --brxip   <ip_address/mask>
    Specify ip/mask for ceph-brx and it only makes sense for --fuse/--kernel options
    (default: 192.168.255.254/16, netns ip: 192.168.0.1/16 ~ 192.168.255.253/16)
    $ unshare_ns_mount.sh --fuse -m 192.168.0.1:6789 /mnt/cephfs --brxip 172.19.255.254/12
    $ unshare_ns_mount.sh --kernel 192.168.0.1:6789:/ /mnt/cephfs --brxip 172.19.255.254/12

  -h, --help
    Print help

Defaultly it will use the 192.168.X.Y/16 private network IPs for the ceph-brx and netnses as above. And you can also specify your own new ip/mask for the ceph-brx, like:

  $ unshare_ns_mount.sh --fuse /mnt/cephfs --brxip 172.19.100.100/12

Then the each netns will get a new ip from the ranges:

 [172.16.0.1 ~ 172.19.100.99]/12 and [172.19.100.101 ~ 172.31.255.254]/12

Have added the qa/ test case by transfering the bash code to python.

In some case could just s/mount_X.kill()/mount_X.suspend_netns()/ and s/mount_X.kill_cleanup() ...mount() again /mount_X.resume_netns()/