[ Upstream commit 8cfc0c7ed3 ]
ceph_statfs currently stuffs the cluster fsid into the f_fsid field.
This was fine when we only had a single filesystem per cluster, but now
that we have multiples we need to use something that will vary between
them.
Change ceph_statfs to xor each 32-bit chunk of the fsid (aka cluster id)
into the lower bits of the statfs->f_fsid. Change the lower bits to hold
the fscid (filesystem ID within the cluster).
That should give us a value that is guaranteed to be unique between
filesystems within a cluster, and should minimize the chance of
collisions between mounts of different clusters.
URL: https://tracker.ceph.com/issues/52812
Reported-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
c380062d08