[CRIU] [PATCH RFC 0/2] Mount point hash

[Stanislav Kinsburskiy]

This series introduces hash for mount points.
The major reason for it is upcomming NFS migration, which is expected to
heavily search over mount points by mnt_id (to be able to get file system ID
instead of statfs() call, for instance).
The idea is trivial and doesn't require an explicit explanation.
However, there will be two sets of mount points is this series is merged: hash
and list.
List looks redundant and less efficient. Traversing hash table for all the
mounts has the same complexity as over the list: O(n).
But replacing the list with hash will require a lot or code refactoring, and
I'm not sure, does it worth it.
BTW, more hashes can be introduced (with s_dev as a key, for instance; or by
fs->type).