Re: What's a good default TTL for DNS keys in the kernel
From: David Howells
Date: Mon Apr 20 2020 - 09:13:56 EST
Paulo Alcantara <pc@xxxxxx> wrote:
> >> For SMB3/CIFS mounts, Paulo added support last year for automatic
> >> reconnect if the IP address of the server changes. It also is helpful
> >> when DFS (global name space) addresses change.
> >
> > What happens if the IP address the superblock is going to changes, then
> > another mount is made back to the original IP address? Does the second mount
> > just pick the original superblock?
>
> It is going to transparently reconnect to the new ip address, SMB share,
> and cifs superblock is kept unchanged. We, however, update internal
> TCP_Server_Info structure to reflect new destination ip address.
>
> For the second mount, since the hostname (extracted out of the UNC path
> at mount time) resolves to a new ip address and that address was saved earlier
> in TCP_Server_Info structure during reconnect, we will end up
> reusing same cifs superblock as per fs/cifs/connect.c:cifs_match_super().
Would that be a bug?
David