Thoughts on how to communicate to VFS functions that a CREATE is occurring

[Volker Lendecke]

On Sun, Apr 03, 2016 at 10:26:40AM -0700, Richard Sharpe wrote:
> Well, we have implemented it, but it involved changes in Samba that I
> would like to get rid of.
> 
> The feature is sharding of directories across multiple servers in a
> cluster and using DFS referrals to get clients connected to the
> correct server in the cluster.
> 
> When a client asks you for a DFS referral for the directory that is on
> the node they are connected to (which they do, from time to time) we
> need to return the correct information.
> 
> To do all of the above successfully, we have found that we need to
> know, in the VFS layer (and particularly, in STAT, which is pretty
> much the earliest VFS function called) whether we were called for a
> CREATE or for something else.

What is the sequence of events? You get a SMB_CREATE, and you return a
PATH_NOT_COVERED. Then you get an ioctl that asks for the target path.
Is that right?

Intercepting create_fn is not sufficient, because it is called from other
highlevel SMB requests too?

Volker

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