Re: [PATCH v7 0/7] Add O_DENY* support for VFS and CIFS/NFS

From: Pavel Shilovsky
Date: Mon Jan 20 2014 - 04:56:35 EST

2014/1/17 Frank Filz <ffilzlnx@xxxxxxxxxxxxxx>:
> This looks wonderful and will be useful to the Ganesha user space NFS server
> also.
> I do have a couple questions.
> 1. How will this interact with the idea of private locks from the patch set
> Jeff Layton has been pushing?

They don't touch each other.

> 2. If a process opens multiple file descriptors with deny modes, will they
> conflict with each other (which is the behavior we will want for Ganesha).

Yes, a deny mode is associated with file descriptor - so, it will
conflict with any other access/deny modes of file descriptors from any

> 3. Is there any functionality to upgrade or downgrade the access and deny
> modes (thinking in terms of NFS v4 support of OPEN upgrade and
> OPEN_DOWNGRADE operations).

The proposed patchset doesn't allow to change deny modes after an open
is done. But we can add a functionality to let flock syscall change
deny modes as on option.

Best regards,
Pavel Shilovsky.
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