Date: Sat, 12 Apr 2008 13:15:04 -1000 (HST) From: Jeff Roberson <jroberson@jroberson.net> To: Doug Rabson <dfr@rabson.org> Cc: Kirk McKusick <mckusick@mckusick.com>, arch@freebsd.org Subject: Re: VOP_LEASE Message-ID: <20080412131017.S43186@desktop> In-Reply-To: <41ED3941-E5E6-45F0-B880-C1B2861FDE32@rabson.org> References: <200804121703.m3CH3StJ081660@chez.mckusick.com> <41ED3941-E5E6-45F0-B880-C1B2861FDE32@rabson.org>
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On Sat, 12 Apr 2008, Doug Rabson wrote: > > On 12 Apr 2008, at 18:03, Kirk McKusick wrote: > >>> Date: Sat, 12 Apr 2008 02:13:15 -1000 (HST) >>> From: Jeff Roberson <jroberson@jroberson.net> >>> To: arch@freebsd.org >>> Subject: VOP_LEASE >>> >>> As far as I can tell this has never been used. Unless someone can show me >>> otherwise I'm going to go ahead and remove it. >>> >>> Thanks, >>> Jeff >> >> VOP_LEASE is used by NQNFS and NFSv4. It notifies them when a file >> is modified locally so that they know to update any outstanding >> leases (e.g., evict any write lease for the file and do callbacks >> for any read leases for the file). Deleting VOP_LEASE would break >> NFS big time. > > I think our NQNFS support might have been removed some time ago - I can't see > any calls to VOP_LEASE in the code right now. Something like VOP_LEASE would > certainly be useful for a hypothetical future NFSv4 server. I believe that > samba could use it too for its oplocks feature which appears to be similar to > NQNFS's leases and NFSv4's delegations. So the idea with delegations is that close() doesn't actually release the file entirely to make future access cheaper? My issue with VOP_LEASE is only that there are no in kernel implementations of the VOP. I doubt it is applied regularly in syscalls. It also seems odd that it is called without a lock. Is the intent that the server will trap all accesses to a local vnode in order to invalidate the client leases? Thanks, Jeff
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