Re: [PATCH 09/18] nfsd: implement pNFS operations

[Jeff Layton <jeff.layton-7I+n7zu2hftEKMMhf/gKZA@public.gmane.org>]

On Tue,  6 Jan 2015 17:28:32 +0100
Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org> wrote:

> Add support for the GETDEVICEINFO, LAYOUTGET, LAYOUTCOMMIT and
> LAYOUTRETURN NFSv4.1 operations, as well as backing code to manage
> outstanding layouts and devices.
> 
> Layout management is very straight forward, with a nfs4_layout_stateid
> structure that extents nfs4_stid to manage layout stateids as the
> top-level structure.  It is linked into the nfs4_file and nfs4_client
> structures like the other stateids, and contains a linked list of
> layouts that hang of the stateid.  The actual layout operations are
> implemented in layout drivers that are not part of this commit, but
> will be added later.
> 
> The worst part of this commit is the management of the pNFS device IDs,
> which suffers from a specification that is not sanely implementable due
> to the fact that the device-IDs are global and not bound to an export,
> and have a small enough size so that we can't store the fsid portion of
> a file handle, and must never be reused.  As we still do need perform all
> export authentication and validation checks on a device ID passed to
> GETDEVICEINFO we are caught between a rock and a hard place.  To work
> around this issue we add a new hash that maps from a 64-bit integer to a
> fsid so that we can look up the export to authenticate against it,
> a 32-bit integer as a generation that we can bump when changing the device,
> and a currently unused 32-bit integer that could be used in the future
> to handle more than a single device per export.  Entries in this hash
> table are never deleted as we can't reuse the ids anyway, and would have
> a severe lifetime problem anyway as Linux export structures are temporary
> structures that can go away under load.
> 
> Parts of the XDR data, structures and marshaling/unmarshaling code, as
> well as many concepts are derived from the old pNFS server implementation
> from Andy Adamson, Benny Halevy, Dean Hildebrand, Marc Eshel, Fred Isaman,
> Mike Sager, Ricardo Labiaga and many others.
> 
> Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
> ---
>  fs/nfsd/Kconfig                 |  10 +
>  fs/nfsd/Makefile                |   1 +
>  fs/nfsd/export.c                |   8 +
>  fs/nfsd/export.h                |   2 +
>  fs/nfsd/nfs4layouts.c           | 486 ++++++++++++++++++++++++++++++++++++++++
>  fs/nfsd/nfs4proc.c              | 266 ++++++++++++++++++++++
>  fs/nfsd/nfs4state.c             |  16 +-
>  fs/nfsd/nfs4xdr.c               | 306 +++++++++++++++++++++++++
>  fs/nfsd/nfsctl.c                |   9 +-
>  fs/nfsd/nfsd.h                  |  16 +-
>  fs/nfsd/pnfs.h                  |  80 +++++++
>  fs/nfsd/state.h                 |  21 ++
>  fs/nfsd/xdr4.h                  |  60 +++++
>  include/linux/nfs4.h            |   1 +
>  include/uapi/linux/nfsd/debug.h |   1 +
>  15 files changed, 1279 insertions(+), 4 deletions(-)
>  create mode 100644 fs/nfsd/nfs4layouts.c
>  create mode 100644 fs/nfsd/pnfs.h
> 

[...]

> @@ -4845,6 +4856,9 @@ nfsd4_close(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
>  	update_stateid(&stp->st_stid.sc_stateid);
>  	memcpy(&close->cl_stateid, &stp->st_stid.sc_stateid, sizeof(stateid_t));
>  
> +	nfsd4_return_all_file_layouts(stp->st_stateowner->so_client,
> +				      stp->st_stid.sc_file);
> +

Shouldn't the above be conditional on whether the lg_roc was true?

>  	nfsd4_close_open_stateid(stp);
>  
>  	/* put reference from nfs4_preprocess_seqid_op */

-- 
Jeff Layton <jlayton-7I+n7zu2hftEKMMhf/gKZA@public.gmane.org>
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