Re: [PATCH] nfsd41: handle current stateid in open and close

["J. Bruce Fields" <bfields@fieldses.org>]

It's a little verbose, but yes it does nicely collect the current
stateid getting/setting into one place.  Benny, is the more or less what
you were thinking of?

Nits inline below.

On Tue, Dec 06, 2011 at 10:44:07PM +0100, Tigran Mkrtchyan wrote:
> From: Tigran Mkrtchyan <kofemann@gmail.com>
> 
> 
> Signed-off-by: Tigran Mkrtchyan <kofemann@gmail.com>
> ---
>  fs/nfsd/current_stateid.h |   44 ++++++++++++++++++++++++++++++++++++++++++++
>  fs/nfsd/nfs4proc.c        |   22 ++++++++++++++++++----
>  fs/nfsd/nfs4state.c       |   17 +++++++++++++++++
>  fs/nfsd/xdr4.h            |    1 +
>  4 files changed, 80 insertions(+), 4 deletions(-)
>  create mode 100644 fs/nfsd/current_stateid.h
> 
> diff --git a/fs/nfsd/current_stateid.h b/fs/nfsd/current_stateid.h
> new file mode 100644
> index 0000000..f1ad6e9
> --- /dev/null
> +++ b/fs/nfsd/current_stateid.h
> @@ -0,0 +1,44 @@
> +/*
> + *  Copyright (c) 2001 The Regents of the University of Michigan.
> + *  All rights reserved.
> + *
> + *  Kendrick Smith <kmsmith@umich.edu>
> + *  Andy Adamson <andros@umich.edu>

Kendrick and Andy have been busy!  And they're both working at the
University again?

Anyway: on a header file containing only two function prototypes, I'd be
inclined to leave off any copyright notice unless someone's lawyers
absolutely insist on it....

> + *  
> + *  Redistribution and use in source and binary forms, with or without
> + *  modification, are permitted provided that the following conditions
> + *  are met:
> + *  
> + *  1. Redistributions of source code must retain the above copyright
> + *     notice, this list of conditions and the following disclaimer.
> + *  2. Redistributions in binary form must reproduce the above copyright
> + *     notice, this list of conditions and the following disclaimer in the
> + *     documentation and/or other materials provided with the distribution.
> + *  3. Neither the name of the University nor the names of its
> + *     contributors may be used to endorse or promote products derived
> + *     from this software without specific prior written permission.
> + *
> + *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
> + *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
> + *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
> + *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
> + *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
> + *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
> + *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
> + *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
> + *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
> + *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
> + *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
> + *
> + */
> +
> +#ifndef _NFSD4_CURRENT_STATE_H
> +#define _NFSD4_CURRENT_STATE_H
> +
> +#include "state.h"
> +#include "xdr4.h"
> +
> +extern void nfsd4_set_openstateid(struct nfsd4_compound_state *cstate, struct nfsd4_open *open);
> +extern void nfsd4_get_closestateid(struct nfsd4_compound_state *cstate, struct nfsd4_close *close);
> +
> +#endif   /* _NFSD4_CURRENT_STATE_H */
> diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
> index fa38336..bfed3cb 100644
> --- a/fs/nfsd/nfs4proc.c
> +++ b/fs/nfsd/nfs4proc.c
> @@ -39,6 +39,7 @@
>  #include "cache.h"
>  #include "xdr4.h"
>  #include "vfs.h"
> +#include "current_stateid.h"
>  
>  #define NFSDDBG_FACILITY		NFSDDBG_PROC
>  
> @@ -1001,6 +1002,8 @@ static inline void nfsd4_increment_op_stats(u32 opnum)
>  typedef __be32(*nfsd4op_func)(struct svc_rqst *, struct nfsd4_compound_state *,
>  			      void *);
>  typedef u32(*nfsd4op_rsize)(struct svc_rqst *, struct nfsd4_op *op);
> +typedef void(*stateid_setter)(struct nfsd4_compound_state *, void *);
> +typedef void(*stateid_getter)(struct nfsd4_compound_state *, void *);
>  
>  enum nfsd4_op_flags {
>  	ALLOWED_WITHOUT_FH = 1 << 0,	/* No current filehandle required */
> @@ -1026,6 +1029,8 @@ enum nfsd4_op_flags {
>  	 * the v4.0 case).
>  	 */
>  	OP_CACHEME = 1 << 6,
> +	CONSUMES_CURRENT_STATEID = 1 << 7,
> +	PROVIDES_CURRENT_STATEID = 1 << 8,

Or should we just use the fact that op_{get,put}_currentstateid will be
NULL whenever the respective flag would be set?

>  };
>  
>  struct nfsd4_operation {
> @@ -1034,6 +1039,8 @@ struct nfsd4_operation {
>  	char *op_name;
>  	/* Try to get response size before operation */
>  	nfsd4op_rsize op_rsize_bop;
> +	stateid_setter op_get_currentstateid;
> +	stateid_getter op_set_currentstateid;
>  };
>  
>  static struct nfsd4_operation nfsd4_ops[];
> @@ -1216,11 +1223,16 @@ nfsd4_proc_compound(struct svc_rqst *rqstp,
>  		if (op->status)
>  			goto encode_op;
>  
> -		if (opdesc->op_func)
> +		if (opdesc->op_func) {
> +			if (opdesc->op_flags & CONSUMES_CURRENT_STATEID)
> +				opdesc->op_get_currentstateid(cstate, &op->u);
>  			op->status = opdesc->op_func(rqstp, cstate, &op->u);
> -		else
> +		} else
>  			BUG_ON(op->status == nfs_ok);
>  
> +		if (!op->status && opdesc->op_flags & PROVIDES_CURRENT_STATEID)
> +			opdesc->op_set_currentstateid(cstate, &op->u);
> +
>  		if (!op->status && need_wrongsec_check(rqstp))
>  			op->status = check_nfsd_access(cstate->current_fh.fh_export, rqstp);
>  
> @@ -1411,9 +1423,10 @@ static struct nfsd4_operation nfsd4_ops[] = {
>  	},
>  	[OP_CLOSE] = {
>  		.op_func = (nfsd4op_func)nfsd4_close,
> -		.op_flags = OP_MODIFIES_SOMETHING,
> +		.op_flags = OP_MODIFIES_SOMETHING | CONSUMES_CURRENT_STATEID,
>  		.op_name = "OP_CLOSE",
>  		.op_rsize_bop = (nfsd4op_rsize)nfsd4_status_stateid_rsize,
> +		.op_get_currentstateid = (stateid_getter)nfsd4_get_closestateid,
>  	},
>  	[OP_COMMIT] = {
>  		.op_func = (nfsd4op_func)nfsd4_commit,
> @@ -1481,9 +1494,10 @@ static struct nfsd4_operation nfsd4_ops[] = {
>  	},
>  	[OP_OPEN] = {
>  		.op_func = (nfsd4op_func)nfsd4_open,
> -		.op_flags = OP_HANDLES_WRONGSEC | OP_MODIFIES_SOMETHING,
> +		.op_flags = OP_HANDLES_WRONGSEC | OP_MODIFIES_SOMETHING | PROVIDES_CURRENT_STATEID,
>  		.op_name = "OP_OPEN",
>  		.op_rsize_bop = (nfsd4op_rsize)nfsd4_open_rsize,
> +		.op_set_currentstateid = (stateid_setter)nfsd4_set_openstateid,
>  	},
>  	[OP_OPEN_CONFIRM] = {
>  		.op_func = (nfsd4op_func)nfsd4_open_confirm,
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index 47e94e3..9dc1de8 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -51,10 +51,12 @@ time_t nfsd4_grace = 90;
>  static time_t boot_time;
>  static stateid_t zerostateid;             /* bits all 0 */
>  static stateid_t onestateid;              /* bits all 1 */
> +static stateid_t currentstateid;         /* other all 0, seqid 1 */
>  static u64 current_sessionid = 1;
>  
>  #define ZERO_STATEID(stateid) (!memcmp((stateid), &zerostateid, sizeof(stateid_t)))
>  #define ONE_STATEID(stateid)  (!memcmp((stateid), &onestateid, sizeof(stateid_t)))
> +#define CURRENT_STATEID(stateid) (!memcmp((stateid), &currentstateid, sizeof(stateid_t)))
>  
>  /* forward declarations */
>  static int check_for_locks(struct nfs4_file *filp, struct nfs4_lockowner *lowner);
> @@ -4423,6 +4425,8 @@ nfs4_state_init(void)
>  		INIT_LIST_HEAD(&lock_ownerstr_hashtbl[i]);
>  	}
>  	memset(&onestateid, ~0, sizeof(stateid_t));

A project for another day, but the initialization of these constants has
always annoyed me--isn't there any compact way to define these at
compile-time?

--b.

> +	/* seqid 1, other all 0 */
> +	currentstateid.si_generation = 1;
>  	INIT_LIST_HEAD(&close_lru);
>  	INIT_LIST_HEAD(&client_lru);
>  	INIT_LIST_HEAD(&del_recall_lru);
> @@ -4545,3 +4549,16 @@ nfs4_state_shutdown(void)
>  	nfs4_unlock_state();
>  	nfsd4_destroy_callback_queue();
>  }
> +
> +void
> +nfsd4_set_openstateid(struct nfsd4_compound_state *cstate, struct nfsd4_open *open)
> +{
> +	memcpy(&cstate->current_stateid, &open->op_stateid, sizeof(stateid_t));
> +}
> +
> +void
> +nfsd4_get_closestateid(struct nfsd4_compound_state *cstate, struct nfsd4_close *close)
> +{
> +	if (CURRENT_STATEID(&close->cl_stateid))
> +		 memcpy(&close->cl_stateid, &cstate->current_stateid, sizeof(stateid_t));
> +}
> diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
> index 2364747..96f9966 100644
> --- a/fs/nfsd/xdr4.h
> +++ b/fs/nfsd/xdr4.h
> @@ -54,6 +54,7 @@ struct nfsd4_compound_state {
>  	size_t			iovlen;
>  	u32			minorversion;
>  	u32			status;
> +	stateid_t               current_stateid;
>  };
>  
>  static inline bool nfsd4_has_session(struct nfsd4_compound_state *cs)
> -- 
> 1.7.7.3
> 
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