Re: [PATCH v2 2/2] NFSD: Added TEST_STATEID opreation

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

On Mon, May 16, 2011 at 03:43:41PM -0400, bjschuma@netapp.com wrote:
> From: Bryan Schumaker <bjschuma@netapp.com>
> 
> This operation is used by the client to check the validity of a list of
> stateids.
> 
> Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
> ---
>  fs/nfsd/nfs4proc.c  |    5 +++
>  fs/nfsd/nfs4state.c |   53 +++++++++++++++++++++++++++++++
>  fs/nfsd/nfs4xdr.c   |   85 +++++++++++++++++++++++++++++++++++++++++++++++++--
>  fs/nfsd/state.h     |    1 +
>  fs/nfsd/xdr4.h      |   17 ++++++++++
>  5 files changed, 158 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
> index 7e00116..a856f30 100644
> --- a/fs/nfsd/nfs4proc.c
> +++ b/fs/nfsd/nfs4proc.c
> @@ -1412,6 +1412,11 @@ static struct nfsd4_operation nfsd4_ops[] = {
>  		.op_flags = OP_HANDLES_WRONGSEC,
>  		.op_name = "OP_SECINFO_NO_NAME",
>  	},
> +	[OP_TEST_STATEID] = {
> +		.op_func = (nfsd4op_func)nfsd4_test_stateid,
> +		.op_flags = ALLOWED_WITHOUT_FH,
> +		.op_name = "OP_TEST_STATEID",
> +	},
>  	[OP_FREE_STATEID] = {
>  		.op_func = (nfsd4op_func)nfsd4_free_stateid,
>  		.op_flags = ALLOWED_WITHOUT_FH,
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index 043baa0..18e0762 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -37,6 +37,7 @@
>  #include <linux/slab.h>
>  #include <linux/namei.h>
>  #include <linux/swap.h>
> +#include <linux/pagemap.h>
>  #include <linux/sunrpc/svcauth_gss.h>
>  #include <linux/sunrpc/clnt.h>
>  #include "xdr4.h"
> @@ -3136,6 +3137,32 @@ static int is_delegation_stateid(stateid_t *stateid)
>  	return stateid->si_fileid == 0;
>  }
>  
> +static __be32 nfs4_validate_stateid(stateid_t *stateid, int flags, struct file **filpp, struct svc_fh *current_fh)

You're not use current_fh (which makes sense, since test_stateid doesn't
seem to use the current filehandle).

Ditto for callers.

> +{
> +	struct nfs4_stateid *stp = NULL;
> +	__be32 status = nfserr_stale_stateid;
> +
> +	if (STALE_STATEID(stateid))
> +		goto out;
> +
> +	status = nfserr_expired;
> +	stp = search_for_stateid(stateid);
> +	if (!stp)
> +		goto out;
> +	status = nfserr_bad_stateid;
> +
> +	if (!stp->st_stateowner->so_confirmed)
> +		goto out;
> +
> +	status = check_stateid_generation(stateid, &stp->st_stateid, flags);
> +	if (status)
> +		goto out;
> +
> +	status = nfs_ok;
> +out:
> +	return status;
> +}
> +
>  /*
>  * Checks for stateid operations
>  */
> @@ -3252,6 +3279,32 @@ nfsd4_free_file_stateid(stateid_t *stateid)
>  }
>  
>  /*
> + * Test if the stateid is valid
> + */
> +__be32
> +nfsd4_test_stateid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> +		   struct nfsd4_test_stateid *test_stateid)
> +{
> +	test_stateid->ts_saved_state = cstate;
> +	return nfs_ok;
> +}
> +
> +__be32
> +nfsd4_do_test_stateid(stateid_t *stateid, struct nfsd4_compound_state *cstate)
> +{
> +	__be32 ret;
> +	unsigned int lock_flags = LOCK_STATE | RD_STATE | WR_STATE;
> +	unsigned int open_flags = OPEN_STATE | RD_STATE | WR_STATE;
> +	struct svc_fh *current_fh;
> +
> +	current_fh = &cstate->current_fh;
> +	ret = nfs4_validate_stateid(stateid, lock_flags, NULL, current_fh);
> +	if (!ret)
> +		ret = nfs4_validate_stateid(stateid, open_flags, NULL, current_fh);

Do we really need to do this once for each set of flags?

Seems we only use them in check_stateid_generation(), which only uses
them to check the HAS_SESSION case.  (Which actually should be set in
our case?)

> +	return ret;
> +}
> +
> +/*
>   * Free a state id
>   */
>  __be32
> diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
> index 5da6874..2239114 100644
> --- a/fs/nfsd/nfs4xdr.c
> +++ b/fs/nfsd/nfs4xdr.c
> @@ -44,13 +44,14 @@
>  #include <linux/namei.h>
>  #include <linux/statfs.h>
>  #include <linux/utsname.h>
> +#include <linux/pagemap.h>
>  #include <linux/sunrpc/svcauth_gss.h>
>  
>  #include "idmap.h"
>  #include "acl.h"
>  #include "xdr4.h"
>  #include "vfs.h"
> -
> +#include "state.h"
>  
>  #define NFSDDBG_FACILITY		NFSDDBG_XDR
>  
> @@ -131,6 +132,22 @@ xdr_error:					\
>  	}					\
>  } while (0)
>  
> +static void save_buf(struct nfsd4_compoundargs *argp, struct nfsd4_saved_compoundargs *savep)
> +{
> +	savep->p        = argp->p;
> +	savep->end      = argp->end;
> +	savep->pagelen  = argp->pagelen;
> +	savep->pagelist = argp->pagelist;
> +}
> +
> +static void restore_buf(struct nfsd4_compoundargs *argp, struct nfsd4_saved_compoundargs *savep)
> +{
> +	argp->p        = savep->p;
> +	argp->end      = savep->end;
> +	argp->pagelen  = savep->pagelen;
> +	argp->pagelist = savep->pagelist;
> +}
> +
>  static __be32 *read_buf(struct nfsd4_compoundargs *argp, u32 nbytes)
>  {
>  	/* We want more bytes than seem to be available.
> @@ -1274,6 +1291,40 @@ nfsd4_decode_sequence(struct nfsd4_compoundargs *argp,
>  	DECODE_TAIL;
>  }
>  
> +static __be32
> +nfsd4_decode_test_stateid(struct nfsd4_compoundargs *argp, struct nfsd4_test_stateid *test_stateid)
> +{
> +	unsigned int nbytes;
> +	stateid_t si;
> +	int i;
> +	__be32 *p;
> +	__be32 status;
> +
> +	READ_BUF(4);
> +	test_stateid->ts_num_ids = ntohl(*p++);
> +
> +	nbytes = test_stateid->ts_num_ids * sizeof(stateid_t);
> +	if (nbytes > (u32)((char *)argp->end - (char *)argp->p))
> +		goto xdr_error;
> +
> +	test_stateid->ts_saved_args = argp;
> +	save_buf(argp, &test_stateid->ts_savedp);

I guess that works.  It's a little strange.  I can't see an immediate
problem.

--b.

> +
> +	for (i = 0; i < test_stateid->ts_num_ids; i++) {
> +		status = nfsd4_decode_stateid(argp, &si);
> +		if (status)
> +			return status;
> +	}
> +
> +	status = 0;
> +out:
> +	return status;
> +xdr_error:
> +	dprintk("NFSD: xdr error (%s:%d)\n", __FILE__, __LINE__);
> +	status = nfserr_bad_xdr;
> +	goto out;
> +}
> +
>  static __be32 nfsd4_decode_reclaim_complete(struct nfsd4_compoundargs *argp, struct nfsd4_reclaim_complete *rc)
>  {
>  	DECODE_HEAD;
> @@ -1393,7 +1444,7 @@ static nfsd4_dec nfsd41_dec_ops[] = {
>  	[OP_SECINFO_NO_NAME]	= (nfsd4_dec)nfsd4_decode_secinfo_no_name,
>  	[OP_SEQUENCE]		= (nfsd4_dec)nfsd4_decode_sequence,
>  	[OP_SET_SSV]		= (nfsd4_dec)nfsd4_decode_notsupp,
> -	[OP_TEST_STATEID]	= (nfsd4_dec)nfsd4_decode_notsupp,
> +	[OP_TEST_STATEID]	= (nfsd4_dec)nfsd4_decode_test_stateid,
>  	[OP_WANT_DELEGATION]	= (nfsd4_dec)nfsd4_decode_notsupp,
>  	[OP_DESTROY_CLIENTID]	= (nfsd4_dec)nfsd4_decode_notsupp,
>  	[OP_RECLAIM_COMPLETE]	= (nfsd4_dec)nfsd4_decode_reclaim_complete,
> @@ -3166,6 +3217,34 @@ nfsd4_encode_sequence(struct nfsd4_compoundres *resp, int nfserr,
>  	return 0;
>  }
>  
> +__be32
> +nfsd4_encode_test_stateid(struct nfsd4_compoundres *resp, int nfserr,
> +			  struct nfsd4_test_stateid *test_stateid)
> +{
> +	struct nfsd4_compoundargs *argp;
> +	stateid_t si;
> +	__be32 *p;
> +	int i;
> +	int valid;
> +
> +	restore_buf(test_stateid->ts_saved_args, &test_stateid->ts_savedp);
> +	argp = test_stateid->ts_saved_args;
> +
> +	RESERVE_SPACE(4);
> +	*p++ = htonl(test_stateid->ts_num_ids);
> +	resp->p = p;
> +
> +	for (i = 0; i < test_stateid->ts_num_ids; i++) {
> +		nfsd4_decode_stateid(argp, &si);
> +		valid = nfsd4_do_test_stateid(&si, test_stateid->ts_saved_state);
> +		RESERVE_SPACE(4);
> +		*p++ = htonl(valid);
> +		resp->p = p;
> +	}
> +
> +	return nfserr;
> +}
> +
>  static __be32
>  nfsd4_encode_noop(struct nfsd4_compoundres *resp, __be32 nfserr, void *p)
>  {
> @@ -3234,7 +3313,7 @@ static nfsd4_enc nfsd4_enc_ops[] = {
>  	[OP_SECINFO_NO_NAME]	= (nfsd4_enc)nfsd4_encode_secinfo_no_name,
>  	[OP_SEQUENCE]		= (nfsd4_enc)nfsd4_encode_sequence,
>  	[OP_SET_SSV]		= (nfsd4_enc)nfsd4_encode_noop,
> -	[OP_TEST_STATEID]	= (nfsd4_enc)nfsd4_encode_noop,
> +	[OP_TEST_STATEID]	= (nfsd4_enc)nfsd4_encode_test_stateid,
>  	[OP_WANT_DELEGATION]	= (nfsd4_enc)nfsd4_encode_noop,
>  	[OP_DESTROY_CLIENTID]	= (nfsd4_enc)nfsd4_encode_noop,
>  	[OP_RECLAIM_COMPLETE]	= (nfsd4_enc)nfsd4_encode_noop,
> diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
> index 6bd2f3c..3447b04 100644
> --- a/fs/nfsd/state.h
> +++ b/fs/nfsd/state.h
> @@ -482,6 +482,7 @@ extern void nfsd4_recdir_purge_old(void);
>  extern int nfsd4_create_clid_dir(struct nfs4_client *clp);
>  extern void nfsd4_remove_clid_dir(struct nfs4_client *clp);
>  extern void release_session_client(struct nfsd4_session *);
> +extern __be32 nfsd4_do_test_stateid(stateid_t *, struct nfsd4_compound_state *);
>  
>  static inline void
>  nfs4_put_stateowner(struct nfs4_stateowner *so)
> diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
> index ed1784d..628ef97 100644
> --- a/fs/nfsd/xdr4.h
> +++ b/fs/nfsd/xdr4.h
> @@ -342,6 +342,20 @@ struct nfsd4_setclientid_confirm {
>  	nfs4_verifier	sc_confirm;
>  };
>  
> +struct nfsd4_saved_compoundargs {
> +	__be32 *p;
> +	__be32 *end;
> +	int pagelen;
> +	struct page **pagelist;
> +};
> +
> +struct nfsd4_test_stateid {
> +	__be32		ts_num_ids;
> +	struct nfsd4_compoundargs *ts_saved_args;
> +	struct nfsd4_saved_compoundargs ts_savedp;
> +	struct nfsd4_compound_state *ts_saved_state;
> +};
> +
>  struct nfsd4_free_stateid {
>  	stateid_t	fr_stateid;         /* request */
>  	__be32		fr_status;          /* response */
> @@ -437,6 +451,7 @@ struct nfsd4_op {
>  		struct nfsd4_destroy_session	destroy_session;
>  		struct nfsd4_sequence		sequence;
>  		struct nfsd4_reclaim_complete	reclaim_complete;
> +		struct nfsd4_test_stateid	test_stateid;
>  		struct nfsd4_free_stateid	free_stateid;
>  	} u;
>  	struct nfs4_replay *			replay;
> @@ -570,6 +585,8 @@ extern __be32 nfsd4_delegreturn(struct svc_rqst *rqstp,
>  		struct nfsd4_compound_state *, struct nfsd4_delegreturn *dr);
>  extern __be32 nfsd4_renew(struct svc_rqst *rqstp,
>  			  struct nfsd4_compound_state *, clientid_t *clid);
> +extern __be32 nfsd4_test_stateid(struct svc_rqst *rqstp,
> +		struct nfsd4_compound_state *, struct nfsd4_test_stateid *test_stateid);
>  extern __be32 nfsd4_free_stateid(struct svc_rqst *rqstp,
>  		struct nfsd4_compound_state *, struct nfsd4_free_stateid *free_stateid);
>  #endif
> -- 
> 1.7.5.1
>