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

[Bryan Schumaker <bjschuma@netapp.com>]

On 05/18/2011 07:57 PM, J. Bruce Fields wrote:
> 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).

I wasn't using filpp either.  I've removed both from the patch.

> 
> 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?)

I can check for HAS_SESSION using cstate, and then pass the result to nfs4_validate_stateid().
> 
>> +	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
>>
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