nfsd4: properly type op_set_currentstateid callbacks

Given the args union in struct nfsd4_op a name, and pass it to the
op_set_currentstateid callbacks instead of using unsafe function
pointer casts.
Signed-off-by: Christoph Hellwig <hch@lst.de>

fs/nfsd/current_stateid.h

@@ -8,10 +8,14 @@ extern void clear_current_stateid(struct nfsd4_compound_state *cstate);
 /*
  * functions to set current state id
  */
-extern void nfsd4_set_opendowngradestateid(struct nfsd4_compound_state *cstate, struct nfsd4_open_downgrade *);
-extern void nfsd4_set_openstateid(struct nfsd4_compound_state *, struct nfsd4_open *);
-extern void nfsd4_set_lockstateid(struct nfsd4_compound_state *, struct nfsd4_lock *);
-extern void nfsd4_set_closestateid(struct nfsd4_compound_state *, struct nfsd4_close *);
+extern void nfsd4_set_opendowngradestateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+extern void nfsd4_set_openstateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+extern void nfsd4_set_lockstateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+extern void nfsd4_set_closestateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
 
 /*
  * functions to consume current state id

fs/nfsd/nfs4proc.c

@@ -1525,7 +1525,6 @@ 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 {
@@ -1565,7 +1564,8 @@ struct nfsd4_operation {
 	/* Try to get response size before operation */
 	nfsd4op_rsize op_rsize_bop;
 	stateid_getter op_get_currentstateid;
-	stateid_setter op_set_currentstateid;
+	void (*op_set_currentstateid)(struct nfsd4_compound_state *,
+			union nfsd4_op_u *);
 };
 
 static struct nfsd4_operation nfsd4_ops[];
@@ -2104,7 +2104,7 @@ static struct nfsd4_operation nfsd4_ops[] = {
 		.op_name = "OP_CLOSE",
 		.op_rsize_bop = (nfsd4op_rsize)nfsd4_status_stateid_rsize,
 		.op_get_currentstateid = (stateid_getter)nfsd4_get_closestateid,
-		.op_set_currentstateid = (stateid_setter)nfsd4_set_closestateid,
+		.op_set_currentstateid = nfsd4_set_closestateid,
 	},
 	[OP_COMMIT] = {
 		.op_func = (nfsd4op_func)nfsd4_commit,
@@ -2148,7 +2148,7 @@ static struct nfsd4_operation nfsd4_ops[] = {
 		.op_flags = OP_MODIFIES_SOMETHING,
 		.op_name = "OP_LOCK",
 		.op_rsize_bop = (nfsd4op_rsize)nfsd4_lock_rsize,
-		.op_set_currentstateid = (stateid_setter)nfsd4_set_lockstateid,
+		.op_set_currentstateid = nfsd4_set_lockstateid,
 	},
 	[OP_LOCKT] = {
 		.op_func = (nfsd4op_func)nfsd4_lockt,
@@ -2184,7 +2184,7 @@ static struct nfsd4_operation nfsd4_ops[] = {
 		.op_flags = OP_HANDLES_WRONGSEC | OP_MODIFIES_SOMETHING,
 		.op_name = "OP_OPEN",
 		.op_rsize_bop = (nfsd4op_rsize)nfsd4_open_rsize,
-		.op_set_currentstateid = (stateid_setter)nfsd4_set_openstateid,
+		.op_set_currentstateid = nfsd4_set_openstateid,
 	},
 	[OP_OPEN_CONFIRM] = {
 		.op_func = (nfsd4op_func)nfsd4_open_confirm,
@@ -2198,7 +2198,7 @@ static struct nfsd4_operation nfsd4_ops[] = {
 		.op_name = "OP_OPEN_DOWNGRADE",
 		.op_rsize_bop = (nfsd4op_rsize)nfsd4_status_stateid_rsize,
 		.op_get_currentstateid = (stateid_getter)nfsd4_get_opendowngradestateid,
-		.op_set_currentstateid = (stateid_setter)nfsd4_set_opendowngradestateid,
+		.op_set_currentstateid = nfsd4_set_opendowngradestateid,
 	},
 	[OP_PUTFH] = {
 		.op_func = (nfsd4op_func)nfsd4_putfh,

fs/nfsd/nfs4state.c

@@ -7103,27 +7103,31 @@ clear_current_stateid(struct nfsd4_compound_state *cstate)
  * functions to set current state id
  */
 void
-nfsd4_set_opendowngradestateid(struct nfsd4_compound_state *cstate, struct nfsd4_open_downgrade *odp)
+nfsd4_set_opendowngradestateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
 {
-	put_stateid(cstate, &odp->od_stateid);
+	put_stateid(cstate, &u->open_downgrade.od_stateid);
 }
 
 void
-nfsd4_set_openstateid(struct nfsd4_compound_state *cstate, struct nfsd4_open *open)
+nfsd4_set_openstateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
 {
-	put_stateid(cstate, &open->op_stateid);
+	put_stateid(cstate, &u->open.op_stateid);
 }
 
 void
-nfsd4_set_closestateid(struct nfsd4_compound_state *cstate, struct nfsd4_close *close)
+nfsd4_set_closestateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
 {
-	put_stateid(cstate, &close->cl_stateid);
+	put_stateid(cstate, &u->close.cl_stateid);
 }
 
 void
-nfsd4_set_lockstateid(struct nfsd4_compound_state *cstate, struct nfsd4_lock *lock)
+nfsd4_set_lockstateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
 {
-	put_stateid(cstate, &lock->lk_resp_stateid);
+	put_stateid(cstate, &u->lock.lk_resp_stateid);
 }
 
 /*

fs/nfsd/xdr4.h

@@ -539,7 +539,7 @@ struct nfsd4_seek {
 struct nfsd4_op {
 	int					opnum;
 	__be32					status;
-	union {
+	union nfsd4_op_u {
 		struct nfsd4_access		access;
 		struct nfsd4_close		close;
 		struct nfsd4_commit		commit;