xref: /titanic_41/usr/src/uts/common/rpc/svc_rdma.c (revision f6da83d4178694e7113b71d1e452f15b296f73d8)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright (c) 1983, 2010, Oracle and/or its affiliates. All rights reserved.
23  */
24 /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
25 /* All Rights Reserved */
26 /*
27  * Portions of this source code were derived from Berkeley
28  * 4.3 BSD under license from the Regents of the University of
29  * California.
30  */
31 
32 /*
33  * Server side of RPC over RDMA in the kernel.
34  */
35 
36 #include <sys/param.h>
37 #include <sys/types.h>
38 #include <sys/user.h>
39 #include <sys/sysmacros.h>
40 #include <sys/proc.h>
41 #include <sys/file.h>
42 #include <sys/errno.h>
43 #include <sys/kmem.h>
44 #include <sys/debug.h>
45 #include <sys/systm.h>
46 #include <sys/cmn_err.h>
47 #include <sys/kstat.h>
48 #include <sys/vtrace.h>
49 #include <sys/debug.h>
50 
51 #include <rpc/types.h>
52 #include <rpc/xdr.h>
53 #include <rpc/auth.h>
54 #include <rpc/clnt.h>
55 #include <rpc/rpc_msg.h>
56 #include <rpc/svc.h>
57 #include <rpc/rpc_rdma.h>
58 #include <sys/ddi.h>
59 #include <sys/sunddi.h>
60 
61 #include <inet/common.h>
62 #include <inet/ip.h>
63 #include <inet/ip6.h>
64 
65 #include <nfs/nfs.h>
66 #include <sys/sdt.h>
67 
68 #define	SVC_RDMA_SUCCESS 0
69 #define	SVC_RDMA_FAIL -1
70 
71 #define	SVC_CREDIT_FACTOR (0.5)
72 
73 #define	MSG_IS_RPCSEC_GSS(msg)		\
74 	((msg)->rm_reply.rp_acpt.ar_verf.oa_flavor == RPCSEC_GSS)
75 
76 
77 uint32_t rdma_bufs_granted = RDMA_BUFS_GRANT;
78 
79 /*
80  * RDMA transport specific data associated with SVCMASTERXPRT
81  */
82 struct rdma_data {
83 	SVCMASTERXPRT 	*rd_xprt;	/* back ptr to SVCMASTERXPRT */
84 	struct rdma_svc_data rd_data;	/* rdma data */
85 	rdma_mod_t	*r_mod;		/* RDMA module containing ops ptr */
86 };
87 
88 /*
89  * Plugin connection specific data stashed away in clone SVCXPRT
90  */
91 struct clone_rdma_data {
92 	bool_t		cloned;		/* xprt cloned for thread processing */
93 	CONN		*conn;		/* RDMA connection */
94 	rdma_buf_t	rpcbuf;		/* RPC req/resp buffer */
95 	struct clist	*cl_reply;	/* reply chunk buffer info */
96 	struct clist	*cl_wlist;		/* write list clist */
97 };
98 
99 
100 #define	MAXADDRLEN	128	/* max length for address mask */
101 
102 /*
103  * Routines exported through ops vector.
104  */
105 static bool_t		svc_rdma_krecv(SVCXPRT *, mblk_t *, struct rpc_msg *);
106 static bool_t		svc_rdma_ksend(SVCXPRT *, struct rpc_msg *);
107 static bool_t		svc_rdma_kgetargs(SVCXPRT *, xdrproc_t, caddr_t);
108 static bool_t		svc_rdma_kfreeargs(SVCXPRT *, xdrproc_t, caddr_t);
109 void			svc_rdma_kdestroy(SVCMASTERXPRT *);
110 static int		svc_rdma_kdup(struct svc_req *, caddr_t, int,
111 				struct dupreq **, bool_t *);
112 static void		svc_rdma_kdupdone(struct dupreq *, caddr_t,
113 				void (*)(), int, int);
114 static int32_t		*svc_rdma_kgetres(SVCXPRT *, int);
115 static void		svc_rdma_kfreeres(SVCXPRT *);
116 static void		svc_rdma_kclone_destroy(SVCXPRT *);
117 static void		svc_rdma_kstart(SVCMASTERXPRT *);
118 void			svc_rdma_kstop(SVCMASTERXPRT *);
119 static void		svc_rdma_kclone_xprt(SVCXPRT *, SVCXPRT *);
120 static void		svc_rdma_ktattrs(SVCXPRT *, int, void **);
121 
122 static int	svc_process_long_reply(SVCXPRT *, xdrproc_t,
123 			caddr_t, struct rpc_msg *, bool_t, int *,
124 			int *, int *, unsigned int *);
125 
126 static int	svc_compose_rpcmsg(SVCXPRT *, CONN *, xdrproc_t,
127 			caddr_t, rdma_buf_t *, XDR **, struct rpc_msg *,
128 			bool_t, uint_t *);
129 static bool_t rpcmsg_length(xdrproc_t,
130 		caddr_t,
131 		struct rpc_msg *, bool_t, int);
132 
133 /*
134  * Server transport operations vector.
135  */
136 struct svc_ops rdma_svc_ops = {
137 	svc_rdma_krecv,		/* Get requests */
138 	svc_rdma_kgetargs,	/* Deserialize arguments */
139 	svc_rdma_ksend,		/* Send reply */
140 	svc_rdma_kfreeargs,	/* Free argument data space */
141 	svc_rdma_kdestroy,	/* Destroy transport handle */
142 	svc_rdma_kdup,		/* Check entry in dup req cache */
143 	svc_rdma_kdupdone,	/* Mark entry in dup req cache as done */
144 	svc_rdma_kgetres,	/* Get pointer to response buffer */
145 	svc_rdma_kfreeres,	/* Destroy pre-serialized response header */
146 	svc_rdma_kclone_destroy,	/* Destroy a clone xprt */
147 	svc_rdma_kstart,	/* Tell `ready-to-receive' to rpcmod */
148 	svc_rdma_kclone_xprt,	/* Transport specific clone xprt */
149 	svc_rdma_ktattrs	/* Get Transport Attributes */
150 };
151 
152 /*
153  * Server statistics
154  * NOTE: This structure type is duplicated in the NFS fast path.
155  */
156 struct {
157 	kstat_named_t	rscalls;
158 	kstat_named_t	rsbadcalls;
159 	kstat_named_t	rsnullrecv;
160 	kstat_named_t	rsbadlen;
161 	kstat_named_t	rsxdrcall;
162 	kstat_named_t	rsdupchecks;
163 	kstat_named_t	rsdupreqs;
164 	kstat_named_t	rslongrpcs;
165 	kstat_named_t	rstotalreplies;
166 	kstat_named_t	rstotallongreplies;
167 	kstat_named_t	rstotalinlinereplies;
168 } rdmarsstat = {
169 	{ "calls",	KSTAT_DATA_UINT64 },
170 	{ "badcalls",	KSTAT_DATA_UINT64 },
171 	{ "nullrecv",	KSTAT_DATA_UINT64 },
172 	{ "badlen",	KSTAT_DATA_UINT64 },
173 	{ "xdrcall",	KSTAT_DATA_UINT64 },
174 	{ "dupchecks",	KSTAT_DATA_UINT64 },
175 	{ "dupreqs",	KSTAT_DATA_UINT64 },
176 	{ "longrpcs",	KSTAT_DATA_UINT64 },
177 	{ "totalreplies",	KSTAT_DATA_UINT64 },
178 	{ "totallongreplies",	KSTAT_DATA_UINT64 },
179 	{ "totalinlinereplies",	KSTAT_DATA_UINT64 },
180 };
181 
182 kstat_named_t *rdmarsstat_ptr = (kstat_named_t *)&rdmarsstat;
183 uint_t rdmarsstat_ndata = sizeof (rdmarsstat) / sizeof (kstat_named_t);
184 
185 #define	RSSTAT_INCR(x)	atomic_add_64(&rdmarsstat.x.value.ui64, 1)
186 /*
187  * Create a transport record.
188  * The transport record, output buffer, and private data structure
189  * are allocated.  The output buffer is serialized into using xdrmem.
190  * There is one transport record per user process which implements a
191  * set of services.
192  */
193 /* ARGSUSED */
194 int
195 svc_rdma_kcreate(char *netid, SVC_CALLOUT_TABLE *sct, int id,
196     rdma_xprt_group_t *started_xprts)
197 {
198 	int error;
199 	SVCMASTERXPRT *xprt;
200 	struct rdma_data *rd;
201 	rdma_registry_t *rmod;
202 	rdma_xprt_record_t *xprt_rec;
203 	queue_t	*q;
204 	/*
205 	 * modload the RDMA plugins is not already done.
206 	 */
207 	if (!rdma_modloaded) {
208 		/*CONSTANTCONDITION*/
209 		ASSERT(sizeof (struct clone_rdma_data) <= SVC_P2LEN);
210 
211 		mutex_enter(&rdma_modload_lock);
212 		if (!rdma_modloaded) {
213 			error = rdma_modload();
214 		}
215 		mutex_exit(&rdma_modload_lock);
216 
217 		if (error)
218 			return (error);
219 	}
220 
221 	/*
222 	 * master_xprt_count is the count of master transport handles
223 	 * that were successfully created and are ready to recieve for
224 	 * RDMA based access.
225 	 */
226 	error = 0;
227 	xprt_rec = NULL;
228 	rw_enter(&rdma_lock, RW_READER);
229 	if (rdma_mod_head == NULL) {
230 		started_xprts->rtg_count = 0;
231 		rw_exit(&rdma_lock);
232 		if (rdma_dev_available)
233 			return (EPROTONOSUPPORT);
234 		else
235 			return (ENODEV);
236 	}
237 
238 	/*
239 	 * If we have reached here, then atleast one RDMA plugin has loaded.
240 	 * Create a master_xprt, make it start listenining on the device,
241 	 * if an error is generated, record it, we might need to shut
242 	 * the master_xprt.
243 	 * SVC_START() calls svc_rdma_kstart which calls plugin binding
244 	 * routines.
245 	 */
246 	for (rmod = rdma_mod_head; rmod != NULL; rmod = rmod->r_next) {
247 
248 		/*
249 		 * One SVCMASTERXPRT per RDMA plugin.
250 		 */
251 		xprt = kmem_zalloc(sizeof (*xprt), KM_SLEEP);
252 		xprt->xp_ops = &rdma_svc_ops;
253 		xprt->xp_sct = sct;
254 		xprt->xp_type = T_RDMA;
255 		mutex_init(&xprt->xp_req_lock, NULL, MUTEX_DEFAULT, NULL);
256 		mutex_init(&xprt->xp_thread_lock, NULL, MUTEX_DEFAULT, NULL);
257 		xprt->xp_req_head = (mblk_t *)0;
258 		xprt->xp_req_tail = (mblk_t *)0;
259 		xprt->xp_threads = 0;
260 		xprt->xp_detached_threads = 0;
261 
262 		rd = kmem_zalloc(sizeof (*rd), KM_SLEEP);
263 		xprt->xp_p2 = (caddr_t)rd;
264 		rd->rd_xprt = xprt;
265 		rd->r_mod = rmod->r_mod;
266 
267 		q = &rd->rd_data.q;
268 		xprt->xp_wq = q;
269 		q->q_ptr = &rd->rd_xprt;
270 		xprt->xp_netid = NULL;
271 
272 		/*
273 		 * Each of the plugins will have their own Service ID
274 		 * to listener specific mapping, like port number for VI
275 		 * and service name for IB.
276 		 */
277 		rd->rd_data.svcid = id;
278 		error = svc_xprt_register(xprt, id);
279 		if (error) {
280 			DTRACE_PROBE(krpc__e__svcrdma__xprt__reg);
281 			goto cleanup;
282 		}
283 
284 		SVC_START(xprt);
285 		if (!rd->rd_data.active) {
286 			svc_xprt_unregister(xprt);
287 			error = rd->rd_data.err_code;
288 			goto cleanup;
289 		}
290 
291 		/*
292 		 * This is set only when there is atleast one or more
293 		 * transports successfully created. We insert the pointer
294 		 * to the created RDMA master xprt into a separately maintained
295 		 * list. This way we can easily reference it later to cleanup,
296 		 * when NFS kRPC service pool is going away/unregistered.
297 		 */
298 		started_xprts->rtg_count ++;
299 		xprt_rec = kmem_alloc(sizeof (*xprt_rec), KM_SLEEP);
300 		xprt_rec->rtr_xprt_ptr = xprt;
301 		xprt_rec->rtr_next = started_xprts->rtg_listhead;
302 		started_xprts->rtg_listhead = xprt_rec;
303 		continue;
304 cleanup:
305 		SVC_DESTROY(xprt);
306 		if (error == RDMA_FAILED)
307 			error = EPROTONOSUPPORT;
308 	}
309 
310 	rw_exit(&rdma_lock);
311 
312 	/*
313 	 * Don't return any error even if a single plugin was started
314 	 * successfully.
315 	 */
316 	if (started_xprts->rtg_count == 0)
317 		return (error);
318 	return (0);
319 }
320 
321 /*
322  * Cleanup routine for freeing up memory allocated by
323  * svc_rdma_kcreate()
324  */
325 void
326 svc_rdma_kdestroy(SVCMASTERXPRT *xprt)
327 {
328 	struct rdma_data *rd = (struct rdma_data *)xprt->xp_p2;
329 
330 
331 	mutex_destroy(&xprt->xp_req_lock);
332 	mutex_destroy(&xprt->xp_thread_lock);
333 	kmem_free(rd, sizeof (*rd));
334 	kmem_free(xprt, sizeof (*xprt));
335 }
336 
337 
338 static void
339 svc_rdma_kstart(SVCMASTERXPRT *xprt)
340 {
341 	struct rdma_svc_data *svcdata;
342 	rdma_mod_t *rmod;
343 
344 	svcdata = &((struct rdma_data *)xprt->xp_p2)->rd_data;
345 	rmod = ((struct rdma_data *)xprt->xp_p2)->r_mod;
346 
347 	/*
348 	 * Create a listener for  module at this port
349 	 */
350 
351 	if (rmod->rdma_count != 0)
352 		(*rmod->rdma_ops->rdma_svc_listen)(svcdata);
353 	else
354 		svcdata->err_code = RDMA_FAILED;
355 }
356 
357 void
358 svc_rdma_kstop(SVCMASTERXPRT *xprt)
359 {
360 	struct rdma_svc_data *svcdata;
361 	rdma_mod_t *rmod;
362 
363 	svcdata	= &((struct rdma_data *)xprt->xp_p2)->rd_data;
364 	rmod = ((struct rdma_data *)xprt->xp_p2)->r_mod;
365 
366 	/*
367 	 * Call the stop listener routine for each plugin. If rdma_count is
368 	 * already zero set active to zero.
369 	 */
370 	if (rmod->rdma_count != 0)
371 		(*rmod->rdma_ops->rdma_svc_stop)(svcdata);
372 	else
373 		svcdata->active = 0;
374 	if (svcdata->active)
375 		DTRACE_PROBE(krpc__e__svcrdma__kstop);
376 }
377 
378 /* ARGSUSED */
379 static void
380 svc_rdma_kclone_destroy(SVCXPRT *clone_xprt)
381 {
382 
383 	struct clone_rdma_data *cdrp;
384 	cdrp = (struct clone_rdma_data *)clone_xprt->xp_p2buf;
385 
386 	/*
387 	 * Only free buffers and release connection when cloned is set.
388 	 */
389 	if (cdrp->cloned != TRUE)
390 		return;
391 
392 	rdma_buf_free(cdrp->conn, &cdrp->rpcbuf);
393 	if (cdrp->cl_reply) {
394 		clist_free(cdrp->cl_reply);
395 		cdrp->cl_reply = NULL;
396 	}
397 	RDMA_REL_CONN(cdrp->conn);
398 
399 	cdrp->cloned = 0;
400 }
401 
402 /*
403  * Clone the xprt specific information.  It will be freed by
404  * SVC_CLONE_DESTROY.
405  */
406 static void
407 svc_rdma_kclone_xprt(SVCXPRT *src_xprt, SVCXPRT *dst_xprt)
408 {
409 	struct clone_rdma_data *srcp2;
410 	struct clone_rdma_data *dstp2;
411 
412 	srcp2 = (struct clone_rdma_data *)src_xprt->xp_p2buf;
413 	dstp2 = (struct clone_rdma_data *)dst_xprt->xp_p2buf;
414 
415 	if (srcp2->conn != NULL) {
416 		srcp2->cloned = TRUE;
417 		*dstp2 = *srcp2;
418 	}
419 }
420 
421 static void
422 svc_rdma_ktattrs(SVCXPRT *clone_xprt, int attrflag, void **tattr)
423 {
424 	CONN	*conn;
425 	*tattr = NULL;
426 
427 	switch (attrflag) {
428 	case SVC_TATTR_ADDRMASK:
429 		conn = ((struct clone_rdma_data *)clone_xprt->xp_p2buf)->conn;
430 		ASSERT(conn != NULL);
431 		if (conn)
432 			*tattr = (void *)&conn->c_addrmask;
433 	}
434 }
435 
436 static bool_t
437 svc_rdma_krecv(SVCXPRT *clone_xprt, mblk_t *mp, struct rpc_msg *msg)
438 {
439 	XDR	*xdrs;
440 	CONN	*conn;
441 	rdma_recv_data_t	*rdp = (rdma_recv_data_t *)mp->b_rptr;
442 	struct clone_rdma_data *crdp;
443 	struct clist	*cl = NULL;
444 	struct clist	*wcl = NULL;
445 	struct clist	*cllong = NULL;
446 
447 	rdma_stat	status;
448 	uint32_t vers, op, pos, xid;
449 	uint32_t rdma_credit;
450 	uint32_t wcl_total_length = 0;
451 	bool_t	wwl = FALSE;
452 
453 	crdp = (struct clone_rdma_data *)clone_xprt->xp_p2buf;
454 	RSSTAT_INCR(rscalls);
455 	conn = rdp->conn;
456 
457 	status = rdma_svc_postrecv(conn);
458 	if (status != RDMA_SUCCESS) {
459 		DTRACE_PROBE(krpc__e__svcrdma__krecv__postrecv);
460 		goto badrpc_call;
461 	}
462 
463 	xdrs = &clone_xprt->xp_xdrin;
464 	xdrmem_create(xdrs, rdp->rpcmsg.addr, rdp->rpcmsg.len, XDR_DECODE);
465 	xid = *(uint32_t *)rdp->rpcmsg.addr;
466 	XDR_SETPOS(xdrs, sizeof (uint32_t));
467 
468 	if (! xdr_u_int(xdrs, &vers) ||
469 	    ! xdr_u_int(xdrs, &rdma_credit) ||
470 	    ! xdr_u_int(xdrs, &op)) {
471 		DTRACE_PROBE(krpc__e__svcrdma__krecv__uint);
472 		goto xdr_err;
473 	}
474 
475 	/* Checking if the status of the recv operation was normal */
476 	if (rdp->status != 0) {
477 		DTRACE_PROBE1(krpc__e__svcrdma__krecv__invalid__status,
478 		    int, rdp->status);
479 		goto badrpc_call;
480 	}
481 
482 	if (! xdr_do_clist(xdrs, &cl)) {
483 		DTRACE_PROBE(krpc__e__svcrdma__krecv__do__clist);
484 		goto xdr_err;
485 	}
486 
487 	if (!xdr_decode_wlist_svc(xdrs, &wcl, &wwl, &wcl_total_length, conn)) {
488 		DTRACE_PROBE(krpc__e__svcrdma__krecv__decode__wlist);
489 		if (cl)
490 			clist_free(cl);
491 		goto xdr_err;
492 	}
493 	crdp->cl_wlist = wcl;
494 
495 	crdp->cl_reply = NULL;
496 	(void) xdr_decode_reply_wchunk(xdrs, &crdp->cl_reply);
497 
498 	/*
499 	 * A chunk at 0 offset indicates that the RPC call message
500 	 * is in a chunk. Get the RPC call message chunk.
501 	 */
502 	if (cl != NULL && op == RDMA_NOMSG) {
503 
504 		/* Remove RPC call message chunk from chunklist */
505 		cllong = cl;
506 		cl = cl->c_next;
507 		cllong->c_next = NULL;
508 
509 
510 		/* Allocate and register memory for the RPC call msg chunk */
511 		cllong->rb_longbuf.type = RDMA_LONG_BUFFER;
512 		cllong->rb_longbuf.len = cllong->c_len > LONG_REPLY_LEN ?
513 		    cllong->c_len : LONG_REPLY_LEN;
514 
515 		if (rdma_buf_alloc(conn, &cllong->rb_longbuf)) {
516 			clist_free(cllong);
517 			goto cll_malloc_err;
518 		}
519 
520 		cllong->u.c_daddr3 = cllong->rb_longbuf.addr;
521 
522 		if (cllong->u.c_daddr == NULL) {
523 			DTRACE_PROBE(krpc__e__svcrdma__krecv__nomem);
524 			rdma_buf_free(conn, &cllong->rb_longbuf);
525 			clist_free(cllong);
526 			goto cll_malloc_err;
527 		}
528 
529 		status = clist_register(conn, cllong, CLIST_REG_DST);
530 		if (status) {
531 			DTRACE_PROBE(krpc__e__svcrdma__krecv__clist__reg);
532 			rdma_buf_free(conn, &cllong->rb_longbuf);
533 			clist_free(cllong);
534 			goto cll_malloc_err;
535 		}
536 
537 		/*
538 		 * Now read the RPC call message in
539 		 */
540 		status = RDMA_READ(conn, cllong, WAIT);
541 		if (status) {
542 			DTRACE_PROBE(krpc__e__svcrdma__krecv__read);
543 			(void) clist_deregister(conn, cllong);
544 			rdma_buf_free(conn, &cllong->rb_longbuf);
545 			clist_free(cllong);
546 			goto cll_malloc_err;
547 		}
548 
549 		status = clist_syncmem(conn, cllong, CLIST_REG_DST);
550 		(void) clist_deregister(conn, cllong);
551 
552 		xdrrdma_create(xdrs, (caddr_t)(uintptr_t)cllong->u.c_daddr3,
553 		    cllong->c_len, 0, cl, XDR_DECODE, conn);
554 
555 		crdp->rpcbuf = cllong->rb_longbuf;
556 		crdp->rpcbuf.len = cllong->c_len;
557 		clist_free(cllong);
558 		RDMA_BUF_FREE(conn, &rdp->rpcmsg);
559 	} else {
560 		pos = XDR_GETPOS(xdrs);
561 		xdrrdma_create(xdrs, rdp->rpcmsg.addr + pos,
562 		    rdp->rpcmsg.len - pos, 0, cl, XDR_DECODE, conn);
563 		crdp->rpcbuf = rdp->rpcmsg;
564 
565 		/* Use xdrrdmablk_ops to indicate there is a read chunk list */
566 		if (cl != NULL) {
567 			int32_t flg = XDR_RDMA_RLIST_REG;
568 
569 			XDR_CONTROL(xdrs, XDR_RDMA_SET_FLAGS, &flg);
570 			xdrs->x_ops = &xdrrdmablk_ops;
571 		}
572 	}
573 
574 	if (crdp->cl_wlist) {
575 		int32_t flg = XDR_RDMA_WLIST_REG;
576 
577 		XDR_CONTROL(xdrs, XDR_RDMA_SET_WLIST, crdp->cl_wlist);
578 		XDR_CONTROL(xdrs, XDR_RDMA_SET_FLAGS, &flg);
579 	}
580 
581 	if (! xdr_callmsg(xdrs, msg)) {
582 		DTRACE_PROBE(krpc__e__svcrdma__krecv__callmsg);
583 		RSSTAT_INCR(rsxdrcall);
584 		goto callmsg_err;
585 	}
586 
587 	/*
588 	 * Point the remote transport address in the service_transport
589 	 * handle at the address in the request.
590 	 */
591 	clone_xprt->xp_rtaddr.buf = conn->c_raddr.buf;
592 	clone_xprt->xp_rtaddr.len = conn->c_raddr.len;
593 	clone_xprt->xp_rtaddr.maxlen = conn->c_raddr.len;
594 
595 	clone_xprt->xp_lcladdr.buf = conn->c_laddr.buf;
596 	clone_xprt->xp_lcladdr.len = conn->c_laddr.len;
597 	clone_xprt->xp_lcladdr.maxlen = conn->c_laddr.len;
598 
599 	/*
600 	 * In case of RDMA, connection management is
601 	 * entirely done in rpcib module and netid in the
602 	 * SVCMASTERXPRT is NULL. Initialize the clone netid
603 	 * from the connection.
604 	 */
605 
606 	clone_xprt->xp_netid = conn->c_netid;
607 
608 	clone_xprt->xp_xid = xid;
609 	crdp->conn = conn;
610 
611 	freeb(mp);
612 
613 	return (TRUE);
614 
615 callmsg_err:
616 	rdma_buf_free(conn, &crdp->rpcbuf);
617 
618 cll_malloc_err:
619 	if (cl)
620 		clist_free(cl);
621 xdr_err:
622 	XDR_DESTROY(xdrs);
623 
624 badrpc_call:
625 	RDMA_BUF_FREE(conn, &rdp->rpcmsg);
626 	RDMA_REL_CONN(conn);
627 	freeb(mp);
628 	RSSTAT_INCR(rsbadcalls);
629 	return (FALSE);
630 }
631 
632 static int
633 svc_process_long_reply(SVCXPRT * clone_xprt,
634     xdrproc_t xdr_results, caddr_t xdr_location,
635     struct rpc_msg *msg, bool_t has_args, int *msglen,
636     int *freelen, int *numchunks, unsigned int *final_len)
637 {
638 	int status;
639 	XDR xdrslong;
640 	struct clist *wcl = NULL;
641 	int count = 0;
642 	int alloc_len;
643 	char  *memp;
644 	rdma_buf_t long_rpc = {0};
645 	struct clone_rdma_data *crdp;
646 
647 	crdp = (struct clone_rdma_data *)clone_xprt->xp_p2buf;
648 
649 	bzero(&xdrslong, sizeof (xdrslong));
650 
651 	/* Choose a size for the long rpc response */
652 	if (MSG_IS_RPCSEC_GSS(msg)) {
653 		alloc_len = RNDUP(MAX_AUTH_BYTES + *msglen);
654 	} else {
655 		alloc_len = RNDUP(*msglen);
656 	}
657 
658 	if (alloc_len <= 64 * 1024) {
659 		if (alloc_len > 32 * 1024) {
660 			alloc_len = 64 * 1024;
661 		} else {
662 			if (alloc_len > 16 * 1024) {
663 				alloc_len = 32 * 1024;
664 			} else {
665 				alloc_len = 16 * 1024;
666 			}
667 		}
668 	}
669 
670 	long_rpc.type = RDMA_LONG_BUFFER;
671 	long_rpc.len = alloc_len;
672 	if (rdma_buf_alloc(crdp->conn, &long_rpc)) {
673 		return (SVC_RDMA_FAIL);
674 	}
675 
676 	memp = long_rpc.addr;
677 	xdrmem_create(&xdrslong, memp, alloc_len, XDR_ENCODE);
678 
679 	msg->rm_xid = clone_xprt->xp_xid;
680 
681 	if (!(xdr_replymsg(&xdrslong, msg) &&
682 	    (!has_args || SVCAUTH_WRAP(&clone_xprt->xp_auth, &xdrslong,
683 	    xdr_results, xdr_location)))) {
684 		rdma_buf_free(crdp->conn, &long_rpc);
685 		DTRACE_PROBE(krpc__e__svcrdma__longrep__authwrap);
686 		return (SVC_RDMA_FAIL);
687 	}
688 
689 	*final_len = XDR_GETPOS(&xdrslong);
690 
691 	DTRACE_PROBE1(krpc__i__replylen, uint_t, *final_len);
692 	*numchunks = 0;
693 	*freelen = 0;
694 
695 	wcl = crdp->cl_reply;
696 	wcl->rb_longbuf = long_rpc;
697 
698 	count = *final_len;
699 	while ((wcl != NULL) && (count > 0)) {
700 
701 		if (wcl->c_dmemhandle.mrc_rmr == 0)
702 			break;
703 
704 		DTRACE_PROBE2(krpc__i__write__chunks, uint32_t, count,
705 		    uint32_t, wcl->c_len);
706 
707 		if (wcl->c_len > count) {
708 			wcl->c_len = count;
709 		}
710 		wcl->w.c_saddr3 = (caddr_t)memp;
711 
712 		count -= wcl->c_len;
713 		*numchunks +=  1;
714 		memp += wcl->c_len;
715 		wcl = wcl->c_next;
716 	}
717 
718 	/*
719 	 * Make rest of the chunks 0-len
720 	 */
721 	while (wcl != NULL) {
722 		if (wcl->c_dmemhandle.mrc_rmr == 0)
723 			break;
724 		wcl->c_len = 0;
725 		wcl = wcl->c_next;
726 	}
727 
728 	wcl = crdp->cl_reply;
729 
730 	/*
731 	 * MUST fail if there are still more data
732 	 */
733 	if (count > 0) {
734 		rdma_buf_free(crdp->conn, &long_rpc);
735 		DTRACE_PROBE(krpc__e__svcrdma__longrep__dlen__clist);
736 		return (SVC_RDMA_FAIL);
737 	}
738 
739 	if (clist_register(crdp->conn, wcl, CLIST_REG_SOURCE) != RDMA_SUCCESS) {
740 		rdma_buf_free(crdp->conn, &long_rpc);
741 		DTRACE_PROBE(krpc__e__svcrdma__longrep__clistreg);
742 		return (SVC_RDMA_FAIL);
743 	}
744 
745 	status = clist_syncmem(crdp->conn, wcl, CLIST_REG_SOURCE);
746 
747 	if (status) {
748 		(void) clist_deregister(crdp->conn, wcl);
749 		rdma_buf_free(crdp->conn, &long_rpc);
750 		DTRACE_PROBE(krpc__e__svcrdma__longrep__syncmem);
751 		return (SVC_RDMA_FAIL);
752 	}
753 
754 	status = RDMA_WRITE(crdp->conn, wcl, WAIT);
755 
756 	(void) clist_deregister(crdp->conn, wcl);
757 	rdma_buf_free(crdp->conn, &wcl->rb_longbuf);
758 
759 	if (status != RDMA_SUCCESS) {
760 		DTRACE_PROBE(krpc__e__svcrdma__longrep__write);
761 		return (SVC_RDMA_FAIL);
762 	}
763 
764 	return (SVC_RDMA_SUCCESS);
765 }
766 
767 
768 static int
769 svc_compose_rpcmsg(SVCXPRT * clone_xprt, CONN * conn, xdrproc_t xdr_results,
770     caddr_t xdr_location, rdma_buf_t *rpcreply, XDR ** xdrs,
771     struct rpc_msg *msg, bool_t has_args, uint_t *len)
772 {
773 	/*
774 	 * Get a pre-allocated buffer for rpc reply
775 	 */
776 	rpcreply->type = SEND_BUFFER;
777 	if (rdma_buf_alloc(conn, rpcreply)) {
778 		DTRACE_PROBE(krpc__e__svcrdma__rpcmsg__reply__nofreebufs);
779 		return (SVC_RDMA_FAIL);
780 	}
781 
782 	xdrrdma_create(*xdrs, rpcreply->addr, rpcreply->len,
783 	    0, NULL, XDR_ENCODE, conn);
784 
785 	msg->rm_xid = clone_xprt->xp_xid;
786 
787 	if (has_args) {
788 		if (!(xdr_replymsg(*xdrs, msg) &&
789 		    (!has_args ||
790 		    SVCAUTH_WRAP(&clone_xprt->xp_auth, *xdrs,
791 		    xdr_results, xdr_location)))) {
792 			rdma_buf_free(conn, rpcreply);
793 			DTRACE_PROBE(
794 			    krpc__e__svcrdma__rpcmsg__reply__authwrap1);
795 			return (SVC_RDMA_FAIL);
796 		}
797 	} else {
798 		if (!xdr_replymsg(*xdrs, msg)) {
799 			rdma_buf_free(conn, rpcreply);
800 			DTRACE_PROBE(
801 			    krpc__e__svcrdma__rpcmsg__reply__authwrap2);
802 			return (SVC_RDMA_FAIL);
803 		}
804 	}
805 
806 	*len = XDR_GETPOS(*xdrs);
807 
808 	return (SVC_RDMA_SUCCESS);
809 }
810 
811 /*
812  * Send rpc reply.
813  */
814 static bool_t
815 svc_rdma_ksend(SVCXPRT * clone_xprt, struct rpc_msg *msg)
816 {
817 	XDR *xdrs_rpc = &(clone_xprt->xp_xdrout);
818 	XDR xdrs_rhdr;
819 	CONN *conn = NULL;
820 	rdma_buf_t rbuf_resp = {0}, rbuf_rpc_resp = {0};
821 
822 	struct clone_rdma_data *crdp;
823 	struct clist *cl_read = NULL;
824 	struct clist *cl_send = NULL;
825 	struct clist *cl_write = NULL;
826 	xdrproc_t xdr_results;		/* results XDR encoding function */
827 	caddr_t xdr_location;		/* response results pointer */
828 
829 	int retval = FALSE;
830 	int status, msglen, num_wreply_segments = 0;
831 	uint32_t rdma_credit = 0;
832 	int freelen = 0;
833 	bool_t has_args;
834 	uint_t  final_resp_len, rdma_response_op, vers;
835 
836 	bzero(&xdrs_rhdr, sizeof (XDR));
837 	crdp = (struct clone_rdma_data *)clone_xprt->xp_p2buf;
838 	conn = crdp->conn;
839 
840 	/*
841 	 * If there is a result procedure specified in the reply message,
842 	 * it will be processed in the xdr_replymsg and SVCAUTH_WRAP.
843 	 * We need to make sure it won't be processed twice, so we null
844 	 * it for xdr_replymsg here.
845 	 */
846 	has_args = FALSE;
847 	if (msg->rm_reply.rp_stat == MSG_ACCEPTED &&
848 	    msg->rm_reply.rp_acpt.ar_stat == SUCCESS) {
849 		if ((xdr_results = msg->acpted_rply.ar_results.proc) != NULL) {
850 			has_args = TRUE;
851 			xdr_location = msg->acpted_rply.ar_results.where;
852 			msg->acpted_rply.ar_results.proc = xdr_void;
853 			msg->acpted_rply.ar_results.where = NULL;
854 		}
855 	}
856 
857 	/*
858 	 * Given the limit on the inline response size (RPC_MSG_SZ),
859 	 * there is a need to make a guess as to the overall size of
860 	 * the response.  If the resultant size is beyond the inline
861 	 * size, then the server needs to use the "reply chunk list"
862 	 * provided by the client (if the client provided one).  An
863 	 * example of this type of response would be a READDIR
864 	 * response (e.g. a small directory read would fit in RPC_MSG_SZ
865 	 * and that is the preference but it may not fit)
866 	 *
867 	 * Combine the encoded size and the size of the true results
868 	 * and then make the decision about where to encode and send results.
869 	 *
870 	 * One important note, this calculation is ignoring the size
871 	 * of the encoding of the authentication overhead.  The reason
872 	 * for this is rooted in the complexities of access to the
873 	 * encoded size of RPCSEC_GSS related authentiation,
874 	 * integrity, and privacy.
875 	 *
876 	 * If it turns out that the encoded authentication bumps the
877 	 * response over the RPC_MSG_SZ limit, then it may need to
878 	 * attempt to encode for the reply chunk list.
879 	 */
880 
881 	/*
882 	 * Calculating the "sizeof" the RPC response header and the
883 	 * encoded results.
884 	 */
885 	msglen = xdr_sizeof(xdr_replymsg, msg);
886 
887 	if (msglen > 0) {
888 		RSSTAT_INCR(rstotalreplies);
889 	}
890 	if (has_args)
891 		msglen += xdrrdma_sizeof(xdr_results, xdr_location,
892 		    rdma_minchunk, NULL, NULL);
893 
894 	DTRACE_PROBE1(krpc__i__svcrdma__ksend__msglen, int, msglen);
895 
896 	status = SVC_RDMA_SUCCESS;
897 
898 	if (msglen < RPC_MSG_SZ) {
899 		/*
900 		 * Looks like the response will fit in the inline
901 		 * response; let's try
902 		 */
903 		RSSTAT_INCR(rstotalinlinereplies);
904 
905 		rdma_response_op = RDMA_MSG;
906 
907 		status = svc_compose_rpcmsg(clone_xprt, conn, xdr_results,
908 		    xdr_location, &rbuf_rpc_resp, &xdrs_rpc, msg,
909 		    has_args, &final_resp_len);
910 
911 		DTRACE_PROBE1(krpc__i__srdma__ksend__compose_status,
912 		    int, status);
913 		DTRACE_PROBE1(krpc__i__srdma__ksend__compose_len,
914 		    int, final_resp_len);
915 
916 		if (status == SVC_RDMA_SUCCESS && crdp->cl_reply) {
917 			clist_free(crdp->cl_reply);
918 			crdp->cl_reply = NULL;
919 		}
920 	}
921 
922 	/*
923 	 * If the encode failed (size?) or the message really is
924 	 * larger than what is allowed, try the response chunk list.
925 	 */
926 	if (status != SVC_RDMA_SUCCESS || msglen >= RPC_MSG_SZ) {
927 		/*
928 		 * attempting to use a reply chunk list when there
929 		 * isn't one won't get very far...
930 		 */
931 		if (crdp->cl_reply == NULL) {
932 			DTRACE_PROBE(krpc__e__svcrdma__ksend__noreplycl);
933 			goto out;
934 		}
935 
936 		RSSTAT_INCR(rstotallongreplies);
937 
938 		msglen = xdr_sizeof(xdr_replymsg, msg);
939 		msglen += xdrrdma_sizeof(xdr_results, xdr_location, 0,
940 		    NULL, NULL);
941 
942 		status = svc_process_long_reply(clone_xprt, xdr_results,
943 		    xdr_location, msg, has_args, &msglen, &freelen,
944 		    &num_wreply_segments, &final_resp_len);
945 
946 		DTRACE_PROBE1(krpc__i__svcrdma__ksend__longreplen,
947 		    int, final_resp_len);
948 
949 		if (status != SVC_RDMA_SUCCESS) {
950 			DTRACE_PROBE(krpc__e__svcrdma__ksend__compose__failed);
951 			goto out;
952 		}
953 
954 		rdma_response_op = RDMA_NOMSG;
955 	}
956 
957 	DTRACE_PROBE1(krpc__i__svcrdma__ksend__rdmamsg__len,
958 	    int, final_resp_len);
959 
960 	rbuf_resp.type = SEND_BUFFER;
961 	if (rdma_buf_alloc(conn, &rbuf_resp)) {
962 		rdma_buf_free(conn, &rbuf_rpc_resp);
963 		DTRACE_PROBE(krpc__e__svcrdma__ksend__nofreebufs);
964 		goto out;
965 	}
966 
967 	rdma_credit = rdma_bufs_granted;
968 
969 	vers = RPCRDMA_VERS;
970 	xdrmem_create(&xdrs_rhdr, rbuf_resp.addr, rbuf_resp.len, XDR_ENCODE);
971 	(*(uint32_t *)rbuf_resp.addr) = msg->rm_xid;
972 	/* Skip xid and set the xdr position accordingly. */
973 	XDR_SETPOS(&xdrs_rhdr, sizeof (uint32_t));
974 	if (!xdr_u_int(&xdrs_rhdr, &vers) ||
975 	    !xdr_u_int(&xdrs_rhdr, &rdma_credit) ||
976 	    !xdr_u_int(&xdrs_rhdr, &rdma_response_op)) {
977 		rdma_buf_free(conn, &rbuf_rpc_resp);
978 		rdma_buf_free(conn, &rbuf_resp);
979 		DTRACE_PROBE(krpc__e__svcrdma__ksend__uint);
980 		goto out;
981 	}
982 
983 	/*
984 	 * Now XDR the read chunk list, actually always NULL
985 	 */
986 	(void) xdr_encode_rlist_svc(&xdrs_rhdr, cl_read);
987 
988 	/*
989 	 * encode write list -- we already drove RDMA_WRITEs
990 	 */
991 	cl_write = crdp->cl_wlist;
992 	if (!xdr_encode_wlist(&xdrs_rhdr, cl_write)) {
993 		DTRACE_PROBE(krpc__e__svcrdma__ksend__enc__wlist);
994 		rdma_buf_free(conn, &rbuf_rpc_resp);
995 		rdma_buf_free(conn, &rbuf_resp);
996 		goto out;
997 	}
998 
999 	/*
1000 	 * XDR encode the RDMA_REPLY write chunk
1001 	 */
1002 	if (!xdr_encode_reply_wchunk(&xdrs_rhdr, crdp->cl_reply,
1003 	    num_wreply_segments)) {
1004 		rdma_buf_free(conn, &rbuf_rpc_resp);
1005 		rdma_buf_free(conn, &rbuf_resp);
1006 		goto out;
1007 	}
1008 
1009 	clist_add(&cl_send, 0, XDR_GETPOS(&xdrs_rhdr), &rbuf_resp.handle,
1010 	    rbuf_resp.addr, NULL, NULL);
1011 
1012 	if (rdma_response_op == RDMA_MSG) {
1013 		clist_add(&cl_send, 0, final_resp_len, &rbuf_rpc_resp.handle,
1014 		    rbuf_rpc_resp.addr, NULL, NULL);
1015 	}
1016 
1017 	status = RDMA_SEND(conn, cl_send, msg->rm_xid);
1018 
1019 	if (status == RDMA_SUCCESS) {
1020 		retval = TRUE;
1021 	}
1022 
1023 out:
1024 	/*
1025 	 * Free up sendlist chunks
1026 	 */
1027 	if (cl_send != NULL)
1028 		clist_free(cl_send);
1029 
1030 	/*
1031 	 * Destroy private data for xdr rdma
1032 	 */
1033 	if (clone_xprt->xp_xdrout.x_ops != NULL) {
1034 		XDR_DESTROY(&(clone_xprt->xp_xdrout));
1035 	}
1036 
1037 	if (crdp->cl_reply) {
1038 		clist_free(crdp->cl_reply);
1039 		crdp->cl_reply = NULL;
1040 	}
1041 
1042 	/*
1043 	 * This is completely disgusting.  If public is set it is
1044 	 * a pointer to a structure whose first field is the address
1045 	 * of the function to free that structure and any related
1046 	 * stuff.  (see rrokfree in nfs_xdr.c).
1047 	 */
1048 	if (xdrs_rpc->x_public) {
1049 		/* LINTED pointer alignment */
1050 		(**((int (**)()) xdrs_rpc->x_public)) (xdrs_rpc->x_public);
1051 	}
1052 
1053 	if (xdrs_rhdr.x_ops != NULL) {
1054 		XDR_DESTROY(&xdrs_rhdr);
1055 	}
1056 
1057 	return (retval);
1058 }
1059 
1060 /*
1061  * Deserialize arguments.
1062  */
1063 static bool_t
1064 svc_rdma_kgetargs(SVCXPRT *clone_xprt, xdrproc_t xdr_args, caddr_t args_ptr)
1065 {
1066 	if ((SVCAUTH_UNWRAP(&clone_xprt->xp_auth, &clone_xprt->xp_xdrin,
1067 	    xdr_args, args_ptr)) != TRUE)
1068 		return (FALSE);
1069 	return (TRUE);
1070 }
1071 
1072 static bool_t
1073 svc_rdma_kfreeargs(SVCXPRT *clone_xprt, xdrproc_t xdr_args,
1074     caddr_t args_ptr)
1075 {
1076 	struct clone_rdma_data *crdp;
1077 	bool_t retval;
1078 
1079 	/*
1080 	 * If the cloned bit is true, then this transport specific
1081 	 * rmda data has been duplicated into another cloned xprt. Do
1082 	 * not free, or release the connection, it is still in use.  The
1083 	 * buffers will be freed and the connection released later by
1084 	 * SVC_CLONE_DESTROY().
1085 	 */
1086 	crdp = (struct clone_rdma_data *)clone_xprt->xp_p2buf;
1087 	if (crdp->cloned == TRUE) {
1088 		crdp->cloned = 0;
1089 		return (TRUE);
1090 	}
1091 
1092 	/*
1093 	 * Free the args if needed then XDR_DESTROY
1094 	 */
1095 	if (args_ptr) {
1096 		XDR	*xdrs = &clone_xprt->xp_xdrin;
1097 
1098 		xdrs->x_op = XDR_FREE;
1099 		retval = (*xdr_args)(xdrs, args_ptr);
1100 	}
1101 
1102 	XDR_DESTROY(&(clone_xprt->xp_xdrin));
1103 	rdma_buf_free(crdp->conn, &crdp->rpcbuf);
1104 	if (crdp->cl_reply) {
1105 		clist_free(crdp->cl_reply);
1106 		crdp->cl_reply = NULL;
1107 	}
1108 	RDMA_REL_CONN(crdp->conn);
1109 
1110 	return (retval);
1111 }
1112 
1113 /* ARGSUSED */
1114 static int32_t *
1115 svc_rdma_kgetres(SVCXPRT *clone_xprt, int size)
1116 {
1117 	return (NULL);
1118 }
1119 
1120 /* ARGSUSED */
1121 static void
1122 svc_rdma_kfreeres(SVCXPRT *clone_xprt)
1123 {
1124 }
1125 
1126 /*
1127  * the dup cacheing routines below provide a cache of non-failure
1128  * transaction id's.  rpc service routines can use this to detect
1129  * retransmissions and re-send a non-failure response.
1130  */
1131 
1132 /*
1133  * MAXDUPREQS is the number of cached items.  It should be adjusted
1134  * to the service load so that there is likely to be a response entry
1135  * when the first retransmission comes in.
1136  */
1137 #define	MAXDUPREQS	1024
1138 
1139 /*
1140  * This should be appropriately scaled to MAXDUPREQS.
1141  */
1142 #define	DRHASHSZ	257
1143 
1144 #if ((DRHASHSZ & (DRHASHSZ - 1)) == 0)
1145 #define	XIDHASH(xid)	((xid) & (DRHASHSZ - 1))
1146 #else
1147 #define	XIDHASH(xid)	((xid) % DRHASHSZ)
1148 #endif
1149 #define	DRHASH(dr)	XIDHASH((dr)->dr_xid)
1150 #define	REQTOXID(req)	((req)->rq_xprt->xp_xid)
1151 
1152 static int	rdmandupreqs = 0;
1153 int	rdmamaxdupreqs = MAXDUPREQS;
1154 static kmutex_t rdmadupreq_lock;
1155 static struct dupreq *rdmadrhashtbl[DRHASHSZ];
1156 static int	rdmadrhashstat[DRHASHSZ];
1157 
1158 static void unhash(struct dupreq *);
1159 
1160 /*
1161  * rdmadrmru points to the head of a circular linked list in lru order.
1162  * rdmadrmru->dr_next == drlru
1163  */
1164 struct dupreq *rdmadrmru;
1165 
1166 /*
1167  * svc_rdma_kdup searches the request cache and returns 0 if the
1168  * request is not found in the cache.  If it is found, then it
1169  * returns the state of the request (in progress or done) and
1170  * the status or attributes that were part of the original reply.
1171  */
1172 static int
1173 svc_rdma_kdup(struct svc_req *req, caddr_t res, int size, struct dupreq **drpp,
1174 	bool_t *dupcachedp)
1175 {
1176 	struct dupreq *dr;
1177 	uint32_t xid;
1178 	uint32_t drhash;
1179 	int status;
1180 
1181 	xid = REQTOXID(req);
1182 	mutex_enter(&rdmadupreq_lock);
1183 	RSSTAT_INCR(rsdupchecks);
1184 	/*
1185 	 * Check to see whether an entry already exists in the cache.
1186 	 */
1187 	dr = rdmadrhashtbl[XIDHASH(xid)];
1188 	while (dr != NULL) {
1189 		if (dr->dr_xid == xid &&
1190 		    dr->dr_proc == req->rq_proc &&
1191 		    dr->dr_prog == req->rq_prog &&
1192 		    dr->dr_vers == req->rq_vers &&
1193 		    dr->dr_addr.len == req->rq_xprt->xp_rtaddr.len &&
1194 		    bcmp((caddr_t)dr->dr_addr.buf,
1195 		    (caddr_t)req->rq_xprt->xp_rtaddr.buf,
1196 		    dr->dr_addr.len) == 0) {
1197 			status = dr->dr_status;
1198 			if (status == DUP_DONE) {
1199 				bcopy(dr->dr_resp.buf, res, size);
1200 				if (dupcachedp != NULL)
1201 					*dupcachedp = (dr->dr_resfree != NULL);
1202 			} else {
1203 				dr->dr_status = DUP_INPROGRESS;
1204 				*drpp = dr;
1205 			}
1206 			RSSTAT_INCR(rsdupreqs);
1207 			mutex_exit(&rdmadupreq_lock);
1208 			return (status);
1209 		}
1210 		dr = dr->dr_chain;
1211 	}
1212 
1213 	/*
1214 	 * There wasn't an entry, either allocate a new one or recycle
1215 	 * an old one.
1216 	 */
1217 	if (rdmandupreqs < rdmamaxdupreqs) {
1218 		dr = kmem_alloc(sizeof (*dr), KM_NOSLEEP);
1219 		if (dr == NULL) {
1220 			mutex_exit(&rdmadupreq_lock);
1221 			return (DUP_ERROR);
1222 		}
1223 		dr->dr_resp.buf = NULL;
1224 		dr->dr_resp.maxlen = 0;
1225 		dr->dr_addr.buf = NULL;
1226 		dr->dr_addr.maxlen = 0;
1227 		if (rdmadrmru) {
1228 			dr->dr_next = rdmadrmru->dr_next;
1229 			rdmadrmru->dr_next = dr;
1230 		} else {
1231 			dr->dr_next = dr;
1232 		}
1233 		rdmandupreqs++;
1234 	} else {
1235 		dr = rdmadrmru->dr_next;
1236 		while (dr->dr_status == DUP_INPROGRESS) {
1237 			dr = dr->dr_next;
1238 			if (dr == rdmadrmru->dr_next) {
1239 				mutex_exit(&rdmadupreq_lock);
1240 				return (DUP_ERROR);
1241 			}
1242 		}
1243 		unhash(dr);
1244 		if (dr->dr_resfree) {
1245 			(*dr->dr_resfree)(dr->dr_resp.buf);
1246 		}
1247 	}
1248 	dr->dr_resfree = NULL;
1249 	rdmadrmru = dr;
1250 
1251 	dr->dr_xid = REQTOXID(req);
1252 	dr->dr_prog = req->rq_prog;
1253 	dr->dr_vers = req->rq_vers;
1254 	dr->dr_proc = req->rq_proc;
1255 	if (dr->dr_addr.maxlen < req->rq_xprt->xp_rtaddr.len) {
1256 		if (dr->dr_addr.buf != NULL)
1257 			kmem_free(dr->dr_addr.buf, dr->dr_addr.maxlen);
1258 		dr->dr_addr.maxlen = req->rq_xprt->xp_rtaddr.len;
1259 		dr->dr_addr.buf = kmem_alloc(dr->dr_addr.maxlen, KM_NOSLEEP);
1260 		if (dr->dr_addr.buf == NULL) {
1261 			dr->dr_addr.maxlen = 0;
1262 			dr->dr_status = DUP_DROP;
1263 			mutex_exit(&rdmadupreq_lock);
1264 			return (DUP_ERROR);
1265 		}
1266 	}
1267 	dr->dr_addr.len = req->rq_xprt->xp_rtaddr.len;
1268 	bcopy(req->rq_xprt->xp_rtaddr.buf, dr->dr_addr.buf, dr->dr_addr.len);
1269 	if (dr->dr_resp.maxlen < size) {
1270 		if (dr->dr_resp.buf != NULL)
1271 			kmem_free(dr->dr_resp.buf, dr->dr_resp.maxlen);
1272 		dr->dr_resp.maxlen = (unsigned int)size;
1273 		dr->dr_resp.buf = kmem_alloc(size, KM_NOSLEEP);
1274 		if (dr->dr_resp.buf == NULL) {
1275 			dr->dr_resp.maxlen = 0;
1276 			dr->dr_status = DUP_DROP;
1277 			mutex_exit(&rdmadupreq_lock);
1278 			return (DUP_ERROR);
1279 		}
1280 	}
1281 	dr->dr_status = DUP_INPROGRESS;
1282 
1283 	drhash = (uint32_t)DRHASH(dr);
1284 	dr->dr_chain = rdmadrhashtbl[drhash];
1285 	rdmadrhashtbl[drhash] = dr;
1286 	rdmadrhashstat[drhash]++;
1287 	mutex_exit(&rdmadupreq_lock);
1288 	*drpp = dr;
1289 	return (DUP_NEW);
1290 }
1291 
1292 /*
1293  * svc_rdma_kdupdone marks the request done (DUP_DONE or DUP_DROP)
1294  * and stores the response.
1295  */
1296 static void
1297 svc_rdma_kdupdone(struct dupreq *dr, caddr_t res, void (*dis_resfree)(),
1298 	int size, int status)
1299 {
1300 	ASSERT(dr->dr_resfree == NULL);
1301 	if (status == DUP_DONE) {
1302 		bcopy(res, dr->dr_resp.buf, size);
1303 		dr->dr_resfree = dis_resfree;
1304 	}
1305 	dr->dr_status = status;
1306 }
1307 
1308 /*
1309  * This routine expects that the mutex, rdmadupreq_lock, is already held.
1310  */
1311 static void
1312 unhash(struct dupreq *dr)
1313 {
1314 	struct dupreq *drt;
1315 	struct dupreq *drtprev = NULL;
1316 	uint32_t drhash;
1317 
1318 	ASSERT(MUTEX_HELD(&rdmadupreq_lock));
1319 
1320 	drhash = (uint32_t)DRHASH(dr);
1321 	drt = rdmadrhashtbl[drhash];
1322 	while (drt != NULL) {
1323 		if (drt == dr) {
1324 			rdmadrhashstat[drhash]--;
1325 			if (drtprev == NULL) {
1326 				rdmadrhashtbl[drhash] = drt->dr_chain;
1327 			} else {
1328 				drtprev->dr_chain = drt->dr_chain;
1329 			}
1330 			return;
1331 		}
1332 		drtprev = drt;
1333 		drt = drt->dr_chain;
1334 	}
1335 }
1336 
1337 bool_t
1338 rdma_get_wchunk(struct svc_req *req, iovec_t *iov, struct clist *wlist)
1339 {
1340 	struct clist	*clist;
1341 	uint32_t	tlen;
1342 
1343 	if (req->rq_xprt->xp_type != T_RDMA) {
1344 		return (FALSE);
1345 	}
1346 
1347 	tlen = 0;
1348 	clist = wlist;
1349 	while (clist) {
1350 		tlen += clist->c_len;
1351 		clist = clist->c_next;
1352 	}
1353 
1354 	/*
1355 	 * set iov to addr+len of first segment of first wchunk of
1356 	 * wlist sent by client.  krecv() already malloc'd a buffer
1357 	 * large enough, but registration is deferred until we write
1358 	 * the buffer back to (NFS) client using RDMA_WRITE.
1359 	 */
1360 	iov->iov_base = (caddr_t)(uintptr_t)wlist->w.c_saddr;
1361 	iov->iov_len = tlen;
1362 
1363 	return (TRUE);
1364 }
1365 
1366 /*
1367  * routine to setup the read chunk lists
1368  */
1369 
1370 int
1371 rdma_setup_read_chunks(struct clist *wcl, uint32_t count, int *wcl_len)
1372 {
1373 	int		data_len, avail_len;
1374 	uint_t		round_len;
1375 
1376 	data_len = avail_len = 0;
1377 
1378 	while (wcl != NULL && count > 0) {
1379 		if (wcl->c_dmemhandle.mrc_rmr == 0)
1380 			break;
1381 
1382 		if (wcl->c_len < count) {
1383 			data_len += wcl->c_len;
1384 			avail_len = 0;
1385 		} else {
1386 			data_len += count;
1387 			avail_len = wcl->c_len - count;
1388 			wcl->c_len = count;
1389 		}
1390 		count -= wcl->c_len;
1391 
1392 		if (count == 0)
1393 			break;
1394 
1395 		wcl = wcl->c_next;
1396 	}
1397 
1398 	/*
1399 	 * MUST fail if there are still more data
1400 	 */
1401 	if (count > 0) {
1402 		DTRACE_PROBE2(krpc__e__rdma_setup_read_chunks_clist_len,
1403 		    int, data_len, int, count);
1404 		return (FALSE);
1405 	}
1406 
1407 	/*
1408 	 * Round up the last chunk to 4-byte boundary
1409 	 */
1410 	*wcl_len = roundup(data_len, BYTES_PER_XDR_UNIT);
1411 	round_len = *wcl_len - data_len;
1412 
1413 	if (round_len) {
1414 
1415 		/*
1416 		 * If there is space in the current chunk,
1417 		 * add the roundup to the chunk.
1418 		 */
1419 		if (avail_len >= round_len) {
1420 			wcl->c_len += round_len;
1421 		} else  {
1422 			/*
1423 			 * try the next one.
1424 			 */
1425 			wcl = wcl->c_next;
1426 			if ((wcl == NULL) || (wcl->c_len < round_len)) {
1427 				DTRACE_PROBE1(
1428 				    krpc__e__rdma_setup_read_chunks_rndup,
1429 				    int, round_len);
1430 				return (FALSE);
1431 			}
1432 			wcl->c_len = round_len;
1433 		}
1434 	}
1435 
1436 	wcl = wcl->c_next;
1437 
1438 	/*
1439 	 * Make rest of the chunks 0-len
1440 	 */
1441 
1442 	clist_zero_len(wcl);
1443 
1444 	return (TRUE);
1445 }
1446