2 * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
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43 * This file contains the guts of the RPC RDMA protocol, and
44 * does marshaling/unmarshaling, etc. It is also where interfacing
45 * to the Linux RPC framework lives.
48 #include "xprt_rdma.h"
50 #include <linux/highmem.h>
52 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
53 # define RPCDBG_FACILITY RPCDBG_TRANS
56 enum rpcrdma_chunktype {
64 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
65 static const char transfertypes[][12] = {
66 "pure inline", /* no chunks */
67 " read chunk", /* some argument via rdma read */
68 "*read chunk", /* entire request via rdma read */
69 "write chunk", /* some result via rdma write */
70 "reply chunk" /* entire reply via rdma write */
75 * Chunk assembly from upper layer xdr_buf.
77 * Prepare the passed-in xdr_buf into representation as RPC/RDMA chunk
78 * elements. Segments are then coalesced when registered, if possible
79 * within the selected memreg mode.
81 * Returns positive number of segments converted, or a negative errno.
85 rpcrdma_convert_iovs(struct xdr_buf *xdrbuf, unsigned int pos,
86 enum rpcrdma_chunktype type, struct rpcrdma_mr_seg *seg, int nsegs)
92 if (pos == 0 && xdrbuf->head[0].iov_len) {
93 seg[n].mr_page = NULL;
94 seg[n].mr_offset = xdrbuf->head[0].iov_base;
95 seg[n].mr_len = xdrbuf->head[0].iov_len;
99 len = xdrbuf->page_len;
100 ppages = xdrbuf->pages + (xdrbuf->page_base >> PAGE_SHIFT);
101 page_base = xdrbuf->page_base & ~PAGE_MASK;
103 while (len && n < nsegs) {
105 /* alloc the pagelist for receiving buffer */
106 ppages[p] = alloc_page(GFP_ATOMIC);
110 seg[n].mr_page = ppages[p];
111 seg[n].mr_offset = (void *)(unsigned long) page_base;
112 seg[n].mr_len = min_t(u32, PAGE_SIZE - page_base, len);
113 if (seg[n].mr_len > PAGE_SIZE)
115 len -= seg[n].mr_len;
118 page_base = 0; /* page offset only applies to first page */
121 /* Message overflows the seg array */
122 if (len && n == nsegs)
125 if (xdrbuf->tail[0].iov_len) {
126 /* the rpcrdma protocol allows us to omit any trailing
127 * xdr pad bytes, saving the server an RDMA operation. */
128 if (xdrbuf->tail[0].iov_len < 4 && xprt_rdma_pad_optimize)
131 /* Tail remains, but we're out of segments */
133 seg[n].mr_page = NULL;
134 seg[n].mr_offset = xdrbuf->tail[0].iov_base;
135 seg[n].mr_len = xdrbuf->tail[0].iov_len;
143 * Create read/write chunk lists, and reply chunks, for RDMA
145 * Assume check against THRESHOLD has been done, and chunks are required.
146 * Assume only encoding one list entry for read|write chunks. The NFSv3
147 * protocol is simple enough to allow this as it only has a single "bulk
148 * result" in each procedure - complicated NFSv4 COMPOUNDs are not. (The
149 * RDMA/Sessions NFSv4 proposal addresses this for future v4 revs.)
151 * When used for a single reply chunk (which is a special write
152 * chunk used for the entire reply, rather than just the data), it
153 * is used primarily for READDIR and READLINK which would otherwise
154 * be severely size-limited by a small rdma inline read max. The server
155 * response will come back as an RDMA Write, followed by a message
156 * of type RDMA_NOMSG carrying the xid and length. As a result, reply
157 * chunks do not provide data alignment, however they do not require
158 * "fixup" (moving the response to the upper layer buffer) either.
160 * Encoding key for single-list chunks (HLOO = Handle32 Length32 Offset64):
162 * Read chunklist (a linked list):
163 * N elements, position P (same P for all chunks of same arg!):
164 * 1 - PHLOO - 1 - PHLOO - ... - 1 - PHLOO - 0
166 * Write chunklist (a list of (one) counted array):
168 * 1 - N - HLOO - HLOO - ... - HLOO - 0
170 * Reply chunk (a counted array):
172 * 1 - N - HLOO - HLOO - ... - HLOO
174 * Returns positive RPC/RDMA header size, or negative errno.
178 rpcrdma_create_chunks(struct rpc_rqst *rqst, struct xdr_buf *target,
179 struct rpcrdma_msg *headerp, enum rpcrdma_chunktype type)
181 struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
182 struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
183 int n, nsegs, nchunks = 0;
185 struct rpcrdma_mr_seg *seg = req->rl_segments;
186 struct rpcrdma_read_chunk *cur_rchunk = NULL;
187 struct rpcrdma_write_array *warray = NULL;
188 struct rpcrdma_write_chunk *cur_wchunk = NULL;
189 __be32 *iptr = headerp->rm_body.rm_chunks;
190 int (*map)(struct rpcrdma_xprt *, struct rpcrdma_mr_seg *, int, bool);
192 if (type == rpcrdma_readch || type == rpcrdma_areadch) {
193 /* a read chunk - server will RDMA Read our memory */
194 cur_rchunk = (struct rpcrdma_read_chunk *) iptr;
196 /* a write or reply chunk - server will RDMA Write our memory */
197 *iptr++ = xdr_zero; /* encode a NULL read chunk list */
198 if (type == rpcrdma_replych)
199 *iptr++ = xdr_zero; /* a NULL write chunk list */
200 warray = (struct rpcrdma_write_array *) iptr;
201 cur_wchunk = (struct rpcrdma_write_chunk *) (warray + 1);
204 if (type == rpcrdma_replych || type == rpcrdma_areadch)
207 pos = target->head[0].iov_len;
209 nsegs = rpcrdma_convert_iovs(target, pos, type, seg, RPCRDMA_MAX_SEGS);
213 map = r_xprt->rx_ia.ri_ops->ro_map;
215 n = map(r_xprt, seg, nsegs, cur_wchunk != NULL);
218 if (cur_rchunk) { /* read */
219 cur_rchunk->rc_discrim = xdr_one;
220 /* all read chunks have the same "position" */
221 cur_rchunk->rc_position = cpu_to_be32(pos);
222 cur_rchunk->rc_target.rs_handle =
223 cpu_to_be32(seg->mr_rkey);
224 cur_rchunk->rc_target.rs_length =
225 cpu_to_be32(seg->mr_len);
227 (__be32 *)&cur_rchunk->rc_target.rs_offset,
229 dprintk("RPC: %s: read chunk "
230 "elem %d@0x%llx:0x%x pos %u (%s)\n", __func__,
231 seg->mr_len, (unsigned long long)seg->mr_base,
232 seg->mr_rkey, pos, n < nsegs ? "more" : "last");
234 r_xprt->rx_stats.read_chunk_count++;
235 } else { /* write/reply */
236 cur_wchunk->wc_target.rs_handle =
237 cpu_to_be32(seg->mr_rkey);
238 cur_wchunk->wc_target.rs_length =
239 cpu_to_be32(seg->mr_len);
241 (__be32 *)&cur_wchunk->wc_target.rs_offset,
243 dprintk("RPC: %s: %s chunk "
244 "elem %d@0x%llx:0x%x (%s)\n", __func__,
245 (type == rpcrdma_replych) ? "reply" : "write",
246 seg->mr_len, (unsigned long long)seg->mr_base,
247 seg->mr_rkey, n < nsegs ? "more" : "last");
249 if (type == rpcrdma_replych)
250 r_xprt->rx_stats.reply_chunk_count++;
252 r_xprt->rx_stats.write_chunk_count++;
253 r_xprt->rx_stats.total_rdma_request += seg->mr_len;
260 /* success. all failures return above */
261 req->rl_nchunks = nchunks;
264 * finish off header. If write, marshal discrim and nchunks.
267 iptr = (__be32 *) cur_rchunk;
268 *iptr++ = xdr_zero; /* finish the read chunk list */
269 *iptr++ = xdr_zero; /* encode a NULL write chunk list */
270 *iptr++ = xdr_zero; /* encode a NULL reply chunk */
272 warray->wc_discrim = xdr_one;
273 warray->wc_nchunks = cpu_to_be32(nchunks);
274 iptr = (__be32 *) cur_wchunk;
275 if (type == rpcrdma_writech) {
276 *iptr++ = xdr_zero; /* finish the write chunk list */
277 *iptr++ = xdr_zero; /* encode a NULL reply chunk */
282 * Return header size.
284 return (unsigned char *)iptr - (unsigned char *)headerp;
287 if (r_xprt->rx_ia.ri_memreg_strategy == RPCRDMA_FRMR)
290 for (pos = 0; nchunks--;)
291 pos += r_xprt->rx_ia.ri_ops->ro_unmap(r_xprt,
292 &req->rl_segments[pos]);
297 * Copy write data inline.
298 * This function is used for "small" requests. Data which is passed
299 * to RPC via iovecs (or page list) is copied directly into the
300 * pre-registered memory buffer for this request. For small amounts
301 * of data, this is efficient. The cutoff value is tunable.
304 rpcrdma_inline_pullup(struct rpc_rqst *rqst, int pad)
306 int i, npages, curlen;
308 unsigned char *srcp, *destp;
309 struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
311 struct page **ppages;
313 destp = rqst->rq_svec[0].iov_base;
314 curlen = rqst->rq_svec[0].iov_len;
317 * Do optional padding where it makes sense. Alignment of write
318 * payload can help the server, if our setting is accurate.
320 pad -= (curlen + 36/*sizeof(struct rpcrdma_msg_padded)*/);
321 if (pad < 0 || rqst->rq_slen - curlen < RPCRDMA_INLINE_PAD_THRESH)
322 pad = 0; /* don't pad this request */
324 dprintk("RPC: %s: pad %d destp 0x%p len %d hdrlen %d\n",
325 __func__, pad, destp, rqst->rq_slen, curlen);
327 copy_len = rqst->rq_snd_buf.page_len;
329 if (rqst->rq_snd_buf.tail[0].iov_len) {
330 curlen = rqst->rq_snd_buf.tail[0].iov_len;
331 if (destp + copy_len != rqst->rq_snd_buf.tail[0].iov_base) {
332 memmove(destp + copy_len,
333 rqst->rq_snd_buf.tail[0].iov_base, curlen);
334 r_xprt->rx_stats.pullup_copy_count += curlen;
336 dprintk("RPC: %s: tail destp 0x%p len %d\n",
337 __func__, destp + copy_len, curlen);
338 rqst->rq_svec[0].iov_len += curlen;
340 r_xprt->rx_stats.pullup_copy_count += copy_len;
342 page_base = rqst->rq_snd_buf.page_base;
343 ppages = rqst->rq_snd_buf.pages + (page_base >> PAGE_SHIFT);
344 page_base &= ~PAGE_MASK;
345 npages = PAGE_ALIGN(page_base+copy_len) >> PAGE_SHIFT;
346 for (i = 0; copy_len && i < npages; i++) {
347 curlen = PAGE_SIZE - page_base;
348 if (curlen > copy_len)
350 dprintk("RPC: %s: page %d destp 0x%p len %d curlen %d\n",
351 __func__, i, destp, copy_len, curlen);
352 srcp = kmap_atomic(ppages[i]);
353 memcpy(destp, srcp+page_base, curlen);
355 rqst->rq_svec[0].iov_len += curlen;
360 /* header now contains entire send message */
365 * Marshal a request: the primary job of this routine is to choose
366 * the transfer modes. See comments below.
368 * Uses multiple RDMA IOVs for a request:
369 * [0] -- RPC RDMA header, which uses memory from the *start* of the
370 * preregistered buffer that already holds the RPC data in
372 * [1] -- the RPC header/data, marshaled by RPC and the NFS protocol.
373 * [2] -- optional padding.
374 * [3] -- if padded, header only in [1] and data here.
376 * Returns zero on success, otherwise a negative errno.
380 rpcrdma_marshal_req(struct rpc_rqst *rqst)
382 struct rpc_xprt *xprt = rqst->rq_xprt;
383 struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
384 struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
386 size_t rpclen, padlen;
388 enum rpcrdma_chunktype rtype, wtype;
389 struct rpcrdma_msg *headerp;
392 * rpclen gets amount of data in first buffer, which is the
393 * pre-registered buffer.
395 base = rqst->rq_svec[0].iov_base;
396 rpclen = rqst->rq_svec[0].iov_len;
398 headerp = rdmab_to_msg(req->rl_rdmabuf);
399 /* don't byte-swap XID, it's already done in request */
400 headerp->rm_xid = rqst->rq_xid;
401 headerp->rm_vers = rpcrdma_version;
402 headerp->rm_credit = cpu_to_be32(r_xprt->rx_buf.rb_max_requests);
403 headerp->rm_type = rdma_msg;
406 * Chunks needed for results?
408 * o If the expected result is under the inline threshold, all ops
409 * return as inline (but see later).
410 * o Large non-read ops return as a single reply chunk.
411 * o Large read ops return data as write chunk(s), header as inline.
413 * Note: the NFS code sending down multiple result segments implies
414 * the op is one of read, readdir[plus], readlink or NFSv4 getacl.
418 * This code can handle read chunks, write chunks OR reply
419 * chunks -- only one type. If the request is too big to fit
420 * inline, then we will choose read chunks. If the request is
421 * a READ, then use write chunks to separate the file data
422 * into pages; otherwise use reply chunks.
424 if (rqst->rq_rcv_buf.buflen <= RPCRDMA_INLINE_READ_THRESHOLD(rqst))
425 wtype = rpcrdma_noch;
426 else if (rqst->rq_rcv_buf.page_len == 0)
427 wtype = rpcrdma_replych;
428 else if (rqst->rq_rcv_buf.flags & XDRBUF_READ)
429 wtype = rpcrdma_writech;
431 wtype = rpcrdma_replych;
434 * Chunks needed for arguments?
436 * o If the total request is under the inline threshold, all ops
437 * are sent as inline.
438 * o Large non-write ops are sent with the entire message as a
439 * single read chunk (protocol 0-position special case).
440 * o Large write ops transmit data as read chunk(s), header as
443 * Note: the NFS code sending down multiple argument segments
444 * implies the op is a write.
445 * TBD check NFSv4 setacl
447 if (rqst->rq_snd_buf.len <= RPCRDMA_INLINE_WRITE_THRESHOLD(rqst))
448 rtype = rpcrdma_noch;
449 else if (rqst->rq_snd_buf.page_len == 0)
450 rtype = rpcrdma_areadch;
452 rtype = rpcrdma_readch;
454 /* The following simplification is not true forever */
455 if (rtype != rpcrdma_noch && wtype == rpcrdma_replych)
456 wtype = rpcrdma_noch;
457 if (rtype != rpcrdma_noch && wtype != rpcrdma_noch) {
458 dprintk("RPC: %s: cannot marshal multiple chunk lists\n",
463 hdrlen = RPCRDMA_HDRLEN_MIN;
467 * Pull up any extra send data into the preregistered buffer.
468 * When padding is in use and applies to the transfer, insert
469 * it and change the message type.
471 if (rtype == rpcrdma_noch) {
473 padlen = rpcrdma_inline_pullup(rqst,
474 RPCRDMA_INLINE_PAD_VALUE(rqst));
477 headerp->rm_type = rdma_msgp;
478 headerp->rm_body.rm_padded.rm_align =
479 cpu_to_be32(RPCRDMA_INLINE_PAD_VALUE(rqst));
480 headerp->rm_body.rm_padded.rm_thresh =
481 cpu_to_be32(RPCRDMA_INLINE_PAD_THRESH);
482 headerp->rm_body.rm_padded.rm_pempty[0] = xdr_zero;
483 headerp->rm_body.rm_padded.rm_pempty[1] = xdr_zero;
484 headerp->rm_body.rm_padded.rm_pempty[2] = xdr_zero;
485 hdrlen += 2 * sizeof(u32); /* extra words in padhdr */
486 if (wtype != rpcrdma_noch) {
487 dprintk("RPC: %s: invalid chunk list\n",
492 headerp->rm_body.rm_nochunks.rm_empty[0] = xdr_zero;
493 headerp->rm_body.rm_nochunks.rm_empty[1] = xdr_zero;
494 headerp->rm_body.rm_nochunks.rm_empty[2] = xdr_zero;
495 /* new length after pullup */
496 rpclen = rqst->rq_svec[0].iov_len;
498 * Currently we try to not actually use read inline.
499 * Reply chunks have the desirable property that
500 * they land, packed, directly in the target buffers
501 * without headers, so they require no fixup. The
502 * additional RDMA Write op sends the same amount
503 * of data, streams on-the-wire and adds no overhead
504 * on receive. Therefore, we request a reply chunk
505 * for non-writes wherever feasible and efficient.
507 if (wtype == rpcrdma_noch)
508 wtype = rpcrdma_replych;
512 if (rtype != rpcrdma_noch) {
513 hdrlen = rpcrdma_create_chunks(rqst, &rqst->rq_snd_buf,
515 wtype = rtype; /* simplify dprintk */
517 } else if (wtype != rpcrdma_noch) {
518 hdrlen = rpcrdma_create_chunks(rqst, &rqst->rq_rcv_buf,
524 dprintk("RPC: %s: %s: hdrlen %zd rpclen %zd padlen %zd"
525 " headerp 0x%p base 0x%p lkey 0x%x\n",
526 __func__, transfertypes[wtype], hdrlen, rpclen, padlen,
527 headerp, base, rdmab_lkey(req->rl_rdmabuf));
530 * initialize send_iov's - normally only two: rdma chunk header and
531 * single preregistered RPC header buffer, but if padding is present,
532 * then use a preregistered (and zeroed) pad buffer between the RPC
533 * header and any write data. In all non-rdma cases, any following
534 * data has been copied into the RPC header buffer.
536 req->rl_send_iov[0].addr = rdmab_addr(req->rl_rdmabuf);
537 req->rl_send_iov[0].length = hdrlen;
538 req->rl_send_iov[0].lkey = rdmab_lkey(req->rl_rdmabuf);
540 req->rl_send_iov[1].addr = rdmab_addr(req->rl_sendbuf);
541 req->rl_send_iov[1].length = rpclen;
542 req->rl_send_iov[1].lkey = rdmab_lkey(req->rl_sendbuf);
547 struct rpcrdma_ep *ep = &r_xprt->rx_ep;
549 req->rl_send_iov[2].addr = rdmab_addr(ep->rep_padbuf);
550 req->rl_send_iov[2].length = padlen;
551 req->rl_send_iov[2].lkey = rdmab_lkey(ep->rep_padbuf);
553 req->rl_send_iov[3].addr = req->rl_send_iov[1].addr + rpclen;
554 req->rl_send_iov[3].length = rqst->rq_slen - rpclen;
555 req->rl_send_iov[3].lkey = rdmab_lkey(req->rl_sendbuf);
564 * Chase down a received write or reply chunklist to get length
565 * RDMA'd by server. See map at rpcrdma_create_chunks()! :-)
568 rpcrdma_count_chunks(struct rpcrdma_rep *rep, unsigned int max, int wrchunk, __be32 **iptrp)
570 unsigned int i, total_len;
571 struct rpcrdma_write_chunk *cur_wchunk;
572 char *base = (char *)rdmab_to_msg(rep->rr_rdmabuf);
574 i = be32_to_cpu(**iptrp);
577 cur_wchunk = (struct rpcrdma_write_chunk *) (*iptrp + 1);
580 struct rpcrdma_segment *seg = &cur_wchunk->wc_target;
583 xdr_decode_hyper((__be32 *)&seg->rs_offset, &off);
584 dprintk("RPC: %s: chunk %d@0x%llx:0x%x\n",
586 be32_to_cpu(seg->rs_length),
587 (unsigned long long)off,
588 be32_to_cpu(seg->rs_handle));
590 total_len += be32_to_cpu(seg->rs_length);
593 /* check and adjust for properly terminated write chunk */
595 __be32 *w = (__be32 *) cur_wchunk;
596 if (*w++ != xdr_zero)
598 cur_wchunk = (struct rpcrdma_write_chunk *) w;
600 if ((char *)cur_wchunk > base + rep->rr_len)
603 *iptrp = (__be32 *) cur_wchunk;
608 * Scatter inline received data back into provided iov's.
611 rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len, int pad)
613 int i, npages, curlen, olen;
615 struct page **ppages;
618 curlen = rqst->rq_rcv_buf.head[0].iov_len;
619 if (curlen > copy_len) { /* write chunk header fixup */
621 rqst->rq_rcv_buf.head[0].iov_len = curlen;
624 dprintk("RPC: %s: srcp 0x%p len %d hdrlen %d\n",
625 __func__, srcp, copy_len, curlen);
627 /* Shift pointer for first receive segment only */
628 rqst->rq_rcv_buf.head[0].iov_base = srcp;
634 rpcx_to_rdmax(rqst->rq_xprt)->rx_stats.fixup_copy_count += olen;
635 page_base = rqst->rq_rcv_buf.page_base;
636 ppages = rqst->rq_rcv_buf.pages + (page_base >> PAGE_SHIFT);
637 page_base &= ~PAGE_MASK;
639 if (copy_len && rqst->rq_rcv_buf.page_len) {
640 npages = PAGE_ALIGN(page_base +
641 rqst->rq_rcv_buf.page_len) >> PAGE_SHIFT;
642 for (; i < npages; i++) {
643 curlen = PAGE_SIZE - page_base;
644 if (curlen > copy_len)
646 dprintk("RPC: %s: page %d"
647 " srcp 0x%p len %d curlen %d\n",
648 __func__, i, srcp, copy_len, curlen);
649 destp = kmap_atomic(ppages[i]);
650 memcpy(destp + page_base, srcp, curlen);
651 flush_dcache_page(ppages[i]);
652 kunmap_atomic(destp);
661 if (copy_len && rqst->rq_rcv_buf.tail[0].iov_len) {
663 if (curlen > rqst->rq_rcv_buf.tail[0].iov_len)
664 curlen = rqst->rq_rcv_buf.tail[0].iov_len;
665 if (rqst->rq_rcv_buf.tail[0].iov_base != srcp)
666 memmove(rqst->rq_rcv_buf.tail[0].iov_base, srcp, curlen);
667 dprintk("RPC: %s: tail srcp 0x%p len %d curlen %d\n",
668 __func__, srcp, copy_len, curlen);
669 rqst->rq_rcv_buf.tail[0].iov_len = curlen;
670 copy_len -= curlen; ++i;
672 rqst->rq_rcv_buf.tail[0].iov_len = 0;
675 /* implicit padding on terminal chunk */
676 unsigned char *p = rqst->rq_rcv_buf.tail[0].iov_base;
678 p[rqst->rq_rcv_buf.tail[0].iov_len++] = 0;
682 dprintk("RPC: %s: %d bytes in"
683 " %d extra segments (%d lost)\n",
684 __func__, olen, i, copy_len);
686 /* TBD avoid a warning from call_decode() */
687 rqst->rq_private_buf = rqst->rq_rcv_buf;
691 rpcrdma_connect_worker(struct work_struct *work)
693 struct rpcrdma_ep *ep =
694 container_of(work, struct rpcrdma_ep, rep_connect_worker.work);
695 struct rpcrdma_xprt *r_xprt =
696 container_of(ep, struct rpcrdma_xprt, rx_ep);
697 struct rpc_xprt *xprt = &r_xprt->rx_xprt;
699 spin_lock_bh(&xprt->transport_lock);
700 if (++xprt->connect_cookie == 0) /* maintain a reserved value */
701 ++xprt->connect_cookie;
702 if (ep->rep_connected > 0) {
703 if (!xprt_test_and_set_connected(xprt))
704 xprt_wake_pending_tasks(xprt, 0);
706 if (xprt_test_and_clear_connected(xprt))
707 xprt_wake_pending_tasks(xprt, -ENOTCONN);
709 spin_unlock_bh(&xprt->transport_lock);
713 * This function is called when an async event is posted to
714 * the connection which changes the connection state. All it
715 * does at this point is mark the connection up/down, the rpc
716 * timers do the rest.
719 rpcrdma_conn_func(struct rpcrdma_ep *ep)
721 schedule_delayed_work(&ep->rep_connect_worker, 0);
725 * Called as a tasklet to do req/reply match and complete a request
726 * Errors must result in the RPC task either being awakened, or
727 * allowed to timeout, to discover the errors at that time.
730 rpcrdma_reply_handler(struct rpcrdma_rep *rep)
732 struct rpcrdma_msg *headerp;
733 struct rpcrdma_req *req;
734 struct rpc_rqst *rqst;
735 struct rpc_xprt *xprt = rep->rr_xprt;
736 struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
742 /* Check status. If bad, signal disconnect and return rep to pool */
743 if (rep->rr_len == ~0U) {
744 rpcrdma_recv_buffer_put(rep);
745 if (r_xprt->rx_ep.rep_connected == 1) {
746 r_xprt->rx_ep.rep_connected = -EIO;
747 rpcrdma_conn_func(&r_xprt->rx_ep);
751 if (rep->rr_len < RPCRDMA_HDRLEN_MIN) {
752 dprintk("RPC: %s: short/invalid reply\n", __func__);
755 headerp = rdmab_to_msg(rep->rr_rdmabuf);
756 if (headerp->rm_vers != rpcrdma_version) {
757 dprintk("RPC: %s: invalid version %d\n",
758 __func__, be32_to_cpu(headerp->rm_vers));
762 /* Get XID and try for a match. */
763 spin_lock(&xprt->transport_lock);
764 rqst = xprt_lookup_rqst(xprt, headerp->rm_xid);
766 spin_unlock(&xprt->transport_lock);
767 dprintk("RPC: %s: reply 0x%p failed "
768 "to match any request xid 0x%08x len %d\n",
769 __func__, rep, be32_to_cpu(headerp->rm_xid),
772 r_xprt->rx_stats.bad_reply_count++;
773 rep->rr_func = rpcrdma_reply_handler;
774 if (rpcrdma_ep_post_recv(&r_xprt->rx_ia, &r_xprt->rx_ep, rep))
775 rpcrdma_recv_buffer_put(rep);
780 /* get request object */
781 req = rpcr_to_rdmar(rqst);
783 spin_unlock(&xprt->transport_lock);
784 dprintk("RPC: %s: duplicate reply 0x%p to RPC "
785 "request 0x%p: xid 0x%08x\n", __func__, rep, req,
786 be32_to_cpu(headerp->rm_xid));
790 dprintk("RPC: %s: reply 0x%p completes request 0x%p\n"
791 " RPC request 0x%p xid 0x%08x\n",
792 __func__, rep, req, rqst,
793 be32_to_cpu(headerp->rm_xid));
795 /* from here on, the reply is no longer an orphan */
797 xprt->reestablish_timeout = 0;
799 /* check for expected message types */
800 /* The order of some of these tests is important. */
801 switch (headerp->rm_type) {
803 /* never expect read chunks */
804 /* never expect reply chunks (two ways to check) */
805 /* never expect write chunks without having offered RDMA */
806 if (headerp->rm_body.rm_chunks[0] != xdr_zero ||
807 (headerp->rm_body.rm_chunks[1] == xdr_zero &&
808 headerp->rm_body.rm_chunks[2] != xdr_zero) ||
809 (headerp->rm_body.rm_chunks[1] != xdr_zero &&
810 req->rl_nchunks == 0))
812 if (headerp->rm_body.rm_chunks[1] != xdr_zero) {
813 /* count any expected write chunks in read reply */
814 /* start at write chunk array count */
815 iptr = &headerp->rm_body.rm_chunks[2];
816 rdmalen = rpcrdma_count_chunks(rep,
817 req->rl_nchunks, 1, &iptr);
818 /* check for validity, and no reply chunk after */
819 if (rdmalen < 0 || *iptr++ != xdr_zero)
822 ((unsigned char *)iptr - (unsigned char *)headerp);
823 status = rep->rr_len + rdmalen;
824 r_xprt->rx_stats.total_rdma_reply += rdmalen;
825 /* special case - last chunk may omit padding */
827 rdmalen = 4 - rdmalen;
831 /* else ordinary inline */
833 iptr = (__be32 *)((unsigned char *)headerp +
835 rep->rr_len -= RPCRDMA_HDRLEN_MIN;
836 status = rep->rr_len;
838 /* Fix up the rpc results for upper layer */
839 rpcrdma_inline_fixup(rqst, (char *)iptr, rep->rr_len, rdmalen);
843 /* never expect read or write chunks, always reply chunks */
844 if (headerp->rm_body.rm_chunks[0] != xdr_zero ||
845 headerp->rm_body.rm_chunks[1] != xdr_zero ||
846 headerp->rm_body.rm_chunks[2] != xdr_one ||
847 req->rl_nchunks == 0)
849 iptr = (__be32 *)((unsigned char *)headerp +
851 rdmalen = rpcrdma_count_chunks(rep, req->rl_nchunks, 0, &iptr);
854 r_xprt->rx_stats.total_rdma_reply += rdmalen;
855 /* Reply chunk buffer already is the reply vector - no fixup. */
861 dprintk("%s: invalid rpcrdma reply header (type %d):"
862 " chunks[012] == %d %d %d"
863 " expected chunks <= %d\n",
864 __func__, be32_to_cpu(headerp->rm_type),
865 headerp->rm_body.rm_chunks[0],
866 headerp->rm_body.rm_chunks[1],
867 headerp->rm_body.rm_chunks[2],
870 r_xprt->rx_stats.bad_reply_count++;
874 credits = be32_to_cpu(headerp->rm_credit);
876 credits = 1; /* don't deadlock */
877 else if (credits > r_xprt->rx_buf.rb_max_requests)
878 credits = r_xprt->rx_buf.rb_max_requests;
881 xprt->cwnd = credits << RPC_CWNDSHIFT;
882 if (xprt->cwnd > cwnd)
883 xprt_release_rqst_cong(rqst->rq_task);
885 dprintk("RPC: %s: xprt_complete_rqst(0x%p, 0x%p, %d)\n",
886 __func__, xprt, rqst, status);
887 xprt_complete_rqst(rqst->rq_task, status);
888 spin_unlock(&xprt->transport_lock);