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
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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 static const char transfertypes[][12] = {
65 "inline", /* no chunks */
66 "read list", /* some argument via rdma read */
67 "*read list", /* entire request via rdma read */
68 "write list", /* some result via rdma write */
69 "reply chunk" /* entire reply via rdma write */
72 /* Returns size of largest RPC-over-RDMA header in a Call message
74 * The largest Call header contains a full-size Read list and a
75 * minimal Reply chunk.
77 static unsigned int rpcrdma_max_call_header_size(unsigned int maxsegs)
81 /* Fixed header fields and list discriminators */
82 size = RPCRDMA_HDRLEN_MIN;
84 /* Maximum Read list size */
85 maxsegs += 2; /* segment for head and tail buffers */
86 size = maxsegs * sizeof(struct rpcrdma_read_chunk);
88 /* Minimal Read chunk size */
89 size += sizeof(__be32); /* segment count */
90 size += sizeof(struct rpcrdma_segment);
91 size += sizeof(__be32); /* list discriminator */
93 dprintk("RPC: %s: max call header size = %u\n",
98 /* Returns size of largest RPC-over-RDMA header in a Reply message
100 * There is only one Write list or one Reply chunk per Reply
101 * message. The larger list is the Write list.
103 static unsigned int rpcrdma_max_reply_header_size(unsigned int maxsegs)
107 /* Fixed header fields and list discriminators */
108 size = RPCRDMA_HDRLEN_MIN;
110 /* Maximum Write list size */
111 maxsegs += 2; /* segment for head and tail buffers */
112 size = sizeof(__be32); /* segment count */
113 size += maxsegs * sizeof(struct rpcrdma_segment);
114 size += sizeof(__be32); /* list discriminator */
116 dprintk("RPC: %s: max reply header size = %u\n",
121 void rpcrdma_set_max_header_sizes(struct rpcrdma_ia *ia,
122 struct rpcrdma_create_data_internal *cdata,
123 unsigned int maxsegs)
125 ia->ri_max_inline_write = cdata->inline_wsize -
126 rpcrdma_max_call_header_size(maxsegs);
127 ia->ri_max_inline_read = cdata->inline_rsize -
128 rpcrdma_max_reply_header_size(maxsegs);
131 /* The client can send a request inline as long as the RPCRDMA header
132 * plus the RPC call fit under the transport's inline limit. If the
133 * combined call message size exceeds that limit, the client must use
134 * the read chunk list for this operation.
136 static bool rpcrdma_args_inline(struct rpcrdma_xprt *r_xprt,
137 struct rpc_rqst *rqst)
139 struct rpcrdma_ia *ia = &r_xprt->rx_ia;
141 return rqst->rq_snd_buf.len <= ia->ri_max_inline_write;
144 /* The client can't know how large the actual reply will be. Thus it
145 * plans for the largest possible reply for that particular ULP
146 * operation. If the maximum combined reply message size exceeds that
147 * limit, the client must provide a write list or a reply chunk for
150 static bool rpcrdma_results_inline(struct rpcrdma_xprt *r_xprt,
151 struct rpc_rqst *rqst)
153 struct rpcrdma_ia *ia = &r_xprt->rx_ia;
155 return rqst->rq_rcv_buf.buflen <= ia->ri_max_inline_read;
159 rpcrdma_tail_pullup(struct xdr_buf *buf)
161 size_t tlen = buf->tail[0].iov_len;
162 size_t skip = tlen & 3;
164 /* Do not include the tail if it is only an XDR pad */
168 /* xdr_write_pages() adds a pad at the beginning of the tail
169 * if the content in "buf->pages" is unaligned. Force the
170 * tail's actual content to land at the next XDR position
171 * after the head instead.
174 unsigned char *src, *dst;
177 src = buf->tail[0].iov_base;
178 dst = buf->head[0].iov_base;
179 dst += buf->head[0].iov_len;
184 dprintk("RPC: %s: skip=%zu, memmove(%p, %p, %zu)\n",
185 __func__, skip, dst, src, tlen);
187 for (count = tlen; count; count--)
194 /* Split "vec" on page boundaries into segments. FMR registers pages,
195 * not a byte range. Other modes coalesce these segments into a single
199 rpcrdma_convert_kvec(struct kvec *vec, struct rpcrdma_mr_seg *seg, int n)
205 base = vec->iov_base;
206 page_offset = offset_in_page(base);
207 remaining = vec->iov_len;
208 while (remaining && n < RPCRDMA_MAX_SEGS) {
209 seg[n].mr_page = NULL;
210 seg[n].mr_offset = base;
211 seg[n].mr_len = min_t(u32, PAGE_SIZE - page_offset, remaining);
212 remaining -= seg[n].mr_len;
213 base += seg[n].mr_len;
221 * Chunk assembly from upper layer xdr_buf.
223 * Prepare the passed-in xdr_buf into representation as RPC/RDMA chunk
224 * elements. Segments are then coalesced when registered, if possible
225 * within the selected memreg mode.
227 * Returns positive number of segments converted, or a negative errno.
231 rpcrdma_convert_iovs(struct xdr_buf *xdrbuf, unsigned int pos,
232 enum rpcrdma_chunktype type, struct rpcrdma_mr_seg *seg)
234 int len, n, p, page_base;
235 struct page **ppages;
239 n = rpcrdma_convert_kvec(&xdrbuf->head[0], seg, n);
240 if (n == RPCRDMA_MAX_SEGS)
244 len = xdrbuf->page_len;
245 ppages = xdrbuf->pages + (xdrbuf->page_base >> PAGE_SHIFT);
246 page_base = xdrbuf->page_base & ~PAGE_MASK;
248 while (len && n < RPCRDMA_MAX_SEGS) {
250 /* alloc the pagelist for receiving buffer */
251 ppages[p] = alloc_page(GFP_ATOMIC);
255 seg[n].mr_page = ppages[p];
256 seg[n].mr_offset = (void *)(unsigned long) page_base;
257 seg[n].mr_len = min_t(u32, PAGE_SIZE - page_base, len);
258 if (seg[n].mr_len > PAGE_SIZE)
260 len -= seg[n].mr_len;
263 page_base = 0; /* page offset only applies to first page */
266 /* Message overflows the seg array */
267 if (len && n == RPCRDMA_MAX_SEGS)
270 /* When encoding the read list, the tail is always sent inline */
271 if (type == rpcrdma_readch)
274 if (xdrbuf->tail[0].iov_len) {
275 /* the rpcrdma protocol allows us to omit any trailing
276 * xdr pad bytes, saving the server an RDMA operation. */
277 if (xdrbuf->tail[0].iov_len < 4 && xprt_rdma_pad_optimize)
279 n = rpcrdma_convert_kvec(&xdrbuf->tail[0], seg, n);
280 if (n == RPCRDMA_MAX_SEGS)
287 pr_err("rpcrdma: segment array overflow\n");
291 static inline __be32 *
292 xdr_encode_rdma_segment(__be32 *iptr, struct rpcrdma_mw *mw)
294 *iptr++ = cpu_to_be32(mw->mw_handle);
295 *iptr++ = cpu_to_be32(mw->mw_length);
296 return xdr_encode_hyper(iptr, mw->mw_offset);
299 /* XDR-encode the Read list. Supports encoding a list of read
300 * segments that belong to a single read chunk.
302 * Encoding key for single-list chunks (HLOO = Handle32 Length32 Offset64):
304 * Read chunklist (a linked list):
305 * N elements, position P (same P for all chunks of same arg!):
306 * 1 - PHLOO - 1 - PHLOO - ... - 1 - PHLOO - 0
308 * Returns a pointer to the XDR word in the RDMA header following
309 * the end of the Read list, or an error pointer.
312 rpcrdma_encode_read_list(struct rpcrdma_xprt *r_xprt,
313 struct rpcrdma_req *req, struct rpc_rqst *rqst,
314 __be32 *iptr, enum rpcrdma_chunktype rtype)
316 struct rpcrdma_mr_seg *seg;
317 struct rpcrdma_mw *mw;
321 if (rtype == rpcrdma_noch) {
322 *iptr++ = xdr_zero; /* item not present */
326 pos = rqst->rq_snd_buf.head[0].iov_len;
327 if (rtype == rpcrdma_areadch)
329 seg = req->rl_segments;
330 nsegs = rpcrdma_convert_iovs(&rqst->rq_snd_buf, pos, rtype, seg);
332 return ERR_PTR(nsegs);
335 n = r_xprt->rx_ia.ri_ops->ro_map(r_xprt, seg, nsegs,
339 list_add(&mw->mw_list, &req->rl_registered);
341 *iptr++ = xdr_one; /* item present */
343 /* All read segments in this chunk
344 * have the same "position".
346 *iptr++ = cpu_to_be32(pos);
347 iptr = xdr_encode_rdma_segment(iptr, mw);
349 dprintk("RPC: %5u %s: pos %u %u@0x%016llx:0x%08x (%s)\n",
350 rqst->rq_task->tk_pid, __func__, pos,
351 mw->mw_length, (unsigned long long)mw->mw_offset,
352 mw->mw_handle, n < nsegs ? "more" : "last");
354 r_xprt->rx_stats.read_chunk_count++;
359 /* Finish Read list */
360 *iptr++ = xdr_zero; /* Next item not present */
364 /* XDR-encode the Write list. Supports encoding a list containing
365 * one array of plain segments that belong to a single write chunk.
367 * Encoding key for single-list chunks (HLOO = Handle32 Length32 Offset64):
369 * Write chunklist (a list of (one) counted array):
371 * 1 - N - HLOO - HLOO - ... - HLOO - 0
373 * Returns a pointer to the XDR word in the RDMA header following
374 * the end of the Write list, or an error pointer.
377 rpcrdma_encode_write_list(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
378 struct rpc_rqst *rqst, __be32 *iptr,
379 enum rpcrdma_chunktype wtype)
381 struct rpcrdma_mr_seg *seg;
382 struct rpcrdma_mw *mw;
383 int n, nsegs, nchunks;
386 if (wtype != rpcrdma_writech) {
387 *iptr++ = xdr_zero; /* no Write list present */
391 seg = req->rl_segments;
392 nsegs = rpcrdma_convert_iovs(&rqst->rq_rcv_buf,
393 rqst->rq_rcv_buf.head[0].iov_len,
396 return ERR_PTR(nsegs);
398 *iptr++ = xdr_one; /* Write list present */
399 segcount = iptr++; /* save location of segment count */
403 n = r_xprt->rx_ia.ri_ops->ro_map(r_xprt, seg, nsegs,
407 list_add(&mw->mw_list, &req->rl_registered);
409 iptr = xdr_encode_rdma_segment(iptr, mw);
411 dprintk("RPC: %5u %s: %u@0x016%llx:0x%08x (%s)\n",
412 rqst->rq_task->tk_pid, __func__,
413 mw->mw_length, (unsigned long long)mw->mw_offset,
414 mw->mw_handle, n < nsegs ? "more" : "last");
416 r_xprt->rx_stats.write_chunk_count++;
417 r_xprt->rx_stats.total_rdma_request += seg->mr_len;
423 /* Update count of segments in this Write chunk */
424 *segcount = cpu_to_be32(nchunks);
426 /* Finish Write list */
427 *iptr++ = xdr_zero; /* Next item not present */
431 /* XDR-encode the Reply chunk. Supports encoding an array of plain
432 * segments that belong to a single write (reply) chunk.
434 * Encoding key for single-list chunks (HLOO = Handle32 Length32 Offset64):
436 * Reply chunk (a counted array):
438 * 1 - N - HLOO - HLOO - ... - HLOO
440 * Returns a pointer to the XDR word in the RDMA header following
441 * the end of the Reply chunk, or an error pointer.
444 rpcrdma_encode_reply_chunk(struct rpcrdma_xprt *r_xprt,
445 struct rpcrdma_req *req, struct rpc_rqst *rqst,
446 __be32 *iptr, enum rpcrdma_chunktype wtype)
448 struct rpcrdma_mr_seg *seg;
449 struct rpcrdma_mw *mw;
450 int n, nsegs, nchunks;
453 if (wtype != rpcrdma_replych) {
454 *iptr++ = xdr_zero; /* no Reply chunk present */
458 seg = req->rl_segments;
459 nsegs = rpcrdma_convert_iovs(&rqst->rq_rcv_buf, 0, wtype, seg);
461 return ERR_PTR(nsegs);
463 *iptr++ = xdr_one; /* Reply chunk present */
464 segcount = iptr++; /* save location of segment count */
468 n = r_xprt->rx_ia.ri_ops->ro_map(r_xprt, seg, nsegs,
472 list_add(&mw->mw_list, &req->rl_registered);
474 iptr = xdr_encode_rdma_segment(iptr, mw);
476 dprintk("RPC: %5u %s: %u@0x%016llx:0x%08x (%s)\n",
477 rqst->rq_task->tk_pid, __func__,
478 mw->mw_length, (unsigned long long)mw->mw_offset,
479 mw->mw_handle, n < nsegs ? "more" : "last");
481 r_xprt->rx_stats.reply_chunk_count++;
482 r_xprt->rx_stats.total_rdma_request += seg->mr_len;
488 /* Update count of segments in the Reply chunk */
489 *segcount = cpu_to_be32(nchunks);
495 * Copy write data inline.
496 * This function is used for "small" requests. Data which is passed
497 * to RPC via iovecs (or page list) is copied directly into the
498 * pre-registered memory buffer for this request. For small amounts
499 * of data, this is efficient. The cutoff value is tunable.
501 static void rpcrdma_inline_pullup(struct rpc_rqst *rqst)
503 int i, npages, curlen;
505 unsigned char *srcp, *destp;
506 struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
508 struct page **ppages;
510 destp = rqst->rq_svec[0].iov_base;
511 curlen = rqst->rq_svec[0].iov_len;
514 dprintk("RPC: %s: destp 0x%p len %d hdrlen %d\n",
515 __func__, destp, rqst->rq_slen, curlen);
517 copy_len = rqst->rq_snd_buf.page_len;
519 if (rqst->rq_snd_buf.tail[0].iov_len) {
520 curlen = rqst->rq_snd_buf.tail[0].iov_len;
521 if (destp + copy_len != rqst->rq_snd_buf.tail[0].iov_base) {
522 memmove(destp + copy_len,
523 rqst->rq_snd_buf.tail[0].iov_base, curlen);
524 r_xprt->rx_stats.pullup_copy_count += curlen;
526 dprintk("RPC: %s: tail destp 0x%p len %d\n",
527 __func__, destp + copy_len, curlen);
528 rqst->rq_svec[0].iov_len += curlen;
530 r_xprt->rx_stats.pullup_copy_count += copy_len;
532 page_base = rqst->rq_snd_buf.page_base;
533 ppages = rqst->rq_snd_buf.pages + (page_base >> PAGE_SHIFT);
534 page_base &= ~PAGE_MASK;
535 npages = PAGE_ALIGN(page_base+copy_len) >> PAGE_SHIFT;
536 for (i = 0; copy_len && i < npages; i++) {
537 curlen = PAGE_SIZE - page_base;
538 if (curlen > copy_len)
540 dprintk("RPC: %s: page %d destp 0x%p len %d curlen %d\n",
541 __func__, i, destp, copy_len, curlen);
542 srcp = kmap_atomic(ppages[i]);
543 memcpy(destp, srcp+page_base, curlen);
545 rqst->rq_svec[0].iov_len += curlen;
550 /* header now contains entire send message */
554 * Marshal a request: the primary job of this routine is to choose
555 * the transfer modes. See comments below.
557 * Prepares up to two IOVs per Call message:
559 * [0] -- RPC RDMA header
560 * [1] -- the RPC header/data
562 * Returns zero on success, otherwise a negative errno.
566 rpcrdma_marshal_req(struct rpc_rqst *rqst)
568 struct rpc_xprt *xprt = rqst->rq_xprt;
569 struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
570 struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
571 enum rpcrdma_chunktype rtype, wtype;
572 struct rpcrdma_msg *headerp;
578 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
579 if (test_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state))
580 return rpcrdma_bc_marshal_reply(rqst);
583 headerp = rdmab_to_msg(req->rl_rdmabuf);
584 /* don't byte-swap XID, it's already done in request */
585 headerp->rm_xid = rqst->rq_xid;
586 headerp->rm_vers = rpcrdma_version;
587 headerp->rm_credit = cpu_to_be32(r_xprt->rx_buf.rb_max_requests);
588 headerp->rm_type = rdma_msg;
590 /* When the ULP employs a GSS flavor that guarantees integrity
591 * or privacy, direct data placement of individual data items
594 ddp_allowed = !(rqst->rq_cred->cr_auth->au_flags &
595 RPCAUTH_AUTH_DATATOUCH);
598 * Chunks needed for results?
600 * o If the expected result is under the inline threshold, all ops
602 * o Large read ops return data as write chunk(s), header as
604 * o Large non-read ops return as a single reply chunk.
606 if (rpcrdma_results_inline(r_xprt, rqst))
607 wtype = rpcrdma_noch;
608 else if (ddp_allowed && rqst->rq_rcv_buf.flags & XDRBUF_READ)
609 wtype = rpcrdma_writech;
611 wtype = rpcrdma_replych;
614 * Chunks needed for arguments?
616 * o If the total request is under the inline threshold, all ops
617 * are sent as inline.
618 * o Large write ops transmit data as read chunk(s), header as
620 * o Large non-write ops are sent with the entire message as a
621 * single read chunk (protocol 0-position special case).
623 * This assumes that the upper layer does not present a request
624 * that both has a data payload, and whose non-data arguments
625 * by themselves are larger than the inline threshold.
627 if (rpcrdma_args_inline(r_xprt, rqst)) {
628 rtype = rpcrdma_noch;
629 rpcrdma_inline_pullup(rqst);
630 rpclen = rqst->rq_svec[0].iov_len;
631 } else if (ddp_allowed && rqst->rq_snd_buf.flags & XDRBUF_WRITE) {
632 rtype = rpcrdma_readch;
633 rpclen = rqst->rq_svec[0].iov_len;
634 rpclen += rpcrdma_tail_pullup(&rqst->rq_snd_buf);
636 r_xprt->rx_stats.nomsg_call_count++;
637 headerp->rm_type = htonl(RDMA_NOMSG);
638 rtype = rpcrdma_areadch;
642 /* This implementation supports the following combinations
643 * of chunk lists in one RPC-over-RDMA Call message:
648 * - Read list + Reply chunk
650 * It might not yet support the following combinations:
652 * - Read list + Write list
654 * It does not support the following combinations:
656 * - Write list + Reply chunk
657 * - Read list + Write list + Reply chunk
659 * This implementation supports only a single chunk in each
660 * Read or Write list. Thus for example the client cannot
661 * send a Call message with a Position Zero Read chunk and a
662 * regular Read chunk at the same time.
664 iptr = headerp->rm_body.rm_chunks;
665 iptr = rpcrdma_encode_read_list(r_xprt, req, rqst, iptr, rtype);
668 iptr = rpcrdma_encode_write_list(r_xprt, req, rqst, iptr, wtype);
671 iptr = rpcrdma_encode_reply_chunk(r_xprt, req, rqst, iptr, wtype);
674 hdrlen = (unsigned char *)iptr - (unsigned char *)headerp;
676 if (hdrlen + rpclen > RPCRDMA_INLINE_WRITE_THRESHOLD(rqst))
679 dprintk("RPC: %5u %s: %s/%s: hdrlen %zd rpclen %zd\n",
680 rqst->rq_task->tk_pid, __func__,
681 transfertypes[rtype], transfertypes[wtype],
684 req->rl_send_iov[0].addr = rdmab_addr(req->rl_rdmabuf);
685 req->rl_send_iov[0].length = hdrlen;
686 req->rl_send_iov[0].lkey = rdmab_lkey(req->rl_rdmabuf);
689 if (rtype == rpcrdma_areadch)
692 req->rl_send_iov[1].addr = rdmab_addr(req->rl_sendbuf);
693 req->rl_send_iov[1].length = rpclen;
694 req->rl_send_iov[1].lkey = rdmab_lkey(req->rl_sendbuf);
700 pr_err("rpcrdma: send overflow: hdrlen %zd rpclen %zu %s/%s\n",
701 hdrlen, rpclen, transfertypes[rtype], transfertypes[wtype]);
702 iptr = ERR_PTR(-EIO);
705 r_xprt->rx_ia.ri_ops->ro_unmap_safe(r_xprt, req, false);
706 return PTR_ERR(iptr);
710 * Chase down a received write or reply chunklist to get length
711 * RDMA'd by server. See map at rpcrdma_create_chunks()! :-)
714 rpcrdma_count_chunks(struct rpcrdma_rep *rep, int wrchunk, __be32 **iptrp)
716 unsigned int i, total_len;
717 struct rpcrdma_write_chunk *cur_wchunk;
718 char *base = (char *)rdmab_to_msg(rep->rr_rdmabuf);
720 i = be32_to_cpu(**iptrp);
721 cur_wchunk = (struct rpcrdma_write_chunk *) (*iptrp + 1);
724 struct rpcrdma_segment *seg = &cur_wchunk->wc_target;
727 xdr_decode_hyper((__be32 *)&seg->rs_offset, &off);
728 dprintk("RPC: %s: chunk %d@0x%llx:0x%x\n",
730 be32_to_cpu(seg->rs_length),
731 (unsigned long long)off,
732 be32_to_cpu(seg->rs_handle));
734 total_len += be32_to_cpu(seg->rs_length);
737 /* check and adjust for properly terminated write chunk */
739 __be32 *w = (__be32 *) cur_wchunk;
740 if (*w++ != xdr_zero)
742 cur_wchunk = (struct rpcrdma_write_chunk *) w;
744 if ((char *)cur_wchunk > base + rep->rr_len)
747 *iptrp = (__be32 *) cur_wchunk;
752 * rpcrdma_inline_fixup - Scatter inline received data into rqst's iovecs
753 * @rqst: controlling RPC request
754 * @srcp: points to RPC message payload in receive buffer
755 * @copy_len: remaining length of receive buffer content
756 * @pad: Write chunk pad bytes needed (zero for pure inline)
758 * The upper layer has set the maximum number of bytes it can
759 * receive in each component of rq_rcv_buf. These values are set in
760 * the head.iov_len, page_len, tail.iov_len, and buflen fields.
762 * Unlike the TCP equivalent (xdr_partial_copy_from_skb), in
763 * many cases this function simply updates iov_base pointers in
764 * rq_rcv_buf to point directly to the received reply data, to
765 * avoid copying reply data.
767 * Returns the count of bytes which had to be memcopied.
770 rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len, int pad)
772 unsigned long fixup_copy_count;
773 int i, npages, curlen;
775 struct page **ppages;
778 /* The head iovec is redirected to the RPC reply message
779 * in the receive buffer, to avoid a memcopy.
781 rqst->rq_rcv_buf.head[0].iov_base = srcp;
782 rqst->rq_private_buf.head[0].iov_base = srcp;
784 /* The contents of the receive buffer that follow
785 * head.iov_len bytes are copied into the page list.
787 curlen = rqst->rq_rcv_buf.head[0].iov_len;
788 if (curlen > copy_len)
790 dprintk("RPC: %s: srcp 0x%p len %d hdrlen %d\n",
791 __func__, srcp, copy_len, curlen);
795 page_base = rqst->rq_rcv_buf.page_base;
796 ppages = rqst->rq_rcv_buf.pages + (page_base >> PAGE_SHIFT);
797 page_base &= ~PAGE_MASK;
798 fixup_copy_count = 0;
799 if (copy_len && rqst->rq_rcv_buf.page_len) {
802 pagelist_len = rqst->rq_rcv_buf.page_len;
803 if (pagelist_len > copy_len)
804 pagelist_len = copy_len;
805 npages = PAGE_ALIGN(page_base + pagelist_len) >> PAGE_SHIFT;
806 for (i = 0; i < npages; i++) {
807 curlen = PAGE_SIZE - page_base;
808 if (curlen > pagelist_len)
809 curlen = pagelist_len;
811 dprintk("RPC: %s: page %d"
812 " srcp 0x%p len %d curlen %d\n",
813 __func__, i, srcp, copy_len, curlen);
814 destp = kmap_atomic(ppages[i]);
815 memcpy(destp + page_base, srcp, curlen);
816 flush_dcache_page(ppages[i]);
817 kunmap_atomic(destp);
820 fixup_copy_count += curlen;
821 pagelist_len -= curlen;
827 /* Implicit padding for the last segment in a Write
828 * chunk is inserted inline at the front of the tail
829 * iovec. The upper layer ignores the content of
830 * the pad. Simply ensure inline content in the tail
831 * that follows the Write chunk is properly aligned.
837 /* The tail iovec is redirected to the remaining data
838 * in the receive buffer, to avoid a memcopy.
840 if (copy_len || pad) {
841 rqst->rq_rcv_buf.tail[0].iov_base = srcp;
842 rqst->rq_private_buf.tail[0].iov_base = srcp;
845 return fixup_copy_count;
849 rpcrdma_connect_worker(struct work_struct *work)
851 struct rpcrdma_ep *ep =
852 container_of(work, struct rpcrdma_ep, rep_connect_worker.work);
853 struct rpcrdma_xprt *r_xprt =
854 container_of(ep, struct rpcrdma_xprt, rx_ep);
855 struct rpc_xprt *xprt = &r_xprt->rx_xprt;
857 spin_lock_bh(&xprt->transport_lock);
858 if (++xprt->connect_cookie == 0) /* maintain a reserved value */
859 ++xprt->connect_cookie;
860 if (ep->rep_connected > 0) {
861 if (!xprt_test_and_set_connected(xprt))
862 xprt_wake_pending_tasks(xprt, 0);
864 if (xprt_test_and_clear_connected(xprt))
865 xprt_wake_pending_tasks(xprt, -ENOTCONN);
867 spin_unlock_bh(&xprt->transport_lock);
870 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
871 /* By convention, backchannel calls arrive via rdma_msg type
872 * messages, and never populate the chunk lists. This makes
873 * the RPC/RDMA header small and fixed in size, so it is
874 * straightforward to check the RPC header's direction field.
877 rpcrdma_is_bcall(struct rpcrdma_msg *headerp)
879 __be32 *p = (__be32 *)headerp;
881 if (headerp->rm_type != rdma_msg)
883 if (headerp->rm_body.rm_chunks[0] != xdr_zero)
885 if (headerp->rm_body.rm_chunks[1] != xdr_zero)
887 if (headerp->rm_body.rm_chunks[2] != xdr_zero)
891 if (p[7] != headerp->rm_xid)
894 if (p[8] != cpu_to_be32(RPC_CALL))
899 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
902 * This function is called when an async event is posted to
903 * the connection which changes the connection state. All it
904 * does at this point is mark the connection up/down, the rpc
905 * timers do the rest.
908 rpcrdma_conn_func(struct rpcrdma_ep *ep)
910 schedule_delayed_work(&ep->rep_connect_worker, 0);
913 /* Process received RPC/RDMA messages.
915 * Errors must result in the RPC task either being awakened, or
916 * allowed to timeout, to discover the errors at that time.
919 rpcrdma_reply_handler(struct rpcrdma_rep *rep)
921 struct rpcrdma_msg *headerp;
922 struct rpcrdma_req *req;
923 struct rpc_rqst *rqst;
924 struct rpcrdma_xprt *r_xprt = rep->rr_rxprt;
925 struct rpc_xprt *xprt = &r_xprt->rx_xprt;
927 int rdmalen, status, rmerr;
930 dprintk("RPC: %s: incoming rep %p\n", __func__, rep);
932 if (rep->rr_len == RPCRDMA_BAD_LEN)
934 if (rep->rr_len < RPCRDMA_HDRLEN_ERR)
937 headerp = rdmab_to_msg(rep->rr_rdmabuf);
938 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
939 if (rpcrdma_is_bcall(headerp))
943 /* Match incoming rpcrdma_rep to an rpcrdma_req to
944 * get context for handling any incoming chunks.
946 spin_lock_bh(&xprt->transport_lock);
947 rqst = xprt_lookup_rqst(xprt, headerp->rm_xid);
951 req = rpcr_to_rdmar(rqst);
955 /* Sanity checking has passed. We are now committed
956 * to complete this transaction.
958 list_del_init(&rqst->rq_list);
959 spin_unlock_bh(&xprt->transport_lock);
960 dprintk("RPC: %s: reply %p completes request %p (xid 0x%08x)\n",
961 __func__, rep, req, be32_to_cpu(headerp->rm_xid));
963 /* from here on, the reply is no longer an orphan */
965 xprt->reestablish_timeout = 0;
967 if (headerp->rm_vers != rpcrdma_version)
970 /* check for expected message types */
971 /* The order of some of these tests is important. */
972 switch (headerp->rm_type) {
974 /* never expect read chunks */
975 /* never expect reply chunks (two ways to check) */
976 /* never expect write chunks without having offered RDMA */
977 if (headerp->rm_body.rm_chunks[0] != xdr_zero ||
978 (headerp->rm_body.rm_chunks[1] == xdr_zero &&
979 headerp->rm_body.rm_chunks[2] != xdr_zero) ||
980 (headerp->rm_body.rm_chunks[1] != xdr_zero &&
981 list_empty(&req->rl_registered)))
983 if (headerp->rm_body.rm_chunks[1] != xdr_zero) {
984 /* count any expected write chunks in read reply */
985 /* start at write chunk array count */
986 iptr = &headerp->rm_body.rm_chunks[2];
987 rdmalen = rpcrdma_count_chunks(rep, 1, &iptr);
988 /* check for validity, and no reply chunk after */
989 if (rdmalen < 0 || *iptr++ != xdr_zero)
992 ((unsigned char *)iptr - (unsigned char *)headerp);
993 status = rep->rr_len + rdmalen;
994 r_xprt->rx_stats.total_rdma_reply += rdmalen;
995 /* special case - last chunk may omit padding */
997 rdmalen = 4 - rdmalen;
1001 /* else ordinary inline */
1003 iptr = (__be32 *)((unsigned char *)headerp +
1004 RPCRDMA_HDRLEN_MIN);
1005 rep->rr_len -= RPCRDMA_HDRLEN_MIN;
1006 status = rep->rr_len;
1009 r_xprt->rx_stats.fixup_copy_count +=
1010 rpcrdma_inline_fixup(rqst, (char *)iptr, rep->rr_len,
1015 /* never expect read or write chunks, always reply chunks */
1016 if (headerp->rm_body.rm_chunks[0] != xdr_zero ||
1017 headerp->rm_body.rm_chunks[1] != xdr_zero ||
1018 headerp->rm_body.rm_chunks[2] != xdr_one ||
1019 list_empty(&req->rl_registered))
1021 iptr = (__be32 *)((unsigned char *)headerp +
1022 RPCRDMA_HDRLEN_MIN);
1023 rdmalen = rpcrdma_count_chunks(rep, 0, &iptr);
1026 r_xprt->rx_stats.total_rdma_reply += rdmalen;
1027 /* Reply chunk buffer already is the reply vector - no fixup. */
1036 dprintk("RPC: %5u %s: invalid rpcrdma reply (type %u)\n",
1037 rqst->rq_task->tk_pid, __func__,
1038 be32_to_cpu(headerp->rm_type));
1040 r_xprt->rx_stats.bad_reply_count++;
1045 /* Invalidate and flush the data payloads before waking the
1046 * waiting application. This guarantees the memory region is
1047 * properly fenced from the server before the application
1048 * accesses the data. It also ensures proper send flow
1049 * control: waking the next RPC waits until this RPC has
1050 * relinquished all its Send Queue entries.
1052 if (!list_empty(&req->rl_registered))
1053 r_xprt->rx_ia.ri_ops->ro_unmap_sync(r_xprt, req);
1055 spin_lock_bh(&xprt->transport_lock);
1057 xprt->cwnd = atomic_read(&r_xprt->rx_buf.rb_credits) << RPC_CWNDSHIFT;
1058 if (xprt->cwnd > cwnd)
1059 xprt_release_rqst_cong(rqst->rq_task);
1061 xprt_complete_rqst(rqst->rq_task, status);
1062 spin_unlock_bh(&xprt->transport_lock);
1063 dprintk("RPC: %s: xprt_complete_rqst(0x%p, 0x%p, %d)\n",
1064 __func__, xprt, rqst, status);
1068 rpcrdma_recv_buffer_put(rep);
1069 if (r_xprt->rx_ep.rep_connected == 1) {
1070 r_xprt->rx_ep.rep_connected = -EIO;
1071 rpcrdma_conn_func(&r_xprt->rx_ep);
1075 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1077 rpcrdma_bc_receive_call(r_xprt, rep);
1081 /* If the incoming reply terminated a pending RPC, the next
1082 * RPC call will post a replacement receive buffer as it is
1086 dprintk("RPC: %s: invalid version %d\n",
1087 __func__, be32_to_cpu(headerp->rm_vers));
1089 r_xprt->rx_stats.bad_reply_count++;
1093 rmerr = be32_to_cpu(headerp->rm_body.rm_error.rm_err);
1096 pr_err("%s: server reports header version error (%u-%u)\n",
1098 be32_to_cpu(headerp->rm_body.rm_error.rm_vers_low),
1099 be32_to_cpu(headerp->rm_body.rm_error.rm_vers_high));
1102 pr_err("%s: server reports header decoding error\n",
1106 pr_err("%s: server reports unknown error %d\n",
1109 status = -EREMOTEIO;
1110 r_xprt->rx_stats.bad_reply_count++;
1113 /* If no pending RPC transaction was matched, post a replacement
1114 * receive buffer before returning.
1117 dprintk("RPC: %s: short/invalid reply\n", __func__);
1121 spin_unlock_bh(&xprt->transport_lock);
1122 dprintk("RPC: %s: no match for incoming xid 0x%08x len %d\n",
1123 __func__, be32_to_cpu(headerp->rm_xid),
1128 spin_unlock_bh(&xprt->transport_lock);
1130 "duplicate reply %p to RPC request %p: xid 0x%08x\n",
1131 __func__, rep, req, be32_to_cpu(headerp->rm_xid));
1134 r_xprt->rx_stats.bad_reply_count++;
1135 if (rpcrdma_ep_post_recv(&r_xprt->rx_ia, &r_xprt->rx_ep, rep))
1136 rpcrdma_recv_buffer_put(rep);