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linux/net/sunrpc/xprtrdma/rpc_rdma.c

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/*
* Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the BSD-type
* license below:
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
*
* Neither the name of the Network Appliance, Inc. nor the names of
* its contributors may be used to endorse or promote products
* derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* rpc_rdma.c
*
* This file contains the guts of the RPC RDMA protocol, and
* does marshaling/unmarshaling, etc. It is also where interfacing
* to the Linux RPC framework lives.
*/
#include "xprt_rdma.h"
#include <linux/highmem.h>
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
# define RPCDBG_FACILITY RPCDBG_TRANS
#endif
enum rpcrdma_chunktype {
rpcrdma_noch = 0,
rpcrdma_readch,
rpcrdma_areadch,
rpcrdma_writech,
rpcrdma_replych
};
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
static const char transfertypes[][12] = {
"pure inline", /* no chunks */
" read chunk", /* some argument via rdma read */
"*read chunk", /* entire request via rdma read */
"write chunk", /* some result via rdma write */
"reply chunk" /* entire reply via rdma write */
};
#endif
/* The client can send a request inline as long as the RPCRDMA header
* plus the RPC call fit under the transport's inline limit. If the
* combined call message size exceeds that limit, the client must use
* the read chunk list for this operation.
*/
static bool rpcrdma_args_inline(struct rpc_rqst *rqst)
{
unsigned int callsize = RPCRDMA_HDRLEN_MIN + rqst->rq_snd_buf.len;
return callsize <= RPCRDMA_INLINE_WRITE_THRESHOLD(rqst);
}
/* The client can't know how large the actual reply will be. Thus it
* plans for the largest possible reply for that particular ULP
* operation. If the maximum combined reply message size exceeds that
* limit, the client must provide a write list or a reply chunk for
* this request.
*/
static bool rpcrdma_results_inline(struct rpc_rqst *rqst)
{
unsigned int repsize = RPCRDMA_HDRLEN_MIN + rqst->rq_rcv_buf.buflen;
return repsize <= RPCRDMA_INLINE_READ_THRESHOLD(rqst);
}
static int
rpcrdma_tail_pullup(struct xdr_buf *buf)
{
size_t tlen = buf->tail[0].iov_len;
size_t skip = tlen & 3;
/* Do not include the tail if it is only an XDR pad */
if (tlen < 4)
return 0;
/* xdr_write_pages() adds a pad at the beginning of the tail
* if the content in "buf->pages" is unaligned. Force the
* tail's actual content to land at the next XDR position
* after the head instead.
*/
if (skip) {
unsigned char *src, *dst;
unsigned int count;
src = buf->tail[0].iov_base;
dst = buf->head[0].iov_base;
dst += buf->head[0].iov_len;
src += skip;
tlen -= skip;
dprintk("RPC: %s: skip=%zu, memmove(%p, %p, %zu)\n",
__func__, skip, dst, src, tlen);
for (count = tlen; count; count--)
*dst++ = *src++;
}
return tlen;
}
/*
* Chunk assembly from upper layer xdr_buf.
*
* Prepare the passed-in xdr_buf into representation as RPC/RDMA chunk
* elements. Segments are then coalesced when registered, if possible
* within the selected memreg mode.
*
* Returns positive number of segments converted, or a negative errno.
*/
static int
rpcrdma_convert_iovs(struct xdr_buf *xdrbuf, unsigned int pos,
enum rpcrdma_chunktype type, struct rpcrdma_mr_seg *seg, int nsegs)
{
int len, n = 0, p;
int page_base;
struct page **ppages;
if (pos == 0 && xdrbuf->head[0].iov_len) {
seg[n].mr_page = NULL;
seg[n].mr_offset = xdrbuf->head[0].iov_base;
seg[n].mr_len = xdrbuf->head[0].iov_len;
++n;
}
len = xdrbuf->page_len;
ppages = xdrbuf->pages + (xdrbuf->page_base >> PAGE_SHIFT);
page_base = xdrbuf->page_base & ~PAGE_MASK;
p = 0;
while (len && n < nsegs) {
if (!ppages[p]) {
/* alloc the pagelist for receiving buffer */
ppages[p] = alloc_page(GFP_ATOMIC);
if (!ppages[p])
return -ENOMEM;
}
seg[n].mr_page = ppages[p];
seg[n].mr_offset = (void *)(unsigned long) page_base;
seg[n].mr_len = min_t(u32, PAGE_SIZE - page_base, len);
if (seg[n].mr_len > PAGE_SIZE)
return -EIO;
len -= seg[n].mr_len;
++n;
++p;
page_base = 0; /* page offset only applies to first page */
}
/* Message overflows the seg array */
if (len && n == nsegs)
return -EIO;
/* When encoding the read list, the tail is always sent inline */
if (type == rpcrdma_readch)
return n;
if (xdrbuf->tail[0].iov_len) {
/* the rpcrdma protocol allows us to omit any trailing
* xdr pad bytes, saving the server an RDMA operation. */
if (xdrbuf->tail[0].iov_len < 4 && xprt_rdma_pad_optimize)
return n;
if (n == nsegs)
/* Tail remains, but we're out of segments */
return -EIO;
seg[n].mr_page = NULL;
seg[n].mr_offset = xdrbuf->tail[0].iov_base;
seg[n].mr_len = xdrbuf->tail[0].iov_len;
++n;
}
return n;
}
/*
* Create read/write chunk lists, and reply chunks, for RDMA
*
* Assume check against THRESHOLD has been done, and chunks are required.
* Assume only encoding one list entry for read|write chunks. The NFSv3
* protocol is simple enough to allow this as it only has a single "bulk
* result" in each procedure - complicated NFSv4 COMPOUNDs are not. (The
* RDMA/Sessions NFSv4 proposal addresses this for future v4 revs.)
*
* When used for a single reply chunk (which is a special write
* chunk used for the entire reply, rather than just the data), it
* is used primarily for READDIR and READLINK which would otherwise
* be severely size-limited by a small rdma inline read max. The server
* response will come back as an RDMA Write, followed by a message
* of type RDMA_NOMSG carrying the xid and length. As a result, reply
* chunks do not provide data alignment, however they do not require
* "fixup" (moving the response to the upper layer buffer) either.
*
* Encoding key for single-list chunks (HLOO = Handle32 Length32 Offset64):
*
* Read chunklist (a linked list):
* N elements, position P (same P for all chunks of same arg!):
* 1 - PHLOO - 1 - PHLOO - ... - 1 - PHLOO - 0
*
* Write chunklist (a list of (one) counted array):
* N elements:
* 1 - N - HLOO - HLOO - ... - HLOO - 0
*
* Reply chunk (a counted array):
* N elements:
* 1 - N - HLOO - HLOO - ... - HLOO
*
* Returns positive RPC/RDMA header size, or negative errno.
*/
static ssize_t
rpcrdma_create_chunks(struct rpc_rqst *rqst, struct xdr_buf *target,
struct rpcrdma_msg *headerp, enum rpcrdma_chunktype type)
{
struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
int n, nsegs, nchunks = 0;
unsigned int pos;
struct rpcrdma_mr_seg *seg = req->rl_segments;
struct rpcrdma_read_chunk *cur_rchunk = NULL;
struct rpcrdma_write_array *warray = NULL;
struct rpcrdma_write_chunk *cur_wchunk = NULL;
__be32 *iptr = headerp->rm_body.rm_chunks;
int (*map)(struct rpcrdma_xprt *, struct rpcrdma_mr_seg *, int, bool);
if (type == rpcrdma_readch || type == rpcrdma_areadch) {
/* a read chunk - server will RDMA Read our memory */
cur_rchunk = (struct rpcrdma_read_chunk *) iptr;
} else {
/* a write or reply chunk - server will RDMA Write our memory */
*iptr++ = xdr_zero; /* encode a NULL read chunk list */
if (type == rpcrdma_replych)
*iptr++ = xdr_zero; /* a NULL write chunk list */
warray = (struct rpcrdma_write_array *) iptr;
cur_wchunk = (struct rpcrdma_write_chunk *) (warray + 1);
}
if (type == rpcrdma_replych || type == rpcrdma_areadch)
pos = 0;
else
pos = target->head[0].iov_len;
nsegs = rpcrdma_convert_iovs(target, pos, type, seg, RPCRDMA_MAX_SEGS);
if (nsegs < 0)
return nsegs;
map = r_xprt->rx_ia.ri_ops->ro_map;
do {
n = map(r_xprt, seg, nsegs, cur_wchunk != NULL);
if (n <= 0)
goto out;
if (cur_rchunk) { /* read */
cur_rchunk->rc_discrim = xdr_one;
/* all read chunks have the same "position" */
cur_rchunk->rc_position = cpu_to_be32(pos);
cur_rchunk->rc_target.rs_handle =
cpu_to_be32(seg->mr_rkey);
cur_rchunk->rc_target.rs_length =
cpu_to_be32(seg->mr_len);
xdr_encode_hyper(
(__be32 *)&cur_rchunk->rc_target.rs_offset,
seg->mr_base);
dprintk("RPC: %s: read chunk "
"elem %d@0x%llx:0x%x pos %u (%s)\n", __func__,
seg->mr_len, (unsigned long long)seg->mr_base,
seg->mr_rkey, pos, n < nsegs ? "more" : "last");
cur_rchunk++;
r_xprt->rx_stats.read_chunk_count++;
} else { /* write/reply */
cur_wchunk->wc_target.rs_handle =
cpu_to_be32(seg->mr_rkey);
cur_wchunk->wc_target.rs_length =
cpu_to_be32(seg->mr_len);
xdr_encode_hyper(
(__be32 *)&cur_wchunk->wc_target.rs_offset,
seg->mr_base);
dprintk("RPC: %s: %s chunk "
"elem %d@0x%llx:0x%x (%s)\n", __func__,
(type == rpcrdma_replych) ? "reply" : "write",
seg->mr_len, (unsigned long long)seg->mr_base,
seg->mr_rkey, n < nsegs ? "more" : "last");
cur_wchunk++;
if (type == rpcrdma_replych)
r_xprt->rx_stats.reply_chunk_count++;
else
r_xprt->rx_stats.write_chunk_count++;
r_xprt->rx_stats.total_rdma_request += seg->mr_len;
}
nchunks++;
seg += n;
nsegs -= n;
} while (nsegs);
/* success. all failures return above */
req->rl_nchunks = nchunks;
/*
* finish off header. If write, marshal discrim and nchunks.
*/
if (cur_rchunk) {
iptr = (__be32 *) cur_rchunk;
*iptr++ = xdr_zero; /* finish the read chunk list */
*iptr++ = xdr_zero; /* encode a NULL write chunk list */
*iptr++ = xdr_zero; /* encode a NULL reply chunk */
} else {
warray->wc_discrim = xdr_one;
warray->wc_nchunks = cpu_to_be32(nchunks);
iptr = (__be32 *) cur_wchunk;
if (type == rpcrdma_writech) {
*iptr++ = xdr_zero; /* finish the write chunk list */
*iptr++ = xdr_zero; /* encode a NULL reply chunk */
}
}
/*
* Return header size.
*/
return (unsigned char *)iptr - (unsigned char *)headerp;
out:
for (pos = 0; nchunks--;)
pos += r_xprt->rx_ia.ri_ops->ro_unmap(r_xprt,
&req->rl_segments[pos]);
return n;
}
/*
* Copy write data inline.
* This function is used for "small" requests. Data which is passed
* to RPC via iovecs (or page list) is copied directly into the
* pre-registered memory buffer for this request. For small amounts
* of data, this is efficient. The cutoff value is tunable.
*/
static void rpcrdma_inline_pullup(struct rpc_rqst *rqst)
{
int i, npages, curlen;
int copy_len;
unsigned char *srcp, *destp;
struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
int page_base;
struct page **ppages;
destp = rqst->rq_svec[0].iov_base;
curlen = rqst->rq_svec[0].iov_len;
destp += curlen;
dprintk("RPC: %s: destp 0x%p len %d hdrlen %d\n",
__func__, destp, rqst->rq_slen, curlen);
copy_len = rqst->rq_snd_buf.page_len;
if (rqst->rq_snd_buf.tail[0].iov_len) {
curlen = rqst->rq_snd_buf.tail[0].iov_len;
if (destp + copy_len != rqst->rq_snd_buf.tail[0].iov_base) {
memmove(destp + copy_len,
rqst->rq_snd_buf.tail[0].iov_base, curlen);
r_xprt->rx_stats.pullup_copy_count += curlen;
}
dprintk("RPC: %s: tail destp 0x%p len %d\n",
__func__, destp + copy_len, curlen);
rqst->rq_svec[0].iov_len += curlen;
}
r_xprt->rx_stats.pullup_copy_count += copy_len;
page_base = rqst->rq_snd_buf.page_base;
ppages = rqst->rq_snd_buf.pages + (page_base >> PAGE_SHIFT);
page_base &= ~PAGE_MASK;
npages = PAGE_ALIGN(page_base+copy_len) >> PAGE_SHIFT;
for (i = 0; copy_len && i < npages; i++) {
curlen = PAGE_SIZE - page_base;
if (curlen > copy_len)
curlen = copy_len;
dprintk("RPC: %s: page %d destp 0x%p len %d curlen %d\n",
__func__, i, destp, copy_len, curlen);
srcp = kmap_atomic(ppages[i]);
memcpy(destp, srcp+page_base, curlen);
kunmap_atomic(srcp);
rqst->rq_svec[0].iov_len += curlen;
destp += curlen;
copy_len -= curlen;
page_base = 0;
}
/* header now contains entire send message */
}
/*
* Marshal a request: the primary job of this routine is to choose
* the transfer modes. See comments below.
*
* Uses multiple RDMA IOVs for a request:
* [0] -- RPC RDMA header, which uses memory from the *start* of the
* preregistered buffer that already holds the RPC data in
* its middle.
* [1] -- the RPC header/data, marshaled by RPC and the NFS protocol.
* [2] -- optional padding.
* [3] -- if padded, header only in [1] and data here.
*
* Returns zero on success, otherwise a negative errno.
*/
int
rpcrdma_marshal_req(struct rpc_rqst *rqst)
{
struct rpc_xprt *xprt = rqst->rq_xprt;
struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
char *base;
size_t rpclen;
ssize_t hdrlen;
enum rpcrdma_chunktype rtype, wtype;
struct rpcrdma_msg *headerp;
#if defined(CONFIG_SUNRPC_BACKCHANNEL)
if (test_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state))
return rpcrdma_bc_marshal_reply(rqst);
#endif
/*
* rpclen gets amount of data in first buffer, which is the
* pre-registered buffer.
*/
base = rqst->rq_svec[0].iov_base;
rpclen = rqst->rq_svec[0].iov_len;
headerp = rdmab_to_msg(req->rl_rdmabuf);
/* don't byte-swap XID, it's already done in request */
headerp->rm_xid = rqst->rq_xid;
headerp->rm_vers = rpcrdma_version;
headerp->rm_credit = cpu_to_be32(r_xprt->rx_buf.rb_max_requests);
headerp->rm_type = rdma_msg;
/*
* Chunks needed for results?
*
* o Read ops return data as write chunk(s), header as inline.
* o If the expected result is under the inline threshold, all ops
* return as inline.
* o Large non-read ops return as a single reply chunk.
*/
if (rqst->rq_rcv_buf.flags & XDRBUF_READ)
wtype = rpcrdma_writech;
else if (rpcrdma_results_inline(rqst))
wtype = rpcrdma_noch;
else
wtype = rpcrdma_replych;
/*
* Chunks needed for arguments?
*
* o If the total request is under the inline threshold, all ops
* are sent as inline.
* o Large write ops transmit data as read chunk(s), header as
* inline.
* o Large non-write ops are sent with the entire message as a
* single read chunk (protocol 0-position special case).
*
* This assumes that the upper layer does not present a request
* that both has a data payload, and whose non-data arguments
* by themselves are larger than the inline threshold.
*/
if (rpcrdma_args_inline(rqst)) {
rtype = rpcrdma_noch;
} else if (rqst->rq_snd_buf.flags & XDRBUF_WRITE) {
rtype = rpcrdma_readch;
} else {
r_xprt->rx_stats.nomsg_call_count++;
headerp->rm_type = htonl(RDMA_NOMSG);
rtype = rpcrdma_areadch;
rpclen = 0;
}
/* The following simplification is not true forever */
if (rtype != rpcrdma_noch && wtype == rpcrdma_replych)
wtype = rpcrdma_noch;
if (rtype != rpcrdma_noch && wtype != rpcrdma_noch) {
dprintk("RPC: %s: cannot marshal multiple chunk lists\n",
__func__);
return -EIO;
}
hdrlen = RPCRDMA_HDRLEN_MIN;
/*
* Pull up any extra send data into the preregistered buffer.
* When padding is in use and applies to the transfer, insert
* it and change the message type.
*/
if (rtype == rpcrdma_noch) {
rpcrdma_inline_pullup(rqst);
headerp->rm_body.rm_nochunks.rm_empty[0] = xdr_zero;
headerp->rm_body.rm_nochunks.rm_empty[1] = xdr_zero;
headerp->rm_body.rm_nochunks.rm_empty[2] = xdr_zero;
/* new length after pullup */
rpclen = rqst->rq_svec[0].iov_len;
} else if (rtype == rpcrdma_readch)
rpclen += rpcrdma_tail_pullup(&rqst->rq_snd_buf);
if (rtype != rpcrdma_noch) {
hdrlen = rpcrdma_create_chunks(rqst, &rqst->rq_snd_buf,
headerp, rtype);
wtype = rtype; /* simplify dprintk */
} else if (wtype != rpcrdma_noch) {
hdrlen = rpcrdma_create_chunks(rqst, &rqst->rq_rcv_buf,
headerp, wtype);
}
if (hdrlen < 0)
return hdrlen;
dprintk("RPC: %s: %s: hdrlen %zd rpclen %zd"
" headerp 0x%p base 0x%p lkey 0x%x\n",
__func__, transfertypes[wtype], hdrlen, rpclen,
headerp, base, rdmab_lkey(req->rl_rdmabuf));
/*
* initialize send_iov's - normally only two: rdma chunk header and
* single preregistered RPC header buffer, but if padding is present,
* then use a preregistered (and zeroed) pad buffer between the RPC
* header and any write data. In all non-rdma cases, any following
* data has been copied into the RPC header buffer.
*/
req->rl_send_iov[0].addr = rdmab_addr(req->rl_rdmabuf);
req->rl_send_iov[0].length = hdrlen;
req->rl_send_iov[0].lkey = rdmab_lkey(req->rl_rdmabuf);
req->rl_niovs = 1;
if (rtype == rpcrdma_areadch)
return 0;
req->rl_send_iov[1].addr = rdmab_addr(req->rl_sendbuf);
req->rl_send_iov[1].length = rpclen;
req->rl_send_iov[1].lkey = rdmab_lkey(req->rl_sendbuf);
req->rl_niovs = 2;
return 0;
}
/*
* Chase down a received write or reply chunklist to get length
* RDMA'd by server. See map at rpcrdma_create_chunks()! :-)
*/
static int
rpcrdma_count_chunks(struct rpcrdma_rep *rep, unsigned int max, int wrchunk, __be32 **iptrp)
{
unsigned int i, total_len;
struct rpcrdma_write_chunk *cur_wchunk;
char *base = (char *)rdmab_to_msg(rep->rr_rdmabuf);
i = be32_to_cpu(**iptrp);
if (i > max)
return -1;
cur_wchunk = (struct rpcrdma_write_chunk *) (*iptrp + 1);
total_len = 0;
while (i--) {
struct rpcrdma_segment *seg = &cur_wchunk->wc_target;
ifdebug(FACILITY) {
u64 off;
xdr_decode_hyper((__be32 *)&seg->rs_offset, &off);
dprintk("RPC: %s: chunk %d@0x%llx:0x%x\n",
__func__,
be32_to_cpu(seg->rs_length),
(unsigned long long)off,
be32_to_cpu(seg->rs_handle));
}
total_len += be32_to_cpu(seg->rs_length);
++cur_wchunk;
}
/* check and adjust for properly terminated write chunk */
if (wrchunk) {
__be32 *w = (__be32 *) cur_wchunk;
if (*w++ != xdr_zero)
return -1;
cur_wchunk = (struct rpcrdma_write_chunk *) w;
}
if ((char *)cur_wchunk > base + rep->rr_len)
return -1;
*iptrp = (__be32 *) cur_wchunk;
return total_len;
}
/*
* Scatter inline received data back into provided iov's.
*/
static void
rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len, int pad)
{
int i, npages, curlen, olen;
char *destp;
struct page **ppages;
int page_base;
curlen = rqst->rq_rcv_buf.head[0].iov_len;
if (curlen > copy_len) { /* write chunk header fixup */
curlen = copy_len;
rqst->rq_rcv_buf.head[0].iov_len = curlen;
}
dprintk("RPC: %s: srcp 0x%p len %d hdrlen %d\n",
__func__, srcp, copy_len, curlen);
/* Shift pointer for first receive segment only */
rqst->rq_rcv_buf.head[0].iov_base = srcp;
srcp += curlen;
copy_len -= curlen;
olen = copy_len;
i = 0;
rpcx_to_rdmax(rqst->rq_xprt)->rx_stats.fixup_copy_count += olen;
page_base = rqst->rq_rcv_buf.page_base;
ppages = rqst->rq_rcv_buf.pages + (page_base >> PAGE_SHIFT);
page_base &= ~PAGE_MASK;
if (copy_len && rqst->rq_rcv_buf.page_len) {
npages = PAGE_ALIGN(page_base +
rqst->rq_rcv_buf.page_len) >> PAGE_SHIFT;
for (; i < npages; i++) {
curlen = PAGE_SIZE - page_base;
if (curlen > copy_len)
curlen = copy_len;
dprintk("RPC: %s: page %d"
" srcp 0x%p len %d curlen %d\n",
__func__, i, srcp, copy_len, curlen);
destp = kmap_atomic(ppages[i]);
memcpy(destp + page_base, srcp, curlen);
flush_dcache_page(ppages[i]);
kunmap_atomic(destp);
srcp += curlen;
copy_len -= curlen;
if (copy_len == 0)
break;
page_base = 0;
}
}
if (copy_len && rqst->rq_rcv_buf.tail[0].iov_len) {
curlen = copy_len;
if (curlen > rqst->rq_rcv_buf.tail[0].iov_len)
curlen = rqst->rq_rcv_buf.tail[0].iov_len;
if (rqst->rq_rcv_buf.tail[0].iov_base != srcp)
memmove(rqst->rq_rcv_buf.tail[0].iov_base, srcp, curlen);
dprintk("RPC: %s: tail srcp 0x%p len %d curlen %d\n",
__func__, srcp, copy_len, curlen);
rqst->rq_rcv_buf.tail[0].iov_len = curlen;
copy_len -= curlen; ++i;
} else
rqst->rq_rcv_buf.tail[0].iov_len = 0;
if (pad) {
/* implicit padding on terminal chunk */
unsigned char *p = rqst->rq_rcv_buf.tail[0].iov_base;
while (pad--)
p[rqst->rq_rcv_buf.tail[0].iov_len++] = 0;
}
if (copy_len)
dprintk("RPC: %s: %d bytes in"
" %d extra segments (%d lost)\n",
__func__, olen, i, copy_len);
/* TBD avoid a warning from call_decode() */
rqst->rq_private_buf = rqst->rq_rcv_buf;
}
void
rpcrdma_connect_worker(struct work_struct *work)
{
struct rpcrdma_ep *ep =
container_of(work, struct rpcrdma_ep, rep_connect_worker.work);
struct rpcrdma_xprt *r_xprt =
container_of(ep, struct rpcrdma_xprt, rx_ep);
struct rpc_xprt *xprt = &r_xprt->rx_xprt;
spin_lock_bh(&xprt->transport_lock);
if (++xprt->connect_cookie == 0) /* maintain a reserved value */
++xprt->connect_cookie;
if (ep->rep_connected > 0) {
if (!xprt_test_and_set_connected(xprt))
xprt_wake_pending_tasks(xprt, 0);
} else {
if (xprt_test_and_clear_connected(xprt))
xprt_wake_pending_tasks(xprt, -ENOTCONN);
}
spin_unlock_bh(&xprt->transport_lock);
}
#if defined(CONFIG_SUNRPC_BACKCHANNEL)
/* By convention, backchannel calls arrive via rdma_msg type
* messages, and never populate the chunk lists. This makes
* the RPC/RDMA header small and fixed in size, so it is
* straightforward to check the RPC header's direction field.
*/
static bool
rpcrdma_is_bcall(struct rpcrdma_msg *headerp)
{
__be32 *p = (__be32 *)headerp;
if (headerp->rm_type != rdma_msg)
return false;
if (headerp->rm_body.rm_chunks[0] != xdr_zero)
return false;
if (headerp->rm_body.rm_chunks[1] != xdr_zero)
return false;
if (headerp->rm_body.rm_chunks[2] != xdr_zero)
return false;
/* sanity */
if (p[7] != headerp->rm_xid)
return false;
/* call direction */
if (p[8] != cpu_to_be32(RPC_CALL))
return false;
return true;
}
#endif /* CONFIG_SUNRPC_BACKCHANNEL */
/*
* This function is called when an async event is posted to
* the connection which changes the connection state. All it
* does at this point is mark the connection up/down, the rpc
* timers do the rest.
*/
void
rpcrdma_conn_func(struct rpcrdma_ep *ep)
{
schedule_delayed_work(&ep->rep_connect_worker, 0);
}
/* Process received RPC/RDMA messages.
*
* Errors must result in the RPC task either being awakened, or
* allowed to timeout, to discover the errors at that time.
*/
void
rpcrdma_reply_handler(struct rpcrdma_rep *rep)
{
struct rpcrdma_msg *headerp;
struct rpcrdma_req *req;
struct rpc_rqst *rqst;
struct rpcrdma_xprt *r_xprt = rep->rr_rxprt;
struct rpc_xprt *xprt = &r_xprt->rx_xprt;
__be32 *iptr;
int rdmalen, status;
unsigned long cwnd;
u32 credits;
dprintk("RPC: %s: incoming rep %p\n", __func__, rep);
if (rep->rr_len == RPCRDMA_BAD_LEN)
goto out_badstatus;
if (rep->rr_len < RPCRDMA_HDRLEN_MIN)
goto out_shortreply;
headerp = rdmab_to_msg(rep->rr_rdmabuf);
if (headerp->rm_vers != rpcrdma_version)
goto out_badversion;
#if defined(CONFIG_SUNRPC_BACKCHANNEL)
if (rpcrdma_is_bcall(headerp))
goto out_bcall;
#endif
/* Match incoming rpcrdma_rep to an rpcrdma_req to
* get context for handling any incoming chunks.
*/
spin_lock_bh(&xprt->transport_lock);
rqst = xprt_lookup_rqst(xprt, headerp->rm_xid);
if (!rqst)
goto out_nomatch;
req = rpcr_to_rdmar(rqst);
if (req->rl_reply)
goto out_duplicate;
/* Sanity checking has passed. We are now committed
* to complete this transaction.
*/
list_del_init(&rqst->rq_list);
spin_unlock_bh(&xprt->transport_lock);
dprintk("RPC: %s: reply 0x%p completes request 0x%p\n"
" RPC request 0x%p xid 0x%08x\n",
__func__, rep, req, rqst,
be32_to_cpu(headerp->rm_xid));
/* from here on, the reply is no longer an orphan */
req->rl_reply = rep;
xprt->reestablish_timeout = 0;
/* check for expected message types */
/* The order of some of these tests is important. */
switch (headerp->rm_type) {
case rdma_msg:
/* never expect read chunks */
/* never expect reply chunks (two ways to check) */
/* never expect write chunks without having offered RDMA */
if (headerp->rm_body.rm_chunks[0] != xdr_zero ||
(headerp->rm_body.rm_chunks[1] == xdr_zero &&
headerp->rm_body.rm_chunks[2] != xdr_zero) ||
(headerp->rm_body.rm_chunks[1] != xdr_zero &&
req->rl_nchunks == 0))
goto badheader;
if (headerp->rm_body.rm_chunks[1] != xdr_zero) {
/* count any expected write chunks in read reply */
/* start at write chunk array count */
iptr = &headerp->rm_body.rm_chunks[2];
rdmalen = rpcrdma_count_chunks(rep,
req->rl_nchunks, 1, &iptr);
/* check for validity, and no reply chunk after */
if (rdmalen < 0 || *iptr++ != xdr_zero)
goto badheader;
rep->rr_len -=
((unsigned char *)iptr - (unsigned char *)headerp);
status = rep->rr_len + rdmalen;
r_xprt->rx_stats.total_rdma_reply += rdmalen;
/* special case - last chunk may omit padding */
if (rdmalen &= 3) {
rdmalen = 4 - rdmalen;
status += rdmalen;
}
} else {
/* else ordinary inline */
rdmalen = 0;
iptr = (__be32 *)((unsigned char *)headerp +
RPCRDMA_HDRLEN_MIN);
rep->rr_len -= RPCRDMA_HDRLEN_MIN;
status = rep->rr_len;
}
/* Fix up the rpc results for upper layer */
rpcrdma_inline_fixup(rqst, (char *)iptr, rep->rr_len, rdmalen);
break;
case rdma_nomsg:
/* never expect read or write chunks, always reply chunks */
if (headerp->rm_body.rm_chunks[0] != xdr_zero ||
headerp->rm_body.rm_chunks[1] != xdr_zero ||
headerp->rm_body.rm_chunks[2] != xdr_one ||
req->rl_nchunks == 0)
goto badheader;
iptr = (__be32 *)((unsigned char *)headerp +
RPCRDMA_HDRLEN_MIN);
rdmalen = rpcrdma_count_chunks(rep, req->rl_nchunks, 0, &iptr);
if (rdmalen < 0)
goto badheader;
r_xprt->rx_stats.total_rdma_reply += rdmalen;
/* Reply chunk buffer already is the reply vector - no fixup. */
status = rdmalen;
break;
badheader:
default:
dprintk("%s: invalid rpcrdma reply header (type %d):"
" chunks[012] == %d %d %d"
" expected chunks <= %d\n",
__func__, be32_to_cpu(headerp->rm_type),
headerp->rm_body.rm_chunks[0],
headerp->rm_body.rm_chunks[1],
headerp->rm_body.rm_chunks[2],
req->rl_nchunks);
status = -EIO;
r_xprt->rx_stats.bad_reply_count++;
break;
}
/* Invalidate and flush the data payloads before waking the
* waiting application. This guarantees the memory region is
* properly fenced from the server before the application
* accesses the data. It also ensures proper send flow
* control: waking the next RPC waits until this RPC has
* relinquished all its Send Queue entries.
*/
if (req->rl_nchunks)
r_xprt->rx_ia.ri_ops->ro_unmap_sync(r_xprt, req);
credits = be32_to_cpu(headerp->rm_credit);
if (credits == 0)
credits = 1; /* don't deadlock */
else if (credits > r_xprt->rx_buf.rb_max_requests)
credits = r_xprt->rx_buf.rb_max_requests;
spin_lock_bh(&xprt->transport_lock);
cwnd = xprt->cwnd;
xprt->cwnd = credits << RPC_CWNDSHIFT;
if (xprt->cwnd > cwnd)
xprt_release_rqst_cong(rqst->rq_task);
xprt_complete_rqst(rqst->rq_task, status);
spin_unlock_bh(&xprt->transport_lock);
dprintk("RPC: %s: xprt_complete_rqst(0x%p, 0x%p, %d)\n",
__func__, xprt, rqst, status);
return;
out_badstatus:
rpcrdma_recv_buffer_put(rep);
if (r_xprt->rx_ep.rep_connected == 1) {
r_xprt->rx_ep.rep_connected = -EIO;
rpcrdma_conn_func(&r_xprt->rx_ep);
}
return;
#if defined(CONFIG_SUNRPC_BACKCHANNEL)
out_bcall:
rpcrdma_bc_receive_call(r_xprt, rep);
return;
#endif
out_shortreply:
dprintk("RPC: %s: short/invalid reply\n", __func__);
goto repost;
out_badversion:
dprintk("RPC: %s: invalid version %d\n",
__func__, be32_to_cpu(headerp->rm_vers));
goto repost;
out_nomatch:
spin_unlock_bh(&xprt->transport_lock);
dprintk("RPC: %s: no match for incoming xid 0x%08x len %d\n",
__func__, be32_to_cpu(headerp->rm_xid),
rep->rr_len);
goto repost;
out_duplicate:
spin_unlock_bh(&xprt->transport_lock);
dprintk("RPC: %s: "
"duplicate reply %p to RPC request %p: xid 0x%08x\n",
__func__, rep, req, be32_to_cpu(headerp->rm_xid));
repost:
r_xprt->rx_stats.bad_reply_count++;
if (rpcrdma_ep_post_recv(&r_xprt->rx_ia, &r_xprt->rx_ep, rep))
rpcrdma_recv_buffer_put(rep);
}
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