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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
};
static const char transfertypes[][12] = {
"inline", /* no chunks */
"read list", /* some argument via rdma read */
"*read list", /* entire request via rdma read */
"write list", /* some result via rdma write */
"reply chunk" /* entire reply via rdma write */
};
/* Returns size of largest RPC-over-RDMA header in a Call message
*
* The largest Call header contains a full-size Read list and a
* minimal Reply chunk.
*/
static unsigned int rpcrdma_max_call_header_size(unsigned int maxsegs)
{
unsigned int size;
/* Fixed header fields and list discriminators */
size = RPCRDMA_HDRLEN_MIN;
/* Maximum Read list size */
maxsegs += 2; /* segment for head and tail buffers */
size = maxsegs * sizeof(struct rpcrdma_read_chunk);
/* Minimal Read chunk size */
size += sizeof(__be32); /* segment count */
size += sizeof(struct rpcrdma_segment);
size += sizeof(__be32); /* list discriminator */
dprintk("RPC: %s: max call header size = %u\n",
__func__, size);
return size;
}
/* Returns size of largest RPC-over-RDMA header in a Reply message
*
* There is only one Write list or one Reply chunk per Reply
* message. The larger list is the Write list.
*/
static unsigned int rpcrdma_max_reply_header_size(unsigned int maxsegs)
{
unsigned int size;
/* Fixed header fields and list discriminators */
size = RPCRDMA_HDRLEN_MIN;
/* Maximum Write list size */
maxsegs += 2; /* segment for head and tail buffers */
size = sizeof(__be32); /* segment count */
size += maxsegs * sizeof(struct rpcrdma_segment);
size += sizeof(__be32); /* list discriminator */
dprintk("RPC: %s: max reply header size = %u\n",
__func__, size);
return size;
}
void rpcrdma_set_max_header_sizes(struct rpcrdma_ia *ia,
struct rpcrdma_create_data_internal *cdata,
unsigned int maxsegs)
{
ia->ri_max_inline_write = cdata->inline_wsize -
rpcrdma_max_call_header_size(maxsegs);
ia->ri_max_inline_read = cdata->inline_rsize -
rpcrdma_max_reply_header_size(maxsegs);
}
/* 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 rpcrdma_xprt *r_xprt,
struct rpc_rqst *rqst)
{
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
return rqst->rq_snd_buf.len <= ia->ri_max_inline_write;
}
/* 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 rpcrdma_xprt *r_xprt,
struct rpc_rqst *rqst)
{
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
return rqst->rq_rcv_buf.buflen <= ia->ri_max_inline_read;
}
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;
}
/* Split "vec" on page boundaries into segments. FMR registers pages,
* not a byte range. Other modes coalesce these segments into a single
* MR when they can.
*/
static int
rpcrdma_convert_kvec(struct kvec *vec, struct rpcrdma_mr_seg *seg,
int n, int nsegs)
{
size_t page_offset;
u32 remaining;
char *base;
base = vec->iov_base;
page_offset = offset_in_page(base);
remaining = vec->iov_len;
while (remaining && n < nsegs) {
seg[n].mr_page = NULL;
seg[n].mr_offset = base;
seg[n].mr_len = min_t(u32, PAGE_SIZE - page_offset, remaining);
remaining -= seg[n].mr_len;
base += seg[n].mr_len;
++n;
page_offset = 0;
}
return n;
}
/*
* 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) {
n = rpcrdma_convert_kvec(&xdrbuf->head[0], seg, n, nsegs);
if (n == nsegs)
return -EIO;
}
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;
n = rpcrdma_convert_kvec(&xdrbuf->tail[0], seg, n, nsegs);
if (n == nsegs)
return -EIO;
}
return n;
}
static inline __be32 *
xdr_encode_rdma_segment(__be32 *iptr, struct rpcrdma_mr_seg *seg)
{
*iptr++ = cpu_to_be32(seg->mr_rkey);
*iptr++ = cpu_to_be32(seg->mr_len);
return xdr_encode_hyper(iptr, seg->mr_base);
}
/* XDR-encode the Read list. Supports encoding a list of read
* segments that belong to a single read chunk.
*
* 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
*
* Returns a pointer to the XDR word in the RDMA header following
* the end of the Read list, or an error pointer.
*/
static __be32 *
rpcrdma_encode_read_list(struct rpcrdma_xprt *r_xprt,
struct rpcrdma_req *req, struct rpc_rqst *rqst,
__be32 *iptr, enum rpcrdma_chunktype rtype)
{
struct rpcrdma_mr_seg *seg = req->rl_nextseg;
unsigned int pos;
int n, nsegs;
if (rtype == rpcrdma_noch) {
*iptr++ = xdr_zero; /* item not present */
return iptr;
}
pos = rqst->rq_snd_buf.head[0].iov_len;
if (rtype == rpcrdma_areadch)
pos = 0;
nsegs = rpcrdma_convert_iovs(&rqst->rq_snd_buf, pos, rtype, seg,
RPCRDMA_MAX_SEGS - req->rl_nchunks);
if (nsegs < 0)
return ERR_PTR(nsegs);
do {
n = r_xprt->rx_ia.ri_ops->ro_map(r_xprt, seg, nsegs, false);
if (n <= 0)
return ERR_PTR(n);
*iptr++ = xdr_one; /* item present */
/* All read segments in this chunk
* have the same "position".
*/
*iptr++ = cpu_to_be32(pos);
iptr = xdr_encode_rdma_segment(iptr, seg);
dprintk("RPC: %5u %s: read segment pos %u "
"%d@0x%016llx:0x%08x (%s)\n",
rqst->rq_task->tk_pid, __func__, pos,
seg->mr_len, (unsigned long long)seg->mr_base,
seg->mr_rkey, n < nsegs ? "more" : "last");
r_xprt->rx_stats.read_chunk_count++;
req->rl_nchunks++;
seg += n;
nsegs -= n;
} while (nsegs);
req->rl_nextseg = seg;
/* Finish Read list */
*iptr++ = xdr_zero; /* Next item not present */
return iptr;
}
/* XDR-encode the Write list. Supports encoding a list containing
* one array of plain segments that belong to a single write chunk.
*
* Encoding key for single-list chunks (HLOO = Handle32 Length32 Offset64):
*
* Write chunklist (a list of (one) counted array):
* N elements:
* 1 - N - HLOO - HLOO - ... - HLOO - 0
*
* Returns a pointer to the XDR word in the RDMA header following
* the end of the Write list, or an error pointer.
*/
static __be32 *
rpcrdma_encode_write_list(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
struct rpc_rqst *rqst, __be32 *iptr,
enum rpcrdma_chunktype wtype)
{
struct rpcrdma_mr_seg *seg = req->rl_nextseg;
int n, nsegs, nchunks;
__be32 *segcount;
if (wtype != rpcrdma_writech) {
*iptr++ = xdr_zero; /* no Write list present */
return iptr;
}
nsegs = rpcrdma_convert_iovs(&rqst->rq_rcv_buf,
rqst->rq_rcv_buf.head[0].iov_len,
wtype, seg,
RPCRDMA_MAX_SEGS - req->rl_nchunks);
if (nsegs < 0)
return ERR_PTR(nsegs);
*iptr++ = xdr_one; /* Write list present */
segcount = iptr++; /* save location of segment count */
nchunks = 0;
do {
n = r_xprt->rx_ia.ri_ops->ro_map(r_xprt, seg, nsegs, true);
if (n <= 0)
return ERR_PTR(n);
iptr = xdr_encode_rdma_segment(iptr, seg);
dprintk("RPC: %5u %s: write segment "
"%d@0x016%llx:0x%08x (%s)\n",
rqst->rq_task->tk_pid, __func__,
seg->mr_len, (unsigned long long)seg->mr_base,
seg->mr_rkey, n < nsegs ? "more" : "last");
r_xprt->rx_stats.write_chunk_count++;
r_xprt->rx_stats.total_rdma_request += seg->mr_len;
req->rl_nchunks++;
nchunks++;
seg += n;
nsegs -= n;
} while (nsegs);
req->rl_nextseg = seg;
/* Update count of segments in this Write chunk */
*segcount = cpu_to_be32(nchunks);
/* Finish Write list */
*iptr++ = xdr_zero; /* Next item not present */
return iptr;
}
/* XDR-encode the Reply chunk. Supports encoding an array of plain
* segments that belong to a single write (reply) chunk.
*
* Encoding key for single-list chunks (HLOO = Handle32 Length32 Offset64):
*
* Reply chunk (a counted array):
* N elements:
* 1 - N - HLOO - HLOO - ... - HLOO
*
* Returns a pointer to the XDR word in the RDMA header following
* the end of the Reply chunk, or an error pointer.
*/
static __be32 *
rpcrdma_encode_reply_chunk(struct rpcrdma_xprt *r_xprt,
struct rpcrdma_req *req, struct rpc_rqst *rqst,
__be32 *iptr, enum rpcrdma_chunktype wtype)
{
struct rpcrdma_mr_seg *seg = req->rl_nextseg;
int n, nsegs, nchunks;
__be32 *segcount;
if (wtype != rpcrdma_replych) {
*iptr++ = xdr_zero; /* no Reply chunk present */
return iptr;
}
nsegs = rpcrdma_convert_iovs(&rqst->rq_rcv_buf, 0, wtype, seg,
RPCRDMA_MAX_SEGS - req->rl_nchunks);
if (nsegs < 0)
return ERR_PTR(nsegs);
*iptr++ = xdr_one; /* Reply chunk present */
segcount = iptr++; /* save location of segment count */
nchunks = 0;
do {
n = r_xprt->rx_ia.ri_ops->ro_map(r_xprt, seg, nsegs, true);
if (n <= 0)
return ERR_PTR(n);
iptr = xdr_encode_rdma_segment(iptr, seg);
dprintk("RPC: %5u %s: reply segment "
"%d@0x%016llx:0x%08x (%s)\n",
rqst->rq_task->tk_pid, __func__,
seg->mr_len, (unsigned long long)seg->mr_base,
seg->mr_rkey, n < nsegs ? "more" : "last");
r_xprt->rx_stats.reply_chunk_count++;
r_xprt->rx_stats.total_rdma_request += seg->mr_len;
req->rl_nchunks++;
nchunks++;
seg += n;
nsegs -= n;
} while (nsegs);
req->rl_nextseg = seg;
/* Update count of segments in the Reply chunk */
*segcount = cpu_to_be32(nchunks);
return iptr;
}
/*
* 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.
*
* Prepares up to two IOVs per Call message:
*
* [0] -- RPC RDMA header
* [1] -- the RPC header/data
*
* 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);
enum rpcrdma_chunktype rtype, wtype;
struct rpcrdma_msg *headerp;
ssize_t hdrlen;
size_t rpclen;
__be32 *iptr;
#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
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 If the expected result is under the inline threshold, all ops
* return as inline.
* o Large read ops return data as write chunk(s), header as
* inline.
* o Large non-read ops return as a single reply chunk.
*/
if (rpcrdma_results_inline(r_xprt, rqst))
wtype = rpcrdma_noch;
else if (rqst->rq_rcv_buf.flags & XDRBUF_READ)
wtype = rpcrdma_writech;
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(r_xprt, rqst)) {
rtype = rpcrdma_noch;
rpcrdma_inline_pullup(rqst);
rpclen = rqst->rq_svec[0].iov_len;
} else if (rqst->rq_snd_buf.flags & XDRBUF_WRITE) {
rtype = rpcrdma_readch;
rpclen = rqst->rq_svec[0].iov_len;
rpclen += rpcrdma_tail_pullup(&rqst->rq_snd_buf);
} else {
r_xprt->rx_stats.nomsg_call_count++;
headerp->rm_type = htonl(RDMA_NOMSG);
rtype = rpcrdma_areadch;
rpclen = 0;
}
/* This implementation supports the following combinations
* of chunk lists in one RPC-over-RDMA Call message:
*
* - Read list
* - Write list
* - Reply chunk
* - Read list + Reply chunk
*
* It might not yet support the following combinations:
*
* - Read list + Write list
*
* It does not support the following combinations:
*
* - Write list + Reply chunk
* - Read list + Write list + Reply chunk
*
* This implementation supports only a single chunk in each
* Read or Write list. Thus for example the client cannot
* send a Call message with a Position Zero Read chunk and a
* regular Read chunk at the same time.
*/
req->rl_nchunks = 0;
req->rl_nextseg = req->rl_segments;
iptr = headerp->rm_body.rm_chunks;
iptr = rpcrdma_encode_read_list(r_xprt, req, rqst, iptr, rtype);
if (IS_ERR(iptr))
goto out_unmap;
iptr = rpcrdma_encode_write_list(r_xprt, req, rqst, iptr, wtype);
if (IS_ERR(iptr))
goto out_unmap;
iptr = rpcrdma_encode_reply_chunk(r_xprt, req, rqst, iptr, wtype);
if (IS_ERR(iptr))
goto out_unmap;
hdrlen = (unsigned char *)iptr - (unsigned char *)headerp;
if (hdrlen + rpclen > RPCRDMA_INLINE_WRITE_THRESHOLD(rqst))
goto out_overflow;
dprintk("RPC: %5u %s: %s/%s: hdrlen %zd rpclen %zd\n",
rqst->rq_task->tk_pid, __func__,
transfertypes[rtype], transfertypes[wtype],
hdrlen, rpclen);
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;
out_overflow:
pr_err("rpcrdma: send overflow: hdrlen %zd rpclen %zu %s/%s\n",
hdrlen, rpclen, transfertypes[rtype], transfertypes[wtype]);
/* Terminate this RPC. Chunks registered above will be
* released by xprt_release -> xprt_rmda_free .
*/
return -EIO;
out_unmap:
r_xprt->rx_ia.ri_ops->ro_unmap_safe(r_xprt, req, false);
return PTR_ERR(iptr);
}
/*
* 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, rmerr;
unsigned long cwnd;
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_ERR)
goto out_shortreply;
headerp = rdmab_to_msg(rep->rr_rdmabuf);
#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 %p completes request %p (xid 0x%08x)\n",
__func__, rep, req, be32_to_cpu(headerp->rm_xid));
/* from here on, the reply is no longer an orphan */
req->rl_reply = rep;
xprt->reestablish_timeout = 0;
if (headerp->rm_vers != rpcrdma_version)
goto out_badversion;
/* 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;
case rdma_error:
goto out_rdmaerr;
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;
}
out:
/* 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);
spin_lock_bh(&xprt->transport_lock);
cwnd = xprt->cwnd;
xprt->cwnd = atomic_read(&r_xprt->rx_buf.rb_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
/* If the incoming reply terminated a pending RPC, the next
* RPC call will post a replacement receive buffer as it is
* being marshaled.
*/
out_badversion:
dprintk("RPC: %s: invalid version %d\n",
__func__, be32_to_cpu(headerp->rm_vers));
status = -EIO;
r_xprt->rx_stats.bad_reply_count++;
goto out;
out_rdmaerr:
rmerr = be32_to_cpu(headerp->rm_body.rm_error.rm_err);
switch (rmerr) {
case ERR_VERS:
pr_err("%s: server reports header version error (%u-%u)\n",
__func__,
be32_to_cpu(headerp->rm_body.rm_error.rm_vers_low),
be32_to_cpu(headerp->rm_body.rm_error.rm_vers_high));
break;
case ERR_CHUNK:
pr_err("%s: server reports header decoding error\n",
__func__);
break;
default:
pr_err("%s: server reports unknown error %d\n",
__func__, rmerr);
}
status = -EREMOTEIO;
r_xprt->rx_stats.bad_reply_count++;
goto out;
/* If no pending RPC transaction was matched, post a replacement
* receive buffer before returning.
*/
out_shortreply:
dprintk("RPC: %s: short/invalid reply\n", __func__);
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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