[PATCH 3.12 34/72] Fix regression in NFSRDMA server

From: Jiri Slaby
Date: Mon Nov 23 2015 - 08:20:59 EST


From: Tom Tucker <tom@xxxxxx>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

commit 7e4359e2611f95a97037e2b6905eab52f28afbeb upstream.

The server regression was caused by the addition of rq_next_page
(afc59400d6c65bad66d4ad0b2daf879cbff8e23e). There were a few places that
were missed with the update of the rq_respages array.

Signed-off-by: Tom Tucker <tom@xxxxxx>
Tested-by: Steve Wise <swise@xxxxxx>
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 12 ++++--------
net/sunrpc/xprtrdma/svc_rdma_sendto.c | 1 +
2 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
index 0ce75524ed21..8d904e4eef15 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -90,6 +90,7 @@ static void rdma_build_arg_xdr(struct svc_rqst *rqstp,
sge_no++;
}
rqstp->rq_respages = &rqstp->rq_pages[sge_no];
+ rqstp->rq_next_page = rqstp->rq_respages + 1;

/* We should never run out of SGE because the limit is defined to
* support the max allowed RPC data length
@@ -169,6 +170,7 @@ static int map_read_chunks(struct svcxprt_rdma *xprt,
*/
head->arg.pages[page_no] = rqstp->rq_arg.pages[page_no];
rqstp->rq_respages = &rqstp->rq_arg.pages[page_no+1];
+ rqstp->rq_next_page = rqstp->rq_respages + 1;

byte_count -= sge_bytes;
ch_bytes -= sge_bytes;
@@ -276,6 +278,7 @@ static int fast_reg_read_chunks(struct svcxprt_rdma *xprt,

/* rq_respages points one past arg pages */
rqstp->rq_respages = &rqstp->rq_arg.pages[page_no];
+ rqstp->rq_next_page = rqstp->rq_respages + 1;

/* Create the reply and chunk maps */
offset = 0;
@@ -520,13 +523,6 @@ next_sge:
for (ch_no = 0; &rqstp->rq_pages[ch_no] < rqstp->rq_respages; ch_no++)
rqstp->rq_pages[ch_no] = NULL;

- /*
- * Detach res pages. If svc_release sees any it will attempt to
- * put them.
- */
- while (rqstp->rq_next_page != rqstp->rq_respages)
- *(--rqstp->rq_next_page) = NULL;
-
return err;
}

@@ -550,7 +546,7 @@ static int rdma_read_complete(struct svc_rqst *rqstp,

/* rq_respages starts after the last arg page */
rqstp->rq_respages = &rqstp->rq_arg.pages[page_no];
- rqstp->rq_next_page = &rqstp->rq_arg.pages[page_no];
+ rqstp->rq_next_page = rqstp->rq_respages + 1;

/* Rebuild rq_arg head and tail. */
rqstp->rq_arg.head[0] = head->arg.head[0];
diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
index c1d124dc772b..11e90f8c0fc5 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
@@ -625,6 +625,7 @@ static int send_reply(struct svcxprt_rdma *rdma,
if (page_no+1 >= sge_no)
ctxt->sge[page_no+1].length = 0;
}
+ rqstp->rq_next_page = rqstp->rq_respages + 1;
BUG_ON(sge_no > rdma->sc_max_sge);
memset(&send_wr, 0, sizeof send_wr);
ctxt->wr_op = IB_WR_SEND;
--
2.6.3

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