From: Chuck Lever <chuck.lever@oracle.com>
To: trondmy@hammerspace.com
Cc: linux-nfs@vger.kernel.org, linux-rdma@vger.kernel.org
Subject: [PATCH v3 05/26] xprtrdma: Do not refresh Receive Queue while it is draining
Date: Mon, 19 Apr 2021 14:02:09 -0400 [thread overview]
Message-ID: <161885532997.38598.5957438962258396970.stgit@manet.1015granger.net> (raw)
In-Reply-To: <161885481568.38598.16682844600209775665.stgit@manet.1015granger.net>
Currently the Receive completion handler refreshes the Receive Queue
whenever a successful Receive completion occurs.
On disconnect, xprtrdma drains the Receive Queue. The first few
Receive completions after a disconnect are typically successful,
until the first flushed Receive.
This means the Receive completion handler continues to post more
Receive WRs after the drain sentinel has been posted. The late-
posted Receives flush after the drain sentinel has completed,
leading to a crash later in rpcrdma_xprt_disconnect().
To prevent this crash, xprtrdma has to ensure that the Receive
handler stops posting Receives before ib_drain_rq() posts its
drain sentinel.
Suggested-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
net/sunrpc/xprtrdma/verbs.c | 13 +++++++++++++
net/sunrpc/xprtrdma/xprt_rdma.h | 1 +
2 files changed, 14 insertions(+)
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index ec912cf9c618..d8ed69442219 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -101,6 +101,12 @@ static void rpcrdma_xprt_drain(struct rpcrdma_xprt *r_xprt)
struct rpcrdma_ep *ep = r_xprt->rx_ep;
struct rdma_cm_id *id = ep->re_id;
+ /* Wait for rpcrdma_post_recvs() to leave its critical
+ * section.
+ */
+ if (atomic_inc_return(&ep->re_receiving) > 1)
+ wait_for_completion(&ep->re_done);
+
/* Flush Receives, then wait for deferred Reply work
* to complete.
*/
@@ -414,6 +420,7 @@ static int rpcrdma_ep_create(struct rpcrdma_xprt *r_xprt)
__module_get(THIS_MODULE);
device = id->device;
ep->re_id = id;
+ reinit_completion(&ep->re_done);
ep->re_max_requests = r_xprt->rx_xprt.max_reqs;
ep->re_inline_send = xprt_rdma_max_inline_write;
@@ -1385,6 +1392,9 @@ void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp)
if (!temp)
needed += RPCRDMA_MAX_RECV_BATCH;
+ if (atomic_inc_return(&ep->re_receiving) > 1)
+ goto out;
+
/* fast path: all needed reps can be found on the free list */
wr = NULL;
while (needed) {
@@ -1410,6 +1420,9 @@ void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp)
rc = ib_post_recv(ep->re_id->qp, wr,
(const struct ib_recv_wr **)&bad_wr);
+ if (atomic_dec_return(&ep->re_receiving) > 0)
+ complete(&ep->re_done);
+
out:
trace_xprtrdma_post_recvs(r_xprt, count, rc);
if (rc) {
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index fe3be985e239..31404326f29f 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -83,6 +83,7 @@ struct rpcrdma_ep {
unsigned int re_max_inline_recv;
int re_async_rc;
int re_connect_status;
+ atomic_t re_receiving;
atomic_t re_force_disconnect;
struct ib_qp_init_attr re_attr;
wait_queue_head_t re_connect_wait;
next prev parent reply other threads:[~2021-04-19 18:02 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-19 18:01 [PATCH v3 00/26] NFS/RDMA client patches for next Chuck Lever
2021-04-19 18:01 ` [PATCH v3 01/26] SUNRPC: Move fault injection call sites Chuck Lever
2021-04-19 18:05 ` Chuck Lever III
2021-04-19 18:01 ` [PATCH v3 02/26] SUNRPC: Remove trace_xprt_transmit_queued Chuck Lever
2021-04-19 18:01 ` [PATCH v3 03/26] SUNRPC: Add tracepoint that fires when an RPC is retransmitted Chuck Lever
2021-04-19 18:02 ` [PATCH v3 04/26] xprtrdma: Avoid Receive Queue wrapping Chuck Lever
2021-04-19 18:02 ` Chuck Lever [this message]
2021-04-19 18:02 ` [PATCH v3 06/26] xprtrdma: Put flushed Receives on free list instead of destroying them Chuck Lever
2021-04-19 18:02 ` [PATCH v3 07/26] xprtrdma: Improve locking around rpcrdma_rep destruction Chuck Lever
2021-04-23 21:06 ` Trond Myklebust
2021-04-24 17:39 ` Chuck Lever III
2021-04-24 17:59 ` Trond Myklebust
2021-04-19 18:02 ` [PATCH v3 08/26] xprtrdma: Improve commentary around rpcrdma_reps_unmap() Chuck Lever
2021-04-19 18:02 ` [PATCH v3 09/26] xprtrdma: Improve locking around rpcrdma_rep creation Chuck Lever
2021-04-19 18:02 ` [PATCH v3 10/26] xprtrdma: Fix cwnd update ordering Chuck Lever
2021-04-19 18:02 ` [PATCH v3 11/26] xprtrdma: Delete rpcrdma_recv_buffer_put() Chuck Lever
2021-04-19 18:02 ` [PATCH v3 12/26] xprtrdma: rpcrdma_mr_pop() already does list_del_init() Chuck Lever
2021-04-19 18:03 ` [PATCH v3 13/26] xprtrdma: Rename frwr_release_mr() Chuck Lever
2021-04-19 18:03 ` [PATCH v3 14/26] xprtrdma: Clarify use of barrier in frwr_wc_localinv_done() Chuck Lever
2021-04-19 18:03 ` [PATCH v3 15/26] xprtrdma: Do not recycle MR after FastReg/LocalInv flushes Chuck Lever
2021-04-25 14:19 ` Dan Aloni
2021-04-25 16:21 ` Chuck Lever III
2021-04-25 17:00 ` Dan Aloni
2021-04-19 18:03 ` [PATCH v3 16/26] xprtrdma: Do not wake RPC consumer on a failed LocalInv Chuck Lever
2021-04-19 18:03 ` [PATCH v3 17/26] xprtrdma: Avoid Send Queue wrapping Chuck Lever
2021-04-19 18:03 ` [PATCH v3 18/26] xprtrdma: Add tracepoints showing FastReg WRs and remote invalidation Chuck Lever
2021-04-19 18:03 ` [PATCH v3 19/26] xprtrdma: Add an rpcrdma_mr_completion_class Chuck Lever
2021-04-19 18:03 ` [PATCH v3 20/26] xprtrdma: Don't display r_xprt memory addresses in tracepoints Chuck Lever
2021-04-19 18:03 ` [PATCH v3 21/26] xprtrdma: Remove the RPC/RDMA QP event handler Chuck Lever
2021-04-19 18:03 ` [PATCH v3 22/26] xprtrdma: Move fr_cid to struct rpcrdma_mr Chuck Lever
2021-04-19 18:04 ` [PATCH v3 23/26] xprtrdma: Move cqe " Chuck Lever
2021-04-19 18:04 ` [PATCH v3 24/26] xprtrdma: Move fr_linv_done field " Chuck Lever
2021-04-19 18:04 ` [PATCH v3 25/26] xprtrdma: Move the Work Request union " Chuck Lever
2021-04-19 18:04 ` [PATCH v3 26/26] xprtrdma: Move fr_mr field " Chuck Lever
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