From: Chuck Lever <chuck.lever@oracle.com>
To: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org
Subject: [PATCH v1 4/8] xprtrdma: Improve locking around rpcrdma_rep destruction
Date: Wed, 31 Mar 2021 15:36:23 -0400 [thread overview]
Message-ID: <161721938342.515226.14847295549827213112.stgit@manet.1015granger.net> (raw)
In-Reply-To: <161721926778.515226.9805598788670386587.stgit@manet.1015granger.net>
Currently rpcrdma_reps_destroy() assumes that, at transport
tear-down, the content of the rb_free_reps list is the same as the
content of the rb_all_reps list. Although that is usually true,
using the rb_all_reps list should be more reliable because of
the way it's managed. And, rpcrdma_reps_unmap() uses rb_all_reps;
these two should both traverse the "all" list.
Instead, ensure that all rpcrdma_reps are always destroyed whether
they are on the rep free list or not. Also ensure that rpcrdma_rep
destruction logic is protected by the rb_lock.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
net/sunrpc/xprtrdma/verbs.c | 31 ++++++++++++++++++++++++-------
1 file changed, 24 insertions(+), 7 deletions(-)
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 92af272f9cc9..fe250d554695 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -1000,16 +1000,23 @@ struct rpcrdma_rep *rpcrdma_rep_create(struct rpcrdma_xprt *r_xprt,
return NULL;
}
-/* No locking needed here. This function is invoked only by the
- * Receive completion handler, or during transport shutdown.
- */
-static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep)
+static void rpcrdma_rep_destroy_locked(struct rpcrdma_rep *rep)
{
- list_del(&rep->rr_all);
rpcrdma_regbuf_free(rep->rr_rdmabuf);
kfree(rep);
}
+static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep)
+{
+ struct rpcrdma_buffer *buf = &rep->rr_rxprt->rx_buf;
+
+ spin_lock(&buf->rb_lock);
+ list_del(&rep->rr_all);
+ spin_unlock(&buf->rb_lock);
+
+ rpcrdma_rep_destroy_locked(rep);
+}
+
static struct rpcrdma_rep *rpcrdma_rep_get_locked(struct rpcrdma_buffer *buf)
{
struct llist_node *node;
@@ -1042,8 +1049,18 @@ static void rpcrdma_reps_destroy(struct rpcrdma_buffer *buf)
{
struct rpcrdma_rep *rep;
- while ((rep = rpcrdma_rep_get_locked(buf)) != NULL)
- rpcrdma_rep_destroy(rep);
+ spin_lock(&buf->rb_lock);
+ while ((rep = list_first_entry_or_null(&buf->rb_all_reps,
+ struct rpcrdma_rep,
+ rr_all)) != NULL) {
+ list_del(&rep->rr_all);
+ spin_unlock(&buf->rb_lock);
+
+ rpcrdma_rep_destroy_locked(rep);
+
+ spin_lock(&buf->rb_lock);
+ }
+ spin_unlock(&buf->rb_lock);
}
/**
next prev parent reply other threads:[~2021-03-31 19:37 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-31 19:35 [PATCH v1 0/8] xprtrdma Receive Queue fixes Chuck Lever
2021-03-31 19:36 ` [PATCH v1 1/8] xprtrdma: Avoid Receive Queue wrapping Chuck Lever
2021-03-31 20:05 ` Tom Talpey
2021-03-31 19:36 ` [PATCH v1 2/8] xprtrdma: Do not post Receives after disconnect Chuck Lever
2021-03-31 19:59 ` Tom Talpey
2021-03-31 20:31 ` Chuck Lever
2021-03-31 21:22 ` Tom Talpey
2021-04-01 16:56 ` Chuck Lever
2021-03-31 19:36 ` [PATCH v1 3/8] xprtrdma: Put flushed Receives on free list instead of destroying them Chuck Lever
2021-03-31 20:02 ` Tom Talpey
2021-03-31 19:36 ` Chuck Lever [this message]
2021-03-31 19:36 ` [PATCH v1 5/8] xprtrdma: Improve commentary around rpcrdma_reps_unmap() Chuck Lever
2021-03-31 19:36 ` [PATCH v1 6/8] xprtrdma: Improve locking around rpcrdma_rep creation Chuck Lever
2021-03-31 19:36 ` [PATCH v1 7/8] xprtrdma: Fix cwnd update ordering Chuck Lever
2021-03-31 19:36 ` [PATCH v1 8/8] xprtrdma: Delete rpcrdma_recv_buffer_put() Chuck Lever
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