From: Trond Myklebust <trondmy@gmail.com>
To: linux-nfs@vger.kernel.org
Subject: [PATCH 2/3] SUNRPC: Skip zero-refcount transports
Date: Tue, 16 Jul 2019 16:04:32 -0400 [thread overview]
Message-ID: <20190716200433.38758-2-trond.myklebust@hammerspace.com> (raw)
In-Reply-To: <20190716200433.38758-1-trond.myklebust@hammerspace.com>
When looking for the next transport to use for an RPC call, skip those
that are in the process of being destroyed and that have a zero refcount.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
net/sunrpc/xprtmultipath.c | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)
diff --git a/net/sunrpc/xprtmultipath.c b/net/sunrpc/xprtmultipath.c
index 5df4e7adedf0..c12778e1235e 100644
--- a/net/sunrpc/xprtmultipath.c
+++ b/net/sunrpc/xprtmultipath.c
@@ -193,10 +193,22 @@ void xprt_iter_default_rewind(struct rpc_xprt_iter *xpi)
WRITE_ONCE(xpi->xpi_cursor, NULL);
}
+static
+bool xprt_is_active(const struct rpc_xprt *xprt)
+{
+ return kref_read(&xprt->kref) != 0;
+}
+
static
struct rpc_xprt *xprt_switch_find_first_entry(struct list_head *head)
{
- return list_first_or_null_rcu(head, struct rpc_xprt, xprt_switch);
+ struct rpc_xprt *pos;
+
+ list_for_each_entry_rcu(pos, head, xprt_switch) {
+ if (xprt_is_active(pos))
+ return pos;
+ }
+ return NULL;
}
static
@@ -214,9 +226,12 @@ struct rpc_xprt *xprt_switch_find_current_entry(struct list_head *head,
const struct rpc_xprt *cur)
{
struct rpc_xprt *pos;
+ bool found = false;
list_for_each_entry_rcu(pos, head, xprt_switch) {
if (cur == pos)
+ found = true;
+ if (found && xprt_is_active(pos))
return pos;
}
return NULL;
@@ -261,9 +276,12 @@ struct rpc_xprt *xprt_switch_find_next_entry(struct list_head *head,
const struct rpc_xprt *cur)
{
struct rpc_xprt *pos, *prev = NULL;
+ bool found = false;
list_for_each_entry_rcu(pos, head, xprt_switch) {
if (cur == prev)
+ found = true;
+ if (found && xprt_is_active(pos))
return pos;
prev = pos;
}
--
2.21.0
next prev parent reply other threads:[~2019-07-16 20:06 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-16 20:04 [PATCH 1/3] SUNRPC: Replace division by multiplication in calculation of queue length Trond Myklebust
2019-07-16 20:04 ` Trond Myklebust [this message]
2019-07-16 20:04 ` [PATCH 3/3] SUNRPC: Fix a hang in xprt_switch_set_next_cursor() Trond Myklebust
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