From 00650931e52e97fe64096bec167f5a6780dfd94a Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@inktank.com>
Date: Fri, 20 Jul 2012 15:33:04 -0700
Subject: [PATCH] libceph: move msgr clear_standby under con mutex protection
Avoid dropping and retaking con->mutex in the ceph_con_send() case by
leaving locking up to the caller.
Signed-off-by: Sage Weil <sage@inktank.com>
---
net/ceph/messenger.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 9aaf539942ac..1a3cb4a4f180 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -2441,12 +2441,10 @@ static void clear_standby(struct ceph_connection *con)
{
/* come back from STANDBY? */
if (test_and_clear_bit(STANDBY, &con->state)) {
- mutex_lock(&con->mutex);
dout("clear_standby %p and ++connect_seq\n", con);
con->connect_seq++;
WARN_ON(test_bit(WRITE_PENDING, &con->flags));
WARN_ON(test_bit(KEEPALIVE_PENDING, &con->flags));
- mutex_unlock(&con->mutex);
}
}
@@ -2483,11 +2481,12 @@ void ceph_con_send(struct ceph_connection *con, struct ceph_msg *msg)
le32_to_cpu(msg->hdr.front_len),
le32_to_cpu(msg->hdr.middle_len),
le32_to_cpu(msg->hdr.data_len));
+
+ clear_standby(con);
mutex_unlock(&con->mutex);
/* if there wasn't anything waiting to send before, queue
* new work */
- clear_standby(con);
if (test_and_set_bit(WRITE_PENDING, &con->flags) == 0)
queue_con(con);
}
@@ -2574,7 +2573,9 @@ void ceph_msg_revoke_incoming(struct ceph_msg *msg)
void ceph_con_keepalive(struct ceph_connection *con)
{
dout("con_keepalive %p\n", con);
+ mutex_lock(&con->mutex);
clear_standby(con);
+ mutex_unlock(&con->mutex);
if (test_and_set_bit(KEEPALIVE_PENDING, &con->flags) == 0 &&
test_and_set_bit(WRITE_PENDING, &con->flags) == 0)
queue_con(con);
--
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