[PATCH 107/270] libceph: just set SOCK_CLOSED when state changes
Herton Ronaldo Krzesinski
herton.krzesinski at canonical.com
Mon Nov 26 16:56:37 UTC 2012
3.5.7u1 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Alex Elder <elder at inktank.com>
commit d65c9e0b9eb43d14ece9dd843506ccba06162ee7 upstream.
When a TCP_CLOSE or TCP_CLOSE_WAIT event occurs, the SOCK_CLOSED
connection flag bit is set, and if it had not been previously set
queue_con() is called to ensure con_work() will get a chance to
handle the changed state.
con_work() atomically checks--and if set, clears--the SOCK_CLOSED
bit if it was set. This means that even if the bit were set
repeatedly, the related processing in con_work() only gets called
once per transition of the bit from 0 to 1.
What's important then is that we ensure con_work() gets called *at
least* once when a socket close event occurs, not that it gets
called *exactly* once.
The work queue mechanism already takes care of queueing work
only if it is not already queued, so there's no need for us
to call queue_con() conditionally.
So this patch just makes it so the SOCK_CLOSED flag gets set
unconditionally in ceph_sock_state_change().
Signed-off-by: Alex Elder <elder at inktank.com>
Reviewed-by: Sage Weil <sage at inktank.com>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
---
net/ceph/messenger.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 5bd243e..cd1aaa8 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -261,8 +261,8 @@ static void ceph_sock_state_change(struct sock *sk)
case TCP_CLOSE_WAIT:
dout("%s TCP_CLOSE_WAIT\n", __func__);
con_sock_state_closing(con);
- if (!test_and_set_bit(SOCK_CLOSED, &con->flags))
- queue_con(con);
+ set_bit(SOCK_CLOSED, &con->flags);
+ queue_con(con);
break;
case TCP_ESTABLISHED:
dout("%s TCP_ESTABLISHED\n", __func__);
--
1.7.9.5
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