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Subject[ 126/171] libceph: just set SOCK_CLOSED when state changes
Date
3.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Alex Elder <elder@inktank.com>

(cherry picked from commit d65c9e0b9eb43d14ece9dd843506ccba06162ee7)

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@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/ceph/messenger.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -261,8 +261,8 @@ static void ceph_sock_state_change(struc
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__);



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