From: Alex Elder Date: Thu, 21 Jun 2012 02:53:53 +0000 (-0500) Subject: libceph: don't touch con state in con_close_socket() X-Git-Tag: v3.6-rc1~36^2~90 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=456ea46865787283088b23a8a7f69244513b95f0;p=platform%2Fkernel%2Flinux-exynos.git libceph: don't touch con state in con_close_socket() In con_close_socket(), a connection's SOCK_CLOSED flag gets set and then cleared while its shutdown method is called and its reference gets dropped. Previously, that flag got set only if it had not already been set, so setting it in con_close_socket() might have prevented additional processing being done on a socket being shut down. We no longer set SOCK_CLOSED in the socket event routine conditionally, so setting that bit here no longer provides whatever benefit it might have provided before. A race condition could still leave the SOCK_CLOSED bit set even after we've issued the call to con_close_socket(), so we still clear that bit after shutting the socket down. Add a comment explaining the reason for this. Signed-off-by: Alex Elder Reviewed-by: Sage Weil --- diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index cebef85..cfcca1f 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -392,10 +392,16 @@ static int con_close_socket(struct ceph_connection *con) dout("con_close_socket on %p sock %p\n", con, con->sock); if (!con->sock) return 0; - set_bit(SOCK_CLOSED, &con->flags); rc = con->sock->ops->shutdown(con->sock, SHUT_RDWR); sock_release(con->sock); con->sock = NULL; + + /* + * Forcibly clear the SOCK_CLOSE flag. It gets set + * independent of the connection mutex, and we could have + * received a socket close event before we had the chance to + * shut the socket down. + */ clear_bit(SOCK_CLOSED, &con->flags); con_sock_state_closed(con); return rc;