]> git.karo-electronics.de Git - linux-beck.git/commit
RDS: fix rds-ping spinlock recursion
authorjeff.liu <jeff.liu@oracle.com>
Mon, 8 Oct 2012 18:57:27 +0000 (18:57 +0000)
committerDavid S. Miller <davem@davemloft.net>
Tue, 9 Oct 2012 17:57:23 +0000 (13:57 -0400)
commit5175a5e76bbdf20a614fb47ce7a38f0f39e70226
tree83a7113b1b7fd3f6d7b2222d66884da291afe328
parent4085a7f0a09c73ef3e9de113c9f04d78c79be645
RDS: fix rds-ping spinlock recursion

This is the revised patch for fixing rds-ping spinlock recursion
according to Venkat's suggestions.

RDS ping/pong over TCP feature has been broken for years(2.6.39 to
3.6.0) since we have to set TCP cork and call kernel_sendmsg() between
ping/pong which both need to lock "struct sock *sk". However, this
lock has already been hold before rds_tcp_data_ready() callback is
triggerred. As a result, we always facing spinlock resursion which
would resulting in system panic.

Given that RDS ping is only used to test the connectivity and not for
serious performance measurements, we can queue the pong transmit to
rds_wq as a delayed response.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
CC: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
CC: David S. Miller <davem@davemloft.net>
CC: James Morris <james.l.morris@oracle.com>
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/rds/send.c