From 1b9c12ba2fdf802a23630f70eddb0e821296634e Mon Sep 17 00:00:00 2001 From: Stefan Richter Date: Sat, 26 Jan 2008 17:43:23 +0100 Subject: [PATCH] firewire: fw-sbp2: fix logout before login retry This fixes a "can't recognize device" kind of bug. If the SCSI INQUIRY failed and hence __scsi_add_device failed due to a bus reset, we tried a logout and then waited for the already scheduled login work to happen. So far so good, but the generation used for the logout was outdated, hence the logout never reached the target. The target might therefore deny the subsequent relogin attempt, which would also leave the target inaccessible. Therefore fetch a fresh device->generation for the logout. Use memory barriers to prevent our plan being foiled by compiler or hardware optimizations. Signed-off-by: Stefan Richter --- drivers/firewire/fw-sbp2.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/firewire/fw-sbp2.c b/drivers/firewire/fw-sbp2.c index f2a9a33b47a1..a15e3c7d21d3 100644 --- a/drivers/firewire/fw-sbp2.c +++ b/drivers/firewire/fw-sbp2.c @@ -716,7 +716,11 @@ static void sbp2_login(struct work_struct *work) sdev = __scsi_add_device(shost, 0, 0, scsilun_to_int(&eight_bytes_lun), lu); if (IS_ERR(sdev)) { - sbp2_send_management_orb(lu, node_id, generation, + smp_rmb(); /* generation may have changed */ + generation = device->generation; + smp_rmb(); /* node_id must not be older than generation */ + + sbp2_send_management_orb(lu, device->node_id, generation, SBP2_LOGOUT_REQUEST, lu->login_id, NULL); /* * Set this back to sbp2_login so we fall back and