From 0dcfeb7e3c8695c5aa3677dda8efb9bef2e7e64d Mon Sep 17 00:00:00 2001 From: Stefan Richter Date: Wed, 22 Oct 2008 00:28:36 +0200 Subject: firewire: fw-sbp2: delay first login to avoid retries This optimizes firewire-sbp2's device probe for the case that the local node and the SBP-2 node were discovered at the same time. In this case, fw-core's bus management work and fw-sbp2's login and SCSI probe work are scheduled in parallel (in the globally shared workqueue and in fw-sbp2's workqueue, respectively). The bus reset from fw-core may then disturb and extremely delay the login and SCSI probe because the latter fails with several command timeouts and retries and has to be retried from scratch. We avoid this particular situation of sbp2_login() and fw_card_bm_work() running in parallel by delaying the first sbp2_login() a little bit. This is meant to be a short-term fix for https://bugzilla.redhat.com/show_bug.cgi?id=466679. In the long run, the SCSI probe, i.e. fw-sbp2's call of __scsi_add_device(), should be parallelized with sbp2_reconnect(). Problem reported and fix tested and confirmed by Alex Kanavin. Signed-off-by: Stefan Richter --- drivers/firewire/fw-sbp2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/firewire/fw-sbp2.c') diff --git a/drivers/firewire/fw-sbp2.c b/drivers/firewire/fw-sbp2.c index ef0b9b419c27..17bf0e1468e6 100644 --- a/drivers/firewire/fw-sbp2.c +++ b/drivers/firewire/fw-sbp2.c @@ -1147,7 +1147,7 @@ static int sbp2_probe(struct device *dev) /* Do the login in a workqueue so we can easily reschedule retries. */ list_for_each_entry(lu, &tgt->lu_list, link) - sbp2_queue_work(lu, 0); + sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5)); return 0; fail_tgt_put: -- cgit v1.2.2 From cd1f70fdb4823c97328a1f151f328eb36fafd579 Mon Sep 17 00:00:00 2001 From: Jay Fenlason Date: Fri, 24 Oct 2008 15:26:20 -0400 Subject: firewire: fw-sbp2: fix races 1: There is a small race between queue_delayed_work() and its corresponding kref_get(). Do the kref_get first, and _put it again if the queue_delayed_work() failed, so there is no chance of the kref going to zero while the work is scheduled. 2: An SBP2_LOGOUT_REQUEST could be sent out with a login_id full of garbage. Initialize it to an invalid value so we can tell if we ever got a valid login_id. 3: The node ID and generation may have changed but the new values may not yet have been recorded in lu and tgt when the final logout is attempted. Use the latest values from the device in sbp2_release_target(). Signed-off-by: Jay Fenlason Signed-off-by: Stefan Richter --- drivers/firewire/fw-sbp2.c | 36 ++++++++++++++++++++++++++---------- 1 file changed, 26 insertions(+), 10 deletions(-) (limited to 'drivers/firewire/fw-sbp2.c') diff --git a/drivers/firewire/fw-sbp2.c b/drivers/firewire/fw-sbp2.c index 17bf0e1468e6..d334cac5e1fc 100644 --- a/drivers/firewire/fw-sbp2.c +++ b/drivers/firewire/fw-sbp2.c @@ -173,6 +173,9 @@ struct sbp2_target { int blocked; /* ditto */ }; +/* Impossible login_id, to detect logout attempt before successful login */ +#define INVALID_LOGIN_ID 0x10000 + /* * Per section 7.4.8 of the SBP-2 spec, a mgt_ORB_timeout value can be * provided in the config rom. Most devices do provide a value, which @@ -788,9 +791,20 @@ static void sbp2_release_target(struct kref *kref) scsi_remove_device(sdev); scsi_device_put(sdev); } - sbp2_send_management_orb(lu, tgt->node_id, lu->generation, - SBP2_LOGOUT_REQUEST, lu->login_id, NULL); - + if (lu->login_id != INVALID_LOGIN_ID) { + int generation, node_id; + /* + * tgt->node_id may be obsolete here if we failed + * during initial login or after a bus reset where + * the topology changed. + */ + generation = device->generation; + smp_rmb(); /* node_id vs. generation */ + node_id = device->node_id; + sbp2_send_management_orb(lu, node_id, generation, + SBP2_LOGOUT_REQUEST, + lu->login_id, NULL); + } fw_core_remove_address_handler(&lu->address_handler); list_del(&lu->link); kfree(lu); @@ -805,19 +819,20 @@ static void sbp2_release_target(struct kref *kref) static struct workqueue_struct *sbp2_wq; +static void sbp2_target_put(struct sbp2_target *tgt) +{ + kref_put(&tgt->kref, sbp2_release_target); +} + /* * Always get the target's kref when scheduling work on one its units. * Each workqueue job is responsible to call sbp2_target_put() upon return. */ static void sbp2_queue_work(struct sbp2_logical_unit *lu, unsigned long delay) { - if (queue_delayed_work(sbp2_wq, &lu->work, delay)) - kref_get(&lu->tgt->kref); -} - -static void sbp2_target_put(struct sbp2_target *tgt) -{ - kref_put(&tgt->kref, sbp2_release_target); + kref_get(&lu->tgt->kref); + if (!queue_delayed_work(sbp2_wq, &lu->work, delay)) + sbp2_target_put(lu->tgt); } /* @@ -978,6 +993,7 @@ static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry) lu->tgt = tgt; lu->lun = lun_entry & 0xffff; + lu->login_id = INVALID_LOGIN_ID; lu->retries = 0; lu->has_sdev = false; lu->blocked = false; -- cgit v1.2.2 From a1f64819fe9f136c98d572794a35a7e377c951ef Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Thu, 30 Oct 2008 01:41:56 +0100 Subject: firewire: struct device - replace bus_id with dev_name(), dev_set_name() Acked-by: Greg Kroah-Hartman Signed-off-by: Kay Sievers Signed-off-by: Stefan Richter --- drivers/firewire/fw-sbp2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/firewire/fw-sbp2.c') diff --git a/drivers/firewire/fw-sbp2.c b/drivers/firewire/fw-sbp2.c index d334cac5e1fc..97df6dac3a82 100644 --- a/drivers/firewire/fw-sbp2.c +++ b/drivers/firewire/fw-sbp2.c @@ -1135,7 +1135,7 @@ static int sbp2_probe(struct device *dev) tgt->unit = unit; kref_init(&tgt->kref); INIT_LIST_HEAD(&tgt->lu_list); - tgt->bus_id = unit->device.bus_id; + tgt->bus_id = dev_name(&unit->device); tgt->guid = (u64)device->config_rom[3] << 32 | device->config_rom[4]; if (fw_device_enable_phys_dma(device) < 0) -- cgit v1.2.2