From 5d7f6d1071eadd020edb2cf366d358e0f6d0a0f9 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Thu, 12 Jan 2012 11:47:24 -0800 Subject: [PATCH] [SCSI] libsas: fix sas_unregister_ports vs sas_drain_work We need to hold drain_mutex across the unregistration as port down events queue device removal as chained events, so we need to make sure no other drainers are active. [ 1118.673968] WARNING: at kernel/workqueue.c:996 __queue_work+0x11a/0x326() [ 1118.681982] Hardware name: S2600CP [ 1118.686193] Modules linked in: isci(-) libsas scsi_transport_sas nls_utf8 ipv6 uinput sg iTCO_wdt iTCO_vendor_support i2c_i801 i2c_core ioatdma dca sd_mod sr_mod cdrom ahci libahci libata [last unloaded: scsi_transport_sas] [ 1118.709893] Pid: 6831, comm: rmmod Not tainted 3.2.0-isci+ #1 [ 1118.716727] Call Trace: [ 1118.719867] [] warn_slowpath_common+0x85/0x9d [ 1118.727000] [] warn_slowpath_null+0x1a/0x1c [ 1118.733942] [] __queue_work+0x11a/0x326 [ 1118.740481] [] queue_work_on+0x1b/0x22 [ 1118.746925] [] queue_work+0x37/0x3e [ 1118.753105] [] ? sas_discover_event+0x55/0x82 [libsas] [ 1118.761094] [] scsi_queue_work+0x42/0x44 [ 1118.767717] [] sas_discover_event+0x69/0x82 [libsas] [ 1118.775509] [] sas_unregister_dev+0xc3/0xcc [libsas] [ 1118.783319] [] sas_unregister_domain_devices+0x4a/0xc8 [libsas] [ 1118.792731] [] sas_deform_port+0x60/0x1a6 [libsas] [ 1118.800339] [] sas_unregister_ports+0x33/0x44 [libsas] [ 1118.808342] [] sas_unregister_ha+0x41/0x6b [libsas] [ 1118.816055] [] isci_unregister+0x22/0x4d [isci] [ 1118.823384] [] isci_pci_remove+0x2e/0x60 [isci] Reported-by: Jacek Danecki Signed-off-by: Dan Williams Signed-off-by: James Bottomley --- drivers/scsi/libsas/sas_event.c | 19 +++++++++++++------ drivers/scsi/libsas/sas_init.c | 18 +++++++++++------- drivers/scsi/libsas/sas_internal.h | 1 + 3 files changed, 25 insertions(+), 13 deletions(-) diff --git a/drivers/scsi/libsas/sas_event.c b/drivers/scsi/libsas/sas_event.c index dbfaceeea0f7..16639bbae629 100644 --- a/drivers/scsi/libsas/sas_event.c +++ b/drivers/scsi/libsas/sas_event.c @@ -51,15 +51,11 @@ static void sas_queue_event(int event, unsigned long *pending, } } -int sas_drain_work(struct sas_ha_struct *ha) + +void __sas_drain_work(struct sas_ha_struct *ha) { struct workqueue_struct *wq = ha->core.shost->work_q; struct work_struct *w, *_w; - int err; - - err = mutex_lock_interruptible(&ha->drain_mutex); - if (err) - return err; set_bit(SAS_HA_DRAINING, &ha->state); /* flush submitters */ @@ -75,6 +71,17 @@ int sas_drain_work(struct sas_ha_struct *ha) sas_queue_work(ha, w); } spin_unlock_irq(&ha->state_lock); +} + +int sas_drain_work(struct sas_ha_struct *ha) +{ + int err; + + err = mutex_lock_interruptible(&ha->drain_mutex); + if (err) + return err; + if (test_bit(SAS_HA_REGISTERED, &ha->state)) + __sas_drain_work(ha); mutex_unlock(&ha->drain_mutex); return 0; diff --git a/drivers/scsi/libsas/sas_init.c b/drivers/scsi/libsas/sas_init.c index dc93e1181469..09c14ca3fbd5 100644 --- a/drivers/scsi/libsas/sas_init.c +++ b/drivers/scsi/libsas/sas_init.c @@ -160,18 +160,22 @@ int sas_register_ha(struct sas_ha_struct *sas_ha) int sas_unregister_ha(struct sas_ha_struct *sas_ha) { - unsigned long flags; - /* Set the state to unregistered to avoid further unchained - * events to be queued + * events to be queued, and flush any in-progress drainers */ - spin_lock_irqsave(&sas_ha->state_lock, flags); + mutex_lock(&sas_ha->drain_mutex); + spin_lock_irq(&sas_ha->state_lock); clear_bit(SAS_HA_REGISTERED, &sas_ha->state); - spin_unlock_irqrestore(&sas_ha->state_lock, flags); - sas_drain_work(sas_ha); + spin_unlock_irq(&sas_ha->state_lock); + __sas_drain_work(sas_ha); + mutex_unlock(&sas_ha->drain_mutex); sas_unregister_ports(sas_ha); - sas_drain_work(sas_ha); + + /* flush unregistration work */ + mutex_lock(&sas_ha->drain_mutex); + __sas_drain_work(sas_ha); + mutex_unlock(&sas_ha->drain_mutex); if (sas_ha->lldd_max_execute_num > 1) { sas_shutdown_queue(sas_ha); diff --git a/drivers/scsi/libsas/sas_internal.h b/drivers/scsi/libsas/sas_internal.h index 4157f6e1eda2..7818c4673c3a 100644 --- a/drivers/scsi/libsas/sas_internal.h +++ b/drivers/scsi/libsas/sas_internal.h @@ -70,6 +70,7 @@ int sas_init_events(struct sas_ha_struct *sas_ha); void sas_shutdown_queue(struct sas_ha_struct *sas_ha); void sas_disable_revalidation(struct sas_ha_struct *ha); void sas_enable_revalidation(struct sas_ha_struct *ha); +void __sas_drain_work(struct sas_ha_struct *ha); void sas_deform_port(struct asd_sas_phy *phy, int gone); -- GitLab