From 22b9153faa2263aa89625de25e71c7d44c8dbd16 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Fri, 9 Mar 2012 11:00:06 -0800 Subject: [SCSI] libsas: introduce sas_work to fix sas_drain_work vs sas_queue_work When requeuing work to a draining workqueue the last work instance may not be idle, so sas_queue_work() must not touch work->entry. Introduce sas_work with a drain_node list_head to have a private list for collecting work deferred due to drain collision. Fixes reports like: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [] process_one_work+0x2e/0x338 Signed-off-by: Dan Williams Signed-off-by: James Bottomley --- include/scsi/libsas.h | 40 ++++++++++++++++++++++++++++++++++++---- 1 file changed, 36 insertions(+), 4 deletions(-) (limited to 'include/scsi/libsas.h') diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h index 5f5ed1b8b41..f4f1c96dca7 100644 --- a/include/scsi/libsas.h +++ b/include/scsi/libsas.h @@ -217,11 +217,29 @@ struct domain_device { struct kref kref; }; -struct sas_discovery_event { +struct sas_work { + struct list_head drain_node; struct work_struct work; +}; + +static inline void INIT_SAS_WORK(struct sas_work *sw, void (*fn)(struct work_struct *)) +{ + INIT_WORK(&sw->work, fn); + INIT_LIST_HEAD(&sw->drain_node); +} + +struct sas_discovery_event { + struct sas_work work; struct asd_sas_port *port; }; +static inline struct sas_discovery_event *to_sas_discovery_event(struct work_struct *work) +{ + struct sas_discovery_event *ev = container_of(work, typeof(*ev), work.work); + + return ev; +} + struct sas_discovery { struct sas_discovery_event disc_work[DISC_NUM_EVENTS]; unsigned long pending; @@ -244,7 +262,7 @@ struct asd_sas_port { struct list_head destroy_list; enum sas_linkrate linkrate; - struct work_struct work; + struct sas_work work; /* public: */ int id; @@ -270,10 +288,17 @@ struct asd_sas_port { }; struct asd_sas_event { - struct work_struct work; + struct sas_work work; struct asd_sas_phy *phy; }; +static inline struct asd_sas_event *to_asd_sas_event(struct work_struct *work) +{ + struct asd_sas_event *ev = container_of(work, typeof(*ev), work.work); + + return ev; +} + /* The phy pretty much is controlled by the LLDD. * The class only reads those fields. */ @@ -333,10 +358,17 @@ struct scsi_core { }; struct sas_ha_event { - struct work_struct work; + struct sas_work work; struct sas_ha_struct *ha; }; +static inline struct sas_ha_event *to_sas_ha_event(struct work_struct *work) +{ + struct sas_ha_event *ev = container_of(work, typeof(*ev), work.work); + + return ev; +} + enum sas_ha_state { SAS_HA_REGISTERED, SAS_HA_DRAINING, -- cgit v1.2.3