[112/117] SCSI: fix locking around blk_abort_request()

From: Greg KH
Date: Mon May 10 2010 - 19:26:41 EST


2.6.33-stable review patch. If anyone has any objections, please let us know.

------------------

From: Tejun Heo <tj@xxxxxxxxxx>

commit 70b25f890ce9f0520c64075ce9225a5b020a513e upstream.

blk_abort_request() expects queue lock to be held by the caller.
Grab it before calling the function.

Lack of this synchronization led to infinite loop on corrupt
q->timeout_list.

Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: James Bottomley <James.Bottomley@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
drivers/scsi/libsas/sas_ata.c | 4 ++++
drivers/scsi/libsas/sas_scsi_host.c | 4 ++++
2 files changed, 8 insertions(+)

--- a/drivers/scsi/libsas/sas_ata.c
+++ b/drivers/scsi/libsas/sas_ata.c
@@ -394,11 +394,15 @@ int sas_ata_init_host_and_port(struct do
void sas_ata_task_abort(struct sas_task *task)
{
struct ata_queued_cmd *qc = task->uldd_task;
+ struct request_queue *q = qc->scsicmd->device->request_queue;
struct completion *waiting;
+ unsigned long flags;

/* Bounce SCSI-initiated commands to the SCSI EH */
if (qc->scsicmd) {
+ spin_lock_irqsave(q->queue_lock, flags);
blk_abort_request(qc->scsicmd->request);
+ spin_unlock_irqrestore(q->queue_lock, flags);
scsi_schedule_eh(qc->scsicmd->device->host);
return;
}
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -1029,6 +1029,8 @@ int __sas_task_abort(struct sas_task *ta
void sas_task_abort(struct sas_task *task)
{
struct scsi_cmnd *sc = task->uldd_task;
+ struct request_queue *q = sc->device->request_queue;
+ unsigned long flags;

/* Escape for libsas internal commands */
if (!sc) {
@@ -1043,7 +1045,9 @@ void sas_task_abort(struct sas_task *tas
return;
}

+ spin_lock_irqsave(q->queue_lock, flags);
blk_abort_request(sc->request);
+ spin_unlock_irqrestore(q->queue_lock, flags);
scsi_schedule_eh(sc->device->host);
}



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/