pm8001: add a new spinlock to protect the CCB
Patch adds a new spinlock to protect the ccb management.
It may happen that concurrent threads become the same tag value
from the 'alloc' function', the spinlock prevents this situation.
Signed-off-by: Tomas Henzl <thenzl@redhat.com>
Acked-by: Suresh Thiagarajan <Suresh.Thiagarajan@pmcs.com>
Acked-by: Jack Wang <xjtuwjp@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/drivers/scsi/pm8001/pm8001_sas.c b/drivers/scsi/pm8001/pm8001_sas.c
index be55859..34cea82 100644
--- a/drivers/scsi/pm8001/pm8001_sas.c
+++ b/drivers/scsi/pm8001/pm8001_sas.c
@@ -77,11 +77,16 @@
{
unsigned int tag;
void *bitmap = pm8001_ha->tags;
+ unsigned long flags;
+ spin_lock_irqsave(&pm8001_ha->bitmap_lock, flags);
tag = find_first_zero_bit(bitmap, pm8001_ha->tags_num);
- if (tag >= pm8001_ha->tags_num)
+ if (tag >= pm8001_ha->tags_num) {
+ spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
return -SAS_QUEUE_FULL;
+ }
set_bit(tag, bitmap);
+ spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
*tag_out = tag;
return 0;
}