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authorTomas Henzl <thenzl@redhat.com>2014-07-09 17:21:01 +0530
committerChristoph Hellwig <hch@lst.de>2014-07-25 17:17:04 -0400
commit646cdf0083e3d4a9b995f37b72c3c8a22d9307de (patch)
treef0730421a40f2037a840489a8afdce0e4b2c1598 /drivers/scsi/pm8001/pm8001_sas.c
parent5533abca06e07121697ed1d30863ce03e7c518e5 (diff)
download96b-common-646cdf0083e3d4a9b995f37b72c3c8a22d9307de.tar.gz
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>
Diffstat (limited to 'drivers/scsi/pm8001/pm8001_sas.c')
-rw-r--r--drivers/scsi/pm8001/pm8001_sas.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/scsi/pm8001/pm8001_sas.c b/drivers/scsi/pm8001/pm8001_sas.c
index be55859042cd..34cea8291772 100644
--- a/drivers/scsi/pm8001/pm8001_sas.c
+++ b/drivers/scsi/pm8001/pm8001_sas.c
@@ -77,11 +77,16 @@ inline int pm8001_tag_alloc(struct pm8001_hba_info *pm8001_ha, u32 *tag_out)
{
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;
}