libata: Fix a potential race condition in ata_scsi_park_show()
Peter Moulder has pointed out that there is a slight chance that a
negative value might be passed to jiffies_to_msecs() in
ata_scsi_park_show(). This is fixed by saving the value of jiffies in a
local variable, thus also reducing code since the volatile variable
jiffies is accessed only once.
Signed-off-by: Elias Oltmanns <eo@nebensachen.de>
Signed-off-by: Tejun Heo <tj.kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index bbb30d8..3fa75ea 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -190,7 +190,7 @@
struct ata_port *ap;
struct ata_link *link;
struct ata_device *dev;
- unsigned long flags;
+ unsigned long flags, now;
unsigned int uninitialized_var(msecs);
int rc = 0;
@@ -208,10 +208,11 @@
}
link = dev->link;
+ now = jiffies;
if (ap->pflags & ATA_PFLAG_EH_IN_PROGRESS &&
link->eh_context.unloaded_mask & (1 << dev->devno) &&
- time_after(dev->unpark_deadline, jiffies))
- msecs = jiffies_to_msecs(dev->unpark_deadline - jiffies);
+ time_after(dev->unpark_deadline, now))
+ msecs = jiffies_to_msecs(dev->unpark_deadline - now);
else
msecs = 0;