In some situations barrier counter may become negative.
Calling lower_barrier with barrier=0 results barrier become negative.
It is harm situation and may cause process hang when we call wait_barrier()
This patch introduces additional condition in lower_barrier function-
decrement barrier counter only if it is raised.
It prevents to become barrier variable negative.
Signed-off-by: Krzysztof Wojcik <krzysztof.wojcik@xxxxxxxxx>
---
drivers/md/raid1.c | 3 ++-
drivers/md/raid10.c | 3 ++-
2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index a23ffa3..fa7077b 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -660,7 +660,8 @@ static void lower_barrier(conf_t *conf)
unsigned long flags;
BUG_ON(conf->barrier <= 0);
spin_lock_irqsave(&conf->resync_lock, flags);
- conf->barrier--;
+ if (conf->barrier > 0)
+ conf->barrier--;
spin_unlock_irqrestore(&conf->resync_lock, flags);
wake_up(&conf->wait_barrier);
}
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 3b607b2..c9e46a9 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -727,7 +727,8 @@ static void lower_barrier(conf_t *conf)
{
unsigned long flags;
spin_lock_irqsave(&conf->resync_lock, flags);
- conf->barrier--;
+ if (conf->barrier > 0)
+ conf->barrier--;
spin_unlock_irqrestore(&conf->resync_lock, flags);
wake_up(&conf->wait_barrier);
}
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
