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: NTomas Henzl <thenzl@redhat.com>
Acked-by: NSuresh Thiagarajan <Suresh.Thiagarajan@pmcs.com>
Acked-by: NJack Wang <xjtuwjp@gmail.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>