md/raid6: use valid sector values to determine if an I/O should wait on the reshape
JIRA: https://issues.redhat.com/browse/RHEL-17276
Brew: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=57891912
Upstream Status: kernel/git/torvalds/linux.git
Signed-off-by: Nigel Croxon ncroxon@redhat.com
Edited by Nigel Croxon