Commits
Shaohua Li committed f6b6ec5cfac
raid5-cache: add journal hot add/remove support Add support for journal disk hot add/remove. Mostly trival checks in md part. The raid5 part is a little tricky. For hot-remove, we can't wait pending write as it's called from raid5d. The wait will cause deadlock. We simplily fail the hot-remove. A hot-remove retry can success eventually since if journal disk is faulty all pending write will be failed and finish. For hot-add, since an array supporting journal but without journal disk will be marked read-only, we are safe to hot add journal without stopping IO (should be read IO, while journal only handles write IO). Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>