From 8db87912c9a8771c53b98845cd5516ea63b22e1e Mon Sep 17 00:00:00 2001 From: Guoqing Jiang Date: Tue, 24 Oct 2017 15:11:52 +0800 Subject: md-cluster: Use a small window for raid10 resync Suspending the entire device for resync could take too long. Resync in small chunks. cluster's resync window is maintained in r10conf as cluster_sync_low and cluster_sync_high, and processed in raid10's sync_request(). If the current resync is outside the cluster resync window: 1. Set the cluster_sync_low to curr_resync_completed. 2. Set cluster_sync_high to cluster_sync_low + stripe size. 3. Send a message to all nodes so they may add it in their suspension list. Note: We only support "near" raid10 so far, resync a far or offset raid10 array could have trouble. So raid10_run checks the layout of clustered raid10, it will refuse to run if the layout is not correct. With the "near" layout we process one stripe at a time progressing monotonically through the address space. So we can have a sliding window of whole-stripes which moves through the array suspending IO on other nodes, and both resync which uses array addresses and recovery which uses device addresses can stay within this window. Signed-off-by: Guoqing Jiang Signed-off-by: Shaohua Li --- drivers/md/raid10.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'drivers/md/raid10.h') diff --git a/drivers/md/raid10.h b/drivers/md/raid10.h index 735ce1a..2bef4e8 100644 --- a/drivers/md/raid10.h +++ b/drivers/md/raid10.h @@ -88,6 +88,12 @@ struct r10conf { * the new thread here until we fully activate the array. */ struct md_thread *thread; + + /* + * Keep track of cluster resync window to send to other nodes. + */ + sector_t cluster_sync_low; + sector_t cluster_sync_high; }; /* -- cgit v1.1