md-cluster: Use a small window for resync

Suspending the entire device for resync could take too long. Resync
in small chunks.

cluster's resync window (32M) is maintained in r1conf as
cluster_sync_low and cluster_sync_high and processed in
raid1's sync_request(). If the current resync is outside the cluster
resync window:

1. Set the cluster_sync_low to curr_resync_completed.
2. Check if the sync will fit in the new window, if not issue a
   wait_barrier() and set cluster_sync_low to sector_nr.
3. Set cluster_sync_high to cluster_sync_low + resync_window.
4. Send a message to all nodes so they may add it in their suspension
   list.

bitmap_cond_end_sync is modified to allow to force a sync inorder
to get the curr_resync_completed uptodate with the sector passed.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NeilBrown <neilb@suse.de>
This commit is contained in:
Goldwyn Rodrigues
2015-08-19 08:14:42 +10:00
parent 3c462c880b
commit c40f341f1e
9 changed files with 43 additions and 53 deletions

View File

@@ -90,6 +90,8 @@ static void r1bio_pool_free(void *r1_bio, void *data)
#define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
#define RESYNC_WINDOW (RESYNC_BLOCK_SIZE * RESYNC_DEPTH)
#define RESYNC_WINDOW_SECTORS (RESYNC_WINDOW >> 9)
#define CLUSTER_RESYNC_WINDOW (16 * RESYNC_WINDOW)
#define CLUSTER_RESYNC_WINDOW_SECTORS (CLUSTER_RESYNC_WINDOW >> 9)
#define NEXT_NORMALIO_DISTANCE (3 * RESYNC_WINDOW_SECTORS)
static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
@@ -2488,6 +2490,13 @@ static sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipp
bitmap_close_sync(mddev->bitmap);
close_sync(conf);
if (mddev_is_clustered(mddev)) {
conf->cluster_sync_low = 0;
conf->cluster_sync_high = 0;
/* Send zeros to mark end of resync */
md_cluster_ops->resync_info_update(mddev, 0, 0);
}
return 0;
}
@@ -2508,7 +2517,12 @@ static sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipp
return sync_blocks;
}
bitmap_cond_end_sync(mddev->bitmap, sector_nr);
/* we are incrementing sector_nr below. To be safe, we check against
* sector_nr + two times RESYNC_SECTORS
*/
bitmap_cond_end_sync(mddev->bitmap, sector_nr,
mddev_is_clustered(mddev) && (sector_nr + 2 * RESYNC_SECTORS > conf->cluster_sync_high));
r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
raise_barrier(conf, sector_nr);
@@ -2699,6 +2713,16 @@ static sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipp
bio_full:
r1_bio->sectors = nr_sectors;
if (mddev_is_clustered(mddev) &&
conf->cluster_sync_high < sector_nr + nr_sectors) {
conf->cluster_sync_low = mddev->curr_resync_completed;
conf->cluster_sync_high = conf->cluster_sync_low + CLUSTER_RESYNC_WINDOW_SECTORS;
/* Send resync message */
md_cluster_ops->resync_info_update(mddev,
conf->cluster_sync_low,
conf->cluster_sync_high);
}
/* For a user-requested sync, we read all readable devices and do a
* compare
*/