If the node received RESYNCING message which means
another node will perform resync with the area, then
we don't want to do it again in another node.
Let's set RESYNC_MASK and clear NEEDED_MASK for the
region from old-low to new-low which has finished
syncing, and the region from old-hi to new-hi is about
to syncing, bitmap_sync_with_cluste is introduced for
the purpose.
Reviewed-by: NeilBrown <neilb@xxxxxxxx>
Signed-off-by: Guoqing Jiang <gqjiang@xxxxxxxx>
---
drivers/md/bitmap.c | 21 +++++++++++++++++++++
drivers/md/bitmap.h | 3 +++
drivers/md/md-cluster.c | 27 +++++++++++++++++++++++++++
3 files changed, 51 insertions(+)
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 00cf1c1..2e198f3 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -1597,6 +1597,27 @@ void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector, bool force)
}
EXPORT_SYMBOL(bitmap_cond_end_sync);
+void bitmap_sync_with_cluster(struct mddev *mddev,
+ sector_t old_lo, sector_t old_hi,
+ sector_t new_lo, sector_t new_hi)
+{
+ struct bitmap *bitmap = mddev->bitmap;
+ sector_t sector, blocks = 0;
+
+ for (sector = old_lo; sector < new_lo; ) {
+ bitmap_end_sync(bitmap, sector, &blocks, 0);
+ sector += blocks;
+ }
+ WARN((blocks > new_lo) && old_lo, "alignment is not correct for lo\n");
+
+ for (sector = old_hi; sector < new_hi; ) {
+ bitmap_start_sync(bitmap, sector, &blocks, 0);
+ sector += blocks;
+ }
+ WARN((blocks > new_hi) && old_hi, "alignment is not correct for hi\n");
+}
+EXPORT_SYMBOL(bitmap_sync_with_cluster);
+
static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
{
/* For each chunk covered by any of these sectors, set the
diff --git a/drivers/md/bitmap.h b/drivers/md/bitmap.h
index 5e3fcd6..5b6dd63 100644
--- a/drivers/md/bitmap.h
+++ b/drivers/md/bitmap.h
@@ -258,6 +258,9 @@ int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted);
void bitmap_close_sync(struct bitmap *bitmap);
void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector, bool force);
+void bitmap_sync_with_cluster(struct mddev *mddev,
+ sector_t old_lo, sector_t old_hi,
+ sector_t new_lo, sector_t new_hi);
void bitmap_unplug(struct bitmap *bitmap);
void bitmap_daemon_work(struct mddev *mddev);
diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c
index 30f1160..a55b5f4 100644
--- a/drivers/md/md-cluster.c
+++ b/drivers/md/md-cluster.c
@@ -85,6 +85,9 @@ struct md_cluster_info {
struct completion newdisk_completion;
wait_queue_head_t wait;
unsigned long state;
+ /* record the region in RESYNCING message */
+ sector_t sync_low;
+ sector_t sync_hi;
};
enum msg_type {
@@ -411,6 +414,30 @@ static void process_suspend_info(struct mddev *mddev,
md_wakeup_thread(mddev->thread);
return;
}
+
+ /*
+ * The bitmaps are not same for different nodes
+ * if RESYNCING is happening in one node, then
+ * the node which received the RESYNCING message
+ * probably will perform resync with the region
+ * [lo, hi] again, so we could reduce resync time
+ * a lot if we can ensure that the bitmaps among
+ * different nodes are match up well.
+ *
+ * sync_low/hi is used to record the region which
+ * arrived in the previous RESYNCING message,
+ *
+ * Call bitmap_sync_with_cluster to clear
+ * NEEDED_MASK and set RESYNC_MASK since
+ * resync thread is running in another node,
+ * so we don't need to do the resync again
+ * with the same section */
+ bitmap_sync_with_cluster(mddev, cinfo->sync_low,
+ cinfo->sync_hi,
+ lo, hi);
+ cinfo->sync_low = lo;
+ cinfo->sync_hi = hi;
+
s = kzalloc(sizeof(struct suspend_info), GFP_KERNEL);
if (!s)
return;
--
2.6.6
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