On Mon, Feb 20 2017, Ming Lei wrote:

On Thu, Feb 16, 2017 at 12:39 PM, NeilBrown [off-list ref] wrote:

quoted

+static void inc_pending(struct r1conf *conf, sector_t start_next_window,
+                       sector_t bi_sector)
+{
+       /* The current request requires multiple r1_bio, so
+        * we need to increment the pending count, and the corresponding
+        * window count.
+        */
+       spin_lock(&conf->resync_lock);
+       conf->nr_pending++;

Just be curious, in current code 'nr_pending' is increased in wait_barrier(),
and looks this patch introduces inc_pending() to do that on each r10_bio, but
not see any change in wait_barrier(), so that means there might be issue in
current implementation about operating on this counter?

Did you read the more detailed description in the previous raid10.c
patch?
This patch follows the same logic as that patch.

NeilBrown