md/raid10: reset the 'first' at the end of loop

commit 6f287ca6046edd34ed83aafb7f9033c9c2e809e2 upstream.

We need to set "first = 0' at the end of rdev_for_each
loop, so we can get the array's min_offset_diff correctly
otherwise min_offset_diff just means the last rdev's
offset diff.

[only the first chunk, due to b506335e5d2b ("md/raid10: skip spare disk as
'first' disk") being already applied - gregkh]

Suggested-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 18a4271bf5691a3d8c50152837f36ea5f079b4b4..6a7b9b1dcfe3b25a42941b9852e9829ae0b693d0 100644 (file)
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -3681,6 +3681,7 @@ static int raid10_run(struct mddev *mddev)
 
                if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
                        discard_supported = true;
+               first = 0;
        }
 
        if (mddev->queue) {