From b66f204fcdb797b85050f3f6af6b4967247fd0f5 Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Tue, 3 Dec 2013 14:30:44 +0100
Subject: [PATCH 14/37] block: write: Handle COR dependency after I/O throttling

Message-id: <1392117622-28812-15-git-send-email-kwolf@redhat.com>
Patchwork-id: 57179
O-Subject: [RHEL-7.0 qemu-kvm PATCH v2 14/37] block: write: Handle COR dependency after I/O throttling
Bugzilla: 748906
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Max Reitz <mreitz@redhat.com>

First waiting for all COR requests to complete and calling the
throttling function afterwards means that the request could be delayed
and we still need to wait for the COR request even if it was issued only
after the throttled write request.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
(cherry picked from commit 244eadef5c797c674b0aef96366671be4b33d03a)

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
---
 block.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/block.c b/block.c
index e6b6ed4..d8168f5 100644
--- a/block.c
+++ b/block.c
@@ -2997,6 +2997,10 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
     assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
     assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
 
+    if (bs->copy_on_read_in_flight) {
+        wait_for_overlapping_requests(bs, sector_num, nb_sectors);
+    }
+
     tracked_request_begin(&req, bs, sector_num, nb_sectors, true);
 
     if (flags & BDRV_REQ_ZERO_WRITE) {
@@ -3044,10 +3048,6 @@ static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
         return -EIO;
     }
 
-    if (bs->copy_on_read_in_flight) {
-        wait_for_overlapping_requests(bs, sector_num, nb_sectors);
-    }
-
     /* throttling disk I/O */
     if (bs->io_limits_enabled) {
         bdrv_io_limits_intercept(bs, true, nb_sectors);
-- 
1.7.1