From 49b0a4709b289f28c97633d8b3145213df1d8fc1 Mon Sep 17 00:00:00 2001
From: John Snow <jsnow@redhat.com>
Date: Tue, 24 Jul 2018 12:43:07 +0200
Subject: [PATCH 231/268] block: Move request tracking to children in copy
 offloading

RH-Author: John Snow <jsnow@redhat.com>
Message-id: <20180718225511.14878-14-jsnow@redhat.com>
Patchwork-id: 81393
O-Subject: [RHEL-7.6 qemu-kvm-rhev PATCH 13/35] block: Move request tracking to children in copy offloading
Bugzilla: 1207657
RH-Acked-by: Eric Blake <eblake@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Fam Zheng <famz@redhat.com>

From: Fam Zheng <famz@redhat.com>

in_flight and tracked requests need to be tracked in every layer during
recursion. For now the only user is qemu-img convert where overlapping
requests and IOThreads don't exist, therefore this change doesn't make
much difference form user point of view, but it is incorrect as part of
the API. Fix it.

Reported-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit 37aec7d75eb0d035a0db4f2cf9ad8b1b0c10f91b)
Signed-off-by: John Snow <jsnow@redhat.com>
---
 block/io.c | 60 +++++++++++++++++++++++++++++-------------------------------
 1 file changed, 29 insertions(+), 31 deletions(-)

diff --git a/block/io.c b/block/io.c
index ac36d1c..136a5d0 100644
--- a/block/io.c
+++ b/block/io.c
@@ -2847,6 +2847,9 @@ static int coroutine_fn bdrv_co_copy_range_internal(BdrvChild *src,
                                                     BdrvRequestFlags flags,
                                                     bool recurse_src)
 {
+    BdrvTrackedRequest src_req, dst_req;
+    BlockDriverState *src_bs = src->bs;
+    BlockDriverState *dst_bs = dst->bs;
     int ret;
 
     if (!src || !dst || !src->bs || !dst->bs) {
@@ -2870,17 +2873,32 @@ static int coroutine_fn bdrv_co_copy_range_internal(BdrvChild *src,
         || src->bs->encrypted || dst->bs->encrypted) {
         return -ENOTSUP;
     }
+
+    bdrv_inc_in_flight(src_bs);
+    bdrv_inc_in_flight(dst_bs);
+    tracked_request_begin(&src_req, src_bs, src_offset,
+                          bytes, BDRV_TRACKED_READ);
+    tracked_request_begin(&dst_req, dst_bs, dst_offset,
+                          bytes, BDRV_TRACKED_WRITE);
+
+    wait_serialising_requests(&src_req);
+    wait_serialising_requests(&dst_req);
     if (recurse_src) {
-        return src->bs->drv->bdrv_co_copy_range_from(src->bs,
-                                                     src, src_offset,
-                                                     dst, dst_offset,
-                                                     bytes, flags);
+        ret = src->bs->drv->bdrv_co_copy_range_from(src->bs,
+                                                    src, src_offset,
+                                                    dst, dst_offset,
+                                                    bytes, flags);
     } else {
-        return dst->bs->drv->bdrv_co_copy_range_to(dst->bs,
-                                                   src, src_offset,
-                                                   dst, dst_offset,
-                                                   bytes, flags);
+        ret = dst->bs->drv->bdrv_co_copy_range_to(dst->bs,
+                                                  src, src_offset,
+                                                  dst, dst_offset,
+                                                  bytes, flags);
     }
+    tracked_request_end(&src_req);
+    tracked_request_end(&dst_req);
+    bdrv_dec_in_flight(src_bs);
+    bdrv_dec_in_flight(dst_bs);
+    return ret;
 }
 
 /* Copy range from @src to @dst.
@@ -2911,29 +2929,9 @@ int coroutine_fn bdrv_co_copy_range(BdrvChild *src, uint64_t src_offset,
                                     BdrvChild *dst, uint64_t dst_offset,
                                     uint64_t bytes, BdrvRequestFlags flags)
 {
-    BdrvTrackedRequest src_req, dst_req;
-    BlockDriverState *src_bs = src->bs;
-    BlockDriverState *dst_bs = dst->bs;
-    int ret;
-
-    bdrv_inc_in_flight(src_bs);
-    bdrv_inc_in_flight(dst_bs);
-    tracked_request_begin(&src_req, src_bs, src_offset,
-                          bytes, BDRV_TRACKED_READ);
-    tracked_request_begin(&dst_req, dst_bs, dst_offset,
-                          bytes, BDRV_TRACKED_WRITE);
-
-    wait_serialising_requests(&src_req);
-    wait_serialising_requests(&dst_req);
-    ret = bdrv_co_copy_range_from(src, src_offset,
-                                  dst, dst_offset,
-                                  bytes, flags);
-
-    tracked_request_end(&src_req);
-    tracked_request_end(&dst_req);
-    bdrv_dec_in_flight(src_bs);
-    bdrv_dec_in_flight(dst_bs);
-    return ret;
+    return bdrv_co_copy_range_from(src, src_offset,
+                                   dst, dst_offset,
+                                   bytes, flags);
 }
 
 static void bdrv_parent_cb_resize(BlockDriverState *bs)
-- 
1.8.3.1