Re: [Qemu-block] [PATCH v3 0/3] add bdrv_co_drain_begin/end BlockDriver callbacks

[Stefan Hajnoczi]

On Sat, Sep 23, 2017 at 02:14:08PM +0300, Manos Pitsidianakis wrote:
> This patch series renames bdrv_co_drain to bdrv_co_drain_begin and adds a new 
> bdrv_co_drain_end callback to match bdrv_drained_begin/end and 
> drained_begin/end of BdrvChild. This is needed because the throttle driver 
> (block/throttle.c) needs a way to mark the end of the drain in order to 
> toggle 
> io_limits_disabled correctly.
> 
> Based-on: <address@hidden>
>     "block/throttle-groups.c: allocate RestartData on the heap"
>     Which fixes a coroutine crash in block/throttle-groups.c
> 
> v3:
>   fixed commit message typo in first patch [Fam]
>   rephrased doc comment based on mailing discussion
> v2: 
>   add doc for callbacks and change order of request polling for completion 
>   [Stefan]
> 
> Manos Pitsidianakis (3):
>   block: add bdrv_co_drain_end callback
>   block: rename bdrv_co_drain to bdrv_co_drain_begin
>   block/throttle.c: add bdrv_co_drain_begin/end callbacks
> 
>  include/block/block_int.h | 13 ++++++++++---
>  block/io.c                | 48 
> +++++++++++++++++++++++++++++++++--------------
>  block/qed.c               |  6 +++---
>  block/throttle.c          | 18 ++++++++++++++++++
>  4 files changed, 65 insertions(+), 20 deletions(-)

Oops, this seems to cause a qemu-iotests failure.  Please take a look:

$ ./check -qcow2 184
184 0s ... - output mismatch (see 184.out.bad)
--- /home/stefanha/qemu/tests/qemu-iotests/184.out      2017-09-19 
14:51:46.673854437 +0100
+++ 184.out.bad 2017-09-26 11:13:06.946610239 +0100
@@ -142,6 +142,9 @@
         "guest": false
     }
 }
+./common.config: line 118:  9196 Segmentation fault      (core dumped) ( if [ 
-n "${QEMU_NEED_PID}" ]; then
+    echo $BASHPID > "${QEMU_TEST_DIR}/qemu-${_QEMU_HANDLE}.pid";
+fi; exec "$QEMU_PROG" $QEMU_OPTIONS "$@" )