[Qemu-devel] [PATCH 03/11] blockdev: acquire AioContext in blockdev_mark_auto_del()

[Stefan Hajnoczi <stefanha@redhat.com>]

When an emulated storage controller is unrealized it will call
blockdev_mark_auto_del().  This will cancel any running block job (and
that eventually releases its reference to the BDS so it can be freed).

Since the block job may be executing in another AioContext we must
acquire/release to ensure thread safety.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 blockdev.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/blockdev.c b/blockdev.c
index 270425d..5e38f34 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -89,14 +89,21 @@ static const int if_max_devs[IF_COUNT] = {
 void blockdev_mark_auto_del(BlockDriverState *bs)
 {
     DriveInfo *dinfo = drive_get_by_blockdev(bs);
+    AioContext *aio_context;
 
     if (dinfo && !dinfo->enable_auto_del) {
         return;
     }
 
+    aio_context = bdrv_get_aio_context(bs);
+    aio_context_acquire(aio_context);
+
     if (bs->job) {
         block_job_cancel(bs->job);
     }
+
+    aio_context_release(aio_context);
+
     if (dinfo) {
         dinfo->auto_del = 1;
     }
-- 
1.9.3