block: Add bdrv_co_get_self_request()

Cc: qemu-stable@nongnu.org
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20191101152510.11719-3-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>

2 files changed, 19 insertions, 0 deletions

diff --git a/block/io.c b/block/io.c
index 039c0d49c9..f75777f5ea 100644
--- a/block/io.c
+++ b/block/io.c
@@ -743,6 +743,24 @@ static bool is_request_serialising_and_aligned(BdrvTrackedRequest *req)
 }
 
 /**
+ * Return the tracked request on @bs for the current coroutine, or
+ * NULL if there is none.
+ */
+BdrvTrackedRequest *coroutine_fn bdrv_co_get_self_request(BlockDriverState *bs)
+{
+    BdrvTrackedRequest *req;
+    Coroutine *self = qemu_coroutine_self();
+
+    QLIST_FOREACH(req, &bs->tracked_requests, list) {
+        if (req->co == self) {
+            return req;
+        }
+    }
+
+    return NULL;
+}
+
+/**
  * Round a region to cluster boundaries
  */
 void bdrv_round_to_clusters(BlockDriverState *bs,
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 32fa323b63..dd033d0b37 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -1001,6 +1001,7 @@ void bdrv_unapply_subtree_drain(BdrvChild *child, BlockDriverState *old_parent);
 
 bool coroutine_fn bdrv_wait_serialising_requests(BdrvTrackedRequest *self);
 void bdrv_mark_request_serialising(BdrvTrackedRequest *req, uint64_t align);
+BdrvTrackedRequest *coroutine_fn bdrv_co_get_self_request(BlockDriverState *bs);
 
 int get_tmp_filename(char *filename, int size);
 BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,