diff options
| -rw-r--r-- | block.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/block.c b/block.c index ecc5b442d4..50ce2be48e 100644 --- a/block.c +++ b/block.c @@ -1099,6 +1099,7 @@ struct BdrvTrackedRequest { int nb_sectors; bool is_write; QLIST_ENTRY(BdrvTrackedRequest) list; + Coroutine *co; /* owner, used for deadlock detection */ CoQueue wait_queue; /* coroutines blocked on this request */ }; @@ -1126,6 +1127,7 @@ static void tracked_request_begin(BdrvTrackedRequest *req, .sector_num = sector_num, .nb_sectors = nb_sectors, .is_write = is_write, + .co = qemu_coroutine_self(), }; qemu_co_queue_init(&req->wait_queue); @@ -1189,6 +1191,12 @@ static void coroutine_fn wait_for_overlapping_requests(BlockDriverState *bs, QLIST_FOREACH(req, &bs->tracked_requests, list) { if (tracked_request_overlaps(req, cluster_sector_num, cluster_nb_sectors)) { + /* Hitting this means there was a reentrant request, for + * example, a block driver issuing nested requests. This must + * never happen since it means deadlock. + */ + assert(qemu_coroutine_self() != req->co); + qemu_co_queue_wait(&req->wait_queue); retry = true; break; |