[PATCH] hw/nvme: fix control flow statement

[Dmitry Tikhov <d.tihov@yadro.com>]

Since there is no else after nvme_dsm_cb invocation, metadata associated
with non-zero block range is currently zeroed. Also this behaviour leads
to segfault since we schedule iocb->bh two times. First when entering
nvme_dsm_cb with iocb->idx == iocb->nr and second on call stack unwinding
by calling blk_aio_pwrite_zeroes and subsequent nvme_dsm_cb callback
because of missing else statement.

Signed-off-by: Dmitry Tikhov <d.tihov@yadro.com>
---
 hw/nvme/ctrl.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/hw/nvme/ctrl.c b/hw/nvme/ctrl.c
index 03760ddeae..7ebd2aa326 100644
--- a/hw/nvme/ctrl.c
+++ b/hw/nvme/ctrl.c
@@ -2372,11 +2372,12 @@ static void nvme_dsm_md_cb(void *opaque, int ret)
         }
 
         nvme_dsm_cb(iocb, 0);
+    } else {
+        iocb->aiocb = blk_aio_pwrite_zeroes(ns->blkconf.blk, nvme_moff(ns, slba),
+                                            nvme_m2b(ns, nlb), BDRV_REQ_MAY_UNMAP,
+                                            nvme_dsm_cb, iocb);
     }
 
-    iocb->aiocb = blk_aio_pwrite_zeroes(ns->blkconf.blk, nvme_moff(ns, slba),
-                                        nvme_m2b(ns, nlb), BDRV_REQ_MAY_UNMAP,
-                                        nvme_dsm_cb, iocb);
     return;
 
 done:
-- 
2.35.1