From a82cafe92d4c98b068456a52e9c078cf12b02e59 Mon Sep 17 00:00:00 2001 From: Conghui Chen Date: Wed, 23 Jan 2019 18:05:51 +0000 Subject: [PATCH] dm: storage: change DISCARD to synchronous mode For virtio-blk, when the backend is a regular file, the discard and is implemented by fallocate(), but this function will not wait for the discard command handled by disk. So, add fdatasync to make sure the DISCARD is executed synchronously. Tracked-On: #2547 Signed-off-by: Conghui Chen Acked-by: Wang Yu --- devicemodel/hw/block_if.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/devicemodel/hw/block_if.c b/devicemodel/hw/block_if.c index 67a573e75..2a06b7ecf 100644 --- a/devicemodel/hw/block_if.c +++ b/devicemodel/hw/block_if.c @@ -313,6 +313,8 @@ blockif_process_discard(struct blockif_ctxt *bc, struct blockif_req *br) */ err = fallocate(bc->fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, arg[i][0], arg[i][1]); + if (!err) + err = fdatasync(bc->fd); } if (err) { WPRINTF(("Failed to discard offset=%ld nbytes=%ld err code: %d\n",