Re: [PATCH v7 5/6] nbd: partition nbd_read_stat() into nbd_read_reply() and nbd_handle_reply()

Prepare to fix uaf in nbd_read_stat(), no functional changes.

Signed-off-by: Yu Kuai <redacted>
---
 drivers/block/nbd.c | 76 +++++++++++++++++++++++++++------------------
 1 file changed, 45 insertions(+), 31 deletions(-)

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 22c91d8901f6..9a7bbf8ebe74 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c

@@ -694,38 +694,45 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index)
 	return 0;
 }
 
-/* NULL returned = something went wrong, inform userspace */
-static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index)
+static int nbd_read_reply(struct nbd_device *nbd, int index,
+			  struct nbd_reply *reply)
 {
-	struct nbd_config *config = nbd->config;
-	int result;
-	struct nbd_reply reply;
-	struct nbd_cmd *cmd;
-	struct request *req = NULL;
-	u64 handle;
-	u16 hwq;
-	u32 tag;
-	struct kvec iov = {.iov_base = &reply, .iov_len = sizeof(reply)};
+	struct kvec iov = {.iov_base = reply, .iov_len = sizeof(*reply)};
 	struct iov_iter to;
-	int ret = 0;
+	int result;
 
-	reply.magic = 0;
-	iov_iter_kvec(&to, READ, &iov, 1, sizeof(reply));
+	reply->magic = 0;
+	iov_iter_kvec(&to, READ, &iov, 1, sizeof(*reply));
 	result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL, NULL);
-	if (result <= 0) {
-		if (!nbd_disconnected(config))
+	if (result < 0) {
+		if (!nbd_disconnected(nbd->config))