Re: [Qemu-devel] [PATCH 05/19] nbd/server: refactor nbd_co_receive_request

[Eric Blake]

On 05/30/2017 09:30 AM, Vladimir Sementsov-Ogievskiy wrote:
> Move function tail, about receiving next request out of the function.
> Error path is simplified and nbd_co_receive_request becomes more
> corresponding to its name.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy 
> ---
>  nbd/server.c | 41 +
>  1 file changed, 13 insertions(+), 28 deletions(-)

Quite the diffstat.

Reviewed-by: Eric Blake 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.   +1-919-301-3266
Virtualization:  qemu.org | libvirt.org



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[Qemu-devel] [PATCH 05/19] nbd/server: refactor nbd_co_receive_request

[Vladimir Sementsov-Ogievskiy]

Move function tail, about receiving next request out of the function.
Error path is simplified and nbd_co_receive_request becomes more
corresponding to its name.

Signed-off-by: Vladimir Sementsov-Ogievskiy 
---
 nbd/server.c | 41 +
 1 file changed, 13 insertions(+), 28 deletions(-)

diff --git a/nbd/server.c b/nbd/server.c
index fcf35f0270..546bf3ae61 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -1006,14 +1006,11 @@ static int nbd_co_send_reply(NBDRequestData *req, 
NBDReply *reply, int len)
 static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request)
 {
 NBDClient *client = req->client;
-int rc;
 
 g_assert(qemu_in_coroutine());
 assert(client->recv_coroutine == qemu_coroutine_self());
-rc = nbd_receive_request(client->ioc, request);
-if (rc < 0) {
-rc = -EIO;
-goto out;
+if (nbd_receive_request(client->ioc, request) < 0) {
+return -EIO;
 }
 
 TRACE("Decoding type");
@@ -1027,8 +1024,7 @@ static int nbd_co_receive_request(NBDRequestData *req, 
NBDRequest *request)
 /* Special case: we're going to disconnect without a reply,
  * whether or not flags, from, or len are bogus */
 TRACE("Request type is DISCONNECT");
-rc = -EIO;
-goto out;
+return -EIO;
 }
 
 /* Check for sanity in the parameters, part 1.  Defer as many
@@ -1036,22 +1032,19 @@ static int nbd_co_receive_request(NBDRequestData *req, 
NBDRequest *request)
  * payload, so we can try and keep the connection alive.  */
 if ((request->from + request->len) < request->from) {
 LOG("integer overflow detected, you're probably being attacked");
-rc = -EINVAL;
-goto out;
+return -EINVAL;
 }
 
 if (request->type == NBD_CMD_READ || request->type == NBD_CMD_WRITE) {
 if (request->len > NBD_MAX_BUFFER_SIZE) {
 LOG("len (%" PRIu32" ) is larger than max len (%u)",
 request->len, NBD_MAX_BUFFER_SIZE);
-rc = -EINVAL;
-goto out;
+return -EINVAL;
 }
 
 req->data = blk_try_blockalign(client->exp->blk, request->len);
 if (req->data == NULL) {
-rc = -ENOMEM;
-goto out;
+return -ENOMEM;
 }
 }
 if (request->type == NBD_CMD_WRITE) {
@@ -1059,8 +1052,7 @@ static int nbd_co_receive_request(NBDRequestData *req, 
NBDRequest *request)
 
 if (read_sync(client->ioc, req->data, request->len, NULL) < 0) {
 LOG("reading from socket failed");
-rc = -EIO;
-goto out;
+return -EIO;
 }
 req->complete = true;
 }
@@ -1070,28 +1062,19 @@ static int nbd_co_receive_request(NBDRequestData *req, 
NBDRequest *request)
 LOG("operation past EOF; From: %" PRIu64 ", Len: %" PRIu32
 ", Size: %" PRIu64, request->from, request->len,
 (uint64_t)client->exp->size);
-rc = request->type == NBD_CMD_WRITE ? -ENOSPC : -EINVAL;
-goto out;
+return request->type == NBD_CMD_WRITE ? -ENOSPC : -EINVAL;
 }
 if (request->flags & ~(NBD_CMD_FLAG_FUA | NBD_CMD_FLAG_NO_HOLE)) {
 LOG("unsupported flags (got 0x%x)", request->flags);
-rc = -EINVAL;
-goto out;
+return -EINVAL;
 }
 if (request->type != NBD_CMD_WRITE_ZEROES &&
 (request->flags & NBD_CMD_FLAG_NO_HOLE)) {
 LOG("unexpected flags (got 0x%x)", request->flags);
-rc = -EINVAL;
-goto out;
+return -EINVAL;
 }
 
-rc = 0;
-
-out:
-client->recv_coroutine = NULL;
-nbd_client_receive_next_request(client);
-
-return rc;
+return 0;
 }
 
 /* Owns a reference to the NBDClient passed as opaque.  */
@@ -1113,6 +1096,8 @@ static coroutine_fn void nbd_trip(void *opaque)
 
 req = nbd_request_get(client);
 ret = nbd_co_receive_request(req, );
+client->recv_coroutine = NULL;
+nbd_client_receive_next_request(client);
 if (ret == -EIO) {
 goto out;
 }
-- 
2.11.1