[PATCH cluster 04/12] pmxcfs: server: simplify ipc message response logic

[Daniel Kral <d.kral@proxmox.com>]

The response should always be empty for negative results. Simplify the
logic here to truncate the response string to remove the unnecessary
`resp` and `resp_data_len` variables.

This is done in preparation of the following patch, which reports and
discards the response data if the response data exceeds the maximum
message size allowed by the client's buffer.

No functional changes intended.

Signed-off-by: Daniel Kral <d.kral@proxmox.com>
---
 src/pmxcfs/server.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/src/pmxcfs/server.c b/src/pmxcfs/server.c
index 22e812c..abe1bee 100644
--- a/src/pmxcfs/server.c
+++ b/src/pmxcfs/server.c
@@ -171,8 +171,6 @@ static int32_t s1_msg_process_fn(qb_ipcs_connection_t *c, void *data, size_t siz
     int32_t request_size __attribute__((aligned(8))) = req_pt->size;
     cfs_debug("process msg:%d, size:%d", request_id, request_size);
 
-    char *resp = NULL;
-
     g_string_truncate(outbuf, 0);
 
     int32_t result = -ECHRNG;
@@ -451,24 +449,23 @@ static int32_t s1_msg_process_fn(qb_ipcs_connection_t *c, void *data, size_t siz
 
     cfs_debug("process result %d", result);
 
-    if (result >= 0) {
-        resp = outbuf->str;
+    /* Do not send the response body in case of an error */
+    if (result < 0) {
+        g_string_truncate(outbuf, 0);
     }
 
     int iov_len = 2;
     struct iovec iov[iov_len];
     struct qb_ipc_response_header res_header;
 
-    int resp_data_len = resp ? outbuf->len : 0;
-
     res_header.id = request_id;
-    res_header.size = sizeof(res_header) + resp_data_len;
+    res_header.size = sizeof(res_header) + outbuf->len;
     res_header.error = result;
 
     iov[0].iov_base = (char *)&res_header;
     iov[0].iov_len = sizeof(res_header);
-    iov[1].iov_base = resp;
-    iov[1].iov_len = resp_data_len;
+    iov[1].iov_base = outbuf->str;
+    iov[1].iov_len = outbuf->len;
 
     ssize_t res = qb_ipcs_response_sendv(c, iov, iov_len);
     if (res < 0) {
-- 
2.47.3