fabrics: restructrure nvmf_get_discovery_log

Move the initial header read into the do while loop. This simplifies
the loop flow into first read header if there are records fetch them
too.

With this we keep the genctr and numrec in sync for both get log
invocation.

Signed-off-by: Daniel Wagner <[email protected]>

Author: dwsuse

src/nvme/fabrics.c

@@ -773,66 +773,57 @@ int nvmf_get_discovery_log(nvme_ctrl_t c, struct nvmf_discovery_log **logp,
 			   int max_retries)
 {
 	nvme_root_t r = c->s && c->s->h ? c->s->h->r : NULL;
-	struct nvmf_discovery_log *log;
-	int hdr, ret, retries = 0;
+	struct nvmf_discovery_log *log = NULL;
+	int ret, retries = 0;
 	const char *name = nvme_ctrl_get_name(c);
 	uint64_t genctr, numrec;
 	unsigned int size;
 
-	hdr = sizeof(struct nvmf_discovery_log);
-	log = malloc(hdr);
-	if (!log) {
-		nvme_msg(r, LOG_ERR,
-			 "could not allocate memory for discovery log header\n");
-		errno = ENOMEM;
-		return -1;
-	}
-	memset(log, 0, hdr);
-
-	nvme_msg(r, LOG_DEBUG, "%s: discover length %d\n", name, 0x100);
-	ret = nvme_discovery_log(nvme_ctrl_get_fd(c), 0x100, log, true);
-	if (ret) {
-		nvme_msg(r, LOG_INFO, "%s: discover failed, error %d\n",
-			 name, errno);
-		goto out_free_log;
-	}
-
 	do {
-		numrec = le64_to_cpu(log->numrec);
-		genctr = le64_to_cpu(log->genctr);
-
-		if (numrec == 0) {
-			*logp = log;
-			return 0;
-		}
-
-		size = sizeof(struct nvmf_discovery_log) +
-			sizeof(struct nvmf_disc_log_entry) * (numrec);
+		size = sizeof(struct nvmf_discovery_log);
 
 		free(log);
-		log = malloc(size);
+		log = calloc(1, size);
 		if (!log) {
 			nvme_msg(r, LOG_ERR,
-				 "could not alloc memory for discovery log page\n");
+				 "could not allocate memory for discovery log header\n");
 			errno = ENOMEM;
 			return -1;
 		}
-		memset(log, 0, size);
 
-		nvme_msg(r, LOG_DEBUG, "%s: discover length %d\n", name, size);
-		ret = nvme_discovery_log(nvme_ctrl_get_fd(c), size, log, false);
+		nvme_msg(r, LOG_DEBUG, "%s: get header (try %d/%d)\n",
+			name, retries, max_retries);
+		ret = nvme_discovery_log(nvme_ctrl_get_fd(c), size, log, true);
 		if (ret) {
 			nvme_msg(r, LOG_INFO,
 				 "%s: discover try %d/%d failed, error %d\n",
 				 name, retries, max_retries, errno);
 			goto out_free_log;
 		}
 
+		numrec = le64_to_cpu(log->numrec);
 		genctr = le64_to_cpu(log->genctr);
+
+		if (numrec == 0)
+			break;
+
+		size = sizeof(struct nvmf_discovery_log) +
+			sizeof(struct nvmf_disc_log_entry) * numrec;
+
+		free(log);
+		log = calloc(1, size);
+		if (!log) {
+			nvme_msg(r, LOG_ERR,
+				 "could not alloc memory for discovery log page\n");
+			errno = ENOMEM;
+			return -1;
+		}
+
 		nvme_msg(r, LOG_DEBUG,
-			 "%s: discover genctr %" PRIu64 ", retry\n",
-			 name, genctr);
-		ret = nvme_discovery_log(nvme_ctrl_get_fd(c), hdr, log, true);
+			 "%s: get header and %" PRIu64
+			 " records (length %d genctr %" PRIu64 ")\n",
+			 name, numrec, size, genctr);
+		ret = nvme_discovery_log(nvme_ctrl_get_fd(c), size, log, false);
 		if (ret) {
 			nvme_msg(r, LOG_INFO,
 				 "%s: discover try %d/%d failed, error %d\n",