nvme: Refactor get telemetry log page helper

Refactor the helper to use explicit code paths instead of conditions to
steer the code flow. This is way simpler to read and the resulting code
size is only growing 88 bytes.

Signed-off-by: Daniel Wagner <dwagner@suse.de>

diff --git a/nvme.c b/nvme.c
index 48c61b674a181627048508f4377c3881da2bbeef..6dc9ba2b8e1f9270a89980432609925c07837e98 100644 (file)
--- a/nvme.c
+++ b/nvme.c
@@ -631,77 +631,130 @@ static int parse_telemetry_da(struct nvme_dev *dev,
                return -EINVAL;
        }
 
+       if (*size == NVME_LOG_TELEM_BLOCK_SIZE) {
+               fprintf(stderr, "ERROR: No telemetry data block\n");
+               return -ENOENT;
+       }
        return 0;
 }
 
-static int get_telemetry_log_helper(struct nvme_dev *dev, bool create,
-                                   bool ctrl, struct nvme_telemetry_log **buf,
-                                   enum nvme_telemetry_da da,
-                                   size_t *size)
+static int get_log_telemetry_ctrl(struct nvme_dev *dev, size_t size,
+                                 struct nvme_telemetry_log **buf)
 {
-       static const __u32 xfer = NVME_LOG_TELEM_BLOCK_SIZE;
-       struct nvme_telemetry_log *telem;
-       void *log, *tmp;
+       struct nvme_telemetry_log *log;
        int err;
-       *size = 0;
 
-       log = calloc(1, xfer);
+       log = calloc(1, size);
        if (!log)
-               return -ENOMEM;
+               return -errno;
 
-       if (ctrl) {
-               /* set rae = true so it won't clear the current telemetry log in controller */
-               err = nvme_cli_get_log_telemetry_ctrl(dev, true, 0, xfer, log);
-       } else {
-               if (create)
-                       err = nvme_cli_get_log_create_telemetry_host(dev, log);
-               else
-                       err = nvme_cli_get_log_telemetry_host(dev, 0, xfer, log);
+       err = nvme_cli_get_log_telemetry_ctrl(dev, true, 0, size, log);
+       if (err) {
+               free(log);
+               return -errno;
+       }
+
+       *buf = log;
+       return 0;
+}
+
+static int get_log_telemetry_host(struct nvme_dev *dev, size_t size,
+                                 struct nvme_telemetry_log **buf)
+{
+       struct nvme_telemetry_log *log;
+       int err;
+
+       log = calloc(1, size);
+       if (!log)
+               return -errno;
+
+       err = nvme_cli_get_log_telemetry_host(dev, 0, size, log);
+       if (err) {
+               free(log);
+               return -errno;
        }
 
+       *buf = log;
+       return 0;
+}
+
+static int __create_telemetry_log_host(struct nvme_dev *dev,
+                                      enum nvme_telemetry_da da,
+                                      size_t *size,
+                                      struct nvme_telemetry_log **buf)
+{
+       struct nvme_telemetry_log log = { 0 };
+       int err;
+
+       err = nvme_cli_get_log_create_telemetry_host(dev, &log);
+       if (err)
+               return -errno;
+
+       *size = NVME_LOG_TELEM_BLOCK_SIZE;
+       return get_log_telemetry_host(dev, NVME_LOG_TELEM_BLOCK_SIZE, buf);
+}
+
+static int __get_telemetry_log_ctrl(struct nvme_dev *dev,
+                                   enum nvme_telemetry_da da,
+                                   size_t *size,
+                                   struct nvme_telemetry_log **buf)
+{
+       struct nvme_telemetry_log *log;
+       int err;
+
+       log = calloc(1, NVME_LOG_TELEM_BLOCK_SIZE);
+       if (!log)
+               return -errno;
+
+       /*
+        * set rae = true so it won't clear the current telemetry log in
+        * controller
+        */
+       err = nvme_cli_get_log_telemetry_ctrl(dev, true, 0,
+                                             NVME_LOG_TELEM_BLOCK_SIZE,
+                                             log);
        if (err)
                goto free;
 
-       telem = log;
-       if (ctrl && !telem->ctrlavail) {
+       if (!log->ctrlavail) {
+               *size = NVME_LOG_TELEM_BLOCK_SIZE;
                *buf = log;
-               *size = xfer;
+
                printf("Warning: Telemetry Controller-Initiated Data Not Available.\n");
                return 0;
        }
 
-       err = parse_telemetry_da(dev, da, telem, size);
+       err = parse_telemetry_da(dev, da, log, size);
        if (err)
                goto free;
 
-       if (xfer == *size) {
-               fprintf(stderr, "ERROR: No telemetry data block\n");
-               err = -ENOENT;
-               goto free;
-       }
+       return get_log_telemetry_ctrl(dev, *size, buf);
 
-       tmp = realloc(log, *size);
-       if (!tmp) {
-               err = -ENOMEM;
-               goto free;
-       }
-       log = tmp;
-
-       if (ctrl) {
-               err = nvme_cli_get_log_telemetry_ctrl(dev, true, 0, *size, log);
-       } else {
-               err = nvme_cli_get_log_telemetry_host(dev, 0, *size, log);
-       }
-
-       if (!err) {
-               *buf = log;
-               return 0;
-       }
 free:
        free(log);
        return err;
 }
 
+static int __get_telemetry_log_host(struct nvme_dev *dev,
+                                   enum nvme_telemetry_da da,
+                                   size_t *size,
+                                   struct nvme_telemetry_log **buf)
+{
+       struct nvme_telemetry_log log = { 0 };
+       int err;
+
+       err = nvme_cli_get_log_telemetry_host(dev, 0,
+                                             NVME_LOG_TELEM_BLOCK_SIZE,
+                                             &log);
+       if (err)
+               return  err;
+
+       err = parse_telemetry_da(dev, da, &log, size);
+       if (err)
+               return err;
+
+       return get_log_telemetry_host(dev, *size, buf);
+}
 
 static int get_telemetry_log(int argc, char **argv, struct command *cmd,
                             struct plugin *plugin)
@@ -711,7 +764,7 @@ static int get_telemetry_log(int argc, char **argv, struct command *cmd,
        const char *hgen = "Have the host tell the controller to generate the report";
        const char *cgen = "Gather report generated by the controller.";
        const char *dgen = "Pick which telemetry data area to report. Default is 3 to fetch areas 1-3. Valid options are 1, 2, 3, 4.";
-       struct nvme_telemetry_log *log;
+       struct nvme_telemetry_log *log = NULL;
        int err = 0, output;
        size_t total_size;
        __u8 *data_ptr = NULL;
@@ -759,17 +812,14 @@ static int get_telemetry_log(int argc, char **argv, struct command *cmd,
        }
 
        if (cfg.ctrl_init)
-               /* Create Telemetry Host-Initiated Data = false, Controller-Initiated = true */
-               err = get_telemetry_log_helper(dev, false, true, &log,
-                                              cfg.data_area, &total_size);
+               err = __get_telemetry_log_ctrl(dev, cfg.data_area,
+                                              &total_size, &log);
        else if (cfg.host_gen)
-               /* Create Telemetry Host-Initiated Data = true, Controller-Initiated = false */
-               err = get_telemetry_log_helper(dev, true, false, &log,
-                                              cfg.data_area, &total_size);
+               err = __create_telemetry_log_host(dev, cfg.data_area,
+                                                 &total_size, &log);
        else
-               /* Create Telemetry Host-Initiated Data = false, Controller-Initiated = false */
-               err = get_telemetry_log_helper(dev, false, false, &log,
-                                              cfg.data_area, &total_size);
+               err = __get_telemetry_log_host(dev, cfg.data_area,
+                                              &total_size, &log);
 
        if (err < 0) {
                fprintf(stderr, "get-telemetry-log: %s\n",