set metadata priority to maximum and use macros for min and max priorities

Author: ashwin-simplyblock

include/spdk/priority_class.h

@@ -8,5 +8,7 @@ class mask PRIORITY_CLASS_MASK to get the priority class as an integer
 #define PRIORITY_CLASS_BITS_POS (64 - NBITS_PRIORITY_CLASS)
 #define PRIORITY_CLASS_MASK (0xFFFFFFFFFFFFFFFF << PRIORITY_CLASS_BITS_POS)
 #define MASK_OUT_PRIORITY_CLASS (~PRIORITY_CLASS_MASK)
+#define MIN_PRIORITY_CLASS 0
+#define MAX_PRIORITY_CLASS ((1 << NBITS_PRIORITY_CLASS) - 1)
 
 #endif

lib/blob/blobstore.c

@@ -3915,6 +3915,8 @@ bs_alloc(struct spdk_bs_dev *dev, struct spdk_bs_opts *opts, struct spdk_blob_st
 	bs->md_thread = spdk_get_thread();
 	assert(bs->md_thread != NULL);
 
+	bs->priority_class = MAX_PRIORITY_CLASS; // max priority for metadata I/O
+
 	/*
 	 * Do not use bs_lba_to_cluster() here since blockcnt may not be an
 	 *  even multiple of the cluster size.
@@ -10300,8 +10302,6 @@ void
 spdk_blob_set_priority_class(struct spdk_blob* blob, int priority_class)
 {
 	blob->priority_class = priority_class;
-	int old_bs_priority_class = blob->bs->priority_class;
-	blob->bs->priority_class = spdk_max(old_bs_priority_class, blob->priority_class);
 }
 
 SPDK_LOG_REGISTER_COMPONENT(blob)

module/bdev/lvol/vbdev_lvol_rpc.c

@@ -369,10 +369,8 @@ rpc_bdev_lvol_create(struct spdk_jsonrpc_request *request,
 		clear_method = LVOL_CLEAR_WITH_DEFAULT;
 	}
 
-	const int min_priority_class = 0;
-	const int max_priority_class = (1 << NBITS_PRIORITY_CLASS) - 1;
-	if (!(req.lvol_priority_class >= min_priority_class && req.lvol_priority_class <= max_priority_class)) {
-		SPDK_ERRLOG("lvol priority class is not within the allowed range of [%d, %d]", min_priority_class, max_priority_class);
+	if (!(req.lvol_priority_class >= MIN_PRIORITY_CLASS && req.lvol_priority_class <= MAX_PRIORITY_CLASS)) {
+		SPDK_ERRLOG("lvol priority class is not within the allowed range of [%d, %d]", MIN_PRIORITY_CLASS, MAX_PRIORITY_CLASS);
 		spdk_jsonrpc_send_error_response(request, -EINVAL, spdk_strerror(EINVAL));
 		goto cleanup;
 	}
@@ -1712,10 +1710,8 @@ void rpc_bdev_lvol_set_priority_class(struct spdk_jsonrpc_request *request,
 		goto cleanup;
 	}
 
-	const int min_priority_class = 0;
-	const int max_priority_class = (1 << NBITS_PRIORITY_CLASS) - 1;
-	if (!(req.lvol_priority_class >= min_priority_class && req.lvol_priority_class <= max_priority_class)) {
-		SPDK_ERRLOG("lvol priority class is not within the allowed range of [%d, %d]", min_priority_class, max_priority_class);
+	if (!(req.lvol_priority_class >= MIN_PRIORITY_CLASS && req.lvol_priority_class <= MAX_PRIORITY_CLASS)) {
+		SPDK_ERRLOG("lvol priority class is not within the allowed range of [%d, %d]", MIN_PRIORITY_CLASS, MAX_PRIORITY_CLASS);
 		spdk_jsonrpc_send_error_response(request, -EINVAL, spdk_strerror(EINVAL));
 		goto cleanup;
 	}