ocf/rpc: Add bdev_ocf_set_cache_mode method

This method allows to dynamically switch cache mode on OCF bdev

Signed-off-by: Rafal Stefanowski <rafal.stefanowski@intel.com>
Change-Id: I933273e35bb9f29528657f8f6800c6b52dde32e5
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/6547
Community-CI: Broadcom CI
Community-CI: Mellanox Build Bot
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>

doc/jsonrpc.md

@@ -2232,6 +2232,47 @@ Example response:
 }
 ~~~
 
+## bdev_ocf_set_cache_mode {#rpc_bdev_ocf_set_cache_mode}
+
+Set new cache mode on OCF bdev.
+
+### Parameters
+
+Name                    | Optional | Type        | Description
+----------------------- | -------- | ----------- | -----------
+name                    | Required | string      | Bdev name
+mode                    | Required | string      | OCF cache mode: wb, wt, pt, wa, wi, wo
+
+### Response
+
+New cache mode name.
+
+### Example
+
+Example request:
+
+~~~
+{
+  "params": {
+    "name": "ocf0",
+    "mode": "pt",
+  },
+  "jsonrpc": "2.0",
+  "method": "bdev_ocf_set_cache_mode",
+  "id": 1
+}
+~~~
+
+Example response:
+
+~~~
+{
+  "jsonrpc": "2.0",
+  "id": 1,
+  "result": "pt"
+}
+~~~
+
 ## bdev_malloc_create {#rpc_bdev_malloc_create}
 
 Construct @ref bdev_config_malloc

module/bdev/ocf/vbdev_ocf.c

@@ -1479,6 +1479,31 @@ vbdev_ocf_construct(const char *vbdev_name,
 	}
 }
 
+/* Set new cache mode on OCF cache */
+void
+vbdev_ocf_set_cache_mode(struct vbdev_ocf *vbdev,
+			 const char *cache_mode_name,
+			 void (*cb)(int, struct vbdev_ocf *, void *),
+			 void *cb_arg)
+{
+	ocf_cache_t cache;
+	ocf_cache_mode_t cache_mode;
+	int rc;
+
+	cache = vbdev->ocf_cache;
+	cache_mode = ocf_get_cache_mode(cache_mode_name);
+
+	rc = ocf_mngt_cache_trylock(cache);
+	if (rc) {
+		cb(rc, vbdev, cb_arg);
+		return;
+	}
+
+	rc = ocf_mngt_cache_set_mode(cache, cache_mode);
+	ocf_mngt_cache_unlock(cache);
+	cb(rc, vbdev, cb_arg);
+}
+
 /* This called if new device is created in SPDK application
  * If that device named as one of base bdevs of OCF vbdev,
  * claim and open them */

module/bdev/ocf/vbdev_ocf.h

@@ -203,6 +203,13 @@ int vbdev_ocf_delete(struct vbdev_ocf *vbdev, void (*cb)(void *, int), void *cb_
 
 int vbdev_ocf_delete_clean(struct vbdev_ocf *vbdev, void (*cb)(void *, int), void *cb_arg);
 
+/* Set new cache mode on OCF cache */
+void vbdev_ocf_set_cache_mode(
+	struct vbdev_ocf *vbdev,
+	const char *cache_mode_name,
+	void (*cb)(int, struct vbdev_ocf *, void *),
+	void *cb_arg);
+
 typedef void (*vbdev_ocf_foreach_fn)(struct vbdev_ocf *, void *);
 
 /* Execute fn for each OCF device that is online or waits for base devices */

module/bdev/ocf/vbdev_ocf_rpc.c

@@ -33,6 +33,7 @@
 
 #include "vbdev_ocf.h"
 #include "stats.h"
+#include "utils.h"
 #include "spdk/log.h"
 #include "spdk/rpc.h"
 #include "spdk/string.h"
@@ -359,3 +360,71 @@ end:
 }
 SPDK_RPC_REGISTER("bdev_ocf_get_bdevs", rpc_bdev_ocf_get_bdevs, SPDK_RPC_RUNTIME)
 SPDK_RPC_REGISTER_ALIAS_DEPRECATED(bdev_ocf_get_bdevs, get_ocf_bdevs)
+
+/* Structure to hold the parameters for this RPC method. */
+struct rpc_bdev_ocf_set_cache_mode {
+	char *name;			/* main vbdev name */
+	char *mode;			/* OCF cache mode to switch to */
+};
+
+static void
+free_rpc_bdev_ocf_set_cache_mode(struct rpc_bdev_ocf_set_cache_mode *r)
+{
+	free(r->name);
+	free(r->mode);
+}
+
+/* Structure to decode the input parameters for this RPC method. */
+static const struct spdk_json_object_decoder rpc_bdev_ocf_set_cache_mode_decoders[] = {
+	{"name", offsetof(struct rpc_bdev_ocf_set_cache_mode, name), spdk_json_decode_string},
+	{"mode", offsetof(struct rpc_bdev_ocf_set_cache_mode, mode), spdk_json_decode_string},
+};
+
+static void
+cache_mode_cb(int status, struct vbdev_ocf *vbdev, void *cb_arg)
+{
+	struct spdk_jsonrpc_request *request = cb_arg;
+	struct spdk_json_write_ctx *w;
+
+	if (status) {
+		spdk_jsonrpc_send_error_response_fmt(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR,
+						     "Could not change OCF vbdev cache mode: %d",
+						     status);
+	} else {
+		w = spdk_jsonrpc_begin_result(request);
+		spdk_json_write_string(w, ocf_get_cache_modename(
+					       ocf_cache_get_mode(vbdev->ocf_cache)));
+		spdk_jsonrpc_end_result(request, w);
+	}
+}
+
+static void
+rpc_bdev_ocf_set_cache_mode(struct spdk_jsonrpc_request *request,
+			    const struct spdk_json_val *params)
+{
+	struct rpc_bdev_ocf_set_cache_mode req = {NULL};
+	struct vbdev_ocf *vbdev;
+	int status;
+
+	status = spdk_json_decode_object(params, rpc_bdev_ocf_set_cache_mode_decoders,
+					 SPDK_COUNTOF(rpc_bdev_ocf_set_cache_mode_decoders),
+					 &req);
+	if (status) {
+		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INVALID_PARAMS,
+						 "Invalid parameters");
+		goto end;
+	}
+
+	vbdev = vbdev_ocf_get_by_name(req.name);
+	if (vbdev == NULL) {
+		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INVALID_PARAMS,
+						 spdk_strerror(ENODEV));
+		goto end;
+	}
+
+	vbdev_ocf_set_cache_mode(vbdev, req.mode, cache_mode_cb, request);
+
+end:
+	free_rpc_bdev_ocf_set_cache_mode(&req);
+}
+SPDK_RPC_REGISTER("bdev_ocf_set_cache_mode", rpc_bdev_ocf_set_cache_mode, SPDK_RPC_RUNTIME)

scripts/rpc.py

@@ -325,6 +325,16 @@ if __name__ == "__main__":
     p.add_argument('name', nargs='?', default=None, help='name of OCF vbdev or name of cache device or name of core device (optional)')
     p.set_defaults(func=bdev_ocf_get_bdevs)
 
+    def bdev_ocf_set_cache_mode(args):
+        print_json(rpc.bdev.bdev_ocf_set_cache_mode(args.client,
+                                                    name=args.name,
+                                                    mode=args.mode))
+    p = subparsers.add_parser('bdev_ocf_set_cache_mode',
+                              help='Set cache mode of OCF block device')
+    p.add_argument('name', help='Name of OCF bdev')
+    p.add_argument('mode', help='OCF cache mode', choices=['wb', 'wt', 'pt', 'wa', 'wi', 'wo'])
+    p.set_defaults(func=bdev_ocf_set_cache_mode)
+
     def bdev_malloc_create(args):
         num_blocks = (args.total_size * 1024 * 1024) // args.block_size
         print_json(rpc.bdev.bdev_malloc_create(args.client,

scripts/rpc/bdev.py

@@ -204,6 +204,24 @@ def bdev_ocf_get_bdevs(client, name=None):
     return client.call('bdev_ocf_get_bdevs', params)
 
 
+def bdev_ocf_set_cache_mode(client, name, mode):
+    """Set cache mode of OCF block device
+
+    Args:
+        name: name of OCF bdev
+        mode: OCF cache mode: {'wb', 'wt', 'pt', 'wa', 'wi', 'wo'}
+
+    Returns:
+        New cache mode name
+    """
+    params = {
+        'name': name,
+        'mode': mode,
+    }
+
+    return client.call('bdev_ocf_set_cache_mode', params)
+
+
 @deprecated_alias('construct_malloc_bdev')
 def bdev_malloc_create(client, num_blocks, block_size, name=None, uuid=None):
     """Construct a malloc block device.

test/ocf/management/configuration-change.sh

@@ -0,0 +1,29 @@
+#!/usr/bin/env bash
+
+curdir=$(dirname $(readlink -f "${BASH_SOURCE[0]}"))
+rootdir=$(readlink -f $curdir/../../..)
+source $rootdir/test/common/autotest_common.sh
+
+rpc_py=$rootdir/scripts/rpc.py
+cache_modes=(wt wb pt wa wi wo)
+
+$SPDK_BIN_DIR/iscsi_tgt &
+spdk_pid=$!
+
+waitforlisten $spdk_pid
+
+# Prepare OCF cache
+$rpc_py bdev_malloc_create 101 512 -b Malloc0
+$rpc_py bdev_malloc_create 101 512 -b Malloc1
+$rpc_py bdev_ocf_create Cache wt Malloc0 Malloc1
+
+$rpc_py bdev_ocf_get_bdevs | jq -e \
+	'.[0] | .started and .cache.attached and .core.attached'
+
+# Change cache mode
+for cache_mode in "${cache_modes[@]}"; do
+	$rpc_py bdev_ocf_set_cache_mode Cache $cache_mode
+done
+
+trap - SIGINT SIGTERM EXIT
+killprocess $spdk_pid

test/ocf/ocf.sh

@@ -12,3 +12,4 @@ run_test "ocf_create_destruct" "$testdir/management/create-destruct.sh"
 run_test "ocf_multicore" "$testdir/management/multicore.sh"
 run_test "ocf_persistent_metadata" "$testdir/management/persistent-metadata.sh"
 run_test "ocf_remove" "$testdir/management/remove.sh"
+run_test "ocf_configuration_change" "$testdir/management/configuration-change.sh"