block/rnbd: introduce rnbd_access_modes

Add one new array (marked with __maybe_unused to prevent gcc warning about
"defined but not used" with W=1), then we can remove rnbd_access_mode_str
and rnbd-common.c accordingly.
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Link: https://lore.kernel.org/r/20230524070026.2932-4-guoqing.jiang@linux.devSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/rnbd/Makefile

@@ -3,13 +3,11 @@
 ccflags-y := -I$(srctree)/drivers/infiniband/ulp/rtrs
 
 rnbd-client-y := rnbd-clt.o \
-		  rnbd-clt-sysfs.o \
-		  rnbd-common.o
+		  rnbd-clt-sysfs.o
 
 CFLAGS_rnbd-srv-trace.o = -I$(src)
 
-rnbd-server-y := rnbd-common.o \
-		  rnbd-srv.o \
+rnbd-server-y := rnbd-srv.o \
 		  rnbd-srv-sysfs.o \
 		  rnbd-srv-trace.o
 

drivers/block/rnbd/rnbd-clt-sysfs.c

@@ -278,7 +278,7 @@ static ssize_t access_mode_show(struct kobject *kobj,
 
 	dev = container_of(kobj, struct rnbd_clt_dev, kobj);
 
-	return sysfs_emit(page, "%s\n", rnbd_access_mode_str(dev->access_mode));
+	return sysfs_emit(page, "%s\n", rnbd_access_modes[dev->access_mode].str);
 }
 
 static struct kobj_attribute rnbd_clt_access_mode =
@@ -596,7 +596,7 @@ static ssize_t rnbd_clt_map_device_store(struct kobject *kobj,
 
 	pr_info("Mapping device %s on session %s, (access_mode: %s, nr_poll_queues: %d)\n",
 		pathname, sessname,
-		rnbd_access_mode_str(access_mode),
+		rnbd_access_modes[access_mode].str,
 		nr_poll_queues);
 
 	dev = rnbd_clt_map_device(sessname, paths, path_cnt, port_nr, pathname,

drivers/block/rnbd/rnbd-common.c

-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * RDMA Network Block Driver
- *
- * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
- * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
- * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
- */
-#include "rnbd-proto.h"
-
-const char *rnbd_access_mode_str(enum rnbd_access_mode mode)
-{
-	switch (mode) {
-	case RNBD_ACCESS_RO:
-		return "ro";
-	case RNBD_ACCESS_RW:
-		return "rw";
-	case RNBD_ACCESS_MIGRATION:
-		return "migration";
-	default:
-		return "unknown";
-	}
-}

drivers/block/rnbd/rnbd-proto.h

@@ -61,6 +61,15 @@ enum rnbd_access_mode {
 	RNBD_ACCESS_MIGRATION,
 };
 
+static const __maybe_unused struct {
+	enum rnbd_access_mode mode;
+	const char *str;
+} rnbd_access_modes[] = {
+	[RNBD_ACCESS_RO] = {RNBD_ACCESS_RO, "ro"},
+	[RNBD_ACCESS_RW] = {RNBD_ACCESS_RW, "rw"},
+	[RNBD_ACCESS_MIGRATION] = {RNBD_ACCESS_MIGRATION, "migration"},
+};
+
 /**
  * struct rnbd_msg_sess_info - initial session info from client to server
  * @hdr:		message header

drivers/block/rnbd/rnbd-srv-sysfs.c

@@ -103,7 +103,7 @@ static ssize_t access_mode_show(struct kobject *kobj,
 	sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
 
 	return sysfs_emit(page, "%s\n",
-			  rnbd_access_mode_str(sess_dev->access_mode));
+			  rnbd_access_modes[sess_dev->access_mode].str);
 }
 
 static struct kobj_attribute rnbd_srv_dev_session_access_mode_attr =

drivers/block/rnbd/rnbd-srv.c

@@ -483,7 +483,7 @@ static int rnbd_srv_check_update_open_perm(struct rnbd_srv_dev *srv_dev,
 			pr_err("Mapping device '%s' for session %s with RW permissions failed. Device already opened as 'RW' by %d client(s), access mode %s.\n",
 			       srv_dev->id, srv_sess->sessname,
 			       srv_dev->open_write_cnt,
-			       rnbd_access_mode_str(access_mode));
+			       rnbd_access_modes[access_mode].str);
 		}
 		break;
 	case RNBD_ACCESS_MIGRATION:
@@ -494,7 +494,7 @@ static int rnbd_srv_check_update_open_perm(struct rnbd_srv_dev *srv_dev,
 			pr_err("Mapping device '%s' for session %s with migration permissions failed. Device already opened as 'RW' by %d client(s), access mode %s.\n",
 			       srv_dev->id, srv_sess->sessname,
 			       srv_dev->open_write_cnt,
-			       rnbd_access_mode_str(access_mode));
+			       rnbd_access_modes[access_mode].str);
 		}
 		break;
 	default: