nbd: add nbd path into spdk_nbd_disk

Upcoming nbd RPC functions need to track nbd_path.
Export spdk_nbd_disk's nbd_path and bdev_name by
short functions, and list these functions into
nbd_internal.h

Change-Id: I0ca021a5c83e860ad7513b89c9c7783722ab875a
Signed-off-by: Xiaodong Liu <xiaodong.liu@intel.com>
Reviewed-on: https://review.gerrithub.io/390343
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>

lib/nbd/nbd.c

@@ -37,6 +37,7 @@
 #include <linux/nbd.h>
 
 #include "spdk/nbd.h"
+#include "nbd_internal.h"
 #include "spdk/bdev.h"
 #include "spdk/endian.h"
 #include "spdk/env.h"
@@ -72,6 +73,7 @@ struct spdk_nbd_disk {
 	struct spdk_bdev_desc	*bdev_desc;
 	struct spdk_io_channel	*ch;
 	int			dev_fd;
+	char			*nbd_path;
 	int			kernel_sp_fd;
 	int			spdk_sp_fd;
 	struct nbd_io		io;
@@ -98,6 +100,18 @@ spdk_nbd_fini(void)
 {
 }
 
+const char *
+spdk_nbd_disk_get_nbd_path(struct spdk_nbd_disk *nbd)
+{
+	return nbd->nbd_path;
+}
+
+const char *
+spdk_nbd_disk_get_bdev_name(struct spdk_nbd_disk *nbd)
+{
+	return spdk_bdev_get_name(nbd->bdev);
+}
+
 static bool
 is_read(enum spdk_bdev_io_type io_type)
 {
@@ -135,6 +149,10 @@ _nbd_stop(struct spdk_nbd_disk *nbd)
 		close(nbd->dev_fd);
 	}
 
+	if (nbd->nbd_path) {
+		free(nbd->nbd_path);
+	}
+
 	if (nbd->spdk_sp_fd >= 0) {
 		close(nbd->spdk_sp_fd);
 	}
@@ -473,6 +491,12 @@ spdk_nbd_start(const char *bdev_name, const char *nbd_path)
 
 	nbd->spdk_sp_fd = sp[0];
 	nbd->kernel_sp_fd = sp[1];
+	nbd->nbd_path = strdup(nbd_path);
+	if (!nbd->nbd_path) {
+		SPDK_ERRLOG("strdup allocation failure\n");
+		goto err;
+	}
+
 	nbd->dev_fd = open(nbd_path, O_RDWR);
 	if (nbd->dev_fd == -1) {
 		spdk_strerror_r(errno, buf, sizeof(buf));

lib/nbd/nbd_internal.h

@@ -0,0 +1,44 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright (c) Intel Corporation.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef SPDK_NBD_INTERNAL_H
+#define SPDK_NBD_INTERNAL_H
+
+#include "spdk/stdinc.h"
+#include "spdk/nbd.h"
+
+const char *spdk_nbd_disk_get_nbd_path(struct spdk_nbd_disk *nbd);
+
+const char *spdk_nbd_disk_get_bdev_name(struct spdk_nbd_disk *nbd);
+
+#endif /* SPDK_NBD_INTERNAL_H */