bdev/aio: The user now provides the names of AIO bdevs

The user now must choose the name for each AIO bdev. This
provides consistency for names across restarts.

Change-Id: I13ced1d02bb28c51d314512d60f739499b0c7d8d
Signed-off-by: Ben Walker <benjamin.walker@intel.com>

doc/bdev/getting_started.md

@@ -62,9 +62,10 @@ Configuration file syntax:
 
 ~~~
 [AIO]
-  # normal file or block device
-  AIO /dev/sdb
-  AIO /dev/sdc
+  # AIO <file name> <bdev name>
+  # The file name is the backing device
+  # The bdev name can be referenced from elsewhere in the configuration file.
+  AIO /dev/sdb AIO0
 ~~~
 
 This exports 2 aio block devices, named AIO0 and AIO1.

etc/spdk/iscsi.conf.in

@@ -130,10 +130,14 @@
   Whitelist 00:04.1
 
 # Users must change this section to match the /dev/sdX devices to be
-#  exported as iSCSI LUNs. The devices are accessed using Linux AIO.
+# exported as iSCSI LUNs. The devices are accessed using Linux AIO.
+# The format is:
+# AIO <file name> <bdev name>
+# The file name is the backing device
+# The bdev name can be referenced from elsewhere in the configuration file.
 [AIO]
-  AIO /dev/sdb
-  AIO /dev/sdc
+  AIO /dev/sdb AIO0
+  AIO /dev/sdc AIO1
 
 # The Split virtual block device slices block devices into multiple smaller bdevs.
 [Split]

etc/spdk/nvmf.conf.in

@@ -43,11 +43,15 @@
   NumberOfLuns 8
   LunSizeInMB 64
 
-# Users must change this section to match the /dev/sdX devices to be virtual
-# NVMe devices. The devices are accessed using Linux AIO.
+# Users must change this section to match the /dev/sdX devices to be
+# exported as iSCSI LUNs. The devices are accessed using Linux AIO.
+# The format is:
+# AIO <file name> <bdev name>
+# The file name is the backing device
+# The bdev name can be referenced from elsewhere in the configuration file.
 [AIO]
-  AIO /dev/sdb
-  AIO /dev/sdc
+  AIO /dev/sdb AIO0
+  AIO /dev/sdc AIO1
 
 # Define NVMf protocol global options
 [Nvmf]

lib/bdev/aio/blockdev_aio.c

@@ -48,8 +48,6 @@
 
 #include "spdk_internal/log.h"
 
-static int g_blockdev_count = 0;
-
 static int blockdev_aio_initialize(void);
 static void aio_free_disk(struct file_disk *fdisk);
 
@@ -341,7 +339,7 @@ static void aio_free_disk(struct file_disk *fdisk)
 }
 
 struct spdk_bdev *
-create_aio_disk(char *fname)
+create_aio_disk(const char *name, const char *fname)
 {
 	struct file_disk *fdisk;
 
@@ -360,8 +358,7 @@ create_aio_disk(char *fname)
 	fdisk->size = spdk_fd_get_size(fdisk->fd);
 
 	TAILQ_INIT(&fdisk->sync_completion_list);
-	snprintf(fdisk->disk.name, SPDK_BDEV_MAX_NAME_LENGTH, "AIO%d",
-		 g_blockdev_count);
+	snprintf(fdisk->disk.name, SPDK_BDEV_MAX_NAME_LENGTH, "%s", name);
 	snprintf(fdisk->disk.product_name, SPDK_BDEV_MAX_PRODUCT_NAME_LENGTH, "AIO disk");
 
 	fdisk->disk.need_aligned_buffer = 1;
@@ -371,7 +368,6 @@ create_aio_disk(char *fname)
 	fdisk->disk.ctxt = fdisk;
 
 	fdisk->disk.fn_table = &aio_fn_table;
-	g_blockdev_count++;
 
 	spdk_io_device_register(&fdisk->disk, blockdev_aio_create_cb, blockdev_aio_destroy_cb,
 				sizeof(struct blockdev_aio_io_channel));
@@ -386,38 +382,42 @@ error_return:
 
 static int blockdev_aio_initialize(void)
 {
+	size_t i;
+	struct spdk_conf_section *sp;
 	struct spdk_bdev *bdev;
-	int i;
-	const char *val = NULL;
-	char *file;
-	struct spdk_conf_section *sp = spdk_conf_find_section(NULL, "AIO");
-	bool skip_missing = false;
 
-	if (sp != NULL) {
-		val = spdk_conf_section_get_val(sp, "SkipMissingFiles");
-	}
-	if (val != NULL && !strcmp(val, "Yes")) {
-		skip_missing = true;
+	sp = spdk_conf_find_section(NULL, "AIO");
+	if (!sp) {
+		return 0;
 	}
 
-	if (sp != NULL) {
-		for (i = 0; ; i++) {
-			val = spdk_conf_section_get_nval(sp, "AIO", i);
-			if (val == NULL)
-				break;
-			file = spdk_conf_section_get_nmval(sp, "AIO", i, 0);
-			if (file == NULL) {
-				SPDK_ERRLOG("AIO%d: format error\n", i);
-				return -1;
-			}
+	i = 0;
+	while (true) {
+		const char *file;
+		const char *name;
 
-			bdev = create_aio_disk(file);
-
-			if (bdev == NULL && !skip_missing) {
-				return -1;
-			}
+		file = spdk_conf_section_get_nmval(sp, "AIO", i, 0);
+		if (!file) {
+			break;
 		}
+
+		name = spdk_conf_section_get_nmval(sp, "AIO", i, 1);
+		if (!name) {
+			SPDK_ERRLOG("No name provided for AIO disk with file %s\n", file);
+			i++;
+			continue;
+		}
+
+		bdev = create_aio_disk(name, file);
+		if (!bdev) {
+			SPDK_ERRLOG("Unable to create AIO bdev from file %s\n", file);
+			i++;
+			continue;
+		}
+
+		i++;
 	}
+
 	return 0;
 }
 

lib/bdev/aio/blockdev_aio.h

@@ -57,7 +57,7 @@ struct blockdev_aio_io_channel {
 
 struct file_disk {
 	struct spdk_bdev	disk;	/* this must be first element */
-	char			*file;
+	const char		*file;
 	int			fd;
 	char			disk_name[SPDK_BDEV_MAX_NAME_LENGTH];
 	uint64_t		size;
@@ -69,6 +69,6 @@ struct file_disk {
 	TAILQ_HEAD(, blockdev_aio_task) sync_completion_list;
 };
 
-struct spdk_bdev *create_aio_disk(char *fname);
+struct spdk_bdev *create_aio_disk(const char *name, const char *fname);
 
 #endif // SPDK_BLOCKDEV_AIO_H

lib/bdev/aio/blockdev_aio_rpc.c

@@ -38,16 +38,19 @@
 #include "spdk_internal/log.h"
 
 struct rpc_construct_aio {
+	char *name;
 	char *fname;
 };
 
 static void
 free_rpc_construct_aio(struct rpc_construct_aio *req)
 {
+	free(req->name);
 	free(req->fname);
 }
 
 static const struct spdk_json_object_decoder rpc_construct_aio_decoders[] = {
+	{"name", offsetof(struct rpc_construct_aio, name), spdk_json_decode_string},
 	{"fname", offsetof(struct rpc_construct_aio, fname), spdk_json_decode_string},
 };
 
@@ -67,7 +70,7 @@ spdk_rpc_construct_aio_bdev(struct spdk_jsonrpc_server_conn *conn,
 		goto invalid;
 	}
 
-	bdev = create_aio_disk(req.fname);
+	bdev = create_aio_disk(req.name, req.fname);
 	if (bdev == NULL) {
 		goto invalid;
 	}

scripts/rpc.py

@@ -165,11 +165,14 @@ p.set_defaults(func=construct_malloc_bdev)
 
 
 def construct_aio_bdev(args):
-    params = {'fname': args.fname}
+    params = {'name': args.name,
+              'fname': args.fname}
+
     print_array(jsonrpc_call('construct_aio_bdev', params))
 
 p = subparsers.add_parser('construct_aio_bdev', help='Add a bdev with aio backend')
 p.add_argument('fname', help='Path to device or file (ex: /dev/sda)')
+p.add_argument('name', help='Block device name')
 p.set_defaults(func=construct_aio_bdev)
 
 def construct_nvme_bdev(args):

test/lib/bdev/bdev.conf.in

@@ -14,9 +14,4 @@
   Split Malloc2 8 1
 
 [AIO]
-  # skip these blockdevs if the /dev/ramX nodes do not exist
-  #  so that the blockdev tests can still run on systems that
-  #  do not have /dev/ramX nodes configured
-  SkipMissingFiles Yes
-  # Linux AIO backend
-  AIO /dev/ram0
+  AIO /dev/ram0 AIO0