bdev/aio: Add support for blockdev_aio_get_spdk_running_config().

Change-Id: I7458a89c89b0605e5806768c03ef519fc222bce5
Signed-off-by: Chunyang Hui <Chunyang.hui@intel.com>
Reviewed-on: https://review.gerrithub.io/375256
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: GangCao <gang.cao@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>

lib/bdev/aio/bdev_aio.c

@@ -47,6 +47,8 @@
 
 static int bdev_aio_initialize(void);
 static void aio_free_disk(struct file_disk *fdisk);
+static void bdev_aio_get_spdk_running_config(FILE *fp);
+static TAILQ_HEAD(, file_disk) g_aio_disk_head;
 
 #define SPDK_AIO_QUEUE_DEPTH 128
 
@@ -56,7 +58,8 @@ bdev_aio_get_ctx_size(void)
 	return sizeof(struct bdev_aio_task);
 }
 
-SPDK_BDEV_MODULE_REGISTER(aio, bdev_aio_initialize, NULL, NULL, bdev_aio_get_ctx_size, NULL)
+SPDK_BDEV_MODULE_REGISTER(aio, bdev_aio_initialize, NULL, bdev_aio_get_spdk_running_config,
+			  bdev_aio_get_ctx_size, NULL)
 
 static int
 bdev_aio_open(struct file_disk *disk)
@@ -167,6 +170,7 @@ bdev_aio_destruct(void *ctx)
 	struct file_disk *fdisk = ctx;
 	int rc = 0;
 
+	TAILQ_REMOVE(&g_aio_disk_head, fdisk, link);
 	rc = bdev_aio_close(fdisk);
 	if (rc < 0) {
 		SPDK_ERRLOG("bdev_aio_close() failed\n");
@@ -397,6 +401,7 @@ create_aio_disk(const char *name, const char *filename, uint32_t block_size)
 			SPDK_ERRLOG("Block size could not be auto-detected\n");
 			goto error_return;
 		}
+		fdisk->block_size_override = false;
 		block_size = detected_block_size;
 	} else {
 		if (block_size < detected_block_size) {
@@ -409,6 +414,7 @@ create_aio_disk(const char *name, const char *filename, uint32_t block_size)
 				     "auto-detected block size %" PRIu32 "\n",
 				     block_size, detected_block_size);
 		}
+		fdisk->block_size_override = true;
 	}
 
 	if (block_size < 512) {
@@ -437,6 +443,8 @@ create_aio_disk(const char *name, const char *filename, uint32_t block_size)
 	spdk_io_device_register(&fdisk->fd, bdev_aio_create_cb, bdev_aio_destroy_cb,
 				sizeof(struct bdev_aio_io_channel));
 	spdk_bdev_register(&fdisk->disk);
+
+	TAILQ_INSERT_TAIL(&g_aio_disk_head, fdisk, link);
 	return &fdisk->disk;
 
 error_return:
@@ -452,6 +460,7 @@ bdev_aio_initialize(void)
 	struct spdk_conf_section *sp;
 	struct spdk_bdev *bdev;
 
+	TAILQ_INIT(&g_aio_disk_head);
 	sp = spdk_conf_find_section(NULL, "AIO");
 	if (!sp) {
 		return 0;
@@ -494,4 +503,35 @@ bdev_aio_initialize(void)
 	return 0;
 }
 
+static void
+bdev_aio_get_spdk_running_config(FILE *fp)
+{
+	char 	*file;
+	char 	*name;
+	uint32_t block_size;
+	struct 	 file_disk *fdisk;
+
+	fprintf(fp,
+		"\n"
+		"# Users must change this section to match the /dev/sdX devices to be\n"
+		"# exported as iSCSI LUNs. The devices are accessed using Linux AIO.\n"
+		"# The format is:\n"
+		"# AIO <file name> <bdev name> [<block size>]\n"
+		"# The file name is the backing device\n"
+		"# The bdev name can be referenced from elsewhere in the configuration file.\n"
+		"# Block size may be omitted to automatically detect the block size of a disk.\n"
+		"[AIO]\n");
+
+	TAILQ_FOREACH(fdisk, &g_aio_disk_head, link) {
+		file = fdisk->filename;
+		name = fdisk->disk.name;
+		block_size = fdisk->disk.blocklen;
+		fprintf(fp, "  AIO %s %s ", file, name);
+		if (fdisk->block_size_override)
+			fprintf(fp, "%d", block_size);
+		fprintf(fp, "\n");
+	}
+	fprintf(fp, "\n");
+}
+
 SPDK_LOG_REGISTER_TRACE_FLAG("aio", SPDK_TRACE_AIO)

lib/bdev/aio/bdev_aio.h

@@ -58,6 +58,8 @@ struct file_disk {
 	struct spdk_bdev	disk;
 	char			*filename;
 	int			fd;
+	TAILQ_ENTRY(file_disk)  link;
+	bool			block_size_override;
 };
 
 struct spdk_bdev *create_aio_disk(const char *name, const char *filename, uint32_t block_size);