Commit efdd6edb authored by Xiaodong Liu's avatar Xiaodong Liu Committed by Darek Stojaczyk
Browse files

nbd: optional nbd_device in start_nbd_disk 

Enhance RPC method start_nbd_disk to take nbd_device as
one optional parameter. If it is not assigned, automaticly
choose an available nbd device path from /dev/nbd0 to
/dev/nbdN.
For github issue #324:
https://github.com/spdk/spdk/issues/324



Change-Id: I72c064d8bd476df342f5aa0af4d6120eb021c7ed
Signed-off-by: default avatarXiaodong Liu <xiaodong.liu@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/440453


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
Reviewed-by: default avatarDarek Stojaczyk <dariusz.stojaczyk@intel.com>
parent bfd1e46e

CHANGELOG.md

+3 −0
Original line number Diff line number Diff line
@@ -74,6 +74,9 @@ that common usage of those functions is to call them just before terminating the 


New `get_spdk_version` RPC method is introduced to get version info of the running SPDK application.



The `start_nbd_disk` RPC method now take nbd_device as an optional parameter. If nbd_device

is specified, use that specified nbd device. If it's not specified, pick available one.



## v19.01:



### ocf bdev

lib/nbd/nbd_rpc.c

+130 −14
Original line number Diff line number Diff line
@@ -44,6 +44,10 @@ 
struct rpc_start_nbd_disk {

	char *bdev_name;

	char *nbd_device;

	/* Used to search one available nbd device */

	int nbd_idx;

	bool nbd_idx_specified;

	struct spdk_jsonrpc_request *request;

};



static void
@@ -51,19 +55,107 @@ free_rpc_start_nbd_disk(struct rpc_start_nbd_disk *req) 
{

	free(req->bdev_name);

	free(req->nbd_device);

	free(req);

}



static const struct spdk_json_object_decoder rpc_start_nbd_disk_decoders[] = {

	{"bdev_name", offsetof(struct rpc_start_nbd_disk, bdev_name), spdk_json_decode_string},

	{"nbd_device", offsetof(struct rpc_start_nbd_disk, nbd_device), spdk_json_decode_string},

	{"nbd_device", offsetof(struct rpc_start_nbd_disk, nbd_device), spdk_json_decode_string, true},

};



/* Return 0 to indicate the nbd_device might be available,

 * or non-zero to indicate the nbd_device is invalid or in using.

 */

static int

check_available_nbd_disk(char *nbd_device)

{

	char nbd_block_path[256];

	char tail[2];

	int rc;

	unsigned int nbd_idx;

	struct spdk_nbd_disk *nbd;



	/* nbd device path must be in format of /dev/nbd<num>, with no tail. */

	rc = sscanf(nbd_device, "/dev/nbd%u%1s", &nbd_idx, tail);

	if (rc != 1) {

		return -1;

	}



	/* make sure nbd_device is not registered inside SPDK */

	nbd = spdk_nbd_disk_find_by_nbd_path(nbd_device);

	if (nbd) {

		/* nbd_device is in using */

		return 1;

	}



	/* A valid pid file in /sys/block indicates the device is in using */

	snprintf(nbd_block_path, 256, "/sys/block/nbd%u/pid", nbd_idx);



	rc = open(nbd_block_path, O_RDONLY);

	if (rc < 0) {

		if (errno == ENOENT) {

			/* nbd_device might be available */

			return 0;

		} else {

			SPDK_ERRLOG("Failed to check PID file %s: %s\n", nbd_block_path, spdk_strerror(errno));

			return -1;

		}

	}



	close(rc);



	/* nbd_device is in using */

	return 1;

}



static char *

find_available_nbd_disk(int nbd_idx, int *next_nbd_idx)

{

	int i, rc;

	char nbd_device[20];



	for (i = nbd_idx; ; i++) {

		snprintf(nbd_device, 20, "/dev/nbd%d", i);

		/* Check whether an nbd device exists in order to reach the last one nbd device */

		rc = access(nbd_device, F_OK);

		if (rc != 0) {

			break;

		}



		rc = check_available_nbd_disk(nbd_device);

		if (rc == 0) {

			if (next_nbd_idx != NULL) {

				*next_nbd_idx = i + 1;

			}



			return strdup(nbd_device);

		}

	}



	return NULL;

}



static void

spdk_rpc_start_nbd_done(void *cb_arg, struct spdk_nbd_disk *nbd, int rc)

{

	struct spdk_jsonrpc_request *request = cb_arg;

	struct rpc_start_nbd_disk *req = cb_arg;

	struct spdk_jsonrpc_request *request = req->request;

	struct spdk_json_write_ctx *w;



	/* Check whether it's automatic nbd-device assignment */

	if (rc == -EBUSY && req->nbd_idx_specified == false) {

		free(req->nbd_device);



		req->nbd_device = find_available_nbd_disk(req->nbd_idx, &req->nbd_idx);

		if (req->nbd_device != NULL) {

			spdk_nbd_start(req->bdev_name, req->nbd_device,

				       spdk_rpc_start_nbd_done, req);

			return;

		}



		SPDK_INFOLOG(SPDK_LOG_NBD, "There is no available nbd device.\n");

	}



	if (rc) {

		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INVALID_PARAMS, "Invalid parameters");

		return;
@@ -76,40 +168,64 @@ spdk_rpc_start_nbd_done(void *cb_arg, struct spdk_nbd_disk *nbd, int rc) 


	spdk_json_write_string(w, spdk_nbd_get_path(nbd));

	spdk_jsonrpc_end_result(request, w);



	free_rpc_start_nbd_disk(req);

}



static void

spdk_rpc_start_nbd_disk(struct spdk_jsonrpc_request *request,

			const struct spdk_json_val *params)

{

	struct rpc_start_nbd_disk req = {};

	struct spdk_nbd_disk *nbd;

	struct rpc_start_nbd_disk *req;

	int rc;



	req = calloc(1, sizeof(*req));

	if (req == NULL) {

		SPDK_ERRLOG("could not allocate start_nbd_disk request.\n");

		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR, "Out of memory");

		return;

	}



	if (spdk_json_decode_object(params, rpc_start_nbd_disk_decoders,

				    SPDK_COUNTOF(rpc_start_nbd_disk_decoders),

				    &req)) {

				    req)) {

		SPDK_ERRLOG("spdk_json_decode_object failed\n");

		goto invalid;

	}



	if (req.nbd_device == NULL || req.bdev_name == NULL) {

	if (req->bdev_name == NULL) {

		goto invalid;

	}



	/* make sure nbd_device is not registered */

	nbd = spdk_nbd_disk_find_by_nbd_path(req.nbd_device);

	if (nbd) {

	if (req->nbd_device != NULL) {

		req->nbd_idx_specified = true;

		rc = check_available_nbd_disk(req->nbd_device);

		if (rc == 1) {

			SPDK_DEBUGLOG(SPDK_LOG_NBD, "NBD device %s is in using.\n", req->nbd_device);

			goto invalid;

		}



		if (rc != 0) {

			SPDK_DEBUGLOG(SPDK_LOG_NBD, "Illegal nbd_device %s.\n", req->nbd_device);

			goto invalid;

		}

	} else {

		req->nbd_idx = 0;

		req->nbd_device = find_available_nbd_disk(req->nbd_idx, &req->nbd_idx);

		if (req->nbd_device == NULL) {

			SPDK_INFOLOG(SPDK_LOG_NBD, "There is no available nbd device.\n");

			goto invalid;

		}

	}



	spdk_nbd_start(req.bdev_name, req.nbd_device,

		       spdk_rpc_start_nbd_done, request);

	req->request = request;

	spdk_nbd_start(req->bdev_name, req->nbd_device,

		       spdk_rpc_start_nbd_done, req);



	free_rpc_start_nbd_disk(&req);

	return;



invalid:

	free_rpc_start_nbd_disk(&req);

	free_rpc_start_nbd_disk(req);

	spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INVALID_PARAMS, "Invalid parameters");

}

scripts/rpc.py

+1 −1
Original line number Diff line number Diff line
@@ -1327,7 +1327,7 @@ Format: 'user:u1 secret:s1 muser:mu1 msecret:ms1,user:u2 secret:s2 muser:mu2 mse 


    p = subparsers.add_parser('start_nbd_disk', help='Export a bdev as a nbd disk')

    p.add_argument('bdev_name', help='Blockdev name to be exported. Example: Malloc0.')

    p.add_argument('nbd_device', help='Nbd device name to be assigned. Example: /dev/nbd0.')

    p.add_argument('nbd_device', help='Nbd device name to be assigned. Example: /dev/nbd0.', nargs='?')

    p.set_defaults(func=start_nbd_disk)



    def stop_nbd_disk(args):

scripts/rpc/nbd.py

+3 −2
Original line number Diff line number Diff line 
def start_nbd_disk(client, bdev_name, nbd_device):

    params = {

        'bdev_name': bdev_name,

        'nbd_device': nbd_device

        'bdev_name': bdev_name

    }

    if nbd_device:

        params['nbd_device'] = nbd_device

    return client.call('start_nbd_disk', params)

test/bdev/blockdev.sh

+1 −0
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ function nbd_function_test() { 
		echo "Process nbd pid: $nbd_pid"

		waitforlisten $nbd_pid $rpc_server



		nbd_rpc_start_stop_verify $rpc_server "${bdev_list[*]}"

		nbd_rpc_data_verify $rpc_server "${bdev_list[*]}" "${nbd_list[*]}"



		$rpc_py -s $rpc_server delete_passthru_bdev TestPT