Commit fa649869 authored by Konrad Sztyber's avatar Konrad Sztyber Committed by Tomasz Zawadzki
Browse files

bdev: add timeout option to bdev_get_bdevs RPC 



This opption allows the bdev_get_bdevs RPC to block until a bdev with
specified name appears.  It can be useful, when a bdev is created
asynchronously and the exact moment at which it appears is not known.
For instance, with a discovery service, a bdev is created when a
namespace on a remote NVMeoF target is added, but it's not possible to
specify when that happens exactly.

Signed-off-by: default avatarKonrad Sztyber <konrad.sztyber@intel.com>
Change-Id: I6c1f974fba445376ca9d45aac2639202547410cc
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/11960


Community-CI: Mellanox Build Bot
Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com>
Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <smatsumoto@nvidia.com>
Reviewed-by: default avatarTomasz Zawadzki <tomasz.zawadzki@intel.com>
parent c0415fed

CHANGELOG.md

+5 −0
Original line number Diff line number Diff line
@@ -34,6 +34,11 @@ bdev_crypto_create RPC now requires hexlified 'key' and 'key2' params for all pm 
Unhexlifying is performed during RPC command processing and the vbdev crypto module runs on

binary keys as before.



### bdev



Added a timeout option to the `bdev_get_bdevs` RPC.  It allows the user to specify the amount of

time to wait until a bdev with a given name appears in the system.



### bdev_nvme



Added `bdev_nvme_add_error_injection` and `bdev_nvme_remove_error_injection` RPCs to add and

doc/jsonrpc.md

+4 −1
Original line number Diff line number Diff line
@@ -1607,11 +1607,14 @@ Get information about block devices (bdevs). 
#### Parameters



The user may specify no parameters in order to list all block devices, or a block device may be

specified by name.

specified by name.  If a timeout is specified, the method will block until a bdev with a specified

name appears or the timeout expires.  By default, the timeout is zero, meaning the method returns

immediately whether the bdev exists or not.



Name                    | Optional | Type        | Description

----------------------- | -------- | ----------- | -----------

name                    | Optional | string      | Block device name

timeout                 | Optional | number      | Time (ms) to wait for a bdev with specified name to appear



#### Response

lib/bdev/bdev_rpc.c

+69 −4
Original line number Diff line number Diff line
@@ -442,6 +442,14 @@ rpc_dump_bdev_info(struct spdk_json_write_ctx *w, 


struct rpc_bdev_get_bdevs {

	char		*name;

	uint64_t	timeout;

};



struct rpc_bdev_get_bdevs_ctx {

	struct rpc_bdev_get_bdevs	rpc;

	struct spdk_jsonrpc_request	*request;

	struct spdk_poller		*poller;

	uint64_t			timeout_ticks;

};



static void
@@ -452,13 +460,45 @@ free_rpc_bdev_get_bdevs(struct rpc_bdev_get_bdevs *r) 


static const struct spdk_json_object_decoder rpc_bdev_get_bdevs_decoders[] = {

	{"name", offsetof(struct rpc_bdev_get_bdevs, name), spdk_json_decode_string, true},

	{"timeout", offsetof(struct rpc_bdev_get_bdevs, timeout), spdk_json_decode_uint64, true},

};



static int

get_bdevs_poller(void *_ctx)

{

	struct rpc_bdev_get_bdevs_ctx *ctx = _ctx;

	struct spdk_json_write_ctx *w;

	struct spdk_bdev *bdev;



	bdev = spdk_bdev_get_by_name(ctx->rpc.name);

	if (bdev == NULL && spdk_get_ticks() < ctx->timeout_ticks) {

		return SPDK_POLLER_BUSY;

	}



	if (bdev == NULL) {

		SPDK_ERRLOG("Timed out while waiting for bdev '%s' to appear\n", ctx->rpc.name);

		spdk_jsonrpc_send_error_response(ctx->request, -ENODEV, spdk_strerror(ENODEV));

	} else {

		w = spdk_jsonrpc_begin_result(ctx->request);

		spdk_json_write_array_begin(w);

		rpc_dump_bdev_info(w, bdev);

		spdk_json_write_array_end(w);

		spdk_jsonrpc_end_result(ctx->request, w);

	}



	spdk_poller_unregister(&ctx->poller);

	free_rpc_bdev_get_bdevs(&ctx->rpc);

	free(ctx);



	return SPDK_POLLER_BUSY;

}



static void

rpc_bdev_get_bdevs(struct spdk_jsonrpc_request *request,

		   const struct spdk_json_val *params)

{

	struct rpc_bdev_get_bdevs req = {};

	struct rpc_bdev_get_bdevs_ctx *ctx;

	struct spdk_json_write_ctx *w;

	struct spdk_bdev *bdev = NULL;
@@ -475,11 +515,36 @@ rpc_bdev_get_bdevs(struct spdk_jsonrpc_request *request, 
	if (req.name) {

		bdev = spdk_bdev_get_by_name(req.name);

		if (bdev == NULL) {

			if (req.timeout == 0) {

				SPDK_ERRLOG("bdev '%s' does not exist\n", req.name);

				spdk_jsonrpc_send_error_response(request, -ENODEV, spdk_strerror(ENODEV));

				free_rpc_bdev_get_bdevs(&req);

				return;

			}



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

			if (ctx == NULL) {

				SPDK_ERRLOG("Failed to allocate bdev_get_bdevs context\n");

				spdk_jsonrpc_send_error_response(request, -ENOMEM, spdk_strerror(ENOMEM));

				free_rpc_bdev_get_bdevs(&req);

				return;

			}



			ctx->poller = SPDK_POLLER_REGISTER(get_bdevs_poller, ctx, 10 * 1000);

			if (ctx->poller == NULL) {

				SPDK_ERRLOG("Failed to register bdev_get_bdevs poller\n");

				spdk_jsonrpc_send_error_response(request, -ENOMEM, spdk_strerror(ENOMEM));

				free_rpc_bdev_get_bdevs(&req);

				free(ctx);

				return;

			}



			memcpy(&ctx->rpc, &req, sizeof(req));

			ctx->timeout_ticks = spdk_get_ticks() + req.timeout *

					     spdk_get_ticks_hz() / 1000ull;

			ctx->request = request;

			return;

		}

	}



	free_rpc_bdev_get_bdevs(&req);

scripts/rpc.py

+5 −1
Original line number Diff line number Diff line
@@ -1003,11 +1003,15 @@ if __name__ == "__main__": 


    def bdev_get_bdevs(args):

        print_dict(rpc.bdev.bdev_get_bdevs(args.client,

                                           name=args.name))

                                           name=args.name, timeout=args.timeout_ms))



    p = subparsers.add_parser('bdev_get_bdevs', aliases=['get_bdevs'],

                              help='Display current blockdev list or required blockdev')

    p.add_argument('-b', '--name', help="Name of the Blockdev. Example: Nvme0n1", required=False)

    p.add_argument('-t', '--timeout-ms', help="""Time in ms to wait for the bdev to appear (only used

    with the -b|--name option). The default timeout is 0, meaning the RPC returns immediately

    whether the bdev exists or not.""",

                   type=int, required=False)

    p.set_defaults(func=bdev_get_bdevs)



    def bdev_get_iostat(args):

scripts/rpc/bdev.py

+4 −1
Original line number Diff line number Diff line
@@ -1281,11 +1281,12 @@ def bdev_ftl_delete(client, name): 




@deprecated_alias('get_bdevs')

def bdev_get_bdevs(client, name=None):

def bdev_get_bdevs(client, name=None, timeout=None):

    """Get information about block devices.



    Args:

        name: bdev name to query (optional; if omitted, query all bdevs)

        timeout: time in ms to wait for the bdev with specified name to appear



    Returns:

        List of bdev information objects.
@@ -1293,6 +1294,8 @@ def bdev_get_bdevs(client, name=None): 
    params = {}

    if name:

        params['name'] = name

    if timeout:

        params['timeout'] = timeout

    return client.call('bdev_get_bdevs', params)