Commit 7571c2bb authored by Daniel Verkamp's avatar Daniel Verkamp
Browse files

nbd: move poller out of lib into app 



This allows the library user the flexibility to use a different
threading model.

It also provides a way to indicate when the connection is closed so the
app can cleanly shut down.

Change-Id: Ibc196c0b8334fcb8f50d0233def16c6acf3c90d6
Signed-off-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
Reviewed-on: https://review.gerrithub.io/372377


Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
parent b483027a

include/spdk/nbd.h

+8 −0
Original line number Diff line number Diff line
@@ -37,6 +37,14 @@ 
struct spdk_bdev;



int spdk_nbd_start(struct spdk_bdev *bdev, const char *nbd_path);



/**

 * Poll an NBD instance.

 *

 * \return 0 on success or negated errno values on error (e.g. connection closed).

 */

int spdk_nbd_poll(void);



void spdk_nbd_stop(void);



#endif

lib/nbd/nbd.c

+30 −29
Original line number Diff line number Diff line
@@ -39,7 +39,6 @@ 
#include "spdk/bdev.h"

#include "spdk/endian.h"

#include "spdk/env.h"

#include "spdk/event.h"

#include "spdk/log.h"

#include "spdk/util.h"

#include "spdk/io_channel.h"
@@ -73,7 +72,6 @@ struct nbd_disk { 
	struct spdk_bdev_desc	*bdev_desc;

	struct spdk_io_channel	*ch;

	int			fd;

	struct spdk_poller	*poller;

	struct nbd_io		io;

	uint32_t		buf_align;

};
@@ -110,18 +108,17 @@ spdk_nbd_stop(void) 
	close(g_nbd_disk.fd);

}



static uint64_t

static int64_t

read_from_socket(int fd, void *buf, size_t length)

{

	ssize_t bytes_read;



	bytes_read = read(fd, buf, length);

	if (bytes_read == 0) {

		spdk_app_stop(-1);

		return 0;

		return -EIO;

	} else if (bytes_read == -1) {

		if (errno != EAGAIN) {

			spdk_app_stop(-1);

			return -errno;

		}

		return 0;

	} else {
@@ -129,18 +126,17 @@ read_from_socket(int fd, void *buf, size_t length) 
	}

}



static uint64_t

static int64_t

write_to_socket(int fd, void *buf, size_t length)

{

	ssize_t bytes_written;



	bytes_written = write(fd, buf, length);

	if (bytes_written == 0) {

		spdk_app_stop(-1);

		return 0;

		return -EIO;

	} else if (bytes_written == -1) {

		if (errno != EAGAIN) {

			spdk_app_stop(-1);

			return -errno;

		}

		return 0;

	} else {
@@ -198,7 +194,7 @@ nbd_submit_bdev_io(struct spdk_bdev *bdev, struct spdk_bdev_desc *desc, 
	}

}



static void

static int

process_request(struct nbd_disk *nbd)

{

	struct nbd_io	*io = &nbd->io;
@@ -212,8 +208,7 @@ process_request(struct nbd_disk *nbd) 
	io->payload = spdk_dma_malloc(io->payload_size, nbd->buf_align, NULL);

	if (io->payload == NULL) {

		SPDK_ERRLOG("could not allocate io->payload of size %d\n", io->payload_size);

		spdk_app_stop(-1);

		return;

		return -ENOMEM;

	}



	assert(from_be32(&io->req.magic) == NBD_REQUEST_MAGIC);
@@ -228,8 +223,7 @@ process_request(struct nbd_disk *nbd) 
		io->payload_in_progress = true;

		break;

	case NBD_CMD_DISC:

		spdk_nbd_stop();

		return;

		return -ECONNRESET;

#ifdef NBD_FLAG_SEND_FLUSH

	case NBD_CMD_FLUSH:

		io->type = SPDK_BDEV_IO_TYPE_FLUSH;
@@ -243,32 +237,38 @@ process_request(struct nbd_disk *nbd) 
		break;

#endif

	}



	return 0;

}



static void

nbd_poll(void *arg)

int

spdk_nbd_poll(void)

{

	struct nbd_disk *nbd = arg;

	struct nbd_disk *nbd = &g_nbd_disk;

	struct nbd_io	*io = &nbd->io;

	int		fd = nbd->fd;

	uint64_t	ret;

	int64_t		ret;

	int		rc;



	if (io->req_in_progress) {

		ret = read_from_socket(fd, (char *)&io->req + io->offset, sizeof(io->req) - io->offset);

		if (ret == 0) {

			return;

		if (ret <= 0) {

			return ret;

		}

		io->offset += ret;

		if (io->offset == sizeof(io->req)) {

			io->req_in_progress = false;

			process_request(nbd);

			rc = process_request(nbd);

			if (rc != 0) {

				return rc;

			}

		}

	}



	if (io->payload_in_progress && is_write(io->type)) {

		ret = read_from_socket(fd, io->payload + io->offset, io->payload_size - io->offset);

		if (ret == 0) {

			return;

		if (ret <= 0) {

			return ret;

		}

		io->offset += ret;

		if (io->offset == io->payload_size) {
@@ -280,8 +280,8 @@ nbd_poll(void *arg) 


	if (io->resp_in_progress) {

		ret = write_to_socket(fd, (char *)&io->resp + io->offset, sizeof(io->resp) - io->offset);

		if (ret == 0) {

			return;

		if (ret <= 0) {

			return ret;

		}

		io->offset += ret;

		if (io->offset == sizeof(io->resp)) {
@@ -297,8 +297,8 @@ nbd_poll(void *arg) 


	if (io->payload_in_progress && is_read(io->type)) {

		ret = write_to_socket(fd, io->payload + io->offset, io->payload_size - io->offset);

		if (ret == 0) {

			return;

		if (ret <= 0) {

			return ret;

		}

		io->offset += ret;

		if (io->offset == io->payload_size) {
@@ -307,6 +307,8 @@ nbd_poll(void *arg) 
			io->offset = 0;

		}

	}



	return 0;

}



static void
@@ -408,6 +410,5 @@ spdk_nbd_start(struct spdk_bdev *bdev, const char *nbd_path) 
	to_be32(&g_nbd_disk.io.resp.magic, NBD_REPLY_MAGIC);

	g_nbd_disk.io.req_in_progress = true;



	spdk_poller_register(&g_nbd_disk.poller, nbd_poll, &g_nbd_disk, spdk_env_get_current_core(), 0);

	return 0;

}

test/lib/bdev/nbd/nbd.c

+16 −0
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ 
#include "spdk/log.h"

#include "spdk/util.h"



static struct spdk_poller *g_nbd_poller;

static char *g_bdev_name;

static char *g_nbd_name = "/dev/nbd0";
@@ -50,10 +51,23 @@ static char *g_nbd_name = "/dev/nbd0"; 
static void

nbd_shutdown(void)

{

	spdk_poller_unregister(&g_nbd_poller, NULL);

	spdk_nbd_stop();

	spdk_app_stop(0);

}



static void

nbd_poll(void *arg)

{

	int rc;



	rc = spdk_nbd_poll();

	if (rc < 0) {

		SPDK_NOTICELOG("spdk_nbd_poll() returned %d; shutting down", rc);

		nbd_shutdown();

	}

}



static void

nbd_start(void *arg1, void *arg2)

{
@@ -72,6 +86,8 @@ nbd_start(void *arg1, void *arg2) 
		spdk_app_stop(-1);

		return;

	}



	spdk_poller_register(&g_nbd_poller, nbd_poll, NULL, spdk_env_get_current_core(), 0);

}



static void usage(char *program_name)