Commit bd069288 authored by Daniel Verkamp's avatar Daniel Verkamp Committed by Jim Harris
Browse files

bdev/rbd: support readv/writev with multiple iovs 



Previously, the RBD bdev only supported a single iovec entry, which is
not sufficient for the bdev API.

Change-Id: Ic18257bae0363b9c01e091547e5b41bae0a21e9a
Signed-off-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
Reviewed-on: https://review.gerrithub.io/401259


Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
parent afe51a15

lib/bdev/rbd/bdev_rbd.c

+67 −14
Original line number Diff line number Diff line
@@ -45,6 +45,7 @@ 
#include "spdk/io_channel.h"

#include "spdk/json.h"

#include "spdk/string.h"

#include "spdk/util.h"



#include "spdk_internal/bdev.h"

#include "spdk_internal/log.h"
@@ -70,6 +71,12 @@ struct bdev_rbd_io_channel { 
	struct spdk_poller *poller;

};



struct bdev_rbd_io {

	uint64_t remaining_len;

	int num_segments;

	bool failed;

};



static void

bdev_rbd_free(struct bdev_rbd *rbd)

{
@@ -199,21 +206,56 @@ bdev_rbd_start_aio(rbd_image_t image, struct spdk_bdev_io *bdev_io, 


static int bdev_rbd_library_init(void);



static int

bdev_rbd_get_ctx_size(void)

{

	return sizeof(struct bdev_rbd_io);

}



SPDK_BDEV_MODULE_REGISTER(rbd, bdev_rbd_library_init, NULL, NULL,

			  NULL, NULL)

			  bdev_rbd_get_ctx_size, NULL)



static int64_t

bdev_rbd_rw(struct bdev_rbd *disk, struct spdk_io_channel *ch,

	    struct spdk_bdev_io *bdev_io, struct iovec *iov,

	    int iovcnt, size_t len, uint64_t offset)

{

	struct bdev_rbd_io *rbd_io = (struct bdev_rbd_io *)bdev_io->driver_ctx;

	struct bdev_rbd_io_channel *rbdio_ch = spdk_io_channel_get_ctx(ch);

	size_t remaining = len;

	int i, rc;



	if (iovcnt != 1 || iov->iov_len != len) {

		return -1;

	rbd_io->remaining_len = 0;

	rbd_io->num_segments = 0;

	rbd_io->failed = false;



	for (i = 0; i < iovcnt && remaining > 0; i++) {

		size_t seg_len = spdk_min(remaining, iov[i].iov_len);



		rc = bdev_rbd_start_aio(rbdio_ch->image, bdev_io, iov[i].iov_base, offset, seg_len);

		if (rc) {

			/*

			 * This bdev_rbd_start_aio() call failed, but if any previous ones were

			 * submitted, we need to wait for them to finish.

			 */

			if (rbd_io->num_segments == 0) {

				/* No previous I/O submitted - return error code immediately. */

				return rc;

			}



			/* Return and wait for outstanding I/O to complete. */

			rbd_io->failed = true;

			return 0;

		}



	return bdev_rbd_start_aio(rbdio_ch->image, bdev_io, iov->iov_base, offset, len);

		rbd_io->num_segments++;

		rbd_io->remaining_len += seg_len;



		offset += seg_len;

		remaining -= seg_len;

	}



	return 0;

}



static int64_t
@@ -308,7 +350,7 @@ bdev_rbd_io_poll(void *arg) 
	int i, io_status, rc;

	rbd_completion_t comps[SPDK_RBD_QUEUE_DEPTH];

	struct spdk_bdev_io *bdev_io;

	enum spdk_bdev_io_status status;

	struct bdev_rbd_io *rbd_io;



	rc = poll(&ch->pfd, 1, 0);
@@ -320,23 +362,34 @@ bdev_rbd_io_poll(void *arg) 
	rc = rbd_poll_io_events(ch->image, comps, SPDK_RBD_QUEUE_DEPTH);

	for (i = 0; i < rc; i++) {

		bdev_io = rbd_aio_get_arg(comps[i]);

		rbd_io = (struct bdev_rbd_io *)bdev_io->driver_ctx;

		io_status = rbd_aio_get_return_value(comps[i]);



		assert(rbd_io->num_segments > 0);

		rbd_io->num_segments--;



		if (bdev_io->type == SPDK_BDEV_IO_TYPE_READ) {

			if ((int)(bdev_io->u.bdev.num_blocks * bdev_io->bdev->blocklen) == io_status) {

				status = SPDK_BDEV_IO_STATUS_SUCCESS;

			} else {

				status = SPDK_BDEV_IO_STATUS_FAILED;

			if (io_status > 0) {

				/* For reads, io_status is the length */

				rbd_io->remaining_len -= io_status;

			}



			if (rbd_io->num_segments == 0 && rbd_io->remaining_len != 0) {

				rbd_io->failed = true;

			}

		} else {

			/* For others, 0 means success */

			if (!io_status) {

				status = SPDK_BDEV_IO_STATUS_SUCCESS;

			} else {

				status = SPDK_BDEV_IO_STATUS_FAILED;

			if (io_status != 0) {

				rbd_io->failed = true;

			}

		}



		rbd_aio_release(comps[i]);

		spdk_bdev_io_complete(bdev_io, status);



		if (rbd_io->num_segments == 0) {

			spdk_bdev_io_complete(bdev_io,

					      rbd_io->failed ? SPDK_BDEV_IO_STATUS_FAILED : SPDK_BDEV_IO_STATUS_SUCCESS);

		}

	}

}