Commit ea952fca authored by Jim Harris's avatar Jim Harris Committed by Ben Walker
Browse files

bdev/split: remove resubmit logic 



Issue each I/O to the base bdev as a new discrete I/O rather
than resubmitting the original I/O.  This enables some
upcoming changes to better handle queueing and reset-related
work at the generic bdev layer, which will also deprecate
the resubmit I/O logic.

Signed-off-by: default avatarJim Harris <james.r.harris@intel.com>
Change-Id: Ic1caa89014981e948edfec5e8eaaacd41a73d49c

Reviewed-on: https://review.gerrithub.io/375495


Reviewed-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
parent 2a751434

lib/bdev/split/vbdev_split.c

+65 −46
Original line number Diff line number Diff line
@@ -43,6 +43,7 @@ 
#include "spdk/endian.h"

#include "spdk/string.h"

#include "spdk/io_channel.h"

#include "spdk/util.h"



#include "spdk_internal/bdev.h"

#include "spdk_internal/log.h"
@@ -67,75 +68,70 @@ struct split_disk { 


static TAILQ_HEAD(, split_disk) g_split_disks = TAILQ_HEAD_INITIALIZER(g_split_disks);



static void

split_read(struct split_disk *split_disk, struct spdk_bdev_io *bdev_io)

{

	bdev_io->u.read.offset += split_disk->offset_bytes;

}



static void

split_write(struct split_disk *split_disk, struct spdk_bdev_io *bdev_io)

{

	bdev_io->u.write.offset += split_disk->offset_bytes;

}



static void

split_unmap(struct split_disk *split_disk, struct spdk_bdev_io *bdev_io)

{

	bdev_io->u.unmap.offset += split_disk->offset_bytes;

}



static void

split_flush(struct split_disk *split_disk, struct spdk_bdev_io *bdev_io)

{

	bdev_io->u.flush.offset += split_disk->offset_bytes;

}

struct split_channel {

	struct split_disk	*disk;

	struct spdk_io_channel	*base_ch;

};



static void

_vbdev_split_complete_reset(struct spdk_bdev_io *bdev_io, bool success, void *cb_arg)

vbdev_split_complete_io(struct spdk_bdev_io *bdev_io, bool success, void *cb_arg)

{

	struct spdk_bdev_io *split_io = cb_arg;

	struct spdk_io_channel *base_ch = *(struct spdk_io_channel **)split_io->driver_ctx;

	int status = success ? SPDK_BDEV_IO_STATUS_SUCCESS : SPDK_BDEV_IO_STATUS_FAILED;



	spdk_put_io_channel(base_ch);

	spdk_bdev_io_complete(split_io, success);

	spdk_bdev_io_complete(split_io, status);

	spdk_bdev_free_io(bdev_io);

}



static void

vbdev_split_submit_request(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)

{

	struct split_disk *split_disk = bdev_io->bdev->ctxt;

	struct spdk_io_channel *base_ch;

	struct split_channel *split_ch = spdk_io_channel_get_ctx(ch);

	struct split_disk *split_disk = split_ch->disk;

	struct spdk_io_channel *base_ch = split_ch->base_ch;

	struct spdk_bdev_desc *base_desc = split_disk->base->desc;

	uint64_t offset;

	int rc = 0;



	/* Modify the I/O to adjust for the offset within the base bdev. */

	switch (bdev_io->type) {

	case SPDK_BDEV_IO_TYPE_READ:

		split_read(split_disk, bdev_io);

		offset = bdev_io->u.read.offset + split_disk->offset_bytes;

		rc = spdk_bdev_readv(base_desc, base_ch, bdev_io->u.read.iovs,

				     bdev_io->u.read.iovcnt, offset,

				     bdev_io->u.read.len, vbdev_split_complete_io,

				     bdev_io);

		break;

	case SPDK_BDEV_IO_TYPE_WRITE:

		split_write(split_disk, bdev_io);

		offset = bdev_io->u.write.offset + split_disk->offset_bytes;

		rc = spdk_bdev_writev(base_desc, base_ch, bdev_io->u.write.iovs,

				      bdev_io->u.write.iovcnt, offset,

				      bdev_io->u.write.len, vbdev_split_complete_io,

				      bdev_io);

		break;

	case SPDK_BDEV_IO_TYPE_UNMAP:

		split_unmap(split_disk, bdev_io);

		offset = bdev_io->u.unmap.offset + split_disk->offset_bytes;

		rc = spdk_bdev_unmap(base_desc, base_ch, offset, bdev_io->u.unmap.len,

				     vbdev_split_complete_io, bdev_io);

		break;

	case SPDK_BDEV_IO_TYPE_FLUSH:

		split_flush(split_disk, bdev_io);

		offset = bdev_io->u.flush.offset + split_disk->offset_bytes;

		rc = spdk_bdev_flush(base_desc, base_ch, offset, bdev_io->u.flush.len,

				     vbdev_split_complete_io, bdev_io);

		break;

	case SPDK_BDEV_IO_TYPE_RESET:

		base_ch = spdk_get_io_channel(split_disk->base->bdev);

		*(struct spdk_io_channel **)bdev_io->driver_ctx = base_ch;

		spdk_bdev_reset(split_disk->base->desc, base_ch,

				_vbdev_split_complete_reset, bdev_io);

		return;

		rc = spdk_bdev_reset(split_disk->base->desc, base_ch,

				     vbdev_split_complete_io, bdev_io);

		break;

	default:

		SPDK_ERRLOG("split: unknown I/O type %d\n", bdev_io->type);

		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);

		return;

	}



	/* Submit the modified I/O to the underlying bdev. */

	spdk_bdev_io_resubmit(bdev_io, split_disk->base->desc);

	if (rc != 0) {

		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);

	}

}



static void
@@ -174,6 +170,7 @@ vbdev_split_free(struct split_disk *split_disk) 


	split_base = split_disk->base;



	spdk_io_device_unregister(&split_disk->base, NULL);

	TAILQ_REMOVE(&g_split_disks, split_disk, tailq);

	free(split_disk->disk.name);

	free(split_disk);
@@ -218,7 +215,7 @@ vbdev_split_get_io_channel(void *ctx) 
{

	struct split_disk *split_disk = ctx;



	return split_disk->base->bdev->fn_table->get_io_channel(split_disk->base->bdev);

	return spdk_get_io_channel(&split_disk->base);

}



static int
@@ -247,6 +244,29 @@ static struct spdk_bdev_fn_table vbdev_split_fn_table = { 
	.dump_config_json	= vbdev_split_dump_config_json,

};



static int

split_channel_create_cb(void *io_device, void *ctx_buf)

{

	struct split_disk *disk = SPDK_CONTAINEROF(io_device, struct split_disk, base);

	struct split_channel *ch = ctx_buf;



	ch->disk = disk;

	ch->base_ch = spdk_bdev_get_io_channel(disk->base->desc);

	if (ch->base_ch == NULL) {

		return -1;

	}



	return 0;

}



static void

split_channel_destroy_cb(void *io_device, void *ctx_buf)

{

	struct split_channel *ch = ctx_buf;



	spdk_put_io_channel(ch->base_ch);

}



static int

vbdev_split_create(struct spdk_bdev *base_bdev, uint64_t split_count, uint64_t split_size_mb)

{
@@ -347,6 +367,9 @@ vbdev_split_create(struct spdk_bdev *base_bdev, uint64_t split_count, uint64_t s 


		vbdev_split_base_get_ref(split_base, d);



		spdk_io_device_register(&d->base, split_channel_create_cb, split_channel_destroy_cb,

					sizeof(struct split_channel));



		spdk_vbdev_register(&d->disk, &base_bdev, 1);



		TAILQ_INSERT_TAIL(&g_split_disks, d, tailq);
@@ -447,11 +470,7 @@ vbdev_split_fini(void) 
static int

vbdev_split_get_ctx_size(void)

{

	/*

	 * Note: this context is only used for RESET operations, since it is the only

	 *  I/O type that does not just resubmit to the base bdev.

	 */

	return sizeof(struct spdk_io_channel *);

	return 0;

}



SPDK_BDEV_MODULE_REGISTER(split, vbdev_split_init, vbdev_split_fini, NULL,