Commit 51d7f9b1 authored by matthewb's avatar matthewb Committed by Ben Walker
Browse files

lib/bdev: Removed ZCOPY emulation 



ZCOPY emulation is not required. Modules can check if the bdev module
supports ZCOPY.  If not supported the module uses the existing
READ and WRITE operations.

Signed-off-by: default avatarmatthewb <matthew.burbridge@hpe.com>
Change-Id: Idac0a4d27a79a6c7e567c420e15637e826c347c8
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/6815


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarMichael Haeuptle <michaelhaeuptle@gmail.com>
Reviewed-by: default avatarAleksey Marchuk <alexeymar@mellanox.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Community-CI: Mellanox Build Bot
parent b333f006

CHANGELOG.md

+5 −0
Original line number Diff line number Diff line
@@ -46,6 +46,11 @@ to create a rbd bdev with an already registered Rados Cluster Object. 
New RPC `bdev_rbd_get_clusters_info` was added, it allows to get the info of the registered

Rados Cluster names.



### bdev



Removed ZCOPY emulation: The bdev module can be checked to see if it supports ZCOPY

and if not supported then use existing READ/WRITE commands.



## v21.04:



### accel

lib/bdev/bdev.c

+1 −58
Original line number Diff line number Diff line
@@ -2574,11 +2574,6 @@ spdk_bdev_io_type_supported(struct spdk_bdev *bdev, enum spdk_bdev_io_type io_ty 
			/* The bdev layer will emulate write zeroes as long as write is supported. */

			supported = bdev_io_type_supported(bdev, SPDK_BDEV_IO_TYPE_WRITE);

			break;

		case SPDK_BDEV_IO_TYPE_ZCOPY:

			/* Zero copy can be emulated with regular read and write */

			supported = bdev_io_type_supported(bdev, SPDK_BDEV_IO_TYPE_READ) &&

				    bdev_io_type_supported(bdev, SPDK_BDEV_IO_TYPE_WRITE);

			break;

		default:

			break;

		}
@@ -4318,29 +4313,6 @@ spdk_bdev_comparev_and_writev_blocks(struct spdk_bdev_desc *desc, struct spdk_io 
				   bdev_comparev_and_writev_blocks_locked, bdev_io);

}



static void

bdev_zcopy_get_buf(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io, bool success)

{

	if (!success) {

		/* Don't use spdk_bdev_io_complete here - this bdev_io was never actually submitted. */

		bdev_io->internal.status = SPDK_BDEV_IO_STATUS_NOMEM;

		bdev_io->internal.cb(bdev_io, success, bdev_io->internal.caller_ctx);

		return;

	}



	if (bdev_io->u.bdev.zcopy.populate) {

		/* Read the real data into the buffer */

		bdev_io->type = SPDK_BDEV_IO_TYPE_READ;

		bdev_io->internal.status = SPDK_BDEV_IO_STATUS_PENDING;

		bdev_io_submit(bdev_io);

		return;

	}



	/* Don't use spdk_bdev_io_complete here - this bdev_io was never actually submitted. */

	bdev_io->internal.status = SPDK_BDEV_IO_STATUS_SUCCESS;

	bdev_io->internal.cb(bdev_io, success, bdev_io->internal.caller_ctx);

}



int

spdk_bdev_zcopy_start(struct spdk_bdev_desc *desc, struct spdk_io_channel *ch,

		      uint64_t offset_blocks, uint64_t num_blocks,
@@ -4381,13 +4353,7 @@ spdk_bdev_zcopy_start(struct spdk_bdev_desc *desc, struct spdk_io_channel *ch, 
	bdev_io->u.bdev.zcopy.start = 1;

	bdev_io_init(bdev_io, bdev, cb_arg, cb);



	if (bdev_io_type_supported(bdev, SPDK_BDEV_IO_TYPE_ZCOPY)) {

	bdev_io_submit(bdev_io);

	} else {

		/* Emulate zcopy by allocating a buffer */

		spdk_bdev_io_get_buf(bdev_io, bdev_zcopy_get_buf,

				     bdev_io->u.bdev.num_blocks * bdev->blocklen);

	}



	return 0;

}
@@ -4396,16 +4362,6 @@ int 
spdk_bdev_zcopy_end(struct spdk_bdev_io *bdev_io, bool commit,

		    spdk_bdev_io_completion_cb cb, void *cb_arg)

{

	struct spdk_bdev *bdev = bdev_io->bdev;



	if (bdev_io->type == SPDK_BDEV_IO_TYPE_READ) {

		/* This can happen if the zcopy was emulated in start */

		if (bdev_io->u.bdev.zcopy.start != 1) {

			return -EINVAL;

		}

		bdev_io->type = SPDK_BDEV_IO_TYPE_ZCOPY;

	}



	if (bdev_io->type != SPDK_BDEV_IO_TYPE_ZCOPY) {

		return -EINVAL;

	}
@@ -4416,19 +4372,6 @@ spdk_bdev_zcopy_end(struct spdk_bdev_io *bdev_io, bool commit, 
	bdev_io->internal.cb = cb;

	bdev_io->internal.status = SPDK_BDEV_IO_STATUS_PENDING;



	if (bdev_io_type_supported(bdev, SPDK_BDEV_IO_TYPE_ZCOPY)) {

		bdev_io_submit(bdev_io);

		return 0;

	}



	if (!bdev_io->u.bdev.zcopy.commit) {

		/* Don't use spdk_bdev_io_complete here - this bdev_io was never actually submitted. */

		bdev_io->internal.status = SPDK_BDEV_IO_STATUS_SUCCESS;

		bdev_io->internal.cb(bdev_io, true, bdev_io->internal.caller_ctx);

		return 0;

	}



	bdev_io->type = SPDK_BDEV_IO_TYPE_WRITE;

	bdev_io_submit(bdev_io);



	return 0;