Commit c9dc522b authored by Seth Howell's avatar Seth Howell Committed by Daniel Verkamp
Browse files

bdev_nvme: add support for write_zeroes 



In this iteration, we only support write_zeroes in the form of a
deallocate call that returns all zeroes.

Change-Id: Ica837ce70672174df63012719de60463fdb799cf
Signed-off-by: default avatarSeth Howell <seth.howell@intel.com>
Reviewed-on: https://review.gerrithub.io/372005


Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
parent 670dc20f

lib/bdev/nvme/bdev_nvme.c

+24 −0
Original line number Diff line number Diff line
@@ -376,6 +376,13 @@ _bdev_nvme_submit_request(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_ 
					bdev_io->u.write.len,

					bdev_io->u.write.offset);



	case SPDK_BDEV_IO_TYPE_WRITE_ZEROES:

		return bdev_nvme_unmap((struct nvme_bdev *)bdev_io->bdev->ctxt,

				       ch,

				       (struct nvme_bdev_io *)bdev_io->driver_ctx,

				       bdev_io->u.write.len,

				       bdev_io->u.write.offset);



	case SPDK_BDEV_IO_TYPE_UNMAP:

		return bdev_nvme_unmap((struct nvme_bdev *)bdev_io->bdev->ctxt,

				       ch,
@@ -442,6 +449,23 @@ bdev_nvme_io_type_supported(void *ctx, enum spdk_bdev_io_type io_type) 
		cdata = spdk_nvme_ctrlr_get_data(nbdev->nvme_ctrlr->ctrlr);

		return cdata->oncs.dsm;



	case SPDK_BDEV_IO_TYPE_WRITE_ZEROES:

		cdata = spdk_nvme_ctrlr_get_data(nbdev->nvme_ctrlr->ctrlr);

		/*

		 * If an NVMe controller guarantees reading unallocated blocks returns zero,

		 * we can implement WRITE_ZEROES as an NVMe deallocate command.

		 */

		if (cdata->oncs.dsm &&

		    spdk_nvme_ns_get_dealloc_logical_block_read_value(nbdev->ns) == SPDK_NVME_DEALLOC_READ_00) {

			return true;

		}

		/*

		 * The NVMe controller write_zeroes function is currently not used by our driver.

		 * If a user submits an arbitrarily large write_zeroes request to the controller, the request will fail.

		 * Until this is resolved, we only claim support for write_zeroes if deallocated blocks return 0's when read.

		 */

		return false;



	default:

		return false;

	}