Commit e18788d3 authored by Changpeng Liu's avatar Changpeng Liu Committed by Tomasz Zawadzki
Browse files

vhost-blk: process VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP correctly 



Flag VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP is only used for WRITE
ZEROES command, vhost-blk target may tell VM via 'write_zeroes_may_unmap'
configuration that the backend can support this flag, however, Linux
generic block driver doesn't have such logic, it will enable this
flag by default(without REQ_NOUNMAP) with WRITE ZEROES command,
so the backend may choose to ignore this flag, because WRITE ZEROES
with this flag isn't mandatory.

Fix issue #1714.

Change-Id: Ic9388f39269720a23c00d41cba585d2a5abc3cfb
Signed-off-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/5565


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Mellanox Build Bot
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: default avatar <dongx.yi@intel.com>
parent dffb272c

lib/vhost/vhost_blk.c

+12 −4
Original line number Diff line number Diff line
@@ -464,6 +464,12 @@ process_blk_request(struct spdk_vhost_blk_task *task, 
			return -1;

		}



		if (desc->flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP) {

			SPDK_ERRLOG("UNMAP flag is only used for WRITE ZEROES command\n");

			invalid_blk_request(task, VIRTIO_BLK_S_UNSUPP);

			return -1;

		}



		rc = spdk_bdev_unmap(bvdev->bdev_desc, bvsession->io_channel,

				     desc->sector * 512, desc->num_sectors * 512,

				     blk_request_complete_cb, task);
@@ -485,11 +491,13 @@ process_blk_request(struct spdk_vhost_blk_task *task, 
			return -1;

		}



		/* Zeroed and Unmap the range, SPDK doen't support it. */

		/* Unmap this range, SPDK doesn't support it, kernel will enable this flag by default

		 * without checking unmap feature is negociated or not, the flag isn't mandatory, so

		 * just print a warning.

		 */

		if (desc->flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP) {

			SPDK_NOTICELOG("Can't support Write Zeroes with Unmap flag\n");

			invalid_blk_request(task, VIRTIO_BLK_S_UNSUPP);

			return -1;

			SPDK_WARNLOG("Ignore the unmap flag for WRITE ZEROES from %"PRIx64", len %"PRIx64"\n",

				     (uint64_t)desc->sector * 512, (uint64_t)desc->num_sectors * 512);

		}



		rc = spdk_bdev_write_zeroes(bvdev->bdev_desc, bvsession->io_channel,