nvmet: set WZDS and DRB if device supports BLK_FEAT_WRITE_ZEROES_UNMAP

Set WZDS and DRB bit to the namespace dlfeat if the underlying block
device supports BLK_FEAT_WRITE_ZEROES_UNMAP, make the nvme target
device supports unmaped write zeroes command.

Signed-off-by: Zhang Yi <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>

Author: zhangyi089

drivers/nvme/target/io-cmd-bdev.c

@@ -46,6 +46,10 @@ void nvmet_bdev_set_limits(struct block_device *bdev, struct nvme_id_ns *id)
 	id->npda = id->npdg;
 	/* NOWS = Namespace Optimal Write Size */
 	id->nows = to0based(bdev_io_opt(bdev) / bdev_logical_block_size(bdev));
+
+	/* Set WZDS and DRB if device supports unmapped write zeroes */
+	if (bdev_write_zeroes_unmap(bdev))
+		id->dlfeat = (1 << 3) | 0x1;
 }
 
 void nvmet_bdev_ns_disable(struct nvmet_ns *ns)