[PATCH 5/5] nvmet: implement copy support for bdev backed target

Keith Busch
2025-05-21T22:31:20Z

From: Keith Busch <kbusch@kernel.org>

The nvme block device target type does not have any particular limits on
copy commands, so all the settings are the protocol's max.

Signed-off-by: Keith Busch <kbusch@kernel.org>
---
drivers/nvme/target/io-cmd-bdev.c | 52 +++++++++++++++++++++++++++++++
1 file changed, 52 insertions(+)

diff --git a/drivers/nvme/target/io-cmd-bdev.c b/drivers/nvme/target/io-cmd-bdev.c
index 83be0657e6df4..d90dedcd2352f 100644
--- a/drivers/nvme/target/io-cmd-bdev.c
+++ b/drivers/nvme/target/io-cmd-bdev.c
@@ -46,6 +46,11 @@ 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));
+
+ /* Copy offload support */
+ id->mssrl = cpu_to_le16(U16_MAX);
+ id->mcl = cpu_to_le32(U32_MAX);
+ id->msrc = U8_MAX;
}

void nvmet_bdev_ns_disable(struct nvmet_ns *ns)
@@ -412,6 +417,50 @@ static void nvmet_bdev_execute_discard(struct nvmet_req *req)
}
}

+static void nvmet_bdev_execute_copy(struct nvmet_req *req)
+{
+ struct bio_vec *bv, fast_bv[UIO_FASTIOV];
+ struct nvme_copy_range range;
+ u64 dst_sector, slba;
+ u16 status, nlb, nr;
+ int ret, i;
+
+ nr = req->cmd->copy.nr_range + 1;
+ if (nr <= UIO_FASTIOV) {
+ bv = fast_bv;
+ } else {
+ bv = kmalloc_array(nr, sizeof(*bv), GFP_KERNEL);
+ if (!bv) {
+ status = NVME_SC_INTERNAL;
+ goto done;
+ }
+ }
+
+ for (i = 0; i < nr; i++) {
+ status = nvmet_copy_from_sgl(req, i * sizeof(range), &range,
+ sizeof(range));
+ if (status)
+ goto done;
+
+ slba = le64_to_cpu(range.slba);
+ nlb = le16_to_cpu(range.nlb) + 1;
+ bv[i].bv_sector = nvmet_lba_to_sect(req->ns, slba);
+ bv[i].bv_sectors = nvmet_lba_to_sect(req->ns, nlb);
+ }
+
+ dst_sector = nvmet_lba_to_sect(req->ns, req->cmd->copy.sdlba);
+ ret = blkdev_copy_range(req->ns->bdev, dst_sector, bv, nr, GFP_KERNEL);
+ if (ret) {
+ req->error_slba = le64_to_cpu(dst_sector);
+ status = errno_to_nvme_status(req, ret);
+ } else
+ status = NVME_SC_SUCCESS;
+done:
+ nvmet_req_complete(req, status);
+ if (bv != fast_bv)
+ kfree(bv);
+}
+
static void nvmet_bdev_execute_dsm(struct nvmet_req *req)
{
if (!nvmet_check_data_len_lte(req, nvmet_dsm_len(req)))
@@ -474,6 +523,9 @@ u16 nvmet_bdev_parse_io_cmd(struct nvmet_req *req)
case nvme_cmd_write_zeroes:
req->execute = nvmet_bdev_execute_write_zeroes;
return 0;
+ case nvme_cmd_copy:
+ req->execute = nvmet_bdev_execute_copy;
+ return 0;
default:
return nvmet_report_invalid_opcode(req);
}
--
2.47.1