[PATCH v9 6/9] nvmet: add copy command support for bdev and file ns

Chaitanya Kulkarni chaitanyak at nvidia.com
Mon Apr 24 23:36:51 PDT 2023


On 4/11/23 01:10, Anuj Gupta wrote:
> From: Nitesh Shetty <nj.shetty at samsung.com>
>
> Add support for handling target command on target.

what is target command ?

command that you have added is :nvme_cmd_copy

> For bdev-ns we call into blkdev_issue_copy, which the block layer
> completes by a offloaded copy request to backend bdev or by emulating the
> request.
>
> For file-ns we call vfs_copy_file_range to service our request.
>
> Currently target always shows copy capability by setting
> NVME_CTRL_ONCS_COPY in controller ONCS.

there is nothing mentioned about target/loop.c in commit log ?

> Signed-off-by: Nitesh Shetty <nj.shetty at samsung.com>
> Signed-off-by: Anuj Gupta <anuj20.g at samsung.com>
> ---
>   drivers/nvme/target/admin-cmd.c   |  9 +++--
>   drivers/nvme/target/io-cmd-bdev.c | 58 +++++++++++++++++++++++++++++++
>   drivers/nvme/target/io-cmd-file.c | 52 +++++++++++++++++++++++++++
>   drivers/nvme/target/loop.c        |  6 ++++
>   drivers/nvme/target/nvmet.h       |  1 +
>   5 files changed, 124 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
> index 80099df37314..978786ec6a9e 100644
> --- a/drivers/nvme/target/admin-cmd.c
> +++ b/drivers/nvme/target/admin-cmd.c
> @@ -433,8 +433,7 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
>   	id->nn = cpu_to_le32(NVMET_MAX_NAMESPACES);
>   	id->mnan = cpu_to_le32(NVMET_MAX_NAMESPACES);
>   	id->oncs = cpu_to_le16(NVME_CTRL_ONCS_DSM |
> -			NVME_CTRL_ONCS_WRITE_ZEROES);
> -
> +			NVME_CTRL_ONCS_WRITE_ZEROES | NVME_CTRL_ONCS_COPY);
>   	/* XXX: don't report vwc if the underlying device is write through */
>   	id->vwc = NVME_CTRL_VWC_PRESENT;
>   
> @@ -536,6 +535,12 @@ static void nvmet_execute_identify_ns(struct nvmet_req *req)
>   
>   	if (req->ns->bdev)
>   		nvmet_bdev_set_limits(req->ns->bdev, id);
> +	else {
> +		id->msrc = (u8)to0based(BIO_MAX_VECS - 1);
> +		id->mssrl = cpu_to_le16(BIO_MAX_VECS <<
> +				(PAGE_SHIFT - SECTOR_SHIFT));
> +		id->mcl = cpu_to_le32(le16_to_cpu(id->mssrl));
> +	}
>   
>   	/*
>   	 * We just provide a single LBA format that matches what the
> diff --git a/drivers/nvme/target/io-cmd-bdev.c b/drivers/nvme/target/io-cmd-bdev.c
> index c2d6cea0236b..0af273097aa4 100644
> --- a/drivers/nvme/target/io-cmd-bdev.c
> +++ b/drivers/nvme/target/io-cmd-bdev.c
> @@ -46,6 +46,19 @@ 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 limits*/

above comment doesn't make any sense ...

> +	if (bdev_max_copy_sectors(bdev)) {
> +		id->msrc = id->msrc;
> +		id->mssrl = cpu_to_le16((bdev_max_copy_sectors(bdev) <<
> +				SECTOR_SHIFT) / bdev_logical_block_size(bdev));
> +		id->mcl = cpu_to_le32(id->mssrl);
> +	} else {
> +		id->msrc = (u8)to0based(BIO_MAX_VECS - 1);
> +		id->mssrl = cpu_to_le16((BIO_MAX_VECS << PAGE_SHIFT) /
> +				bdev_logical_block_size(bdev));
> +		id->mcl = cpu_to_le32(id->mssrl);
> +	}
>   }
>   
>   void nvmet_bdev_ns_disable(struct nvmet_ns *ns)
> @@ -184,6 +197,19 @@ static void nvmet_bio_done(struct bio *bio)
>   	nvmet_req_bio_put(req, bio);
>   }
>   
> +static void nvmet_bdev_copy_end_io(void *private, int comp_len)
> +{
> +	struct nvmet_req *req = (struct nvmet_req *)private;
> +
> +	if (comp_len == req->copy_len) {
> +		req->cqe->result.u32 = cpu_to_le32(1);
> +		nvmet_req_complete(req, errno_to_nvme_status(req, 0));
> +	} else {
> +		req->cqe->result.u32 = cpu_to_le32(0);
> +		nvmet_req_complete(req, blk_to_nvme_status(req, BLK_STS_IOERR));
> +	}
> +}
> +

please reduce calls for nvmet_req_complete().

+static void nvmet_bdev_copy_end_io(void *private, int comp_len)
+{
+	struct nvmet_req *req = (struct nvmet_req *)private;
+	u16 status;
+
+	if (comp_len == req->copy_len) {
+		req->cqe->result.u32 = cpu_to_le32(1);
+		status = errno_to_nvme_status(req, 0));
+	} else {
+		req->cqe->result.u32 = cpu_to_le32(0);
+		status = blk_to_nvme_status(req, BLK_STS_IOERR));
+	}
+	nvmet_req_complete(req, status);
+}
+

>   #ifdef CONFIG_BLK_DEV_INTEGRITY
>   static int nvmet_bdev_alloc_bip(struct nvmet_req *req, struct bio *bio,
>   				struct sg_mapping_iter *miter)
> @@ -450,6 +476,34 @@ static void nvmet_bdev_execute_write_zeroes(struct nvmet_req *req)
>   	}
>   }
>   
> +/* At present we handle only one range entry */

please add explanation why ...

> +static void nvmet_bdev_execute_copy(struct nvmet_req *req)
> +{
> +	struct nvme_copy_range range;
> +	struct nvme_command *cmnd = req->cmd;

don't use cmnd, cmd is used everywhere and matches req->cmd,
applies to everywhere in this patch...

> +	int ret;

wrong return type is should be u16 since nvmet_copy_from_sgl()
returns u16 if I remember correctly.

> +
> +

no extra white line between declaration and body of functions

> +	ret = nvmet_copy_from_sgl(req, 0, &range, sizeof(range));
> +	if (ret)
> +		goto out;
> +
> +	ret = blkdev_issue_copy(req->ns->bdev,
> +		le64_to_cpu(cmnd->copy.sdlba) << req->ns->blksize_shift,
> +		req->ns->bdev,
> +		le64_to_cpu(range.slba) << req->ns->blksize_shift,
> +		(le16_to_cpu(range.nlb) + 1) << req->ns->blksize_shift,
> +		nvmet_bdev_copy_end_io, (void *)req, GFP_KERNEL);
> +	if (ret) {
> +		req->cqe->result.u32 = cpu_to_le32(0);
> +		nvmet_req_complete(req, blk_to_nvme_status(req, BLK_STS_IOERR));
> +	}
> +
> +	return;
> +out:
> +	nvmet_req_complete(req, errno_to_nvme_status(req, ret));
> +}
> +

again one call to nvmet_req_complete() can do the same job.
consider following totally untested  :-
/* TODO: add detailed comment here why you support one range ? */
static void nvmet_bdev_execute_copy(struct nvmet_req *req)
{
         u32 blkshift = req->ns->blksize_shift;
         struct nvme_command *cmnd = req->cmd;
         struct nvme_copy_range range;
         u16 status;

         status = nvmet_copy_from_sgl(req, 0, &range, sizeof(range));
         if (status) {
                 goto out;
         }

         ret = blkdev_issue_copy(req->ns->bdev,
                                 le64_to_cpu(cmnd->copy.sdlba) << blkshift,
                                 req->ns->bdev,
                                 le64_to_cpu(range.slba) << blksize_shift,
                                 (le16_to_cpu(range.nlb) + 1) << 
blksize_shift,
                                 nvmet_bdev_copy_end_io, (void *)req, 
GFP_KERNEL);
         if (ret) {
                 req->cqe->result.u32 = cpu_to_le32(0);
                 status = blk_to_nvme_status(req, BLK_STS_IOERR);
out:
                 nvmet_req_complete(req, status);
         }
}

>   u16 nvmet_bdev_parse_io_cmd(struct nvmet_req *req)
>   {
>   	switch (req->cmd->common.opcode) {
> @@ -468,6 +522,10 @@ 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);
>   	}
> diff --git a/drivers/nvme/target/io-cmd-file.c b/drivers/nvme/target/io-cmd-file.c
> index 2d068439b129..69f198ecec77 100644
> --- a/drivers/nvme/target/io-cmd-file.c
> +++ b/drivers/nvme/target/io-cmd-file.c
> @@ -322,6 +322,49 @@ static void nvmet_file_dsm_work(struct work_struct *w)
>   	}
>   }
>   
> +static void nvmet_file_copy_work(struct work_struct *w)
> +{
> +	struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
> +	int nr_range;
> +	loff_t pos;
> +	struct nvme_command *cmnd = req->cmd;
> +	int ret = 0, len = 0, src, id;

reverse tree style for declaration ...

> +
> +	nr_range = cmnd->copy.nr_range + 1;
> +	pos = le64_to_cpu(req->cmd->copy.sdlba) << req->ns->blksize_shift;

you have a cmd variable above and you are still using req->cmd ?
why create a variable on stack then ? u don't need that variable
anyways...

> +	if (unlikely(pos + req->transfer_len > req->ns->size)) {
> +		nvmet_req_complete(req, errno_to_nvme_status(req, -ENOSPC));
> +		return;
> +	}
> +
> +	for (id = 0 ; id < nr_range; id++) {
> +		struct nvme_copy_range range;
> +
> +		ret = nvmet_copy_from_sgl(req, id * sizeof(range), &range,
> +					sizeof(range));
> +		if (ret)
> +			goto out;
> +
> +		len = (le16_to_cpu(range.nlb) + 1) << (req->ns->blksize_shift);
> +		src = (le64_to_cpu(range.slba) << (req->ns->blksize_shift));
> +		ret = vfs_copy_file_range(req->ns->file, src, req->ns->file,
> +					pos, len, 0);

5th paramaeter to vfs_copy_file_range() is size_t you have used int
for len ? also
vfs_copy_file_range() returns ssize_t you are catching it in int ?

> +out:
> +		if (ret != len) {
> +			pos += ret;
> +			req->cqe->result.u32 = cpu_to_le32(id);
> +			nvmet_req_complete(req, ret < 0 ?
> +					errno_to_nvme_status(req, ret) :
> +					errno_to_nvme_status(req, -EIO));

again plz don't add multiple nvmet_req_complete() calls

> +			return;
> +
> +		} else
> +			pos += len;
> +	}
> +
> +	nvmet_req_complete(req, 0);
> +
> +}

wrt above comments consider following totally untested :-

static void nvmet_file_copy_work(struct work_struct *w)
{
         struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
         int nr_range = req->cmd->copy.nr_range + 1;
         u16 status = 0;
         int src, id;
         ssize_t ret;
         size_t len;
         loff_t pos;

         pos = le64_to_cpu(req->cmd->copy.sdlba) << req->ns->blksize_shift;
         if (unlikely(pos + req->transfer_len > req->ns->size)) {
                 nvmet_req_complete(req, errno_to_nvme_status(req, 
-ENOSPC));
                 return;
         }

         for (id = 0 ; id < nr_range; id++) {
                 struct nvme_copy_range range;

                 status = nvmet_copy_from_sgl(req, id * sizeof(range), 
&range,
                                         sizeof(range));
                 if (status)
                         goto out;

                 src = (le64_to_cpu(range.slba) << 
(req->ns->blksize_shift));
                 len = (le16_to_cpu(range.nlb) + 1) << 
(req->ns->blksize_shift);

                 ret = vfs_copy_file_range(req->ns->file, src, 
req->ns->file,
                                         pos, len, 0);

                 if (ret != len) {
                         req->cqe->result.u32 = cpu_to_le32(id);
                         if (ret < 0)
                                 status = errno_to_nvme_status(req, ret);
                         else
                                 status = errno_to_nvme_status(req, -EIO);
                         goto out;
                 }
                 pos += ret;
         }
out:
         nvmet_req_complete(req, status);
}


>   static void nvmet_file_execute_dsm(struct nvmet_req *req)
>   {
>   	if (!nvmet_check_data_len_lte(req, nvmet_dsm_len(req)))
> @@ -330,6 +373,12 @@ static void nvmet_file_execute_dsm(struct nvmet_req *req)
>   	queue_work(nvmet_wq, &req->f.work);
>   }
>   
> +static void nvmet_file_execute_copy(struct nvmet_req *req)
> +{
> +	INIT_WORK(&req->f.work, nvmet_file_copy_work);
> +	queue_work(nvmet_wq, &req->f.work);
> +}
> +
>   static void nvmet_file_write_zeroes_work(struct work_struct *w)
>   {
>   	struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
> @@ -376,6 +425,9 @@ u16 nvmet_file_parse_io_cmd(struct nvmet_req *req)
>   	case nvme_cmd_write_zeroes:
>   		req->execute = nvmet_file_execute_write_zeroes;
>   		return 0;
> +	case nvme_cmd_copy:
> +		req->execute = nvmet_file_execute_copy;
> +		return 0;
>   	default:
>   		return nvmet_report_invalid_opcode(req);
>   	}
> diff --git a/drivers/nvme/target/loop.c b/drivers/nvme/target/loop.c
> index f2d24b2d992f..d18ed8067a15 100644
> --- a/drivers/nvme/target/loop.c
> +++ b/drivers/nvme/target/loop.c
> @@ -146,6 +146,12 @@ static blk_status_t nvme_loop_queue_rq(struct blk_mq_hw_ctx *hctx,
>   		return ret;
>   
>   	nvme_start_request(req);
> +	if (unlikely((req->cmd_flags & REQ_COPY) &&
> +				(req_op(req) == REQ_OP_READ))) {
> +		blk_mq_set_request_complete(req);
> +		blk_mq_end_request(req, BLK_STS_OK);
> +		return BLK_STS_OK;
> +	}
>   	iod->cmd.common.flags |= NVME_CMD_SGL_METABUF;
>   	iod->req.port = queue->ctrl->port;
>   	if (!nvmet_req_init(&iod->req, &queue->nvme_cq,
> diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
> index 89bedfcd974c..69ed4c8469e5 100644
> --- a/drivers/nvme/target/nvmet.h
> +++ b/drivers/nvme/target/nvmet.h
> @@ -393,6 +393,7 @@ struct nvmet_req {
>   	struct device		*p2p_client;
>   	u16			error_loc;
>   	u64			error_slba;
> +	size_t			copy_len;
>   };
>   
>   #define NVMET_MAX_MPOOL_BVEC		16

-ck




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