fix data transfer size caculation for special payload requests

fix data transfer size caculation for special payload requests

[Christoph Hellwig]

Hi all,

the first two fixes fix a regression in 4.10-rc1 where the data transfer
size for discard commands wasn't set properly, leading to hangs with
Hyper-V VMs.  The use the new data transfer size helper added in patch 1
more widely.

[PATCH 1/4] block: add blk_rq_payload_bytes

[Christoph Hellwig]

Add a helper to calculate the actual data transfer size for special
payload requests.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 include/linux/blkdev.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index ff3d774..1ca8e8f 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1000,6 +1000,19 @@ static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
 	return blk_rq_cur_bytes(rq) >> 9;
 }
 
+/*
+ * Some commands like WRITE SAME have a payload or data transfer size which
+ * is different from the size of the request.  Any driver that supports such
+ * commands using the RQF_SPECIAL_PAYLOAD flag needs to use this helper to
+ * calculate the data transfer size.
+ */
+static inline unsigned int blk_rq_payload_bytes(struct request *rq)
+{
+	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
+		return rq->special_vec.bv_len;
+	return blk_rq_bytes(rq);
+}
+
 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
 						     int op)
 {
-- 
2.1.4

Re: [PATCH 1/4] block: add blk_rq_payload_bytes

[Hannes Reinecke]

On 01/13/2017 12:29 PM, Christoph Hellwig wrote:
> Add a helper to calculate the actual data transfer size for special
> payload requests.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  include/linux/blkdev.h | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index ff3d774..1ca8e8f 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -1000,6 +1000,19 @@ static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
>  	return blk_rq_cur_bytes(rq) >> 9;
>  }
>  
> +/*
> + * Some commands like WRITE SAME have a payload or data transfer size which
> + * is different from the size of the request.  Any driver that supports such
> + * commands using the RQF_SPECIAL_PAYLOAD flag needs to use this helper to
> + * calculate the data transfer size.
> + */
> +static inline unsigned int blk_rq_payload_bytes(struct request *rq)
> +{
> +	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
> +		return rq->special_vec.bv_len;
> +	return blk_rq_bytes(rq);
> +}
> +
>  static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
>  						     int op)
>  {
> 
Reviewed-by: Hannes Reinecke <hare@suse.com>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		   Teamlead Storage & Networking
hare@suse.de			               +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 N�rnberg
GF: F. Imend�rffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG N�rnberg)

Re: [PATCH 1/4] block: add blk_rq_payload_bytes

[Sagi Grimberg]

> Add a helper to calculate the actual data transfer size for special
> payload requests.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  include/linux/blkdev.h | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
>
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index ff3d774..1ca8e8f 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -1000,6 +1000,19 @@ static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
>  	return blk_rq_cur_bytes(rq) >> 9;
>  }
>
> +/*
> + * Some commands like WRITE SAME have a payload or data transfer size which

Don't you mean here DISCARD?

> + * is different from the size of the request.  Any driver that supports such
> + * commands using the RQF_SPECIAL_PAYLOAD flag needs to use this helper to
> + * calculate the data transfer size.
> + */
> +static inline unsigned int blk_rq_payload_bytes(struct request *rq)
> +{
> +	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
> +		return rq->special_vec.bv_len;
> +	return blk_rq_bytes(rq);
> +}
> +
>  static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
>  						     int op)
>  {
>

[PATCH 2/4] scsi: use blk_rq_payload_bytes

[Christoph Hellwig]

Without that we'll pass a wrong payload size in cmd->sdb, which
can lead to hangs with drivers that need the total transfer size.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Chris Valean <v-chvale@microsoft.com>
Reported-by: Dexuan Cui <decui@microsoft.com>
Fixes: f9d03f96 ("block: improve handling of the magic discard payload")
---
 drivers/scsi/scsi_lib.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index c35b6de..ad4ff8f 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1018,7 +1018,7 @@ static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb)
 	count = blk_rq_map_sg(req->q, req, sdb->table.sgl);
 	BUG_ON(count > sdb->table.nents);
 	sdb->table.nents = count;
-	sdb->length = blk_rq_bytes(req);
+	sdb->length = blk_rq_payload_bytes(req);
 	return BLKPREP_OK;
 }
 
-- 
2.1.4

Re: [PATCH 2/4] scsi: use blk_rq_payload_bytes

[Hannes Reinecke]

On 01/13/2017 12:29 PM, Christoph Hellwig wrote:
> Without that we'll pass a wrong payload size in cmd->sdb, which
> can lead to hangs with drivers that need the total transfer size.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Reported-by: Chris Valean <v-chvale@microsoft.com>
> Reported-by: Dexuan Cui <decui@microsoft.com>
> Fixes: f9d03f96 ("block: improve handling of the magic discard payload")
> ---
>  drivers/scsi/scsi_lib.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
> index c35b6de..ad4ff8f 100644
> --- a/drivers/scsi/scsi_lib.c
> +++ b/drivers/scsi/scsi_lib.c
> @@ -1018,7 +1018,7 @@ static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb)
>  	count = blk_rq_map_sg(req->q, req, sdb->table.sgl);
>  	BUG_ON(count > sdb->table.nents);
>  	sdb->table.nents = count;
> -	sdb->length = blk_rq_bytes(req);
> +	sdb->length = blk_rq_payload_bytes(req);
>  	return BLKPREP_OK;
>  }
>  
> 
Reviewed-by: Hannes Reinecke <hare@suse.com>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		   Teamlead Storage & Networking
hare@suse.de			               +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 N�rnberg
GF: F. Imend�rffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG N�rnberg)

Re: [PATCH 2/4] scsi: use blk_rq_payload_bytes

[Sagi Grimberg]

Looks good,

Reviewed-by: Sagi Grimberg <sagi@grimberg.me>

[PATCH 3/4] nvme: use blk_rq_payload_bytes

[Christoph Hellwig]

The new blk_rq_payload_bytes generalizes the payload length hacks
that nvme_map_len did before.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/nvme/host/fc.c   |  5 ++---
 drivers/nvme/host/nvme.h |  8 --------
 drivers/nvme/host/pci.c  | 19 ++++++++-----------
 drivers/nvme/host/rdma.c | 13 +++++--------
 4 files changed, 15 insertions(+), 30 deletions(-)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index aa0bc60..fcc9dcf 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -1654,13 +1654,12 @@ nvme_fc_map_data(struct nvme_fc_ctrl *ctrl, struct request *rq,
 		struct nvme_fc_fcp_op *op)
 {
 	struct nvmefc_fcp_req *freq = &op->fcp_req;
-	u32 map_len = nvme_map_len(rq);
 	enum dma_data_direction dir;
 	int ret;
 
 	freq->sg_cnt = 0;
 
-	if (!map_len)
+	if (!blk_rq_payload_bytes(rq))
 		return 0;
 
 	freq->sg_table.sgl = freq->first_sgl;
@@ -1854,7 +1853,7 @@ nvme_fc_queue_rq(struct blk_mq_hw_ctx *hctx,
 	if (ret)
 		return ret;
 
-	data_len = nvme_map_len(rq);
+	data_len = blk_rq_payload_bytes(rq);
 	if (data_len)
 		io_dir = ((rq_data_dir(rq) == WRITE) ?
 					NVMEFC_FCP_WRITE : NVMEFC_FCP_READ);
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 6377e14..aead6d0 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -225,14 +225,6 @@ static inline u64 nvme_block_nr(struct nvme_ns *ns, sector_t sector)
 	return (sector >> (ns->lba_shift - 9));
 }
 
-static inline unsigned nvme_map_len(struct request *rq)
-{
-	if (req_op(rq) == REQ_OP_DISCARD)
-		return sizeof(struct nvme_dsm_range);
-	else
-		return blk_rq_bytes(rq);
-}
-
 static inline void nvme_cleanup_cmd(struct request *req)
 {
 	if (req->rq_flags & RQF_SPECIAL_PAYLOAD) {
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 19beeb7..3faefab 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -306,11 +306,11 @@ static __le64 **iod_list(struct request *req)
 	return (__le64 **)(iod->sg + blk_rq_nr_phys_segments(req));
 }
 
-static int nvme_init_iod(struct request *rq, unsigned size,
-		struct nvme_dev *dev)
+static int nvme_init_iod(struct request *rq, struct nvme_dev *dev)
 {
 	struct nvme_iod *iod = blk_mq_rq_to_pdu(rq);
 	int nseg = blk_rq_nr_phys_segments(rq);
+	unsigned int size = blk_rq_payload_bytes(rq);
 
 	if (nseg > NVME_INT_PAGES || size > NVME_INT_BYTES(dev)) {
 		iod->sg = kmalloc(nvme_iod_alloc_size(dev, size, nseg), GFP_ATOMIC);
@@ -420,12 +420,11 @@ static void nvme_dif_complete(u32 p, u32 v, struct t10_pi_tuple *pi)
 }
 #endif
 
-static bool nvme_setup_prps(struct nvme_dev *dev, struct request *req,
-		int total_len)
+static bool nvme_setup_prps(struct nvme_dev *dev, struct request *req)
 {
 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
 	struct dma_pool *pool;
-	int length = total_len;
+	int length = blk_rq_payload_bytes(req);
 	struct scatterlist *sg = iod->sg;
 	int dma_len = sg_dma_len(sg);
 	u64 dma_addr = sg_dma_address(sg);
@@ -501,7 +500,7 @@ static bool nvme_setup_prps(struct nvme_dev *dev, struct request *req,
 }
 
 static int nvme_map_data(struct nvme_dev *dev, struct request *req,
-		unsigned size, struct nvme_command *cmnd)
+		struct nvme_command *cmnd)
 {
 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
 	struct request_queue *q = req->q;
@@ -519,7 +518,7 @@ static int nvme_map_data(struct nvme_dev *dev, struct request *req,
 				DMA_ATTR_NO_WARN))
 		goto out;
 
-	if (!nvme_setup_prps(dev, req, size))
+	if (!nvme_setup_prps(dev, req))
 		goto out_unmap;
 
 	ret = BLK_MQ_RQ_QUEUE_ERROR;
@@ -580,7 +579,6 @@ static int nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
 	struct nvme_dev *dev = nvmeq->dev;
 	struct request *req = bd->rq;
 	struct nvme_command cmnd;
-	unsigned map_len;
 	int ret = BLK_MQ_RQ_QUEUE_OK;
 
 	/*
@@ -600,13 +598,12 @@ static int nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
 	if (ret != BLK_MQ_RQ_QUEUE_OK)
 		return ret;
 
-	map_len = nvme_map_len(req);
-	ret = nvme_init_iod(req, map_len, dev);
+	ret = nvme_init_iod(req, dev);
 	if (ret != BLK_MQ_RQ_QUEUE_OK)
 		goto out_free_cmd;
 
 	if (blk_rq_nr_phys_segments(req))
-		ret = nvme_map_data(dev, req, map_len, &cmnd);
+		ret = nvme_map_data(dev, req, &cmnd);
 
 	if (ret != BLK_MQ_RQ_QUEUE_OK)
 		goto out_cleanup_iod;
diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index 34e5648..557f29b 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -981,8 +981,7 @@ static int nvme_rdma_map_sg_fr(struct nvme_rdma_queue *queue,
 }
 
 static int nvme_rdma_map_data(struct nvme_rdma_queue *queue,
-		struct request *rq, unsigned int map_len,
-		struct nvme_command *c)
+		struct request *rq, struct nvme_command *c)
 {
 	struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
 	struct nvme_rdma_device *dev = queue->device;
@@ -1014,9 +1013,9 @@ static int nvme_rdma_map_data(struct nvme_rdma_queue *queue,
 	}
 
 	if (count == 1) {
-		if (rq_data_dir(rq) == WRITE &&
-		    map_len <= nvme_rdma_inline_data_size(queue) &&
-		    nvme_rdma_queue_idx(queue))
+		if (rq_data_dir(rq) == WRITE && nvme_rdma_queue_idx(queue) &&
+		    blk_rq_payload_bytes(rq) <=
+				nvme_rdma_inline_data_size(queue))
 			return nvme_rdma_map_sg_inline(queue, req, c);
 
 		if (dev->pd->flags & IB_PD_UNSAFE_GLOBAL_RKEY)
@@ -1444,7 +1443,6 @@ static int nvme_rdma_queue_rq(struct blk_mq_hw_ctx *hctx,
 	struct nvme_command *c = sqe->data;
 	bool flush = false;
 	struct ib_device *dev;
-	unsigned int map_len;
 	int ret;
 
 	WARN_ON_ONCE(rq->tag < 0);
@@ -1462,8 +1460,7 @@ static int nvme_rdma_queue_rq(struct blk_mq_hw_ctx *hctx,
 
 	blk_mq_start_request(rq);
 
-	map_len = nvme_map_len(rq);
-	ret = nvme_rdma_map_data(queue, rq, map_len, c);
+	ret = nvme_rdma_map_data(queue, rq, c);
 	if (ret < 0) {
 		dev_err(queue->ctrl->ctrl.device,
 			     "Failed to map data (%d)\n", ret);
-- 
2.1.4

Re: [PATCH 3/4] nvme: use blk_rq_payload_bytes

[Hannes Reinecke]

On 01/13/2017 12:29 PM, Christoph Hellwig wrote:
> The new blk_rq_payload_bytes generalizes the payload length hacks
> that nvme_map_len did before.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  drivers/nvme/host/fc.c   |  5 ++---
>  drivers/nvme/host/nvme.h |  8 --------
>  drivers/nvme/host/pci.c  | 19 ++++++++-----------
>  drivers/nvme/host/rdma.c | 13 +++++--------
>  4 files changed, 15 insertions(+), 30 deletions(-)
> 
[ .. ]
Reviewed-by: Hannes Reinecke <hare@suse.com>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		   Teamlead Storage & Networking
hare@suse.de			               +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 N�rnberg
GF: F. Imend�rffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG N�rnberg)

Re: [PATCH 3/4] nvme: use blk_rq_payload_bytes

[Sagi Grimberg]

This looks good,

Reviewed-by: Sagi Grimberg <sagi@grimberg.me>

Re: [PATCH 3/4] nvme: use blk_rq_payload_bytes

[Sagi Grimberg]

> @@ -1014,9 +1013,9 @@ static int nvme_rdma_map_data(struct nvme_rdma_queue *queue,
>  	}
>

Christoph, a little above here we still look at blk_rq_bytes(),
shouldn't that look at blk_rq_payload_bytes() too?

>  	if (count == 1) {
> -		if (rq_data_dir(rq) == WRITE &&
> -		    map_len <= nvme_rdma_inline_data_size(queue) &&
> -		    nvme_rdma_queue_idx(queue))
> +		if (rq_data_dir(rq) == WRITE && nvme_rdma_queue_idx(queue) &&
> +		    blk_rq_payload_bytes(rq) <=
> +				nvme_rdma_inline_data_size(queue))
>  			return nvme_rdma_map_sg_inline(queue, req, c);
>
>  		if (dev->pd->flags & IB_PD_UNSAFE_GLOBAL_RKEY)

_______________________________________________
Linux-nvme mailing list
Linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme

Re: [PATCH 3/4] nvme: use blk_rq_payload_bytes

[Christoph Hellwig]

On Tue, Jan 17, 2017 at 10:06:51PM +0200, Sagi Grimberg wrote:
>
>> @@ -1014,9 +1013,9 @@ static int nvme_rdma_map_data(struct nvme_rdma_queue *queue,
>>  	}
>>
>
> Christoph, a little above here we still look at blk_rq_bytes(),
> shouldn't that look at blk_rq_payload_bytes() too?

The check is ok for now as it's just zero vs non-zero.  It's somewhat
broken for Write Zeroes, though.  I've fixed it in this series
which I need to submit:

	http://git.infradead.org/users/hch/block.git/shortlog/refs/heads/write-zeroes-take-2

Re: [PATCH 3/4] nvme: use blk_rq_payload_bytes

[Sagi Grimberg]

>>> @@ -1014,9 +1013,9 @@ static int nvme_rdma_map_data(struct nvme_rdma_queue *queue,
>>>  	}
>>>
>>
>> Christoph, a little above here we still look at blk_rq_bytes(),
>> shouldn't that look at blk_rq_payload_bytes() too?
>
> The check is ok for now as it's just zero vs non-zero.  It's somewhat
> broken for Write Zeroes, though.  I've fixed it in this series
> which I need to submit:
>
> 	http://git.infradead.org/users/hch/block.git/shortlog/refs/heads/write-zeroes-take-2
>

I see, thanks for the clarification.

[PATCH 4/4] sd: remove __data_len hack for WRITE SAME

[Christoph Hellwig]

Now that we have the blk_rq_payload_bytes helper available to determine
the actual I/O size we don't need to mess around with __data_len for
WRITE SAME.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/scsi/sd.c | 17 +----------------
 1 file changed, 1 insertion(+), 16 deletions(-)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index b193304..1fbb1ec 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -836,7 +836,6 @@ static int sd_setup_write_same_cmnd(struct scsi_cmnd *cmd)
 	struct bio *bio = rq->bio;
 	sector_t sector = blk_rq_pos(rq);
 	unsigned int nr_sectors = blk_rq_sectors(rq);
-	unsigned int nr_bytes = blk_rq_bytes(rq);
 	int ret;
 
 	if (sdkp->device->no_write_same)
@@ -869,21 +868,7 @@ static int sd_setup_write_same_cmnd(struct scsi_cmnd *cmd)
 
 	cmd->transfersize = sdp->sector_size;
 	cmd->allowed = SD_MAX_RETRIES;
-
-	/*
-	 * For WRITE_SAME the data transferred in the DATA IN buffer is
-	 * different from the amount of data actually written to the target.
-	 *
-	 * We set up __data_len to the amount of data transferred from the
-	 * DATA IN buffer so that blk_rq_map_sg set up the proper S/G list
-	 * to transfer a single sector of data first, but then reset it to
-	 * the amount of data to be written right after so that the I/O path
-	 * knows how much to actually write.
-	 */
-	rq->__data_len = sdp->sector_size;
-	ret = scsi_init_io(cmd);
-	rq->__data_len = nr_bytes;
-	return ret;
+	return scsi_init_io(cmd);
 }
 
 static int sd_setup_flush_cmnd(struct scsi_cmnd *cmd)
-- 
2.1.4

Re: [PATCH 4/4] sd: remove __data_len hack for WRITE SAME

[Hannes Reinecke]

On 01/13/2017 12:29 PM, Christoph Hellwig wrote:
> Now that we have the blk_rq_payload_bytes helper available to determine
> the actual I/O size we don't need to mess around with __data_len for
> WRITE SAME.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  drivers/scsi/sd.c | 17 +----------------
>  1 file changed, 1 insertion(+), 16 deletions(-)
> 
> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
> index b193304..1fbb1ec 100644
> --- a/drivers/scsi/sd.c
> +++ b/drivers/scsi/sd.c
> @@ -836,7 +836,6 @@ static int sd_setup_write_same_cmnd(struct scsi_cmnd *cmd)
>  	struct bio *bio = rq->bio;
>  	sector_t sector = blk_rq_pos(rq);
>  	unsigned int nr_sectors = blk_rq_sectors(rq);
> -	unsigned int nr_bytes = blk_rq_bytes(rq);
>  	int ret;
>  
>  	if (sdkp->device->no_write_same)
> @@ -869,21 +868,7 @@ static int sd_setup_write_same_cmnd(struct scsi_cmnd *cmd)
>  
>  	cmd->transfersize = sdp->sector_size;
>  	cmd->allowed = SD_MAX_RETRIES;
> -
> -	/*
> -	 * For WRITE_SAME the data transferred in the DATA IN buffer is
> -	 * different from the amount of data actually written to the target.
> -	 *
> -	 * We set up __data_len to the amount of data transferred from the
> -	 * DATA IN buffer so that blk_rq_map_sg set up the proper S/G list
> -	 * to transfer a single sector of data first, but then reset it to
> -	 * the amount of data to be written right after so that the I/O path
> -	 * knows how much to actually write.
> -	 */
> -	rq->__data_len = sdp->sector_size;
> -	ret = scsi_init_io(cmd);
> -	rq->__data_len = nr_bytes;
> -	return ret;
> +	return scsi_init_io(cmd);
>  }
>  
>  static int sd_setup_flush_cmnd(struct scsi_cmnd *cmd)
> 
Reviewed-by: Hannes Reinecke <hare@suse.com>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		   Teamlead Storage & Networking
hare@suse.de			               +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 N�rnberg
GF: F. Imend�rffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG N�rnberg)

Re: [PATCH 4/4] sd: remove __data_len hack for WRITE SAME

[Sagi Grimberg]

Looks good,

Reviewed-by: Sagi Grimberg <sagi@grimberg.me>

Re: fix data transfer size caculation for special payload requests

[Jens Axboe]

On Fri, Jan 13 2017, Christoph Hellwig wrote:
> Hi all,
> 
> the first two fixes fix a regression in 4.10-rc1 where the data transfer
> size for discard commands wasn't set properly, leading to hangs with
> Hyper-V VMs.  The use the new data transfer size helper added in patch 1
> more widely.

Added for this series, thanks.

-- 
Jens Axboe