Re: [PATCH 0/3] iscsi bidi & varlen support

[Boaz Harrosh <bharrosh@panasas.com>]

On Tue, Feb 12 2008 at 22:17 +0200, Pete Wyckoff <pw@osc.edu> wrote:
> pw@osc.edu wrote on Tue, 12 Feb 2008 15:12 -0500:
>> bharrosh@panasas.com wrote on Thu, 31 Jan 2008 20:08 +0200:
>>> Cheers after 1.3 years these can go in.
>>>
>>> [PATCH 1/3] iscsi: extended cdb support
>>>    The varlen support is not yet in mainline for
>>>   block and scsi-ml. But the API for drivers will
>>>   not change. All LLD need to do is max_command to
>>>   the it's maximum and be ready for bigger commands.
>>>   This is what's done here. Once these commands start
>>>   coming iscsi will be ready for them.
>>>
>>> [PATCH 2/3] iscsi: bidi support - libiscsi
>>> [PATCH 3/3] iscsi: bidi support - iscsi_tcp
>>>   bidirectional commands support in iscsi.
>>>   iSER is not yet ready, but it will not break.
>>>   There is already a mechanism in libiscsi that will
>>>   return error if bidi commands are sent iSER way.
>>>
>>> Pete please send me the iSER bits so we can port them
>>> to this latest version.
>>>
>>> Mike these patches are ontop of iscs branch of the iscsi
>>> git tree, they will apply but for compilation you will need
>>> to sync with Linus mainline. The patches are for the in-tree
>>> iscsi code. I own you the compat patch for the out-off-tree
>>> code, but this I will only be Sunday.
>> Here's the patch to add bidi support to iSER too.  It works
>> with my setup, but could use more testing.  Note that this does
>> rely on the 3 patches quoted above.
> 
> Similar, for varlen support to iSER.  Probably apply this one before
> the bidi one I just sent.
> 
> 		-- Pete
> 
> 
> From: Pete Wyckoff <pw@osc.edu>
> Subject: [PATCH] iscsi iser: varlen
> 
> Handle variable-length CDBs in iSER.
> 
> Signed-off-by: Pete Wyckoff <pw@osc.edu>
> ---
>  drivers/infiniband/ulp/iser/iscsi_iser.c     |    5 +++--
>  drivers/infiniband/ulp/iser/iscsi_iser.h     |    2 +-
>  drivers/infiniband/ulp/iser/iser_initiator.c |   16 ++++++++++------
>  3 files changed, 14 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.c b/drivers/infiniband/ulp/iser/iscsi_iser.c
> index 5f2284d..9dfc310 100644
> --- a/drivers/infiniband/ulp/iser/iscsi_iser.c
> +++ b/drivers/infiniband/ulp/iser/iscsi_iser.c
> @@ -401,7 +401,8 @@ iscsi_iser_session_create(struct iscsi_transport *iscsit,
>  		ctask      = session->cmds[i];
>  		iser_ctask = ctask->dd_data;
>  		ctask->hdr = (struct iscsi_cmd *)&iser_ctask->desc.iscsi_header;
> -		ctask->hdr_max = sizeof(iser_ctask->desc.iscsi_header);
> +		ctask->hdr_max = sizeof(iser_ctask->desc.iscsi_header) +
> +				 sizeof(iser_ctask->desc.hdrextbuf);
>  	}
>  
>  	for (i = 0; i < session->mgmtpool_max; i++) {
> @@ -604,7 +605,7 @@ static struct iscsi_transport iscsi_iser_transport = {
>  	.host_template          = &iscsi_iser_sht,
>  	.conndata_size		= sizeof(struct iscsi_conn),
>  	.max_lun                = ISCSI_ISER_MAX_LUN,
> -	.max_cmd_len            = ISCSI_ISER_MAX_CMD_LEN,
> +	.max_cmd_len            = 260,

Same bug I had. .max_cmd_len is still char, before the varlen patch to scsi-ml.
So it must be at most 252, Until that patch is introduced and it can return to
the correct 260 or better yet SCSI_MAX_VARLEN_CDB_SIZE. That also is only 
defined in the scsi-ml varlen patch.

>  	/* session management */
>  	.create_session         = iscsi_iser_session_create,
>  	.destroy_session        = iscsi_session_teardown,
> diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.h b/drivers/infiniband/ulp/iser/iscsi_iser.h
> index db8f81a..66905df 100644
> --- a/drivers/infiniband/ulp/iser/iscsi_iser.h
> +++ b/drivers/infiniband/ulp/iser/iscsi_iser.h
> @@ -90,7 +90,6 @@
>  /* FMR space for 1 MB of 4k-page transfers, plus 1 if not page aligned */
>  #define ISCSI_ISER_SG_TABLESIZE         (((1<<20) >> SHIFT_4K) + 1)
>  #define ISCSI_ISER_MAX_LUN		256
> -#define ISCSI_ISER_MAX_CMD_LEN		16
>  
>  /* QP settings */
>  /* Maximal bounds on received asynchronous PDUs */
> @@ -217,6 +216,7 @@ enum iser_desc_type {
>  struct iser_desc {
>  	struct iser_hdr              iser_header;
>  	struct iscsi_hdr             iscsi_header;
> +	char			     hdrextbuf[ISCSI_MAX_AHS_SIZE];
>  	struct iser_regd_buf         hdr_regd_buf;
>  	void                         *data;         /* used by RX & TX_CONTROL */
>  	struct iser_regd_buf         data_regd_buf; /* used by RX & TX_CONTROL */
> diff --git a/drivers/infiniband/ulp/iser/iser_initiator.c b/drivers/infiniband/ulp/iser/iser_initiator.c
> index 83247f1..ea3f5dc 100644
> --- a/drivers/infiniband/ulp/iser/iser_initiator.c
> +++ b/drivers/infiniband/ulp/iser/iser_initiator.c
> @@ -246,9 +246,13 @@ post_rx_kmalloc_failure:
>  	return err;
>  }
>  
> -/* creates a new tx descriptor and adds header regd buffer */
> +/**
> + * iser_create_send_desc - creates a new tx descriptor and adds header regd buffer
> + * @iscsi_hdr_len: length of &struct iscsi_hdr and any AHSes in hdrextbuf
> + */
>  static void iser_create_send_desc(struct iscsi_iser_conn *iser_conn,
> -				  struct iser_desc       *tx_desc)
> +				  struct iser_desc       *tx_desc,
> +				  int iscsi_hdr_len)
>  {
>  	struct iser_regd_buf *regd_hdr = &tx_desc->hdr_regd_buf;
>  	struct iser_dto      *send_dto = &tx_desc->dto;
> @@ -256,7 +260,7 @@ static void iser_create_send_desc(struct iscsi_iser_conn *iser_conn,
>  	memset(regd_hdr, 0, sizeof(struct iser_regd_buf));
>  	regd_hdr->device  = iser_conn->ib_conn->device;
>  	regd_hdr->virt_addr  = tx_desc; /* == &tx_desc->iser_header */
> -	regd_hdr->data_size  = ISER_TOTAL_HEADERS_LEN;
> +	regd_hdr->data_size  = sizeof(struct iser_hdr) + iscsi_hdr_len;
>  
>  	send_dto->ib_conn         = iser_conn->ib_conn;
>  	send_dto->notify_enable   = 1;
> @@ -342,7 +346,7 @@ int iser_send_command(struct iscsi_conn     *conn,
>  	iser_ctask->desc.type = ISCSI_TX_SCSI_COMMAND;
>  	send_dto = &iser_ctask->desc.dto;
>  	send_dto->ctask = iser_ctask;
> -	iser_create_send_desc(iser_conn, &iser_ctask->desc);
> +	iser_create_send_desc(iser_conn, &iser_ctask->desc, ctask->hdr_len);
>  
>  	if (hdr->flags & ISCSI_FLAG_CMD_READ)
>  		data_buf = &iser_ctask->data[ISER_DIR_IN];
> @@ -435,7 +439,7 @@ int iser_send_data_out(struct iscsi_conn     *conn,
>  	/* build the tx desc regd header and add it to the tx desc dto */
>  	send_dto = &tx_desc->dto;
>  	send_dto->ctask = iser_ctask;
> -	iser_create_send_desc(iser_conn, tx_desc);
> +	iser_create_send_desc(iser_conn, tx_desc, ctask->hdr_len);
>  
>  	iser_reg_single(iser_conn->ib_conn->device,
>  			send_dto->regd[0], DMA_TO_DEVICE);
> @@ -492,7 +496,7 @@ int iser_send_control(struct iscsi_conn *conn,
>  	mdesc->type = ISCSI_TX_CONTROL;
>  	send_dto = &mdesc->dto;
>  	send_dto->ctask = NULL;
> -	iser_create_send_desc(iser_conn, mdesc);
> +	iser_create_send_desc(iser_conn, mdesc, sizeof(struct iscsi_hdr));
>  
>  	device = iser_conn->ib_conn->device;
>  

I'm afraid the varlen patches to block and scsi-ml are waiting because of
me. There are more things I need to check, before they can get approved.

Once I do that, and varlen gets accepted, iSER and iscsi_tcp can go up 
to 260 for the .max_cmd_len as they should.

Boaz