lkml.org 
[lkml]   [2014]   [Jan]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 01/14] target: Add DIF related base definitions
On 1/8/2014 10:36 PM, Nicholas A. Bellinger wrote:
> From: Nicholas Bellinger <nab@linux-iscsi.org>
>
> This patch adds DIF related definitions to target_core_base.h
> that includes enums for target_prot_op + target_prot_type +
> target_prot_version + target_guard_type + target_pi_error.
>
> Also included is struct se_dif_v1_tuple, along with changes
> to struct se_cmd, struct se_dev_attrib, and struct se_device.
>
> Also, add new se_subsystem_api->[init,free]_prot() callers
> used by target core code to setup backend specific protection
> information after the device has been configured.
>
> Enums taken from Sagi Grimberg's original patch.
>
> Cc: Martin K. Petersen <martin.petersen@oracle.com>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Hannes Reinecke <hare@suse.de>
> Cc: Sagi Grimberg <sagig@mellanox.com>
> Cc: Or Gerlitz <ogerlitz@mellanox.com>
> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
>
> target: more defs
>
> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
> ---
> include/target/target_core_backend.h | 2 ++
> include/target/target_core_base.h | 59 ++++++++++++++++++++++++++++++++++
> 2 files changed, 61 insertions(+)
>
> diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
> index 39e0114..930f30d 100644
> --- a/include/target/target_core_backend.h
> +++ b/include/target/target_core_backend.h
> @@ -41,6 +41,8 @@ struct se_subsystem_api {
> unsigned int (*get_io_opt)(struct se_device *);
> unsigned char *(*get_sense_buffer)(struct se_cmd *);
> bool (*get_write_cache)(struct se_device *);
> + int (*init_prot)(struct se_device *);
> + void (*free_prot)(struct se_device *);
> };
>
> struct sbc_ops {
> diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
> index 45412a6..15f402c 100644
> --- a/include/target/target_core_base.h
> +++ b/include/target/target_core_base.h
> @@ -166,6 +166,7 @@ enum se_cmd_flags_table {
> SCF_COMPARE_AND_WRITE = 0x00080000,
> SCF_COMPARE_AND_WRITE_POST = 0x00100000,
> SCF_CMD_XCOPY_PASSTHROUGH = 0x00200000,
> + SCF_PROT = 0x00400000,
> };
>
> /* struct se_dev_entry->lun_flags and struct se_lun->lun_access */
> @@ -414,6 +415,45 @@ struct se_tmr_req {
> struct list_head tmr_list;
> };
>
> +enum target_prot_op {
> + TARGET_PROT_NORMAL,
> + TARGET_PROT_READ_INSERT,
> + TARGET_PROT_WRITE_INSERT,
> + TARGET_PROT_READ_STRIP,
> + TARGET_PROT_WRITE_STRIP,
> + TARGET_PROT_READ_PASS,
> + TARGET_PROT_WRITE_PASS,
> +};
> +
> +enum target_prot_type {
> + TARGET_DIF_TYPE0_PROT,
> + TARGET_DIF_TYPE1_PROT,
> + TARGET_DIF_TYPE2_PROT,
> + TARGET_DIF_TYPE3_PROT,
> +};
> +
> +enum target_prot_version {
> + TARGET_DIF_V1 = 1,
> + TARGET_DIF_V2 = 2,
> +};
> +
> +enum target_guard_type {
> + TARGET_DIX_GUARD_CRC = 1,
> + TARGET_DIX_GUARD_IP = 2,
> +};
> +
> +enum target_pi_error {
> + TARGET_GUARD_CHECK_FAILED = 0x1,
> + TARGET_APPTAG_CHECK_FAILED = 0x2,
> + TARGET_REFTAG_CHECK_FAILED = 0x3,
> +};
> +
> +struct se_dif_v1_tuple {
> + __be16 guard_tag;
> + __be16 app_tag;
> + __be32 ref_tag;
> +};
> +
> struct se_cmd {
> /* SAM response code being sent to initiator */
> u8 scsi_status;
> @@ -498,6 +538,20 @@ struct se_cmd {
>
> /* Used for lun->lun_ref counting */
> bool lun_ref_active;
> +
> + /* DIF related members */
> + enum target_prot_op prot_op;
> + enum target_prot_type prot_type;
> + enum target_guard_type bg_type;
> + u16 bg_seed;
> + u16 reftag_seed;
> + u32 apptag_seed;
> + u32 prot_length;
> + struct scatterlist *t_prot_sg;
> + unsigned int t_prot_nents;
> + bool prot_interleaved;
> + enum target_pi_error pi_err;
> + u32 block_num;
> };

Some of these guys are unreferenced... I figured these should provide
necessary info both for the transport and the backstores.

Regarding prot_interleaved, I don't remember if we agreed to allow
backstores to store the protection interleaved with the data, which
seems to make some sense in pSCSI.
Anyway, I added this flag simply because some transports support it
(iSER) and it might be useful to avoid de-interleaving + re-interleaving
the buffers.
In my toy example I modified fileio to support both storing
data+protection interleaved and storing protection in a seperate
file.protection
(without verify - left it for the transport) and let the user choose via
configfs (protection_handover).

I think we should hear more opinions here.

>
> struct se_ua {
> @@ -609,6 +663,9 @@ struct se_dev_attrib {
> int emulate_tpws;
> int emulate_caw;
> int emulate_3pc;
> + enum target_prot_type pi_prot_type;
> + enum target_prot_version pi_prot_version;
> + enum target_guard_type pi_guard_type;
> int enforce_pr_isids;
> int is_nonrot;
> int emulate_rest_reord;
> @@ -739,6 +796,8 @@ struct se_device {
> /* Linked list for struct se_hba struct se_device list */
> struct list_head dev_list;
> struct se_lun xcopy_lun;
> + /* Protection Information */
> + int prot_length;
> };
>
> struct se_hba {



\
 
 \ /
  Last update: 2014-01-09 16:01    [W:0.297 / U:0.992 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site