Re: [PATCH-v2 03/17] target/sbc: Add DIF setup in sbc_check_prot+ sbc_parse_cdb

From: Sagi Grimberg
Date: Sun Jan 19 2014 - 06:44:09 EST


On 1/19/2014 4:44 AM, Nicholas A. Bellinger wrote:
From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>

This patch adds sbc_check_prot() for performing various DIF
related CDB sanity checks, along with setting cmd->prot_type
once sanity checks have passed.

Also, add calls in sbc_parse_cdb() for READ_[10,12,16] +
WRITE_[10,12,16] to perform DIF sanity checking.

v2 changes:
- Make sbc_check_prot defined as static (Fengguang + Wei)
- Remove unprotected READ/WRITE warning (mkp)
- Populate cmd->prot_type + friends (Sagi)
- Drop SCF_PROT usage

Cc: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxx>
Cc: Sagi Grimberg <sagig@xxxxxxxxxxxx>
Cc: Or Gerlitz <ogerlitz@xxxxxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/target_core_sbc.c | 62 ++++++++++++++++++++++++++++++++++++++
1 file changed, 62 insertions(+)

diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index 6863dbe..91a92f3 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -563,6 +563,44 @@ sbc_compare_and_write(struct se_cmd *cmd)
return TCM_NO_SENSE;
}
+static bool
+sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
+ u32 sectors)
+{
+ if (!cmd->t_prot_sg || !cmd->t_prot_nents)
+ return true;
+
+ switch (dev->dev_attrib.pi_prot_type) {
+ case TARGET_DIF_TYPE3_PROT:
+ if (!(cdb[1] & 0xe0))
+ return true;
+
+ cmd->reftag_seed = 0xffffffff;
+ break;
+ case TARGET_DIF_TYPE2_PROT:
+ if (cdb[1] & 0xe0)
+ return false;
+
+ cmd->reftag_seed = cmd->t_task_lba;
+ break;
+ case TARGET_DIF_TYPE1_PROT:
+ if (!(cdb[1] & 0xe0))
+ return true;
+
+ cmd->reftag_seed = cmd->t_task_lba;
+ break;
+ case TARGET_DIF_TYPE0_PROT:
+ default:
+ return true;
+ }
+
+ cmd->prot_type = dev->dev_attrib.pi_prot_type;
+ cmd->prot_length = dev->prot_length * sectors;
+ cmd->prot_handover = PROT_SEPERATED;

I know that we are not planning to support interleaved mode at the moment, But I think
that the protection handover type is the backstore preference and should be taken from se_dev.
But it is not that important for now...

Sagi.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/