Regards,
Quinn Tran
On 3/28/14 5:16 PM, "sagi grimberg" <sagig@xxxxxxxxxxxx> wrote:
>On 3/29/2014 2:05 AM, Quinn Tran wrote:
>> This patch is borrow code from
>>
>> commit 0f5e2ec46dd64579c0770f3822764f94db4fa465
>> Author: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
>> Date: Sat Jan 18 09:32:56 2014 +0000
>>
>> target/file: Add DIF protection init/format support
>>
>> This patch adds support for DIF protection init/format support into
>> the FILEIO backend.
>>
>> It involves using a seperate $FILE.protection for storing PI that
>>is
>> opened via fd_init_prot() using the common pi_prot_type attribute.
>> The actual formatting of the protection is done via
>>fd_format_prot()
>> using the common pi_prot_format attribute, that will populate the
>> initial PI data based upon the currently configured pi_prot_type.
>>
>> Based on original FILEIO code from Sagi.
>>
>> v1 changes:
>> - Fix sparse warnings in fd_init_format_buf (Fengguang)
>>
>> 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_rd.c | 64
>>++++++++++++++++++++++++++++++++++++++++-
>> 1 file changed, 63 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/target/target_core_rd.c
>>b/drivers/target/target_core_rd.c
>> index 66a5aba..01dda0b 100644
>> --- a/drivers/target/target_core_rd.c
>> +++ b/drivers/target/target_core_rd.c
>> @@ -603,7 +603,7 @@ static int rd_init_prot(struct se_device *dev)
>> {
>> struct rd_dev *rd_dev = RD_DEV(dev);
>>
>> - if (!dev->dev_attrib.pi_prot_type)
>> + if (!dev->dev_attrib.pi_prot_type)
>> return 0;
>>
>> return rd_build_prot_space(rd_dev, dev->prot_length);
>> @@ -616,6 +616,67 @@ static void rd_free_prot(struct se_device *dev)
>> rd_release_prot_space(rd_dev);
>> }
>>
>> +static void rd_init_format_buf(struct se_device *dev, unsigned char
>>*buf,
>> + u32 unit_size, u32 *ref_tag, u16 app_tag,
>> + bool inc_reftag)
>> +{
>> + unsigned char *p = buf;
>> + int i;
>> +
>> + for (i = 0; i < unit_size; i += dev->prot_length) {
>> + *((u16 *)&p[0]) = 0xffff;
>> + *((__be16 *)&p[2]) = cpu_to_be16(app_tag);
>> + *((__be32 *)&p[4]) = cpu_to_be32(*ref_tag);
>> +
>> + if (inc_reftag)
>> + (*ref_tag)++;
>> +
>> + p += dev->prot_length;
>> + }
>> +}
>> +
>> +static int rd_format_prot(struct se_device *dev)
>> +{
>> + struct rd_dev *rd_dev = RD_DEV(dev);
>> + u32 ref_tag = 0;
>> + int i,j;
>> + bool inc_reftag = false;
>> + struct rd_dev_sg_table *pt;
>> + struct scatterlist *sg;
>> + void *paddr;
>> +
>> + if (!dev->dev_attrib.pi_prot_type) {
>> + pr_err("Unable to format_prot while pi_prot_type == 0\n");
>> + return -ENODEV;
>> + }
>> +
>> + switch (dev->dev_attrib.pi_prot_type) {
>> + case TARGET_DIF_TYPE3_PROT:
>> + ref_tag = 0xffffffff;
>> + break;
>> + case TARGET_DIF_TYPE2_PROT:
>> + case TARGET_DIF_TYPE1_PROT:
>> + inc_reftag = true;
>> + break;
>> + default:
>> + break;
>> + }
>> +
>> + for (i=0; i < rd_dev->sg_prot_count; i++) {
>> + pt= &rd_dev->sg_prot_array[i];
>> + for_each_sg(pt->sg_table, sg, pt->rd_sg_count, j) {
>> + paddr = kmap(sg_page(sg)) + sg->offset;
>> +
>> + rd_init_format_buf(dev, paddr, sg->length, &ref_tag,
>> + 0xffff, inc_reftag);
>> + kunmap(paddr);
>> + }
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +
>> static struct sbc_ops rd_sbc_ops = {
>> .execute_rw = rd_execute_rw,
>> };
>> @@ -642,6 +703,7 @@ static struct se_subsystem_api rd_mcp_template = {
>> .get_device_type = sbc_get_device_type,
>> .get_blocks = rd_get_blocks,
>> .init_prot = rd_init_prot,
>> + .format_prot = rd_format_prot,
>> .free_prot = rd_free_prot,
>> };
>>
>
>This patch is redundant altogether. rd_mcp already init protection with
>escape values:
>rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0xff);
QT> I see. Will re-examine my code to live without this function.
>
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