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);
--
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