target/rd: Add DIF protection into rd_execute_rw

This patch adds support for DIF protection into rd_execute_rw() code
for WRITE/READ I/O using sbc_dif_verify_[write,read]() logic.

It also adds rd_get_prot_table() for locating protection SGLs
assoicated with the ramdisk backend device.

v2 changes:
  - Make rd_execute_rw() to u32 sectors count instead of sector_t
  - Drop SCF_PROT usage

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>

diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c
index 660961d..66a5aba 100644 (file)
--- a/drivers/target/target_core_rd.c
+++ b/drivers/target/target_core_rd.c
@@ -356,6 +356,26 @@ static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
        return NULL;
 }
 
+static struct rd_dev_sg_table *rd_get_prot_table(struct rd_dev *rd_dev, u32 page)
+{
+       struct rd_dev_sg_table *sg_table;
+       u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
+                               sizeof(struct scatterlist));
+
+       i = page / sg_per_table;
+       if (i < rd_dev->sg_prot_count) {
+               sg_table = &rd_dev->sg_prot_array[i];
+               if ((sg_table->page_start_offset <= page) &&
+                    (sg_table->page_end_offset >= page))
+                       return sg_table;
+       }
+
+       pr_err("Unable to locate struct prot rd_dev_sg_table for page: %u\n",
+                       page);
+
+       return NULL;
+}
+
 static sense_reason_t
 rd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
              enum dma_data_direction data_direction)
@@ -370,6 +390,7 @@ rd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
        u32 rd_page;
        u32 src_len;
        u64 tmp;
+       sense_reason_t rc;
 
        if (dev->rd_flags & RDF_NULLIO) {
                target_complete_cmd(cmd, SAM_STAT_GOOD);
@@ -392,6 +413,28 @@ rd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
                        data_direction == DMA_FROM_DEVICE ? "Read" : "Write",
                        cmd->t_task_lba, rd_size, rd_page, rd_offset);
 
+       if (cmd->prot_type && data_direction == DMA_TO_DEVICE) {
+               struct rd_dev_sg_table *prot_table;
+               struct scatterlist *prot_sg;
+               u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size;
+               u32 prot_offset, prot_page;
+
+               tmp = cmd->t_task_lba * se_dev->prot_length;
+               prot_offset = do_div(tmp, PAGE_SIZE);
+               prot_page = tmp;
+
+               prot_table = rd_get_prot_table(dev, prot_page);
+               if (!prot_table)
+                       return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+
+               prot_sg = &prot_table->sg_table[prot_page - prot_table->page_start_offset];
+
+               rc = sbc_dif_verify_write(cmd, cmd->t_task_lba, sectors, 0,
+                                         prot_sg, prot_offset);
+               if (rc)
+                       return rc;
+       }
+
        src_len = PAGE_SIZE - rd_offset;
        sg_miter_start(&m, sgl, sgl_nents,
                        data_direction == DMA_FROM_DEVICE ?
@@ -453,6 +496,28 @@ rd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
        }
        sg_miter_stop(&m);
 
+       if (cmd->prot_type && data_direction == DMA_FROM_DEVICE) {
+               struct rd_dev_sg_table *prot_table;
+               struct scatterlist *prot_sg;
+               u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size;
+               u32 prot_offset, prot_page;
+
+               tmp = cmd->t_task_lba * se_dev->prot_length;
+               prot_offset = do_div(tmp, PAGE_SIZE);
+               prot_page = tmp;
+
+               prot_table = rd_get_prot_table(dev, prot_page);
+               if (!prot_table)
+                       return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+
+               prot_sg = &prot_table->sg_table[prot_page - prot_table->page_start_offset];
+
+               rc = sbc_dif_verify_read(cmd, cmd->t_task_lba, sectors, 0,
+                                        prot_sg, prot_offset);
+               if (rc)
+                       return rc;
+       }
+
        target_complete_cmd(cmd, SAM_STAT_GOOD);
        return 0;
 }