+void dump_sector(unsigned char *buf, int len)
+{
+ int i, j;
+
+ printk(KERN_ERR ">>> Sector Dump <<<\n");
+
+ for (i = 0 ; i < len ; i += 16) {
+ printk(KERN_ERR "%04d: ", i);
+
+ for (j = 0 ; j < 16 ; j++) {
+ unsigned char c = buf[i+j];
+ if (c >= 0x20 && c < 0x7e)
+ printk(" %c ", buf[i+j]);
+ else
+ printk("%02x ", buf[i+j]);
+ }
+
+ printk("\n");
+ }
+}
+
+static int prot_verify_write(struct scsi_cmnd *SCpnt, sector_t start_sec,
+ unsigned int sectors)
+{
+ int i, j, ret;
+ struct sd_dif_tuple *sdt;
+ struct scatterlist *dsgl = scsi_sglist(SCpnt);
+ struct scatterlist *psgl = scsi_prot_sglist(SCpnt);
+ void *daddr, *paddr;
+ sector_t tmp_sec = start_sec;
+ sector_t sector;
+ int ppage_offset;
+ unsigned short csum;
+
+ sector = do_div(tmp_sec, sdebug_store_sectors);
+
+ if (((SCpnt->cmnd[1] >> 5) & 7) != 1) {
+ printk(KERN_WARNING "scsi_debug: WRPROTECT != 1\n");
+ return 0;
+ }
+
+ BUG_ON(scsi_sg_count(SCpnt) == 0);
+ BUG_ON(scsi_prot_sg_count(SCpnt) == 0);
+
+ paddr = kmap_atomic(sg_page(psgl), KM_IRQ1) + psgl->offset;
+ ppage_offset = 0;
+
+ /* For each data page */
+ scsi_for_each_sg(SCpnt, dsgl, scsi_sg_count(SCpnt), i) {
+ daddr = kmap_atomic(sg_page(dsgl), KM_IRQ0) + dsgl->offset;
+
+ /* For each sector-sized chunk in data page */
+ for (j = 0 ; j < dsgl->length ; j += scsi_debug_sector_size) {
+
+ /* If we're at the end of the current
+ * protection page advance to the next one
+ */
+ if (ppage_offset >= psgl->length) {
+ kunmap_atomic(paddr, KM_IRQ1);
+ psgl = sg_next(psgl);
+ BUG_ON(psgl == NULL);
+ paddr = kmap_atomic(sg_page(psgl), KM_IRQ1)
+ + psgl->offset;
+ ppage_offset = 0;
+ }
+
+ sdt = paddr + ppage_offset;
+
+ switch (scsi_debug_guard) {
+ case 1:
+ csum = ip_compute_csum(daddr,
+ scsi_debug_sector_size);
+ break;
+ case 0:
+ csum = cpu_to_be16(crc_t10dif(daddr,
+ scsi_debug_sector_size));
+ break;
+ default:
+ BUG();
+ ret = 0;
+ goto out;
+ }
+
+ if (sdt->guard_tag != csum) {
+ printk(KERN_ERR
+ "%s: GUARD check failed on sector %lu " \
+ "rcvd 0x%04x, calculated 0x%04x\n",
+ __func__, (unsigned long)sector,
+ be16_to_cpu(sdt->guard_tag),
+ be16_to_cpu(csum));
+ ret = 0x01;
+ dump_sector(daddr, scsi_debug_sector_size);
+ goto out;
+ }
+
+ if (scsi_debug_dif != SD_DIF_TYPE3_PROTECTION &&
+ be32_to_cpu(sdt->ref_tag)
+ != (start_sec & 0xffffffff)) {
+ printk(KERN_ERR
+ "%s: REF check failed on sector %lu\n",
+ __func__, (unsigned long)sector);
+ ret = 0x03;
+ dump_sector(daddr, scsi_debug_sector_size);
+ goto out;
+ }
+
+ /* Would be great to copy this in bigger
+ * chunks. However, for the sake of
+ * correctness we need to verify each sector
+ * before writing it to "stable" storage
+ */
+ memcpy(dif_storep + dif_offset(sector), sdt, 8);
+
+ sector++;
+
+ if (sector == sdebug_store_sectors)
+ sector = 0; /* Force wrap */
+
+ start_sec++;
+ daddr += scsi_debug_sector_size;
+ ppage_offset += sizeof(struct sd_dif_tuple);
+ }
+
+ kunmap_atomic(daddr, KM_IRQ0);
+ }
+
+ kunmap_atomic(paddr, KM_IRQ1);
+
+ dix_writes++;
+
+ return 0;
+
+out:
+ dif_errors++;
+ kunmap_atomic(daddr, KM_IRQ0);
+ kunmap_atomic(paddr, KM_IRQ1);
+ return ret;
+}
+