target: Fix WRITE_SAME_[16,32] number of blocks=0 case
This patch fixes the handling of WRITE_SAME_[16,32] emulation where a
WRITE_SAME_* CDB with number of blocks=0 was being rejected by SCSI
expected data transfer length overflow checking in target core.
It changes both CDB cases in transport_generic_cmd_sequencer() to use
dev->se_sub_dev->se_dev_attrib.block_size to match what sg_write_same
is sending us with --num=0. It also fixes target_emulate_write_same()
to properly determine the num_blocks with --num=0 case to determine the
remaining range for dev->transport->do_discard().
Reported-by: Chris Greiveldinger <chris.greiveldinger@rnanetworks.com>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/target_core_cdb.c b/drivers/target/target_core_cdb.c
index 95195d7..8d5a0fc 100644
--- a/drivers/target/target_core_cdb.c
+++ b/drivers/target/target_core_cdb.c
@@ -1008,18 +1008,30 @@
* Note this is not used for TCM/pSCSI passthrough
*/
static int
-target_emulate_write_same(struct se_task *task)
+target_emulate_write_same(struct se_task *task, int write_same32)
{
struct se_cmd *cmd = task->task_se_cmd;
struct se_device *dev = cmd->se_dev;
- sector_t lba = cmd->t_task.t_task_lba;
- unsigned int range;
+ sector_t range, lba = cmd->t_task.t_task_lba;
+ unsigned int num_blocks;
int ret;
+ /*
+ * Extract num_blocks from the WRITE_SAME_* CDB. Then use the explict
+ * range when non zero is supplied, otherwise calculate the remaining
+ * range based on ->get_blocks() - starting LBA.
+ */
+ if (write_same32)
+ num_blocks = get_unaligned_be32(&cmd->t_task.t_task_cdb[28]);
+ else
+ num_blocks = get_unaligned_be32(&cmd->t_task.t_task_cdb[10]);
- range = (cmd->data_length / dev->se_sub_dev->se_dev_attrib.block_size);
+ if (num_blocks != 0)
+ range = num_blocks;
+ else
+ range = (dev->transport->get_blocks(dev) - lba);
- printk(KERN_INFO "WRITE_SAME UNMAP: LBA: %llu Range: %u\n",
- (unsigned long long)lba, range);
+ printk(KERN_INFO "WRITE_SAME UNMAP: LBA: %llu Range: %llu\n",
+ (unsigned long long)lba, (unsigned long long)range);
ret = dev->transport->do_discard(dev, lba, range);
if (ret < 0) {
@@ -1081,7 +1093,7 @@
" for: %s\n", dev->transport->name);
return PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
}
- ret = target_emulate_write_same(task);
+ ret = target_emulate_write_same(task, 0);
break;
case VARIABLE_LENGTH_CMD:
service_action =
@@ -1094,7 +1106,7 @@
dev->transport->name);
return PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
}
- ret = target_emulate_write_same(task);
+ ret = target_emulate_write_same(task, 1);
break;
default:
printk(KERN_ERR "Unsupported VARIABLE_LENGTH_CMD SA:"