target: Fix WRITE_SAME_[16,32] number of blocks=0 case

[firefly-linux-kernel-4.4.55.git] / drivers / target / target_core_cdb.c

diff --git a/drivers/target/target_core_cdb.c b/drivers/target/target_core_cdb.c
index 95195d7181010514900758cb254e06b466360556..8d5a0fc3a22053a8632ec9e7af856c4339b87611 100644 (file)
--- a/drivers/target/target_core_cdb.c
+++ b/drivers/target/target_core_cdb.c
@@ -1008,18 +1008,30 @@ target_emulate_unmap(struct se_task *task)
  * 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 @@ transport_emulate_control_cdb(struct se_task *task)
                                        " 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 @@ transport_emulate_control_cdb(struct se_task *task)
                                        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:"