From: Roland Dreier <roland@xxxxxxxxxxxxxxx>
When an initiator sends an allocation length bigger than what its
command consumes, the target should only return the actual response data
and set the residual length to the unused part of the allocation length.
Add a helper function that command handlers (INQUIRY, READ CAPACITY,
etc) can use to do this correctly.
Signed-off-by: Roland Dreier <roland@xxxxxxxxxxxxxxx>
---
drivers/target/target_core_transport.c | 17 +++++++++++++++++
include/target/target_core_backend.h | 1 +
2 files changed, 18 insertions(+)
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 2179feed0d63..afc666df4728 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -703,6 +703,23 @@ void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
}
EXPORT_SYMBOL(target_complete_cmd);
+void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
+{
+ if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
+ if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
+ cmd->residual_count += cmd->data_length - length;
+ } else {
+ cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
+ cmd->residual_count = cmd->data_length - length;
+ }
+
+ cmd->data_length = length;
+ }
+
+ target_complete_cmd(cmd, scsi_status);
+}
+EXPORT_SYMBOL(target_complete_cmd_with_length);
+
static void target_add_to_state_list(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index 3a1c1eea1fff..9adc1bca1178 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -59,6 +59,7 @@ int transport_subsystem_register(struct se_subsystem_api *);
void transport_subsystem_release(struct se_subsystem_api *);
void target_complete_cmd(struct se_cmd *, u8);
+void target_complete_cmd_with_length(struct se_cmd *, u8, int);
sense_reason_t spc_parse_cdb(struct se_cmd *cmd, unsigned int *size);
sense_reason_t spc_emulate_report_luns(struct se_cmd *cmd);
--
2.0.0
--
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