target: Address legacy PYX_TRANSPORT_* return code breakage

This patch removes legacy usage of PYX_TRANSPORT_* return codes in a number
of locations and addresses cases where transport_generic_request_failure()
was returning the incorrect sense upon CHECK_CONDITION status after the
v3.1 converson to use errno return codes.

This includes the conversion of transport_generic_request_failure() to
process cmd->scsi_sense_reason and handle extra TCM_RESERVATION_CONFLICT
before calling transport_send_check_condition_and_sense() to queue up
response status.  It also drops PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES legacy
usgae, and returns TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE w/ a response
for these cases.

transport_generic_allocate_tasks(), transport_generic_new_cmd(), backend
SCF_SCSI_DATA_SG_IO_CDB ->do_task(), and emulated ->execute_task() have
all been updated to set se_cmd->scsi_sense_reason and return errno codes
universally upon failure.  This includes cmd->scsi_sense_reason assignment
in target_core_alua.c, target_core_pr.c and target_core_cdb.c emulation code.

Finally it updates fabric modules to remove the legacy usage, and for
TFO->new_cmd_map() callers forwards return values outside of fabric code.
iscsi-target has also been updated to remove a handful of special cases
related to the cleanup and signaling QUEUE_FULL handling w/ ft_write_pending()

(v2: Drop extra SCF_SCSI_CDB_EXCEPTION check during failure from
     transport_generic_new_cmd, and re-add missing task->task_error_status
     assignment in transport_complete_task)

Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

2 files changed, 3 insertions, 9 deletions

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 0fd96c10271d..4d81e1007c92 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -1017,11 +1017,6 @@ done:
                                 " non-existent or non-exported iSCSI LUN:"
                                 " 0x%016Lx\n", get_unaligned_le64(&hdr->lun));
                 }
-                if (ret == PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES)
-                        return iscsit_add_reject_from_cmd(
-                                        ISCSI_REASON_BOOKMARK_NO_RESOURCES,
-                                        1, 1, buf, cmd);
-
                 send_check_condition = 1;
                 goto attach_cmd;
         }
@@ -1123,7 +1118,7 @@ attach_cmd:
          * the backend memory allocation.
          */
         ret = transport_generic_new_cmd(&cmd->se_cmd);
-        if ((ret < 0) || (cmd->se_cmd.se_cmd_flags & SCF_SE_CMD_FAILED)) {
+        if (ret < 0) {
                 immed_ret = IMMEDIATE_DATA_NORMAL_OPERATION;
                 dump_immediate_data = 1;
                 goto after_immediate_data;
@@ -1341,7 +1336,7 @@ static int iscsit_handle_data_out(struct iscsi_conn *conn, unsigned char *buf)
 
                 spin_lock_irqsave(&se_cmd->t_state_lock, flags);
                 if (!(se_cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) ||
-                     (se_cmd->se_cmd_flags & SCF_SE_CMD_FAILED))
+                     (se_cmd->se_cmd_flags & SCF_SCSI_CDB_EXCEPTION))
                         dump_unsolicited_data = 1;
                 spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
 
diff --git a/drivers/target/iscsi/iscsi_target_erl1.c b/drivers/target/iscsi/iscsi_target_erl1.c
index c4c68da3e500..101b1beb3bca 100644
--- a/drivers/target/iscsi/iscsi_target_erl1.c
+++ b/drivers/target/iscsi/iscsi_target_erl1.c
@@ -938,8 +938,7 @@ int iscsit_execute_cmd(struct iscsi_cmd *cmd, int ooo)
                  * handle the SCF_SCSI_RESERVATION_CONFLICT case here as well.
                  */
                 if (se_cmd->se_cmd_flags & SCF_SCSI_CDB_EXCEPTION) {
-                        if (se_cmd->se_cmd_flags &
-                                        SCF_SCSI_RESERVATION_CONFLICT) {
+                        if (se_cmd->scsi_sense_reason == TCM_RESERVATION_CONFLICT) {
                                 cmd->i_state = ISTATE_SEND_STATUS;
                                 spin_unlock_bh(&cmd->istate_lock);
                                 iscsit_add_cmd_to_response_queue(cmd, cmd->conn,