[PATCH v3 3/4] scsi: target: iscsi: Claim the completion in __iscsit_check_dataout_hdr()

[Laurence Oberman <loberman@redhat.com>]

Commit d5869dae5080 ("scsi: target: iscsi: Fix hang for aborted
WRITE_PENDING commands") made __iscsit_check_dataout_hdr() complete an
aborted WRITE once the final DataOut PDU for the last outstanding R2T has
been received. That call records nothing to say the command has been
completed.

target_complete_cmd() on a command that already has CMD_T_ABORTED set goes
to target_cmd_interrupted(), which queues target_abort_work and returns
without setting CMD_T_COMPLETE and without changing t_state. The command
therefore stays in TRANSPORT_WRITE_PENDING and on conn_cmd_list until
target_abort_work reaches iscsit_aborted_task(). If the connection drops in
that window, iscsit_release_commands_from_conn() finds the command still in
TRANSPORT_WRITE_PENDING and completes it a second time, which
re-initialises and re-queues an se_cmd->work that is already queued.

Route this site through iscsit_complete_aborted_cmd() so that the
completion is claimed and connection teardown leaves the command alone. The
helper makes the same iscsit_stop_dataout_timer() and target_complete_cmd()
calls when it takes the claim, so the completing path is unchanged.

Fixes: d5869dae5080 ("scsi: target: iscsi: Fix hang for aborted WRITE_PENDING commands")
Cc: stable@vger.kernel.org
Signed-off-by: Laurence Oberman <loberman@redhat.com>
---

Notes:
    This depends on patch 1 of this series, which adds
    iscsit_complete_aborted_cmd().  d5869dae5080 has been backported to 5.10.y,
    5.15.y, 6.1.y, 6.6.y, 6.12.y, 6.18.y and 7.2.y, none of which carry the
    helper, so a backport to those branches needs patch 1 as well, or the claim
    open-coded.  Happy to send a standalone version for stable if you would
    rather not carry patch 1 there.

 drivers/target/iscsi/iscsi_target.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 3dad7f6..83184de 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -1533,10 +1533,8 @@ __iscsit_check_dataout_hdr(struct iscsit_conn *conn, void *buf,
 		 */
 		if (se_cmd->transport_state & CMD_T_ABORTED) {
 			if (hdr->flags & ISCSI_FLAG_CMD_FINAL &&
-			    --cmd->outstanding_r2ts < 1) {
-				iscsit_stop_dataout_timer(cmd);
-				target_complete_cmd(se_cmd, SAM_STAT_TASK_ABORTED);
-			}
+			    --cmd->outstanding_r2ts < 1)
+				iscsit_complete_aborted_cmd(cmd);
 
 			return iscsit_dump_data_payload(conn, payload_length, 1);
 		}
-- 
2.43.0