target: Fix LUN_RESET active TMR descriptor handling
authorNicholas Bellinger <nab@linux-iscsi.org>
Tue, 12 Jan 2016 05:53:05 +0000 (21:53 -0800)
committerNicholas Bellinger <nab@linux-iscsi.org>
Wed, 3 Feb 2016 22:09:47 +0000 (14:09 -0800)
commita6d9bb1c9605cd4f44e2d8290dc4d0e88f20292d
tree451fc518e71e8c51e983785c90d690b98a6cd098
parentfebe562c20dfa8f33bee7d419c6b517986a5aa33
target: Fix LUN_RESET active TMR descriptor handling

This patch fixes a NULL pointer se_cmd->cmd_kref < 0
refcount bug during TMR LUN_RESET with active TMRs,
triggered during se_cmd + se_tmr_req descriptor
shutdown + release via core_tmr_drain_tmr_list().

To address this bug, go ahead and obtain a local
kref_get_unless_zero(&se_cmd->cmd_kref) for active I/O
to set CMD_T_ABORTED, and transport_wait_for_tasks()
followed by the final target_put_sess_cmd() to drop
the local ->cmd_kref.

Also add two new checks within target_tmr_work() to
avoid CMD_T_ABORTED -> TFO->queue_tm_rsp() callbacks
ahead of invoking the backend -> fabric put in
transport_cmd_check_stop_to_fabric().

For good measure, also change core_tmr_release_req()
to use list_del_init() ahead of se_tmr_req memory
free.

Reviewed-by: Quinn Tran <quinn.tran@qlogic.com>
Cc: Himanshu Madhani <himanshu.madhani@qlogic.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Andy Grover <agrover@redhat.com>
Cc: Mike Christie <mchristi@redhat.com>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
drivers/target/target_core_tmr.c
drivers/target/target_core_transport.c