From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Hi folks,
Here is -v2 series to address two LUN_RESET active
I/O + TMR se_cmd->cmd_kref < 0 bugs as reported
recently by Quinn & Co. This bug can occur during
active I/O remote port TMR LUN_RESET with multi-port
LIO configurations.
To address this bug, it adds __target_check_io_state()
common handler for ABORT_TASK + LUN_RESET I/O abort
cases, and moves remaining se_cmd SGL page + release
into target_free_cmd_mem() to now be called directly
from the final target_release_cmd_kref() callback.
Following __target_check_io_state(), it also obtains
kref_get_unless_zero(&se_cmd->cmd_kref) for TMR descs
during LUN_RESET in core_tmr_drain_tmr_list(), in order
to utilize common transport_wait_for_tasks() code when
se_cmd + se_tmr_req descriptors are being aborted or
shutdown.
At this point the changes are able to survive multi-port
active I/O LUN_RESET using iscsi-target ports against
Linux + ESX hosts with TAS=1.
Note there is still a known issue wrt multi-port active
I/O LUN_RESET when se_session shutdown occurs at the
same time, that I'm still groking and will need to be
addressed for -v3 code.
Quinn + Co, please have a look at qla2xxx + TAS with
this series when you've got a moment, and let us know
how active I/O LUN_RESET works with your test-case.
Thank you,
--nab
v2 changes:
- Fix TAS handling for multi-session se_node_acls
- Change target_complete_cmd() to check for ABORTED || STOP
- Avoid calling target_remove_from_state_list() with
se_cmd->t_state_lock held in transport_cmd_check_stop()
- Add missing target_free_cmd_mem() in target_put_sess_cmd()
special case.
- Add a more useful __target_check_io_state() comment
- Use assert_spin_locked() + WARN_ON_ONCE() when necessary
- Drop unnecessary !list_empty check
Nicholas Bellinger (3):
target: Fix LUN_RESET active I/O handling for ACK_KREF
target: Fix LUN_RESET active TMR descriptor handling
target: Fix TAS handling for multi-session se_node_acls
drivers/target/target_core_tmr.c | 104 ++++++++++++++++++++++++---------
drivers/target/target_core_transport.c | 73 ++++++++++++++---------
include/target/target_core_base.h | 1 +
3 files changed, 122 insertions(+), 56 deletions(-)
--
1.9.1
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