scsi: qla2xxx: deadlock by configfs_depend_item
authorAnatoliy Glagolev <glagolig@gmail.com>
Thu, 6 Dec 2018 23:48:45 +0000 (16:48 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 5 Dec 2019 14:34:43 +0000 (15:34 +0100)
commitf2970af1d3849139635a50ab4261505a8f3e44d7
treeae441a280a0273dba92d35a7f9a82c5452bcb7b1
parentc041756df25eef38d9f29b29fa21c76bf062510d
scsi: qla2xxx: deadlock by configfs_depend_item

[ Upstream commit 17b18eaa6f59044a5172db7d07149e31ede0f920 ]

The intent of invoking configfs_depend_item in commit 7474f52a82d51
("tcm_qla2xxx: Perform configfs depend/undepend for base_tpg")
was to prevent a physical Fibre Channel port removal when
virtual (NPIV) ports announced through that physical port are active.
The change does not work as expected: it makes enabled physical port
dependent on target configfs subsystem (the port's parent), something
the configfs guarantees anyway.

Besides, scheduling work in a worker thread and waiting for the work's
completion is not really a valid workaround for the requirement not to call
configfs_depend_item from a configfs callback: the call occasionally
deadlocks.

Thus, removing configfs_depend_item calls does not break anything and fixes
the deadlock problem.

Signed-off-by: Anatoliy Glagolev <glagolig@gmail.com>
Acked-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/scsi/qla2xxx/tcm_qla2xxx.c
drivers/scsi/qla2xxx/tcm_qla2xxx.h