From 17b18eaa6f59044a5172db7d07149e31ede0f920 Mon Sep 17 00:00:00 2001 From: Anatoliy Glagolev Date: Thu, 6 Dec 2018 16:48:45 -0700 Subject: [PATCH] scsi: qla2xxx: deadlock by configfs_depend_item 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 Acked-by: Himanshu Madhani Signed-off-by: Martin K. Petersen --- drivers/scsi/qla2xxx/tcm_qla2xxx.c | 48 +++++------------------------- drivers/scsi/qla2xxx/tcm_qla2xxx.h | 3 -- 2 files changed, 8 insertions(+), 43 deletions(-) diff --git a/drivers/scsi/qla2xxx/tcm_qla2xxx.c b/drivers/scsi/qla2xxx/tcm_qla2xxx.c index fc312a5eab75..283e6b80abb5 100644 --- a/drivers/scsi/qla2xxx/tcm_qla2xxx.c +++ b/drivers/scsi/qla2xxx/tcm_qla2xxx.c @@ -954,38 +954,14 @@ static ssize_t tcm_qla2xxx_tpg_enable_show(struct config_item *item, atomic_read(&tpg->lport_tpg_enabled)); } -static void tcm_qla2xxx_depend_tpg(struct work_struct *work) -{ - struct tcm_qla2xxx_tpg *base_tpg = container_of(work, - struct tcm_qla2xxx_tpg, tpg_base_work); - struct se_portal_group *se_tpg = &base_tpg->se_tpg; - struct scsi_qla_host *base_vha = base_tpg->lport->qla_vha; - - if (!target_depend_item(&se_tpg->tpg_group.cg_item)) { - atomic_set(&base_tpg->lport_tpg_enabled, 1); - qlt_enable_vha(base_vha); - } - complete(&base_tpg->tpg_base_comp); -} - -static void tcm_qla2xxx_undepend_tpg(struct work_struct *work) -{ - struct tcm_qla2xxx_tpg *base_tpg = container_of(work, - struct tcm_qla2xxx_tpg, tpg_base_work); - struct se_portal_group *se_tpg = &base_tpg->se_tpg; - struct scsi_qla_host *base_vha = base_tpg->lport->qla_vha; - - if (!qlt_stop_phase1(base_vha->vha_tgt.qla_tgt)) { - atomic_set(&base_tpg->lport_tpg_enabled, 0); - target_undepend_item(&se_tpg->tpg_group.cg_item); - } - complete(&base_tpg->tpg_base_comp); -} - static ssize_t tcm_qla2xxx_tpg_enable_store(struct config_item *item, const char *page, size_t count) { struct se_portal_group *se_tpg = to_tpg(item); + struct se_wwn *se_wwn = se_tpg->se_tpg_wwn; + struct tcm_qla2xxx_lport *lport = container_of(se_wwn, + struct tcm_qla2xxx_lport, lport_wwn); + struct scsi_qla_host *vha = lport->qla_vha; struct tcm_qla2xxx_tpg *tpg = container_of(se_tpg, struct tcm_qla2xxx_tpg, se_tpg); unsigned long op; @@ -1004,24 +980,16 @@ static ssize_t tcm_qla2xxx_tpg_enable_store(struct config_item *item, if (atomic_read(&tpg->lport_tpg_enabled)) return -EEXIST; - INIT_WORK(&tpg->tpg_base_work, tcm_qla2xxx_depend_tpg); + atomic_set(&tpg->lport_tpg_enabled, 1); + qlt_enable_vha(vha); } else { if (!atomic_read(&tpg->lport_tpg_enabled)) return count; - INIT_WORK(&tpg->tpg_base_work, tcm_qla2xxx_undepend_tpg); + atomic_set(&tpg->lport_tpg_enabled, 0); + qlt_stop_phase1(vha->vha_tgt.qla_tgt); } - init_completion(&tpg->tpg_base_comp); - schedule_work(&tpg->tpg_base_work); - wait_for_completion(&tpg->tpg_base_comp); - if (op) { - if (!atomic_read(&tpg->lport_tpg_enabled)) - return -ENODEV; - } else { - if (atomic_read(&tpg->lport_tpg_enabled)) - return -EPERM; - } return count; } diff --git a/drivers/scsi/qla2xxx/tcm_qla2xxx.h b/drivers/scsi/qla2xxx/tcm_qla2xxx.h index 7550ba2831c3..147cf6c90366 100644 --- a/drivers/scsi/qla2xxx/tcm_qla2xxx.h +++ b/drivers/scsi/qla2xxx/tcm_qla2xxx.h @@ -48,9 +48,6 @@ struct tcm_qla2xxx_tpg { struct tcm_qla2xxx_tpg_attrib tpg_attrib; /* Returned by tcm_qla2xxx_make_tpg() */ struct se_portal_group se_tpg; - /* Items for dealing with configfs_depend_item */ - struct completion tpg_base_comp; - struct work_struct tpg_base_work; }; struct tcm_qla2xxx_fc_loopid {