From: Bart Van Assche bvanassche@acm.org
[ Upstream commit 300ec7415c1fed5c73660f50c8e14a67e236dc0a ]
Since fc_remote_port_delete() must be called with interrupts enabled, do not disable interrupts when calling that function. Remove the lockin calls from around the put_sess() call. This is safe because the function that is called when the final reference is dropped, qlt_unreg_sess(), grabs the proper locks. This patch avoids that lockdep reports the following:
WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected kworker/2:1/62 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: 0000000009e679b3 (&(&k->k_lock)->rlock){+.+.}, at: klist_next+0x43/0x1d0
and this task is already holding: 00000000a033b71c (&(&ha->tgt.sess_lock)->rlock){-...}, at: qla24xx_delete_sess_fn+0x55/0xf0 [qla2xxx_scst] which would create a new lock dependency: (&(&ha->tgt.sess_lock)->rlock){-...} -> (&(&k->k_lock)->rlock){+.+.}
but this new dependency connects a HARDIRQ-irq-safe lock: (&(&ha->tgt.sess_lock)->rlock){-...}
... which became HARDIRQ-irq-safe at: lock_acquire+0xe3/0x200 _raw_spin_lock_irqsave+0x3d/0x60 qla24xx_report_id_acquisition+0xa69/0xe30 [qla2xxx_scst] qla24xx_process_response_queue+0x69e/0x1270 [qla2xxx_scst] qla24xx_msix_rsp_q+0x79/0xf0 [qla2xxx_scst] __handle_irq_event_percpu+0x79/0x3c0 handle_irq_event_percpu+0x70/0xf0 handle_irq_event+0x5a/0x8b handle_edge_irq+0x12c/0x310 handle_irq+0x192/0x20a do_IRQ+0x73/0x160 ret_from_intr+0x0/0x1d default_idle+0x23/0x1f0 arch_cpu_idle+0x15/0x20 default_idle_call+0x35/0x40 do_idle+0x2bb/0x2e0 cpu_startup_entry+0x1d/0x20 start_secondary+0x2a8/0x320 secondary_startup_64+0xa4/0xb0
to a HARDIRQ-irq-unsafe lock: (&(&k->k_lock)->rlock){+.+.}
... which became HARDIRQ-irq-unsafe at: ... lock_acquire+0xe3/0x200 _raw_spin_lock+0x32/0x50 klist_add_tail+0x33/0xb0 device_add+0x7e1/0xb50 device_create_groups_vargs+0x11c/0x150 device_create_with_groups+0x89/0xb0 vtconsole_class_init+0xb2/0x124 do_one_initcall+0xc5/0x3ce kernel_init_freeable+0x295/0x32e kernel_init+0x11/0x11b ret_from_fork+0x3a/0x50
other info that might help us debug this:
Possible interrupt unsafe locking scenario:
CPU0 CPU1 ---- ---- lock(&(&k->k_lock)->rlock); local_irq_disable(); lock(&(&ha->tgt.sess_lock)->rlock); lock(&(&k->k_lock)->rlock); <Interrupt> lock(&(&ha->tgt.sess_lock)->rlock);
*** DEADLOCK ***
3 locks held by kworker/2:1/62: #0: 00000000a4319c16 ((wq_completion)"qla2xxx_wq"){+.+.}, at: process_one_work+0x437/0xa80 #1: 00000000ffa34c42 ((work_completion)(&sess->del_work)){+.+.}, at: process_one_work+0x437/0xa80 #2: 00000000a033b71c (&(&ha->tgt.sess_lock)->rlock){-...}, at: qla24xx_delete_sess_fn+0x55/0xf0 [qla2xxx_scst]
the dependencies between HARDIRQ-irq-safe lock and the holding lock: -> (&(&ha->tgt.sess_lock)->rlock){-...} ops: 8 { IN-HARDIRQ-W at: lock_acquire+0xe3/0x200 _raw_spin_lock_irqsave+0x3d/0x60 qla24xx_report_id_acquisition+0xa69/0xe30 [qla2xxx_scst] qla24xx_process_response_queue+0x69e/0x1270 [qla2xxx_scst] qla24xx_msix_rsp_q+0x79/0xf0 [qla2xxx_scst] __handle_irq_event_percpu+0x79/0x3c0 handle_irq_event_percpu+0x70/0xf0 handle_irq_event+0x5a/0x8b handle_edge_irq+0x12c/0x310 handle_irq+0x192/0x20a do_IRQ+0x73/0x160 ret_from_intr+0x0/0x1d default_idle+0x23/0x1f0 arch_cpu_idle+0x15/0x20 default_idle_call+0x35/0x40 do_idle+0x2bb/0x2e0 cpu_startup_entry+0x1d/0x20 start_secondary+0x2a8/0x320 secondary_startup_64+0xa4/0xb0 INITIAL USE at: lock_acquire+0xe3/0x200 _raw_spin_lock_irqsave+0x3d/0x60 qla24xx_report_id_acquisition+0xa69/0xe30 [qla2xxx_scst] qla24xx_process_response_queue+0x69e/0x1270 [qla2xxx_scst] qla24xx_msix_rsp_q+0x79/0xf0 [qla2xxx_scst] __handle_irq_event_percpu+0x79/0x3c0 handle_irq_event_percpu+0x70/0xf0 handle_irq_event+0x5a/0x8b handle_edge_irq+0x12c/0x310 handle_irq+0x192/0x20a do_IRQ+0x73/0x160 ret_from_intr+0x0/0x1d default_idle+0x23/0x1f0 arch_cpu_idle+0x15/0x20 default_idle_call+0x35/0x40 do_idle+0x2bb/0x2e0 cpu_startup_entry+0x1d/0x20 start_secondary+0x2a8/0x320 secondary_startup_64+0xa4/0xb0 } ... key at: [<ffffffffa0c0d080>] __key.85462+0x0/0xfffffffffff7df80 [qla2xxx_scst] ... acquired at: lock_acquire+0xe3/0x200 _raw_spin_lock_irqsave+0x3d/0x60 klist_next+0x43/0x1d0 device_for_each_child+0x96/0x110 scsi_target_block+0x3c/0x40 [scsi_mod] fc_remote_port_delete+0xe7/0x1c0 [scsi_transport_fc] qla2x00_mark_device_lost+0xa0b/0xa30 [qla2xxx_scst] qlt_unreg_sess+0x1c6/0x380 [qla2xxx_scst] qla24xx_delete_sess_fn+0xe6/0xf0 [qla2xxx_scst] process_one_work+0x511/0xa80 worker_thread+0x67/0x5b0 kthread+0x1d2/0x1f0 ret_from_fork+0x3a/0x50
the dependencies between the lock to be acquired and HARDIRQ-irq-unsafe lock: -> (&(&k->k_lock)->rlock){+.+.} ops: 13831 { HARDIRQ-ON-W at: lock_acquire+0xe3/0x200 _raw_spin_lock+0x32/0x50 klist_add_tail+0x33/0xb0 device_add+0x7e1/0xb50 device_create_groups_vargs+0x11c/0x150 device_create_with_groups+0x89/0xb0 vtconsole_class_init+0xb2/0x124 do_one_initcall+0xc5/0x3ce kernel_init_freeable+0x295/0x32e kernel_init+0x11/0x11b ret_from_fork+0x3a/0x50 SOFTIRQ-ON-W at: lock_acquire+0xe3/0x200 _raw_spin_lock+0x32/0x50 klist_add_tail+0x33/0xb0 device_add+0x7e1/0xb50 device_create_groups_vargs+0x11c/0x150 device_create_with_groups+0x89/0xb0 vtconsole_class_init+0xb2/0x124 do_one_initcall+0xc5/0x3ce kernel_init_freeable+0x295/0x32e kernel_init+0x11/0x11b ret_from_fork+0x3a/0x50 INITIAL USE at: lock_acquire+0xe3/0x200 _raw_spin_lock+0x32/0x50 klist_add_tail+0x33/0xb0 device_add+0x7e1/0xb50 device_create_groups_vargs+0x11c/0x150 device_create_with_groups+0x89/0xb0 vtconsole_class_init+0xb2/0x124 do_one_initcall+0xc5/0x3ce kernel_init_freeable+0x295/0x32e kernel_init+0x11/0x11b ret_from_fork+0x3a/0x50 } ... key at: [<ffffffff83ed8780>] __key.15491+0x0/0x40 ... acquired at: lock_acquire+0xe3/0x200 _raw_spin_lock_irqsave+0x3d/0x60 klist_next+0x43/0x1d0 device_for_each_child+0x96/0x110 scsi_target_block+0x3c/0x40 [scsi_mod] fc_remote_port_delete+0xe7/0x1c0 [scsi_transport_fc] qla2x00_mark_device_lost+0xa0b/0xa30 [qla2xxx_scst] qlt_unreg_sess+0x1c6/0x380 [qla2xxx_scst] qla24xx_delete_sess_fn+0xe6/0xf0 [qla2xxx_scst] process_one_work+0x511/0xa80 worker_thread+0x67/0x5b0 kthread+0x1d2/0x1f0 ret_from_fork+0x3a/0x50
stack backtrace: CPU: 2 PID: 62 Comm: kworker/2:1 Tainted: G O 5.0.7-dbg+ #8 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Workqueue: qla2xxx_wq qla24xx_delete_sess_fn [qla2xxx_scst] Call Trace: dump_stack+0x86/0xca check_usage.cold.52+0x473/0x563 __lock_acquire+0x11c0/0x23e0 lock_acquire+0xe3/0x200 _raw_spin_lock_irqsave+0x3d/0x60 klist_next+0x43/0x1d0 device_for_each_child+0x96/0x110 scsi_target_block+0x3c/0x40 [scsi_mod] fc_remote_port_delete+0xe7/0x1c0 [scsi_transport_fc] qla2x00_mark_device_lost+0xa0b/0xa30 [qla2xxx_scst] qlt_unreg_sess+0x1c6/0x380 [qla2xxx_scst] qla24xx_delete_sess_fn+0xe6/0xf0 [qla2xxx_scst] process_one_work+0x511/0xa80 worker_thread+0x67/0x5b0 kthread+0x1d2/0x1f0 ret_from_fork+0x3a/0x50
Cc: Himanshu Madhani hmadhani@marvell.com Cc: Giridhar Malavali gmalavali@marvell.com Signed-off-by: Bart Van Assche bvanassche@acm.org 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/qla_target.c | 25 ++++++++----------------- drivers/scsi/qla2xxx/tcm_qla2xxx.c | 2 -- 2 files changed, 8 insertions(+), 19 deletions(-)
diff --git a/drivers/scsi/qla2xxx/qla_target.c b/drivers/scsi/qla2xxx/qla_target.c index 697eee1d88474..b210a8296c275 100644 --- a/drivers/scsi/qla2xxx/qla_target.c +++ b/drivers/scsi/qla2xxx/qla_target.c @@ -680,7 +680,6 @@ int qla24xx_async_notify_ack(scsi_qla_host_t *vha, fc_port_t *fcport, void qla24xx_do_nack_work(struct scsi_qla_host *vha, struct qla_work_evt *e) { fc_port_t *t; - unsigned long flags;
switch (e->u.nack.type) { case SRB_NACK_PRLI: @@ -693,10 +692,8 @@ void qla24xx_do_nack_work(struct scsi_qla_host *vha, struct qla_work_evt *e) if (t) { ql_log(ql_log_info, vha, 0xd034, "%s create sess success %p", __func__, t); - spin_lock_irqsave(&vha->hw->tgt.sess_lock, flags); /* create sess has an extra kref */ vha->hw->tgt.tgt_ops->put_sess(e->u.nack.fcport); - spin_unlock_irqrestore(&vha->hw->tgt.sess_lock, flags); } break; } @@ -708,9 +705,6 @@ void qla24xx_delete_sess_fn(struct work_struct *work) { fc_port_t *fcport = container_of(work, struct fc_port, del_work); struct qla_hw_data *ha = fcport->vha->hw; - unsigned long flags; - - spin_lock_irqsave(&ha->tgt.sess_lock, flags);
if (fcport->se_sess) { ha->tgt.tgt_ops->shutdown_sess(fcport); @@ -718,7 +712,6 @@ void qla24xx_delete_sess_fn(struct work_struct *work) } else { qlt_unreg_sess(fcport); } - spin_unlock_irqrestore(&ha->tgt.sess_lock, flags); }
/* @@ -787,8 +780,9 @@ void qlt_fc_port_added(struct scsi_qla_host *vha, fc_port_t *fcport) fcport->port_name, sess->loop_id); sess->local = 0; } - ha->tgt.tgt_ops->put_sess(sess); spin_unlock_irqrestore(&ha->tgt.sess_lock, flags); + + ha->tgt.tgt_ops->put_sess(sess); }
/* @@ -4242,9 +4236,7 @@ static void __qlt_do_work(struct qla_tgt_cmd *cmd) /* * Drop extra session reference from qla_tgt_handle_cmd_for_atio*( */ - spin_lock_irqsave(&ha->tgt.sess_lock, flags); ha->tgt.tgt_ops->put_sess(sess); - spin_unlock_irqrestore(&ha->tgt.sess_lock, flags); return;
out_term: @@ -4261,9 +4253,7 @@ static void __qlt_do_work(struct qla_tgt_cmd *cmd) target_free_tag(sess->se_sess, &cmd->se_cmd); spin_unlock_irqrestore(qpair->qp_lock_ptr, flags);
- spin_lock_irqsave(&ha->tgt.sess_lock, flags); ha->tgt.tgt_ops->put_sess(sess); - spin_unlock_irqrestore(&ha->tgt.sess_lock, flags); }
static void qlt_do_work(struct work_struct *work) @@ -4472,9 +4462,7 @@ static int qlt_handle_cmd_for_atio(struct scsi_qla_host *vha, if (!cmd) { ql_dbg(ql_dbg_io, vha, 0x3062, "qla_target(%d): Allocation of cmd failed\n", vha->vp_idx); - spin_lock_irqsave(&ha->tgt.sess_lock, flags); ha->tgt.tgt_ops->put_sess(sess); - spin_unlock_irqrestore(&ha->tgt.sess_lock, flags); return -EBUSY; }
@@ -6318,17 +6306,19 @@ static void qlt_abort_work(struct qla_tgt *tgt, }
rc = __qlt_24xx_handle_abts(vha, &prm->abts, sess); - ha->tgt.tgt_ops->put_sess(sess); spin_unlock_irqrestore(&ha->tgt.sess_lock, flags2);
+ ha->tgt.tgt_ops->put_sess(sess); + if (rc != 0) goto out_term; return;
out_term2: + spin_unlock_irqrestore(&ha->tgt.sess_lock, flags2); + if (sess) ha->tgt.tgt_ops->put_sess(sess); - spin_unlock_irqrestore(&ha->tgt.sess_lock, flags2);
out_term: spin_lock_irqsave(&ha->hardware_lock, flags); @@ -6386,9 +6376,10 @@ static void qlt_tmr_work(struct qla_tgt *tgt, scsilun_to_int((struct scsi_lun *)&a->u.isp24.fcp_cmnd.lun);
rc = qlt_issue_task_mgmt(sess, unpacked_lun, fn, iocb, 0); - ha->tgt.tgt_ops->put_sess(sess); spin_unlock_irqrestore(&ha->tgt.sess_lock, flags);
+ ha->tgt.tgt_ops->put_sess(sess); + if (rc != 0) goto out_term; return; diff --git a/drivers/scsi/qla2xxx/tcm_qla2xxx.c b/drivers/scsi/qla2xxx/tcm_qla2xxx.c index d6104f23f697f..e58becb790fa3 100644 --- a/drivers/scsi/qla2xxx/tcm_qla2xxx.c +++ b/drivers/scsi/qla2xxx/tcm_qla2xxx.c @@ -359,7 +359,6 @@ static void tcm_qla2xxx_put_sess(struct fc_port *sess) if (!sess) return;
- assert_spin_locked(&sess->vha->hw->tgt.sess_lock); kref_put(&sess->sess_kref, tcm_qla2xxx_release_session); }
@@ -832,7 +831,6 @@ static void tcm_qla2xxx_clear_nacl_from_fcport_map(struct fc_port *sess)
static void tcm_qla2xxx_shutdown_sess(struct fc_port *sess) { - assert_spin_locked(&sess->vha->hw->tgt.sess_lock); target_sess_cmd_list_set_waiting(sess->se_sess); }