From b0e17a9b0df29590c45dfb296f541270a5941f41 Mon Sep 17 00:00:00 2001 From: Brian King Date: Tue, 1 Aug 2017 10:21:30 -0500 Subject: [PATCH] scsi: ipr: Fix scsi-mq lockdep issue Fixes the following lockdep warning that can occur when scsi-mq is enabled with ipr due to ipr calling scsi_unblock_requests from irq context. The fix is to move the call to scsi_unblock_requests to ipr's existing workqueue. stack backtrace: CPU: 28 PID: 0 Comm: swapper/28 Not tainted 4.13.0-rc2-gcc6x-gf74c89b #1 Call Trace: [c000001fffe97550] [c000000000b50818] dump_stack+0xe8/0x160 (unreliable) [c000001fffe97590] [c0000000001586d0] print_usage_bug+0x2d0/0x390 [c000001fffe97640] [c000000000158f34] mark_lock+0x7a4/0x8e0 [c000001fffe976f0] [c00000000015a000] __lock_acquire+0x6a0/0x1a70 [c000001fffe97860] [c00000000015befc] lock_acquire+0xec/0x2e0 [c000001fffe97930] [c000000000b71514] _raw_spin_lock+0x44/0x70 [c000001fffe97960] [c0000000005b60f4] blk_mq_sched_dispatch_requests+0xa4/0x2a0 [c000001fffe979c0] [c0000000005acac0] __blk_mq_run_hw_queue+0x100/0x2c0 [c000001fffe97a00] [c0000000005ad478] __blk_mq_delay_run_hw_queue+0x118/0x130 [c000001fffe97a40] [c0000000005ad61c] blk_mq_start_hw_queues+0x6c/0xa0 [c000001fffe97a80] [c000000000797aac] scsi_kick_queue+0x2c/0x60 [c000001fffe97aa0] [c000000000797cf0] scsi_run_queue+0x210/0x360 [c000001fffe97b10] [c00000000079b888] scsi_run_host_queues+0x48/0x80 [c000001fffe97b40] [c0000000007b6090] ipr_ioa_bringdown_done+0x70/0x1e0 [c000001fffe97bc0] [c0000000007bc860] ipr_reset_ioa_job+0x80/0xf0 [c000001fffe97bf0] [c0000000007b4d50] ipr_reset_timer_done+0xd0/0x100 [c000001fffe97c30] [c0000000001937bc] call_timer_fn+0xdc/0x4b0 [c000001fffe97cf0] [c000000000193d08] expire_timers+0x178/0x330 [c000001fffe97d60] [c0000000001940c8] run_timer_softirq+0xb8/0x120 [c000001fffe97de0] [c000000000b726a8] __do_softirq+0x168/0x6d8 [c000001fffe97ef0] [c0000000000df2c8] irq_exit+0x108/0x150 [c000001fffe97f10] [c000000000017bf4] __do_irq+0x2a4/0x4a0 [c000001fffe97f90] [c00000000002da50] call_do_irq+0x14/0x24 [c0000007fad93aa0] [c000000000017e8c] do_IRQ+0x9c/0x140 [c0000007fad93af0] [c000000000008b98] hardware_interrupt_common+0x138/0x140 Reported-by: Michael Ellerman Signed-off-by: Brian King Signed-off-by: Martin K. Petersen --- drivers/scsi/ipr.c | 33 +++++++++++++++++++-------------- drivers/scsi/ipr.h | 2 ++ 2 files changed, 21 insertions(+), 14 deletions(-) diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c index b0c68d24db01..da5bdbdcce52 100644 --- a/drivers/scsi/ipr.c +++ b/drivers/scsi/ipr.c @@ -3351,6 +3351,16 @@ static void ipr_worker_thread(struct work_struct *work) return; } + if (ioa_cfg->scsi_unblock) { + ioa_cfg->scsi_unblock = 0; + ioa_cfg->scsi_blocked = 0; + spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags); + scsi_unblock_requests(ioa_cfg->host); + spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags); + if (ioa_cfg->scsi_blocked) + scsi_block_requests(ioa_cfg->host); + } + if (!ioa_cfg->scan_enabled) { spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags); return; @@ -7211,9 +7221,8 @@ static int ipr_ioa_bringdown_done(struct ipr_cmnd *ipr_cmd) ENTER; if (!ioa_cfg->hrrq[IPR_INIT_HRRQ].removing_ioa) { ipr_trace; - spin_unlock_irq(ioa_cfg->host->host_lock); - scsi_unblock_requests(ioa_cfg->host); - spin_lock_irq(ioa_cfg->host->host_lock); + ioa_cfg->scsi_unblock = 1; + schedule_work(&ioa_cfg->work_q); } ioa_cfg->in_reset_reload = 0; @@ -7287,13 +7296,7 @@ static int ipr_ioa_reset_done(struct ipr_cmnd *ipr_cmd) list_add_tail(&ipr_cmd->queue, &ipr_cmd->hrrq->hrrq_free_q); wake_up_all(&ioa_cfg->reset_wait_q); - spin_unlock(ioa_cfg->host->host_lock); - scsi_unblock_requests(ioa_cfg->host); - spin_lock(ioa_cfg->host->host_lock); - - if (!ioa_cfg->hrrq[IPR_INIT_HRRQ].allow_cmds) - scsi_block_requests(ioa_cfg->host); - + ioa_cfg->scsi_unblock = 1; schedule_work(&ioa_cfg->work_q); LEAVE; return IPR_RC_JOB_RETURN; @@ -9249,8 +9252,11 @@ static void _ipr_initiate_ioa_reset(struct ipr_ioa_cfg *ioa_cfg, spin_unlock(&ioa_cfg->hrrq[i]._lock); } wmb(); - if (!ioa_cfg->hrrq[IPR_INIT_HRRQ].removing_ioa) + if (!ioa_cfg->hrrq[IPR_INIT_HRRQ].removing_ioa) { + ioa_cfg->scsi_unblock = 0; + ioa_cfg->scsi_blocked = 1; scsi_block_requests(ioa_cfg->host); + } ipr_cmd = ipr_get_free_ipr_cmnd(ioa_cfg); ioa_cfg->reset_cmd = ipr_cmd; @@ -9306,9 +9312,8 @@ static void ipr_initiate_ioa_reset(struct ipr_ioa_cfg *ioa_cfg, wake_up_all(&ioa_cfg->reset_wait_q); if (!ioa_cfg->hrrq[IPR_INIT_HRRQ].removing_ioa) { - spin_unlock_irq(ioa_cfg->host->host_lock); - scsi_unblock_requests(ioa_cfg->host); - spin_lock_irq(ioa_cfg->host->host_lock); + ioa_cfg->scsi_unblock = 1; + schedule_work(&ioa_cfg->work_q); } return; } else { diff --git a/drivers/scsi/ipr.h b/drivers/scsi/ipr.h index e98a87a65335..c7f0e9e3cd7d 100644 --- a/drivers/scsi/ipr.h +++ b/drivers/scsi/ipr.h @@ -1488,6 +1488,8 @@ struct ipr_ioa_cfg { u8 cfg_locked:1; u8 clear_isr:1; u8 probe_done:1; + u8 scsi_unblock:1; + u8 scsi_blocked:1; u8 revid; -- 2.20.1