Kernel panic - not syncing: Watchdog detected hard LOCKUP on cpu 21
Pid: 13242, comm: flush-8:80 Tainted: G W -- ------------
2.6.32-573.el6.x86_64 #1
Call Trace:
<NMI> [<ffffffff81537a84>] ? panic+0xa7/0x16f
[<ffffffff810149c9>] ? sched_clock+0x9/0x10
[<ffffffff810ed4bd>] ? watchdog_overflow_callback+0xcd/0xd0
[<ffffffff81124037>] ? __perf_event_overflow+0xa7/0x240
[<ffffffff8101dc54>] ? x86_perf_event_set_period+0xf4/0x180
[<ffffffff81124684>] ? perf_event_overflow+0x14/0x20
[<ffffffff81024a02>] ? intel_pmu_handle_irq+0x202/0x3f0
[<ffffffff8153cd89>] ? perf_event_nmi_handler+0x39/0xb0
[<ffffffff8153e845>] ? notifier_call_chain+0x55/0x80
[<ffffffff81389ba0>] ? scsi_done+0x0/0x60
[<ffffffff8153e8aa>] ? atomic_notifier_call_chain+0x1a/0x20
[<ffffffff810a788e>] ? notify_die+0x2e/0x30
[<ffffffff8153c503>] ? do_nmi+0x1c3/0x350
[<ffffffff8153bdc0>] ? nmi+0x20/0x30
[<ffffffff81389ba0>] ? scsi_done+0x0/0x60
[<ffffffff81389ba0>] ? scsi_done+0x0/0x60
[<ffffffff8153b62e>] ? _spin_lock+0x1e/0x30
<<EOE>> [<ffffffffa00e2eaf>] ? iscsi_queuecommand+0x7f/0x4e0 [libiscsi]
[<ffffffff81389df5>] ? scsi_dispatch_cmd+0xe5/0x310
[<ffffffff813927be>] ? scsi_request_fn+0x5be/0x750
[<ffffffff81089bad>] ? del_timer+0x7d/0xe0
[<ffffffff81273542>] ? __generic_unplug_device+0x32/0x40
[<ffffffff8126e823>] ? elv_insert+0xd3/0x190
[<ffffffff8126e920>] ? __elv_add_request+0x40/0x90
In beiscsi_alloc_pdu, _bh versions of spin_lock are being used for
protecting SGLs and WRBs. _bh versions are needed as the function gets
invoked in process context and BLOCK_IOPOLL softirq.
In spin_unlock_bh, after releasing the lock and enabling BH, do_softirq
is called which executes till last SOFTIRQ.
beiscsi_alloc_pdu is called under session lock. Through block layer,
iSCSI stack in some cases send IOs with interrupts disabled. In such paths,
CPU will get stuck for a while for session lock with interrupts disabled
because in other CPU do_softirq is executing under session lock thus
causing hard lock up.
Use spin_lock_irqsave/spin_lock_irqrestore as the driver can't be sure
in all paths interrupts are enabled.
Signed-off-by: Jitendra Bhivare <jitendra.bhiv...@broadcom.com>
---
drivers/scsi/be2iscsi/be_main.c | 37 +++++++++++++++++++++++--------------
1 file changed, 23 insertions(+), 14 deletions(-)
diff --git a/drivers/scsi/be2iscsi/be_main.c b/drivers/scsi/be2iscsi/be_main.c
index f05e773..02d24d5 100644
--- a/drivers/scsi/be2iscsi/be_main.c
+++ b/drivers/scsi/be2iscsi/be_main.c
@@ -1131,8 +1131,9 @@ beiscsi_process_async_pdu(struct beiscsi_conn
*beiscsi_conn,
static struct sgl_handle *alloc_io_sgl_handle(struct beiscsi_hba *phba)
{
struct sgl_handle *psgl_handle;
+ unsigned long flags;
- spin_lock_bh(&phba->io_sgl_lock);
+ spin_lock_irqsave(&phba->io_sgl_lock, flags);
if (phba->io_sgl_hndl_avbl) {
beiscsi_log(phba, KERN_INFO, BEISCSI_LOG_IO,
"BM_%d : In alloc_io_sgl_handle,"
@@ -1150,14 +1151,16 @@ static struct sgl_handle *alloc_io_sgl_handle(struct
beiscsi_hba *phba)
phba->io_sgl_alloc_index++;
} else
psgl_handle = NULL;
- spin_unlock_bh(&phba->io_sgl_lock);
+ spin_unlock_irqrestore(&phba->io_sgl_lock, flags);
return psgl_handle;
}
static void
free_io_sgl_handle(struct beiscsi_hba *phba, struct sgl_handle *psgl_handle)
{
- spin_lock_bh(&phba->io_sgl_lock);
+ unsigned long flags;
+
+ spin_lock_irqsave(&phba->io_sgl_lock, flags);
beiscsi_log(phba, KERN_INFO, BEISCSI_LOG_IO,
"BM_%d : In free_,io_sgl_free_index=%d\n",
phba->io_sgl_free_index);
@@ -1172,7 +1175,7 @@ free_io_sgl_handle(struct beiscsi_hba *phba, struct
sgl_handle *psgl_handle)
"value there=%p\n", phba->io_sgl_free_index,
phba->io_sgl_hndl_base
[phba->io_sgl_free_index]);
- spin_unlock_bh(&phba->io_sgl_lock);
+ spin_unlock_irqrestore(&phba->io_sgl_lock, flags);
return;
}
phba->io_sgl_hndl_base[phba->io_sgl_free_index] = psgl_handle;
@@ -1181,7 +1184,7 @@ free_io_sgl_handle(struct beiscsi_hba *phba, struct
sgl_handle *psgl_handle)
phba->io_sgl_free_index = 0;
else
phba->io_sgl_free_index++;
- spin_unlock_bh(&phba->io_sgl_lock);
+ spin_unlock_irqrestore(&phba->io_sgl_lock, flags);
}
static inline struct wrb_handle *
@@ -1189,15 +1192,16 @@ beiscsi_get_wrb_handle(struct hwi_wrb_context
*pwrb_context,
unsigned int wrbs_per_cxn)
{
struct wrb_handle *pwrb_handle;
+ unsigned long flags;
- spin_lock_bh(&pwrb_context->wrb_lock);
+ spin_lock_irqsave(&pwrb_context->wrb_lock, flags);
pwrb_handle = pwrb_context->pwrb_handle_base[pwrb_context->alloc_index];
pwrb_context->wrb_handles_available--;
if (pwrb_context->alloc_index == (wrbs_per_cxn - 1))
pwrb_context->alloc_index = 0;
else
pwrb_context->alloc_index++;
- spin_unlock_bh(&pwrb_context->wrb_lock);
+ spin_unlock_irqrestore(&pwrb_context->wrb_lock, flags);
return pwrb_handle;
}
@@ -1229,14 +1233,16 @@ beiscsi_put_wrb_handle(struct hwi_wrb_context
*pwrb_context,
struct wrb_handle *pwrb_handle,
unsigned int wrbs_per_cxn)
{
- spin_lock_bh(&pwrb_context->wrb_lock);
+ unsigned long flags;
+
+ spin_lock_irqsave(&pwrb_context->wrb_lock, flags);
pwrb_context->pwrb_handle_base[pwrb_context->free_index] = pwrb_handle;
pwrb_context->wrb_handles_available++;
if (pwrb_context->free_index == (wrbs_per_cxn - 1))
pwrb_context->free_index = 0;
else
pwrb_context->free_index++;
- spin_unlock_bh(&pwrb_context->wrb_lock);
+ spin_unlock_irqrestore(&pwrb_context->wrb_lock, flags);
}
/**
@@ -1265,8 +1271,9 @@ free_wrb_handle(struct beiscsi_hba *phba, struct
hwi_wrb_context *pwrb_context,
static struct sgl_handle *alloc_mgmt_sgl_handle(struct beiscsi_hba *phba)
{
struct sgl_handle *psgl_handle;
+ unsigned long flags;
- spin_lock_bh(&phba->mgmt_sgl_lock);
+ spin_lock_irqsave(&phba->mgmt_sgl_lock, flags);
if (phba->eh_sgl_hndl_avbl) {
psgl_handle = phba->eh_sgl_hndl_base[phba->eh_sgl_alloc_index];
phba->eh_sgl_hndl_base[phba->eh_sgl_alloc_index] = NULL;
@@ -1284,14 +1291,16 @@ static struct sgl_handle *alloc_mgmt_sgl_handle(struct
beiscsi_hba *phba)
phba->eh_sgl_alloc_index++;
} else
psgl_handle = NULL;
- spin_unlock_bh(&phba->mgmt_sgl_lock);
+ spin_unlock_irqrestore(&phba->mgmt_sgl_lock, flags);
return psgl_handle;
}
void
free_mgmt_sgl_handle(struct beiscsi_hba *phba, struct sgl_handle *psgl_handle)
{
- spin_lock_bh(&phba->mgmt_sgl_lock);
+ unsigned long flags;
+
+ spin_lock_irqsave(&phba->mgmt_sgl_lock, flags);
beiscsi_log(phba, KERN_INFO, BEISCSI_LOG_CONFIG,
"BM_%d : In free_mgmt_sgl_handle,"
"eh_sgl_free_index=%d\n",
@@ -1306,7 +1315,7 @@ free_mgmt_sgl_handle(struct beiscsi_hba *phba, struct
sgl_handle *psgl_handle)
"BM_%d : Double Free in eh SGL ,"
"eh_sgl_free_index=%d\n",
phba->eh_sgl_free_index);
- spin_unlock_bh(&phba->mgmt_sgl_lock);
+ spin_unlock_irqrestore(&phba->mgmt_sgl_lock, flags);
return;
}
phba->eh_sgl_hndl_base[phba->eh_sgl_free_index] = psgl_handle;
@@ -1316,7 +1325,7 @@ free_mgmt_sgl_handle(struct beiscsi_hba *phba, struct
sgl_handle *psgl_handle)
phba->eh_sgl_free_index = 0;
else
phba->eh_sgl_free_index++;
- spin_unlock_bh(&phba->mgmt_sgl_lock);
+ spin_unlock_irqrestore(&phba->mgmt_sgl_lock, flags);
}
static void
--
1.9.1
--
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