* [PATCH] block: Fix possible sleep in invalid context
@ 2013-07-01 15:28 Sujit Reddy Thumma
2013-07-01 22:17 ` Andrew Morton
2013-07-02 3:04 ` Aaron Lu
0 siblings, 2 replies; 6+ messages in thread
From: Sujit Reddy Thumma @ 2013-07-01 15:28 UTC (permalink / raw)
To: Aaron Lu, Jens Axboe
Cc: linux-pm, linux-scsi, stable, Sujit Reddy Thumma, linux-arm-msm,
linux-kernel
When block runtime PM is enabled following warning is seen
while resuming the device.
BUG: sleeping function called from invalid context at
.../drivers/base/power/runtime.c:923
in_atomic(): 1, irqs_disabled(): 128, pid: 12, name: kworker/0:1
[<c0014448>] (unwind_backtrace+0x0/0x120) from
[<c03120e4>] (__pm_runtime_suspend+0x34/0xa0) from
[<c021c33c>] (blk_post_runtime_resume+0x4c/0x5c) from
[<c03297cc>] (scsi_runtime_resume+0x90/0xb4) from
[<c0310940>] (__rpm_callback+0x30/0x58) from
[<c0310980>] (rpm_callback+0x18/0x28) from
[<c0311ab0>] (rpm_resume+0x3dc/0x540) from
[<c03120a4>] (pm_runtime_work+0x8c/0x98) from
[<c007767c>] (process_one_work+0x238/0x3e4) from
[<c0077b90>] (worker_thread+0x1ac/0x2ac) from
[<c007cfdc>] (kthread+0x88/0x94) from
[<c000ece0>] (kernel_thread_exit+0x0/0x8)
Fix this by releasing spin_lock_irq() before calling
pm_runtime_autosuspend() in blk_post_runtime_resume().
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Cc: stable@vger.kernel.org
---
block/blk-core.c | 6 ++++--
1 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 33c33bc..2456116 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -3159,16 +3159,18 @@ EXPORT_SYMBOL(blk_pre_runtime_resume);
*/
void blk_post_runtime_resume(struct request_queue *q, int err)
{
- spin_lock_irq(q->queue_lock);
if (!err) {
+ spin_lock_irq(q->queue_lock);
q->rpm_status = RPM_ACTIVE;
__blk_run_queue(q);
pm_runtime_mark_last_busy(q->dev);
+ spin_unlock_irq(q->queue_lock);
pm_runtime_autosuspend(q->dev);
} else {
+ spin_lock_irq(q->queue_lock);
q->rpm_status = RPM_SUSPENDED;
+ spin_unlock_irq(q->queue_lock);
}
- spin_unlock_irq(q->queue_lock);
}
EXPORT_SYMBOL(blk_post_runtime_resume);
#endif
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation.
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] block: Fix possible sleep in invalid context
2013-07-01 15:28 [PATCH] block: Fix possible sleep in invalid context Sujit Reddy Thumma
@ 2013-07-01 22:17 ` Andrew Morton
2013-07-01 22:24 ` James Bottomley
2013-07-02 3:04 ` Aaron Lu
1 sibling, 1 reply; 6+ messages in thread
From: Andrew Morton @ 2013-07-01 22:17 UTC (permalink / raw)
To: Sujit Reddy Thumma
Cc: Aaron Lu, Jens Axboe, linux-pm, linux-scsi, stable, linux-arm-msm,
linux-kernel
On Mon, 1 Jul 2013 20:58:35 +0530 Sujit Reddy Thumma <sthumma@codeaurora.org> wrote:
> When block runtime PM is enabled following warning is seen
> while resuming the device.
>
> BUG: sleeping function called from invalid context at
> .../drivers/base/power/runtime.c:923
> in_atomic(): 1, irqs_disabled(): 128, pid: 12, name: kworker/0:1
> [<c0014448>] (unwind_backtrace+0x0/0x120) from
> [<c03120e4>] (__pm_runtime_suspend+0x34/0xa0) from
> [<c021c33c>] (blk_post_runtime_resume+0x4c/0x5c) from
> [<c03297cc>] (scsi_runtime_resume+0x90/0xb4) from
> [<c0310940>] (__rpm_callback+0x30/0x58) from
> [<c0310980>] (rpm_callback+0x18/0x28) from
> [<c0311ab0>] (rpm_resume+0x3dc/0x540) from
> [<c03120a4>] (pm_runtime_work+0x8c/0x98) from
> [<c007767c>] (process_one_work+0x238/0x3e4) from
> [<c0077b90>] (worker_thread+0x1ac/0x2ac) from
> [<c007cfdc>] (kthread+0x88/0x94) from
> [<c000ece0>] (kernel_thread_exit+0x0/0x8)
>
> Fix this by releasing spin_lock_irq() before calling
> pm_runtime_autosuspend() in blk_post_runtime_resume().
>
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -3159,16 +3159,18 @@ EXPORT_SYMBOL(blk_pre_runtime_resume);
> */
> void blk_post_runtime_resume(struct request_queue *q, int err)
> {
> - spin_lock_irq(q->queue_lock);
> if (!err) {
> + spin_lock_irq(q->queue_lock);
> q->rpm_status = RPM_ACTIVE;
> __blk_run_queue(q);
> pm_runtime_mark_last_busy(q->dev);
> + spin_unlock_irq(q->queue_lock);
> pm_runtime_autosuspend(q->dev);
> } else {
> + spin_lock_irq(q->queue_lock);
> q->rpm_status = RPM_SUSPENDED;
> + spin_unlock_irq(q->queue_lock);
> }
> - spin_unlock_irq(q->queue_lock);
> }
> EXPORT_SYMBOL(blk_post_runtime_resume);
> #endif
I suppose we can do this cleanly enough:
--- a/block/blk-core.c~block-fix-possible-sleep-in-invalid-context-fix
+++ a/block/blk-core.c
@@ -3159,15 +3159,14 @@ EXPORT_SYMBOL(blk_pre_runtime_resume);
*/
void blk_post_runtime_resume(struct request_queue *q, int err)
{
+ spin_lock_irq(q->queue_lock);
if (!err) {
- spin_lock_irq(q->queue_lock);
q->rpm_status = RPM_ACTIVE;
__blk_run_queue(q);
pm_runtime_mark_last_busy(q->dev);
spin_unlock_irq(q->queue_lock);
pm_request_autosuspend(q->dev);
} else {
- spin_lock_irq(q->queue_lock);
q->rpm_status = RPM_SUSPENDED;
spin_unlock_irq(q->queue_lock);
}
_
I wonder if we actually need locking around that second write to
q->rpm_status.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] block: Fix possible sleep in invalid context
2013-07-01 22:17 ` Andrew Morton
@ 2013-07-01 22:24 ` James Bottomley
2013-07-01 22:30 ` Andrew Morton
0 siblings, 1 reply; 6+ messages in thread
From: James Bottomley @ 2013-07-01 22:24 UTC (permalink / raw)
To: Andrew Morton
Cc: Sujit Reddy Thumma, Aaron Lu, Jens Axboe, linux-pm, linux-scsi,
stable, linux-arm-msm, linux-kernel
On Mon, 2013-07-01 at 15:17 -0700, Andrew Morton wrote:
> On Mon, 1 Jul 2013 20:58:35 +0530 Sujit Reddy Thumma <sthumma@codeaurora.org> wrote:
>
> > When block runtime PM is enabled following warning is seen
> > while resuming the device.
> >
> > BUG: sleeping function called from invalid context at
> > .../drivers/base/power/runtime.c:923
> > in_atomic(): 1, irqs_disabled(): 128, pid: 12, name: kworker/0:1
> > [<c0014448>] (unwind_backtrace+0x0/0x120) from
> > [<c03120e4>] (__pm_runtime_suspend+0x34/0xa0) from
> > [<c021c33c>] (blk_post_runtime_resume+0x4c/0x5c) from
> > [<c03297cc>] (scsi_runtime_resume+0x90/0xb4) from
> > [<c0310940>] (__rpm_callback+0x30/0x58) from
> > [<c0310980>] (rpm_callback+0x18/0x28) from
> > [<c0311ab0>] (rpm_resume+0x3dc/0x540) from
> > [<c03120a4>] (pm_runtime_work+0x8c/0x98) from
> > [<c007767c>] (process_one_work+0x238/0x3e4) from
> > [<c0077b90>] (worker_thread+0x1ac/0x2ac) from
> > [<c007cfdc>] (kthread+0x88/0x94) from
> > [<c000ece0>] (kernel_thread_exit+0x0/0x8)
> >
> > Fix this by releasing spin_lock_irq() before calling
> > pm_runtime_autosuspend() in blk_post_runtime_resume().
> >
> > --- a/block/blk-core.c
> > +++ b/block/blk-core.c
> > @@ -3159,16 +3159,18 @@ EXPORT_SYMBOL(blk_pre_runtime_resume);
> > */
> > void blk_post_runtime_resume(struct request_queue *q, int err)
> > {
> > - spin_lock_irq(q->queue_lock);
> > if (!err) {
> > + spin_lock_irq(q->queue_lock);
> > q->rpm_status = RPM_ACTIVE;
> > __blk_run_queue(q);
> > pm_runtime_mark_last_busy(q->dev);
> > + spin_unlock_irq(q->queue_lock);
> > pm_runtime_autosuspend(q->dev);
> > } else {
> > + spin_lock_irq(q->queue_lock);
> > q->rpm_status = RPM_SUSPENDED;
> > + spin_unlock_irq(q->queue_lock);
> > }
> > - spin_unlock_irq(q->queue_lock);
> > }
> > EXPORT_SYMBOL(blk_post_runtime_resume);
> > #endif
>
> I suppose we can do this cleanly enough:
>
> --- a/block/blk-core.c~block-fix-possible-sleep-in-invalid-context-fix
> +++ a/block/blk-core.c
> @@ -3159,15 +3159,14 @@ EXPORT_SYMBOL(blk_pre_runtime_resume);
> */
> void blk_post_runtime_resume(struct request_queue *q, int err)
> {
> + spin_lock_irq(q->queue_lock);
> if (!err) {
> - spin_lock_irq(q->queue_lock);
> q->rpm_status = RPM_ACTIVE;
> __blk_run_queue(q);
> pm_runtime_mark_last_busy(q->dev);
> spin_unlock_irq(q->queue_lock);
> pm_request_autosuspend(q->dev);
> } else {
> - spin_lock_irq(q->queue_lock);
> q->rpm_status = RPM_SUSPENDED;
> spin_unlock_irq(q->queue_lock);
> }
> _
>
>
> I wonder if we actually need locking around that second write to
> q->rpm_status.
Shouldn't: it's an int, which makes it a 32 bit quantity we believe to
have atomic write properties on every platform.
James
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] block: Fix possible sleep in invalid context
2013-07-01 22:24 ` James Bottomley
@ 2013-07-01 22:30 ` Andrew Morton
0 siblings, 0 replies; 6+ messages in thread
From: Andrew Morton @ 2013-07-01 22:30 UTC (permalink / raw)
To: James Bottomley
Cc: Sujit Reddy Thumma, Aaron Lu, Jens Axboe, linux-pm, linux-scsi,
stable, linux-arm-msm, linux-kernel
On Mon, 01 Jul 2013 15:24:11 -0700 James Bottomley <James.Bottomley@hansenpartnership.com> wrote:
> > --- a/block/blk-core.c~block-fix-possible-sleep-in-invalid-context-fix
> > +++ a/block/blk-core.c
> > @@ -3159,15 +3159,14 @@ EXPORT_SYMBOL(blk_pre_runtime_resume);
> > */
> > void blk_post_runtime_resume(struct request_queue *q, int err)
> > {
> > + spin_lock_irq(q->queue_lock);
> > if (!err) {
> > - spin_lock_irq(q->queue_lock);
> > q->rpm_status = RPM_ACTIVE;
> > __blk_run_queue(q);
> > pm_runtime_mark_last_busy(q->dev);
> > spin_unlock_irq(q->queue_lock);
> > pm_request_autosuspend(q->dev);
> > } else {
> > - spin_lock_irq(q->queue_lock);
> > q->rpm_status = RPM_SUSPENDED;
> > spin_unlock_irq(q->queue_lock);
> > }
> > _
> >
> >
> > I wonder if we actually need locking around that second write to
> > q->rpm_status.
>
> Shouldn't: it's an int, which makes it a 32 bit quantity we believe to
> have atomic write properties on every platform.
Yes, but. If there's some other code path which does:
spin_lock(queue_lock);
x = q->rpm_status;
...
y = q->rpm_status;
...
<assumes x == y>
spin_unlock(queue_lock);
then it blows up if we make the suggested change. Stranger things have
happened...
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] block: Fix possible sleep in invalid context
2013-07-01 15:28 [PATCH] block: Fix possible sleep in invalid context Sujit Reddy Thumma
2013-07-01 22:17 ` Andrew Morton
@ 2013-07-02 3:04 ` Aaron Lu
2013-07-02 3:27 ` Sujit Reddy Thumma
1 sibling, 1 reply; 6+ messages in thread
From: Aaron Lu @ 2013-07-02 3:04 UTC (permalink / raw)
To: Sujit Reddy Thumma
Cc: Jens Axboe, linux-pm, linux-scsi, stable, linux-arm-msm,
linux-kernel, 'James Bottomley', Andrew Morton
On 07/01/2013 11:28 PM, Sujit Reddy Thumma wrote:
> When block runtime PM is enabled following warning is seen
> while resuming the device.
>
> BUG: sleeping function called from invalid context at
> .../drivers/base/power/runtime.c:923
> in_atomic(): 1, irqs_disabled(): 128, pid: 12, name: kworker/0:1
> [<c0014448>] (unwind_backtrace+0x0/0x120) from
> [<c03120e4>] (__pm_runtime_suspend+0x34/0xa0) from
> [<c021c33c>] (blk_post_runtime_resume+0x4c/0x5c) from
> [<c03297cc>] (scsi_runtime_resume+0x90/0xb4) from
> [<c0310940>] (__rpm_callback+0x30/0x58) from
> [<c0310980>] (rpm_callback+0x18/0x28) from
> [<c0311ab0>] (rpm_resume+0x3dc/0x540) from
> [<c03120a4>] (pm_runtime_work+0x8c/0x98) from
> [<c007767c>] (process_one_work+0x238/0x3e4) from
> [<c0077b90>] (worker_thread+0x1ac/0x2ac) from
> [<c007cfdc>] (kthread+0x88/0x94) from
> [<c000ece0>] (kernel_thread_exit+0x0/0x8)
>
> Fix this by releasing spin_lock_irq() before calling
> pm_runtime_autosuspend() in blk_post_runtime_resume().
Hi Sujit,
Thanks for testing out block layer runtime PM!
As for the problem here, it is already fixed by:
commit c60855cdb976c632b3bf8922eeab8a0e78edfc04
Author: Aaron Lu <aaron.lu@intel.com>
Date: Fri May 17 15:47:20 2013 +0800
blkpm: avoid sleep when holding queue lock
-Aaron
>
> Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
> Cc: stable@vger.kernel.org
> ---
> block/blk-core.c | 6 ++++--
> 1 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/block/blk-core.c b/block/blk-core.c
> index 33c33bc..2456116 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -3159,16 +3159,18 @@ EXPORT_SYMBOL(blk_pre_runtime_resume);
> */
> void blk_post_runtime_resume(struct request_queue *q, int err)
> {
> - spin_lock_irq(q->queue_lock);
> if (!err) {
> + spin_lock_irq(q->queue_lock);
> q->rpm_status = RPM_ACTIVE;
> __blk_run_queue(q);
> pm_runtime_mark_last_busy(q->dev);
> + spin_unlock_irq(q->queue_lock);
> pm_runtime_autosuspend(q->dev);
> } else {
> + spin_lock_irq(q->queue_lock);
> q->rpm_status = RPM_SUSPENDED;
> + spin_unlock_irq(q->queue_lock);
> }
> - spin_unlock_irq(q->queue_lock);
> }
> EXPORT_SYMBOL(blk_post_runtime_resume);
> #endif
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] block: Fix possible sleep in invalid context
2013-07-02 3:04 ` Aaron Lu
@ 2013-07-02 3:27 ` Sujit Reddy Thumma
0 siblings, 0 replies; 6+ messages in thread
From: Sujit Reddy Thumma @ 2013-07-02 3:27 UTC (permalink / raw)
To: Aaron Lu
Cc: Jens Axboe, linux-pm, linux-scsi, stable, linux-arm-msm,
linux-kernel, 'James Bottomley', Andrew Morton
On 7/2/2013 8:34 AM, Aaron Lu wrote:
>> Fix this by releasing spin_lock_irq() before calling
>> >pm_runtime_autosuspend() in blk_post_runtime_resume().
> Hi Sujit,
>
> Thanks for testing out block layer runtime PM!
>
> As for the problem here, it is already fixed by:
>
> commit c60855cdb976c632b3bf8922eeab8a0e78edfc04
> Author: Aaron Lu<aaron.lu@intel.com>
> Date: Fri May 17 15:47:20 2013 +0800
>
> blkpm: avoid sleep when holding queue lock
Thanks Aaron. I see that is merged in 3.10-rc6.
Please ignore this patch.
--
Regards,
Sujit
^ permalink raw reply [flat|nested] 6+ messages in thread
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2013-07-01 15:28 [PATCH] block: Fix possible sleep in invalid context Sujit Reddy Thumma
2013-07-01 22:17 ` Andrew Morton
2013-07-01 22:24 ` James Bottomley
2013-07-01 22:30 ` Andrew Morton
2013-07-02 3:04 ` Aaron Lu
2013-07-02 3:27 ` Sujit Reddy Thumma
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