* [Qemu-devel] [PATCH] block/nvme: call blk_drain in NVMe reset code to avoid lockups
@ 2018-11-06 12:16 Igor Druzhinin
2018-11-14 17:42 ` Igor Druzhinin
2018-11-22 14:32 ` Kevin Wolf
0 siblings, 2 replies; 5+ messages in thread
From: Igor Druzhinin @ 2018-11-06 12:16 UTC (permalink / raw)
To: keith.busch, kwolf, mreitz; +Cc: qemu-devel, qemu-block, Igor Druzhinin
When blk_flush called in NVMe reset path S/C queues are already freed
which means that re-entering AIO handling loop having some IO requests
unfinished will lockup or crash as their SG structures being potentially
reused. Call blk_drain before freeing the queues to avoid this nasty
scenario.
Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
---
hw/block/nvme.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index fc7dacb..cdf836e 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -797,6 +797,8 @@ static void nvme_clear_ctrl(NvmeCtrl *n)
{
int i;
+ blk_drain(n->conf.blk);
+
for (i = 0; i < n->num_queues; i++) {
if (n->sq[i] != NULL) {
nvme_free_sq(n->sq[i], n);
--
2.7.4
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [Qemu-devel] [PATCH] block/nvme: call blk_drain in NVMe reset code to avoid lockups
2018-11-06 12:16 [Qemu-devel] [PATCH] block/nvme: call blk_drain in NVMe reset code to avoid lockups Igor Druzhinin
@ 2018-11-14 17:42 ` Igor Druzhinin
2018-11-20 17:31 ` Igor Druzhinin
2018-11-22 14:32 ` Kevin Wolf
1 sibling, 1 reply; 5+ messages in thread
From: Igor Druzhinin @ 2018-11-14 17:42 UTC (permalink / raw)
To: keith.busch, kwolf, mreitz; +Cc: qemu-devel, qemu-block
On 06/11/2018 12:16, Igor Druzhinin wrote:
> When blk_flush called in NVMe reset path S/C queues are already freed
> which means that re-entering AIO handling loop having some IO requests
> unfinished will lockup or crash as their SG structures being potentially
> reused. Call blk_drain before freeing the queues to avoid this nasty
> scenario.
>
> Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
> ---
> hw/block/nvme.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/hw/block/nvme.c b/hw/block/nvme.c
> index fc7dacb..cdf836e 100644
> --- a/hw/block/nvme.c
> +++ b/hw/block/nvme.c
> @@ -797,6 +797,8 @@ static void nvme_clear_ctrl(NvmeCtrl *n)
> {
> int i;
>
> + blk_drain(n->conf.blk);
> +
> for (i = 0; i < n->num_queues; i++) {
> if (n->sq[i] != NULL) {
> nvme_free_sq(n->sq[i], n);
>
ping?
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [Qemu-devel] [PATCH] block/nvme: call blk_drain in NVMe reset code to avoid lockups
2018-11-14 17:42 ` Igor Druzhinin
@ 2018-11-20 17:31 ` Igor Druzhinin
2018-11-20 17:52 ` Paolo Bonzini
0 siblings, 1 reply; 5+ messages in thread
From: Igor Druzhinin @ 2018-11-20 17:31 UTC (permalink / raw)
To: keith.busch, kwolf, mreitz; +Cc: qemu-devel, qemu-block, pbonzini
On 14/11/2018 17:42, Igor Druzhinin wrote:
> On 06/11/2018 12:16, Igor Druzhinin wrote:
>> When blk_flush called in NVMe reset path S/C queues are already freed
>> which means that re-entering AIO handling loop having some IO requests
>> unfinished will lockup or crash as their SG structures being potentially
>> reused. Call blk_drain before freeing the queues to avoid this nasty
>> scenario.
>>
>> Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
>> ---
>> hw/block/nvme.c | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/hw/block/nvme.c b/hw/block/nvme.c
>> index fc7dacb..cdf836e 100644
>> --- a/hw/block/nvme.c
>> +++ b/hw/block/nvme.c
>> @@ -797,6 +797,8 @@ static void nvme_clear_ctrl(NvmeCtrl *n)
>> {
>> int i;
>>
>> + blk_drain(n->conf.blk);
>> +
>> for (i = 0; i < n->num_queues; i++) {
>> if (n->sq[i] != NULL) {
>> nvme_free_sq(n->sq[i], n);
>>
>
> ping?
>
CC: Paolo Bonzini <pbonzini@redhat.com>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [Qemu-devel] [PATCH] block/nvme: call blk_drain in NVMe reset code to avoid lockups
2018-11-20 17:31 ` Igor Druzhinin
@ 2018-11-20 17:52 ` Paolo Bonzini
0 siblings, 0 replies; 5+ messages in thread
From: Paolo Bonzini @ 2018-11-20 17:52 UTC (permalink / raw)
To: Igor Druzhinin, keith.busch, kwolf, mreitz; +Cc: qemu-devel, qemu-block
On 20/11/18 18:31, Igor Druzhinin wrote:
> On 14/11/2018 17:42, Igor Druzhinin wrote:
>> On 06/11/2018 12:16, Igor Druzhinin wrote:
>>> When blk_flush called in NVMe reset path S/C queues are already freed
>>> which means that re-entering AIO handling loop having some IO requests
>>> unfinished will lockup or crash as their SG structures being potentially
>>> reused. Call blk_drain before freeing the queues to avoid this nasty
>>> scenario.
>>>
>>> Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
>>> ---
>>> hw/block/nvme.c | 2 ++
>>> 1 file changed, 2 insertions(+)
>>>
>>> diff --git a/hw/block/nvme.c b/hw/block/nvme.c
>>> index fc7dacb..cdf836e 100644
>>> --- a/hw/block/nvme.c
>>> +++ b/hw/block/nvme.c
>>> @@ -797,6 +797,8 @@ static void nvme_clear_ctrl(NvmeCtrl *n)
>>> {
>>> int i;
>>>
>>> + blk_drain(n->conf.blk);
>>> +
>>> for (i = 0; i < n->num_queues; i++) {
>>> if (n->sq[i] != NULL) {
>>> nvme_free_sq(n->sq[i], n);
>>>
>>
>> ping?
>>
>
> CC: Paolo Bonzini <pbonzini@redhat.com>
>
Looks good to me. Kevin, Max?
Paolo
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH] block/nvme: call blk_drain in NVMe reset code to avoid lockups
2018-11-06 12:16 [Qemu-devel] [PATCH] block/nvme: call blk_drain in NVMe reset code to avoid lockups Igor Druzhinin
2018-11-14 17:42 ` Igor Druzhinin
@ 2018-11-22 14:32 ` Kevin Wolf
1 sibling, 0 replies; 5+ messages in thread
From: Kevin Wolf @ 2018-11-22 14:32 UTC (permalink / raw)
To: Igor Druzhinin; +Cc: keith.busch, mreitz, qemu-devel, qemu-block
Am 06.11.2018 um 13:16 hat Igor Druzhinin geschrieben:
> When blk_flush called in NVMe reset path S/C queues are already freed
> which means that re-entering AIO handling loop having some IO requests
> unfinished will lockup or crash as their SG structures being potentially
> reused. Call blk_drain before freeing the queues to avoid this nasty
> scenario.
>
> Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Thanks, applied to the block branch.
Kevin
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2018-11-22 14:32 UTC | newest]
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2018-11-06 12:16 [Qemu-devel] [PATCH] block/nvme: call blk_drain in NVMe reset code to avoid lockups Igor Druzhinin
2018-11-14 17:42 ` Igor Druzhinin
2018-11-20 17:31 ` Igor Druzhinin
2018-11-20 17:52 ` Paolo Bonzini
2018-11-22 14:32 ` Kevin Wolf
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