* [PATCH] lightnvm: add a lock to prevent before the race condition on pblk remove
@ 2019-03-19 14:24 Marcin Dziegielewski
2019-03-21 9:17 ` Javier González
0 siblings, 1 reply; 3+ messages in thread
From: Marcin Dziegielewski @ 2019-03-19 14:24 UTC (permalink / raw)
To: mb, javier, hans.holmberg
Cc: linux-block, marcin.dziegielewski, igor.j.konopko
When we trigger nvm target remove during device hot unplug, we
have a chance to hit general protection fault caused by use of
nvm_dev which was freed from another (hot unplug) thread (in
nvm_unregister function).
This patch introduce lock in nvme_ioctl_dev_remove function to
prevent us before a situation like described above.
Signed-off-by: Marcin Dziegielewski <marcin.dziegielewski@intel.com>
---
drivers/lightnvm/core.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index 5f82036..84f0b9a 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -1335,11 +1335,13 @@ static long nvm_ioctl_dev_remove(struct file *file, void __user *arg)
return -EINVAL;
}
+ down_read(&nvm_lock);
list_for_each_entry(dev, &nvm_devices, devices) {
ret = nvm_remove_tgt(dev, &remove);
if (!ret)
break;
}
+ up_read(&nvm_lock);
return ret;
}
--
1.8.3.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] lightnvm: add a lock to prevent before the race condition on pblk remove
2019-03-19 14:24 [PATCH] lightnvm: add a lock to prevent before the race condition on pblk remove Marcin Dziegielewski
@ 2019-03-21 9:17 ` Javier González
2019-03-25 11:05 ` Matias Bjørling
0 siblings, 1 reply; 3+ messages in thread
From: Javier González @ 2019-03-21 9:17 UTC (permalink / raw)
To: Marcin Dziegielewski
Cc: Matias Bjørling, Hans Holmberg, linux-block, Konopko, Igor J
[-- Attachment #1: Type: text/plain, Size: 1195 bytes --]
> On 19 Mar 2019, at 15.24, Marcin Dziegielewski <marcin.dziegielewski@intel.com> wrote:
>
> When we trigger nvm target remove during device hot unplug, we
> have a chance to hit general protection fault caused by use of
> nvm_dev which was freed from another (hot unplug) thread (in
> nvm_unregister function).
>
> This patch introduce lock in nvme_ioctl_dev_remove function to
> prevent us before a situation like described above.
>
> Signed-off-by: Marcin Dziegielewski <marcin.dziegielewski@intel.com>
> ---
> drivers/lightnvm/core.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
> index 5f82036..84f0b9a 100644
> --- a/drivers/lightnvm/core.c
> +++ b/drivers/lightnvm/core.c
> @@ -1335,11 +1335,13 @@ static long nvm_ioctl_dev_remove(struct file *file, void __user *arg)
> return -EINVAL;
> }
>
> + down_read(&nvm_lock);
> list_for_each_entry(dev, &nvm_devices, devices) {
> ret = nvm_remove_tgt(dev, &remove);
> if (!ret)
> break;
> }
> + up_read(&nvm_lock);
>
> return ret;
> }
> --
> 1.8.3.1
Looks good to me.
Reviewed-by: Javier González <javier@javigon.com>
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^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] lightnvm: add a lock to prevent before the race condition on pblk remove
2019-03-21 9:17 ` Javier González
@ 2019-03-25 11:05 ` Matias Bjørling
0 siblings, 0 replies; 3+ messages in thread
From: Matias Bjørling @ 2019-03-25 11:05 UTC (permalink / raw)
To: Javier González, Marcin Dziegielewski
Cc: Hans Holmberg, linux-block, Konopko, Igor J
On 3/21/19 10:17 AM, Javier González wrote:
>> On 19 Mar 2019, at 15.24, Marcin Dziegielewski <marcin.dziegielewski@intel.com> wrote:
>>
>> When we trigger nvm target remove during device hot unplug, we
>> have a chance to hit general protection fault caused by use of
>> nvm_dev which was freed from another (hot unplug) thread (in
>> nvm_unregister function).
>>
>> This patch introduce lock in nvme_ioctl_dev_remove function to
>> prevent us before a situation like described above.
>>
>> Signed-off-by: Marcin Dziegielewski <marcin.dziegielewski@intel.com>
>> ---
>> drivers/lightnvm/core.c | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
>> index 5f82036..84f0b9a 100644
>> --- a/drivers/lightnvm/core.c
>> +++ b/drivers/lightnvm/core.c
>> @@ -1335,11 +1335,13 @@ static long nvm_ioctl_dev_remove(struct file *file, void __user *arg)
>> return -EINVAL;
>> }
>>
>> + down_read(&nvm_lock);
>> list_for_each_entry(dev, &nvm_devices, devices) {
>> ret = nvm_remove_tgt(dev, &remove);
>> if (!ret)
>> break;
>> }
>> + up_read(&nvm_lock);
>>
>> return ret;
>> }
>> --
>> 1.8.3.1
>
> Looks good to me.
>
>
> Reviewed-by: Javier González <javier@javigon.com>
>
Thanks Marcin. I've reworded the description a bit before pulling it in.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2019-03-19 14:24 [PATCH] lightnvm: add a lock to prevent before the race condition on pblk remove Marcin Dziegielewski
2019-03-21 9:17 ` Javier González
2019-03-25 11:05 ` Matias Bjørling
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