2019-08-12 12:26:30

by Sun Ke

Subject: [PATCH] nbd: add a missed nbd_config_put() in nbd_xmit_timeout()

When try to get the lock failed, before return, execute the
nbd_config_put() to decrease the nbd->config_refs.

If the nbd->config_refs is added but not decreased. Then will not
execute nbd_clear_sock() in nbd_config_put(). bd->task_setup will
not be cleared away. Finally, print"Device being setup by another
task" in nbd_add_sock() and nbd device can not be reused.

Fixes: 8f3ea35929a0 ("nbd: handle unexpected replies better")
Signed-off-by: Sun Ke <[email protected]>
---
drivers/block/nbd.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index e21d2de..a69a90a 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -357,8 +357,10 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req,
}
config = nbd->config;

- if (!mutex_trylock(&cmd->lock))
+ if (!mutex_trylock(&cmd->lock)) {
+ nbd_config_put(nbd);
return BLK_EH_RESET_TIMER;
+ }

if (config->num_connections > 1) {
dev_err_ratelimited(nbd_to_dev(nbd),
--
2.7.4

2019-08-12 15:35:34

by Mike Christie

Subject: Re: [PATCH] nbd: add a missed nbd_config_put() in nbd_xmit_timeout()

On 08/12/2019 07:31 AM, Sun Ke wrote:
> When try to get the lock failed, before return, execute the
> nbd_config_put() to decrease the nbd->config_refs.
>
> If the nbd->config_refs is added but not decreased. Then will not
> execute nbd_clear_sock() in nbd_config_put(). bd->task_setup will
> not be cleared away. Finally, print"Device being setup by another
> task" in nbd_add_sock() and nbd device can not be reused.
>
> Fixes: 8f3ea35929a0 ("nbd: handle unexpected replies better")
> Signed-off-by: Sun Ke <[email protected]>
> ---
> drivers/block/nbd.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
> index e21d2de..a69a90a 100644
> --- a/drivers/block/nbd.c
> +++ b/drivers/block/nbd.c
> @@ -357,8 +357,10 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req,
> }
> config = nbd->config;
>
> - if (!mutex_trylock(&cmd->lock))
> + if (!mutex_trylock(&cmd->lock)) {
> + nbd_config_put(nbd);
> return BLK_EH_RESET_TIMER;
> + }
>
> if (config->num_connections > 1) {
> dev_err_ratelimited(nbd_to_dev(nbd),
>

I just sent the same patch

https://www.spinics.net/lists/linux-block/msg43718.html

here

https://www.spinics.net/lists/linux-block/msg43715.html

so it looks good to me.

Reviewed-by: Mike Christie <[email protected]>

2019-08-13 04:30:34

by Sun Ke

Subject: Re: [PATCH] nbd: add a missed nbd_config_put() in nbd_xmit_timeout()

Thanks for your review.

在 2019/8/12 23:34, Mike Christie 写道:
> On 08/12/2019 07:31 AM, Sun Ke wrote:
>> When try to get the lock failed, before return, execute the
>> nbd_config_put() to decrease the nbd->config_refs.
>>
>> If the nbd->config_refs is added but not decreased. Then will not
>> execute nbd_clear_sock() in nbd_config_put(). bd->task_setup will
>> not be cleared away. Finally, print"Device being setup by another
>> task" in nbd_add_sock() and nbd device can not be reused.
>>
>> Fixes: 8f3ea35929a0 ("nbd: handle unexpected replies better")
>> Signed-off-by: Sun Ke <[email protected]>
>> ---
>> drivers/block/nbd.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
>> index e21d2de..a69a90a 100644
>> --- a/drivers/block/nbd.c
>> +++ b/drivers/block/nbd.c
>> @@ -357,8 +357,10 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req,
>> }
>> config = nbd->config;
>>
>> - if (!mutex_trylock(&cmd->lock))
>> + if (!mutex_trylock(&cmd->lock)) {
>> + nbd_config_put(nbd);
>> return BLK_EH_RESET_TIMER;
>> + }
>>
>> if (config->num_connections > 1) {
>> dev_err_ratelimited(nbd_to_dev(nbd),
>>
>
> I just sent the same patch
>
> https://www.spinics.net/lists/linux-block/msg43718.html
>
> here
>
> https://www.spinics.net/lists/linux-block/msg43715.html
>
> so it looks good to me.
>
> Reviewed-by: Mike Christie <[email protected]>
>
> .
>

2019-08-15 01:32:46

by Sun Ke

Subject: Re: [PATCH] nbd: add a missed nbd_config_put() in nbd_xmit_timeout()

ping

?? 2019/8/12 20:31, Sun Ke д??:
> When try to get the lock failed, before return, execute the
> nbd_config_put() to decrease the nbd->config_refs.
>
> If the nbd->config_refs is added but not decreased. Then will not
> execute nbd_clear_sock() in nbd_config_put(). bd->task_setup will
> not be cleared away. Finally, print"Device being setup by another
> task" in nbd_add_sock() and nbd device can not be reused.
>
> Fixes: 8f3ea35929a0 ("nbd: handle unexpected replies better")
> Signed-off-by: Sun Ke <[email protected]>
> ---
> drivers/block/nbd.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
> index e21d2de..a69a90a 100644
> --- a/drivers/block/nbd.c
> +++ b/drivers/block/nbd.c
> @@ -357,8 +357,10 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req,
> }
> config = nbd->config;
>
> - if (!mutex_trylock(&cmd->lock))
> + if (!mutex_trylock(&cmd->lock)) {
> + nbd_config_put(nbd);
> return BLK_EH_RESET_TIMER;
> + }
>
> if (config->num_connections > 1) {
> dev_err_ratelimited(nbd_to_dev(nbd),
>

2019-08-15 03:17:12

by Mike Christie

Subject: Re: [PATCH] nbd: add a missed nbd_config_put() in nbd_xmit_timeout()

Josef had ackd my patch for the same thing here:

https://www.spinics.net/lists/linux-block/msg43800.html

so maybe Jens will pick that up with the rest of the set Josef had acked:

https://www.spinics.net/lists/linux-block/msg43809.html

to make it easier.

On 08/14/2019 08:27 PM, sunke (E) wrote:
> ping
>
> ?? 2019/8/12 20:31, Sun Ke д??:
>> When try to get the lock failed, before return, execute the
>> nbd_config_put() to decrease the nbd->config_refs.
>>
>> If the nbd->config_refs is added but not decreased. Then will not
>> execute nbd_clear_sock() in nbd_config_put(). bd->task_setup will
>> not be cleared away. Finally, print"Device being setup by another
>> task" in nbd_add_sock() and nbd device can not be reused.
>>
>> Fixes: 8f3ea35929a0 ("nbd: handle unexpected replies better")
>> Signed-off-by: Sun Ke <[email protected]>
>> ---
>> drivers/block/nbd.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
>> index e21d2de..a69a90a 100644
>> --- a/drivers/block/nbd.c
>> +++ b/drivers/block/nbd.c
>> @@ -357,8 +357,10 @@ static enum blk_eh_timer_return
>> nbd_xmit_timeout(struct request *req,
>> }
>> config = nbd->config;
>> - if (!mutex_trylock(&cmd->lock))
>> + if (!mutex_trylock(&cmd->lock)) {
>> + nbd_config_put(nbd);
>> return BLK_EH_RESET_TIMER;
>> + }
>> if (config->num_connections > 1) {
>> dev_err_ratelimited(nbd_to_dev(nbd),
>>
>