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

From: Mike Christie
Date: Wed Aug 14 2019 - 23:16:34 EST


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
>
> 在 2019/8/12 20:31, Sun Ke 写道:
>> 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 <sunke32@xxxxxxxxxx>
>> ---
>> 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),
>>
>