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

From: sunke (E)
Date: Tue Aug 13 2019 - 00:28:34 EST


Thanks for your review.

å 2019/8/12 23:34, Mike Christie åé:
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 <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),


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 <mchristi@xxxxxxxxxx>

.