From: Logan Gunthorpe Date: Wed, 31 Jul 2019 23:35:32 +0000 (-0600) Subject: nvmet-loop: Flush nvme_delete_wq when removing the port X-Git-Tag: microblaze-v5.4-rc1~51^2~5^2~6 X-Git-Url: http://git.monstr.eu/?a=commitdiff_plain;h=86b9a63e595ff03f9d0a7b92b6acc231fecefc29;p=linux-2.6-microblaze.git nvmet-loop: Flush nvme_delete_wq when removing the port After calling nvme_loop_delete_ctrl(), the controllers will not yet be deleted because nvme_delete_ctrl() only schedules work to do the delete. This means a race can occur if a port is removed but there are still active controllers trying to access that memory. To fix this, flush the nvme_delete_wq before returning from nvme_loop_remove_port() so that any controllers that might be in the process of being deleted won't access a freed port. Signed-off-by: Logan Gunthorpe Reviewed-by: Sagi Grimberg Reviewed-by: Max Gurtovoy Reviewed-by : Chaitanya Kulkarni Signed-off-by: Sagi Grimberg --- diff --git a/drivers/nvme/target/loop.c b/drivers/nvme/target/loop.c index b16dc3981c69..0940c5024a34 100644 --- a/drivers/nvme/target/loop.c +++ b/drivers/nvme/target/loop.c @@ -654,6 +654,14 @@ static void nvme_loop_remove_port(struct nvmet_port *port) mutex_lock(&nvme_loop_ports_mutex); list_del_init(&port->entry); mutex_unlock(&nvme_loop_ports_mutex); + + /* + * Ensure any ctrls that are in the process of being + * deleted are in fact deleted before we return + * and free the port. This is to prevent active + * ctrls from using a port after it's freed. + */ + flush_workqueue(nvme_delete_wq); } static const struct nvmet_fabrics_ops nvme_loop_ops = {