Each ublk queue is started before adding disk, we have to cancel queues in
ublk_stop_dev() so that ubq daemon can be exited, otherwise DEL_DEV command
may hang forever.
Also avoid to cancel queues two times by checking if queue is ready,
otherwise use-after-free on io_uring may be triggered because ublk_stop_dev
is called by ublk_remove() too.
Fixes: 71f28f3136af ("ublk_drv: add io_uring based userspace block driver")
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
drivers/block/ublk_drv.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 3f1906965ac8..7ece4c2ef062 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -788,16 +788,27 @@ static void ublk_daemon_monitor_work(struct work_struct *work)
UBLK_DAEMON_MONITOR_PERIOD);
}
+static inline bool ublk_queue_ready(struct ublk_queue *ubq)
+{
+ return ubq->nr_io_ready == ubq->q_depth;
+}
+
static void ublk_cancel_queue(struct ublk_queue *ubq)
{
int i;
+ if (!ublk_queue_ready(ubq))
+ return;
+
for (i = 0; i < ubq->q_depth; i++) {
struct ublk_io *io = &ubq->ios[i];
if (io->flags & UBLK_IO_FLAG_ACTIVE)
io_uring_cmd_done(io->cmd, UBLK_IO_RES_ABORT, 0);
}
+
+ /* all io commands are canceled */
+ ubq->nr_io_ready = 0;
}
/* Cancel all pending commands, must be called after del_gendisk() returns */
@@ -818,19 +829,14 @@ static void ublk_stop_dev(struct ublk_device *ub)
del_gendisk(ub->ub_disk);
ub->dev_info.state = UBLK_S_DEV_DEAD;
ub->dev_info.ublksrv_pid = -1;
- ublk_cancel_dev(ub);
put_disk(ub->ub_disk);
ub->ub_disk = NULL;
unlock:
+ ublk_cancel_dev(ub);
mutex_unlock(&ub->mutex);
cancel_delayed_work_sync(&ub->monitor_work);
}
-static inline bool ublk_queue_ready(struct ublk_queue *ubq)
-{
- return ubq->nr_io_ready == ubq->q_depth;
-}
-
/* device can only be started after all IOs are ready */
static void ublk_mark_io_ready(struct ublk_device *ub, struct ublk_queue *ubq)
{
--
2.31.1
