ublk_ch_release() is called after ublk char device is closed, when all
uring_cmd are done, so it is perfect fine to move ublk device reset to
ublk_ch_release() from ublk_ctrl_start_recovery().
This way can avoid to grab the exiting daemon task_struct too long.
However, reset of the following ublk IO flags has to be moved until ublk
io_uring queues are ready:
- ubq->canceling
For requeuing IO in case of ublk_nosrv_dev_should_queue_io() before device
is recovered
- ubq->fail_io
For failing IO in case of UBLK_F_USER_RECOVERY_FAIL_IO before device is
recovered
- ublk_io->flags
For preventing using io->cmd
With this way, recovery is simplified a lot.
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
drivers/block/ublk_drv.c | 121 +++++++++++++++++++++++----------------
1 file changed, 72 insertions(+), 49 deletions(-)
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index a479969fd77e..1fe39cf85b2f 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -1074,7 +1074,7 @@ static inline struct ublk_uring_cmd_pdu *ublk_get_uring_cmd_pdu(
static inline bool ubq_daemon_is_dying(struct ublk_queue *ubq)
{
- return ubq->ubq_daemon->flags & PF_EXITING;
+ return !ubq->ubq_daemon || ubq->ubq_daemon->flags & PF_EXITING;
}
/* todo: handle partial completion */
@@ -1470,6 +1470,37 @@ static const struct blk_mq_ops ublk_mq_ops = {
.timeout = ublk_timeout,
};
+static void ublk_queue_reinit(struct ublk_device *ub, struct ublk_queue *ubq)
+{
+ int i;
+
+ /* All old ioucmds have to be completed */
+ ubq->nr_io_ready = 0;
+
+ /*
+ * old daemon is PF_EXITING, put it now
+ *
+ * It could be NULL in case of closing one quisced device.
+ */
+ if (ubq->ubq_daemon)
+ put_task_struct(ubq->ubq_daemon);
+ /* We have to reset it to NULL, otherwise ub won't accept new FETCH_REQ */
+ ubq->ubq_daemon = NULL;
+ ubq->timeout = false;
+
+ for (i = 0; i < ubq->q_depth; i++) {
+ struct ublk_io *io = &ubq->ios[i];
+
+ /*
+ * UBLK_IO_FLAG_CANCELED is kept for avoiding to touch
+ * io->cmd
+ */
+ io->flags &= UBLK_IO_FLAG_CANCELED;
+ io->cmd = NULL;
+ io->addr = 0;
+ }
+}
+
static int ublk_ch_open(struct inode *inode, struct file *filp)
{
struct ublk_device *ub = container_of(inode->i_cdev,
@@ -1481,10 +1512,26 @@ static int ublk_ch_open(struct inode *inode, struct file *filp)
return 0;
}
+static void ublk_reset_ch_dev(struct ublk_device *ub)
+{
+ int i;
+
+ for (i = 0; i < ub->dev_info.nr_hw_queues; i++)
+ ublk_queue_reinit(ub, ublk_get_queue(ub, i));
+
+ /* set to NULL, otherwise new ubq_daemon cannot mmap the io_cmd_buf */
+ ub->mm = NULL;
+ ub->nr_queues_ready = 0;
+ ub->nr_privileged_daemon = 0;
+}
+
static int ublk_ch_release(struct inode *inode, struct file *filp)
{
struct ublk_device *ub = filp->private_data;
+ /* all uring_cmd has been done now, reset device & ubq */
+ ublk_reset_ch_dev(ub);
+
clear_bit(UB_STATE_OPEN, &ub->state);
return 0;
}
@@ -1831,6 +1878,24 @@ static void ublk_nosrv_work(struct work_struct *work)
ublk_cancel_dev(ub);
}
+/* reset ublk io_uring queue & io flags */
+static void ublk_reset_io_flags(struct ublk_device *ub)
+{
+ int i, j;
+
+ for (i = 0; i < ub->dev_info.nr_hw_queues; i++) {
+ struct ublk_queue *ubq = ublk_get_queue(ub, i);
+
+ /* UBLK_IO_FLAG_CANCELED can be cleared now */
+ spin_lock(&ubq->cancel_lock);
+ for (j = 0; j < ubq->q_depth; j++)
+ ubq->ios[j].flags &= ~UBLK_IO_FLAG_CANCELED;
+ spin_unlock(&ubq->cancel_lock);
+ ubq->canceling = false;
+ ubq->fail_io = false;
+ }
+}
+
/* device can only be started after all IOs are ready */
static void ublk_mark_io_ready(struct ublk_device *ub, struct ublk_queue *ubq)
__must_hold(&ub->mutex)
@@ -1844,8 +1909,12 @@ static void ublk_mark_io_ready(struct ublk_device *ub, struct ublk_queue *ubq)
if (capable(CAP_SYS_ADMIN))
ub->nr_privileged_daemon++;
}
- if (ub->nr_queues_ready == ub->dev_info.nr_hw_queues)
+
+ if (ub->nr_queues_ready == ub->dev_info.nr_hw_queues) {
+ /* now we are ready for handling ublk io request */
+ ublk_reset_io_flags(ub);
complete_all(&ub->completion);
+ }
}
static void ublk_handle_need_get_data(struct ublk_device *ub, int q_id,
@@ -2954,41 +3023,14 @@ static int ublk_ctrl_set_params(struct ublk_device *ub,
return ret;
}
-static void ublk_queue_reinit(struct ublk_device *ub, struct ublk_queue *ubq)
-{
- int i;
-
- WARN_ON_ONCE(!(ubq->ubq_daemon && ubq_daemon_is_dying(ubq)));
-
- /* All old ioucmds have to be completed */
- ubq->nr_io_ready = 0;
- /* old daemon is PF_EXITING, put it now */
- put_task_struct(ubq->ubq_daemon);
- /* We have to reset it to NULL, otherwise ub won't accept new FETCH_REQ */
- ubq->ubq_daemon = NULL;
- ubq->timeout = false;
-
- for (i = 0; i < ubq->q_depth; i++) {
- struct ublk_io *io = &ubq->ios[i];
-
- /* forget everything now and be ready for new FETCH_REQ */
- io->flags = 0;
- io->cmd = NULL;
- io->addr = 0;
- }
-}
-
static int ublk_ctrl_start_recovery(struct ublk_device *ub,
const struct ublksrv_ctrl_cmd *header)
{
int ret = -EINVAL;
- int i;
mutex_lock(&ub->mutex);
if (ublk_nosrv_should_stop_dev(ub))
goto out_unlock;
- if (!ub->nr_queues_ready)
- goto out_unlock;
/*
* START_RECOVERY is only allowd after:
*
@@ -3012,12 +3054,6 @@ static int ublk_ctrl_start_recovery(struct ublk_device *ub,
goto out_unlock;
}
pr_devel("%s: start recovery for dev id %d.\n", __func__, header->dev_id);
- for (i = 0; i < ub->dev_info.nr_hw_queues; i++)
- ublk_queue_reinit(ub, ublk_get_queue(ub, i));
- /* set to NULL, otherwise new ubq_daemon cannot mmap the io_cmd_buf */
- ub->mm = NULL;
- ub->nr_queues_ready = 0;
- ub->nr_privileged_daemon = 0;
init_completion(&ub->completion);
ret = 0;
out_unlock:
@@ -3030,7 +3066,6 @@ static int ublk_ctrl_end_recovery(struct ublk_device *ub,
{
int ublksrv_pid = (int)header->data[0];
int ret = -EINVAL;
- int i;
pr_devel("%s: Waiting for new ubq_daemons(nr: %d) are ready, dev id %d...\n",
__func__, ub->dev_info.nr_hw_queues, header->dev_id);
@@ -3050,22 +3085,10 @@ static int ublk_ctrl_end_recovery(struct ublk_device *ub,
goto out_unlock;
}
ub->dev_info.ublksrv_pid = ublksrv_pid;
+ ub->dev_info.state = UBLK_S_DEV_LIVE;
pr_devel("%s: new ublksrv_pid %d, dev id %d\n",
__func__, ublksrv_pid, header->dev_id);
-
- blk_mq_quiesce_queue(ub->ub_disk->queue);
- ub->dev_info.state = UBLK_S_DEV_LIVE;
- for (i = 0; i < ub->dev_info.nr_hw_queues; i++) {
- struct ublk_queue *ubq = ublk_get_queue(ub, i);
-
- ubq->canceling = false;
- ubq->fail_io = false;
- }
- blk_mq_unquiesce_queue(ub->ub_disk->queue);
- pr_devel("%s: queue unquiesced, dev id %d.\n",
- __func__, header->dev_id);
blk_mq_kick_requeue_list(ub->ub_disk->queue);
-
ret = 0;
out_unlock:
mutex_unlock(&ub->mutex);
--
2.47.0
