Commit 97e8ba31 authored by Caleb Sander Mateos's avatar Caleb Sander Mateos Committed by Jens Axboe
Browse files

ublk: consolidate nr_io_ready and nr_queues_ready 



ublk_mark_io_ready() tracks whether all the ublk_device's I/Os have been
fetched by incrementing ublk_queue's nr_io_ready count and incrementing
ublk_device's nr_queues_ready count if the whole queue is ready.
Simplify the logic by just tracking the total number of fetched I/Os on
each ublk_device. When this count reaches nr_hw_queues * queue_depth,
the ublk_device is ready to receive I/O.

Signed-off-by: default avatarCaleb Sander Mateos <csander@purestorage.com>
Reviewed-by: default avatarMing Lei <ming.lei@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent e0ed2bca

drivers/block/ublk_drv.c

+12 −16
Original line number Diff line number Diff line
@@ -201,7 +201,6 @@ struct ublk_queue { 
	bool force_abort;

	bool canceling;

	bool fail_io; /* copy of dev->state == UBLK_S_DEV_FAIL_IO */

	unsigned short nr_io_ready;	/* how many ios setup */

	spinlock_t		cancel_lock;

	struct ublk_device *dev;

	struct ublk_io ios[];
@@ -234,7 +233,7 @@ struct ublk_device { 
	struct ublk_params	params;



	struct completion	completion;

	unsigned int		nr_queues_ready;

	u32			nr_io_ready;

	bool 			unprivileged_daemons;

	struct mutex cancel_mutex;

	bool canceling;
@@ -1499,9 +1498,6 @@ 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;



	for (i = 0; i < ubq->q_depth; i++) {

		struct ublk_io *io = &ubq->ios[i];
@@ -1550,7 +1546,7 @@ static void ublk_reset_ch_dev(struct ublk_device *ub) 


	/* set to NULL, otherwise new tasks cannot mmap io_cmd_buf */

	ub->mm = NULL;

	ub->nr_queues_ready = 0;

	ub->nr_io_ready = 0;

	ub->unprivileged_daemons = false;

	ub->ublksrv_tgid = -1;

}
@@ -1848,9 +1844,11 @@ static void ublk_uring_cmd_cancel_fn(struct io_uring_cmd *cmd, 
	ublk_cancel_cmd(ubq, pdu->tag, issue_flags);

}



static inline bool ublk_queue_ready(struct ublk_queue *ubq)

static inline bool ublk_dev_ready(const struct ublk_device *ub)

{

	return ubq->nr_io_ready == ubq->q_depth;

	u32 total = (u32)ub->dev_info.nr_hw_queues * ub->dev_info.queue_depth;



	return ub->nr_io_ready == total;

}



static void ublk_cancel_queue(struct ublk_queue *ubq)
@@ -1974,16 +1972,14 @@ static void ublk_reset_io_flags(struct ublk_device *ub) 
}



/* device can only be started after all IOs are ready */

static void ublk_mark_io_ready(struct ublk_device *ub, struct ublk_queue *ubq)

static void ublk_mark_io_ready(struct ublk_device *ub)

	__must_hold(&ub->mutex)

{

	ubq->nr_io_ready++;

	if (ublk_queue_ready(ubq))

		ub->nr_queues_ready++;

	if (!ub->unprivileged_daemons && !capable(CAP_SYS_ADMIN))

		ub->unprivileged_daemons = true;



	if (ub->nr_queues_ready == ub->dev_info.nr_hw_queues) {

	ub->nr_io_ready++;

	if (ublk_dev_ready(ub)) {

		/* now we are ready for handling ublk io request */

		ublk_reset_io_flags(ub);

		complete_all(&ub->completion);
@@ -2189,8 +2185,8 @@ static int ublk_fetch(struct io_uring_cmd *cmd, struct ublk_queue *ubq, 
	 * FETCH, so it is fine even for IO_URING_F_NONBLOCK.

	 */

	mutex_lock(&ub->mutex);

	/* UBLK_IO_FETCH_REQ is only allowed before queue is setup */

	if (ublk_queue_ready(ubq)) {

	/* UBLK_IO_FETCH_REQ is only allowed before dev is setup */

	if (ublk_dev_ready(ub)) {

		ret = -EBUSY;

		goto out;

	}
@@ -2209,7 +2205,7 @@ static int ublk_fetch(struct io_uring_cmd *cmd, struct ublk_queue *ubq, 
		goto out;



	WRITE_ONCE(io->task, get_task_struct(current));

	ublk_mark_io_ready(ub, ubq);

	ublk_mark_io_ready(ub);

out:

	mutex_unlock(&ub->mutex);

	return ret;