]> git.ipfire.org Git - thirdparty/kernel/linux.git/commitdiff
selftests: ublk: kublk: move per-thread data out of ublk_queue
authorUday Shankar <ushankar@purestorage.com>
Thu, 29 May 2025 23:47:14 +0000 (17:47 -0600)
committerJens Axboe <axboe@kernel.dk>
Sat, 31 May 2025 20:38:39 +0000 (14:38 -0600)
Towards the goal of decoupling ublk_queues from ublk server threads,
move resources/data that should be per-thread rather than per-queue out
of ublk_queue and into a new struct ublk_thread.

Signed-off-by: Uday Shankar <ushankar@purestorage.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250529-ublk_task_per_io-v8-5-e9d3b119336a@purestorage.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
tools/testing/selftests/ublk/kublk.c
tools/testing/selftests/ublk/kublk.h

index 2d6d163b74483a07066f47fd36781782ce25a16e..40431a8357a8f74d7d62e271e9090c8708c3ecc5 100644 (file)
@@ -348,8 +348,8 @@ static void ublk_ctrl_dump(struct ublk_dev *dev)
 
                for (i = 0; i < info->nr_hw_queues; i++) {
                        ublk_print_cpu_set(&affinity[i], buf, sizeof(buf));
-                       printf("\tqueue %u: tid %d affinity(%s)\n",
-                                       i, dev->q[i].tid, buf);
+                       printf("\tqueue %u: affinity(%s)\n",
+                                       i, buf);
                }
                free(affinity);
        }
@@ -419,18 +419,16 @@ static void ublk_queue_deinit(struct ublk_queue *q)
                free(q->ios[i].buf_addr);
 }
 
-static void ublk_thread_deinit(struct ublk_queue *q)
+static void ublk_thread_deinit(struct ublk_thread *t)
 {
-       q->tid = 0;
+       io_uring_unregister_buffers(&t->ring);
 
-       io_uring_unregister_buffers(&q->ring);
+       io_uring_unregister_ring_fd(&t->ring);
 
-       io_uring_unregister_ring_fd(&q->ring);
-
-       if (q->ring.ring_fd > 0) {
-               io_uring_unregister_files(&q->ring);
-               close(q->ring.ring_fd);
-               q->ring.ring_fd = -1;
+       if (t->ring.ring_fd > 0) {
+               io_uring_unregister_files(&t->ring);
+               close(t->ring.ring_fd);
+               t->ring.ring_fd = -1;
        }
 }
 
@@ -445,7 +443,6 @@ static int ublk_queue_init(struct ublk_queue *q, unsigned extra_flags)
        q->tgt_ops = dev->tgt.ops;
        q->state = 0;
        q->q_depth = depth;
-       q->cmd_inflight = 0;
 
        if (dev->dev_info.flags & (UBLK_F_SUPPORT_ZERO_COPY | UBLK_F_AUTO_BUF_REG)) {
                q->state |= UBLKSRV_NO_BUF;
@@ -470,6 +467,7 @@ static int ublk_queue_init(struct ublk_queue *q, unsigned extra_flags)
        for (i = 0; i < q->q_depth; i++) {
                q->ios[i].buf_addr = NULL;
                q->ios[i].flags = UBLKSRV_NEED_FETCH_RQ | UBLKSRV_IO_FREE;
+               q->ios[i].tag = i;
 
                if (q->state & UBLKSRV_NO_BUF)
                        continue;
@@ -490,47 +488,46 @@ static int ublk_queue_init(struct ublk_queue *q, unsigned extra_flags)
        return -ENOMEM;
 }
 
-static int ublk_thread_init(struct ublk_queue *q)
+static int ublk_thread_init(struct ublk_thread *t)
 {
-       struct ublk_dev *dev = q->dev;
+       struct ublk_dev *dev = t->dev;
        int ring_depth = dev->tgt.sq_depth, cq_depth = dev->tgt.cq_depth;
        int ret;
 
-       q->tid = gettid();
-
-       ret = ublk_setup_ring(&q->ring, ring_depth, cq_depth,
+       ret = ublk_setup_ring(&t->ring, ring_depth, cq_depth,
                        IORING_SETUP_COOP_TASKRUN |
                        IORING_SETUP_SINGLE_ISSUER |
                        IORING_SETUP_DEFER_TASKRUN);
        if (ret < 0) {
-               ublk_err("ublk dev %d queue %d setup io_uring failed %d\n",
-                               q->dev->dev_info.dev_id, q->q_id, ret);
+               ublk_err("ublk dev %d thread %d setup io_uring failed %d\n",
+                               dev->dev_info.dev_id, t->idx, ret);
                goto fail;
        }
 
        if (dev->dev_info.flags & (UBLK_F_SUPPORT_ZERO_COPY | UBLK_F_AUTO_BUF_REG)) {
-               ret = io_uring_register_buffers_sparse(&q->ring, q->q_depth);
+               ret = io_uring_register_buffers_sparse(
+                       &t->ring, dev->dev_info.queue_depth);
                if (ret) {
-                       ublk_err("ublk dev %d queue %d register spare buffers failed %d",
-                                       dev->dev_info.dev_id, q->q_id, ret);
+                       ublk_err("ublk dev %d thread %d register spare buffers failed %d",
+                                       dev->dev_info.dev_id, t->idx, ret);
                        goto fail;
                }
        }
 
-       io_uring_register_ring_fd(&q->ring);
+       io_uring_register_ring_fd(&t->ring);
 
-       ret = io_uring_register_files(&q->ring, dev->fds, dev->nr_fds);
+       ret = io_uring_register_files(&t->ring, dev->fds, dev->nr_fds);
        if (ret) {
-               ublk_err("ublk dev %d queue %d register files failed %d\n",
-                               q->dev->dev_info.dev_id, q->q_id, ret);
+               ublk_err("ublk dev %d thread %d register files failed %d\n",
+                               t->dev->dev_info.dev_id, t->idx, ret);
                goto fail;
        }
 
        return 0;
 fail:
-       ublk_thread_deinit(q);
-       ublk_err("ublk dev %d queue %d thread init failed\n",
-                       dev->dev_info.dev_id, q->q_id);
+       ublk_thread_deinit(t);
+       ublk_err("ublk dev %d thread %d init failed\n",
+                       dev->dev_info.dev_id, t->idx);
        return -ENOMEM;
 }
 
@@ -589,8 +586,10 @@ static void ublk_set_auto_buf_reg(const struct ublk_queue *q,
        sqe->addr = ublk_auto_buf_reg_to_sqe_addr(&buf);
 }
 
-int ublk_queue_io_cmd(struct ublk_queue *q, struct ublk_io *io, unsigned tag)
+int ublk_queue_io_cmd(struct ublk_io *io)
 {
+       struct ublk_thread *t = io->t;
+       struct ublk_queue *q = ublk_io_to_queue(io);
        struct ublksrv_io_cmd *cmd;
        struct io_uring_sqe *sqe[1];
        unsigned int cmd_op = 0;
@@ -615,13 +614,13 @@ int ublk_queue_io_cmd(struct ublk_queue *q, struct ublk_io *io, unsigned tag)
        else if (io->flags & UBLKSRV_NEED_FETCH_RQ)
                cmd_op = UBLK_U_IO_FETCH_REQ;
 
-       if (io_uring_sq_space_left(&q->ring) < 1)
-               io_uring_submit(&q->ring);
+       if (io_uring_sq_space_left(&t->ring) < 1)
+               io_uring_submit(&t->ring);
 
-       ublk_io_alloc_sqes(ublk_get_io(q, tag), sqe, 1);
+       ublk_io_alloc_sqes(io, sqe, 1);
        if (!sqe[0]) {
-               ublk_err("%s: run out of sqe %d, tag %d\n",
-                               __func__, q->q_id, tag);
+               ublk_err("%s: run out of sqe. thread %u, tag %d\n",
+                               __func__, t->idx, io->tag);
                return -1;
        }
 
@@ -636,7 +635,7 @@ int ublk_queue_io_cmd(struct ublk_queue *q, struct ublk_io *io, unsigned tag)
        sqe[0]->opcode  = IORING_OP_URING_CMD;
        sqe[0]->flags   = IOSQE_FIXED_FILE;
        sqe[0]->rw_flags        = 0;
-       cmd->tag        = tag;
+       cmd->tag        = io->tag;
        cmd->q_id       = q->q_id;
        if (!(q->state & UBLKSRV_NO_BUF))
                cmd->addr       = (__u64) (uintptr_t) io->buf_addr;
@@ -644,37 +643,46 @@ int ublk_queue_io_cmd(struct ublk_queue *q, struct ublk_io *io, unsigned tag)
                cmd->addr       = 0;
 
        if (q->state & UBLKSRV_AUTO_BUF_REG)
-               ublk_set_auto_buf_reg(q, sqe[0], tag);
+               ublk_set_auto_buf_reg(q, sqe[0], io->tag);
 
-       user_data = build_user_data(tag, _IOC_NR(cmd_op), 0, q->q_id, 0);
+       user_data = build_user_data(io->tag, _IOC_NR(cmd_op), 0, q->q_id, 0);
        io_uring_sqe_set_data64(sqe[0], user_data);
 
        io->flags = 0;
 
-       q->cmd_inflight += 1;
+       t->cmd_inflight += 1;
 
-       ublk_dbg(UBLK_DBG_IO_CMD, "%s: (qid %d tag %u cmd_op %u) iof %x stopping %d\n",
-                       __func__, q->q_id, tag, cmd_op,
-                       io->flags, !!(q->state & UBLKSRV_QUEUE_STOPPING));
+       ublk_dbg(UBLK_DBG_IO_CMD, "%s: (thread %u qid %d tag %u cmd_op %u) iof %x stopping %d\n",
+                       __func__, t->idx, q->q_id, io->tag, cmd_op,
+                       io->flags, !!(t->state & UBLKSRV_THREAD_STOPPING));
        return 1;
 }
 
-static void ublk_submit_fetch_commands(struct ublk_queue *q)
+static void ublk_submit_fetch_commands(struct ublk_thread *t)
 {
+       /*
+        * Service exclusively the queue whose q_id matches our thread
+        * index. This may change in the future.
+        */
+       struct ublk_queue *q = &t->dev->q[t->idx];
+       struct ublk_io *io;
        int i = 0;
 
-       for (i = 0; i < q->q_depth; i++)
-               ublk_queue_io_cmd(q, &q->ios[i], i);
+       for (i = 0; i < q->q_depth; i++) {
+               io = &q->ios[i];
+               io->t = t;
+               ublk_queue_io_cmd(io);
+       }
 }
 
-static int ublk_queue_is_idle(struct ublk_queue *q)
+static int ublk_thread_is_idle(struct ublk_thread *t)
 {
-       return !io_uring_sq_ready(&q->ring) && !q->io_inflight;
+       return !io_uring_sq_ready(&t->ring) && !t->io_inflight;
 }
 
-static int ublk_queue_is_done(struct ublk_queue *q)
+static int ublk_thread_is_done(struct ublk_thread *t)
 {
-       return (q->state & UBLKSRV_QUEUE_STOPPING) && ublk_queue_is_idle(q);
+       return (t->state & UBLKSRV_THREAD_STOPPING) && ublk_thread_is_idle(t);
 }
 
 static inline void ublksrv_handle_tgt_cqe(struct ublk_queue *q,
@@ -692,15 +700,16 @@ static inline void ublksrv_handle_tgt_cqe(struct ublk_queue *q,
                q->tgt_ops->tgt_io_done(q, tag, cqe);
 }
 
-static void ublk_handle_cqe(struct ublk_dev *dev,
+static void ublk_handle_cqe(struct ublk_thread *t,
                struct io_uring_cqe *cqe, void *data)
 {
+       struct ublk_dev *dev = t->dev;
        unsigned q_id = user_data_to_q_id(cqe->user_data);
        struct ublk_queue *q = &dev->q[q_id];
        unsigned tag = user_data_to_tag(cqe->user_data);
        unsigned cmd_op = user_data_to_op(cqe->user_data);
        int fetch = (cqe->res != UBLK_IO_RES_ABORT) &&
-               !(q->state & UBLKSRV_QUEUE_STOPPING);
+               !(t->state & UBLKSRV_THREAD_STOPPING);
        struct ublk_io *io;
 
        if (cqe->res < 0 && cqe->res != -ENODEV)
@@ -711,7 +720,7 @@ static void ublk_handle_cqe(struct ublk_dev *dev,
                        __func__, cqe->res, q->q_id, tag, cmd_op,
                        is_target_io(cqe->user_data),
                        user_data_to_tgt_data(cqe->user_data),
-                       (q->state & UBLKSRV_QUEUE_STOPPING));
+                       (t->state & UBLKSRV_THREAD_STOPPING));
 
        /* Don't retrieve io in case of target io */
        if (is_target_io(cqe->user_data)) {
@@ -720,10 +729,10 @@ static void ublk_handle_cqe(struct ublk_dev *dev,
        }
 
        io = &q->ios[tag];
-       q->cmd_inflight--;
+       t->cmd_inflight--;
 
        if (!fetch) {
-               q->state |= UBLKSRV_QUEUE_STOPPING;
+               t->state |= UBLKSRV_THREAD_STOPPING;
                io->flags &= ~UBLKSRV_NEED_FETCH_RQ;
        }
 
@@ -733,7 +742,7 @@ static void ublk_handle_cqe(struct ublk_dev *dev,
                        q->tgt_ops->queue_io(q, tag);
        } else if (cqe->res == UBLK_IO_RES_NEED_GET_DATA) {
                io->flags |= UBLKSRV_NEED_GET_DATA | UBLKSRV_IO_FREE;
-               ublk_queue_io_cmd(q, io, tag);
+               ublk_queue_io_cmd(io);
        } else {
                /*
                 * COMMIT_REQ will be completed immediately since no fetching
@@ -747,87 +756,92 @@ static void ublk_handle_cqe(struct ublk_dev *dev,
        }
 }
 
-static int ublk_reap_events_uring(struct ublk_queue *q)
+static int ublk_reap_events_uring(struct ublk_thread *t)
 {
        struct io_uring_cqe *cqe;
        unsigned head;
        int count = 0;
 
-       io_uring_for_each_cqe(&q->ring, head, cqe) {
-               ublk_handle_cqe(q->dev, cqe, NULL);
+       io_uring_for_each_cqe(&t->ring, head, cqe) {
+               ublk_handle_cqe(t, cqe, NULL);
                count += 1;
        }
-       io_uring_cq_advance(&q->ring, count);
+       io_uring_cq_advance(&t->ring, count);
 
        return count;
 }
 
-static int ublk_process_io(struct ublk_queue *q)
+static int ublk_process_io(struct ublk_thread *t)
 {
        int ret, reapped;
 
-       ublk_dbg(UBLK_DBG_QUEUE, "dev%d-q%d: to_submit %d inflight cmd %u stopping %d\n",
-                               q->dev->dev_info.dev_id,
-                               q->q_id, io_uring_sq_ready(&q->ring),
-                               q->cmd_inflight,
-                               (q->state & UBLKSRV_QUEUE_STOPPING));
+       ublk_dbg(UBLK_DBG_THREAD, "dev%d-t%u: to_submit %d inflight cmd %u stopping %d\n",
+                               t->dev->dev_info.dev_id,
+                               t->idx, io_uring_sq_ready(&t->ring),
+                               t->cmd_inflight,
+                               (t->state & UBLKSRV_THREAD_STOPPING));
 
-       if (ublk_queue_is_done(q))
+       if (ublk_thread_is_done(t))
                return -ENODEV;
 
-       ret = io_uring_submit_and_wait(&q->ring, 1);
-       reapped = ublk_reap_events_uring(q);
+       ret = io_uring_submit_and_wait(&t->ring, 1);
+       reapped = ublk_reap_events_uring(t);
 
-       ublk_dbg(UBLK_DBG_QUEUE, "submit result %d, reapped %d stop %d idle %d\n",
-                       ret, reapped, (q->state & UBLKSRV_QUEUE_STOPPING),
-                       (q->state & UBLKSRV_QUEUE_IDLE));
+       ublk_dbg(UBLK_DBG_THREAD, "submit result %d, reapped %d stop %d idle %d\n",
+                       ret, reapped, (t->state & UBLKSRV_THREAD_STOPPING),
+                       (t->state & UBLKSRV_THREAD_IDLE));
 
        return reapped;
 }
 
-static void ublk_queue_set_sched_affinity(const struct ublk_queue *q,
+static void ublk_thread_set_sched_affinity(const struct ublk_thread *t,
                cpu_set_t *cpuset)
 {
         if (sched_setaffinity(0, sizeof(*cpuset), cpuset) < 0)
-                ublk_err("ublk dev %u queue %u set affinity failed",
-                                q->dev->dev_info.dev_id, q->q_id);
+               ublk_err("ublk dev %u thread %u set affinity failed",
+                               t->dev->dev_info.dev_id, t->idx);
 }
 
-struct ublk_queue_info {
-       struct ublk_queue       *q;
-       sem_t                   *queue_sem;
+struct ublk_thread_info {
+       struct ublk_dev         *dev;
+       unsigned                idx;
+       sem_t                   *ready;
        cpu_set_t               *affinity;
 };
 
 static void *ublk_io_handler_fn(void *data)
 {
-       struct ublk_queue_info *info = data;
-       struct ublk_queue *q = info->q;
-       int dev_id = q->dev->dev_info.dev_id;
+       struct ublk_thread_info *info = data;
+       struct ublk_thread *t = &info->dev->threads[info->idx];
+       int dev_id = info->dev->dev_info.dev_id;
        int ret;
 
-       ret = ublk_thread_init(q);
+       t->dev = info->dev;
+       t->idx = info->idx;
+
+       ret = ublk_thread_init(t);
        if (ret) {
-               ublk_err("ublk dev %d queue %d thread init failed\n",
-                               dev_id, q->q_id);
+               ublk_err("ublk dev %d thread %u init failed\n",
+                               dev_id, t->idx);
                return NULL;
        }
        /* IO perf is sensitive with queue pthread affinity on NUMA machine*/
-       ublk_queue_set_sched_affinity(q, info->affinity);
-       sem_post(info->queue_sem);
+       ublk_thread_set_sched_affinity(t, info->affinity);
+       sem_post(info->ready);
 
-       ublk_dbg(UBLK_DBG_QUEUE, "tid %d: ublk dev %d queue %d started\n",
-                       q->tid, dev_id, q->q_id);
+       ublk_dbg(UBLK_DBG_THREAD, "tid %d: ublk dev %d thread %u started\n",
+                       gettid(), dev_id, t->idx);
 
        /* submit all io commands to ublk driver */
-       ublk_submit_fetch_commands(q);
+       ublk_submit_fetch_commands(t);
        do {
-               if (ublk_process_io(q) < 0)
+               if (ublk_process_io(t) < 0)
                        break;
        } while (1);
 
-       ublk_dbg(UBLK_DBG_QUEUE, "ublk dev %d queue %d exited\n", dev_id, q->q_id);
-       ublk_thread_deinit(q);
+       ublk_dbg(UBLK_DBG_THREAD, "tid %d: ublk dev %d thread %d exiting\n",
+                gettid(), dev_id, t->idx);
+       ublk_thread_deinit(t);
        return NULL;
 }
 
@@ -870,21 +884,20 @@ static int ublk_send_dev_event(const struct dev_ctx *ctx, struct ublk_dev *dev,
 static int ublk_start_daemon(const struct dev_ctx *ctx, struct ublk_dev *dev)
 {
        const struct ublksrv_ctrl_dev_info *dinfo = &dev->dev_info;
-       struct ublk_queue_info *qinfo;
+       struct ublk_thread_info *tinfo;
        unsigned extra_flags = 0;
        cpu_set_t *affinity_buf;
        void *thread_ret;
-       sem_t queue_sem;
+       sem_t ready;
        int ret, i;
 
        ublk_dbg(UBLK_DBG_DEV, "%s enter\n", __func__);
 
-       qinfo = (struct ublk_queue_info *)calloc(sizeof(struct ublk_queue_info),
-                       dinfo->nr_hw_queues);
-       if (!qinfo)
+       tinfo = calloc(sizeof(struct ublk_thread_info), dinfo->nr_hw_queues);
+       if (!tinfo)
                return -ENOMEM;
 
-       sem_init(&queue_sem, 0, 0);
+       sem_init(&ready, 0, 0);
        ret = ublk_dev_prep(ctx, dev);
        if (ret)
                return ret;
@@ -907,17 +920,18 @@ static int ublk_start_daemon(const struct dev_ctx *ctx, struct ublk_dev *dev)
                        goto fail;
                }
 
-               qinfo[i].q = &dev->q[i];
-               qinfo[i].queue_sem = &queue_sem;
-               qinfo[i].affinity = &affinity_buf[i];
-               pthread_create(&dev->q[i].thread, NULL,
+               tinfo[i].dev = dev;
+               tinfo[i].idx = i;
+               tinfo[i].ready = &ready;
+               tinfo[i].affinity = &affinity_buf[i];
+               pthread_create(&dev->threads[i].thread, NULL,
                                ublk_io_handler_fn,
-                               &qinfo[i]);
+                               &tinfo[i]);
        }
 
        for (i = 0; i < dinfo->nr_hw_queues; i++)
-               sem_wait(&queue_sem);
-       free(qinfo);
+               sem_wait(&ready);
+       free(tinfo);
        free(affinity_buf);
 
        /* everything is fine now, start us */
@@ -940,7 +954,7 @@ static int ublk_start_daemon(const struct dev_ctx *ctx, struct ublk_dev *dev)
 
        /* wait until we are terminated */
        for (i = 0; i < dinfo->nr_hw_queues; i++)
-               pthread_join(dev->q[i].thread, &thread_ret);
+               pthread_join(dev->threads[i].thread, &thread_ret);
  fail:
        for (i = 0; i < dinfo->nr_hw_queues; i++)
                ublk_queue_deinit(&dev->q[i]);
index 64da26725fe1d840b4c61df38206fb3eecd06c22..3a2ae095bee18633acd5a9c923cfab2d14fe3bff 100644 (file)
 #define UBLK_IO_MAX_BYTES               (1 << 20)
 #define UBLK_MAX_QUEUES_SHIFT          5
 #define UBLK_MAX_QUEUES                 (1 << UBLK_MAX_QUEUES_SHIFT)
+#define UBLK_MAX_THREADS_SHIFT         5
+#define UBLK_MAX_THREADS               (1 << UBLK_MAX_THREADS_SHIFT)
 #define UBLK_QUEUE_DEPTH                1024
 
 #define UBLK_DBG_DEV            (1U << 0)
-#define UBLK_DBG_QUEUE          (1U << 1)
+#define UBLK_DBG_THREAD         (1U << 1)
 #define UBLK_DBG_IO_CMD         (1U << 2)
 #define UBLK_DBG_IO             (1U << 3)
 #define UBLK_DBG_CTRL_CMD       (1U << 4)
@@ -62,6 +64,7 @@
 
 struct ublk_dev;
 struct ublk_queue;
+struct ublk_thread;
 
 struct stripe_ctx {
        /* stripe */
@@ -130,6 +133,7 @@ struct ublk_io {
 
        unsigned short tgt_ios;
        void *private_data;
+       struct ublk_thread *t;
 };
 
 struct ublk_tgt_ops {
@@ -168,28 +172,37 @@ struct ublk_tgt {
 struct ublk_queue {
        int q_id;
        int q_depth;
-       unsigned int cmd_inflight;
-       unsigned int io_inflight;
        struct ublk_dev *dev;
        const struct ublk_tgt_ops *tgt_ops;
        struct ublksrv_io_desc *io_cmd_buf;
-       struct io_uring ring;
+
        struct ublk_io ios[UBLK_QUEUE_DEPTH];
-#define UBLKSRV_QUEUE_STOPPING (1U << 0)
-#define UBLKSRV_QUEUE_IDLE     (1U << 1)
 #define UBLKSRV_NO_BUF         (1U << 2)
 #define UBLKSRV_ZC             (1U << 3)
 #define UBLKSRV_AUTO_BUF_REG           (1U << 4)
 #define UBLKSRV_AUTO_BUF_REG_FALLBACK  (1U << 5)
        unsigned state;
-       pid_t tid;
+};
+
+struct ublk_thread {
+       struct ublk_dev *dev;
+       struct io_uring ring;
+       unsigned int cmd_inflight;
+       unsigned int io_inflight;
+
        pthread_t thread;
+       unsigned idx;
+
+#define UBLKSRV_THREAD_STOPPING        (1U << 0)
+#define UBLKSRV_THREAD_IDLE    (1U << 1)
+       unsigned state;
 };
 
 struct ublk_dev {
        struct ublk_tgt tgt;
        struct ublksrv_ctrl_dev_info  dev_info;
        struct ublk_queue q[UBLK_MAX_QUEUES];
+       struct ublk_thread threads[UBLK_MAX_THREADS];
 
        int fds[MAX_BACK_FILES + 1];    /* fds[0] points to /dev/ublkcN */
        int nr_fds;
@@ -214,7 +227,7 @@ struct ublk_dev {
 
 
 extern unsigned int ublk_dbg_mask;
-extern int ublk_queue_io_cmd(struct ublk_queue *q, struct ublk_io *io, unsigned tag);
+extern int ublk_queue_io_cmd(struct ublk_io *io);
 
 
 static inline int ublk_io_auto_zc_fallback(const struct ublksrv_io_desc *iod)
@@ -299,7 +312,7 @@ static inline struct ublk_queue *ublk_io_to_queue(const struct ublk_io *io)
 static inline int ublk_io_alloc_sqes(struct ublk_io *io,
                struct io_uring_sqe *sqes[], int nr_sqes)
 {
-       struct io_uring *ring = &ublk_io_to_queue(io)->ring;
+       struct io_uring *ring = &io->t->ring;
        unsigned left = io_uring_sq_space_left(ring);
        int i;
 
@@ -390,7 +403,7 @@ static inline int ublk_complete_io(struct ublk_queue *q, unsigned tag, int res)
 
        ublk_mark_io_done(io, res);
 
-       return ublk_queue_io_cmd(q, io, tag);
+       return ublk_queue_io_cmd(io);
 }
 
 static inline void ublk_queued_tgt_io(struct ublk_queue *q, unsigned tag, int queued)
@@ -400,7 +413,7 @@ static inline void ublk_queued_tgt_io(struct ublk_queue *q, unsigned tag, int qu
        else {
                struct ublk_io *io = ublk_get_io(q, tag);
 
-               q->io_inflight += queued;
+               io->t->io_inflight += queued;
                io->tgt_ios = queued;
                io->result = 0;
        }
@@ -410,7 +423,7 @@ static inline int ublk_completed_tgt_io(struct ublk_queue *q, unsigned tag)
 {
        struct ublk_io *io = ublk_get_io(q, tag);
 
-       q->io_inflight--;
+       io->t->io_inflight--;
 
        return --io->tgt_ios == 0;
 }