[PATCH AUTOSEL 5.16 21/30] nvmet: use a private workqueue instead of the system workqueue

From: Sasha Levin
Date: Wed Apr 06 2022 - 21:32:01 EST

From: Sagi Grimberg <sagi@xxxxxxxxxxx>

[ Upstream commit 8832cf922151e9dfa2821736beb0ae2dd3968b6e ]

Any attempt to flush kernel-global WQs has possibility of deadlock
so we should simply stop using them, instead introduce nvmet_wq
which is the generic nvmet workqueue for work elements that
don't explicitly require a dedicated workqueue (by the mere fact
that they are using the system_wq).

Changes were done using the following replaces:

- s/schedule_work(/queue_work(nvmet_wq, /g
- s/schedule_delayed_work(/queue_delayed_work(nvmet_wq, /g
- s/flush_scheduled_work()/flush_workqueue(nvmet_wq)/g

Reported-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sagi Grimberg <sagi@xxxxxxxxxxx>
Reviewed-by: Chaitanya Kulkarni <kch@xxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/nvme/target/admin-cmd.c | 2 +-
drivers/nvme/target/configfs.c | 2 +-
drivers/nvme/target/core.c | 24 ++++++++++++++++++------
drivers/nvme/target/fc.c | 8 ++++----
drivers/nvme/target/fcloop.c | 16 ++++++++--------
drivers/nvme/target/io-cmd-file.c | 6 +++---
drivers/nvme/target/loop.c | 4 ++--
drivers/nvme/target/nvmet.h | 1 +
drivers/nvme/target/passthru.c | 2 +-
drivers/nvme/target/rdma.c | 12 ++++++------
drivers/nvme/target/tcp.c | 10 +++++-----
11 files changed, 50 insertions(+), 37 deletions(-)

diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index 6fb24746de06..c3a9df5545cf 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -984,7 +984,7 @@ void nvmet_execute_async_event(struct nvmet_req *req)
ctrl->async_event_cmds[ctrl->nr_async_event_cmds++] = req;
mutex_unlock(&ctrl->lock);

- schedule_work(&ctrl->async_event_work);
+ queue_work(nvmet_wq, &ctrl->async_event_work);
}

void nvmet_execute_keep_alive(struct nvmet_req *req)
diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index 496d775c6770..cea30e4f5053 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -1554,7 +1554,7 @@ static void nvmet_port_release(struct config_item *item)
struct nvmet_port *port = to_nvmet_port(item);

/* Let inflight controllers teardown complete */
- flush_scheduled_work();
+ flush_workqueue(nvmet_wq);
list_del(&port->global_entry);

kfree(port->ana_state);
diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 626caf6f1e4b..1c026a21f218 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -20,6 +20,9 @@ struct workqueue_struct *zbd_wq;
static const struct nvmet_fabrics_ops *nvmet_transports[NVMF_TRTYPE_MAX];
static DEFINE_IDA(cntlid_ida);

+struct workqueue_struct *nvmet_wq;
+EXPORT_SYMBOL_GPL(nvmet_wq);
+
/*
* This read/write semaphore is used to synchronize access to configuration
* information on a target system that will result in discovery log page
@@ -205,7 +208,7 @@ void nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
list_add_tail(&aen->entry, &ctrl->async_events);
mutex_unlock(&ctrl->lock);

- schedule_work(&ctrl->async_event_work);
+ queue_work(nvmet_wq, &ctrl->async_event_work);
}

static void nvmet_add_to_changed_ns_log(struct nvmet_ctrl *ctrl, __le32 nsid)
@@ -385,7 +388,7 @@ static void nvmet_keep_alive_timer(struct work_struct *work)
if (reset_tbkas) {
pr_debug("ctrl %d reschedule traffic based keep-alive timer\n",
ctrl->cntlid);
- schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ);
+ queue_delayed_work(nvmet_wq, &ctrl->ka_work, ctrl->kato * HZ);
return;
}

@@ -403,7 +406,7 @@ void nvmet_start_keep_alive_timer(struct nvmet_ctrl *ctrl)
pr_debug("ctrl %d start keep-alive timer for %d secs\n",
ctrl->cntlid, ctrl->kato);

- schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ);
+ queue_delayed_work(nvmet_wq, &ctrl->ka_work, ctrl->kato * HZ);
}

void nvmet_stop_keep_alive_timer(struct nvmet_ctrl *ctrl)
@@ -1479,7 +1482,7 @@ void nvmet_ctrl_fatal_error(struct nvmet_ctrl *ctrl)
mutex_lock(&ctrl->lock);
if (!(ctrl->csts & NVME_CSTS_CFS)) {
ctrl->csts |= NVME_CSTS_CFS;
- schedule_work(&ctrl->fatal_err_work);
+ queue_work(nvmet_wq, &ctrl->fatal_err_work);
}
mutex_unlock(&ctrl->lock);
}
@@ -1620,9 +1623,15 @@ static int __init nvmet_init(void)
goto out_free_zbd_work_queue;
}

+ nvmet_wq = alloc_workqueue("nvmet-wq", WQ_MEM_RECLAIM, 0);
+ if (!nvmet_wq) {
+ error = -ENOMEM;
+ goto out_free_buffered_work_queue;
+ }
+
error = nvmet_init_discovery();
if (error)
- goto out_free_work_queue;
+ goto out_free_nvmet_work_queue;

error = nvmet_init_configfs();
if (error)
@@ -1631,7 +1640,9 @@ static int __init nvmet_init(void)

out_exit_discovery:
nvmet_exit_discovery();
-out_free_work_queue:
+out_free_nvmet_work_queue:
+ destroy_workqueue(nvmet_wq);
+out_free_buffered_work_queue:
destroy_workqueue(buffered_io_wq);
out_free_zbd_work_queue:
destroy_workqueue(zbd_wq);
@@ -1643,6 +1654,7 @@ static void __exit nvmet_exit(void)
nvmet_exit_configfs();
nvmet_exit_discovery();
ida_destroy(&cntlid_ida);
+ destroy_workqueue(nvmet_wq);
destroy_workqueue(buffered_io_wq);
destroy_workqueue(zbd_wq);

diff --git a/drivers/nvme/target/fc.c b/drivers/nvme/target/fc.c
index 22b5108168a6..c43bc5e1c7a2 100644
--- a/drivers/nvme/target/fc.c
+++ b/drivers/nvme/target/fc.c
@@ -1491,7 +1491,7 @@ __nvmet_fc_free_assocs(struct nvmet_fc_tgtport *tgtport)
list_for_each_entry_rcu(assoc, &tgtport->assoc_list, a_list) {
if (!nvmet_fc_tgt_a_get(assoc))
continue;
- if (!schedule_work(&assoc->del_work))
+ if (!queue_work(nvmet_wq, &assoc->del_work))
/* already deleting - release local reference */
nvmet_fc_tgt_a_put(assoc);
}
@@ -1546,7 +1546,7 @@ nvmet_fc_invalidate_host(struct nvmet_fc_target_port *target_port,
continue;
assoc->hostport->invalid = 1;
noassoc = false;
- if (!schedule_work(&assoc->del_work))
+ if (!queue_work(nvmet_wq, &assoc->del_work))
/* already deleting - release local reference */
nvmet_fc_tgt_a_put(assoc);
}
@@ -1592,7 +1592,7 @@ nvmet_fc_delete_ctrl(struct nvmet_ctrl *ctrl)
nvmet_fc_tgtport_put(tgtport);

if (found_ctrl) {
- if (!schedule_work(&assoc->del_work))
+ if (!queue_work(nvmet_wq, &assoc->del_work))
/* already deleting - release local reference */
nvmet_fc_tgt_a_put(assoc);
return;
@@ -2060,7 +2060,7 @@ nvmet_fc_rcv_ls_req(struct nvmet_fc_target_port *target_port,
iod->rqstdatalen = lsreqbuf_len;
iod->hosthandle = hosthandle;

- schedule_work(&iod->work);
+ queue_work(nvmet_wq, &iod->work);

return 0;
}
diff --git a/drivers/nvme/target/fcloop.c b/drivers/nvme/target/fcloop.c
index 54606f1872b4..5c16372f3b53 100644
--- a/drivers/nvme/target/fcloop.c
+++ b/drivers/nvme/target/fcloop.c
@@ -360,7 +360,7 @@ fcloop_h2t_ls_req(struct nvme_fc_local_port *localport,
spin_lock(&rport->lock);
list_add_tail(&rport->ls_list, &tls_req->ls_list);
spin_unlock(&rport->lock);
- schedule_work(&rport->ls_work);
+ queue_work(nvmet_wq, &rport->ls_work);
return ret;
}

@@ -393,7 +393,7 @@ fcloop_h2t_xmt_ls_rsp(struct nvmet_fc_target_port *targetport,
spin_lock(&rport->lock);
list_add_tail(&rport->ls_list, &tls_req->ls_list);
spin_unlock(&rport->lock);
- schedule_work(&rport->ls_work);
+ queue_work(nvmet_wq, &rport->ls_work);
}

return 0;
@@ -448,7 +448,7 @@ fcloop_t2h_ls_req(struct nvmet_fc_target_port *targetport, void *hosthandle,
spin_lock(&tport->lock);
list_add_tail(&tport->ls_list, &tls_req->ls_list);
spin_unlock(&tport->lock);
- schedule_work(&tport->ls_work);
+ queue_work(nvmet_wq, &tport->ls_work);
return ret;
}

@@ -480,7 +480,7 @@ fcloop_t2h_xmt_ls_rsp(struct nvme_fc_local_port *localport,
spin_lock(&tport->lock);
list_add_tail(&tport->ls_list, &tls_req->ls_list);
spin_unlock(&tport->lock);
- schedule_work(&tport->ls_work);
+ queue_work(nvmet_wq, &tport->ls_work);
}

return 0;
@@ -520,7 +520,7 @@ fcloop_tgt_discovery_evt(struct nvmet_fc_target_port *tgtport)
tgt_rscn->tport = tgtport->private;
INIT_WORK(&tgt_rscn->work, fcloop_tgt_rscn_work);

- schedule_work(&tgt_rscn->work);
+ queue_work(nvmet_wq, &tgt_rscn->work);
}

static void
@@ -739,7 +739,7 @@ fcloop_fcp_req(struct nvme_fc_local_port *localport,
INIT_WORK(&tfcp_req->tio_done_work, fcloop_tgt_fcprqst_done_work);
kref_init(&tfcp_req->ref);

- schedule_work(&tfcp_req->fcp_rcv_work);
+ queue_work(nvmet_wq, &tfcp_req->fcp_rcv_work);

return 0;
}
@@ -921,7 +921,7 @@ fcloop_fcp_req_release(struct nvmet_fc_target_port *tgtport,
{
struct fcloop_fcpreq *tfcp_req = tgt_fcp_req_to_fcpreq(tgt_fcpreq);

- schedule_work(&tfcp_req->tio_done_work);
+ queue_work(nvmet_wq, &tfcp_req->tio_done_work);
}

static void
@@ -976,7 +976,7 @@ fcloop_fcp_abort(struct nvme_fc_local_port *localport,

if (abortio)
/* leave the reference while the work item is scheduled */
- WARN_ON(!schedule_work(&tfcp_req->abort_rcv_work));
+ WARN_ON(!queue_work(nvmet_wq, &tfcp_req->abort_rcv_work));
else {
/*
* as the io has already had the done callback made,
diff --git a/drivers/nvme/target/io-cmd-file.c b/drivers/nvme/target/io-cmd-file.c
index 6be6e59d273b..80f079a7015d 100644
--- a/drivers/nvme/target/io-cmd-file.c
+++ b/drivers/nvme/target/io-cmd-file.c
@@ -292,7 +292,7 @@ static void nvmet_file_execute_flush(struct nvmet_req *req)
if (!nvmet_check_transfer_len(req, 0))
return;
INIT_WORK(&req->f.work, nvmet_file_flush_work);
- schedule_work(&req->f.work);
+ queue_work(nvmet_wq, &req->f.work);
}

static void nvmet_file_execute_discard(struct nvmet_req *req)
@@ -352,7 +352,7 @@ static void nvmet_file_execute_dsm(struct nvmet_req *req)
if (!nvmet_check_data_len_lte(req, nvmet_dsm_len(req)))
return;
INIT_WORK(&req->f.work, nvmet_file_dsm_work);
- schedule_work(&req->f.work);
+ queue_work(nvmet_wq, &req->f.work);
}

static void nvmet_file_write_zeroes_work(struct work_struct *w)
@@ -382,7 +382,7 @@ static void nvmet_file_execute_write_zeroes(struct nvmet_req *req)
if (!nvmet_check_transfer_len(req, 0))
return;
INIT_WORK(&req->f.work, nvmet_file_write_zeroes_work);
- schedule_work(&req->f.work);
+ queue_work(nvmet_wq, &req->f.work);
}

u16 nvmet_file_parse_io_cmd(struct nvmet_req *req)
diff --git a/drivers/nvme/target/loop.c b/drivers/nvme/target/loop.c
index eb1094254c82..2a968eeddda3 100644
--- a/drivers/nvme/target/loop.c
+++ b/drivers/nvme/target/loop.c
@@ -166,7 +166,7 @@ static blk_status_t nvme_loop_queue_rq(struct blk_mq_hw_ctx *hctx,
iod->req.transfer_len = blk_rq_payload_bytes(req);
}

- schedule_work(&iod->work);
+ queue_work(nvmet_wq, &iod->work);
return BLK_STS_OK;
}

@@ -187,7 +187,7 @@ static void nvme_loop_submit_async_event(struct nvme_ctrl *arg)
return;
}

- schedule_work(&iod->work);
+ queue_work(nvmet_wq, &iod->work);
}

static int nvme_loop_init_iod(struct nvme_loop_ctrl *ctrl,
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index af193423c10b..ff26dbde8c1e 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -366,6 +366,7 @@ struct nvmet_req {

extern struct workqueue_struct *buffered_io_wq;
extern struct workqueue_struct *zbd_wq;
+extern struct workqueue_struct *nvmet_wq;

static inline void nvmet_set_result(struct nvmet_req *req, u32 result)
{
diff --git a/drivers/nvme/target/passthru.c b/drivers/nvme/target/passthru.c
index f0efb3537989..6220e1dd961a 100644
--- a/drivers/nvme/target/passthru.c
+++ b/drivers/nvme/target/passthru.c
@@ -281,7 +281,7 @@ static void nvmet_passthru_execute_cmd(struct nvmet_req *req)
if (req->p.use_workqueue || effects) {
INIT_WORK(&req->p.work, nvmet_passthru_execute_cmd_work);
req->p.rq = rq;
- schedule_work(&req->p.work);
+ queue_work(nvmet_wq, &req->p.work);
} else {
rq->end_io_data = req;
blk_execute_rq_nowait(ns ? ns->disk : NULL, rq, 0,
diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c
index 1deb4043e242..0ebfe2191165 100644
--- a/drivers/nvme/target/rdma.c
+++ b/drivers/nvme/target/rdma.c
@@ -1584,7 +1584,7 @@ static int nvmet_rdma_queue_connect(struct rdma_cm_id *cm_id,

if (queue->host_qid == 0) {
/* Let inflight controller teardown complete */
- flush_scheduled_work();
+ flush_workqueue(nvmet_wq);
}

ret = nvmet_rdma_cm_accept(cm_id, queue, &event->param.conn);
@@ -1669,7 +1669,7 @@ static void __nvmet_rdma_queue_disconnect(struct nvmet_rdma_queue *queue)

if (disconnect) {
rdma_disconnect(queue->cm_id);
- schedule_work(&queue->release_work);
+ queue_work(nvmet_wq, &queue->release_work);
}
}

@@ -1699,7 +1699,7 @@ static void nvmet_rdma_queue_connect_fail(struct rdma_cm_id *cm_id,
mutex_unlock(&nvmet_rdma_queue_mutex);

pr_err("failed to connect queue %d\n", queue->idx);
- schedule_work(&queue->release_work);
+ queue_work(nvmet_wq, &queue->release_work);
}

/**
@@ -1773,7 +1773,7 @@ static int nvmet_rdma_cm_handler(struct rdma_cm_id *cm_id,
if (!queue) {
struct nvmet_rdma_port *port = cm_id->context;

- schedule_delayed_work(&port->repair_work, 0);
+ queue_delayed_work(nvmet_wq, &port->repair_work, 0);
break;
}
fallthrough;
@@ -1903,7 +1903,7 @@ static void nvmet_rdma_repair_port_work(struct work_struct *w)
nvmet_rdma_disable_port(port);
ret = nvmet_rdma_enable_port(port);
if (ret)
- schedule_delayed_work(&port->repair_work, 5 * HZ);
+ queue_delayed_work(nvmet_wq, &port->repair_work, 5 * HZ);
}

static int nvmet_rdma_add_port(struct nvmet_port *nport)
@@ -2053,7 +2053,7 @@ static void nvmet_rdma_remove_one(struct ib_device *ib_device, void *client_data
}
mutex_unlock(&nvmet_rdma_queue_mutex);

- flush_scheduled_work();
+ flush_workqueue(nvmet_wq);
}

static struct ib_client nvmet_rdma_ib_client = {
diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index 7c1c43ce466b..31bab7477d53 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -1269,7 +1269,7 @@ static void nvmet_tcp_schedule_release_queue(struct nvmet_tcp_queue *queue)
spin_lock(&queue->state_lock);
if (queue->state != NVMET_TCP_Q_DISCONNECTING) {
queue->state = NVMET_TCP_Q_DISCONNECTING;
- schedule_work(&queue->release_work);
+ queue_work(nvmet_wq, &queue->release_work);
}
spin_unlock(&queue->state_lock);
}
@@ -1684,7 +1684,7 @@ static void nvmet_tcp_listen_data_ready(struct sock *sk)
goto out;

if (sk->sk_state == TCP_LISTEN)
- schedule_work(&port->accept_work);
+ queue_work(nvmet_wq, &port->accept_work);
out:
read_unlock_bh(&sk->sk_callback_lock);
}
@@ -1815,7 +1815,7 @@ static u16 nvmet_tcp_install_queue(struct nvmet_sq *sq)

if (sq->qid == 0) {
/* Let inflight controller teardown complete */
- flush_scheduled_work();
+ flush_workqueue(nvmet_wq);
}

queue->nr_cmds = sq->size * 2;
@@ -1876,12 +1876,12 @@ static void __exit nvmet_tcp_exit(void)

nvmet_unregister_transport(&nvmet_tcp_ops);

- flush_scheduled_work();
+ flush_workqueue(nvmet_wq);
mutex_lock(&nvmet_tcp_queue_mutex);
list_for_each_entry(queue, &nvmet_tcp_queue_list, queue_list)
kernel_sock_shutdown(queue->sock, SHUT_RDWR);
mutex_unlock(&nvmet_tcp_queue_mutex);
- flush_scheduled_work();
+ flush_workqueue(nvmet_wq);

destroy_workqueue(nvmet_tcp_wq);
}
--
2.35.1