[PATCH AUTOSEL 6.6 31/47] nvme: ensure reset state check ordering

From: Keith Busch kbusch@kernel.org

[ Upstream commit e6e7f7ac03e40795346f1b2994a05f507ad8d345 ]

A different CPU may be setting the ctrl->state value, so ensure proper barriers to prevent optimizing to a stale state. Normally it isn't a problem to observe the wrong state as it is merely advisory to take a quicker path during initialization and error recovery, but seeing an old state can report unexpected ENETRESET errors when a reset request was in fact successful.

Reported-by: Minh Hoang mh2022@meta.com Reviewed-by: Sagi Grimberg sagi@grimberg.me Signed-off-by: Keith Busch kbusch@kernel.org Signed-off-by: Hannes Reinecke hare@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nvme/host/core.c | 42 +++++++++++++++++++++------------------- drivers/nvme/host/fc.c | 6 +++--- drivers/nvme/host/pci.c | 14 +++++++------- drivers/nvme/host/rdma.c | 23 +++++++++++++--------- drivers/nvme/host/tcp.c | 27 ++++++++++++++++---------- 5 files changed, 63 insertions(+), 49 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index c09048984a277..4e7bda7749caa 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -131,7 +131,7 @@ void nvme_queue_scan(struct nvme_ctrl *ctrl) /* * Only new queue scan work when admin and IO queues are both alive */ - if (ctrl->state == NVME_CTRL_LIVE && ctrl->tagset) + if (nvme_ctrl_state(ctrl) == NVME_CTRL_LIVE && ctrl->tagset) queue_work(nvme_wq, &ctrl->scan_work); }

@@ -143,7 +143,7 @@ void nvme_queue_scan(struct nvme_ctrl *ctrl) */ int nvme_try_sched_reset(struct nvme_ctrl *ctrl) { - if (ctrl->state != NVME_CTRL_RESETTING) + if (nvme_ctrl_state(ctrl) != NVME_CTRL_RESETTING) return -EBUSY; if (!queue_work(nvme_reset_wq, &ctrl->reset_work)) return -EBUSY; @@ -156,7 +156,7 @@ static void nvme_failfast_work(struct work_struct *work) struct nvme_ctrl *ctrl = container_of(to_delayed_work(work), struct nvme_ctrl, failfast_work);

- if (ctrl->state != NVME_CTRL_CONNECTING) + if (nvme_ctrl_state(ctrl) != NVME_CTRL_CONNECTING) return;

set_bit(NVME_CTRL_FAILFAST_EXPIRED, &ctrl->flags); @@ -200,7 +200,7 @@ int nvme_reset_ctrl_sync(struct nvme_ctrl *ctrl) ret = nvme_reset_ctrl(ctrl); if (!ret) { flush_work(&ctrl->reset_work); - if (ctrl->state != NVME_CTRL_LIVE) + if (nvme_ctrl_state(ctrl) != NVME_CTRL_LIVE) ret = -ENETRESET; }

@@ -499,7 +499,7 @@ bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl,

spin_lock_irqsave(&ctrl->lock, flags);

- old_state = ctrl->state; + old_state = nvme_ctrl_state(ctrl); switch (new_state) { case NVME_CTRL_LIVE: switch (old_state) { @@ -567,7 +567,7 @@ bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl, }

if (changed) { - ctrl->state = new_state; + WRITE_ONCE(ctrl->state, new_state); wake_up_all(&ctrl->state_wq); }

@@ -575,11 +575,11 @@ bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl, if (!changed) return false;

- if (ctrl->state == NVME_CTRL_LIVE) { + if (new_state == NVME_CTRL_LIVE) { if (old_state == NVME_CTRL_CONNECTING) nvme_stop_failfast_work(ctrl); nvme_kick_requeue_lists(ctrl); - } else if (ctrl->state == NVME_CTRL_CONNECTING && + } else if (new_state == NVME_CTRL_CONNECTING && old_state == NVME_CTRL_RESETTING) { nvme_start_failfast_work(ctrl); } @@ -592,7 +592,7 @@ EXPORT_SYMBOL_GPL(nvme_change_ctrl_state); */ static bool nvme_state_terminal(struct nvme_ctrl *ctrl) { - switch (ctrl->state) { + switch (nvme_ctrl_state(ctrl)) { case NVME_CTRL_NEW: case NVME_CTRL_LIVE: case NVME_CTRL_RESETTING: @@ -617,7 +617,7 @@ bool nvme_wait_reset(struct nvme_ctrl *ctrl) wait_event(ctrl->state_wq, nvme_change_ctrl_state(ctrl, NVME_CTRL_RESETTING) || nvme_state_terminal(ctrl)); - return ctrl->state == NVME_CTRL_RESETTING; + return nvme_ctrl_state(ctrl) == NVME_CTRL_RESETTING; } EXPORT_SYMBOL_GPL(nvme_wait_reset);

@@ -704,9 +704,11 @@ EXPORT_SYMBOL_GPL(nvme_init_request); blk_status_t nvme_fail_nonready_command(struct nvme_ctrl *ctrl, struct request *rq) { - if (ctrl->state != NVME_CTRL_DELETING_NOIO && - ctrl->state != NVME_CTRL_DELETING && - ctrl->state != NVME_CTRL_DEAD && + enum nvme_ctrl_state state = nvme_ctrl_state(ctrl); + + if (state != NVME_CTRL_DELETING_NOIO && + state != NVME_CTRL_DELETING && + state != NVME_CTRL_DEAD && !test_bit(NVME_CTRL_FAILFAST_EXPIRED, &ctrl->flags) && !blk_noretry_request(rq) && !(rq->cmd_flags & REQ_NVME_MPATH)) return BLK_STS_RESOURCE; @@ -736,7 +738,7 @@ bool __nvme_check_ready(struct nvme_ctrl *ctrl, struct request *rq, * command, which is require to set the queue live in the * appropinquate states. */ - switch (ctrl->state) { + switch (nvme_ctrl_state(ctrl)) { case NVME_CTRL_CONNECTING: if (blk_rq_is_passthrough(rq) && nvme_is_fabrics(req->cmd) && (req->cmd->fabrics.fctype == nvme_fabrics_type_connect || @@ -2531,7 +2533,7 @@ static void nvme_set_latency_tolerance(struct device *dev, s32 val)

if (ctrl->ps_max_latency_us != latency) { ctrl->ps_max_latency_us = latency; - if (ctrl->state == NVME_CTRL_LIVE) + if (nvme_ctrl_state(ctrl) == NVME_CTRL_LIVE) nvme_configure_apst(ctrl); } } @@ -3217,7 +3219,7 @@ static int nvme_dev_open(struct inode *inode, struct file *file) struct nvme_ctrl *ctrl = container_of(inode->i_cdev, struct nvme_ctrl, cdev);

- switch (ctrl->state) { + switch (nvme_ctrl_state(ctrl)) { case NVME_CTRL_LIVE: break; default: @@ -3903,7 +3905,7 @@ static void nvme_scan_work(struct work_struct *work) int ret;

/* No tagset on a live ctrl means IO queues could not created */ - if (ctrl->state != NVME_CTRL_LIVE || !ctrl->tagset) + if (nvme_ctrl_state(ctrl) != NVME_CTRL_LIVE || !ctrl->tagset) return;

/* @@ -3973,7 +3975,7 @@ void nvme_remove_namespaces(struct nvme_ctrl *ctrl) * removing the namespaces' disks; fail all the queues now to avoid * potentially having to clean up the failed sync later. */ - if (ctrl->state == NVME_CTRL_DEAD) + if (nvme_ctrl_state(ctrl) == NVME_CTRL_DEAD) nvme_mark_namespaces_dead(ctrl);

/* this is a no-op when called from the controller reset handler */ @@ -4055,7 +4057,7 @@ static void nvme_async_event_work(struct work_struct *work) * flushing ctrl async_event_work after changing the controller state * from LIVE and before freeing the admin queue. */ - if (ctrl->state == NVME_CTRL_LIVE) + if (nvme_ctrl_state(ctrl) == NVME_CTRL_LIVE) ctrl->ops->submit_async_event(ctrl); }

@@ -4439,7 +4441,7 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev, { int ret;

- ctrl->state = NVME_CTRL_NEW; + WRITE_ONCE(ctrl->state, NVME_CTRL_NEW); clear_bit(NVME_CTRL_FAILFAST_EXPIRED, &ctrl->flags); spin_lock_init(&ctrl->lock); mutex_init(&ctrl->scan_lock); diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c index a15b37750d6e9..8ba8d1393535f 100644 --- a/drivers/nvme/host/fc.c +++ b/drivers/nvme/host/fc.c @@ -557,7 +557,7 @@ nvme_fc_rport_get(struct nvme_fc_rport *rport) static void nvme_fc_resume_controller(struct nvme_fc_ctrl *ctrl) { - switch (ctrl->ctrl.state) { + switch (nvme_ctrl_state(&ctrl->ctrl)) { case NVME_CTRL_NEW: case NVME_CTRL_CONNECTING: /* @@ -793,7 +793,7 @@ nvme_fc_ctrl_connectivity_loss(struct nvme_fc_ctrl *ctrl) "NVME-FC{%d}: controller connectivity lost. Awaiting " "Reconnect", ctrl->cnum);

- switch (ctrl->ctrl.state) { + switch (nvme_ctrl_state(&ctrl->ctrl)) { case NVME_CTRL_NEW: case NVME_CTRL_LIVE: /* @@ -3316,7 +3316,7 @@ nvme_fc_reconnect_or_delete(struct nvme_fc_ctrl *ctrl, int status) unsigned long recon_delay = ctrl->ctrl.opts->reconnect_delay * HZ; bool recon = true;

- if (ctrl->ctrl.state != NVME_CTRL_CONNECTING) + if (nvme_ctrl_state(&ctrl->ctrl) != NVME_CTRL_CONNECTING) return;

if (portptr->port_state == FC_OBJSTATE_ONLINE) { diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 3f0c9ee09a12b..0b4ee3164e660 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -1234,7 +1234,7 @@ static bool nvme_should_reset(struct nvme_dev *dev, u32 csts) bool nssro = dev->subsystem && (csts & NVME_CSTS_NSSRO);

/* If there is a reset/reinit ongoing, we shouldn't reset again. */ - switch (dev->ctrl.state) { + switch (nvme_ctrl_state(&dev->ctrl)) { case NVME_CTRL_RESETTING: case NVME_CTRL_CONNECTING: return false; @@ -1322,7 +1322,7 @@ static enum blk_eh_timer_return nvme_timeout(struct request *req) * cancellation error. All outstanding requests are completed on * shutdown, so we return BLK_EH_DONE. */ - switch (dev->ctrl.state) { + switch (nvme_ctrl_state(&dev->ctrl)) { case NVME_CTRL_CONNECTING: nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_DELETING); fallthrough; @@ -1594,7 +1594,7 @@ static int nvme_setup_io_queues_trylock(struct nvme_dev *dev) /* * Controller is in wrong state, fail early. */ - if (dev->ctrl.state != NVME_CTRL_CONNECTING) { + if (nvme_ctrl_state(&dev->ctrl) != NVME_CTRL_CONNECTING) { mutex_unlock(&dev->shutdown_lock); return -ENODEV; } @@ -2574,13 +2574,13 @@ static bool nvme_pci_ctrl_is_dead(struct nvme_dev *dev)

static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown) { + enum nvme_ctrl_state state = nvme_ctrl_state(&dev->ctrl); struct pci_dev *pdev = to_pci_dev(dev->dev); bool dead;

mutex_lock(&dev->shutdown_lock); dead = nvme_pci_ctrl_is_dead(dev); - if (dev->ctrl.state == NVME_CTRL_LIVE || - dev->ctrl.state == NVME_CTRL_RESETTING) { + if (state == NVME_CTRL_LIVE || state == NVME_CTRL_RESETTING) { if (pci_is_enabled(pdev)) nvme_start_freeze(&dev->ctrl); /* @@ -2691,7 +2691,7 @@ static void nvme_reset_work(struct work_struct *work) bool was_suspend = !!(dev->ctrl.ctrl_config & NVME_CC_SHN_NORMAL); int result;

- if (dev->ctrl.state != NVME_CTRL_RESETTING) { + if (nvme_ctrl_state(&dev->ctrl) != NVME_CTRL_RESETTING) { dev_warn(dev->ctrl.device, "ctrl state %d is not RESETTING\n", dev->ctrl.state); result = -ENODEV; @@ -3193,7 +3193,7 @@ static int nvme_suspend(struct device *dev) nvme_wait_freeze(ctrl); nvme_sync_queues(ctrl);

- if (ctrl->state != NVME_CTRL_LIVE) + if (nvme_ctrl_state(ctrl) != NVME_CTRL_LIVE) goto unfreeze;

/* diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c index a7fea4cbacd75..c04317a966b38 100644 --- a/drivers/nvme/host/rdma.c +++ b/drivers/nvme/host/rdma.c @@ -984,10 +984,11 @@ static void nvme_rdma_free_ctrl(struct nvme_ctrl *nctrl)

static void nvme_rdma_reconnect_or_remove(struct nvme_rdma_ctrl *ctrl) { + enum nvme_ctrl_state state = nvme_ctrl_state(&ctrl->ctrl); + /* If we are resetting/deleting then do nothing */ - if (ctrl->ctrl.state != NVME_CTRL_CONNECTING) { - WARN_ON_ONCE(ctrl->ctrl.state == NVME_CTRL_NEW || - ctrl->ctrl.state == NVME_CTRL_LIVE); + if (state != NVME_CTRL_CONNECTING) { + WARN_ON_ONCE(state == NVME_CTRL_NEW || state == NVME_CTRL_LIVE); return; }

@@ -1059,8 +1060,10 @@ static int nvme_rdma_setup_ctrl(struct nvme_rdma_ctrl *ctrl, bool new) * unless we're during creation of a new controller to * avoid races with teardown flow. */ - WARN_ON_ONCE(ctrl->ctrl.state != NVME_CTRL_DELETING && - ctrl->ctrl.state != NVME_CTRL_DELETING_NOIO); + enum nvme_ctrl_state state = nvme_ctrl_state(&ctrl->ctrl); + + WARN_ON_ONCE(state != NVME_CTRL_DELETING && + state != NVME_CTRL_DELETING_NOIO); WARN_ON_ONCE(new); ret = -EINVAL; goto destroy_io; @@ -1128,8 +1131,10 @@ static void nvme_rdma_error_recovery_work(struct work_struct *work)

if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING)) { /* state change failure is ok if we started ctrl delete */ - WARN_ON_ONCE(ctrl->ctrl.state != NVME_CTRL_DELETING && - ctrl->ctrl.state != NVME_CTRL_DELETING_NOIO); + enum nvme_ctrl_state state = nvme_ctrl_state(&ctrl->ctrl); + + WARN_ON_ONCE(state != NVME_CTRL_DELETING && + state != NVME_CTRL_DELETING_NOIO); return; }

@@ -1161,7 +1166,7 @@ static void nvme_rdma_wr_error(struct ib_cq *cq, struct ib_wc *wc, struct nvme_rdma_queue *queue = wc->qp->qp_context; struct nvme_rdma_ctrl *ctrl = queue->ctrl;

- if (ctrl->ctrl.state == NVME_CTRL_LIVE) + if (nvme_ctrl_state(&ctrl->ctrl) == NVME_CTRL_LIVE) dev_info(ctrl->ctrl.device, "%s for CQE 0x%p failed with status %s (%d)\n", op, wc->wr_cqe, @@ -1944,7 +1949,7 @@ static enum blk_eh_timer_return nvme_rdma_timeout(struct request *rq) dev_warn(ctrl->ctrl.device, "I/O %d QID %d timeout\n", rq->tag, nvme_rdma_queue_idx(queue));

- if (ctrl->ctrl.state != NVME_CTRL_LIVE) { + if (nvme_ctrl_state(&ctrl->ctrl) != NVME_CTRL_LIVE) { /* * If we are resetting, connecting or deleting we should * complete immediately because we may block controller diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index 5b332d9f87fc3..f1d62d74426f0 100644 --- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -1993,10 +1993,11 @@ static void nvme_tcp_teardown_io_queues(struct nvme_ctrl *ctrl,

static void nvme_tcp_reconnect_or_remove(struct nvme_ctrl *ctrl) { + enum nvme_ctrl_state state = nvme_ctrl_state(ctrl); + /* If we are resetting/deleting then do nothing */ - if (ctrl->state != NVME_CTRL_CONNECTING) { - WARN_ON_ONCE(ctrl->state == NVME_CTRL_NEW || - ctrl->state == NVME_CTRL_LIVE); + if (state != NVME_CTRL_CONNECTING) { + WARN_ON_ONCE(state == NVME_CTRL_NEW || state == NVME_CTRL_LIVE); return; }

@@ -2056,8 +2057,10 @@ static int nvme_tcp_setup_ctrl(struct nvme_ctrl *ctrl, bool new) * unless we're during creation of a new controller to * avoid races with teardown flow. */ - WARN_ON_ONCE(ctrl->state != NVME_CTRL_DELETING && - ctrl->state != NVME_CTRL_DELETING_NOIO); + enum nvme_ctrl_state state = nvme_ctrl_state(ctrl); + + WARN_ON_ONCE(state != NVME_CTRL_DELETING && + state != NVME_CTRL_DELETING_NOIO); WARN_ON_ONCE(new); ret = -EINVAL; goto destroy_io; @@ -2124,8 +2127,10 @@ static void nvme_tcp_error_recovery_work(struct work_struct *work)

if (!nvme_change_ctrl_state(ctrl, NVME_CTRL_CONNECTING)) { /* state change failure is ok if we started ctrl delete */ - WARN_ON_ONCE(ctrl->state != NVME_CTRL_DELETING && - ctrl->state != NVME_CTRL_DELETING_NOIO); + enum nvme_ctrl_state state = nvme_ctrl_state(ctrl); + + WARN_ON_ONCE(state != NVME_CTRL_DELETING && + state != NVME_CTRL_DELETING_NOIO); return; }

@@ -2155,8 +2160,10 @@ static void nvme_reset_ctrl_work(struct work_struct *work)

if (!nvme_change_ctrl_state(ctrl, NVME_CTRL_CONNECTING)) { /* state change failure is ok if we started ctrl delete */ - WARN_ON_ONCE(ctrl->state != NVME_CTRL_DELETING && - ctrl->state != NVME_CTRL_DELETING_NOIO); + enum nvme_ctrl_state state = nvme_ctrl_state(ctrl); + + WARN_ON_ONCE(state != NVME_CTRL_DELETING && + state != NVME_CTRL_DELETING_NOIO); return; }

@@ -2274,7 +2281,7 @@ static enum blk_eh_timer_return nvme_tcp_timeout(struct request *rq) nvme_tcp_queue_id(req->queue), nvme_cid(rq), pdu->hdr.type, opc, nvme_opcode_str(qid, opc, fctype));

- if (ctrl->state != NVME_CTRL_LIVE) { + if (nvme_ctrl_state(ctrl) != NVME_CTRL_LIVE) { /* * If we are resetting, connecting or deleting we should * complete immediately because we may block controller