Messages in this thread Patch in this message | | | Subject | Re: [PATCH 2/2] nvme-core: Fix deadlock when deleting the ctrl while scanning | From | Sagi Grimberg <> | Date | Thu, 18 Jul 2019 17:31:00 -0700 |
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> [1]: Or actually: -- diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 76cd3dd8736a..a0e2072fe73e 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -3576,6 +3576,12 @@ void nvme_remove_namespaces(struct nvme_ctrl *ctrl) struct nvme_ns *ns, *next; LIST_HEAD(ns_list);
+ mutex_lock(&ctrl->scan_lock); + list_for_each_entry(ns, &ctrl->namespaces, list) + if (nvme_mpath_clear_current_path(ns)) + kblockd_schedule_work(&ns->head->requeue_work); + mutex_lock(&ctrl->scan_lock); + /* prevent racing with ns scanning */ flush_work(&ctrl->scan_work);
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index a9a927677970..0e7e41381388 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -109,18 +109,22 @@ static const char *nvme_ana_state_names[] = { [NVME_ANA_CHANGE] = "change", };
-void nvme_mpath_clear_current_path(struct nvme_ns *ns) +bool nvme_mpath_clear_current_path(struct nvme_ns *ns) { struct nvme_ns_head *head = ns->head; + bool changed = false; int node;
if (!head) - return; + return changed;
for_each_node(node) { - if (ns == rcu_access_pointer(head->current_path[node])) + if (ns == rcu_access_pointer(head->current_path[node])) { rcu_assign_pointer(head->current_path[node], NULL); + changed = true; + } } + return changed; }
static bool nvme_path_is_disabled(struct nvme_ns *ns) @@ -231,6 +235,24 @@ inline struct nvme_ns *nvme_find_path(struct nvme_ns_head *head) return ns; }
+static bool nvme_available_path(struct nvme_ns_head *head) +{ + struct nvme_ns *ns; + + list_for_each_entry_rcu(ns, &head->list, siblings) { + switch (ns->ctrl->state) { + case NVME_CTRL_LIVE: + case NVME_CTRL_RESETTING: + case NVME_CTRL_CONNECTING: + /* fallthru */ + return true; + default: + break; + } + } + return false; +} + static blk_qc_t nvme_ns_head_make_request(struct request_queue *q, struct bio *bio) { @@ -257,14 +279,14 @@ static blk_qc_t nvme_ns_head_make_request(struct request_queue *q, disk_devt(ns->head->disk), bio->bi_iter.bi_sector); ret = direct_make_request(bio); - } else if (!list_empty_careful(&head->list)) { - dev_warn_ratelimited(dev, "no path available - requeuing I/O\n"); + } else if (nvme_available_path(head)) { + dev_warn_ratelimited(dev, "no usable path - requeuing I/O\n");
spin_lock_irq(&head->requeue_lock); bio_list_add(&head->requeue_list, bio); spin_unlock_irq(&head->requeue_lock); } else { - dev_warn_ratelimited(dev, "no path - failing I/O\n"); + dev_warn_ratelimited(dev, "no available path - failing I/O\n");
bio->bi_status = BLK_STS_IOERR; bio_endio(bio); diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h index 716a876119c8..915179368d30 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -496,7 +496,7 @@ void nvme_mpath_remove_disk(struct nvme_ns_head *head); int nvme_mpath_init(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id); void nvme_mpath_uninit(struct nvme_ctrl *ctrl); void nvme_mpath_stop(struct nvme_ctrl *ctrl); -void nvme_mpath_clear_current_path(struct nvme_ns *ns); +bool nvme_mpath_clear_current_path(struct nvme_ns *ns); struct nvme_ns *nvme_find_path(struct nvme_ns_head *head);
static inline void nvme_mpath_check_last_path(struct nvme_ns *ns) --
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