diff options
| -rw-r--r-- | drivers/nvme/host/core.c | 8 | ||||
| -rw-r--r-- | drivers/nvme/host/multipath.c | 130 | ||||
| -rw-r--r-- | drivers/nvme/host/nvme.h | 16 | ||||
| -rw-r--r-- | drivers/nvme/host/sysfs.c | 7 |
4 files changed, 147 insertions, 14 deletions
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index af871d268fcb..6d11f8b19633 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -3743,7 +3743,7 @@ static struct nvme_ns_head *nvme_find_ns_head(struct nvme_ctrl *ctrl, */ if (h->ns_id != nsid || !nvme_is_unique_nsid(ctrl, h)) continue; - if (!list_empty(&h->list) && nvme_tryget_ns_head(h)) + if (nvme_tryget_ns_head(h)) return h; } @@ -3987,7 +3987,8 @@ static int nvme_init_ns_head(struct nvme_ns *ns, struct nvme_ns_info *info) } } else { ret = -EINVAL; - if (!info->is_shared || !head->shared) { + if ((!info->is_shared || !head->shared) && + !list_empty(&head->list)) { dev_err(ctrl->device, "Duplicate unshared namespace %d\n", info->nsid); @@ -4191,7 +4192,8 @@ static void nvme_ns_remove(struct nvme_ns *ns) mutex_lock(&ns->ctrl->subsys->lock); list_del_rcu(&ns->siblings); if (list_empty(&ns->head->list)) { - list_del_init(&ns->head->entry); + if (!nvme_mpath_queue_if_no_path(ns->head)) + list_del_init(&ns->head->entry); last_path = true; } mutex_unlock(&ns->ctrl->subsys->lock); diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index 250f3da67cc9..2db326d6114f 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -442,7 +442,17 @@ static bool nvme_available_path(struct nvme_ns_head *head) break; } } - return false; + + /* + * If "head->delayed_removal_secs" is configured (i.e., non-zero), do + * not immediately fail I/O. Instead, requeue the I/O for the configured + * duration, anticipating that if there's a transient link failure then + * it may recover within this time window. This parameter is exported to + * userspace via sysfs, and its default value is zero. It is internally + * mapped to NVME_NSHEAD_QUEUE_IF_NO_PATH. When delayed_removal_secs is + * non-zero, this flag is set to true. When zero, the flag is cleared. + */ + return nvme_mpath_queue_if_no_path(head); } static void nvme_ns_head_submit_bio(struct bio *bio) @@ -617,6 +627,40 @@ static void nvme_requeue_work(struct work_struct *work) } } +static void nvme_remove_head(struct nvme_ns_head *head) +{ + if (test_and_clear_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) { + /* + * requeue I/O after NVME_NSHEAD_DISK_LIVE has been cleared + * to allow multipath to fail all I/O. + */ + kblockd_schedule_work(&head->requeue_work); + + nvme_cdev_del(&head->cdev, &head->cdev_device); + synchronize_srcu(&head->srcu); + del_gendisk(head->disk); + nvme_put_ns_head(head); + } +} + +static void nvme_remove_head_work(struct work_struct *work) +{ + struct nvme_ns_head *head = container_of(to_delayed_work(work), + struct nvme_ns_head, remove_work); + bool shutdown = false; + + mutex_lock(&head->subsys->lock); + if (list_empty(&head->list)) { + list_del_init(&head->entry); + shutdown = true; + } + mutex_unlock(&head->subsys->lock); + if (shutdown) + nvme_remove_head(head); + + module_put(THIS_MODULE); +} + int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head) { struct queue_limits lim; @@ -626,6 +670,8 @@ int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head) spin_lock_init(&head->requeue_lock); INIT_WORK(&head->requeue_work, nvme_requeue_work); INIT_WORK(&head->partition_scan_work, nvme_partition_scan_work); + INIT_DELAYED_WORK(&head->remove_work, nvme_remove_head_work); + head->delayed_removal_secs = 0; /* * Add a multipath node if the subsystems supports multiple controllers. @@ -659,6 +705,7 @@ int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head) set_bit(GD_SUPPRESS_PART_SCAN, &head->disk->state); sprintf(head->disk->disk_name, "nvme%dn%d", ctrl->subsys->instance, head->instance); + nvme_tryget_ns_head(head); return 0; } @@ -1015,6 +1062,49 @@ static ssize_t numa_nodes_show(struct device *dev, struct device_attribute *attr } DEVICE_ATTR_RO(numa_nodes); +static ssize_t delayed_removal_secs_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct gendisk *disk = dev_to_disk(dev); + struct nvme_ns_head *head = disk->private_data; + int ret; + + mutex_lock(&head->subsys->lock); + ret = sysfs_emit(buf, "%u\n", head->delayed_removal_secs); + mutex_unlock(&head->subsys->lock); + return ret; +} + +static ssize_t delayed_removal_secs_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + struct gendisk *disk = dev_to_disk(dev); + struct nvme_ns_head *head = disk->private_data; + unsigned int sec; + int ret; + + ret = kstrtouint(buf, 0, &sec); + if (ret < 0) + return ret; + + mutex_lock(&head->subsys->lock); + head->delayed_removal_secs = sec; + if (sec) + set_bit(NVME_NSHEAD_QUEUE_IF_NO_PATH, &head->flags); + else + clear_bit(NVME_NSHEAD_QUEUE_IF_NO_PATH, &head->flags); + mutex_unlock(&head->subsys->lock); + /* + * Ensure that update to NVME_NSHEAD_QUEUE_IF_NO_PATH is seen + * by its reader. + */ + synchronize_srcu(&head->srcu); + + return count; +} + +DEVICE_ATTR_RW(delayed_removal_secs); + static int nvme_lookup_ana_group_desc(struct nvme_ctrl *ctrl, struct nvme_ana_group_desc *desc, void *data) { @@ -1138,18 +1228,38 @@ void nvme_mpath_add_disk(struct nvme_ns *ns, __le32 anagrpid) void nvme_mpath_shutdown_disk(struct nvme_ns_head *head) { - if (!head->disk) - return; - if (test_and_clear_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) { - nvme_cdev_del(&head->cdev, &head->cdev_device); + bool shutdown = false; + + mutex_lock(&head->subsys->lock); + /* + * We are called when all paths have been removed, and at that point + * head->list is expected to be empty. However, nvme_remove_ns() and + * nvme_init_ns_head() can run concurrently and so if head->delayed_ + * removal_secs is configured, it is possible that by the time we reach + * this point, head->list may no longer be empty. Therefore, we recheck + * head->list here. If it is no longer empty then we skip enqueuing the + * delayed head removal work. + */ + if (!list_empty(&head->list)) + goto out; + + if (head->delayed_removal_secs) { /* - * requeue I/O after NVME_NSHEAD_DISK_LIVE has been cleared - * to allow multipath to fail all I/O. + * Ensure that no one could remove this module while the head + * remove work is pending. */ - synchronize_srcu(&head->srcu); - kblockd_schedule_work(&head->requeue_work); - del_gendisk(head->disk); + if (!try_module_get(THIS_MODULE)) + goto out; + queue_delayed_work(nvme_wq, &head->remove_work, + head->delayed_removal_secs * HZ); + } else { + list_del_init(&head->entry); + shutdown = true; } +out: + mutex_unlock(&head->subsys->lock); + if (shutdown) + nvme_remove_head(head); } void nvme_mpath_remove_disk(struct nvme_ns_head *head) diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h index 7aad581271c7..f20076f6f06a 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -506,7 +506,10 @@ struct nvme_ns_head { struct work_struct partition_scan_work; struct mutex lock; unsigned long flags; -#define NVME_NSHEAD_DISK_LIVE 0 + struct delayed_work remove_work; + unsigned int delayed_removal_secs; +#define NVME_NSHEAD_DISK_LIVE 0 +#define NVME_NSHEAD_QUEUE_IF_NO_PATH 1 struct nvme_ns __rcu *current_path[]; #endif }; @@ -989,12 +992,19 @@ extern struct device_attribute dev_attr_ana_grpid; extern struct device_attribute dev_attr_ana_state; extern struct device_attribute dev_attr_queue_depth; extern struct device_attribute dev_attr_numa_nodes; +extern struct device_attribute dev_attr_delayed_removal_secs; extern struct device_attribute subsys_attr_iopolicy; static inline bool nvme_disk_is_ns_head(struct gendisk *disk) { return disk->fops == &nvme_ns_head_ops; } +static inline bool nvme_mpath_queue_if_no_path(struct nvme_ns_head *head) +{ + if (test_bit(NVME_NSHEAD_QUEUE_IF_NO_PATH, &head->flags)) + return true; + return false; +} #else #define multipath false static inline bool nvme_ctrl_use_ana(struct nvme_ctrl *ctrl) @@ -1082,6 +1092,10 @@ static inline bool nvme_disk_is_ns_head(struct gendisk *disk) { return false; } +static inline bool nvme_mpath_queue_if_no_path(struct nvme_ns_head *head) +{ + return false; +} #endif /* CONFIG_NVME_MULTIPATH */ int nvme_ns_get_unique_id(struct nvme_ns *ns, u8 id[16], diff --git a/drivers/nvme/host/sysfs.c b/drivers/nvme/host/sysfs.c index 6d31226f7a4f..a48d30c31d51 100644 --- a/drivers/nvme/host/sysfs.c +++ b/drivers/nvme/host/sysfs.c @@ -260,6 +260,7 @@ static struct attribute *nvme_ns_attrs[] = { &dev_attr_ana_state.attr, &dev_attr_queue_depth.attr, &dev_attr_numa_nodes.attr, + &dev_attr_delayed_removal_secs.attr, #endif &dev_attr_io_passthru_err_log_enabled.attr, NULL, @@ -296,6 +297,12 @@ static umode_t nvme_ns_attrs_are_visible(struct kobject *kobj, if (nvme_disk_is_ns_head(dev_to_disk(dev))) return 0; } + if (a == &dev_attr_delayed_removal_secs.attr) { + struct gendisk *disk = dev_to_disk(dev); + + if (!nvme_disk_is_ns_head(disk)) + return 0; + } #endif return a->mode; } |