[PATCH 1/2] nvme: add 'fail_if_no_path' sysfs attribute
From: Hannes Reinecke <hare@suse.de>
Date: 2021-02-23 11:59:56
Subsystem:
nvm express driver, the rest · Maintainers:
Keith Busch, Jens Axboe, Christoph Hellwig, Sagi Grimberg, Linus Torvalds
In some setups like RAID or cluster we need to return an I/O error once all paths are unavailable to allow the upper layers to start their own error recovery (like redirecting I/O to other mirrors). This patch adds a sysfs attribute 'fail_if_no_path' to allow the admin to enable that behaviour instead of the current 'queue until a path becomes available' policy. Signed-off-by: Hannes Reinecke <hare@suse.de> --- drivers/nvme/host/core.c | 5 ++++ drivers/nvme/host/multipath.c | 43 +++++++++++++++++++++++++++++++++-- drivers/nvme/host/nvme.h | 2 ++ 3 files changed, 48 insertions(+), 2 deletions(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 4de6a3a13575..2fb3ecc0c53b 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c@@ -3464,6 +3464,7 @@ static struct attribute *nvme_ns_id_attrs[] = { #ifdef CONFIG_NVME_MULTIPATH &dev_attr_ana_grpid.attr, &dev_attr_ana_state.attr, + &dev_attr_fail_if_no_path.attr, #endif NULL, };
@@ -3494,6 +3495,10 @@ static umode_t nvme_ns_id_attrs_are_visible(struct kobject *kobj, if (!nvme_ctrl_use_ana(nvme_get_ns_from_dev(dev)->ctrl)) return 0; } + if (a == &dev_attr_fail_if_no_path.attr) { + if (dev_to_disk(dev)->fops == &nvme_bdev_ops) + return 0; + } #endif return a->mode; }
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 0696319adaf6..d5773ea105b1 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c@@ -283,10 +283,18 @@ static bool nvme_available_path(struct nvme_ns_head *head) continue; switch (ns->ctrl->state) { case NVME_CTRL_LIVE: + if (!test_bit(NVME_NSHEAD_FAIL_IF_NO_PATH, + &head->flags)) + return true; + if (ns->ana_state != NVME_ANA_INACCESSIBLE && + ns->ana_state != NVME_ANA_PERSISTENT_LOSS) + return true; case NVME_CTRL_RESETTING: - case NVME_CTRL_CONNECTING: /* fallthru */ - return true; + case NVME_CTRL_CONNECTING: + if (!test_bit(NVME_NSHEAD_FAIL_IF_NO_PATH, + &head->flags)) + return true; default: break; }
@@ -641,6 +649,37 @@ static ssize_t ana_state_show(struct device *dev, struct device_attribute *attr, } DEVICE_ATTR_RO(ana_state); +static ssize_t fail_if_no_path_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; + + return sprintf(buf, "%d\n", + test_bit(NVME_NSHEAD_FAIL_IF_NO_PATH, &head->flags) ? + 1 : 0); +} + +static ssize_t fail_if_no_path_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; + int fail_if_no_path, err; + + err = kstrtoint(buf, 10, &fail_if_no_path); + if (err) + return -EINVAL; + + if (fail_if_no_path <= 0) + clear_bit(NVME_NSHEAD_FAIL_IF_NO_PATH, &head->flags); + else + set_bit(NVME_NSHEAD_FAIL_IF_NO_PATH, &head->flags); + return count; +} +DEVICE_ATTR(fail_if_no_path, S_IRUGO | S_IWUSR, + fail_if_no_path_show, fail_if_no_path_store); + static int nvme_lookup_ana_group_desc(struct nvme_ctrl *ctrl, struct nvme_ana_group_desc *desc, void *data) {
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 07b34175c6ce..3d2513f8194d 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h@@ -418,6 +418,7 @@ struct nvme_ns_head { struct mutex lock; unsigned long flags; #define NVME_NSHEAD_DISK_LIVE 0 +#define NVME_NSHEAD_FAIL_IF_NO_PATH 1 struct nvme_ns __rcu *current_path[]; #endif };
@@ -694,6 +695,7 @@ static inline void nvme_trace_bio_complete(struct request *req) extern struct device_attribute dev_attr_ana_grpid; extern struct device_attribute dev_attr_ana_state; +extern struct device_attribute dev_attr_fail_if_no_path; extern struct device_attribute subsys_attr_iopolicy; #else
--
2.29.2
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