* [PATCH v2] nvme: invalidate paths during rescan
@ 2021-07-30 7:10 Daniel Wagner
2021-08-11 1:18 ` Sagi Grimberg
0 siblings, 1 reply; 3+ messages in thread
From: Daniel Wagner @ 2021-07-30 7:10 UTC (permalink / raw)
To: linux-nvme; +Cc: Hannes Reinecke, Daniel Wagner
From: Hannes Reinecke <hare@suse.de>
When triggering a rescan due to a namespace resize we will be
receiving AENs on every controller, triggering a rescan of all
attached namespaces. If multipath is active only the current path and
the ns_head disk will be updated, the other paths will still refer to
the old size until AENs for the remaining controllers are received.
If I/O comes in before that it might be routed to one of the old
paths, triggering an I/O failure with 'access beyond end of device'.
With this patch the old paths are skipped from multipath path
selection until the controller serving these paths has been rescanned.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Tested-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
---
v2:
- removed churn from failed rebase.
v1:
- https://lore.kernel.org/linux-nvme/20210729194630.i5mhvvgb73duojqq@beryllium.lan/
drivers/nvme/host/core.c | 2 ++
drivers/nvme/host/multipath.c | 16 ++++++++++++++++
drivers/nvme/host/nvme.h | 5 +++++
3 files changed, 23 insertions(+)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index dfd9dec0c1f6..20a079083129 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1877,6 +1877,7 @@ static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_id_ns *id)
goto out_unfreeze;
}
+ clear_bit(NVME_NS_INVALIDATED, &ns->flags);
blk_mq_unfreeze_queue(ns->disk->queue);
if (blk_queue_is_zoned(ns->queue)) {
@@ -1888,6 +1889,7 @@ static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_id_ns *id)
if (nvme_ns_head_multipath(ns->head)) {
blk_mq_freeze_queue(ns->head->disk->queue);
nvme_update_disk_info(ns->head->disk, ns, id);
+ nvme_mpath_invalidate_paths(ns);
blk_stack_limits(&ns->head->disk->queue->limits,
&ns->queue->limits, 0);
blk_queue_update_readahead(ns->head->disk->queue);
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 3f32c5e86bfc..579020ae058d 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -147,6 +147,21 @@ void nvme_mpath_clear_ctrl_paths(struct nvme_ctrl *ctrl)
mutex_unlock(&ctrl->scan_lock);
}
+void nvme_mpath_invalidate_paths(struct nvme_ns *ns)
+{
+ struct nvme_ns_head *head = ns->head;
+ sector_t capacity = get_capacity(head->disk);
+ int node;
+
+ for_each_node(node)
+ rcu_assign_pointer(head->current_path[node], NULL);
+
+ list_for_each_entry_rcu(ns, &head->list, siblings) {
+ if (capacity != get_capacity(ns->disk))
+ set_bit(NVME_NS_INVALIDATED, &ns->flags);
+ }
+}
+
static bool nvme_path_is_disabled(struct nvme_ns *ns)
{
/*
@@ -158,6 +173,7 @@ static bool nvme_path_is_disabled(struct nvme_ns *ns)
ns->ctrl->state != NVME_CTRL_DELETING)
return true;
if (test_bit(NVME_NS_ANA_PENDING, &ns->flags) ||
+ test_bit(NVME_NS_INVALIDATED, &ns->flags) ||
test_bit(NVME_NS_REMOVING, &ns->flags))
return true;
return false;
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 5cd1fa3b8464..b72c891907f7 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -467,6 +467,7 @@ struct nvme_ns {
#define NVME_NS_DEAD 1
#define NVME_NS_ANA_PENDING 2
#define NVME_NS_FORCE_RO 3
+#define NVME_NS_INVALIDATED 4
struct cdev cdev;
struct device cdev_device;
@@ -715,6 +716,7 @@ void nvme_mpath_init_ctrl(struct nvme_ctrl *ctrl);
void nvme_mpath_uninit(struct nvme_ctrl *ctrl);
void nvme_mpath_stop(struct nvme_ctrl *ctrl);
bool nvme_mpath_clear_current_path(struct nvme_ns *ns);
+void nvme_mpath_invalidate_paths(struct nvme_ns *ns);
void nvme_mpath_clear_ctrl_paths(struct nvme_ctrl *ctrl);
void nvme_mpath_shutdown_disk(struct nvme_ns_head *head);
@@ -762,6 +764,9 @@ static inline bool nvme_mpath_clear_current_path(struct nvme_ns *ns)
{
return false;
}
+static inline void nvme_mpath_invalidate_paths(struct nvme_ns *ns)
+{
+}
static inline void nvme_mpath_clear_ctrl_paths(struct nvme_ctrl *ctrl)
{
}
--
2.29.2
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http://lists.infradead.org/mailman/listinfo/linux-nvme
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH v2] nvme: invalidate paths during rescan
2021-07-30 7:10 [PATCH v2] nvme: invalidate paths during rescan Daniel Wagner
@ 2021-08-11 1:18 ` Sagi Grimberg
2021-08-11 15:22 ` Daniel Wagner
0 siblings, 1 reply; 3+ messages in thread
From: Sagi Grimberg @ 2021-08-11 1:18 UTC (permalink / raw)
To: Daniel Wagner, linux-nvme; +Cc: Hannes Reinecke
On 7/30/21 12:10 AM, Daniel Wagner wrote:
> From: Hannes Reinecke <hare@suse.de>
>
> When triggering a rescan due to a namespace resize we will be
> receiving AENs on every controller, triggering a rescan of all
> attached namespaces. If multipath is active only the current path and
> the ns_head disk will be updated, the other paths will still refer to
> the old size until AENs for the remaining controllers are received.
>
> If I/O comes in before that it might be routed to one of the old
> paths, triggering an I/O failure with 'access beyond end of device'.
> With this patch the old paths are skipped from multipath path
> selection until the controller serving these paths has been rescanned.
>
> Signed-off-by: Hannes Reinecke <hare@suse.de>
> Tested-by: Daniel Wagner <dwagner@suse.de>
> Signed-off-by: Daniel Wagner <dwagner@suse.de>
> ---
> v2:
> - removed churn from failed rebase.
> v1:
> - https://lore.kernel.org/linux-nvme/20210729194630.i5mhvvgb73duojqq@beryllium.lan/
>
> drivers/nvme/host/core.c | 2 ++
> drivers/nvme/host/multipath.c | 16 ++++++++++++++++
> drivers/nvme/host/nvme.h | 5 +++++
> 3 files changed, 23 insertions(+)
>
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index dfd9dec0c1f6..20a079083129 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -1877,6 +1877,7 @@ static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_id_ns *id)
> goto out_unfreeze;
> }
>
> + clear_bit(NVME_NS_INVALIDATED, &ns->flags);
> blk_mq_unfreeze_queue(ns->disk->queue);
>
> if (blk_queue_is_zoned(ns->queue)) {
> @@ -1888,6 +1889,7 @@ static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_id_ns *id)
> if (nvme_ns_head_multipath(ns->head)) {
> blk_mq_freeze_queue(ns->head->disk->queue);
> nvme_update_disk_info(ns->head->disk, ns, id);
> + nvme_mpath_invalidate_paths(ns);
> blk_stack_limits(&ns->head->disk->queue->limits,
> &ns->queue->limits, 0);
> blk_queue_update_readahead(ns->head->disk->queue);
> diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
> index 3f32c5e86bfc..579020ae058d 100644
> --- a/drivers/nvme/host/multipath.c
> +++ b/drivers/nvme/host/multipath.c
> @@ -147,6 +147,21 @@ void nvme_mpath_clear_ctrl_paths(struct nvme_ctrl *ctrl)
> mutex_unlock(&ctrl->scan_lock);
> }
>
> +void nvme_mpath_invalidate_paths(struct nvme_ns *ns)
invalidate is not a great name for this very specific case here.
> +{
> + struct nvme_ns_head *head = ns->head;
> + sector_t capacity = get_capacity(head->disk);
> + int node;
> +
> + for_each_node(node)
> + rcu_assign_pointer(head->current_path[node], NULL);
Here the ns can get re-selected as the current path.
> +
> + list_for_each_entry_rcu(ns, &head->list, siblings) {
> + if (capacity != get_capacity(ns->disk))
> + set_bit(NVME_NS_INVALIDATED, &ns->flags);
maybe instead of invalidated reverse the polarity with
NVME_NS_READY? clear it here and set it in update_ns_info?
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http://lists.infradead.org/mailman/listinfo/linux-nvme
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH v2] nvme: invalidate paths during rescan
2021-08-11 1:18 ` Sagi Grimberg
@ 2021-08-11 15:22 ` Daniel Wagner
0 siblings, 0 replies; 3+ messages in thread
From: Daniel Wagner @ 2021-08-11 15:22 UTC (permalink / raw)
To: Sagi Grimberg; +Cc: linux-nvme, Hannes Reinecke
Hi Sagi,
On Tue, Aug 10, 2021 at 06:18:01PM -0700, Sagi Grimberg wrote:
> > +void nvme_mpath_invalidate_paths(struct nvme_ns *ns)
>
> invalidate is not a great name for this very specific case here.
Okay, I opted for nvme_mpath_revalidate_paths() as we already have
nvme_revalidate_zones() which does also capacity checks too.
> > +{
> > + struct nvme_ns_head *head = ns->head;
> > + sector_t capacity = get_capacity(head->disk);
> > + int node;
> > +
> > + for_each_node(node)
> > + rcu_assign_pointer(head->current_path[node], NULL);
>
> Here the ns can get re-selected as the current path.
This is on purpose. By clearing all current_path the next
nvme_find_path() will select a valid current_path which might be the
same path.
> > +
> > + list_for_each_entry_rcu(ns, &head->list, siblings) {
> > + if (capacity != get_capacity(ns->disk))
> > + set_bit(NVME_NS_INVALIDATED, &ns->flags);
>
> maybe instead of invalidated reverse the polarity with
> NVME_NS_READY? clear it here and set it in update_ns_info?
Will do, see next version.
Thanks for the feedback!
Daniel
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^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-07-30 7:10 [PATCH v2] nvme: invalidate paths during rescan Daniel Wagner
2021-08-11 1:18 ` Sagi Grimberg
2021-08-11 15:22 ` Daniel Wagner
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