[PATCH v6 2/6] nvme-fc: marginal path handling
John Meneghini
jmeneghi at redhat.com
Mon Jun 23 08:59:16 PDT 2025
Reviewed-by: John Meneghini <jmeneghi at redhat.com>
On 6/20/25 1:56 PM, Bryan Gurney wrote:
> From: Hannes Reinecke <hare at kernel.org>
>
> FPIN LI (link integrity) messages are received when the attached
> fabric detects hardware errors. In response to these messages I/O
> should be directed away from the affected ports, and only used
> if the 'optimized' paths are unavailable.
> To handle this a new controller flag 'NVME_CTRL_MARGINAL' is added
> which will cause the multipath scheduler to skip these paths when
> checking for 'optimized' paths. They are, however, still eligible
> for non-optimized path selected. The flag is cleared upon reset as then the
> faulty hardware might be replaced.
>
> Signed-off-by: Hannes Reinecke <hare at kernel.org>
> Tested-by: Bryan Gurney <bgurney at redhat.com>
> ---
> drivers/nvme/host/core.c | 1 +
> drivers/nvme/host/fc.c | 4 ++++
> drivers/nvme/host/multipath.c | 17 +++++++++++------
> drivers/nvme/host/nvme.h | 6 ++++++
> 4 files changed, 22 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index 3da5ac71a9b0..ac03ef7baab9 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -5040,6 +5040,7 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev,
> WRITE_ONCE(ctrl->state, NVME_CTRL_NEW);
> ctrl->passthru_err_log_enabled = false;
> clear_bit(NVME_CTRL_FAILFAST_EXPIRED, &ctrl->flags);
> + clear_bit(NVME_CTRL_MARGINAL, &ctrl->flags);
> spin_lock_init(&ctrl->lock);
> mutex_init(&ctrl->namespaces_lock);
>
> diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
> index 014b387f1e8b..7e81c815bb83 100644
> --- a/drivers/nvme/host/fc.c
> +++ b/drivers/nvme/host/fc.c
> @@ -786,6 +786,10 @@ nvme_fc_ctrl_connectivity_loss(struct nvme_fc_ctrl *ctrl)
> "Reconnect", ctrl->cnum);
>
> set_bit(ASSOC_FAILED, &ctrl->flags);
> +
> + /* clear 'marginal' flag as controller will be reset */
> + clear_bit(NVME_CTRL_MARGINAL, &ctrl->flags);
> +
> nvme_reset_ctrl(&ctrl->ctrl);
> }
>
> diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
> index 1062467595f3..003954985675 100644
> --- a/drivers/nvme/host/multipath.c
> +++ b/drivers/nvme/host/multipath.c
> @@ -324,11 +324,14 @@ static struct nvme_ns *__nvme_find_path(struct nvme_ns_head *head, int node)
>
> switch (ns->ana_state) {
> case NVME_ANA_OPTIMIZED:
> - if (distance < found_distance) {
> - found_distance = distance;
> - found = ns;
> + if (!nvme_ctrl_is_marginal(ns->ctrl)) {
> + if (distance < found_distance) {
> + found_distance = distance;
> + found = ns;
> + }
> + break;
> }
> - break;
> + fallthrough;
> case NVME_ANA_NONOPTIMIZED:
> if (distance < fallback_distance) {
> fallback_distance = distance;
> @@ -381,7 +384,8 @@ static struct nvme_ns *nvme_round_robin_path(struct nvme_ns_head *head)
>
> if (ns->ana_state == NVME_ANA_OPTIMIZED) {
> found = ns;
> - goto out;
> + if (!nvme_ctrl_is_marginal(ns->ctrl))
> + goto out;
> }
> if (ns->ana_state == NVME_ANA_NONOPTIMIZED)
> found = ns;
> @@ -445,7 +449,8 @@ static struct nvme_ns *nvme_queue_depth_path(struct nvme_ns_head *head)
> static inline bool nvme_path_is_optimized(struct nvme_ns *ns)
> {
> return nvme_ctrl_state(ns->ctrl) == NVME_CTRL_LIVE &&
> - ns->ana_state == NVME_ANA_OPTIMIZED;
> + ns->ana_state == NVME_ANA_OPTIMIZED &&
> + !nvme_ctrl_is_marginal(ns->ctrl);
> }
>
> static struct nvme_ns *nvme_numa_path(struct nvme_ns_head *head)
> diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
> index 7df2ea21851f..71a5c5f87db6 100644
> --- a/drivers/nvme/host/nvme.h
> +++ b/drivers/nvme/host/nvme.h
> @@ -275,6 +275,7 @@ enum nvme_ctrl_flags {
> NVME_CTRL_SKIP_ID_CNS_CS = 4,
> NVME_CTRL_DIRTY_CAPABILITY = 5,
> NVME_CTRL_FROZEN = 6,
> + NVME_CTRL_MARGINAL = 7,
> };
>
> struct nvme_ctrl {
> @@ -417,6 +418,11 @@ static inline enum nvme_ctrl_state nvme_ctrl_state(struct nvme_ctrl *ctrl)
> return READ_ONCE(ctrl->state);
> }
>
> +static inline bool nvme_ctrl_is_marginal(struct nvme_ctrl *ctrl)
> +{
> + return test_bit(NVME_CTRL_MARGINAL, &ctrl->flags);
> +}
> +
> enum nvme_iopolicy {
> NVME_IOPOLICY_NUMA,
> NVME_IOPOLICY_RR,
More information about the Linux-nvme
mailing list