From: Mike Snitzer snitzer@redhat.com

nvme: Return BLK_STS_TARGET if the DNR bit is set

BZ: 1948690 Upstream Status: RHEL-only

Signed-off-by: Mike Snitzer snitzer@redhat.com

rhel-8.git commit ef4ab90c12db5e0e50800ec323736b95be7a6ff5 Author: Mike Snitzer snitzer@redhat.com Date: Tue Aug 25 21:52:45 2020 -0400

[nvme] nvme: Return BLK_STS_TARGET if the DNR bit is set

Message-id: 20200825215248.2291-8-snitzer@redhat.com Patchwork-id: 325178 Patchwork-instance: patchwork O-Subject: [RHEL8.3 PATCH 07/10] nvme: Return BLK_STS_TARGET if the DNR bit is set Bugzilla: 1843515 RH-Acked-by: David Milburn dmilburn@redhat.com RH-Acked-by: Gopal Tiwari gtiwari@redhat.com RH-Acked-by: Ewan Milne emilne@redhat.com

BZ: 1843515 Upstream Status: RHEL-only

If the DNR bit is set we should not retry the command, even if the standard status evaluation indicates so.

SUSE is carrying this patch in their kernel: https://lwn.net/Articles/800370/

Based on patch posted for upstream inclusion but rejected: v1: https://lore.kernel.org/linux-nvme/20190806111036.113233-1-hare@suse.de/ v2: https://lore.kernel.org/linux-nvme/20190807071208.101882-1-hare@suse.de/ v2-keith: https://lore.kernel.org/linux-nvme/20190807144725.GB25621@localhost.localdom... v3: https://lore.kernel.org/linux-nvme/20190812075147.79598-1-hare@suse.de/ v3-keith: https://lore.kernel.org/linux-nvme/20190813141510.GB32686@localhost.localdom...

This commit's change is basically "v3-keith".

Signed-off-by: Mike Snitzer snitzer@redhat.com Signed-off-by: Frantisek Hrbata fhrbata@redhat.com

diff a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -237,6 +237,9 @@ static void nvme_delete_ctrl_sync(struct nvme_ctrl *ctrl)

static blk_status_t nvme_error_status(u16 status) { + if (unlikely(status & NVME_SC_DNR)) + return BLK_STS_TARGET; + switch (status & 0x7ff) { case NVME_SC_SUCCESS: return BLK_STS_OK;

-- https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1024

From: Mike Snitzer snitzer@redhat.com

nvme: decouple basic ANA log page re-read support from native multipathing

BZ: 1948690 Upstream Status: RHEL-only

This commit offers a more refined version of this rhel-8.git commit: b904f4b8e0f90 [nvme] nvme: decouple basic ANA log page re-read support from native multipathing

Whether or not ANA is present is a choice of the target implementation; the host (and whether it supports multipathing) has _zero_ influence on this. If the target declares a path as 'inaccessible' the path _is_ inaccessible to the host. As such, ANA support should be functional even if native multipathing is not.

Introduce ability to always re-read ANA log page as required due to ANA error and make current ANA state available via sysfs -- even if native multipathing is disabled on the host (e.g. nvme_core.multipath=N). This is achieved by factoring out nvme_update_ana() and calling it in nvme_complete_rq() for all FAILOVER requests.

This affords userspace access to the current ANA state independent of which layer might be doing multipathing. This makes 'nvme list-subsys' show ANA state for all NVMe subsystems with multiple controllers. It also allows userspace multipath-tools to rely on the NVMe driver for ANA support while dm-multipath takes care of multipathing.

And as always, if embedded NVMe users do not want any performance overhead associated with ANA or native NVMe multipathing they can disable CONFIG_NVME_MULTIPATH.

Signed-off-by: Mike Snitzer snitzer@redhat.com

diff a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -340,6 +340,8 @@ static inline void nvme_end_req(struct request *req)

static inline void nvme_failup_req(struct request *req) { + nvme_update_ana(req); + nvme_req(req)->status = NVME_SC_HOST_PATH_ERROR; nvme_end_req(req); } diff a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -65,13 +65,10 @@ void nvme_set_disk_name(char *disk_name, struct nvme_ns *ns, } }

-void nvme_failover_req(struct request *req) +void nvme_update_ana(struct request *req) { struct nvme_ns *ns = req->q->queuedata; u16 status = nvme_req(req)->status & 0x7ff; - unsigned long flags; - - nvme_mpath_clear_current_path(ns);

/* * If we got back an ANA error, we know the controller is alive but not @@ -82,6 +79,15 @@ void nvme_failover_req(struct request *req) set_bit(NVME_NS_ANA_PENDING, &ns->flags); queue_work(nvme_wq, &ns->ctrl->ana_work); } +} + +void nvme_failover_req(struct request *req) +{ + struct nvme_ns *ns = req->q->queuedata; + unsigned long flags; + + nvme_mpath_clear_current_path(ns); + nvme_update_ana(req);

spin_lock_irqsave(&ns->head->requeue_lock, flags); blk_steal_bios(&ns->head->requeue_list, req); diff a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -664,6 +664,7 @@ void nvme_mpath_start_freeze(struct nvme_subsystem *subsys); void nvme_set_disk_name(char *disk_name, struct nvme_ns *ns, struct nvme_ctrl *ctrl, int *flags); void nvme_failover_req(struct request *req); +void nvme_update_ana(struct request *req); void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl); int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl,struct nvme_ns_head *head); void nvme_mpath_add_disk(struct nvme_ns *ns, struct nvme_id_ns *id); @@ -714,6 +715,9 @@ static inline void nvme_set_disk_name(char *disk_name, struct nvme_ns *ns, static inline void nvme_failover_req(struct request *req) { } +static inline void nvme_update_ana(struct request *req) +{ +} static inline void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl) { }

-- https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1024