2021-03-08 10:46:28

by Niklas Cassel

Subject: [PATCH] Revert "nvme: cleanup zone information initialization"

From: Niklas Cassel <[email protected]>

This reverts commit 73d90386b559d6f4c3c5db5e6bb1b68aae8fd3e7.

Commit 73d90386b559 ("nvme: cleanup zone information initialization")
introduced the following warning at boot:
WARNING: CPU: 0 PID: 7 at block/blk-settings.c:252 blk_queue_max_zone_append_sectors+0x7d/0x90

The warning is the result of chunk_sectors being 0.

Worse, this causes the sysfs attribute zone_append_max_bytes to
be incorrectly reported as 0, which will break user space applications
relying on this attribute.

Looking at the commit, it probably assumes that calling
nvme_set_chunk_sectors() will cause chunk_sectors to be set.

However, looking at nvme_set_chunk_sectors(), chunk_sectors
is only set if namespace optimal i/o boundary (noiob) is non-zero.

A noiob value of zero is perfectly valid according to the spec,
and simply means that the namespace does not report an optimal i/o
boundary. Hence, we cannot assume that chunk_sectors is set after
nvme_set_chunk_sectors() has been called.

Signed-off-by: Niklas Cassel <[email protected]>
---
drivers/nvme/host/core.c | 11 +++++------
drivers/nvme/host/zns.c | 11 ++++++++---
2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index e68a8c4ac5a6..a38b509eeb80 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2210,18 +2210,17 @@ static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_id_ns *id)
ns->lba_shift = id->lbaf[lbaf].ds;
nvme_set_queue_limits(ns->ctrl, ns->queue);

- ret = nvme_configure_metadata(ns, id);
- if (ret)
- goto out_unfreeze;
- nvme_set_chunk_sectors(ns, id);
- nvme_update_disk_info(ns->disk, ns, id);
-
if (ns->head->ids.csi == NVME_CSI_ZNS) {
ret = nvme_update_zone_info(ns, lbaf);
if (ret)
goto out_unfreeze;
}

+ ret = nvme_configure_metadata(ns, id);
+ if (ret)
+ goto out_unfreeze;
+ nvme_set_chunk_sectors(ns, id);
+ nvme_update_disk_info(ns->disk, ns, id);
blk_mq_unfreeze_queue(ns->disk->queue);

if (blk_queue_is_zoned(ns->queue)) {
diff --git a/drivers/nvme/host/zns.c b/drivers/nvme/host/zns.c
index c7e3ec561ba0..1dfe9a3500e3 100644
--- a/drivers/nvme/host/zns.c
+++ b/drivers/nvme/host/zns.c
@@ -9,7 +9,13 @@

int nvme_revalidate_zones(struct nvme_ns *ns)
{
- return blk_revalidate_disk_zones(ns->disk, NULL);
+ struct request_queue *q = ns->queue;
+ int ret;
+
+ ret = blk_revalidate_disk_zones(ns->disk, NULL);
+ if (!ret)
+ blk_queue_max_zone_append_sectors(q, ns->ctrl->max_zone_append);
+ return ret;
}

static int nvme_set_max_append(struct nvme_ctrl *ctrl)
@@ -103,11 +109,10 @@ int nvme_update_zone_info(struct nvme_ns *ns, unsigned lbaf)
goto free_data;
}

- blk_queue_set_zoned(ns->disk, BLK_ZONED_HM);
+ q->limits.zoned = BLK_ZONED_HM;
blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q);
blk_queue_max_open_zones(q, le32_to_cpu(id->mor) + 1);
blk_queue_max_active_zones(q, le32_to_cpu(id->mar) + 1);
- blk_queue_max_zone_append_sectors(q, ns->ctrl->max_zone_append);
free_data:
kfree(id);
return status;
--
2.29.2

2021-03-08 16:34:22

by Kanchan Joshi

Subject: Re: [PATCH] Revert "nvme: cleanup zone information initialization"

On Mon, Mar 8, 2021 at 4:21 PM Niklas Cassel <[email protected]> wrote:
>
> From: Niklas Cassel <[email protected]>
>
> This reverts commit 73d90386b559d6f4c3c5db5e6bb1b68aae8fd3e7.
>
> Commit 73d90386b559 ("nvme: cleanup zone information initialization")
> introduced the following warning at boot:
> WARNING: CPU: 0 PID: 7 at block/blk-settings.c:252 blk_queue_max_zone_append_sectors+0x7d/0x90
>
> The warning is the result of chunk_sectors being 0.

This looks same as what Chaitanya posted the fix for -
https://lore.kernel.org/linux-nvme/[email protected]/

2021-03-08 16:55:04

by Niklas Cassel

Subject: Re: [PATCH] Revert "nvme: cleanup zone information initialization"

On Mon, Mar 08, 2021 at 10:02:05PM +0530, Kanchan Joshi wrote:
> On Mon, Mar 8, 2021 at 4:21 PM Niklas Cassel <[email protected]> wrote:
> >
> > From: Niklas Cassel <[email protected]>
> >
> > This reverts commit 73d90386b559d6f4c3c5db5e6bb1b68aae8fd3e7.
> >
> > Commit 73d90386b559 ("nvme: cleanup zone information initialization")
> > introduced the following warning at boot:
> > WARNING: CPU: 0 PID: 7 at block/blk-settings.c:252 blk_queue_max_zone_append_sectors+0x7d/0x90
> >
> > The warning is the result of chunk_sectors being 0.
>
> This looks same as what Chaitanya posted the fix for -
> https://lore.kernel.org/linux-nvme/[email protected]/

Hello Kanchan,

Indeed, thanks for telling me.

Kind regards,
Niklas