[PATCH v3] nvme: skip the zoned limits update if the zone info query failed

[PATCH v3] nvme: skip the zoned limits update if the zone info query failed

[Chao Shi]

nvme_query_zone_info() returns either a negative errno or a positive
NVMe status code, but nvme_update_ns_info_block() only tests for the
negative case:

	ret = nvme_query_zone_info(ns, lbaf, &zi);
	if (ret < 0)
		goto out;

If the device fails the Identify Namespace (I/O Command Set specific)
command, or the Identify Controller command issued by
nvme_set_max_append(), the positive status falls through and setup
continues with the zero-initialized zone info.  nvme_update_zone_info()
then marks the queue zoned with chunk_sectors and ns->head->zsze set to
zero.

blk_validate_zoned_limits() does not check chunk_sectors, so the limits
commit succeeds.  blk_revalidate_disk_zones() does reject the zero zone
size, but by then the limits are live and nothing rolls them back, so
I/O keeps being submitted to a zoned queue with a zero zone size and
disk_zone_no() shifts by ilog2(0):

  nvme0n1: Invalid non power of two zone size (0)
  UBSAN: shift-out-of-bounds in include/linux/blkdev.h:747:16
  shift exponent -1 is negative
   disk_zone_no include/linux/blkdev.h:747 [inline]
   bio_straddles_zones include/linux/blkdev.h:1058 [inline]
   blk_zone_wplug_handle_write block/blk-zoned.c:1423 [inline]
   blk_zone_plug_bio.cold+0x25/0x1c8 block/blk-zoned.c:1605
   blk_mq_submit_bio+0x18fb/0x2870 block/blk-mq.c:3196
   submit_bh_wbc+0x575/0x740 fs/buffer.c:2824
   __block_write_full_folio+0x728/0xdd0 fs/buffer.c:1933

Any device, firmware or NVMe-oF target that fails this one command
reaches this.

Skip the zoned limits update in that case, and log which of the two
things happened: during a revalidation the queue keeps the zone
geometry it was last validated with, and on a first scan the namespace
is registered without zoned limits, so that it is still available as a
handle for admin commands.  Neither of the paths in
nvme_query_zone_info() that return a positive status logs anything, so
the failure would otherwise be silent.

zi.zone_size is an exact indicator: every path that returns a positive
status returns before it is assigned, and after that the only failure
left is -ENODEV, which the caller already handles.

Fixes: c85c9ab926a5 ("nvme: split nvme_update_zone_info")
Cc: stable@vger.kernel.org
Cc: Weidong Zhu <weizhu@fiu.edu>
Suggested-by: Keith Busch <kbusch@kernel.org>
Found by FuzzNvme.

Signed-off-by: Chao Shi <coshi036@gmail.com>
---
Changes since v2:
- Mention the revalidation case in the comment, and warn about which
  of the two outcomes happened.  Both per Christoph's review.

Changes since v1:
- Only skip the zoned limits instead of failing the whole update.
- Gate on zi.zone_size, not zi.max_open_zones, where 0 is legal.

v1: https://lore.kernel.org/linux-nvme/20260814160954.2839507-1-coshi036@gmail.com/
v2: https://lore.kernel.org/linux-nvme/20260816191729.2865523-1-coshi036@gmail.com/

 drivers/nvme/host/core.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 453c1f0b2dd0..5ceab58e8e4d 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2447,9 +2447,26 @@ static int nvme_update_ns_info_block(struct nvme_ns *ns,
 	if (!nvme_update_disk_info(ns, id, nvm, &lim))
 		capacity = 0;
 
+	/*
+	 * A failed zone info query leaves zi zero-initialized, so skip the
+	 * zoned limits update instead of configuring the queue from it.
+	 * During a revalidation that keeps the zone geometry the queue was
+	 * last validated with; on a first scan the namespace is registered
+	 * without zoned limits, so that it is still available as a handle
+	 * for admin commands.
+	 */
 	if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) &&
-	    ns->head->ids.csi == NVME_CSI_ZNS)
-		nvme_update_zone_info(ns, &lim, &zi);
+	    ns->head->ids.csi == NVME_CSI_ZNS) {
+		if (zi.zone_size)
+			nvme_update_zone_info(ns, &lim, &zi);
+		else
+			dev_warn(ns->ctrl->device,
+				 "zone info query failed for nsid %u, %s\n",
+				 ns->head->ns_id,
+				 blk_queue_is_zoned(ns->disk->queue) ?
+				 "keeping the previous zone limits" :
+				 "not enabling zoned mode");
+	}
 
 	if ((ns->ctrl->vwc & NVME_CTRL_VWC_PRESENT) && !info->no_vwc)
 		lim.features |= BLK_FEAT_WRITE_CACHE | BLK_FEAT_FUA;
-- 
2.43.0

Re: [PATCH v3] nvme: skip the zoned limits update if the zone info query failed

[Christoph Hellwig]

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>