[PATCH 6.12.y 2/4] nvme: refactor the atomic write unit detection

[Sasha Levin <sashal@kernel.org>]

From: Christoph Hellwig <hch@lst.de>

[ Upstream commit b2e607fecac15e07f50269c080e2e71b5049dfa2 ]

Move all the code out of nvme_update_disk_info into the helper, and
rename the helper to have a somewhat less clumsy name.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: John Garry <john.g.garry@oracle.com>

Stable adaptation for 6.12:
- Keep the existing atomic write helper refactor, but omit
  BLK_FEAT_ATOMIC_WRITES: this tree enables atomic writes through the
  hardware limits and does not define that feature flag.
- Call the existing discard setup helper from nvme_update_disk_info()
  after setting logical_block_size. Save the disk-info validity result
  and defer clearing capacity until after atomic-size validation. This
  preserves the result while leaving the zoned update insertion point
  clear for 3838e80fcfb32e62baffb63c6dc0a60153665a4d.
- Adapt the preceding dependency's atomic-size error path to the
  single-argument blk_mq_unfreeze_queue() API and cancel the pending
  limits update before unfreezing, releasing limits_lock on rejection.

No additional functions are introduced.

Stable-dep-of: 3838e80fcfb3 ("nvme: skip the zoned limits update if the zone info query failed")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/nvme/host/core.c | 84 ++++++++++++++++++++++------------------
 1 file changed, 46 insertions(+), 38 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 3f2586086f6ec..deffad78d1dcf 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1995,20 +1995,50 @@ static void nvme_configure_metadata(struct nvme_ctrl *ctrl,
 }
 
 
-static void nvme_update_atomic_write_disk_info(struct nvme_ns *ns,
-			struct nvme_id_ns *id, struct queue_limits *lim,
-			u32 bs, u32 atomic_bs)
+static u32 nvme_configure_atomic_write(struct nvme_ns *ns,
+		struct nvme_id_ns *id, struct queue_limits *lim, u32 bs)
 {
-	unsigned int boundary = 0;
+	u32 atomic_bs, boundary = 0;
 
-	if (id->nsfeat & NVME_NS_FEAT_ATOMICS && id->nawupf) {
-		if (le16_to_cpu(id->nabspf))
+	/*
+	 * We do not support an offset for the atomic boundaries.
+	 */
+	if (id->nabo)
+		return bs;
+
+	if ((id->nsfeat & NVME_NS_FEAT_ATOMICS) && id->nawupf) {
+		/*
+		 * Use the per-namespace atomic write unit when available.
+		 */
+		atomic_bs = (1 + le16_to_cpu(id->nawupf)) * bs;
+		if (id->nabspf)
 			boundary = (le16_to_cpu(id->nabspf) + 1) * bs;
+	} else {
+		/*
+		 * Use the controller wide atomic write unit.  This sucks
+		 * because the limit is defined in terms of logical blocks while
+		 * namespaces can have different formats, and because there is
+		 * no clear language in the specification prohibiting different
+		 * values for different controllers in the subsystem.
+		 */
+		atomic_bs = (1 + ns->ctrl->awupf) * bs;
+	}
+
+	if (!ns->ctrl->subsys->atomic_bs) {
+		ns->ctrl->subsys->atomic_bs = atomic_bs;
+	} else if (ns->ctrl->subsys->atomic_bs != atomic_bs) {
+		dev_err_ratelimited(ns->ctrl->device,
+			"%s: Inconsistent Atomic Write Size, Namespace will not be added: Subsystem=%d bytes, Controller/Namespace=%d bytes\n",
+			ns->disk ? ns->disk->disk_name : "?",
+			ns->ctrl->subsys->atomic_bs,
+			atomic_bs);
 	}
+
 	lim->atomic_write_hw_max = atomic_bs;
 	lim->atomic_write_hw_boundary = boundary;
 	lim->atomic_write_hw_unit_min = bs;
 	lim->atomic_write_hw_unit_max = rounddown_pow_of_two(atomic_bs);
+	return atomic_bs;
 }
 
 static u32 nvme_max_drv_segments(struct nvme_ctrl *ctrl)
@@ -2046,34 +2076,8 @@ static bool nvme_update_disk_info(struct nvme_ns *ns, struct nvme_id_ns *id,
 		valid = false;
 	}
 
-	atomic_bs = phys_bs = bs;
-	if (id->nabo == 0) {
-		/*
-		 * Bit 1 indicates whether NAWUPF is defined for this namespace
-		 * and whether it should be used instead of AWUPF. If NAWUPF ==
-		 * 0 then AWUPF must be used instead.
-		 */
-		if (id->nsfeat & NVME_NS_FEAT_ATOMICS && id->nawupf)
-			atomic_bs = (1 + le16_to_cpu(id->nawupf)) * bs;
-		else
-			atomic_bs = (1 + ns->ctrl->awupf) * bs;
-
-		/*
-		 * Set subsystem atomic bs.
-		 */
-		if (ns->ctrl->subsys->atomic_bs) {
-			if (atomic_bs != ns->ctrl->subsys->atomic_bs) {
-				dev_err_ratelimited(ns->ctrl->device,
-					"%s: Inconsistent Atomic Write Size, Namespace will not be added: Subsystem=%d bytes, Controller/Namespace=%d bytes\n",
-					ns->disk ? ns->disk->disk_name : "?",
-					ns->ctrl->subsys->atomic_bs,
-					atomic_bs);
-			}
-		} else
-			ns->ctrl->subsys->atomic_bs = atomic_bs;
-
-		nvme_update_atomic_write_disk_info(ns, id, lim, bs, atomic_bs);
-	}
+	phys_bs = bs;
+	atomic_bs = nvme_configure_atomic_write(ns, id, lim, bs);
 
 	if (id->nsfeat & NVME_NS_FEAT_IO_OPT) {
 		/* NPWG = Namespace Preferred Write Granularity */
@@ -2097,6 +2101,7 @@ static bool nvme_update_disk_info(struct nvme_ns *ns, struct nvme_id_ns *id,
 		lim->max_write_zeroes_sectors = UINT_MAX;
 	else
 		lim->max_write_zeroes_sectors = ns->ctrl->max_zeroes_sectors;
+	nvme_config_discard(ns, lim);
 	return valid;
 }
 
@@ -2171,6 +2176,7 @@ static int nvme_update_ns_info_block(struct nvme_ns *ns,
 	struct nvme_id_ns *id;
 	sector_t capacity;
 	unsigned lbaf;
+	bool valid;
 	int ret;
 
 	ret = nvme_identify_ns(ns->ctrl, info->nsid, &id);
@@ -2207,20 +2213,22 @@ static int nvme_update_ns_info_block(struct nvme_ns *ns,
 	nvme_set_ctrl_limits(ns->ctrl, &lim);
 	nvme_configure_metadata(ns->ctrl, ns->head, id, nvm, info);
 	nvme_set_chunk_sectors(ns, id, &lim);
-	if (!nvme_update_disk_info(ns, id, &lim))
-		capacity = 0;
+	valid = nvme_update_disk_info(ns, id, &lim);
 
 	/*
 	 * Validate the max atomic write size fits within the subsystem's
 	 * atomic write capabilities.
 	 */
 	if (lim.atomic_write_hw_max > ns->ctrl->subsys->atomic_bs) {
-		blk_mq_unfreeze_queue(ns->disk->queue, memflags);
+		queue_limits_cancel_update(ns->disk->queue);
+		blk_mq_unfreeze_queue(ns->disk->queue);
 		ret = -ENXIO;
 		goto out;
 	}
 
-	nvme_config_discard(ns, &lim);
+	if (!valid)
+		capacity = 0;
+
 	if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) &&
 	    ns->head->ids.csi == NVME_CSI_ZNS)
 		nvme_update_zone_info(ns, &lim, &zi);
-- 
2.53.0