From: Christoph Hellwig <hch@lst.de>
Date: Fri, 10 Jan 2025 05:47:15 +0000 (+0100)
Subject: nvme: fix queue freeze vs limits lock order
X-Git-Tag: v6.14-rc1~202^2~28
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=473106dd3aa964a62314d858f6602c95e40e6270;p=thirdparty%2Fkernel%2Flinux.git

nvme: fix queue freeze vs limits lock order

Match the locking order used by the core block code by only freezing
the queue after taking the limits lock.

Unlike most queue updates this does not use the
queue_limits_commit_update_frozen helper as the nvme driver want the
queue frozen for more than just the limits update.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20250110054726.1499538-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index c2250ddef5a29..1ccf17f6ea7f2 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2128,9 +2128,10 @@ static int nvme_update_ns_info_generic(struct nvme_ns *ns,
 	struct queue_limits lim;
 	int ret;
 
-	blk_mq_freeze_queue(ns->disk->queue);
 	lim = queue_limits_start_update(ns->disk->queue);
 	nvme_set_ctrl_limits(ns->ctrl, &lim);
+
+	blk_mq_freeze_queue(ns->disk->queue);
 	ret = queue_limits_commit_update(ns->disk->queue, &lim);
 	set_disk_ro(ns->disk, nvme_ns_is_readonly(ns, info));
 	blk_mq_unfreeze_queue(ns->disk->queue);
@@ -2177,12 +2178,12 @@ static int nvme_update_ns_info_block(struct nvme_ns *ns,
 			goto out;
 	}
 
+	lim = queue_limits_start_update(ns->disk->queue);
+
 	blk_mq_freeze_queue(ns->disk->queue);
 	ns->head->lba_shift = id->lbaf[lbaf].ds;
 	ns->head->nuse = le64_to_cpu(id->nuse);
 	capacity = nvme_lba_to_sect(ns->head, le64_to_cpu(id->nsze));
-
-	lim = queue_limits_start_update(ns->disk->queue);
 	nvme_set_ctrl_limits(ns->ctrl, &lim);
 	nvme_configure_metadata(ns->ctrl, ns->head, id, nvm, info);
 	nvme_set_chunk_sectors(ns, id, &lim);
@@ -2285,6 +2286,7 @@ static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_ns_info *info)
 		struct queue_limits *ns_lim = &ns->disk->queue->limits;
 		struct queue_limits lim;
 
+		lim = queue_limits_start_update(ns->head->disk->queue);
 		blk_mq_freeze_queue(ns->head->disk->queue);
 		/*
 		 * queue_limits mixes values that are the hardware limitations
@@ -2301,7 +2303,6 @@ static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_ns_info *info)
 		 * the splitting limits in to make sure we still obey possibly
 		 * lower limitations of other controllers.
 		 */
-		lim = queue_limits_start_update(ns->head->disk->queue);
 		lim.logical_block_size = ns_lim->logical_block_size;
 		lim.physical_block_size = ns_lim->physical_block_size;
 		lim.io_min = ns_lim->io_min;