[PATCHv2 04/17] nvme: add Clang context annotations for nvme_ns_head::requeue_list

[Nilay Shroff <nilay@linux.ibm.com>]

nvme_ns_head::requeue_list is protected by
nvme_ns_head::requeue_lock. Annotate requeue_list with
__guarded_by(&requeue_lock) so that Clang's context analysis can
validate accesses to the list.

Replace spin_lock_init(&head->requeue_lock) with
scoped_guard(spinlock_init)(&head->requeue_lock). The guard-based
initialization generates synthetic lock acquire and release events
visible to Clang's context analysis, allowing initialization of the
guarded nvme_ns_head::requeue_list in nvme_mpath_alloc_disk() without
triggering context analysis warnings.

Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
---
 drivers/nvme/host/multipath.c | 4 ++--
 drivers/nvme/host/nvme.h      | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index a275c03e7c59..9e7f12fe8cd6 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -706,8 +706,8 @@ int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head)
 	struct queue_limits lim;
 
 	mutex_init(&head->lock);
-	bio_list_init(&head->requeue_list);
-	spin_lock_init(&head->requeue_lock);
+	scoped_guard(spinlock_init, &head->requeue_lock)
+		bio_list_init(&head->requeue_list);
 	INIT_WORK(&head->requeue_work, nvme_requeue_work);
 	INIT_WORK(&head->partition_scan_work, nvme_partition_scan_work);
 	INIT_DELAYED_WORK(&head->remove_work, nvme_remove_head_work);
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 6bea0947eeb0..f60852944709 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -555,7 +555,7 @@ struct nvme_ns_head {
 	u16			nr_plids;
 	u16			*plids;
 #ifdef CONFIG_NVME_MULTIPATH
-	struct bio_list		requeue_list;
+	struct bio_list		requeue_list __guarded_by(&requeue_lock);
 	spinlock_t		requeue_lock;
 	struct work_struct	requeue_work;
 	struct work_struct	partition_scan_work;
-- 
2.53.0