From 86f9536c2d8f4496f1e45cb0a70ca1b3a7d89106 Mon Sep 17 00:00:00 2001 From: Nilay Shroff Date: Mon, 13 Jul 2026 17:24:06 +0530 Subject: [PATCH] nvme: add context annotations for nvme_ns_head::srcu Add Clang lock context annotations for helpers that operate under head->srcu read-side protection. The path selection helpers invoked by nvme_find_path() access SRCU- protected data through srcu_dereference() or list APIs which iterate through rcu protected list and therefore require the caller to hold head->srcu. Annotate these helpers and nvme_find_path() with __must_hold_shared(&head->srcu) so that Clang's lock context analysis can verify the SRCU locking requirements across the call chain. Also update nvme_ns_head_ctrl_ioctl() to use __releases_shared() to match the shared SRCU read-side lock acquired through srcu_read_lock(). Reviewed-by: Christoph Hellwig Signed-off-by: Nilay Shroff Signed-off-by: Keith Busch --- drivers/nvme/host/ioctl.c | 2 +- drivers/nvme/host/multipath.c | 6 ++++++ drivers/nvme/host/nvme.h | 3 ++- 3 files changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c index d5a8f375953b..bae52bd5bdd2 100644 --- a/drivers/nvme/host/ioctl.c +++ b/drivers/nvme/host/ioctl.c @@ -692,7 +692,7 @@ int nvme_ns_chr_uring_cmd_iopoll(struct io_uring_cmd *ioucmd, static int nvme_ns_head_ctrl_ioctl(struct nvme_ns *ns, unsigned int cmd, void __user *argp, struct nvme_ns_head *head, int srcu_idx, bool open_for_write) - __releases(&head->srcu) + __releases_shared(&head->srcu) { struct nvme_ctrl *ctrl = ns->ctrl; int ret; diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index c850a4bf7380..b9bb9777da96 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -325,6 +325,7 @@ static bool nvme_path_is_disabled(struct nvme_ns *ns) } static struct nvme_ns *__nvme_find_path(struct nvme_ns_head *head, int node) + __must_hold_shared(&head->srcu) { int found_distance = INT_MAX, fallback_distance = INT_MAX, distance; struct nvme_ns *found = NULL, *fallback = NULL, *ns; @@ -367,6 +368,7 @@ static struct nvme_ns *__nvme_find_path(struct nvme_ns_head *head, int node) static struct nvme_ns *nvme_next_ns(struct nvme_ns_head *head, struct nvme_ns *ns) + __must_hold_shared(&head->srcu) { ns = list_next_or_null_rcu(&head->list, &ns->siblings, struct nvme_ns, siblings); @@ -376,6 +378,7 @@ static struct nvme_ns *nvme_next_ns(struct nvme_ns_head *head, } static struct nvme_ns *nvme_round_robin_path(struct nvme_ns_head *head) + __must_hold_shared(&head->srcu) { struct nvme_ns *ns, *found = NULL; int node = numa_node_id(); @@ -424,6 +427,7 @@ static struct nvme_ns *nvme_round_robin_path(struct nvme_ns_head *head) } static struct nvme_ns *nvme_queue_depth_path(struct nvme_ns_head *head) + __must_hold_shared(&head->srcu) { struct nvme_ns *best_opt = NULL, *best_nonopt = NULL, *ns; unsigned int min_depth_opt = UINT_MAX, min_depth_nonopt = UINT_MAX; @@ -467,6 +471,7 @@ static inline bool nvme_path_is_optimized(struct nvme_ns *ns) } static struct nvme_ns *nvme_numa_path(struct nvme_ns_head *head) + __must_hold_shared(&head->srcu) { int node = numa_node_id(); struct nvme_ns *ns; @@ -492,6 +497,7 @@ inline struct nvme_ns *nvme_find_path(struct nvme_ns_head *head) } static bool nvme_available_path(struct nvme_ns_head *head) + __must_hold_shared(&head->srcu) { struct nvme_ns *ns; diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h index 26859aea3e2d..ec9dea4d7fb9 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -1033,7 +1033,8 @@ extern const struct attribute_group *nvme_dev_attr_groups[]; extern const struct block_device_operations nvme_bdev_ops; void nvme_delete_ctrl_sync(struct nvme_ctrl *ctrl); -struct nvme_ns *nvme_find_path(struct nvme_ns_head *head); +struct nvme_ns *nvme_find_path(struct nvme_ns_head *head) + __must_hold_shared(&head->srcu); #ifdef CONFIG_NVME_MULTIPATH static inline bool nvme_ctrl_use_ana(struct nvme_ctrl *ctrl) {