From 4ed7f3d7d435bf5b63da2814dc9270f5ba896011 Mon Sep 17 00:00:00 2001 From: Mohamed Khalfella Date: Sat, 22 Aug 2026 17:46:41 -0700 Subject: [PATCH] nvme: remove stale namespaces by NSID range during scan nvme_scan_ns_list() drops the stale namespaces in each gap in the reported NSID list one NSID at a time. Every iteration calls nvme_find_get_ns() to look the namespace up and removes it if it is present. The loop runs once per NSID in the gap rather than once per namespace actually present. NSIDs are 32-bit, so a target with a sparse NSID space can make a single gap spin the loop billions of times with nothing to remove. watchdog: BUG: soft lockup - CPU#4 stuck for 26s! Workqueue: nvme-wq nvme_scan_work [nvme_core] RIP: 0010:__srcu_read_unlock+0xb/0x20 Call Trace: nvme_find_get_ns+0x7d/0xb0 [nvme_core] nvme_scan_ns_list+0xe8/0x280 [nvme_core] nvme_scan_work+0x18a/0x280 [nvme_core] process_one_work+0x197/0x380 worker_thread+0x2fe/0x410 kthread+0xe0/0x100 Rename nvme_remove_invalid_namespaces() to nvme_remove_nsid_range() and give it an open (start, end) NSID range. ctrl->namespaces is sorted by NSID, so the whole gap is dropped in a single walk that stops once end is reached. This bounds the work by the namespaces that are present instead of by the size of the gap. Fixes: 540c801c65eb ("NVMe: Implement namespace list scanning") Signed-off-by: Mohamed Khalfella Reviewed-by: Sagi Grimberg Reviewed-by: Randy Jennings Signed-off-by: Keith Busch --- drivers/nvme/host/core.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 9739ce38b73a..32cd1e9a1193 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -155,8 +155,6 @@ static const struct class nvme_ns_chr_class = { }; static void nvme_put_subsystem(struct nvme_subsystem *subsys); -static void nvme_remove_invalid_namespaces(struct nvme_ctrl *ctrl, - unsigned nsid); static void nvme_update_keep_alive(struct nvme_ctrl *ctrl, struct nvme_command *cmd); static int nvme_get_log_lsi(struct nvme_ctrl *ctrl, u32 nsid, u8 log_page, @@ -4516,15 +4514,16 @@ static void nvme_scan_ns_async(void *data, async_cookie_t cookie) nvme_scan_ns(scan_info->ctrl, nsid); } -static void nvme_remove_invalid_namespaces(struct nvme_ctrl *ctrl, - unsigned nsid) +static void nvme_remove_nsid_range(struct nvme_ctrl *ctrl, u32 start, u32 end) { struct nvme_ns *ns, *next; LIST_HEAD(rm_list); mutex_lock(&ctrl->namespaces_lock); list_for_each_entry_safe(ns, next, &ctrl->namespaces, list) { - if (ns->head->ns_id > nsid) { + if (ns->head->ns_id >= end) + break; + if (ns->head->ns_id > start) { list_del_rcu(&ns->list); synchronize_srcu(&ctrl->srcu); list_add_tail_rcu(&ns->list, &rm_list); @@ -4574,13 +4573,14 @@ static int nvme_scan_ns_list(struct nvme_ctrl *ctrl) goto out; async_schedule_domain(nvme_scan_ns_async, &scan_info, &domain); - while (++prev < nsid) - nvme_ns_remove_by_nsid(ctrl, prev); + if (prev + 1 < nsid) + nvme_remove_nsid_range(ctrl, prev, nsid); + prev = max(prev + 1, nsid); } async_synchronize_full_domain(&domain); } out: - nvme_remove_invalid_namespaces(ctrl, prev); + nvme_remove_nsid_range(ctrl, prev, UINT_MAX); free: async_synchronize_full_domain(&domain); kfree(ns_list); @@ -4600,7 +4600,7 @@ static void nvme_scan_ns_sequential(struct nvme_ctrl *ctrl) for (i = 1; i <= nn; i++) nvme_scan_ns(ctrl, i); - nvme_remove_invalid_namespaces(ctrl, nn); + nvme_remove_nsid_range(ctrl, nn, UINT_MAX); } static void nvme_clear_changed_ns_log(struct nvme_ctrl *ctrl)