From 3db835dd8f9a78e9709cb48b77d89b41792e9281 Mon Sep 17 00:00:00 2001 From: fuyuanli Date: Mon, 25 Aug 2025 17:15:08 +0800 Subject: [PATCH] ntb: Add mutex to make link_event_callback executed linearly. Since the CPU selected by schedule_work is uncertain, multiple link_event callbacks may be executed at same time. For example, after peer's link is up, it is down quickly before local link_work completed. If link_cleanup is added to the workqueue of another CPU, then link_work and link_cleanup may be executed at the same time. So add a mutex to prevent them from being executed concurrently. Signed-off-by: fuyuanli Reviewed-by: Logan Gunthorpe Reviewed-by: Dave Jiang Signed-off-by: Jon Mason --- drivers/ntb/ntb_transport.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c index 4f775c3e218f..eb875e3db2e3 100644 --- a/drivers/ntb/ntb_transport.c +++ b/drivers/ntb/ntb_transport.c @@ -59,6 +59,7 @@ #include #include #include +#include #include "linux/ntb.h" #include "linux/ntb_transport.h" @@ -241,6 +242,9 @@ struct ntb_transport_ctx { struct work_struct link_cleanup; struct dentry *debugfs_node_dir; + + /* Make sure workq of link event be executed serially */ + struct mutex link_event_lock; }; enum { @@ -1024,6 +1028,7 @@ static void ntb_transport_link_cleanup_work(struct work_struct *work) struct ntb_transport_ctx *nt = container_of(work, struct ntb_transport_ctx, link_cleanup); + guard(mutex)(&nt->link_event_lock); ntb_transport_link_cleanup(nt); } @@ -1047,6 +1052,8 @@ static void ntb_transport_link_work(struct work_struct *work) u32 val; int rc = 0, i, spad; + guard(mutex)(&nt->link_event_lock); + /* send the local info, in the opposite order of the way we read it */ if (nt->use_msi) { -- 2.47.3