[patch 3/5] scsi/bnx2i: Prevent recursive cpuhotplug locking

From: Thomas Gleixner
Date: Mon Jul 24 2017 - 06:55:31 EST


The BNX2I module init/exit code installs/removes the hotplug callbacks with
the cpu hotplug lock held. This worked with the old CPU locking
implementation which allowed recursive locking, but with the new percpu
rwsem based mechanism this is not longer allowed.

Use the _cpuslocked() variants to fix this.

Reported-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
drivers/scsi/bnx2i/bnx2i_init.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)

--- a/drivers/scsi/bnx2i/bnx2i_init.c
+++ b/drivers/scsi/bnx2i/bnx2i_init.c
@@ -516,15 +516,16 @@ static int __init bnx2i_mod_init(void)
for_each_online_cpu(cpu)
bnx2i_percpu_thread_create(cpu);

- err = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
- "scsi/bnx2i:online",
- bnx2i_cpu_online, NULL);
+ err = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN,
+ "scsi/bnx2i:online",
+ bnx2i_cpu_online, NULL);
if (err < 0)
goto remove_threads;
bnx2i_online_state = err;

- cpuhp_setup_state_nocalls(CPUHP_SCSI_BNX2I_DEAD, "scsi/bnx2i:dead",
- NULL, bnx2i_cpu_dead);
+ cpuhp_setup_state_nocalls_cpuslocked(CPUHP_SCSI_BNX2I_DEAD,
+ "scsi/bnx2i:dead",
+ NULL, bnx2i_cpu_dead);
put_online_cpus();
return 0;

@@ -574,8 +575,8 @@ static void __exit bnx2i_mod_exit(void)
for_each_online_cpu(cpu)
bnx2i_percpu_thread_destroy(cpu);

- cpuhp_remove_state_nocalls(bnx2i_online_state);
- cpuhp_remove_state_nocalls(CPUHP_SCSI_BNX2I_DEAD);
+ cpuhp_remove_state_nocalls_cpuslocked(bnx2i_online_state);
+ cpuhp_remove_state_nocalls_cpuslocked(CPUHP_SCSI_BNX2I_DEAD);
put_online_cpus();

iscsi_unregister_transport(&bnx2i_iscsi_transport);