From: Saravana Kannan <saravanak@google.com> stable inclusion from stable-v5.10.122 commit 71cbce75031aed26c72c2dc8a83111d181685f1b category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5W6OE Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 5ee76c256e928455212ab759c51d198fedbe7523 ] Mounting NFS rootfs was timing out when deferred_probe_timeout was non-zero [1]. This was because ip_auto_config() initcall times out waiting for the network interfaces to show up when deferred_probe_timeout was non-zero. While ip_auto_config() calls wait_for_device_probe() to make sure any currently running deferred probe work or asynchronous probe finishes, that wasn't sufficient to account for devices being deferred until deferred_probe_timeout. Commit 35a672363ab3 ("driver core: Ensure wait_for_device_probe() waits until the deferred_probe_timeout fires") tried to fix that by making sure wait_for_device_probe() waits for deferred_probe_timeout to expire before returning. However, if wait_for_device_probe() is called from the kernel_init() context: - Before deferred_probe_initcall() [2], it causes the boot process to hang due to a deadlock. - After deferred_probe_initcall() [3], it blocks kernel_init() from continuing till deferred_probe_timeout expires and beats the point of deferred_probe_timeout that's trying to wait for userspace to load modules. Neither of this is good. So revert the changes to wait_for_device_probe(). [1] - https://lore.kernel.org/lkml/TYAPR01MB45443DF63B9EF29054F7C41FD8C60@TYAPR01M... [2] - https://lore.kernel.org/lkml/YowHNo4sBjr9ijZr@dev-arch.thelio-3990X/ [3] - https://lore.kernel.org/lkml/Yo3WvGnNk3LvLb7R@linutronix.de/ Fixes: 35a672363ab3 ("driver core: Ensure wait_for_device_probe() waits until the deferred_probe_timeout fires") Cc: John Stultz <jstultz@google.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Naresh Kamboju <naresh.kamboju@linaro.org> Cc: Basil Eljuse <Basil.Eljuse@arm.com> Cc: Ferry Toth <fntoth@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Anders Roxell <anders.roxell@linaro.org> Cc: linux-pm@vger.kernel.org Reported-by: Nathan Chancellor <nathan@kernel.org> Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: John Stultz <jstultz@google.com> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20220526034609.480766-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> Reviewed-by: Wei Li <liwei391@huawei.com> --- drivers/base/dd.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/drivers/base/dd.c b/drivers/base/dd.c index c72f6f5b3297..96181a3bb267 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -250,7 +250,6 @@ DEFINE_SHOW_ATTRIBUTE(deferred_devs); int driver_deferred_probe_timeout; EXPORT_SYMBOL_GPL(driver_deferred_probe_timeout); -static DECLARE_WAIT_QUEUE_HEAD(probe_timeout_waitqueue); static int __init deferred_probe_timeout_setup(char *str) { @@ -302,7 +301,6 @@ static void deferred_probe_timeout_work_func(struct work_struct *work) list_for_each_entry(p, &deferred_probe_pending_list, deferred_probe) dev_info(p->device, "deferred probe pending\n"); mutex_unlock(&deferred_probe_mutex); - wake_up_all(&probe_timeout_waitqueue); } static DECLARE_DELAYED_WORK(deferred_probe_timeout_work, deferred_probe_timeout_work_func); @@ -706,9 +704,6 @@ int driver_probe_done(void) */ void wait_for_device_probe(void) { - /* wait for probe timeout */ - wait_event(probe_timeout_waitqueue, !driver_deferred_probe_timeout); - /* wait for the deferred probe workqueue to finish */ flush_work(&deferred_probe_work); -- 2.20.1