Hello, kernel test robot noticed "WARNING:inconsistent_lock_state" on: commit: 9a4131bb20fbeb5980c3e21709488b9c4ef2eee5 ("[RFC v2 1/1] fs/namespace: defer RCU sync for MNT_DETACH umount") url: https://github.com/intel-lab-lkp/linux/commits/Lucas-Karpinski/fs-namespace-defer-RCU-sync-for-MNT_DETACH-umount/20240427-035724 base: https://git.kernel.org/cgit/linux/kernel/git/vfs/vfs.git vfs.all patch link: https://lore.kernel.org/all/20240426195429.28547-2-lkarpins@xxxxxxxxxx/ patch subject: [RFC v2 1/1] fs/namespace: defer RCU sync for MNT_DETACH umount in testcase: boot compiler: gcc-7 test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G (please refer to attached dmesg/kmsg for entire log/backtrace) +---------------------------------------------------+------------+------------+ | | eea3260250 | 9a4131bb20 | +---------------------------------------------------+------------+------------+ | WARNING:inconsistent_lock_state | 0 | 12 | | inconsistent{SOFTIRQ-ON-W}->{IN-SOFTIRQ-W}usage | 0 | 12 | +---------------------------------------------------+------------+------------+ If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <oliver.sang@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-lkp/202404302220.f8959d4c-oliver.sang@xxxxxxxxx [ 19.407878][ C0] [ 19.408164][ C0] ================================ [ 19.408629][ C0] WARNING: inconsistent lock state [ 19.409083][ C0] 6.9.0-rc3-00075-g9a4131bb20fb #2 Tainted: G W TN [ 19.409757][ C0] -------------------------------- [ 19.410209][ C0] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. [ 19.410777][ C0] ksoftirqd/0/10 [HC0[0]:SC1[3]:HE1:SE0] takes: [ 19.411306][ C0] ffffffff83066cd0 (mount_lock){+.?.}-{2:2}, at: mntput_no_expire (include/linux/seqlock.h:469 include/linux/seqlock.h:495 include/linux/seqlock.h:823 fs/namespace.c:114 fs/namespace.c:1314) [ 19.412072][ C0] {SOFTIRQ-ON-W} state was registered at: [ 19.412574][ C0] lock_acquire (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5756) [ 19.412999][ C0] _raw_spin_lock (include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) [ 19.413421][ C0] vfs_create_mount (include/linux/seqlock.h:469 include/linux/seqlock.h:495 include/linux/seqlock.h:823 fs/namespace.c:114 fs/namespace.c:1122) [ 19.413862][ C0] fc_mount (fs/namespace.c:1134) [ 19.414246][ C0] vfs_kern_mount (fs/namespace.c:1148 fs/namespace.c:1181) [ 19.414713][ C0] kern_mount (fs/namespace.c:5248) [ 19.415106][ C0] shmem_init (mm/shmem.c:4684) [ 19.415508][ C0] mnt_init (fs/namespace.c:5232) [ 19.415907][ C0] vfs_caches_init (fs/dcache.c:3187) [ 19.416333][ C0] start_kernel (init/main.c:1058) [ 19.416760][ C0] x86_64_start_reservations (arch/x86/kernel/head64.c:495) [ 19.417245][ C0] x86_64_start_kernel (arch/x86/kernel/head64.c:488) [ 19.417694][ C0] common_startup_64 (arch/x86/kernel/head_64.S:421) [ 19.418133][ C0] irq event stamp: 868370 [ 19.418530][ C0] hardirqs last enabled at (868370): __local_bh_enable_ip (arch/x86/include/asm/paravirt.h:698 kernel/softirq.c:387) [ 19.419370][ C0] hardirqs last disabled at (868369): __local_bh_enable_ip (kernel/softirq.c:364 (discriminator 1)) [ 19.420216][ C0] softirqs last enabled at (868292): __do_softirq (arch/x86/include/asm/preempt.h:26 kernel/softirq.c:401 kernel/softirq.c:583) [ 19.421025][ C0] softirqs last disabled at (868297): run_ksoftirqd (kernel/softirq.c:411 kernel/softirq.c:925) [ 19.421823][ C0] [ 19.421823][ C0] other info that might help us debug this: [ 19.422522][ C0] Possible unsafe locking scenario: [ 19.422522][ C0] [ 19.423184][ C0] CPU0 [ 19.423510][ C0] ---- [ 19.423838][ C0] lock(mount_lock); [ 19.424225][ C0] <Interrupt> [ 19.424567][ C0] lock(mount_lock); [ 19.425115][ C0] [ 19.425115][ C0] *** DEADLOCK *** [ 19.425115][ C0] [ 19.425858][ C0] 2 locks held by ksoftirqd/0/10: [ 19.426297][ C0] #0: ffffffff8301d700 (rcu_callback){....}-{0:0}, at: rcu_process_callbacks (include/linux/bottom_half.h:20 kernel/rcu/tiny.c:133) [ 19.427122][ C0] #1: ffffffff8301d7c0 (rcu_read_lock){....}-{1:2}, at: mntput_no_expire (include/linux/rcupdate.h:329 include/linux/rcupdate.h:781 fs/namespace.c:1299) [ 19.427921][ C0] [ 19.427921][ C0] stack backtrace: [ 19.428459][ C0] CPU: 0 PID: 10 Comm: ksoftirqd/0 Tainted: G W TN 6.9.0-rc3-00075-g9a4131bb20fb #2 [ 19.429328][ C0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 [ 19.430179][ C0] Call Trace: [ 19.430505][ C0] <TASK> [ 19.430805][ C0] dump_stack_lvl (arch/x86/include/asm/paravirt.h:687 (discriminator 3) arch/x86/include/asm/irqflags.h:127 (discriminator 3) lib/dump_stack.c:117 (discriminator 3)) [ 19.431221][ C0] mark_lock+0x473/0x4c0 [ 19.431661][ C0] ? __lock_acquire (kernel/locking/lockdep.c:4599 kernel/locking/lockdep.c:5091) [ 19.432102][ C0] ? __lock_acquire (include/linux/hash.h:78 kernel/locking/lockdep.c:3759 kernel/locking/lockdep.c:3782 kernel/locking/lockdep.c:3837 kernel/locking/lockdep.c:5137) [ 19.432550][ C0] ? __lock_acquire (kernel/locking/lockdep.c:4567 kernel/locking/lockdep.c:5091) [ 19.432989][ C0] __lock_acquire (kernel/locking/lockdep.c:4567 kernel/locking/lockdep.c:5091) [ 19.433415][ C0] ? __lock_acquire (kernel/locking/lockdep.c:5134 (discriminator 9)) [ 19.433856][ C0] lock_acquire (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5756) [ 19.434269][ C0] ? mntput_no_expire (include/linux/seqlock.h:469 include/linux/seqlock.h:495 include/linux/seqlock.h:823 fs/namespace.c:114 fs/namespace.c:1314) [ 19.434708][ C0] ? mntput_no_expire (include/linux/rcupdate.h:329 include/linux/rcupdate.h:781 fs/namespace.c:1299) [ 19.435144][ C0] _raw_spin_lock (include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) [ 19.435555][ C0] ? mntput_no_expire (include/linux/seqlock.h:469 include/linux/seqlock.h:495 include/linux/seqlock.h:823 fs/namespace.c:114 fs/namespace.c:1314) [ 19.435994][ C0] mntput_no_expire (include/linux/seqlock.h:469 include/linux/seqlock.h:495 include/linux/seqlock.h:823 fs/namespace.c:114 fs/namespace.c:1314) [ 19.436421][ C0] ? rcu_process_callbacks (include/linux/bottom_half.h:20 kernel/rcu/tiny.c:133) [ 19.436900][ C0] free_mounts (fs/namespace.c:1571) [ 19.437291][ C0] ? __x64_sys_mount_setattr (fs/namespace.c:1574) [ 19.437772][ C0] ? __x64_sys_mount_setattr (fs/namespace.c:1574) [ 19.438253][ C0] delayed_mount_release (fs/namespace.c:1579) [ 19.438699][ C0] rcu_process_callbacks (include/linux/rcupdate.h:339 kernel/rcu/tiny.c:103 kernel/rcu/tiny.c:134) [ 19.439151][ C0] __do_softirq (arch/x86/include/asm/atomic.h:23 include/linux/atomic/atomic-arch-fallback.h:457 include/linux/jump_label.h:260 include/linux/jump_label.h:270 include/trace/events/irq.h:142 kernel/softirq.c:555) [ 19.439556][ C0] ? smpboot_thread_fn (kernel/smpboot.c:112) [ 19.439997][ C0] ? sort_range (kernel/smpboot.c:107) [ 19.440389][ C0] run_ksoftirqd (kernel/softirq.c:411 kernel/softirq.c:925) [ 19.443032][ C0] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) [ 19.443510][ C0] kthread (kernel/kthread.c:388) [ 19.443887][ C0] ? kthread_complete_and_exit (kernel/kthread.c:341) [ 19.444367][ C0] ret_from_fork (arch/x86/kernel/process.c:153) [ 19.444788][ C0] ? kthread_complete_and_exit (kernel/kthread.c:341) [ 19.445269][ C0] ret_from_fork_asm (arch/x86/entry/entry_64.S:253) [ 19.445696][ C0] </TASK> The kernel config and materials to reproduce are available at: https://download.01.org/0day-ci/archive/20240430/202404302220.f8959d4c-oliver.sang@xxxxxxxxx -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki