Kernel v5.19.16 works without issues.
Booting v6.0.3:
[ 0.000000] microcode: microcode updated early to revision 0xf0, date = 2021-11-12
[ 0.000000] Linux version 6.0.3+ (root@dunno) (gcc (Gentoo 11.3.0 p4) 11.3.0, GNU ld (Gentoo 2.38 p4) 2.38) #288 SMP PREEMPT Sat Oct 22 22:07:33 CEST 2022
[ 0.000000] Command line:
[ ... ]
[ 34.150421] br0: port 2(veth2a8760a2) entered blocking state
[ 34.150423] br0: port 2(veth2a8760a2) entered forwarding state
[ 34.890258] new mount options do not match the existing superblock, will be ignored
[ 88.487151] rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 6667 jiffies s: 301 root: 0x2/.
[ 88.487156] rcu: blocking rcu_node structures (internal RCU debug):
[ 88.487157] Task dump for CPU 1:
[ 88.487158] task:kworker/u16:5 state:R running task stack: 0 pid: 122 ppid: 2 flags:0x00004008
[ 88.487161] Workqueue: btrfs-cache btrfs_work_helper
[ 88.487165] Call Trace:
[ 88.487166] <TASK>
[ 88.487167] ? __schedule+0x241/0x650
[ 88.487170] ? crc32c_pcl_intel_update+0xa1/0xb0
[ 88.487172] ? crc32c+0x1e/0x40
[ 88.487174] ? folio_wait_bit_common+0x17e/0x350
[ 88.487176] ? filemap_invalidate_unlock_two+0x30/0x30
[ 88.487177] ? __load_free_space_cache+0x25e/0x4a0
[ 88.487179] ? pmdp_collapse_flush+0x30/0x30
[ 88.487180] ? folio_clear_dirty_for_io+0x94/0x180
[ 88.487182] ? __load_free_space_cache+0x25e/0x4a0
[ 88.487183] ? kmem_cache_alloc+0x110/0x360
[ 88.487185] ? sysvec_apic_timer_interrupt+0xb/0x90
[ 88.487186] ? asm_sysvec_apic_timer_interrupt+0x16/0x20
[ 88.487188] ? queued_spin_lock_slowpath+0x3d/0x190
[ 88.487190] ? __btrfs_remove_free_space_cache+0x9/0x30
[ 88.487191] ? load_free_space_cache+0x313/0x380
[ 88.487193] ? __clear_extent_bit+0x29e/0x490
[ 88.487194] ? caching_thread+0x385/0x4f0
[ 88.487197] ? dequeue_entity+0xd8/0x250
[ 88.487198] ? btrfs_work_helper+0xcd/0x1e0
[ 88.487200] ? process_one_work+0x1aa/0x300
[ 88.487202] ? worker_thread+0x48/0x3c0
[ 88.487204] ? rescuer_thread+0x3c0/0x3c0
[ 88.487206] ? kthread+0xd1/0x100
[ 88.487207] ? kthread_complete_and_exit+0x20/0x20
[ 88.487209] ? ret_from_fork+0x1f/0x30
[ 88.487210] </TASK>
[ 97.557150] rcu: INFO: rcu_preempt self-detected stall on CPU
[ 97.557152] rcu: 1-....: (17999 ticks this GP) idle=7034/1/0x4000000000000000 softirq=2073/2073 fqs=5999
[ 97.557154] (t=18000 jiffies g=2401 q=2899 ncpus=8)
[ 97.557156] NMI backtrace for cpu 1
[ 97.557157] CPU: 1 PID: 122 Comm: kworker/u16:5 Not tainted 6.0.3+ #288
[ 97.557159] Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./Z270M-ITX/ac, BIOS P2.60 03/16/2018
[ 97.557160] Workqueue: btrfs-cache btrfs_work_helper
[ 97.557163] Call Trace:
[ 97.557165] <IRQ>
[ 97.557186] dump_stack_lvl+0x34/0x44
[ 97.557188] nmi_cpu_backtrace.cold+0x30/0x70
[ 97.557189] ? lapic_can_unplug_cpu+0x80/0x80
[ 97.557191] nmi_trigger_cpumask_backtrace+0x95/0xa0
[ 97.557193] rcu_dump_cpu_stacks+0xb3/0xea
[ 97.557196] rcu_sched_clock_irq.cold+0x1d7/0x699
[ 97.557197] ? raw_notifier_call_chain+0x3c/0x50
[ 97.557198] ? timekeeping_update+0xaa/0x280
[ 97.557200] ? timekeeping_advance+0x35e/0x520
[ 97.557201] ? trigger_load_balance+0x5c/0x390
[ 97.557203] update_process_times+0x56/0x90
[ 97.557205] tick_sched_timer+0x83/0x90
[ 97.557206] ? tick_sched_do_timer+0x90/0x90
[ 97.557206] ? tick_sched_do_timer+0x90/0x90
[ 97.557208] __hrtimer_run_queues+0x10b/0x1b0
[ 97.557209] hrtimer_interrupt+0x109/0x230
[ 97.557210] __sysvec_apic_timer_interrupt+0x47/0x60
[ 97.557213] sysvec_apic_timer_interrupt+0x6d/0x90
[ 97.557215] </IRQ>
[ 97.557215] <TASK>
[ 97.557216] asm_sysvec_apic_timer_interrupt+0x16/0x20
[ 97.557218] RIP: 0010:queued_spin_lock_slowpath+0x3d/0x190
[ 97.557220] Code: 0f ba 2a 08 8b 02 0f 92 c1 0f b6 c9 c1 e1 08 30 e4 09 c8 a9 00 01 ff ff 0f 85 ef 00 00 00 85 c0 74 0e 8b 02 84 c0 74 08 f3 90 <8b> 02 84 c0 75 f8 b8 01 00 00 00 66 89 02 c3 8b 37 b8 00 02 00 00
[ 97.557221] RSP: 0018:ffff888105977ca0 EFLAGS: 00000202
[ 97.557222] RAX: 0000000000000101 RBX: ffff888111df7cc0 RCX: 0000000000000000
[ 97.557223] RDX: ffff888105977ce0 RSI: 0000000000000000 RDI: ffff888105977ce0
[ 97.557224] RBP: ffff888105977ce0 R08: ffff8881336dff88 R09: ffff888105977cf0
[ 97.557224] R10: ffff888105977ce8 R11: ffff888100911d00 R12: ffff88810b06cc00
[ 97.557225] R13: 000000000336e000 R14: 0000000000000001 R15: ffff8881022c5605
[ 97.557226] __btrfs_remove_free_space_cache+0x9/0x30
[ 97.557229] load_free_space_cache+0x313/0x380
[ 97.557230] ? __clear_extent_bit+0x29e/0x490
[ 97.557232] caching_thread+0x385/0x4f0
[ 97.557234] ? dequeue_entity+0xd8/0x250
[ 97.557235] btrfs_work_helper+0xcd/0x1e0
[ 97.557237] process_one_work+0x1aa/0x300
[ 97.557240] worker_thread+0x48/0x3c0
[ 97.557241] ? rescuer_thread+0x3c0/0x3c0
[ 97.557243] kthread+0xd1/0x100
[ 97.557245] ? kthread_complete_and_exit+0x20/0x20
[ 97.557246] ret_from_fork+0x1f/0x30
[ 97.557248] </TASK>
[ 151.633996] rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 25611 jiffies s: 301 root: 0x2/.
[ 151.634000] rcu: blocking rcu_node structures (internal RCU debug):
[ 151.634000] Task dump for CPU 1:
[ 151.634001] task:kworker/u16:5 state:R running task stack: 0 pid: 122 ppid: 2 flags:0x00004008
[ 151.634004] Workqueue: btrfs-cache btrfs_work_helper
[ 151.634008] Call Trace:
[ 151.634008] <TASK>
[ 151.634009] ? __schedule+0x241/0x650
[ 151.634013] ? crc32c_pcl_intel_update+0xa1/0xb0
[ 151.634014] ? crc32c+0x1e/0x40
[ ... ]
-------------------------
Reverting
commit 3ea7c50339859394dd667184b5b16eee1ebb53bc
Author: Josef Bacik <josef@xxxxxxxxxxxxxx>
Date: Mon Aug 8 16:10:26 2022 -0400
btrfs: call __btrfs_remove_free_space_cache_locked on cache load failure
[ Upstream commit 8a1ae2781dee9fc21ca82db682d37bea4bd074ad ]
Now that lockdep is staying enabled through our entire CI runs I started
seeing the following stack in generic/475
------------------------
fixes the problem with dmesg
[ 31.250172] br0: port 2(veth2a020081) entered blocking state
[ 31.250175] br0: port 2(veth2a020081) entered forwarding state
[ 31.924193] new mount options do not match the existing superblock, will be ignored
[ 34.334304] BTRFS warning (device sdb3): block group 35530997760 has wrong amount of free space
[ 34.334314] BTRFS warning (device sdb3): failed to load free space cache for block group 35530997760, rebuilding it now
It is still reproducible.
-- Earny
