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[2403:580d:fda1::299]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-320f4909b8bsm25045840a91.16.2025.08.10.15.32.43 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 10 Aug 2025 15:32:49 -0700 (PDT) Message-ID: Date: Mon, 11 Aug 2025 08:02:40 +0930 Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [syzbot] [btrfs?] INFO: task hung in __alloc_workqueue (2) To: syzbot , anna-maria@linutronix.de, clm@fb.com, dsterba@suse.com, frederic@kernel.org, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, tglx@linutronix.de, tj@kernel.org, jiangshanlai@gmail.com References: <6899154b.050a0220.51d73.0094.GAE@google.com> Content-Language: en-US From: Qu Wenruo Autocrypt: addr=wqu@suse.com; keydata= xsBNBFnVga8BCACyhFP3ExcTIuB73jDIBA/vSoYcTyysFQzPvez64TUSCv1SgXEByR7fju3o 8RfaWuHCnkkea5luuTZMqfgTXrun2dqNVYDNOV6RIVrc4YuG20yhC1epnV55fJCThqij0MRL 1NxPKXIlEdHvN0Kov3CtWA+R1iNN0RCeVun7rmOrrjBK573aWC5sgP7YsBOLK79H3tmUtz6b 9Imuj0ZyEsa76Xg9PX9Hn2myKj1hfWGS+5og9Va4hrwQC8ipjXik6NKR5GDV+hOZkktU81G5 gkQtGB9jOAYRs86QG/b7PtIlbd3+pppT0gaS+wvwMs8cuNG+Pu6KO1oC4jgdseFLu7NpABEB AAHNGFF1IFdlbnJ1byA8d3F1QHN1c2UuY29tPsLAlAQTAQgAPgIbAwULCQgHAgYVCAkKCwIE FgIDAQIeAQIXgBYhBC3fcuWlpVuonapC4cI9kfOhJf6oBQJnEXVgBQkQ/lqxAAoJEMI9kfOh Jf6o+jIH/2KhFmyOw4XWAYbnnijuYqb/obGae8HhcJO2KIGcxbsinK+KQFTSZnkFxnbsQ+VY fvtWBHGt8WfHcNmfjdejmy9si2jyy8smQV2jiB60a8iqQXGmsrkuR+AM2V360oEbMF3gVvim 2VSX2IiW9KERuhifjseNV1HLk0SHw5NnXiWh1THTqtvFFY+CwnLN2GqiMaSLF6gATW05/sEd V17MdI1z4+WSk7D57FlLjp50F3ow2WJtXwG8yG8d6S40dytZpH9iFuk12Sbg7lrtQxPPOIEU rpmZLfCNJJoZj603613w/M8EiZw6MohzikTWcFc55RLYJPBWQ+9puZtx1DopW2jOwE0EWdWB rwEIAKpT62HgSzL9zwGe+WIUCMB+nOEjXAfvoUPUwk+YCEDcOdfkkM5FyBoJs8TCEuPXGXBO Cl5P5B8OYYnkHkGWutAVlUTV8KESOIm/KJIA7jJA+Ss9VhMjtePfgWexw+P8itFRSRrrwyUf E+0WcAevblUi45LjWWZgpg3A80tHP0iToOZ5MbdYk7YFBE29cDSleskfV80ZKxFv6koQocq0 vXzTfHvXNDELAuH7Ms/WJcdUzmPyBf3Oq6mKBBH8J6XZc9LjjNZwNbyvsHSrV5bgmu/THX2n g/3be+iqf6OggCiy3I1NSMJ5KtR0q2H2Nx2Vqb1fYPOID8McMV9Ll6rh8S8AEQEAAcLAfAQY AQgAJgIbDBYhBC3fcuWlpVuonapC4cI9kfOhJf6oBQJnEXWBBQkQ/lrSAAoJEMI9kfOhJf6o cakH+QHwDszsoYvmrNq36MFGgvAHRjdlrHRBa4A1V1kzd4kOUokongcrOOgHY9yfglcvZqlJ qfa4l+1oxs1BvCi29psteQTtw+memmcGruKi+YHD7793zNCMtAtYidDmQ2pWaLfqSaryjlzR /3tBWMyvIeWZKURnZbBzWRREB7iWxEbZ014B3gICqZPDRwwitHpH8Om3eZr7ygZck6bBa4MU o1XgbZcspyCGqu1xF/bMAY2iCDcq6ULKQceuKkbeQ8qxvt9hVxJC2W3lHq8dlK1pkHPDg9wO JoAXek8MF37R8gpLoGWl41FIUb3hFiu3zhDDvslYM4BmzI18QgQTQnotJH8= In-Reply-To: <6899154b.050a0220.51d73.0094.GAE@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit 在 2025/8/11 07:25, syzbot 写道: > Hello, > > syzbot found the following issue on: > > HEAD commit: 479058002c32 Merge tag 'ata-6.17-rc1-fixes' of git://git.k.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=1315e042580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=943d6f7b1ddd8799 > dashboard link: https://syzkaller.appspot.com/bug?extid=ead9101689c4ca30dbe8 > compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11d262f0580000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/7226b9adab95/disk-47905800.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/b10c6c12e41f/vmlinux-47905800.xz > kernel image: https://storage.googleapis.com/syzbot-assets/7e99b92d1763/bzImage-47905800.xz > mounted in repro: https://storage.googleapis.com/syzbot-assets/1ca3e7130df3/mount_0.gz > fsck result: OK (log: https://syzkaller.appspot.com/x/fsck.log?x=17f2f6a2580000) > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+ead9101689c4ca30dbe8@syzkaller.appspotmail.com > > INFO: task syz.1.170:8358 blocked for more than 143 seconds. > Tainted: G W 6.16.0-syzkaller-11852-g479058002c32 #0 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > task:syz.1.170 state:D stack:26024 pid:8358 tgid:8358 ppid:6003 task_flags:0x400140 flags:0x00004006 > Call Trace: > > context_switch kernel/sched/core.c:5357 [inline] > __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 > __schedule_loop kernel/sched/core.c:7043 [inline] > schedule+0x165/0x360 kernel/sched/core.c:7058 > schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 > do_wait_for_common kernel/sched/completion.c:100 [inline] > __wait_for_common kernel/sched/completion.c:121 [inline] > wait_for_common kernel/sched/completion.c:132 [inline] > wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153 > kthread_flush_worker+0x1c6/0x240 kernel/kthread.c:1563 This is flushing pwq_release_worker during error handling, and I didn't see anything btrfs specific except btrfs is allocating an ordered workqueue which utilizes WQ_UNBOUND flag. And that WQ_UNBOUND flag is pretty widely used among other filesystems, maybe it's just btrfs have too many workqueues triggering this? Adding workqueue maintainers. Thanks, Qu > __alloc_workqueue+0x146b/0x1b70 kernel/workqueue.c:5763 > alloc_workqueue_noprof+0xd4/0x210 kernel/workqueue.c:5786 > btrfs_init_workqueues+0x42c/0x6c0 fs/btrfs/disk-io.c:2000 > open_ctree+0x11ef/0x3a10 fs/btrfs/disk-io.c:3424 > btrfs_fill_super fs/btrfs/super.c:977 [inline] > btrfs_get_tree_super fs/btrfs/super.c:1937 [inline] > btrfs_get_tree_subvol fs/btrfs/super.c:2074 [inline] > btrfs_get_tree+0xf55/0x1820 fs/btrfs/super.c:2108 > vfs_get_tree+0x92/0x2b0 fs/super.c:1815 > do_new_mount+0x2a2/0x9e0 fs/namespace.c:3805 > do_mount fs/namespace.c:4133 [inline] > __do_sys_mount fs/namespace.c:4344 [inline] > __se_sys_mount+0x317/0x410 fs/namespace.c:4321 > do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] > do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > RIP: 0033:0x7fb27169038a > RSP: 002b:00007ffefe6fdaf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 > RAX: ffffffffffffffda RBX: 00007ffefe6fdb80 RCX: 00007fb27169038a > RDX: 00002000000055c0 RSI: 0000200000000200 RDI: 00007ffefe6fdb40 > RBP: 00002000000055c0 R08: 00007ffefe6fdb80 R09: 000000000300000a > R10: 000000000300000a R11: 0000000000000246 R12: 0000200000000200 > R13: 00007ffefe6fdb40 R14: 00000000000055a3 R15: 0000200000000080 > > > Showing all locks held in the system: > 1 lock held by khungtaskd/38: > #0: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] > #0: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] > #0: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 > 1 lock held by udevd/5207: > #0: ffff8880358bfa18 (&ep->lock){++++}-{3:3}, at: write_lock_irq include/linux/rwlock_rt.h:104 [inline] > #0: ffff8880358bfa18 (&ep->lock){++++}-{3:3}, at: ep_poll fs/eventpoll.c:2127 [inline] > #0: ffff8880358bfa18 (&ep->lock){++++}-{3:3}, at: do_epoll_wait+0x84d/0xbb0 fs/eventpoll.c:2560 > 2 locks held by getty/5598: > #0: ffff88823bfae8a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 > #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1410 drivers/tty/n_tty.c:2222 > 3 locks held by kworker/u8:3/5911: > 3 locks held by kworker/u8:7/5942: > 6 locks held by udevd/6060: > 1 lock held by udevd/6069: > 1 lock held by udevd/6190: > 6 locks held by udevd/6237: > #0: ffff88802205eea8 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:884 [inline] > #0: ffff88802205eea8 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_read_iter+0x2ff/0x440 block/fops.c:848 > #1: ffff88803b280250 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:472 [inline] > #1: ffff88803b280250 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/mmap_lock.c:277 [inline] > #1: ffff88803b280250 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x32/0x300 mm/mmap_lock.c:337 > #2: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] > #2: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] > #2: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: ___pte_offset_map+0x29/0x200 mm/pgtable-generic.c:286 > #3: ffff888026394c58 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] > #3: ffff888026394c58 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: __pte_offset_map_lock+0x13e/0x210 mm/pgtable-generic.c:401 > #4: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] > #4: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] > #4: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] > #4: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1bb/0x2c0 kernel/locking/spinlock_rt.c:57 > #5: ffff8880b8833490 ((lock)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] > #5: ffff8880b8833490 ((lock)#2){+.+.}-{3:3}, at: __folio_batch_add_and_move+0x170/0x540 mm/swap.c:-1 > 2 locks held by kworker/u8:9/6857: > 1 lock held by syz.1.170/8358: > #0: ffff88802315a0d0 (&type->s_umount_key#53/1){+.+.}-{4:4}, at: alloc_super+0x204/0x990 fs/super.c:345 > 4 locks held by kworker/u8:11/10100: > 1 lock held by syz.3.381/11502: > 2 locks held by syz.4.382/11516: > #0: ffff88805e1a80d0 (&type->s_umount_key#53/1){+.+.}-{4:4}, at: alloc_super+0x204/0x990 fs/super.c:345 > #1: ffffffff8d611078 (bit_wait_table + i){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] > #1: ffffffff8d611078 (bit_wait_table + i){+.+.}-{3:3}, at: finish_wait kernel/sched/wait.c:394 [inline] > #1: ffffffff8d611078 (bit_wait_table + i){+.+.}-{3:3}, at: __wait_on_bit+0x1ff/0x300 kernel/sched/wait_bit.c:55 > 3 locks held by syz.0.383/11517: > #0: ffff88801aa94488 (sb_writers#5){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3107 [inline] > #0: ffff88801aa94488 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x217/0xaa0 fs/read_write.c:682 > #1: ffff888054b3c598 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] > #1: ffff888054b3c598 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: shmem_file_write_iter+0x82/0x120 mm/shmem.c:3518 > #2: ffff8880b8833490 ((lock)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] > #2: ffff8880b8833490 ((lock)#2){+.+.}-{3:3}, at: __folio_batch_add_and_move+0x170/0x540 mm/swap.c:-1 > 3 locks held by syz.5.384/11518: > #0: ffff88801aa94488 (sb_writers#5){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3107 [inline] > #0: ffff88801aa94488 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x217/0xaa0 fs/read_write.c:682 > #1: ffff8880254a6e88 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] > #1: ffff8880254a6e88 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: shmem_file_write_iter+0x82/0x120 mm/shmem.c:3518 > #2: ffff8880b8833490 ((lock)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] > #2: ffff8880b8833490 ((lock)#2){+.+.}-{3:3}, at: __folio_batch_add_and_move+0x170/0x540 mm/swap.c:-1 > 7 locks held by syz.2.385/11535: > 1 lock held by udevadm/11536: > > ============================================= > > NMI backtrace for cpu 1 > CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Tainted: G W 6.16.0-syzkaller-11852-g479058002c32 #0 PREEMPT_{RT,(full)} > Tainted: [W]=WARN > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 > Call Trace: > > dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 > nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 > nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 > trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] > check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] > watchdog+0xf93/0xfe0 kernel/hung_task.c:491 > kthread+0x711/0x8a0 kernel/kthread.c:463 > ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 > > Sending NMI from CPU 1 to CPUs 0: > NMI backtrace for cpu 0 > CPU: 0 UID: 0 PID: 5911 Comm: kworker/u8:3 Tainted: G W 6.16.0-syzkaller-11852-g479058002c32 #0 PREEMPT_{RT,(full)} > Tainted: [W]=WARN > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 > Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet > RIP: 0010:get_timer_this_cpu_base kernel/time/timer.c:939 [inline] > RIP: 0010:__mod_timer+0x81c/0xf60 kernel/time/timer.c:1101 > Code: 01 00 00 00 48 8b 5c 24 20 41 0f b6 44 2d 00 84 c0 0f 85 72 06 00 00 8b 2b e8 f0 bb 49 09 41 89 c5 89 c3 bf 08 00 00 00 89 c6 0f c1 12 00 41 83 fd 07 44 89 34 24 0f 87 69 06 00 00 e8 4c bc > RSP: 0018:ffffc90004fff680 EFLAGS: 00000082 > RAX: 0000000000000000 RBX: 0000000000000000 RCX: f9fab87ca5ec6a00 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008 > RBP: 0000000000200000 R08: 0000000000000000 R09: 0000000000000000 > R10: dffffc0000000000 R11: fffff520009ffeac R12: ffff8880b8825a80 > R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000802 > FS: 0000000000000000(0000) GS:ffff8881268cd000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f46b6524000 CR3: 000000003afb2000 CR4: 00000000003526f0 > Call Trace: > > queue_delayed_work_on+0x18b/0x280 kernel/workqueue.c:2559 > queue_delayed_work include/linux/workqueue.h:684 [inline] > batadv_forw_packet_queue+0x239/0x2a0 net/batman-adv/send.c:691 > batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:842 [inline] > batadv_iv_ogm_schedule+0x892/0xf00 net/batman-adv/bat_iv_ogm.c:874 > batadv_iv_send_outstanding_bat_ogm_packet+0x6c6/0x7e0 net/batman-adv/bat_iv_ogm.c:1714 > process_one_work kernel/workqueue.c:3236 [inline] > process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 > worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 > kthread+0x711/0x8a0 kernel/kthread.c:463 > ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 > > > > --- > This report is generated by a bot. 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