From: syzbot <syzbot+4248e91deb3db78358a2@syzkaller.appspotmail.com>
To: chandan.babu@oracle.com, djwong@kernel.org,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-xfs@vger.kernel.org, syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [xfs?] possible deadlock in xfs_icwalk_ag (2)
Date: Wed, 14 Aug 2024 07:12:25 -0700 [thread overview]
Message-ID: <000000000000c61f9a061fa550db@google.com> (raw)
In-Reply-To: <000000000000e33add0616358204@google.com>
syzbot has found a reproducer for the following issue on:
HEAD commit: 6b0f8db921ab Merge tag 'execve-v6.11-rc4' of git://git.ker..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=149dea91980000
kernel config: https://syzkaller.appspot.com/x/.config?x=801d05d1ea4be1b8
dashboard link: https://syzkaller.appspot.com/bug?extid=4248e91deb3db78358a2
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10aa45cb980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17b59205980000
Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-6b0f8db9.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b407dbb66544/vmlinux-6b0f8db9.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5c1cf0f1b692/bzImage-6b0f8db9.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/ddaad63422d8/mount_0.gz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4248e91deb3db78358a2@syzkaller.appspotmail.com
======================================================
WARNING: possible circular locking dependency detected
6.11.0-rc3-syzkaller-00013-g6b0f8db921ab #0 Not tainted
------------------------------------------------------
kswapd0/80 is trying to acquire lock:
ffff88803ba5a7d8 (&xfs_nondir_ilock_class#3){++++}-{3:3}, at: xfs_reclaim_inode fs/xfs/xfs_icache.c:944 [inline]
ffff88803ba5a7d8 (&xfs_nondir_ilock_class#3){++++}-{3:3}, at: xfs_icwalk_process_inode fs/xfs/xfs_icache.c:1630 [inline]
ffff88803ba5a7d8 (&xfs_nondir_ilock_class#3){++++}-{3:3}, at: xfs_icwalk_ag+0x120e/0x1ad0 fs/xfs/xfs_icache.c:1712
but task is already holding lock:
ffffffff8ea2fce0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6841 [inline]
ffffffff8ea2fce0 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xbb4/0x35a0 mm/vmscan.c:7223
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (fs_reclaim){+.+.}-{0:0}:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
__fs_reclaim_acquire mm/page_alloc.c:3823 [inline]
fs_reclaim_acquire+0x88/0x140 mm/page_alloc.c:3837
might_alloc include/linux/sched/mm.h:334 [inline]
slab_pre_alloc_hook mm/slub.c:3939 [inline]
slab_alloc_node mm/slub.c:4017 [inline]
__do_kmalloc_node mm/slub.c:4157 [inline]
__kmalloc_noprof+0xa9/0x400 mm/slub.c:4170
kmalloc_noprof include/linux/slab.h:685 [inline]
xfs_attr_shortform_list+0x753/0x1900 fs/xfs/xfs_attr_list.c:117
xfs_attr_list+0x1d0/0x270 fs/xfs/xfs_attr_list.c:595
xfs_vn_listxattr+0x1d2/0x2c0 fs/xfs/xfs_xattr.c:341
vfs_listxattr fs/xattr.c:493 [inline]
listxattr+0x107/0x290 fs/xattr.c:841
path_listxattr fs/xattr.c:865 [inline]
__do_sys_listxattr fs/xattr.c:877 [inline]
__se_sys_listxattr fs/xattr.c:874 [inline]
__x64_sys_listxattr+0x173/0x230 fs/xattr.c:874
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (&xfs_nondir_ilock_class#3){++++}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3133 [inline]
check_prevs_add kernel/locking/lockdep.c:3252 [inline]
validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868
__lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
down_write_nested+0xa2/0x220 kernel/locking/rwsem.c:1695
xfs_reclaim_inode fs/xfs/xfs_icache.c:944 [inline]
xfs_icwalk_process_inode fs/xfs/xfs_icache.c:1630 [inline]
xfs_icwalk_ag+0x120e/0x1ad0 fs/xfs/xfs_icache.c:1712
xfs_icwalk fs/xfs/xfs_icache.c:1761 [inline]
xfs_reclaim_inodes_nr+0x2d4/0x3e0 fs/xfs/xfs_icache.c:1010
super_cache_scan+0x40f/0x4b0 fs/super.c:227
do_shrink_slab+0x701/0x1160 mm/shrinker.c:435
shrink_slab+0x1090/0x14c0 mm/shrinker.c:662
shrink_one+0x43b/0x850 mm/vmscan.c:4815
shrink_many mm/vmscan.c:4876 [inline]
lru_gen_shrink_node mm/vmscan.c:4954 [inline]
shrink_node+0x3799/0x3de0 mm/vmscan.c:5934
kswapd_shrink_node mm/vmscan.c:6762 [inline]
balance_pgdat mm/vmscan.c:6954 [inline]
kswapd+0x1bcd/0x35a0 mm/vmscan.c:7223
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(fs_reclaim);
lock(&xfs_nondir_ilock_class#3);
lock(fs_reclaim);
lock(&xfs_nondir_ilock_class#3);
*** DEADLOCK ***
2 locks held by kswapd0/80:
#0: ffffffff8ea2fce0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6841 [inline]
#0: ffffffff8ea2fce0 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xbb4/0x35a0 mm/vmscan.c:7223
#1: ffff88803a4000e0 (&type->s_umount_key#44){.+.+}-{3:3}, at: super_trylock_shared fs/super.c:562 [inline]
#1: ffff88803a4000e0 (&type->s_umount_key#44){.+.+}-{3:3}, at: super_cache_scan+0x94/0x4b0 fs/super.c:196
stack backtrace:
CPU: 0 UID: 0 PID: 80 Comm: kswapd0 Not tainted 6.11.0-rc3-syzkaller-00013-g6b0f8db921ab #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:93 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2186
check_prev_add kernel/locking/lockdep.c:3133 [inline]
check_prevs_add kernel/locking/lockdep.c:3252 [inline]
validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868
__lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
down_write_nested+0xa2/0x220 kernel/locking/rwsem.c:1695
xfs_reclaim_inode fs/xfs/xfs_icache.c:944 [inline]
xfs_icwalk_process_inode fs/xfs/xfs_icache.c:1630 [inline]
xfs_icwalk_ag+0x120e/0x1ad0 fs/xfs/xfs_icache.c:1712
xfs_icwalk fs/xfs/xfs_icache.c:1761 [inline]
xfs_reclaim_inodes_nr+0x2d4/0x3e0 fs/xfs/xfs_icache.c:1010
super_cache_scan+0x40f/0x4b0 fs/super.c:227
do_shrink_slab+0x701/0x1160 mm/shrinker.c:435
shrink_slab+0x1090/0x14c0 mm/shrinker.c:662
shrink_one+0x43b/0x850 mm/vmscan.c:4815
shrink_many mm/vmscan.c:4876 [inline]
lru_gen_shrink_node mm/vmscan.c:4954 [inline]
shrink_node+0x3799/0x3de0 mm/vmscan.c:5934
kswapd_shrink_node mm/vmscan.c:6762 [inline]
balance_pgdat mm/vmscan.c:6954 [inline]
kswapd+0x1bcd/0x35a0 mm/vmscan.c:7223
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
prev parent reply other threads:[~2024-08-14 14:12 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-16 12:02 [syzbot] [xfs?] possible deadlock in xfs_icwalk_ag (2) syzbot
2024-08-14 14:12 ` syzbot [this message]
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