[v6.6] possible deadlock in ocfs2_lock_global_qf (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 7a137e9bfa0e Linux 6.6.127
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1032fc02580000
kernel config: https://syzkaller.appspot.com/x/.config?x=2a950bf7c0bff9f9
dashboard link: https://syzkaller.appspot.com/bug?extid=8e3565cd6ea0945c6d7a
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/04a02efb4a79/disk-7a137e9b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f7b848f192f0/vmlinux-7a137e9b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/77a981f90b3d/bzImage-7a137e9b.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8e3565...@syzkaller.appspotmail.com

ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.385/8401 is trying to acquire lock:
ffff88804c5714a0 (&ocfs2_quota_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_lock_global_qf+0x202/0x290 fs/ocfs2/quota_global.c:314

but task is already holding lock:
ffff88804c571818 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
ffff88804c571818 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7){+.+.}-{3:3}, at: ocfs2_lock_global_qf+0x1db/0x290 fs/ocfs2/quota_global.c:313

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7){+.+.}-{3:3}:
down_write+0x97/0x200 kernel/locking/rwsem.c:1573
inode_lock include/linux/fs.h:804 [inline]
ocfs2_lock_global_qf+0x1db/0x290 fs/ocfs2/quota_global.c:313
ocfs2_acquire_dquot+0x2a1/0xb10 fs/ocfs2/quota_global.c:816
dqget+0x77c/0xeb0 fs/quota/dquot.c:990
__dquot_initialize+0x3c7/0xcd0 fs/quota/dquot.c:1518
ocfs2_get_init_inode+0x148/0x1c0 fs/ocfs2/namei.c:202
ocfs2_symlink+0xbf9/0x2700 fs/ocfs2/namei.c:1878
vfs_symlink+0x138/0x2b0 fs/namei.c:4481
do_symlinkat+0x1ba/0x400 fs/namei.c:4507
__do_sys_symlinkat fs/namei.c:4523 [inline]
__se_sys_symlinkat fs/namei.c:4520 [inline]
__x64_sys_symlinkat+0x99/0xb0 fs/namei.c:4520
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #3 (&dquot->dq_lock){+.+.}-{3:3}:
__mutex_lock_common kernel/locking/mutex.c:603 [inline]
__mutex_lock+0x136/0xcc0 kernel/locking/mutex.c:747
wait_on_dquot fs/quota/dquot.c:358 [inline]
dqget+0x6fc/0xeb0 fs/quota/dquot.c:985
__dquot_initialize+0x3c7/0xcd0 fs/quota/dquot.c:1518
ocfs2_get_init_inode+0x148/0x1c0 fs/ocfs2/namei.c:202
ocfs2_symlink+0xbf9/0x2700 fs/ocfs2/namei.c:1878
vfs_symlink+0x138/0x2b0 fs/namei.c:4481
do_symlinkat+0x1ba/0x400 fs/namei.c:4507
__do_sys_symlinkat fs/namei.c:4523 [inline]
__se_sys_symlinkat fs/namei.c:4520 [inline]
__x64_sys_symlinkat+0x99/0xb0 fs/namei.c:4520
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #2 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4){+.+.}-{3:3}:
down_write+0x97/0x200 kernel/locking/rwsem.c:1573
inode_lock include/linux/fs.h:804 [inline]
ocfs2_remove_inode fs/ocfs2/inode.c:655 [inline]
ocfs2_wipe_inode fs/ocfs2/inode.c:818 [inline]
ocfs2_delete_inode fs/ocfs2/inode.c:1079 [inline]
ocfs2_evict_inode+0x1d84/0x41e0 fs/ocfs2/inode.c:1219
evict+0x4ca/0x8d0 fs/inode.c:705
ocfs2_dentry_iput+0x24e/0x390 fs/ocfs2/dcache.c:418
__dentry_kill+0x431/0x650 fs/dcache.c:611
dentry_kill+0xb8/0x290 fs/dcache.c:-1
dput+0xfe/0x1e0 fs/dcache.c:918
do_renameat2+0x8f9/0xce0 fs/namei.c:5035
__do_sys_rename fs/namei.c:5079 [inline]
__se_sys_rename fs/namei.c:5077 [inline]
__x64_sys_rename+0x86/0x90 fs/namei.c:5077
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #1 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]){+.+.}-{3:3}:
down_write+0x97/0x200 kernel/locking/rwsem.c:1573
inode_lock include/linux/fs.h:804 [inline]
ocfs2_del_inode_from_orphan+0x12f/0x7a0 fs/ocfs2/namei.c:2716
ocfs2_dio_end_io_write fs/ocfs2/aops.c:2333 [inline]
ocfs2_dio_end_io+0x546/0x1200 fs/ocfs2/aops.c:2431
dio_complete+0x254/0x710 fs/direct-io.c:282
__blockdev_direct_IO+0x2ea8/0x3500 fs/direct-io.c:1308
ocfs2_direct_IO+0x235/0x2a0 fs/ocfs2/aops.c:2468
generic_file_direct_write+0x1d4/0x3e0 mm/filemap.c:3956
__generic_file_write_iter+0x11b/0x230 mm/filemap.c:4112
ocfs2_file_write_iter+0x167a/0x1e80 fs/ocfs2/file.c:2468
do_iter_readv_writev fs/read_write.c:-1 [inline]
do_iter_write+0x738/0xc30 fs/read_write.c:860
vfs_writev fs/read_write.c:933 [inline]
do_writev+0x27f/0x480 fs/read_write.c:976
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&ocfs2_quota_ip_alloc_sem_key){++++}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain kernel/locking/lockdep.c:3869 [inline]
__lock_acquire+0x2df1/0x7d40 kernel/locking/lockdep.c:5137
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
down_write+0x97/0x200 kernel/locking/rwsem.c:1573
ocfs2_lock_global_qf+0x202/0x290 fs/ocfs2/quota_global.c:314
ocfs2_acquire_dquot+0x2a1/0xb10 fs/ocfs2/quota_global.c:816
dqget+0x77c/0xeb0 fs/quota/dquot.c:990
__dquot_initialize+0x3c7/0xcd0 fs/quota/dquot.c:1518
ocfs2_get_init_inode+0x148/0x1c0 fs/ocfs2/namei.c:202
ocfs2_symlink+0xbf9/0x2700 fs/ocfs2/namei.c:1878
vfs_symlink+0x138/0x2b0 fs/namei.c:4481
do_symlinkat+0x1ba/0x400 fs/namei.c:4507
__do_sys_symlinkat fs/namei.c:4523 [inline]
__se_sys_symlinkat fs/namei.c:4520 [inline]
__x64_sys_symlinkat+0x99/0xb0 fs/namei.c:4520
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

Chain exists of:
&ocfs2_quota_ip_alloc_sem_key --> &dquot->dq_lock --> &ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7);
lock(&dquot->dq_lock);
lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7);
lock(&ocfs2_quota_ip_alloc_sem_key);

*** DEADLOCK ***

5 locks held by syz.0.385/8401:
#0: ffff88807c4fe418 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412
#1: ffff8880776ba658 (&type->i_mutex_dir_key#15/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline]
#1: ffff8880776ba658 (&type->i_mutex_dir_key#15/1){+.+.}-{3:3}, at: filename_create+0x20c/0x480 fs/namei.c:3890
#2: ffff88805b833498 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#2: ffff88805b833498 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4){+.+.}-{3:3}, at: ocfs2_reserve_suballoc_bits+0x16e/0x44c0 fs/ocfs2/suballoc.c:782
#3: ffff8880776f20a8 (&dquot->dq_lock){+.+.}-{3:3}, at: ocfs2_acquire_dquot+0x28f/0xb10 fs/ocfs2/quota_global.c:811
#4: ffff88804c571818 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#4: ffff88804c571818 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7){+.+.}-{3:3}, at: ocfs2_lock_global_qf+0x1db/0x290 fs/ocfs2/quota_global.c:313

stack backtrace:
CPU: 0 PID: 8401 Comm: syz.0.385 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
<TASK>
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
check_noncircular+0x2fc/0x400 kernel/locking/lockdep.c:2187
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain kernel/locking/lockdep.c:3869 [inline]
__lock_acquire+0x2df1/0x7d40 kernel/locking/lockdep.c:5137
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
down_write+0x97/0x200 kernel/locking/rwsem.c:1573
ocfs2_lock_global_qf+0x202/0x290 fs/ocfs2/quota_global.c:314
ocfs2_acquire_dquot+0x2a1/0xb10 fs/ocfs2/quota_global.c:816
dqget+0x77c/0xeb0 fs/quota/dquot.c:990
__dquot_initialize+0x3c7/0xcd0 fs/quota/dquot.c:1518
ocfs2_get_init_inode+0x148/0x1c0 fs/ocfs2/namei.c:202
ocfs2_symlink+0xbf9/0x2700 fs/ocfs2/namei.c:1878
vfs_symlink+0x138/0x2b0 fs/namei.c:4481
do_symlinkat+0x1ba/0x400 fs/namei.c:4507
__do_sys_symlinkat fs/namei.c:4523 [inline]
__se_sys_symlinkat fs/namei.c:4520 [inline]
__x64_sys_symlinkat+0x99/0xb0 fs/namei.c:4520
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f1a7919c629
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1a79fdf028 EFLAGS: 00000246 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 00007f1a79415fa0 RCX: 00007f1a7919c629
RDX: 0000200000000000 RSI: ffffffffffffff9c RDI: 0000200000001040
RBP: 00007f1a79232b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1a79416038 R14: 00007f1a79415fa0 R15: 00007ffde700e128
</TASK>


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