[v6.1] possible deadlock in ocfs2_lock_global_qf (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: fb28aa725e05 Linux 6.1.180
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1749edb9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=872c04466179833f
dashboard link: https://syzkaller.appspot.com/bug?extid=193dbb8aeea8afc0ad13
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d420eb944682/disk-fb28aa72.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/affae450ab23/vmlinux-fb28aa72.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b9e6919ed519/Image-fb28aa72.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+193dbb...@syzkaller.appspotmail.com

JBD2: Ignoring recovery information on journal
ocfs2: Mounting device (7,3) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.3.261/5728 is trying to acquire lock:
ffff0001000ea2e0 (&ocfs2_quota_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_lock_global_qf+0x1ac/0x23c fs/ocfs2/quota_global.c:314

but task is already holding lock:
ffff0001000ea648 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
ffff0001000ea648 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7){+.+.}-{3:3}, at: ocfs2_lock_global_qf+0x190/0x23c fs/ocfs2/quota_global.c:313

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #5 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7){+.+.}-{3:3}:
down_write+0x5c/0x88 kernel/locking/rwsem.c:1573
inode_lock include/linux/fs.h:758 [inline]
ocfs2_lock_global_qf+0x190/0x23c fs/ocfs2/quota_global.c:313
ocfs2_acquire_dquot+0x260/0xab0 fs/ocfs2/quota_global.c:816
dqget+0x638/0xa98 fs/quota/dquot.c:1013
__dquot_initialize+0x2e4/0xb30 fs/quota/dquot.c:1542
dquot_initialize+0x24/0x34 fs/quota/dquot.c:1604
ocfs2_get_init_inode+0x140/0x1b4 fs/ocfs2/namei.c:202
ocfs2_mknod+0x7d4/0x218c fs/ocfs2/namei.c:310
ocfs2_mkdir+0x19c/0x51c fs/ocfs2/namei.c:657
vfs_mkdir+0x314/0x4d8 fs/namei.c:4114
do_mkdirat+0x1b8/0x3ec fs/namei.c:4139
__do_sys_mkdirat fs/namei.c:4154 [inline]
__se_sys_mkdirat fs/namei.c:4152 [inline]
__arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4152
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

-> #4 (&dquot->dq_lock){+.+.}-{3:3}:
__mutex_lock_common+0x1a0/0x1f3c kernel/locking/mutex.c:603
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
dquot_commit+0x54/0x1c8 fs/quota/dquot.c:535
ext4_write_dquot+0x1b4/0x320 fs/ext4/super.c:6817
ext4_mark_dquot_dirty+0xe8/0x150 fs/ext4/super.c:6894
mark_dquot_dirty fs/quota/dquot.c:400 [inline]
mark_all_dquot_dirty+0x108/0x424 fs/quota/dquot.c:440
__dquot_alloc_space+0x564/0xcfc fs/quota/dquot.c:1777
dquot_alloc_space_nodirty include/linux/quotaops.h:293 [inline]
dquot_alloc_space include/linux/quotaops.h:306 [inline]
dquot_alloc_block include/linux/quotaops.h:330 [inline]
ext4_mb_new_blocks+0xd40/0x4244 fs/ext4/mballoc.c:5740
ext4_ext_map_blocks+0x1330/0x563c fs/ext4/extents.c:4361
ext4_map_blocks+0x7b0/0x160c fs/ext4/inode.c:681
ext4_getblk+0x178/0x680 fs/ext4/inode.c:892
ext4_bread+0x3c/0x1a8 fs/ext4/inode.c:948
ext4_append+0x23c/0x488 fs/ext4/namei.c:83
ext4_init_new_dir+0x270/0x4f0 fs/ext4/namei.c:3030
ext4_mkdir+0x3b8/0xa28 fs/ext4/namei.c:3076
vfs_mkdir+0x314/0x4d8 fs/namei.c:4114
do_mkdirat+0x1b8/0x3ec fs/namei.c:4139
__do_sys_mkdirat fs/namei.c:4154 [inline]
__se_sys_mkdirat fs/namei.c:4152 [inline]
__arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4152
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

-> #3 (&ei->i_data_sem){++++}-{3:3}:
down_write+0x5c/0x88 kernel/locking/rwsem.c:1573
ext4_map_blocks+0x720/0x160c fs/ext4/inode.c:674
mpage_map_one_extent fs/ext4/inode.c:2436 [inline]
mpage_map_and_submit_extent fs/ext4/inode.c:2489 [inline]
ext4_writepages+0xdbc/0x28fc fs/ext4/inode.c:2857
do_writepages+0x2c4/0x50c mm/page-writeback.c:2491
__writeback_single_inode+0x164/0x157c fs/fs-writeback.c:1673
writeback_sb_inodes+0x870/0x1470 fs/fs-writeback.c:1964
__writeback_inodes_wb+0x104/0x370 fs/fs-writeback.c:2035
wb_writeback+0x420/0xfdc fs/fs-writeback.c:2140
wb_check_background_flush fs/fs-writeback.c:2206 [inline]
wb_do_writeback fs/fs-writeback.c:2294 [inline]
wb_workfn+0xb40/0xe18 fs/fs-writeback.c:2321
process_one_work+0x7e4/0x13bc kernel/workqueue.c:2292
worker_thread+0x8cc/0xfe8 kernel/workqueue.c:2439
kthread+0x254/0x2e0 kernel/kthread.c:376
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850

-> #2 (jbd2_handle){++++}-{0:0}:
jbd2_journal_lock_updates+0xa8/0x318 fs/jbd2/transaction.c:880
__ocfs2_flush_truncate_log+0x268/0x10a4 fs/ocfs2/alloc.c:6029
ocfs2_flush_truncate_log fs/ocfs2/alloc.c:6076 [inline]
ocfs2_truncate_log_worker+0xa4/0x1a4 fs/ocfs2/alloc.c:6089
process_one_work+0x7e4/0x13bc kernel/workqueue.c:2292
worker_thread+0x8cc/0xfe8 kernel/workqueue.c:2439
kthread+0x254/0x2e0 kernel/kthread.c:376
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850

-> #1 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#2){+.+.}-{3:3}:
down_write+0x5c/0x88 kernel/locking/rwsem.c:1573
inode_lock include/linux/fs.h:758 [inline]
ocfs2_remove_btree_range+0x56c/0x12e8 fs/ocfs2/alloc.c:5742
ocfs2_commit_truncate+0x880/0x1980 fs/ocfs2/alloc.c:7353
ocfs2_truncate_file+0xc04/0x14dc fs/ocfs2/file.c:505
ocfs2_setattr+0x12a0/0x1950 fs/ocfs2/file.c:1212
notify_change+0xb5c/0xe20 fs/attr.c:499
do_truncate+0x188/0x20c fs/open.c:65
vfs_truncate+0x23c/0x2b0 fs/open.c:111
do_sys_truncate+0xec/0x1b4 fs/open.c:134
__do_sys_truncate fs/open.c:146 [inline]
__se_sys_truncate fs/open.c:144 [inline]
__arm64_sys_truncate+0x5c/0x70 fs/open.c:144
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

-> #0 (&ocfs2_quota_ip_alloc_sem_key){++++}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3095 [inline]
check_prevs_add kernel/locking/lockdep.c:3214 [inline]
validate_chain kernel/locking/lockdep.c:3830 [inline]
__lock_acquire+0x2808/0x6634 kernel/locking/lockdep.c:5063
lock_acquire+0x20c/0x638 kernel/locking/lockdep.c:5676
down_write+0x5c/0x88 kernel/locking/rwsem.c:1573
ocfs2_lock_global_qf+0x1ac/0x23c fs/ocfs2/quota_global.c:314
ocfs2_acquire_dquot+0x260/0xab0 fs/ocfs2/quota_global.c:816
dqget+0x638/0xa98 fs/quota/dquot.c:1013
__dquot_initialize+0x2e4/0xb30 fs/quota/dquot.c:1542
dquot_initialize+0x24/0x34 fs/quota/dquot.c:1604
ocfs2_get_init_inode+0x140/0x1b4 fs/ocfs2/namei.c:202
ocfs2_mknod+0x7d4/0x218c fs/ocfs2/namei.c:310
ocfs2_mkdir+0x19c/0x51c fs/ocfs2/namei.c:657
vfs_mkdir+0x314/0x4d8 fs/namei.c:4114
do_mkdirat+0x1b8/0x3ec fs/namei.c:4139
__do_sys_mkdirat fs/namei.c:4154 [inline]
__se_sys_mkdirat fs/namei.c:4152 [inline]
__arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4152
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

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.3.261/5728:
#0: ffff0000cb7a4460 (sb_writers#31){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:402
#1: ffff0001000fc2c8 (&type->i_mutex_dir_key#20/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline]
#1: ffff0001000fc2c8 (&type->i_mutex_dir_key#20/1){+.+.}-{3:3}, at: filename_create+0x1b0/0x3a8 fs/namei.c:3884
#2: ffff0001000edf48 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
#2: ffff0001000edf48 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4){+.+.}-{3:3}, at: ocfs2_reserve_suballoc_bits+0x110/0x3d40 fs/ocfs2/suballoc.c:804
#3: ffff00010005a0a8 (&dquot->dq_lock){+.+.}-{3:3}, at: ocfs2_acquire_dquot+0x254/0xab0 fs/ocfs2/quota_global.c:811
#4: ffff0001000ea648 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
#4: ffff0001000ea648 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7){+.+.}-{3:3}, at: ocfs2_lock_global_qf+0x190/0x23c fs/ocfs2/quota_global.c:313

stack backtrace:
CPU: 1 PID: 5728 Comm: syz.3.261 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026
Call trace:
dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:158
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
__dump_stack+0x30/0x40 lib/dump_stack.c:88
dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106
dump_stack+0x1c/0x5c lib/dump_stack.c:113
print_circular_bug+0x148/0x1b0 kernel/locking/lockdep.c:2048
check_noncircular+0x264/0x2f8 kernel/locking/lockdep.c:2170
check_prev_add kernel/locking/lockdep.c:3095 [inline]
check_prevs_add kernel/locking/lockdep.c:3214 [inline]
validate_chain kernel/locking/lockdep.c:3830 [inline]
__lock_acquire+0x2808/0x6634 kernel/locking/lockdep.c:5063
lock_acquire+0x20c/0x638 kernel/locking/lockdep.c:5676
down_write+0x5c/0x88 kernel/locking/rwsem.c:1573
ocfs2_lock_global_qf+0x1ac/0x23c fs/ocfs2/quota_global.c:314
ocfs2_acquire_dquot+0x260/0xab0 fs/ocfs2/quota_global.c:816
dqget+0x638/0xa98 fs/quota/dquot.c:1013
__dquot_initialize+0x2e4/0xb30 fs/quota/dquot.c:1542
dquot_initialize+0x24/0x34 fs/quota/dquot.c:1604
ocfs2_get_init_inode+0x140/0x1b4 fs/ocfs2/namei.c:202
ocfs2_mknod+0x7d4/0x218c fs/ocfs2/namei.c:310
ocfs2_mkdir+0x19c/0x51c fs/ocfs2/namei.c:657
vfs_mkdir+0x314/0x4d8 fs/namei.c:4114
do_mkdirat+0x1b8/0x3ec fs/namei.c:4139
__do_sys_mkdirat fs/namei.c:4154 [inline]
__se_sys_mkdirat fs/namei.c:4152 [inline]
__arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4152
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585


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