loop0: detected capacity change from 0 to 512
EXT4-fs (loop0): Quota format mount options ignored when QUOTA feature is enabled
ext4 filesystem being mounted at /145/file0 supports timestamps until 2038-01-19 (0x7fffffff)
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.162/5006 is trying to acquire lock:
ffff888061c555a8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x5a/0x410 fs/quota/dquot.c:532

but task is already holding lock:
ffff888071eeb450 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x994/0x1190 fs/ext4/inode.c:4258

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&ei->i_data_sem/2){++++}-{3:3}:
       down_write+0x38/0x60 kernel/locking/rwsem.c:1551
       ext4_map_blocks+0x8c4/0x1a50 fs/ext4/inode.c:668
       ext4_getblk+0x176/0x670 fs/ext4/inode.c:872
       ext4_bread+0x26/0x180 fs/ext4/inode.c:925
       ext4_quota_write+0x237/0x580 fs/ext4/super.c:6623
       write_blk fs/quota/quota_tree.c:64 [inline]
       find_free_dqentry fs/quota/quota_tree.c:307 [inline]
       do_insert_tree+0x1193/0x19c0 fs/quota/quota_tree.c:364
       do_insert_tree+0x5c4/0x19c0 fs/quota/quota_tree.c:366
       do_insert_tree+0x5c4/0x19c0 fs/quota/quota_tree.c:366
       do_insert_tree+0x5c4/0x19c0 fs/quota/quota_tree.c:366
       dq_insert_tree fs/quota/quota_tree.c:392 [inline]
       qtree_write_dquot+0x354/0x4a0 fs/quota/quota_tree.c:411
       v2_write_dquot+0x108/0x190 fs/quota/quota_v2.c:358
       dquot_acquire+0x2d5/0x520 fs/quota/dquot.c:497
       ext4_acquire_dquot+0x2e3/0x4a0 fs/ext4/super.c:6232
       dqget+0x713/0xbb0 fs/quota/dquot.c:1010
       __dquot_initialize+0x324/0xd00 fs/quota/dquot.c:1539
       ext4_file_open+0x2e4/0x700 fs/ext4/file.c:855
       do_dentry_open+0x7f7/0xf90 fs/open.c:826
       do_open fs/namei.c:3616 [inline]
       path_openat+0x2718/0x2fb0 fs/namei.c:3750
       do_filp_open+0x1df/0x400 fs/namei.c:3777
       do_sys_openat2+0x14b/0x500 fs/open.c:1255
       do_sys_open fs/open.c:1271 [inline]
       __do_sys_creat fs/open.c:1347 [inline]
       __se_sys_creat fs/open.c:1341 [inline]
       __x64_sys_creat+0x8c/0xb0 fs/open.c:1341
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #1 (&s->s_dquot.dqio_sem){++++}-{3:3}:
       down_read+0x44/0x2e0 kernel/locking/rwsem.c:1498
       v2_read_dquot+0x4a/0x110 fs/quota/quota_v2.c:332
       dquot_acquire+0x152/0x520 fs/quota/dquot.c:488
       ext4_acquire_dquot+0x2e3/0x4a0 fs/ext4/super.c:6232
       dqget+0x713/0xbb0 fs/quota/dquot.c:1010
       __dquot_initialize+0x324/0xd00 fs/quota/dquot.c:1539
       ext4_file_open+0x2e4/0x700 fs/ext4/file.c:855
       do_dentry_open+0x7f7/0xf90 fs/open.c:826
       do_open fs/namei.c:3616 [inline]
       path_openat+0x2718/0x2fb0 fs/namei.c:3750
       do_filp_open+0x1df/0x400 fs/namei.c:3777
       do_sys_openat2+0x14b/0x500 fs/open.c:1255
       do_sys_open fs/open.c:1271 [inline]
       __do_sys_creat fs/open.c:1347 [inline]
       __se_sys_creat fs/open.c:1341 [inline]
       __x64_sys_creat+0x8c/0xb0 fs/open.c:1341
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #0 (&dquot->dq_lock){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain kernel/locking/lockdep.c:3788 [inline]
       __lock_acquire+0x2c66/0x7b50 kernel/locking/lockdep.c:5012
       lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
       __mutex_lock_common+0x1e5/0x2400 kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
       dquot_commit+0x5a/0x410 fs/quota/dquot.c:532
       ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6212
       mark_dquot_dirty fs/quota/dquot.c:397 [inline]
       mark_all_dquot_dirty+0x1e3/0x400 fs/quota/dquot.c:437
       __dquot_free_space+0x7c3/0xb80 fs/quota/dquot.c:1964
       dquot_free_space_nodirty include/linux/quotaops.h:369 [inline]
       dquot_free_space include/linux/quotaops.h:374 [inline]
       dquot_free_block include/linux/quotaops.h:385 [inline]
       ext4_mb_clear_bb fs/ext4/mballoc.c:6164 [inline]
       ext4_free_blocks+0x1b1b/0x24c0 fs/ext4/mballoc.c:6294
       ext4_remove_blocks fs/ext4/extents.c:2540 [inline]
       ext4_ext_rm_leaf fs/ext4/extents.c:2706 [inline]
       ext4_ext_remove_space+0x2106/0x41a0 fs/ext4/extents.c:2954
       ext4_ext_truncate+0x182/0x230 fs/ext4/extents.c:4504
       ext4_truncate+0xa41/0x1190 fs/ext4/inode.c:4263
       ext4_setattr+0x117c/0x1b70 fs/ext4/inode.c:5620
       notify_change+0xbc6/0xee0 fs/attr.c:505
       do_truncate+0x1ac/0x240 fs/open.c:65
       handle_truncate fs/namei.c:3273 [inline]
       do_open fs/namei.c:3620 [inline]
       path_openat+0x293b/0x2fb0 fs/namei.c:3750
       do_filp_open+0x1df/0x400 fs/namei.c:3777
       do_sys_openat2+0x14b/0x500 fs/open.c:1255
       do_sys_open fs/open.c:1271 [inline]
       __do_sys_creat fs/open.c:1347 [inline]
       __se_sys_creat fs/open.c:1341 [inline]
       __x64_sys_creat+0x8c/0xb0 fs/open.c:1341
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

other info that might help us debug this:

Chain exists of:
  &dquot->dq_lock --> &s->s_dquot.dqio_sem --> &ei->i_data_sem/2

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ei->i_data_sem/2);
                               lock(&s->s_dquot.dqio_sem);
                               lock(&ei->i_data_sem/2);
  lock(&dquot->dq_lock);

 *** DEADLOCK ***

5 locks held by syz.0.162/5006:
 #0: ffff88805beea460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386
 #1: ffff888071eeb5c8 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff888071eeb5c8 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: do_truncate+0x198/0x240 fs/open.c:63
 #2: ffff888071eeb768 (mapping.invalidate_lock){++++}-{3:3}, at: filemap_invalidate_lock include/linux/fs.h:832 [inline]
 #2: ffff888071eeb768 (mapping.invalidate_lock){++++}-{3:3}, at: ext4_setattr+0xf40/0x1b70 fs/ext4/inode.c:5543
 #3: ffff888071eeb450 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x994/0x1190 fs/ext4/inode.c:4258
 #4: ffffffff8c4418d8 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:312

stack backtrace:
CPU: 0 PID: 5006 Comm: syz.0.162 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain kernel/locking/lockdep.c:3788 [inline]
 __lock_acquire+0x2c66/0x7b50 kernel/locking/lockdep.c:5012
 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
 __mutex_lock_common+0x1e5/0x2400 kernel/locking/mutex.c:596
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 dquot_commit+0x5a/0x410 fs/quota/dquot.c:532
 ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6212
 mark_dquot_dirty fs/quota/dquot.c:397 [inline]
 mark_all_dquot_dirty+0x1e3/0x400 fs/quota/dquot.c:437
 __dquot_free_space+0x7c3/0xb80 fs/quota/dquot.c:1964
 dquot_free_space_nodirty include/linux/quotaops.h:369 [inline]
 dquot_free_space include/linux/quotaops.h:374 [inline]
 dquot_free_block include/linux/quotaops.h:385 [inline]
 ext4_mb_clear_bb fs/ext4/mballoc.c:6164 [inline]
 ext4_free_blocks+0x1b1b/0x24c0 fs/ext4/mballoc.c:6294
 ext4_remove_blocks fs/ext4/extents.c:2540 [inline]
 ext4_ext_rm_leaf fs/ext4/extents.c:2706 [inline]
 ext4_ext_remove_space+0x2106/0x41a0 fs/ext4/extents.c:2954
 ext4_ext_truncate+0x182/0x230 fs/ext4/extents.c:4504
 ext4_truncate+0xa41/0x1190 fs/ext4/inode.c:4263
 ext4_setattr+0x117c/0x1b70 fs/ext4/inode.c:5620
 notify_change+0xbc6/0xee0 fs/attr.c:505
 do_truncate+0x1ac/0x240 fs/open.c:65
 handle_truncate fs/namei.c:3273 [inline]
 do_open fs/namei.c:3620 [inline]
 path_openat+0x293b/0x2fb0 fs/namei.c:3750
 do_filp_open+0x1df/0x400 fs/namei.c:3777
 do_sys_openat2+0x14b/0x500 fs/open.c:1255
 do_sys_open fs/open.c:1271 [inline]
 __do_sys_creat fs/open.c:1347 [inline]
 __se_sys_creat fs/open.c:1341 [inline]
 __x64_sys_creat+0x8c/0xb0 fs/open.c:1341
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7ff45cc95019
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:00007ffcb46d1908 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007ff45cf1cfa0 RCX: 00007ff45cc95019
RDX: 0000000000000000 RSI: 00000000000000a0 RDI: 0000200000000180
RBP: 00007ff45cd2c00c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff45cf1cfac R14: 00007ff45cf1cfa0 R15: 00007ff45cf1cfa0
 </TASK>