======================================================
WARNING: possible circular locking dependency detected
5.15.0-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.4/9601 is trying to acquire lock:
ffff88806bdf2b28 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x4d/0x420 fs/quota/dquot.c:474

but task is already holding lock:
ffff8880459b1668 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x5e1/0x17d0 fs/ext4/inode.c:630

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_read+0x98/0x440 kernel/locking/rwsem.c:1474
       ext4_map_blocks+0x381/0x17d0 fs/ext4/inode.c:560
       ext4_getblk+0x144/0x6b0 fs/ext4/inode.c:847
       ext4_bread+0x2a/0x1c0 fs/ext4/inode.c:900
       ext4_quota_write+0x26d/0x690 fs/ext4/super.c:6486
       write_blk+0x12e/0x220 fs/quota/quota_tree.c:64
       get_free_dqblk+0x104/0x2c0 fs/quota/quota_tree.c:93
       do_insert_tree+0x63a/0x11f0 fs/quota/quota_tree.c:300
       do_insert_tree+0xd90/0x11f0 fs/quota/quota_tree.c:331
       do_insert_tree+0xd90/0x11f0 fs/quota/quota_tree.c:331
       do_insert_tree+0xd90/0x11f0 fs/quota/quota_tree.c:331
       dq_insert_tree fs/quota/quota_tree.c:357 [inline]
       qtree_write_dquot+0x3b0/0x570 fs/quota/quota_tree.c:376
       v2_write_dquot+0x11c/0x250 fs/quota/quota_v2.c:358
       dquot_acquire+0x2c5/0x590 fs/quota/dquot.c:441
       ext4_acquire_dquot+0x254/0x3b0 fs/ext4/super.c:6155
       dqget+0x679/0x1080 fs/quota/dquot.c:899
       __dquot_initialize+0x560/0xbe0 fs/quota/dquot.c:1477
       ext4_create+0x90/0x4d0 fs/ext4/namei.c:2739
       lookup_open.isra.0+0xfe4/0x13d0 fs/namei.c:3280
       open_last_lookups fs/namei.c:3350 [inline]
       path_openat+0x9b8/0x2750 fs/namei.c:3556
       do_filp_open+0x1aa/0x400 fs/namei.c:3586
       do_sys_openat2+0x16d/0x4d0 fs/open.c:1212
       do_sys_open fs/open.c:1228 [inline]
       __do_sys_creat fs/open.c:1304 [inline]
       __se_sys_creat fs/open.c:1298 [inline]
       __x64_sys_creat+0xc9/0x120 fs/open.c:1298
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #1 (&s->s_dquot.dqio_sem){++++}-{3:3}:
       down_read+0x98/0x440 kernel/locking/rwsem.c:1474
       v2_read_dquot+0x49/0x120 fs/quota/quota_v2.c:332
       dquot_acquire+0x12e/0x590 fs/quota/dquot.c:432
       ext4_acquire_dquot+0x254/0x3b0 fs/ext4/super.c:6155
       dqget+0x679/0x1080 fs/quota/dquot.c:899
       __dquot_initialize+0x560/0xbe0 fs/quota/dquot.c:1477
       ext4_create+0x90/0x4d0 fs/ext4/namei.c:2739
       lookup_open.isra.0+0xfe4/0x13d0 fs/namei.c:3280
       open_last_lookups fs/namei.c:3350 [inline]
       path_openat+0x9b8/0x2750 fs/namei.c:3556
       do_filp_open+0x1aa/0x400 fs/namei.c:3586
       do_sys_openat2+0x16d/0x4d0 fs/open.c:1212
       do_sys_open fs/open.c:1228 [inline]
       __do_sys_creat fs/open.c:1304 [inline]
       __se_sys_creat fs/open.c:1298 [inline]
       __x64_sys_creat+0xc9/0x120 fs/open.c:1298
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #0 (&dquot->dq_lock){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3066 [inline]
       check_prevs_add kernel/locking/lockdep.c:3189 [inline]
       validate_chain kernel/locking/lockdep.c:3804 [inline]
       __lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5030
       lock_acquire kernel/locking/lockdep.c:5640 [inline]
       lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5605
       __mutex_lock_common kernel/locking/mutex.c:607 [inline]
       __mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:740
       dquot_commit+0x4d/0x420 fs/quota/dquot.c:474
       ext4_write_dquot+0x24e/0x310 fs/ext4/super.c:6139
       ext4_mark_dquot_dirty fs/ext4/super.c:6187 [inline]
       ext4_mark_dquot_dirty+0x111/0x1b0 fs/ext4/super.c:6181
       mark_dquot_dirty fs/quota/dquot.c:345 [inline]
       mark_all_dquot_dirty fs/quota/dquot.c:383 [inline]
       __dquot_alloc_space+0x5d4/0xb60 fs/quota/dquot.c:1707
       dquot_alloc_space_nodirty include/linux/quotaops.h:297 [inline]
       dquot_alloc_space include/linux/quotaops.h:310 [inline]
       dquot_alloc_block include/linux/quotaops.h:334 [inline]
       ext4_mb_new_blocks+0x5b1/0x51f0 fs/ext4/mballoc.c:5548
       ext4_ext_map_blocks+0x1fa4/0x6140 fs/ext4/extents.c:4250
       ext4_map_blocks+0x653/0x17d0 fs/ext4/inode.c:637
       _ext4_get_block+0x241/0x590 fs/ext4/inode.c:793
       ext4_block_write_begin+0x539/0x1140 fs/ext4/inode.c:1078
       ext4_write_begin+0x4c7/0x14d0 fs/ext4/inode.c:1202
       ext4_da_write_begin+0x5c4/0xad0 fs/ext4/inode.c:2944
       generic_perform_write+0x205/0x510 mm/filemap.c:3748
       ext4_buffered_write_iter+0x1ac/0x3b0 fs/ext4/file.c:269
       ext4_file_write_iter+0x423/0x14e0 fs/ext4/file.c:681
       call_write_iter include/linux/fs.h:2162 [inline]
       new_sync_write+0x429/0x660 fs/read_write.c:503
       vfs_write+0x7cd/0xae0 fs/read_write.c:590
       ksys_write+0x12d/0x250 fs/read_write.c:643
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x44/0xae

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-executor.4/9601:
 #0: ffff88801e4db9f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990
 #1: ffff88804450c460 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x12d/0x250 fs/read_write.c:643
 #2: ffff8880459b17e0 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:783 [inline]
 #2: ffff8880459b17e0 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: ext4_buffered_write_iter+0xb6/0x3b0 fs/ext4/file.c:263
 #3: ffff8880459b1668 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x5e1/0x17d0 fs/ext4/inode.c:630
 #4: ffffffff8bb464b8 (dquot_srcu){....}-{0:0}, at: i_dquot fs/quota/dquot.c:924 [inline]
 #4: ffffffff8bb464b8 (dquot_srcu){....}-{0:0}, at: __dquot_alloc_space+0x1b4/0xb60 fs/quota/dquot.c:1669

stack backtrace:
CPU: 1 PID: 9601 Comm: syz-executor.4 Not tainted 5.15.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2146
 check_prev_add kernel/locking/lockdep.c:3066 [inline]
 check_prevs_add kernel/locking/lockdep.c:3189 [inline]
 validate_chain kernel/locking/lockdep.c:3804 [inline]
 __lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5030
 lock_acquire kernel/locking/lockdep.c:5640 [inline]
 lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5605
 __mutex_lock_common kernel/locking/mutex.c:607 [inline]
 __mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:740
 dquot_commit+0x4d/0x420 fs/quota/dquot.c:474
 ext4_write_dquot+0x24e/0x310 fs/ext4/super.c:6139
 ext4_mark_dquot_dirty fs/ext4/super.c:6187 [inline]
 ext4_mark_dquot_dirty+0x111/0x1b0 fs/ext4/super.c:6181
 mark_dquot_dirty fs/quota/dquot.c:345 [inline]
 mark_all_dquot_dirty fs/quota/dquot.c:383 [inline]
 __dquot_alloc_space+0x5d4/0xb60 fs/quota/dquot.c:1707
 dquot_alloc_space_nodirty include/linux/quotaops.h:297 [inline]
 dquot_alloc_space include/linux/quotaops.h:310 [inline]
 dquot_alloc_block include/linux/quotaops.h:334 [inline]
 ext4_mb_new_blocks+0x5b1/0x51f0 fs/ext4/mballoc.c:5548
 ext4_ext_map_blocks+0x1fa4/0x6140 fs/ext4/extents.c:4250
 ext4_map_blocks+0x653/0x17d0 fs/ext4/inode.c:637
 _ext4_get_block+0x241/0x590 fs/ext4/inode.c:793
 ext4_block_write_begin+0x539/0x1140 fs/ext4/inode.c:1078
 ext4_write_begin+0x4c7/0x14d0 fs/ext4/inode.c:1202
 ext4_da_write_begin+0x5c4/0xad0 fs/ext4/inode.c:2944
 generic_perform_write+0x205/0x510 mm/filemap.c:3748
 ext4_buffered_write_iter+0x1ac/0x3b0 fs/ext4/file.c:269
 ext4_file_write_iter+0x423/0x14e0 fs/ext4/file.c:681
 call_write_iter include/linux/fs.h:2162 [inline]
 new_sync_write+0x429/0x660 fs/read_write.c:503
 vfs_write+0x7cd/0xae0 fs/read_write.c:590
 ksys_write+0x12d/0x250 fs/read_write.c:643
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f5ce6b69ae9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5ce40df188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5ce6c7cf60 RCX: 00007f5ce6b69ae9
RDX: 000000000d4ba0ff RSI: 00000000200009c0 RDI: 0000000000000004
RBP: 00007f5ce6bc3f45 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe5c02194f R14: 00007f5ce40df300 R15: 0000000000022000
 </TASK>