EXT4-fs (loop1): mounted filesystem without journal. Opts: ,errors=continue. Quota mode: writeback.
======================================================
WARNING: possible circular locking dependency detected
5.13.0-rc7-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.1/23111 is trying to acquire lock:
ffff888080c76428 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x57/0x360 fs/quota/dquot.c:474

but task is already holding lock:
ffff888080c99668 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x9e5/0x1cb0 fs/ext4/inode.c:631

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&ei->i_data_sem/2){++++}-{3:3}:
       lock_acquire+0x17f/0x720 kernel/locking/lockdep.c:5512
       down_read+0x3b/0x50 kernel/locking/rwsem.c:1353
       ext4_map_blocks+0x266/0x1cb0 fs/ext4/inode.c:561
       ext4_getblk+0x187/0x6c0 fs/ext4/inode.c:848
       ext4_bread+0x2a/0x1c0 fs/ext4/inode.c:900
       ext4_quota_write+0x2c7/0x5b0 fs/ext4/super.c:6603
       write_blk fs/quota/quota_tree.c:73 [inline]
       get_free_dqblk+0x335/0x660 fs/quota/quota_tree.c:102
       do_insert_tree+0x247/0x1d30 fs/quota/quota_tree.c:309
       do_insert_tree+0x659/0x1d30 fs/quota/quota_tree.c:340
       do_insert_tree+0x659/0x1d30 fs/quota/quota_tree.c:340
       do_insert_tree+0x659/0x1d30 fs/quota/quota_tree.c:340
       dq_insert_tree fs/quota/quota_tree.c:366 [inline]
       qtree_write_dquot+0x3b1/0x530 fs/quota/quota_tree.c:385
       v2_write_dquot+0x110/0x1a0 fs/quota/quota_v2.c:358
       dquot_acquire+0x2d7/0x5b0 fs/quota/dquot.c:441
       ext4_acquire_dquot+0x2e0/0x400 fs/ext4/super.c:6262
       dqget+0x999/0xdc0 fs/quota/dquot.c:899
       __dquot_initialize+0x291/0xd40 fs/quota/dquot.c:1477
       ext4_xattr_set+0xdc/0x380 fs/ext4/xattr.c:2481
       __vfs_setxattr+0x3ab/0x3e0 fs/xattr.c:180
       __vfs_setxattr_noperm+0x128/0x4f0 fs/xattr.c:214
       vfs_setxattr+0x228/0x440 fs/xattr.c:301
       setxattr+0x17c/0x2c0 fs/xattr.c:575
       path_setxattr+0x198/0x260 fs/xattr.c:595
       __do_sys_setxattr fs/xattr.c:611 [inline]
       __se_sys_setxattr fs/xattr.c:607 [inline]
       __x64_sys_setxattr+0xb7/0xd0 fs/xattr.c:607
       do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #1 (&s->s_dquot.dqio_sem){++++}-{3:3}:
       lock_acquire+0x17f/0x720 kernel/locking/lockdep.c:5512
       down_read+0x3b/0x50 kernel/locking/rwsem.c:1353
       v2_read_dquot+0x4a/0x100 fs/quota/quota_v2.c:332
       dquot_acquire+0x144/0x5b0 fs/quota/dquot.c:432
       ext4_acquire_dquot+0x2e0/0x400 fs/ext4/super.c:6262
       dqget+0x999/0xdc0 fs/quota/dquot.c:899
       __dquot_initialize+0x291/0xd40 fs/quota/dquot.c:1477
       ext4_xattr_set+0xdc/0x380 fs/ext4/xattr.c:2481
       __vfs_setxattr+0x3ab/0x3e0 fs/xattr.c:180
       __vfs_setxattr_noperm+0x128/0x4f0 fs/xattr.c:214
       vfs_setxattr+0x228/0x440 fs/xattr.c:301
       setxattr+0x17c/0x2c0 fs/xattr.c:575
       path_setxattr+0x198/0x260 fs/xattr.c:595
       __do_sys_setxattr fs/xattr.c:611 [inline]
       __se_sys_setxattr fs/xattr.c:607 [inline]
       __x64_sys_setxattr+0xb7/0xd0 fs/xattr.c:607
       do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #0 (&dquot->dq_lock){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:2938 [inline]
       check_prevs_add+0x4f9/0x5b60 kernel/locking/lockdep.c:3061
       validate_chain kernel/locking/lockdep.c:3676 [inline]
       __lock_acquire+0x4307/0x6040 kernel/locking/lockdep.c:4902
       lock_acquire+0x17f/0x720 kernel/locking/lockdep.c:5512
       __mutex_lock_common+0x1bf/0x3100 kernel/locking/mutex.c:959
       __mutex_lock kernel/locking/mutex.c:1104 [inline]
       mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1119
       dquot_commit+0x57/0x360 fs/quota/dquot.c:474
       ext4_write_dquot+0x1e4/0x2b0 fs/ext4/super.c:6246
       mark_dquot_dirty fs/quota/dquot.c:345 [inline]
       mark_all_dquot_dirty fs/quota/dquot.c:383 [inline]
       __dquot_alloc_space+0xa18/0x1020 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+0xe85/0x2470 fs/ext4/mballoc.c:5476
       ext4_ext_map_blocks+0x2be3/0x7210 fs/ext4/extents.c:4241
       ext4_map_blocks+0xab3/0x1cb0 fs/ext4/inode.c:638
       _ext4_get_block+0x24b/0x710 fs/ext4/inode.c:794
       ext4_block_write_begin+0x63a/0x1250 fs/ext4/inode.c:1077
       ext4_write_begin+0x5cc/0x1350 fs/ext4/ext4_jbd2.h:498
       ext4_da_write_begin+0x384/0x10c0 fs/ext4/inode.c:2960
       generic_perform_write+0x28c/0x540 mm/filemap.c:3660
       ext4_buffered_write_iter+0x41c/0x590 fs/ext4/file.c:269
       ext4_file_write_iter+0x8f7/0x1b90 fs/ext4/file.c:519
       call_write_iter include/linux/fs.h:2114 [inline]
       new_sync_write fs/read_write.c:518 [inline]
       vfs_write+0xa39/0xc90 fs/read_write.c:605
       ksys_write+0x171/0x2a0 fs/read_write.c:658
       do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47
       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.1/23111:
 #0: ffff88802f5f5270 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x24e/0x2f0 fs/file.c:974
 #1: ffff888018966460 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x21b/0xc90 fs/read_write.c:601
 #2: ffff888080c99878 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:774 [inline]
 #2: ffff888080c99878 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_buffered_write_iter+0xaf/0x590 fs/ext4/file.c:263
 #3: ffff888080c99668 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x9e5/0x1cb0 fs/ext4/inode.c:631
 #4: ffffffff8d03b658 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:266

stack backtrace:
CPU: 1 PID: 23111 Comm: syz-executor.1 Not tainted 5.13.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x202/0x31e lib/dump_stack.c:120
 print_circular_bug+0xb17/0xdc0 kernel/locking/lockdep.c:2007
 check_noncircular+0x2cc/0x390 kernel/locking/lockdep.c:2129
 check_prev_add kernel/locking/lockdep.c:2938 [inline]
 check_prevs_add+0x4f9/0x5b60 kernel/locking/lockdep.c:3061
 validate_chain kernel/locking/lockdep.c:3676 [inline]
 __lock_acquire+0x4307/0x6040 kernel/locking/lockdep.c:4902
 lock_acquire+0x17f/0x720 kernel/locking/lockdep.c:5512
 __mutex_lock_common+0x1bf/0x3100 kernel/locking/mutex.c:959
 __mutex_lock kernel/locking/mutex.c:1104 [inline]
 mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1119
 dquot_commit+0x57/0x360 fs/quota/dquot.c:474
 ext4_write_dquot+0x1e4/0x2b0 fs/ext4/super.c:6246
 mark_dquot_dirty fs/quota/dquot.c:345 [inline]
 mark_all_dquot_dirty fs/quota/dquot.c:383 [inline]
 __dquot_alloc_space+0xa18/0x1020 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+0xe85/0x2470 fs/ext4/mballoc.c:5476
 ext4_ext_map_blocks+0x2be3/0x7210 fs/ext4/extents.c:4241
 ext4_map_blocks+0xab3/0x1cb0 fs/ext4/inode.c:638
 _ext4_get_block+0x24b/0x710 fs/ext4/inode.c:794
 ext4_block_write_begin+0x63a/0x1250 fs/ext4/inode.c:1077
 ext4_write_begin+0x5cc/0x1350 fs/ext4/ext4_jbd2.h:498
 ext4_da_write_begin+0x384/0x10c0 fs/ext4/inode.c:2960
 generic_perform_write+0x28c/0x540 mm/filemap.c:3660
 ext4_buffered_write_iter+0x41c/0x590 fs/ext4/file.c:269
 ext4_file_write_iter+0x8f7/0x1b90 fs/ext4/file.c:519
 call_write_iter include/linux/fs.h:2114 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0xa39/0xc90 fs/read_write.c:605
 ksys_write+0x171/0x2a0 fs/read_write.c:658
 do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665d9
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:00007fe10d11c188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 000000000d4ba0ff RSI: 00000000200009c0 RDI: 0000000000000004
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffe055d341f R14: 00007fe10d11c300 R15: 0000000000022000