loop4: detected capacity change from 0 to 512
EXT4-fs (loop4): mounted filesystem without journal. Quota mode: writeback.
======================================================
WARNING: possible circular locking dependency detected
6.1.15-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.4/6894 is trying to acquire lock:
ffff0000dd9d48c0 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x794/0x1884 fs/ext4/inode.c:644

but task is already holding lock:
ffff0000cd832208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x11c/0x188 fs/quota/quota_v2.c:354

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&s->s_dquot.dqio_sem){++++}-{3:3}:
       down_read+0x5c/0x78 kernel/locking/rwsem.c:1509
       v2_read_dquot+0x50/0x11c fs/quota/quota_v2.c:332
       dquot_acquire+0x130/0x5c4 fs/quota/dquot.c:435
       ext4_acquire_dquot+0x270/0x398 fs/ext4/super.c:6740
       dqget+0x844/0xc48 fs/quota/dquot.c:914
       __dquot_initialize+0x344/0xb54 fs/quota/dquot.c:1492
       dquot_initialize+0x24/0x34 fs/quota/dquot.c:1550
       ext4_mkdir+0x15c/0xa64 fs/ext4/namei.c:2985
       vfs_mkdir+0x334/0x4e4 fs/namei.c:4036
       do_mkdirat+0x20c/0x610 fs/namei.c:4061
       __do_sys_mkdirat fs/namei.c:4076 [inline]
       __se_sys_mkdirat fs/namei.c:4074 [inline]
       __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4074
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
       el0_svc+0x58/0x168 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:581

-> #1 (&dquot->dq_lock){+.+.}-{3:3}:
       __mutex_lock_common+0x190/0x21a0 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+0x54/0x240 fs/quota/dquot.c:479
       ext4_write_dquot+0x1b0/0x284 fs/ext4/super.c:6724
       ext4_mark_dquot_dirty+0xe8/0x140 fs/ext4/super.c:6772
       mark_dquot_dirty fs/quota/dquot.c:346 [inline]
       mark_all_dquot_dirty fs/quota/dquot.c:384 [inline]
       __dquot_alloc_space+0x47c/0xd00 fs/quota/dquot.c:1722
       dquot_alloc_space_nodirty include/linux/quotaops.h:300 [inline]
       dquot_alloc_space include/linux/quotaops.h:313 [inline]
       dquot_alloc_block include/linux/quotaops.h:337 [inline]
       ext4_mb_new_blocks+0x1020/0x49c8 fs/ext4/mballoc.c:5573
       ext4_ext_map_blocks+0x1740/0x688c fs/ext4/extents.c:4287
       ext4_map_blocks+0x828/0x1884 fs/ext4/inode.c:651
       ext4_getblk+0x198/0x6ec fs/ext4/inode.c:864
       ext4_bread+0x3c/0x1b0 fs/ext4/inode.c:920
       ext4_append+0x260/0x4cc fs/ext4/namei.c:83
       ext4_init_new_dir+0x294/0x8e4 fs/ext4/namei.c:2956
       ext4_mkdir+0x3d4/0xa64 fs/ext4/namei.c:3002
       vfs_mkdir+0x334/0x4e4 fs/namei.c:4036
       do_mkdirat+0x20c/0x610 fs/namei.c:4061
       __do_sys_mkdirat fs/namei.c:4076 [inline]
       __se_sys_mkdirat fs/namei.c:4074 [inline]
       __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4074
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
       el0_svc+0x58/0x168 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:581

-> #0 (&ei->i_data_sem/2){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3097 [inline]
       check_prevs_add kernel/locking/lockdep.c:3216 [inline]
       validate_chain kernel/locking/lockdep.c:3831 [inline]
       __lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5055
       lock_acquire+0x2f8/0x8dc kernel/locking/lockdep.c:5668
       down_write+0x5c/0x88 kernel/locking/rwsem.c:1562
       ext4_map_blocks+0x794/0x1884 fs/ext4/inode.c:644
       ext4_getblk+0x198/0x6ec fs/ext4/inode.c:864
       ext4_bread+0x3c/0x1b0 fs/ext4/inode.c:920
       ext4_quota_write+0x230/0x54c fs/ext4/super.c:7106
       write_blk fs/quota/quota_tree.c:64 [inline]
       find_free_dqentry fs/quota/quota_tree.c:312 [inline]
       do_insert_tree+0xa64/0x1474 fs/quota/quota_tree.c:373
       do_insert_tree+0x510/0x1474 fs/quota/quota_tree.c:375
       do_insert_tree+0x510/0x1474 fs/quota/quota_tree.c:375
       do_insert_tree+0x510/0x1474 fs/quota/quota_tree.c:375
       dq_insert_tree fs/quota/quota_tree.c:401 [inline]
       qtree_write_dquot+0x318/0x488 fs/quota/quota_tree.c:420
       v2_write_dquot+0xf4/0x188 fs/quota/quota_v2.c:358
       dquot_acquire+0x2c4/0x5c4 fs/quota/dquot.c:444
       ext4_acquire_dquot+0x270/0x398 fs/ext4/super.c:6740
       dqget+0x844/0xc48 fs/quota/dquot.c:914
       __dquot_initialize+0x2cc/0xb54 fs/quota/dquot.c:1492
       dquot_initialize+0x24/0x34 fs/quota/dquot.c:1550
       ext4_create+0xb4/0x480 fs/ext4/namei.c:2802
       lookup_open fs/namei.c:3413 [inline]
       open_last_lookups fs/namei.c:3481 [inline]
       path_openat+0xea8/0x2540 fs/namei.c:3711
       do_filp_open+0x1bc/0x3cc fs/namei.c:3741
       do_sys_openat2+0x128/0x3d8 fs/open.c:1310
       do_sys_open fs/open.c:1326 [inline]
       __do_sys_openat fs/open.c:1342 [inline]
       __se_sys_openat fs/open.c:1337 [inline]
       __arm64_sys_openat+0x1f0/0x240 fs/open.c:1337
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
       el0_svc+0x58/0x168 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:581

other info that might help us debug this:

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

 Possible unsafe locking scenario:

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

 *** DEADLOCK ***

4 locks held by syz-executor.4/6894:
 #0: ffff0000cd832460 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:393
 #1: ffff0001066de850 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline]
 #1: ffff0001066de850 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: open_last_lookups fs/namei.c:3478 [inline]
 #1: ffff0001066de850 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: path_openat+0x5e8/0x2540 fs/namei.c:3711
 #2: ffff0000e08a1068 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_acquire+0x68/0x5c4 fs/quota/dquot.c:432
 #3: ffff0000cd832208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x11c/0x188 fs/quota/quota_v2.c:354

stack backtrace:
CPU: 0 PID: 6894 Comm: syz-executor.4 Not tainted 6.1.15-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Call trace:
 dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 dump_stack+0x1c/0x58 lib/dump_stack.c:113
 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2055
 check_noncircular+0x2cc/0x378 kernel/locking/lockdep.c:2177
 check_prev_add kernel/locking/lockdep.c:3097 [inline]
 check_prevs_add kernel/locking/lockdep.c:3216 [inline]
 validate_chain kernel/locking/lockdep.c:3831 [inline]
 __lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5055
 lock_acquire+0x2f8/0x8dc kernel/locking/lockdep.c:5668
 down_write+0x5c/0x88 kernel/locking/rwsem.c:1562
 ext4_map_blocks+0x794/0x1884 fs/ext4/inode.c:644
 ext4_getblk+0x198/0x6ec fs/ext4/inode.c:864
 ext4_bread+0x3c/0x1b0 fs/ext4/inode.c:920
 ext4_quota_write+0x230/0x54c fs/ext4/super.c:7106
 write_blk fs/quota/quota_tree.c:64 [inline]
 find_free_dqentry fs/quota/quota_tree.c:312 [inline]
 do_insert_tree+0xa64/0x1474 fs/quota/quota_tree.c:373
 do_insert_tree+0x510/0x1474 fs/quota/quota_tree.c:375
 do_insert_tree+0x510/0x1474 fs/quota/quota_tree.c:375
 do_insert_tree+0x510/0x1474 fs/quota/quota_tree.c:375
 dq_insert_tree fs/quota/quota_tree.c:401 [inline]
 qtree_write_dquot+0x318/0x488 fs/quota/quota_tree.c:420
 v2_write_dquot+0xf4/0x188 fs/quota/quota_v2.c:358
 dquot_acquire+0x2c4/0x5c4 fs/quota/dquot.c:444
 ext4_acquire_dquot+0x270/0x398 fs/ext4/super.c:6740
 dqget+0x844/0xc48 fs/quota/dquot.c:914
 __dquot_initialize+0x2cc/0xb54 fs/quota/dquot.c:1492
 dquot_initialize+0x24/0x34 fs/quota/dquot.c:1550
 ext4_create+0xb4/0x480 fs/ext4/namei.c:2802
 lookup_open fs/namei.c:3413 [inline]
 open_last_lookups fs/namei.c:3481 [inline]
 path_openat+0xea8/0x2540 fs/namei.c:3711
 do_filp_open+0x1bc/0x3cc fs/namei.c:3741
 do_sys_openat2+0x128/0x3d8 fs/open.c:1310
 do_sys_open fs/open.c:1326 [inline]
 __do_sys_openat fs/open.c:1342 [inline]
 __se_sys_openat fs/open.c:1337 [inline]
 __arm64_sys_openat+0x1f0/0x240 fs/open.c:1337
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x168 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:581