EXT4-fs (loop2): mounted filesystem without journal. Opts: ,errors=continue. Quota mode: writeback.
======================================================
WARNING: possible circular locking dependency detected
5.15.184-syzkaller #0 Not tainted
------------------------------------------------------
syz.2.212/4673 is trying to acquire lock:
ffff0000de75dc30 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x288/0x167c fs/ext4/inode.c:598

but task is already holding lock:
ffff0000d723a208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x114/0x180 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+0xc0/0x390 kernel/locking/rwsem.c:1498
       v2_read_dquot+0x4c/0x118 fs/quota/quota_v2.c:332
       dquot_acquire+0x120/0x510 fs/quota/dquot.c:463
       ext4_acquire_dquot+0x270/0x428 fs/ext4/super.c:6200
       dqget+0x658/0xcf4 fs/quota/dquot.c:988
       __dquot_initialize+0x264/0xa80 fs/quota/dquot.c:1517
       dquot_initialize+0x24/0x34 fs/quota/dquot.c:1579
       ext4_process_orphan+0x5c/0x2b4 fs/ext4/orphan.c:329
       ext4_orphan_cleanup+0x888/0xf8c fs/ext4/orphan.c:474
       ext4_fill_super+0x7a5c/0x812c fs/ext4/super.c:4975
       mount_bdev+0x264/0x358 fs/super.c:1400
       ext4_mount+0x44/0x58 fs/ext4/super.c:6627
       legacy_get_tree+0xd4/0x16c fs/fs_context.c:611
       vfs_get_tree+0x90/0x274 fs/super.c:1530
       do_new_mount+0x228/0x810 fs/namespace.c:3014
       path_mount+0x5b4/0x1000 fs/namespace.c:3344
       do_mount fs/namespace.c:3357 [inline]
       __do_sys_mount fs/namespace.c:3565 [inline]
       __se_sys_mount fs/namespace.c:3542 [inline]
       __arm64_sys_mount+0x514/0x5e4 fs/namespace.c:3542
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
       el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
       el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
       el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

-> #1 (&dquot->dq_lock){+.+.}-{3:3}:
       __mutex_lock_common+0x194/0x1edc kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_nested+0xac/0x11c kernel/locking/mutex.c:743
       dquot_commit+0x50/0x1c4 fs/quota/dquot.c:507
       ext4_write_dquot+0x1b4/0x31c fs/ext4/super.c:6180
       ext4_mark_dquot_dirty+0xe8/0x140 fs/ext4/super.c:6257
       mark_dquot_dirty fs/quota/dquot.c:372 [inline]
       mark_all_dquot_dirty+0x108/0x424 fs/quota/dquot.c:412
       __dquot_alloc_space+0x560/0xd0c fs/quota/dquot.c:1752
       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+0xd30/0x4024 fs/ext4/mballoc.c:5739
       ext4_ext_map_blocks+0xf70/0x5628 fs/ext4/extents.c:4339
       ext4_map_blocks+0x7b8/0x167c fs/ext4/inode.c:673
       ext4_getblk+0x138/0x5f0 fs/ext4/inode.c:870
       ext4_bread+0x3c/0x1d4 fs/ext4/inode.c:923
       ext4_append+0x238/0x474 fs/ext4/namei.c:83
       ext4_init_new_dir+0x258/0x864 fs/ext4/namei.c:3030
       ext4_mkdir+0x3c0/0xa40 fs/ext4/namei.c:3076
       vfs_mkdir+0x314/0x4d4 fs/namei.c:4065
       do_mkdirat+0x1bc/0x508 fs/namei.c:4090
       __do_sys_mkdirat fs/namei.c:4105 [inline]
       __se_sys_mkdirat fs/namei.c:4103 [inline]
       __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4103
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
       el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
       el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
       el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

-> #0 (&ei->i_data_sem/2){++++}-{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+0x2928/0x651c kernel/locking/lockdep.c:5012
       lock_acquire+0x1f4/0x620 kernel/locking/lockdep.c:5623
       down_read+0xc0/0x390 kernel/locking/rwsem.c:1498
       ext4_map_blocks+0x288/0x167c fs/ext4/inode.c:598
       ext4_getblk+0x138/0x5f0 fs/ext4/inode.c:870
       ext4_bread+0x3c/0x1d4 fs/ext4/inode.c:923
       ext4_quota_write+0x220/0x52c fs/ext4/super.c:6591
       write_blk fs/quota/quota_tree.c:64 [inline]
       get_free_dqblk+0x2d4/0x680 fs/quota/quota_tree.c:125
       find_free_dqentry fs/quota/quota_tree.c:271 [inline]
       do_insert_tree+0x920/0x1424 fs/quota/quota_tree.c:364
       do_insert_tree+0x450/0x1424 fs/quota/quota_tree.c:366
       do_insert_tree+0x450/0x1424 fs/quota/quota_tree.c:366
       do_insert_tree+0x450/0x1424 fs/quota/quota_tree.c:366
       dq_insert_tree fs/quota/quota_tree.c:392 [inline]
       qtree_write_dquot+0x2c4/0x3f8 fs/quota/quota_tree.c:411
       v2_write_dquot+0xf0/0x180 fs/quota/quota_v2.c:358
       dquot_acquire+0x2b0/0x510 fs/quota/dquot.c:472
       ext4_acquire_dquot+0x270/0x428 fs/ext4/super.c:6200
       dqget+0x658/0xcf4 fs/quota/dquot.c:988
       __dquot_initialize+0x264/0xa80 fs/quota/dquot.c:1517
       dquot_initialize+0x24/0x34 fs/quota/dquot.c:1579
       ext4_create+0x94/0x3fc fs/ext4/namei.c:2876
       lookup_open fs/namei.c:3462 [inline]
       open_last_lookups fs/namei.c:3532 [inline]
       path_openat+0x1144/0x26e4 fs/namei.c:3739
       do_filp_open+0x164/0x330 fs/namei.c:3769
       do_sys_openat2+0x128/0x3d8 fs/open.c:1253
       do_sys_open fs/open.c:1269 [inline]
       __do_sys_openat fs/open.c:1285 [inline]
       __se_sys_openat fs/open.c:1280 [inline]
       __arm64_sys_openat+0x120/0x154 fs/open.c:1280
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
       el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
       el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
       el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

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.2.212/4673:
 #0: ffff0000d723a460 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:377
 #1: ffff0000de75c9b8 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff0000de75c9b8 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: open_last_lookups fs/namei.c:3529 [inline]
 #1: ffff0000de75c9b8 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: path_openat+0x5f4/0x26e4 fs/namei.c:3739
 #2: ffff0000de49e268 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_acquire+0x60/0x510 fs/quota/dquot.c:460
 #3: ffff0000d723a208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x114/0x180 fs/quota/quota_v2.c:354

stack backtrace:
CPU: 1 PID: 4673 Comm: syz.2.212 Not tainted 5.15.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call trace:
 dump_backtrace+0x0/0x43c arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106
 dump_stack+0x1c/0x5c lib/dump_stack.c:113
 print_circular_bug+0x148/0x1b0 kernel/locking/lockdep.c:2011
 check_noncircular+0x240/0x2d4 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+0x2928/0x651c kernel/locking/lockdep.c:5012
 lock_acquire+0x1f4/0x620 kernel/locking/lockdep.c:5623
 down_read+0xc0/0x390 kernel/locking/rwsem.c:1498
 ext4_map_blocks+0x288/0x167c fs/ext4/inode.c:598
 ext4_getblk+0x138/0x5f0 fs/ext4/inode.c:870
 ext4_bread+0x3c/0x1d4 fs/ext4/inode.c:923
 ext4_quota_write+0x220/0x52c fs/ext4/super.c:6591
 write_blk fs/quota/quota_tree.c:64 [inline]
 get_free_dqblk+0x2d4/0x680 fs/quota/quota_tree.c:125
 find_free_dqentry fs/quota/quota_tree.c:271 [inline]
 do_insert_tree+0x920/0x1424 fs/quota/quota_tree.c:364
 do_insert_tree+0x450/0x1424 fs/quota/quota_tree.c:366
 do_insert_tree+0x450/0x1424 fs/quota/quota_tree.c:366
 do_insert_tree+0x450/0x1424 fs/quota/quota_tree.c:366
 dq_insert_tree fs/quota/quota_tree.c:392 [inline]
 qtree_write_dquot+0x2c4/0x3f8 fs/quota/quota_tree.c:411
 v2_write_dquot+0xf0/0x180 fs/quota/quota_v2.c:358
 dquot_acquire+0x2b0/0x510 fs/quota/dquot.c:472
 ext4_acquire_dquot+0x270/0x428 fs/ext4/super.c:6200
 dqget+0x658/0xcf4 fs/quota/dquot.c:988
 __dquot_initialize+0x264/0xa80 fs/quota/dquot.c:1517
 dquot_initialize+0x24/0x34 fs/quota/dquot.c:1579
 ext4_create+0x94/0x3fc fs/ext4/namei.c:2876
 lookup_open fs/namei.c:3462 [inline]
 open_last_lookups fs/namei.c:3532 [inline]
 path_openat+0x1144/0x26e4 fs/namei.c:3739
 do_filp_open+0x164/0x330 fs/namei.c:3769
 do_sys_openat2+0x128/0x3d8 fs/open.c:1253
 do_sys_open fs/open.c:1269 [inline]
 __do_sys_openat fs/open.c:1285 [inline]
 __se_sys_openat fs/open.c:1280 [inline]
 __arm64_sys_openat+0x120/0x154 fs/open.c:1280
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584