======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.5.616/7086 is trying to acquire lock:
ffff888020fa6628 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x33c/0x1b30 fs/ext4/inode.c:598

but task is already holding lock:
ffff888021550208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x12b/0x190 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+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:463
       ext4_acquire_dquot+0x2d9/0x4a0 fs/ext4/super.c:6230
       dqget+0x778/0xeb0 fs/quota/dquot.c:988
       __dquot_initialize+0x3c3/0xcd0 fs/quota/dquot.c:1517
       ext4_process_orphan+0x54/0x300 fs/ext4/orphan.c:327
       ext4_orphan_cleanup+0xad2/0x1320 fs/ext4/orphan.c:472
       ext4_fill_super+0x8e25/0x95a0 fs/ext4/super.c:5000
       mount_bdev+0x287/0x3c0 fs/super.c:1400
       legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
       vfs_get_tree+0x88/0x270 fs/super.c:1530
       do_new_mount+0x24a/0xa40 fs/namespace.c:3034
       do_mount fs/namespace.c:3377 [inline]
       __do_sys_mount fs/namespace.c:3585 [inline]
       __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
       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 (&dquot->dq_lock){+.+.}-{3:3}:
       __mutex_lock_common+0x1e3/0x2400 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:507
       ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6210
       mark_dquot_dirty fs/quota/dquot.c:372 [inline]
       mark_all_dquot_dirty+0xf9/0x400 fs/quota/dquot.c:412
       __dquot_alloc_space+0x5d0/0xe20 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+0xf81/0x4980 fs/ext4/mballoc.c:5750
       ext4_ext_map_blocks+0x191c/0x6580 fs/ext4/extents.c:4341
       ext4_map_blocks+0x98e/0x1b30 fs/ext4/inode.c:673
       ext4_getblk+0x176/0x670 fs/ext4/inode.c:870
       ext4_bread+0x26/0x180 fs/ext4/inode.c:923
       ext4_append+0x2be/0x560 fs/ext4/namei.c:83
       ext4_init_new_dir+0x2a2/0x940 fs/ext4/namei.c:3030
       ext4_mkdir+0x4fb/0xce0 fs/ext4/namei.c:3076
       vfs_mkdir+0x387/0x570 fs/namei.c:4073
       do_mkdirat+0x1df/0x5b0 fs/namei.c:4098
       __do_sys_mkdirat fs/namei.c:4113 [inline]
       __se_sys_mkdirat fs/namei.c:4111 [inline]
       __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4111
       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 (&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+0x2c42/0x7d10 kernel/locking/lockdep.c:5012
       lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
       down_read+0x44/0x2e0 kernel/locking/rwsem.c:1498
       ext4_map_blocks+0x33c/0x1b30 fs/ext4/inode.c:598
       ext4_getblk+0x176/0x670 fs/ext4/inode.c:870
       ext4_bread+0x26/0x180 fs/ext4/inode.c:923
       ext4_quota_write+0x236/0x580 fs/ext4/super.c:6621
       write_blk fs/quota/quota_tree.c:64 [inline]
       get_free_dqblk+0x387/0x7d0 fs/quota/quota_tree.c:125
       do_insert_tree+0x214/0x1970 fs/quota/quota_tree.c:335
       do_insert_tree+0x5b1/0x1970 fs/quota/quota_tree.c:366
       dq_insert_tree fs/quota/quota_tree.c:392 [inline]
       qtree_write_dquot+0x361/0x4b0 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:472
       ext4_acquire_dquot+0x2d9/0x4a0 fs/ext4/super.c:6230
       dqget+0x778/0xeb0 fs/quota/dquot.c:988
       __dquot_initialize+0x3c3/0xcd0 fs/quota/dquot.c:1517
       ext4_cross_rename fs/ext4/namei.c:4133 [inline]
       ext4_rename2+0x814/0x30e0 fs/ext4/namei.c:4268
       vfs_rename+0xbe1/0x1100 fs/namei.c:4840
       do_renameat2+0x8b7/0xf60 fs/namei.c:4993
       __do_sys_renameat2 fs/namei.c:5026 [inline]
       __se_sys_renameat2 fs/namei.c:5023 [inline]
       __x64_sys_renameat2+0xce/0xe0 fs/namei.c:5023
       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:
  &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 ***

8 locks held by syz.5.616/7086:
 #0: ffff888021550460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386
 #1: ffff888021550748 (&type->s_vfs_rename_key#2){+.+.}-{3:3}, at: lock_rename fs/namei.c:3024 [inline]
 #1: ffff888021550748 (&type->s_vfs_rename_key#2){+.+.}-{3:3}, at: do_renameat2+0x375/0xf60 fs/namei.c:4932
 #2: ffff888020fa53b0 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline]
 #2: ffff888020fa53b0 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: lock_two_directories fs/namei.c:-1 [inline]
 #2: ffff888020fa53b0 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: lock_rename fs/namei.c:3025 [inline]
 #2: ffff888020fa53b0 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: do_renameat2+0x407/0xf60 fs/namei.c:4932
 #3: ffff888072d949b8 (&type->i_mutex_dir_key#4/5){+.+.}-{3:3}, at: lock_rename include/linux/fs.h:-1 [inline]
 #3: ffff888072d949b8 (&type->i_mutex_dir_key#4/5){+.+.}-{3:3}, at: do_renameat2+0x43d/0xf60 fs/namei.c:4932
 #4: ffff888072d93fc0 (&type->i_mutex_dir_key#4/2){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline]
 #4: ffff888072d93fc0 (&type->i_mutex_dir_key#4/2){+.+.}-{3:3}, at: vfs_rename+0x792/0x1100 fs/namei.c:4803
 #5: ffff888072d935c8 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #5: ffff888072d935c8 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: vfs_rename+0x839/0x1100 fs/namei.c:-1
 #6: ffff888072e82428 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_acquire+0x63/0x520 fs/quota/dquot.c:460
 #7: ffff888021550208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x12b/0x190 fs/quota/quota_v2.c:354

stack backtrace:
CPU: 1 PID: 7086 Comm: syz.5.616 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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+0x2c42/0x7d10 kernel/locking/lockdep.c:5012
 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
 down_read+0x44/0x2e0 kernel/locking/rwsem.c:1498
 ext4_map_blocks+0x33c/0x1b30 fs/ext4/inode.c:598
 ext4_getblk+0x176/0x670 fs/ext4/inode.c:870
 ext4_bread+0x26/0x180 fs/ext4/inode.c:923
 ext4_quota_write+0x236/0x580 fs/ext4/super.c:6621
 write_blk fs/quota/quota_tree.c:64 [inline]
 get_free_dqblk+0x387/0x7d0 fs/quota/quota_tree.c:125
 do_insert_tree+0x214/0x1970 fs/quota/quota_tree.c:335
 do_insert_tree+0x5b1/0x1970 fs/quota/quota_tree.c:366
 dq_insert_tree fs/quota/quota_tree.c:392 [inline]
 qtree_write_dquot+0x361/0x4b0 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:472
 ext4_acquire_dquot+0x2d9/0x4a0 fs/ext4/super.c:6230
 dqget+0x778/0xeb0 fs/quota/dquot.c:988
 __dquot_initialize+0x3c3/0xcd0 fs/quota/dquot.c:1517
 ext4_cross_rename fs/ext4/namei.c:4133 [inline]
 ext4_rename2+0x814/0x30e0 fs/ext4/namei.c:4268
 vfs_rename+0xbe1/0x1100 fs/namei.c:4840
 do_renameat2+0x8b7/0xf60 fs/namei.c:4993
 __do_sys_renameat2 fs/namei.c:5026 [inline]
 __se_sys_renameat2 fs/namei.c:5023 [inline]
 __x64_sys_renameat2+0xce/0xe0 fs/namei.c:5023
 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: 0033:0x7f0511d08799
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:00007f050ff41028 EFLAGS: 00000246 ORIG_RAX: 000000000000013c
RAX: ffffffffffffffda RBX: 00007f0511f82090 RCX: 00007f0511d08799
RDX: 0000000000000005 RSI: 0000200000000480 RDI: ffffffffffffff9c
RBP: 00007f0511d9ebd9 R08: 0000000000000002 R09: 0000000000000000
R10: 00002000000004c0 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0511f82128 R14: 00007f0511f82090 R15: 00007ffe131feb18
 </TASK>
Quota error (device loop5): do_check_range: Getting dqdh_next_free 4294967294 out of range 0-8
Quota error (device loop5): qtree_write_dquot: Error -117 occurred while creating quota
EXT4-fs error (device loop5): ext4_acquire_dquot:6234: comm syz.5.616: Failed to acquire dquot type 0