======================================================
WARNING: possible circular locking dependency detected
6.4.0-rc7-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.1/7050 is trying to acquire lock:
ffff88807cfc5be0 (&delayed_node->mutex){+.+.}-{3:3}, at: __btrfs_release_delayed_node+0x9c/0x960 fs/btrfs/delayed-inode.c:256

but task is already holding lock:
ffff88806b176c00 (btrfs-tree-00/1){+.+.}-{3:3}, at: __btrfs_tree_lock+0x31/0x1b0 fs/btrfs/locking.c:198

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (btrfs-tree-00/1){+.+.}-{3:3}:
       reacquire_held_locks+0x3aa/0x660 kernel/locking/lockdep.c:5230
       __lock_release kernel/locking/lockdep.c:5419 [inline]
       lock_release+0x36f/0x9d0 kernel/locking/lockdep.c:5725
       up_write+0x79/0x580 kernel/locking/rwsem.c:1625
       btrfs_tree_unlock_rw fs/btrfs/locking.h:189 [inline]
       btrfs_unlock_up_safe+0x11c/0x2d0 fs/btrfs/locking.c:239
       search_leaf fs/btrfs/ctree.c:1986 [inline]
       btrfs_search_slot+0x1e6b/0x26d0 fs/btrfs/ctree.c:2230
       btrfs_insert_empty_items+0x94/0x130 fs/btrfs/ctree.c:4376
       btrfs_insert_delayed_item fs/btrfs/delayed-inode.c:746 [inline]
       btrfs_insert_delayed_items fs/btrfs/delayed-inode.c:824 [inline]
       __btrfs_commit_inode_delayed_items+0xc60/0x2080 fs/btrfs/delayed-inode.c:1111
       __btrfs_run_delayed_items+0x17f/0x310 fs/btrfs/delayed-inode.c:1153
       btrfs_commit_transaction+0xc04/0x2a90 fs/btrfs/transaction.c:2377
       create_snapshot+0x40f/0x6d0 fs/btrfs/ioctl.c:845
       btrfs_mksubvol+0x4ec/0x650 fs/btrfs/ioctl.c:995
       btrfs_mksnapshot+0x98/0xd0 fs/btrfs/ioctl.c:1041
       __btrfs_ioctl_snap_create+0x27b/0x360 fs/btrfs/ioctl.c:1294
       btrfs_ioctl_snap_create+0x10f/0x160 fs/btrfs/ioctl.c:1321
       btrfs_ioctl+0xa8b/0xb60
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:870 [inline]
       __se_sys_ioctl+0xa7/0xf0 fs/ioctl.c:856
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (&delayed_node->mutex){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3113 [inline]
       check_prevs_add kernel/locking/lockdep.c:3232 [inline]
       validate_chain+0x166b/0x58f0 kernel/locking/lockdep.c:3847
       __lock_acquire+0x1316/0x2070 kernel/locking/lockdep.c:5088
       lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5705
       __mutex_lock_common+0x1d8/0x2530 kernel/locking/mutex.c:603
       __mutex_lock kernel/locking/mutex.c:747 [inline]
       mutex_lock_nested+0x1b/0x20 kernel/locking/mutex.c:799
       __btrfs_release_delayed_node+0x9c/0x960 fs/btrfs/delayed-inode.c:256
       btrfs_release_delayed_node fs/btrfs/delayed-inode.c:281 [inline]
       __btrfs_run_delayed_items+0x218/0x310 fs/btrfs/delayed-inode.c:1156
       btrfs_commit_transaction+0xc04/0x2a90 fs/btrfs/transaction.c:2377
       create_snapshot+0x40f/0x6d0 fs/btrfs/ioctl.c:845
       btrfs_mksubvol+0x4ec/0x650 fs/btrfs/ioctl.c:995
       btrfs_mksnapshot+0x98/0xd0 fs/btrfs/ioctl.c:1041
       __btrfs_ioctl_snap_create+0x27b/0x360 fs/btrfs/ioctl.c:1294
       btrfs_ioctl_snap_create+0x10f/0x160 fs/btrfs/ioctl.c:1321
       btrfs_ioctl+0xa8b/0xb60
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:870 [inline]
       __se_sys_ioctl+0xa7/0xf0 fs/ioctl.c:856
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(btrfs-tree-00/1);
                               lock(&delayed_node->mutex);
                               lock(btrfs-tree-00/1);
  lock(&delayed_node->mutex);

 *** DEADLOCK ***

9 locks held by syz-executor.1/7050:
 #0: ffff888063fb4448 (sb_writers#14){.+.+}-{0:0}, at: mnt_want_write_file+0x5b/0x1a0 fs/namespace.c:438
 #1: ffff88806c86eb50 (&type->i_mutex_dir_key#8/1){+.+.}-{3:3}, at: btrfs_mksubvol+0x1c7/0x650 fs/btrfs/ioctl.c:967
 #2: ffff88802091cbe0 (&fs_info->subvol_sem){++++}-{3:3}, at: btrfs_mksubvol+0x469/0x650 fs/btrfs/ioctl.c:989
 #3: ffff888063fb4638 (sb_internal#2){.+.+}-{0:0}, at: create_snapshot+0x3b3/0x6d0 fs/btrfs/ioctl.c:837
 #4: ffff88802091e438 (btrfs_trans_completed){++++}-{0:0}, at: btrfs_commit_transaction+0xb02/0x2a90 fs/btrfs/transaction.c:2335
 #5: ffff88802091e410 (btrfs_trans_super_committed){.+.+}-{0:0}, at: btrfs_commit_transaction+0xb42/0x2a90 fs/btrfs/transaction.c:2336
 #6: ffff88802091e3e8 (btrfs_trans_unblocked){++++}-{0:0}, at: btrfs_commit_transaction+0xb75/0x2a90 fs/btrfs/transaction.c:2337
 #7: ffff88802091ccb0 (&fs_info->reloc_mutex){+.+.}-{3:3}, at: btrfs_commit_transaction+0xbec/0x2a90 fs/btrfs/transaction.c:2356
 #8: ffff88806b176c00 (btrfs-tree-00/1){+.+.}-{3:3}, at: __btrfs_tree_lock+0x31/0x1b0 fs/btrfs/locking.c:198

stack backtrace:
CPU: 1 PID: 7050 Comm: syz-executor.1 Not tainted 6.4.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x167/0x220 lib/dump_stack.c:106
 check_noncircular+0x2fe/0x3b0 kernel/locking/lockdep.c:2188
 check_prev_add kernel/locking/lockdep.c:3113 [inline]
 check_prevs_add kernel/locking/lockdep.c:3232 [inline]
 validate_chain+0x166b/0x58f0 kernel/locking/lockdep.c:3847
 __lock_acquire+0x1316/0x2070 kernel/locking/lockdep.c:5088
 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5705
 __mutex_lock_common+0x1d8/0x2530 kernel/locking/mutex.c:603
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x1b/0x20 kernel/locking/mutex.c:799
 __btrfs_release_delayed_node+0x9c/0x960 fs/btrfs/delayed-inode.c:256
 btrfs_release_delayed_node fs/btrfs/delayed-inode.c:281 [inline]
 __btrfs_run_delayed_items+0x218/0x310 fs/btrfs/delayed-inode.c:1156
 btrfs_commit_transaction+0xc04/0x2a90 fs/btrfs/transaction.c:2377
 create_snapshot+0x40f/0x6d0 fs/btrfs/ioctl.c:845
 btrfs_mksubvol+0x4ec/0x650 fs/btrfs/ioctl.c:995
 btrfs_mksnapshot+0x98/0xd0 fs/btrfs/ioctl.c:1041
 __btrfs_ioctl_snap_create+0x27b/0x360 fs/btrfs/ioctl.c:1294
 btrfs_ioctl_snap_create+0x10f/0x160 fs/btrfs/ioctl.c:1321
 btrfs_ioctl+0xa8b/0xb60
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xa7/0xf0 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f2bed47cae9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2bee2650c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2bed59c120 RCX: 00007f2bed47cae9
RDX: 0000000020002180 RSI: 0000000050009401 RDI: 0000000000000008
RBP: 00007f2bed4c847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f2bed59c120 R15: 00007fff4d7d74b8
 </TASK>
------------[ cut here ]------------
BTRFS: Transaction aborted (error -17)
WARNING: CPU: 1 PID: 7050 at fs/btrfs/delayed-inode.c:1158 __btrfs_run_delayed_items+0x2d4/0x310 fs/btrfs/delayed-inode.c:1158
Modules linked in:
CPU: 1 PID: 7050 Comm: syz-executor.1 Not tainted 6.4.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
RIP: 0010:__btrfs_run_delayed_items+0x2d4/0x310 fs/btrfs/delayed-inode.c:1158
Code: 89 d9 80 e1 07 fe c1 38 c1 0f 8c a0 fd ff ff 48 89 df e8 7f 81 af fe e9 93 fd ff ff 48 c7 c7 20 88 65 88 89 ee e8 6c 41 36 fe <0f> 0b eb 92 f3 0f 1e fa 48 b8 00 00 00 00 00 fc ff df 41 80 3c 07
RSP: 0018:ffffc900093978f8 EFLAGS: 00010246
RAX: a56575f168482e00 RBX: ffff88802091c000 RCX: 0000000000000002
RDX: 0000000000000001 RSI: 0000000000000008 RDI: 0000000000000001
RBP: 00000000ffffffef R08: dffffc0000000000 R09: fffff52001272e9d
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88807cfc5b20
R13: 00000000ffffffff R14: ffff888074f7bc78 R15: 1ffff1100e9ef799
FS:  00007f2bee2656c0(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020004000 CR3: 000000002254c000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 btrfs_commit_transaction+0xc04/0x2a90 fs/btrfs/transaction.c:2377
 create_snapshot+0x40f/0x6d0 fs/btrfs/ioctl.c:845
 btrfs_mksubvol+0x4ec/0x650 fs/btrfs/ioctl.c:995
 btrfs_mksnapshot+0x98/0xd0 fs/btrfs/ioctl.c:1041
 __btrfs_ioctl_snap_create+0x27b/0x360 fs/btrfs/ioctl.c:1294
 btrfs_ioctl_snap_create+0x10f/0x160 fs/btrfs/ioctl.c:1321
 btrfs_ioctl+0xa8b/0xb60
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xa7/0xf0 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f2bed47cae9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2bee2650c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2bed59c120 RCX: 00007f2bed47cae9
RDX: 0000000020002180 RSI: 0000000050009401 RDI: 0000000000000008
RBP: 00007f2bed4c847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f2bed59c120 R15: 00007fff4d7d74b8
 </TASK>