loop0: detected capacity change from 0 to 32768
BTRFS: device fsid 395ef67a-297e-477c-816d-cd80a5b93e5d devid 1 transid 8 /dev/loop0 (7:0) scanned by syz.0.0 (5326)
BTRFS info (device loop0): first mount of filesystem 395ef67a-297e-477c-816d-cd80a5b93e5d
BTRFS info (device loop0): using sha256 checksum algorithm
BTRFS info (device loop0): enabling ssd optimizations
BTRFS info (device loop0): turning on async discard
BTRFS info (device loop0): enabling free space tree
BTRFS info (device loop0): last unmount of filesystem 395ef67a-297e-477c-816d-cd80a5b93e5d
------------[ cut here ]------------
fs_info->delayed_refs_rsv.reserved > 0
WARNING: fs/btrfs/block-rsv.c:472 at btrfs_release_global_block_rsv+0x2e4/0x300 fs/btrfs/block-rsv.c:472, CPU#0: syz.0.0/5326
Modules linked in:
CPU: 0 UID: 0 PID: 5326 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:btrfs_release_global_block_rsv+0x2e4/0x300 fs/btrfs/block-rsv.c:472
Code: 0f 0b 90 e9 c1 fe ff ff e8 49 21 b3 fd 90 0f 0b 90 e9 eb fe ff ff e8 3b 21 b3 fd 90 0f 0b 90 e9 15 ff ff ff e8 2d 21 b3 fd 90 <0f> 0b 90 e9 46 ff ff ff e8 1f 21 b3 fd 90 0f 0b 90 e9 69 ff ff ff
RSP: 0018:ffffc9000e067888 EFLAGS: 00010246
RAX: ffffffff84128e53 RBX: ffff888042d24478 RCX: 0000000000100000
RDX: ffffc90020001000 RSI: 00000000000fffff RDI: 0000000000100000
RBP: ffff888042d24188 R08: ffff888038d7a023 R09: 1ffff110071af404
R10: dffffc0000000000 R11: ffffed10071af405 R12: dead000000000100
R13: 0000000000000000 R14: 00000000000a0000 R15: dffffc0000000000
FS:  00007fc942c386c0(0000) GS:ffff88808ca55000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000001fc6f000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 btrfs_free_block_groups+0xe04/0x1110 fs/btrfs/block-group.c:4679
 close_ctree+0x809/0x1380 fs/btrfs/disk-io.c:4467
 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646
 kill_anon_super+0x3b/0x70 fs/super.c:1292
 btrfs_kill_super+0x41/0x50 fs/btrfs/super.c:2127
 deactivate_locked_super+0xbc/0x130 fs/super.c:476
 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 get_signal+0x11eb/0x1330 kernel/signal.c:2807
 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc941d9c799
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:00007fc942c37fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: 00000000001006e4 RBX: 00007fc942015fa0 RCX: 00007fc941d9c799
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000005
RBP: 00007fc941e32c99 R08: 0000000000000000 R09: 0000000000000000
R10: 000000007fffeffd R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc942016038 R14: 00007fc942015fa0 R15: 00007ffe690cbc38
 </TASK>