BTRFS error (device loop0 state M): allocation failed flags 2, wanted 4096 tree-log 0, relocation: 0 BTRFS info (device loop0 state M): space_info SYSTEM (sub-group id 0) has 8155136 free, is not full BTRFS info (device loop0 state M): space_info total=12451840, used=4096, pinned=0, reserved=0, may_use=98304, readonly=4194304 zone_unusable=0 BTRFS info (device loop0 state M): global_block_rsv: size 983040 reserved 978944 BTRFS info (device loop0 state M): trans_block_rsv: size 262144 reserved 262144 BTRFS info (device loop0 state M): chunk_block_rsv: size 98304 reserved 94208 BTRFS info (device loop0 state M): remap_block_rsv: size 0 reserved 0 BTRFS info (device loop0 state M): delayed_block_rsv: size 0 reserved 0 BTRFS info (device loop0 state M): delayed_refs_rsv: size 131072 reserved 131072 BTRFS info (device loop0 state M): block group 1048576 has 4194304 bytes, 0 used 0 pinned 0 reserved 0 delalloc 0 super 0 zone_unusable (4194304 bytes available) [readonly] BTRFS critical (device loop0 state M): entry offset 1048576, bytes 4194304, bitmap no BTRFS info (device loop0 state M): block group has cluster?: no BTRFS info (device loop0 state M): 0 free space entries at or bigger than 4096 bytes BTRFS info (device loop0 state M): block group 8519680 has 8257536 bytes, 4096 used 0 pinned 0 reserved 0 delalloc 0 super 0 zone_unusable (8253440 bytes available) BTRFS critical (device loop0 state M): entry offset 8523776, bytes 8253440, bitmap no BTRFS info (device loop0 state M): block group has cluster?: no BTRFS info (device loop0 state M): 1 free space entries at or bigger than 4096 bytes BTRFS info (device loop0 state M): 12447744 bytes available across all block groups ------------[ cut here ]------------ BTRFS: Transaction aborted (error -28) WARNING: fs/btrfs/volumes.c:3470 at btrfs_remove_chunk+0xe0d/0x15f0 fs/btrfs/volumes.c:3470, CPU#0: syz.0.0/5317 Modules linked in: CPU: 0 UID: 0 PID: 5317 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_remove_chunk+0xe10/0x15f0 fs/btrfs/volumes.c:3470 Code: d7 ce fd e9 ee 00 00 00 e8 cd db b3 fd 84 c0 74 23 e8 f4 d6 ce fd e9 db 00 00 00 e8 ea d6 ce fd 48 8d 3d 03 20 24 0c 44 89 ee <67> 48 0f b9 3a e9 02 01 00 00 e8 51 e7 b7 07 89 c3 31 ff 89 c6 e8 RSP: 0018:ffffc9000e46f860 EFLAGS: 00010283 RAX: ffffffff83f6c096 RBX: ffff888000960001 RCX: 0000000000100000 RDX: ffffc90020001000 RSI: 00000000ffffffe4 RDI: ffffffff901ae0a0 RBP: ffffc9000e46f9b0 R08: ffff8880352e4900 R09: 0000000000000003 R10: 00000000fffffffb R11: 0000000000000002 R12: ffff88801185d6f0 R13: ffffffffffffffe4 R14: dffffc0000000000 R15: 0000000000000000 FS: 00007f49b465d6c0(0000) GS:ffff88808ca5e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056462f783c00 CR3: 000000001eea3000 CR4: 0000000000352ef0 Call Trace: btrfs_delete_unused_bgs+0xf0f/0x1200 fs/btrfs/block-group.c:1757 btrfs_remount_ro fs/btrfs/super.c:1369 [inline] btrfs_reconfigure+0xbc0/0x2180 fs/btrfs/super.c:1551 reconfigure_super+0x227/0x8a0 fs/super.c:1080 do_remount fs/namespace.c:3388 [inline] path_mount+0xdc5/0x10e0 fs/namespace.c:4138 do_mount fs/namespace.c:4159 [inline] __do_sys_mount fs/namespace.c:4348 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4325 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f49b379c139 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:00007f49b465d028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f49b3a16090 RCX: 00007f49b379c139 RDX: 0000000000000000 RSI: 0000200000000100 RDI: 0000000000000000 RBP: 00007f49b38327e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000021 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f49b3a16128 R14: 00007f49b3a16090 R15: 00007ffc71cc2968 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: fd std 1: e9 ee 00 00 00 jmp 0xf4 6: e8 cd db b3 fd call 0xfdb3dbd8 b: 84 c0 test %al,%al d: 74 23 je 0x32 f: e8 f4 d6 ce fd call 0xfdced708 14: e9 db 00 00 00 jmp 0xf4 19: e8 ea d6 ce fd call 0xfdced708 1e: 48 8d 3d 03 20 24 0c lea 0xc242003(%rip),%rdi # 0xc242028 25: 44 89 ee mov %r13d,%esi * 28: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2d: e9 02 01 00 00 jmp 0x134 32: e8 51 e7 b7 07 call 0x7b7e788 37: 89 c3 mov %eax,%ebx 39: 31 ff xor %edi,%edi 3b: 89 c6 mov %eax,%esi 3d: e8 .byte 0xe8