ASSERTion in remove_free_space_extent()

[morbidrsa]

When running fstetsts' generic/068 on zoned null_blk devices, with zone-size 128M, zone-capacity 64M and a max-active-zones value of 14 triggers the following ASSERT() in remove_free_space_extent():

    found_start = key.objectid;
    found_end = key.objectid + key.offset;
    ASSERT(start >= found_start && end <= found_end);

Here's a preliminary analysis with gdb in the moment the ASSERT() has triggered.

[johannes@redsun91:linux (btrfs-misc-next)]$ gdb vmlinux 
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Reading symbols from vmlinux...
(gdb) target remote localhost:1234
Remote debugging using localhost:1234
warning: Remote gdbserver does not support determining executable automatically.
RHEL <=6.8 and <=7.2 versions of gdbserver do not support such automatic executable detection.
The following versions of gdbserver support it:
- Upstream version of gdbserver (unsupported) 7.10 or later
- Red Hat Developer Toolset (DTS) version of gdbserver from DTS 4.0 or later (only on x86_64)
- RHEL-7.3 versions of gdbserver (on any architecture)
amd_e400_idle () at arch/x86/kernel/process.c:796
796                     return;
(gdb) lx-symbols 
loading vmlinux
scanning for modules in /home/johannes/src/linux
loading @0xffffffffa00cc000: /home/johannes/src/linux/fs/btrfs/btrfs.ko
loading @0xffffffffa00c3000: /home/johannes/src/linux/crypto/blake2b_generic.ko
loading @0xffffffffa00b8000: /home/johannes/src/linux/crypto/xor.ko
loading @0xffffffffa00b1000: /home/johannes/src/linux/lib/lzo/lzo_compress.ko
loading @0xffffffffa00a7000: /home/johannes/src/linux/lib/zlib_deflate/zlib_deflate.ko
loading @0xffffffffa0085000: /home/johannes/src/linux/lib/raid6/raid6_pq.ko
loading @0xffffffffa0063000: /home/johannes/src/linux/lib/zstd/zstd_decompress.ko
loading @0xffffffffa0014000: /home/johannes/src/linux/lib/zstd/zstd_compress.ko
loading @0xffffffffa000d000: /home/johannes/src/linux/lib/xxhash.ko
loading @0xffffffffa0000000: /home/johannes/src/linux/drivers/block/null_blk/null_blk.ko
(gdb) break fs/btrfs/free-space-tree.c:737 if !(start >= found_start && end <= found_end)
Breakpoint 1 at 0xffffffffa0176086: file fs/btrfs/free-space-tree.c, line 737.
(gdb) c
Continuing.
[Switching to Thread 1.2]

Thread 2 hit Breakpoint 1, remove_free_space_extent (size=1407963136, start=1407971328, path=0xffff88811318c5b0, block_group=0xffff88810d3c1000, trans=0xffff888100472a28) at fs/btrfs/free-space-tree.c:737
737             ASSERT(start >= found_start && end <= found_end);
(gdb) p start
$1 = 1407971328
(gdb) p found_start
$2 = 1407963136
(gdb) p end
$3 = 1407995904
(gdb) p found_end
$4 = 1407967232
(gdb) p size
$5 = 1407963136
(gdb) p key
$6 = {
  objectid = 1407963136,
  type = 199 '\307',
  offset = 4096
}
(gdb) p *path
$7 = {
  nodes = {0xffff888113e75770, 0x0 <fixed_percpu_data>, 0x0 <fixed_percpu_data>, 0x0 <fixed_percpu_data>, 0x0 <fixed_percpu_data>, 0x0 <fixed_percpu_data>, 0x0 <fixed_percpu_data>, 0x0 <fixed_percpu_data>},
  slots = {106, 0, 0, 0, 0, 0, 0, 0},
  locks = "\001\000\000\000\000\000\000",
  reada = 0 '\000',
  lowest_level = 0 '\000',
  search_for_split = 0,
  keep_locks = 0,
  skip_locking = 0,
  search_commit_root = 0,
  need_commit_sem = 0,
  skip_release_on_error = 0,
  search_for_extension = 0
}
(gdb) p *path->nodes[0]
$8 = {
  start = 2561048576,
  len = 16384,
  bflags = 531,
  fs_info = 0xffff88810d42d000,
  refs_lock = {
    {
      rlock = {
        raw_lock = {
          {
            val = {
              counter = 0
            },
            {
              locked = 0 '\000',
              pending = 0 '\000'
            },
            {
              locked_pending = 0,
              tail = 0
            }
          }
        }
      }
    }
  },
  refs = {
    counter = 3
  },
  io_pages = {
    counter = 0
  },
  read_mirror = 0,
  callback_head = {
    next = 0x0 <fixed_percpu_data>,
    func = 0x0 <fixed_percpu_data>
  },
  lock_owner = 703,
  log_index = -1 '\377',
  lock = {
    count = {
      counter = 1
    },
    owner = {
      counter = -131387140126720
    },
    osq = {
      tail = {
        counter = 0
      }
    },
    wait_lock = {
      raw_lock = {
        {
          val = {
            counter = 0
          },
          {
            locked = 0 '\000',
            pending = 0 '\000'
          },
          {
            locked_pending = 0,
            tail = 0
          }
        }
      }
    },
    wait_list = {
      next = 0xffff888113e757d0,
      prev = 0xffff888113e757d0
    }
  },
  pages = {0xffffea0004425ac0, 0xffffea0004425b00, 0xffffea0004425b40, 0xffffea0004425b80, 0x0 <fixed_percpu_data> <repeats 12 times>},
  release_list = {
    next = 0xffff888113e75860,
    prev = 0xffff888113e75860
  },
  leak_list = {
    next = 0xffff888113e75760,
    prev = 0xffff888113e75650
  }
}
(gdb) p *block_group
$9 = {
  fs_info = 0xffff88810d42d000,
  inode = 0x0 <fixed_percpu_data>,
  lock = {
    {
      rlock = {
        raw_lock = {
          {
            val = {
              counter = 0
            },
            {
              locked = 0 '\000',
              pending = 0 '\000'
            },
            {
              locked_pending = 0,
              tail = 0
            }
          }
        }
      }
    }
  },
  start = 1342177280,
  length = 134217728,
  pinned = 0,
  reserved = 118784,
  used = 50720768,
  delalloc_bytes = 0,
  bytes_super = 0,
  flags = 1,
  cache_generation = 0,
  global_root_id = 256,
  bitmap_high_thresh = 179,
  bitmap_low_thresh = 79,
  data_rwsem = {
    count = {
      counter = 0
    },
    owner = {
      counter = -131387291393023
    },
    osq = {
      tail = {
        counter = 0
      }
    },
    wait_lock = {
      raw_lock = {
        {
          val = {
            counter = 0
          },
          {
            locked = 0 '\000',
            pending = 0 '\000'
          },
          {
            locked_pending = 0,
            tail = 0
          }
        }
      }
    },
    wait_list = {
      next = 0xffff88810d3c1088,
      prev = 0xffff88810d3c1088
    }
  },
  full_stripe_len = 4096,
  ro = 0,
  iref = 0,
  has_caching_ctl = 0,
  removed = 0,
  to_copy = 0,
  relocating_repair = 0,
  chunk_item_inserted = 1,
  zone_is_active = 1,
  disk_cache_state = 0,
  cached = 3,
  caching_ctl = 0x0 <fixed_percpu_data>,
  last_byte_to_unpin = 18446744073709551615,
  space_info = 0xffff88810d89a200,
  free_space_ctl = 0xffff88810b1d6e40,
  cache_node = {
    __rb_parent_color = 1,
    rb_right = 0xffff88810d3c3cd0,
    rb_left = 0xffff88810d3c38d0
  },
  list = {
    next = 0xffff88810d3c30e8,
    prev = 0xffff88810d89a328
  },
  refs = {
    refs = {
      counter = 3
    }
  },
  cluster_list = {
    next = 0xffff88810d3c1100,
    prev = 0xffff88810d3c1100
  },
  bg_list = {
    next = 0xffff88810d3c1110,
    prev = 0xffff88810d3c1110
  },
  ro_list = {
    next = 0xffff88810d3c1120,
    prev = 0xffff88810d3c1120
  },
  frozen = {
    counter = 0
  },
  discard_list = {
    next = 0xffff88810d3c1138,
    prev = 0xffff88810d3c1138
  },
  discard_index = 0,
  discard_eligible_time = 0,
  discard_cursor = 0,
  discard_state = BTRFS_DISCARD_EXTENTS,
  dirty_list = {
    next = 0xffff88810d3c1168,
    prev = 0xffff88810d3c1168
  },
  io_list = {
    next = 0xffff88810d3c1178,
    prev = 0xffff88810d3c1178
  },
  io_ctl = {
    cur = 0x0 <fixed_percpu_data>,
    orig = 0x0 <fixed_percpu_data>,
    page = 0x0 <fixed_percpu_data>,
    pages = 0x0 <fixed_percpu_data>,
    fs_info = 0x0 <fixed_percpu_data>,
    inode = 0x0 <fixed_percpu_data>,
    size = 0,
    index = 0,
    num_pages = 0,
    entries = 0,
    bitmaps = 0
  },
  reservations = {
    counter = 0
  },
  nocow_writers = {
    counter = 0
  },
  free_space_lock = {
    owner = {
      counter = -131387140126720
    },
    wait_lock = {
      raw_lock = {
        {
          val = {
            counter = 0
          },
          {
            locked = 0 '\000',
            pending = 0 '\000'
          },
          {
            locked_pending = 0,
            tail = 0
          }
        }
      }
    },
    osq = {
      tail = {
        counter = 0
      }
    },
    wait_list = {
      next = 0xffff88810d3c11e8,
      prev = 0xffff88810d3c11e8
    }
  },
  needs_free_space = 0,
  seq_zone = true,
  swap_extents = 0,
  full_stripe_locks_root = {
    root = {
      rb_node = 0x0 <fixed_percpu_data>
    },
    lock = {
      owner = {
        counter = 0
      },
      wait_lock = {
        raw_lock = {
          {
            val = {
              counter = 0
            },
            {
              locked = 0 '\000',
              pending = 0 '\000'
            },
            {
              locked_pending = 0,
              tail = 0
            }
          }
        }
      },
      osq = {
        tail = {
          counter = 0
        }
      },
      wait_list = {
        next = 0xffff88810d3c1220,
        prev = 0xffff88810d3c1220
      }
    }
  },
  alloc_offset = 67108864,
  zone_unusable = 83378176,
  zone_capacity = 67108864,
  meta_write_pointer = 1342177280,
  physical_map = 0xffff8881161dee80,
  active_bg_list = {
    next = 0xffff88810d3c3e58,
    prev = 0xffff88810d3c3a58
  }
}
(gdb) p *block_group->space_info
$10 = {
  lock = {
    {
      rlock = {
        raw_lock = {
          {
            val = {
              counter = 0
            },
            {
              locked = 0 '\000',
              pending = 0 '\000'
            },
            {
              locked_pending = 0,
              tail = 0
            }
          }
        }
      }
    }
  },
  total_bytes = 536870912,
  bytes_used = 76361728,
  bytes_pinned = 2240512,
  bytes_reserved = 1384448,
  bytes_may_use = 118784,
  bytes_readonly = 130383872,
  bytes_zone_unusable = 244887552,
  max_extent_size = 0,
  clamp = 6,
  full = 0,
  chunk_alloc = 0,
  flush = 0,
  force_alloc = 0,
  disk_used = 76361728,
  disk_total = 536870912,
  flags = 1,
  list = {
    next = 0xffff88810d89b870,
    prev = 0xffff88810d42d698
  },
  ro_bgs = {
    next = 0xffff88810d3c3120,
    prev = 0xffff88810d3c3120
  },
  priority_tickets = {
    next = 0xffff88810d89a290,
    prev = 0xffff88810d89a290
  },
  tickets = {
    next = 0xffff88810d89a2a0,
    prev = 0xffff88810d89a2a0
  },
  reclaim_size = 0,
  tickets_id = 7,
  groups_sem = {
    count = {
      counter = 0
    },
    owner = {
      counter = -131387291393023
    },
    osq = {
      tail = {
        counter = 0
      }
    },
    wait_lock = {
      raw_lock = {
        {
          val = {
            counter = 0
          },
          {
            locked = 0 '\000',
            pending = 0 '\000'
          },
          {
            locked_pending = 0,
            tail = 0
          }
        }
      }
    },
    wait_list = {
      next = 0xffff88810d89a2d8,
      prev = 0xffff88810d89a2d8
    }
  },
  block_groups = {{
      next = 0xffff88810d89a2e8,
      prev = 0xffff88810d89a2e8
    }, {
      next = 0xffff88810d89a2f8,
      prev = 0xffff88810d89a2f8
    }, {
      next = 0xffff88810d89a308,
      prev = 0xffff88810d89a308
    }, {
      next = 0xffff88810d89a318,
      prev = 0xffff88810d89a318
    }, {
      next = 0xffff88810d3c10e8,
      prev = 0xffff88810d3c24e8
    }, {
      next = 0xffff88810d89a338,
      prev = 0xffff88810d89a338
    }, {
      next = 0xffff88810d89a348,
      prev = 0xffff88810d89a348
    }, {
      next = 0xffff88810d89a358,
      prev = 0xffff88810d89a358
    }, {
      next = 0xffff88810d89a368,
      prev = 0xffff88810d89a368
    }},
  kobj = {
    name = 0xffff888100c92a80 "data",
    entry = {
      next = 0xffff88810d89a380,
      prev = 0xffff88810d89a380
    },
    parent = 0xffff88811a5e8380,
    kset = 0x0 <fixed_percpu_data>,
    ktype = 0xffffffffa0200ac0 <space_info_ktype>,
    sd = 0xffff88810f7ff100,
    kref = {
      refcount = {
        refs = {
          counter = 2
        }
      }
    },
    state_initialized = 1,
    state_in_sysfs = 1,
    state_add_uevent_sent = 0,
    state_remove_uevent_sent = 0,
    uevent_suppress = 0
  },
  block_group_kobjs = {0x0 <fixed_percpu_data>, 0x0 <fixed_percpu_data>, 0x0 <fixed_percpu_data>, 0x0 <fixed_percpu_data>, 0xffff8881030b4488, 0x0 <fixed_percpu_data>, 0x0 <fixed_percpu_data>, 0x0 <fixed_percpu_data>, 0x0 <fixed_percpu_data>}
}
(gdb) p *block_group->physical_map 
$11 = {
  type = 1,
  io_align = 65536,
  io_width = 65536,
  stripe_len = 65536,
  num_stripes = 1,
  sub_stripes = 1,
  verified_stripes = 371060352,
  stripes = 0xffff8881161deea8
}
(gdb) p *block_group->physical_map->stripes
$12 = {
  dev = 0xffff88810d8a1400,
  physical = 1342177280,
  length = 0
}
(gdb) p *block_group->physical_map->stripes->dev
$13 = {
  dev_list = {
    next = 0xffff88810d8a0298,
    prev = 0xffff88810d8a0298
  },
  dev_alloc_list = {
    next = 0xffff88810d8a02a8,
    prev = 0xffff88810d8a02a8
  },
  post_commit_list = {
    next = 0xffff88810d8a1420,
    prev = 0xffff88810d8a1420
  },
  fs_devices = 0xffff88810d8a0200,
  fs_info = 0xffff88810d42d000,
  name = 0xffff88810035b520,
  generation = 6,
  bdev = 0xffff8881006f3700,
  zone_info = 0xffff88810d89be00,
  mode = 131,
  devt = 263192577,
  dev_state = 3,
  last_flush_error = 0 '\000',
  devid = 1,
  total_bytes = 13421772800,
  disk_total_bytes = 13421772800,
  bytes_used = 1073741824,
  io_align = 4096,
  io_width = 4096,
  type = 0,
  sector_size = 4096,
  uuid = "z\335\313P\217\222K\361\207Tg\252?\035\351", <incomplete sequence \337>,
  commit_total_bytes = 13421772800,
  commit_bytes_used = 1073741824,
  flush_bio = 0xffff88810f75bc80,
  flush_wait = {
    done = 0,
    wait = {
      lock = {
        raw_lock = {
          {
            val = {
              counter = 0
            },
            {
              locked = 0 '\000',
              pending = 0 '\000'
            },
            {
              locked_pending = 0,
              tail = 0
            }
          }
        }
      },
      task_list = {
        next = 0x0 <fixed_percpu_data>,
        prev = 0x0 <fixed_percpu_data>
      }
    }
  },
  scrub_ctx = 0x0 <fixed_percpu_data>,
  dev_stats_valid = 1,
  dev_stats_ccnt = {
    counter = 2
  },
  dev_stat_values = {{
      counter = 2
    }, {
      counter = 0
    }, {
      counter = 0
    }, {
      counter = 0
    }, {
      counter = 0
    }},
  alloc_state = {
    state = {
      rb_node = 0xffff8881233da010
    },
    fs_info = 0x0 <fixed_percpu_data>,
    private_data = 0x0 <fixed_percpu_data>,
    dirty_bytes = 1073741824,
    track_uptodate = false,
    owner = 11 '\v',
    lock = {
      {
        rlock = {
          raw_lock = {
            {
              val = {
                counter = 0
              },
              {
                locked = 0 '\000',
                pending = 0 '\000'
              },
              {
                locked_pending = 0,
                tail = 0
              }
            }
          }
        }
      }
    }
  },
  kobj_unregister = {
    done = 0,
    wait = {
      lock = {
        raw_lock = {
          {
            val = {
              counter = 0
            },
            {
              locked = 0 '\000',
              pending = 0 '\000'
            },
            {
              locked_pending = 0,
              tail = 0
            }
          }
        }
      },
      task_list = {
        next = 0xffff88810d8a1558,
        prev = 0xffff88810d8a1558
      }
    }
  },
  devid_kobj = {
    name = 0xffff888100c92a08 "1",
    entry = {
      next = 0xffff88810d8a1570,
      prev = 0xffff88810d8a1570
    },
    parent = 0xffff88811a5e85c0,
    kset = 0x0 <fixed_percpu_data>,
    ktype = 0xffffffffa0200720 <devid_ktype>,
    sd = 0xffff88810ed7a200,
    kref = {
      refcount = {
        refs = {
          counter = 1
        }
      }
    },
    state_initialized = 1,
    state_in_sysfs = 1,
    state_add_uevent_sent = 0,
    state_remove_uevent_sent = 0,
    uevent_suppress = 0
  },
  scrub_speed_max = 0
}
(gdb) p *block_group->physical_map->stripes->dev->zone_info
$14 = {
  zone_size = 134217728,
  zone_size_shift = 27 '\033',
  nr_zones = 100,
  max_active_zones = 14,
  active_zones_left = {
    counter = 6
  },
  seq_zones = 0xffff88810b448cc0,
  empty_zones = 0xffff88810b448cd0,
  active_zones = 0xffff88810b448ce0,
  zone_cache = 0x0 <fixed_percpu_data>,
  sb_zones = {{
      start = 0,
      len = 262144,
      wp = 2552,
      type = 2 '\002',
      cond = 2 '\002',
      non_seq = 0 '\000',
      reset = 0 '\000',
      resv = "\000\000\000",
      capacity = 131072,
      reserved = '\000' <repeats 23 times>
    }, {
      start = 262144,
      len = 262144,
      wp = 262144,
      type = 2 '\002',
      cond = 1 '\001',
      non_seq = 0 '\000',
      reset = 0 '\000',
      resv = "\000\000\000",
      capacity = 131072,
      reserved = '\000' <repeats 23 times>
    }, {
      start = 0,
      len = 0,
      wp = 0,
      type = 0 '\000',
      cond = 0 '\000',
      non_seq = 0 '\000',
      reset = 0 '\000',
      resv = "\000\000\000",
      capacity = 0,
      reserved = '\000' <repeats 23 times>
    }, {
      start = 0,
      len = 0,
      wp = 0,
      type = 0 '\000',
      cond = 0 '\000',
      non_seq = 0 '\000',
      reset = 0 '\000',
      resv = "\000\000\000",
      capacity = 0,
      reserved = '\000' <repeats 23 times>
    }, {
      start = 0,
      len = 0,
      wp = 0,
      type = 0 '\000',
      cond = 0 '\000',
      non_seq = 0 '\000',
      reset = 0 '\000',
      resv = "\000\000\000",
      capacity = 0,
      reserved = '\000' <repeats 23 times>
    }, {
      start = 0,
      len = 0,
      wp = 0,
      type = 0 '\000',
      cond = 0 '\000',
      non_seq = 0 '\000',
      reset = 0 '\000',
      resv = "\000\000\000",
      capacity = 0,
      reserved = '\000' <repeats 23 times>
    }}
}

[morbidrsa]

Here's the stack trace

generic/068     [    1.398244] run fstests generic/068 at 2022-03-07 13:17:03
[   12.527832] assertion failed: start >= found_start && end <= found_end, in fs/btrfs/free-space-tree.c:737
[   12.528876] ------------[ cut here ]------------
[   12.529399] kernel BUG at fs/btrfs/ctree.h:3551!
[   12.529908] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[   12.530381] CPU: 0 PID: 694 Comm: kworker/u4:3 Not tainted 5.17.0-rc6-dennis #84
[   12.531160] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1.fc35 04/01/2014
[   12.531960] Workqueue: events_unbound btrfs_reclaim_bgs_work [btrfs]
[   12.532614] RIP: 0010:assertfail.constprop.0+0x18/0x1a [btrfs]
[   12.533182] Code: 9a 26 1b a0 48 c7 c7 70 d8 1b a0 e8 84 02 43 e1 0f 0b 89 f1 48 c7 c2 cd 26 1b a0 48 89 fe 48 c7 c7 98 d8 1b a0 e8 6a 02 43 e1 <0f> 0b be 8c 00 00 00 48 c7 c7 f9 26 1b a0 e8 d5 ff ff ff be 91 00
[   12.533391] RSP: 0018:ffffc90000cffa58 EFLAGS: 00010282
[   12.533391] RAX: 000000000000005d RBX: 0000000063f5c000 RCX: 0000000000000000
[   12.533391] RDX: 0000000000000001 RSI: 00000000ffffffea RDI: 00000000ffffffff
[   12.533391] RBP: ffff888116a59400 R08: ffffffff81ea4f88 R09: 00000000ffffefff
[   12.533391] R10: ffffffff81e34fa0 R11: ffffffff81e34fa0 R12: ffff888114d42460
[   12.533391] R13: ffff88810045ddd0 R14: 0000000063f9d000 R15: ffff88810408e800
[   12.533391] FS:  0000000000000000(0000) GS:ffff888627c00000(0000) knlGS:0000000000000000
[   12.533391] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   12.533391] CR2: 00007f36a24d9000 CR3: 00000001518d0000 CR4: 00000000000006b0
[   12.533391] Call Trace:
[   12.533391]  <TASK>
[   12.533391]  __remove_from_free_space_tree.cold+0x11/0x22 [btrfs]
[   12.542073]  ? setup_items_for_insert.isra.0+0x2bf/0x3f0 [btrfs]
[   12.542073]  remove_from_free_space_tree+0x80/0x110 [btrfs]
[   12.542073]  alloc_reserved_file_extent+0x1b4/0x240 [btrfs]
[   12.542073]  __btrfs_run_delayed_refs+0x692/0xf30 [btrfs]
[   12.542073]  ? btrfs_btree_balance_dirty+0x2f/0x50 [btrfs]
[   12.542073]  btrfs_run_delayed_refs+0x81/0x1e0 [btrfs]
[   12.542073]  btrfs_commit_transaction+0x54/0xaf0 [btrfs]
[   12.542073]  ? start_transaction+0xc2/0x5b0 [btrfs]
[   12.542073]  ? _raw_read_lock_irqsave+0x20/0x40
[   12.542073]  relocate_block_group+0x320/0x550 [btrfs]
[   12.542073]  btrfs_relocate_block_group+0x1f9/0x3a0 [btrfs]
[   12.542073]  btrfs_relocate_chunk+0x36/0xf0 [btrfs]
[   12.542073]  btrfs_reclaim_bgs_work.cold+0x4f/0x74 [btrfs]
[   12.542073]  process_one_work+0x1b0/0x310
[   12.542073]  worker_thread+0x48/0x3d0
[   12.542073]  ? rescuer_thread+0x3a0/0x3a0
[   12.542073]  kthread+0xed/0x120
[   12.550506]  ? kthread_complete_and_exit+0x20/0x20
[   12.550506]  ret_from_fork+0x22/0x30
[   12.550506]  </TASK>
[   12.550506] Modules linked in: btrfs blake2b_generic xor lzo_compress zlib_deflate raid6_pq zstd_decompress zstd_compress xxhash null_blk
[   12.553118] ---[ end trace 0000000000000000 ]---
[   12.553574] RIP: 0010:assertfail.constprop.0+0x18/0x1a [btrfs]
[   12.554206] Code: 9a 26 1b a0 48 c7 c7 70 d8 1b a0 e8 84 02 43 e1 0f 0b 89 f1 48 c7 c2 cd 26 1b a0 48 89 fe 48 c7 c7 98 d8 1b a0 e8 6a 02 43 e1 <0f> 0b be 8c 00 00 00 48 c7 c7 f9 26 1b a0 e8 d5 ff ff ff be 91 00
[   12.556091] RSP: 0018:ffffc90000cffa58 EFLAGS: 00010282
[   12.556570] RAX: 000000000000005d RBX: 0000000063f5c000 RCX: 0000000000000000
[   12.557269] RDX: 0000000000000001 RSI: 00000000ffffffea RDI: 00000000ffffffff
[   12.557940] RBP: ffff888116a59400 R08: ffffffff81ea4f88 R09: 00000000ffffefff
[   12.558629] R10: ffffffff81e34fa0 R11: ffffffff81e34fa0 R12: ffff888114d42460
[   12.559319] R13: ffff88810045ddd0 R14: 0000000063f9d000 R15: ffff88810408e800
[   12.560014] FS:  0000000000000000(0000) GS:ffff888627c00000(0000) knlGS:0000000000000000
[   12.560766] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   12.561329] CR2: 00007f36a24d9000 CR3: 00000001518d0000 CR4: 00000000000006b0

[naota]

While it can be interesting to trace what happening here, but I just want to disable FREESPACE_TREE on zoned btrfs in the first place.

Since we do the simple sequential allocation, it's no use to maintain the tree. And, actually, I think the zoned allocator is not doing the maintenance correctly.

[naota]

It should be fixed with 343d8a30851c ("btrfs: zoned: prevent allocation from previous data relocation BG")