(gdb) p/x *rreq
$3 = {
  {
    work = {
      data = {
        counter = 0xfffffffe00000
      },
      entry = {
        next = 0xffff8898b7df6908,
        prev = 0xffff8898b7df6908
      },
      func = 0xffffffff81b44e90
    },
    rcu = {
      next = 0xfffffffe00000,
      func = 0xffff8898b7df6908
    }
  },
  inode = 0xffff889886939518,
  mapping = 0xffff889886939670,
  iocb = 0x0,
  cache_resources = {
    ops = 0xffffffff845fd480,
    cache_priv = 0xffff8898b876ed20,
    cache_priv2 = 0xffff8898a7b29700,
    debug_id = 0x2,
    inval_counter = 0x0
  },
  ractl = 0xffff8898b88b7980,
  proc_link = {
    next = 0xffffffff857668a0,
    prev = 0xffff8898b7df3c60
  },
  subrequests = {
    next = 0xffff8898b87fd568,
    prev = 0xffff8898b87fd568
  },
  io_streams = {{
      construct = 0x0,
      sreq_max_len = 0x10000,
      sreq_max_segs = 0x0,
      submit_off = 0x0,
      submit_len = 0x0,
      submit_extendable_to = 0x0,
      prepare_write = 0x0,
      issue_write = 0x0,
      subrequests = {
        next = 0xffff8898b7df69b0,
        prev = 0xffff8898b7df69b0
      },
      front = 0x0,
      collected_to = 0x0,
      transferred = 0x0,
      source = 0x0,
      error = 0x0,
      stream_nr = 0x0,
      avail = 0x0,
      active = 0x0,
      need_retry = 0x0,
      failed = 0x0
    }, {
      construct = 0x0,
      sreq_max_len = 0x0,
      sreq_max_segs = 0x0,
      submit_off = 0x0,
      submit_len = 0x0,
      submit_extendable_to = 0x0,
      prepare_write = 0x0,
      issue_write = 0x0,
      subrequests = {
        next = 0xffff8898b7df6a18,
        prev = 0xffff8898b7df6a18
      },
      front = 0x0,
      collected_to = 0x0,
      transferred = 0x0,
      source = 0x0,
      error = 0x0,
      stream_nr = 0x0,
      avail = 0x0,
      active = 0x0,
      need_retry = 0x0,
      failed = 0x0
    }},
  group = 0x0,
  buffer = 0xffff8898b8000000,
  buffer_tail = 0xffff8898b8000000,
  iter = {
    iter_type = 0x4,
    nofault = 0x0,
    data_source = 0x0,
    iov_offset = 0x0,
    {
      __ubuf_iovec = {
        iov_base = 0xffff8898b8000000,
        iov_len = 0x0
      },
      {
        {
          __iov = 0xffff8898b8000000,
          kvec = 0xffff8898b8000000,
          bvec = 0xffff8898b8000000,
          folioq = 0xffff8898b8000000,
          xarray = 0xffff8898b8000000,
          ubuf = 0xffff8898b8000000
        },
        count = 0x0
      }
    },
    {
      nr_segs = 0x1,
      folioq_slot = 0x1,
      xarray_start = 0x1
    }
  },
  io_iter = {
    iter_type = 0x0,
    nofault = 0x0,
    data_source = 0x0,
    iov_offset = 0x0,
    {
      __ubuf_iovec = {
        iov_base = 0x0,
        iov_len = 0x0
      },
      {
        {
          __iov = 0x0,
          kvec = 0x0,
          bvec = 0x0,
          folioq = 0x0,
          xarray = 0x0,
          ubuf = 0x0
        },
        count = 0x0
      }
    },
    {
      nr_segs = 0x0,
      folioq_slot = 0x0,
      xarray_start = 0x0
    }
  },
  netfs_priv = 0xffff8898b041fa00,
  netfs_priv2 = 0x0,
  direct_bv = 0x0,
  direct_bv_count = 0x0,
  debug_id = 0x8,
  rsize = 0x0,
  wsize = 0x7fffffff,
  subreq_counter = {
    counter = 0x8
  },
  nr_group_rel = 0x0,
  lock = {
    {
      rlock = {
        raw_lock = {
          {
            val = {
              counter = 0x0
            },
            {
              locked = 0x0,
              pending = 0x0
            },
            {
              locked_pending = 0x0,
              tail = 0x0
            }
          }
        }
      }
    }
  },
  nr_outstanding = {
    counter = 0x1
  },
  submitted = 0x200000,
  len0 = 0x40000,
  len = 0x40000,
  transferred = 0x0,
  error = 0x0,
  origin = 0x0,
  direct_bv_unpin = 0x0,
  buffer_head_slot = 0x0,
  buffer_tail_slot = 0x0,
  i_size = 0x776749,
  start0 = 0x1c0000,
  start = 0x1c0000,
  issued_to = {
    counter = 0x0
  },
  collected_to = 0x0,
  cleaned_to = 0x0,
  no_unlock_folio = 0x0,
  prev_donated = 0x0,
  ref = {
    refs = {
      counter = 0x1
    }
  },
  flags = 0x80000020,
  netfs_ops = 0xffffffff8459dba0,
  cleanup = 0x0
}
(gdb) p/x *subreq
$4 = {
  rreq = 0xffff8898b7df6900,
  work = {
    data = {
      counter = 0xfffffffe00000
    },
    entry = {
      next = 0xffff8898b87fd550,
      prev = 0xffff8898b87fd550
    },
    func = 0x0
  },
  rreq_link = {
    next = 0xffff8898b7df6970,
    prev = 0xffff8898b7df6970
  },
  io_iter = {
    iter_type = 0x4,
    nofault = 0x0,
    data_source = 0x0,
    iov_offset = 0x34000,
    {
      __ubuf_iovec = {
        iov_base = 0xffff8898b8000000,
        iov_len = 0x6000
      },
      {
        {
          __iov = 0xffff8898b8000000,
          kvec = 0xffff8898b8000000,
          bvec = 0xffff8898b8000000,
          folioq = 0xffff8898b8000000,
          xarray = 0xffff8898b8000000,
          ubuf = 0xffff8898b8000000
        },
        count = 0x6000
      }
    },
    {
      nr_segs = 0x0,
      folioq_slot = 0x0,
      xarray_start = 0x0
    }
  },
  start0 = 0x1f4000,
  start = 0x1c6000,
  len0 = 0xc000,
  len = 0x3a000,
  transferred = 0x3a000,
  consumed = 0x0,
  prev_donated = 0x0,
  next_donated = 0x0,
  ref = {
    refs = {
      counter = 0x2
    }
  },
  error = 0x0,
  debug_index = 0x7,
  nr_segs = 0x0,
  retry_count = 0x0,
  source = 0x2,
  stream_nr = 0x0,
  curr_folioq_slot = 0x0,
  curr_folio_order = 0x6,
  curr_folioq = 0xffff8898b8000000,
  flags = 0x1
}