)]}'
{
  "commit": "ef99bf480de9bde9d3b2afdf05324670fab4e571",
  "tree": "49afa5fd6e7e8060f3601c04bb25b96e14d14a39",
  "parents": [
    "6409bb05a9831f6af36a20b97cda13059c2ef1b6"
  ],
  "author": {
    "name": "NeilBrown",
    "email": "neilb@suse.de",
    "time": "Tue May 22 13:55:08 2012 +1000"
  },
  "committer": {
    "name": "NeilBrown",
    "email": "neilb@suse.de",
    "time": "Tue May 22 13:55:08 2012 +1000"
  },
  "message": "md/bitmap: allow a bitmap with no backing storage.\n\nAn md bitmap comprises two parts\n - internal counting of active writes per \u0027chunk\u0027.\n - external storage of whether there are any active writes on\n   each chunk\n\nThe second requires the first, but the first doesn\u0027t require the\nsecond.\n\nNot having backing storage means that the bitmap cannot expedite\nresync after a crash, but it still allows us to expedite the recovery\nof a recently-removed device.\n\nSo: allow a bitmap to exist even if there is no backing device.\nIn that case we default to 128M chunks.\n\nA particular value of this is that we can remove and re-add a bitmap\n(possibly of a different granularity) on a degraded array, and not\nlose the information needed to fast-recover the missing device.\n\nWe don\u0027t actually activate these bitmaps yet - that will come\nin a later patch.\n\nSigned-off-by: NeilBrown \u003cneilb@suse.de\u003e\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "ac688fb54e1d535892074a2445cd7aacc7eedb1c",
      "old_mode": 33188,
      "old_path": "drivers/md/bitmap.c",
      "new_id": "c042efd019c3935fcd944be0e996664c0d5a2c3b",
      "new_mode": 33188,
      "new_path": "drivers/md/bitmap.c"
    },
    {
      "type": "modify",
      "old_id": "9a677f2078a75258251807798e119631a6954769",
      "old_mode": 33188,
      "old_path": "drivers/md/md.c",
      "new_id": "607771bb7e9210f7b62c6c9b30b89e017bad2eea",
      "new_mode": 33188,
      "new_path": "drivers/md/md.c"
    }
  ]
}