)]}'
{
  "commit": "6746aff74da293b5fd24e5c68b870b721e86cd5f",
  "tree": "6d2b9e99d247e788c13665ce5e8a0753538ef641",
  "parents": [
    "257187362123f15d9d1e09918cf87cebbea4e786"
  ],
  "author": {
    "name": "Wu Fengguang",
    "email": "fengguang.wu@intel.com",
    "time": "Wed Sep 16 11:50:14 2009 +0200"
  },
  "committer": {
    "name": "Andi Kleen",
    "email": "ak@linux.intel.com",
    "time": "Wed Sep 16 11:50:14 2009 +0200"
  },
  "message": "HWPOISON: shmem: call set_page_dirty() with locked page\n\nThe dirtying of page and set_page_dirty() can be moved into the page lock.\n\n- In shmem_write_end(), the page was dirtied while the page lock was held,\n  but it\u0027s being marked dirty just after dropping the page lock.\n- In shmem_symlink(), both dirtying and marking can be moved into page lock.\n\nIt\u0027s valuable for the hwpoison code to know whether one bad page can be dropped\nwithout losing data. It mainly judges by testing the PG_dirty bit after taking\nthe page lock. So it becomes important that the dirtying of page and the\nmarking of dirtiness are both done inside the page lock. Which is a common\npractice, but sadly not a rule.\n\nThe noticeable exceptions are\n- mapped pages\n- pages with buffer_heads\nThe above pages could go dirty at any time. Fortunately the hwpoison will\nunmap the page and release the buffer_heads beforehand anyway.\n\nMany other types of pages (eg. metadata pages) can also be dirtied at will by\ntheir owners, the hwpoison code cannot do meaningful things to them anyway.\nOnly the dirtiness of pagecache pages owned by regular files are interested.\n\nv2: AK: Add comment about set_page_dirty rules (suggested by Peter Zijlstra)\n\nAcked-by: Hugh Dickins \u003chugh.dickins@tiscali.co.uk\u003e\nReviewed-by: WANG Cong \u003cxiyou.wangcong@gmail.com\u003e\nSigned-off-by: Wu Fengguang \u003cfengguang.wu@intel.com\u003e\nSigned-off-by: Andi Kleen \u003cak@linux.intel.com\u003e\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "dd73d29c15a8697043f705a6419aa3990ee57599",
      "old_mode": 33188,
      "old_path": "mm/page-writeback.c",
      "new_id": "bba82c414ba81eb5aaa521a6e31fd0fdbe787d11",
      "new_mode": 33188,
      "new_path": "mm/page-writeback.c"
    },
    {
      "type": "modify",
      "old_id": "5a0b3d4055f347898b92f481d8ecdb793f9e62a0",
      "old_mode": 33188,
      "old_path": "mm/shmem.c",
      "new_id": "46936601e37f62dc57d004656b1c2f509914de02",
      "new_mode": 33188,
      "new_path": "mm/shmem.c"
    }
  ]
}