linux-imx

 * Lock ordering in mm:

 *

 * inode->i_mutex   (while writing or truncating, not reading or faulting)

 *   mm->mmap_sem

 *     page->flags PG_locked (lock_page)

 *       hugetlbfs_i_mmap_rwsem_key (in huge_pmd_share)

 *         mapping->i_mmap_rwsem

 *           anon_vma->rwsem

 *             mm->page_table_lock or pte_lock

 *               swap_lock (in swap_duplicate, swap_info_get)

 *                 mmlist_lock (in mmput, drain_mmlist and others)

 *                 mapping->private_lock (in __set_page_dirty_buffers)

 *                   mem_cgroup_{begin,end}_page_stat (memcg->move_lock)

 *                     i_pages lock (widely used)

 *                 inode->i_lock (in set_page_dirty's __mark_inode_dirty)

 *                 bdi.wb->list_lock (in set_page_dirty's __mark_inode_dirty)

 *                   sb_lock (within inode_lock in fs/fs-writeback.c)

 *                   i_pages lock (widely used, in set_page_dirty,

 *                             in arch-dependent flush_dcache_mmap_lock,