[block:for-5.15/block 48/54] mm/page-writeback.c:2036:6: error: redefinition of 'laptop_sync_completion'

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git for-5.15/block
head:   99d26de2f6d79badc80f55b54bd90d4cb9d1ad90
commit: 5ed964f8e54eb3191b8b7b45aeb52672a0c995dc [48/54] mm: hide laptop_mode_wb_timer entirely behind the BDI API
config: hexagon-randconfig-r032-20210810 (attached as .config)
compiler: clang version 12.0.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git/commit/?id=5ed964f8e54eb3191b8b7b45aeb52672a0c995dc
        git remote add block https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git
        git fetch --no-tags block for-5.15/block
        git checkout 5ed964f8e54eb3191b8b7b45aeb52672a0c995dc
        # save the attached .config to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross O=build_dir ARCH=hexagon SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

Note: the block/for-5.15/block HEAD 99d26de2f6d79badc80f55b54bd90d4cb9d1ad90 builds fine.
      It only hurts bisectibility.

All errors (new ones prefixed by >>):

   mm/page-writeback.c:2013:6: warning: no previous prototype for function 'laptop_mode_timer_fn' [-Wmissing-prototypes]
   void laptop_mode_timer_fn(struct timer_list *t)
        ^
   mm/page-writeback.c:2013:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void laptop_mode_timer_fn(struct timer_list *t)
   ^
   static 
   mm/page-writeback.c:2026:6: warning: no previous prototype for function 'laptop_io_completion' [-Wmissing-prototypes]
   void laptop_io_completion(struct backing_dev_info *info)
        ^
   mm/page-writeback.c:2026:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void laptop_io_completion(struct backing_dev_info *info)
   ^
   static 
>> mm/page-writeback.c:2036:6: error: redefinition of 'laptop_sync_completion'
   void laptop_sync_completion(void)
        ^
   include/linux/writeback.h:345:20: note: previous definition is here
   static inline void laptop_sync_completion(void) { }
                      ^
   2 warnings and 1 error generated.
--
>> mm/backing-dev.c:810:42: error: use of undeclared identifier 'laptop_mode_timer_fn'
           timer_setup(&bdi->laptop_mode_wb_timer, laptop_mode_timer_fn, 0);
                                                   ^
   1 error generated.


vim +/laptop_sync_completion +2036 mm/page-writeback.c

^1da177e4c3f41 Linus Torvalds  2005-04-16  2030  
^1da177e4c3f41 Linus Torvalds  2005-04-16  2031  /*
^1da177e4c3f41 Linus Torvalds  2005-04-16  2032   * We're in laptop mode and we've just synced. The sync's writes will have
^1da177e4c3f41 Linus Torvalds  2005-04-16  2033   * caused another writeback to be scheduled by laptop_io_completion.
^1da177e4c3f41 Linus Torvalds  2005-04-16  2034   * Nothing needs to be written back anymore, so we unschedule the writeback.
^1da177e4c3f41 Linus Torvalds  2005-04-16  2035   */
^1da177e4c3f41 Linus Torvalds  2005-04-16 @2036  void laptop_sync_completion(void)
^1da177e4c3f41 Linus Torvalds  2005-04-16  2037  {
31373d09da5b7f Matthew Garrett 2010-04-06  2038  	struct backing_dev_info *bdi;
31373d09da5b7f Matthew Garrett 2010-04-06  2039  
31373d09da5b7f Matthew Garrett 2010-04-06  2040  	rcu_read_lock();
31373d09da5b7f Matthew Garrett 2010-04-06  2041  
31373d09da5b7f Matthew Garrett 2010-04-06  2042  	list_for_each_entry_rcu(bdi, &bdi_list, bdi_list)
31373d09da5b7f Matthew Garrett 2010-04-06  2043  		del_timer(&bdi->laptop_mode_wb_timer);
31373d09da5b7f Matthew Garrett 2010-04-06  2044  
31373d09da5b7f Matthew Garrett 2010-04-06  2045  	rcu_read_unlock();
^1da177e4c3f41 Linus Torvalds  2005-04-16  2046  }
^1da177e4c3f41 Linus Torvalds  2005-04-16  2047  

:::::: The code at line 2036 was first introduced by commit
:::::: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Linux-2.6.12-rc2

:::::: TO: Linus Torvalds <torvalds@xxxxxxxxxxxxxxx>
:::::: CC: Linus Torvalds <torvalds@xxxxxxxxxxxxxxx>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

Attachment: .config.gz
Description: application/gzip