Hi Jianchao, FYI, the error/warning still remains. tree: https://gitee.com/openeuler/kernel.git openEuler-1.0-LTS head: 08111f03f1ec65598372cfe9bf64f366d575671e commit: 5f100bc6aabbe30e55cf20af8e163bb6dba3a3aa [1593/1593] block: fix the DISCARD request merge config: arm64-defconfig (https://download.01.org/0day-ci/archive/20250425/202504250657.SBZLGq3K-lkp@i...) compiler: aarch64-linux-gcc (GCC) 14.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250425/202504250657.SBZLGq3K-lkp@i...) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202504250657.SBZLGq3K-lkp@intel.com/ All warnings (new ones prefixed by >>):

...

block/blk-merge.c:688:16: warning: no previous prototype for 'blk_try_req_merge' [-Wmissing-prototypes] 688 | enum elv_merge blk_try_req_merge(struct request *req, struct request *next) | ^~~~~~~~~~~~~~~~~

vim +/blk_try_req_merge +688 block/blk-merge.c 687

688 enum elv_merge blk_try_req_merge(struct request *req, struct request *next) 689 { 690 if (blk_discard_mergable(req)) 691 return ELEVATOR_DISCARD_MERGE; 692 else if (blk_rq_pos(req) + blk_rq_sectors(req) == blk_rq_pos(next)) 693 return ELEVATOR_BACK_MERGE; 694 695 return ELEVATOR_NO_MERGE; 696 } 697

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