Re: [PATCH 1/2] zram: introduce compressed data writeback

[kernel test robot <lkp@intel.com>]

Hi Sergey,

kernel test robot noticed the following build warnings:

[auto build test WARNING on akpm-mm/mm-everything]
[also build test WARNING on next-20251128]
[cannot apply to axboe/for-next linus/master v6.18-rc7]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Sergey-Senozhatsky/zram-introduce-compressed-data-writeback/20251129-010716
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20251128170442.2988502-2-senozhatsky%40chromium.org
patch subject: [PATCH 1/2] zram: introduce compressed data writeback
config: x86_64-randconfig-011-20251129 (https://download.01.org/0day-ci/archive/20251129/202511291628.NZif1jdx-lkp@intel.com/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251129/202511291628.NZif1jdx-lkp@intel.com/reproduce)

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/202511291628.NZif1jdx-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/block/zram/zram_drv.c:2099:12: warning: 'zram_read_from_zspool_raw' defined but not used [-Wunused-function]
    2099 | static int zram_read_from_zspool_raw(struct zram *zram, struct page *page,
         |            ^~~~~~~~~~~~~~~~~~~~~~~~~


vim +/zram_read_from_zspool_raw +2099 drivers/block/zram/zram_drv.c

  2098	
> 2099	static int zram_read_from_zspool_raw(struct zram *zram, struct page *page,
  2100					     u32 index)
  2101	{
  2102		struct zcomp_strm *zstrm;
  2103		unsigned long handle;
  2104		unsigned int size;
  2105		void *src;
  2106	
  2107		handle = zram_get_handle(zram, index);
  2108		size = zram_get_obj_size(zram, index);
  2109	
  2110		/*
  2111		 * We need to get stream just for ->local_copy buffer, in
  2112		 * case if object spans two physical pages. No decompression
  2113		 * takes place here, as we read raw compressed data.
  2114		 */
  2115		zstrm = zcomp_stream_get(zram->comps[ZRAM_PRIMARY_COMP]);
  2116		src = zs_obj_read_begin(zram->mem_pool, handle, zstrm->local_copy);
  2117		memcpy_to_page(page, 0, src, size);
  2118		zs_obj_read_end(zram->mem_pool, handle, src);
  2119		zcomp_stream_put(zstrm);
  2120	
  2121		return 0;
  2122	}
  2123	

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