Hi Boris,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on kdave/for-next]
[also build test ERROR on next-20221116]
[cannot apply to linus/master v6.1-rc5]
[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/Boris-Burkov/btrfs-data-block-group-size-classes/20221117-032311
base:   https://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux.git for-next
patch link:    https://lore.kernel.org/r/b0bf853ab9d2039ce883a5bc2086f8833c528ebf.1668626092.git.boris%40bur.io
patch subject: [PATCH v2 4/4] btrfs: load block group size class when caching
config: i386-randconfig-a011-20211213
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
reproduce (this is a W=1 build):
        # https://github.com/intel-lab-lkp/linux/commit/dfa5c0e232156b57322889d221646f891f5da3b8
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Boris-Burkov/btrfs-data-block-group-size-classes/20221117-032311
        git checkout dfa5c0e232156b57322889d221646f891f5da3b8
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   ld: fs/btrfs/block-group.o: in function `sample_block_group_extent_item':
>> fs/btrfs/block-group.c:584: undefined reference to `__udivdi3'
   pahole: .tmp_vmlinux.btf: No such file or directory
   .btf.vmlinux.bin.o: file not recognized: file format not recognized


vim +584 fs/btrfs/block-group.c

   542	
   543	/*
   544	 * Get an arbitrary extent item index / max_index through the block group
   545	 *
   546	 * @block_group: the block group to sample from
   547	 * @index: the integral step through the block group to grab from
   548	 * @max_index: the granularity of the sampling
   549	 * @key: return value parameter for the item we find
   550	 *
   551	 * pre-conditions on indices:
   552	 * 0 <= index <= max_index
   553	 * 0 < max_index
   554	 *
   555	 * Returns: 0 on success, 1 if the search didn't yield a useful item, negative
   556	 * error code on error.
   557	 */
   558	static int sample_block_group_extent_item(struct btrfs_block_group *block_group,
   559						  int index, int max_index,
   560						  struct btrfs_key *key)
   561	{
   562		struct btrfs_fs_info *fs_info = block_group->fs_info;
   563		struct btrfs_root *extent_root;
   564		int ret = 0;
   565		u64 search_offset;
   566		struct btrfs_path *path;
   567	
   568		ASSERT(index >= 0);
   569		ASSERT(index <= max_index);
   570		ASSERT(max_index > 0);
   571	
   572		path = btrfs_alloc_path();
   573		if (!path)
   574			return -ENOMEM;
   575	
   576		down_read(&fs_info->commit_root_sem);
   577		extent_root = btrfs_extent_root(fs_info, max_t(u64, block_group->start,
   578							       BTRFS_SUPER_INFO_OFFSET));
   579	
   580		path->skip_locking = 1;
   581		path->search_commit_root = 1;
   582		path->reada = READA_FORWARD;
   583	
 > 584		search_offset = index * (block_group->length / max_index);
   585		key->objectid = block_group->start + search_offset;
   586		key->offset = 0;
   587		key->type = BTRFS_EXTENT_ITEM_KEY;
   588	
   589		ret = btrfs_search_slot(NULL, extent_root, key, path, 0, 0);
   590		if (ret != 0)
   591			goto out;
   592		if (key->objectid < block_group->start ||
   593		    key->objectid > block_group->start + block_group->length) {
   594			ret = 1;
   595			goto out;
   596		}
   597		if (key->type != BTRFS_EXTENT_ITEM_KEY) {
   598			ret = 1;
   599			goto out;
   600		}
   601	out:
   602		btrfs_free_path(path);
   603		up_read(&fs_info->commit_root_sem);
   604		return ret;
   605	}
   606	

-- 
0-DAY CI Kernel Test Service
https://01.org/lkp