Re: [PATCH v3 3/9] block: prevent race condition on bi_status in __bio_chain_endio

From: kernel test robot

Date: Sat Dec 06 2025 - 13:01:59 EST


Hi zhangshida,

kernel test robot noticed the following build warnings:

[auto build test WARNING on axboe/for-next]
[also build test WARNING on xfs-linux/for-next nvdimm/libnvdimm-for-next linus/master brauner-vfs/vfs.all v6.18 next-20251205]
[cannot apply to nvdimm/dax-misc]
[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/zhangshida/md-bcache-fix-improper-use-of-bi_end_io/20251129-170348
base: https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux.git for-next
patch link: https://lore.kernel.org/r/20251129090122.2457896-4-zhangshida%40kylinos.cn
patch subject: [PATCH v3 3/9] block: prevent race condition on bi_status in __bio_chain_endio
config: loongarch-randconfig-r133-20251130 (https://download.01.org/0day-ci/archive/20251207/202512070122.my7vkR7A-lkp@xxxxxxxxx/config)
compiler: loongarch64-linux-gcc (GCC) 14.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251207/202512070122.my7vkR7A-lkp@xxxxxxxxx/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@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202512070122.my7vkR7A-lkp@xxxxxxxxx/

sparse warnings: (new ones prefixed by >>)
>> block/bio.c:319:17: sparse: sparse: cast from restricted blk_status_t
>> block/bio.c:319:17: sparse: sparse: cast from restricted blk_status_t
>> block/bio.c:319:17: sparse: sparse: cast to restricted blk_status_t

vim +319 block/bio.c

313
314 static struct bio *__bio_chain_endio(struct bio *bio)
315 {
316 struct bio *parent = bio->bi_private;
317
318 if (bio->bi_status)
> 319 cmpxchg(&parent->bi_status, 0, bio->bi_status);
320
321 bio_put(bio);
322 return parent;
323 }
324

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