Re: [PATCH v3 7/8] block: add nowait flag for __blkdev_issue_zero_pages

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

Hi Pavel,

kernel test robot noticed the following build warnings:

[auto build test WARNING on axboe-block/for-next]
[also build test WARNING on akpm-mm/mm-everything linus/master v6.11-rc6 next-20240905]
[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/Pavel-Begunkov/io_uring-cmd-expose-iowq-to-cmds/20240904-222012
base:   https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git for-next
patch link:    https://lore.kernel.org/r/292fa1c611adb064efe16ab741aad65c2128ada8.1725459175.git.asml.silence%40gmail.com
patch subject: [PATCH v3 7/8] block: add nowait flag for __blkdev_issue_zero_pages
config: i386-randconfig-141-20240906 (https://download.01.org/0day-ci/archive/20240906/202409061126.hKdAymJK-lkp@intel.com/config)
compiler: clang version 18.1.5 (https://github.com/llvm/llvm-project 617a15a9eac96088ae5e9134248d8236e34b91b1)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240906/202409061126.hKdAymJK-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/202409061126.hKdAymJK-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> block/blk-lib.c:200:12: warning: variable 'opf' set but not used [-Wunused-but-set-variable]
     200 |         blk_opf_t opf = REQ_OP_WRITE;
         |                   ^
   1 warning generated.


vim +/opf +200 block/blk-lib.c

   195	
   196	int blkdev_issue_zero_pages_bio(struct block_device *bdev,
   197			sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
   198			struct bio **biop, unsigned int flags)
   199	{
 > 200		blk_opf_t opf = REQ_OP_WRITE;
   201	
   202		if (flags & BLKDEV_ZERO_PAGES_NOWAIT) {
   203			sector_t max_bio_sectors = BIO_MAX_VECS << PAGE_SECTORS_SHIFT;
   204	
   205			if (nr_sects > max_bio_sectors)
   206				return -EAGAIN;
   207			opf |= REQ_NOWAIT;
   208		}
   209	
   210		while (nr_sects) {
   211			unsigned int nr_vecs = __blkdev_sectors_to_bio_pages(nr_sects);
   212			struct bio *bio;
   213	
   214			bio = bio_alloc(bdev, nr_vecs, REQ_OP_WRITE, gfp_mask);
   215			if (!bio)
   216				return -ENOMEM;
   217			bio->bi_iter.bi_sector = sector;
   218	
   219			if ((flags & BLKDEV_ZERO_KILLABLE) &&
   220			    fatal_signal_pending(current))
   221				return -EINTR;
   222	
   223			do {
   224				unsigned int len, added;
   225	
   226				len = min_t(sector_t,
   227					PAGE_SIZE, nr_sects << SECTOR_SHIFT);
   228				added = bio_add_page(bio, ZERO_PAGE(0), len, 0);
   229				if (added < len)
   230					break;
   231				nr_sects -= added >> SECTOR_SHIFT;
   232				sector += added >> SECTOR_SHIFT;
   233			} while (nr_sects);
   234	
   235			*biop = bio_chain_and_submit(*biop, bio);
   236			cond_resched();
   237		}
   238	
   239		return 0;
   240	}
   241	

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