block/blk-map.c:254:16: warning: variable 'added' set but not used
From: kernel test robot
Date: Fri Aug 12 2022 - 10:13:53 EST
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 7ebfc85e2cd7b08f518b526173e9a33b56b3913b
commit: 480cb846c27bda4e14d98a45a9f50c250f38f266 block: convert to advancing variants of iov_iter_get_pages{,_alloc}()
date: 4 days ago
config: i386-randconfig-a002 (https://download.01.org/0day-ci/archive/20220812/202208122209.qe4Bg8hH-lkp@xxxxxxxxx/config)
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 5f1c7e2cc5a3c07cbc2412e851a7283c1841f520)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=480cb846c27bda4e14d98a45a9f50c250f38f266
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 480cb846c27bda4e14d98a45a9f50c250f38f266
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross 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@xxxxxxxxx>
All warnings (new ones prefixed by >>):
>> block/blk-map.c:254:16: warning: variable 'added' set but not used [-Wunused-but-set-variable]
size_t offs, added = 0;
^
1 warning generated.
vim +/added +254 block/blk-map.c
130879f1ee0e25 Christoph Hellwig 2020-03-27 233
7589ad6729d6a7 Christoph Hellwig 2020-08-27 234 static int bio_map_user_iov(struct request *rq, struct iov_iter *iter,
7589ad6729d6a7 Christoph Hellwig 2020-08-27 235 gfp_t gfp_mask)
130879f1ee0e25 Christoph Hellwig 2020-03-27 236 {
7589ad6729d6a7 Christoph Hellwig 2020-08-27 237 unsigned int max_sectors = queue_max_hw_sectors(rq->q);
066ff571011d84 Christoph Hellwig 2022-04-06 238 unsigned int nr_vecs = iov_iter_npages(iter, BIO_MAX_VECS);
393bb12e00580a Christoph Hellwig 2021-03-31 239 struct bio *bio;
130879f1ee0e25 Christoph Hellwig 2020-03-27 240 int ret;
7589ad6729d6a7 Christoph Hellwig 2020-08-27 241 int j;
130879f1ee0e25 Christoph Hellwig 2020-03-27 242
130879f1ee0e25 Christoph Hellwig 2020-03-27 243 if (!iov_iter_count(iter))
7589ad6729d6a7 Christoph Hellwig 2020-08-27 244 return -EINVAL;
130879f1ee0e25 Christoph Hellwig 2020-03-27 245
066ff571011d84 Christoph Hellwig 2022-04-06 246 bio = bio_kmalloc(nr_vecs, gfp_mask);
130879f1ee0e25 Christoph Hellwig 2020-03-27 247 if (!bio)
7589ad6729d6a7 Christoph Hellwig 2020-08-27 248 return -ENOMEM;
066ff571011d84 Christoph Hellwig 2022-04-06 249 bio_init(bio, NULL, bio->bi_inline_vecs, nr_vecs, req_op(rq));
130879f1ee0e25 Christoph Hellwig 2020-03-27 250
130879f1ee0e25 Christoph Hellwig 2020-03-27 251 while (iov_iter_count(iter)) {
130879f1ee0e25 Christoph Hellwig 2020-03-27 252 struct page **pages;
130879f1ee0e25 Christoph Hellwig 2020-03-27 253 ssize_t bytes;
130879f1ee0e25 Christoph Hellwig 2020-03-27 @254 size_t offs, added = 0;
130879f1ee0e25 Christoph Hellwig 2020-03-27 255 int npages;
130879f1ee0e25 Christoph Hellwig 2020-03-27 256
480cb846c27bda Al Viro 2022-06-09 257 bytes = iov_iter_get_pages_alloc2(iter, &pages, LONG_MAX, &offs);
130879f1ee0e25 Christoph Hellwig 2020-03-27 258 if (unlikely(bytes <= 0)) {
130879f1ee0e25 Christoph Hellwig 2020-03-27 259 ret = bytes ? bytes : -EFAULT;
130879f1ee0e25 Christoph Hellwig 2020-03-27 260 goto out_unmap;
130879f1ee0e25 Christoph Hellwig 2020-03-27 261 }
130879f1ee0e25 Christoph Hellwig 2020-03-27 262
130879f1ee0e25 Christoph Hellwig 2020-03-27 263 npages = DIV_ROUND_UP(offs + bytes, PAGE_SIZE);
130879f1ee0e25 Christoph Hellwig 2020-03-27 264
7ab89db9790172 Michal Orzel 2022-04-23 265 if (unlikely(offs & queue_dma_alignment(rq->q)))
130879f1ee0e25 Christoph Hellwig 2020-03-27 266 j = 0;
7ab89db9790172 Michal Orzel 2022-04-23 267 else {
130879f1ee0e25 Christoph Hellwig 2020-03-27 268 for (j = 0; j < npages; j++) {
130879f1ee0e25 Christoph Hellwig 2020-03-27 269 struct page *page = pages[j];
130879f1ee0e25 Christoph Hellwig 2020-03-27 270 unsigned int n = PAGE_SIZE - offs;
130879f1ee0e25 Christoph Hellwig 2020-03-27 271 bool same_page = false;
130879f1ee0e25 Christoph Hellwig 2020-03-27 272
130879f1ee0e25 Christoph Hellwig 2020-03-27 273 if (n > bytes)
130879f1ee0e25 Christoph Hellwig 2020-03-27 274 n = bytes;
130879f1ee0e25 Christoph Hellwig 2020-03-27 275
7589ad6729d6a7 Christoph Hellwig 2020-08-27 276 if (!bio_add_hw_page(rq->q, bio, page, n, offs,
e4581105771b35 Christoph Hellwig 2020-05-12 277 max_sectors, &same_page)) {
130879f1ee0e25 Christoph Hellwig 2020-03-27 278 if (same_page)
130879f1ee0e25 Christoph Hellwig 2020-03-27 279 put_page(page);
130879f1ee0e25 Christoph Hellwig 2020-03-27 280 break;
130879f1ee0e25 Christoph Hellwig 2020-03-27 281 }
130879f1ee0e25 Christoph Hellwig 2020-03-27 282
130879f1ee0e25 Christoph Hellwig 2020-03-27 283 added += n;
130879f1ee0e25 Christoph Hellwig 2020-03-27 284 bytes -= n;
130879f1ee0e25 Christoph Hellwig 2020-03-27 285 offs = 0;
130879f1ee0e25 Christoph Hellwig 2020-03-27 286 }
130879f1ee0e25 Christoph Hellwig 2020-03-27 287 }
130879f1ee0e25 Christoph Hellwig 2020-03-27 288 /*
130879f1ee0e25 Christoph Hellwig 2020-03-27 289 * release the pages we didn't map into the bio, if any
130879f1ee0e25 Christoph Hellwig 2020-03-27 290 */
130879f1ee0e25 Christoph Hellwig 2020-03-27 291 while (j < npages)
130879f1ee0e25 Christoph Hellwig 2020-03-27 292 put_page(pages[j++]);
130879f1ee0e25 Christoph Hellwig 2020-03-27 293 kvfree(pages);
130879f1ee0e25 Christoph Hellwig 2020-03-27 294 /* couldn't stuff something into bio? */
480cb846c27bda Al Viro 2022-06-09 295 if (bytes) {
480cb846c27bda Al Viro 2022-06-09 296 iov_iter_revert(iter, bytes);
130879f1ee0e25 Christoph Hellwig 2020-03-27 297 break;
130879f1ee0e25 Christoph Hellwig 2020-03-27 298 }
480cb846c27bda Al Viro 2022-06-09 299 }
130879f1ee0e25 Christoph Hellwig 2020-03-27 300
393bb12e00580a Christoph Hellwig 2021-03-31 301 ret = blk_rq_append_bio(rq, bio);
7589ad6729d6a7 Christoph Hellwig 2020-08-27 302 if (ret)
393bb12e00580a Christoph Hellwig 2021-03-31 303 goto out_unmap;
7589ad6729d6a7 Christoph Hellwig 2020-08-27 304 return 0;
7589ad6729d6a7 Christoph Hellwig 2020-08-27 305
130879f1ee0e25 Christoph Hellwig 2020-03-27 306 out_unmap:
130879f1ee0e25 Christoph Hellwig 2020-03-27 307 bio_release_pages(bio, false);
066ff571011d84 Christoph Hellwig 2022-04-06 308 bio_uninit(bio);
066ff571011d84 Christoph Hellwig 2022-04-06 309 kfree(bio);
7589ad6729d6a7 Christoph Hellwig 2020-08-27 310 return ret;
130879f1ee0e25 Christoph Hellwig 2020-03-27 311 }
130879f1ee0e25 Christoph Hellwig 2020-03-27 312
:::::: The code at line 254 was first introduced by commit
:::::: 130879f1ee0e25b0391b8c78b3baac6fe41f4d38 block: move bio_map_* to blk-map.c
:::::: TO: Christoph Hellwig <hch@xxxxxx>
:::::: CC: Jens Axboe <axboe@xxxxxxxxx>
--
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https://01.org/lkp