[bcache:for-next 9/19] drivers/md/bcache/nvm-pages.c:238:34: warning: Unsigned variable 'i' can't be negative so it is unnecessary to test it.

[bcache:for-next 9/19] drivers/md/bcache/nvm-pages.c:238:34: warning: Unsigned variable 'i' can't be negative so it is unnecessary to test it.

[kernel test robot]

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CC: kbuild-all(a)lists.01.org
TO: Qiaowei Ren <qiaowei.ren@intel.com>
CC: Coly Li <colyli@suse.de>
CC: Jianpeng Ma <jianpeng.ma@intel.com>

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/colyli/linux-bcache.git for-next
head:   78729af1b480ca5a3edb9547b97b59ed3dd72440
commit: 7719cf7684941455e7d6505d2554623a19b7184b [9/19] bcache: initialization of the buddy
:::::: branch date: 2 days ago
:::::: commit date: 2 days ago
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0

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


cppcheck possible warnings: (new ones prefixed by >>, may not real problems)

   In file included from drivers/md/bcache/nvm-pages.c:
   drivers/md/bcache/nvm-pages.c:173:4: warning: Either the condition '!extents' is redundant or there is possible null pointer dereference: extents. [nullPointerRedundantCheck]
      extents->ns = only_set->nss[j];
      ^
   drivers/md/bcache/nvm-pages.c:185:10: note: Assuming that condition '!extents' is not redundant
        if (!extents) {
            ^
   drivers/md/bcache/nvm-pages.c:173:4: note: Null pointer dereference
      extents->ns = only_set->nss[j];
      ^
>> drivers/md/bcache/nvm-pages.c:238:34: warning: Unsigned variable 'i' can't be negative so it is unnecessary to test it. [unsignedPositive]
      for (i = BCH_MAX_ORDER - 1; i >= 0 ; i--) {
                                    ^

vim +238 drivers/md/bcache/nvm-pages.c

384227b99f4131 Qiaowei Ren 2021-02-08  225  
7719cf76849414 Qiaowei Ren 2021-02-08  226  static void init_nvm_free_space(struct bch_nvm_namespace *ns)
7719cf76849414 Qiaowei Ren 2021-02-08  227  {
7719cf76849414 Qiaowei Ren 2021-02-08  228  	unsigned int start, end, i;
7719cf76849414 Qiaowei Ren 2021-02-08  229  	struct page *page;
7719cf76849414 Qiaowei Ren 2021-02-08  230  	long long pages;
7719cf76849414 Qiaowei Ren 2021-02-08  231  	pgoff_t pgoff_start;
7719cf76849414 Qiaowei Ren 2021-02-08  232  
7719cf76849414 Qiaowei Ren 2021-02-08  233  	bitmap_for_each_clear_region(ns->pages_bitmap, start, end, 0, ns->pages_total) {
7719cf76849414 Qiaowei Ren 2021-02-08  234  		pgoff_start = start;
7719cf76849414 Qiaowei Ren 2021-02-08  235  		pages = end - start;
7719cf76849414 Qiaowei Ren 2021-02-08  236  
7719cf76849414 Qiaowei Ren 2021-02-08  237  		while (pages) {
7719cf76849414 Qiaowei Ren 2021-02-08 @238  			for (i = BCH_MAX_ORDER - 1; i >= 0 ; i--) {
7719cf76849414 Qiaowei Ren 2021-02-08  239  				if ((pgoff_start % (1 << i) == 0) && (pages >= (1 << i)))
7719cf76849414 Qiaowei Ren 2021-02-08  240  					break;
7719cf76849414 Qiaowei Ren 2021-02-08  241  			}
7719cf76849414 Qiaowei Ren 2021-02-08  242  
7719cf76849414 Qiaowei Ren 2021-02-08  243  			page = nvm_vaddr_to_page(ns, nvm_pgoff_to_vaddr(ns, pgoff_start));
7719cf76849414 Qiaowei Ren 2021-02-08  244  			page->index = pgoff_start;
7719cf76849414 Qiaowei Ren 2021-02-08  245  			set_page_private(page, i);
7719cf76849414 Qiaowei Ren 2021-02-08  246  			__SetPageBuddy(page);
7719cf76849414 Qiaowei Ren 2021-02-08  247  			list_add((struct list_head *)&page->zone_device_data, &ns->free_area[i]);
7719cf76849414 Qiaowei Ren 2021-02-08  248  
7719cf76849414 Qiaowei Ren 2021-02-08  249  			pgoff_start += 1 << i;
7719cf76849414 Qiaowei Ren 2021-02-08  250  			pages -= 1 << i;
7719cf76849414 Qiaowei Ren 2021-02-08  251  		}
7719cf76849414 Qiaowei Ren 2021-02-08  252  	}
7719cf76849414 Qiaowei Ren 2021-02-08  253  

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