[intel-lts:pr/59 1/1] drivers/block/loop.c:662:16: warning: variable 'inode' set but not used

[intel-lts:pr/59 1/1] drivers/block/loop.c:662:16: warning: variable 'inode' set but not used

[kernel test robot]

Hi Theodore,

FYI, the error/warning still remains.

tree:   https://github.com/intel/linux-intel-lts.git pr/59
head:   19ae9bc73680fd6c1c95edb5b7e2aaa790e7f011
commit: 6f9f5797fc7de2e9f801b2f7af0726e1349d33a4 [1/1] loop: add recursion validation to LOOP_CHANGE_FD
config: sh-randconfig-002-20250218 (https://download.01.org/0day-ci/archive/20250219/202502190714.GkOSy4o2-lkp@intel.com/config)
compiler: sh4-linux-gcc (GCC) 7.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250219/202502190714.GkOSy4o2-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/202502190714.GkOSy4o2-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/block/loop.c: In function 'loop_change_fd':
>> drivers/block/loop.c:662:16: warning: variable 'inode' set but not used [-Wunused-but-set-variable]
     struct inode *inode;
                   ^~~~~


vim +/inode +662 drivers/block/loop.c

6f9f5797fc7de2 Theodore Ts'o  2018-05-07  649  
^1da177e4c3f41 Linus Torvalds 2005-04-16  650  /*
^1da177e4c3f41 Linus Torvalds 2005-04-16  651   * loop_change_fd switched the backing store of a loopback device to
^1da177e4c3f41 Linus Torvalds 2005-04-16  652   * a new file. This is useful for operating system installers to free up
^1da177e4c3f41 Linus Torvalds 2005-04-16  653   * the original file and in High Availability environments to switch to
^1da177e4c3f41 Linus Torvalds 2005-04-16  654   * an alternative location for the content in case of server meltdown.
^1da177e4c3f41 Linus Torvalds 2005-04-16  655   * This can only work if the loop device is used read-only, and if the
^1da177e4c3f41 Linus Torvalds 2005-04-16  656   * new backing store is the same size and type as the old backing store.
^1da177e4c3f41 Linus Torvalds 2005-04-16  657   */
bb21488482bd36 Al Viro        2008-03-02  658  static int loop_change_fd(struct loop_device *lo, struct block_device *bdev,
bb21488482bd36 Al Viro        2008-03-02  659  			  unsigned int arg)
^1da177e4c3f41 Linus Torvalds 2005-04-16  660  {
^1da177e4c3f41 Linus Torvalds 2005-04-16  661  	struct file	*file, *old_file;
^1da177e4c3f41 Linus Torvalds 2005-04-16 @662  	struct inode	*inode;
^1da177e4c3f41 Linus Torvalds 2005-04-16  663  	int		error;
^1da177e4c3f41 Linus Torvalds 2005-04-16  664  
^1da177e4c3f41 Linus Torvalds 2005-04-16  665  	error = -ENXIO;
^1da177e4c3f41 Linus Torvalds 2005-04-16  666  	if (lo->lo_state != Lo_bound)
^1da177e4c3f41 Linus Torvalds 2005-04-16  667  		goto out;
^1da177e4c3f41 Linus Torvalds 2005-04-16  668  
^1da177e4c3f41 Linus Torvalds 2005-04-16  669  	/* the loop device has to be read-only */
^1da177e4c3f41 Linus Torvalds 2005-04-16  670  	error = -EINVAL;
^1da177e4c3f41 Linus Torvalds 2005-04-16  671  	if (!(lo->lo_flags & LO_FLAGS_READ_ONLY))
^1da177e4c3f41 Linus Torvalds 2005-04-16  672  		goto out;
^1da177e4c3f41 Linus Torvalds 2005-04-16  673  
^1da177e4c3f41 Linus Torvalds 2005-04-16  674  	error = -EBADF;
^1da177e4c3f41 Linus Torvalds 2005-04-16  675  	file = fget(arg);
^1da177e4c3f41 Linus Torvalds 2005-04-16  676  	if (!file)
^1da177e4c3f41 Linus Torvalds 2005-04-16  677  		goto out;
^1da177e4c3f41 Linus Torvalds 2005-04-16  678  
6f9f5797fc7de2 Theodore Ts'o  2018-05-07  679  	error = loop_validate_file(file, bdev);
6f9f5797fc7de2 Theodore Ts'o  2018-05-07  680  	if (error)
6f9f5797fc7de2 Theodore Ts'o  2018-05-07  681  		goto out_putf;
6f9f5797fc7de2 Theodore Ts'o  2018-05-07  682  
^1da177e4c3f41 Linus Torvalds 2005-04-16  683  	inode = file->f_mapping->host;
^1da177e4c3f41 Linus Torvalds 2005-04-16  684  	old_file = lo->lo_backing_file;
^1da177e4c3f41 Linus Torvalds 2005-04-16  685  
^1da177e4c3f41 Linus Torvalds 2005-04-16  686  	error = -EINVAL;
^1da177e4c3f41 Linus Torvalds 2005-04-16  687  
^1da177e4c3f41 Linus Torvalds 2005-04-16  688  	/* size of the new backing store needs to be the same */
^1da177e4c3f41 Linus Torvalds 2005-04-16  689  	if (get_loop_size(lo, file) != get_loop_size(lo, old_file))
^1da177e4c3f41 Linus Torvalds 2005-04-16  690  		goto out_putf;
^1da177e4c3f41 Linus Torvalds 2005-04-16  691  
^1da177e4c3f41 Linus Torvalds 2005-04-16  692  	/* and ... switch */
43cade803ebeb0 Omar Sandoval  2017-08-24  693  	blk_mq_freeze_queue(lo->lo_queue);
43cade803ebeb0 Omar Sandoval  2017-08-24  694  	mapping_set_gfp_mask(old_file->f_mapping, lo->old_gfp_mask);
43cade803ebeb0 Omar Sandoval  2017-08-24  695  	lo->lo_backing_file = file;
43cade803ebeb0 Omar Sandoval  2017-08-24  696  	lo->old_gfp_mask = mapping_gfp_mask(file->f_mapping);
43cade803ebeb0 Omar Sandoval  2017-08-24  697  	mapping_set_gfp_mask(file->f_mapping,
43cade803ebeb0 Omar Sandoval  2017-08-24  698  			     lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS));
43cade803ebeb0 Omar Sandoval  2017-08-24  699  	loop_update_dio(lo);
43cade803ebeb0 Omar Sandoval  2017-08-24  700  	blk_mq_unfreeze_queue(lo->lo_queue);
^1da177e4c3f41 Linus Torvalds 2005-04-16  701  
^1da177e4c3f41 Linus Torvalds 2005-04-16  702  	fput(old_file);
e03c8dd14915fa Kay Sievers    2011-08-23  703  	if (lo->lo_flags & LO_FLAGS_PARTSCAN)
06f0e9e68c0d81 Ming Lei       2015-05-06  704  		loop_reread_partitions(lo, bdev);
^1da177e4c3f41 Linus Torvalds 2005-04-16  705  	return 0;
^1da177e4c3f41 Linus Torvalds 2005-04-16  706  
^1da177e4c3f41 Linus Torvalds 2005-04-16  707   out_putf:
^1da177e4c3f41 Linus Torvalds 2005-04-16  708  	fput(file);
^1da177e4c3f41 Linus Torvalds 2005-04-16  709   out:
^1da177e4c3f41 Linus Torvalds 2005-04-16  710  	return error;
^1da177e4c3f41 Linus Torvalds 2005-04-16  711  }
^1da177e4c3f41 Linus Torvalds 2005-04-16  712  

:::::: The code at line 662 was first introduced by commit
:::::: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Linux-2.6.12-rc2

:::::: TO: Linus Torvalds <torvalds@ppc970.osdl.org>
:::::: CC: Linus Torvalds <torvalds@ppc970.osdl.org>

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki