Hi Sargun,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on miklos-vfs/overlayfs-next]
[also build test WARNING on linus/master v5.10-rc5 next-20201124]
[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]

url:    https://github.com/0day-ci/linux/commits/Sargun-Dhillon/Make-overlayfs-volatile-mounts-reusable/20201125-184754
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs.git overlayfs-next
config: arc-randconfig-m031-20201125 (attached as .config)
compiler: arc-elf-gcc (GCC) 9.3.0
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://github.com/0day-ci/linux/commit/2fee0f742c2bb44771e51ed73ec7faf50165832a
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Sargun-Dhillon/Make-overlayfs-volatile-mounts-reusable/20201125-184754
        git checkout 2fee0f742c2bb44771e51ed73ec7faf50165832a
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arc 

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

All warnings (new ones prefixed by >>):

   In file included from include/linux/kernel.h:16,
                    from include/linux/list.h:9,
                    from include/linux/wait.h:7,
                    from include/linux/wait_bit.h:8,
                    from include/linux/fs.h:6,
                    from fs/overlayfs/readdir.c:7:
   fs/overlayfs/readdir.c: In function 'ovl_verify_volatile_info':
>> include/linux/kern_levels.h:5:18: warning: format '%ld' expects argument of type 'long int', but argument 3 has type 'unsigned int' [-Wformat=]
       5 | #define KERN_SOH "\001"  /* ASCII Start Of Header */
         |                  ^~~~~~
   include/linux/printk.h:140:10: note: in definition of macro 'no_printk'
     140 |   printk(fmt, ##__VA_ARGS__);  \
         |          ^~~
   include/linux/kern_levels.h:15:20: note: in expansion of macro 'KERN_SOH'
      15 | #define KERN_DEBUG KERN_SOH "7" /* debug-level messages */
         |                    ^~~~~~~~
   include/linux/printk.h:430:12: note: in expansion of macro 'KERN_DEBUG'
     430 |  no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
         |            ^~~~~~~~~~
   fs/overlayfs/readdir.c:1097:3: note: in expansion of macro 'pr_debug'
    1097 |   pr_debug("ovl_volatile_info is of size %d expected %ld\n", err,
         |   ^~~~~~~~
   fs/overlayfs/readdir.c:1097:56: note: format string is defined here
    1097 |   pr_debug("ovl_volatile_info is of size %d expected %ld\n", err,
         |                                                      ~~^
         |                                                        |
         |                                                        long int
         |                                                      %d

vim +5 include/linux/kern_levels.h

314ba3520e513a7 Joe Perches 2012-07-30  4  
04d2c8c83d0e3ac Joe Perches 2012-07-30 @5  #define KERN_SOH	"\001"		/* ASCII Start Of Header */
04d2c8c83d0e3ac Joe Perches 2012-07-30  6  #define KERN_SOH_ASCII	'\001'
04d2c8c83d0e3ac Joe Perches 2012-07-30  7  

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org