Re: [PATCH v1 2/3] overlay: Add the ability to remount volatile directories when safe

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

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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-20201125]
[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: powerpc64-randconfig-r005-20201125 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 77e98eaee2e8d4b9b297b66fda5b1e51e2a69999)
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
        # install powerpc64 cross compiling tool for clang build
        # apt-get install binutils-powerpc64-linux-gnu
        # 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=clang make.cross ARCH=powerpc64 

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 >>):

>> fs/overlayfs/readdir.c:1098:5: warning: format specifies type 'long' but the argument has type 'unsigned int' [-Wformat]
                            sizeof(info));
                            ^~~~~~~~~~~~
   include/linux/printk.h:424:26: note: expanded from macro 'pr_debug'
           dynamic_pr_debug(fmt, ##__VA_ARGS__)
                            ~~~    ^~~~~~~~~~~
   include/linux/dynamic_debug.h:158:22: note: expanded from macro 'dynamic_pr_debug'
                              pr_fmt(fmt), ##__VA_ARGS__)
                                     ~~~     ^~~~~~~~~~~
   include/linux/dynamic_debug.h:147:56: note: expanded from macro '_dynamic_func_call'
           __dynamic_func_call(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__)
                                                                 ^~~~~~~~~~~
   include/linux/dynamic_debug.h:129:15: note: expanded from macro '__dynamic_func_call'
                   func(&id, ##__VA_ARGS__);               \
                               ^~~~~~~~~~~
   1 warning generated.

vim +1098 fs/overlayfs/readdir.c

  1064	
  1065	/*
  1066	 * Returns 1 if d_type is supported, 0 not supported/unknown. Negative values
  1067	 * if error is encountered.
  1068	 */
  1069	int ovl_check_d_type_supported(struct path *realpath)
  1070	{
  1071		int err;
  1072		struct ovl_readdir_data rdd = {
  1073			.ctx.actor = ovl_check_d_type,
  1074			.d_type_supported = false,
  1075		};
  1076	
  1077		err = ovl_dir_read(realpath, &rdd);
  1078		if (err)
  1079			return err;
  1080	
  1081		return rdd.d_type_supported;
  1082	}
  1083	static int ovl_verify_volatile_info(struct ovl_fs *ofs,
  1084					    struct dentry *volatiledir)
  1085	{
  1086		int err;
  1087		struct ovl_volatile_info info;
  1088	
  1089		err = ovl_do_getxattr(ofs, volatiledir, OVL_XATTR_VOLATILE, &info,
  1090				      sizeof(info));
  1091		if (err < 0) {
  1092			pr_debug("Unable to read volatile xattr: %d\n", err);
  1093			return -EINVAL;
  1094		}
  1095	
  1096		if (err != sizeof(info)) {
  1097			pr_debug("ovl_volatile_info is of size %d expected %ld\n", err,
> 1098				 sizeof(info));
  1099			return -EINVAL;
  1100		}
  1101	
  1102		if (!uuid_equal(&ovl_boot_id, &info.ovl_boot_id)) {
  1103			pr_debug("boot id has changed (reboot or module reloaded)\n");
  1104			return -EINVAL;
  1105		}
  1106	
  1107		if (volatiledir->d_sb->s_instance_id != info.s_instance_id) {
  1108			pr_debug("workdir has been unmounted and remounted\n");
  1109			return -EINVAL;
  1110		}
  1111	
  1112		return 1;
  1113	}
  1114	

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

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