Hi Andreas,

I love your patch! Perhaps something to improve:

[auto build test WARNING on ext4/dev]
[also build test WARNING on tytso-fscrypt/master v5.5-rc7 next-20200124]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Andreas-Dilger/ext4-don-t-assume-that-mmp_nodename-bdevname-have-NUL/20200126-053627
base:   https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git dev
config: x86_64-defconfig (attached as .config)
compiler: gcc-7 (Debian 7.5.0-3) 7.5.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

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

All warnings (new ones prefixed by >>):

   fs/ext4/mmp.c: In function '__dump_mmp_msg':
>> fs/ext4/mmp.c:123:73: warning: field precision specifier '.*' expects argument of type 'int', but argument 6 has type 'long unsigned int' [-Wformat=]
             "MMP failure info: last update time: %llu, last update node: %.*s, last update device: %.*s",
                                                                          ~~^~
   fs/ext4/mmp.c:123:99: warning: field precision specifier '.*' expects argument of type 'int', but argument 8 has type 'long unsigned int' [-Wformat=]
             "MMP failure info: last update time: %llu, last update node: %.*s, last update device: %.*s",
                                                                                                    ~~^~
   In file included from fs/ext4/mmp.c:6:0:
   fs/ext4/mmp.c: In function 'ext4_multi_mount_protect':
   fs/ext4/mmp.c:382:57: warning: field precision specifier '.*' expects argument of type 'int', but argument 5 has type 'long unsigned int' [-Wformat=]
     EXT4_SB(sb)->s_mmp_tsk = kthread_run(kmmpd, mmpd_data, "kmmpd-%.*s",
                                                            ^
   include/linux/kthread.h:26:55: note: in definition of macro 'kthread_create'
     kthread_create_on_node(threadfn, data, NUMA_NO_NODE, namefmt, ##arg)
                                                          ^~~~~~~
>> fs/ext4/mmp.c:382:27: note: in expansion of macro 'kthread_run'
     EXT4_SB(sb)->s_mmp_tsk = kthread_run(kmmpd, mmpd_data, "kmmpd-%.*s",
                              ^~~~~~~~~~~

vim +123 fs/ext4/mmp.c

   114	
   115	/*
   116	 * Dump as much information as possible to help the admin.
   117	 */
   118	void __dump_mmp_msg(struct super_block *sb, struct mmp_struct *mmp,
   119			    const char *function, unsigned int line, const char *msg)
   120	{
   121		__ext4_warning(sb, function, line, "%s", msg);
   122		__ext4_warning(sb, function, line,
 > 123			       "MMP failure info: last update time: %llu, last update node: %.*s, last update device: %.*s",
   124			       (long long unsigned int)le64_to_cpu(mmp->mmp_time),
   125			       sizeof(mmp->mmp_nodename), mmp->mmp_nodename,
   126			       sizeof(mmp->mmp_bdevname), mmp->mmp_bdevname);
   127	}
   128	

---
0-DAY kernel test infrastructure                 Open Source Technology Center
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