[vfs:work.d_path 3/14] fs/d_path.c:359:25: sparse: sparse: context imbalance in '__dentry_path' - wrong count at exit

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

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CC: kbuild-all(a)lists.01.org
CC: linux-fsdevel(a)vger.kernel.org
TO: Al Viro <viro@zeniv.linux.org.uk>

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git work.d_path
head:   e4b275531887fef7f7d8a7284bfc32f0fbbd4208
commit: 3acca043261fa6268961d152ea2505e217eabcba [3/14] d_path: regularize handling of root dentry in __dentry_path()
:::::: branch date: 3 weeks ago
:::::: commit date: 3 weeks ago
config: riscv-randconfig-s031-20210608 (attached as .config)
compiler: riscv32-linux-gcc (GCC) 9.3.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # apt-get install sparse
        # sparse version: v0.6.3-341-g8af24329-dirty
        # https://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git/commit/?id=3acca043261fa6268961d152ea2505e217eabcba
        git remote add vfs https://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git
        git fetch --no-tags vfs work.d_path
        git checkout 3acca043261fa6268961d152ea2505e217eabcba
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' W=1 ARCH=riscv 

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


sparse warnings: (new ones prefixed by >>)
   fs/d_path.c:159:9: sparse: sparse: context imbalance in 'prepend_path' - wrong count at exit
>> fs/d_path.c:359:25: sparse: sparse: context imbalance in '__dentry_path' - wrong count at exit

vim +/__dentry_path +359 fs/d_path.c

7a5cf791a74764 Al Viro 2018-03-05  325  
7a5cf791a74764 Al Viro 2018-03-05  326  /*
7a5cf791a74764 Al Viro 2018-03-05  327   * Write full pathname from the root of the filesystem into the buffer.
7a5cf791a74764 Al Viro 2018-03-05  328   */
3a291c974cf7ff Al Viro 2021-05-17  329  static char *__dentry_path(const struct dentry *d, char *p, int buflen)
7a5cf791a74764 Al Viro 2018-03-05  330  {
a2bbe66493ee38 Al Viro 2019-07-07  331  	const struct dentry *dentry;
3acca043261fa6 Al Viro 2021-05-17  332  	char *end;
7a5cf791a74764 Al Viro 2018-03-05  333  	int len, seq = 0;
7a5cf791a74764 Al Viro 2018-03-05  334  
7a5cf791a74764 Al Viro 2018-03-05  335  	rcu_read_lock();
7a5cf791a74764 Al Viro 2018-03-05  336  restart:
7a5cf791a74764 Al Viro 2018-03-05  337  	dentry = d;
3a291c974cf7ff Al Viro 2021-05-17  338  	end = p;
7a5cf791a74764 Al Viro 2018-03-05  339  	len = buflen;
7a5cf791a74764 Al Viro 2018-03-05  340  	read_seqbegin_or_lock(&rename_lock, &seq);
7a5cf791a74764 Al Viro 2018-03-05  341  	while (!IS_ROOT(dentry)) {
a2bbe66493ee38 Al Viro 2019-07-07  342  		const struct dentry *parent = dentry->d_parent;
7a5cf791a74764 Al Viro 2018-03-05  343  
7a5cf791a74764 Al Viro 2018-03-05  344  		prefetch(parent);
3acca043261fa6 Al Viro 2021-05-17  345  		if (unlikely(prepend_name(&end, &len, &dentry->d_name) < 0))
7a5cf791a74764 Al Viro 2018-03-05  346  			break;
7a5cf791a74764 Al Viro 2018-03-05  347  
7a5cf791a74764 Al Viro 2018-03-05  348  		dentry = parent;
7a5cf791a74764 Al Viro 2018-03-05  349  	}
7a5cf791a74764 Al Viro 2018-03-05  350  	if (!(seq & 1))
7a5cf791a74764 Al Viro 2018-03-05  351  		rcu_read_unlock();
7a5cf791a74764 Al Viro 2018-03-05  352  	if (need_seqretry(&rename_lock, seq)) {
7a5cf791a74764 Al Viro 2018-03-05  353  		seq = 1;
7a5cf791a74764 Al Viro 2018-03-05  354  		goto restart;
7a5cf791a74764 Al Viro 2018-03-05  355  	}
7a5cf791a74764 Al Viro 2018-03-05  356  	done_seqretry(&rename_lock, seq);
3acca043261fa6 Al Viro 2021-05-17  357  	if (len == buflen)
3acca043261fa6 Al Viro 2021-05-17  358  		prepend(&end, &len, "/", 1);
3acca043261fa6 Al Viro 2021-05-17 @359  	return len >= 0 ? end : ERR_PTR(-ENAMETOOLONG);
7a5cf791a74764 Al Viro 2018-03-05  360  }
7a5cf791a74764 Al Viro 2018-03-05  361  

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

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