[chao:dev-test 6/6] fs/f2fs/super.c:2916:26: warning: variable 'inode' is uninitialized when used here

[chao:dev-test 6/6] fs/f2fs/super.c:2916:26: warning: variable 'inode' is uninitialized when used here

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git dev-test
head:   fd78b242ba1bbc77bdfb3d58a3cec054d3f18ed1
commit: fd78b242ba1bbc77bdfb3d58a3cec054d3f18ed1 [6/6] f2fs: fix potential deadlock due to unpaired node_write lock invoking
config: i386-randconfig-a013-20230501 (https://download.01.org/0day-ci/archive/20230504/202305040319.EAx2MRsG-lkp@intel.com/config)
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1)
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://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git/commit/?id=fd78b242ba1bbc77bdfb3d58a3cec054d3f18ed1
        git remote add chao https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git
        git fetch --no-tags chao dev-test
        git checkout fd78b242ba1bbc77bdfb3d58a3cec054d3f18ed1
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash fs/f2fs/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202305040319.EAx2MRsG-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> fs/f2fs/super.c:2916:26: warning: variable 'inode' is uninitialized when used here [-Wuninitialized]
           f2fs_down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
                                   ^~~~~
   fs/f2fs/super.c:2903:21: note: initialize the variable 'inode' to silence this warning
           struct inode *inode;
                              ^
                               = NULL
   1 warning generated.


vim +/inode +2916 fs/f2fs/super.c

  2899	
  2900	static int f2fs_quota_on(struct super_block *sb, int type, int format_id,
  2901								const struct path *path)
  2902	{
  2903		struct inode *inode;
  2904		int err;
  2905	
  2906		/* if quota sysfile exists, deny enabling quota with specific file */
  2907		if (f2fs_sb_has_quota_ino(F2FS_SB(sb))) {
  2908			f2fs_err(F2FS_SB(sb), "quota sysfile already exists");
  2909			return -EBUSY;
  2910		}
  2911	
  2912		err = f2fs_quota_sync(sb, type);
  2913		if (err)
  2914			return err;
  2915	
> 2916		f2fs_down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
  2917		filemap_invalidate_lock(inode->i_mapping);
  2918	
  2919		truncate_pagecache(inode, i_size_read(inode));
  2920	
  2921		if (get_dirty_pages(inode))
  2922			err = -EAGAIN;
  2923		else
  2924			err = dquot_quota_on(sb, type, format_id, path);
  2925	
  2926		filemap_invalidate_unlock(inode->i_mapping);
  2927		f2fs_up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
  2928		if (err)
  2929			return err;
  2930	
  2931		inode = d_inode(path->dentry);
  2932	
  2933		inode_lock(inode);
  2934		F2FS_I(inode)->i_flags |= F2FS_NOATIME_FL | F2FS_IMMUTABLE_FL;
  2935		f2fs_set_inode_flags(inode);
  2936		inode_unlock(inode);
  2937		f2fs_mark_inode_dirty_sync(inode, false);
  2938		return 0;
  2939	}
  2940	

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