[PATCH] staging: erofs: fix an error handling in erofs_readdir()

[Philip Li]

On Sun, Aug 18, 2019 at 09:25:04PM +0800, Gao Xiang wrote:
> On Sun, Aug 18, 2019 at 09:17:52PM +0800, kbuild test robot wrote:
> > Hi Gao,
> > 
> > I love your patch! Yet something to improve:
> > 
> > [auto build test ERROR on linus/master]
> > [cannot apply to v5.3-rc4 next-20190816]
> > [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
> 
> ... those patches should be applied to staging tree
> since linux-next has not been updated yet...
thanks for the feedback, we will consider this to our todo list.

> 
> Thanks,
> Gao Xiang
> 
> > 
> > url:    https://github.com/0day-ci/linux/commits/Gao-Xiang/staging-erofs-fix-an-error-handling-in-erofs_readdir/20190818-191344
> > config: arm64-allyesconfig (attached as .config)
> > compiler: aarch64-linux-gcc (GCC) 7.4.0
> > reproduce:
> >         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> >         chmod +x ~/bin/make.cross
> >         # save the attached .config to linux build tree
> >         GCC_VERSION=7.4.0 make.cross ARCH=arm64 
> > 
> > If you fix the issue, kindly add following tag
> > Reported-by: kbuild test robot <lkp at intel.com>
> > 
> > All errors (new ones prefixed by >>):
> > 
> >    drivers/staging/erofs/dir.c: In function 'erofs_readdir':
> > >> drivers/staging/erofs/dir.c:110:11: error: 'EFSCORRUPTED' undeclared (first use in this function); did you mean 'FS_NRSUPER'?
> >        err = -EFSCORRUPTED;
> >               ^~~~~~~~~~~~
> >               FS_NRSUPER
> >    drivers/staging/erofs/dir.c:110:11: note: each undeclared identifier is reported only once for each function it appears in
> > 
> > vim +110 drivers/staging/erofs/dir.c
> > 
> >     85	
> >     86	static int erofs_readdir(struct file *f, struct dir_context *ctx)
> >     87	{
> >     88		struct inode *dir = file_inode(f);
> >     89		struct address_space *mapping = dir->i_mapping;
> >     90		const size_t dirsize = i_size_read(dir);
> >     91		unsigned int i = ctx->pos / EROFS_BLKSIZ;
> >     92		unsigned int ofs = ctx->pos % EROFS_BLKSIZ;
> >     93		int err = 0;
> >     94		bool initial = true;
> >     95	
> >     96		while (ctx->pos < dirsize) {
> >     97			struct page *dentry_page;
> >     98			struct erofs_dirent *de;
> >     99			unsigned int nameoff, maxsize;
> >    100	
> >    101			dentry_page = read_mapping_page(mapping, i, NULL);
> >    102			if (dentry_page == ERR_PTR(-ENOMEM)) {
> >    103				errln("no memory to readdir of logical block %u of nid %llu",
> >    104				      i, EROFS_V(dir)->nid);
> >    105				err = -ENOMEM;
> >    106				break;
> >    107			} else if (IS_ERR(dentry_page)) {
> >    108				errln("fail to readdir of logical block %u of nid %llu",
> >    109				      i, EROFS_V(dir)->nid);
> >  > 110				err = -EFSCORRUPTED;
> >    111				break;
> >    112			}
> >    113	
> >    114			de = (struct erofs_dirent *)kmap(dentry_page);
> >    115	
> >    116			nameoff = le16_to_cpu(de->nameoff);
> >    117	
> >    118			if (unlikely(nameoff < sizeof(struct erofs_dirent) ||
> >    119				     nameoff >= PAGE_SIZE)) {
> >    120				errln("%s, invalid de[0].nameoff %u",
> >    121				      __func__, nameoff);
> >    122	
> >    123				err = -EIO;
> >    124				goto skip_this;
> >    125			}
> >    126	
> >    127			maxsize = min_t(unsigned int,
> >    128					dirsize - ctx->pos + ofs, PAGE_SIZE);
> >    129	
> >    130			/* search dirents at the arbitrary position */
> >    131			if (unlikely(initial)) {
> >    132				initial = false;
> >    133	
> >    134				ofs = roundup(ofs, sizeof(struct erofs_dirent));
> >    135				if (unlikely(ofs >= nameoff))
> >    136					goto skip_this;
> >    137			}
> >    138	
> >    139			err = erofs_fill_dentries(ctx, de, &ofs, nameoff, maxsize);
> >    140	skip_this:
> >    141			kunmap(dentry_page);
> >    142	
> >    143			put_page(dentry_page);
> >    144	
> >    145			ctx->pos = blknr_to_addr(i) + ofs;
> >    146	
> >    147			if (unlikely(err))
> >    148				break;
> >    149			++i;
> >    150			ofs = 0;
> >    151		}
> >    152		return err < 0 ? err : 0;
> >    153	}
> >    154	
> > 
> > ---
> > 0-DAY kernel test infrastructure                Open Source Technology Center
> > https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
> 
>