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

[Gao Xiang]

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,
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
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