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

[Gao Xiang]

Hi Philip,

On Tue, Aug 20, 2019 at 02:50:38PM +0800, Philip Li wrote:
> 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.

Yes, many confusing reports anyway...
(Just my personal suggestion, maybe we can add some hints on the patch email
to indicate which tree can be applied successfully for ci in the future...)

Thanks,
Gao Xiang

> 
> > 
> > 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
> > 
> >