Re: [PATCH v4] erofs: avoid using generic_block_bmap

[Huang Jianan]

Thanks for review, i will update it soon.

在 2020/12/9 19:39, Gao Xiang 写道:
> Hi Jianan,
>
> On Wed, Dec 09, 2020 at 06:08:41PM +0800, Chao Yu wrote:
> > On 2020/12/9 10:39, Huang Jianan wrote:
> > > iblock indicates the number of i_blkbits-sized blocks rather than
> > > sectors.
> > >
> > > In addition, considering buffer_head limits mapped size to 32-bits,
> > > should avoid using generic_block_bmap.
> > >
> > > Fixes: 9da681e017a3 ("staging: erofs: support bmap")
> > > Signed-off-by: Huang Jianan <huangjianan@xxxxxxxx>
> > > Signed-off-by: Guo Weichao <guoweichao@xxxxxxxx>
> Could you send out an updated version? I might get a point to freeze
> dev branch since it needs some time on linux-next....
>
> Thanks,
> Gao Xiang
>
> > > ---
> > >    fs/erofs/data.c | 30 ++++++++++--------------------
> > >    1 file changed, 10 insertions(+), 20 deletions(-)
> > >
> > > diff --git a/fs/erofs/data.c b/fs/erofs/data.c
> > > index 347be146884c..d6ea0a216b57 100644
> > > --- a/fs/erofs/data.c
> > > +++ b/fs/erofs/data.c
> > > @@ -312,36 +312,26 @@ static void erofs_raw_access_readahead(struct readahead_control *rac)
> > >    		submit_bio(bio);
> > >    }
> > > -static int erofs_get_block(struct inode *inode, sector_t iblock,
> > > -			   struct buffer_head *bh, int create)
> > > -{
> > > -	struct erofs_map_blocks map = {
> > > -		.m_la = iblock << 9,
> > > -	};
> > > -	int err;
> > > -
> > > -	err = erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW);
> > > -	if (err)
> > > -		return err;
> > > -
> > > -	if (map.m_flags & EROFS_MAP_MAPPED)
> > > -		bh->b_blocknr = erofs_blknr(map.m_pa);
> > > -
> > > -	return err;
> > > -}
> > > -
> > >    static sector_t erofs_bmap(struct address_space *mapping, sector_t block)
> > >    {
> > >    	struct inode *inode = mapping->host;
> > > +	struct erofs_map_blocks map = {
> > > +		.m_la = blknr_to_addr(block),
> > > +	};
> > > +	sector_t blknr = 0;
> > It could be removed?
> >
> > >    	if (EROFS_I(inode)->datalayout == EROFS_INODE_FLAT_INLINE) {
> > >    		erofs_blk_t blks = i_size_read(inode) >> LOG_BLOCK_SIZE;
> > >    		if (block >> LOG_SECTORS_PER_BLOCK >= blks)
> > > -			return 0;
> > return 0;
> >
> > > +			goto out;
> > >    	}
> > > -	return generic_block_bmap(mapping, block, erofs_get_block);
> > > +	if (!erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW))
> > > +		blknr = erofs_blknr(map.m_pa);
> > return erofs_blknr(map.m_pa);
> >
> > > +
> > > +out:
> > > +	return blknr;
> > return 0;
> >
> > Anyway, LGTM.
> >
> > Reviewed-by: Chao Yu <yuchao0@xxxxxxxxxx>
> >
> > Thanks,
> >
> > >    }
> > >    /* for uncompressed (aligned) files and raw access for other files */