Re: [PATCH] erofs-utils: do not check ->idata_size for compressed files in erofs_prepare_inode_buffer()

[Gao Xiang <hsiangkao@linux.alibaba.com>]

Hi Yue,

On Thu, Jun 17, 2021 at 04:29:54PM +0800, Yue Hu wrote:
> From: Yue Hu <huyue2@yulong.com>
> 
> erofs_write_compressed_file() will always set inode->idata_size = 0
> if succeed, that means no tail-end data for compressed files. So, no
> need to call erofs_prepare_tail_block() which is used to handle
> tail-end data for that case. Just skip it.

Thanks for the patch, due to somewhat long time so I don't quite
remember the exact logic here now...

Yet from the description before, it's not strictly correct
since my original intention would be to support tail-packing
inline compressed data which is similar to uncompressed case
to decrease tail extent I/O and save more space.

BTW, if you have some interest, would you like to implement it? :)

Thanks,
Gao Xiang

> 
> Also, correct 'a inode' -> 'an inode'.
> 
> Signed-off-by: Yue Hu <huyue2@yulong.com>
> ---
>  lib/inode.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/inode.c b/lib/inode.c
> index b6108db..b5f66de 100644
> --- a/lib/inode.c
> +++ b/lib/inode.c
> @@ -111,7 +111,7 @@ struct erofs_dentry *erofs_d_alloc(struct erofs_inode *parent,
>  	return d;
>  }
>  
> -/* allocate main data for a inode */
> +/* allocate main data for an inode */
>  static int __allocate_inode_bh_data(struct erofs_inode *inode,
>  				    unsigned long nblocks)
>  {
> @@ -572,11 +572,11 @@ static int erofs_prepare_inode_buffer(struct erofs_inode *inode)
>  		int ret;
>  
>  		inode->datalayout = EROFS_INODE_FLAT_PLAIN;
> -noinline:
>  		/* expend an extra block for tail-end data */
>  		ret = erofs_prepare_tail_block(inode);
>  		if (ret)
>  			return ret;
> +noinline:
>  		bh = erofs_balloc(INODE, inodesize, 0, 0);
>  		if (IS_ERR(bh))
>  			return PTR_ERR(bh);
> -- 
> 1.9.1