[PATCH 2/2] erofs-utils: introduce tarerofs

[Gao Xiang]

On 2023/7/11 14:12, Jingbo Xu wrote:
> From: Gao Xiang <hsiangkao at linux.alibaba.com>
> 
> Let's try to add a new mode "tarerofs" for mkfs.erofs.
> 
> It mainly aims at two use cases:
>   - Convert a tarball (or later tarballs with a merged view) into
>     a full EROFS image [--tar=f];
> 
>   - Generate an EROFS manifest image to reuse tar data [--tar=i],
>     which also enables EROFS 512-byte blocks.
> 
> The second use case is mainly prepared for OCI direct mount without
> OCI blob unpacking.  This also adds another `--aufs` option to
> transform aufs special files into overlayfs metadata.
> 
> [ Note that `--tar=f` generates lots of temporary files for now which
>    can impact performance since the original tar stream(s) may be
>    non-seekable. ]
> 
> Signed-off-by: Gao Xiang <hsiangkao at linux.alibaba.com>
> Signed-off-by: Jingbo Xu <jefflexu at linux.alibaba.com>
> ---
> change log:
> 1. don't return prematurely for special device files (in
> erofs_mkfs_build_tree()).  Otherwise erofs_mkfs_build_tree() may
> mistakenly return a positive integer number returned from
> erofs_prepare_xattr_ibody(), and mistakenly make it as the pointer to
> the root inode, which will cause mkfs.erofs segmentation fault.
> 2. automatically create parent directory if it's not included as an
> entry in the tarball stream. (refer to tarerofs_init_default_dir())


struct erofs_dentry *tarerofs_mkdir(struct erofs_inode *dir, const char *s)
{
	struct inode *inode;

	inode = erofs_new_inode();
	if (IS_ERR(inode))
		return inode;

	inode->i_mode = S_IFDIR | 0755;
	inode->i_parent = dir;
	inode->i_uid = getuid();
	inode->i_gid = getgid();
	inode->i_mtime = sbi.build_time;
	inode->i_mtime_nsec = sbi.build_time_nsec;
	tarerofs_init_empty_dir(inode);

	d = erofs_d_alloc(pwd, s);
	d->type = EROFS_FT_DIR;
	d->inode = inode;
	return d;

}
?


Otherwise it looks good to me.

Thanks,
Gao Xiang