[PATCH v2] erofs-utils: add --hardlink-dereference option

[Gao Xiang]

On 2024/12/12 21:56, Paul Meyer wrote:
> Add option --hardlink-dereference to dereference hardlinks when
> creating an image. Instead of reusing the inode, hardlinks are added
> as separate inodes. This is useful for reproducible builds, when the
> rootfs is space-optimized using hardlinks on some machines, but not on
> others.
> 

The subject and commit message is still unchanged...

> Co-authored-by: Leonard Cohnen <leonard.cohnen at gmail.com>
> Signed-off-by: Paul Meyer <katexochen0 at gmail.com>
> ---
> 
> v1: https://lore.kernel.org/all/20241211150734.97830-1-katexochen0@gmail.com/
> change since v1:
>   - rename option to --hard-dereference
>   - add usage
> 
>   include/erofs/config.h | 1 +
>   lib/inode.c            | 2 +-
>   mkfs/main.c            | 5 +++++
>   3 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/include/erofs/config.h b/include/erofs/config.h
> index cff4cea..bb03e70 100644
> --- a/include/erofs/config.h
> +++ b/include/erofs/config.h
> @@ -58,6 +58,7 @@ struct erofs_configure {
>   	bool c_extra_ea_name_prefixes;
>   	bool c_xattr_name_filter;
>   	bool c_ovlfs_strip;
> +	bool c_hard_dereference;
>   
>   #ifdef HAVE_LIBSELINUX
>   	struct selabel_handle *sehnd;
> diff --git a/lib/inode.c b/lib/inode.c
> index 7e5c581..0404a8d 100644
> --- a/lib/inode.c
> +++ b/lib/inode.c
> @@ -1141,7 +1141,7 @@ static struct erofs_inode *erofs_iget_from_srcpath(struct erofs_sb_info *sbi,
>   	 * hard-link, just return it. Also don't lookup for directories
>   	 * since hard-link directory isn't allowed.
>   	 */
> -	if (!S_ISDIR(st.st_mode)) {
> +	if (!S_ISDIR(st.st_mode) && (!cfg.c_hard_dereference)) {
>   		inode = erofs_iget(st.st_dev, st.st_ino);
>   		if (inode)
>   			return inode;
> diff --git a/mkfs/main.c b/mkfs/main.c
> index d422787..7eb86f5 100644
> --- a/mkfs/main.c
> +++ b/mkfs/main.c
> @@ -85,6 +85,7 @@ static struct option long_options[] = {
>   	{"mkfs-time", no_argument, NULL, 525},
>   	{"all-time", no_argument, NULL, 526},
>   	{"sort", required_argument, NULL, 527},
> +	{"hard-dereference", no_argument, NULL, 528},
>   	{0, 0, 0, 0},
>   };
>   
> @@ -214,6 +215,7 @@ static void usage(int argc, char **argv)
>   #ifdef EROFS_MT_ENABLED
>   		, erofs_get_available_processors() /* --workers= */
>   #endif
> +		" --hard-dereference    dereference hardlinks, add links as separate inodes\n"


Does it compile with EROFS_MT_ENABLED?...

Also `--hard-dereference` should be moved upwards to match
alphabetical order.

Thanks,
Gao Xiang

>   	);
>   }
>   
> @@ -846,6 +848,9 @@ static int mkfs_parse_options_cfg(int argc, char *argv[])
>   			if (!strcmp(optarg, "none"))
>   				erofstar.try_no_reorder = true;
>   			break;
> +		case 528:
> +			cfg.c_hard_dereference = true;
> +			break;
>   		case 'V':
>   			version();
>   			exit(0);