[PATCH] erofs-utils: fsck: add --xattr option

[Gao Xiang]

On 2024/9/3 15:35, Hongzhen Luo wrote:
> The current `fsck --extract` does not support exporting the extended
> attributes of files. This patch adds `--xattr` option to dump the
> extended attributes.

only `--xattrs` is not helpful, you'd better to add both
`--xattrs` and `--no-xattrs`, and makes `--xattrs` enabled
by default.

> 
> Signed-off-by: Hongzhen Luo <hongzhen at linux.alibaba.com>
> ---
>   fsck/main.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 61 insertions(+)
> 
> diff --git a/fsck/main.c b/fsck/main.c
> index 28f1e7e..6a71791 100644
> --- a/fsck/main.c
> +++ b/fsck/main.c
> @@ -9,6 +9,7 @@
>   #include <utime.h>
>   #include <unistd.h>
>   #include <sys/stat.h>
> +#include <sys/xattr.h>
>   #include "erofs/print.h"
>   #include "erofs/compress.h"
>   #include "erofs/decompress.h"
> @@ -31,6 +32,7 @@ struct erofsfsck_cfg {
>   	bool overwrite;
>   	bool preserve_owner;
>   	bool preserve_perms;
> +	bool xattr;

	bool dump_xattrs;

>   };
>   static struct erofsfsck_cfg fsckcfg;
>   
> @@ -48,6 +50,7 @@ static struct option long_options[] = {
>   	{"no-preserve-owner", no_argument, 0, 10},
>   	{"no-preserve-perms", no_argument, 0, 11},
>   	{"offset", required_argument, 0, 12},
> +	{"xattr", no_argument, 0, 13},

--xattrs, --no-xattrs

>   	{0, 0, 0, 0},
>   };
>   
> @@ -98,6 +101,7 @@ static void usage(int argc, char **argv)
>   		" --extract[=X]          check if all files are well encoded, optionally\n"
>   		"                        extract to X\n"
>   		" --offset=#             skip # bytes at the beginning of IMAGE\n"
> +		" --xattr                dump extended attributes\n"
>   		"\n"
>   		" -a, -A, -y             no-op, for compatibility with fsck of other filesystems\n"
>   		"\n"
> @@ -225,6 +229,9 @@ static int erofsfsck_parse_options_cfg(int argc, char **argv)
>   				return -EINVAL;
>   			}
>   			break;
> +		case 13:
> +			fsckcfg.xattr = true;
> +			break;
>   		default:
>   			return -EINVAL;
>   		}
> @@ -411,6 +418,53 @@ out:
>   	return ret;
>   }
>   
> +static int erofs_dump_xattr(struct erofs_inode *inode)

erofsfsck_dump_xattrs

> +{
> +	char *keylst, *key;
> +	ssize_t kllen;
> +	int ret;
> +
> +	if (!fsckcfg.extract_path)

If extract_path is none, please keep reading the xattrs
but don't dump these.

> +		return 0;
> +	kllen = erofs_listxattr(inode, NULL, 0);
> +	if (kllen <= 0)
> +		return kllen;
> +	keylst = malloc(kllen);
> +	if (!keylst)
> +		return -ENOMEM;
> +	ret = erofs_listxattr(inode, keylst, kllen);
> +	if (ret < 0)
> +		goto out;
> +	for (key = keylst; key < keylst + kllen; key += strlen(key) + 1) {
> +		void *value = NULL;
> +		size_t size = 0;
> +
> +		ret = erofs_getxattr(inode, key, NULL, 0);
> +		if (ret < 0)
> +			goto out;

why not just `break;` this?

> +		if (ret) {
> +			size = ret;
> +			value = malloc(size);
> +			if (!value) {
> +				ret = -ENOMEM;
> +				goto out;

same here.

> +			}
> +			ret = erofs_getxattr(inode, key, value, size);
> +			if (ret < 0) {
> +				free(value);
> +				goto out;

same here.

> +			}
> +			ret = setxattr(fsckcfg.extract_path, key, value, size, 0);
> +			free(value);
> +			if (ret)
> +				goto out;

same here.

Thanks,
Gao Xiang

> +		}
> +	}
> +out:
> +	free(keylst);
> +	return ret;
> +}