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

[Hongzhen Luo]

The current `fsck --extract` does not support exporting the extended
attributes of files. This patch adds `--xattr` option to dump the
extended attributes.

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;
 };
 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},
 	{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)
+{
+	char *keylst, *key;
+	ssize_t kllen;
+	int ret;
+
+	if (!fsckcfg.extract_path)
+		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;
+		if (ret) {
+			size = ret;
+			value = malloc(size);
+			if (!value) {
+				ret = -ENOMEM;
+				goto out;
+			}
+			ret = erofs_getxattr(inode, key, value, size);
+			if (ret < 0) {
+				free(value);
+				goto out;
+			}
+			ret = setxattr(fsckcfg.extract_path, key, value, size, 0);
+			free(value);
+			if (ret)
+				goto out;
+		}
+	}
+out:
+	free(keylst);
+	return ret;
+}
+
 static int erofs_verify_inode_data(struct erofs_inode *inode, int outfd)
 {
 	struct erofs_map_blocks map = {
@@ -909,6 +963,12 @@ static int erofsfsck_check_inode(erofs_nid_t pnid, erofs_nid_t nid)
 	if (ret && ret != -ECANCELED)
 		goto out;
 
+	if (fsckcfg.xattr) {
+		ret = erofs_dump_xattr(&inode);
+		if (ret)
+			return ret;
+	}
+
 	/* XXXX: the dir depth should be restricted in order to avoid loops */
 	if (S_ISDIR(inode.i_mode)) {
 		struct erofs_dir_context ctx = {
@@ -955,6 +1015,7 @@ int main(int argc, char *argv[])
 	fsckcfg.overwrite = false;
 	fsckcfg.preserve_owner = fsckcfg.superuser;
 	fsckcfg.preserve_perms = fsckcfg.superuser;
+	fsckcfg.xattr = false;
 
 	err = erofsfsck_parse_options_cfg(argc, argv);
 	if (err) {
-- 
2.43.5