[PATCH v7 3/4] erofs-utils: mkfs: introduce --s3=... option
Gao Xiang
hsiangkao at linux.alibaba.com
Fri Aug 8 13:15:07 AEST 2025
From: Yifan Zhao <zhaoyifan28 at huawei.com>
It introduces configuration options for the upcoming experimental S3
support, including configuration parsing and `passwd_file` reading
logic.
Users can specify the following options:
- S3 service endpoint (required);
- S3 credentials file in the format $ak:%sk (optional);
- S3 API calling style (optional);
- S3 API signature version (optional, only V2 is currently supported).
Signed-off-by: Yifan Zhao <zhaoyifan28 at huawei.com>
Signed-off-by: Gao Xiang <hsiangkao at linux.alibaba.com>
---
lib/liberofs_s3.h | 40 ++++++++
mkfs/main.c | 226 +++++++++++++++++++++++++++++++++++++++-------
2 files changed, 234 insertions(+), 32 deletions(-)
create mode 100644 lib/liberofs_s3.h
diff --git a/lib/liberofs_s3.h b/lib/liberofs_s3.h
new file mode 100644
index 0000000..4d3555e
--- /dev/null
+++ b/lib/liberofs_s3.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0+ OR Apache-2.0 */
+/*
+ * Copyright (C) 2025 HUAWEI, Inc.
+ * http://www.huawei.com/
+ * Created by Yifan Zhao <zhaoyifan28 at huawei.com>
+ */
+#ifndef __EROFS_S3_H
+#define __EROFS_S3_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+enum s3erofs_url_style {
+ S3EROFS_URL_STYLE_PATH, // Path style: https://s3.amazonaws.com/bucket/object
+ S3EROFS_URL_STYLE_VIRTUAL_HOST, // Virtual host style: https://bucket.s3.amazonaws.com/object
+};
+
+enum s3erofs_signature_version {
+ S3EROFS_SIGNATURE_VERSION_2,
+ S3EROFS_SIGNATURE_VERSION_4,
+};
+
+#define S3_ACCESS_KEY_LEN 256
+#define S3_SECRET_KEY_LEN 256
+
+struct erofs_s3 {
+ const char *endpoint;
+ char access_key[S3_ACCESS_KEY_LEN + 1];
+ char secret_key[S3_SECRET_KEY_LEN + 1];
+
+ enum s3erofs_url_style url_style;
+ enum s3erofs_signature_version sig;
+};
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/mkfs/main.c b/mkfs/main.c
index ab27b77..a7d3f31 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -31,6 +31,7 @@
#include "../lib/liberofs_private.h"
#include "../lib/liberofs_uuid.h"
#include "../lib/liberofs_metabox.h"
+#include "../lib/liberofs_s3.h"
#include "../lib/compressor.h"
static struct option long_options[] = {
@@ -92,6 +93,9 @@ static struct option long_options[] = {
#endif
{"fsalignblks", required_argument, NULL, 531},
{"vmdk-desc", required_argument, NULL, 532},
+#ifdef S3EROFS_ENABLED
+ {"s3", required_argument, NULL, 533},
+#endif
{0, 0, 0, 0},
};
@@ -174,8 +178,8 @@ static void usage(int argc, char **argv)
" --chunksize=# generate chunk-based files with #-byte chunks\n"
" --clean=X run full clean build (default) or:\n"
" --incremental=X run incremental build\n"
- " (X = data|rvsp; data=full data, rvsp=space is allocated\n"
- " and filled with zeroes)\n"
+ " X = data|rvsp|0 (data: full data, rvsp: space fallocated\n"
+ " 0: inodes zeroed)\n"
" --compress-hints=X specify a file to configure per-file compression strategy\n"
" --dsunit=# align all data block addresses to multiples of #\n"
" --exclude-path=X avoid including file X (X = exact literal path)\n"
@@ -197,6 +201,12 @@ static void usage(int argc, char **argv)
" --root-xattr-isize=# ensure the inline xattr size of the root directory is # bytes at least\n"
" --aufs replace aufs special files with overlayfs metadata\n"
" --sort=<path,none> data sorting order for tarballs as input (default: path)\n"
+#ifdef S3EROFS_ENABLED
+ " --s3=X generate an image from S3-compatible object store\n"
+ " [,passwd_file=Y] X=endpoint, Y=s3fs-compatible password file\n"
+ " [,urlstyle=Z] S3 API calling style (Z = vhost|path) (default: vhost)\n"
+ " [,sig=<2,4>] S3 API signature version (default: 2)\n"
+#endif
" --tar=X generate a full or index-only image from a tarball(-ish) source\n"
" (X = f|i|headerball; f=full mode, i=index mode,\n"
" headerball=file data is omited in the source stream)\n"
@@ -247,16 +257,23 @@ static struct erofs_tarfile erofstar = {
static bool incremental_mode;
static u8 metabox_algorithmid;
+#ifdef S3EROFS_ENABLED
+static struct erofs_s3 s3cfg;
+#endif
+
enum {
EROFS_MKFS_DATA_IMPORT_DEFAULT,
EROFS_MKFS_DATA_IMPORT_FULLDATA,
EROFS_MKFS_DATA_IMPORT_RVSP,
- EROFS_MKFS_DATA_IMPORT_SPARSE,
+ EROFS_MKFS_DATA_IMPORT_ZEROFILL,
} dataimport_mode;
static enum {
EROFS_MKFS_SOURCE_LOCALDIR,
EROFS_MKFS_SOURCE_TAR,
+#ifdef S3EROFS_ENABLED
+ EROFS_MKFS_SOURCE_S3,
+#endif
EROFS_MKFS_SOURCE_REBUILD,
} source_mode;
@@ -522,6 +539,137 @@ static void mkfs_parse_tar_cfg(char *cfg)
erofstar.index_mode = true;
}
+#ifdef S3EROFS_ENABLED
+static int mkfs_parse_s3_cfg_passwd(const char *filepath, char *ak, char *sk)
+{
+ struct stat st;
+ int fd, n, ret;
+ char buf[S3_ACCESS_KEY_LEN + S3_SECRET_KEY_LEN + 3];
+ char *colon;
+
+ fd = open(filepath, O_RDONLY);
+ if (fd < 0) {
+ erofs_err("failed to open passwd_file %s", filepath);
+ return -errno;
+ }
+
+ ret = fstat(fd, &st);
+ if (ret) {
+ ret = -errno;
+ goto err;
+ }
+
+ if (!S_ISREG(st.st_mode)) {
+ erofs_err("%s is not a regular file", filepath);
+ ret = -EINVAL;
+ goto err;
+ }
+
+ if ((st.st_mode & 077) != 0)
+ erofs_warn("passwd_file %s should not be accessible by group or others",
+ filepath);
+
+ if (st.st_size > S3_ACCESS_KEY_LEN + S3_SECRET_KEY_LEN + 3) {
+ erofs_err("passwd_file %s is too large (size: %llu)", filepath,
+ st.st_size | 0ULL);
+ ret = -EINVAL;
+ goto err;
+ }
+
+ n = read(fd, buf, st.st_size);
+ if (n < 0) {
+ ret = -errno;
+ goto err;
+ }
+ buf[n] = '\0';
+
+ while (n > 0 && (buf[n - 1] == '\n' || buf[n - 1] == '\r'))
+ buf[--n] = '\0';
+
+ colon = strchr(buf, ':');
+ if (!colon) {
+ ret = -EINVAL;
+ goto err;
+ }
+ *colon = '\0';
+
+ strcpy(ak, buf);
+ strcpy(sk, colon + 1);
+
+err:
+ close(fd);
+ return ret;
+}
+
+static int mkfs_parse_s3_cfg(char *cfg_str)
+{
+ char *p, *q, *opt;
+ int ret = 0;
+
+ if (source_mode != EROFS_MKFS_SOURCE_LOCALDIR)
+ return -EINVAL;
+ source_mode = EROFS_MKFS_SOURCE_S3;
+
+ if (!cfg_str) {
+ erofs_err("s3: missing parameter");
+ return -EINVAL;
+ }
+
+ s3cfg.url_style = S3EROFS_URL_STYLE_VIRTUAL_HOST;
+ s3cfg.sig = S3EROFS_SIGNATURE_VERSION_2;
+
+ p = strchr(cfg_str, ',');
+ if (p) {
+ s3cfg.endpoint = strndup(cfg_str, p - cfg_str);
+ } else {
+ s3cfg.endpoint = strdup(cfg_str);
+ return 0;
+ }
+
+ opt = p + 1;
+ while (opt) {
+ q = strchr(opt, ',');
+ if (q)
+ *q = '\0';
+
+ if ((p = strstr(opt, "passwd_file="))) {
+ p += sizeof("passwd_file=") - 1;
+ ret = mkfs_parse_s3_cfg_passwd(p, s3cfg.access_key,
+ s3cfg.secret_key);
+ if (ret)
+ return ret;
+ } else if ((p = strstr(opt, "urlstyle="))) {
+ p += sizeof("urlstyle=") - 1;
+ if (strncmp(p, "vhost", 5) == 0) {
+ s3cfg.url_style = S3EROFS_URL_STYLE_VIRTUAL_HOST;
+ } else if (strncmp(p, "path", 4) == 0) {
+ s3cfg.url_style = S3EROFS_URL_STYLE_PATH;
+ } else {
+ erofs_err("invalid S3 addressing style %s", p);
+ return -EINVAL;
+ }
+ } else if ((p = strstr(opt, "sig="))) {
+ p += strlen("sig=");
+ if (strncmp(p, "4", 1) == 0) {
+ erofs_warn("AWS Signature Version 4 is not supported yet, using Version 2");
+ } else if (strncmp(p, "2", 1) == 0) {
+ s3cfg.sig = S3EROFS_SIGNATURE_VERSION_2;
+ } else {
+ erofs_err("Invalid AWS Signature Version %s", p);
+ return -EINVAL;
+ }
+ } else {
+ erofs_err("invalid --s3 option %s", opt);
+ return -EINVAL;
+ }
+
+ opt = q ? q + 1 : NULL;
+ }
+
+ return 0;
+}
+#endif
+
static int mkfs_parse_one_compress_alg(char *alg,
struct erofs_compr_opts *copts)
{
@@ -670,6 +818,13 @@ static int mkfs_parse_sources(int argc, char *argv[], int optind)
erofstar.ios.dumpfd = fd;
}
break;
+#ifdef S3EROFS_ENABLED
+ case EROFS_MKFS_SOURCE_S3:
+ cfg.c_src_path = strdup(argv[optind++]);
+ if (!cfg.c_src_path)
+ return -ENOMEM;
+ break;
+#endif
default:
erofs_err("unexpected source_mode: %d", source_mode);
return -EINVAL;
@@ -997,6 +1152,8 @@ static int mkfs_parse_options_cfg(int argc, char *argv[])
dataimport_mode = EROFS_MKFS_DATA_IMPORT_FULLDATA;
} else if (!strcmp(optarg, "rvsp")) {
dataimport_mode = EROFS_MKFS_DATA_IMPORT_RVSP;
+ } else if (!strcmp(optarg, "0")) {
+ dataimport_mode = EROFS_MKFS_DATA_IMPORT_ZEROFILL;
} else {
errno = 0;
dataimport_mode = strtol(optarg, &endptr, 0);
@@ -1058,6 +1215,13 @@ static int mkfs_parse_options_cfg(int argc, char *argv[])
return -EINVAL;
}
break;
+#ifdef S3EROFS_ENABLED
+ case 533:
+ err = mkfs_parse_s3_cfg(optarg);
+ if (err)
+ return err;
+ break;
+#endif
case 'V':
version();
exit(0);
@@ -1538,35 +1702,7 @@ int main(int argc, char **argv)
erofs_inode_manager_init();
- if (source_mode == EROFS_MKFS_SOURCE_TAR) {
- root = erofs_rebuild_make_root(&g_sbi);
- if (IS_ERR(root)) {
- err = PTR_ERR(root);
- goto exit;
- }
-
- while (!(err = tarerofs_parse_tar(root, &erofstar)));
-
- if (err < 0)
- goto exit;
-
- err = erofs_rebuild_dump_tree(root, incremental_mode);
- if (err < 0)
- goto exit;
- } else if (source_mode == EROFS_MKFS_SOURCE_REBUILD) {
- root = erofs_rebuild_make_root(&g_sbi);
- if (IS_ERR(root)) {
- err = PTR_ERR(root);
- goto exit;
- }
-
- err = erofs_mkfs_rebuild_load_trees(root);
- if (err)
- goto exit;
- err = erofs_rebuild_dump_tree(root, incremental_mode);
- if (err)
- goto exit;
- } else {
+ if (source_mode == EROFS_MKFS_SOURCE_LOCALDIR) {
err = erofs_build_shared_xattrs_from_path(&g_sbi, cfg.c_src_path);
if (err) {
erofs_err("failed to build shared xattrs: %s",
@@ -1583,6 +1719,32 @@ int main(int argc, char **argv)
root = NULL;
goto exit;
}
+ } else {
+ root = erofs_rebuild_make_root(&g_sbi);
+ if (IS_ERR(root)) {
+ err = PTR_ERR(root);
+ goto exit;
+ }
+
+ if (source_mode == EROFS_MKFS_SOURCE_TAR) {
+ while (!(err = tarerofs_parse_tar(root, &erofstar)))
+ ;
+ if (err < 0)
+ goto exit;
+ } else if (source_mode == EROFS_MKFS_SOURCE_REBUILD) {
+ err = erofs_mkfs_rebuild_load_trees(root);
+ if (err)
+ goto exit;
+#ifdef S3EROFS_ENABLED
+ } else if (source_mode == EROFS_MKFS_SOURCE_S3) {
+ err = -EOPNOTSUPP;
+ goto exit;
+#endif
+ }
+
+ err = erofs_rebuild_dump_tree(root, incremental_mode);
+ if (err)
+ goto exit;
}
if (tar_index_512b) {
--
2.43.5
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