diff --git a/man/repart.d.xml b/man/repart.d.xml
index a79724a93e..261c673249 100644
--- a/man/repart.d.xml
+++ b/man/repart.d.xml
@@ -500,6 +500,21 @@
attributes.
+
+ Subvolumes=
+
+ Takes one or more absolute paths, separated by whitespace, each declaring a directory
+ that should be a subvolume within the new file system. This option may be used more than once to
+ specify multiple directories. Note that this setting does not create the directories themselves, that
+ can be configured with MakeDirectories= and CopyFiles=.
+
+ Note that this option only takes effect if the target filesystem supports subvolumes, such as
+ btrfs.
+
+ Note that due to limitations of mkfs.btrfs, this option is only supported
+ when running with .
+
+
Encrypt=
diff --git a/src/partition/repart.c b/src/partition/repart.c
index 0a335b2cc1..decf4e8589 100644
--- a/src/partition/repart.c
+++ b/src/partition/repart.c
@@ -243,6 +243,7 @@ typedef struct Partition {
char **exclude_files_source;
char **exclude_files_target;
char **make_directories;
+ char **subvolumes;
EncryptMode encrypt;
VerityMode verity;
char *verity_match_key;
@@ -389,6 +390,7 @@ static Partition* partition_free(Partition *p) {
strv_free(p->exclude_files_source);
strv_free(p->exclude_files_target);
strv_free(p->make_directories);
+ strv_free(p->subvolumes);
free(p->verity_match_key);
free(p->roothash);
@@ -417,6 +419,7 @@ static void partition_foreignize(Partition *p) {
p->exclude_files_source = strv_free(p->exclude_files_source);
p->exclude_files_target = strv_free(p->exclude_files_target);
p->make_directories = strv_free(p->make_directories);
+ p->subvolumes = strv_free(p->subvolumes);
p->verity_match_key = mfree(p->verity_match_key);
p->priority = 0;
@@ -1503,7 +1506,7 @@ static int config_parse_make_dirs(
void *data,
void *userdata) {
- Partition *partition = ASSERT_PTR(data);
+ char ***sv = ASSERT_PTR(data);
const char *p = ASSERT_PTR(rvalue);
int r;
@@ -1531,7 +1534,7 @@ static int config_parse_make_dirs(
if (r < 0)
continue;
- r = strv_consume(&partition->make_directories, TAKE_PTR(d));
+ r = strv_consume(sv, TAKE_PTR(d));
if (r < 0)
return log_oom();
}
@@ -1626,7 +1629,7 @@ static int partition_read_definition(Partition *p, const char *path, const char
{ "Partition", "CopyFiles", config_parse_copy_files, 0, &p->copy_files },
{ "Partition", "ExcludeFiles", config_parse_exclude_files, 0, &p->exclude_files_source },
{ "Partition", "ExcludeFilesTarget", config_parse_exclude_files, 0, &p->exclude_files_target },
- { "Partition", "MakeDirectories", config_parse_make_dirs, 0, p },
+ { "Partition", "MakeDirectories", config_parse_make_dirs, 0, &p->make_directories },
{ "Partition", "Encrypt", config_parse_encrypt, 0, &p->encrypt },
{ "Partition", "Verity", config_parse_verity, 0, &p->verity },
{ "Partition", "VerityMatchKey", config_parse_string, 0, &p->verity_match_key },
@@ -1636,6 +1639,7 @@ static int partition_read_definition(Partition *p, const char *path, const char
{ "Partition", "GrowFileSystem", config_parse_tristate, 0, &p->growfs },
{ "Partition", "SplitName", config_parse_string, 0, &p->split_name_format },
{ "Partition", "Minimize", config_parse_minimize, 0, &p->minimize },
+ { "Partition", "Subvolumes", config_parse_make_dirs, 0, &p->subvolumes },
{}
};
int r;
@@ -1749,6 +1753,10 @@ static int partition_read_definition(Partition *p, const char *path, const char
"SizeMinBytes=/SizeMaxBytes= cannot be used with Verity=%s",
verity_mode_to_string(p->verity));
+ if (!strv_isempty(p->subvolumes) && arg_offline != 0)
+ return log_syntax(NULL, LOG_ERR, path, 1, SYNTHETIC_ERRNO(EOPNOTSUPP),
+ "Subvolumes= can only be used with --offline=no");
+
/* Verity partitions are read only, let's imply the RO flag hence, unless explicitly configured otherwise. */
if ((IN_SET(p->type.designator,
PARTITION_ROOT_VERITY,
@@ -4304,6 +4312,66 @@ static int make_copy_files_denylist(
return 0;
}
+static int add_subvolume_path(const char *path, Set **subvolumes) {
+ _cleanup_free_ struct stat *st = NULL;
+ int r;
+
+ assert(path);
+ assert(subvolumes);
+
+ st = new(struct stat, 1);
+ if (!st)
+ return log_oom();
+
+ r = chase_and_stat(path, arg_root, CHASE_PREFIX_ROOT, NULL, st);
+ if (r == -ENOENT)
+ return 0;
+ if (r < 0)
+ return log_error_errno(r, "Failed to stat source file '%s/%s': %m", strempty(arg_root), path);
+
+ r = set_ensure_put(subvolumes, &inode_hash_ops, st);
+ if (r < 0)
+ return log_oom();
+ if (r > 0)
+ TAKE_PTR(st);
+
+ return 0;
+}
+
+static int make_subvolumes_set(
+ Context *context,
+ const Partition *p,
+ const char *source,
+ const char *target,
+ Set **ret) {
+ _cleanup_set_free_ Set *subvolumes = NULL;
+ int r;
+
+ assert(context);
+ assert(p);
+ assert(target);
+ assert(ret);
+
+ STRV_FOREACH(subvolume, p->subvolumes) {
+ _cleanup_free_ char *path = NULL;
+
+ const char *s = path_startswith(*subvolume, target);
+ if (!s)
+ continue;
+
+ path = path_join(source, s);
+ if (!path)
+ return log_oom();
+
+ r = add_subvolume_path(path, &subvolumes);
+ if (r < 0)
+ return r;
+ }
+
+ *ret = TAKE_PTR(subvolumes);
+ return 0;
+}
+
static int do_copy_files(Context *context, Partition *p, const char *root) {
int r;
@@ -4337,12 +4405,17 @@ static int do_copy_files(Context *context, Partition *p, const char *root) {
STRV_FOREACH_PAIR(source, target, p->copy_files) {
_cleanup_hashmap_free_ Hashmap *denylist = NULL;
+ _cleanup_set_free_ Set *subvolumes_by_source_inode = NULL;
_cleanup_close_ int sfd = -EBADF, pfd = -EBADF, tfd = -EBADF;
r = make_copy_files_denylist(context, p, *source, *target, &denylist);
if (r < 0)
return r;
+ r = make_subvolumes_set(context, p, *source, *target, &subvolumes_by_source_inode);
+ if (r < 0)
+ return r;
+
sfd = chase_and_open(*source, arg_root, CHASE_PREFIX_ROOT, O_CLOEXEC|O_NOCTTY, NULL);
if (sfd < 0)
return log_error_errno(sfd, "Failed to open source file '%s%s': %m", strempty(arg_root), *source);
@@ -4368,7 +4441,7 @@ static int do_copy_files(Context *context, Partition *p, const char *root) {
if (r < 0)
return log_error_errno(r, "Failed to extract directory from '%s': %m", *target);
- r = mkdir_p_root(root, dn, UID_INVALID, GID_INVALID, 0755, NULL);
+ r = mkdir_p_root(root, dn, UID_INVALID, GID_INVALID, 0755, p->subvolumes);
if (r < 0)
return log_error_errno(r, "Failed to create parent directory '%s': %m", dn);
@@ -4381,14 +4454,14 @@ static int do_copy_files(Context *context, Partition *p, const char *root) {
pfd, fn,
UID_INVALID, GID_INVALID,
COPY_REFLINK|COPY_HOLES|COPY_MERGE|COPY_REPLACE|COPY_SIGINT|COPY_HARDLINKS|COPY_ALL_XATTRS|COPY_GRACEFUL_WARN|COPY_TRUNCATE,
- denylist, NULL);
+ denylist, subvolumes_by_source_inode);
} else
r = copy_tree_at(
sfd, ".",
tfd, ".",
UID_INVALID, GID_INVALID,
COPY_REFLINK|COPY_HOLES|COPY_MERGE|COPY_REPLACE|COPY_SIGINT|COPY_HARDLINKS|COPY_ALL_XATTRS|COPY_GRACEFUL_WARN|COPY_TRUNCATE,
- denylist, NULL);
+ denylist, subvolumes_by_source_inode);
if (r < 0)
return log_error_errno(r, "Failed to copy '%s%s' to '%s%s': %m",
strempty(arg_root), *source, strempty(root), *target);
@@ -4408,7 +4481,7 @@ static int do_copy_files(Context *context, Partition *p, const char *root) {
if (r < 0)
return log_error_errno(r, "Failed to extract directory from '%s': %m", *target);
- r = mkdir_p_root(root, dn, UID_INVALID, GID_INVALID, 0755, NULL);
+ r = mkdir_p_root(root, dn, UID_INVALID, GID_INVALID, 0755, p->subvolumes);
if (r < 0)
return log_error_errno(r, "Failed to create parent directory: %m");
@@ -4440,8 +4513,7 @@ static int do_make_directories(Partition *p, const char *root) {
assert(root);
STRV_FOREACH(d, p->make_directories) {
-
- r = mkdir_p_root(root, *d, UID_INVALID, GID_INVALID, 0755, NULL);
+ r = mkdir_p_root(root, *d, UID_INVALID, GID_INVALID, 0755, p->subvolumes);
if (r < 0)
return log_error_errno(r, "Failed to create directory '%s' in file system: %m", *d);
}