shared: introduce mkfs-util.c/.h

Let's move the "mkfs" code from homed there, plus other related code.

This way we can easily reuse it from other places.

6 files changed, 128 insertions, 79 deletions

diff --git a/src/basic/path-util.c b/src/basic/path-util.c
index c4e022b3a1..c463ae23ab 100644
--- a/src/basic/path-util.c
+++ b/src/basic/path-util.c
@@ -726,18 +726,6 @@ int fsck_exists(const char *fstype) {
         return binary_is_good(checker);
 }
 
-int mkfs_exists(const char *fstype) {
-        const char *mkfs;
-
-        assert(fstype);
-
-        if (streq(fstype, "auto"))
-                return -EINVAL;
-
-        mkfs = strjoina("mkfs.", fstype);
-        return binary_is_good(mkfs);
-}
-
 int parse_path_argument_and_warn(const char *path, bool suppress_root, char **arg) {
         char *p;
         int r;
diff --git a/src/basic/path-util.h b/src/basic/path-util.h
index 30031fca8e..99c4e35782 100644
--- a/src/basic/path-util.h
+++ b/src/basic/path-util.h
@@ -85,7 +85,6 @@ int find_binary(const char *name, char **filename);
 bool paths_check_timestamp(const char* const* paths, usec_t *paths_ts_usec, bool update);
 
 int fsck_exists(const char *fstype);
-int mkfs_exists(const char *fstype);
 
 /* Iterates through the path prefixes of the specified path, going up
  * the tree, to root. Also returns "" (and not "/"!) for the root
diff --git a/src/home/homework-luks.c b/src/home/homework-luks.c
index 1fcf17806e..1fe0465cfb 100644
--- a/src/home/homework-luks.c
+++ b/src/home/homework-luks.c
@@ -24,6 +24,7 @@
 #include "memory-util.h"
 #include "missing_magic.h"
 #include "mkdir.h"
+#include "mkfs-util.h"
 #include "mount-util.h"
 #include "openssl-util.h"
 #include "parse-util.h"
@@ -1371,71 +1372,6 @@ int home_trim_luks(UserRecord *h) {
         return 0;
 }
 
-static int run_mkfs(
-                const char *node,
-                const char *fstype,
-                const char *label,
-                sd_id128_t uuid,
-                bool discard) {
-
-        int r;
-
-        assert(node);
-        assert(fstype);
-        assert(label);
-
-        r = mkfs_exists(fstype);
-        if (r < 0)
-                return log_error_errno(r, "Failed to check if mkfs for file system %s exists: %m", fstype);
-        if (r == 0)
-                return log_error_errno(SYNTHETIC_ERRNO(EPROTONOSUPPORT), "No mkfs for file system %s installed.", fstype);
-
-        r = safe_fork("(mkfs)", FORK_RESET_SIGNALS|FORK_RLIMIT_NOFILE_SAFE|FORK_DEATHSIG|FORK_LOG|FORK_WAIT|FORK_STDOUT_TO_STDERR, NULL);
-        if (r < 0)
-                return r;
-        if (r == 0) {
-                const char *mkfs;
-                char suuid[37];
-
-                /* Child */
-
-                mkfs = strjoina("mkfs.", fstype);
-                id128_to_uuid_string(uuid, suuid);
-
-                if (streq(fstype, "ext4"))
-                        execlp(mkfs, mkfs,
-                               "-L", label,
-                               "-U", suuid,
-                               "-I", "256",
-                               "-O", "has_journal",
-                               "-m", "0",
-                               "-E", discard ? "lazy_itable_init=1,discard" : "lazy_itable_init=1,nodiscard",
-                               node, NULL);
-                else if (streq(fstype, "btrfs")) {
-                        if (discard)
-                                execlp(mkfs, mkfs, "-L", label, "-U", suuid, node, NULL);
-                        else
-                                execlp(mkfs, mkfs, "-L", label, "-U", suuid, "--nodiscard", node, NULL);
-                } else if (streq(fstype, "xfs")) {
-                        const char *j;
-
-                        j = strjoina("uuid=", suuid);
-                        if (discard)
-                                execlp(mkfs, mkfs, "-L", label, "-m", j, "-m", "reflink=1", node, NULL);
-                        else
-                                execlp(mkfs, mkfs, "-L", label, "-m", j, "-m", "reflink=1", "-K", node, NULL);
-                } else {
-                        log_error("Cannot make file system: %s", fstype);
-                        _exit(EXIT_FAILURE);
-                }
-
-                log_error_errno(errno, "Failed to execute %s: %m", mkfs);
-                _exit(EXIT_FAILURE);
-        }
-
-        return 0;
-}
-
 static struct crypt_pbkdf_type* build_good_pbkdf(struct crypt_pbkdf_type *buffer, UserRecord *hr) {
         assert(buffer);
         assert(hr);
@@ -2083,7 +2019,7 @@ int home_create_luks(
 
         log_info("Setting up LUKS device %s completed.", dm_node);
 
-        r = run_mkfs(dm_node, fstype, user_record_user_name_and_realm(h), fs_uuid, user_record_luks_discard(h));
+        r = make_filesystem(dm_node, fstype, user_record_user_name_and_realm(h), fs_uuid, user_record_luks_discard(h));
         if (r < 0)
                 goto fail;
 
diff --git a/src/shared/meson.build b/src/shared/meson.build
index d192a4d8d7..39bf5523d6 100644
--- a/src/shared/meson.build
+++ b/src/shared/meson.build
@@ -166,6 +166,8 @@ shared_sources = files('''
         macvlan-util.c
         macvlan-util.h
         main-func.h
+        mkfs-util.c
+        mkfs-util.h
         module-util.h
         mount-util.c
         mount-util.h
diff --git a/src/shared/mkfs-util.c b/src/shared/mkfs-util.c
new file mode 100644
index 0000000000..a78f68e398
--- /dev/null
+++ b/src/shared/mkfs-util.c
@@ -0,0 +1,114 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include "id128-util.h"
+#include "mkfs-util.h"
+#include "path-util.h"
+#include "process-util.h"
+#include "string-util.h"
+
+int mkfs_exists(const char *fstype) {
+        const char *mkfs;
+        int r;
+
+        assert(fstype);
+
+        if (STR_IN_SET(fstype, "auto", "swap")) /* these aren't real file system types, refuse early */
+                return -EINVAL;
+
+        mkfs = strjoina("mkfs.", fstype);
+        if (!filename_is_valid(mkfs)) /* refuse file system types with slashes and similar */
+                return -EINVAL;
+
+        r = find_binary(mkfs, NULL);
+        if (r == -ENOENT)
+                return false;
+        if (r < 0)
+                return r;
+
+        return true;
+}
+
+int make_filesystem(
+                const char *node,
+                const char *fstype,
+                const char *label,
+                sd_id128_t uuid,
+                bool discard) {
+
+        _cleanup_free_ char *mkfs = NULL;
+        int r;
+
+        assert(node);
+        assert(fstype);
+        assert(label);
+
+        if (streq(fstype, "swap")) {
+                r = find_binary("mkswap", &mkfs);
+                if (r == -ENOENT)
+                        return log_error_errno(SYNTHETIC_ERRNO(EPROTONOSUPPORT), "mkswap binary not available.");
+                if (r < 0)
+                        return log_error_errno(r, "Failed to determine whether mkswap binary exists: %m");
+        } else {
+                r = mkfs_exists(fstype);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to determine whether mkfs binary for %s exists: %m", fstype);
+                if (r == 0)
+                        return log_error_errno(SYNTHETIC_ERRNO(EPROTONOSUPPORT), "mkfs binary for %s is not available.", fstype);
+
+                mkfs = strjoin("mkfs.", fstype);
+                if (!mkfs)
+                        return log_oom();
+        }
+
+        r = safe_fork("(mkfs)", FORK_RESET_SIGNALS|FORK_RLIMIT_NOFILE_SAFE|FORK_DEATHSIG|FORK_LOG|FORK_WAIT|FORK_STDOUT_TO_STDERR, NULL);
+        if (r < 0)
+                return r;
+        if (r == 0) {
+                char suuid[ID128_UUID_STRING_MAX];
+
+                /* Child */
+                id128_to_uuid_string(uuid, suuid);
+
+                if (streq(fstype, "ext4"))
+                        (void) execlp(mkfs, mkfs,
+                               "-L", label,
+                               "-U", suuid,
+                               "-I", "256",
+                               "-O", "has_journal",
+                               "-m", "0",
+                               "-E", discard ? "lazy_itable_init=1,discard" : "lazy_itable_init=1,nodiscard",
+                               node, NULL);
+
+                else if (streq(fstype, "btrfs")) {
+                        if (discard)
+                                (void) execlp(mkfs, mkfs, "-L", label, "-U", suuid, node, NULL);
+                        else
+                                (void) execlp(mkfs, mkfs, "-L", label, "-U", suuid, "--nodiscard", node, NULL);
+
+                } else if (streq(fstype, "xfs")) {
+                        const char *j;
+
+                        j = strjoina("uuid=", suuid);
+                        if (discard)
+                                (void) execlp(mkfs, mkfs, "-L", label, "-m", j, "-m", "reflink=1", node, NULL);
+                        else
+                                (void) execlp(mkfs, mkfs, "-L", label, "-m", j, "-m", "reflink=1", "-K", node, NULL);
+
+                } else if (streq(fstype, "swap")) {
+
+                        (void) execlp(mkfs, mkfs,
+                               "-L", label,
+                               "-U", suuid,
+                               node, NULL);
+
+                } else
+                        /* Generic fallback for all other file systems */
+                        (void) execlp(mkfs, mkfs, node, NULL);
+
+                log_error_errno(errno, "Failed to execute %s: %m", mkfs);
+
+                _exit(EXIT_FAILURE);
+        }
+
+        return 0;
+}
diff --git a/src/shared/mkfs-util.h b/src/shared/mkfs-util.h
new file mode 100644
index 0000000000..54e9b931e6
--- /dev/null
+++ b/src/shared/mkfs-util.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+
+#include "sd-id128.h"
+
+int mkfs_exists(const char *fstype);
+
+int make_filesystem(const char *node, const char *fstype, const char *label, sd_id128_t uuid, bool discard);