src/shared/mkfs-util.c

/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include "id128-util.h"
#include "mkfs-util.h"
#include "path-util.h"
#include "process-util.h"
#include "stdio-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_executable(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_executable("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, "vfat")) {
                        char mangled_label[8 + 3 + 1], vol_id[8 + 1];

                        /* Classic FAT only allows 11 character uppercase labels */
                        strncpy(mangled_label, label, sizeof(mangled_label)-1);
                        mangled_label[sizeof(mangled_label)-1] = 0;
                        ascii_strupper(mangled_label);

                        xsprintf(vol_id, "%08" PRIx32,
                                 ((uint32_t) uuid.bytes[0] << 24) |
                                 ((uint32_t) uuid.bytes[1] << 16) |
                                 ((uint32_t) uuid.bytes[2] << 8) |
                                 ((uint32_t) uuid.bytes[3])); /* Take first 32 byte of UUID */

                        (void) execlp(mkfs, mkfs,
                                      "-i", vol_id,
                                      "-n", mangled_label,
                                      "-F", "32",  /* yes, we force FAT32 here */
                                      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;
}