fs_mgr/fs_mgr_format.cpp

/*
 * Copyright (C) 2015 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/wait.h>
#include <errno.h>
#include <cutils/partition_utils.h>
#include <sys/mount.h>

#include <ext4_utils/ext4_utils.h>
#include <ext4_utils/ext4.h>
#include <ext4_utils/make_ext4fs.h>
#include <selinux/selinux.h>
#include <selinux/label.h>
#include <selinux/android.h>

#include "fs_mgr_priv.h"
#include "cryptfs.h"

extern "C" {
extern struct fs_info info;     /* magic global from ext4_utils */
extern void reset_ext4fs_info();
}

static int format_ext4(char *fs_blkdev, char *fs_mnt_point, bool crypt_footer)
{
    uint64_t dev_sz;
    int fd, rc = 0;

    if ((fd = open(fs_blkdev, O_WRONLY)) < 0) {
        PERROR << "Cannot open block device";
        return -1;
    }

    if ((ioctl(fd, BLKGETSIZE64, &dev_sz)) == -1) {
        PERROR << "Cannot get block device size";
        close(fd);
        return -1;
    }

    struct selabel_handle *sehandle = selinux_android_file_context_handle();
    if (!sehandle) {
        /* libselinux logs specific error */
        LERROR << "Cannot initialize android file_contexts";
        close(fd);
        return -1;
    }

    /* Format the partition using the calculated length */
    reset_ext4fs_info();
    info.len = (off64_t)dev_sz;
    if (crypt_footer) {
        info.len -= CRYPT_FOOTER_OFFSET;
    }

    /* Use make_ext4fs_internal to avoid wiping an already-wiped partition. */
    rc = make_ext4fs_internal(fd, NULL, NULL, fs_mnt_point, 0, 0, 0, 0, 0, 0, sehandle, 0, 0, NULL, NULL, NULL);
    if (rc) {
        LERROR << "make_ext4fs returned " << rc;
    }
    close(fd);

    if (sehandle) {
        selabel_close(sehandle);
    }

    return rc;
}

static int format_f2fs(char *fs_blkdev)
{
    char * args[3];
    int pid;
    int rc = 0;

    args[0] = (char *)"/sbin/mkfs.f2fs";
    args[1] = fs_blkdev;
    args[2] = (char *)0;

    pid = fork();
    if (pid < 0) {
       return pid;
    }
    if (!pid) {
        /* This doesn't return */
        execv("/sbin/mkfs.f2fs", args);
        exit(1);
    }
    for(;;) {
        pid_t p = waitpid(pid, &rc, 0);
        if (p != pid) {
            LERROR << "Error waiting for child process - " << p;
            rc = -1;
            break;
        }
        if (WIFEXITED(rc)) {
            rc = WEXITSTATUS(rc);
            LINFO << args[0] << " done, status " << rc;
            if (rc) {
                rc = -1;
            }
            break;
        }
        LERROR << "Still waiting for " << args[0] << "...";
    }

    return rc;
}

int fs_mgr_do_format(struct fstab_rec *fstab, bool crypt_footer)
{
    int rc = -EINVAL;

    LERROR << __FUNCTION__ << ": Format " << fstab->blk_device
           << " as '" << fstab->fs_type << "'";

    if (!strncmp(fstab->fs_type, "f2fs", 4)) {
        rc = format_f2fs(fstab->blk_device);
    } else if (!strncmp(fstab->fs_type, "ext4", 4)) {
        rc = format_ext4(fstab->blk_device, fstab->mount_point, crypt_footer);
    } else {
        LERROR << "File system type '" << fstab->fs_type << "' is not supported";
    }

    return rc;
}