--- /dev/null
+/*
+ * Copyright (C) 2016 Felix Fietkau <nbd@nbd.name>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1
+ * as published by the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#define F2FS_MINSIZE (100 * 1024 * 1024)
+#define _FILE_OFFSET_BITS 64
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/mount.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "libfstools.h"
+#include "volume.h"
+
+#include <linux/loop.h>
+
+#define ROOTDEV_OVERLAY_ALIGN (64ULL * 1024ULL)
+
+struct squashfs_super_block {
+ uint32_t s_magic;
+ uint32_t pad0[9];
+ uint64_t bytes_used;
+};
+
+struct rootdev_volume {
+ struct volume v;
+ uint64_t offset;
+ char loop_name[32];
+};
+
+static const char *rootdev;
+static struct driver rootdisk_driver;
+
+static char *get_blockdev(dev_t dev)
+{
+ const char *dirname = "/dev";
+ DIR *dir = opendir(dirname);
+ struct dirent *d;
+ struct stat st;
+ static char buf[256];
+ char *ret = NULL;
+
+ if (!dir)
+ return ret;
+
+ while ((d = readdir(dir)) != NULL) {
+ snprintf(buf, sizeof(buf), "%s/%s", dirname, d->d_name);
+
+ if (lstat(buf, &st) != 0)
+ continue;
+
+ if (!S_ISBLK(st.st_mode))
+ continue;
+
+ if (st.st_rdev != dev)
+ continue;
+
+ ret = buf;
+ break;
+ }
+
+ closedir(dir);
+ return ret;
+}
+
+static char *get_rootdev(const char *dir)
+{
+ struct stat st;
+
+ if (stat(dir, &st))
+ return NULL;
+
+ return get_blockdev(S_ISBLK(st.st_mode) ? st.st_rdev : st.st_dev);
+}
+
+static int get_squashfs(struct squashfs_super_block *sb)
+{
+ FILE *f;
+ int len;
+
+ f = fopen(rootdev, "r");
+ if (!f)
+ return -1;
+
+ len = fread(sb, sizeof(*sb), 1, f);
+ fclose(f);
+
+ if (len != 1)
+ return -1;
+
+ return 0;
+}
+
+static bool rootdisk_use_f2fs(struct rootdev_volume *p)
+{
+ uint64_t size = 0;
+ bool ret = false;
+ int fd;
+
+ fd = open(rootdev, O_RDONLY);
+ if (ioctl(fd, BLKGETSIZE64, &size) == 0)
+ ret = size - p->offset > F2FS_MINSIZE;
+ close(fd);
+
+ return ret;
+}
+
+static struct volume *rootdisk_volume_find(char *name)
+{
+ struct squashfs_super_block sb;
+ struct rootdev_volume *p;
+
+ if (strcmp(name, "rootfs_data") != 0)
+ return NULL;
+
+ if (!rootdev)
+ rootdev = get_rootdev("/");
+ if (!rootdev)
+ rootdev = get_rootdev("/rom");
+ if (!rootdev)
+ return NULL;
+
+ if (strstr(rootdev, "mtdblock") ||
+ strstr(rootdev, "ubiblock"))
+ return NULL;
+
+ if (get_squashfs(&sb))
+ return NULL;
+
+ if (memcmp(&sb.s_magic, "hsqs", sizeof(sb.s_magic)) != 0)
+ return NULL;
+
+ p = calloc(1, sizeof(*p));
+ p->v.drv = &rootdisk_driver;
+ p->v.name = "rootfs_data";
+
+ p->offset = le64_to_cpu(sb.bytes_used);
+ p->offset = ((p->offset + (ROOTDEV_OVERLAY_ALIGN - 1)) &
+ ~(ROOTDEV_OVERLAY_ALIGN - 1));
+
+ return &p->v;
+}
+
+static int rootdisk_volume_identify(struct volume *v)
+{
+ struct rootdev_volume *p = container_of(v, struct rootdev_volume, v);
+ int ret = FS_NONE;
+ uint32_t magic = 0;
+ FILE *f;
+
+ f = fopen(rootdev, "r");
+ if (!f)
+ return ret;
+
+ fseeko(f, p->offset + 0x400, SEEK_SET);
+ fread(&magic, sizeof(magic), 1, f);
+
+ if (magic == cpu_to_le32(0xF2F52010))
+ ret = FS_F2FS;
+
+ magic = 0;
+ fseeko(f, p->offset + 0x438, SEEK_SET);
+ fread(&magic, sizeof(magic), 1, f);
+ if ((le32_to_cpu(magic) & 0xffff) == 0xef53)
+ ret = FS_EXT4;
+
+ fclose(f);
+
+ return ret;
+}
+
+static int rootdisk_create_loop(struct rootdev_volume *p)
+{
+ struct loop_info64 info;
+ int ret = -1;
+ int fd = -1;
+ int i, ffd;
+
+ ffd = open(rootdev, O_RDWR);
+ if (ffd < 0)
+ return -1;
+
+ for (i = 0; i < 8; i++) {
+ snprintf(p->loop_name, sizeof(p->loop_name), "/dev/loop%d",
+ i);
+
+ if (fd >= 0)
+ close(fd);
+
+ fd = open(p->loop_name, O_RDWR);
+ if (fd < 0)
+ continue;
+
+ if (ioctl(fd, LOOP_GET_STATUS64, &info) == 0) {
+ if (strcmp((char *) info.lo_file_name, rootdev) != 0)
+ continue;
+ if (info.lo_offset != p->offset)
+ continue;
+ ret = 0;
+ break;
+ }
+
+ if (errno != ENXIO)
+ continue;
+
+ if (ioctl(fd, LOOP_SET_FD, ffd) != 0)
+ continue;
+
+ memset(&info, 0, sizeof(info));
+ snprintf((char *) info.lo_file_name, sizeof(info.lo_file_name), "%s",
+ rootdev);
+ info.lo_offset = p->offset;
+
+ if (ioctl(fd, LOOP_SET_STATUS64, &info) != 0) {
+ ioctl(fd, LOOP_CLR_FD, 0);
+ continue;
+ }
+
+ ret = 0;
+ break;
+ }
+
+ if (fd >= 0)
+ close(fd);
+
+ close(ffd);
+
+ if (ret)
+ p->loop_name[0] = 0;
+
+ return ret;
+}
+
+static int rootdisk_volume_init(struct volume *v)
+{
+ struct rootdev_volume *p = container_of(v, struct rootdev_volume, v);
+ char str[128];
+
+ if (!p->loop_name[0] && rootdisk_create_loop(p) != 0)
+ return -1;
+
+ v->type = BLOCKDEV;
+ v->blk = p->loop_name;
+
+ switch (rootdisk_volume_identify(v)) {
+ case FS_NONE:
+ ULOG_INFO("rootdisk overlay filesystem has not been formatted yet\n");
+ if (rootdisk_use_f2fs(p))
+ snprintf(str, sizeof(str), "mkfs.f2fs -l rootfs_data %s", v->blk);
+ else
+ snprintf(str, sizeof(str), "mkfs.ext4 %s", v->blk);
+ system(str);
+ break;
+ default:
+ break;
+ }
+ return 0;
+}
+
+static struct driver rootdisk_driver = {
+ .name = "rootdisk",
+ .find = rootdisk_volume_find,
+ .init = rootdisk_volume_init,
+ .identify = rootdisk_volume_identify,
+};
+
+DRIVER(rootdisk_driver);
projects / project / fstools.git / commitdiff