From bf4f08af9b8fe991216023a906182744eb1e4645 Mon Sep 17 00:00:00 2001 From: Ram Chandra Jangir Date: Fri, 11 Mar 2016 22:01:42 +0530 Subject: [PATCH] fstools: support for ext4fs overlay This change will enables eMMC (ext4 fs) boot support, when we try to boot from eMMC card then it will read partition names from /sys/block/mmcblkX/mmcblkXY/uevent file and will mount the rootfs_data partition as ext4fs overlay. Signed-off-by: Ram Chandra Jangir --- CMakeLists.txt | 1 + libfstools/ext4.c | 193 ++++++++++++++++++++++++++++++++++++++++ libfstools/find.c | 3 +- libfstools/libfstools.h | 1 + libfstools/overlay.c | 14 +++ libfstools/volume.h | 1 + mount_root.c | 2 + 7 files changed, 214 insertions(+), 1 deletion(-) create mode 100644 libfstools/ext4.c diff --git a/CMakeLists.txt b/CMakeLists.txt index a6002e5..5117e8e 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -11,6 +11,7 @@ ADD_LIBRARY(fstools SHARED libfstools/overlay.c libfstools/volume.c libfstools/mtd.c + libfstools/ext4.c libfstools/mount.c libfstools/ubi.c libfstools/find.c) diff --git a/libfstools/ext4.c b/libfstools/ext4.c new file mode 100644 index 0000000..f648aa8 --- /dev/null +++ b/libfstools/ext4.c @@ -0,0 +1,193 @@ +/* + * Copyright (c) 2016, The Linux Foundation. All rights reserved. + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +*/ + + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "libfstools.h" + +#include "volume.h" + +#define ext4_sysfs_path "/sys/block/mmcblk*/mmcblk*/uevent" +#define MAX_SIZE 128 + +#define EXT_SB_OFF 0x400 +#define EXT_SB_KBOFF (EXT_SB_OFF >> 10) +#define EXT_SB_MAGIC "\123\357" +#define EXT_MAG_OFF 0x38 + +struct ext4_priv { + char *name; + char *devname; +}; + +static struct driver ext4_driver; + +static int ext4_volume_init(struct volume *v) +{ + char buf[MAX_SIZE]; + struct ext4_priv *p; + + p = (struct ext4_priv*)v->priv; + snprintf(buf, sizeof(buf), "/dev/%s",p->devname); + + v->name = strdup(p->name); + v->type = EXT4VOLUME; + v->blk = strdup(buf); + return 0; +} + +static int +ext4_part_match(char *dev, char *name, char *filename) +{ + FILE *fp; + char buf[MAX_SIZE]; + char devname[MAX_SIZE]; + int i; + int ret = -1; + + fp = fopen(filename, "r"); + if (!fp) + return ret; + + while (fgets(buf, sizeof(buf), fp)) { + if (strstr(buf, "DEVNAME")) { + strcpy(devname, buf + strlen("DEVNAME=")); + continue; + } + /* Match partition name */ + if (strstr(buf, name)) { + ret = 0; + break; + } + } + + fclose(fp); + + /* make sure the string is \0 terminated */ + devname[sizeof(devname) - 1] = '\0'; + + /* remove trailing whitespace */ + i = strlen(devname) - 1; + while (i > 0 && devname[i] <= ' ') + devname[i--] = '\0'; + + strcpy(dev, devname); + return ret; +} + +static int ext4_find_devname(char *dev, char *name) +{ + int i; + glob_t gl; + + if (glob(ext4_sysfs_path, GLOB_NOESCAPE | GLOB_MARK, NULL, &gl) < 0) + return -1; + + for (i = 0; i < gl.gl_pathc; i++) { + if (!ext4_part_match(dev, name, gl.gl_pathv[i])) { + globfree(&gl); + return 0; + } + } + + globfree(&gl); + return -1; +} + +static int check_for_mtd(const char *mtd) +{ + FILE *fp; + char dev[MAX_SIZE]; + + if ((fp = fopen("/proc/mtd", "r"))) { + while (fgets(dev, sizeof(dev), fp)) { + if (strstr(dev, mtd)) { + fclose(fp); + return -1; + } + } + } + fclose(fp); + return 0; +} + +static int ext4_volume_find(struct volume *v, char *name) +{ + char buf[MAX_SIZE]; + struct ext4_priv *p; + + if (find_filesystem("ext4")) + return -1; + + if (check_for_mtd(name)) + return -1; + + if (ext4_find_devname(buf, name)) + return -1; + + p = calloc(1, sizeof(struct ext4_priv)); + if (!p) + return -1; + + v->priv = p; + v->drv = &ext4_driver; + + p->devname = strdup(buf); + p->name = strdup(name); + return ext4_volume_init(v); +} + +static int ext4_volume_identify(struct volume *v) +{ + char magic[32] = { 0 }; + int off = (EXT_SB_KBOFF * 1024) + EXT_MAG_OFF; + int fd; + + fd = open(v->blk, O_RDONLY); + if (fd == -1) + return -1; + + lseek(fd, off, SEEK_SET); + read(fd, magic, sizeof(EXT_SB_MAGIC) - 1); + close(fd); + + if (v->type == EXT4VOLUME && + !memcmp(EXT_SB_MAGIC, magic, sizeof(EXT_SB_MAGIC) - 1)) { + return FS_EXT4FS; + } + + ULOG_ERR("ext4 is not ready - marker found\n"); + return FS_DEADCODE; +} + +static struct driver ext4_driver = { + .name = "ext4", + .find = ext4_volume_find, + .init = ext4_volume_init, + .identify = ext4_volume_identify, +}; + +DRIVER(ext4_driver); diff --git a/libfstools/find.c b/libfstools/find.c index 0440052..9fd83c9 100644 --- a/libfstools/find.c +++ b/libfstools/find.c @@ -102,7 +102,8 @@ find_mount_point(char *block, int mtd_only) if (mtd_only && strncmp(t, "jffs2", 5) && - strncmp(t, "ubifs", 5)) { + strncmp(t, "ubifs", 5) && + strncmp(t, "ext4", 4)) { fclose(fp); ULOG_ERR("block is mounted with wrong fs\n"); return NULL; diff --git a/libfstools/libfstools.h b/libfstools/libfstools.h index 31d9f9e..940c504 100644 --- a/libfstools/libfstools.h +++ b/libfstools/libfstools.h @@ -26,6 +26,7 @@ enum { FS_JFFS2, FS_DEADCODE, FS_UBIFS, + FS_EXT4FS, }; enum fs_state { diff --git a/libfstools/overlay.c b/libfstools/overlay.c index cdac23e..f8088f9 100644 --- a/libfstools/overlay.c +++ b/libfstools/overlay.c @@ -245,6 +245,16 @@ jffs2_switch(struct volume *v) ret = -1; } break; + + case FS_EXT4FS: + ret = overlay_mount(v, "ext4"); + if (ret) + break; + if (mount_move("/tmp", "", "/overlay") || fopivot("/overlay", "/rom")) { + ULOG_ERR("switching to ext4fs failed\n"); + ret = -1; + } + break; } if (ret) @@ -270,6 +280,10 @@ static int overlay_mount_fs(struct volume *v) case FS_UBIFS: fstype = "ubifs"; break; + + case FS_EXT4FS: + fstype = "ext4"; + break; } volume_init(v); diff --git a/libfstools/volume.h b/libfstools/volume.h index 9c679f7..b74bd50 100644 --- a/libfstools/volume.h +++ b/libfstools/volume.h @@ -47,6 +47,7 @@ enum { NANDFLASH, NORFLASH, UBIVOLUME, + EXT4VOLUME, }; struct volume { diff --git a/mount_root.c b/mount_root.c index bf70265..47a3409 100644 --- a/mount_root.c +++ b/mount_root.c @@ -68,6 +68,7 @@ start(int argc, char *argv[1]) case FS_JFFS2: case FS_UBIFS: + case FS_EXT4FS: mount_overlay(data); break; @@ -106,6 +107,7 @@ done(int argc, char *argv[1]) case FS_JFFS2: case FS_UBIFS: + case FS_EXT4FS: fs_state_set("/overlay", FS_STATE_READY); break; } -- 2.25.1