[LEDE-DEV] [PATCH 1/3] fstools: support for ext4fs overlay
josua.mayer97 at gmail.com
josua.mayer97 at gmail.com
Tue Aug 9 08:08:38 PDT 2016
From: Ram Chandra Jangir <rjangi at codeaurora.org>
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 <rjangi at codeaurora.org>
---
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 7db28c0..7c89685 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 <sys/mount.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <asm/byteorder.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <mtd/mtd-user.h>
+#include <glob.h>
+
+#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 6e06b45..608ce5d 100644
--- a/mount_root.c
+++ b/mount_root.c
@@ -72,6 +72,7 @@ start(int argc, char *argv[1])
case FS_JFFS2:
case FS_UBIFS:
+ case FS_EXT4FS:
mount_overlay(data);
break;
@@ -110,6 +111,7 @@ done(int argc, char *argv[1])
case FS_JFFS2:
case FS_UBIFS:
+ case FS_EXT4FS:
fs_state_set("/overlay", FS_STATE_READY);
break;
}
--
2.6.6
More information about the Lede-dev
mailing list