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From ece50ef6d4b5191636c971ee3896ca22fa538625 Mon Sep 17 00:00:00 2001
From: Gabor Juhos <juhosg@openwrt.org>
Date: Tue, 5 Nov 2013 16:16:03 +0100
Subject: [PATCH] mount_root: fix jffs2 handling on MTD devices emulated by
gluebi
The jffs2_ready() function in mount_root.c checks
the presence of various JFFS2 markers at the start
of a given MTD device. The function works on NOR
flashes because JFFS2 puts 'cleanmarker' nodes at
the start of freshly erased blocks.
However if jffs2 is used on a MTD device emulated
by the gluebi layer, the 'cleanmarker' nodes are
not present and the jffs2_ready() function fails.
Update the code to handle jffs2 correctly even on
MTD devices emulated by the gluebi layer.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
---
mount_root.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 83 insertions(+), 7 deletions(-)
--- a/mount_root.c
+++ b/mount_root.c
@@ -54,6 +54,14 @@ enum {
FS_DEADCODE,
};
+enum mtd_type {
+ MTD_TYPE_NOT_FOUND,
+ MTD_TYPE_NOR,
+ MTD_TYPE_NAND,
+ MTD_TYPE_UBI,
+ MTD_TYPE_UNKNOWN,
+};
+
static const char *argv0;
/* this is a raw syscall - man 2 pivot_root */
@@ -223,6 +231,64 @@ static int find_mtd_char(char *name, cha
return 0;
}
+static enum mtd_type mtd_get_type(char *index)
+{
+ static char p[256];
+ static char buf[32];
+ FILE *fp;
+ size_t sz;
+
+ snprintf(p, sizeof(p), "/sys/class/mtd/mtd%s/type", index);
+
+ fp = fopen(p, "r");
+ if (!fp) {
+ ERROR("unable to open %s\n", p);
+ return MTD_TYPE_NOT_FOUND;
+ }
+
+ memset(buf, 0, sizeof(buf));
+ sz = fread(buf, 1, sizeof(buf) - 1, fp);
+ fclose(fp);
+
+ if (sz <= 1) {
+ ERROR("unable to read from %s\n", p);
+ return MTD_TYPE_UNKNOWN;
+ }
+
+ while (sz > 0) {
+ sz--;
+
+ if (buf[sz] != '\n')
+ break;
+
+ buf[sz] = 0;
+ }
+
+ if (strcmp(buf, "nor") == 0)
+ return MTD_TYPE_NOR;
+
+ if (strcmp(buf, "nand") == 0)
+ return MTD_TYPE_NAND;
+
+ if (strcmp(buf, "ubi") == 0)
+ return MTD_TYPE_UBI;
+
+ ERROR("mtd%s has unknow type '%s'\n", index, buf);
+ return MTD_TYPE_UNKNOWN;
+}
+
+static enum mtd_type mtd_get_type_by_name(char *name)
+{
+ char *index;
+
+ index = find_mtd_index(name);
+ if (!index)
+ return MTD_TYPE_NOT_FOUND;
+
+ return mtd_get_type(index);
+}
+
+
static int mtd_unlock(char *mtd)
{
struct erase_info_user mtdlock;
@@ -277,7 +343,7 @@ static int mtd_mount_jffs2(void)
return mtd_unlock(rootfs_data);
}
-static int jffs2_ready(char *mtd)
+static int jffs2_ready(char *mtd, enum mtd_type type)
{
FILE *fp = fopen(mtd, "r");
__u32 deadc0de;
@@ -298,16 +364,21 @@ static int jffs2_ready(char *mtd)
}
deadc0de = __be32_to_cpu(deadc0de);
- jffs2 = __be16_to_cpu(deadc0de >> 16);
+ if (deadc0de == 0xdeadc0de) {
+ LOG("jffs2 is not ready - EOF marker found\n");
+ return FS_DEADCODE;
+ }
+ jffs2 = __be16_to_cpu(deadc0de >> 16);
if (jffs2 == 0x1985) {
LOG("jffs2 is ready\n");
return FS_JFFS2;
}
- if (deadc0de == 0xdeadc0de) {
- LOG("jffs2 is not ready - marker found\n");
- return FS_DEADCODE;
+ if (type == MTD_TYPE_UBI &&
+ deadc0de == 0xffffffff) {
+ LOG("jffs2 is ready\n");
+ return FS_JFFS2;
}
ERROR("No jffs2 marker was found\n");
@@ -638,6 +709,7 @@ static int main_switch2jffs(int argc, ch
char mtd[32];
char *mp;
int ret = -1;
+ enum mtd_type type;
if (find_overlay_mount("overlayfs:/tmp/root"))
return -1;
@@ -659,7 +731,8 @@ static int main_switch2jffs(int argc, ch
return ret;
}
- switch (jffs2_ready(mtd)) {
+ type = mtd_get_type_by_name("rootfs_data");
+ switch (jffs2_ready(mtd, type)) {
case FS_NONE:
ERROR("no jffs2 marker found\n");
/* fall through */
@@ -781,12 +854,15 @@ int main(int argc, char **argv)
LOG("mounting /dev/root\n");
mount("/dev/root", "/", NULL, MS_NOATIME | MS_REMOUNT, 0);
} else {
+ enum mtd_type type;
+
if (!extroot("")) {
fprintf(stderr, "mount_root: switched to extroot\n");
return 0;
}
- switch (jffs2_ready(mtd)) {
+ type = mtd_get_type_by_name("rootfs_data");
+ switch (jffs2_ready(mtd, type)) {
case FS_NONE:
case FS_DEADCODE:
return ramoverlay();
|
