delay accessing misc partition until its device exists

When the misc partition is on an emmc device, recovery can get started
and try to access it before the kernel has actually created the
device.  Try statting the device before reading or writing it; delay
up to 10 seconds waiting for the device to exist.

Change-Id: I988442d5701394d7152bfab3c571e7548c364f61
This commit is contained in:
Doug Zongker 2011-04-22 09:26:44 -07:00 committed by Mike Lockwood
parent 4762633cf8
commit f4bb554ee9

View File

@ -22,6 +22,8 @@
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
static int get_bootloader_message_mtd(struct bootloader_message *out, const Volume* v);
static int set_bootloader_message_mtd(const struct bootloader_message *in, const Volume* v);
@ -132,8 +134,26 @@ static int set_bootloader_message_mtd(const struct bootloader_message *in,
// for misc partitions on block devices
// ------------------------------------
static void wait_for_device(const char* fn) {
int tries = 0;
int ret;
struct stat buf;
do {
++tries;
ret = stat(fn, &buf);
if (ret) {
printf("stat %s try %d: %s\n", fn, tries, strerror(errno));
sleep(1);
}
} while (ret && tries < 10);
if (ret) {
printf("failed to stat %s\n", fn);
}
}
static int get_bootloader_message_block(struct bootloader_message *out,
const Volume* v) {
wait_for_device(v->device);
FILE* f = fopen(v->device, "rb");
if (f == NULL) {
LOGE("Can't open %s\n(%s)\n", v->device, strerror(errno));
@ -155,6 +175,7 @@ static int get_bootloader_message_block(struct bootloader_message *out,
static int set_bootloader_message_block(const struct bootloader_message *in,
const Volume* v) {
wait_for_device(v->device);
FILE* f = fopen(v->device, "wb");
if (f == NULL) {
LOGE("Can't open %s\n(%s)\n", v->device, strerror(errno));