platform_system_core/adb/remount_service.c
2009-03-03 19:32:55 -08:00

103 lines
2.4 KiB
C

/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <sys/mount.h>
#include <errno.h>
#include "sysdeps.h"
#define TRACE_TAG TRACE_ADB
#include "adb.h"
static int system_ro = 1;
/* Returns the mount number of the requested partition from /proc/mtd */
static int find_mount(const char *findme)
{
int fd;
int res;
int size;
char *token = NULL;
const char delims[] = "\n";
char buf[1024];
fd = unix_open("/proc/mtd", O_RDONLY);
if (fd < 0)
return -errno;
buf[sizeof(buf) - 1] = '\0';
size = adb_read(fd, buf, sizeof(buf) - 1);
adb_close(fd);
token = strtok(buf, delims);
while (token) {
char mtdname[16];
int mtdnum, mtdsize, mtderasesize;
res = sscanf(token, "mtd%d: %x %x %15s",
&mtdnum, &mtdsize, &mtderasesize, mtdname);
if (res == 4 && !strcmp(mtdname, findme))
return mtdnum;
token = strtok(NULL, delims);
}
return -1;
}
/* Init mounts /system as read only, remount to enable writes. */
static int remount_system()
{
int num;
char source[64];
if (system_ro == 0) {
return 0;
}
if ((num = find_mount("\"system\"")) < 0)
return -1;
snprintf(source, sizeof source, "/dev/block/mtdblock%d", num);
system_ro = mount(source, "/system", "yaffs2", MS_REMOUNT, NULL);
return system_ro;
}
static void write_string(int fd, const char* str)
{
writex(fd, str, strlen(str));
}
void remount_service(int fd, void *cookie)
{
int ret = remount_system();
if (!ret)
write_string(fd, "remount succeeded\n");
else {
char buffer[200];
snprintf(buffer, sizeof(buffer), "remount failed: %s\n", strerror(errno));
write_string(fd, buffer);
}
adb_close(fd);
}