platform_system_core/vold/volmgr_vfat.c

150 lines
4.2 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 <errno.h>
#include <sys/mount.h>
#include "vold.h"
#include "volmgr.h"
#include "volmgr_vfat.h"
#include "logwrapper.h"
#define VFAT_DEBUG 0
static char FSCK_MSDOS_PATH[] = "/system/bin/fsck_msdos";
int vfat_identify(blkdev_t *dev)
{
#if VFAT_DEBUG
LOG_VOL("vfat_identify(%d:%d):", dev->major, dev->minor);
#endif
return 0; // XXX: Implement
}
int vfat_check(blkdev_t *dev)
{
int rc;
boolean rw = true;
#if VFAT_DEBUG
LOG_VOL("vfat_check(%d:%d):", dev->major, dev->minor);
#endif
if (access(FSCK_MSDOS_PATH, X_OK)) {
LOGE("vfat_check(%d:%d): %s not found (skipping checks)",
dev->major, dev->minor, FSCK_MSDOS_PATH);
return 0;
}
int pass = 1;
do {
char *args[5];
args[0] = FSCK_MSDOS_PATH;
args[1] = "-p";
args[2] = "-f";
args[3] = blkdev_get_devpath(dev);
args[4] = NULL;
rc = logwrap(4, args, 1);
free(args[3]);
if (rc == 0) {
LOG_VOL("Filesystem check completed OK");
return 0;
} else if (rc == 2) {
LOG_VOL("Filesystem check failed (not a FAT filesystem)");
return -ENODATA;
} else if (rc == 4) {
if (pass++ <= 3) {
LOG_VOL("Filesystem modified - rechecking (pass %d)",
pass);
continue;
} else {
LOG_VOL("Failing check after too many rechecks");
return -EIO;
}
} else if (rc == -11) {
LOG_VOL("Filesystem check crashed");
return -EIO;
} else {
LOG_VOL("Filesystem check failed (unknown exit code %d)", rc);
return -EIO;
}
} while (0);
return 0;
}
int vfat_mount(blkdev_t *dev, volume_t *vol, boolean safe_mode)
{
int flags, rc;
char *devpath;
devpath = blkdev_get_devpath(dev);
#if VFAT_DEBUG
LOG_VOL("vfat_mount(%d:%d, %s, %d):", dev->major, dev->minor, vol->mount_point, safe_mode);
#endif
flags = MS_NODEV | MS_NOEXEC | MS_NOSUID | MS_DIRSYNC;
if (vol->state == volstate_mounted) {
LOG_VOL("Remounting %d:%d on %s, safe mode %d", dev->major,
dev->minor, vol->mount_point, safe_mode);
flags |= MS_REMOUNT;
}
/*
* The mount masks restrict access so that:
* 1. The 'system' user cannot access the SD card at all -
* (protects system_server from grabbing file references)
* 2. Group users can RWX
* 3. Others can only RX
*/
rc = mount(devpath, vol->mount_point, "vfat", flags,
"utf8,uid=1000,gid=1015,fmask=702,dmask=702,shortname=mixed");
if (rc && errno == EROFS) {
LOGE("vfat_mount(%d:%d, %s): Read only filesystem - retrying mount RO",
dev->major, dev->minor, vol->mount_point);
flags |= MS_RDONLY;
rc = mount(devpath, vol->mount_point, "vfat", flags,
"utf8,uid=1000,gid=1015,fmask=702,dmask=702,shortname=mixed");
}
if (rc == 0) {
char *lost_path;
asprintf(&lost_path, "%s/LOST.DIR", vol->mount_point);
if (access(lost_path, F_OK)) {
/*
* Create a LOST.DIR in the root so we have somewhere to put
* lost cluster chains (fsck_msdos doesn't currently do this)
*/
if (mkdir(lost_path, 0755)) {
LOGE("Unable to create LOST.DIR (%s)", strerror(errno));
}
}
free(lost_path);
}
#if VFAT_DEBUG
LOG_VOL("vfat_mount(%s, %d:%d): mount rc = %d", dev->major,k dev->minor,
vol->mount_point, rc);
#endif
free (devpath);
return rc;
}