platform_system_core/vold/blkdev.c

324 lines
8.2 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 <stdlib.h>
#include <string.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <linux/fs.h>
#include <linux/msdos_fs.h>
#include "vold.h"
#include "blkdev.h"
#include "diskmbr.h"
#define DEBUG_BLKDEV 0
static blkdev_list_t *list_root = NULL;
static blkdev_t *_blkdev_create(blkdev_t *disk, char *devpath, int major,
int minor, char *type, struct media *media);
static int fat_valid_media(unsigned char media)
{
return 0xf8 <= media || media == 0xf0;
}
char *blkdev_get_devpath(blkdev_t *blk)
{
char *dp = malloc(256);
sprintf(dp, "%s/vold/%d:%d", DEVPATH, blk->major, blk->minor);
return dp;
}
int blkdev_refresh(blkdev_t *blk)
{
int fd = 0;
char *devpath = NULL;
unsigned char *block = NULL;
int i, rc;
if (!(block = malloc(512)))
goto out;
/*
* Get the device size
*/
devpath = blkdev_get_devpath(blk);
if ((fd = open(devpath, O_RDONLY)) < 0) {
LOGE("Unable to open device '%s' (%s)", devpath, strerror(errno));
return -errno;
}
if (ioctl(fd, BLKGETSIZE, &blk->nr_sec)) {
LOGE("Unable to get device size (%m)");
return -errno;
}
close(fd);
free(devpath);
/*
* Open the disk partition table
*/
devpath = blkdev_get_devpath(blk->disk);
if ((fd = open(devpath, O_RDONLY)) < 0) {
LOGE("Unable to open device '%s' (%s)", devpath,
strerror(errno));
free(devpath);
return -errno;
}
free(devpath);
if ((rc = read(fd, block, 512)) != 512) {
LOGE("Unable to read device partition table (%d, %s)",
rc, strerror(errno));
goto out;
}
/*
* If we're a disk, then process the partition table. Otherwise we're
* a partition so get the partition type
*/
if (blk->type == blkdev_disk) {
blk->nr_parts = 0;
if ((block[0x1fe] != 0x55) || (block[0x1ff] != 0xAA)) {
LOGI("Disk %d:%d does not contain a partition table",
blk->major, blk->minor);
goto out;
}
for (i = 0; i < 4; i++) {
struct dos_partition part;
dos_partition_dec(block + DOSPARTOFF + i * sizeof(struct dos_partition), &part);
if (part.dp_flag != 0 && part.dp_flag != 0x80) {
struct fat_boot_sector *fb = (struct fat_boot_sector *) &block[0];
if (!i && fb->reserved && fb->fats && fat_valid_media(fb->media)) {
LOGI("Detected FAT filesystem in partition table");
break;
} else {
LOGI("Partition table looks corrupt");
break;
}
}
if (part.dp_size != 0 && part.dp_typ != 0)
blk->nr_parts++;
}
} else if (blk->type == blkdev_partition) {
struct dos_partition part;
int part_no = blk->minor -1;
if (part_no < 4) {
dos_partition_dec(block + DOSPARTOFF + part_no * sizeof(struct dos_partition), &part);
blk->part_type = part.dp_typ;
} else {
LOGW("Skipping partition %d", part_no);
}
}
out:
if (block)
free(block);
char tmp[255];
char tmp2[32];
sprintf(tmp, "%s (blkdev %d:%d), %u secs (%u MB)",
(blk->type == blkdev_disk ? "Disk" : "Partition"),
blk->major, blk->minor,
blk->nr_sec,
(uint32_t) (((uint64_t) blk->nr_sec * 512) / 1024) / 1024);
if (blk->type == blkdev_disk)
sprintf(tmp2, " %d partitions", blk->nr_parts);
else
sprintf(tmp2, " type 0x%x", blk->part_type);
strcat(tmp, tmp2);
LOGI(tmp);
close(fd);
return 0;
}
blkdev_t *blkdev_create(blkdev_t *disk, char *devpath, int major, int minor, struct media *media, char *type)
{
return _blkdev_create(disk, devpath, major, minor, type, media);
}
static blkdev_t *_blkdev_create(blkdev_t *disk, char *devpath, int major,
int minor, char *type, struct media *media)
{
blkdev_t *new;
struct blkdev_list *list_entry;
if (disk && disk->type != blkdev_disk) {
LOGE("Non disk parent specified for blkdev!");
return NULL;
}
if (!(new = malloc(sizeof(blkdev_t))))
return NULL;
memset(new, 0, sizeof(blkdev_t));
if (!(list_entry = malloc(sizeof(struct blkdev_list)))) {
free (new);
return NULL;
}
list_entry->dev = new;
list_entry->next = NULL;
if (!list_root)
list_root = list_entry;
else {
struct blkdev_list *list_scan = list_root;
while (list_scan->next)
list_scan = list_scan->next;
list_scan->next = list_entry;
}
if (devpath)
new->devpath = strdup(devpath);
new->major = major;
new->minor = minor;
new->media = media;
new->nr_sec = 0xffffffff;
if (disk)
new->disk = disk;
else
new->disk = new; // Note the self disk pointer
/* Create device nodes */
char nodepath[255];
mode_t mode = 0666 | S_IFBLK;
dev_t dev = (major << 8) | minor;
sprintf(nodepath, "%s/vold/%d:%d", DEVPATH, major, minor);
if (mknod(nodepath, mode, dev) < 0) {
LOGE("Error making device nodes for '%s' (%s)",
nodepath, strerror(errno));
}
if (!strcmp(type, "disk"))
new->type = blkdev_disk;
else if (!strcmp(type, "partition"))
new->type = blkdev_partition;
else {
LOGE("Unknown block device type '%s'", type);
new->type = blkdev_unknown;
}
return new;
}
void blkdev_destroy(blkdev_t *blkdev)
{
struct blkdev_list *list_next;
if (list_root->dev == blkdev) {
list_next = list_root->next;
free (list_root);
list_root = list_next;
} else {
struct blkdev_list *list_scan = list_root;
while (list_scan->next->dev != blkdev)
list_scan = list_scan -> next;
list_next = list_scan->next->next;
free(list_scan->next);
list_scan->next = list_next;
}
if (blkdev->devpath)
free(blkdev->devpath);
char nodepath[255];
sprintf(nodepath, "%s/vold/%d:%d", DEVPATH, blkdev->major, blkdev->minor);
unlink(nodepath);
free(blkdev);
}
blkdev_t *blkdev_lookup_by_path(char *devpath)
{
struct blkdev_list *list_scan = list_root;
while (list_scan) {
if (!strcmp(list_scan->dev->devpath, devpath))
return list_scan->dev;
list_scan = list_scan->next;
}
return NULL;
}
blkdev_t *blkdev_lookup_by_devno(int maj, int min)
{
struct blkdev_list *list_scan = list_root;
while (list_scan) {
if ((list_scan->dev->major == maj) &&
(list_scan->dev->minor == min))
return list_scan->dev;
list_scan = list_scan->next;
}
return NULL;
}
/*
* Given a disk device, return the number of partitions which
* have yet to be processed.
*/
int blkdev_get_num_pending_partitions(blkdev_t *blk)
{
struct blkdev_list *list_scan = list_root;
int num = blk->nr_parts;
if (blk->type != blkdev_disk)
return -EINVAL;
while (list_scan) {
if (list_scan->dev->type != blkdev_partition)
goto next;
if (list_scan->dev->major != blk->major)
goto next;
if (list_scan->dev->nr_sec != 0xffffffff &&
list_scan->dev->devpath) {
num--;
}
next:
list_scan = list_scan->next;
}
return num;
}