vold/blkdev.c - third_party/android/platform/system/core - Git at Google


 /*
  * 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 (%s)", strerror(errno));
         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 = 0660 | 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;
 }

	/*
	* 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 (%s)", strerror(errno));
	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 = 0660 \| 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;
	}