fs/partitions/check.c - kernel/msm-4.9 - Gitiles

 /*
  *  fs/partitions/check.c
  *
  *  Code extracted from drivers/block/genhd.c
  *  Copyright (C) 1991-1998  Linus Torvalds
  *  Re-organised Feb 1998 Russell King
  *
  *  We now have independent partition support from the
  *  block drivers, which allows all the partition code to
  *  be grouped in one location, and it to be mostly self
  *  contained.
  *
  *  Added needed MAJORS for new pairs, {hdi,hdj}, {hdk,hdl}
  */

 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/fs.h>
 #include <linux/kmod.h>
 #include <linux/ctype.h>
 #include <linux/genhd.h>

 #include "check.h"

 #include "acorn.h"
 #include "amiga.h"
 #include "atari.h"
 #include "ldm.h"
 #include "mac.h"
 #include "msdos.h"
 #include "osf.h"
 #include "sgi.h"
 #include "sun.h"
 #include "ibm.h"
 #include "ultrix.h"
 #include "efi.h"
 #include "karma.h"
 #include "sysv68.h"

 #ifdef CONFIG_BLK_DEV_MD
 extern void md_autodetect_dev(dev_t dev);
 #endif

 int warn_no_part = 1; /*This is ugly: should make genhd removable media aware*/

 static int (*check_part[])(struct parsed_partitions *, struct block_device *) = {
 	/*
 	 * Probe partition formats with tables at disk address 0
 	 * that also have an ADFS boot block at 0xdc0.
 	 */
 #ifdef CONFIG_ACORN_PARTITION_ICS
 	adfspart_check_ICS,
 #endif
 #ifdef CONFIG_ACORN_PARTITION_POWERTEC
 	adfspart_check_POWERTEC,
 #endif
 #ifdef CONFIG_ACORN_PARTITION_EESOX
 	adfspart_check_EESOX,
 #endif

 	/*
 	 * Now move on to formats that only have partition info at
 	 * disk address 0xdc0.  Since these may also have stale
 	 * PC/BIOS partition tables, they need to come before
 	 * the msdos entry.
 	 */
 #ifdef CONFIG_ACORN_PARTITION_CUMANA
 	adfspart_check_CUMANA,
 #endif
 #ifdef CONFIG_ACORN_PARTITION_ADFS
 	adfspart_check_ADFS,
 #endif

 #ifdef CONFIG_EFI_PARTITION
 	efi_partition,		/* this must come before msdos */
 #endif
 #ifdef CONFIG_SGI_PARTITION
 	sgi_partition,
 #endif
 #ifdef CONFIG_LDM_PARTITION
 	ldm_partition,		/* this must come before msdos */
 #endif
 #ifdef CONFIG_MSDOS_PARTITION
 	msdos_partition,
 #endif
 #ifdef CONFIG_OSF_PARTITION
 	osf_partition,
 #endif
 #ifdef CONFIG_SUN_PARTITION
 	sun_partition,
 #endif
 #ifdef CONFIG_AMIGA_PARTITION
 	amiga_partition,
 #endif
 #ifdef CONFIG_ATARI_PARTITION
 	atari_partition,
 #endif
 #ifdef CONFIG_MAC_PARTITION
 	mac_partition,
 #endif
 #ifdef CONFIG_ULTRIX_PARTITION
 	ultrix_partition,
 #endif
 #ifdef CONFIG_IBM_PARTITION
 	ibm_partition,
 #endif
 #ifdef CONFIG_KARMA_PARTITION
 	karma_partition,
 #endif
 #ifdef CONFIG_SYSV68_PARTITION
 	sysv68_partition,
 #endif
 	NULL
 };

 /*
  * disk_name() is used by partition check code and the genhd driver.
  * It formats the devicename of the indicated disk into
  * the supplied buffer (of size at least 32), and returns
  * a pointer to that same buffer (for convenience).
  */

 char *disk_name(struct gendisk *hd, int part, char *buf)
 {
 	if (!part)
 		snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
 	else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
 		snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, part);
 	else
 		snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, part);

 	return buf;
 }

 const char *bdevname(struct block_device *bdev, char *buf)
 {
 	int part = MINOR(bdev->bd_dev) - bdev->bd_disk->first_minor;
 	return disk_name(bdev->bd_disk, part, buf);
 }

 EXPORT_SYMBOL(bdevname);

 /*
  * There's very little reason to use this, you should really
  * have a struct block_device just about everywhere and use
  * bdevname() instead.
  */
 const char *__bdevname(dev_t dev, char *buffer)
 {
 	scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)",
 				MAJOR(dev), MINOR(dev));
 	return buffer;
 }

 EXPORT_SYMBOL(__bdevname);

 static struct parsed_partitions *
 check_partition(struct gendisk *hd, struct block_device *bdev)
 {
 	struct parsed_partitions *state;
 	int i, res, err;

 	state = kmalloc(sizeof(struct parsed_partitions), GFP_KERNEL);
 	if (!state)
 		return NULL;

 	disk_name(hd, 0, state->name);
 	printk(KERN_INFO " %s:", state->name);
 	if (isdigit(state->name[strlen(state->name)-1]))
 		sprintf(state->name, "p");

 	state->limit = hd->minors;
 	i = res = err = 0;
 	while (!res && check_part[i]) {
 		memset(&state->parts, 0, sizeof(state->parts));
 		res = check_part[i++](state, bdev);
 		if (res < 0) {
 			/* We have hit an I/O error which we don't report now.
 		 	* But record it, and let the others do their job.
 		 	*/
 			err = res;
 			res = 0;
 		}

 	}
 	if (res > 0)
 		return state;
 	if (err)
 	/* The partition is unrecognized. So report I/O errors if there were any */
 		res = err;
 	if (!res)
 		printk(" unknown partition table\n");
 	else if (warn_no_part)
 		printk(" unable to read partition table\n");
 	kfree(state);
 	return ERR_PTR(res);
 }

 static ssize_t part_start_show(struct device *dev,
 			       struct device_attribute *attr, char *buf)
 {
 	struct hd_struct *p = dev_to_part(dev);

 	return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect);
 }

 static ssize_t part_size_show(struct device *dev,
 			      struct device_attribute *attr, char *buf)
 {
 	struct hd_struct *p = dev_to_part(dev);
 	return sprintf(buf, "%llu\n",(unsigned long long)p->nr_sects);
 }

 static ssize_t part_stat_show(struct device *dev,
 			      struct device_attribute *attr, char *buf)
 {
 	struct hd_struct *p = dev_to_part(dev);

 	preempt_disable();
 	part_round_stats(p);
 	preempt_enable();
 	return sprintf(buf,
 		"%8lu %8lu %8llu %8u "
 		"%8lu %8lu %8llu %8u "
 		"%8u %8u %8u"
 		"\n",
 		part_stat_read(p, ios[READ]),
 		part_stat_read(p, merges[READ]),
 		(unsigned long long)part_stat_read(p, sectors[READ]),
 		jiffies_to_msecs(part_stat_read(p, ticks[READ])),
 		part_stat_read(p, ios[WRITE]),
 		part_stat_read(p, merges[WRITE]),
 		(unsigned long long)part_stat_read(p, sectors[WRITE]),
 		jiffies_to_msecs(part_stat_read(p, ticks[WRITE])),
 		p->in_flight,
 		jiffies_to_msecs(part_stat_read(p, io_ticks)),
 		jiffies_to_msecs(part_stat_read(p, time_in_queue)));
 }

 #ifdef CONFIG_FAIL_MAKE_REQUEST
 static ssize_t part_fail_show(struct device *dev,
 			      struct device_attribute *attr, char *buf)
 {
 	struct hd_struct *p = dev_to_part(dev);

 	return sprintf(buf, "%d\n", p->make_it_fail);
 }

 static ssize_t part_fail_store(struct device *dev,
 			       struct device_attribute *attr,
 			       const char *buf, size_t count)
 {
 	struct hd_struct *p = dev_to_part(dev);
 	int i;

 	if (count > 0 && sscanf(buf, "%d", &i) > 0)
 		p->make_it_fail = (i == 0) ? 0 : 1;

 	return count;
 }
 #endif

 static DEVICE_ATTR(start, S_IRUGO, part_start_show, NULL);
 static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
 static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
 #ifdef CONFIG_FAIL_MAKE_REQUEST
 static struct device_attribute dev_attr_fail =
 	__ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
 #endif

 static struct attribute *part_attrs[] = {
 	&dev_attr_start.attr,
 	&dev_attr_size.attr,
 	&dev_attr_stat.attr,
 #ifdef CONFIG_FAIL_MAKE_REQUEST
 	&dev_attr_fail.attr,
 #endif
 	NULL
 };

 static struct attribute_group part_attr_group = {
 	.attrs = part_attrs,
 };

 static struct attribute_group *part_attr_groups[] = {
 	&part_attr_group,
 	NULL
 };

 static void part_release(struct device *dev)
 {
 	struct hd_struct *p = dev_to_part(dev);
 	free_part_stats(p);
 	kfree(p);
 }

 struct device_type part_type = {
 	.name		= "partition",
 	.groups		= part_attr_groups,
 	.release	= part_release,
 };

 static inline void partition_sysfs_add_subdir(struct hd_struct *p)
 {
 	struct kobject *k;

 	k = kobject_get(&p->dev.kobj);
 	p->holder_dir = kobject_create_and_add("holders", k);
 	kobject_put(k);
 }

 static inline void disk_sysfs_add_subdirs(struct gendisk *disk)
 {
 	struct kobject *k;

 	k = kobject_get(&disk->dev.kobj);
 	disk->holder_dir = kobject_create_and_add("holders", k);
 	disk->slave_dir = kobject_create_and_add("slaves", k);
 	kobject_put(k);
 }

 void delete_partition(struct gendisk *disk, int part)
 {
 	struct hd_struct *p = disk->part[part-1];

 	if (!p)
 		return;
 	if (!p->nr_sects)
 		return;
 	disk->part[part-1] = NULL;
 	p->start_sect = 0;
 	p->nr_sects = 0;
 	part_stat_set_all(p, 0);
 	kobject_put(p->holder_dir);
 	device_del(&p->dev);
 	put_device(&p->dev);
 }

 static ssize_t whole_disk_show(struct device *dev,
 			       struct device_attribute *attr, char *buf)
 {
 	return 0;
 }
 static DEVICE_ATTR(whole_disk, S_IRUSR | S_IRGRP | S_IROTH,
 		   whole_disk_show, NULL);

 void add_partition(struct gendisk *disk, int part, sector_t start, sector_t len, int flags)
 {
 	struct hd_struct *p;
 	int err;

 	p = kzalloc(sizeof(*p), GFP_KERNEL);
 	if (!p)
 		return;

 	if (!init_part_stats(p)) {
 		kfree(p);
 		return;
 	}
 	p->start_sect = start;
 	p->nr_sects = len;
 	p->partno = part;
 	p->policy = disk->policy;

 	if (isdigit(disk->dev.bus_id[strlen(disk->dev.bus_id)-1]))
 		snprintf(p->dev.bus_id, BUS_ID_SIZE,
 		"%sp%d", disk->dev.bus_id, part);
 	else
 		snprintf(p->dev.bus_id, BUS_ID_SIZE,
 			 "%s%d", disk->dev.bus_id, part);

 	device_initialize(&p->dev);
 	p->dev.devt = MKDEV(disk->major, disk->first_minor + part);
 	p->dev.class = &block_class;
 	p->dev.type = &part_type;
 	p->dev.parent = &disk->dev;
 	disk->part[part-1] = p;

 	/* delay uevent until 'holders' subdir is created */
 	p->dev.uevent_suppress = 1;
 	device_add(&p->dev);
 	partition_sysfs_add_subdir(p);
 	p->dev.uevent_suppress = 0;
 	if (flags & ADDPART_FLAG_WHOLEDISK)
 		err = device_create_file(&p->dev, &dev_attr_whole_disk);

 	/* suppress uevent if the disk supresses it */
 	if (!disk->dev.uevent_suppress)
 		kobject_uevent(&p->dev.kobj, KOBJ_ADD);
 }

 /* Not exported, helper to add_disk(). */
 void register_disk(struct gendisk *disk)
 {
 	struct block_device *bdev;
 	char *s;
 	int i;
 	struct hd_struct *p;
 	int err;

 	disk->dev.parent = disk->driverfs_dev;
 	disk->dev.devt = MKDEV(disk->major, disk->first_minor);

 	strlcpy(disk->dev.bus_id, disk->disk_name, KOBJ_NAME_LEN);
 	/* ewww... some of these buggers have / in the name... */
 	s = strchr(disk->dev.bus_id, '/');
 	if (s)
 		*s = '!';

 	/* delay uevents, until we scanned partition table */
 	disk->dev.uevent_suppress = 1;

 	if (device_add(&disk->dev))
 		return;
 #ifndef CONFIG_SYSFS_DEPRECATED
 	err = sysfs_create_link(block_depr, &disk->dev.kobj,
 				kobject_name(&disk->dev.kobj));
 	if (err) {
 		device_del(&disk->dev);
 		return;
 	}
 #endif
 	disk_sysfs_add_subdirs(disk);

 	/* No minors to use for partitions */
 	if (disk->minors == 1)
 		goto exit;

 	/* No such device (e.g., media were just removed) */
 	if (!get_capacity(disk))
 		goto exit;

 	bdev = bdget_disk(disk, 0);
 	if (!bdev)
 		goto exit;

 	bdev->bd_invalidated = 1;
 	err = blkdev_get(bdev, FMODE_READ, 0);
 	if (err < 0)
 		goto exit;
 	blkdev_put(bdev);

 exit:
 	/* announce disk after possible partitions are created */
 	disk->dev.uevent_suppress = 0;
 	kobject_uevent(&disk->dev.kobj, KOBJ_ADD);

 	/* announce possible partitions */
 	for (i = 1; i < disk->minors; i++) {
 		p = disk->part[i-1];
 		if (!p || !p->nr_sects)
 			continue;
 		kobject_uevent(&p->dev.kobj, KOBJ_ADD);
 	}
 }

 int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 {
 	struct parsed_partitions *state;
 	int p, res;

 	if (bdev->bd_part_count)
 		return -EBUSY;
 	res = invalidate_partition(disk, 0);
 	if (res)
 		return res;
 	bdev->bd_invalidated = 0;
 	for (p = 1; p < disk->minors; p++)
 		delete_partition(disk, p);
 	if (disk->fops->revalidate_disk)
 		disk->fops->revalidate_disk(disk);
 	if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
 		return 0;
 	if (IS_ERR(state))	/* I/O error reading the partition table */
 		return -EIO;

 	/* tell userspace that the media / partition table may have changed */
 	kobject_uevent(&disk->dev.kobj, KOBJ_CHANGE);

 	for (p = 1; p < state->limit; p++) {
 		sector_t size = state->parts[p].size;
 		sector_t from = state->parts[p].from;
 		if (!size)
 			continue;
 		if (from + size > get_capacity(disk)) {
 			printk(" %s: p%d exceeds device capacity\n",
 				disk->disk_name, p);
 		}
 		add_partition(disk, p, from, size, state->parts[p].flags);
 #ifdef CONFIG_BLK_DEV_MD
 		if (state->parts[p].flags & ADDPART_FLAG_RAID)
 			md_autodetect_dev(bdev->bd_dev+p);
 #endif
 	}
 	kfree(state);
 	return 0;
 }

 unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
 {
 	struct address_space *mapping = bdev->bd_inode->i_mapping;
 	struct page *page;

 	page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
 				 NULL);
 	if (!IS_ERR(page)) {
 		if (PageError(page))
 			goto fail;
 		p->v = page;
 		return (unsigned char *)page_address(page) +  ((n & ((1 << (PAGE_CACHE_SHIFT - 9)) - 1)) << 9);
 fail:
 		page_cache_release(page);
 	}
 	p->v = NULL;
 	return NULL;
 }

 EXPORT_SYMBOL(read_dev_sector);

 void del_gendisk(struct gendisk *disk)
 {
 	int p;

 	/* invalidate stuff */
 	for (p = disk->minors - 1; p > 0; p--) {
 		invalidate_partition(disk, p);
 		delete_partition(disk, p);
 	}
 	invalidate_partition(disk, 0);
 	disk->capacity = 0;
 	disk->flags &= ~GENHD_FL_UP;
 	unlink_gendisk(disk);
 	disk_stat_set_all(disk, 0);
 	disk->stamp = 0;

 	kobject_put(disk->holder_dir);
 	kobject_put(disk->slave_dir);
 	disk->driverfs_dev = NULL;
 #ifndef CONFIG_SYSFS_DEPRECATED
 	sysfs_remove_link(block_depr, disk->dev.bus_id);
 #endif
 	device_del(&disk->dev);
 }
	/*
	* fs/partitions/check.c
	*
	* Code extracted from drivers/block/genhd.c
	* Copyright (C) 1991-1998 Linus Torvalds
	* Re-organised Feb 1998 Russell King
	*
	* We now have independent partition support from the
	* block drivers, which allows all the partition code to
	* be grouped in one location, and it to be mostly self
	* contained.
	*
	* Added needed MAJORS for new pairs, {hdi,hdj}, {hdk,hdl}
	*/

	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/fs.h>
	#include <linux/kmod.h>
	#include <linux/ctype.h>
	#include <linux/genhd.h>

	#include "check.h"

	#include "acorn.h"
	#include "amiga.h"
	#include "atari.h"
	#include "ldm.h"
	#include "mac.h"
	#include "msdos.h"
	#include "osf.h"
	#include "sgi.h"
	#include "sun.h"
	#include "ibm.h"
	#include "ultrix.h"
	#include "efi.h"
	#include "karma.h"
	#include "sysv68.h"

	#ifdef CONFIG_BLK_DEV_MD
	extern void md_autodetect_dev(dev_t dev);
	#endif

	int warn_no_part = 1; /This is ugly: should make genhd removable media aware/

	static int (check_part[])(struct parsed_partitions , struct block_device *) = {
	/*
	* Probe partition formats with tables at disk address 0
	* that also have an ADFS boot block at 0xdc0.
	*/
	#ifdef CONFIG_ACORN_PARTITION_ICS
	adfspart_check_ICS,
	#endif
	#ifdef CONFIG_ACORN_PARTITION_POWERTEC
	adfspart_check_POWERTEC,
	#endif
	#ifdef CONFIG_ACORN_PARTITION_EESOX
	adfspart_check_EESOX,
	#endif

	/*
	* Now move on to formats that only have partition info at
	* disk address 0xdc0. Since these may also have stale
	* PC/BIOS partition tables, they need to come before
	* the msdos entry.
	*/
	#ifdef CONFIG_ACORN_PARTITION_CUMANA
	adfspart_check_CUMANA,
	#endif
	#ifdef CONFIG_ACORN_PARTITION_ADFS
	adfspart_check_ADFS,
	#endif

	#ifdef CONFIG_EFI_PARTITION
	efi_partition, /* this must come before msdos */
	#endif
	#ifdef CONFIG_SGI_PARTITION
	sgi_partition,
	#endif
	#ifdef CONFIG_LDM_PARTITION
	ldm_partition, /* this must come before msdos */
	#endif
	#ifdef CONFIG_MSDOS_PARTITION
	msdos_partition,
	#endif
	#ifdef CONFIG_OSF_PARTITION
	osf_partition,
	#endif
	#ifdef CONFIG_SUN_PARTITION
	sun_partition,
	#endif
	#ifdef CONFIG_AMIGA_PARTITION
	amiga_partition,
	#endif
	#ifdef CONFIG_ATARI_PARTITION
	atari_partition,
	#endif
	#ifdef CONFIG_MAC_PARTITION
	mac_partition,
	#endif
	#ifdef CONFIG_ULTRIX_PARTITION
	ultrix_partition,
	#endif
	#ifdef CONFIG_IBM_PARTITION
	ibm_partition,
	#endif
	#ifdef CONFIG_KARMA_PARTITION
	karma_partition,
	#endif
	#ifdef CONFIG_SYSV68_PARTITION
	sysv68_partition,
	#endif
	NULL
	};

	/*
	* disk_name() is used by partition check code and the genhd driver.
	* It formats the devicename of the indicated disk into
	* the supplied buffer (of size at least 32), and returns
	* a pointer to that same buffer (for convenience).
	*/

	char disk_name(struct gendisk hd, int part, char *buf)
	{
	if (!part)
	snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
	else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
	snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, part);
	else
	snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, part);

	return buf;
	}

	const char bdevname(struct block_device bdev, char *buf)
	{
	int part = MINOR(bdev->bd_dev) - bdev->bd_disk->first_minor;
	return disk_name(bdev->bd_disk, part, buf);
	}

	EXPORT_SYMBOL(bdevname);

	/*
	* There's very little reason to use this, you should really
	* have a struct block_device just about everywhere and use
	* bdevname() instead.
	*/
	const char __bdevname(dev_t dev, char buffer)
	{
	scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)",
	MAJOR(dev), MINOR(dev));
	return buffer;
	}

	EXPORT_SYMBOL(__bdevname);

	static struct parsed_partitions *
	check_partition(struct gendisk hd, struct block_device bdev)
	{
	struct parsed_partitions *state;
	int i, res, err;

	state = kmalloc(sizeof(struct parsed_partitions), GFP_KERNEL);
	if (!state)
	return NULL;

	disk_name(hd, 0, state->name);
	printk(KERN_INFO " %s:", state->name);
	if (isdigit(state->name[strlen(state->name)-1]))
	sprintf(state->name, "p");

	state->limit = hd->minors;
	i = res = err = 0;
	while (!res && check_part[i]) {
	memset(&state->parts, 0, sizeof(state->parts));
	res = check_part[i++](state, bdev);
	if (res < 0) {
	/* We have hit an I/O error which we don't report now.
	* But record it, and let the others do their job.
	*/
	err = res;
	res = 0;
	}

	}
	if (res > 0)
	return state;
	if (err)
	/* The partition is unrecognized. So report I/O errors if there were any */
	res = err;
	if (!res)
	printk(" unknown partition table\n");
	else if (warn_no_part)
	printk(" unable to read partition table\n");
	kfree(state);
	return ERR_PTR(res);
	}

	static ssize_t part_start_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct hd_struct *p = dev_to_part(dev);

	return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect);
	}

	static ssize_t part_size_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct hd_struct *p = dev_to_part(dev);
	return sprintf(buf, "%llu\n",(unsigned long long)p->nr_sects);
	}

	static ssize_t part_stat_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct hd_struct *p = dev_to_part(dev);

	preempt_disable();
	part_round_stats(p);
	preempt_enable();
	return sprintf(buf,
	"%8lu %8lu %8llu %8u "
	"%8lu %8lu %8llu %8u "
	"%8u %8u %8u"
	"\n",
	part_stat_read(p, ios[READ]),
	part_stat_read(p, merges[READ]),
	(unsigned long long)part_stat_read(p, sectors[READ]),
	jiffies_to_msecs(part_stat_read(p, ticks[READ])),
	part_stat_read(p, ios[WRITE]),
	part_stat_read(p, merges[WRITE]),
	(unsigned long long)part_stat_read(p, sectors[WRITE]),
	jiffies_to_msecs(part_stat_read(p, ticks[WRITE])),
	p->in_flight,
	jiffies_to_msecs(part_stat_read(p, io_ticks)),
	jiffies_to_msecs(part_stat_read(p, time_in_queue)));
	}

	#ifdef CONFIG_FAIL_MAKE_REQUEST
	static ssize_t part_fail_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct hd_struct *p = dev_to_part(dev);

	return sprintf(buf, "%d\n", p->make_it_fail);
	}

	static ssize_t part_fail_store(struct device *dev,
	struct device_attribute *attr,
	const char *buf, size_t count)
	{
	struct hd_struct *p = dev_to_part(dev);
	int i;

	if (count > 0 && sscanf(buf, "%d", &i) > 0)
	p->make_it_fail = (i == 0) ? 0 : 1;

	return count;
	}
	#endif

	static DEVICE_ATTR(start, S_IRUGO, part_start_show, NULL);
	static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
	static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
	#ifdef CONFIG_FAIL_MAKE_REQUEST
	static struct device_attribute dev_attr_fail =
	__ATTR(make-it-fail, S_IRUGO\|S_IWUSR, part_fail_show, part_fail_store);
	#endif

	static struct attribute *part_attrs[] = {
	&dev_attr_start.attr,
	&dev_attr_size.attr,
	&dev_attr_stat.attr,
	#ifdef CONFIG_FAIL_MAKE_REQUEST
	&dev_attr_fail.attr,
	#endif
	NULL
	};

	static struct attribute_group part_attr_group = {
	.attrs = part_attrs,
	};

	static struct attribute_group *part_attr_groups[] = {
	&part_attr_group,
	NULL
	};

	static void part_release(struct device *dev)
	{
	struct hd_struct *p = dev_to_part(dev);
	free_part_stats(p);
	kfree(p);
	}

	struct device_type part_type = {
	.name = "partition",
	.groups = part_attr_groups,
	.release = part_release,
	};

	static inline void partition_sysfs_add_subdir(struct hd_struct *p)
	{
	struct kobject *k;

	k = kobject_get(&p->dev.kobj);
	p->holder_dir = kobject_create_and_add("holders", k);
	kobject_put(k);
	}

	static inline void disk_sysfs_add_subdirs(struct gendisk *disk)
	{
	struct kobject *k;

	k = kobject_get(&disk->dev.kobj);
	disk->holder_dir = kobject_create_and_add("holders", k);
	disk->slave_dir = kobject_create_and_add("slaves", k);
	kobject_put(k);
	}

	void delete_partition(struct gendisk *disk, int part)
	{
	struct hd_struct *p = disk->part[part-1];

	if (!p)
	return;
	if (!p->nr_sects)
	return;
	disk->part[part-1] = NULL;
	p->start_sect = 0;
	p->nr_sects = 0;
	part_stat_set_all(p, 0);
	kobject_put(p->holder_dir);
	device_del(&p->dev);
	put_device(&p->dev);
	}

	static ssize_t whole_disk_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	return 0;
	}
	static DEVICE_ATTR(whole_disk, S_IRUSR \| S_IRGRP \| S_IROTH,
	whole_disk_show, NULL);

	void add_partition(struct gendisk *disk, int part, sector_t start, sector_t len, int flags)
	{
	struct hd_struct *p;
	int err;

	p = kzalloc(sizeof(*p), GFP_KERNEL);
	if (!p)
	return;

	if (!init_part_stats(p)) {
	kfree(p);
	return;
	}
	p->start_sect = start;
	p->nr_sects = len;
	p->partno = part;
	p->policy = disk->policy;

	if (isdigit(disk->dev.bus_id[strlen(disk->dev.bus_id)-1]))
	snprintf(p->dev.bus_id, BUS_ID_SIZE,
	"%sp%d", disk->dev.bus_id, part);
	else
	snprintf(p->dev.bus_id, BUS_ID_SIZE,
	"%s%d", disk->dev.bus_id, part);

	device_initialize(&p->dev);
	p->dev.devt = MKDEV(disk->major, disk->first_minor + part);
	p->dev.class = &block_class;
	p->dev.type = &part_type;
	p->dev.parent = &disk->dev;
	disk->part[part-1] = p;

	/* delay uevent until 'holders' subdir is created */
	p->dev.uevent_suppress = 1;
	device_add(&p->dev);
	partition_sysfs_add_subdir(p);
	p->dev.uevent_suppress = 0;
	if (flags & ADDPART_FLAG_WHOLEDISK)
	err = device_create_file(&p->dev, &dev_attr_whole_disk);

	/* suppress uevent if the disk supresses it */
	if (!disk->dev.uevent_suppress)
	kobject_uevent(&p->dev.kobj, KOBJ_ADD);
	}

	/* Not exported, helper to add_disk(). */
	void register_disk(struct gendisk *disk)
	{
	struct block_device *bdev;
	char *s;
	int i;
	struct hd_struct *p;
	int err;

	disk->dev.parent = disk->driverfs_dev;
	disk->dev.devt = MKDEV(disk->major, disk->first_minor);

	strlcpy(disk->dev.bus_id, disk->disk_name, KOBJ_NAME_LEN);
	/* ewww... some of these buggers have / in the name... */
	s = strchr(disk->dev.bus_id, '/');
	if (s)
	*s = '!';

	/* delay uevents, until we scanned partition table */
	disk->dev.uevent_suppress = 1;

	if (device_add(&disk->dev))
	return;
	#ifndef CONFIG_SYSFS_DEPRECATED
	err = sysfs_create_link(block_depr, &disk->dev.kobj,
	kobject_name(&disk->dev.kobj));
	if (err) {
	device_del(&disk->dev);
	return;
	}
	#endif
	disk_sysfs_add_subdirs(disk);

	/* No minors to use for partitions */
	if (disk->minors == 1)
	goto exit;

	/* No such device (e.g., media were just removed) */
	if (!get_capacity(disk))
	goto exit;

	bdev = bdget_disk(disk, 0);
	if (!bdev)
	goto exit;

	bdev->bd_invalidated = 1;
	err = blkdev_get(bdev, FMODE_READ, 0);
	if (err < 0)
	goto exit;
	blkdev_put(bdev);

	exit:
	/* announce disk after possible partitions are created */
	disk->dev.uevent_suppress = 0;
	kobject_uevent(&disk->dev.kobj, KOBJ_ADD);

	/* announce possible partitions */
	for (i = 1; i < disk->minors; i++) {
	p = disk->part[i-1];
	if (!p \|\| !p->nr_sects)
	continue;
	kobject_uevent(&p->dev.kobj, KOBJ_ADD);
	}
	}

	int rescan_partitions(struct gendisk disk, struct block_device bdev)
	{
	struct parsed_partitions *state;
	int p, res;

	if (bdev->bd_part_count)
	return -EBUSY;
	res = invalidate_partition(disk, 0);
	if (res)
	return res;
	bdev->bd_invalidated = 0;
	for (p = 1; p < disk->minors; p++)
	delete_partition(disk, p);
	if (disk->fops->revalidate_disk)
	disk->fops->revalidate_disk(disk);
	if (!get_capacity(disk) \|\| !(state = check_partition(disk, bdev)))
	return 0;
	if (IS_ERR(state)) /* I/O error reading the partition table */
	return -EIO;

	/* tell userspace that the media / partition table may have changed */
	kobject_uevent(&disk->dev.kobj, KOBJ_CHANGE);

	for (p = 1; p < state->limit; p++) {
	sector_t size = state->parts[p].size;
	sector_t from = state->parts[p].from;
	if (!size)
	continue;
	if (from + size > get_capacity(disk)) {
	printk(" %s: p%d exceeds device capacity\n",
	disk->disk_name, p);
	}
	add_partition(disk, p, from, size, state->parts[p].flags);
	#ifdef CONFIG_BLK_DEV_MD
	if (state->parts[p].flags & ADDPART_FLAG_RAID)
	md_autodetect_dev(bdev->bd_dev+p);
	#endif
	}
	kfree(state);
	return 0;
	}

	unsigned char read_dev_sector(struct block_device bdev, sector_t n, Sector *p)
	{
	struct address_space *mapping = bdev->bd_inode->i_mapping;
	struct page *page;

	page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
	NULL);
	if (!IS_ERR(page)) {
	if (PageError(page))
	goto fail;
	p->v = page;
	return (unsigned char *)page_address(page) + ((n & ((1 << (PAGE_CACHE_SHIFT - 9)) - 1)) << 9);
	fail:
	page_cache_release(page);
	}
	p->v = NULL;
	return NULL;
	}

	EXPORT_SYMBOL(read_dev_sector);

	void del_gendisk(struct gendisk *disk)
	{
	int p;

	/* invalidate stuff */
	for (p = disk->minors - 1; p > 0; p--) {
	invalidate_partition(disk, p);
	delete_partition(disk, p);
	}
	invalidate_partition(disk, 0);
	disk->capacity = 0;
	disk->flags &= ~GENHD_FL_UP;
	unlink_gendisk(disk);
	disk_stat_set_all(disk, 0);
	disk->stamp = 0;

	kobject_put(disk->holder_dir);
	kobject_put(disk->slave_dir);
	disk->driverfs_dev = NULL;
	#ifndef CONFIG_SYSFS_DEPRECATED
	sysfs_remove_link(block_depr, disk->dev.bus_id);
	#endif
	device_del(&disk->dev);
	}