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/* *  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. */ #include <linux/init.h>#include <linux/module.h>#include <linux/fs.h>#include <linux/slab.h>#include <linux/kmod.h>#include <linux/ctype.h>#include <linux/genhd.h>#include <linux/blktrace_api.h> #include "partitions/check.h" #ifdef CONFIG_BLK_DEV_MDextern void md_autodetect_dev(dev_t dev);#endif /* * 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 partno, char *buf){	if (!partno)		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, partno);	else		snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, partno); 	return buf;} const char *bdevname(struct block_device *bdev, char *buf){	return disk_name(bdev->bd_disk, bdev->bd_part->partno, 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 ssize_t part_partition_show(struct device *dev,				   struct device_attribute *attr, char *buf){	struct hd_struct *p = dev_to_part(dev); 	return sprintf(buf, "%d\n", p->partno);} 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);} 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_ro_show(struct device *dev,			    struct device_attribute *attr, char *buf){	struct hd_struct *p = dev_to_part(dev);	return sprintf(buf, "%d\n", p->policy ? 1 : 0);} static ssize_t part_alignment_offset_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->alignment_offset);} static ssize_t part_discard_alignment_show(struct device *dev,					   struct device_attribute *attr, char *buf){	struct hd_struct *p = dev_to_part(dev);	return sprintf(buf, "%u\n", p->discard_alignment);} ssize_t part_stat_show(struct device *dev,		       struct device_attribute *attr, char *buf){	struct hd_struct *p = dev_to_part(dev);	int cpu; 	cpu = part_stat_lock();	part_round_stats(cpu, p);	part_stat_unlock();	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])),		part_in_flight(p),		jiffies_to_msecs(part_stat_read(p, io_ticks)),		jiffies_to_msecs(part_stat_read(p, time_in_queue)));} ssize_t part_inflight_show(struct device *dev,			struct device_attribute *attr, char *buf){	struct hd_struct *p = dev_to_part(dev); 	return sprintf(buf, "%8u %8u\n", atomic_read(&p->in_flight[0]),		atomic_read(&p->in_flight[1]));} #ifdef CONFIG_FAIL_MAKE_REQUESTssize_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);} 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(partition, S_IRUGO, part_partition_show, NULL);static DEVICE_ATTR(start, S_IRUGO, part_start_show, NULL);static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);static DEVICE_ATTR(ro, S_IRUGO, part_ro_show, NULL);static DEVICE_ATTR(alignment_offset, S_IRUGO, part_alignment_offset_show, NULL);static DEVICE_ATTR(discard_alignment, S_IRUGO, part_discard_alignment_show,		   NULL);static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_show, NULL);#ifdef CONFIG_FAIL_MAKE_REQUESTstatic 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_partition.attr,	&dev_attr_start.attr,	&dev_attr_size.attr,	&dev_attr_ro.attr,	&dev_attr_alignment_offset.attr,	&dev_attr_discard_alignment.attr,	&dev_attr_stat.attr,	&dev_attr_inflight.attr,#ifdef CONFIG_FAIL_MAKE_REQUEST	&dev_attr_fail.attr,#endif	NULL}; static struct attribute_group part_attr_group = {	.attrs = part_attrs,}; static const struct attribute_group *part_attr_groups[] = {	&part_attr_group,#ifdef CONFIG_BLK_DEV_IO_TRACE	&blk_trace_attr_group,#endif	NULL}; static void part_release(struct device *dev){	struct hd_struct *p = dev_to_part(dev);	free_part_stats(p);	free_part_info(p);	kfree(p);} struct device_type part_type = {	.name		= "partition",	.groups		= part_attr_groups,	.release	= part_release,}; static void delete_partition_rcu_cb(struct rcu_head *head){	struct hd_struct *part = container_of(head, struct hd_struct, rcu_head); 	part->start_sect = 0;	part->nr_sects = 0;	part_stat_set_all(part, 0);	put_device(part_to_dev(part));} void __delete_partition(struct hd_struct *part){	call_rcu(&part->rcu_head, delete_partition_rcu_cb);} void delete_partition(struct gendisk *disk, int partno){	struct disk_part_tbl *ptbl = disk->part_tbl;	struct hd_struct *part; 	if (partno >= ptbl->len)		return; 	part = ptbl->part[partno];	if (!part)		return; 	blk_free_devt(part_devt(part));	rcu_assign_pointer(ptbl->part[partno], NULL);	rcu_assign_pointer(ptbl->last_lookup, NULL);	kobject_put(part->holder_dir);	device_del(part_to_dev(part)); 	hd_struct_put(part);} 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); struct hd_struct *add_partition(struct gendisk *disk, int partno,				sector_t start, sector_t len, int flags,				struct partition_meta_info *info){	struct hd_struct *p;	dev_t devt = MKDEV(0, 0);	struct device *ddev = disk_to_dev(disk);	struct device *pdev;	struct disk_part_tbl *ptbl;	const char *dname;	int err; 	err = disk_expand_part_tbl(disk, partno);	if (err)		return ERR_PTR(err);	ptbl = disk->part_tbl; 	if (ptbl->part[partno])		return ERR_PTR(-EBUSY); 	p = kzalloc(sizeof(*p), GFP_KERNEL);	if (!p)		return ERR_PTR(-EBUSY); 	if (!init_part_stats(p)) {		err = -ENOMEM;		goto out_free;	}	pdev = part_to_dev(p); 	p->start_sect = start;	p->alignment_offset =		queue_limit_alignment_offset(&disk->queue->limits, start);	p->discard_alignment =		queue_limit_discard_alignment(&disk->queue->limits, start);	p->nr_sects = len;	p->partno = partno;	p->policy = get_disk_ro(disk); 	if (info) {		struct partition_meta_info *pinfo = alloc_part_info(disk);		if (!pinfo)			goto out_free_stats;		memcpy(pinfo, info, sizeof(*info));		p->info = pinfo;	} 	dname = dev_name(ddev);	if (isdigit(dname[strlen(dname) - 1]))		dev_set_name(pdev, "%sp%d", dname, partno);	else		dev_set_name(pdev, "%s%d", dname, partno); 	device_initialize(pdev);	pdev->class = &block_class;	pdev->type = &part_type;	pdev->parent = ddev; 	err = blk_alloc_devt(p, &devt);	if (err)		goto out_free_info;	pdev->devt = devt; 	/* delay uevent until 'holders' subdir is created */	dev_set_uevent_suppress(pdev, 1);	err = device_add(pdev);	if (err)		goto out_put; 	err = -ENOMEM;	p->holder_dir = kobject_create_and_add("holders", &pdev->kobj);	if (!p->holder_dir)		goto out_del; 	dev_set_uevent_suppress(pdev, 0);	if (flags & ADDPART_FLAG_WHOLEDISK) {		err = device_create_file(pdev, &dev_attr_whole_disk);		if (err)			goto out_del;	} 	/* everything is up and running, commence */	rcu_assign_pointer(ptbl->part[partno], p); 	/* suppress uevent if the disk suppresses it */	if (!dev_get_uevent_suppress(ddev))		kobject_uevent(&pdev->kobj, KOBJ_ADD); 	hd_ref_init(p);	return p; out_free_info:	free_part_info(p);out_free_stats:	free_part_stats(p);out_free:	kfree(p);	return ERR_PTR(err);out_del:	kobject_put(p->holder_dir);	device_del(pdev);out_put:	put_device(pdev);	blk_free_devt(devt);	return ERR_PTR(err);} static bool disk_unlock_native_capacity(struct gendisk *disk){	const struct block_device_operations *bdops = disk->fops; 	if (bdops->unlock_native_capacity &&	    !(disk->flags & GENHD_FL_NATIVE_CAPACITY)) {		printk(KERN_CONT "enabling native capacity\n");		bdops->unlock_native_capacity(disk);		disk->flags |= GENHD_FL_NATIVE_CAPACITY;		return true;	} else {		printk(KERN_CONT "truncated\n");		return false;	}} static int drop_partitions(struct gendisk *disk, struct block_device *bdev){	struct disk_part_iter piter;	struct hd_struct *part;	int res; 	if (bdev->bd_part_count)		return -EBUSY;	res = invalidate_partition(disk, 0);	if (res)		return res; 	disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);	while ((part = disk_part_iter_next(&piter)))		delete_partition(disk, part->partno);	disk_part_iter_exit(&piter); 	return 0;} int rescan_partitions(struct gendisk *disk, struct block_device *bdev){	struct parsed_partitions *state = NULL;	struct hd_struct *part;	int p, highest, res;rescan:	if (state && !IS_ERR(state)) {		kfree(state);		state = NULL;	} 	res = drop_partitions(disk, bdev);	if (res)		return res; 	if (disk->fops->revalidate_disk)		disk->fops->revalidate_disk(disk);	check_disk_size_change(disk, bdev);	bdev->bd_invalidated = 0;	if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))		return 0;	if (IS_ERR(state)) {		/*		 * I/O error reading the partition table.  If any		 * partition code tried to read beyond EOD, retry		 * after unlocking native capacity.		 */		if (PTR_ERR(state) == -ENOSPC) {			printk(KERN_WARNING "%s: partition table beyond EOD, ",			       disk->disk_name);			if (disk_unlock_native_capacity(disk))				goto rescan;		}		return -EIO;	}	/*	 * If any partition code tried to read beyond EOD, try	 * unlocking native capacity even if partition table is	 * successfully read as we could be missing some partitions.	 */	if (state->access_beyond_eod) {		printk(KERN_WARNING		       "%s: partition table partially beyond EOD, ",		       disk->disk_name);		if (disk_unlock_native_capacity(disk))			goto rescan;	} 	/* tell userspace that the media / partition table may have changed */	kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE); 	/* Detect the highest partition number and preallocate	 * disk->part_tbl.  This is an optimization and not strictly	 * necessary.	 */	for (p = 1, highest = 0; p < state->limit; p++)		if (state->parts[p].size)			highest = p; 	disk_expand_part_tbl(disk, highest); 	/* add partitions */	for (p = 1; p < state->limit; p++) {		sector_t size, from;		struct partition_meta_info *info = NULL; 		size = state->parts[p].size;		if (!size)			continue; 		from = state->parts[p].from;		if (from >= get_capacity(disk)) {			printk(KERN_WARNING			       "%s: p%d start %llu is beyond EOD, ",			       disk->disk_name, p, (unsigned long long) from);			if (disk_unlock_native_capacity(disk))				goto rescan;			continue;		} 		if (from + size > get_capacity(disk)) {			printk(KERN_WARNING			       "%s: p%d size %llu extends beyond EOD, ",			       disk->disk_name, p, (unsigned long long) size); 			if (disk_unlock_native_capacity(disk)) {				/* free state and restart */				goto rescan;			} else {

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