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// SPDX-License-Identifier: GPL-2.0/* * Copyright (C) 1991-1998  Linus Torvalds * Re-organised Feb 1998 Russell King * Copyright (C) 2020 Christoph Hellwig */#include <linux/fs.h>#include <linux/major.h>#include <linux/slab.h>#include <linux/string.h>#include <linux/sysfs.h>#include <linux/ctype.h>#include <linux/vmalloc.h>#include <linux/raid/detect.h>#include "check.h" static int (*const check_part[])(struct parsed_partitions *) = {	/*	 * 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_CMDLINE_PARTITION	cmdline_partition,#endif#ifdef CONFIG_OF_PARTITION	of_partition,		/* cmdline have priority to OF */#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}; static struct parsed_partitions *allocate_partitions(struct gendisk *hd){	struct parsed_partitions *state;	int nr = DISK_MAX_PARTS; 	state = kzalloc_obj(*state);	if (!state)		return NULL; 	state->parts = vzalloc(array_size(nr, sizeof(state->parts[0])));	if (!state->parts) {		kfree(state);		return NULL;	} 	state->limit = nr; 	return state;} static void free_partitions(struct parsed_partitions *state){	vfree(state->parts);	kfree(state);} static struct parsed_partitions *check_partition(struct gendisk *hd){	struct parsed_partitions *state;	int i, res, err; 	state = allocate_partitions(hd);	if (!state)		return NULL;	state->pp_buf.buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);	if (!state->pp_buf.buffer) {		free_partitions(state);		return NULL;	}	seq_buf_init(&state->pp_buf, state->pp_buf.buffer, PAGE_SIZE); 	state->disk = hd;	strscpy(state->name, hd->disk_name);	seq_buf_printf(&state->pp_buf, " %s:", state->name);	if (isdigit(state->name[strlen(state->name)-1]))		sprintf(state->name, "p"); 	i = res = err = 0;	while (!res && check_part[i]) {		memset(state->parts, 0, state->limit * sizeof(state->parts[0]));		res = check_part[i++](state);		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) {		printk(KERN_INFO "%s", seq_buf_str(&state->pp_buf)); 		kfree(state->pp_buf.buffer);		return state;	}	if (state->access_beyond_eod)		err = -ENOSPC;	/*	 * The partition is unrecognized. So report I/O errors if there were any	 */	if (err)		res = err;	if (res) {		seq_buf_puts(&state->pp_buf,			     " unable to read partition table\n");		printk(KERN_INFO "%s", seq_buf_str(&state->pp_buf));	} 	kfree(state->pp_buf.buffer);	free_partitions(state);	return ERR_PTR(res);} static ssize_t part_partition_show(struct device *dev,				   struct device_attribute *attr, char *buf){	return sysfs_emit(buf, "%d\n", bdev_partno(dev_to_bdev(dev)));} static ssize_t part_start_show(struct device *dev,			       struct device_attribute *attr, char *buf){	return sysfs_emit(buf, "%llu\n", dev_to_bdev(dev)->bd_start_sect);} static ssize_t part_ro_show(struct device *dev,			    struct device_attribute *attr, char *buf){	return sysfs_emit(buf, "%d\n", bdev_read_only(dev_to_bdev(dev)));} static ssize_t part_alignment_offset_show(struct device *dev,					  struct device_attribute *attr, char *buf){	return sysfs_emit(buf, "%u\n", bdev_alignment_offset(dev_to_bdev(dev)));} static ssize_t part_discard_alignment_show(struct device *dev,					   struct device_attribute *attr, char *buf){	return sysfs_emit(buf, "%u\n", bdev_discard_alignment(dev_to_bdev(dev)));} static DEVICE_ATTR(partition, 0444, part_partition_show, NULL);static DEVICE_ATTR(start, 0444, part_start_show, NULL);static DEVICE_ATTR(size, 0444, part_size_show, NULL);static DEVICE_ATTR(ro, 0444, part_ro_show, NULL);static DEVICE_ATTR(alignment_offset, 0444, part_alignment_offset_show, NULL);static DEVICE_ATTR(discard_alignment, 0444, part_discard_alignment_show, NULL);static DEVICE_ATTR(stat, 0444, part_stat_show, NULL);static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL);#ifdef CONFIG_FAIL_MAKE_REQUESTstatic struct device_attribute dev_attr_fail =	__ATTR(make-it-fail, 0644, 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 const 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){	put_disk(dev_to_bdev(dev)->bd_disk);	bdev_drop(dev_to_bdev(dev));} static int part_uevent(const struct device *dev, struct kobj_uevent_env *env){	const struct block_device *part = dev_to_bdev(dev); 	add_uevent_var(env, "PARTN=%u", bdev_partno(part));	if (part->bd_meta_info && part->bd_meta_info->volname[0])		add_uevent_var(env, "PARTNAME=%s", part->bd_meta_info->volname);	if (part->bd_meta_info && part->bd_meta_info->uuid[0])		add_uevent_var(env, "PARTUUID=%s", part->bd_meta_info->uuid);	return 0;} const struct device_type part_type = {	.name		= "partition",	.groups		= part_attr_groups,	.release	= part_release,	.uevent		= part_uevent,}; void drop_partition(struct block_device *part){	lockdep_assert_held(&part->bd_disk->open_mutex); 	xa_erase(&part->bd_disk->part_tbl, bdev_partno(part));	kobject_put(part->bd_holder_dir); 	device_del(&part->bd_device);	put_device(&part->bd_device);} static ssize_t whole_disk_show(struct device *dev,			       struct device_attribute *attr, char *buf){	return 0;}static const DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL); /* * Must be called either with open_mutex held, before a disk can be opened or * after all disk users are gone. */static struct block_device *add_partition(struct gendisk *disk, int partno,				sector_t start, sector_t len, int flags,				struct partition_meta_info *info){	dev_t devt = MKDEV(0, 0);	struct device *ddev = disk_to_dev(disk);	struct device *pdev;	struct block_device *bdev;	const char *dname;	int err; 	lockdep_assert_held(&disk->open_mutex); 	if (partno >= DISK_MAX_PARTS)		return ERR_PTR(-EINVAL); 	/*	 * Partitions are not supported on zoned block devices that are used as	 * such.	 */	if (bdev_is_zoned(disk->part0)) {		pr_warn("%s: partitions not supported on host managed zoned block device\n",			disk->disk_name);		return ERR_PTR(-ENXIO);	} 	if (xa_load(&disk->part_tbl, partno))		return ERR_PTR(-EBUSY); 	/* ensure we always have a reference to the whole disk */	get_device(disk_to_dev(disk)); 	err = -ENOMEM;	bdev = bdev_alloc(disk, partno);	if (!bdev)		goto out_put_disk; 	bdev->bd_start_sect = start;	bdev_set_nr_sectors(bdev, len); 	pdev = &bdev->bd_device;	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; 	/* in consecutive minor range? */	if (bdev_partno(bdev) < disk->minors) {		devt = MKDEV(disk->major, disk->first_minor + bdev_partno(bdev));	} else {		err = blk_alloc_ext_minor();		if (err < 0)			goto out_put;		devt = MKDEV(BLOCK_EXT_MAJOR, err);	}	pdev->devt = devt; 	if (info) {		err = -ENOMEM;		bdev->bd_meta_info = kmemdup(info, sizeof(*info), GFP_KERNEL);		if (!bdev->bd_meta_info)			goto out_put;	} 	/* delay uevent until 'holders' subdir is created */	dev_set_uevent_suppress(pdev, 1);	err = device_add(pdev);	if (err)		goto out_put; 	err = -ENOMEM;	bdev->bd_holder_dir = kobject_create_and_add("holders", &pdev->kobj);	if (!bdev->bd_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;	} 	if (flags & ADDPART_FLAG_READONLY)		bdev_set_flag(bdev, BD_READ_ONLY); 	/* everything is up and running, commence */	err = xa_insert(&disk->part_tbl, partno, bdev, GFP_KERNEL);	if (err)		goto out_del;	bdev_add(bdev, devt); 	/* suppress uevent if the disk suppresses it */	if (!dev_get_uevent_suppress(ddev))		kobject_uevent(&pdev->kobj, KOBJ_ADD);	return bdev; out_del:	kobject_put(bdev->bd_holder_dir);	device_del(pdev);out_put:	put_device(pdev);	return ERR_PTR(err);out_put_disk:	put_disk(disk);	return ERR_PTR(err);} static bool partition_overlaps(struct gendisk *disk, sector_t start,		sector_t length, int skip_partno){	struct block_device *part;	bool overlap = false;	unsigned long idx; 	rcu_read_lock();	xa_for_each_start(&disk->part_tbl, idx, part, 1) {		if (bdev_partno(part) != skip_partno &&		    start < part->bd_start_sect + bdev_nr_sectors(part) &&		    start + length > part->bd_start_sect) {			overlap = true;			break;		}	}	rcu_read_unlock(); 	return overlap;} int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,		sector_t length){	struct block_device *part;	int ret; 	mutex_lock(&disk->open_mutex);	if (!disk_live(disk)) {		ret = -ENXIO;		goto out;	} 	if (disk->flags & GENHD_FL_NO_PART) {		ret = -EINVAL;		goto out;	} 	if (partition_overlaps(disk, start, length, -1)) {		ret = -EBUSY;		goto out;	} 	part = add_partition(disk, partno, start, length,			ADDPART_FLAG_NONE, NULL);	ret = PTR_ERR_OR_ZERO(part);out:	mutex_unlock(&disk->open_mutex);	return ret;} int bdev_del_partition(struct gendisk *disk, int partno){	struct block_device *part = NULL;	int ret = -ENXIO; 	mutex_lock(&disk->open_mutex);	part = xa_load(&disk->part_tbl, partno);	if (!part)		goto out_unlock; 	ret = -EBUSY;	if (atomic_read(&part->bd_openers))		goto out_unlock; 	/*	 * We verified that @part->bd_openers is zero above and so	 * @part->bd_holder{_ops} can't be set. And since we hold	 * @disk->open_mutex the device can't be claimed by anyone.	 *	 * So no need to call @part->bd_holder_ops->mark_dead() here.	 * Just delete the partition and invalidate it.	 */ 	bdev_unhash(part);	invalidate_bdev(part);	drop_partition(part);	ret = 0;out_unlock:	mutex_unlock(&disk->open_mutex);	return ret;} int bdev_resize_partition(struct gendisk *disk, int partno, sector_t start,		sector_t length){	struct block_device *part = NULL;	int ret = -ENXIO; 	mutex_lock(&disk->open_mutex);	part = xa_load(&disk->part_tbl, partno);	if (!part)		goto out_unlock;

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