1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 1991-1998  Linus Torvalds
4 * Re-organised Feb 1998 Russell King
5 */
6#include <linux/fs.h>
7#include <linux/slab.h>
8#include <linux/ctype.h>
9#include <linux/genhd.h>
10#include <linux/vmalloc.h>
11#include <linux/blktrace_api.h>
12#include <linux/raid/detect.h>
13#include "check.h"
14
15static int (*check_part[])(struct parsed_partitions *) = {
16	/*
17	 * Probe partition formats with tables at disk address 0
18	 * that also have an ADFS boot block at 0xdc0.
19	 */
20#ifdef CONFIG_ACORN_PARTITION_ICS
21	adfspart_check_ICS,
22#endif
23#ifdef CONFIG_ACORN_PARTITION_POWERTEC
24	adfspart_check_POWERTEC,
25#endif
26#ifdef CONFIG_ACORN_PARTITION_EESOX
27	adfspart_check_EESOX,
28#endif
29
30	/*
31	 * Now move on to formats that only have partition info at
32	 * disk address 0xdc0.  Since these may also have stale
33	 * PC/BIOS partition tables, they need to come before
34	 * the msdos entry.
35	 */
36#ifdef CONFIG_ACORN_PARTITION_CUMANA
37	adfspart_check_CUMANA,
38#endif
39#ifdef CONFIG_ACORN_PARTITION_ADFS
40	adfspart_check_ADFS,
41#endif
42
43#ifdef CONFIG_CMDLINE_PARTITION
44	cmdline_partition,
45#endif
46#ifdef CONFIG_EFI_PARTITION
47	efi_partition,		/* this must come before msdos */
48#endif
49#ifdef CONFIG_SGI_PARTITION
50	sgi_partition,
51#endif
52#ifdef CONFIG_LDM_PARTITION
53	ldm_partition,		/* this must come before msdos */
54#endif
55#ifdef CONFIG_MSDOS_PARTITION
56	msdos_partition,
57#endif
58#ifdef CONFIG_OSF_PARTITION
59	osf_partition,
60#endif
61#ifdef CONFIG_SUN_PARTITION
62	sun_partition,
63#endif
64#ifdef CONFIG_AMIGA_PARTITION
65	amiga_partition,
66#endif
67#ifdef CONFIG_ATARI_PARTITION
68	atari_partition,
69#endif
70#ifdef CONFIG_MAC_PARTITION
71	mac_partition,
72#endif
73#ifdef CONFIG_ULTRIX_PARTITION
74	ultrix_partition,
75#endif
76#ifdef CONFIG_IBM_PARTITION
77	ibm_partition,
78#endif
79#ifdef CONFIG_KARMA_PARTITION
80	karma_partition,
81#endif
82#ifdef CONFIG_SYSV68_PARTITION
83	sysv68_partition,
84#endif
85	NULL
86};
87
88static struct parsed_partitions *allocate_partitions(struct gendisk *hd)
89{
90	struct parsed_partitions *state;
91	int nr;
92
93	state = kzalloc(sizeof(*state), GFP_KERNEL);
94	if (!state)
95		return NULL;
96
97	nr = disk_max_parts(hd);
98	state->parts = vzalloc(array_size(nr, sizeof(state->parts[0])));
99	if (!state->parts) {
100		kfree(state);
101		return NULL;
102	}
103
104	state->limit = nr;
105
106	return state;
107}
108
109static void free_partitions(struct parsed_partitions *state)
110{
111	vfree(state->parts);
112	kfree(state);
113}
114
115static struct parsed_partitions *check_partition(struct gendisk *hd,
116		struct block_device *bdev)
117{
118	struct parsed_partitions *state;
119	int i, res, err;
120
121	state = allocate_partitions(hd);
122	if (!state)
123		return NULL;
124	state->pp_buf = (char *)__get_free_page(GFP_KERNEL);
125	if (!state->pp_buf) {
126		free_partitions(state);
127		return NULL;
128	}
129	state->pp_buf[0] = '\0';
130
131	state->bdev = bdev;
132	disk_name(hd, 0, state->name);
133	snprintf(state->pp_buf, PAGE_SIZE, " %s:", state->name);
134	if (isdigit(state->name[strlen(state->name)-1]))
135		sprintf(state->name, "p");
136
137	i = res = err = 0;
138	while (!res && check_part[i]) {
139		memset(state->parts, 0, state->limit * sizeof(state->parts[0]));
140		res = check_part[i++](state);
141		if (res < 0) {
142			/*
143			 * We have hit an I/O error which we don't report now.
144			 * But record it, and let the others do their job.
145			 */
146			err = res;
147			res = 0;
148		}
149
150	}
151	if (res > 0) {
152		printk(KERN_INFO "%s", state->pp_buf);
153
154		free_page((unsigned long)state->pp_buf);
155		return state;
156	}
157	if (state->access_beyond_eod)
158		err = -ENOSPC;
159	/*
160	 * The partition is unrecognized. So report I/O errors if there were any
161	 */
162	if (err)
163		res = err;
164	if (res) {
165		strlcat(state->pp_buf,
166			" unable to read partition table\n", PAGE_SIZE);
167		printk(KERN_INFO "%s", state->pp_buf);
168	}
169
170	free_page((unsigned long)state->pp_buf);
171	free_partitions(state);
172	return ERR_PTR(res);
173}
174
175static ssize_t part_partition_show(struct device *dev,
176				   struct device_attribute *attr, char *buf)
177{
178	struct hd_struct *p = dev_to_part(dev);
179
180	return sprintf(buf, "%d\n", p->partno);
181}
182
183static ssize_t part_start_show(struct device *dev,
184			       struct device_attribute *attr, char *buf)
185{
186	struct hd_struct *p = dev_to_part(dev);
187
188	return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect);
189}
190
191static ssize_t part_ro_show(struct device *dev,
192			    struct device_attribute *attr, char *buf)
193{
194	struct hd_struct *p = dev_to_part(dev);
195	return sprintf(buf, "%d\n", p->policy ? 1 : 0);
196}
197
198static ssize_t part_alignment_offset_show(struct device *dev,
199					  struct device_attribute *attr, char *buf)
200{
201	struct hd_struct *p = dev_to_part(dev);
202
203	return sprintf(buf, "%u\n",
204		queue_limit_alignment_offset(&part_to_disk(p)->queue->limits,
205				p->start_sect));
206}
207
208static ssize_t part_discard_alignment_show(struct device *dev,
209					   struct device_attribute *attr, char *buf)
210{
211	struct hd_struct *p = dev_to_part(dev);
212
213	return sprintf(buf, "%u\n",
214		queue_limit_discard_alignment(&part_to_disk(p)->queue->limits,
215				p->start_sect));
216}
217
218static DEVICE_ATTR(partition, 0444, part_partition_show, NULL);
219static DEVICE_ATTR(start, 0444, part_start_show, NULL);
220static DEVICE_ATTR(size, 0444, part_size_show, NULL);
221static DEVICE_ATTR(ro, 0444, part_ro_show, NULL);
222static DEVICE_ATTR(alignment_offset, 0444, part_alignment_offset_show, NULL);
223static DEVICE_ATTR(discard_alignment, 0444, part_discard_alignment_show, NULL);
224static DEVICE_ATTR(stat, 0444, part_stat_show, NULL);
225static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL);
226#ifdef CONFIG_FAIL_MAKE_REQUEST
227static struct device_attribute dev_attr_fail =
228	__ATTR(make-it-fail, 0644, part_fail_show, part_fail_store);
229#endif
230
231static struct attribute *part_attrs[] = {
232	&dev_attr_partition.attr,
233	&dev_attr_start.attr,
234	&dev_attr_size.attr,
235	&dev_attr_ro.attr,
236	&dev_attr_alignment_offset.attr,
237	&dev_attr_discard_alignment.attr,
238	&dev_attr_stat.attr,
239	&dev_attr_inflight.attr,
240#ifdef CONFIG_FAIL_MAKE_REQUEST
241	&dev_attr_fail.attr,
242#endif
243	NULL
244};
245
246static struct attribute_group part_attr_group = {
247	.attrs = part_attrs,
248};
249
250static const struct attribute_group *part_attr_groups[] = {
251	&part_attr_group,
252#ifdef CONFIG_BLK_DEV_IO_TRACE
253	&blk_trace_attr_group,
254#endif
255	NULL
256};
257
258static void part_release(struct device *dev)
259{
260	struct hd_struct *p = dev_to_part(dev);
261	blk_free_devt(dev->devt);
262	hd_free_part(p);
263	kfree(p);
264}
265
266static int part_uevent(struct device *dev, struct kobj_uevent_env *env)
267{
268	struct hd_struct *part = dev_to_part(dev);
269
270	add_uevent_var(env, "PARTN=%u", part->partno);
271	if (part->info && part->info->volname[0])
272		add_uevent_var(env, "PARTNAME=%s", part->info->volname);
273	return 0;
274}
275
276struct device_type part_type = {
277	.name		= "partition",
278	.groups		= part_attr_groups,
279	.release	= part_release,
280	.uevent		= part_uevent,
281};
282
283static void hd_struct_free_work(struct work_struct *work)
284{
285	struct hd_struct *part =
286		container_of(to_rcu_work(work), struct hd_struct, rcu_work);
287	struct gendisk *disk = part_to_disk(part);
288
289	/*
290	 * Release the disk reference acquired in delete_partition here.
291	 * We can't release it in hd_struct_free because the final put_device
292	 * needs process context and thus can't be run directly from a
293	 * percpu_ref ->release handler.
294	 */
295	put_device(disk_to_dev(disk));
296
297	part->start_sect = 0;
298	part->nr_sects = 0;
299	part_stat_set_all(part, 0);
300	put_device(part_to_dev(part));
301}
302
303static void hd_struct_free(struct percpu_ref *ref)
304{
305	struct hd_struct *part = container_of(ref, struct hd_struct, ref);
306	struct gendisk *disk = part_to_disk(part);
307	struct disk_part_tbl *ptbl =
308		rcu_dereference_protected(disk->part_tbl, 1);
309
310	rcu_assign_pointer(ptbl->last_lookup, NULL);
311
312	INIT_RCU_WORK(&part->rcu_work, hd_struct_free_work);
313	queue_rcu_work(system_wq, &part->rcu_work);
314}
315
316int hd_ref_init(struct hd_struct *part)
317{
318	if (percpu_ref_init(&part->ref, hd_struct_free, 0, GFP_KERNEL))
319		return -ENOMEM;
320	return 0;
321}
322
323/*
324 * Must be called either with bd_mutex held, before a disk can be opened or
325 * after all disk users are gone.
326 */
327void delete_partition(struct hd_struct *part)
328{
329	struct gendisk *disk = part_to_disk(part);
330	struct disk_part_tbl *ptbl =
331		rcu_dereference_protected(disk->part_tbl, 1);
332	struct block_device *bdev;
333
334	/*
335	 * ->part_tbl is referenced in this part's release handler, so
336	 *  we have to hold the disk device
337	 */
338	get_device(disk_to_dev(disk));
339	rcu_assign_pointer(ptbl->part[part->partno], NULL);
340	kobject_put(part->holder_dir);
341	device_del(part_to_dev(part));
342
343	/*
344	 * Remove gendisk pointer from idr so that it cannot be looked up
345	 * while RCU period before freeing gendisk is running to prevent
346	 * use-after-free issues. Note that the device number stays
347	 * "in-use" until we really free the gendisk.
348	 */
349	blk_invalidate_devt(part_devt(part));
350
351	bdev = bdget_part(part);
352	if (bdev) {
353		remove_inode_hash(bdev->bd_inode);
354		bdput(bdev);
355	}
356	percpu_ref_kill(&part->ref);
357}
358
359static ssize_t whole_disk_show(struct device *dev,
360			       struct device_attribute *attr, char *buf)
361{
362	return 0;
363}
364static DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL);
365
366/*
367 * Must be called either with bd_mutex held, before a disk can be opened or
368 * after all disk users are gone.
369 */
370static struct hd_struct *add_partition(struct gendisk *disk, int partno,
371				sector_t start, sector_t len, int flags,
372				struct partition_meta_info *info)
373{
374	struct hd_struct *p;
375	dev_t devt = MKDEV(0, 0);
376	struct device *ddev = disk_to_dev(disk);
377	struct device *pdev;
378	struct disk_part_tbl *ptbl;
379	const char *dname;
380	int err;
381
382	/*
383	 * Partitions are not supported on zoned block devices that are used as
384	 * such.
385	 */
386	switch (disk->queue->limits.zoned) {
387	case BLK_ZONED_HM:
388		pr_warn("%s: partitions not supported on host managed zoned block device\n",
389			disk->disk_name);
390		return ERR_PTR(-ENXIO);
391	case BLK_ZONED_HA:
392		pr_info("%s: disabling host aware zoned block device support due to partitions\n",
393			disk->disk_name);
394		disk->queue->limits.zoned = BLK_ZONED_NONE;
395		break;
396	case BLK_ZONED_NONE:
397		break;
398	}
399
400	err = disk_expand_part_tbl(disk, partno);
401	if (err)
402		return ERR_PTR(err);
403	ptbl = rcu_dereference_protected(disk->part_tbl, 1);
404
405	if (ptbl->part[partno])
406		return ERR_PTR(-EBUSY);
407
408	p = kzalloc(sizeof(*p), GFP_KERNEL);
409	if (!p)
410		return ERR_PTR(-EBUSY);
411
412	p->dkstats = alloc_percpu(struct disk_stats);
413	if (!p->dkstats) {
414		err = -ENOMEM;
415		goto out_free;
416	}
417
418	hd_sects_seq_init(p);
419	pdev = part_to_dev(p);
420
421	p->start_sect = start;
422	p->nr_sects = len;
423	p->partno = partno;
424	p->policy = get_disk_ro(disk);
425
426	if (info) {
427		struct partition_meta_info *pinfo;
428
429		pinfo = kzalloc_node(sizeof(*pinfo), GFP_KERNEL, disk->node_id);
430		if (!pinfo) {
431			err = -ENOMEM;
432			goto out_free_stats;
433		}
434		memcpy(pinfo, info, sizeof(*info));
435		p->info = pinfo;
436	}
437
438	dname = dev_name(ddev);
439	if (isdigit(dname[strlen(dname) - 1]))
440		dev_set_name(pdev, "%sp%d", dname, partno);
441	else
442		dev_set_name(pdev, "%s%d", dname, partno);
443
444	device_initialize(pdev);
445	pdev->class = &block_class;
446	pdev->type = &part_type;
447	pdev->parent = ddev;
448
449	err = blk_alloc_devt(p, &devt);
450	if (err)
451		goto out_free_info;
452	pdev->devt = devt;
453
454	/* delay uevent until 'holders' subdir is created */
455	dev_set_uevent_suppress(pdev, 1);
456	err = device_add(pdev);
457	if (err)
458		goto out_put;
459
460	err = -ENOMEM;
461	p->holder_dir = kobject_create_and_add("holders", &pdev->kobj);
462	if (!p->holder_dir)
463		goto out_del;
464
465	dev_set_uevent_suppress(pdev, 0);
466	if (flags & ADDPART_FLAG_WHOLEDISK) {
467		err = device_create_file(pdev, &dev_attr_whole_disk);
468		if (err)
469			goto out_del;
470	}
471
472	err = hd_ref_init(p);
473	if (err) {
474		if (flags & ADDPART_FLAG_WHOLEDISK)
475			goto out_remove_file;
476		goto out_del;
477	}
478
479	/* everything is up and running, commence */
480	rcu_assign_pointer(ptbl->part[partno], p);
481
482	/* suppress uevent if the disk suppresses it */
483	if (!dev_get_uevent_suppress(ddev))
484		kobject_uevent(&pdev->kobj, KOBJ_ADD);
485	return p;
486
487out_free_info:
488	kfree(p->info);
489out_free_stats:
490	free_percpu(p->dkstats);
491out_free:
492	kfree(p);
493	return ERR_PTR(err);
494out_remove_file:
495	device_remove_file(pdev, &dev_attr_whole_disk);
496out_del:
497	kobject_put(p->holder_dir);
498	device_del(pdev);
499out_put:
500	put_device(pdev);
501	return ERR_PTR(err);
502}
503
504static bool partition_overlaps(struct gendisk *disk, sector_t start,
505		sector_t length, int skip_partno)
506{
507	struct disk_part_iter piter;
508	struct hd_struct *part;
509	bool overlap = false;
510
511	disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
512	while ((part = disk_part_iter_next(&piter))) {
513		if (part->partno == skip_partno ||
514		    start >= part->start_sect + part->nr_sects ||
515		    start + length <= part->start_sect)
516			continue;
517		overlap = true;
518		break;
519	}
520
521	disk_part_iter_exit(&piter);
522	return overlap;
523}
524
525int bdev_add_partition(struct block_device *bdev, int partno,
526		sector_t start, sector_t length)
527{
528	struct hd_struct *part;
529	struct gendisk *disk = bdev->bd_disk;
530	int ret;
531
532	mutex_lock(&bdev->bd_mutex);
533	if (!(disk->flags & GENHD_FL_UP)) {
534		ret = -ENXIO;
535		goto out;
536	}
537
538	if (partition_overlaps(disk, start, length, -1)) {
539		ret = -EBUSY;
540		goto out;
541	}
542
543	part = add_partition(disk, partno, start, length,
544			ADDPART_FLAG_NONE, NULL);
545	ret = PTR_ERR_OR_ZERO(part);
546out:
547	mutex_unlock(&bdev->bd_mutex);
548	return ret;
549}
550
551int bdev_del_partition(struct block_device *bdev, int partno)
552{
553	struct block_device *bdevp;
554	struct hd_struct *part = NULL;
555	int ret;
556
557	bdevp = bdget_disk(bdev->bd_disk, partno);
558	if (!bdevp)
559		return -ENXIO;
560
561	mutex_lock(&bdevp->bd_mutex);
562	mutex_lock_nested(&bdev->bd_mutex, 1);
563
564	ret = -ENXIO;
565	part = disk_get_part(bdev->bd_disk, partno);
566	if (!part)
567		goto out_unlock;
568
569	ret = -EBUSY;
570	if (bdevp->bd_openers)
571		goto out_unlock;
572
573	sync_blockdev(bdevp);
574	invalidate_bdev(bdevp);
575
576	delete_partition(part);
577	ret = 0;
578out_unlock:
579	mutex_unlock(&bdev->bd_mutex);
580	mutex_unlock(&bdevp->bd_mutex);
581	bdput(bdevp);
582	if (part)
583		disk_put_part(part);
584	return ret;
585}
586
587int bdev_resize_partition(struct block_device *bdev, int partno,
588		sector_t start, sector_t length)
589{
590	struct block_device *bdevp;
591	struct hd_struct *part;
592	int ret = 0;
593
594	part = disk_get_part(bdev->bd_disk, partno);
595	if (!part)
596		return -ENXIO;
597
598	ret = -ENOMEM;
599	bdevp = bdget_part(part);
600	if (!bdevp)
601		goto out_put_part;
602
603	mutex_lock(&bdevp->bd_mutex);
604	mutex_lock_nested(&bdev->bd_mutex, 1);
605
606	ret = -EINVAL;
607	if (start != part->start_sect)
608		goto out_unlock;
609
610	ret = -EBUSY;
611	if (partition_overlaps(bdev->bd_disk, start, length, partno))
612		goto out_unlock;
613
614	part_nr_sects_write(part, length);
615	bd_set_nr_sectors(bdevp, length);
616
617	ret = 0;
618out_unlock:
619	mutex_unlock(&bdevp->bd_mutex);
620	mutex_unlock(&bdev->bd_mutex);
621	bdput(bdevp);
622out_put_part:
623	disk_put_part(part);
624	return ret;
625}
626
627static bool disk_unlock_native_capacity(struct gendisk *disk)
628{
629	const struct block_device_operations *bdops = disk->fops;
630
631	if (bdops->unlock_native_capacity &&
632	    !(disk->flags & GENHD_FL_NATIVE_CAPACITY)) {
633		printk(KERN_CONT "enabling native capacity\n");
634		bdops->unlock_native_capacity(disk);
635		disk->flags |= GENHD_FL_NATIVE_CAPACITY;
636		return true;
637	} else {
638		printk(KERN_CONT "truncated\n");
639		return false;
640	}
641}
642
643int blk_drop_partitions(struct block_device *bdev)
644{
645	struct disk_part_iter piter;
646	struct hd_struct *part;
647
648	if (bdev->bd_part_count)
649		return -EBUSY;
650
651	sync_blockdev(bdev);
652	invalidate_bdev(bdev);
653
654	disk_part_iter_init(&piter, bdev->bd_disk, DISK_PITER_INCL_EMPTY);
655	while ((part = disk_part_iter_next(&piter)))
656		delete_partition(part);
657	disk_part_iter_exit(&piter);
658
659	return 0;
660}
661#ifdef CONFIG_S390
662/* for historic reasons in the DASD driver */
663EXPORT_SYMBOL_GPL(blk_drop_partitions);
664#endif
665
666static bool blk_add_partition(struct gendisk *disk, struct block_device *bdev,
667		struct parsed_partitions *state, int p)
668{
669	sector_t size = state->parts[p].size;
670	sector_t from = state->parts[p].from;
671	struct hd_struct *part;
672
673	if (!size)
674		return true;
675
676	if (from >= get_capacity(disk)) {
677		printk(KERN_WARNING
678		       "%s: p%d start %llu is beyond EOD, ",
679		       disk->disk_name, p, (unsigned long long) from);
680		if (disk_unlock_native_capacity(disk))
681			return false;
682		return true;
683	}
684
685	if (from + size > get_capacity(disk)) {
686		printk(KERN_WARNING
687		       "%s: p%d size %llu extends beyond EOD, ",
688		       disk->disk_name, p, (unsigned long long) size);
689
690		if (disk_unlock_native_capacity(disk))
691			return false;
692
693		/*
694		 * We can not ignore partitions of broken tables created by for
695		 * example camera firmware, but we limit them to the end of the
696		 * disk to avoid creating invalid block devices.
697		 */
698		size = get_capacity(disk) - from;
699	}
700
701	part = add_partition(disk, p, from, size, state->parts[p].flags,
702			     &state->parts[p].info);
703	if (IS_ERR(part) && PTR_ERR(part) != -ENXIO) {
704		printk(KERN_ERR " %s: p%d could not be added: %ld\n",
705		       disk->disk_name, p, -PTR_ERR(part));
706		return true;
707	}
708
709	if (IS_BUILTIN(CONFIG_BLK_DEV_MD) &&
710	    (state->parts[p].flags & ADDPART_FLAG_RAID))
711		md_autodetect_dev(part_to_dev(part)->devt);
712
713	return true;
714}
715
716int blk_add_partitions(struct gendisk *disk, struct block_device *bdev)
717{
718	struct parsed_partitions *state;
719	int ret = -EAGAIN, p, highest;
720
721	if (!disk_part_scan_enabled(disk))
722		return 0;
723
724	state = check_partition(disk, bdev);
725	if (!state)
726		return 0;
727	if (IS_ERR(state)) {
728		/*
729		 * I/O error reading the partition table.  If we tried to read
730		 * beyond EOD, retry after unlocking the native capacity.
731		 */
732		if (PTR_ERR(state) == -ENOSPC) {
733			printk(KERN_WARNING "%s: partition table beyond EOD, ",
734			       disk->disk_name);
735			if (disk_unlock_native_capacity(disk))
736				return -EAGAIN;
737		}
738		return -EIO;
739	}
740
741	/*
742	 * Partitions are not supported on host managed zoned block devices.
743	 */
744	if (disk->queue->limits.zoned == BLK_ZONED_HM) {
745		pr_warn("%s: ignoring partition table on host managed zoned block device\n",
746			disk->disk_name);
747		ret = 0;
748		goto out_free_state;
749	}
750
751	/*
752	 * If we read beyond EOD, try unlocking native capacity even if the
753	 * partition table was successfully read as we could be missing some
754	 * partitions.
755	 */
756	if (state->access_beyond_eod) {
757		printk(KERN_WARNING
758		       "%s: partition table partially beyond EOD, ",
759		       disk->disk_name);
760		if (disk_unlock_native_capacity(disk))
761			goto out_free_state;
762	}
763
764	/* tell userspace that the media / partition table may have changed */
765	kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
766
767	/*
768	 * Detect the highest partition number and preallocate disk->part_tbl.
769	 * This is an optimization and not strictly necessary.
770	 */
771	for (p = 1, highest = 0; p < state->limit; p++)
772		if (state->parts[p].size)
773			highest = p;
774	disk_expand_part_tbl(disk, highest);
775
776	for (p = 1; p < state->limit; p++)
777		if (!blk_add_partition(disk, bdev, state, p))
778			goto out_free_state;
779
780	ret = 0;
781out_free_state:
782	free_partitions(state);
783	return ret;
784}
785
786void *read_part_sector(struct parsed_partitions *state, sector_t n, Sector *p)
787{
788	struct address_space *mapping = state->bdev->bd_inode->i_mapping;
789	struct page *page;
790
791	if (n >= get_capacity(state->bdev->bd_disk)) {
792		state->access_beyond_eod = true;
793		return NULL;
794	}
795
796	page = read_mapping_page(mapping,
797			(pgoff_t)(n >> (PAGE_SHIFT - 9)), NULL);
798	if (IS_ERR(page))
799		goto out;
800	if (PageError(page))
801		goto out_put_page;
802
803	p->v = page;
804	return (unsigned char *)page_address(page) +
805			((n & ((1 << (PAGE_SHIFT - 9)) - 1)) << SECTOR_SHIFT);
806out_put_page:
807	put_page(page);
808out:
809	p->v = NULL;
810	return NULL;
811}
812