Commit 83cbce95 authored by Luis Chamberlain's avatar Luis Chamberlain Committed by Jens Axboe
Browse files

block: add error handling for device_add_disk / add_disk 



Properly unwind on errors in device_add_disk.  This is the initial work
as drivers are not converted yet, which will follow in separate patches.

Signed-off-by: default avatarLuis Chamberlain <mcgrof@kernel.org>
[hch: major rebase.  All bugs are probably mine]
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20210818144542.19305-10-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 92e7755e

block/genhd.c

+58 −34
Original line number Diff line number Diff line
@@ -417,11 +417,8 @@ static void disk_scan_partitions(struct gendisk *disk) 
 *

 * This function registers the partitioning information in @disk

 * with the kernel.

 *

 * FIXME: error handling

 */



void device_add_disk(struct device *parent, struct gendisk *disk,

int device_add_disk(struct device *parent, struct gendisk *disk,

		     const struct attribute_group **groups)



{
@@ -444,7 +441,8 @@ void device_add_disk(struct device *parent, struct gendisk *disk, 
	 * and all partitions from the extended dev_t space.

	 */

	if (disk->major) {

		WARN_ON(!disk->minors);

		if (WARN_ON(!disk->minors))

			return -EINVAL;



		if (disk->minors > DISK_MAX_PARTS) {

			pr_err("block: can't allocate more than %d partitions\n",
@@ -452,19 +450,20 @@ void device_add_disk(struct device *parent, struct gendisk *disk, 
			disk->minors = DISK_MAX_PARTS;

		}

	} else {

		WARN_ON(disk->minors);

		if (WARN_ON(disk->minors))

			return -EINVAL;



		ret = blk_alloc_ext_minor();

		if (ret < 0) {

			WARN_ON(1);

			return;

		}

		if (ret < 0)

			return ret;

		disk->major = BLOCK_EXT_MAJOR;

		disk->first_minor = MINOR(ret);

		disk->flags |= GENHD_FL_EXT_DEVT;

	}



	disk_alloc_events(disk);

	ret = disk_alloc_events(disk);

	if (ret)

		goto out_free_ext_minor;



	/* delay uevents, until we scanned partition table */

	dev_set_uevent_suppress(ddev, 1);
@@ -474,15 +473,14 @@ void device_add_disk(struct device *parent, struct gendisk *disk, 
	dev_set_name(ddev, "%s", disk->disk_name);

	if (!(disk->flags & GENHD_FL_HIDDEN))

		ddev->devt = MKDEV(disk->major, disk->first_minor);

	if (device_add(ddev))

		return;

	ret = device_add(ddev);

	if (ret)

		goto out_disk_release_events;

	if (!sysfs_deprecated) {

		ret = sysfs_create_link(block_depr, &ddev->kobj,

					kobject_name(&ddev->kobj));

		if (ret) {

			device_del(ddev);

			return;

		}

		if (ret)

			goto out_device_del;

	}



	/*
@@ -492,23 +490,25 @@ void device_add_disk(struct device *parent, struct gendisk *disk, 
	 */

	pm_runtime_set_memalloc_noio(ddev, true);



	blk_integrity_add(disk);

	ret = blk_integrity_add(disk);

	if (ret)

		goto out_del_block_link;



	disk->part0->bd_holder_dir =

		kobject_create_and_add("holders", &ddev->kobj);

	if (!disk->part0->bd_holder_dir)

		goto out_del_integrity;

	disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);

	if (!disk->slave_dir)

		goto out_put_holder_dir;



	/*

	 * XXX: this is a mess, can't wait for real error handling in add_disk.

	 * Make sure ->slave_dir is NULL if we failed some of the registration

	 * so that the cleanup in bd_unlink_disk_holder works properly.

	 */

	if (bd_register_pending_holders(disk) < 0) {

		kobject_put(disk->slave_dir);

		disk->slave_dir = NULL;

	}

	ret = bd_register_pending_holders(disk);

	if (ret < 0)

		goto out_put_slave_dir;



	blk_register_queue(disk);

	ret = blk_register_queue(disk);

	if (ret)

		goto out_put_slave_dir;



	if (disk->flags & GENHD_FL_HIDDEN) {

		/*
@@ -520,13 +520,13 @@ void device_add_disk(struct device *parent, struct gendisk *disk, 
	} else {

		ret = bdi_register(disk->bdi, "%u:%u",

				   disk->major, disk->first_minor);

		WARN_ON(ret);

		if (ret)

			goto out_unregister_queue;

		bdi_set_owner(disk->bdi, ddev);

		if (disk->bdi->dev) {

		ret = sysfs_create_link(&ddev->kobj,

					&disk->bdi->dev->kobj, "bdi");

			WARN_ON(ret);

		}

		if (ret)

			goto out_unregister_bdi;



		bdev_add(disk->part0, ddev->devt);

		disk_scan_partitions(disk);
@@ -541,6 +541,30 @@ void device_add_disk(struct device *parent, struct gendisk *disk, 


	disk_update_readahead(disk);

	disk_add_events(disk);

	return 0;



out_unregister_bdi:

	if (!(disk->flags & GENHD_FL_HIDDEN))

		bdi_unregister(disk->bdi);

out_unregister_queue:

	blk_unregister_queue(disk);

out_put_slave_dir:

	kobject_put(disk->slave_dir);

out_put_holder_dir:

	kobject_put(disk->part0->bd_holder_dir);

out_del_integrity:

	blk_integrity_del(disk);

out_del_block_link:

	if (!sysfs_deprecated)

		sysfs_remove_link(block_depr, dev_name(ddev));

out_device_del:

	device_del(ddev);

out_disk_release_events:

	disk_release_events(disk);

out_free_ext_minor:

	if (disk->major == BLOCK_EXT_MAJOR)

		blk_free_ext_minor(disk->first_minor);

	return WARN_ON_ONCE(ret); /* keep until all callers handle errors */

}

EXPORT_SYMBOL(device_add_disk);

include/linux/genhd.h

+4 −4
Original line number Diff line number Diff line
@@ -214,11 +214,11 @@ static inline dev_t disk_devt(struct gendisk *disk) 
void disk_uevent(struct gendisk *disk, enum kobject_action action);



/* block/genhd.c */

extern void device_add_disk(struct device *parent, struct gendisk *disk,

int device_add_disk(struct device *parent, struct gendisk *disk,

		const struct attribute_group **groups);

static inline void add_disk(struct gendisk *disk)

static inline int add_disk(struct gendisk *disk)

{

	device_add_disk(NULL, disk, NULL);

	return device_add_disk(NULL, disk, NULL);

}

extern void del_gendisk(struct gendisk *gp);