Commit 73acaff5 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by openeuler-sync-bot
Browse files

md: fix error handling in md_alloc 

mainline inclusion
from mainline-v6.0-rc1
commit c57094a6
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I81XCK

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c57094a6e1ed5dd2d6401f79b8e6da34dd28f959



--------------------------------

Error handling in md_alloc is a mess.  Untangle it to just free the mddev
directly before add_disk is called and thus the gendisk is globally
visible.  After that clear the hold flag and let the mddev_put take care
of cleaning up the mddev through the usual mechanisms.

Fixes: 5e55e2f5 ("[PATCH] md: convert compile time warnings into runtime warnings")
Fixes: 9be68dd7 ("md: add error handling support for add_disk()")
Fixes: 7ad10691 ("md: properly unwind when failing to add the kobject in md_alloc")
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Signed-off-by: default avatarSong Liu <song@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>

Conflict:
	drivers/md/md.c
	Commit 8b9ab626 ("block: remove blk_cleanup_disk") change
	blk_cleanup_disk() to put_disk(). Keep using blk_cleanup_disk()
	here. And add_disk_safe().

Signed-off-by: default avatarLi Nan <linan122@huawei.com>
(cherry picked from commit 6d01bb59)
parent 024dc8ec

drivers/md/md.c

+32 −13
Original line number Diff line number Diff line
@@ -800,6 +800,15 @@ static struct mddev *mddev_alloc(dev_t unit) 
	return ERR_PTR(error);

}



static void mddev_free(struct mddev *mddev)

{

	spin_lock(&all_mddevs_lock);

	list_del(&mddev->all_mddevs);

	spin_unlock(&all_mddevs_lock);



	kfree(mddev);

}



static const struct attribute_group md_redundancy_group;



void mddev_unlock(struct mddev *mddev)
@@ -5736,8 +5745,8 @@ static int md_alloc(dev_t dev, char *name) 
	mutex_lock(&disks_mutex);

	mddev = mddev_alloc(dev);

	if (IS_ERR(mddev)) {

		mutex_unlock(&disks_mutex);

		return PTR_ERR(mddev);

		error = PTR_ERR(mddev);

		goto out_unlock;

	}



	partitioned = (MAJOR(mddev->unit) != MD_MAJOR);
@@ -5755,7 +5764,7 @@ static int md_alloc(dev_t dev, char *name) 
			    strcmp(mddev2->gendisk->disk_name, name) == 0) {

				spin_unlock(&all_mddevs_lock);

				error = -EEXIST;

				goto out_unlock_disks_mutex;

				goto out_free_mddev;

			}

		spin_unlock(&all_mddevs_lock);

	}
@@ -5768,7 +5777,7 @@ static int md_alloc(dev_t dev, char *name) 
	error = -ENOMEM;

	disk = blk_alloc_disk(NUMA_NO_NODE);

	if (!disk)

		goto out_unlock_disks_mutex;

		goto out_free_mddev;



	disk->major = MAJOR(mddev->unit);

	disk->first_minor = unit << shift;
@@ -5794,26 +5803,36 @@ static int md_alloc(dev_t dev, char *name) 
	mddev->gendisk = disk;

	error = add_disk_safe(disk);

	if (error)

		goto out_cleanup_disk;

		goto out_put_disk;



	kobject_init(&mddev->kobj, &md_ktype);

	error = kobject_add(&mddev->kobj, &disk_to_dev(disk)->kobj, "%s", "md");

	if (error)

		goto out_del_gendisk;

	if (error) {

		/*

		 * The disk is already live at this point.  Clear the hold flag

		 * and let mddev_put take care of the deletion, as it isn't any

		 * different from a normal close on last release now.

		 */

		mddev->hold_active = 0;

		goto done;

	}



	kobject_uevent(&mddev->kobj, KOBJ_ADD);

	mddev->sysfs_state = sysfs_get_dirent_safe(mddev->kobj.sd, "array_state");

	mddev->sysfs_level = sysfs_get_dirent_safe(mddev->kobj.sd, "level");

	goto out_unlock_disks_mutex;



out_del_gendisk:

	del_gendisk(disk);

out_cleanup_disk:

	blk_cleanup_disk(disk);

out_unlock_disks_mutex:

done:

	mutex_unlock(&disks_mutex);

	mddev_put(mddev);

	return error;



out_put_disk:

	blk_cleanup_disk(disk);

out_free_mddev:

	mddev_free(mddev);

out_unlock:

	mutex_unlock(&disks_mutex);

	return error;

}



static struct kobject *md_probe(dev_t dev, int *part, void *data)