Commit d7a66574 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: unhash the whole device inode earlier 



Unhash the whole device inode early in del_gendisk.  This allows to
remove the first GENHD_FL_UP check in the open path as we simply
won't find a just removed inode.  The second non-racy check after
taking open_mutex is still kept.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210722075402.983367-4-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent a45e43ca

block/genhd.c

+1 −6
Original line number Diff line number Diff line
@@ -585,6 +585,7 @@ void del_gendisk(struct gendisk *disk) 
	disk_del_events(disk);



	mutex_lock(&disk->open_mutex);

	remove_inode_hash(disk->part0->bd_inode);

	disk->flags &= ~GENHD_FL_UP;

	blk_drop_partitions(disk);

	mutex_unlock(&disk->open_mutex);
@@ -592,12 +593,6 @@ void del_gendisk(struct gendisk *disk) 
	fsync_bdev(disk->part0);

	__invalidate_device(disk->part0, true);



	/*

	 * Unhash the bdev inode for this device so that it can't be looked

	 * up any more even if openers still hold references to it.

	 */

	remove_inode_hash(disk->part0->bd_inode);



	set_capacity(disk, 0);



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

fs/block_dev.c

+1 −1
Original line number Diff line number Diff line
@@ -1340,7 +1340,7 @@ struct block_device *blkdev_get_no_open(dev_t dev) 
	disk = bdev->bd_disk;

	if (!kobject_get_unless_zero(&disk_to_dev(disk)->kobj))

		goto bdput;

	if ((disk->flags & (GENHD_FL_UP | GENHD_FL_HIDDEN)) != GENHD_FL_UP)

	if (disk->flags & GENHD_FL_HIDDEN)

		goto put_disk;

	if (!try_module_get(bdev->bd_disk->fops->owner))

		goto put_disk;