From f44f1ab5a2dcd4e16eab850fd08e40ff2d0c28d4 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Thu, 2 Feb 2017 15:56:49 +0100 Subject: block: Unhash block device inodes on gendisk destruction Currently, block device inodes stay around after corresponding gendisk hash died until memory reclaim finds them and frees them. Since we will make block device inode pin the bdi, we want to free the block device inode as soon as the device goes away so that bdi does not stay around unnecessarily. Furthermore we need to avoid issues when new device with the same major,minor pair gets created since reusing the bdi structure would be rather difficult in this case. Unhashing block device inode on gendisk destruction nicely deals with these problems. Once last block device inode reference is dropped (which may be directly in del_gendisk()), the inode gets evicted. Furthermore if the major,minor pair gets reallocated, we are guaranteed to get new block device inode even if old block device inode is not yet evicted and thus we avoid issues with possible reuse of bdi. Reviewed-by: Christoph Hellwig Signed-off-by: Jan Kara Signed-off-by: Jens Axboe --- block/genhd.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'block/genhd.c') diff --git a/block/genhd.c b/block/genhd.c index fcd6d4fae657..f2f22d0e8e14 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -648,6 +648,8 @@ void del_gendisk(struct gendisk *disk) disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE); while ((part = disk_part_iter_next(&piter))) { + bdev_unhash_inode(MKDEV(disk->major, + disk->first_minor + part->partno)); invalidate_partition(disk, part->partno); delete_partition(disk, part->partno); } -- cgit v1.2.3