• Jan Kara's avatar
    block: Unhash block device inodes on gendisk destruction · f44f1ab5
    Jan Kara authored
    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: default avatarChristoph Hellwig <hch@lst.de>
    Signed-off-by: default avatarJan Kara <jack@suse.cz>
    Signed-off-by: default avatarJens Axboe <axboe@fb.com>
    f44f1ab5
block_dev.c 55.6 KB