On Wed, Jun 15, 2022 at 05:04:57PM -0700, Eric Biggers wrote: > One more thing. I'm trying to add support for STATX_DIOALIGN on block devices. > Unfortunately I don't think it is going to work, at all, since the inode is for > the device node and not the block device itself. This is true even after the > file is opened (I previously thought that at least that case would work). For an open file the block device inode is pointed to by file->f_mapping->host. > Were you expecting that this would work on block devices? It seems they will > need a different API -- a new BLK* ioctl, or files in /sys/block/$dev/queue. blkdev_get_no_open on inode->i_rdev gets you the block device, which then has bdev->bd_inode point to the underlying block device, although for a block device those limit probably would be retrieved not from the inode but the gendisk / request_queue anyway.