On Mon, Aug 25, 2025 at 04:56:55PM +0800, Ming Lei wrote:

`stat $BDEV_PATH` never works for getting bdev size, so it looks wrong
to call vfs_getattr_nosec() with bdev path for retrieving bdev's size.

Exactly.

So just wondering why not take the following more readable way?

	/* vfs_getattr() never works for retrieving bdev size */
	if (S_ISBLK(stat.mode)) {
		loopsize = i_size_read(file->f_mapping->host);
	} else {
          ret = vfs_getattr_nosec(&file->f_path, &stat, STATX_SIZE, 0);
          if (ret)
                  return 0;
          loopsize = stat.size;
	}

Also the above looks like how application reads file size in case of bdev
involved.

That's not just more readable, but simply the way to go.  Maybe split
it into a helper for readability, though.