Re: [PATCH] direct IO breaks root filesystem

[Linus Torvalds]

On Tue, 11 Dec 2001, GOTO Masanori wrote:
> I, however, found another problem.
> Accessing with inode size unit (== 4096 byte) is ok, but if I accessed
> with block size unit, generic_direct_IO() returns error.  The reason
> is that blocksize is designated as inode->i_blkbits, and its value is
> not disk minimal block size (512), but inode's unit size (4096).

That is not a bug, but a feature.

We _always_ have to do the IO in "inode size" chunks, and if you want to
change it, you have to change it at a higher level (ie you should set the
blocksize with the "BLKBSZSET" ioctl.)

		Linus