Re: [PATCH 2/2] ext4: add ext4_iget_normal() which is to be used for dir tree lookups

[Theodore Ts'o <tytso@mit.edu>]

On Mon, Oct 06, 2014 at 05:09:03PM +0200, Jan Kara wrote:
> > +	if (ret_inode && !IS_ERR(ret_inode) &&
> > +	    ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
> > +		make_bad_inode(ret_inode);
> > +	return ret_inode;
>   Hum, why don't we just return an error (like EIO) when invalid inode
> number is passed?

Yeah, I guess we can do that.  We need to support the make_bad_inode()
for the sake of EXT4_IOC_SWAP_BOOT.  But that code path doesn't need
to use ext4_iget_normal().  So yeah, in the case of
ext4_iget_normal(), we should be able to just return -EIO and let the
userspace fail fast with the open(2) instead of later on with the
read(2) or write(2) or truncate(2) call.

						- Ted