Large EAs for ext4

Hi,

These are the updated patches for adding large EA support to ext4. Changes suggested by Mingming and Andreas for earlier patches have been incorporated in this version.

Large EAs with values greater than half the filesystem blocksize are stored in an external inode.

Patch 1/2 - EA inodes are not connected to any directory and hence ext4_new_inode() cannot make a decision about where to allocate the EA inode. So we add a new goal argument to ext4_new_inode() so that the EA inode can be allocated close to the parent inode.

Patch 2/2 - Adds actual support for large EAs.

Thanks,
Kalpak