vfs: export new_inode_pseudo

vfs: export new_inode_pseudo

Ceph needs to be able to allocate inodes ahead of a create that might
involve a fscrypt-encrypted inode. new_inode() almost fits the bill,
but it puts the inode on the sb->s_inodes list and when we go to hash
it, that might be done again.

We could work around that by setting I_CREATING on the new inode, but
that causes ilookup5 to return -ESTALE if something tries to find it
before I_NEW is cleared. This is desirable behavior for most
filesystems, but doesn't work for ceph.

To work around all of this, just use new_inode_pseudo which doesn't add
it to the sb->s_inodes list.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jeff Layton <jlayton@kernel.org>