defined ceph_osdc_readpages() and ceph_osdc_readpage_filler().

defined ceph_osdc_readpages() and ceph_osdc_readpage_filler().

renamed do_ceph_read as ceph_readpage_async(),
 do_ceph_write as ceph_writepage_async() respectively.

now ceph_writepage method is really used,

and buggy unlock_page() functions were removed, to avoid kernel panics.

Conflicts:

	src/kernel/addr.c
	src/kernel/file.c
	src/kernel/osd_client.c
	src/kernel/osd_client.h