ceph: remove redundant code for max file size verification

Both ceph_update_writeable_page and ceph_setattr will verify file size
with max size ceph supported.
There are two caller for ceph_update_writeable_page, ceph_write_begin and
ceph_page_mkwrite. For ceph_write_begin, we have already verified the size in
generic_write_checks of ceph_write_iter; for ceph_page_mkwrite, we have no
chance to change file size when mmap. Likewise we have already verified the size
in inode_change_ok when we call ceph_setattr.
So let's remove the redundant code for max file size verification.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Reviewed-by: Yan, Zheng <zyan@redhat.com>

fs/ceph/addr.c

@@ -1076,12 +1076,6 @@ retry_locked:
 	/* past end of file? */
 	i_size = inode->i_size;   /* caller holds i_mutex */
 
-	if (i_size + len > inode->i_sb->s_maxbytes) {
-		/* file is too big */
-		r = -EINVAL;
-		goto fail;
-	}
-
 	if (page_off >= i_size ||
 	    (pos_in_page == 0 && (pos+len) >= i_size &&
 	     end_in_page - pos_in_page != PAGE_CACHE_SIZE)) {
@@ -1099,9 +1093,6 @@ retry_locked:
 	if (r < 0)
 		goto fail_nosnap;
 	goto retry_locked;
-
-fail:
-	up_read(&mdsc->snap_rwsem);
 fail_nosnap:
 	unlock_page(page);
 	return r;