Write out & wait on a file range
int filemap_write_and_wait_range(struct address_space * mapping, loff_t lstart, loff_t lend);
mapping
the address_space for the pages
lstart
offset in bytes where the range starts
lend
offset in bytes where the range ends (inclusive)
Write out and wait upon file offsets lstart->lend, inclusive.
Note that `lend' is inclusive (describes the last byte to be written) so that this function can be used to write to the very end-of-file (end = -1).