rem: if (ch && ch->size == size && ch->offset == offset) { sf->readahead = NULL;
add: if (ch && ch->offset == offset && ch->size == size) { ch->refs++;
context: static struct read_chunk *search_read_chunk(struct sshfs_file *sf, size_t size,                                            off_t offset){    struct read_chunk *ch = sf->readahead;    if (ch && ch->size == size && ch->offset == offset) {        sf->readahead = NULL;        return ch;    } else        return NULL;}