Hi Mikulas, Sorry to trouble you again. I'm reading the source code of dm-writecache, and noticed: ----------------------------------------------------- static struct wc_memory_entry *memory_entry(struct dm_writecache *wc, struct wc_entry *e) { if (is_power_of_2(sizeof(struct wc_entry)) && 0) // why this? return &sb(wc)->entries[e - wc->entries]; else return &sb(wc)->entries[e->index]; } Seems there is something wrong with the if condition, right? Thanks, shenghui -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel