drbd: fix bitmap writeout after aborted resync

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

diff --git a/drivers/block/drbd/drbd_bitmap.c b/drivers/block/drbd/drbd_bitmap.c
index 092f827..fcbc5e1 100644 (file)
--- a/drivers/block/drbd/drbd_bitmap.c
+++ b/drivers/block/drbd/drbd_bitmap.c
@@ -1448,13 +1448,21 @@ static inline void bm_set_full_words_within_one_page(struct drbd_bitmap *b,
 {
        int i;
        int bits;
+       int changed = 0;
        unsigned long *paddr = kmap_atomic(b->bm_pages[page_nr], KM_IRQ1);
        for (i = first_word; i < last_word; i++) {
                bits = hweight_long(paddr[i]);
                paddr[i] = ~0UL;
-               b->bm_set += BITS_PER_LONG - bits;
+               changed += BITS_PER_LONG - bits;
        }
        kunmap_atomic(paddr, KM_IRQ1);
+       if (changed) {
+               /* We only need lazy writeout, the information is still in the
+                * remote bitmap as well, and is reconstructed during the next
+                * bitmap exchange, if lost locally due to a crash. */
+               bm_set_page_lazy_writeout(b->bm_pages[page_nr]);
+               b->bm_set += changed;
+       }
 }
 
 /* Same thing as drbd_bm_set_bits,