rbd: flush dcache after zeroing page data
Neither zero_bio_chain() nor zero_pages() contains a call to flush
caches after zeroing a portion of a page. This can cause problems
on architectures that have caches that allow virtual address
aliasing.
This resolves:
http://tracker.ceph.com/issues/4777
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 291802c..cb728a0 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1126,6 +1126,7 @@
buf = bvec_kmap_irq(bv, &flags);
memset(buf + remainder, 0,
bv->bv_len - remainder);
+ flush_dcache_page(bv->bv_page);
bvec_kunmap_irq(buf, &flags);
}
pos += bv->bv_len;
@@ -1158,6 +1159,7 @@
local_irq_save(flags);
kaddr = kmap_atomic(*page);
memset(kaddr + page_offset, 0, length);
+ flush_dcache_page(*page);
kunmap_atomic(kaddr);
local_irq_restore(flags);