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Commit e2156054 authored by Alex Elder's avatar Alex Elder Committed by Sage Weil
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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: default avatarAlex Elder <elder@inktank.com>
Reviewed-by: default avatarJosh Durgin <josh.durgin@inktank.com>
parent 96e4dac6

drivers/block/rbd.c

+2 −0
Original line number Diff line number Diff line
@@ -1126,6 +1126,7 @@ static void zero_bio_chain(struct bio *chain, int start_ofs) 
				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 @@ static void zero_pages(struct page **pages, u64 offset, u64 end) 
		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);