block: Fix bio_copy_data()

The memcpy() in bio_copy_data() was using the wrong offset vars, leading
to data corruption in weird unusual setups.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.9
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/bio.c b/fs/bio.c
index b3b20ed9510e5ccc285195cce7aa7e3f524ed063..ea5035da4d9a0cd9fd6f5f657bb01272c63175c3 100644 (file)
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -917,8 +917,8 @@ void bio_copy_data(struct bio *dst, struct bio *src)
                src_p = kmap_atomic(src_bv->bv_page);
                dst_p = kmap_atomic(dst_bv->bv_page);
 
-               memcpy(dst_p + dst_bv->bv_offset,
-                      src_p + src_bv->bv_offset,
+               memcpy(dst_p + dst_offset,
+                      src_p + src_offset,
                       bytes);
 
                kunmap_atomic(dst_p);