39 lines
1.6 KiB
Diff
39 lines
1.6 KiB
Diff
|
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
|
||
|
|
Date: Thu, 12 Mar 2020 11:19:49 +0300
|
||
|
|
Subject: block/io: fix bdrv_co_do_copy_on_readv
|
||
|
|
|
||
|
|
Git-commit: 4ab78b19189a81038e744728ed949d09aa477550
|
||
|
|
|
||
|
|
Prior to 1143ec5ebf4 it was OK to qemu_iovec_from_buf() from aligned-up
|
||
|
|
buffer to original qiov, as qemu_iovec_from_buf() will stop at qiov end
|
||
|
|
anyway.
|
||
|
|
|
||
|
|
But after 1143ec5ebf4 we assume that bdrv_co_do_copy_on_readv works on
|
||
|
|
part of original qiov, defined by qiov_offset and bytes. So we must not
|
||
|
|
touch qiov behind qiov_offset+bytes bound. Fix it.
|
||
|
|
|
||
|
|
Cc: qemu-stable@nongnu.org # v4.2
|
||
|
|
Fixes: 1143ec5ebf4
|
||
|
|
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
|
||
|
|
Reviewed-by: John Snow <jsnow@redhat.com>
|
||
|
|
Message-id: 20200312081949.5350-1-vsementsov@virtuozzo.com
|
||
|
|
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
|
||
|
|
Signed-off-by: Bruce Rogers <brogers@suse.com>
|
||
|
|
---
|
||
|
|
block/io.c | 2 +-
|
||
|
|
1 file changed, 1 insertion(+), 1 deletion(-)
|
||
|
|
|
||
|
|
diff --git a/block/io.c b/block/io.c
|
||
|
|
index d1f1ee9138c7af82352e9277f22b..c2c3aab9ee3d1d4d494ce98a6d8b 100644
|
||
|
|
--- a/block/io.c
|
||
|
|
+++ b/block/io.c
|
||
|
|
@@ -1395,7 +1395,7 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
|
||
|
|
if (!(flags & BDRV_REQ_PREFETCH)) {
|
||
|
|
qemu_iovec_from_buf(qiov, qiov_offset + progress,
|
||
|
|
bounce_buffer + skip_bytes,
|
||
|
|
- pnum - skip_bytes);
|
||
|
|
+ MIN(pnum - skip_bytes, bytes - progress));
|
||
|
|
}
|
||
|
|
} else if (!(flags & BDRV_REQ_PREFETCH)) {
|
||
|
|
/* Read directly into the destination */
|