@@ -925,9 +925,11 @@ bdrv_driver_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
return drv->bdrv_co_pwritev_compressed(bs, offset, bytes, qiov);
}
-static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs,
+static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
int64_t offset, unsigned int bytes, QEMUIOVector *qiov)
{
+ BlockDriverState *bs = child->bs;
+
/* Perform I/O through a temporary buffer so that users who scribble over
* their read buffer while the operation is in progress do not end up
* modifying the image file. This is critical for zero-copy guest I/O
@@ -943,6 +945,8 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs,
size_t skip_bytes;
int ret;
+ assert(child->perm & (BLK_PERM_WRITE_UNCHANGED | BLK_PERM_WRITE));
+
/* Cover entire cluster so no additional backing file I/O is required when
* allocating cluster in the image file.
*/
@@ -1051,7 +1055,7 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child,
}
if (!ret || pnum != nb_sectors) {
- ret = bdrv_co_do_copy_on_readv(bs, offset, bytes, qiov);
+ ret = bdrv_co_do_copy_on_readv(child, offset, bytes, qiov);
goto out;
}
}
@@ -1334,6 +1338,7 @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child,
assert(!waited || !req->serialising);
assert(req->overlap_offset <= offset);
assert(offset + bytes <= req->overlap_offset + req->overlap_bytes);
+ assert(child->perm & BLK_PERM_WRITE);
ret = notifier_with_return_list_notify(&bs->before_write_notifiers, req);
This adds assertions that ensure that the necessary write permissions have been granted before someone attempts to write to a node. Signed-off-by: Kevin Wolf <kwolf@redhat.com> --- block/io.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)