block: Mark public read/write functions GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pread*/pwrite*() need to hold a reader lock for the graph.

For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-12-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 8 insertions, 6 deletions

diff --git a/include/block/block_int-io.h b/include/block/block_int-io.h
index 4bb6ccaa34..34d4b0fb8e 100644
--- a/include/block/block_int-io.h
+++ b/include/block/block_int-io.h
@@ -44,33 +44,35 @@ int coroutine_fn GRAPH_RDLOCK bdrv_co_pdiscard_snapshot(BlockDriverState *bs,
     int64_t offset, int64_t bytes);
 
 
-int coroutine_fn bdrv_co_preadv(BdrvChild *child,
+int coroutine_fn GRAPH_RDLOCK bdrv_co_preadv(BdrvChild *child,
     int64_t offset, int64_t bytes, QEMUIOVector *qiov,
     BdrvRequestFlags flags);
-int coroutine_fn bdrv_co_preadv_part(BdrvChild *child,
+int coroutine_fn GRAPH_RDLOCK bdrv_co_preadv_part(BdrvChild *child,
     int64_t offset, int64_t bytes,
     QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags);
-int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
+int coroutine_fn GRAPH_RDLOCK bdrv_co_pwritev(BdrvChild *child,
     int64_t offset, int64_t bytes, QEMUIOVector *qiov,
     BdrvRequestFlags flags);
-int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,
+int coroutine_fn GRAPH_RDLOCK bdrv_co_pwritev_part(BdrvChild *child,
     int64_t offset, int64_t bytes,
     QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags);
 
-static inline int coroutine_fn bdrv_co_pread(BdrvChild *child,
+static inline int coroutine_fn GRAPH_RDLOCK bdrv_co_pread(BdrvChild *child,
     int64_t offset, int64_t bytes, void *buf, BdrvRequestFlags flags)
 {
     QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
     IO_CODE();
+    assert_bdrv_graph_readable();
 
     return bdrv_co_preadv(child, offset, bytes, &qiov, flags);
 }
 
-static inline int coroutine_fn bdrv_co_pwrite(BdrvChild *child,
+static inline int coroutine_fn GRAPH_RDLOCK bdrv_co_pwrite(BdrvChild *child,
     int64_t offset, int64_t bytes, const void *buf, BdrvRequestFlags flags)
 {
     QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
     IO_CODE();
+    assert_bdrv_graph_readable();
 
     return bdrv_co_pwritev(child, offset, bytes, &qiov, flags);
 }