[v2] block: Protect AIO context change with perm API

[Qemu-devel] [PATCH v2 15/16] block: Add perm assertion on blk_set_aio_context

Posted by Fam Zheng 8 years, 9 months ago

Now that all BB users comply with the BLK_PERM_AIO_CONTEXT_CHANGE
rule, we can assert it.

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 block/block-backend.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/block/block-backend.c b/block/block-backend.c
index 6133917..166edac 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -1670,8 +1670,12 @@ static AioContext *blk_aiocb_get_aio_context(BlockAIOCB *acb)
 
 void blk_set_aio_context(BlockBackend *blk, AioContext *new_context)
 {
+    uint64_t perm, shared_perm;
     BlockDriverState *bs = blk_bs(blk);
 
+    blk_get_perm(blk, &perm, &shared_perm);
+    assert(perm & BLK_PERM_AIO_CONTEXT_CHANGE);
+
     blk->aio_context = new_context;
     if (bs) {
         if (blk->public.throttle_state) {
-- 
2.9.3

Re: [Qemu-devel] [Qemu-block] [PATCH v2 15/16] block: Add perm assertion on blk_set_aio_context

Posted by Stefan Hajnoczi 8 years, 9 months ago

On Wed, Apr 19, 2017 at 05:43:55PM +0800, Fam Zheng wrote:
> Now that all BB users comply with the BLK_PERM_AIO_CONTEXT_CHANGE
> rule, we can assert it.
> 
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  block/block-backend.c | 4 ++++
>  1 file changed, 4 insertions(+)

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>