Re: [PATCH v4 02/11] nbd/server.c: add missing coroutine_fn annotations

[Kevin Wolf]

Am 16.11.2022 um 13:22 hat Emanuele Giuseppe Esposito geschrieben:
> These functions end up calling bdrv_*() implemented as generated_co_wrapper
> functions.
> In addition, they also happen to be always called in coroutine context,
> meaning all callers are coroutine_fn.
> This means that the g_c_w function will enter the qemu_in_coroutine()
> case and eventually suspend (or in other words call qemu_coroutine_yield()).
> Therefore we need to mark such functions coroutine_fn too.
> 
> Signed-off-by: Emanuele Giuseppe Esposito 

Here, too, it would be better to convert the callers to new blk_co_*()
wrappers instead of going through g_c_w even though we know that we are
in coroutine context.

Doesn't make the patch less correct, though.

Reviewed-by: Kevin Wolf 

[PATCH v4 02/11] nbd/server.c: add missing coroutine_fn annotations

[Emanuele Giuseppe Esposito]

These functions end up calling bdrv_*() implemented as generated_co_wrapper
functions.
In addition, they also happen to be always called in coroutine context,
meaning all callers are coroutine_fn.
This means that the g_c_w function will enter the qemu_in_coroutine()
case and eventually suspend (or in other words call qemu_coroutine_yield()).
Therefore we need to mark such functions coroutine_fn too.

Signed-off-by: Emanuele Giuseppe Esposito 
---
 nbd/server.c | 21 -
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/nbd/server.c b/nbd/server.c
index ada16089f3..e2eec0cf46 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -2141,8 +2141,9 @@ static int nbd_extent_array_add(NBDExtentArray *ea,
 return 0;
 }
 
-static int blockstatus_to_extents(BlockDriverState *bs, uint64_t offset,
-  uint64_t bytes, NBDExtentArray *ea)
+static int coroutine_fn blockstatus_to_extents(BlockDriverState *bs,
+   uint64_t offset, uint64_t bytes,
+   NBDExtentArray *ea)
 {
 while (bytes) {
 uint32_t flags;
@@ -2168,8 +2169,9 @@ static int blockstatus_to_extents(BlockDriverState *bs, 
uint64_t offset,
 return 0;
 }
 
-static int blockalloc_to_extents(BlockDriverState *bs, uint64_t offset,
- uint64_t bytes, NBDExtentArray *ea)
+static int coroutine_fn blockalloc_to_extents(BlockDriverState *bs,
+  uint64_t offset, uint64_t bytes,
+  NBDExtentArray *ea)
 {
 while (bytes) {
 int64_t num;
@@ -2220,11 +,12 @@ static int nbd_co_send_extents(NBDClient *client, 
uint64_t handle,
 }
 
 /* Get block status from the exported device and send it to the client */
-static int nbd_co_send_block_status(NBDClient *client, uint64_t handle,
-BlockDriverState *bs, uint64_t offset,
-uint32_t length, bool dont_fragment,
-bool last, uint32_t context_id,
-Error **errp)
+static int
+coroutine_fn nbd_co_send_block_status(NBDClient *client, uint64_t handle,
+  BlockDriverState *bs, uint64_t offset,
+  uint32_t length, bool dont_fragment,
+  bool last, uint32_t context_id,
+  Error **errp)
 {
 int ret;
 unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BLOCK_STATUS_EXTENTS;
-- 
2.31.1