2024-02-13 10:13:17

by Arnd Bergmann

[permalink] [raw]
Subject: [PATCH] drbd: fix function cast warnings in state machine

From: Arnd Bergmann <[email protected]>

There are four state machines in drbd that use a common infrastructure, with
a cast to an incompatible function type in REMEMBER_STATE_CHANGE that clang-16
now warns about:

drivers/block/drbd/drbd_state.c:1632:3: error: cast from 'int (*)(struct sk_buff *, unsigned int, struct drbd_resource_state_change *, enum drbd_notification_type)' to 'typeof (last_func)' (aka 'int (*)(struct sk_buff *, unsigned int, void *, enum drbd_notification_type)') converts to incompatible function type [-Werror,-Wcast-function-type-strict]
1632 | REMEMBER_STATE_CHANGE(notify_resource_state_change,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1633 | resource_state_change, NOTIFY_CHANGE);
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/block/drbd/drbd_state.c:1619:17: note: expanded from macro 'REMEMBER_STATE_CHANGE'
1619 | last_func = (typeof(last_func))func; \
| ^~~~~~~~~~~~~~~~~~~~~~~
drivers/block/drbd/drbd_state.c:1641:4: error: cast from 'int (*)(struct sk_buff *, unsigned int, struct drbd_connection_state_change *, enum drbd_notification_type)' to 'typeof (last_func)' (aka 'int (*)(struct sk_buff *, unsigned int, void *, enum drbd_notification_type)') converts to incompatible function type [-Werror,-Wcast-function-type-strict]
1641 | REMEMBER_STATE_CHANGE(notify_connection_state_change,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1642 | connection_state_change, NOTIFY_CHANGE);
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Change these all to actually expect a void pointer to be passed, which
matches the caller.

Signed-off-by: Arnd Bergmann <[email protected]>
---
drivers/block/drbd/drbd_state.c | 24 ++++++++++++++----------
drivers/block/drbd/drbd_state_change.h | 8 ++++----
2 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c
index 287a8d1d3f70..e858e7e0383f 100644
--- a/drivers/block/drbd/drbd_state.c
+++ b/drivers/block/drbd/drbd_state.c
@@ -1542,9 +1542,10 @@ int drbd_bitmap_io_from_worker(struct drbd_device *device,

int notify_resource_state_change(struct sk_buff *skb,
unsigned int seq,
- struct drbd_resource_state_change *resource_state_change,
+ void *state_change,
enum drbd_notification_type type)
{
+ struct drbd_resource_state_change *resource_state_change = state_change;
struct drbd_resource *resource = resource_state_change->resource;
struct resource_info resource_info = {
.res_role = resource_state_change->role[NEW],
@@ -1558,13 +1559,14 @@ int notify_resource_state_change(struct sk_buff *skb,

int notify_connection_state_change(struct sk_buff *skb,
unsigned int seq,
- struct drbd_connection_state_change *connection_state_change,
+ void *state_change,
enum drbd_notification_type type)
{
- struct drbd_connection *connection = connection_state_change->connection;
+ struct drbd_connection_state_change *p = state_change;
+ struct drbd_connection *connection = p->connection;
struct connection_info connection_info = {
- .conn_connection_state = connection_state_change->cstate[NEW],
- .conn_role = connection_state_change->peer_role[NEW],
+ .conn_connection_state = p->cstate[NEW],
+ .conn_role = p->peer_role[NEW],
};

return notify_connection_state(skb, seq, connection, &connection_info, type);
@@ -1572,9 +1574,10 @@ int notify_connection_state_change(struct sk_buff *skb,

int notify_device_state_change(struct sk_buff *skb,
unsigned int seq,
- struct drbd_device_state_change *device_state_change,
+ void *state_change,
enum drbd_notification_type type)
{
+ struct drbd_device_state_change *device_state_change = state_change;
struct drbd_device *device = device_state_change->device;
struct device_info device_info = {
.dev_disk_state = device_state_change->disk_state[NEW],
@@ -1585,9 +1588,10 @@ int notify_device_state_change(struct sk_buff *skb,

int notify_peer_device_state_change(struct sk_buff *skb,
unsigned int seq,
- struct drbd_peer_device_state_change *p,
+ void *state_change,
enum drbd_notification_type type)
{
+ struct drbd_peer_device_state_change *p = state_change;
struct drbd_peer_device *peer_device = p->peer_device;
struct peer_device_info peer_device_info = {
.peer_repl_state = p->repl_state[NEW],
@@ -1605,8 +1609,8 @@ static void broadcast_state_change(struct drbd_state_change *state_change)
struct drbd_resource_state_change *resource_state_change = &state_change->resource[0];
bool resource_state_has_changed;
unsigned int n_device, n_connection, n_peer_device, n_peer_devices;
- int (*last_func)(struct sk_buff *, unsigned int, void *,
- enum drbd_notification_type) = NULL;
+ int (*last_func)(struct sk_buff *, unsigned int,
+ void *, enum drbd_notification_type) = NULL;
void *last_arg = NULL;

#define HAS_CHANGED(state) ((state)[OLD] != (state)[NEW])
@@ -1616,7 +1620,7 @@ static void broadcast_state_change(struct drbd_state_change *state_change)
})
#define REMEMBER_STATE_CHANGE(func, arg, type) \
({ FINAL_STATE_CHANGE(type | NOTIFY_CONTINUES); \
- last_func = (typeof(last_func))func; \
+ last_func = func; \
last_arg = arg; \
})

diff --git a/drivers/block/drbd/drbd_state_change.h b/drivers/block/drbd/drbd_state_change.h
index 9d78d8e3912e..a56a57d67686 100644
--- a/drivers/block/drbd/drbd_state_change.h
+++ b/drivers/block/drbd/drbd_state_change.h
@@ -46,19 +46,19 @@ extern void forget_state_change(struct drbd_state_change *);

extern int notify_resource_state_change(struct sk_buff *,
unsigned int,
- struct drbd_resource_state_change *,
+ void *,
enum drbd_notification_type type);
extern int notify_connection_state_change(struct sk_buff *,
unsigned int,
- struct drbd_connection_state_change *,
+ void *,
enum drbd_notification_type type);
extern int notify_device_state_change(struct sk_buff *,
unsigned int,
- struct drbd_device_state_change *,
+ void *,
enum drbd_notification_type type);
extern int notify_peer_device_state_change(struct sk_buff *,
unsigned int,
- struct drbd_peer_device_state_change *,
+ void *,
enum drbd_notification_type type);

#endif /* DRBD_STATE_CHANGE_H */
--
2.39.2



2024-02-13 16:18:58

by Jens Axboe

[permalink] [raw]
Subject: Re: [PATCH] drbd: fix function cast warnings in state machine


On Tue, 13 Feb 2024 11:03:01 +0100, Arnd Bergmann wrote:
> There are four state machines in drbd that use a common infrastructure, with
> a cast to an incompatible function type in REMEMBER_STATE_CHANGE that clang-16
> now warns about:
>
> drivers/block/drbd/drbd_state.c:1632:3: error: cast from 'int (*)(struct sk_buff *, unsigned int, struct drbd_resource_state_change *, enum drbd_notification_type)' to 'typeof (last_func)' (aka 'int (*)(struct sk_buff *, unsigned int, void *, enum drbd_notification_type)') converts to incompatible function type [-Werror,-Wcast-function-type-strict]
> 1632 | REMEMBER_STATE_CHANGE(notify_resource_state_change,
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 1633 | resource_state_change, NOTIFY_CHANGE);
> | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/block/drbd/drbd_state.c:1619:17: note: expanded from macro 'REMEMBER_STATE_CHANGE'
> 1619 | last_func = (typeof(last_func))func; \
> | ^~~~~~~~~~~~~~~~~~~~~~~
> drivers/block/drbd/drbd_state.c:1641:4: error: cast from 'int (*)(struct sk_buff *, unsigned int, struct drbd_connection_state_change *, enum drbd_notification_type)' to 'typeof (last_func)' (aka 'int (*)(struct sk_buff *, unsigned int, void *, enum drbd_notification_type)') converts to incompatible function type [-Werror,-Wcast-function-type-strict]
> 1641 | REMEMBER_STATE_CHANGE(notify_connection_state_change,
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 1642 | connection_state_change, NOTIFY_CHANGE);
> | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> [...]

Applied, thanks!

[1/1] drbd: fix function cast warnings in state machine
commit: fe0b1e9a73d60f01fdc391925be74e823af7c91d

Best regards,
--
Jens Axboe