2015-07-30 23:00:00

by Greg KH

[permalink] [raw]
Subject: [PATCH] char: make misc_deregister a void function

From: Greg Kroah-Hartman <[email protected]>

With well over 200+ users of this api, there are a mere 12 users that
actually cheked the return value of this function. And all of them
really didn't do anything with that information as the system or module
was shutting down no matter what.

So stop pretending like it matters, and just return void from
misc_deregister(). If something goes wrong in the call, you will get a
WARNING splat in the syslog so you know how to fix up your driver.
Other than that, there's nothing that can go wrong.

Cc: Alasdair Kergon <[email protected]>
Cc: Mike Snitzer <[email protected]>
Cc: Neil Brown <[email protected]>
Cc: Alessandro Zummo <[email protected]>
Cc: Alexandre Belloni <[email protected]>
Cc: Oleg Drokin <[email protected]>
Cc: Andreas Dilger <[email protected]>
Cc: "Michael S. Tsirkin" <[email protected]>
Cc: Wim Van Sebroeck <[email protected]>
Cc: Christine Caulfield <[email protected]>
Cc: David Teigland <[email protected]>
Cc: Mark Fasheh <[email protected]>
Cc: Joel Becker <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---

If the different subsystem maintainers want to give me an ack for this,
I'd appreciate it. I'd like to just take the single patch in through
the char-misc tree in one piece.


drivers/char/misc.c | 9 +++------
drivers/md/dm-ioctl.c | 4 +---
drivers/misc/vmw_vmci/vmci_host.c | 5 +----
drivers/rtc/rtc-ds1374.c | 5 ++---
drivers/staging/android/ashmem.c | 5 +----
drivers/staging/android/ion/ion_test.c | 3 ++-
drivers/staging/lustre/lustre/libcfs/module.c | 4 +---
drivers/vhost/scsi.c | 4 ++--
drivers/watchdog/at91rm9200_wdt.c | 5 ++---
drivers/watchdog/ks8695_wdt.c | 9 +++------
drivers/watchdog/ts72xx_wdt.c | 3 ++-
fs/dlm/user.c | 9 +++------
fs/ocfs2/stack_user.c | 9 +--------
include/linux/miscdevice.h | 2 +-
14 files changed, 25 insertions(+), 51 deletions(-)


--- a/drivers/char/misc.c
+++ b/drivers/char/misc.c
@@ -243,17 +243,15 @@ int misc_register(struct miscdevice * mi
* @misc: device to unregister
*
* Unregister a miscellaneous device that was previously
- * successfully registered with misc_register(). Success
- * is indicated by a zero return, a negative errno code
- * indicates an error.
+ * successfully registered with misc_register().
*/

-int misc_deregister(struct miscdevice *misc)
+void misc_deregister(struct miscdevice *misc)
{
int i = DYNAMIC_MINORS - misc->minor - 1;

if (WARN_ON(list_empty(&misc->list)))
- return -EINVAL;
+ return;

mutex_lock(&misc_mtx);
list_del(&misc->list);
@@ -261,7 +259,6 @@ int misc_deregister(struct miscdevice *m
if (i < DYNAMIC_MINORS && i >= 0)
clear_bit(i, misc_minors);
mutex_unlock(&misc_mtx);
- return 0;
}

EXPORT_SYMBOL(misc_register);
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1919,9 +1919,7 @@ int __init dm_interface_init(void)

void dm_interface_exit(void)
{
- if (misc_deregister(&_dm_misc) < 0)
- DMERR("misc_deregister failed for control device");
-
+ misc_deregister(&_dm_misc);
dm_hash_exit();
}

--- a/drivers/misc/vmw_vmci/vmci_host.c
+++ b/drivers/misc/vmw_vmci/vmci_host.c
@@ -1035,10 +1035,7 @@ void __exit vmci_host_exit(void)

vmci_host_device_initialized = false;

- error = misc_deregister(&vmci_host_miscdev);
- if (error)
- pr_warn("Error unregistering character device: %d\n", error);
-
+ misc_deregister(&vmci_host_miscdev);
vmci_ctx_destroy(host_context);
vmci_qp_broker_exit();

--- a/drivers/rtc/rtc-ds1374.c
+++ b/drivers/rtc/rtc-ds1374.c
@@ -666,9 +666,8 @@ static int ds1374_remove(struct i2c_clie
#ifdef CONFIG_RTC_DRV_DS1374_WDT
int res;

- res = misc_deregister(&ds1374_miscdev);
- if (!res)
- ds1374_miscdev.parent = NULL;
+ misc_deregister(&ds1374_miscdev);
+ ds1374_miscdev.parent = NULL;
unregister_reboot_notifier(&ds1374_wdt_notifier);
#endif

--- a/drivers/staging/android/ashmem.c
+++ b/drivers/staging/android/ashmem.c
@@ -867,10 +867,7 @@ static void __exit ashmem_exit(void)

unregister_shrinker(&ashmem_shrinker);

- ret = misc_deregister(&ashmem_misc);
- if (unlikely(ret))
- pr_err("failed to unregister misc device!\n");
-
+ misc_deregister(&ashmem_misc);
kmem_cache_destroy(ashmem_range_cachep);
kmem_cache_destroy(ashmem_area_cachep);

--- a/drivers/staging/android/ion/ion_test.c
+++ b/drivers/staging/android/ion/ion_test.c
@@ -269,7 +269,8 @@ static int ion_test_remove(struct platfo
if (!testdev)
return -ENODATA;

- return misc_deregister(&testdev->misc);
+ misc_deregister(&testdev->misc);
+ return 0;
}

static struct platform_device *ion_test_pdev;
--- a/drivers/staging/lustre/lustre/libcfs/module.c
+++ b/drivers/staging/lustre/lustre/libcfs/module.c
@@ -467,9 +467,7 @@ static void exit_libcfs_module(void)
cfs_crypto_unregister();
cfs_wi_shutdown();

- rc = misc_deregister(&libcfs_dev);
- if (rc)
- CERROR("misc_deregister error %d\n", rc);
+ misc_deregister(&libcfs_dev);

cfs_cpu_fini();

--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -1573,9 +1573,9 @@ static int __init vhost_scsi_register(vo
return misc_register(&vhost_scsi_misc);
}

-static int vhost_scsi_deregister(void)
+static void vhost_scsi_deregister(void)
{
- return misc_deregister(&vhost_scsi_misc);
+ misc_deregister(&vhost_scsi_misc);
}

static char *vhost_scsi_dump_proto_id(struct vhost_scsi_tport *tport)
--- a/drivers/watchdog/at91rm9200_wdt.c
+++ b/drivers/watchdog/at91rm9200_wdt.c
@@ -269,9 +269,8 @@ static int at91wdt_remove(struct platfor
if (res)
dev_warn(dev, "failed to unregister restart handler\n");

- res = misc_deregister(&at91wdt_miscdev);
- if (!res)
- at91wdt_miscdev.parent = NULL;
+ misc_deregister(&at91wdt_miscdev);
+ at91wdt_miscdev.parent = NULL;

return res;
}
--- a/drivers/watchdog/ks8695_wdt.c
+++ b/drivers/watchdog/ks8695_wdt.c
@@ -254,13 +254,10 @@ static int ks8695wdt_probe(struct platfo

static int ks8695wdt_remove(struct platform_device *pdev)
{
- int res;
+ misc_deregister(&ks8695wdt_miscdev);
+ ks8695wdt_miscdev.parent = NULL;

- res = misc_deregister(&ks8695wdt_miscdev);
- if (!res)
- ks8695wdt_miscdev.parent = NULL;
-
- return res;
+ return 0;
}

static void ks8695wdt_shutdown(struct platform_device *pdev)
--- a/drivers/watchdog/ts72xx_wdt.c
+++ b/drivers/watchdog/ts72xx_wdt.c
@@ -428,7 +428,8 @@ static int ts72xx_wdt_probe(struct platf

static int ts72xx_wdt_remove(struct platform_device *pdev)
{
- return misc_deregister(&ts72xx_wdt_miscdev);
+ misc_deregister(&ts72xx_wdt_miscdev);
+ return 0;
}

static struct platform_driver ts72xx_wdt_driver = {
--- a/fs/dlm/user.c
+++ b/fs/dlm/user.c
@@ -362,18 +362,15 @@ fail:

int dlm_device_deregister(struct dlm_ls *ls)
{
- int error;
-
/* The device is not registered. This happens when the lockspace
was never used from userspace, or when device_create_lockspace()
calls dlm_release_lockspace() after the register fails. */
if (!ls->ls_device.name)
return 0;

- error = misc_deregister(&ls->ls_device);
- if (!error)
- kfree(ls->ls_device.name);
- return error;
+ misc_deregister(&ls->ls_device);
+ kfree(ls->ls_device.name);
+ return 0;
}

static int device_user_purge(struct dlm_user_proc *proc,
--- a/fs/ocfs2/stack_user.c
+++ b/fs/ocfs2/stack_user.c
@@ -655,14 +655,7 @@ static int ocfs2_control_init(void)

static void ocfs2_control_exit(void)
{
- int rc;
-
- rc = misc_deregister(&ocfs2_control_device);
- if (rc)
- printk(KERN_ERR
- "ocfs2: Unable to deregister ocfs2_control device "
- "(errno %d)\n",
- -rc);
+ misc_deregister(&ocfs2_control_device);
}

static void fsdlm_lock_ast_wrapper(void *astarg)
--- a/include/linux/miscdevice.h
+++ b/include/linux/miscdevice.h
@@ -67,7 +67,7 @@ struct miscdevice {
};

extern int misc_register(struct miscdevice *misc);
-extern int misc_deregister(struct miscdevice *misc);
+extern void misc_deregister(struct miscdevice *misc);

#define MODULE_ALIAS_MISCDEV(minor) \
MODULE_ALIAS("char-major-" __stringify(MISC_MAJOR) \


2015-07-30 23:42:00

by Mike Snitzer

[permalink] [raw]
Subject: Re: char: make misc_deregister a void function

On Thu, Jul 30 2015 at 6:59pm -0400,
Greg Kroah-Hartman <[email protected]> wrote:

> From: Greg Kroah-Hartman <[email protected]>
>
> With well over 200+ users of this api, there are a mere 12 users that
> actually cheked the return value of this function. And all of them
> really didn't do anything with that information as the system or module
> was shutting down no matter what.
>
> So stop pretending like it matters, and just return void from
> misc_deregister(). If something goes wrong in the call, you will get a
> WARNING splat in the syslog so you know how to fix up your driver.
> Other than that, there's nothing that can go wrong.
>
> Cc: Alasdair Kergon <[email protected]>
> Cc: Mike Snitzer <[email protected]>
> Cc: Neil Brown <[email protected]>
> Cc: Alessandro Zummo <[email protected]>
> Cc: Alexandre Belloni <[email protected]>
> Cc: Oleg Drokin <[email protected]>
> Cc: Andreas Dilger <[email protected]>
> Cc: "Michael S. Tsirkin" <[email protected]>
> Cc: Wim Van Sebroeck <[email protected]>
> Cc: Christine Caulfield <[email protected]>
> Cc: David Teigland <[email protected]>
> Cc: Mark Fasheh <[email protected]>
> Cc: Joel Becker <[email protected]>
> Signed-off-by: Greg Kroah-Hartman <[email protected]>
>
> ---
>
> If the different subsystem maintainers want to give me an ack for this,
> I'd appreciate it. I'd like to just take the single patch in through
> the char-misc tree in one piece.

For DM:
Acked-by: Mike Snitzer <[email protected]>

2015-07-31 09:38:42

by Alessandro Zummo

[permalink] [raw]
Subject: Re: [PATCH] char: make misc_deregister a void function

On Thu, 30 Jul 2015 15:59:57 -0700
Greg Kroah-Hartman <[email protected]> wrote:

> If the different subsystem maintainers want to give me an ack for this,
> I'd appreciate it. I'd like to just take the single patch in through
> the char-misc tree in one piece.

RTC

Acked-by: Alessandro Zummo <[email protected]>

--

Best regards,

Alessandro Zummo - CEO,
Tower Technologies - Torino, Italy

http://www.towertech.it

2015-07-31 13:06:10

by Alexandre Belloni

[permalink] [raw]
Subject: Re: [PATCH] char: make misc_deregister a void function

Hi,

On 30/07/2015 at 15:59:57 -0700, Greg Kroah-Hartman wrote :
> From: Greg Kroah-Hartman <[email protected]>
>
> With well over 200+ users of this api, there are a mere 12 users that
> actually cheked the return value of this function. And all of them
^
small typo here

> really didn't do anything with that information as the system or module
> was shutting down no matter what.
>
> So stop pretending like it matters, and just return void from
> misc_deregister(). If something goes wrong in the call, you will get a
> WARNING splat in the syslog so you know how to fix up your driver.
> Other than that, there's nothing that can go wrong.
>
> Cc: Alasdair Kergon <[email protected]>
> Cc: Mike Snitzer <[email protected]>
> Cc: Neil Brown <[email protected]>
> Cc: Alessandro Zummo <[email protected]>
> Cc: Alexandre Belloni <[email protected]>
> Cc: Oleg Drokin <[email protected]>
> Cc: Andreas Dilger <[email protected]>
> Cc: "Michael S. Tsirkin" <[email protected]>
> Cc: Wim Van Sebroeck <[email protected]>
> Cc: Christine Caulfield <[email protected]>
> Cc: David Teigland <[email protected]>
> Cc: Mark Fasheh <[email protected]>
> Cc: Joel Becker <[email protected]>
> Signed-off-by: Greg Kroah-Hartman <[email protected]>

For rtc and at91rm9200_wdt.c:
Acked-by: Alexandre Belloni <[email protected]>

[...]

> --- a/drivers/watchdog/at91rm9200_wdt.c
> +++ b/drivers/watchdog/at91rm9200_wdt.c
> @@ -269,9 +269,8 @@ static int at91wdt_remove(struct platfor
> if (res)
> dev_warn(dev, "failed to unregister restart handler\n");
>
> - res = misc_deregister(&at91wdt_miscdev);
> - if (!res)
> - at91wdt_miscdev.parent = NULL;
> + misc_deregister(&at91wdt_miscdev);
> + at91wdt_miscdev.parent = NULL;
>
> return res;

That one was actually doing something with the return value ;)


--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

2015-07-31 19:31:27

by Joel Becker

[permalink] [raw]
Subject: Re: [PATCH] char: make misc_deregister a void function

Acked-by: Joel Becker <[email protected]>

On Thu, Jul 30, 2015 at 03:59:57PM -0700, Greg Kroah-Hartman wrote:
> From: Greg Kroah-Hartman <[email protected]>
>
> With well over 200+ users of this api, there are a mere 12 users that
> actually cheked the return value of this function. And all of them
> really didn't do anything with that information as the system or module
> was shutting down no matter what.
>
> So stop pretending like it matters, and just return void from
> misc_deregister(). If something goes wrong in the call, you will get a
> WARNING splat in the syslog so you know how to fix up your driver.
> Other than that, there's nothing that can go wrong.
>
> Cc: Alasdair Kergon <[email protected]>
> Cc: Mike Snitzer <[email protected]>
> Cc: Neil Brown <[email protected]>
> Cc: Alessandro Zummo <[email protected]>
> Cc: Alexandre Belloni <[email protected]>
> Cc: Oleg Drokin <[email protected]>
> Cc: Andreas Dilger <[email protected]>
> Cc: "Michael S. Tsirkin" <[email protected]>
> Cc: Wim Van Sebroeck <[email protected]>
> Cc: Christine Caulfield <[email protected]>
> Cc: David Teigland <[email protected]>
> Cc: Mark Fasheh <[email protected]>
> Cc: Joel Becker <[email protected]>
> Signed-off-by: Greg Kroah-Hartman <[email protected]>
>
> ---
>
> If the different subsystem maintainers want to give me an ack for this,
> I'd appreciate it. I'd like to just take the single patch in through
> the char-misc tree in one piece.
>
>
> drivers/char/misc.c | 9 +++------
> drivers/md/dm-ioctl.c | 4 +---
> drivers/misc/vmw_vmci/vmci_host.c | 5 +----
> drivers/rtc/rtc-ds1374.c | 5 ++---
> drivers/staging/android/ashmem.c | 5 +----
> drivers/staging/android/ion/ion_test.c | 3 ++-
> drivers/staging/lustre/lustre/libcfs/module.c | 4 +---
> drivers/vhost/scsi.c | 4 ++--
> drivers/watchdog/at91rm9200_wdt.c | 5 ++---
> drivers/watchdog/ks8695_wdt.c | 9 +++------
> drivers/watchdog/ts72xx_wdt.c | 3 ++-
> fs/dlm/user.c | 9 +++------
> fs/ocfs2/stack_user.c | 9 +--------
> include/linux/miscdevice.h | 2 +-
> 14 files changed, 25 insertions(+), 51 deletions(-)
>
>
> --- a/drivers/char/misc.c
> +++ b/drivers/char/misc.c
> @@ -243,17 +243,15 @@ int misc_register(struct miscdevice * mi
> * @misc: device to unregister
> *
> * Unregister a miscellaneous device that was previously
> - * successfully registered with misc_register(). Success
> - * is indicated by a zero return, a negative errno code
> - * indicates an error.
> + * successfully registered with misc_register().
> */
>
> -int misc_deregister(struct miscdevice *misc)
> +void misc_deregister(struct miscdevice *misc)
> {
> int i = DYNAMIC_MINORS - misc->minor - 1;
>
> if (WARN_ON(list_empty(&misc->list)))
> - return -EINVAL;
> + return;
>
> mutex_lock(&misc_mtx);
> list_del(&misc->list);
> @@ -261,7 +259,6 @@ int misc_deregister(struct miscdevice *m
> if (i < DYNAMIC_MINORS && i >= 0)
> clear_bit(i, misc_minors);
> mutex_unlock(&misc_mtx);
> - return 0;
> }
>
> EXPORT_SYMBOL(misc_register);
> --- a/drivers/md/dm-ioctl.c
> +++ b/drivers/md/dm-ioctl.c
> @@ -1919,9 +1919,7 @@ int __init dm_interface_init(void)
>
> void dm_interface_exit(void)
> {
> - if (misc_deregister(&_dm_misc) < 0)
> - DMERR("misc_deregister failed for control device");
> -
> + misc_deregister(&_dm_misc);
> dm_hash_exit();
> }
>
> --- a/drivers/misc/vmw_vmci/vmci_host.c
> +++ b/drivers/misc/vmw_vmci/vmci_host.c
> @@ -1035,10 +1035,7 @@ void __exit vmci_host_exit(void)
>
> vmci_host_device_initialized = false;
>
> - error = misc_deregister(&vmci_host_miscdev);
> - if (error)
> - pr_warn("Error unregistering character device: %d\n", error);
> -
> + misc_deregister(&vmci_host_miscdev);
> vmci_ctx_destroy(host_context);
> vmci_qp_broker_exit();
>
> --- a/drivers/rtc/rtc-ds1374.c
> +++ b/drivers/rtc/rtc-ds1374.c
> @@ -666,9 +666,8 @@ static int ds1374_remove(struct i2c_clie
> #ifdef CONFIG_RTC_DRV_DS1374_WDT
> int res;
>
> - res = misc_deregister(&ds1374_miscdev);
> - if (!res)
> - ds1374_miscdev.parent = NULL;
> + misc_deregister(&ds1374_miscdev);
> + ds1374_miscdev.parent = NULL;
> unregister_reboot_notifier(&ds1374_wdt_notifier);
> #endif
>
> --- a/drivers/staging/android/ashmem.c
> +++ b/drivers/staging/android/ashmem.c
> @@ -867,10 +867,7 @@ static void __exit ashmem_exit(void)
>
> unregister_shrinker(&ashmem_shrinker);
>
> - ret = misc_deregister(&ashmem_misc);
> - if (unlikely(ret))
> - pr_err("failed to unregister misc device!\n");
> -
> + misc_deregister(&ashmem_misc);
> kmem_cache_destroy(ashmem_range_cachep);
> kmem_cache_destroy(ashmem_area_cachep);
>
> --- a/drivers/staging/android/ion/ion_test.c
> +++ b/drivers/staging/android/ion/ion_test.c
> @@ -269,7 +269,8 @@ static int ion_test_remove(struct platfo
> if (!testdev)
> return -ENODATA;
>
> - return misc_deregister(&testdev->misc);
> + misc_deregister(&testdev->misc);
> + return 0;
> }
>
> static struct platform_device *ion_test_pdev;
> --- a/drivers/staging/lustre/lustre/libcfs/module.c
> +++ b/drivers/staging/lustre/lustre/libcfs/module.c
> @@ -467,9 +467,7 @@ static void exit_libcfs_module(void)
> cfs_crypto_unregister();
> cfs_wi_shutdown();
>
> - rc = misc_deregister(&libcfs_dev);
> - if (rc)
> - CERROR("misc_deregister error %d\n", rc);
> + misc_deregister(&libcfs_dev);
>
> cfs_cpu_fini();
>
> --- a/drivers/vhost/scsi.c
> +++ b/drivers/vhost/scsi.c
> @@ -1573,9 +1573,9 @@ static int __init vhost_scsi_register(vo
> return misc_register(&vhost_scsi_misc);
> }
>
> -static int vhost_scsi_deregister(void)
> +static void vhost_scsi_deregister(void)
> {
> - return misc_deregister(&vhost_scsi_misc);
> + misc_deregister(&vhost_scsi_misc);
> }
>
> static char *vhost_scsi_dump_proto_id(struct vhost_scsi_tport *tport)
> --- a/drivers/watchdog/at91rm9200_wdt.c
> +++ b/drivers/watchdog/at91rm9200_wdt.c
> @@ -269,9 +269,8 @@ static int at91wdt_remove(struct platfor
> if (res)
> dev_warn(dev, "failed to unregister restart handler\n");
>
> - res = misc_deregister(&at91wdt_miscdev);
> - if (!res)
> - at91wdt_miscdev.parent = NULL;
> + misc_deregister(&at91wdt_miscdev);
> + at91wdt_miscdev.parent = NULL;
>
> return res;
> }
> --- a/drivers/watchdog/ks8695_wdt.c
> +++ b/drivers/watchdog/ks8695_wdt.c
> @@ -254,13 +254,10 @@ static int ks8695wdt_probe(struct platfo
>
> static int ks8695wdt_remove(struct platform_device *pdev)
> {
> - int res;
> + misc_deregister(&ks8695wdt_miscdev);
> + ks8695wdt_miscdev.parent = NULL;
>
> - res = misc_deregister(&ks8695wdt_miscdev);
> - if (!res)
> - ks8695wdt_miscdev.parent = NULL;
> -
> - return res;
> + return 0;
> }
>
> static void ks8695wdt_shutdown(struct platform_device *pdev)
> --- a/drivers/watchdog/ts72xx_wdt.c
> +++ b/drivers/watchdog/ts72xx_wdt.c
> @@ -428,7 +428,8 @@ static int ts72xx_wdt_probe(struct platf
>
> static int ts72xx_wdt_remove(struct platform_device *pdev)
> {
> - return misc_deregister(&ts72xx_wdt_miscdev);
> + misc_deregister(&ts72xx_wdt_miscdev);
> + return 0;
> }
>
> static struct platform_driver ts72xx_wdt_driver = {
> --- a/fs/dlm/user.c
> +++ b/fs/dlm/user.c
> @@ -362,18 +362,15 @@ fail:
>
> int dlm_device_deregister(struct dlm_ls *ls)
> {
> - int error;
> -
> /* The device is not registered. This happens when the lockspace
> was never used from userspace, or when device_create_lockspace()
> calls dlm_release_lockspace() after the register fails. */
> if (!ls->ls_device.name)
> return 0;
>
> - error = misc_deregister(&ls->ls_device);
> - if (!error)
> - kfree(ls->ls_device.name);
> - return error;
> + misc_deregister(&ls->ls_device);
> + kfree(ls->ls_device.name);
> + return 0;
> }
>
> static int device_user_purge(struct dlm_user_proc *proc,
> --- a/fs/ocfs2/stack_user.c
> +++ b/fs/ocfs2/stack_user.c
> @@ -655,14 +655,7 @@ static int ocfs2_control_init(void)
>
> static void ocfs2_control_exit(void)
> {
> - int rc;
> -
> - rc = misc_deregister(&ocfs2_control_device);
> - if (rc)
> - printk(KERN_ERR
> - "ocfs2: Unable to deregister ocfs2_control device "
> - "(errno %d)\n",
> - -rc);
> + misc_deregister(&ocfs2_control_device);
> }
>
> static void fsdlm_lock_ast_wrapper(void *astarg)
> --- a/include/linux/miscdevice.h
> +++ b/include/linux/miscdevice.h
> @@ -67,7 +67,7 @@ struct miscdevice {
> };
>
> extern int misc_register(struct miscdevice *misc);
> -extern int misc_deregister(struct miscdevice *misc);
> +extern void misc_deregister(struct miscdevice *misc);
>
> #define MODULE_ALIAS_MISCDEV(minor) \
> MODULE_ALIAS("char-major-" __stringify(MISC_MAJOR) \

--