On (11/13/14 21:37), Mahendran Ganesh wrote:
> Now zsmalloc can be registered as a zpool driver into zpool when
> CONFIG_ZPOOL is enabled. During the init of zsmalloc, when error happens,
> we need to do cleanup. But in current code, it will unregister a not yet
> registered zsmalloc zpool driver(*zs_zpool_driver*).
>
> This patch puts the cleanup in zs_init() instead of calling zs_exit()
> where it will unregister a not-registered zpool driver.
>
> Signed-off-by: Mahendran Ganesh <opensource.ganesh@xxxxxxxxx>
> ---
> mm/zsmalloc.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
> index 839a48c..3d2bb36 100644
> --- a/mm/zsmalloc.c
> +++ b/mm/zsmalloc.c
> @@ -907,10 +907,8 @@ static int zs_init(void)
> __register_cpu_notifier(&zs_cpu_nb);
> for_each_online_cpu(cpu) {
> ret = zs_cpu_notifier(NULL, CPU_UP_PREPARE, (void *)(long)cpu);
> - if (notifier_to_errno(ret)) {
> - cpu_notifier_register_done();
> + if (notifier_to_errno(ret))
> goto fail;
> - }
> }
>
> cpu_notifier_register_done();
> @@ -920,8 +918,14 @@ static int zs_init(void)
> #endif
>
> return 0;
> +
> fail:
> - zs_exit();
> + for_each_online_cpu(cpu)
> + zs_cpu_notifier(NULL, CPU_UP_CANCELED, (void *)(long)cpu);
> + __unregister_cpu_notifier(&zs_cpu_nb);
> +
> + cpu_notifier_register_done();
> +
> return notifier_to_errno(ret);
so we duplicate same code, and there is a bit confusing part
now: zs_cpu_notifier(CPU_UP_CANCELED) and zs_cpu_notifier(CPU_DEAD)
calls.
how about something like this?
Factor out zsmalloc cpu notifier unregistration code and call
it from both zs_exit() and zs_init() error path.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
---
mm/zsmalloc.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index b3b57ef..c4d2d60 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -881,14 +881,10 @@ static struct notifier_block zs_cpu_nb = {
.notifier_call = zs_cpu_notifier
};
-static void zs_exit(void)
+static inline void zs_unregister_cpu_notifier()
{
int cpu;
-#ifdef CONFIG_ZPOOL
- zpool_unregister_driver(&zs_zpool_driver);
-#endif
-
cpu_notifier_register_begin();
for_each_online_cpu(cpu)
@@ -898,6 +894,14 @@ static void zs_exit(void)
cpu_notifier_register_done();
}
+static void zs_exit(void)
+{
+#ifdef CONFIG_ZPOOL
+ zpool_unregister_driver(&zs_zpool_driver);
+#endif
+ zs_unregister_cpu_notifier();
+}
+
static int zs_init(void)
{
int cpu, ret;
@@ -907,10 +911,8 @@ static int zs_init(void)
__register_cpu_notifier(&zs_cpu_nb);
for_each_online_cpu(cpu) {
ret = zs_cpu_notifier(NULL, CPU_UP_PREPARE, (void *)(long)cpu);
- if (notifier_to_errno(ret)) {
- cpu_notifier_register_done();
+ if (notifier_to_errno(ret))
goto fail;
- }
}
cpu_notifier_register_done();
@@ -921,7 +923,7 @@ static int zs_init(void)
return 0;
fail:
- zs_exit();
+ zs_unregister_cpu_notifier();
return notifier_to_errno(ret);
}
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