zsmalloc: fix zs_init cpu notifier error handling (b1b00a5b) · Commits · 戴 / test

Mahendran Ganesh reported that zpool-enabled zsmalloc should not call zpool_unregister_driver() from zs_init() if cpu notifier registration has failed, because error handling is performed before we register the driver via zpool_register_driver() call. Factor out cpu notifier registration and unregistration code and fix zs_init() error handling. link: http://lkml.iu.edu//hypermail/linux/kernel/1411.1/04156.html [akpm@linux-foundation.org: squash bogus gcc warning] [akpm@linux-foundation.org: use __init and __exit] Signed-off-by:

Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reported-by:

Mahendran Ganesh <opensource.ganesh@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

mm/zsmalloc.c

+24 −15

Original line number	Diff line number	Diff line
		@@ -881,14 +881,10 @@ static struct notifier_block zs_cpu_nb = {
		.notifier_call = zs_cpu_notifier
		};

		static void zs_exit(void)
		static void zs_unregister_cpu_notifier(void)
		{
		int cpu;

		#ifdef CONFIG_ZPOOL
		zpool_unregister_driver(&zs_zpool_driver);
		#endif

		cpu_notifier_register_begin();

		for_each_online_cpu(cpu)
		@@ -898,31 +894,44 @@ static void zs_exit(void)
		cpu_notifier_register_done();
		}

		static int zs_init(void)
		static int zs_register_cpu_notifier(void)
		{
		int cpu, ret;
		int cpu, uninitialized_var(ret);

		cpu_notifier_register_begin();

		__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)) {
		if (notifier_to_errno(ret))
		break;
		}

		cpu_notifier_register_done();
		goto fail;
		return notifier_to_errno(ret);
		}

		static void __exit zs_exit(void)
		{
		#ifdef CONFIG_ZPOOL
		zpool_unregister_driver(&zs_zpool_driver);
		#endif
		zs_unregister_cpu_notifier();
		}

		cpu_notifier_register_done();
		static int __init zs_init(void)
		{
		int ret = zs_register_cpu_notifier();

		if (ret) {
		zs_unregister_cpu_notifier();
		return ret;
		}

		#ifdef CONFIG_ZPOOL
		zpool_register_driver(&zs_zpool_driver);
		#endif

		return 0;
		fail:
		zs_exit();
		return notifier_to_errno(ret);
		}

		static unsigned int get_maxobj_per_zspage(int size, int pages_per_zspage)

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