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 Reported-by: Mahendran Ganesh <opensource.gan...@gmail.com> Signed-off-by: Sergey Senozhatsky <sergey.senozhat...@gmail.com> --- mm/zsmalloc.c | 37 +++++++++++++++++++++++-------------- 1 file changed, 23 insertions(+), 14 deletions(-) diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index b3b57ef..b8c2d41 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 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) @@ -898,7 +894,7 @@ static void zs_exit(void) cpu_notifier_register_done(); } -static int zs_init(void) +static int zs_register_cpu_notifier(void) { int cpu, ret; @@ -907,22 +903,35 @@ 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(); - goto fail; - } + if (notifier_to_errno(ret)) + break; } cpu_notifier_register_done(); + return notifier_to_errno(ret); +} + +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 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) -- 2.2.0.rc0.218.ge7f43d6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/