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authorSergey Senozhatsky <sergey.senozhatsky@gmail.com>2014-12-13 01:56:56 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2014-12-13 21:42:50 +0100
commitb1b00a5b8a6cf32e3973507decf1216709b55072 (patch)
tree768a19295b08df9423ebae482949f3dbe35a4c23
parentzram: implement rw_page operation of zram (diff)
downloadlinux-b1b00a5b8a6cf32e3973507decf1216709b55072.tar.xz
linux-b1b00a5b8a6cf32e3973507decf1216709b55072.zip
zsmalloc: fix zs_init cpu notifier error handling
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>
-rw-r--r--mm/zsmalloc.c39
1 files changed, 24 insertions, 15 deletions
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index b3b57ef85830..5481c677e465 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)
@@ -898,31 +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)) {
- cpu_notifier_register_done();
- goto fail;
- }
+ if (notifier_to_errno(ret))
+ break;
}
cpu_notifier_register_done();
+ return notifier_to_errno(ret);
+}
+static void __exit zs_exit(void)
+{
#ifdef CONFIG_ZPOOL
- zpool_register_driver(&zs_zpool_driver);
+ zpool_unregister_driver(&zs_zpool_driver);
#endif
+ zs_unregister_cpu_notifier();
+}
+
+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)