orangefs: Fix kmemleak in orangefs_sysfs_init()

When insert and remove the orangefs module, there are kobjects memory
leaked as below:

unreferenced object 0xffff88810f95af00 (size 64):
comm "insmod", pid 783, jiffies 4294813439 (age 65.512s)
hex dump (first 32 bytes):
a0 83 af 01 81 88 ff ff 08 af 95 0f 81 88 ff ff ................
08 af 95 0f 81 88 ff ff 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000031ab7788>] kmalloc_trace+0x27/0xa0
[<000000005a6e4dfe>] orangefs_sysfs_init+0x42/0x3a0
[<00000000722645ca>] 0xffffffffa02780fe
[<000000004232d9f7>] do_one_initcall+0x87/0x2a0
[<0000000054f22384>] do_init_module+0xdf/0x320
[<000000003263bdea>] load_module+0x2f98/0x3330
[<0000000052cd4153>] __do_sys_finit_module+0x113/0x1b0
[<00000000250ae02b>] do_syscall_64+0x35/0x80
[<00000000f11c03c7>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

unreferenced object 0xffff88810f95ae80 (size 64):
comm "insmod", pid 783, jiffies 4294813439 (age 65.512s)
hex dump (first 32 bytes):
c8 90 0f 02 81 88 ff ff 88 ae 95 0f 81 88 ff ff ................
88 ae 95 0f 81 88 ff ff 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000031ab7788>] kmalloc_trace+0x27/0xa0
[<000000001a4841fa>] orangefs_sysfs_init+0xc7/0x3a0
[<00000000722645ca>] 0xffffffffa02780fe
[<000000004232d9f7>] do_one_initcall+0x87/0x2a0
[<0000000054f22384>] do_init_module+0xdf/0x320
[<000000003263bdea>] load_module+0x2f98/0x3330
[<0000000052cd4153>] __do_sys_finit_module+0x113/0x1b0
[<00000000250ae02b>] do_syscall_64+0x35/0x80
[<00000000f11c03c7>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

unreferenced object 0xffff88810f95ae00 (size 64):
comm "insmod", pid 783, jiffies 4294813440 (age 65.511s)
hex dump (first 32 bytes):
60 87 a1 00 81 88 ff ff 08 ae 95 0f 81 88 ff ff `...............
08 ae 95 0f 81 88 ff ff 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000031ab7788>] kmalloc_trace+0x27/0xa0
[<000000005915e797>] orangefs_sysfs_init+0x12b/0x3a0
[<00000000722645ca>] 0xffffffffa02780fe
[<000000004232d9f7>] do_one_initcall+0x87/0x2a0
[<0000000054f22384>] do_init_module+0xdf/0x320
[<000000003263bdea>] load_module+0x2f98/0x3330
[<0000000052cd4153>] __do_sys_finit_module+0x113/0x1b0
[<00000000250ae02b>] do_syscall_64+0x35/0x80
[<00000000f11c03c7>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

unreferenced object 0xffff88810f95ad80 (size 64):
comm "insmod", pid 783, jiffies 4294813440 (age 65.511s)
hex dump (first 32 bytes):
78 90 0f 02 81 88 ff ff 88 ad 95 0f 81 88 ff ff x...............
88 ad 95 0f 81 88 ff ff 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000031ab7788>] kmalloc_trace+0x27/0xa0
[<000000007a14eb35>] orangefs_sysfs_init+0x1ac/0x3a0
[<00000000722645ca>] 0xffffffffa02780fe
[<000000004232d9f7>] do_one_initcall+0x87/0x2a0
[<0000000054f22384>] do_init_module+0xdf/0x320
[<000000003263bdea>] load_module+0x2f98/0x3330
[<0000000052cd4153>] __do_sys_finit_module+0x113/0x1b0
[<00000000250ae02b>] do_syscall_64+0x35/0x80
[<00000000f11c03c7>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

unreferenced object 0xffff88810f95ac00 (size 64):
comm "insmod", pid 783, jiffies 4294813440 (age 65.531s)
hex dump (first 32 bytes):
e0 ff 67 02 81 88 ff ff 08 ac 95 0f 81 88 ff ff ..g.............
08 ac 95 0f 81 88 ff ff 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000031ab7788>] kmalloc_trace+0x27/0xa0
[<000000001f38adcb>] orangefs_sysfs_init+0x291/0x3a0
[<00000000722645ca>] 0xffffffffa02780fe
[<000000004232d9f7>] do_one_initcall+0x87/0x2a0
[<0000000054f22384>] do_init_module+0xdf/0x320
[<000000003263bdea>] load_module+0x2f98/0x3330
[<0000000052cd4153>] __do_sys_finit_module+0x113/0x1b0
[<00000000250ae02b>] do_syscall_64+0x35/0x80
[<00000000f11c03c7>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

unreferenced object 0xffff88810f95ab80 (size 64):
comm "insmod", pid 783, jiffies 4294813441 (age 65.530s)
hex dump (first 32 bytes):
50 bf 2f 02 81 88 ff ff 88 ab 95 0f 81 88 ff ff P./.............
88 ab 95 0f 81 88 ff ff 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000031ab7788>] kmalloc_trace+0x27/0xa0
[<000000009cc7d95b>] orangefs_sysfs_init+0x2f5/0x3a0
[<00000000722645ca>] 0xffffffffa02780fe
[<000000004232d9f7>] do_one_initcall+0x87/0x2a0
[<0000000054f22384>] do_init_module+0xdf/0x320
[<000000003263bdea>] load_module+0x2f98/0x3330
[<0000000052cd4153>] __do_sys_finit_module+0x113/0x1b0
[<00000000250ae02b>] do_syscall_64+0x35/0x80
[<00000000f11c03c7>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

Should add release function for each kobject_type to free the memory.

Signed-off-by: Zhang Xiaoxu <[e-mail]>
Signed-off-by: Mike Marshall <[e-mail]>

fs/orangefs/orangefs-sysfs.c

···
 };
 ATTRIBUTE_GROUPS(orangefs_default);
 
+static struct kobject *orangefs_obj;
+
+static void orangefs_obj_release(struct kobject *kobj)
+{
+	kfree(orangefs_obj);
+	orangefs_obj = NULL;
+}
+
 static struct kobj_type orangefs_ktype = {
 	.sysfs_ops = &orangefs_sysfs_ops,
 	.default_groups = orangefs_default_groups,
+	.release = orangefs_obj_release,
 };
 
 static struct orangefs_attribute acache_hard_limit_attribute =
···
 };
 ATTRIBUTE_GROUPS(acache_orangefs_default);
 
+static struct kobject *acache_orangefs_obj;
+
+static void acache_orangefs_obj_release(struct kobject *kobj)
+{
+	kfree(acache_orangefs_obj);
+	acache_orangefs_obj = NULL;
+}
+
 static struct kobj_type acache_orangefs_ktype = {
 	.sysfs_ops = &orangefs_sysfs_ops,
 	.default_groups = acache_orangefs_default_groups,
+	.release = acache_orangefs_obj_release,
 };
 
 static struct orangefs_attribute capcache_hard_limit_attribute =
···
 };
 ATTRIBUTE_GROUPS(capcache_orangefs_default);
 
+static struct kobject *capcache_orangefs_obj;
+
+static void capcache_orangefs_obj_release(struct kobject *kobj)
+{
+	kfree(capcache_orangefs_obj);
+	capcache_orangefs_obj = NULL;
+}
+
 static struct kobj_type capcache_orangefs_ktype = {
 	.sysfs_ops = &orangefs_sysfs_ops,
 	.default_groups = capcache_orangefs_default_groups,
+	.release = capcache_orangefs_obj_release,
 };
 
 static struct orangefs_attribute ccache_hard_limit_attribute =
···
 };
 ATTRIBUTE_GROUPS(ccache_orangefs_default);
 
+static struct kobject *ccache_orangefs_obj;
+
+static void ccache_orangefs_obj_release(struct kobject *kobj)
+{
+	kfree(ccache_orangefs_obj);
+	ccache_orangefs_obj = NULL;
+}
+
 static struct kobj_type ccache_orangefs_ktype = {
 	.sysfs_ops = &orangefs_sysfs_ops,
 	.default_groups = ccache_orangefs_default_groups,
+	.release = ccache_orangefs_obj_release,
 };
 
 static struct orangefs_attribute ncache_hard_limit_attribute =
···
 };
 ATTRIBUTE_GROUPS(ncache_orangefs_default);
 
+static struct kobject *ncache_orangefs_obj;
+
+static void ncache_orangefs_obj_release(struct kobject *kobj)
+{
+	kfree(ncache_orangefs_obj);
+	ncache_orangefs_obj = NULL;
+}
+
 static struct kobj_type ncache_orangefs_ktype = {
 	.sysfs_ops = &orangefs_sysfs_ops,
 	.default_groups = ncache_orangefs_default_groups,
+	.release = ncache_orangefs_obj_release,
 };
 
 static struct orangefs_attribute pc_acache_attribute =
···
 };
 ATTRIBUTE_GROUPS(pc_orangefs_default);
 
+static struct kobject *pc_orangefs_obj;
+
+static void pc_orangefs_obj_release(struct kobject *kobj)
+{
+	kfree(pc_orangefs_obj);
+	pc_orangefs_obj = NULL;
+}
+
 static struct kobj_type pc_orangefs_ktype = {
 	.sysfs_ops = &orangefs_sysfs_ops,
 	.default_groups = pc_orangefs_default_groups,
+	.release = pc_orangefs_obj_release,
 };
 
 static struct orangefs_attribute stats_reads_attribute =
···
 };
 ATTRIBUTE_GROUPS(stats_orangefs_default);
 
+static struct kobject *stats_orangefs_obj;
+
+static void stats_orangefs_obj_release(struct kobject *kobj)
+{
+	kfree(stats_orangefs_obj);
+	stats_orangefs_obj = NULL;
+}
+
 static struct kobj_type stats_orangefs_ktype = {
 	.sysfs_ops = &orangefs_sysfs_ops,
 	.default_groups = stats_orangefs_default_groups,
+	.release = stats_orangefs_obj_release,
 };
-
-static struct kobject *orangefs_obj;
-static struct kobject *acache_orangefs_obj;
-static struct kobject *capcache_orangefs_obj;
-static struct kobject *ccache_orangefs_obj;
-static struct kobject *ncache_orangefs_obj;
-static struct kobject *pc_orangefs_obj;
-static struct kobject *stats_orangefs_obj;
 
 int orangefs_sysfs_init(void)
 {