memory leaks in dasd_eckd_check_characteristics() error paths

[Qian Cai]

For some reasons, dasd_eckd_check_characteristics() received -ENOMEM and then
dasd_generic_set_online() emits this message,

dasd: 0.0.0122 Setting the DASD online with discipline ECKD failed with rc=-12

After that, there are several memory leaks below. There are "config_data" and
then stored as,

/* store per path conf_data */
device->path[pos].conf_data = conf_data;

When it processes the error path in Âdasd_generic_set_online(), it calls
dasd_delete_device() which nuke the whole "struct dasd_device" without freeing
the device->path[].conf_data first. Is it safe to free those in
dasd_free_device() without worrying about the double-free? Or, is it better to
free those in dasd_eckd_check_characteristics()'s goto error handling, i.e.,
out_err*?

--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -153,6 +153,9 @@ struct dasd_device *dasd_alloc_device(void)
 */
Âvoid dasd_free_device(struct dasd_device *device)
Â{
+ÂÂÂÂÂÂÂfor (int i = 0; i < 8; i++)
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂkfree(device->path[i].conf_data);
+
ÂÂÂÂÂÂÂÂkfree(device->private);
ÂÂÂÂÂÂÂÂfree_pages((unsigned long) device->ese_mem, 1);
ÂÂÂÂÂÂÂÂfree_page((unsigned long) device->erp_mem);


unreferenced object 0x0fcee900 (size 256):
 comm "dasdconf.sh", pid 446, jiffies 4294940081 (age 170.340s)
 hex dump (first 32 bytes):
ÂÂÂÂdc 01 01 00 f0 f0 f2 f1 f0 f7 f9 f0 f0 c9 c2 d4ÂÂ................
ÂÂÂÂf7 f5 f0 f0 f0 f0 f0 f0 f0 c6 d9 c2 f7 f1 62 33ÂÂ..............b3
 backtrace:
ÂÂÂÂ[<00000000a83b1992>] kmem_cache_alloc_trace+0x200/0x388
ÂÂÂÂ[<00000000048ef3e2>] dasd_eckd_read_conf+0x408/0x1400 [dasd_eckd_mod]
ÂÂÂÂ[<00000000ce31f195>] dasd_eckd_check_characteristics+0x3cc/0x938
[dasd_eckd_mod]
ÂÂÂÂ[<00000000f6f1759b>] dasd_generic_set_online+0x150/0x4c0
ÂÂÂÂ[<00000000efca1efa>] ccw_device_set_online+0x324/0x808
ÂÂÂÂ[<00000000f9779774>] online_store_recog_and_online+0xe8/0x220
ÂÂÂÂ[<00000000349a5446>] online_store+0x2ce/0x420
ÂÂÂÂ[<000000005bd145f8>] kernfs_fop_write+0x1bc/0x270
ÂÂÂÂ[<0000000005664197>] vfs_write+0xce/0x220
ÂÂÂÂ[<0000000044a8bccb>] ksys_write+0xea/0x190
ÂÂÂÂ[<0000000037335938>] system_call+0x296/0x2b4