driver core: Release device_hotplug_lock when store_mem_state returns EINVAL

When inserting a wrong value to /sys/devices/system/memory/memoryX/state file,
following messages are shown. And device_hotplug_lock is never released.

================================================
[ BUG: lock held when returning to user space! ]
3.12.0-rc4-debug+ #3 Tainted: G        W
------------------------------------------------
bash/6442 is leaving the kernel with locks still held!
1 lock held by bash/6442:
 #0:  (device_hotplug_lock){+.+.+.}, at: [<ffffffff8146cbb5>] lock_device_hotplug_sysfs+0x15/0x50

This issue was introdued by commit fa2be40 (drivers: base: use standard
device online/offline for state change).

This patch releases device_hotplug_lcok when store_mem_state returns EINVAL.

Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Reviewed-by: Toshi Kani <toshi.kani@hp.com>
CC: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 9e59f6535c442bbb26d6ad055b93a4b0cf5bef5d..bece691cb5d99d79f761b9400eebf1e9a78c55a2 100644 (file)
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -333,8 +333,10 @@ store_mem_state(struct device *dev,
                online_type = ONLINE_KEEP;
        else if (!strncmp(buf, "offline", min_t(int, count, 7)))
                online_type = -1;
-       else
-               return -EINVAL;
+       else {
+               ret = -EINVAL;
+               goto err;
+       }
 
        switch (online_type) {
        case ONLINE_KERNEL:
@@ -357,6 +359,7 @@ store_mem_state(struct device *dev,
                ret = -EINVAL; /* should never happen */
        }
 
+err:
        unlock_device_hotplug();
 
        if (ret)