From: Ingo Tuchscherer Date: Fri, 12 Apr 2013 15:52:08 +0000 (+0200) Subject: s390/zcrypt: ap bus rescan problem when toggle crypto adapters on/off X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=56bbe686693df7edcca18d1808edd80609e63c31;p=linux.git s390/zcrypt: ap bus rescan problem when toggle crypto adapters on/off The bus rescan process was called simultaneously on every device failure. This finally leads into race conditions (double device add/remove actions). This patch protects the rescan area by mutual exclusion and improves ap_config_timer handling Signed-off-by: Ingo Tuchscherer Signed-off-by: Martin Schwidefsky --- diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c index b8b340ac53321..9de41aa148965 100644 --- a/drivers/s390/crypto/ap_bus.c +++ b/drivers/s390/crypto/ap_bus.c @@ -954,15 +954,11 @@ EXPORT_SYMBOL(ap_driver_unregister); void ap_bus_force_rescan(void) { - /* Delete the AP bus rescan timer. */ - del_timer(&ap_config_timer); - - /* processing a synchonuous bus rescan */ - ap_scan_bus(NULL); - - /* Setup the AP bus rescan timer again. */ - ap_config_timer.expires = jiffies + ap_config_time * HZ; - add_timer(&ap_config_timer); + /* reconfigure the AP bus rescan timer. */ + mod_timer(&ap_config_timer, jiffies + ap_config_time * HZ); + /* processing a asynchronous bus rescan */ + queue_work(ap_work_queue, &ap_config_work); + flush_work(&ap_config_work); } EXPORT_SYMBOL(ap_bus_force_rescan); @@ -1305,8 +1301,9 @@ static void ap_scan_bus(struct work_struct *unused) int rc, i; ap_query_configuration(); - if (ap_select_domain() != 0) + if (ap_select_domain() != 0) { return; + } for (i = 0; i < AP_DEVICES; i++) { qid = AP_MKQID(i, ap_domain_index); dev = bus_find_device(&ap_bus_type, NULL,