Messages in this thread Patch in this message | | | Date | Wed, 25 Feb 2009 16:06:57 +0100 | From | Martin Schwidefsky <> | Subject | [patch/s390 35/46] qdio: add missing tiq_list locking |
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From: Jan Glauber <jang@linux.vnet.ibm.com>
Add a mutex to protect the tiq_list. Although reading the list is done using RCU adding and removing elements from the list must still happen locked since multiple qdio devices may change the list in parallel otherwise.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> ---
drivers/s390/cio/qdio_main.c | 1 + drivers/s390/cio/qdio_thinint.c | 10 +++++++--- 2 files changed, 8 insertions(+), 3 deletions(-)
Index: quilt-2.6/drivers/s390/cio/qdio_main.c =================================================================== --- quilt-2.6.orig/drivers/s390/cio/qdio_main.c +++ quilt-2.6/drivers/s390/cio/qdio_main.c @@ -1112,6 +1112,7 @@ int qdio_shutdown(struct ccw_device *cde if (!irq_ptr) return -ENODEV; + BUG_ON(irqs_disabled()); DBF_EVENT("qshutdown:%4x", cdev->private->schid.sch_no); mutex_lock(&irq_ptr->setup_mutex); Index: quilt-2.6/drivers/s390/cio/qdio_thinint.c =================================================================== --- quilt-2.6.orig/drivers/s390/cio/qdio_thinint.c +++ quilt-2.6/drivers/s390/cio/qdio_thinint.c @@ -31,6 +31,7 @@ /* list of thin interrupt input queues */ static LIST_HEAD(tiq_list); +DEFINE_MUTEX(tiq_list_lock); /* adapter local summary indicator */ static unsigned char *tiqdio_alsi; @@ -95,10 +96,10 @@ void tiqdio_add_input_queues(struct qdio if (!css_qdio_omit_svs && irq_ptr->siga_flag.sync) css_qdio_omit_svs = 1; - for_each_input_queue(irq_ptr, q, i) { + mutex_lock(&tiq_list_lock); + for_each_input_queue(irq_ptr, q, i) list_add_rcu(&q->entry, &tiq_list); - synchronize_rcu(); - } + mutex_unlock(&tiq_list_lock); xchg(irq_ptr->dsci, 1); tasklet_schedule(&tiqdio_tasklet); } @@ -118,7 +119,10 @@ void tiqdio_remove_input_queues(struct q /* if establish triggered an error */ if (!q || !q->entry.prev || !q->entry.next) continue; + + mutex_lock(&tiq_list_lock); list_del_rcu(&q->entry); + mutex_unlock(&tiq_list_lock); synchronize_rcu(); } } -- blue skies, Martin.
"Reality continues to ruin my life." - Calvin.
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