diff options
| author | Andreas Gruenbacher | 2014-08-14 18:33:30 +0200 |
|---|---|---|
| committer | Jens Axboe | 2015-11-25 17:22:00 +0100 |
| commit | 28bc3b8c71cda033a4c013131c635d1148889824 (patch) | |
| tree | ceb03e905cdee0d06cd169f8affe46f722fd14d8 /drivers/block/drbd/drbd_main.c | |
| parent | drbd: drbd_adm_attach(): Add missing drbd_resync_after_changed() (diff) | |
| download | kernel-qcow2-linux-28bc3b8c71cda033a4c013131c635d1148889824.tar.gz kernel-qcow2-linux-28bc3b8c71cda033a4c013131c635d1148889824.tar.xz kernel-qcow2-linux-28bc3b8c71cda033a4c013131c635d1148889824.zip | |
drbd: Fix locking across all resources
Instead of using a rwlock for synchronizing state changes across
resources, take the request locks of all resources for global state
changes. Use resources_mutex to serialize global state changes.
This means that taking the request lock of a resource is now enough to
prevent changes of that resource. (Previously, a read lock on the
global state lock was needed as well.)
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'drivers/block/drbd/drbd_main.c')
| -rw-r--r-- | drivers/block/drbd/drbd_main.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c index 3ee4a44cb225..f66294db3b08 100644 --- a/drivers/block/drbd/drbd_main.c +++ b/drivers/block/drbd/drbd_main.c @@ -117,6 +117,7 @@ module_param_string(usermode_helper, usermode_helper, sizeof(usermode_helper), 0 */ struct idr drbd_devices; struct list_head drbd_resources; +struct mutex resources_mutex; struct kmem_cache *drbd_request_cache; struct kmem_cache *drbd_ee_cache; /* peer requests */ @@ -2923,7 +2924,7 @@ static int __init drbd_init(void) drbd_proc = NULL; /* play safe for drbd_cleanup */ idr_init(&drbd_devices); - rwlock_init(&global_state_lock); + mutex_init(&resources_mutex); INIT_LIST_HEAD(&drbd_resources); err = drbd_genl_register(); @@ -3746,6 +3747,27 @@ int drbd_wait_misc(struct drbd_device *device, struct drbd_interval *i) return 0; } +void lock_all_resources(void) +{ + struct drbd_resource *resource; + int __maybe_unused i = 0; + + mutex_lock(&resources_mutex); + local_irq_disable(); + for_each_resource(resource, &drbd_resources) + spin_lock_nested(&resource->req_lock, i++); +} + +void unlock_all_resources(void) +{ + struct drbd_resource *resource; + + for_each_resource(resource, &drbd_resources) + spin_unlock(&resource->req_lock); + local_irq_enable(); + mutex_unlock(&resources_mutex); +} + #ifdef CONFIG_DRBD_FAULT_INJECTION /* Fault insertion support including random number generator shamelessly * stolen from kernel/rcutorture.c */ |