drbd: Protect accesses to the uuid set with a spinlock
There is at least the worker context, the receiver context, the context of
receiving netlink packts and processes reading a sysfs attribute that access
the uuids.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index f55683a..dfa08b7 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2125,8 +2125,10 @@
if (!get_ldev_if_state(mdev, D_NEGOTIATING))
return 1;
+ spin_lock_irq(&mdev->ldev->md.uuid_lock);
for (i = UI_CURRENT; i < UI_SIZE; i++)
p.uuid[i] = mdev->ldev ? cpu_to_be64(mdev->ldev->md.uuid[i]) : 0;
+ spin_unlock_irq(&mdev->ldev->md.uuid_lock);
mdev->comm_bm_set = drbd_bm_total_weight(mdev);
p.uuid[UI_SIZE] = cpu_to_be64(mdev->comm_bm_set);
@@ -4011,7 +4013,7 @@
}
#endif
-static void drbd_uuid_move_history(struct drbd_conf *mdev) __must_hold(local)
+void drbd_uuid_move_history(struct drbd_conf *mdev) __must_hold(local)
{
int i;
@@ -4019,7 +4021,7 @@
mdev->ldev->md.uuid[i+1] = mdev->ldev->md.uuid[i];
}
-void _drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local)
+void __drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local)
{
if (idx == UI_CURRENT) {
if (mdev->state.role == R_PRIMARY)
@@ -4034,14 +4036,24 @@
drbd_md_mark_dirty(mdev);
}
+void _drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local)
+{
+ unsigned long flags;
+ spin_lock_irqsave(&mdev->ldev->md.uuid_lock, flags);
+ __drbd_uuid_set(mdev, idx, val);
+ spin_unlock_irqrestore(&mdev->ldev->md.uuid_lock, flags);
+}
void drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local)
{
+ unsigned long flags;
+ spin_lock_irqsave(&mdev->ldev->md.uuid_lock, flags);
if (mdev->ldev->md.uuid[idx]) {
drbd_uuid_move_history(mdev);
mdev->ldev->md.uuid[UI_HISTORY_START] = mdev->ldev->md.uuid[idx];
}
- _drbd_uuid_set(mdev, idx, val);
+ __drbd_uuid_set(mdev, idx, val);
+ spin_unlock_irqrestore(&mdev->ldev->md.uuid_lock, flags);
}
/**
@@ -4054,15 +4066,20 @@
void drbd_uuid_new_current(struct drbd_conf *mdev) __must_hold(local)
{
u64 val;
- unsigned long long bm_uuid = mdev->ldev->md.uuid[UI_BITMAP];
+ unsigned long long bm_uuid;
+
+ get_random_bytes(&val, sizeof(u64));
+
+ spin_lock_irq(&mdev->ldev->md.uuid_lock);
+ bm_uuid = mdev->ldev->md.uuid[UI_BITMAP];
if (bm_uuid)
dev_warn(DEV, "bm UUID was already set: %llX\n", bm_uuid);
mdev->ldev->md.uuid[UI_BITMAP] = mdev->ldev->md.uuid[UI_CURRENT];
+ __drbd_uuid_set(mdev, UI_CURRENT, val);
+ spin_unlock_irq(&mdev->ldev->md.uuid_lock);
- get_random_bytes(&val, sizeof(u64));
- _drbd_uuid_set(mdev, UI_CURRENT, val);
drbd_print_uuids(mdev, "new current UUID");
/* get it to stable storage _now_ */
drbd_md_sync(mdev);
@@ -4070,9 +4087,11 @@
void drbd_uuid_set_bm(struct drbd_conf *mdev, u64 val) __must_hold(local)
{
+ unsigned long flags;
if (mdev->ldev->md.uuid[UI_BITMAP] == 0 && val == 0)
return;
+ spin_lock_irqsave(&mdev->ldev->md.uuid_lock, flags);
if (val == 0) {
drbd_uuid_move_history(mdev);
mdev->ldev->md.uuid[UI_HISTORY_START] = mdev->ldev->md.uuid[UI_BITMAP];
@@ -4084,6 +4103,8 @@
mdev->ldev->md.uuid[UI_BITMAP] = val & ~((u64)1);
}
+ spin_unlock_irqrestore(&mdev->ldev->md.uuid_lock, flags);
+
drbd_md_mark_dirty(mdev);
}