[PATCH 5/7] ibmvnic: use a lock to serialize remove/reset
From: Sukadev Bhattiprolu <hidden>
Date: 2021-01-08 07:13:39
Subsystem:
ibm power sriov virtual nic device driver, linux for powerpc (32-bit and 64-bit), networking drivers, the rest · Maintainers:
Haren Myneni, Rick Lindsley, Madhavan Srinivasan, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Use a separate lock to serialze ibmvnic_reset() and ibmvnic_remove()
functions. ibmvnic_reset() schedules work for the worker thread and
ibmvnic_remove() flushes the work before removing the adapter. We
don't want any work to be scheduled once we start removing the
adapter (i.e after we have already flushed the work).
A follow-on patch will convert the ->state_lock from a spinklock
to a mutex to allow us to hold it for longer periods of time.
ibmvnic_reset() can be called from a tasklet and cannot use the
mutex.
Fixes: 6954a9e4192b ("ibmvnic: Flush existing work items before
device removal")
Signed-off-by: Sukadev Bhattiprolu <redacted>
---
drivers/net/ethernet/ibm/ibmvnic.c | 16 +++++++++++++++-
drivers/net/ethernet/ibm/ibmvnic.h | 2 ++
2 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index ad551418ac63..c7675ab0b7e3 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c@@ -2435,6 +2435,7 @@ static int ibmvnic_reset(struct ibmvnic_adapter *adapter, enum ibmvnic_reset_reason reason) { struct net_device *netdev = adapter->netdev; + unsigned long rmflags; int ret; if (adapter->state == VNIC_PROBING) {
@@ -2443,6 +2444,8 @@ static int ibmvnic_reset(struct ibmvnic_adapter *adapter, goto err; } + spin_lock_irqsave(&adapter->remove_lock, rmflags); + /* * If failover is pending don't schedule any other reset. * Instead let the failover complete. If there is already a
@@ -2465,8 +2468,9 @@ static int ibmvnic_reset(struct ibmvnic_adapter *adapter, netdev_dbg(adapter->netdev, "Scheduling reset (reason %d)\n", reason); schedule_work(&adapter->ibmvnic_reset); - return 0; + ret = 0; err: + spin_unlock_irqrestore(&adapter->remove_lock, rmflags); return -ret; }
@@ -5387,6 +5391,7 @@ static int ibmvnic_probe(struct vio_dev *dev, const struct vio_device_id *id) memset(&adapter->pending_resets, 0, sizeof(adapter->pending_resets)); spin_lock_init(&adapter->rwi_lock); spin_lock_init(&adapter->state_lock); + spin_lock_init(&adapter->remove_lock); mutex_init(&adapter->fw_lock); init_completion(&adapter->init_done); init_completion(&adapter->fw_done);
@@ -5459,6 +5464,7 @@ static int ibmvnic_remove(struct vio_dev *dev) { struct net_device *netdev = dev_get_drvdata(&dev->dev); struct ibmvnic_adapter *adapter = netdev_priv(netdev); + unsigned long rmflags; unsigned long flags; spin_lock_irqsave(&adapter->state_lock, flags);
@@ -5467,7 +5473,15 @@ static int ibmvnic_remove(struct vio_dev *dev) return -EBUSY; } + /* If ibmvnic_reset() is scheduling a reset, wait for it to + * finish. Then prevent it from scheduling any more resets + * and have the reset functions ignore any resets that have + * already been scheduled. + */ + spin_lock_irqsave(&adapter->remove_lock, rmflags); adapter->state = VNIC_REMOVING; + spin_unlock_irqrestore(&adapter->remove_lock, rmflags); + spin_unlock_irqrestore(&adapter->state_lock, flags); flush_work(&adapter->ibmvnic_reset);
diff --git a/drivers/net/ethernet/ibm/ibmvnic.h b/drivers/net/ethernet/ibm/ibmvnic.h
index 1179a95a3f92..2779696ade09 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.h
+++ b/drivers/net/ethernet/ibm/ibmvnic.h@@ -1081,6 +1081,8 @@ struct ibmvnic_adapter { spinlock_t rwi_lock; enum ibmvnic_reset_reason pending_resets[VNIC_RESET_MAX-1]; short next_reset; + /* serialize ibmvnic_reset() and ibmvnic_remove() */ + spinlock_t remove_lock; struct work_struct ibmvnic_reset; struct delayed_work ibmvnic_delayed_reset; unsigned long resetting;
--
2.26.2