[PATCH 4/9] drivers: Switch to kvfree_rcu() API

From: Uladzislau Rezki (Sony)
Date: Wed Nov 24 2021 - 06:04:07 EST

Instead of invoking a synchronize_rcu() to free a pointer
after a grace period we can directly make use of new API
that does the same but in more efficient way.

CC: Philipp Reisner <philipp.reisner@xxxxxxxxxx>
CC: "Md. Haris Iqbal" <haris.iqbal@xxxxxxxxx>
CC: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
CC: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxxxxxxxxxxxxx>
CC: Samuel Iglesias Gonsalvez <siglesias@xxxxxxxxxx>
CC: Lee Jones <lee.jones@xxxxxxxxxx>
CC: Jorgen Hansen <jhansen@xxxxxxxxxx>
CC: Raju Rangoju <rajur@xxxxxxxxxxx>
CC: Saeed Mahameed <saeedm@xxxxxxxxxx>
CC: Boris Pismenny <borisp@xxxxxxxxxx>
CC: Jiri Pirko <jiri@xxxxxxxxxx>
CC: "James E.J. Bottomley" <jejb@xxxxxxxxxxxxx>
CC: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
---
drivers/block/drbd/drbd_nl.c | 9 +++------
drivers/block/drbd/drbd_receiver.c | 6 ++----
drivers/block/drbd/drbd_state.c | 3 +--
drivers/block/rnbd/rnbd-srv.c | 3 +--
drivers/crypto/nx/nx-common-pseries.c | 3 +--
drivers/infiniband/hw/hfi1/sdma.c | 3 +--
drivers/ipack/carriers/tpci200.c | 3 +--
drivers/mfd/dln2.c | 6 ++----
drivers/misc/vmw_vmci/vmci_context.c | 6 ++----
drivers/misc/vmw_vmci/vmci_event.c | 3 +--
drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c | 3 +--
drivers/net/ethernet/mellanox/mlx5/core/en/qos.c | 3 +--
drivers/net/ethernet/mellanox/mlx5/core/fpga/tls.c | 3 +--
drivers/net/ethernet/mellanox/mlxsw/core.c | 3 +--
drivers/scsi/device_handler/scsi_dh_alua.c | 3 +--
drivers/scsi/device_handler/scsi_dh_rdac.c | 3 +--
drivers/staging/fwserial/fwserial.c | 3 +--
17 files changed, 22 insertions(+), 44 deletions(-)

diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index 44ccf8b4f4b2..28f4d84945fd 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -1679,8 +1679,7 @@ int drbd_adm_disk_opts(struct sk_buff *skb, struct genl_info *info)
drbd_send_sync_param(peer_device);
}

- synchronize_rcu();
- kfree(old_disk_conf);
+ kvfree_rcu(old_disk_conf);
kfree(old_plan);
mod_timer(&device->request_timer, jiffies + HZ);
goto success;
@@ -2511,8 +2510,7 @@ int drbd_adm_net_opts(struct sk_buff *skb, struct genl_info *info)

mutex_unlock(&connection->resource->conf_update);
mutex_unlock(&connection->data.mutex);
- synchronize_rcu();
- kfree(old_net_conf);
+ kvfree_rcu(old_net_conf);

if (connection->cstate >= C_WF_REPORT_PARAMS) {
struct drbd_peer_device *peer_device;
@@ -2925,8 +2923,7 @@ int drbd_adm_resize(struct sk_buff *skb, struct genl_info *info)
new_disk_conf->disk_size = (sector_t)rs.resize_size;
rcu_assign_pointer(device->ldev->disk_conf, new_disk_conf);
mutex_unlock(&device->resource->conf_update);
- synchronize_rcu();
- kfree(old_disk_conf);
+ kvfree_rcu(old_disk_conf);
new_disk_conf = NULL;
}

diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 1f740e42e457..d73a53242a75 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -3799,8 +3799,7 @@ static int receive_protocol(struct drbd_connection *connection, struct packet_in
drbd_info(connection, "peer data-integrity-alg: %s\n",
integrity_alg[0] ? integrity_alg : "(none)");

- synchronize_rcu();
- kfree(old_net_conf);
+ kvfree_rcu(old_net_conf);
return 0;

disconnect_rcu_unlock:
@@ -4168,8 +4167,7 @@ static int receive_sizes(struct drbd_connection *connection, struct packet_info

rcu_assign_pointer(device->ldev->disk_conf, new_disk_conf);
mutex_unlock(&connection->resource->conf_update);
- synchronize_rcu();
- kfree(old_disk_conf);
+ kvfree_rcu(old_disk_conf);

drbd_info(device, "Peer sets u_size to %lu sectors (old: %lu)\n",
(unsigned long)p_usize, (unsigned long)my_usize);
diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c
index b8a27818ab3f..826e496821c7 100644
--- a/drivers/block/drbd/drbd_state.c
+++ b/drivers/block/drbd/drbd_state.c
@@ -2071,8 +2071,7 @@ static int w_after_conn_state_ch(struct drbd_work *w, int unused)
conn_free_crypto(connection);
mutex_unlock(&connection->resource->conf_update);

- synchronize_rcu();
- kfree(old_conf);
+ kvfree_rcu(old_conf);
}

if (ns_max.susp_fen) {
diff --git a/drivers/block/rnbd/rnbd-srv.c b/drivers/block/rnbd/rnbd-srv.c
index aafecfe97055..373dedd499b4 100644
--- a/drivers/block/rnbd/rnbd-srv.c
+++ b/drivers/block/rnbd/rnbd-srv.c
@@ -808,8 +808,7 @@ static int process_msg_open(struct rnbd_srv_session *srv_sess,

free_srv_sess_dev:
xa_erase(&srv_sess->index_idr, srv_sess_dev->device_id);
- synchronize_rcu();
- kfree(srv_sess_dev);
+ kvfree_rcu(srv_sess_dev);
srv_dev_put:
if (open_msg->access_mode != RNBD_ACCESS_RO) {
mutex_lock(&srv_dev->lock);
diff --git a/drivers/crypto/nx/nx-common-pseries.c b/drivers/crypto/nx/nx-common-pseries.c
index 4e304f6081e4..3faf30120ac9 100644
--- a/drivers/crypto/nx/nx-common-pseries.c
+++ b/drivers/crypto/nx/nx-common-pseries.c
@@ -1061,8 +1061,7 @@ static int nx842_probe(struct vio_dev *viodev,

rcu_assign_pointer(devdata, new_devdata);
spin_unlock_irqrestore(&devdata_mutex, flags);
- synchronize_rcu();
- kfree(old_devdata);
+ kvfree_rcu(old_devdata);

of_reconfig_notifier_register(&nx842_of_nb);

diff --git a/drivers/infiniband/hw/hfi1/sdma.c b/drivers/infiniband/hw/hfi1/sdma.c
index 2b6c24b7b586..0a0caf7360a4 100644
--- a/drivers/infiniband/hw/hfi1/sdma.c
+++ b/drivers/infiniband/hw/hfi1/sdma.c
@@ -1292,8 +1292,7 @@ void sdma_clean(struct hfi1_devdata *dd, size_t num_engines)
sdma_map_free(rcu_access_pointer(dd->sdma_map));
RCU_INIT_POINTER(dd->sdma_map, NULL);
spin_unlock_irq(&dd->sde_map_lock);
- synchronize_rcu();
- kfree(dd->per_sdma);
+ kvfree_rcu(dd->per_sdma);
dd->per_sdma = NULL;

if (dd->sdma_rht) {
diff --git a/drivers/ipack/carriers/tpci200.c b/drivers/ipack/carriers/tpci200.c
index cbfdadecb23b..de29fe594022 100644
--- a/drivers/ipack/carriers/tpci200.c
+++ b/drivers/ipack/carriers/tpci200.c
@@ -180,8 +180,7 @@ static int tpci200_free_irq(struct ipack_device *dev)
slot_irq = tpci200->slots[dev->slot].irq;
/* uninstall handler */
RCU_INIT_POINTER(tpci200->slots[dev->slot].irq, NULL);
- synchronize_rcu();
- kfree(slot_irq);
+ kvfree_rcu(slot_irq);
mutex_unlock(&tpci200->mutex);
return 0;
}
diff --git a/drivers/mfd/dln2.c b/drivers/mfd/dln2.c
index 852129ea0766..365e3e77cac4 100644
--- a/drivers/mfd/dln2.c
+++ b/drivers/mfd/dln2.c
@@ -179,10 +179,8 @@ void dln2_unregister_event_cb(struct platform_device *pdev, u16 id)

spin_unlock_irqrestore(&dln2->event_cb_lock, flags);

- if (found) {
- synchronize_rcu();
- kfree(i);
- }
+ if (found)
+ kvfree_rcu(i);
}
EXPORT_SYMBOL(dln2_unregister_event_cb);

diff --git a/drivers/misc/vmw_vmci/vmci_context.c b/drivers/misc/vmw_vmci/vmci_context.c
index c0b5e339d5a1..6cf3e21c7604 100644
--- a/drivers/misc/vmw_vmci/vmci_context.c
+++ b/drivers/misc/vmw_vmci/vmci_context.c
@@ -687,10 +687,8 @@ int vmci_ctx_remove_notification(u32 context_id, u32 remote_cid)
}
spin_unlock(&context->lock);

- if (found) {
- synchronize_rcu();
- kfree(notifier);
- }
+ if (found)
+ kvfree_rcu(notifier);

vmci_ctx_put(context);

diff --git a/drivers/misc/vmw_vmci/vmci_event.c b/drivers/misc/vmw_vmci/vmci_event.c
index e3436abf39f4..2100297c94ad 100644
--- a/drivers/misc/vmw_vmci/vmci_event.c
+++ b/drivers/misc/vmw_vmci/vmci_event.c
@@ -209,8 +209,7 @@ int vmci_event_unsubscribe(u32 sub_id)
if (!s)
return VMCI_ERROR_NOT_FOUND;

- synchronize_rcu();
- kfree(s);
+ kvfree_rcu(s);

return VMCI_SUCCESS;
}
diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
index dde1cf51d0ab..0619cb94f0e0 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
@@ -7190,8 +7190,7 @@ static void remove_one(struct pci_dev *pdev)
}
pci_release_regions(pdev);
kfree(adapter->mbox_log);
- synchronize_rcu();
- kfree(adapter);
+ kvfree_rcu(adapter);
}

/* "Shutdown" quiesces the device, stopping Ingress Packet and Interrupt
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/qos.c b/drivers/net/ethernet/mellanox/mlx5/core/en/qos.c
index 50977f01a050..eaaf7e33f90b 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/qos.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/qos.c
@@ -388,8 +388,7 @@ static int mlx5e_qos_alloc_queues(struct mlx5e_priv *priv, struct mlx5e_channels
sqs = rcu_replace_pointer(chs->c[i]->qos_sqs, NULL,
lockdep_is_held(&priv->state_lock));

- synchronize_rcu(); /* Sync with NAPI. */
- kvfree(sqs);
+ kvfree_rcu(sqs); /* Sync with NAPI. */
}
return -ENOMEM;
}
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fpga/tls.c b/drivers/net/ethernet/mellanox/mlx5/core/fpga/tls.c
index 29b7339ebfa3..e501eed7fe9f 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/fpga/tls.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/fpga/tls.c
@@ -253,7 +253,7 @@ static void mlx5_fpga_tls_send_teardown_cmd(struct mlx5_core_dev *mdev,
MLX5_SET(tls_cmd, cmd, swid, swid);

mlx5_fpga_tls_flow_to_cmd(flow, cmd);
- kfree(flow);
+ kvfree_rcu(flow);

buf->sg[0].data = cmd;
buf->sg[0].size = MLX5_TLS_COMMAND_SIZE;
@@ -283,7 +283,6 @@ void mlx5_fpga_tls_del_flow(struct mlx5_core_dev *mdev, u32 swid,
return;
}

- synchronize_rcu(); /* before kfree(flow) */
mlx5_fpga_tls_send_teardown_cmd(mdev, flow, swid, flags);
}

diff --git a/drivers/net/ethernet/mellanox/mlxsw/core.c b/drivers/net/ethernet/mellanox/mlxsw/core.c
index 3fd3812b8f31..47c29769759b 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/core.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/core.c
@@ -2190,8 +2190,7 @@ void mlxsw_core_rx_listener_unregister(struct mlxsw_core *mlxsw_core,
if (!rxl_item)
return;
list_del_rcu(&rxl_item->list);
- synchronize_rcu();
- kfree(rxl_item);
+ kvfree_rcu(rxl_item);
}
EXPORT_SYMBOL(mlxsw_core_rx_listener_unregister);

diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index 37d06f993b76..308246ce346a 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -1238,8 +1238,7 @@ static void alua_bus_detach(struct scsi_device *sdev)
kref_put(&pg->kref, release_port_group);
}
sdev->handler_data = NULL;
- synchronize_rcu();
- kfree(h);
+ kvfree_rcu(h);
}

static struct scsi_device_handler alua_dh = {
diff --git a/drivers/scsi/device_handler/scsi_dh_rdac.c b/drivers/scsi/device_handler/scsi_dh_rdac.c
index 66652ab409cc..dc687021ff3a 100644
--- a/drivers/scsi/device_handler/scsi_dh_rdac.c
+++ b/drivers/scsi/device_handler/scsi_dh_rdac.c
@@ -782,8 +782,7 @@ static void rdac_bus_detach( struct scsi_device *sdev )
}
spin_unlock(&list_lock);
sdev->handler_data = NULL;
- synchronize_rcu();
- kfree(h);
+ kvfree_rcu(h);
}

static struct scsi_device_handler rdac_dh = {
diff --git a/drivers/staging/fwserial/fwserial.c b/drivers/staging/fwserial/fwserial.c
index e8fa7f53cd5e..c8539c4f5bea 100644
--- a/drivers/staging/fwserial/fwserial.c
+++ b/drivers/staging/fwserial/fwserial.c
@@ -2116,8 +2116,7 @@ static void fwserial_remove_peer(struct fwtty_peer *peer)
if (port)
fwserial_release_port(port, true);

- synchronize_rcu();
- kfree(peer);
+ kvfree_rcu(peer);
}

/**
--
2.30.2