linux_dsm_epyc7002/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
Erez Shitrit 69956d8326 IB/ipoib: Sync between remove_one to sysfs calls that use rtnl_lock
In order to avoid deadlock between sysfs functions (like create/delete
child) and remove_one (both of them are using the sysfs lock and
rtnl_lock) the driver will use a state mutex for sync.

That will fix traces as the following:
schedule+0x3e/0x90
kernfs_drain+0x75/0xf0
? wait_woken+0x90/0x90
__kernfs_remove+0x12e/0x1c0
kernfs_remove+0x25/0x40
sysfs_remove_dir+0x57/0x90
kobject_del+0x22/0x60
device_del+0x195/0x230
 pm_runtime_set_memalloc_noio+0xac/0xf0
netdev_unregister_kobject+0x71/0x80
rollback_registered_many+0x205/0x2f0
rollback_registered+0x31/0x40
unregister_netdevice_queue+0x58/0xb0
unregister_netdev+0x20/0x30
ipoib_remove_one+0xb7/0x240 [ib_ipoib]
ib_unregister_device+0xbc/0x1b0 [ib_core]
ib_unregister_mad_agent+0x29/0x30 [ib_core]
mlx4_ib_remove+0x67/0x280 [mlx4_ib]
INFO: task echo:24082 blocked for more than 120 seconds.
Tainted: G           OE   4.1.12-37.5.1.el6uek.x86_64 #2
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
message.
Call Trace:
schedule+0x3e/0x90
schedule_preempt_disabled+0xe/0x10
__mutex_lock_slowpath+0x95/0x110
? _rcu_barrier+0x177/0x220
mutex_lock+0x23/0x40
rtnl_lock+0x15/0x20
netdev_run_todo+0x81/0x1f0
rtnl_unlock+0xe/0x10
ipoib_vlan_delete+0x12f/0x1c0 [ib_ipoib]
delete_child+0x69/0x80 [ib_ipoib]
dev_attr_store+0x20/0x30
sysfs_kf_write+0x41/0x50

Signed-off-by: Erez Shitrit <erezsh@mellanox.com>
Reviewed-by: Alex Vesker <valex@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-08-24 16:31:08 -04:00

234 lines
5.8 KiB
C

/*
* Copyright (c) 2004 Topspin Communications. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include <linux/module.h>
#include <linux/sched/signal.h>
#include <linux/init.h>
#include <linux/seq_file.h>
#include <linux/uaccess.h>
#include "ipoib.h"
static ssize_t show_parent(struct device *d, struct device_attribute *attr,
char *buf)
{
struct net_device *dev = to_net_dev(d);
struct ipoib_dev_priv *priv = ipoib_priv(dev);
return sprintf(buf, "%s\n", priv->parent->name);
}
static DEVICE_ATTR(parent, S_IRUGO, show_parent, NULL);
int __ipoib_vlan_add(struct ipoib_dev_priv *ppriv, struct ipoib_dev_priv *priv,
u16 pkey, int type)
{
int result;
priv->max_ib_mtu = ppriv->max_ib_mtu;
/* MTU will be reset when mcast join happens */
priv->dev->mtu = IPOIB_UD_MTU(priv->max_ib_mtu);
priv->mcast_mtu = priv->admin_mtu = priv->dev->mtu;
priv->parent = ppriv->dev;
set_bit(IPOIB_FLAG_SUBINTERFACE, &priv->flags);
ipoib_set_dev_features(priv, ppriv->ca);
priv->pkey = pkey;
memcpy(priv->dev->dev_addr, ppriv->dev->dev_addr, INFINIBAND_ALEN);
memcpy(&priv->local_gid, &ppriv->local_gid, sizeof(priv->local_gid));
set_bit(IPOIB_FLAG_DEV_ADDR_SET, &priv->flags);
priv->dev->broadcast[8] = pkey >> 8;
priv->dev->broadcast[9] = pkey & 0xff;
result = ipoib_dev_init(priv->dev, ppriv->ca, ppriv->port);
if (result < 0) {
ipoib_warn(ppriv, "failed to initialize subinterface: "
"device %s, port %d",
ppriv->ca->name, ppriv->port);
goto err;
}
result = register_netdevice(priv->dev);
if (result) {
ipoib_warn(priv, "failed to initialize; error %i", result);
goto register_failed;
}
/* RTNL childs don't need proprietary sysfs entries */
if (type == IPOIB_LEGACY_CHILD) {
if (ipoib_cm_add_mode_attr(priv->dev))
goto sysfs_failed;
if (ipoib_add_pkey_attr(priv->dev))
goto sysfs_failed;
if (ipoib_add_umcast_attr(priv->dev))
goto sysfs_failed;
if (device_create_file(&priv->dev->dev, &dev_attr_parent))
goto sysfs_failed;
}
priv->child_type = type;
list_add_tail(&priv->list, &ppriv->child_intfs);
return 0;
sysfs_failed:
result = -ENOMEM;
unregister_netdevice(priv->dev);
register_failed:
ipoib_dev_cleanup(priv->dev);
err:
return result;
}
int ipoib_vlan_add(struct net_device *pdev, unsigned short pkey)
{
struct ipoib_dev_priv *ppriv, *priv;
char intf_name[IFNAMSIZ];
struct ipoib_dev_priv *tpriv;
int result;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
ppriv = ipoib_priv(pdev);
if (test_bit(IPOIB_FLAG_GOING_DOWN, &ppriv->flags))
return -EPERM;
snprintf(intf_name, sizeof intf_name, "%s.%04x",
ppriv->dev->name, pkey);
if (!mutex_trylock(&ppriv->sysfs_mutex))
return restart_syscall();
if (!rtnl_trylock()) {
mutex_unlock(&ppriv->sysfs_mutex);
return restart_syscall();
}
priv = ipoib_intf_alloc(ppriv->ca, ppriv->port, intf_name);
if (!priv) {
rtnl_unlock();
mutex_unlock(&ppriv->sysfs_mutex);
return -ENOMEM;
}
down_write(&ppriv->vlan_rwsem);
/*
* First ensure this isn't a duplicate. We check the parent device and
* then all of the legacy child interfaces to make sure the Pkey
* doesn't match.
*/
if (ppriv->pkey == pkey) {
result = -ENOTUNIQ;
goto out;
}
list_for_each_entry(tpriv, &ppriv->child_intfs, list) {
if (tpriv->pkey == pkey &&
tpriv->child_type == IPOIB_LEGACY_CHILD) {
result = -ENOTUNIQ;
goto out;
}
}
result = __ipoib_vlan_add(ppriv, priv, pkey, IPOIB_LEGACY_CHILD);
out:
up_write(&ppriv->vlan_rwsem);
rtnl_unlock();
mutex_unlock(&ppriv->sysfs_mutex);
if (result) {
free_netdev(priv->dev);
kfree(priv);
}
return result;
}
int ipoib_vlan_delete(struct net_device *pdev, unsigned short pkey)
{
struct ipoib_dev_priv *ppriv, *priv, *tpriv;
struct net_device *dev = NULL;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
ppriv = ipoib_priv(pdev);
if (test_bit(IPOIB_FLAG_GOING_DOWN, &ppriv->flags))
return -EPERM;
if (!mutex_trylock(&ppriv->sysfs_mutex))
return restart_syscall();
if (!rtnl_trylock()) {
mutex_unlock(&ppriv->sysfs_mutex);
return restart_syscall();
}
down_write(&ppriv->vlan_rwsem);
list_for_each_entry_safe(priv, tpriv, &ppriv->child_intfs, list) {
if (priv->pkey == pkey &&
priv->child_type == IPOIB_LEGACY_CHILD) {
list_del(&priv->list);
dev = priv->dev;
break;
}
}
up_write(&ppriv->vlan_rwsem);
if (dev) {
ipoib_dbg(ppriv, "delete child vlan %s\n", dev->name);
unregister_netdevice(dev);
}
rtnl_unlock();
mutex_unlock(&ppriv->sysfs_mutex);
if (dev) {
free_netdev(dev);
kfree(priv);
return 0;
}
return -ENODEV;
}