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Message-Id: <20200708150515.44938-4-kgraul@linux.ibm.com>
Date: Wed, 8 Jul 2020 17:05:13 +0200
From: Karsten Graul <kgraul@...ux.ibm.com>
To: davem@...emloft.net
Cc: netdev@...r.kernel.org, linux-s390@...r.kernel.org,
heiko.carstens@...ibm.com, raspl@...ux.ibm.com,
ubraun@...ux.ibm.com
Subject: [PATCH net 3/5] net/smc: fix sleep bug in smc_pnet_find_roce_resource()
From: Ursula Braun <ubraun@...ux.ibm.com>
Tests showed this BUG:
[572555.252867] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:935
[572555.252876] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 131031, name: smcapp
[572555.252879] INFO: lockdep is turned off.
[572555.252883] CPU: 1 PID: 131031 Comm: smcapp Tainted: G O 5.7.0-rc3uschi+ #356
[572555.252885] Hardware name: IBM 3906 M03 703 (LPAR)
[572555.252887] Call Trace:
[572555.252896] [<00000000ac364554>] show_stack+0x94/0xe8
[572555.252901] [<00000000aca1f400>] dump_stack+0xa0/0xe0
[572555.252906] [<00000000ac3c8c10>] ___might_sleep+0x260/0x280
[572555.252910] [<00000000acdc0c98>] __mutex_lock+0x48/0x940
[572555.252912] [<00000000acdc15c2>] mutex_lock_nested+0x32/0x40
[572555.252975] [<000003ff801762d0>] mlx5_lag_get_roce_netdev+0x30/0xc0 [mlx5_core]
[572555.252996] [<000003ff801fb3aa>] mlx5_ib_get_netdev+0x3a/0xe0 [mlx5_ib]
[572555.253007] [<000003ff80063848>] smc_pnet_find_roce_resource+0x1d8/0x310 [smc]
[572555.253011] [<000003ff800602f0>] __smc_connect+0x1f0/0x3e0 [smc]
[572555.253015] [<000003ff80060634>] smc_connect+0x154/0x190 [smc]
[572555.253022] [<00000000acbed8d4>] __sys_connect+0x94/0xd0
[572555.253025] [<00000000acbef620>] __s390x_sys_socketcall+0x170/0x360
[572555.253028] [<00000000acdc6800>] system_call+0x298/0x2b8
[572555.253030] INFO: lockdep is turned off.
Function smc_pnet_find_rdma_dev() might be called from
smc_pnet_find_roce_resource(). It holds the smc_ib_devices list
spinlock while calling infiniband op get_netdev(). At least for mlx5
the get_netdev operation wants mutex serialization, which conflicts
with the smc_ib_devices spinlock.
This patch switches the smc_ib_devices spinlock into a mutex to
allow sleeping when calling get_netdev().
Fixes: a4cf0443c414 ("smc: introduce SMC as an IB-client")
Signed-off-by: Ursula Braun <ubraun@...ux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@...ux.ibm.com>
---
net/smc/smc_core.c | 5 +++--
net/smc/smc_ib.c | 11 ++++++-----
net/smc/smc_ib.h | 3 ++-
net/smc/smc_pnet.c | 21 +++++++++++----------
4 files changed, 22 insertions(+), 18 deletions(-)
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index d695ce71837e..8bf34d9f27e5 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -15,6 +15,7 @@
#include <linux/workqueue.h>
#include <linux/wait.h>
#include <linux/reboot.h>
+#include <linux/mutex.h>
#include <net/tcp.h>
#include <net/sock.h>
#include <rdma/ib_verbs.h>
@@ -1961,14 +1962,14 @@ static void smc_core_going_away(void)
struct smc_ib_device *smcibdev;
struct smcd_dev *smcd;
- spin_lock(&smc_ib_devices.lock);
+ mutex_lock(&smc_ib_devices.mutex);
list_for_each_entry(smcibdev, &smc_ib_devices.list, list) {
int i;
for (i = 0; i < SMC_MAX_PORTS; i++)
set_bit(i, smcibdev->ports_going_away);
}
- spin_unlock(&smc_ib_devices.lock);
+ mutex_unlock(&smc_ib_devices.mutex);
spin_lock(&smcd_dev_list.lock);
list_for_each_entry(smcd, &smcd_dev_list.list, list) {
diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c
index 562a52d01ad1..7637fdebbb78 100644
--- a/net/smc/smc_ib.c
+++ b/net/smc/smc_ib.c
@@ -16,6 +16,7 @@
#include <linux/workqueue.h>
#include <linux/scatterlist.h>
#include <linux/wait.h>
+#include <linux/mutex.h>
#include <rdma/ib_verbs.h>
#include <rdma/ib_cache.h>
@@ -33,7 +34,7 @@
#define SMC_QP_RNR_RETRY 7 /* 7: infinite */
struct smc_ib_devices smc_ib_devices = { /* smc-registered ib devices */
- .lock = __SPIN_LOCK_UNLOCKED(smc_ib_devices.lock),
+ .mutex = __MUTEX_INITIALIZER(smc_ib_devices.mutex),
.list = LIST_HEAD_INIT(smc_ib_devices.list),
};
@@ -565,9 +566,9 @@ static int smc_ib_add_dev(struct ib_device *ibdev)
INIT_WORK(&smcibdev->port_event_work, smc_ib_port_event_work);
atomic_set(&smcibdev->lnk_cnt, 0);
init_waitqueue_head(&smcibdev->lnks_deleted);
- spin_lock(&smc_ib_devices.lock);
+ mutex_lock(&smc_ib_devices.mutex);
list_add_tail(&smcibdev->list, &smc_ib_devices.list);
- spin_unlock(&smc_ib_devices.lock);
+ mutex_unlock(&smc_ib_devices.mutex);
ib_set_client_data(ibdev, &smc_ib_client, smcibdev);
INIT_IB_EVENT_HANDLER(&smcibdev->event_handler, smcibdev->ibdev,
smc_ib_global_event_handler);
@@ -602,9 +603,9 @@ static void smc_ib_remove_dev(struct ib_device *ibdev, void *client_data)
{
struct smc_ib_device *smcibdev = client_data;
- spin_lock(&smc_ib_devices.lock);
+ mutex_lock(&smc_ib_devices.mutex);
list_del_init(&smcibdev->list); /* remove from smc_ib_devices */
- spin_unlock(&smc_ib_devices.lock);
+ mutex_unlock(&smc_ib_devices.mutex);
pr_warn_ratelimited("smc: removing ib device %s\n",
smcibdev->ibdev->name);
smc_smcr_terminate_all(smcibdev);
diff --git a/net/smc/smc_ib.h b/net/smc/smc_ib.h
index e6a696ae15f3..ae6776e1e726 100644
--- a/net/smc/smc_ib.h
+++ b/net/smc/smc_ib.h
@@ -14,6 +14,7 @@
#include <linux/interrupt.h>
#include <linux/if_ether.h>
+#include <linux/mutex.h>
#include <linux/wait.h>
#include <rdma/ib_verbs.h>
#include <net/smc.h>
@@ -25,7 +26,7 @@
struct smc_ib_devices { /* list of smc ib devices definition */
struct list_head list;
- spinlock_t lock; /* protects list of smc ib devices */
+ struct mutex mutex; /* protects list of smc ib devices */
};
extern struct smc_ib_devices smc_ib_devices; /* list of smc ib devices */
diff --git a/net/smc/smc_pnet.c b/net/smc/smc_pnet.c
index 014d91b9778e..d4aac31d39f5 100644
--- a/net/smc/smc_pnet.c
+++ b/net/smc/smc_pnet.c
@@ -12,6 +12,7 @@
#include <linux/module.h>
#include <linux/list.h>
#include <linux/ctype.h>
+#include <linux/mutex.h>
#include <net/netlink.h>
#include <net/genetlink.h>
@@ -129,7 +130,7 @@ static int smc_pnet_remove_by_pnetid(struct net *net, char *pnet_name)
return rc;
/* remove ib devices */
- spin_lock(&smc_ib_devices.lock);
+ mutex_lock(&smc_ib_devices.mutex);
list_for_each_entry(ibdev, &smc_ib_devices.list, list) {
for (ibport = 0; ibport < SMC_MAX_PORTS; ibport++) {
if (ibdev->pnetid_by_user[ibport] &&
@@ -149,7 +150,7 @@ static int smc_pnet_remove_by_pnetid(struct net *net, char *pnet_name)
}
}
}
- spin_unlock(&smc_ib_devices.lock);
+ mutex_unlock(&smc_ib_devices.mutex);
/* remove smcd devices */
spin_lock(&smcd_dev_list.lock);
list_for_each_entry(smcd_dev, &smcd_dev_list.list, list) {
@@ -240,14 +241,14 @@ static bool smc_pnet_apply_ib(struct smc_ib_device *ib_dev, u8 ib_port,
u8 pnet_null[SMC_MAX_PNETID_LEN] = {0};
bool applied = false;
- spin_lock(&smc_ib_devices.lock);
+ mutex_lock(&smc_ib_devices.mutex);
if (smc_pnet_match(ib_dev->pnetid[ib_port - 1], pnet_null)) {
memcpy(ib_dev->pnetid[ib_port - 1], pnet_name,
SMC_MAX_PNETID_LEN);
ib_dev->pnetid_by_user[ib_port - 1] = true;
applied = true;
}
- spin_unlock(&smc_ib_devices.lock);
+ mutex_unlock(&smc_ib_devices.mutex);
return applied;
}
@@ -300,7 +301,7 @@ static struct smc_ib_device *smc_pnet_find_ib(char *ib_name)
{
struct smc_ib_device *ibdev;
- spin_lock(&smc_ib_devices.lock);
+ mutex_lock(&smc_ib_devices.mutex);
list_for_each_entry(ibdev, &smc_ib_devices.list, list) {
if (!strncmp(ibdev->ibdev->name, ib_name,
sizeof(ibdev->ibdev->name)) ||
@@ -311,7 +312,7 @@ static struct smc_ib_device *smc_pnet_find_ib(char *ib_name)
}
ibdev = NULL;
out:
- spin_unlock(&smc_ib_devices.lock);
+ mutex_unlock(&smc_ib_devices.mutex);
return ibdev;
}
@@ -825,7 +826,7 @@ static void _smc_pnet_find_roce_by_pnetid(u8 *pnet_id,
int i;
ini->ib_dev = NULL;
- spin_lock(&smc_ib_devices.lock);
+ mutex_lock(&smc_ib_devices.mutex);
list_for_each_entry(ibdev, &smc_ib_devices.list, list) {
if (ibdev == known_dev)
continue;
@@ -844,7 +845,7 @@ static void _smc_pnet_find_roce_by_pnetid(u8 *pnet_id,
}
}
out:
- spin_unlock(&smc_ib_devices.lock);
+ mutex_unlock(&smc_ib_devices.mutex);
}
/* find alternate roce device with same pnet_id and vlan_id */
@@ -863,7 +864,7 @@ static void smc_pnet_find_rdma_dev(struct net_device *netdev,
{
struct smc_ib_device *ibdev;
- spin_lock(&smc_ib_devices.lock);
+ mutex_lock(&smc_ib_devices.mutex);
list_for_each_entry(ibdev, &smc_ib_devices.list, list) {
struct net_device *ndev;
int i;
@@ -888,7 +889,7 @@ static void smc_pnet_find_rdma_dev(struct net_device *netdev,
}
}
}
- spin_unlock(&smc_ib_devices.lock);
+ mutex_unlock(&smc_ib_devices.mutex);
}
/* Determine the corresponding IB device port based on the hardware PNETID.
--
2.17.1
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