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authorUrsula Braun <ubraun@linux.ibm.com>2020-07-08 18:05:13 +0300
committerDavid S. Miller <davem@davemloft.net>2020-07-08 22:35:15 +0300
commit92f3cb0e11dda530d1daa42d7a11af5a92ed89e4 (patch)
treee26722f5cddc21ef13e0985e9cc05b1bb077a1bc /net/smc/smc_ib.c
parentb7eede757883a9892dcb7bf0280f4890fc74bcf6 (diff)
downloadlinux-92f3cb0e11dda530d1daa42d7a11af5a92ed89e4.tar.xz
net/smc: fix sleep bug in smc_pnet_find_roce_resource()
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@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/smc/smc_ib.c')
-rw-r--r--net/smc/smc_ib.c11
1 files changed, 6 insertions, 5 deletions
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);