From: Leon Romanovsky <leonro@xxxxxxxxxxxx>
SRP logic used device name and port index as symlink to relevant
kobject. This situation caused to device name to be cached and
triggered on the boot the kernel panic below.
[ 8.163181] RPC: Registered rdma transport module.
[ 8.163182] RPC: Registered rdma backchannel transport module.
[ 8.319908] pps_core: LinuxPPS API ver. 1 registered
[ 8.319910] pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giometti <giometti@xxxxxxxx>
[ 8.346610] PTP clock support registered
[ 9.317026] mlx5_core 0000:00:08.0: firmware version: 12.25.1020
[ 9.317157] mlx5_core 0000:00:08.0: 126.016 Gb/s available PCIe bandwidth (8 GT/s x16 link)
[ 9.532121] mlx5_core 0000:00:08.0: E-Switch: Total vports 2, per vport: max uc(1024) max mc(16384)
[ 9.694930] mlx5_core 0000:00:08.1: firmware version: 12.25.1020
[ 9.694995] mlx5_core 0000:00:08.1: 126.016 Gb/s available PCIe bandwidth (8 GT/s x16 link)
[ 9.904603] mlx5_core 0000:00:08.1: E-Switch: Total vports 2, per vport: max uc(1024) max mc(16384)
[ 9.981334] mlx5_core 0000:00:08.0: MLX5E: StrdRq(0) RqSz(1024) StrdSz(256) RxCqeCmprss(0)
[ 10.161993] mlx5_core 0000:00:08.1: MLX5E: StrdRq(0) RqSz(1024) StrdSz(256) RxCqeCmprss(0)
[ 10.162424] mlx5_core 0000:00:08.0 ens8f0: renamed from eth0
[ 10.357080] mlx5_core 0000:00:08.1 ens8f1: renamed from eth0
[ 10.484528] mlx5_ib: Mellanox Connect-IB Infiniband driver v5.0-0
[ 10.622868] sysfs: cannot create duplicate filename '/class/infiniband_srp/srp-mlx5_0-1'
[ 10.622871] CPU: 3 PID: 1107 Comm: modprobe Not tainted 5.1.0-for-upstream-perf-2019-05-12_15-09-52-87 #1
[ 10.622872] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 10.622873] Call Trace:
[ 10.622883] dump_stack+0x5a/0x73
[ 10.622889] sysfs_warn_dup+0x58/0x70
[ 10.622891] sysfs_do_create_link_sd.isra.2+0xa3/0xb0
[ 10.622896] device_add+0x33f/0x660
[ 10.622900] srp_add_one+0x301/0x4f0 [ib_srp]
[ 10.622917] add_client_context+0x99/0xe0 [ib_core]
[ 10.622926] enable_device_and_get+0xd1/0x1b0 [ib_core]
[ 10.622934] ib_register_device+0x533/0x710 [ib_core]
[ 10.622938] ? mutex_lock+0xe/0x30
[ 10.622948] __mlx5_ib_add+0x23/0x70 [mlx5_ib]
[ 10.622983] mlx5_add_device+0x4e/0xd0 [mlx5_core]
[ 10.622999] mlx5_register_interface+0x85/0xc0 [mlx5_core]
[ 10.623000] ? 0xffffffffa0791000
[ 10.623003] do_one_initcall+0x4b/0x1cb
[ 10.623007] ? kmem_cache_alloc_trace+0xc6/0x1d0
[ 10.623009] ? do_init_module+0x22/0x21f
[ 10.623011] do_init_module+0x5a/0x21f
[ 10.623013] load_module+0x17f2/0x1ca0
[ 10.623015] ? m_show+0x1c0/0x1c0
[ 10.623017] __do_sys_finit_module+0x94/0xe0
[ 10.623019] do_syscall_64+0x48/0x120
[ 10.623022] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 10.623038] RIP: 0033:0x7f157cce10d9
[ 10.623039] Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00
48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f
05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 97 ad 2c 00 f7 d8 64 89 01 48
[ 10.623040] RSP: 002b:00007ffd79f91538 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[ 10.623042] RAX: ffffffffffffffda RBX: 0000561a4a8f2d80 RCX: 00007f157cce10d9
[ 10.623043] RDX: 0000000000000000 RSI: 0000561a48e1f85c RDI: 0000000000000001
[ 10.623050] RBP: 0000561a48e1f85c R08: 0000000000000000 R09: 0000000000000000
[ 10.623050] R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
[ 10.623051] R13: 0000561a4a8f2eb0 R14: 0000000000040000 R15: 0000561a4a8f2d80
[ 10.858147] random: crng init done
[ 10.858149] random: 7 urandom warning(s) missed due to ratelimiting
[ 99.994965] FS-Cache: Loaded
[ 100.283059] FS-Cache: Netfs 'nfs' registered for caching
[ 100.322275] Key type dns_resolver registered
[ 100.558079] NFS: Registering the id_resolver key type
[ 100.558086] Key type id_resolver registered
[ 100.558087] Key type id_legacy registered
This panic is caused due to races between device rename during boot and
initialization of new devices for multi-adapter system.
The module load/unload sequence was used to trigger such kernel panic:
sudo modprobe ib_srp
sudo modprobe -r mlx5_ib
sudo modprobe -r mlx5_core
sudo modprobe mlx5_core
Fixes: d21943dd19b5 ("RDMA/core: Implement IB device rename function")
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
---
Changelog
v3->v4:
* fixed typo
v2->v3:
* Tried to be "good kernel developer"
* Dropped RFC
v1-v2:
* Fixed checkpatch warnings
* Rewrote loop to call client->rename
v0->v1:
* Reimplemented
---
drivers/infiniband/core/device.c | 35 +++++++++++++++++++++--------
drivers/infiniband/ulp/srp/ib_srp.c | 18 ++++++++++++++-
include/rdma/ib_verbs.h | 1 +
3 files changed, 44 insertions(+), 10 deletions(-)
diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index a67aaf0e1f76..9fad883018ab 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -410,27 +410,44 @@ static int rename_compat_devs(struct ib_device *device)
int ib_device_rename(struct ib_device *ibdev, const char *name)
{
+ unsigned long index;
+ void *client_data;
int ret;
down_write(&devices_rwsem);
if (!strcmp(name, dev_name(&ibdev->dev))) {
- ret = 0;
- goto out;
+ up_write(&devices_rwsem);
+ return 0;
}
if (__ib_device_get_by_name(name)) {
- ret = -EEXIST;
- goto out;
+ up_write(&devices_rwsem);
+ return -EEXIST;
}
ret = device_rename(&ibdev->dev, name);
- if (ret)
- goto out;
+ if (ret) {
+ up_write(&devices_rwsem);
+ return ret;
+ }
+
strlcpy(ibdev->name, name, IB_DEVICE_NAME_MAX);
ret = rename_compat_devs(ibdev);
-out:
- up_write(&devices_rwsem);
- return ret;
+
+ downgrade_write(&devices_rwsem);
+ down_read(&ibdev->client_data_rwsem);
+ xan_for_each_marked(&ibdev->client_data, index, client_data,
+ CLIENT_DATA_REGISTERED) {
+ struct ib_client *client = xa_load(&clients, index);
+
+ if (!client || !client->rename)
+ continue;
+
+ client->rename(ibdev, client_data);
+ }
+ up_read(&ibdev->client_data_rwsem);
+ up_read(&devices_rwsem);
+ return 0;
}
static int alloc_name(struct ib_device *ibdev, const char *name)
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index be9ddcad8f28..4305da2c9037 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -148,6 +148,7 @@ MODULE_PARM_DESC(ch_count,
static void srp_add_one(struct ib_device *device);
static void srp_remove_one(struct ib_device *device, void *client_data);
+static void srp_rename_dev(struct ib_device *device, void *client_data);
static void srp_recv_done(struct ib_cq *cq, struct ib_wc *wc);
static void srp_handle_qp_err(struct ib_cq *cq, struct ib_wc *wc,
const char *opname);
@@ -162,7 +163,8 @@ static struct workqueue_struct *srp_remove_wq;
static struct ib_client srp_client = {
.name = "srp",
.add = srp_add_one,
- .remove = srp_remove_one
+ .remove = srp_remove_one,
+ .rename = srp_rename_dev
};
static struct ib_sa_client srp_sa_client;
@@ -4112,6 +4114,20 @@ static struct srp_host *srp_add_port(struct srp_device *device, u8 port)
return NULL;
}
+static void srp_rename_dev(struct ib_device *device, void *client_data)
+{
+ struct srp_device *srp_dev = client_data;
+ struct srp_host *host, *tmp_host;
+
+ list_for_each_entry_safe(host, tmp_host, &srp_dev->dev_list, list) {
+ char name[IB_DEVICE_NAME_MAX + 8];
+
+ snprintf(name, sizeof(name), "srp-%s-%d",
+ dev_name(&device->dev), host->port);
+ device_rename(&host->dev, name);
+ }
+}
+
static void srp_add_one(struct ib_device *device)
{
struct srp_device *srp_dev;
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index e9fffa55426b..5ef2fead4ad9 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -2727,6 +2727,7 @@ struct ib_client {
const char *name;
void (*add) (struct ib_device *);
void (*remove)(struct ib_device *, void *client_data);
+ void (*rename)(struct ib_device *dev, void *client_data);
/* Returns the net_dev belonging to this ib_client and matching the
* given parameters.
--
2.20.1
