452bae0aed
A debug patch to turn the standard device_lock() into something that
lockdep can analyze yielded the following:
======================================================
[ INFO: possible circular locking dependency detected ]
4.11.0-rc4+ #106 Tainted: G O
-------------------------------------------------------
lt-libndctl/1898 is trying to acquire lock:
(&dev->nvdimm_mutex/3){+.+.+.}, at: [<ffffffffc023c948>] nd_attach_ndns+0x178/0x1b0 [libnvdimm]
but task is already holding lock:
(&nvdimm_bus->reconfig_mutex){+.+.+.}, at: [<ffffffffc022e0b1>] nvdimm_bus_lock+0x21/0x30 [libnvdimm]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&nvdimm_bus->reconfig_mutex){+.+.+.}:
lock_acquire+0xf6/0x1f0
__mutex_lock+0x88/0x980
mutex_lock_nested+0x1b/0x20
nvdimm_bus_lock+0x21/0x30 [libnvdimm]
nvdimm_namespace_capacity+0x1b/0x40 [libnvdimm]
nvdimm_namespace_common_probe+0x230/0x510 [libnvdimm]
nd_pmem_probe+0x14/0x180 [nd_pmem]
nvdimm_bus_probe+0xa9/0x260 [libnvdimm]
-> #0 (&dev->nvdimm_mutex/3){+.+.+.}:
__lock_acquire+0x1107/0x1280
lock_acquire+0xf6/0x1f0
__mutex_lock+0x88/0x980
mutex_lock_nested+0x1b/0x20
nd_attach_ndns+0x178/0x1b0 [libnvdimm]
nd_namespace_store+0x308/0x3c0 [libnvdimm]
namespace_store+0x87/0x220 [libnvdimm]
In this case '&dev->nvdimm_mutex/3' mirrors '&dev->mutex'.
Fix this by replacing the use of device_lock() with nvdimm_bus_lock() to protect
nd_{attach,detach}_ndns() operations.
Cc: <stable@vger.kernel.org>
Fixes: 8c2f7e8658 ("libnvdimm: infrastructure for btt devices")
Reported-by: Yi Zhang <yizhan@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
135 lines
3.3 KiB
C
135 lines
3.3 KiB
C
/*
|
|
* Copyright(c) 2013-2016 Intel Corporation. All rights reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of version 2 of the GNU General Public License as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* General Public License for more details.
|
|
*/
|
|
#include <linux/device.h>
|
|
#include <linux/sizes.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/mm.h>
|
|
#include "nd-core.h"
|
|
#include "pfn.h"
|
|
#include "nd.h"
|
|
|
|
static void nd_dax_release(struct device *dev)
|
|
{
|
|
struct nd_region *nd_region = to_nd_region(dev->parent);
|
|
struct nd_dax *nd_dax = to_nd_dax(dev);
|
|
struct nd_pfn *nd_pfn = &nd_dax->nd_pfn;
|
|
|
|
dev_dbg(dev, "%s\n", __func__);
|
|
nd_detach_ndns(dev, &nd_pfn->ndns);
|
|
ida_simple_remove(&nd_region->dax_ida, nd_pfn->id);
|
|
kfree(nd_pfn->uuid);
|
|
kfree(nd_dax);
|
|
}
|
|
|
|
static struct device_type nd_dax_device_type = {
|
|
.name = "nd_dax",
|
|
.release = nd_dax_release,
|
|
};
|
|
|
|
bool is_nd_dax(struct device *dev)
|
|
{
|
|
return dev ? dev->type == &nd_dax_device_type : false;
|
|
}
|
|
EXPORT_SYMBOL(is_nd_dax);
|
|
|
|
struct nd_dax *to_nd_dax(struct device *dev)
|
|
{
|
|
struct nd_dax *nd_dax = container_of(dev, struct nd_dax, nd_pfn.dev);
|
|
|
|
WARN_ON(!is_nd_dax(dev));
|
|
return nd_dax;
|
|
}
|
|
EXPORT_SYMBOL(to_nd_dax);
|
|
|
|
static const struct attribute_group *nd_dax_attribute_groups[] = {
|
|
&nd_pfn_attribute_group,
|
|
&nd_device_attribute_group,
|
|
&nd_numa_attribute_group,
|
|
NULL,
|
|
};
|
|
|
|
static struct nd_dax *nd_dax_alloc(struct nd_region *nd_region)
|
|
{
|
|
struct nd_pfn *nd_pfn;
|
|
struct nd_dax *nd_dax;
|
|
struct device *dev;
|
|
|
|
nd_dax = kzalloc(sizeof(*nd_dax), GFP_KERNEL);
|
|
if (!nd_dax)
|
|
return NULL;
|
|
|
|
nd_pfn = &nd_dax->nd_pfn;
|
|
nd_pfn->id = ida_simple_get(&nd_region->dax_ida, 0, 0, GFP_KERNEL);
|
|
if (nd_pfn->id < 0) {
|
|
kfree(nd_dax);
|
|
return NULL;
|
|
}
|
|
|
|
dev = &nd_pfn->dev;
|
|
dev_set_name(dev, "dax%d.%d", nd_region->id, nd_pfn->id);
|
|
dev->groups = nd_dax_attribute_groups;
|
|
dev->type = &nd_dax_device_type;
|
|
dev->parent = &nd_region->dev;
|
|
|
|
return nd_dax;
|
|
}
|
|
|
|
struct device *nd_dax_create(struct nd_region *nd_region)
|
|
{
|
|
struct device *dev = NULL;
|
|
struct nd_dax *nd_dax;
|
|
|
|
if (!is_nd_pmem(&nd_region->dev))
|
|
return NULL;
|
|
|
|
nd_dax = nd_dax_alloc(nd_region);
|
|
if (nd_dax)
|
|
dev = nd_pfn_devinit(&nd_dax->nd_pfn, NULL);
|
|
__nd_device_register(dev);
|
|
return dev;
|
|
}
|
|
|
|
int nd_dax_probe(struct device *dev, struct nd_namespace_common *ndns)
|
|
{
|
|
int rc;
|
|
struct nd_dax *nd_dax;
|
|
struct device *dax_dev;
|
|
struct nd_pfn *nd_pfn;
|
|
struct nd_pfn_sb *pfn_sb;
|
|
struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
|
|
|
|
if (ndns->force_raw)
|
|
return -ENODEV;
|
|
|
|
nvdimm_bus_lock(&ndns->dev);
|
|
nd_dax = nd_dax_alloc(nd_region);
|
|
nd_pfn = &nd_dax->nd_pfn;
|
|
dax_dev = nd_pfn_devinit(nd_pfn, ndns);
|
|
nvdimm_bus_unlock(&ndns->dev);
|
|
if (!dax_dev)
|
|
return -ENOMEM;
|
|
pfn_sb = devm_kzalloc(dev, sizeof(*pfn_sb), GFP_KERNEL);
|
|
nd_pfn->pfn_sb = pfn_sb;
|
|
rc = nd_pfn_validate(nd_pfn, DAX_SIG);
|
|
dev_dbg(dev, "%s: dax: %s\n", __func__,
|
|
rc == 0 ? dev_name(dax_dev) : "<none>");
|
|
if (rc < 0) {
|
|
nd_detach_ndns(dax_dev, &nd_pfn->ndns);
|
|
put_device(dax_dev);
|
|
} else
|
|
__nd_device_register(dax_dev);
|
|
|
|
return rc;
|
|
}
|
|
EXPORT_SYMBOL(nd_dax_probe);
|