OpenCloudOS-Kernel/drivers/nvdimm/dax_devs.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright(c) 2013-2016 Intel Corporation. All rights reserved.
*/
#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, "trace\n");
nd_detach_ndns(dev, &nd_pfn->ndns);
ida_simple_remove(&nd_region->dax_ida, nd_pfn->id);
kfree(nd_pfn->uuid);
kfree(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 device_type nd_dax_device_type = {
.name = "nd_dax",
.release = nd_dax_release,
.groups = nd_pfn_attribute_groups,
};
bool is_nd_dax(struct device *dev)
{
return dev ? dev->type == &nd_dax_device_type : false;
}
EXPORT_SYMBOL(is_nd_dax);
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->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_memory(&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;
switch (ndns->claim_class) {
case NVDIMM_CCLASS_NONE:
case NVDIMM_CCLASS_DAX:
break;
default:
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;
libnvdimm/pfn: fix fsdax-mode namespace info-block zero-fields At namespace creation time there is the potential for the "expected to be zero" fields of a 'pfn' info-block to be filled with indeterminate data. While the kernel buffer is zeroed on allocation it is immediately overwritten by nd_pfn_validate() filling it with the current contents of the on-media info-block location. For fields like, 'flags' and the 'padding' it potentially means that future implementations can not rely on those fields being zero. In preparation to stop using the 'start_pad' and 'end_trunc' fields for section alignment, arrange for fields that are not explicitly initialized to be guaranteed zero. Bump the minor version to indicate it is safe to assume the 'padding' and 'flags' are zero. Otherwise, this corruption is expected to benign since all other critical fields are explicitly initialized. Note The cc: stable is about spreading this new policy to as many kernels as possible not fixing an issue in those kernels. It is not until the change titled "libnvdimm/pfn: Stop padding pmem namespaces to section alignment" where this improper initialization becomes a problem. So if someone decides to backport "libnvdimm/pfn: Stop padding pmem namespaces to section alignment" (which is not tagged for stable), make sure this pre-requisite is flagged. Link: http://lkml.kernel.org/r/156092356065.979959.6681003754765958296.stgit@dwillia2-desk3.amr.corp.intel.com Fixes: 32ab0a3f5170 ("libnvdimm, pmem: 'struct page' for pmem") Signed-off-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [ppc64] Cc: <stable@vger.kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Jane Chu <jane.chu@oracle.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richardw.yang@linux.intel.com> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-19 06:58:36 +08:00
pfn_sb = devm_kmalloc(dev, sizeof(*pfn_sb), GFP_KERNEL);
nd_pfn->pfn_sb = pfn_sb;
rc = nd_pfn_validate(nd_pfn, DAX_SIG);
dev_dbg(dev, "dax: %s\n", rc == 0 ? dev_name(dax_dev) : "<none>");
if (rc < 0) {
libnvdimm: fix nvdimm_bus_lock() vs device_lock() ordering 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: 8c2f7e8658df ("libnvdimm: infrastructure for btt devices") Reported-by: Yi Zhang <yizhan@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-04-29 13:05:14 +08:00
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);