linux/drivers/nvdimm/btt_devs.c
Dan Williams 87a30e1f05 driver-core, libnvdimm: Let device subsystems add local lockdep coverage
For good reason, the standard device_lock() is marked
lockdep_set_novalidate_class() because there is simply no sane way to
describe the myriad ways the device_lock() ordered with other locks.
However, that leaves subsystems that know their own local device_lock()
ordering rules to find lock ordering mistakes manually. Instead,
introduce an optional / additional lockdep-enabled lock that a subsystem
can acquire in all the same paths that the device_lock() is acquired.

A conversion of the NFIT driver and NVDIMM subsystem to a
lockdep-validate device_lock() scheme is included. The
debug_nvdimm_lock() implementation implements the correct lock-class and
stacking order for the libnvdimm device topology hierarchy.

Yes, this is a hack, but hopefully it is a useful hack for other
subsystems device_lock() debug sessions. Quoting Greg:

    "Yeah, it feels a bit hacky but it's really up to a subsystem to mess up
     using it as much as anything else, so user beware :)

     I don't object to it if it makes things easier for you to debug."

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/156341210661.292348.7014034644265455704.stgit@dwillia2-desk3.amr.corp.intel.com
2019-07-18 16:23:27 -07:00

368 lines
8.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
*/
#include <linux/blkdev.h>
#include <linux/device.h>
#include <linux/genhd.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include "nd-core.h"
#include "btt.h"
#include "nd.h"
static void nd_btt_release(struct device *dev)
{
struct nd_region *nd_region = to_nd_region(dev->parent);
struct nd_btt *nd_btt = to_nd_btt(dev);
dev_dbg(dev, "trace\n");
nd_detach_ndns(&nd_btt->dev, &nd_btt->ndns);
ida_simple_remove(&nd_region->btt_ida, nd_btt->id);
kfree(nd_btt->uuid);
kfree(nd_btt);
}
static struct device_type nd_btt_device_type = {
.name = "nd_btt",
.release = nd_btt_release,
};
bool is_nd_btt(struct device *dev)
{
return dev->type == &nd_btt_device_type;
}
EXPORT_SYMBOL(is_nd_btt);
struct nd_btt *to_nd_btt(struct device *dev)
{
struct nd_btt *nd_btt = container_of(dev, struct nd_btt, dev);
WARN_ON(!is_nd_btt(dev));
return nd_btt;
}
EXPORT_SYMBOL(to_nd_btt);
static const unsigned long btt_lbasize_supported[] = { 512, 520, 528,
4096, 4104, 4160, 4224, 0 };
static ssize_t sector_size_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct nd_btt *nd_btt = to_nd_btt(dev);
return nd_size_select_show(nd_btt->lbasize, btt_lbasize_supported, buf);
}
static ssize_t sector_size_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t len)
{
struct nd_btt *nd_btt = to_nd_btt(dev);
ssize_t rc;
nd_device_lock(dev);
nvdimm_bus_lock(dev);
rc = nd_size_select_store(dev, buf, &nd_btt->lbasize,
btt_lbasize_supported);
dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
buf[len - 1] == '\n' ? "" : "\n");
nvdimm_bus_unlock(dev);
nd_device_unlock(dev);
return rc ? rc : len;
}
static DEVICE_ATTR_RW(sector_size);
static ssize_t uuid_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct nd_btt *nd_btt = to_nd_btt(dev);
if (nd_btt->uuid)
return sprintf(buf, "%pUb\n", nd_btt->uuid);
return sprintf(buf, "\n");
}
static ssize_t uuid_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t len)
{
struct nd_btt *nd_btt = to_nd_btt(dev);
ssize_t rc;
nd_device_lock(dev);
rc = nd_uuid_store(dev, &nd_btt->uuid, buf, len);
dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
buf[len - 1] == '\n' ? "" : "\n");
nd_device_unlock(dev);
return rc ? rc : len;
}
static DEVICE_ATTR_RW(uuid);
static ssize_t namespace_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct nd_btt *nd_btt = to_nd_btt(dev);
ssize_t rc;
nvdimm_bus_lock(dev);
rc = sprintf(buf, "%s\n", nd_btt->ndns
? dev_name(&nd_btt->ndns->dev) : "");
nvdimm_bus_unlock(dev);
return rc;
}
static ssize_t namespace_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t len)
{
struct nd_btt *nd_btt = to_nd_btt(dev);
ssize_t rc;
nd_device_lock(dev);
nvdimm_bus_lock(dev);
rc = nd_namespace_store(dev, &nd_btt->ndns, buf, len);
dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
buf[len - 1] == '\n' ? "" : "\n");
nvdimm_bus_unlock(dev);
nd_device_unlock(dev);
return rc;
}
static DEVICE_ATTR_RW(namespace);
static ssize_t size_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct nd_btt *nd_btt = to_nd_btt(dev);
ssize_t rc;
nd_device_lock(dev);
if (dev->driver)
rc = sprintf(buf, "%llu\n", nd_btt->size);
else {
/* no size to convey if the btt instance is disabled */
rc = -ENXIO;
}
nd_device_unlock(dev);
return rc;
}
static DEVICE_ATTR_RO(size);
static ssize_t log_zero_flags_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sprintf(buf, "Y\n");
}
static DEVICE_ATTR_RO(log_zero_flags);
static struct attribute *nd_btt_attributes[] = {
&dev_attr_sector_size.attr,
&dev_attr_namespace.attr,
&dev_attr_uuid.attr,
&dev_attr_size.attr,
&dev_attr_log_zero_flags.attr,
NULL,
};
static struct attribute_group nd_btt_attribute_group = {
.attrs = nd_btt_attributes,
};
static const struct attribute_group *nd_btt_attribute_groups[] = {
&nd_btt_attribute_group,
&nd_device_attribute_group,
&nd_numa_attribute_group,
NULL,
};
static struct device *__nd_btt_create(struct nd_region *nd_region,
unsigned long lbasize, u8 *uuid,
struct nd_namespace_common *ndns)
{
struct nd_btt *nd_btt;
struct device *dev;
nd_btt = kzalloc(sizeof(*nd_btt), GFP_KERNEL);
if (!nd_btt)
return NULL;
nd_btt->id = ida_simple_get(&nd_region->btt_ida, 0, 0, GFP_KERNEL);
if (nd_btt->id < 0)
goto out_nd_btt;
nd_btt->lbasize = lbasize;
if (uuid) {
uuid = kmemdup(uuid, 16, GFP_KERNEL);
if (!uuid)
goto out_put_id;
}
nd_btt->uuid = uuid;
dev = &nd_btt->dev;
dev_set_name(dev, "btt%d.%d", nd_region->id, nd_btt->id);
dev->parent = &nd_region->dev;
dev->type = &nd_btt_device_type;
dev->groups = nd_btt_attribute_groups;
device_initialize(&nd_btt->dev);
if (ndns && !__nd_attach_ndns(&nd_btt->dev, ndns, &nd_btt->ndns)) {
dev_dbg(&ndns->dev, "failed, already claimed by %s\n",
dev_name(ndns->claim));
put_device(dev);
return NULL;
}
return dev;
out_put_id:
ida_simple_remove(&nd_region->btt_ida, nd_btt->id);
out_nd_btt:
kfree(nd_btt);
return NULL;
}
struct device *nd_btt_create(struct nd_region *nd_region)
{
struct device *dev = __nd_btt_create(nd_region, 0, NULL, NULL);
__nd_device_register(dev);
return dev;
}
/**
* nd_btt_arena_is_valid - check if the metadata layout is valid
* @nd_btt: device with BTT geometry and backing device info
* @super: pointer to the arena's info block being tested
*
* Check consistency of the btt info block with itself by validating
* the checksum, and with the parent namespace by verifying the
* parent_uuid contained in the info block with the one supplied in.
*
* Returns:
* false for an invalid info block, true for a valid one
*/
bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super)
{
const u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
u64 checksum;
if (memcmp(super->signature, BTT_SIG, BTT_SIG_LEN) != 0)
return false;
if (!guid_is_null((guid_t *)&super->parent_uuid))
if (memcmp(super->parent_uuid, parent_uuid, 16) != 0)
return false;
checksum = le64_to_cpu(super->checksum);
super->checksum = 0;
if (checksum != nd_sb_checksum((struct nd_gen_sb *) super))
return false;
super->checksum = cpu_to_le64(checksum);
/* TODO: figure out action for this */
if ((le32_to_cpu(super->flags) & IB_FLAG_ERROR_MASK) != 0)
dev_info(&nd_btt->dev, "Found arena with an error flag\n");
return true;
}
EXPORT_SYMBOL(nd_btt_arena_is_valid);
int nd_btt_version(struct nd_btt *nd_btt, struct nd_namespace_common *ndns,
struct btt_sb *btt_sb)
{
if (ndns->claim_class == NVDIMM_CCLASS_BTT2) {
/* Probe/setup for BTT v2.0 */
nd_btt->initial_offset = 0;
nd_btt->version_major = 2;
nd_btt->version_minor = 0;
if (nvdimm_read_bytes(ndns, 0, btt_sb, sizeof(*btt_sb), 0))
return -ENXIO;
if (!nd_btt_arena_is_valid(nd_btt, btt_sb))
return -ENODEV;
if ((le16_to_cpu(btt_sb->version_major) != 2) ||
(le16_to_cpu(btt_sb->version_minor) != 0))
return -ENODEV;
} else {
/*
* Probe/setup for BTT v1.1 (NVDIMM_CCLASS_NONE or
* NVDIMM_CCLASS_BTT)
*/
nd_btt->initial_offset = SZ_4K;
nd_btt->version_major = 1;
nd_btt->version_minor = 1;
if (nvdimm_read_bytes(ndns, SZ_4K, btt_sb, sizeof(*btt_sb), 0))
return -ENXIO;
if (!nd_btt_arena_is_valid(nd_btt, btt_sb))
return -ENODEV;
if ((le16_to_cpu(btt_sb->version_major) != 1) ||
(le16_to_cpu(btt_sb->version_minor) != 1))
return -ENODEV;
}
return 0;
}
EXPORT_SYMBOL(nd_btt_version);
static int __nd_btt_probe(struct nd_btt *nd_btt,
struct nd_namespace_common *ndns, struct btt_sb *btt_sb)
{
int rc;
if (!btt_sb || !ndns || !nd_btt)
return -ENODEV;
if (nvdimm_namespace_capacity(ndns) < SZ_16M)
return -ENXIO;
rc = nd_btt_version(nd_btt, ndns, btt_sb);
if (rc < 0)
return rc;
nd_btt->lbasize = le32_to_cpu(btt_sb->external_lbasize);
nd_btt->uuid = kmemdup(btt_sb->uuid, 16, GFP_KERNEL);
if (!nd_btt->uuid)
return -ENOMEM;
__nd_device_register(&nd_btt->dev);
return 0;
}
int nd_btt_probe(struct device *dev, struct nd_namespace_common *ndns)
{
int rc;
struct device *btt_dev;
struct btt_sb *btt_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_BTT:
case NVDIMM_CCLASS_BTT2:
break;
default:
return -ENODEV;
}
nvdimm_bus_lock(&ndns->dev);
btt_dev = __nd_btt_create(nd_region, 0, NULL, ndns);
nvdimm_bus_unlock(&ndns->dev);
if (!btt_dev)
return -ENOMEM;
btt_sb = devm_kzalloc(dev, sizeof(*btt_sb), GFP_KERNEL);
rc = __nd_btt_probe(to_nd_btt(btt_dev), ndns, btt_sb);
dev_dbg(dev, "btt: %s\n", rc == 0 ? dev_name(btt_dev) : "<none>");
if (rc < 0) {
struct nd_btt *nd_btt = to_nd_btt(btt_dev);
nd_detach_ndns(btt_dev, &nd_btt->ndns);
put_device(btt_dev);
}
return rc;
}
EXPORT_SYMBOL(nd_btt_probe);