Commit 99e6608c authored by Vishal Verma's avatar Vishal Verma Committed by Dan Williams

block: Add badblock management for gendisks

NVDIMM devices, which can behave more like DRAM rather than block
devices, may develop bad cache lines, or 'poison'. A block device
exposed by the pmem driver can then consume poison via a read (or
write), and cause a machine check. On platforms without machine
check recovery features, this would mean a crash.

The block device maintaining a runtime list of all known sectors that
have poison can directly avoid this, and also provide a path forward
to enable proper handling/recovery for DAX faults on such a device.

Use the new badblock management interfaces to add a badblocks list to
gendisks.
Signed-off-by: default avatarVishal Verma <vishal.l.verma@intel.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 9e0e252a
......@@ -20,6 +20,7 @@
#include <linux/idr.h>
#include <linux/log2.h>
#include <linux/pm_runtime.h>
#include <linux/badblocks.h>
#include "blk.h"
......@@ -505,6 +506,16 @@ static int exact_lock(dev_t devt, void *data)
return 0;
}
int disk_alloc_badblocks(struct gendisk *disk)
{
disk->bb = kzalloc(sizeof(*(disk->bb)), GFP_KERNEL);
if (!disk->bb)
return -ENOMEM;
return badblocks_init(disk->bb, 1);
}
EXPORT_SYMBOL(disk_alloc_badblocks);
static void register_disk(struct gendisk *disk)
{
struct device *ddev = disk_to_dev(disk);
......@@ -659,6 +670,11 @@ void del_gendisk(struct gendisk *disk)
blk_unregister_queue(disk);
blk_unregister_region(disk_devt(disk), disk->minors);
if (disk->bb) {
badblocks_free(disk->bb);
kfree(disk->bb);
}
part_stat_set_all(&disk->part0, 0);
disk->part0.stamp = 0;
......@@ -671,6 +687,63 @@ void del_gendisk(struct gendisk *disk)
}
EXPORT_SYMBOL(del_gendisk);
/*
* The gendisk usage of badblocks does not track acknowledgements for
* badblocks. We always assume they are acknowledged.
*/
int disk_check_badblocks(struct gendisk *disk, sector_t s, int sectors,
sector_t *first_bad, int *bad_sectors)
{
if (!disk->bb)
return 0;
return badblocks_check(disk->bb, s, sectors, first_bad, bad_sectors);
}
EXPORT_SYMBOL(disk_check_badblocks);
int disk_set_badblocks(struct gendisk *disk, sector_t s, int sectors)
{
if (!disk->bb)
return 0;
return badblocks_set(disk->bb, s, sectors, 1);
}
EXPORT_SYMBOL(disk_set_badblocks);
int disk_clear_badblocks(struct gendisk *disk, sector_t s, int sectors)
{
if (!disk->bb)
return 0;
return badblocks_clear(disk->bb, s, sectors);
}
EXPORT_SYMBOL(disk_clear_badblocks);
/* sysfs access to bad-blocks list. */
static ssize_t disk_badblocks_show(struct device *dev,
struct device_attribute *attr,
char *page)
{
struct gendisk *disk = dev_to_disk(dev);
if (!disk->bb)
return sprintf(page, "\n");
return badblocks_show(disk->bb, page, 0);
}
static ssize_t disk_badblocks_store(struct device *dev,
struct device_attribute *attr,
const char *page, size_t len)
{
struct gendisk *disk = dev_to_disk(dev);
if (!disk->bb)
return -ENXIO;
return badblocks_store(disk->bb, page, len, 0);
}
/**
* get_gendisk - get partitioning information for a given device
* @devt: device to get partitioning information for
......@@ -989,6 +1062,8 @@ static DEVICE_ATTR(discard_alignment, S_IRUGO, disk_discard_alignment_show,
static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL);
static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_show, NULL);
static DEVICE_ATTR(badblocks, S_IRUGO | S_IWUSR, disk_badblocks_show,
disk_badblocks_store);
#ifdef CONFIG_FAIL_MAKE_REQUEST
static struct device_attribute dev_attr_fail =
__ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
......@@ -1010,6 +1085,7 @@ static struct attribute *disk_attrs[] = {
&dev_attr_capability.attr,
&dev_attr_stat.attr,
&dev_attr_inflight.attr,
&dev_attr_badblocks.attr,
#ifdef CONFIG_FAIL_MAKE_REQUEST
&dev_attr_fail.attr,
#endif
......
......@@ -162,6 +162,7 @@ struct disk_part_tbl {
};
struct disk_events;
struct badblocks;
#if defined(CONFIG_BLK_DEV_INTEGRITY)
......@@ -213,6 +214,7 @@ struct gendisk {
struct kobject integrity_kobj;
#endif /* CONFIG_BLK_DEV_INTEGRITY */
int node_id;
struct badblocks *bb;
};
static inline struct gendisk *part_to_disk(struct hd_struct *part)
......@@ -433,6 +435,11 @@ extern void add_disk(struct gendisk *disk);
extern void del_gendisk(struct gendisk *gp);
extern struct gendisk *get_gendisk(dev_t dev, int *partno);
extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
int disk_alloc_badblocks(struct gendisk *disk);
extern int disk_check_badblocks(struct gendisk *disk, sector_t s, int sectors,
sector_t *first_bad, int *bad_sectors);
extern int disk_set_badblocks(struct gendisk *disk, sector_t s, int sectors);
extern int disk_clear_badblocks(struct gendisk *disk, sector_t s, int sectors);
extern void set_device_ro(struct block_device *bdev, int flag);
extern void set_disk_ro(struct gendisk *disk, int flag);
......
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