dax: enable dax in the presence of known media errors (badblocks)

1/ If a mapping overlaps a bad sector fail the request.

2/ Do not opportunistically report more dax-capable capacity than is
   requested when errors present.

Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
[vishal: fix a conflict with system RAM collision patches]
[vishal: add a 'size' parameter to ->direct_access]
[vishal: fix a conflict with DAX alignment check patches]
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
This commit is contained in:
Dan Williams 2016-02-24 14:02:11 -08:00 committed by Vishal Verma
parent 8b3db9798c
commit 0a70bd4305
6 changed files with 15 additions and 18 deletions

View file

@ -143,7 +143,7 @@ axon_ram_make_request(struct request_queue *queue, struct bio *bio)
*/
static long
axon_ram_direct_access(struct block_device *device, sector_t sector,
void __pmem **kaddr, pfn_t *pfn)
void __pmem **kaddr, pfn_t *pfn, long size)
{
struct axon_ram_bank *bank = device->bd_disk->private_data;
loff_t offset = (loff_t)sector << AXON_RAM_SECTOR_SHIFT;

View file

@ -381,7 +381,7 @@ static int brd_rw_page(struct block_device *bdev, sector_t sector,
#ifdef CONFIG_BLK_DEV_RAM_DAX
static long brd_direct_access(struct block_device *bdev, sector_t sector,
void __pmem **kaddr, pfn_t *pfn)
void __pmem **kaddr, pfn_t *pfn, long size)
{
struct brd_device *brd = bdev->bd_disk->private_data;
struct page *page;

View file

@ -182,14 +182,22 @@ static int pmem_rw_page(struct block_device *bdev, sector_t sector,
}
static long pmem_direct_access(struct block_device *bdev, sector_t sector,
void __pmem **kaddr, pfn_t *pfn)
void __pmem **kaddr, pfn_t *pfn, long size)
{
struct pmem_device *pmem = bdev->bd_disk->private_data;
resource_size_t offset = sector * 512 + pmem->data_offset;
if (unlikely(is_bad_pmem(&pmem->bb, sector, size)))
return -EIO;
*kaddr = pmem->virt_addr + offset;
*pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
/*
* If badblocks are present, limit known good range to the
* requested range.
*/
if (unlikely(pmem->bb.count))
return size;
return pmem->size - pmem->pfn_pad - offset;
}

View file

@ -31,7 +31,7 @@ static void dcssblk_release(struct gendisk *disk, fmode_t mode);
static blk_qc_t dcssblk_make_request(struct request_queue *q,
struct bio *bio);
static long dcssblk_direct_access(struct block_device *bdev, sector_t secnum,
void __pmem **kaddr, pfn_t *pfn);
void __pmem **kaddr, pfn_t *pfn, long size);
static char dcssblk_segments[DCSSBLK_PARM_LEN] = "\0";
@ -883,7 +883,7 @@ dcssblk_make_request(struct request_queue *q, struct bio *bio)
static long
dcssblk_direct_access (struct block_device *bdev, sector_t secnum,
void __pmem **kaddr, pfn_t *pfn)
void __pmem **kaddr, pfn_t *pfn, long size)
{
struct dcssblk_dev_info *dev_info;
unsigned long offset, dev_sz;

View file

@ -29,7 +29,6 @@
#include <linux/log2.h>
#include <linux/cleancache.h>
#include <linux/dax.h>
#include <linux/badblocks.h>
#include <asm/uaccess.h>
#include "internal.h"
@ -501,7 +500,7 @@ long bdev_direct_access(struct block_device *bdev, struct blk_dax_ctl *dax)
sector += get_start_sect(bdev);
if (sector % (PAGE_SIZE / 512))
return -EINVAL;
avail = ops->direct_access(bdev, sector, &dax->addr, &dax->pfn);
avail = ops->direct_access(bdev, sector, &dax->addr, &dax->pfn, size);
if (!avail)
return -ERANGE;
if (avail > 0 && avail & ~PAGE_MASK)
@ -561,7 +560,6 @@ EXPORT_SYMBOL_GPL(bdev_dax_supported);
*/
bool bdev_dax_capable(struct block_device *bdev)
{
struct gendisk *disk = bdev->bd_disk;
struct blk_dax_ctl dax = {
.size = PAGE_SIZE,
};
@ -577,15 +575,6 @@ bool bdev_dax_capable(struct block_device *bdev)
if (bdev_direct_access(bdev, &dax) < 0)
return false;
/*
* If the device has known bad blocks, force all I/O through the
* driver / page cache.
*
* TODO: support finer grained dax error handling
*/
if (disk->bb && disk->bb->count)
return false;
return true;
}

View file

@ -1668,7 +1668,7 @@ struct block_device_operations {
int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
long (*direct_access)(struct block_device *, sector_t, void __pmem **,
pfn_t *);
pfn_t *, long);
unsigned int (*check_events) (struct gendisk *disk,
unsigned int clearing);
/* ->media_changed() is DEPRECATED, use ->check_events() instead */