Commit 4a123dba authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'libnvdimm-fixes-5.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm 

Pull libnvdimm fixes from Dan Williams:
 "A handful of fixes to address a string of mistakes in the mechanism
  for device-mapper to determine if its component devices are dax
  capable.

   - Fix an original bug in device-mapper table reference counting when
     interrogating dax capability in the component device. This bug was
     hidden by the following bug.

   - Fix device-mapper to use the proper helper (dax_supported() instead
     of the leaf helper generic_fsdax_supported()) to determine dax
     operation of a stacked block device configuration. The original
     implementation is only valid for one level of dax-capable block
     device stacking. This bug was discovered while fixing the below
     regression.

   - Fix an infinite recursion regression introduced by broken attempts
     to quiet the generic_fsdax_supported() path and make it bail out
     before logging "dax capability not found" errors"

* tag 'libnvdimm-fixes-5.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  dax: Fix stack overflow when mounting fsdax pmem device
  dm: Call proper helper to determine dax support
  dm/dax: Fix table reference counts
parents bdcf11de d4c5da50

drivers/dax/super.c

+10 −6
Original line number Diff line number Diff line
@@ -85,6 +85,12 @@ bool __generic_fsdax_supported(struct dax_device *dax_dev, 
		return false;

	}



	if (!dax_dev) {

		pr_debug("%s: error: dax unsupported by block device\n",

				bdevname(bdev, buf));

		return false;

	}



	err = bdev_dax_pgoff(bdev, start, PAGE_SIZE, &pgoff);

	if (err) {

		pr_info("%s: error: unaligned partition for dax\n",
@@ -100,12 +106,6 @@ bool __generic_fsdax_supported(struct dax_device *dax_dev, 
		return false;

	}



	if (!dax_dev || !bdev_dax_supported(bdev, blocksize)) {

		pr_debug("%s: error: dax unsupported by block device\n",

				bdevname(bdev, buf));

		return false;

	}



	id = dax_read_lock();

	len = dax_direct_access(dax_dev, pgoff, 1, &kaddr, &pfn);

	len2 = dax_direct_access(dax_dev, pgoff_end, 1, &end_kaddr, &end_pfn);
@@ -325,11 +325,15 @@ EXPORT_SYMBOL_GPL(dax_direct_access); 
bool dax_supported(struct dax_device *dax_dev, struct block_device *bdev,

		int blocksize, sector_t start, sector_t len)

{

	if (!dax_dev)

		return false;



	if (!dax_alive(dax_dev))

		return false;



	return dax_dev->ops->dax_supported(dax_dev, bdev, blocksize, start, len);

}

EXPORT_SYMBOL_GPL(dax_supported);



size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,

		size_t bytes, struct iov_iter *i)

drivers/md/dm-table.c

+7 −3
Original line number Diff line number Diff line
@@ -860,10 +860,14 @@ EXPORT_SYMBOL_GPL(dm_table_set_type); 
int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,

			sector_t start, sector_t len, void *data)

{

	int blocksize = *(int *) data;

	int blocksize = *(int *) data, id;

	bool rc;



	return generic_fsdax_supported(dev->dax_dev, dev->bdev, blocksize,

				       start, len);

	id = dax_read_lock();

	rc = dax_supported(dev->dax_dev, dev->bdev, blocksize, start, len);

	dax_read_unlock(id);



	return rc;

}



/* Check devices support synchronous DAX */

drivers/md/dm.c

+3 −2
Original line number Diff line number Diff line
@@ -1136,15 +1136,16 @@ static bool dm_dax_supported(struct dax_device *dax_dev, struct block_device *bd 
{

	struct mapped_device *md = dax_get_private(dax_dev);

	struct dm_table *map;

	bool ret = false;

	int srcu_idx;

	bool ret;



	map = dm_get_live_table(md, &srcu_idx);

	if (!map)

		return false;

		goto out;



	ret = dm_table_supports_dax(map, device_supports_dax, &blocksize);



out:

	dm_put_live_table(md, srcu_idx);



	return ret;

include/linux/dax.h

+20 −2
Original line number Diff line number Diff line
@@ -130,6 +130,8 @@ static inline bool generic_fsdax_supported(struct dax_device *dax_dev, 
	return __generic_fsdax_supported(dax_dev, bdev, blocksize, start,

			sectors);

}

bool dax_supported(struct dax_device *dax_dev, struct block_device *bdev,

		int blocksize, sector_t start, sector_t len);



static inline void fs_put_dax(struct dax_device *dax_dev)

{
@@ -157,6 +159,13 @@ static inline bool generic_fsdax_supported(struct dax_device *dax_dev, 
	return false;

}



static inline bool dax_supported(struct dax_device *dax_dev,

		struct block_device *bdev, int blocksize, sector_t start,

		sector_t len)

{

	return false;

}



static inline void fs_put_dax(struct dax_device *dax_dev)

{

}
@@ -189,14 +198,23 @@ static inline void dax_unlock_page(struct page *page, dax_entry_t cookie) 
}

#endif



#if IS_ENABLED(CONFIG_DAX)

int dax_read_lock(void);

void dax_read_unlock(int id);

#else

static inline int dax_read_lock(void)

{

	return 0;

}



static inline void dax_read_unlock(int id)

{

}

#endif /* CONFIG_DAX */

bool dax_alive(struct dax_device *dax_dev);

void *dax_get_private(struct dax_device *dax_dev);

long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,

		void **kaddr, pfn_t *pfn);

bool dax_supported(struct dax_device *dax_dev, struct block_device *bdev,

		int blocksize, sector_t start, sector_t len);

size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,

		size_t bytes, struct iov_iter *i);

size_t dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,

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