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Commit e046114a authored by Vishal Verma's avatar Vishal Verma Committed by Dan Williams
Browse files

libnvdimm: clear the internal poison_list when clearing badblocks 



nvdimm_clear_poison cleared the user-visible badblocks, and sent
commands to the NVDIMM to clear the areas marked as 'poison', but it
neglected to clear the same areas from the internal poison_list which is
used to marshal ARS results before sorting them by namespace. As a
result, once on-demand ARS functionality was added:

37b137ff nfit, libnvdimm: allow an ARS scrub to be triggered on demand

A scrub triggered from either sysfs or an MCE was found to be adding
stale entries that had been cleared from gendisk->badblocks, but were
still present in nvdimm_bus->poison_list. Additionally, the stale entries
could be triggered into producing stale disk->badblocks by simply disabling
and re-enabling the namespace or region.

This adds the missing step of clearing poison_list entries when clearing
poison, so that it is always in sync with badblocks.

Fixes: 37b137ff ("nfit, libnvdimm: allow an ARS scrub to be triggered on demand")
Signed-off-by: default avatarVishal Verma <vishal.l.verma@intel.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent bd697a80

drivers/nvdimm/bus.c

+2 −0
Original line number Diff line number Diff line
@@ -213,6 +213,8 @@ long nvdimm_clear_poison(struct device *dev, phys_addr_t phys, 
		return rc;

	if (cmd_rc < 0)

		return cmd_rc;



	nvdimm_clear_from_poison_list(nvdimm_bus, phys, len);

	return clear_err.cleared;

}

EXPORT_SYMBOL_GPL(nvdimm_clear_poison);

drivers/nvdimm/core.c

+69 −4
Original line number Diff line number Diff line
@@ -541,11 +541,12 @@ void nvdimm_badblocks_populate(struct nd_region *nd_region, 
}

EXPORT_SYMBOL_GPL(nvdimm_badblocks_populate);



static int add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)

static int add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length,

			gfp_t flags)

{

	struct nd_poison *pl;



	pl = kzalloc(sizeof(*pl), GFP_KERNEL);

	pl = kzalloc(sizeof(*pl), flags);

	if (!pl)

		return -ENOMEM;
@@ -561,7 +562,7 @@ static int bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length) 
	struct nd_poison *pl;



	if (list_empty(&nvdimm_bus->poison_list))

		return add_poison(nvdimm_bus, addr, length);

		return add_poison(nvdimm_bus, addr, length, GFP_KERNEL);



	/*

	 * There is a chance this is a duplicate, check for those first.
@@ -581,7 +582,7 @@ static int bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length) 
	 * as any overlapping ranges will get resolved when the list is consumed

	 * and converted to badblocks

	 */

	return add_poison(nvdimm_bus, addr, length);

	return add_poison(nvdimm_bus, addr, length, GFP_KERNEL);

}



int nvdimm_bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
@@ -596,6 +597,70 @@ int nvdimm_bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length) 
}

EXPORT_SYMBOL_GPL(nvdimm_bus_add_poison);



void nvdimm_clear_from_poison_list(struct nvdimm_bus *nvdimm_bus,

		phys_addr_t start, unsigned int len)

{

	struct list_head *poison_list = &nvdimm_bus->poison_list;

	u64 clr_end = start + len - 1;

	struct nd_poison *pl, *next;



	nvdimm_bus_lock(&nvdimm_bus->dev);

	WARN_ON_ONCE(list_empty(poison_list));



	/*

	 * [start, clr_end] is the poison interval being cleared.

	 * [pl->start, pl_end] is the poison_list entry we're comparing

	 * the above interval against. The poison list entry may need

	 * to be modified (update either start or length), deleted, or

	 * split into two based on the overlap characteristics

	 */



	list_for_each_entry_safe(pl, next, poison_list, list) {

		u64 pl_end = pl->start + pl->length - 1;



		/* Skip intervals with no intersection */

		if (pl_end < start)

			continue;

		if (pl->start >  clr_end)

			continue;

		/* Delete completely overlapped poison entries */

		if ((pl->start >= start) && (pl_end <= clr_end)) {

			list_del(&pl->list);

			kfree(pl);

			continue;

		}

		/* Adjust start point of partially cleared entries */

		if ((start <= pl->start) && (clr_end > pl->start)) {

			pl->length -= clr_end - pl->start + 1;

			pl->start = clr_end + 1;

			continue;

		}

		/* Adjust pl->length for partial clearing at the tail end */

		if ((pl->start < start) && (pl_end <= clr_end)) {

			/* pl->start remains the same */

			pl->length = start - pl->start;

			continue;

		}

		/*

		 * If clearing in the middle of an entry, we split it into

		 * two by modifying the current entry to represent one half of

		 * the split, and adding a new entry for the second half.

		 */

		if ((pl->start < start) && (pl_end > clr_end)) {

			u64 new_start = clr_end + 1;

			u64 new_len = pl_end - new_start + 1;



			/* Add new entry covering the right half */

			add_poison(nvdimm_bus, new_start, new_len, GFP_NOIO);

			/* Adjust this entry to cover the left half */

			pl->length = start - pl->start;

			continue;

		}

	}

	nvdimm_bus_unlock(&nvdimm_bus->dev);

}

EXPORT_SYMBOL_GPL(nvdimm_clear_from_poison_list);



#ifdef CONFIG_BLK_DEV_INTEGRITY

int nd_integrity_init(struct gendisk *disk, unsigned long meta_size)

{

include/linux/libnvdimm.h

+2 −0
Original line number Diff line number Diff line
@@ -129,6 +129,8 @@ static inline struct nd_blk_region_desc *to_blk_region_desc( 
}



int nvdimm_bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length);

void nvdimm_clear_from_poison_list(struct nvdimm_bus *nvdimm_bus,

		phys_addr_t start, unsigned int len);

struct nvdimm_bus *nvdimm_bus_register(struct device *parent,

		struct nvdimm_bus_descriptor *nfit_desc);

void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus);