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:

37b137f 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: 37b137f ("nfit, libnvdimm: allow an ARS scrub to be triggered on demand")
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Vishal Verma 2016-09-30 17:19:31 -06:00 committed by Dan Williams
parent bd697a80c3
commit e046114af5
3 changed files with 73 additions and 4 deletions

View File

@ -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);

View File

@ -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)
{

View File

@ -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);