4.8-stable review patch. If anyone has any objections, please let me know.
------------------
From: Vishal Verma <vishal.l.verma@xxxxxxxxx>
commit e046114af5fcafe8d6d3f0b6ccb99804bad34bfb upstream.
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@xxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/nvdimm/bus.c | 2 +
drivers/nvdimm/core.c | 73 +++++++++++++++++++++++++++++++++++++++++++---
include/linux/libnvdimm.h | 2 +
3 files changed, 73 insertions(+), 4 deletions(-)
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -217,6 +217,8 @@ long nvdimm_clear_poison(struct device *
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);
--- a/drivers/nvdimm/core.c
+++ b/drivers/nvdimm/core.c
@@ -547,11 +547,12 @@ void nvdimm_badblocks_populate(struct nd
}
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;
@@ -567,7 +568,7 @@ static int bus_add_poison(struct nvdimm_
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.
@@ -587,7 +588,7 @@ static int bus_add_poison(struct nvdimm_
* 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)
@@ -602,6 +603,70 @@ int nvdimm_bus_add_poison(struct nvdimm_
}
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)
{
--- a/include/linux/libnvdimm.h
+++ b/include/linux/libnvdimm.h
@@ -129,6 +129,8 @@ static inline struct nd_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);
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