[PATCH v5 4/9] pmem,mm: Implement ->memory_failure in pmem driver

From: Shiyang Ruan
Date: Sun Jun 27 2021 - 20:03:15 EST


With dax_holder notify support, we are able to notify the memory failure
from pmem driver to upper layers. If there is something not support in
the notify routine, memory_failure will fall back to the generic hanlder.

Signed-off-by: Shiyang Ruan <ruansy.fnst@xxxxxxxxxxx>
---
drivers/nvdimm/pmem.c | 13 +++++++++++++
mm/memory-failure.c | 14 ++++++++++++++
2 files changed, 27 insertions(+)

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index ed10a8b66068..95d79dfb2fc2 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -364,9 +364,22 @@ static void pmem_release_disk(void *__pmem)
put_disk(pmem->disk);
}

+static int pmem_pagemap_memory_failure(struct dev_pagemap *pgmap,
+ unsigned long pfn, unsigned long nr_pfns, int flags)
+{
+ struct pmem_device *pmem =
+ container_of(pgmap, struct pmem_device, pgmap);
+ loff_t offset = PFN_PHYS(pfn) - pmem->phys_addr - pmem->data_offset;
+
+ return dax_holder_notify_failure(pmem->dax_dev, offset,
+ page_size(pfn_to_page(pfn)) * nr_pfns,
+ &flags);
+}
+
static const struct dev_pagemap_ops fsdax_pagemap_ops = {
.kill = pmem_pagemap_kill,
.cleanup = pmem_pagemap_cleanup,
+ .memory_failure = pmem_pagemap_memory_failure,
};

static int pmem_attach_disk(struct device *dev,
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 068753911946..30ce1e653c0a 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1411,6 +1411,20 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags,
*/
SetPageHWPoison(page);

+ /*
+ * Call driver's implementation to handle the memory failure, otherwise
+ * fall back to generic handler.
+ */
+ if (pgmap->ops->memory_failure) {
+ rc = pgmap->ops->memory_failure(pgmap, pfn, 1, flags);
+ /*
+ * Fall back to generic handler too if operation is not
+ * supported inside the driver/device/filesystem.
+ */
+ if (rc != EOPNOTSUPP)
+ goto out;
+ }
+
mf_generic_kill_procs(pfn, flags);
out:
/* drop pgmap ref acquired in caller */
--
2.32.0