[PATCH 05/10] mm, pmem: Implement ->memory_failure() in pmem driver

Shiyang Ruan
2020-12-30T17:00:56Z

Call the ->memory_failure() which is implemented by pmem driver, in
order to finally notify filesystem to handle the corrupted data. The
old collecting and killing processes are moved into
mf_dax_mapping_kill_procs(), which will be called by filesystem.

Signed-off-by: Shiyang Ruan <ruansy.fnst@cn.fujitsu.com>
---
drivers/nvdimm/pmem.c | 24 +++++++++++++++++++++
mm/memory-failure.c | 50 +++++--------------------------------------
2 files changed, 29 insertions(+), 45 deletions(-)

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 875076b0ea6c..4a114937c43b 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -363,9 +363,33 @@ static void pmem_release_disk(void *__pmem)
put_disk(pmem->disk);
}

+static int pmem_pagemap_memory_failure(struct dev_pagemap *pgmap,
+ unsigned long pfn, int flags)
+{
+ struct pmem_device *pdev;
+ struct gendisk *disk;
+ loff_t disk_offset;
+ int rc = 0;
+ unsigned long size = page_size(pfn_to_page(pfn));
+
+ pdev = container_of(pgmap, struct pmem_device, pgmap);
+ disk = pdev->disk;
+ if (!disk)
+ return -ENXIO;
+
+ disk_offset = PFN_PHYS(pfn) - pdev->phys_addr - pdev->data_offset;
+ if (disk->fops->corrupted_range) {
+ rc = disk->fops->corrupted_range(disk, NULL, disk_offset, size, &flags);
+ if (rc == -ENODEV)
+ rc = -ENXIO;
+ }
+ return rc;
+}
+
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 37bc6e2a9564..0109ad607fb8 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1269,28 +1269,11 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags,
struct dev_pagemap *pgmap)
{
struct page *page = pfn_to_page(pfn);
- const bool unmap_success = true;
- unsigned long size = 0;
- struct to_kill *tk;
- LIST_HEAD(to_kill);
int rc = -EBUSY;
- loff_t start;
- dax_entry_t cookie;
-
- /*
- * Prevent the inode from being freed while we are interrogating
- * the address_space, typically this would be handled by
- * lock_page(), but dax pages do not use the page lock. This
- * also prevents changes to the mapping of this pfn until
- * poison signaling is complete.
- */
- cookie = dax_lock_page(page);
- if (!cookie)
- goto out;

if (hwpoison_filter(page)) {
rc = 0;
- goto unlock;
+ goto out;
}

if (pgmap->type == MEMORY_DEVICE_PRIVATE) {
@@ -1298,7 +1281,7 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags,
* TODO: Handle HMM pages which may need coordination
* with device-side memory.
*/
- goto unlock;
+ goto out;
}

/*
@@ -1307,33 +1290,10 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags,
*/
SetPageHWPoison(page);

- /*
- * Unlike System-RAM there is no possibility to swap in a
- * different physical page at a given virtual address, so all
- * userspace consumption of ZONE_DEVICE memory necessitates
- * SIGBUS (i.e. MF_MUST_KILL)
- */
- flags |= MF_ACTION_REQUIRED | MF_MUST_KILL;
- collect_procs_file(page, page->mapping, page->index, &to_kill,
- flags & MF_ACTION_REQUIRED);
+ /* call driver to handle the memory failure */
+ if (pgmap->ops->memory_failure)
+ rc = pgmap->ops->memory_failure(pgmap, pfn, flags);

- list_for_each_entry(tk, &to_kill, nd)
- if (tk->size_shift)
- size = max(size, 1UL << tk->size_shift);
- if (size) {
- /*
- * Unmap the largest mapping to avoid breaking up
- * device-dax mappings which are constant size. The
- * actual size of the mapping being torn down is
- * communicated in siginfo, see kill_proc()
- */
- start = (page->index << PAGE_SHIFT) & ~(size - 1);
- unmap_mapping_range(page->mapping, start, start + size, 0);
- }
- kill_procs(&to_kill, flags & MF_MUST_KILL, !unmap_success, pfn, flags);
- rc = 0;
-unlock:
- dax_unlock_page(page, cookie);
out:
/* drop pgmap ref acquired in caller */
put_dev_pagemap(pgmap);
--
2.29.2