pagemap,pmem: introduce ->memory_failure()

When memory-failure occurs, we call this function which is implemented by
each kind of devices.  For the fsdax case, pmem device driver implements
it.  Pmem device driver will find out the filesystem in which the
corrupted page located in.

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.

Link: https://lkml.kernel.org/r/20220603053738.1218681-4-ruansy.fnst@fujitsu.com
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.wiliams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 629d10fcf53b2c0e828e6b9641189562b105b293..107c9cb3d57d700201c18bb74815b7dc2e0a0702 100644 (file)
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -453,6 +453,21 @@ static void pmem_release_disk(void *__pmem)
        blk_cleanup_disk(pmem->disk);
 }
 
+static int pmem_pagemap_memory_failure(struct dev_pagemap *pgmap,
+               unsigned long pfn, unsigned long nr_pages, int mf_flags)
+{
+       struct pmem_device *pmem =
+                       container_of(pgmap, struct pmem_device, pgmap);
+       u64 offset = PFN_PHYS(pfn) - pmem->phys_addr - pmem->data_offset;
+       u64 len = nr_pages << PAGE_SHIFT;
+
+       return dax_holder_notify_failure(pmem->dax_dev, offset, len, mf_flags);
+}
+
+static const struct dev_pagemap_ops fsdax_pagemap_ops = {
+       .memory_failure         = pmem_pagemap_memory_failure,
+};
+
 static int pmem_attach_disk(struct device *dev,
                struct nd_namespace_common *ndns)
 {
@@ -514,6 +529,7 @@ static int pmem_attach_disk(struct device *dev,
        pmem->pfn_flags = PFN_DEV;
        if (is_nd_pfn(dev)) {
                pmem->pgmap.type = MEMORY_DEVICE_FS_DAX;
+               pmem->pgmap.ops = &fsdax_pagemap_ops;
                addr = devm_memremap_pages(dev, &pmem->pgmap);
                pfn_sb = nd_pfn->pfn_sb;
                pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
@@ -527,6 +543,7 @@ static int pmem_attach_disk(struct device *dev,
                pmem->pgmap.range.end = res->end;
                pmem->pgmap.nr_range = 1;
                pmem->pgmap.type = MEMORY_DEVICE_FS_DAX;
+               pmem->pgmap.ops = &fsdax_pagemap_ops;
                addr = devm_memremap_pages(dev, &pmem->pgmap);
                pmem->pfn_flags |= PFN_MAP;
                bb_range = pmem->pgmap.range;

diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index 09320b7f706cc3c6f10027bd9bd3bd00a4228b5d..19010491a60385f4b8c4952f3a335c631e4c7023 100644 (file)
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -87,6 +87,18 @@ struct dev_pagemap_ops {
         * the page back to a CPU accessible page.
         */
        vm_fault_t (*migrate_to_ram)(struct vm_fault *vmf);
+
+       /*
+        * Handle the memory failure happens on a range of pfns.  Notify the
+        * processes who are using these pfns, and try to recover the data on
+        * them if necessary.  The mf_flags is finally passed to the recover
+        * function through the whole notify routine.
+        *
+        * When this is not implemented, or it returns -EOPNOTSUPP, the caller
+        * will fall back to a common handler called mf_generic_kill_procs().
+        */
+       int (*memory_failure)(struct dev_pagemap *pgmap, unsigned long pfn,
+                             unsigned long nr_pages, int mf_flags);
 };
 
 #define PGMAP_ALTMAP_VALID     (1 << 0)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index f8a8a5d45eba8ec623fc29a99621b79683017772..46c77151f72678e1f91e2582e72e62aa058485b7 100644 (file)
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1748,6 +1748,20 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags,
        if (!pgmap_pfn_valid(pgmap, pfn))
                goto out;
 
+       /*
+        * 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;
+       }
+
        rc = mf_generic_kill_procs(pfn, flags, pgmap);
 out:
        /* drop pgmap ref acquired in caller */