On Fri, Sep 24, 2021 at 09:09:55PM +0800, Shiyang Ruan wrote:
> 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.
>
> Signed-off-by: Shiyang Ruan <ruansy.fnst@xxxxxxxxxxx>
> ---
> drivers/nvdimm/pmem.c | 11 +++++++++++
> include/linux/memremap.h | 9 +++++++++
> mm/memory-failure.c | 14 ++++++++++++++
> 3 files changed, 34 insertions(+)
>
> diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
> index 72de88ff0d30..0dfafad8fcc5 100644
> --- a/drivers/nvdimm/pmem.c
> +++ b/drivers/nvdimm/pmem.c
> @@ -362,9 +362,20 @@ static void pmem_release_disk(void *__pmem)
> del_gendisk(pmem->disk);
> }
>
> +static int pmem_pagemap_memory_failure(struct dev_pagemap *pgmap,
> + unsigned long pfn, size_t size, 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, size, 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/include/linux/memremap.h b/include/linux/memremap.h
> index c0e9d35889e8..36d47bacd46d 100644
> --- a/include/linux/memremap.h
> +++ b/include/linux/memremap.h
> @@ -87,6 +87,15 @@ 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 flag is finally passed to the recover
> + * function through the whole notify routine.
> + */
> + int (*memory_failure)(struct dev_pagemap *pgmap, unsigned long pfn,
> + size_t size, int flags);
> };
>
> #define PGMAP_ALTMAP_VALID (1 << 0)
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 8ff9b52823c0..85eab206b68f 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -1605,6 +1605,20 @@ 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, PAGE_SIZE, flags);
> + /*
> + * Fall back to generic handler too if operation is not
> + * supported inside the driver/device/filesystem.
> + */
> + if (rc != EOPNOTSUPP)
-EOPNOTSUPP? (negative errno)
--D
> + goto out;
> + }
> +
> rc = mf_generic_kill_procs(pfn, flags, pgmap);
> out:
> /* drop pgmap ref acquired in caller */
> --
> 2.33.0
>
>
>
