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[v4,01/10] pagemap: Introduce ->memory_failure()

Message ID 20210604011844.1756145-2-ruansy.fnst@fujitsu.com (mailing list archive)
State Superseded
Headers show
Series fsdax: introduce fs query to support reflink | expand

Commit Message

ruansy.fnst@fujitsu.com June 4, 2021, 1:18 a.m. UTC
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.  And finally call filesystem handler to
deal with this error.

The filesystem will try to recover the corrupted data if possiable.

Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
---
 include/linux/memremap.h | 8 ++++++++
 1 file changed, 8 insertions(+)

Comments

Dan Williams June 16, 2021, 12:18 a.m. UTC | #1
On Thu, Jun 3, 2021 at 6:19 PM Shiyang Ruan <ruansy.fnst@fujitsu.com> wrote:

Hi Ruan, apologies for the delays circling back to this.

>
> 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.  And finally call filesystem handler to
> deal with this error.
>
> The filesystem will try to recover the corrupted data if possiable.
>

Let's move this change to the patch that needs it, this patch does not
do anything on its own.

> Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
> ---
>  include/linux/memremap.h | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/include/linux/memremap.h b/include/linux/memremap.h
> index 45a79da89c5f..473fe18c516a 100644
> --- a/include/linux/memremap.h
> +++ b/include/linux/memremap.h
> @@ -87,6 +87,14 @@ 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 one page.  Notify the processes
> +        * who are using this page, and try to recover the data on this page
> +        * if necessary.
> +        */

I thought we discussed that this needed to be range based here:

https://lore.kernel.org/r/CAPcyv4jhUU3NVD8HLZnJzir+SugB6LnnrgJZ-jP45BZrbJ1dJQ@mail.gmail.com

...but also incorporate Christoph's feedback to not use notifiers.

> +       int (*memory_failure)(struct dev_pagemap *pgmap, unsigned long pfn,
> +                             int flags);

Change this callback to

int (*notify_memory_failure)(struct dev_pagemap *pgmap, unsigned long
pfn, unsigned long nr_pfns)

...to pass a range and to clarify that this callback is for
memory_failure() to notify the pgmap, the pgmap notifies the owner via
the holder callbacks.
diff mbox series

Patch

diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index 45a79da89c5f..473fe18c516a 100644
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -87,6 +87,14 @@  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 one page.  Notify the processes
+	 * who are using this page, and try to recover the data on this page
+	 * if necessary.
+	 */
+	int (*memory_failure)(struct dev_pagemap *pgmap, unsigned long pfn,
+			      int flags);
 };
 
 #define PGMAP_ALTMAP_VALID	(1 << 0)