2019-05-16 18:21:20

by Kamal Dasu

Subject: [PATCH v3 1/2] mtd: Add flag to indicate panic_write

Added a flag to indicate a panic_write so that low level drivers can
use it to take required action where applicable, to ensure oops data
gets written to assigned mtd device.

Signed-off-by: Kamal Dasu <[email protected]>
---
drivers/mtd/mtdcore.c | 3 +++
include/linux/mtd/mtd.h | 6 ++++++
2 files changed, 9 insertions(+)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 76b4264..a83decd 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -1138,6 +1138,9 @@ int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
return -EROFS;
if (!len)
return 0;
+ if (!mtd->oops_panic_write)
+ mtd->oops_panic_write = true;
+
return mtd->_panic_write(mtd, to, len, retlen, buf);
}
EXPORT_SYMBOL_GPL(mtd_panic_write);
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index 677768b..791c34d 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -330,6 +330,12 @@ struct mtd_info {
int (*_get_device) (struct mtd_info *mtd);
void (*_put_device) (struct mtd_info *mtd);

+ /*
+ * flag indicates a panic write, low level drivers can take appropriate
+ * action if required to ensure writes go through
+ */
+ bool oops_panic_write;
+
struct notifier_block reboot_notifier; /* default mode before reboot */

/* ECC status information */
--
1.9.0.138.g2de3478

2019-05-17 09:11:50

by Richard Weinberger

Subject: Re: [PATCH v3 1/2] mtd: Add flag to indicate panic_write

On Thu, May 16, 2019 at 6:42 PM Kamal Dasu <[email protected]> wrote:
>
> Added a flag to indicate a panic_write so that low level drivers can
> use it to take required action where applicable, to ensure oops data
> gets written to assigned mtd device.
>
> Signed-off-by: Kamal Dasu <[email protected]>
> ---
> drivers/mtd/mtdcore.c | 3 +++
> include/linux/mtd/mtd.h | 6 ++++++
> 2 files changed, 9 insertions(+)
>
> diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
> index 76b4264..a83decd 100644
> --- a/drivers/mtd/mtdcore.c
> +++ b/drivers/mtd/mtdcore.c
> @@ -1138,6 +1138,9 @@ int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
> return -EROFS;
> if (!len)
> return 0;
> + if (!mtd->oops_panic_write)
> + mtd->oops_panic_write = true;
> +

You can set the flag unconditionally.
If it is set, it will stay so, and setting it again, won't hurt.

> return mtd->_panic_write(mtd, to, len, retlen, buf);
> }
> EXPORT_SYMBOL_GPL(mtd_panic_write);
> diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
> index 677768b..791c34d 100644
> --- a/include/linux/mtd/mtd.h
> +++ b/include/linux/mtd/mtd.h
> @@ -330,6 +330,12 @@ struct mtd_info {
> int (*_get_device) (struct mtd_info *mtd);
> void (*_put_device) (struct mtd_info *mtd);
>
> + /*
> + * flag indicates a panic write, low level drivers can take appropriate
> + * action if required to ensure writes go through
> + */
> + bool oops_panic_write;
> +

Maybe we find a better name for it.
panic_write_triggered?

--
Thanks,
//richard

2019-06-17 22:15:49

by Richard Weinberger

Subject: Re: [PATCH v3 1/2] mtd: Add flag to indicate panic_write

On Fri, May 17, 2019 at 10:08 AM Richard Weinberger
<[email protected]> wrote:
>
> On Thu, May 16, 2019 at 6:42 PM Kamal Dasu <[email protected]> wrote:
> >
> > Added a flag to indicate a panic_write so that low level drivers can
> > use it to take required action where applicable, to ensure oops data
> > gets written to assigned mtd device.
> >
> > Signed-off-by: Kamal Dasu <[email protected]>
> > ---
> > drivers/mtd/mtdcore.c | 3 +++
> > include/linux/mtd/mtd.h | 6 ++++++
> > 2 files changed, 9 insertions(+)
> >
> > diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
> > index 76b4264..a83decd 100644
> > --- a/drivers/mtd/mtdcore.c
> > +++ b/drivers/mtd/mtdcore.c
> > @@ -1138,6 +1138,9 @@ int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
> > return -EROFS;
> > if (!len)
> > return 0;
> > + if (!mtd->oops_panic_write)
> > + mtd->oops_panic_write = true;
> > +
>
> You can set the flag unconditionally.
> If it is set, it will stay so, and setting it again, won't hurt.
>
> > return mtd->_panic_write(mtd, to, len, retlen, buf);
> > }
> > EXPORT_SYMBOL_GPL(mtd_panic_write);
> > diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
> > index 677768b..791c34d 100644
> > --- a/include/linux/mtd/mtd.h
> > +++ b/include/linux/mtd/mtd.h
> > @@ -330,6 +330,12 @@ struct mtd_info {
> > int (*_get_device) (struct mtd_info *mtd);
> > void (*_put_device) (struct mtd_info *mtd);
> >
> > + /*
> > + * flag indicates a panic write, low level drivers can take appropriate
> > + * action if required to ensure writes go through
> > + */
> > + bool oops_panic_write;
> > +
>
> Maybe we find a better name for it.
> panic_write_triggered?

ping?
I'm happy with the overall approach.
So let's target the upcoming merge window.
Can you please sort my two comments out? :-)

--
Thanks,
//richard

2019-07-01 07:51:51

by Miquel Raynal

Subject: Re: [PATCH v3 1/2] mtd: Add flag to indicate panic_write

Hi Kamal,

Kamal Dasu <[email protected]> wrote on Thu, 16 May 2019 12:41:46
-0400:

> Added a flag to indicate a panic_write so that low level drivers can
> use it to take required action where applicable, to ensure oops data
> gets written to assigned mtd device.
>
> Signed-off-by: Kamal Dasu <[email protected]>
> ---

Applied to nand/next, thanks.

Miquèl