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 <kdasu.kdev@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

2 files changed, 9 insertions, 0 deletions

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 453242d6cf56..408615f29e57 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -1124,6 +1124,9 @@ 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 936a3fdb48b5..4ca8c1c845fb 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -316,6 +316,12 @@ 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 */