On 9 Jan 2019, at 16.30, Kanchan Joshi [off-list ref] wrote:

Exiting write-hints are exposed to user-mode. There is a possiblity
of conflict if kernel happens to use those. This patch introduces four
write-hints for exclusive kernel-mode use.

Signed-off-by: Kanchan Joshi <redacted>
---
include/linux/fs.h | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 811c777..e8548eb 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h

@@ -291,6 +291,11 @@ enum rw_hint {

	WRITE_LIFE_MEDIUM	= RWH_WRITE_LIFE_MEDIUM,
	WRITE_LIFE_LONG		= RWH_WRITE_LIFE_LONG,
	WRITE_LIFE_EXTREME	= RWH_WRITE_LIFE_EXTREME,
+/* below ones are meant for in-kernel use */
+	KERN_WRITE_LIFE_SHORT,
+	KERN_WRITE_LIFE_MEDIUM,
+	KERN_WRITE_LIFE_LONG,
+	KERN_WRITE_LIFE_EXTREME
};