From a26062416ef8add48f16fbadded2b5f6fb84d024 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Fri, 1 Mar 2013 22:45:49 +0000 Subject: dm ioctl: allow message to return data This patch introduces enhanced message support that allows the device-mapper core to recognise messages that are common to all devices, and for messages to return data to userspace. Core messages are processed by the function "message_for_md". If the device mapper doesn't support the message, it is passed to the target driver. If the message returns data, the kernel sets the flag DM_MESSAGE_OUT_FLAG. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon --- include/uapi/linux/dm-ioctl.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include') diff --git a/include/uapi/linux/dm-ioctl.h b/include/uapi/linux/dm-ioctl.h index b8a6bddf0727..7e75b6fd8d45 100644 --- a/include/uapi/linux/dm-ioctl.h +++ b/include/uapi/linux/dm-ioctl.h @@ -336,4 +336,9 @@ enum { */ #define DM_SECURE_DATA_FLAG (1 << 15) /* In */ +/* + * If set, a message generated output data. + */ +#define DM_DATA_OUT_FLAG (1 << 16) /* Out */ + #endif /* _LINUX_DM_IOCTL_H */ -- cgit v1.2.3