From abb864d380854b5427b6b070beb2ebc291ce4d1e Mon Sep 17 00:00:00 2001
From: Ming Lei <ming.lei@redhat.com>
Date: Fri, 6 Jan 2023 12:17:09 +0800
Subject: ublk_drv: add device parameter UBLK_PARAM_TYPE_DEVT
Userspace side only knows device ID, but the associated path of ublkc* and
ublkb* could be changed by udev, and that depends on userspace's policy, so
add parameter of UBLK_PARAM_TYPE_DEVT for retrieving major/minor of the
ublkc* and ublkb*, then user may figure out major/minor of the ublk disks
he/she owns. With major/minor, it is easy to find the device node path.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230106041711.914434-5-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
include/uapi/linux/ublk_cmd.h | 13 +++++++++++++
1 file changed, 13 insertions(+)
(limited to 'include')
diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h
index 8f88e3a29998..4e38b9aa0293 100644
--- a/include/uapi/linux/ublk_cmd.h
+++ b/include/uapi/linux/ublk_cmd.h
@@ -214,6 +214,17 @@ struct ublk_param_discard {
__u16 reserved0;
};
+/*
+ * read-only, can't set via UBLK_CMD_SET_PARAMS, disk_devt is available
+ * after device is started
+ */
+struct ublk_param_devt {
+ __u32 char_major;
+ __u32 char_minor;
+ __u32 disk_major;
+ __u32 disk_minor;
+};
+
struct ublk_params {
/*
* Total length of parameters, userspace has to set 'len' for both
@@ -224,10 +235,12 @@ struct ublk_params {
__u32 len;
#define UBLK_PARAM_TYPE_BASIC (1 << 0)
#define UBLK_PARAM_TYPE_DISCARD (1 << 1)
+#define UBLK_PARAM_TYPE_DEVT (1 << 2)
__u32 types; /* types of parameter included */
struct ublk_param_basic basic;
struct ublk_param_discard discard;
+ struct ublk_param_devt devt;
};
#endif
--
cgit