From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Martin Wilck <mwilck@suse.com>
Date: Thu, 17 Feb 2022 17:22:32 +0100
Subject: [PATCH] libmultipath: enable linear ordering of bus/proto tuple
We categorized protocols by bus/proto_id, while we only differentiate
protocol IDs for SCSI. Allow transforming this into a linear sequence
of bus/protocol IDs by having non-SCSI first, and follwing up with
the different SCSI protocols.
Signed-off-by: Martin Wilck <mwilck@suse.com>
Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
---
libmultipath/structs.c | 10 ++++++++++
libmultipath/structs.h | 14 ++++++++++++--
2 files changed, 22 insertions(+), 2 deletions(-)
diff --git a/libmultipath/structs.c b/libmultipath/structs.c
index dda9884c..aaf85297 100644
--- a/libmultipath/structs.c
+++ b/libmultipath/structs.c
@@ -722,3 +722,13 @@ out:
return 0;
}
+
+unsigned int bus_protocol_id(const struct path *pp) {
+ if (!pp || pp->bus < 0 || pp->bus > SYSFS_BUS_SCSI)
+ return SYSFS_BUS_UNDEF;
+ if (pp->bus != SYSFS_BUS_SCSI)
+ return pp->bus;
+ if ((int)pp->sg_id.proto_id < 0 || pp->sg_id.proto_id > SCSI_PROTOCOL_UNSPEC)
+ return SYSFS_BUS_UNDEF;
+ return SYSFS_BUS_SCSI + pp->sg_id.proto_id;
+}
diff --git a/libmultipath/structs.h b/libmultipath/structs.h
index a5dbad5b..5e29ae38 100644
--- a/libmultipath/structs.h
+++ b/libmultipath/structs.h
@@ -57,12 +57,13 @@ enum failback_mode {
FAILBACK_FOLLOWOVER
};
+/* SYSFS_BUS_SCSI should be last, see bus_protocol_id() */
enum sysfs_buses {
SYSFS_BUS_UNDEF,
- SYSFS_BUS_SCSI,
SYSFS_BUS_CCW,
SYSFS_BUS_CCISS,
SYSFS_BUS_NVME,
+ SYSFS_BUS_SCSI,
};
enum pathstates {
@@ -190,9 +191,18 @@ enum scsi_protocol {
SCSI_PROTOCOL_SAS = 6,
SCSI_PROTOCOL_ADT = 7, /* Media Changers */
SCSI_PROTOCOL_ATA = 8,
- SCSI_PROTOCOL_UNSPEC = 0xf, /* No specific protocol */
+ SCSI_PROTOCOL_USB = 9, /* USB Attached SCSI (UAS), and others */
+ SCSI_PROTOCOL_UNSPEC = 0xa, /* No specific protocol */
};
+/*
+ * Linear ordering of bus/protocol
+ * This assumes that SYSFS_BUS_SCSI is last in enum sysfs_buses
+ * SCSI is the only bus type for which we distinguish protocols.
+ */
+#define LAST_BUS_PROTOCOL_ID (SYSFS_BUS_SCSI + SCSI_PROTOCOL_UNSPEC)
+unsigned int bus_protocol_id(const struct path *pp);
+
enum no_undef_states {
NU_NO = -1,
NU_UNDEF = 0,