[PATCH] path_id: Handle SAS and SATA devices

[hare@suse.de (Hannes Reinecke)]

SAS devices should be referenced by the SAS address of the target;
on the initiator side we assume an identity mapping between SAS
addresses and PCI devnumber.
SATA devices have an identity mapping between SATA links and
linux scsi_host structures, so we can map the host number onto
the SATA link.
For this to work the LUN numbering needs to be updated, too,
as SATA devices do not have the concept of a LUN, whereas normal
SCSI devices have.

Signed-off-by: Hannes Reinecke <hare@suse.de>

diff --git a/extras/path_id/path_id.c b/extras/path_id/path_id.c
index dcee378..1b6c363 100644
--- a/extras/path_id/path_id.c
+++ b/extras/path_id/path_id.c
@@ -97,7 +97,6 @@ static struct udev_device *handle_scsi_fibre_channel(struct udev_device *parent,
 	struct udev_device *targetdev;
 	struct udev_device *fcdev = NULL;
 	const char *port;
-	unsigned int lun;
 
 	targetdev = udev_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_target");
 	if (targetdev = NULL)
@@ -112,8 +111,7 @@ static struct udev_device *handle_scsi_fibre_channel(struct udev_device *parent,
 		goto out;
 	}
 
-	lun = strtoul(udev_device_get_sysnum(parent), NULL, 10);
-	path_prepend(path, "fc-%s:0x%04x%04x00000000", port, lun & 0xffff, (lun >> 16) & 0xffff);
+	path_prepend(path, "fc-%s", port);
 out:
 	udev_device_unref(fcdev);
 	return parent;
@@ -121,7 +119,34 @@ out:
 
 static struct udev_device *handle_scsi_sas(struct udev_device *parent, char **path)
 {
-	return NULL;
+	struct udev *udev  = udev_device_get_udev(parent);
+	struct udev_device *end_dev = NULL;
+	struct udev_device *sas_dev;
+	const char *end_dev_wwn;
+
+	/* Find end device */
+	end_dev = parent;
+	while (1) {
+		end_dev = udev_device_get_parent(end_dev);
+		if (end_dev = NULL)
+			return NULL;
+		if (!strncmp(udev_device_get_sysname(end_dev), "end_device", 10))
+			break;
+	}
+	if (end_dev = NULL)
+		return NULL;
+
+	/* find sas end device */
+	sas_dev = udev_device_new_from_subsystem_sysname(udev, "sas_device", udev_device_get_sysname(end_dev));
+	if (sas_dev = NULL)
+		return NULL;
+
+	end_dev_wwn = udev_device_get_sysattr_value(sas_dev, "sas_address");
+
+	path_prepend(path, "sas-%s", end_dev_wwn);
+
+	udev_device_unref(sas_dev);
+	return end_dev;
 }
 
 static struct udev_device *handle_scsi_iscsi(struct udev_device *parent, char **path)
@@ -174,7 +199,7 @@ static struct udev_device *handle_scsi_iscsi(struct udev_device *parent, char **
 		goto out;
 	}
 
-	path_prepend(path, "ip-%s:%s-iscsi-%s-lun-%s", addr, port, target, udev_device_get_sysnum(parent));
+	path_prepend(path, "ip-%s:%s-iscsi-%s", addr, port, target);
 out:
 	udev_device_unref(sessiondev);
 	udev_device_unref(conndev);
@@ -183,23 +208,34 @@ out:
 
 static struct udev_device *handle_scsi_default(struct udev_device *parent, char **path)
 {
+	struct udev *udev  = udev_device_get_udev(parent);
 	struct udev_device *hostdev;
-	int host, bus, target, lun;
-	const char *name;
+	int host, bus, target;
+	const char *name, *hba, *hostpath;
 	char *base;
 	char *pos;
+	char *type = "scsi";
 	DIR *dir;
 	struct dirent *dent;
-	int basenum;
-
-	hostdev = udev_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_host");
-	if (hostdev = NULL)
-		return NULL;
+	int basenum, hostnum = 0;
 
 	name = udev_device_get_sysname(parent);
-	if (sscanf(name, "%d:%d:%d:%d", &host, &bus, &target, &lun) != 4)
+	if (sscanf(name, "target%d:%d:%d", &host, &bus, &target) != 3)
 		return NULL;
 
+	parent = udev_device_get_parent(parent);
+	/* Check for libata hosts */
+	hostdev = udev_device_new_from_subsystem_sysname(udev, "scsi_host", udev_device_get_sysname(parent));
+	if (hostdev = NULL)
+		return NULL;
+	hba = udev_device_get_sysattr_value(hostdev, "proc_name");
+	if (hba && (!strncmp(hba, "sata", 4) || !strcmp(hba, "ahci")))
+		type = "sata";
+	if (hba && (!strncmp(hba, "pata", 4) || !strncmp(hba, "ata", 3)))
+		type = "ata";
+	udev_device_unref(hostdev);
+	/* Reset to original host path */
+	hostdev = parent;
 	/* rebase host offset to get the local relative number */
 	basenum = -1;
 	base = strdup(udev_device_get_syspath(hostdev));
@@ -227,6 +263,7 @@ static struct udev_device *handle_scsi_default(struct udev_device *parent, char
 		if (strncmp(dent->d_name, "host", 4) != 0)
 			continue;
 		i = strtoul(&dent->d_name[4], &rest, 10);
+		hostnum++;
 		if (rest[0] != '\0')
 			continue;
 		if (basenum = -1 || i < basenum)
@@ -239,20 +276,54 @@ static struct udev_device *handle_scsi_default(struct udev_device *parent, char
 	}
 	host -= basenum;
 
-	path_prepend(path, "scsi-%u:%u:%u:%u", host, bus, target, lun);
+	if (!strcmp(type, "scsi"))
+		path_prepend(path, "scsi-%u:%u:%u", host, bus, target);
+	else
+		path_prepend(path, "%s-%u", type, host);
 out:
 	free(base);
 	return hostdev;
 }
 
+static int scsi_is_sata(const char *name)
+{
+	char syspath[UTIL_PATH_SIZE];
+	struct stat stbuf;
+
+	strcpy(syspath, name);
+	strcat(syspath, "/unload_heads");
+
+	return (stat(syspath, &stbuf) < 0) ? 0 : 1;
+}
+
 static struct udev_device *handle_scsi(struct udev_device *parent, char **path)
 {
+	struct udev *udev  = udev_device_get_udev(parent);
 	const char *devtype;
 	const char *name;
 	const char *id;
 
 	devtype = udev_device_get_devtype(parent);
-	if (devtype = NULL || strcmp(devtype, "scsi_device") != 0)
+	if (devtype = NULL)
+		return parent;
+
+	/* lousy scsi sysfs does not have a "subsystem" for the transport */
+	name = udev_device_get_syspath(parent);
+
+	if (strcmp(devtype, "scsi_device") = 0) {
+		if (!scsi_is_sata(name)) {
+			unsigned int host, bus, target, lun;
+
+			if (sscanf(udev_device_get_sysname(parent),
+				   "%d:%d:%d:%d", &host, &bus, &target, &lun) != 4)
+				return NULL;
+			path_prepend(path, "lun-0x%04x%04x00000000",
+				     lun & 0xffff, (lun >> 16) & 0xffff);
+		}
+		return parent;
+	}
+
+	if (strcmp(devtype, "scsi_host") = 0)
 		return parent;
 
 	/* firewire */
@@ -263,9 +334,6 @@ static struct udev_device *handle_scsi(struct udev_device *parent, char **path)
 		goto out;
 	}
 
-	/* lousy scsi sysfs does not have a "subsystem" for the transport */
-	name = udev_device_get_syspath(parent);
-
 	if (strstr(name, "/rport-") != NULL) {
 		parent = handle_scsi_fibre_channel(parent, path);
 		goto out;