X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fudev%2Fudev-builtin-path_id.c;h=df996cb17aca160fd4496b6769adf82a62f52826;hb=79008bddf679a5e0900369950eb346c9fa687107;hp=ac0f71f83e2f4d01d2f230b1c697f4ac4ee5a4d7;hpb=9ec6e95b046de71c0198cb9d17acc5462dc76c74;p=elogind.git

diff --git a/src/udev/udev-builtin-path_id.c b/src/udev/udev-builtin-path_id.c
index ac0f71f83..df996cb17 100644
--- a/src/udev/udev-builtin-path_id.c
+++ b/src/udev/udev-builtin-path_id.c
@@ -332,7 +332,7 @@ static struct udev_device *handle_scsi_hyperv(struct udev_device *parent, char *
         return parent;
 }
 
-static struct udev_device *handle_scsi(struct udev_device *parent, char **path) {
+static struct udev_device *handle_scsi(struct udev_device *parent, char **path, bool *supported_parent) {
         const char *devtype;
         const char *name;
         const char *id;
@@ -346,6 +346,7 @@ static struct udev_device *handle_scsi(struct udev_device *parent, char **path)
         if (id != NULL) {
                 parent = skip_subsystem(parent, "scsi");
                 path_prepend(path, "ieee1394-0x%s", id);
+                *supported_parent = true;
                 goto out;
         }
 
@@ -354,16 +355,19 @@ static struct udev_device *handle_scsi(struct udev_device *parent, char **path)
 
         if (strstr(name, "/rport-") != NULL) {
                 parent = handle_scsi_fibre_channel(parent, path);
+                *supported_parent = true;
                 goto out;
         }
 
         if (strstr(name, "/end_device-") != NULL) {
                 parent = handle_scsi_sas(parent, path);
+                *supported_parent = true;
                 goto out;
         }
 
         if (strstr(name, "/session") != NULL) {
                 parent = handle_scsi_iscsi(parent, path);
+                *supported_parent = true;
                 goto out;
         }
 
@@ -481,7 +485,8 @@ out:
 static int builtin_path_id(struct udev_device *dev, int argc, char *argv[], bool test) {
         struct udev_device *parent;
         char *path = NULL;
-        bool some_transport = false;
+        bool supported_transport = false;
+        bool supported_parent = false;
 
         /* S390 ccw bus */
         parent = udev_device_get_parent_with_subsystem_devtype(dev, "ccw", NULL);
@@ -501,48 +506,63 @@ static int builtin_path_id(struct udev_device *dev, int argc, char *argv[], bool
                 } else if (streq(subsys, "scsi_tape")) {
                         handle_scsi_tape(parent, &path);
                 } else if (streq(subsys, "scsi")) {
-                        parent = handle_scsi(parent, &path);
-                        some_transport = true;
+                        parent = handle_scsi(parent, &path, &supported_parent);
+                        supported_transport = true;
                 } else if (streq(subsys, "cciss")) {
                         parent = handle_cciss(parent, &path);
-                        some_transport = true;
+                        supported_transport = true;
                 } else if (streq(subsys, "usb")) {
                         parent = handle_usb(parent, &path);
-                        some_transport = true;
+                        supported_transport = true;
                 } else if (streq(subsys, "bcma")) {
                         parent = handle_bcma(parent, &path);
-                        some_transport = true;
+                        supported_transport = true;
                 } else if (streq(subsys, "serio")) {
                         path_prepend(&path, "serio-%s", udev_device_get_sysnum(parent));
                         parent = skip_subsystem(parent, "serio");
                 } else if (streq(subsys, "pci")) {
                         path_prepend(&path, "pci-%s", udev_device_get_sysname(parent));
                         parent = skip_subsystem(parent, "pci");
+                        supported_parent = true;
                 } else if (streq(subsys, "platform")) {
                         path_prepend(&path, "platform-%s", udev_device_get_sysname(parent));
                         parent = skip_subsystem(parent, "platform");
-                        some_transport = true;
+                        supported_transport = true;
+                        supported_parent = true;
                 } else if (streq(subsys, "acpi")) {
                         path_prepend(&path, "acpi-%s", udev_device_get_sysname(parent));
                         parent = skip_subsystem(parent, "acpi");
+                        supported_parent = true;
                 } else if (streq(subsys, "xen")) {
                         path_prepend(&path, "xen-%s", udev_device_get_sysname(parent));
                         parent = skip_subsystem(parent, "xen");
+                        supported_parent = true;
                 } else if (streq(subsys, "scm")) {
                         path_prepend(&path, "scm-%s", udev_device_get_sysname(parent));
                         parent = skip_subsystem(parent, "scm");
-                        some_transport = true;
+                        supported_transport = true;
+                        supported_parent = true;
                 }
 
                 parent = udev_device_get_parent(parent);
         }
 
         /*
-         * Do not return a single-parent-device-only for block
-         * devices, they might have entire buses behind it which
-         * do not get unique IDs only by using the parent device.
+         * Do not return devices with an unknown parent device type. They
+         * might produce conflicting IDs if the parent does not provide a
+         * unique and predictable name.
          */
-        if (!some_transport && streq(udev_device_get_subsystem(dev), "block")) {
+        if (!supported_parent) {
+                free(path);
+                path = NULL;
+        }
+
+        /*
+         * Do not return block devices without a well-known transport. Some
+         * devices do not expose their buses and do not provide a unique
+         * and predictable name that way.
+         */
+        if (streq(udev_device_get_subsystem(dev), "block") && !supported_transport) {
                 free(path);
                 path = NULL;
         }