X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fudev%2Fudev-builtin-path_id.c;h=da0273197bded6645cc0e4ceffe1b3ef1c6c134f;hb=7027ff61a34a12487712b382a061c654acc3a679;hp=09abefc032783bc65941b636b715b521a2791919;hpb=33502ffe2eb7b56cdd018a4fb6830d7828519fad;p=elogind.git

diff --git a/src/udev/udev-builtin-path_id.c b/src/udev/udev-builtin-path_id.c
index 09abefc03..da0273197 100644
--- a/src/udev/udev-builtin-path_id.c
+++ b/src/udev/udev-builtin-path_id.c
@@ -1,7 +1,7 @@
 /*
  * compose persistent device path
  *
- * Copyright (C) 2009-2011 Kay Sievers <kay.sievers@vrfy.org>
+ * Copyright (C) 2009-2011 Kay Sievers <kay@vrfy.org>
  *
  * Logic based on Hannes Reinecke's shell script.
  *
@@ -83,7 +83,7 @@ static struct udev_device *skip_subsystem(struct udev_device *dev, const char *s
                 const char *subsystem;
 
                 subsystem = udev_device_get_subsystem(parent);
-                if (subsystem == NULL || strcmp(subsystem, subsys) != 0)
+                if (subsystem == NULL || !streq(subsystem, subsys))
                         break;
                 dev = parent;
                 parent = udev_device_get_parent(parent);
@@ -97,7 +97,7 @@ static struct udev_device *handle_scsi_fibre_channel(struct udev_device *parent,
         struct udev_device *targetdev;
         struct udev_device *fcdev = NULL;
         const char *port;
-        char *lun = NULL;;
+        char *lun = NULL;
 
         targetdev = udev_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_target");
         if (targetdev == NULL)
@@ -236,7 +236,23 @@ static struct udev_device *handle_scsi_default(struct udev_device *parent, char
         if (sscanf(name, "%d:%d:%d:%d", &host, &bus, &target, &lun) != 4)
                 return NULL;
 
-        /* rebase host offset to get the local relative number */
+        /*
+         * Rebase host offset to get the local relative number
+         *
+         * Note: This is by definition racy, unreliable and too simple.
+         * Please do not copy this model anywhere. It's just a left-over
+         * from the time we had no idea how things should look like in
+         * the end.
+         *
+         * Making assumptions about a global in-kernel counter and use
+         * that to calculate a local offset is a very broken concept. It
+         * can only work as long as things are in strict order.
+         *
+         * The kernel needs to export the instance/port number of a
+         * controller directly, without the need for rebase magic like
+         * this. Manual driver unbind/bind, parallel hotplug/unplug will
+         * get into the way of this "I hope it works" logic.
+         */
         basenum = -1;
         base = strdup(udev_device_get_syspath(hostdev));
         if (base == NULL)
@@ -286,6 +302,42 @@ out:
         return hostdev;
 }
 
+static struct udev_device *handle_scsi_hyperv(struct udev_device *parent, char **path) {
+        struct udev_device *hostdev;
+        struct udev_device *vmbusdev;
+        const char *guid_str;
+        char *lun = NULL;
+        char guid[38];
+        size_t i, k;
+
+        hostdev = udev_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_host");
+        if (!hostdev)
+                return NULL;
+
+        vmbusdev = udev_device_get_parent(hostdev);
+        if (!vmbusdev)
+                return NULL;
+
+        guid_str = udev_device_get_sysattr_value(vmbusdev, "device_id");
+        if (!guid_str)
+                return NULL;
+
+        if (strlen(guid_str) < 37 || guid_str[0] != '{' || guid_str[36] != '}')
+                return NULL;
+
+        for (i = 1, k = 0; i < 36; i++) {
+                if (guid_str[i] == '-')
+                        continue;
+                guid[k++] = guid_str[i];
+        }
+        guid[k] = '\0';
+
+        format_lun_number(parent, &lun);
+        path_prepend(path, "vmbus-%s-%s", guid, lun);
+        free(lun);
+        return parent;
+}
+
 static struct udev_device *handle_scsi(struct udev_device *parent, char **path)
 {
         const char *devtype;
@@ -293,7 +345,7 @@ static struct udev_device *handle_scsi(struct udev_device *parent, char **path)
         const char *id;
 
         devtype = udev_device_get_devtype(parent);
-        if (devtype == NULL || strcmp(devtype, "scsi_device") != 0)
+        if (devtype == NULL || !streq(devtype, "scsi_device"))
                 return parent;
 
         /* firewire */
@@ -304,7 +356,7 @@ 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 */
+        /* scsi sysfs does not have a "subsystem" for the transport */
         name = udev_device_get_syspath(parent);
 
         if (strstr(name, "/rport-") != NULL) {
@@ -323,23 +375,45 @@ static struct udev_device *handle_scsi(struct udev_device *parent, char **path)
         }
 
         /*
-         * We do not support the ATA transport class, it creates duplicated link
-         * names as the fake SCSI host adapters are all separated, they are all
-         * re-based as host == 0. ATA should just stop faking two duplicated
-         * hierarchies for a single topology and leave the SCSI stuff alone;
-         * until that happens, there are no by-path/ links for ATA devices behind
-         * an ATA transport class.
+         * We do not support the ATA transport class, it uses global counters
+         * to name the ata devices which numbers spread across multiple
+         * controllers.
+         *
+         * The real link numbers are not exported. Also, possible chains of ports
+         * behind port multipliers cannot be composed that way.
+         *
+         * Until all that is solved at the kernel level, there are no by-path/
+         * links for ATA devices.
          */
         if (strstr(name, "/ata") != NULL) {
                 parent = NULL;
                 goto out;
         }
 
+        if (strstr(name, "/vmbus_") != NULL) {
+                parent = handle_scsi_hyperv(parent, path);
+                goto out;
+        }
+
         parent = handle_scsi_default(parent, path);
 out:
         return parent;
 }
 
+static struct udev_device *handle_cciss(struct udev_device *parent, char **path)
+{
+        const char *str;
+        unsigned int controller, disk;
+
+        str = udev_device_get_sysname(parent);
+        if (sscanf(str, "c%ud%u%*s", &controller, &disk) != 2)
+                return NULL;
+
+        path_prepend(path, "cciss-disk%u", disk);
+        parent = skip_subsystem(parent, "cciss");
+        return parent;
+}
+
 static void handle_scsi_tape(struct udev_device *dev, char **path)
 {
         const char *name;
@@ -364,7 +438,7 @@ static struct udev_device *handle_usb(struct udev_device *parent, char **path)
         devtype = udev_device_get_devtype(parent);
         if (devtype == NULL)
                 return parent;
-        if (strcmp(devtype, "usb_interface") != 0 && strcmp(devtype, "usb_device") != 0)
+        if (!streq(devtype, "usb_interface") && !streq(devtype, "usb_device"))
                 return parent;
 
         str = udev_device_get_sysname(parent);
@@ -407,6 +481,7 @@ static int builtin_path_id(struct udev_device *dev, int argc, char *argv[], bool
 {
         struct udev_device *parent;
         char *path = NULL;
+        bool some_transport = false;
 
         /* S390 ccw bus */
         parent = udev_device_get_parent_with_subsystem_devtype(dev, "ccw", NULL);
@@ -423,34 +498,54 @@ static int builtin_path_id(struct udev_device *dev, int argc, char *argv[], bool
                 subsys = udev_device_get_subsystem(parent);
                 if (subsys == NULL) {
                         ;
-                } else if (strcmp(subsys, "scsi_tape") == 0) {
+                } else if (streq(subsys, "scsi_tape")) {
                         handle_scsi_tape(parent, &path);
-                } else if (strcmp(subsys, "scsi") == 0) {
+                } else if (streq(subsys, "scsi")) {
                         parent = handle_scsi(parent, &path);
-                } else if (strcmp(subsys, "usb") == 0) {
+                        some_transport = true;
+                } else if (streq(subsys, "cciss")) {
+                        parent = handle_cciss(parent, &path);
+                        some_transport = true;
+                } else if (streq(subsys, "usb")) {
                         parent = handle_usb(parent, &path);
-                } else if (strcmp(subsys, "serio") == 0) {
+                        some_transport = true;
+                } else if (streq(subsys, "serio")) {
                         path_prepend(&path, "serio-%s", udev_device_get_sysnum(parent));
                         parent = skip_subsystem(parent, "serio");
-                } else if (strcmp(subsys, "pci") == 0) {
+                } else if (streq(subsys, "pci")) {
                         path_prepend(&path, "pci-%s", udev_device_get_sysname(parent));
                         parent = skip_subsystem(parent, "pci");
-                } else if (strcmp(subsys, "platform") == 0) {
+                } else if (streq(subsys, "platform")) {
                         path_prepend(&path, "platform-%s", udev_device_get_sysname(parent));
                         parent = skip_subsystem(parent, "platform");
-                } else if (strcmp(subsys, "acpi") == 0) {
+                        some_transport = true;
+                } else if (streq(subsys, "acpi")) {
                         path_prepend(&path, "acpi-%s", udev_device_get_sysname(parent));
                         parent = skip_subsystem(parent, "acpi");
-                } else if (strcmp(subsys, "xen") == 0) {
+                } else if (streq(subsys, "xen")) {
                         path_prepend(&path, "xen-%s", udev_device_get_sysname(parent));
                         parent = skip_subsystem(parent, "xen");
-                } else if (strcmp(subsys, "virtio") == 0) {
+                } else if (streq(subsys, "virtio")) {
                         path_prepend(&path, "virtio-pci-%s", udev_device_get_sysname(parent));
                         parent = skip_subsystem(parent, "virtio");
+                } else if (streq(subsys, "scm")) {
+                        path_prepend(&path, "scm-%s", udev_device_get_sysname(parent));
+                        parent = skip_subsystem(parent, "scm");
                 }
 
                 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.
+         */
+        if (!some_transport && streq(udev_device_get_subsystem(dev), "block")) {
+                free(path);
+                path = NULL;
+        }
+
 out:
         if (path != NULL) {
                 char tag[UTIL_NAME_SIZE];